• 제목/요약/키워드: Cycle change-over

검색결과 206건 처리시간 0.026초

싸이클웨어의 패턴개발을 위한 체표면 변화에 관한 연구 (Considerable Differences of Body Surface Area in the Preparation of Bicycle Wear)

  • 김연행;김여숙
    • 복식문화연구
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    • 제11권3호
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    • pp.375-386
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    • 2003
  • The purpose of this study is to seek the change of body surface according to cycling motions and to give suggestions to the pattern and spare space between body and wear in each bodily parts to be heavily considered for making the bicycle wear. The cycling motions were analyzed by taking the sequential pictures of cycling covering motion by a digital camera. The experiments with gypsum were toward a woman in her twenties. We draw the line standard of the body's surface, separated their gypsum-replicated fragments of body's surface following the analyses of the change in their lengths. As the motions were made, we decided the degree of the changed length as spare space when compared the erected posture with the cycling posture, presenting the pattern of the cycling wear with the preparation of wears for testing. After that, the essential experiments were conducted toward three cycle players wore our experimental wears. Regards their evaluated appearance, evaluations over three points were obtained from all parameters except the width of front armhole. Accordingly, our experimental wears were remarkably understood as a relatively proper wear as bicycle wear.

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상변화 메모리 응용을 위한 ${Ge_1}{Se_1}{Te_2}$ 비정질 칼코게나이드 박막의 전도 록성 (Conductivity Characteristics of ${Ge_1}{Se_1}{Te_2}$ Amorphous Chalcogenide Thin Film for the Phase-Change Memory Application)

  • 최혁;김현구;조원주;정홍배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.32-33
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    • 2006
  • As next generation nonvolatile memory, chalcogenide-based phase change memory can substitute for a conventional flash memory from its high performance. Also, fast writing speed, low writing voltage, high sensing margin, low power consumption and repetition reliability over $10^{15}$ cycle shows its possibility. At our laboratory, we invented ${Ge_1}{Se_1}{Te_2}$ material to alternate with conventional ${Ge_2}{Sb_2}{Te_5}$ for improve its ability. We respect the ${Ge_1}{Se_1}{Te_2}$ material can be a solution for high power consumption problem and long time at 'set' performance. A conductivity experiment from variable temperature was performed to see reliability of repetition at read and write performance. Compare with conventional ${Ge_2}{Sb_2}{Te_5}$ material, these two materials are used as complex compound to get the finest parameter.

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디젤 엔진 연료 분사 타이밍 구간에서의 흡기 포트 스월비 1D 컴퓨터 시뮬레이션 (1D Computer Simulation of Diesel Engine Intake Port Swirl Ratios Considering the Fuel Injection Timing Range)

  • 오대산;이충훈
    • 한국분무공학회지
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    • 제26권2호
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    • pp.81-87
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    • 2021
  • This study was performed to calculate the swirl ratio of a diesel engine intake port by a 1D computer simulation under actual engine operating conditions. The swirl ratio of the intake port was simulated according to the change of the engine speed during the operation of the motoring without fuel injection. The swirl ratio of the intake port was simulated according to changes in the crank angle during the four-cycle operation of intake, compression, expansion and exhaust. The swirl ratio represented by the three regions of the piston, center and squish was simulated. Among the three regions, the piston-region swirl ratio is important for effective air-fuel mixing in the engine cylinder. In particular, it was confirmed during the simulation that the piston swirl ratio before and after the compression top dead center (TDC) point when fuel is injected in the DI diesel engine can have a significant effect on the mixing of air and fuel. It was desirable to set the average piston swirl ratio over a crank angle section before and after compression TDC as the representative swirl ratio of the cylinder head intake port according to the change of the engine speed.

The Design of MSC(Multi-Spectral Camera) Calibration Operation

  • Yong Sang-Soon;Kang Geum-Sil;Jang Young-Jun;Kim Jong-Ah;Kang Song-Doug;Paik Hong-Yul
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.601-603
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    • 2004
  • Multi-Spectral Camera(MSC) is a payload on the KOMPSAT -2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of $20\%$ over the mission lifetime of 3 years with the functions of programmable gain! offset and onboard image data compression/storage. MSC instrument has one(1) channel for panchromatic Imaging and four(4) channel for multi-spectral Imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the configuration, the interface of MSC hardware and the MSC operation concept are described. And the method of the MSC calibration are described and the design of MSC calibration operation to measure the change of MSC after Launch & Early Operation(LEOP) and normal mission operations are discussed and analyzed.

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산업경기순환 하에서 투자행동 비동기화의 효과 (The Effects of Non-synchronized Investment Behavior under Industrial Business Cycles)

  • 김창욱
    • 한국시스템다이내믹스연구
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    • 제12권1호
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    • pp.5-37
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    • 2011
  • This article aims to clarify what is the best investment behavior in Capital Intensive Industries(hereinafter CIIs) which show repeated business cycles. In CIIs, investments is centered in the period of upturns and goes beyond the adequate level because of the time that takes to completion of facilities. This over-investment causes oversupply and downturn, and in period of downturn, investments shrinks under the adequate level. The repeated change of over-investment and under-investment is the reason for the business cycles. In this article, a simulation model replicating the business cycles in CIIs was constructed and the effects of various investment strategies was tested. The results are as follows. First, the investment behavior following market condition causes the ongoing fluctuation of profits. Second, strategic increase in flexibility such as adjustment of facility utilization and shortening of facility construction time contributes to the increase in profit and stabilization of income. Third, in relation to market condition, the constant investment is more profitable in stagnated market and the counter-market investment is more profitable in growing market. In sum, it is desirable not to synchronize their investment with those of competitors.

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한의학의 발전 방향 검토 (The Review of the Direction of Improvement of Oriental Medicine)

  • 신길조
    • 대한중풍순환신경학회지
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    • 제18권1호
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    • pp.1-11
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    • 2017
  • It is difficult to combine oriental and western medicine. Each medicine has a different academic background, perspective on the world, and studying methodology. The claim that two paradigms can not be combined is not obtained from an actual verification, but this means it is so hard to combine two medicines having different backgrounds. The amalgamation of oriental and western medicine should be phased in on the basis of the continuous reciprocal understanding and commitment. First, the strength and weakness of each medicine over the treatment and research are required to be identified. Then, a few complementary areas can be chosen enabling a trial of fusion on a small scale. A cycle of problem solving and a new research can be set by analyzing research results obtained through the implementation over a period of time. In other words, the researchers of oriental and western medicine should repeat a continuous and gradual complementary research process by identifying issues to be improved and complemented through a consensus. Once the methodology obtained through the process of problem solving and proficient implementation is established in a stable condition, a method to widen the fusion area by expanding the operating area and implementation method can be chosen. However, the integral system of oriental medicine shouldn't be substituted by mechanical idea or reductionism. What should be done primarily for oriental medicine is to objectify things through quantification. In particular, the oriental treatment should accept the microscopic diagnosis to determine the structure and observe the biochemical change.

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RC 대형 냉각탑 셀의 손상추정에 관한 연구 (A Study on Damage-Assessment of RC Large Cooling Tower Shells)

  • 노삼영
    • 한국공간정보시스템학회:학술대회논문집
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    • 한국공간정보시스템학회 2004년도 춘계 학술발표회 논문집 제1권1호(통권1호)
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    • pp.279-286
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    • 2004
  • An accumulated crack damage which propagates progressively with time was frequently observed on several engineering structures, This paper numerically demonstrates this damage process on large cooling tower shells under thermal and wind loads. Damage states under varying loads are investigated and the influence of this progressive damage process on the life-cycle of cooling towers discussed. The paper presents briefly some fundamentals of the geometrically and physically non-linear numerical analysis employed for reinforced concrete, especially concerning the models used for concrete, steel reinforcement and the bond between them. As a numerical example an existing cooling tower with noticeable meridian crack damage is analysed. The existing damage state of the cooling tower is determined by quasi-static analyses for temperature, hygric and cyclic wind leading. The change in the dynamical behaviour of the structure as mirrored in its natural frequencies and mode shapes is presented and discussed. Finally, the example shows that such damage processes develop progressively over the life-time of the structures.

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Influence of Surface Functional Group of Carbon Nanotubes for Applications in Electrochemical Capacitors

  • Park, Sul Ki
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.480.2-480.2
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    • 2014
  • Electrochemical capacitors have been the most strong energy storage devices due to high power density and long cycle stability. Pristine carbon nanotubes are promising electrode materials for excellent electrical conductivity and high specific surface area in electrochemical capacitor. However, the practical application of pristine carbon nanotubes was limited by the aggregation into bundles due to van der Waals force. In this research, we explained how multi-walled carbon nanotubes (MWCNT) functionalized by carboxyl, sulfonic, and amine groups (CNT-COOH, CNT-SO3H, CNT-NH2) to improve the performances of MWCNT. Functionalized CNTs showed two- to four-fold increase in capacitance over that of pristine CNTs, while maintaining reasonable cyclic stability. But, the CNT-COOH showed the lowest rate capability of 57% compared to 84%, 86% of CNT-SO3H and CNT-NH2. As demonstrated by the spectroscopic analysis, This reseach showed how surface functional group of carbon nanotubes change capacitor performances.

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한국인의 장내 균총 조성 및 분포 (Composition and Distribution of Intestinal Microbial Flora in Korean)

  • 지근억
    • 한국미생물·생명공학회지
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    • 제22권5호
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    • pp.453-458
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    • 1994
  • Intestinal microbial flora comprise one third of the large intestinal contents in human. They play a significant effects through beneficial and harmful action on the human health. This is the first study which examined the composition of the microflora of the general population in Korea. Bacteroides, Bifidobacterium, Eubacterium, Peptostreptococcus, Lactobacillus, Streptococcus, Escherichia coli, Staphylococcus, Clostridium perfringens, total aerobic bacteria and total anaerrobic bacteria were counted using various selective and non-selective media. Among the bacteria studied the number of Bifidobacterium were greatest in breast-fed infants(30-90 days old), whereas Streptocuccus and Bifidobacterium in bottle-fed infants. In 20-40 age group Bacteroides were predominant followed by Bifidobacterium and Eubacterium. In early group(over 65 years old) Bacteroides were predominant followed by Eubacterium and bifidobacterium. The frequency and number of Cl. perfringens were highest in dlderly group. These results confirm that the microfloral pattern in large intestine change during the life cycle of humans.

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Reconfiguration of Redundant Thrusters by Allocation Method

  • Jin, Jae-Hyun;Tahk, Min-Jea
    • International Journal of Aeronautical and Space Sciences
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    • 제6권2호
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    • pp.76-83
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    • 2005
  • Thrusters are important actuators where air is rare. Since the maintenance or replacement of thrusters is not easy in such an environment, a thrusting system must be highly reliable. Redundant thrusters are used to meet the reliability requirement. In this paper, a reconfiguration problem for those redundant thrusters is discussed, especially the management or distribution logic of redundant thrusters is focused on. The logic has to be changed if faults occur at thrusters. Reconfiguration is to change the distribution logic to accommodate thrusters' faults. The authors propose a reconfiguration algorithm based on the linear programming method. The authors define the reconfiguration problem as an optimization problem. The performance index is a quantity related with total fuel consumption by thrusters. This algorithm can accommodate multiple faults. Numerical examples are given to show the advantage of the proposed algorithm over existing methods.