• Title/Summary/Keyword: Launching characteristics

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A Mathematical and Physical Model for the Design of a Single Stage Coilgun (단일 스테이지 코일건 설계를 위한 수학적 및 물리적 모델)

  • Kim, Ji-Hun;Jeon, Sang-Woon;Kim, Joonyun
    • Aerospace Engineering and Technology
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    • v.12 no.2
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    • pp.74-82
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    • 2013
  • This paper deals with a single stage coilgun which is a variety of EML(ElectroMagnetic Launcher) and can be applied to launching a small satellite. We propose a mathematical and physical model in order to design a single stage coilgun and study physical characteristics related to design parameters. A proposed mathematical and physical model is verified by electromagnetic FEM software FEMM 4.2.

Optimization of Satellite Upper Platform Using the Various Regression Models (다양한 회귀모델을 이용한 인공위성 플랫폼의 최적화)

  • Jeon, Yong-Sung;Park, Jung-Sun
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1430-1435
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    • 2003
  • Satellite upper platform is optimized by response surface method which has non-gradient, semi-glogal, discrete and fast convergency characteristics. Sampling points are extracted by design of experiments using Central Composite Method and Factorial Design. Also response surface is generated by the various regression functions. Structure analysis is execuated with regard for static and dynamic environment in launching stage. As a result response surface method is superior to other optimization method with respect to optimum value and cost of computation time. Also a confidence is varified in the various regression models.

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A Study on the estimation of transport demand in accordance with the changed operating environment of high speed train (고속열차 운행 환경변화에 따른 수송수요예측 연구)

  • Kim, Ick-Hee;Lee, Kyung-Tae;Yang, You-Kyung
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.721-729
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    • 2009
  • Recently, there has been growing necessity to estimate the future travel demand of high speed train because the circumstance of high speed train service is rapidly changing with the launching of 2011 second stage of Gyeongbu high speed railway(Dongdaegu-Busan) and the completion of 2014 first stage of Honam high speed railway(Yongsan-Gwangju), etc. This study was designed to estimate future travel demand by analyzing the transport performance and train service characteristics of Gyeongbu and Honam line. This study presents the maximum load section and the changed future travel demand, which will be applied to establish a train operation plan.

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A High Efficiency Power Conversion Circuit with Wide ZVS Range for Sustaining Power Module of Large Size PDP (넓은 영전압 스위칭 범위를 갖는 대화면 PDP용 유지 전원단을 위한 고효율 전력 변환 회로)

  • Park, K.H.;Lee, W.J.;Youn, M.J.;Moon, G.W.
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.279-282
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    • 2005
  • Recently, due to the launching of digital broadcasting service, a demand of PDP TV with large screen size is sharply rising. PDP power module is mainly divided into power factor correction (PFC) stage and sustaining power stage. Especially, sustaining power module has pulsating load characteristics. So, the hard switching at light load condition causes low efficiency and thermal problem. Therefore, a new power conversion circuit for sustaining power module of 60' PDP is proposed whose ZVS is obtained by additional ZVS tank. This paper presents properties of the proposed converter through mode analysis, numerical analysis. And a 900w prototype for sustaining power module of 60' PDP is produced to verify the analytic results. As an experimental results, ZVS is achieved from full load to 10% load variation and more than 92% of high efficiency is obtained at 10% load condition.

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Design Study for KSLV Integrated Power Plant Test Facility

  • Kang, Sun-Il;Lee, Jung-Ho;Kim, Young-Han;Oh, Seung-Hyup
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.573-576
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    • 2004
  • KARI is achieving the KSLV program according to National Space Technology Development Program. In this paper, the authors are intended to introduce the Integrated Power Plant (abb. IPP) test facility which will be constructed for the variety of tests on KSLV program. IPP test facility refers to comprehensive testing equipment for liquid rocket launch vehicle. Using this facility, KARl can verify the adaptiveness of parts and subsystems for launch vehicle and finally can qualify the system characteristics of launch vehicle doing kinds of test including hot firing test. Using this facility, KARI can simulate the vehicle launching circumstances and it make to predict the performance of launch vehicle when its flight test.

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Family Phenomena and Characteristics by Social-economic Charateristics of the Family (가족의 사회경제적 특성에 따른 가족현상 및 가족특성)

  • Kim, Young-Im;Kim, Hee-Girl;Park, Jin-Kyung;Jung, Hye-Sun
    • Research in Community and Public Health Nursing
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    • v.14 no.2
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    • pp.263-273
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    • 2003
  • Objectives: The purpose of this study was to identify the family phenomenon and characteristics by ICNP such as family shape, life standard. area, and development stage. Method: 1. Sample size was 115. 2. Data analysis method included frequency analysis including ratio. Results: 1. On the distribution of the family phenomena by family shape, the nuclear family showed a higher ratio on the distribution in family communication and the unhealthy life style. The nuclear family was related to children andhad a higher ratio on the inadequate care management of the sick member. The extended family showed the highest ratio on the inadequate care management of sick member. 2. On the distribution of the family phenomena by family life standard, the family with medium life standard showed a higher ratio on the inappropriate family coping, whereas the family with lower life standard appeared to have a higher ratio on the inadequate care management of the sick member. 3. On the distribution of the family phenomena by area. the large city area showed the highest ratio on the inappropriate family coping, the medium and small city area appeared to have the highest ratio on the unhealthy life style. The county area showed the highest ratio on the inadequate care management of sick member. 4. On the distribution of the family phenomena by development stage, the family in rearing period showed a higher ratio on the inappropriate family coping and the lack of family intimacy. Families with preschool children showed a higher ratio on the unhealthy life style, and families with school age children showed the highest ratio on the inappropriate family coping. Families with adolescents appeared to have the highest ratio on the disturbance in family communication, and families with launching young adults showed the highest ratio on the inadequate care management of sick member. 5. On the distribution of the family characteristics by family shape, the nuclear family showed a higher ratio on the family characteristics such as less communication chances among family members and neglect of general child rearing, whereas the third generation family appeared to have a higher ratio on the characteristics such as overburden of housewife's role and short of caring among family members. 6. On the distribution of the family characteristics by family life standard, the family of medium life standard showed higher ratio on the family characteristics such as a few communication chance among family and overburden of housewife's role, and the family of lower life standard appeared to higher ratio on the family characteristics such as short of caring among family members. 7. On the distribution of the family characteristics by area. the large city area showed a higher ratio on the family characteristics such as overburden of housewife's role and neglect of general child rearing. The medium and small city area appeared to have a higher ratio on the family characteristics such as less communication chancec among family members. The county area showed a higher ratio on the family characteristics such as short-term care among family members. 8. On the distribution of the family characteristics by development stage, the family with rearing period showed a higher ratio on the family characteristics such as neglect of general child rearing. Families with preschool children showed a higher ratio on the family characteristics such as less communication chancec among family members. Families with school age children showed a higher ratio on the family characteristics such as overburden of housewife's role. Families with adolescents appeared to have a higher ratio on the family characteristics such as less communication chances among family members. Families with launching young adults showed a higher ratio on the family characteristics such as less communication chances and short-term care among family members.

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Collaborations in Fashion and Arts Across Industry Disciplines (패션, 예술, 산업의 협업사례 고찰)

  • Park, Kyung-Ae;Kim, Sook-Kyung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.7
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    • pp.1152-1163
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    • 2009
  • Product development and marketing that appeal to consumer emotions are important as shown by a variety of product and service industries that integrate fashion and arts into product design and marketing through collaboration. This study attempted to analyze the patterns in the collaborations of fashion and arts across industry disciplines. A total of 278 collaboration cases reported in news articles were collected from internet databases. Cases were categorized into 5 disciplines of fashion-fashion, arts-arts, fashion-arts, fashion-other industries, and arts-other industries, with each category analyzed in frequency distribution and collaboration type along with related partner and industry characteristics. Collaborations with other industries were observed more than internal ones, and individuals (rather than firms) were more involved in collaborations. Though the collaboration characteristics were different by partner category and sub-category, by individual or firm, and by related industries, a variety of collaborations integrating fashion and arts into product design and development, a new brand launching, product line extension, and co-marketing were observed across product and industry disciplines. The study also described fashion and arts that were integrated into consumer life styles.

Numerical Simulation of Aerodynamic Characteristics of a Supersonic Projectile (초음속 발사체의 공력 특성에 관한 수치해석)

  • Lim Chae-Min;Lee Jeong-Min;Kim Heuy-Dong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.86-89
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    • 2005
  • A computational work has been performed to investigate the aerodynamics of a projectile which is launched from the two-stage light gas gun. A moving coordinate method for a multi-domain technique is employed to simulate unsteady projectile flows with a moving boundary. The effect of a virtual mass is added to the axisymmetric unsteady Euler equation system. The computed results reasonably capture the major flow characteristics which we generated in launching the projectile supersonically, such as the interaction between the shock wave and the blast wave, the interaction between the vortical flow and the barrel shock, and the steady under-expanded jet. The present computational results properly predict the velocity, acceleration, and drag histories of the projectile.

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Experimental Study on Acoustic Absorption and Transmission Characteristics of Aluminium and Sandwich Composite Structure (금속 및 샌드위치 복합재 유도탄 구조체의 흡음 및 차음 특성에 관한 실험적 연구)

  • Lee, Yoon-kyu;Lee, Dae-oen;Jin, Byung-Dae;Lee, Dong-min
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.3
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    • pp.288-294
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    • 2018
  • Recently, as the speed and performance of the launcher and the missile have been improved, it is necessary to consider the acoustic load of launching and flight in initial design step. In this paper, an experimental study on acoustic absorption and transmission characteristics of aluminium vs. sandwich composite structures were conducted. The overall noise reduction was evaluated by performing an acoustic test in the reverberation room, and the acoustic absorption and transmission loss of the structures were analyzed by conducting the sound absorption test inside the structure.

Analysis on Preceding Study of Consumer's Store-Choice Model: Focusing on Commercial Sphere Analysis Theories

  • Quan, Zhi-Xuan;Youn, Myoung-Kil
    • The Journal of Industrial Distribution & Business
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    • v.7 no.4
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    • pp.11-16
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    • 2016
  • Purpose - There are numerous theories for retail trade area analysis which are designed to select candidate locations for new stores. In this study, comparative analysis on the characteristics from those of the theories are shown, and the explanation for the power in consumers' store-choice behaviors and their limitations are examined. Also, plans for improving commercial sphere analysis are explored. Research design, data, and methodology - This study is based on literature reviews with normative research methodology. Among many researches regarding the analysis on the location and commercial sphere for launching a new store, researches relying on statistics are excluded in this study since they belong to the marketing research area,. Results - In the Law of retail gravitation, Huff's model multinomial logit model and etc. are mutual complementary mathematical techniques for analyzing commercial spheres and each of them has its own characteristics. These theories rely on the same hypothesis in which consumers are all believed to be behaving rationally under a similar behavioral system. However, the trial in explaining or estimating behavior of choosing a store with only a select size of the population that is objectively estimated by some major properties has limits in its credibility. Conclusion - Research on consumer's spatial behaviors can be fully illustrative and explainable when it has both quantitative approaches such as 'law of retail gravitation', 'logit model' and etc., and qualitative approaches like consumer's 'cognitive structure', 'learning status', 'image formation', 'attitude' and etc.