• Title/Summary/Keyword: Dynamic How Control

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Determining the Compensation Voltages for Dynamic Voltage Restorers by use of PQR Instantaneous Power Theory (PQR 순시전력이론에 의한 동적전압보상기의 보상전압 결정)

  • 김효성;이상준;설승기
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.5
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    • pp.442-449
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    • 2003
  • This paper discusses how to generate the reference compensation voltages in Dynamic Voltage Restorers (DVR) by use of PQR instantaneous power theory. Sensed three-phase terminal voltages are transformed to PQR coordinates without time delay. Since the reference voltage in PQR coordinates is a single dc value, the voltage controller for DVRs is simple and easy to design. Proposed control method can be implemented by feedforward controllers or by feedback controllers. This paper verified the theory by a feedforward controller of a DVR with simulation and experiment.

MANAGEMENT THINKING BEHIND PERFORMANCE MEASURES

  • Yong-Woo Kim ;Glenn Ballard
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.377-382
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    • 2005
  • The tools, methods and measures used for project control reflect underlying theories of management. Management theory has been neglected in the construction industry, which has rather focused on tools and neglected theory. This paper contributes to the theory of project management by introducing and developing two fundamental and competing conceptualizations of management: MBM (Managing-by-Means) and MBR (Managing-by-results). Current project control and performance measurement practice is based on MBR. However, project control based on MBR may not be appropriate for managing dynamic projects. The paper present the Last PlannerTM System (LPS) and Process Variance Control (PVC) as examples of methods reflecting the MBM view. It is argued first that the MBM view is appropriate for managing uncertain, complex and quick projects. The paper also explores how MBR tools and techniques may be appropriately used within an MBM framework.

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Accuracy Simulation Technology for Machine Control Systems (기계장비 제어특성 시뮬레이션 플랫폼 기술)

  • Song, Chang-Kyu;Kim, Byung-Sub;Ro, Seung-Kook;Lee, Sung-Cheul;Min, Byung-Kwon;Jeong, Young-Hun
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.3
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    • pp.292-300
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    • 2011
  • Control systems in machinery equipment provide correction signals to motion units in order to reduce or cancel out the mismatches between sensor feedback signals and command or desired values. In this paper, we introduce a simulator for control characteristics of machinery equipment. The purpose of the simulator development is to provide mechanical system designers with the ability to estimate how much dynamic performance can be achieved from their design parameters and selected devices at the designing phase. The simulator has a database for commercial parts, so that the designers can choose appropriate components for servo controllers, motors, motor drives, and guide ways, etc. and then tune governing parameters such as controller gains and friction coefficients. The simulator simulates the closed-loop control system which is built and parameter-tuned by the designer and shows dynamic responses of the control system. The simulator treats the moving table as a 6 degrees-of-freedom rigid body and considers the motion guide blocks stiffness, damping and their locations as well as sensor locations. The simulator has been under development for one and a half years and has a few years to go before the public release. The primary achievements and features will be presented in this paper.

The Effect of Action on the Balance and the Trunk Control Ability in the Sit Position of Chronic Stroke Patients (동작관찰훈련이 만성 뇌졸중 환자의 앉은 자세에서 균형과 몸통조절능력에 미치는 영향)

  • Hwang, Junhyun;Lee, Yangjin;Joo, Mincheol;Kim, Seongryeol
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.3
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    • pp.1-9
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    • 2019
  • Purpose : To find out how action observation training for chronic stroke patients affects their balance and body control abilities in the posture seated in the rehabilitation of stroke. Methods : This study was conducted on 30 subjects who were diagnosed with stroke. The group conducted motion observation training through video clips, while the control group only conducted physical training, and the general physical therapy was performed equally by both counties. The static balance was measured using Biorescue and the dynamic balance was measured using Modified Functional Reach Test (MFRT), Postural Assessment Scale for Stroke, and Trunk Impairment Scale. Results : Static balance showed statistically significant difference in foot pressure (p<.05) as a result of comparison between pre and post exercise training. Dynamic balance was statistically significant (p>.05) as a result of comparing pre and post differences using modified functional reach test. The trunk control ability was statistically significant (p>.001). Comparison between the results of before and after motion observation training showed a statistically significant difference. Conclusion: This study confirmed that exercise training in sitting position was effective for static, dynamic balance ability and trunk control ability of hemiplegic patients due to stroke. These results suggest that the use of motion monitoring in stroke patients may have a positive impact on the diversity and function of rehabilitation.

The Effects of Neuromuscular Electrical Stimulation of the Quadriceps Femoris on the Balance in Patients with Total Knee Arthroplasty (넙다리네갈래근의 신경근전기자극치료가 무릎관절 전치환술 환자의 균형에 미치는 영향)

  • Hoon Jo;Sang-Cheol Im;Kyoung Kim
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.2
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    • pp.159-168
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    • 2023
  • Purpose : This study aimed to investigate how neuromuscular electrical stimulation (NMES) affects the balance ability of patients who have undergone total knee arthroplasty owing to osteoarthritis. Methods : Thirty patients who had undergone total knee arthroplasty were randomized to an experimental group (n=15) and a control group (n=15). The experimental group received conventional physical therapy for 50 minutes and NMES treatment for 30 minutes, whereas the control group received conventional physical therapy for 50 minutes and active range of motion (AROM) exercises for 30 minutes. Within-group and between-group changes in static and dynamic balance ability before and after the 4-week intervention were analyzed. Results : In the within-group comparison, sway velocity in the center of gravity and total distance were significantly improved in both the experimental and control groups (p<.05), with no significant differences between the groups (p>.05). In the within-group comparison, both the experimental and control groups showed significant improvement in the functional reach test and movement velosity (p<.05). In the between-group comparison, the experimental group showed a significantly better improvement than the control group in the functional reach test (p<.05), but there was no significant difference in the movement velosity test (p>.05). Conclusion : In this study, NMES improved the static and dynamic balance in patients who had undergone total knee arthroplasty. Compared with AROM exercises, there was a greater effect on dynamic balance partially; however, the overall effect was similar. Therefore, NMES may be one option among various interventions to improve the balance ability in patients who have undergone total knee arthroplasty. In particular, this method may be effective when it is difficult to apply balance training for patients with total knee arthroplasty in a clinical setting.

Modeling of Discrete Event Systems with Real-time Temporal Logic Frameworks (실시간 시간논리구조를 이용한 이산 사건 시스템의 모델링)

  • Jeong, Yong-Man;Lee, Won-Hyok;Choi, Jeong-Nae;Hwang, Hyung-Soo
    • Proceedings of the KIEE Conference
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    • 1997.07b
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    • pp.590-592
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    • 1997
  • A Discrete Event Dynamic System is a system whose states change in response to the occurrence of events from a predefined event set. A major difficulty in developing analytical results for the systems is the lack of appropriate modeling techniques. This paper proposes the use of Real-time Temporal Logic as a modeling tool for the analysis and control of DEDS. The Real-time Temporal Logic Frameworks is extended with a suitable structure of modeling hard real-time constraints. Modeling rules are developed for several specific situations. It is shown how the graphical model can be translated to a system of linear equations and constraints.

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A Study on How to Apply GBS (Goal-Based Scenario) to 'Ecology & Environment' Education in High School (GBS(Goal-Based Scenario)에 의한 수업 개발 및 적용 방안 연구: 고등학교 '생태와 환경' 수업 사례 중심으로)

  • Kang, In-Ae;Lee, Myong-Soon
    • Hwankyungkyoyuk
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    • v.21 no.4
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    • pp.94-110
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    • 2008
  • Recently environmental problem becomes such a big issue all over the world that the necessity and importance of the environmental education in school has been simultaneously emphasized. While diverse methods for the environmental education have been researched, this paper, especially focused on a teaching-learning model called GBS (Goal-based scenario), aims to provide a new learner-centered approach for the environmental education. For this purpose, this paper first briefly presents two theoretical backgrounds of GBS (i.e., constructivism and Schank's dynamic memory theory), which is followed by specific and concrete strategies and methods of how to apply GBS in class for the teacher. GBS(Goal-Based Scenario) is a learner-centered model in which learners are presented with a reality-based scenario (or task or problem) and go through several stages of 'missions' to get to a final solution of the given scenario. GBS, while completely resonant with other constructivist learning models in terms of learner-centered approaches, is distinctive from others, when it supplies more specific, structured guides of learning, called 'missions', to the students throughout the whole learning process. In a words, GBS ought to be recognized as an unique learner-centered model compromising the contradictory concepts of 'learner control' and 'structure and specifics' in learning environments still without any damage of constructivist learning principles.

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Simulation Study for a UV Water Disinfection Unit Powered by a Photovoltaic System

  • Riahi, Said;Mami, Abdelkader;Minzu, Viorel
    • International Journal of Computer Science & Network Security
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    • v.22 no.1
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    • pp.175-182
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    • 2022
  • This work presents a simulation model for a specific UV disinfection system (UVDS) powered by a Photovoltaic System. The global UVDS also includes the electronic converters, Electronic Ballast, UV Lamp and Motor Pump. The equations that model the physical components' behaviour are connected to obtain a dynamic global model. The latter is converted in a Simulink/Matlab model, which allows to carry out simulation series concerning the entire UVDS. The physical parameters: the irradiation G and the temperature T, are considered as inputs. series of measurements carried out in order to show how these parameters affect the current, the voltage of the PVs and especially the value of the current of the UV lamp, on the other hand a study on the behavior and the evolution of the parameters of the motor pump such as the armature current, motor torque, speed of rotation and the water flow. The purpose of all this is to realize how important are the two parameters concerning the lamp current and the water flow because they are two very important factors to keep an adequate water quality.

Parameters Identification of Gantry Crane By Using ANSYS

  • Kim, Hwan-Seong;Nguyen, Tuong-Long
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.62.5-62
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    • 2002
  • The main purpose of this paper is to identify the important parameters and to examine their relations to one another while gantry crane structure was modeled. The important elements of the structural analysis are included, such as the stiffness matrix and its relations to the degrees of freedom, the displacement, and frequency responses. To investigate these relations, the parametric modeling of a dynamic system is solved by using the finite element method (ANSYS-Program). Furthermore, EXPRESS schema and C-FAR (change favorable representation) are described how to change the frame length of gantry crane which influences other elements. Since this relationship is established, the results may...

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Mass Spectrometry-Based Proteomic Profiling of Pseudopodia of Metastatic Cancer Cells

  • Choi, Sunkyu
    • Mass Spectrometry Letters
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    • v.11 no.2
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    • pp.25-29
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    • 2020
  • Pseudopodia are dynamic actin cytoskeleton-based membrane protrusions of cells that enable directional cell migration. Pseudopodia of cancer cells play key roles in cancer metastasis. Recent studies using pseudopodial subcellular fractionation methodologies combined with mass spectrometry-based proteomic profiling have provided insight into the pseudopodiome that control the protrusions of invasive metastatic cancer cells. This review highlights how to characterize the protein composition of pseudopodia and develop strategies to identify biomarkers or drug candidates that target reduction or prevention of metastatic cancer.