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

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Assessment of Single-leg Stance Balance Using COP 95% Confidence Ellipse Area (COP 95% Confidence Ellipse Area를 이용한 외발서기 균형 평가)

  • Youm, Chang-Hong;Park, Young-Hoon;Seo, Kuk-Woong
    • Korean Journal of Applied Biomechanics
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    • v.18 no.2
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    • pp.19-27
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    • 2008
  • The purpose of this study was to investigate of assessment of the ability of balance control using COP 95% confidence ellipse area while executing single-leg stance with eyes open and eyes closed through GRF system. The subjects participated in this study were 7 female yoga group and 7 female control group. The yoga training affected to improve the ability of balance control because the yoga group's COP AP and ML standard deviation and COP 95% confidence ellipse area were smaller than control group in both a single-leg stance with eyes open and eyes closed. Visual affected to the ability of balance control in a single-leg stance. I consider COP 95% confidence ellipse area as a high variable for determining the ability of balance control, and therefore suggest that additional studies for various groups and subjects will be required in the future.

Advanced Key Management Architecture Based on Tree Structure for Secure SCADA Communications (안전한 SCADA 통신을 위한 트리 기반의 효율적인 키 관리 구조)

  • Choi, Dong-Hyun;Lee, Sung-Jin;Jeong, Han-Jae;Kang, Dong-Joo;Kim, Hak-Man;Kim, Kyung-Sin;Won, Dong-Ho;Kim, Seung-Joo
    • The KIPS Transactions:PartC
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    • v.16C no.1
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    • pp.37-50
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    • 2009
  • The SCADA(Supervisory Control And Data Acquisition) system is a control system for infrastructure of nation. In the past, the SCADA system was designed without security function because of its closed operating environment. However, the security of the SCADA system has become an issue with connection to the open network caused by improved technology. In this paper we review the constraints and security requirements for SCADA system and propose advanced key management architecture for secure SCADA communications. The contributions of the present work are that our scheme support both message broadcasting and secure communications, while the existing key management schemes for SCADA system don't support message broadcasting. Moreover, by evenly spreading much of the total amount of computation across high power nodes (MTU or SUB-MTU), our protocol avoids any potential performance bottleneck of the system while keeping the burden on low power (RTU) nodes at minimal.

Efficient Sample Digestion Method for Uranium Determination in Soil using Microwave Digestion for Alpha Spectrometry (마이크로파 용해장치를 활용한 토양 중 우라늄의 알파분광분석법)

  • Kim, Chang Jong;Cho, Yoon Hae;Kim, Dae Ji;Chae, Jung Seok;Yun, Ju Yong
    • Journal of Radiation Protection and Research
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    • v.37 no.4
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    • pp.213-218
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    • 2012
  • Alpha spectrometry has been typically used for determination of the uranium isotopes in soil. For a number of uranium analysis in soil samples, rapid sample digestion with limited quantities of mixed acid containing HF will give a contribution for effective management of uranium analysis. Microwave digestion system is evaluated for rapid sample digestion using reference uranium soil (IAEA-375 soil). For completion of 0.5 g of soil digestion by microwave, 3 ml of HF in a 10 ml of mixed acid is minimum requirement volume for completed soil digestion for 80 minutes. Microwave digestion is timely effective techniques for uranium measurement using alpha spectrometry compared to the other methods (open vessel digestion, closed vessel digestion) due to rapid sample digestion. In addition, it can be reduced the occurrence of hazardous substances by minimizing the amount of HF.

A Study on the Improvements of Interior Space regarding the Characteristics of Architectural Design Studio (설계스튜디오의 특성에 따른 실내공간 개선에 관한 연구)

  • Song, Byung-Ha
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.1
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    • pp.454-463
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    • 2013
  • Upon changing architectural education system into 5-year program, the design studio in university should meet the requirement in order to acquire the accredition. This study investigates on student' perceptions and responses, according to the configuration(open, mixed, closed), to their studio environment. Results and suggestions are as follows for all types: First, there should be space for individual activities for the student: Second, excluding space for excluding space for the individual work, seperated area must be provided for co-operative work, such as making models; Third, a clear territorial distintion between the individual and the co-work space should be able to set by the students, using. for instance, movable partition or corridor; Fourth, however, in line with the types, a seperated lecture or seminar room in the open type, a device to prevent distraction such as noise in the mixed type, and more space for co-work in the closed type are also suggested.

Modeling and Control Method for High-power Electromagnetic Transmitter Power Supplies

  • Yu, Fei;Zhang, Yi-Ming
    • Journal of Power Electronics
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    • v.13 no.4
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    • pp.679-691
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    • 2013
  • High-power electromagnetic transmitter power supplies are an important part of deep geophysical exploration equipment. This is especially true in complex environments, where the ability to produce a highly accurate and stable output and safety through redundancy have become the key issues in the design of high-power electromagnetic transmitter power supplies. To solve these issues, a high-frequency switching power cascade based emission power supply is designed. By combining the circuit averaged model and the equivalent controlled source method, a modular mathematical model is established with the on-state loss and transformer induction loss being taken into account. A triple-loop control including an inner current loop, an outer voltage loop and a load current forward feedback, and a digitalized voltage/current sharing control method are proposed for the realization of the rapid, stable and highly accurate output of the system. By using a new algorithm referred to as GAPSO, which integrates a genetic algorithm and a particle swarm algorithm, the parameters of the controller are tuned. A multi-module cascade helps to achieve system redundancy. A simulation analysis of the open-loop system proves the accuracy of the established system and provides a better reflection of the characteristics of the power supply. A parameter tuning simulation proves the effectiveness of the GAPSO algorithm. A closed-loop simulation of the system and field geological exploration experiments demonstrate the effectiveness of the control method. This ensures both the system's excellent stability and the output's accuracy. It also ensures the accuracy of the established mathematical model as well as its ability to meet the requirements of practical field deep exploration.

A Study on the Segmentation for Adaptation of Web Contents in Smart Learning Environment (스마트 학습 환경에서 웹 콘텐츠 적응을 위한 부분화에 관한 연구)

  • Seo, Jin Ho;Kim, Myong Hee;Park, Man-Gon
    • Journal of Korea Multimedia Society
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    • v.19 no.2
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    • pp.325-333
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    • 2016
  • The development of smart technology has brought the conversion of closed traditional e-learning contents into open flexible smart learning contents consisting of learner-centered modules, without the constraints of time and space by use of smart devices from the uniformed and passive classroom between teachers and learners. It has been demanded an open, personalized and customized teaching and learning contents of smart education and training systems according to wide supply of various smart devices. In this paper, we discuss about the status of the smart teaching and learning systems and analyze the characteristics and structure of the web contents for smart education and training systems by use of smart devices. And we propose a method how to block web contents, to extract them, and adapt personalized segments of web contents by adaptive algorithm into smart learning devices. We extract blocks from the web contents based on the smart device information and the preference information of the learners from existing web contents without the hassle of learners environment. After specifying a block priority from the extracted web contents by the adaptive segment algorithm, it can be displayed directly to the screen to fit the individual learning progress of the learners.

Thermal and telemetry module design for satellite camera

  • Kong, Jong-Pil;Yong, Sang-Soon;Heo, Haeng-Pal;Kim, Young-Sun;Youn, Heong-Sik
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.229-234
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    • 2002
  • Under the hostile influence of the extreme space environmental conditions due to the deep space and direct solar flux, the thermal control in space applications is especially of major importance. There are tight temperature range restrictions for electro-optical elements while on the other hand there are low power consumption requirements due to the limited energy sources on the spacecraft. So, we usually have strong requirement of thermal and power control module in space applications. In this paper, the design concept of a thermal and power control module in the MSC(Multi-Spectral Camera) system which will be a payload on KOMPSATII is described in terms of H/W & S/W. This thermal and power control module, called THTM(Thermal and Telemetry Module) in MSC, resides inside the PMU(Payload Management Unit) which is responsible for the proper management of the MSC payload for controlling and monitoring the temperature insides the EOS(Electro-Optic System) and gathering all the analog telemetry from all the MSC sub-units, etc. Particularly, the designed heater controller has the special mode of "duty cycle" in addition to normal closed loop control mode as usual. THTM controls heaters in open loop according to on/off set time designed through analysis in duty cycle mode in case of all thermistor failure whereas it controls heaters by comparing the thermistor value to temperature based on closed loop in normal mode. And a designed THTM provides a checking and protection method against the failure in thermal control command using the test pulse in command itself.

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The Effects of Trunk Stabilization Training Emphasizing Transverse Abdominis Contraction on Static Balance and Game Records for Archers (배가로근 수축을 강조한 체간 안정화 훈련이 양궁선수들의 정적 균형 및 경기기록에 미치는 영향)

  • Lee, So-Young;Seo, Tae-Hwa;Jeong, Yeon-Woo
    • PNF and Movement
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    • v.17 no.2
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    • pp.283-291
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    • 2019
  • Purpose: The purpose of this study was to investigate the effects of trunk stability training on static balance and game records among archers. Methods: The subjects comprised 24 voluntary archers in middle and high school (aged 14-19 years). All the subjects received trunk stability training for an hour per day 3 days a week for 4 weeks. The Tetrax balance system was used to measure the stability index of the subjects' static balance. The subjects' game records were scored using a single FITA round system. All the subjects were measured before the intervention, 2 weeks into the intervention, and 4 weeks after the intervention, with a follow-up measurement 2 weeks later. Results: The results of this study showed that the stability index was significantly different across all the measuring positions after the intervention (p<0.05). Furthermore, the results of the measurements of the standing position with eyes open and closed were significantly different before the intervention compared to 4 weeks after the intervention (p<0.05). The archery position with the head turned to the left and eyes closed was also significantly different pre-intervention compared to 2 weeks after the start of the intervention (p<0.05). Additionally, the archery records were significantly different after the intervention (p<0.05), as well as before the intervention and 4 weeks after the intervention (p<0.05). Conclusion: Trunk stability training can improve static balance in archers. It may also be helpful in improving athletic performance and maintaining the life of the athlete. Accordingly, trunk stability training may prevent and resolve injuries through careful management when playing one-side sports.

Analysis of Phenomena and Characteristics of Family Nursing in Korea by ICNP (ICNP를 적용한 한국 가족의 현상 및 특성 분석)

  • Kim, Young-Im;Kim, Hee-Girl;Yun, Soon-Nyung;Park, Jin-Kyung;Jung, Hye-Sun
    • Research in Community and Public Health Nursing
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    • v.13 no.4
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    • pp.608-617
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    • 2002
  • The purpose of this study was to analyze phenomena and characteristics of family nursing in Korea based on the study by Yun et al. (1999) by ICNP. The subjects of this study were 115 reports on family nursing care in Korea National Open University. The results of this study were as follows; 1. In the phenomenon of family nursing, 'Inappropriate family coping' comprised of 17.0% and 'Inadequate care for a sick member' comprised of 16.8%. 2. It was found that 'A few close neighbors was 62.5%, 'Lack of communication between married couple' was 60.0%, 'Neglet of general child rearing' was 40.9%, 'Closed communication pattern of the head of a family' was 36.0%, and 'Inadequate distribution of each family member's role' was 27.2%. 3. 'Lack of family interaction in community' and 'Social isolation' were combined with 'Lack of family interaction in community', and 'Disturbance in family communication' and 'Lack of family intimacy' were combined with 'Disturbance in family communication'. 4. 'Dual-loading with office work and housework', 'Overload of caring one's elders because of the status as a dual-income family' and 'Lack of family support system' were added into 'Inappropriate family coping'.

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The Effects of Proprioceptive Neuromuscular Facilitation on Lower Extremity Functions of Chronic Stroke Patients (고유수용성신경근촉진법이 만성 뇌졸중환자의 하지기능에 미치는 효과)

  • Song, Hyun-Seung;Kim, Seok-Hwan
    • PNF and Movement
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    • v.12 no.4
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    • pp.225-232
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    • 2014
  • Purpose: The purpose of this study is to determine the effects of proprioceptive neuromuscular facilitation on the lower extremity function of chronic stroke patients. Methods: The participants consist of 26 chronic stroke patients. They were randomly assigned to either an experimental group (n=13) or a control group (n=13) and engaged in exercise three times per week for eight weeks. The experimental group engaged in proprioceptive neuromuscular facilitation exercises and the control group engaged in general mat exercises. To measure lower extremity strength, the sit to stand test and the static balance test (standing on one leg) were used. To measure the stability index (SI) and weight distribution index (WDI), a Tetrax Portable Multiple System (Tetrax Ltd, Israel) was used in addition to a static balance test (standing on one leg). Results: : Lower extremity strength and static balance showed a significant improvement in the experimental group (p<.05). The SI and WDI were significantly improved in the experimental group (p<.05) for tests of standing with their eyes open, standing with their eyes closed, and standing on a sponge with their eyes open. Conclusion: Proprioceptive neuromuscular facilitation exercises have confirmed that lower extremity function improves after exercise interventions in chronic stroke patients.