• Title/Summary/Keyword: Closed system and Open system

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Feasibility Study on the Conjunctive Operation of Water Transmission Systems from Multiple Source with Applying EPAnet (수리해석(水理解析) 모형(模型)을 이용한 다수원(多水源) 송수계통(送水系統)의 연계(連繫) 운영(運營) 방안(方案) 경제성(經濟性) 평가(評價) - 거제시(市)를 대상(對象)으로 -)

  • Ryu, Tae-Sang;Ha, Sung-Ryong
    • Journal of Korean Society of Water and Wastewater
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    • v.21 no.5
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    • pp.609-619
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    • 2007
  • The objective of this paper is to evaluate the feasibility of conjunctive Operation between Multi-regional water supply networks from multiple source as a effective way to meet two conditions: to minimize the electric cost for providing water demanded and meet the water flow rate for satisfying customers. EPAnet Model is used to calculate a hydraulic water distribution condition based on an integrated operation of water supply systems located in short distance. The modeling was conducted on several simulation cases including the individual operation by existing inter-regional water supply networks within short distance, the conjunctive operation of more than two existing networks with valve fully closed and full open constraint. As a study distribution system, water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. It was found that a well-allocated water supply scheme based on a conjunctive operation promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. The result such as unit district costs, pareto optimum pump combination sets will be applied to the optimization for a conjunctive operation of existing inter-regional water supply networks within short distance.

Effects of Core Program Exercise on Static Balance of Females in Their Twenties (코어 프로그램이 20대 여성의 정적균형에 미치는 영향)

  • Hwang, Seung-Joon;Cho, Nam-Jung;Lee, Jeong-Woo
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.8 no.1
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    • pp.31-36
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    • 2010
  • Purpose : The purpose of this study was to investigate the effects of core exercise on the static balance for females in their twenties. Methods : The core exercise program was conducted 3 times per week for 4 weeks. The result is based on the analysis of measuring static balance before and after the core exercise program. By using the GOOD BALANCE system, the assessment of the static balance ability was made before and after the exercise of 6 postures: normal standing, one left leg?and one right leg standing with eyes open and closed respectively. For each case, the experimental data were obtained in 3 items: mean X speed, mean Y speed, and velocity moment. Statistical analysis was performed using SPSS/Win(10.0) version and Willcoxon signed rank test. Results : From the result of this study, we found that mean X speed, mean Y speed and velocity moment of total postures significantly increased after the 4 week program of core exercises. Conclusion : These finding indicate that core exercises could be beneficial to females in their twenties due to the effect of increasing static balance.

Stroke Verification Test and Operational Characteristics Analysis of KSLV-I Kick Motor TVC Nozzle (나로호 킥모터 TVC 노즐 행정확인시험 및 특성 분석)

  • Sun, Byung-Chan;Park, Yong-Kyu;Oh, Choong-Suk;Roh, Woong-Rae
    • Aerospace Engineering and Technology
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    • v.11 no.1
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    • pp.158-168
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    • 2012
  • This paper deals with TVC nozzle stroke verification test and corresponding analysis techniques related to kick motor TVC system of KSLV-I second stage. It is shown that the relationship between TVC stroke and potentiometer voltage is revealed via the open-loop stroke verification test, and other major operational parameters including nozzle alignment error, actuation error, neutral position, radius of nozzle rotation, location of nozzle rotation center, angle conversion coefficients, etc. are analyzed via the closed-loop stroke verification test. The TVC stroke verification test results for the first and second flight model of KSLV-I show that all TVC operational parameters of KSLV-I second stage were normally setup for the first and second flight tests.

Effects of Postural Stability using Electrical Stimulation on the Lower Limb (하지에 인가한 전기 자극이 자세안정성에 미치는 영향)

  • Lee, S.Y.;Yu, M.;Kim, D.W.;Kim, N.G.
    • Journal of Biomedical Engineering Research
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    • v.30 no.3
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    • pp.255-262
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    • 2009
  • The present study analyzed the association between postural control and electrical stimulation by measuring body sway when use the electrical stimulations were applied to different stimulation zones in lower limbs. The subjects were 14 young adults and were, tested for two different visual condition: eyes open and eyes closed. The experiments were also performed in two different stance case: one legged stance and two legged stance while electrical stimulations were applied concurrently or individually to tibialis anterior and triceps surae. Postural responses were assessed by analyzing COP sway path, sum of COP sway measured by a forceplate. The results showed that the direction of the COP shift changed in accordance with the direction of stimulation and showed sensory adaptation as the experiment progressed for two legged stance case. For one legged stance case, concurrent electrical stimulation both sides of muscles was found to be effective for enhancement of postural balance control.

A Study on Flow Control of Network Systems with LonWorks (LonWorks를 이용한 네트웍 시스템의 플로우제어에 관한 연구)

  • Kim, Byeong-Hui;Jo, Gwang-Hyeon;Park, Gyeong-Seop
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.37 no.5
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    • pp.13-21
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    • 2000
  • In this paper, we investigate the performance improvement by applying flow control to LonWorks-based network systems which support various communication media together with interpretable class of systems. To this end, we introduce a circular queue at each node of industrial network systems usually operated in open loop. Then we utilize the feedback information of the number of data in a queue, the data arriving interval in a queue and channel error to make the overall industrial network system in closed loop. We verify the improved performance of the network systems in view of throughput and fairness measures via the experimental results conducted in several field situation.

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Water-Sloshing-Based Electricity Generating Device via Charge Separation and Accumulation (전하 분리와 축적을 통한 물의 슬로싱 현상 기반 전기에너지 발생 장치)

  • Cha, Kyunghwan;Heo, Deokjae;Lee, Sangmin
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.1
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    • pp.98-101
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    • 2022
  • Liquid-based Triboelectric nanogenerator (L-TENG) is one of the alternatives to solid-based Triboelectric nanogenerator (S-TENG) because of the absence of surface damage which can decrease the durability of the generator. However, the L-TENG also has an obvious drawback of significantly lower output than that of S-TENG. This article produces water-sloshing-based electricity generating device (W-ED) with a new design of L-TENG that improves electrical output in portable form. The dual-electrode system, consisting of closed-loop circuit and inner electrode which enables water to contact directly in the bottle, can generate the open-circuit voltage and the short-circuit current of up to 348 V and 5.1 mA, respectively. By investigating the motion of water for each frequency, we propose that W-ED is suitable device for a variety of human motions. We expect that W-ED can be applied in small electrical devices or sensors in daily-use items.

An Alternative Improved-Layout of Rural House Plot (농촌주택의 주거 공간구조 개선방안)

  • 박장혁
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.6
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    • pp.54-63
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    • 1999
  • Considering that rural village had evolved through a long-sustained effort of harmnization with nature, there should be the wisdom not only to reflect the level of rural resident's housing demand, but also to conserve the traditional characteristics of high-valuation in the modern rural housing. In Korea , standard design proposals of rural houses had been made public three times ; in 1972 , 1984 and 1995. so , firstly, this study analysed the inner-space layouts of design proposals mentioned above, from which changes and problems in the past housing design were derived. And also, through, the positive acceptance of residents' opinion living inthe houses built by standard design proposals in 1970 ~1980's, improved design principles and an alternative model were proposed , finally. The inner-space structed of standard design proposals in 1970s was originated from small-scaled and low-priced one, basically under the " open system". In 1980s, the basic design principle changed to the 'closed system' in which the living room being the focus of indoor family life, and , in 1990s, progressively, therural housing developed to the high qualified type by the spatial enlargement and with increased equipements. However, this structural change of rural house brought about the problem of functional separatioon between farming and daily living activities. In details, limited spaces of multipurpose spaces and sanitary facility would be mentioned as problems for improvement. conclusively in this study, newoly arranged "open system" was recommended , as a basic design principle for theinner space structure formation of rural house, which easily links the constituent inner-house spaces to outer one. Based on this principle, the detailed design criterial was proposed as follows ; 1. The living room be directly linked to the front-yard and centrally placed, the addtional space of which could be secured for the special family events by the flexibleuse of its adjacent room or by the housing of male quarters(separated from main building quarter). 2. The kitchen also be directly linked to side-yard and to livng room , for the convenience of farming activities and the shortening of path flow housewife. 3. The expanded toilet-and-bathroom be placed in the directly connected left-hand side to the living room and also be allowed access through multipurpose spaces to out door. 4. The multipurpose spaces be directly connected to the kitchen and the toilet and-bathroom , of which function would be for undressing of working clothes, quickwashing and ordinary working.nd ordinary working.

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The Relationships Between Navigational Pattens and Information Processing Styles of Hypermedia Users (하이퍼미디어 사용자의 정보처리 유형이 정보탐색 패턴에 미치는 영향)

  • 이미자
    • Korean Journal of Cognitive Science
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    • v.12 no.1_2
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    • pp.65-76
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    • 2001
  • This study investigated the relationships between hypermedia users information processing styles and navigational patterns. Three aspects of navigational patterns were investigated: (a) navigational breadth patterns which reveal how comprehensively users access, (b) navigational path patterns which display what sequences users follow. and (c) navigational method patterns which show what methods u users employ when using the system. Information processing styles were measured by the Human Information Processing Styles(HIPS) Survey. The subjects were 102 undergraduate students enrolled in management courses at a university. Participation was voluntary 34 students were selected for each of left, right, and integrated information processor group. The subjects interacted with A.g.i.l.e. TrainerTM program to complete two types of searching tasks 'open-ended and closed-ended tasks' Findings indicated that the information processing style seems to play an important role in how an individual interacts with the hypermedia systems.

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Characteristics of Exportation of Korean TV programs: Focused on MBC Case (지상파 방송프로그램의 해외 판매 특성에 관한 연구: MBC 사례를 중심으로)

  • Lee, Moon-Haeng
    • Korean journal of communication and information
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    • v.59
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    • pp.233-258
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    • 2012
  • The purpose of this study is to research on the mechanism of exportation of Korean TV programs. As a result, the buying countries of Korean TV programs have been relatively diversified : 40 countries across the world. However, examining the frequency of exportation has shown that it primarily focused on few countries such as Japan and Taiwan. Furthermore, drama has been the most preferred genre by foreign countries. Fortunately, remakes, dubbing productions, publications, and merchandising have been started to develop. As for the trade partner, the portion of foreign distributors has been ranked as a the most prioritized type. Therefore, it is necessary to open the existing closed system of distribution of Korean free TV to build more diversified partnership.

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The Effect of the Vestibular Stimulation Training on the Balance of Patient with Chronic Stroke (전정자극 훈련이 만성 뇌졸중 환자의 균형에 미치는 영향)

  • Nam, Ki-Won;Oh, Chae-Eun;Seo, Dong-Yel
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.597-604
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    • 2017
  • This study examined the effects of vestibular stimulation training on the static and dynamic balance of patients with chronic stroke. This study was conducted from July 15th to September 6th, 2014 and 20 subjects diagnosed with stroke participated in this study. The subjects were divided randomly into Group I (general therapeutic exercise, n=10) and Group II (vestibular stimulation training, n=10). Both groups were trained for 40 minutes, 3 times a week, for 6 weeks. The balance ability, static balance and dynamic balance, were evaluated using a Good Balance System and compared before-and-after intervention. In the vestibular training group, there were statistically significant differences in the left-right and anterior-posterior balance with the eyes closed and standing posture, in the left-right and anterior-posterior balance with the eyes open and standing posture, and moving time and distance. In the general therapeutic exercise group, there was no significant difference except in the left-right balance with the eyes open and standing posture. In conclusion, vestibular stimulation training had positive effects on the static and dynamic balance of chronic stroke patients, and this training can be effective in a treatment program to improve the balance ability of stroke patients.