• Title/Summary/Keyword: Mass changes

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Essential Oils in Cured Leaf of Burley Tobacco I. Changes in the Composition of Essential Oils during Air-Curing (버어리종 건조엽의 정유성분 I. 건조기간중 정유성분 조성의 변화)

  • 배성국;김도연;김영회;조천준
    • Journal of the Korean Society of Tobacco Science
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    • v.22 no.2
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    • pp.114-122
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    • 2000
  • This study was carried out to investigate the changes in the composition of essential oils for the improvement of air-curing process of burley tobacco leaves. From the essential oils isolated from the cured tobacco leaves by steam distillation method, 90 compounds including 15 acids and esters, 19 alcohols, 23 aldehydes and ketones, 19 hydrocarbons, and 14 miscellaneous compounds, could be identified by gas chromatography and gas chromatography-mass spectrometry. Among them, acids and esters were gradually decreased during the progress of curing after harvesting. A rapid increase in alcohol content was observed in the earlier stage of curing, but thereafter, decrease followed until the end of curing However, aldehyde and ketone groups were continuously increased during curing and were 3 times higher in quantity after curing than at the harvesting time. The concentration of hydrocarbons was increased in the earlier stage of curing, but gradually decreased from the middle stage. The miscellaneous compounds were continuously increased in content until the end stage of curing, with rapid increased in the earlier stage of curing.

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Changes in Body Composition, Health Status, and Dietary Behavior for Middle-Aged Obese Women in a Weight Control Program at a Community Health Center (보건소 중년 여성 비만관리 프로그램의 운영에 따른 체성분, 건강 상태 및 식행동 변화에 관한 연구)

  • Lee, Byung-Soon
    • The Korean Journal of Food And Nutrition
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    • v.20 no.4
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    • pp.433-439
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    • 2007
  • The purpose of this study was to evaluate the body composition, health status, and dietary behaviors of middle-aged women in a weight control program at a community health center. The study subjects were 66 middle-aged women who lived in Ansan city, and they participated in the program for 24 weeks. Anthropometries, blood pressure, and serum biochemical indices were measured. These measurements were taken both before and after the weight control program, and the data were analyzed using the SPSS 12.0 program. Weight, fat mass, body fat %, and the waist-hip ratio all decreased. According to the decreases in body fat %, blood pressure, serum biochemical indices and dietary behaviors were improved after the weight control program. Thus, this study demonstrated the desirable changes of a weight control program offered at a community health center, for health conditions and physical fitness.

A Study on the Numerical Analysis of Behavior of Spray Droplets and Internal Flow Field of Cylinder in Diesel Engine (디젤기관의 실린더내 유동 및 분무액적 거동의 수치적 연구(I))

  • 장영준;박호준;전충환;김진원
    • Journal of Advanced Marine Engineering and Technology
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    • v.16 no.1
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    • pp.35-46
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    • 1992
  • In this study, we calculated gas flow fields and distribution of fuel droplet and mass fraction using the CONCHAS-SPRAY code which modified to execute in IBM PC and changed three important factors, injection rate pattern (BASIC, I, II, III), different bowl shape and spray type. Especially vortices which be influenced by fuel-air mixing process, evaporation and flame propagation are generated more strongly in the bowl-piston type combustion chamber than in the flat-piston type. As the spray type changes, it is found that conical type produced large and strong vortices and fuel droplets are effictively diffused into the entire combustion chamber. As the injection rate pattern changes I, II, III based on BASIC type, we confirmed that End-of-Injection Effect strongly influence on droplets life time.

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Evaluation of the Groundwater Flow in Fractured Rock Masses (열극암반에서의 지하수 유동 특성 분석)

  • Kim, Gye-Nam;Kim, Jae-Han;An, Jong-Seong
    • Water for future
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    • v.23 no.2
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    • pp.227-237
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    • 1990
  • For a detailed understanding of groundwater flow in rock mass, the effect of major fractures, topography and coefficent of permeability has been evaluated. The numerical model of GFFP-WT was used for the purpose. The results indicate that in the granite porphyry layer with a small permeability, the direction of flow path changes due to convergence of equipotential lines, while the travel time changes due to the presence of fractured in rock masses.

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A Study on Marketing Strategy through Comparison of Fashion Industry Development Process Between Korea and Japan (한국·일본의 패션산업 발전과정 비교를 통한 마케팅 전략 연구)

  • Lee, Ho-Jeong
    • Fashion & Textile Research Journal
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    • v.5 no.4
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    • pp.351-362
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    • 2003
  • To study marketing strategy changes caused by Korea fashion industry development process, the fashion marketing strategy changes of Japan, considered as the most similar one of Korea, was compared. At each period, p! roper cost efficiency strategies, product differentiation strategies, and market segment strategies has been selected and applied. The fashion industry foundation period namely practical usage clothing period of Korea follows 10 years after one of Japan. 90's highly sensitive fashion period namely fashion industry growth period follows 5 years after one of Japan. As entering to fashion industry maturity period with global competition, the time difference falls to less than 5 years. With hosting of 2002's World-Cup, Korea's global competitiveness has increased, and it appears to be possible of being fashion market leader in East Asia and Japan's rival on an equal footing.

A Modeling Study on Aerosol Property Changes due to Sea-Salts (해염성분에 의한 에어로솔 물성변화 모사연구)

  • 김용표
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.2
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    • pp.113-120
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    • 2000
  • Effects of sea-salts on the properties of aerosol collected in a coastal region were studied by applying a gas-particle equilibrium model SCAPE to the measurement data from Korea Cheju Island in summer 1994. It was found that the observed higher ammonium concentrations in fine particles (PM2.5) than in TSP were caused by forced evaporation of ammonium in coarse fraction of aerosol by sea-salts and the degree of evaporation was quantified through an application of SCAPE. By subtracting the sea-salt fraction from the measured concentra-tions the changes of aerosol property were also studied. The concentrations of nitrate at both TSP and PM2.5 decreased when alkaline sea-salt fraction was removed from the measured data. Estimates of aerosol acidity increased for most samples with sea salt loadings, However in some cases with high mass fractions of sea-salt components the aerosol acidity of PM2.5 decreased slightly. This is though to be related with the formation of solid salt with the removal of sea-salts.

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A Study on the Design Trends of Hospital Architecture by Analyzing Block Plans of Korean Hospitals (블록플랜 분석에 의한 한국 병원건축의 설계 경향에 관한 연구)

  • Choi, Kwang-Seok
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.13 no.2
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    • pp.45-52
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    • 2007
  • Hospital Architectures in Korea are continuously erected to old-fashioned design, such as a large self-sufficient, but cost-inefficient hospital, in spite of rapidly changing social and healthcare environment. However, changes are slowly coming from inside of itself. This paper analyzed block plans of 7 best Korean hospitals which constructed in recent 20 years in aspects of the purpose of erection, departmental composition, areal composition, mass design and functional zoning of block plans and then, presented the directions of new design trends of hospital architecture in Korea. It is anticipated that hospital architecture will change immensely in the enlarging process of these minor changes.

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Model Predictive Control of Condensate Recycle Process in a Cogeneration Power Station: I. Controller Design and Numerical Application (열병합 발전소의 응축순환공정에 대한 모델예측제어: I. 제어기 설계와 수치적 적용)

  • Won, Wang-Yun;Lee, Bong-Kook;Lee, Seung-Joo;Lee, Seok-Young;Lee, Kwang-Soon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.12
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    • pp.1202-1208
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    • 2006
  • Development of a model predictive control(MPC) algorithm and its application to the condensate recycle process of a cogeneration power station has been conducted. The cogeneration power station has different characteristics from other industrial processes where MPC has been dominantly applied in that the operating mode changes continuously with seasons and we Ether. Such a characteristic makes it difficulty, a linearized model was derived from mass and pressure balances and linearization. The MPC algorithm has been developed so that the controller tuning is easy with one tuning knob for each output and the constrained optimization is solved by an interior point method. Performance of the MPC algorithm has been verified with the numerically simulated process under various disturbance scenarios and mode changes.

Excavation and Building Damage Assessment - Fundamentals (지반굴착과 주변 구조물 손상평가 - 기본개념)

  • 유충식
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.263-270
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    • 2002
  • During deep excavation, changes in the state of stress in the ground mass around the excavation and subsequent ground losses inevitably occur. These changes in the stress and ground losses are reflected on surrounding ground in the form of ground movements, which eventually Impose strains onto nearby structures through translation, rotation, distortion, and possibly damage. A substantial portion of the cost of deep excavations in urban environments is, therefore, devoted to prevent ground movements. Prediction of ground movements and assessment of the risk of damage to adjacent structures has become an essential part of the planning, design, and construction of a deep excavation project in the urban environments. This paper presents excavation-induced ground movement characteristics as well as important issues related to excavation-induced building damage assessment.

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A Study on Performance Improvement of Automobile Cruise Control System : Disturbance Observer Approach (차량 정속주행 시스템의 성능향상에 관한 연구 : 외란관측기 기법)

  • Yang, Eun-Ji;Jo, Nam-Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.5
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    • pp.15-22
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    • 2014
  • The automobile cruise control system tries to maintain a constant velocity in the face of disturbance mainly caused by mass changes or changes in the slope of a road. The controller should compensate for such disturbances and model uncertainties. In this paper, we study on the disturbance observer based controller for cruise control system. In the presence of disturbances and model uncertainties, we carry out computer simulations in order to compare the performance of the conventional PI controller and DOB controller. From the simulation results, we found that the performance of DOB controller is superior to that of the conventional PI controller.