• Title/Summary/Keyword: Open and Closed

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Closed-loop Sheet Metal Forming Using Dieless Forming Apparatus (무금형 성형장치를 이용한 폐루프 판재성형)

  • 양승훈;박종우;홍예선;양현석
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.05a
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    • pp.62-65
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    • 2002
  • A dieless forming system which consists of hydraulic punch elements and elastomer/fluid pads, was developed for sheet metal forming. 2-D curved surface forming was carried out using open-loop, closed-loop, and repeated forming method. Closed-loop exhibited higher decision than open-loop forming. Repeated forming also showed reduced spring back and possibility of high precision.

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The Effects of Closed Kinetic Chain Exercise and Open Kinetic Chain Exercise on the Knee Position Sense in the Normal Adults

  • Lim, Ga-Rin;Kwon, Eun-Hwa;Kim, Dong-Sung;Kim, Jung-Hyo;Park, Jin;Choi, Eun-Hee;Kim, Sik-Hyun
    • Journal of International Academy of Physical Therapy Research
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    • v.1 no.2
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    • pp.126-135
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    • 2010
  • The purpose of this study is to investigate the effects of closed and open kinetic chain exercise for increasing knee joint function on the knee position sense in the normal adults. Thirty normal adults(male 15, female 15; mean age: $22.13{\pm}2.58$ years) were participated in this study into two groups, each with 15 people. The group I was trained that closed kinetic chain exercise on the knee joint and the group II was trained that open kinetic chain exercise on the knee joint. Exercise programs performed for 4 weeks, 3 times a week were using Shuttle 2000-1 closed kinetic chain exercise and Knee Extensor open kinetic chain exercise(HUR, Filand). The results of this study were as follows: 1) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 2) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 3) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in closed kinetic chain exercise(p<.05). 4) There were statistically significant decreasing of measuring error degree in $0-20^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 5) There were statistically significant decreasing of measuring error degree in $21-40^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). 6) There were statistically significant decreasing of measuring error degree in $41-60^{\circ}$ were found between before and after training in open kinetic chain exercise(p<.05). In conclusion, these results suggest that closed and open kinetic chain exercise has increased in the knee joint proprioception between before and after training. Especially, closed kinetic chain exercise could be more useful intervention than open kinetic chain exercise for increasing proprioceptive sense.

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Some Fuzzy Continuous Mappings and Fuzzy Mildly Normal Spaces

  • Ahn, Y. S.;Choi, K. H.;Hur, K.
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.3
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    • pp.280-285
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    • 2001
  • We introduce the new concepts of some fuzzy continuous and closed mappings and study their properties. Also we investigate the properties of fuzzy mildly normal spaces.

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A Study on Performance Analysis of The Closed Cycle System Using the Diesel Engine (디젤엔진을 이용한 폐회로 시스템의 성능해석에 관한 연구)

  • 박신배;이효근
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.4
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    • pp.446-453
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    • 2000
  • The closed cycle diesel system is operated in closed circuit system where there is non air breathing with working fluid consisted of the combination of oxygen, argon and recycled exhaust gas for obtaining underwater or underground power sources. this study has been carried out to analysis the performance of closed cycle system by means of investigation on the combustion characteristics of diesel engine MTU8V183TE52 operating in open, semi-closed, and closed cycle modes. The combustion in closed mode starts a little bit earlier than in open cycle mode. The oxygen concentration and fuel consumption at 240kW closed cycle running are 21∼24% by volume and 77∼79kg/h, respectively. The maximum cylinder pressure and ignition delay time are investigated 110bar and 8.9degree. Also, The combustion simulation program has been studied to predict whether or not combustion. The results from numerical prediction for the basic, cylinder averaged quantities such as the cylinder pressure and the heat release showed excellent with the experimental data.

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Comparison of the Effects of Closed Kinetic Chain Exercise and Open Kinetic Chain Exercise According to the Shoulder Flexion Angle on Muscle Activation of Serratus Anterior and Upper Trapezius Muscles During Scapular Protraction

  • Park, Ju-jung;Chon, Seung-chul
    • Physical Therapy Korea
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    • v.24 no.4
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    • pp.11-19
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    • 2017
  • Background: Methods for exercising serratus anterior (SA) and upper trapezius (UT) muscles are important for the recovery of patients with various shoulder disorders, yet the efficacy of closed or open kinetic chain exercises have not yet been evaluated. Objects: The purpose of this study was to compare the activation of the SA and UT muscles during scapular protraction considering both closed and open kinetic chain exercises. Methods: Thirty subjects were randomly divided into experimental groups (closed kinetic chain exercise) and control groups (open kinetic chain exercise) in which scapular protraction was performed at $90^{\circ}$ or $125^{\circ}$ shoulder flexion. Electromyographic activity data were collected from the SA and UT muscles per position and exercise method. Results: Separate mixed 2-way analysis of variance showed significant differences in the activation of the SA (F1,28=6.447, p=.017) and the UT (F1,28=35.450, p=.001) muscles between the groups at $90^{\circ}$ and $125^{\circ}$ shoulder flexion. Also, the SA/UT ratio measures at $90^{\circ}$ and $125^{\circ}$ shoulder flexion significantly differed between the groups (F1,28=15.457, p=.001). That is, the closed chain exercise was more effective than open chain exercise for strengthening the SA muscle and controlling the UT muscle, $125^{\circ}$ of shoulder joint was more effective than $90^{\circ}$. Conclusion: The findings suggest that scapular protraction with shoulder $125^{\circ}$ flexion at the closed kinetic chain exercise may be more effective in increasing SA muscle activation and decreasing UT muscle activation as well as increasing the SA/UT ratio than open kinetic chain exercise.

Study on th Agreement of Food Frequency Questionnaires According to the Methods of Collecting Portion Size (섭취분량 설문형에 따른 식품섭취빈도조사법의 일치도 연구)

  • 한명희
    • Journal of Nutrition and Health
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    • v.28 no.8
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    • pp.791-799
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    • 1995
  • Agreement between open question and closed question on portion size of a food frequency questionnaire was assessed for the influence by the restricted choices in closed question on estimated nutrient intakes and agreement of ranking individuals. Dietary intakes of 361 subjects in a rural country, Yang-pyeung Gun were obtained using a interview method. The results are as follows ; 1) Nutrients intakes calculated from closed question on portion size were lower than those calculated from open question on portion size. 2) For most nutrients the percentage of Korean RDA were significantly lower with closed question than open question. 3) Correlation coefficient of nutrient intakes and food intakes obtained by two methods were higher than 0.6 for all nutrients and food items. 4) For each nutrient, misclassification into extreme quartiles was less than 1 percent. 5) These data indicate that closed question on portion size can provide the corresponding information as open question if food frequency questionnarie is used for the ranking of individuals.

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Wind Pressure Spectra for Circular Closed and Open Dome Roofs (원형 밀폐 및 개방형 돔 지붕의 풍압 스펙트럼)

  • Cheon, Dong-jin;Kim, Yong-Chul;Lee, Jong-Ho;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.2
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    • pp.69-76
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    • 2020
  • Wind tunnel tests were conducted to analyze the wind fluctuating pressures on a circular closed and open dome roof with a low span rise. Two dome models with various geometric parameters (height/span ratios and open ratios) were used for fixed span rise ratio dome and wind pressure spectrum were analyzed. The applicability was examined in comparison with the spectral model proposed in the previous studies. The analysis results show that the wind pressure spectrum of open dome roof tends to increase power in the high frequency range and the second peak is found in the area different from the closed dome roof. In addition, according to the comparison analysis with the previous proposed spectral model, it was found that it is not applicable to the closed and open dome roofs with low rise ratio due to the different peak frequencies.

Mean and Fluctuating Pressure Coefficient Distributions for Circular Closed and Open Dome Roofs (원형 밀폐 및 개방형 돔 지붕의 평균 및 변동 풍압 계수)

  • Cheon, Dong-jin;Kim, Yong-Chul;Lee, Jong-Ho;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.1
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    • pp.69-77
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    • 2020
  • In this paper, the mean and fluctuating pressure coefficients derived from the results of wind tunnel tests on closed and open dome roofs were analyzed. The distribution characteristics of the fluctuating pressure according to the opening ratio and the height change were discussed. The analysis results showed that when the roof is open, the overall wind pressure decreases due to the open space, but more fluctuation occurred than the closed dome roof.

REGULAR GLOSED BOOLEAN ALGBRA IN THE SPACE WITH EXTENSION TOPOLOGY

  • Cao, Shangmin
    • The Pure and Applied Mathematics
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    • v.7 no.2
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    • pp.71-78
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    • 2000
  • Any Hausdoroff space on a set which has at least two points a regular closed Boolean algebra different from the indiscrete regular closed Boolean algebra as indiscrete space. The Sierpinski space and the space with finite complement topology on any infinite set etc. do the same. However, there is $T_{0}$ space which does the same with Hausdorpff space as above. The regular closed Boolean algebra in a topological space is isomorphic to that algebra in the space with its open extension topology.

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Library Space Efficiency Improvement Through Closed Access System -Focused on Academic Libraries- (공간효율 개선을 위한 폐가식 도서관 운용 -지역 대학도서관 시설을 중심으로-)

  • Ahn, Joon Suk
    • Journal of the Korean Institute of Rural Architecture
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    • v.18 no.4
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    • pp.17-24
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    • 2016
  • Since the users have direct access to search and browse freely, the open access system has been employed to all the usual modern libraries. However, library space shortage problem created by the continuously increasing printed materials caused the degradation of usability and quality of the library space. Open Access system is superior in user convenience but is inferior in space efficiency. Keeping the open access system is considered as one of the reasons of the space shortage problem. Even though the closed access system does not provide free access or easy browsing for the uses, it's space efficiency is much higher than the open access system. The closed access system should be employed as a plan to relieve space shortage problem. Since the closed access system does not allow the public direct access to books, it is very economical. It also provides much better space efficiency with higher book shelving density. In this article, closed access library system models and their characteristics are examined as the reduction plans for the library space shortage problems.