• Title/Summary/Keyword: Case-control analysis

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Nuclear Power Plants' Main Control Room Case analysis for Specialized Space Design (원자력 발전소 주제어실 사례를 통한 특수공간 디자인에 관한 기초적 연구)

  • Lee, Seung-Hoon;Back, Seong-Kyung;Lee, Sang-Ho
    • Korean Institute of Interior Design Journal
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    • v.16 no.5
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    • pp.81-88
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    • 2007
  • Energy consumption has been increased world widely, and the energy retain is one of the most important economic alternatives. These tendencies expand the nuclear power plants not only quantitatively but also qualitatively. Despite of the increasing construction of nuclear power plants and related facilities, every system in main control room(MCR) has been designed and administered solely based on the safety-first principles because of the specificity of nuclear industry. However, recent main control rooms started with the concept that the operators' performance could be optimized though the organic interrelation between human, machine, and environments. Now, it has been recognised in the scope of Ergonomics and Space Design which acknowledge our living spaces as Man-Environment Interface and this change connotes the MCR spaces should be special spaces rather than ordinary spaces. This research investigated domestic and foreign nuclear power plants' MCRs to suggest basic alternatives which can be applied to future MCR. With the review of characteristics of MCR, an integration of interior design, lighting and Ergonomics was explored and classified as types. Futhermore, the classification of environmental characteristics within the relationships between human, machine, and environments was developed through the case analysis of nuclear power plants. The results of this study will provide a basis of space design for system environments that the high level of safety and function are extremely important.

A Case Study for SMRT Train Open Doors Control System (도시철도의 열차출입문제어에 관한 연구)

  • Won, Yu-Duck;Shim, Won-Sub
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.941-946
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    • 2006
  • It followed in system development and SMRT(Seoul Metropolitan Rapid Transit Co)System reached to an automatic train operation(ATO) and driverless operation(DLM) from the manual operation due to the train driver. The train like the general bus or the car vehicle was not serial riding in a car and the Parallel concept which the numerous passenger rides in a car simultaneously occur frequently the charge of the train driver unmanned bitterly from existing manual handling was a possibility of doing, train open door control(ODM) which bites also ATO, it handles it minimized. Like this ATO/DLM, the control system which bites being a Wayside to Train communication for immediacy, it is a system of the Vital concept the immediacy of the citizen Data evil the radio information transmission and the train of the interface which is accurate from unmanned operation and, will decipher, will accomplish it will guarantee. It respects the passenger accident prevention and an air question environment improvement from subway platform and phul leys the screen door of Platform(PSD) with the fire tube frost it refers and part it treats and to sleep it does, ODM which bites is accuracy and immediacy of altitude and when seeing from the viewpoint which demands the trust of altitude, ODM system the trust of car incest interface in the equipment construction which is safe and the comparative analysis back of the system analysis against the control which bites and case study and other subway system it leads from the research which it sees and signal - train in base grudge to sleep it contributes it does.

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Analysis of Current Control Stability using PI Control in Synchronous Reference Frame for Grid-Connected Inverter with LCL Filter (LCL 필터를 사용하는 계통연계형 인버터의 동기좌표계 PI 전류제어 안정도 해석)

  • Jo, Jongmin;Lee, Taejin;Yun, Donghyun;Cha, Hanju
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.2
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    • pp.168-174
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    • 2016
  • In this paper, current control using PI controller in the synchronous reference frame is analyzed through the relationship among bandwidth, resonance frequency, and sampling frequency in the grid-connected inverter with LCL filter. Stability is investigated by using bode plot in frequency domain and root locus in discrete domain. The feedback variable is the grid current, which is regulated by the PI controller in the synchronous reference frame. System delay is modeled as 1.5Ts, which contains computational and PWM modulator delay. Two resonance frequencies are given at 815 Hz and 3.16 kHz from LCL filter parameters. Sufficient phase and gain margins can be obtained to guarantee stable current control, in case that resonance frequency is above one-sixth of the sampling frequency. Unstable current control is performed when resonance frequency is below one-sixth of the sampling frequency. Analysis results of stability from frequency response and discrete response is the same regardless of resonance frequency. Finally, stability of current control based on theoretical analysis is clearly verified through simulation and experiment in grid-connected inverters with LCL filter.

The Variables Affecting the Internet Overuse of Adolescents - An Analysis by Gender, School Grades and School Systems - (청소년의 인터넷 과다 사용에 영향을 미치는 변인 - 청소년의 성, 학교, 계열별 분석 -)

  • Lee, Kyung-Hwa;Ryu, Kyung-Hee
    • Journal of Korean Home Economics Education Association
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    • v.23 no.2
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    • pp.71-87
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    • 2011
  • In this study, we investigate the individual-, parents-, and family-related variables affecting the internet overuse of adolescents by the gender, school grades and school systems, which is based on surveys of 480 students in the middle and high school, employing multiple regression analysis. Major findings are as follows. 1. In the case of male students, internet use was higher when the students are playing online games more often, when the students are under stress, or when they have lower self control. In the case of female students, internet use was higher when the students are playing online games more often or when the students are visiting pornographic sites more often. 2. In the case of middle school students, internet use was higher when the students play online games more often, when they use file downloads more often, when they have lower self control, or when they have parents who are setting lesser rules on the students' internet use. In the case of high school students, internet use was higher when they play online games more often, when they engage in internet club activities more actively, when they have lower self control, when they use e-mails less frequently, when they have fathers with better internet ability, or when they are under parents' strict control. 3. In the case of academic high school students, internet use was higher when they play online games more often, when they engage in internet club activities more actively, when they visit pornographic sites more often, when they have lower self control, when they have mothers with poor internet ability, when they use e-mails less frequently, or when they have fewer number of close friends. In the cases of vocational high school students, internet use was higher when they play online games more often, when they are under more stress, when they get better grades, when they have fathers with better internet ability, when they are under parents' strict control, or when they have lower self control.

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Discrete Model Reference Adaptive Control Based on Hyperstability Theory (Hyperstability 이론에 기초를 둔 이산기준모델적응제어)

  • 함운철;최계근
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.5
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    • pp.482-489
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    • 1988
  • In this paper, we proposed a generalized model reference adaptive control theory which can be applied to single-input single-output discrete system by using V.M.Popov's hyperstability theory. As the result of theoretical analysis, it is proved that the discrete adaptive control scheme proposed by Narendra is a special case of the adaptive control schemes proposed in this paper. Also we suggest a variety of parameter adaptiations methods of controller through hyperstability theory.

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Self Tuning Control of Interconnected System wsing Offset Rejection Techniques (오프셋 제거방식을 이용한 상호연관 시스템의 적응제어)

  • 양흥석;김영철;박용식
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.214-217
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    • 1987
  • In this paper self tuning control of interconnected systems are dealt in view point of large scale system control. The plant model is given in multiple ARMA process. This process is simplified as independent SISO ARMA process having offset terms. This offset was considered as effects of interconnections. In each decentralized system, self tuning controller with instrumental variable method is adopted. As a result, this algorithm enables the parameter estimation to be unbiased and non-drift. This controller contains a new implicit offset rejection technique. Simulation results considers well with the analysis in case of linear interconnection.

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Determination of Flood Risk Considering Flood Control Ability and Urban Environment Risk (수방능력 및 재해위험을 고려한 침수위험도 결정)

  • Lee, Eui Hoon;Choi, Hyeon Seok;Kim, Joong Hoon
    • Journal of Korea Water Resources Association
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    • v.48 no.9
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    • pp.757-768
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    • 2015
  • Recently, climate change has affected short time concentrated local rainfall and unexpected heavy rain which is increasingly causing life and property damage. In this research, arithmetic average analysis, weighted average analysis, and principal component analysis are used for predicting flood risk. This research is foundation for application of predicting flood risk based on annals of disaster and status of urban planning. Results obtained by arithmetic average analysis, weighted average analysis, and principal component analysis using many factors affect on flood are compared. In case of arithmetic average analysis, each factor has same weights though it is simple method. In case of weighted average analysis, correlation factors are complex by many variables and multicollinearty problem happen though it has different weights. For solving these problems, principal component analysis (PCA) is used because each factor has different weights and the number of variables is smaller than other methods by combining variables. Finally, flood risk assessment considering flood control ability and urban environment risk in former research is predicted.

Study on relationship between the Wirecutter Length and the Control Input of Rotorcraft (회전익 항공기의 전선절단기 길이와 조종입력의 상호관계 연구)

  • Kim, Young-Jin;Lee, Seung-Jae;Chang, In-ki;Shim, Dai-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.1
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    • pp.46-53
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    • 2017
  • This paper shows a length of wirecutter using an analysis based on Rotorcraft's control input and taxiing speed. In case of selecting an inappropriate length of wirecutter which applies to rotorcraft for safety, this causes a collision between blade and wirecuter, or an accident by wire. We review the control input which was used in development stage, and establish the conditions of control input which are needed in taxiing. Based on these conditions, we review the collision possibility between blade and wirecutter through analysis in case of 20, 40, 60 kts taxiing speed. Following, this result is verified by comparison with that of a simulation test in rotorcarft. Finally, in case of high collision possibility, we presented the downsize length to avoid the collision and increment of non-protective area in flight, simultaneously.

Effects of an Integrated Case Management Program on Medication Adherence, Pain, Physical Function and Depression among Korean Medical Aid Beneficiaries with Osteoarthritis (의료급여 관절염환자의 복약순응향상을 위한 통합중재프로그램의 효과)

  • Ahn, Yang Heui
    • Journal of Korean Public Health Nursing
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    • v.28 no.1
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    • pp.32-45
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    • 2014
  • Purpose: The purpose of this study was to test the effectiveness of an eight session integrated case management program for improvement of medication adherence, physical function, pain, and depression among medical aid beneficiaries with osteoarthritis. Method: A nonequivalent control group pre-posttest design was employed. Participants were 55 medical aid beneficiaries who agreed to participate in this study, and were assigned to an experimental group (n=28) or control group (n=27). The framework of this research derived from Cox's Interaction Model of Client Health Behavior guided the overall intervention and the components. The program led by a case manager with a medication calendar, motivating interviewing and coaching strategies and collaboration with a pharmacist. Analysis included change in scores, ${\chi}^2$-test, and t-test. Result: The results showed significant increase in medication adherence, physical function and decrease joint pain, joint stiffness and depression in the experimental group compared to the control group. Conclusion: The eight session integrated case management program indicated an effect on medication adherence, pain, physical function, and depression. Partnership with a pharmacist is recommended for medication adherence and conduct of further studies will be needed in order to determine the long-term effect of an extended integrated program on health outcomes.

Performance Analysis of a Solid Oxide Fuel Cell/Micro Gas Turbine Hybrid System (고체산화물 연료전지/마이크로 가스터빈 하이브리드 시스템의 성능 해석)

  • Yang, Jin-Sik;Song, Tae-Won;Kim, Jae-Hoon;Sohn, Jeong-Lak;Ro, Sung-Tack
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.273-276
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    • 2005
  • Performance analysis of a solid oxide fuel cell/micro gas turbine hybrid system is conducted at design-point and part-load conditions and its results are discussed in this study. With detailed considerations of the heat and mass transfer phenomena along various flow streams of the SOFC, the analysis based on a quasi-2D model reasonably predicts its performance at the design-point operating conditions. In case of part-load operations, performance of the hybrid system to three different operation modes(fuel only control, speed control, and VIGV control) is compared. It is found that the simultaneous control of both supplied fuel and air to the system with a variable MGT rotational speed mode is the optimum choice for the high performance operation. And then, the dynamic characteristics of a solid oxide fuel cell are briefly introduced.

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