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disturbance</title> <meta name="description" content="Search results for: disturbance"> <meta name="keywords" content="disturbance"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block d-lg-none navbar-toggler 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id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="disturbance"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 320</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: disturbance</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">320</span> Disturbance Observer for Lateral Trajectory Tracking Control for Autonomous and Cooperative Driving</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Christian%20Rathgeber">Christian Rathgeber</a>, <a href="https://publications.waset.org/abstracts/search?q=Franz%20Winkler"> Franz Winkler</a>, <a href="https://publications.waset.org/abstracts/search?q=Dirk%20Odenthal"> Dirk Odenthal</a>, <a href="https://publications.waset.org/abstracts/search?q=Steffen%20M%C3%BCller"> Steffen Müller</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this contribution a structure for high level lateral vehicle tracking control based on the disturbance observer is presented. The structure is characterized by stationary compensating side forces disturbances and guaranteeing a cooperative behavior at the same time. Driver inputs are not compensated by the disturbance observer. Moreover the structure is especially useful as it robustly stabilizes the vehicle. Therefore the parameters are selected using the Parameter Space Approach. The implemented algorithms are tested in real world scenarios. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=disturbance%20observer" title="disturbance observer">disturbance observer</a>, <a href="https://publications.waset.org/abstracts/search?q=trajectory%20tracking" title=" trajectory tracking"> trajectory tracking</a>, <a href="https://publications.waset.org/abstracts/search?q=robust%20control" title=" robust control"> robust control</a>, <a href="https://publications.waset.org/abstracts/search?q=autonomous%20driving" title=" autonomous driving"> autonomous driving</a>, <a href="https://publications.waset.org/abstracts/search?q=cooperative%20driving" title=" cooperative driving"> cooperative driving</a> </p> <a href="https://publications.waset.org/abstracts/22619/disturbance-observer-for-lateral-trajectory-tracking-control-for-autonomous-and-cooperative-driving" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22619.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">563</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">319</span> Optimal Linear Quadratic Digital Tracker for the Discrete-Time Proper System with an Unknown Disturbance</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jason%20Sheng-Hong%20Tsai">Jason Sheng-Hong Tsai</a>, <a href="https://publications.waset.org/abstracts/search?q=Faezeh%20Ebrahimzadeh"> Faezeh Ebrahimzadeh</a>, <a href="https://publications.waset.org/abstracts/search?q=Min-Ching%20Chung"> Min-Ching Chung</a>, <a href="https://publications.waset.org/abstracts/search?q=Shu-Mei%20Guo"> Shu-Mei Guo</a>, <a href="https://publications.waset.org/abstracts/search?q=Leang-San%20Shieh"> Leang-San Shieh</a>, <a href="https://publications.waset.org/abstracts/search?q=Tzong-Jiy%20Tsai"> Tzong-Jiy Tsai</a>, <a href="https://publications.waset.org/abstracts/search?q=Li%20Wang"> Li Wang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, we first construct a new state and disturbance estimator using discrete-time proportional plus integral observer to estimate the system state and the unknown external disturbance for the discrete-time system with an input-to-output direct-feedthrough term. Then, the generalized optimal linear quadratic digital tracker design is applied to construct a proportional plus integral observer-based tracker for the system with an unknown external disturbance to have a desired tracking performance. Finally, a numerical simulation is given to demonstrate the effectiveness of the new application of our proposed approach. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=non-minimum%20phase%20system" title="non-minimum phase system">non-minimum phase system</a>, <a href="https://publications.waset.org/abstracts/search?q=optimal%20linear%20quadratic%20tracker" title=" optimal linear quadratic tracker"> optimal linear quadratic tracker</a>, <a href="https://publications.waset.org/abstracts/search?q=proportional%20plus%20integral%20observer" title=" proportional plus integral observer"> proportional plus integral observer</a>, <a href="https://publications.waset.org/abstracts/search?q=state%20and%20disturbance%20estimator" title=" state and disturbance estimator"> state and disturbance estimator</a> </p> <a href="https://publications.waset.org/abstracts/41630/optimal-linear-quadratic-digital-tracker-for-the-discrete-time-proper-system-with-an-unknown-disturbance" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/41630.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">502</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">318</span> Sleep Disturbance in Indonesian School-Aged Children and Its Relationship to Nutritional Aspect</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=William%20Cheng">William Cheng</a>, <a href="https://publications.waset.org/abstracts/search?q=Rini%20Sekartini"> Rini Sekartini</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Background: Sleep is essential for children because it provides enhancement for the neural system activities that give physiologic effects for the body to support growth and development. One of the modifiable factors that relates with sleep is nutrition, which includes nutritional status, iron intake, and magnesium intake. Nutritional status represents the balance between nutritional intake and expenditure, while iron and magnesium are micronutrients that are related to sleep regulation. The aim of this study is to identify prevalence of sleep disturbance among Indonesian children and to evaluate its relation with aspect to nutrition. Methods : A cross-sectional study involving children aged 5 to 7-years-old in an urban primary health care between 2012 and 2013 was carried out. Related data includes anthropometric status, iron intake, and magnesium intake. Iron and magnesium intake was obtained by 24-hours food recall procedure. Sleep Disturbance Scale for Children (SDSC) was used as the diagnostic tool for sleep disturbance, with score under 39 indicating presence of problem. Results: Out of 128 school-aged children included in this study, 28 (23,1%) of them were found to have sleep disturbance. The majority of children had good nutritional status, with only 15,7% that were severely underweight or underweight, and 12,4% that were identified as stunted. On the contrary, 99 children (81,8%) were identified to have inadequate magnesium intake and 56 children (46,3%) with inadequate iron intake. Our analysis showed there was no significant relation between all of the nutritional status indicators and sleep disturbance (p>0,05%). Moreover, inadequate iron and magnesium intake also failed to prove significant relation with sleep disturbance in this population. Conclusion: Almost fourth of school-aged children in Indonesia were found to have sleep disturbance and further study are needed to overcome this problem. According to our finding, there is no correlation between nutritional status, iron intake, magnesium intake, and sleep disturbance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=iron%20intake" title="iron intake">iron intake</a>, <a href="https://publications.waset.org/abstracts/search?q=magnesium%20intake" title=" magnesium intake"> magnesium intake</a>, <a href="https://publications.waset.org/abstracts/search?q=nutritional%20status" title=" nutritional status"> nutritional status</a>, <a href="https://publications.waset.org/abstracts/search?q=school-aged%20children" title=" school-aged children"> school-aged children</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep%20disturbance" title=" sleep disturbance"> sleep disturbance</a> </p> <a href="https://publications.waset.org/abstracts/22945/sleep-disturbance-in-indonesian-school-aged-children-and-its-relationship-to-nutritional-aspect" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22945.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">466</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">317</span> Investigating Safe Operation Condition for Iterative Learning Control under Load Disturbances Effect in Singular Values</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Muhammad%20A.%20Alsubaie">Muhammad A. Alsubaie</a> </p> <p class="card-text"><strong>Abstract:</strong></p> An iterative learning control framework designed in state feedback structure suffers a lack in investigating load disturbance considerations. The presented work discusses the controller previously designed, highlights the disturbance problem, finds new conditions using singular value principle to assure safe operation conditions with error convergence and reference tracking under the influence of load disturbance. It is known that periodic disturbances can be represented by a delay model in a positive feedback loop acting on the system input. This model can be manipulated by isolating the delay model and finding a controller for the overall system around the delay model to remedy the periodic disturbances using the small signal theorem. The overall system is the base for control design and load disturbance investigation. The major finding of this work is the load disturbance condition found which clearly sets safe operation condition under the influence of load disturbances such that the error tends to nearly zero as the system keeps operating trial after trial. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=iterative%20learning%20control" title="iterative learning control">iterative learning control</a>, <a href="https://publications.waset.org/abstracts/search?q=singular%20values" title=" singular values"> singular values</a>, <a href="https://publications.waset.org/abstracts/search?q=state%20feedback" title=" state feedback"> state feedback</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20disturbance" title=" load disturbance"> load disturbance</a> </p> <a href="https://publications.waset.org/abstracts/108485/investigating-safe-operation-condition-for-iterative-learning-control-under-load-disturbances-effect-in-singular-values" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/108485.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">158</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">316</span> Design of a Sliding Controller for Optical Disk Drives</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yu-Sheng%20Lu">Yu-Sheng Lu</a>, <a href="https://publications.waset.org/abstracts/search?q=Chung-Hsin%20Cheng"> Chung-Hsin Cheng</a>, <a href="https://publications.waset.org/abstracts/search?q=Shuen-Shing%20Jan"> Shuen-Shing Jan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the design and implementation of a sliding-mod controller for tracking servo of optical disk drives. The tracking servo is majorly subject to two disturbance sources: radial run-out and shock. The lateral run-out disturbance is mostly repeatable, and a model of such disturbance is incorporated into the controller design to effectively compensate for it. Meanwhile, as a shock disturbance is usually non-repeatable and unpredictable, the sliding-mode controller is employed for its robustness to abrupt perturbations. As a result, a sliding-mode controller design based on the internal model principle is tailored for tracking servo of optical disk drives in order to deal with these two major disturbances. Experimental comparative studies are conducted to investigate the effectiveness of the specially designed controller. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=mechatronics" title="mechatronics">mechatronics</a>, <a href="https://publications.waset.org/abstracts/search?q=optical%20disk%20drive" title=" optical disk drive"> optical disk drive</a>, <a href="https://publications.waset.org/abstracts/search?q=sliding-mode%20control" title=" sliding-mode control"> sliding-mode control</a>, <a href="https://publications.waset.org/abstracts/search?q=servo%20systems" title=" servo systems"> servo systems</a> </p> <a href="https://publications.waset.org/abstracts/9020/design-of-a-sliding-controller-for-optical-disk-drives" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/9020.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">380</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">315</span> Analysis of Gas Disturbance Characteristics in Lunar Sample Storage</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Lv%20Shizeng">Lv Shizeng</a>, <a href="https://publications.waset.org/abstracts/search?q=Han%20Xiao"> Han Xiao</a>, <a href="https://publications.waset.org/abstracts/search?q=Zhang%20Yi"> Zhang Yi</a>, <a href="https://publications.waset.org/abstracts/search?q=Ding%20Wenjing"> Ding Wenjing</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The lunar sample storage device is mainly used for the preparation of the lunar samples, observation, physical analysis and other work. The lunar samples and operating equipment are placed directly inside the storage device. The inside of the storage device is a high purity nitrogen environment to ensure that the sample is not contaminated by the Earth's environment. In order to ensure that the water and oxygen indicators in the storage device meet the sample requirements, a dynamic gas cycle is required between the storage device and the external purification equipment. However, the internal gas disturbance in the storage device can affect the operation of the sample. In this paper, the storage device model is established, and the tetrahedral mesh is established by Tetra/Mixed method. The influence of different inlet position and gas flow on the internal flow field disturbance is calculated, and the disturbed flow area should be avoided during the sampling operation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=lunar%20samples" title="lunar samples">lunar samples</a>, <a href="https://publications.waset.org/abstracts/search?q=gas%20disturbance" title=" gas disturbance"> gas disturbance</a>, <a href="https://publications.waset.org/abstracts/search?q=storage%20device" title=" storage device"> storage device</a>, <a href="https://publications.waset.org/abstracts/search?q=characteristic%20analysis" title=" characteristic analysis"> characteristic analysis</a> </p> <a href="https://publications.waset.org/abstracts/69595/analysis-of-gas-disturbance-characteristics-in-lunar-sample-storage" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/69595.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">294</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">314</span> Disturbance Observer-Based Predictive Functional Critical Control of a Table Drive System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Toshiyuki%20Satoh">Toshiyuki Satoh</a>, <a href="https://publications.waset.org/abstracts/search?q=Hiroki%20Hara"> Hiroki Hara</a>, <a href="https://publications.waset.org/abstracts/search?q=Naoki%20Saito"> Naoki Saito</a>, <a href="https://publications.waset.org/abstracts/search?q=Jun-ya%20Nagase"> Jun-ya Nagase</a>, <a href="https://publications.waset.org/abstracts/search?q=Norihiko%20Saga"> Norihiko Saga</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper addresses a control system design for a table drive system based on the disturbance observer (DOB)-based predictive functional critical control (PFCC). To empower the previously developed DOB-based PFC to handle constraints on controlled outputs, we propose to take a critical control approach. To this end, we derive the transfer function representation of the PFC controller, and yield a detailed design procedure. The effectiveness of the proposed method is confirmed through an experimental evaluation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=critical%20control" title="critical control">critical control</a>, <a href="https://publications.waset.org/abstracts/search?q=disturbance%20observer" title=" disturbance observer"> disturbance observer</a>, <a href="https://publications.waset.org/abstracts/search?q=mechatronics" title=" mechatronics"> mechatronics</a>, <a href="https://publications.waset.org/abstracts/search?q=motion%20control" title=" motion control"> motion control</a>, <a href="https://publications.waset.org/abstracts/search?q=predictive%20functional%20control" title=" predictive functional control"> predictive functional control</a>, <a href="https://publications.waset.org/abstracts/search?q=table%20drive%20systems" title=" table drive systems"> table drive systems</a> </p> <a href="https://publications.waset.org/abstracts/1440/disturbance-observer-based-predictive-functional-critical-control-of-a-table-drive-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/1440.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">487</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">313</span> Active Disturbance Rejection Control for Wind System Based on a DFIG</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=R.%20Chakib">R. Chakib</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Essadki"> A. Essadki</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Cherkaoui"> M. Cherkaoui </a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper proposes the study of a robust control of the doubly fed induction generator (DFIG) used in a wind energy production. The proposed control is based on the linear active disturbance rejection control (ADRC) and it is applied to the control currents rotor of the DFIG, the DC bus voltage and active and reactive power exchanged between the DFIG and the network. The system under study and the proposed control are simulated using MATLAB/SIMULINK. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=doubly%20fed%20induction%20generator%20%28DFIG%29" title="doubly fed induction generator (DFIG)">doubly fed induction generator (DFIG)</a>, <a href="https://publications.waset.org/abstracts/search?q=active%20disturbance%20rejection%20control%20%28ADRC%29" title=" active disturbance rejection control (ADRC)"> active disturbance rejection control (ADRC)</a>, <a href="https://publications.waset.org/abstracts/search?q=vector%20control" title=" vector control"> vector control</a>, <a href="https://publications.waset.org/abstracts/search?q=MPPT" title=" MPPT"> MPPT</a>, <a href="https://publications.waset.org/abstracts/search?q=extended%20state%20observer" title=" extended state observer"> extended state observer</a>, <a href="https://publications.waset.org/abstracts/search?q=back-to-back%20converter" title=" back-to-back converter"> back-to-back converter</a>, <a href="https://publications.waset.org/abstracts/search?q=wind%20turbine" title=" wind turbine"> wind turbine</a> </p> <a href="https://publications.waset.org/abstracts/14697/active-disturbance-rejection-control-for-wind-system-based-on-a-dfig" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/14697.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">486</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">312</span> Relationship between Depression, Stress, and Life Satisfaction among Students </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Rexa%20Pasha">Rexa Pasha</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The aim of this study was to examine the relationship between depression, stress and life satisfaction with sleep disturbance among Islamic Azad University Ahvaz Branch students. Samples in the study included 230 students who were selected by stratified random sampling. For data collection, the Beck Depression Inventory, stress, life satisfaction and quality of sleep (PSQI) was used. Which all have acceptable reliability and validity. This study was correlation and Data analysis using Pearson correlation and multivariate regression significance level (p<o/o5). Results showed that there was a significant positive relationship between depression and stress with sleep disturbance and between life satisfaction and sleep disturbance of students, a significant negative correlation was observed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=depression" title="depression">depression</a>, <a href="https://publications.waset.org/abstracts/search?q=life%20satisfaction" title=" life satisfaction"> life satisfaction</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep%20disorder" title=" sleep disorder"> sleep disorder</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep%20disturbane" title=" sleep disturbane"> sleep disturbane</a> </p> <a href="https://publications.waset.org/abstracts/41483/relationship-between-depression-stress-and-life-satisfaction-among-students" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/41483.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">427</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">311</span> Research Progress on the Correlation between Tinnitus and Sleep Behaviors</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jiajia%20Peng">Jiajia Peng</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Tinnitus is one of the common symptoms of ear diseases and is characterized by an abnormal perception of sound without external stimulation. Tinnitus is agony and seriously affects the life of the general population by approximately 1%. Sleep disturbance is a common problem in patients with tinnitus. Lack of sleep will lead to the accumulation of metabolites in the brain and cannot be cleared in time. These substances enhance sympathetic nerve reactivity in the auditory system, resulting in tinnitus occurrence or aggravation. Then, tinnitus may aggravate sleep disturbance, thus forming a vicious circle. Through a systematic review of the relevant literature, we summarize the research on tinnitus and sleep. Although the results suggest that tinnitus is often accompanied by sleep disturbance, the impact of unfavorable sleep habits on tinnitus is not clear. In particular, the relationships between sleep behaviors and other chronic diseases have been revealed. To reduce the incidence rate of tinnitus, clinicians should pay attention to the relevance between different sleep behaviors and tinnitus. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=tinnitus" title="tinnitus">tinnitus</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep" title=" sleep"> sleep</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep%20factor" title=" sleep factor"> sleep factor</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep%20behavior" title=" sleep behavior"> sleep behavior</a> </p> <a href="https://publications.waset.org/abstracts/144947/research-progress-on-the-correlation-between-tinnitus-and-sleep-behaviors" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/144947.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">161</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">310</span> Effects of Extract from Lactuca sativa on Sleep in Pentobarbital-Induced Sleep and Caffeine-Induced Sleep Disturbance in Mice</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hae%20Dun%20Kim">Hae Dun Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=Joo%20Hyun%20Jang"> Joo Hyun Jang</a>, <a href="https://publications.waset.org/abstracts/search?q=Geu%20Rim%20Seo"> Geu Rim Seo</a>, <a href="https://publications.waset.org/abstracts/search?q=Kyung%20Soo%20Ra"> Kyung Soo Ra</a>, <a href="https://publications.waset.org/abstracts/search?q=Hyung%20Joo%20Suh"> Hyung Joo Suh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Lactuca sativa (lettuce) has been known for its medical property to relieve anxiety and nervous. This study was implemented to investigate sleep-promoting effects of the lettuce alcohol extract (LAE). Caffeine is widely used psychoactive substance known to induced wakefulness and insomnia to its consumers. In the present study, the sedative-hypnotic activity of the LAE was studied using the method of pentobarbital-induced sleep in the mouse model. The LAE was administrated to mice 30 min before the pentobarbital injection. The LAE prolonged the pentobarbital-induced sleep duration and decreased sleep latency. The effects of LAE were comparable to those of induced by diazepam. Another study was performed to examine whether LAE ameliorates caffeine-induced sleep disturbance in mice. Additionally, caffeine (10 mg/kg, p.o) delayed sleep onset and reduced sleep duration of mice. Conversely, LAE treatment (80 or 160 mg/kg, p.o), especially at 160 mg/kg, normalized the sleep disturbance induced by caffeine. LAE supplementation can counter the sleep disturbance induced by caffeine. These results suggest that LAE possess significant sedative-hypnotic activity, which supports the popular use of lettuce for treatment of insomnia and provide the basis for new drug discovery. Furthermore, these results demonstrate that the lettuce extract may be preferable for the treatment of insomnia. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=caffeine" title="caffeine">caffeine</a>, <a href="https://publications.waset.org/abstracts/search?q=Lactuca%20sativa" title=" Lactuca sativa"> Lactuca sativa</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep%20duration" title=" sleep duration"> sleep duration</a>, <a href="https://publications.waset.org/abstracts/search?q=sleep%20latency" title=" sleep latency"> sleep latency</a> </p> <a href="https://publications.waset.org/abstracts/49766/effects-of-extract-from-lactuca-sativa-on-sleep-in-pentobarbital-induced-sleep-and-caffeine-induced-sleep-disturbance-in-mice" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/49766.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">306</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">309</span> Controller Design for Active Suspension System of 1/4 Car with Unknown Mass and Time-Delay </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ali%20Al-Zughaibi">Ali Al-Zughaibi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The purpose of this paper is to present a modeling and control of the quarter car active suspension system with unknown mass, unknown time-delay and road disturbance. The objective of designing the controller by deriving a control law to achieve stability of the system and convergence that can considerably improve the ride comfort and road disturbance handling. Thus is accomplished by using Routh-Herwitz criterion and based on some assumptions. A mathematical proof is given to show the ability of the designed controller to ensure stability and convergence of the active suspension system and dispersion oscillation of system with unknown mass, time-delay and road disturbances. Simulations were also performed for controlling quarter car suspension, where the results obtained from these simulations verify the validity of the proposed design. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=active%20suspension%20system" title="active suspension system">active suspension system</a>, <a href="https://publications.waset.org/abstracts/search?q=time-delay" title=" time-delay"> time-delay</a>, <a href="https://publications.waset.org/abstracts/search?q=disturbance%20rejection" title=" disturbance rejection"> disturbance rejection</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20uncertainty" title=" dynamic uncertainty"> dynamic uncertainty</a> </p> <a href="https://publications.waset.org/abstracts/33796/controller-design-for-active-suspension-system-of-14-car-with-unknown-mass-and-time-delay" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/33796.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">319</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">308</span> Reconstruction and Rejection of External Disturbances in a Dynamical System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Iftikhar%20Ahmad">Iftikhar Ahmad</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Benallegue"> A. Benallegue</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20El%20Hadri"> A. El Hadri</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, we have proposed an observer for the reconstruction and a control law for the rejection application of unknown bounded external disturbance in a dynamical system. The strategy of both the observer and the controller is designed like a second order sliding mode with a proportional-integral (PI) term. Lyapunov theory is used to prove the exponential convergence and stability. Simulations results are given to show the performance of this method. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=non-linear%20systems" title="non-linear systems">non-linear systems</a>, <a href="https://publications.waset.org/abstracts/search?q=sliding%20mode%20observer" title=" sliding mode observer"> sliding mode observer</a>, <a href="https://publications.waset.org/abstracts/search?q=disturbance%20rejection" title=" disturbance rejection"> disturbance rejection</a>, <a href="https://publications.waset.org/abstracts/search?q=nonlinear%20control" title=" nonlinear control"> nonlinear control</a> </p> <a href="https://publications.waset.org/abstracts/44910/reconstruction-and-rejection-of-external-disturbances-in-a-dynamical-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/44910.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">334</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">307</span> Active Disturbance Rejection Control for Maximization of Generated Power from Wind Energy Conversion Systems using a Doubly Fed Induction Generator </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tamou%20Nasser">Tamou Nasser</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Essadki"> Ahmed Essadki</a>, <a href="https://publications.waset.org/abstracts/search?q=Ali%20Boukhriss"> Ali Boukhriss</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the control of doubly fed induction generator (DFIG) used in the wind energy conversion systems. Maximum power point tracking (MPPT) strategy is used to extract the maximum of power during the conversion and taking care that the system does not exceed the operating limits. This is done by acting on the pitch angle to control the orientation of the turbine's blades. Having regard to its robustness and performance, active disturbance rejection control (ADRC) based on the extended state observer (ESO) is employed to achieve the control of both rotor and grid side converters. Simulations are carried out using matlab simulink. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=active%20disturbance%20rejection%20control" title="active disturbance rejection control">active disturbance rejection control</a>, <a href="https://publications.waset.org/abstracts/search?q=extended%20state%20observer" title=" extended state observer"> extended state observer</a>, <a href="https://publications.waset.org/abstracts/search?q=doubly%20fed%20induction%20generator" title=" doubly fed induction generator"> doubly fed induction generator</a>, <a href="https://publications.waset.org/abstracts/search?q=maximum%20power%20point%20tracking" title=" maximum power point tracking"> maximum power point tracking</a> </p> <a href="https://publications.waset.org/abstracts/21302/active-disturbance-rejection-control-for-maximization-of-generated-power-from-wind-energy-conversion-systems-using-a-doubly-fed-induction-generator" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/21302.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">563</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">306</span> Maximization of Generated Power from Wind Energy Conversion Systems Using a Doubly Fed Induction Generator with Active Disturbance Rejection Control</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tamou%20Nasser">Tamou Nasser</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Essadki"> Ahmed Essadki</a>, <a href="https://publications.waset.org/abstracts/search?q=Ali%20Boukhriss"> Ali Boukhriss</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the control of doubly fed induction generator (DFIG) used in the wind energy conversion systems. Maximum power point tracking (MPPT) strategy is used to extract the maximum of power during the conversion and taking care that the system does not exceed the operating limits. This is done by acting on the pitch angle to control the orientation of the turbine's blades. Having regard to its robustness and performance, active disturbance rejection control (ADRC) based on the extended state observer (ESO) is employed to achieve the control of both rotor and grid side converters. Simulations are carried out using matlab simulink. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=active%20disturbance%20rejection%20control" title="active disturbance rejection control">active disturbance rejection control</a>, <a href="https://publications.waset.org/abstracts/search?q=extended%20state%20observer" title=" extended state observer"> extended state observer</a>, <a href="https://publications.waset.org/abstracts/search?q=doubly%20fed%20induction%20generator" title=" doubly fed induction generator"> doubly fed induction generator</a>, <a href="https://publications.waset.org/abstracts/search?q=maximum%20power%20point%20tracking" title=" maximum power point tracking"> maximum power point tracking</a> </p> <a href="https://publications.waset.org/abstracts/21299/maximization-of-generated-power-from-wind-energy-conversion-systems-using-a-doubly-fed-induction-generator-with-active-disturbance-rejection-control" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/21299.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">499</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">305</span> A Linear Active Disturbance Rejection Control for Maximization of Generated Power from Wind Energy Conversion Systems Using a Doubly Fed Induction Generator </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Tamou%20Nasser">Tamou Nasser</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Essadki"> Ahmed Essadki</a>, <a href="https://publications.waset.org/abstracts/search?q=Ali%20Boukhriss"> Ali Boukhriss</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the control of doubly fed induction generator (DFIG) used in the wind energy conversion systems. Maximum power point tracking (MPPT) strategy is used to extract the maximum of power during the conversion and taking care that the system does not exceed the operating limits. This is done by acting on the pitch angle to control the orientation of the turbine's blades. Having regard to its robustness and performance, active disturbance rejection control (ADRC) based on the extended state observer (ESO) is employed to achieve the control of both rotor and grid side converters. Simulations are carried out using MATLAB simulink. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=active%20disturbance%20rejection%20control" title="active disturbance rejection control">active disturbance rejection control</a>, <a href="https://publications.waset.org/abstracts/search?q=extended%20state%20observer" title=" extended state observer"> extended state observer</a>, <a href="https://publications.waset.org/abstracts/search?q=doubly%20fed%20induction%20generator" title=" doubly fed induction generator"> doubly fed induction generator</a>, <a href="https://publications.waset.org/abstracts/search?q=maximum%20power%20point%20tracking" title=" maximum power point tracking"> maximum power point tracking</a> </p> <a href="https://publications.waset.org/abstracts/21303/a-linear-active-disturbance-rejection-control-for-maximization-of-generated-power-from-wind-energy-conversion-systems-using-a-doubly-fed-induction-generator" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/21303.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">524</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">304</span> Study of Formation and Evolution of Disturbance Waves in Annular Flow Using Brightness-Based Laser-Induced Fluorescence (BBLIF) Technique</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Andrey%20Cherdantsev">Andrey Cherdantsev</a>, <a href="https://publications.waset.org/abstracts/search?q=Mikhail%20Cherdantsev"> Mikhail Cherdantsev</a>, <a href="https://publications.waset.org/abstracts/search?q=Sergey%20Isaenkov"> Sergey Isaenkov</a>, <a href="https://publications.waset.org/abstracts/search?q=Dmitriy%20Markovich"> Dmitriy Markovich</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In annular gas-liquid flow, liquid flows as a film along pipe walls sheared by high-velocity gas stream. Film surface is covered by large-scale disturbance waves which affect pressure drop and heat transfer in the system and are necessary for entrainment of liquid droplets from film surface into the core of gas stream. Disturbance waves are a highly complex and their properties are affected by numerous parameters. One of such aspects is flow development, i.e., change of flow properties with the distance from the inlet. In the present work, this question is studied using brightness-based laser-induced fluorescence (BBLIF) technique. This method enables one to perform simultaneous measurements of local film thickness in large number of points with high sampling frequency. In the present experiments first 50 cm of upward and downward annular flow in a vertical pipe of 11.7 mm i.d. is studied with temporal resolution of 10 kHz and spatial resolution of 0.5 mm. Thus, spatiotemporal evolution of film surface can be investigated, including scenarios of formation, acceleration and coalescence of disturbance waves. The behaviour of disturbance waves' velocity depending on phases flow rates and downstream distance was investigated. Besides measuring the waves properties, the goal of the work was to investigate the interrelation between disturbance waves properties and integral characteristics of the flow such as interfacial shear stress and flow rate of dispersed phase. In particular, it was shown that the initial acceleration of disturbance waves, defined by the value of shear stress, linearly decays with downstream distance. This lack of acceleration which may even lead to deceleration is related to liquid entrainment. Flow rate of disperse phase linearly grows with downstream distance. During entrainment events, liquid is extracted directly from disturbance waves, reducing their mass, area of interaction to the gas shear and, hence, velocity. Passing frequency of disturbance waves at each downstream position was measured automatically with a new algorithm of identification of characteristic lines of individual disturbance waves. Scenarios of coalescence of individual disturbance waves were identified. Transition from initial high-frequency Kelvin-Helmholtz waves appearing at the inlet to highly nonlinear disturbance waves with lower frequency was studied near the inlet using 3D realisation of BBLIF method in the same cylindrical channel and in a rectangular duct with cross-section of 5 mm by 50 mm. It was shown that the initial waves are generally two-dimensional but are promptly broken into localised three-dimensional wavelets. Coalescence of these wavelets leads to formation of quasi two-dimensional disturbance waves. Using cross-correlation analysis, loss and restoration of two-dimensionality of film surface with downstream distance were studied quantitatively. It was shown that all the processes occur closer to the inlet at higher gas velocities. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=annular%20flow" title="annular flow">annular flow</a>, <a href="https://publications.waset.org/abstracts/search?q=disturbance%20waves" title=" disturbance waves"> disturbance waves</a>, <a href="https://publications.waset.org/abstracts/search?q=entrainment" title=" entrainment"> entrainment</a>, <a href="https://publications.waset.org/abstracts/search?q=flow%20development" title=" flow development"> flow development</a> </p> <a href="https://publications.waset.org/abstracts/61190/study-of-formation-and-evolution-of-disturbance-waves-in-annular-flow-using-brightness-based-laser-induced-fluorescence-bblif-technique" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/61190.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">251</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">303</span> Spatial Direct Numerical Simulation of Instability Waves in Hypersonic Boundary Layers </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jayahar%20Sivasubramanian">Jayahar Sivasubramanian</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Understanding laminar-turbulent transition process in hyper-sonic boundary layers is crucial for designing viable high speed flight vehicles. The study of transition becomes particularly important in the high speed regime due to the effect of transition on aerodynamic performance and heat transfer. However, even after many years of research, the transition process in hyper-sonic boundary layers is still not understood. This lack of understanding of the physics of the transition process is a major impediment to the development of reliable transition prediction methods. Towards this end, spatial Direct Numerical Simulations are conducted to investigate the instability waves generated by a localized disturbance in a hyper-sonic flat plate boundary layer. In order to model a natural transition scenario, the boundary layer was forced by a short duration (localized) pulse through a hole on the surface of the flat plate. The pulse disturbance developed into a three-dimensional instability wave packet which consisted of a wide range of disturbance frequencies and wave numbers. First, the linear development of the wave packet was studied by forcing the flow with low amplitude (0.001% of the free-stream velocity). The dominant waves within the resulting wave packet were identified as two-dimensional second mode disturbance waves. Hence the wall-pressure disturbance spectrum exhibited a maximum at the span wise mode number k = 0. The spectrum broadened in downstream direction and the lower frequency first mode oblique waves were also identified in the spectrum. However, the peak amplitude remained at k = 0 which shifted to lower frequencies in the downstream direction. In order to investigate the nonlinear transition regime, the flow was forced with a higher amplitude disturbance (5% of the free-stream velocity). The developing wave packet grows linearly at first before reaching the nonlinear regime. The wall pressure disturbance spectrum confirmed that the wave packet developed linearly at first. The response of the flow to the high amplitude pulse disturbance indicated the presence of a fundamental resonance mechanism. Lower amplitude secondary peaks were also identified in the disturbance wave spectrum at approximately half the frequency of the high amplitude frequency band, which would be an indication of a sub-harmonic resonance mechanism. The disturbance spectrum indicates, however, that fundamental resonance is much stronger than sub-harmonic resonance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=boundary%20layer" title="boundary layer">boundary layer</a>, <a href="https://publications.waset.org/abstracts/search?q=DNS" title=" DNS"> DNS</a>, <a href="https://publications.waset.org/abstracts/search?q=hyper%20sonic%20flow" title=" hyper sonic flow"> hyper sonic flow</a>, <a href="https://publications.waset.org/abstracts/search?q=instability%20waves" title=" instability waves"> instability waves</a>, <a href="https://publications.waset.org/abstracts/search?q=wave%20packet" title=" wave packet"> wave packet</a> </p> <a href="https://publications.waset.org/abstracts/138691/spatial-direct-numerical-simulation-of-instability-waves-in-hypersonic-boundary-layers" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/138691.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">183</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">302</span> Predictive Functional Control with Disturbance Observer for Tendon-Driven Balloon Actuator</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jun-ya%20Nagase">Jun-ya Nagase</a>, <a href="https://publications.waset.org/abstracts/search?q=Toshiyuki%20Satoh"> Toshiyuki Satoh</a>, <a href="https://publications.waset.org/abstracts/search?q=Norihiko%20Saga"> Norihiko Saga</a>, <a href="https://publications.waset.org/abstracts/search?q=Koichi%20Suzumori"> Koichi Suzumori</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In recent years, Japanese society has been aging, engendering a labour shortage of young workers. Robots are therefore expected to perform tasks such as rehabilitation, nursing elderly people, and day-to-day work support for elderly people. The pneumatic balloon actuator is a rubber artificial muscle developed for use in a robot hand in such environments. This actuator has a long stroke, and a high power-to-weight ratio compared with the present pneumatic artificial muscle. Moreover, the dynamic characteristics of this actuator resemble those of human muscle. This study evaluated characteristics of force control of balloon actuator using a predictive functional control (PFC) system with disturbance observer. The predictive functional control is a model-based predictive control (MPC) scheme that predicts the future outputs of the actual plants over the prediction horizon and computes the control effort over the control horizon at every sampling instance. For this study, a 1-link finger system using a pneumatic balloon actuator is developed. Then experiments of PFC control with disturbance observer are performed. These experiments demonstrate the feasibility of its control of a pneumatic balloon actuator for a robot hand. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=disturbance%20observer" title="disturbance observer">disturbance observer</a>, <a href="https://publications.waset.org/abstracts/search?q=pneumatic%20balloon" title=" pneumatic balloon"> pneumatic balloon</a>, <a href="https://publications.waset.org/abstracts/search?q=predictive%20functional%20control" title=" predictive functional control"> predictive functional control</a>, <a href="https://publications.waset.org/abstracts/search?q=rubber%20artificial%20muscle" title=" rubber artificial muscle"> rubber artificial muscle</a> </p> <a href="https://publications.waset.org/abstracts/4030/predictive-functional-control-with-disturbance-observer-for-tendon-driven-balloon-actuator" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/4030.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">452</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">301</span> A Fully-Automated Disturbance Analysis Vision for the Smart Grid Based on Smart Switch Data</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bernardo%20Cedano">Bernardo Cedano</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20H.%20Eltom"> Ahmed H. Eltom</a>, <a href="https://publications.waset.org/abstracts/search?q=Bob%20Hay"> Bob Hay</a>, <a href="https://publications.waset.org/abstracts/search?q=Jim%20Glass"> Jim Glass</a>, <a href="https://publications.waset.org/abstracts/search?q=Raga%20Ahmed"> Raga Ahmed </a> </p> <p class="card-text"><strong>Abstract:</strong></p> The deployment of smart grid devices such as smart meters and smart switches (SS) supported by a reliable and fast communications system makes automated distribution possible, and thus, provides great benefits to electric power consumers and providers alike. However, more research is needed before the full utility of smart switch data is realized. This paper presents new automated switching techniques using SS within the electric power grid. A concise background of the SS is provided, and operational examples are shown. Organization and presentation of data obtained from SS are shown in the context of the future goal of total automation of the distribution network. The description of application techniques, the examples of success with SS, and the vision outlined in this paper serve to motivate future research pertinent to disturbance analysis automation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=disturbance%20automation" title="disturbance automation">disturbance automation</a>, <a href="https://publications.waset.org/abstracts/search?q=electric%20power%20grid" title=" electric power grid"> electric power grid</a>, <a href="https://publications.waset.org/abstracts/search?q=smart%20grid" title=" smart grid"> smart grid</a>, <a href="https://publications.waset.org/abstracts/search?q=smart%20switches" title=" smart switches"> smart switches</a> </p> <a href="https://publications.waset.org/abstracts/92721/a-fully-automated-disturbance-analysis-vision-for-the-smart-grid-based-on-smart-switch-data" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/92721.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">309</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">300</span> Augmented ADRC for Trajectory Tracking of a Novel Hydraulic Spherical Motion Mechanism</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bin%20Bian">Bin Bian</a>, <a href="https://publications.waset.org/abstracts/search?q=Liang%20Wang"> Liang Wang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A hydraulic spherical motion mechanism (HSMM) is proposed. Unlike traditional systems using serial or parallel mechanisms for multi-DOF rotations, the HSMM is capable of implementing continuous 2-DOF rotational motions in a single joint without the intermediate transmission mechanisms. It has some advantages of compact structure, low inertia and high stiffness. However, as HSMM is a nonlinear and multivariable system, it is very complicate to realize accuracy control. Therefore, an augmented active disturbance rejection controller (ADRC) is proposed in this paper. Compared with the traditional PD control method, three compensation items, i.e., dynamics compensation term, disturbance compensation term and nonlinear error elimination term, are added into the proposed algorithm to improve the control performance. The ADRC algorithm aims at offsetting the effects of external disturbance and realizing accurate control. Euler angles are applied to describe the orientation of rotor. Lagrange equations are utilized to establish the dynamic model of the HSMM. The stability of this algorithm is validated with detailed derivation. Simulation model is formulated in Matlab/Simulink. The results show that the proposed control algorithm has better competence of trajectory tracking in the presence of uncertainties. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=hydraulic%20spherical%20motion%20mechanism" title="hydraulic spherical motion mechanism">hydraulic spherical motion mechanism</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20model" title=" dynamic model"> dynamic model</a>, <a href="https://publications.waset.org/abstracts/search?q=active%20disturbance%20rejection%20control" title=" active disturbance rejection control"> active disturbance rejection control</a>, <a href="https://publications.waset.org/abstracts/search?q=trajectory%20tracking" title=" trajectory tracking"> trajectory tracking</a> </p> <a href="https://publications.waset.org/abstracts/126959/augmented-adrc-for-trajectory-tracking-of-a-novel-hydraulic-spherical-motion-mechanism" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/126959.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">105</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">299</span> Measurement of Liquid Film Thickness in a Vertical Annular Two Phase Flow Changing the Gas-Liquid Density Ratio</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Shoji%20Mori">Shoji Mori</a>, <a href="https://publications.waset.org/abstracts/search?q=Kunito%20Okuyama"> Kunito Okuyama</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Annular two phase flow is encountered in many industrial equipments, including flow near nuclear fuel rods in boiling water reactor (BWR). Especially, disturbance waves play important roles in the pressure drop, the generation of entrainments, and the dryout of the liquid film. Therefore, it is important to clarify the behavior of disturbance waves and base film. However, most of the previous studies have been performed under atmospheric pressure conditions that provides the properties of liquid and gas which are significantly different from those of a BWR. Therefore, the effect of properties in gas and liquid on liquid film characteristics should be clarified. In this paper we focus on the effect of gas-liquid density ratio on liquid film thickness characteristics. The experiments have been conducted at four density ratio conditions (ρL/ρG =763, 451, 231, and 31). As a result, it is found that and interfacial shear stress collapse not only tF ave but also tF max and tF min successfully under the same liquid mass flow rate conditions irrespective of ρL/ρG, and moreover a non-dimensional parameter tends to collapse tF max，tF ave，and tF min in the wide range of experimental conditions (ρL/ρG：31～763，We：10～1800，ReL:500 ～ 2200). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=two%20phase%20flow" title="two phase flow">two phase flow</a>, <a href="https://publications.waset.org/abstracts/search?q=liquid%20film" title=" liquid film"> liquid film</a>, <a href="https://publications.waset.org/abstracts/search?q=annular%20flow" title=" annular flow"> annular flow</a>, <a href="https://publications.waset.org/abstracts/search?q=disturbance%20wave" title=" disturbance wave"> disturbance wave</a> </p> <a href="https://publications.waset.org/abstracts/34514/measurement-of-liquid-film-thickness-in-a-vertical-annular-two-phase-flow-changing-the-gas-liquid-density-ratio" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/34514.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">389</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">298</span> Observation of Large-Scale Traveling Ionospheric Disturbance over Peninsular Malaysia Using GPS Receivers</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Intan%20Izafina%20Idrus">Intan Izafina Idrus</a>, <a href="https://publications.waset.org/abstracts/search?q=Mardina%20Abdullah"> Mardina Abdullah</a>, <a href="https://publications.waset.org/abstracts/search?q=Alina%20Marie%20Hasbi"> Alina Marie Hasbi</a>, <a href="https://publications.waset.org/abstracts/search?q=Asnawi%20Husin"> Asnawi Husin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the result of large-scale traveling ionospheric disturbance (LSTID) observation during moderate magnetic storm event on 25 October 2011 with SYM-H ~ -160 nT and Kp ~ 7 over Peninsular Malaysia at equatorial region using vertical total electron content (VTEC) from the Global Positioning System (GPS) observation measurement. The propagation of the LSTID signatures in the TEC measurements over Peninsular Malaysia was also investigated using VTEC map. The LSTID was found to propagate equator-ward during this event. The results showed that the LSTID propagated with an average phase velocity of 526.41 m/s and average periods of 140 min. The occurrence of this LSTID was also found to be the subsequent effects of substorm activities in the auroral region. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Global%20Positioning%20System%20%28GPS%29" title="Global Positioning System (GPS)">Global Positioning System (GPS)</a>, <a href="https://publications.waset.org/abstracts/search?q=large-scale%20traveling%20ionospheric%20disturbance%20%28LSTID%29" title=" large-scale traveling ionospheric disturbance (LSTID)"> large-scale traveling ionospheric disturbance (LSTID)</a>, <a href="https://publications.waset.org/abstracts/search?q=moderate%20geomagnetic%20storm" title=" moderate geomagnetic storm"> moderate geomagnetic storm</a>, <a href="https://publications.waset.org/abstracts/search?q=vertical%20total%20electron%20content%20%28VTEC%29" title=" vertical total electron content (VTEC)"> vertical total electron content (VTEC)</a> </p> <a href="https://publications.waset.org/abstracts/2812/observation-of-large-scale-traveling-ionospheric-disturbance-over-peninsular-malaysia-using-gps-receivers" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/2812.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">225</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">297</span> Designing Inventory System with Constrained by Reducing Ordering Cost, Lead Time and Lost Sale Rate and Considering Random Disturbance in Ordering Quantity</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Arezoo%20Heidary">Arezoo Heidary</a>, <a href="https://publications.waset.org/abstracts/search?q=Abolfazl%20Mirzazadeh"> Abolfazl Mirzazadeh</a>, <a href="https://publications.waset.org/abstracts/search?q=Aref%20Gholami-Qadikolaei"> Aref Gholami-Qadikolaei</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the business environment it is very common that a lot received may not be equal to quantity ordered. in this work, a random disturbance in a received quantity is considered. It is assumed a maximum allowable limit for storage space and inventory investment.The impact of lead time and ordering cost reductions once they act dependently is also investigated. Further, considering a mixture of back order and lost sales for allowable shortage system, the effect of investment on reducing lost sale rate is analyzed. For the proposed control system, a Lagrangian method is applied in order to solve the problem and an algorithmic procedure is utilized to achieve optimal solution with the global minimum expected cost. Finally, proves on concavity and convexity of the model in the decision variables are shown. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=stochastic%20inventory%20system" title="stochastic inventory system">stochastic inventory system</a>, <a href="https://publications.waset.org/abstracts/search?q=lead%20time" title=" lead time"> lead time</a>, <a href="https://publications.waset.org/abstracts/search?q=ordering%20cost" title=" ordering cost"> ordering cost</a>, <a href="https://publications.waset.org/abstracts/search?q=lost%20sale%20rate" title=" lost sale rate"> lost sale rate</a>, <a href="https://publications.waset.org/abstracts/search?q=inventory%20constraints" title=" inventory constraints"> inventory constraints</a>, <a href="https://publications.waset.org/abstracts/search?q=random%20disturbance" title=" random disturbance"> random disturbance</a> </p> <a href="https://publications.waset.org/abstracts/17040/designing-inventory-system-with-constrained-by-reducing-ordering-cost-lead-time-and-lost-sale-rate-and-considering-random-disturbance-in-ordering-quantity" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/17040.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">419</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">296</span> Dual-Actuated Vibration Isolation Technology for a Rotary System’s Position Control on a Vibrating Frame: Disturbance Rejection and Active Damping</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kamand%20Bagherian">Kamand Bagherian</a>, <a href="https://publications.waset.org/abstracts/search?q=Nariman%20Niknejad"> Nariman Niknejad</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A vibration isolation technology for precise position control of a rotary system powered by two permanent magnet DC (PMDC) motors is proposed, where this system is mounted on an oscillatory frame. To achieve vibration isolation for this system, active damping and disturbance rejection (ADDR) technology is presented which introduces a cooperation of a main and an auxiliary PMDC, controlled by discrete-time sliding mode control (DTSMC) based schemes. The controller of the main actuator tracks a desired position and the auxiliary actuator simultaneously isolates the induced vibration, as its controller follows a torque trend. To determine this torque trend, a combination of two algorithms is introduced by the ADDR technology. The first torque-trend producing algorithm rejects the disturbance by counteracting the perturbation, estimated using a model-based observer. The second torque trend applies active variable damping to minimize the oscillation of the output shaft. In this practice, the presented technology is implemented on a rotary system with a pendulum attached, mounted on a linear actuator simulating an oscillation-transmitting structure. In addition, the obtained results illustrate the functionality of the proposed technology. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=active%20damping" title="active damping">active damping</a>, <a href="https://publications.waset.org/abstracts/search?q=discrete-time%20nonlinear%20controller" title=" discrete-time nonlinear controller"> discrete-time nonlinear controller</a>, <a href="https://publications.waset.org/abstracts/search?q=disturbance%20tracking%20algorithm" title=" disturbance tracking algorithm"> disturbance tracking algorithm</a>, <a href="https://publications.waset.org/abstracts/search?q=oscillation%20transmitting%20support" title=" oscillation transmitting support"> oscillation transmitting support</a>, <a href="https://publications.waset.org/abstracts/search?q=position%20control" title=" position control"> position control</a>, <a href="https://publications.waset.org/abstracts/search?q=stability%20robustness" title=" stability robustness"> stability robustness</a>, <a href="https://publications.waset.org/abstracts/search?q=vibration%20isolation" title=" vibration isolation"> vibration isolation</a> </p> <a href="https://publications.waset.org/abstracts/127697/dual-actuated-vibration-isolation-technology-for-a-rotary-systems-position-control-on-a-vibrating-frame-disturbance-rejection-and-active-damping" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/127697.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">101</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">295</span> Harmonics and Flicker Levels at Substation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ali%20Borhani%20Manesh">Ali Borhani Manesh</a>, <a href="https://publications.waset.org/abstracts/search?q=Sirus%20Mohammadi"> Sirus Mohammadi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Harmonic distortion is caused by nonlinear devices in the power system. A nonlinear device is one in which the current is not proportional to the applied voltage. Harmonic distortion is present to some degree on all power systems. Proactive monitoring of power quality disturbance levels by electricity utilities is vital to allow cost-effective mitigation when disturbances are perceived to be approaching planning levels and also to protect the security of customer installations. Ensuring that disturbance levels are within limits at the HV and EHV points of supply of the network is essential if satisfactory levels downstream are to be maintained. This paper presents discussion on a power quality monitoring campaign performed at the sub-transmission point of supply of a distribution network with the objective of benchmarking background disturbance levels prior to modifications to the substation and to ensure emissions from HV customers and the downstream MV networks are within acceptable levels. Some discussion on the difficulties involved in such a study is presented. This paper presents a survey of voltage and current harmonic distortion levels at transmission system in Kohgiloye and Boyrahmad. The effects of harmonics on capacitors and power transformers are discussed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=power%20quality" title="power quality">power quality</a>, <a href="https://publications.waset.org/abstracts/search?q=harmonics" title=" harmonics"> harmonics</a>, <a href="https://publications.waset.org/abstracts/search?q=flicker" title=" flicker"> flicker</a>, <a href="https://publications.waset.org/abstracts/search?q=measurement" title=" measurement"> measurement</a>, <a href="https://publications.waset.org/abstracts/search?q=substation" title=" substation"> substation</a> </p> <a href="https://publications.waset.org/abstracts/21026/harmonics-and-flicker-levels-at-substation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/21026.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">696</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">294</span> A Study of Customer Aggression towards Frontline Employees in Some Hotels in Imo State, Nigeria</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Polycarp%20A.%20Igbojekwe">Polycarp A. Igbojekwe</a>, <a href="https://publications.waset.org/abstracts/search?q=Chizoba%20Amajuoyi"> Chizoba Amajuoyi</a>, <a href="https://publications.waset.org/abstracts/search?q=Peterson%20Nwokorie"> Peterson Nwokorie</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The main purpose of this study was to carry out a survey of customer’s aggression towards hotel workers and make contributions on the prevalence and rationale behind customer’s aggression. Data for the study were gathered with a four-point Likert type rating scale. Samples were drawn from frontline hotel employees, managers and customers of twelve (12) hotels selected from three zones of Imo State. Data analyses were conducted using simple percentage, descriptive statistics; and Z-test statistical technique was used to test hypotheses. Among other factors, service failure and verbal abuse by service providers and poor quality product compared to price were identified by customers as the three major factors that can lead to customer aggression. Frontline employees indentified verbal abuse as the most common mode of aggression and that customer aggression causes emotional disturbance in them. The study also revealed that customer aggression is more prevalent in the 1&2 star hotels than it is in 3-5 star hotels. Most of the hotels have not institutionalized systematic approaches needed to effectively face the challenges of customer aggression, thus, customer aggression has become a common feature in the industry. Frontline jobs demand high emotional input. Therefore, we recommend that frontline employees should be given emotional support by their managers and also trained on how to cope with emotional disturbance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=customer%20aggression" title="customer aggression">customer aggression</a>, <a href="https://publications.waset.org/abstracts/search?q=emotional%20disturbance" title=" emotional disturbance"> emotional disturbance</a>, <a href="https://publications.waset.org/abstracts/search?q=employee%20well-being" title=" employee well-being"> employee well-being</a>, <a href="https://publications.waset.org/abstracts/search?q=service%20failure" title=" service failure"> service failure</a>, <a href="https://publications.waset.org/abstracts/search?q=verbal%20abuse" title=" verbal abuse"> verbal abuse</a> </p> <a href="https://publications.waset.org/abstracts/42455/a-study-of-customer-aggression-towards-frontline-employees-in-some-hotels-in-imo-state-nigeria" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/42455.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">276</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">293</span> Plant Species Composition and Frequency Distribution Along a Disturbance Gradient in Kano Metropolis Nigeria</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hamisu%20Jibril">Hamisu Jibril</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The study explores changes in plant species composition along disturbance gradient in urban areas in Nigeria at Bayero University Kano campuses. The aim is to assess changes in plant species composition and distribution within a degraded dryland environment in Kano Metropolis, Nigeria. Vegetation sampling was conducted using plots quadrat and transect methods, and different plant species were identified in the three study sites. Data were analyzed using ANOVA, t-tests and conventional indices to compare species richness, evenness and diversity. The study found no significant differences in species frequency among sites or sampling methods but observed higher species richness, evenness and diversity values in grasses species compared to trees. The study addressed changes in plant species composition along a disturbance gradient in an urban environment, focusing on species richness, evenness, and diversity. The study contributes to understanding the vegetation dynamics in degraded urban environments and highlights the need for conservation efforts. The research also adds to the existing literature by confirming previous findings and suggesting re-planting efforts. The study suggests similarities in plant species composition between old and new campus areas and emphasizes the importance of further investigating factors leading to vegetation loss for conservation purposes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=species%20diversity" title="species diversity">species diversity</a>, <a href="https://publications.waset.org/abstracts/search?q=urban%20kano" title=" urban kano"> urban kano</a>, <a href="https://publications.waset.org/abstracts/search?q=dryland%20environment" title=" dryland environment"> dryland environment</a>, <a href="https://publications.waset.org/abstracts/search?q=vegetation%20sampling" title=" vegetation sampling"> vegetation sampling</a> </p> <a href="https://publications.waset.org/abstracts/184510/plant-species-composition-and-frequency-distribution-along-a-disturbance-gradient-in-kano-metropolis-nigeria" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/184510.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">60</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">292</span> The Effects of Human Activities on Plant Diversity in Tropical Wetlands of Lake Tana (Ethiopia)</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abrehet%20Kahsay%20Mehari">Abrehet Kahsay Mehari</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Aquatic plants provide the physical structure of wetlands and increase their habitat complexity and heterogeneity, and as such, have a profound influence on other biotas. In this study, we investigated how human disturbance activities influenced the species richness and community composition of aquatic plants in the wetlands of Lake Tana, Ethiopia. Twelve wetlands were selected: four lacustrine, four river mouths, and four riverine papyrus swamps. Data on aquatic plants, environmental variables, and human activities were collected during the dry and wet seasons of 2018. A linear mixed effect model and a distance-based Redundancy Analysis (db-RDA) were used to relate aquatic plant species richness and community composition, respectively, to human activities and environmental variables. A total of 113 aquatic plant species, belonging to 38 families, were identified across all wetlands during the dry and wet seasons. Emergent species had the maximum area covered at 73.45 % and attained the highest relative abundance, followed by amphibious and other forms. The mean taxonomic richness of aquatic plants was significantly lower in wetlands with high overall human disturbance scores compared to wetlands with low overall human disturbance scores. Moreover, taxonomic richness showed a negative correlation with livestock grazing, tree plantation, and sand mining. The community composition also varied across wetlands with varying levels of human disturbance and was primarily driven by turnover (i.e., replacement of species) rather than nestedness resultant(i.e., loss of species). Distance-based redundancy analysis revealed that livestock grazing, tree plantation, sand mining, waste dumping, and crop cultivation were significant predictors of variation in aquatic plant communities’ composition in the wetlands. Linear mixed effect models and distance-based redundancy analysis also revealed that water depth, turbidity, conductivity, pH, sediment depth, and temperature were important drivers of variations in aquatic plant species richness and community composition. Papyrus swamps had the highest species richness and supported different plant communities. Conservation efforts should therefore focus on these habitats and measures should be taken to restore the highly disturbed and species poor wetlands near the river mouths. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=species%20richness" title="species richness">species richness</a>, <a href="https://publications.waset.org/abstracts/search?q=community%20composition" title=" community composition"> community composition</a>, <a href="https://publications.waset.org/abstracts/search?q=aquatic%20plants" title=" aquatic plants"> aquatic plants</a>, <a href="https://publications.waset.org/abstracts/search?q=wetlands" title=" wetlands"> wetlands</a>, <a href="https://publications.waset.org/abstracts/search?q=Lake%20Tana" title=" Lake Tana"> Lake Tana</a>, <a href="https://publications.waset.org/abstracts/search?q=human%20disturbance%20activities" title=" human disturbance activities"> human disturbance activities</a> </p> <a href="https://publications.waset.org/abstracts/152793/the-effects-of-human-activities-on-plant-diversity-in-tropical-wetlands-of-lake-tana-ethiopia" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/152793.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">123</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">291</span> A Resilience Process Model of Natural Gas Pipeline Systems</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Zhaoming%20Yang">Zhaoming Yang</a>, <a href="https://publications.waset.org/abstracts/search?q=Qi%20Xiang"> Qi Xiang</a>, <a href="https://publications.waset.org/abstracts/search?q=Qian%20He"> Qian He</a>, <a href="https://publications.waset.org/abstracts/search?q=Michael%20Havbro%20Faber"> Michael Havbro Faber</a>, <a href="https://publications.waset.org/abstracts/search?q=Enrico%20Zio"> Enrico Zio</a>, <a href="https://publications.waset.org/abstracts/search?q=Huai%20Su"> Huai Su</a>, <a href="https://publications.waset.org/abstracts/search?q=Jinjun%20Zhang"> Jinjun Zhang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Resilience is one of the key factors for system safety assessment and optimization, and resilience studies of natural gas pipeline systems (NGPS), especially in terms of process descriptions, are still being explored. Based on the three main stages, which are function loss process, recovery process, and waiting process, the paper has built functions and models which are according to the practical characteristics of NGPS and mainly analyzes the characteristics of deterministic interruptions. The resilience of NGPS also considers the threshold of the system function or users' satisfaction. The outcomes, which quantify the resilience of NGPS in different evaluation views, can be combined with the max flow and shortest path methods, help with the optimization of extra gas supplies and gas routes as well as pipeline maintenance strategies, the quick analysis of disturbance effects and the improvement of NGPS resilience evaluation accuracy. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=natural%20gas%20pipeline%20system" title="natural gas pipeline system">natural gas pipeline system</a>, <a href="https://publications.waset.org/abstracts/search?q=resilience" title=" resilience"> resilience</a>, <a href="https://publications.waset.org/abstracts/search?q=process%20modeling" title=" process modeling"> process modeling</a>, <a href="https://publications.waset.org/abstracts/search?q=deterministic%20disturbance" title=" deterministic disturbance"> deterministic disturbance</a> </p> <a href="https://publications.waset.org/abstracts/162218/a-resilience-process-model-of-natural-gas-pipeline-systems" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/162218.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">126</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">&lsaquo;</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=disturbance&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=disturbance&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=disturbance&page=4">4</a></li> <li class="page-item"><a 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