• Title/Summary/Keyword: Lower System

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A Study on Smoke Movement by Using Large Eddy Simulation I. Smoke Control Systems and Extraction Flowrate (대와류모사를 이용한 연기이동의 연구 I. 제연방식과 배기풍량)

  • 박외철
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.40-45
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    • 2003
  • To evaluate the smoke control systems, the large eddy simulation turbulence model based Fire Dynamics Simulate was applied to a 2m $\times$ 2m $\times$ 2.4m room with an opening. The smoke removal rate was investigated for three different smoke control systems: ventilation, extraction and pressurization. When the opening was closed, the smoke removal rates of the smoke control systems were almost the same as expected. The pressurization system showed a lower smoke removal rate compared with the other two smoke control systems for the room with the opening, and hence the pressurization system might not be efficient for a place with large openings. It was shown that the lower extraction flowrate is, the longer time the ventilation system requires to remove smoke. From these results, the ventilation system is recommended for subway stations where several large openings exist.

The Effect of Exhaust System Components on the Sl Engine Performance (배기구성요소가 SI기관의 성능에 미치는 영향)

  • Park Kyoungsuk;Park Sejong;Son Sungman
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6 s.171
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    • pp.192-198
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    • 2005
  • Recently, Automobile manufacturers regarding stability, economic environmental-friendly problems by the development of automobile. This reason is increasingly strict environmental regulations to lower fuel consumption and reduce emission. Designing more efficient and low emission control exhaust system results in more efficient Performance, reduced back Pressure and higher convert efficiency. Also to reduce the noise and the vibration of the automobile. According to develop variable type muffler, dual muffler and active intelligence exhaust system unit. Improvement in engine performance and fuel consumption rate, higher conversion efficiency demand information of pressure fraction and heat characteristics. To be able to determine these factor fur we experiment on each case of exhaust system unit. In this study, how back pressure is distributed in flow-through in exhaust system and how to design exhaust system flexibleness, efficiency, lower back pressure and optimal performance. This study furnish basic data for engineers, technicians.

Lower Body Type of Women in their Thirties after Childbirth (출산에 따른 30대 여성의 하반신 형태 연구)

  • Lee, Jeong-Ran;Hong, Eun-Suk;Paek, Kyung-Ja
    • Fashion & Textile Research Journal
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    • v.10 no.6
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    • pp.979-988
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    • 2008
  • The purpose of this study is to analyze the lower body size and forms of married women in their thirties who have experienced pregnancy and parturition. Their measurements derived from the direct anthropometry and indirect photographic measures were compared to those of 20's. Improving consumer satisfaction for missy brand, especially in fitness of skirt and pants, some lower body classification were presented. The results were as follows : 1. The characteristics of lower body showed many differences by individuals especially in depth, girth, length and angle measures rather than height and breadth measures. Many items including index, calculations and angles revealed significant differences compared to those of 20's. Several breadth items, crotch length had distinct increase than those of women in twenties. Flattened buttocks side silhouette from waist to hip, buttocks drooping and decrease of inclination implied the influence of pregnancy, parturition and aging. 2. We hardly find out sizing system differences between missy brand and miss brand. Based on waist and hip girth measurements of subjects, sizing system of missy apparel wasn't suitable for their body size. Excessive drop(hip girth-waist girth) of missy brands, 25~30 cm, was almost the same to the drop of miss brands. 3. To improve the size satisfaction of missy women, we classified the lower body into 5 types according to drop, buttocks angle and hip length. Type 1 was small waist with large buttocks projection, and hip length was close to an average. Type 2 was small waist with medium buttocks projection, and the hip length was close to an average. Type 3 was medium waist, with average projection of the buttocks and hip length. Type 4 was large waist, projection of the buttocks and the hip length were close to an average. Type 5 was large waist, projection of the buttocks was small and the hip length was close to an average.

The Effect of Lower Extremity Muscle Strengthening Exercise using Biofeedback System on Lower Extremity Function and Gait in Community-based Elderly (바이오피드백 시스템을 활용한 하지근력 강화운동이 지역사회기반 노인의 하지기능과 보행에 미치는 효과)

  • Park, Tae-Sung;Lee, In-Sook;Jang, Myung-Hun;Shin, Myung-Jun
    • Journal of Convergence for Information Technology
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    • v.10 no.1
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    • pp.195-202
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    • 2020
  • This study is to investigate the effect of lower extremity strength exercise using biofeedback system on community-based elderly. Ten community-based elderly were exercised using the biofeedback system (with functional electrical stimulation) three times a week for six weeks. Data analysis was performed using Wilcoxon signed rank test. Physical function improved significantly, but there was no significant difference in muscle strength and muscle mass. Although elderly people were able to confirm that community-based ICT home biofeedback training could be possible and could lead to improvements in the lower extremity function, further research is needed to demonstrate a clearer effect by expanding the target population, distinguishing the sexes, and providing a personalized training method.

A Study on Development of Monitoring System of Lower Arm Ball Joint Inserting Force (Lower Arm 볼조인트 압입력 모니터링 시스템 개발에 관한 연구)

  • 강택호;김교형
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.648-652
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    • 1994
  • Lower Arm은 전차축식 현가장치에 사용되는 자동차부품으로 바퀴에서 발생되는 제동력이나 코너링력 등을 지탱하는 장치이다. V형의 상하 2개의 서스펜션암의 축에 의해 츠레임에 장착되고 좌우에 있는 Lower Arm끝부분은 볼조인트 및 부싱에 의해 스티어링 너클에 부착된다. 압입부품들은 자동차의 주행중 발생하는 외력에 의하여 이탈될 수 있는 위험성에 항상 노출되어 있어 자동차에 사용하는 압입부품들의 이탈력은 매우 중요하지만 한번 이탈시킨 Lower Arm은 이탈력이 현저히 저하되기 때문에 이탈력 측정에 의한 품질관리는 전량검사가 불가능하게 된다. 본 연구는 Lower Arm에 압입되는 볼조인트의 압입력을 압입거리에 따라 측정하여 Lower Arm에 뚫어진 볼조인트 압입구멍의 크기와 압입력의 상관관계를 실험적으로 구할수 있는 크기와 압입력의 상관관계를 실험적으로 구할 수 있는 모니터링 시스템을 개발하고자 한다.

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Feed Rate Control for the Head-Feed Thresher (수급식탈곡기(穗給式脫穀機)의 공급율제어(供給率制御)(III) -제어(制御)시스템의 응답실험(應答實驗)-)

  • Choi, Y.S.;Chung, C.J.
    • Journal of Biosystems Engineering
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    • v.16 no.2
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    • pp.148-158
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    • 1991
  • This study was undertaken to develop the feed rate control system for the head feed thresher by making use of the microprocessor and to evaluate the response of the system to a various threshing conditions. It was verified the performance of the control system through experiments. Control conditions were determined based on the simulation results of control system. The control system set at RH=500rpm, RL=480rpm for the bundle feed was considered optimum to give a high threshing capability and still to stabilize the feeding seed regardless of the bundle size. The control system for the continuous spread feed set at the range of LH=15mm, and LL=12mm gave a high control performance for the feeding mass of 1.1Kg/m and lower tested. In addition, the feed rate proportionality constant should be set lower than one in order to keep the rotational speed of threshing cylinder within the range of 500~520rpm.

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Experimental Study on Floor Isolation of Main Control Room of Nuclear Power Plant using FPS(Friction Pendulum System) (마찰진자베어링(FPS) 면진시스템을 적용한 원전주제어실의 진동대 실험)

  • Lee, Kyung-Jin;Ham, Kyung-Won;Suh, Yong-Pyo
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.445-452
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    • 2005
  • The seismic characteristics with Friction Pendulum System have been studied using a shaking table system. In this study, we made two kind of floor system (Type I, Type II) and several seismic tests with and without isolation system were conducted to evaluate floor isolation effectiveness of Friction Pendulum System. Both type have showed large reduction effectiveness in acceleration, response spectra but Type II have showed lower acceleration and lower first mode in response spectra, compared to type I. On the basis of test results and consideration of application, it is found that type II is more suitable for floor model of main control room of Nuclear Power Plant.

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The Behaviors of Earthquake Monitoring System for Gyungbu High Speed Railroad on the Odaesan Earthquake (오대산지진 시 경부고속철도 지진감시시스템 거동)

  • Kim, Dae-Sang;Kim, Sung-Il;Choi, Su-Hyun;You, Won-Hee
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.537-540
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    • 2008
  • This paper reviews the operation standards and manuals of earthquake monitoring system for Gyungbu high speed railroad. The domestic earthquake monitoring system detects the acceleration data at the locations of lower part of pier and deck of viaducts and bridges, not like foreign system to do the surface ground accelerations. For the purpose of evaluating the behaviors of the domestic earthquake monitoring system, measured acceleration data on the Odaesan earthquake at Iwon viaduct were analysed. The values of maximum acceleration level of the viaduct were increased from 0.0089g(EW component) of the lower part of pier to 0.014g(EW component) on the deck of the viaduct. And also the predominant periods and frequencies were analysed by the frequency domain analysis.

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Comparison of Solid Circulation Characteristics with Change of Lower Loop Seal Geometry in a Circulating Fluidized Bed (순환유동층에서 하부 루프실 형태 변화에 따른 고체순환 특성 비교)

  • Lee, Dong-Ho;Jo, Sung-Ho;Jin, Gyoung-Tae;Yi, Chang-Keun;Ryu, Ho-Jung;Park, Seung Bin
    • Korean Chemical Engineering Research
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    • v.52 no.4
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    • pp.522-529
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    • 2014
  • Circulating fluidized bed system consists of SEWGS reactor - lower loop seal - regeneration reactor - riser - cyclone - upper loop seal has been used for solid circulation between the SEWGS reactor and the regeneration reactor in a SEWGS system for pre-combustion $CO_2$ capture. A vertical type lower loop seal has been used in current system but this lower loop seal requires high gas flow rate through the lower loop seal for fluidization and smooth solid circulation, and consequently, causes slugging behavior sometimes. To overcome these disadvantages, inclined type lower loop seal was proposed by this study. Solid circulation characteristics with change of lower loop seal geometry were measured and compared in a bubbling - bubbling - riser type circulating fluidized bed using $CO_2$ absorbent (P-78) as bed material at ambient temperature and pressure. We could conclude that the inclined lower loop seal is better than the vertical type lower loop seal from the viewpoints of minimum flow rate requirement for stable solid circulation and solid height change during solid circulation.

The Effect of Backward Pedaling Ergometer Training on Ankle ROM, Lower Extremities Strength, Foot Pressure in Hemiplegia (역방향 에르고미터 훈련이 편마비 환자의 족관절 가동범위와 하지 근력 및 족저압에 미치는 영향)

  • Ha, Mi-Seon;Kim, Eun-Jung;Kim, Myeong-Hee;Oh, Tae-Young
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.3
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    • pp.467-477
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    • 2013
  • PURPOSE: The purpose of this study was to identify the effects of backward pedaling ergometer training on ankle ROM, lower extremities strength, foot pressure in hemiplegia. METHODS: The subjects consisted of control group(n=10) and experimental group(n=10), subjects were trained 5 times a week for 2 weeks each group. Control group were trained forward, experimental group were trained backward pedaling with physical therapy in both groups. Each group measured ankle joint ROM with DUALER IQ and ankle and knee joint flexor and extensor muscle strength by Manual Muscle Test System and foot pressure by Gait view system. RESULTS: The result of this study between pre and post test that experimental group had statistically significantly differences in ankle joint range of motion and lower extremities strength. But foot pressure had not statistically significant differences. There was not significantly difference of variation between groups. CONCLUSION: Therefore these results mean that backward and forward pedaling ergometer training effected an improvement of lower extremities function in hemiplegia.