• Title/Summary/Keyword: Basic Concept

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Development of Elastic Shaft Alignment Design Program (선체변형을 고려한 탄성 축계정렬 설계 프로그램 개발)

  • Choung Joon-Mo;Choe Ick-Heung
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.4 s.148
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    • pp.512-520
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    • 2006
  • The effects of flexibilities of supporting structures on shaft alignment are growing as ship sizes are Increasing mainly for container carrier and LNG carrier. But, most of classification societies not only do not suggest any quantitative guidelines about the flexibilities but also do not have shaft alignment design program considering the flexibility of supporting structures. A newly developed program, which is based on innovative shaft alignment technologies including nonlinear elastic multi-support bearing concept and hull deflection database approach, has S basic modules : 1)fully automated finite element generation module, 2) hull deflection database and it's mapping module on bearings, 3) squeezing and oil film pressure calculation module, 4) optimization module and 5) gap & sag calculation module. First module can generate finite element model including shafts, bearings, bearing seats, hull and engine housing without any misalignment of nodes. Hull deflection database module has built-in absolute deflection data for various ship types, sizes and loading conditions and imposes the transformed relative deflection data on shafting system. The squeezing of lining material and oil film pressures, which are relatively solved by Hertz contact theory and built-in hydrodynamic engine, can be calculated and visualized by pressure calculation module. One of the most representative capabilities is an optimization module based on both DOE and Hooke-Jeeves algorithm.

A Study on the Characteristics of an Air Cavity Attached Under a Flat Plate (평판에 형성된 공기공동 특성에 관한 연구)

  • Kim, Jong-Hyun;Oh, Jae-Young;Seo, Dae-Won;Lee, Seung-Hee
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.5
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    • pp.396-403
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    • 2011
  • The concept of an air lubrication has long been an object of attention since it can be utilized to reduce the frictional resistance, and what is more, it is eco-friendly. The present study examines the basic characteristics of an air cavity with intention of applying the air lubrication technology to the reduction of the resistance of a ship without excessive power increment. For the purpose, an air cavity was created at the bottom of a flat plate by injecting air behind a backward step and the hydrodynamic properties of the air cavity and the surrounding flow has been investigated experimentally and numerically. The influence of the step height and the air flow rate have been more carefully studied since they are presumed to be the main parameters affecting the characteristics of an air cavity. The results indicates that the shapes of the air cavities attached on the flat plate become "U" or "V" type depending on the incoming flow velocity and air flow rate. The study also confirms that the length of the air cavity increases with increase in air flow rate but there is a certain critical limit in the flow rate above which increase in the air cavity length is no more evident.

A Study on the Theory of JangBu(臟腑) in Sasang Constitutional Medicine (사상의학(四象醫學) 장부이론(臟腑理論)의 특징(特徵)에 대(對)한 고찰(考察))

  • Kim, Jeong-Ho;Song, Jeong-Mo
    • Journal of Sasang Constitutional Medicine
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    • v.16 no.1
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    • pp.20-36
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    • 2004
  • After studying the theory of JangBu(臟腑), that is a physiology of Sasang Constitutional Medicine, in Sasang Constitutional Medicine, the author could draw a conclusion as these. 1. The basic thought of Sasang Constitutional Medicine is emphatic on the human beings itself unlike the idea of traditional Oriental Medicine, that accentuate the universe.(The traditional Oriental Medicine has a concept that the human beings follows the order of universe, but Sasang Constitutional Medicine has a different idea that human beings has the free will to the universe and newly comprehend the relationships between human beings and universe.) 2. Like the preceding, the theory of JangBu(臟腑), the physiology of Sasang Constitutional Medicine, is based on the autonomic mechanisms of human body itself. 3. The medical philosophy of Sasang Constitutional Medicine is Sasang(四象), that is Sa(事), Sim(心), Sin(身) and Mul(物). This Sasang is a classification of universe include human beings.(Sa(事) is event, Sim(心) is mind, Sin(身) is body, and Mul(物) is things. these four elements express the universe and human.) 4. The JangBu(臟腑) theory of Sasang Constitutional Medicine regard mind condition as important. The mind condition is divided into two factors. The one is Seong(性) the other is Jeong(情). The Seong(性) is an attitude toward the world, and the Jeong(情) is response to the stimulation from the world. 5. By the actions of Seong(性) and Jeong(情), the human body has different JangBu(臟腑) function, so the human body can be grouped in four constitutions. 6. Because of emphasis on mind condition, the Sasang JangBu(臟腑) theory has activism of human beings itself. 7. This activismor practical philosophy of Sasang JangBu(臟腑) theory, that is a physiology of Sasang Constitutional Medicine, gave birth to ethics or morality in Medical philosophy, that the human practice of ethics or morality bring a health and well being of human body.

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Application of Digital On-Channel Repeater in a DTV Transmission Network in Korea (국내 DTV 방송망에서의 디지털 동일채널중계기의 적용)

  • Suh Young-Woo;Kim Young-Min;Mok Ha-Kyun;Kwon Tae-Hoon;Lee Sang-Gil;Park Sung Ik;Lee Yong-Tae;Eum Homin;Seo Jae Hyun;Kim Heung Mook;Kim Seung Won
    • Journal of Broadcast Engineering
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    • v.10 no.4 s.29
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    • pp.587-598
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    • 2005
  • KBS and ETRI have co-developed an advanced DOCR(Digital On Channel Repeater) which has an equalization and pre-distortion function and can be operated properly under lower isolation of reception and transmission antennas. Field tests of the DOCR were performed twice in Suwon area in 2004 and 2005. This paper summarizes the characteristics of the DOCR system and field test results in Suwon. The changes in DOCR coverage according to the different generations of ATSC DTV receivers were also analyzed. Basic concept to apply the DOCR system in DTV broadcasting networks in Korea is suggested through test results.

Study of the Robustness Bounds with Lyapunoved-Based Stability Concept

  • Jo, Jang-Hyen
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.700-705
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    • 2005
  • The purpose of this project is the derivation and development of techniques for the new estimation of robustness for the systems having uncertainties. The basic ideas to analyze the system which is the originally nonlinear is Lyapunov direct theorems. The nonlinear systems have various forms of terms inside the system equations and this investigation is confined in the form of bounded uncertainties. Bounded means the uncertainties are with same positive/negative range. The number of uncertainties will be the degree of freedoms in the calculation of the stability region. This is so called the robustness bounds. This proposition adopts the theoretical analysis of the Lyapunov direct methods, that is, the sign properties of the Lyapunov function derivative integrated along finite intervals of time, in place of the original method of the sign properties of the time derivative of the Lyapunov function itself. This is the new sufficient criteria to relax the stability condition and is used to generate techniques for the robust design of control systems with structured perturbations. Using this relaxing stability conditions, the selection of Lyapunov candidate function is of various forms. In this paper, the quadratic form is selected. this generated techniques has been demonstrated by recent research interest in the area of robust control design and confirms that estimation of robustness bounds will be improved upon those obtained by results of the original Lyapunov method. In this paper, the symbolic algebraic procedures are utilized and the calculating errors are reduced in the numerical procedures. The application of numerical procedures can prove the improvements in estimations of robustness for one-and more structured perturbations. The applicable systems is assumed to be linear with time-varying with nonlinear bounded perturbations. This new techniques will be extended to other nonlinear systems with various forms of uncertainties, especially in the nonlinear case of the unstructured perturbations and also with various control method.

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Physical Health Status and Depression of a Community-Dwelling Elderly Group (일부 지역사회 노인의 신체건강 상태와 우울)

  • Kim, Nam-Cho;Yang, Soo
    • Journal of Korean Academy of Nursing
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    • v.31 no.6
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    • pp.1012-1020
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    • 2001
  • The purpose of this study was to describe physical health and depression status, as well as to assessing factors that influence the physical health status. Method: The data was collected from July to August 2000. Study participants were 252 community-dwelling elderly who were recruited from 10 senior centers located in Seoul, Korea. Their physical health status was measured using the Physical Health Status Measurement Scale developed by Choi and Jung (1991), and depression was measured using BDI-II developed by Beck et al. (1996). Results: 1) The physical health status score was 4.00 $\pm$0.68 (range :1- 5). The sub-dimension that showed the highest score was personal hygiene ability at 4.62$\pm$0.95, and the lowest score was sexual function at 2.20$\pm$1.38. 2. The depression score was 17.99+9.79 (range : 0-63). Regarding the sub-dimensions, the depression scores were higher in the domain of interest with sexuality, general weakness, difficulty in concentration, and fatigue. 3. Deeper levels of depression were correlated with a declining physical health status. 4. The most influential factor on physical health was depression, and the explaining variance was 31.68%. Conclusion: It is concluded that elder subjects in senior centers had fairly good physical health and self-care ability. Also, they did not have significantly high levels of depression. Therefor, health promotion of elderly, it is recommended that elder individuals should be regarded as a respectful and useful segment of our society. Along with this basic concept, there should be a social milieu that does not snow prejudice. Moreover, health care professionals should give more attention to helping the elderly achieve a minimal level of ALD, and, particularly, to raise sexuality and help energize the lives of elder individuals.

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The characteristics of types and annual trends of pop-up fashion stores - Focused on domestic cases - (패션 팝업 스토어의 연도별 변화 추이 및 유형 특성 - 국내 사례를 중심으로 -)

  • Yu, Jihun;Choi, Doree
    • The Research Journal of the Costume Culture
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    • v.23 no.5
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    • pp.822-834
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    • 2015
  • Contemporary fashion companies have been planning marketing strategies that can promote brands and products more effectively for satisfying consumers' increasingly diversified needs. For this reason, retail spaces have continued to evolve and the modern concept of pop-up stores appeared through this process. Therefore, the object of this study was to research domestic pop-up fashion store cases by collecting article data. These data are from Internet fashion-specialty sites and analyze the types and characteristics of pop-up fashion stores by providing basic information that will be useful in the pop-up fashion stores of companies when they establish their marketing strategies. This study utilized the content analysis method and derived the results by using SPSS Statistics. As a result of this study, the type of "pop-up fashion stores opening in distribution enterprises" comprised the highest percentage of the whole store types and the pop-up fashion stores' management purposes were focused on product introduction, promotion, and market testing. As time passed, not only did pop-up fashion stores' growth rate increased, but also the types of pop-up fashion stores have become more diverse. In other words, contemporary fashion companies are utilizing more pop-up fashion stores as a marketing strategy than before. However, due to the short history of domestic pop-up fashion stores, the variety of research is still insufficient, so more extensive research on pop-up fashion stores is required.

ROHMIP : Route Optimization Employing HMIP Extension for Mobile Networks (ROHMIP : 이동망에서 확장된 HMIP를 적용한 경로 최적학)

  • Rho, Kyung-Taeg;Jung, Soo-Mok
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.6
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    • pp.235-242
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    • 2007
  • Network Mobility Basic Support protocol reduces location-update signaling by making network movements transparent to the mobile nodes (MNs) behind the mobile router (MR), but causes some problems such as sub-optimal routing and multiple encapsulations. This paper proposes an Route Optimization Employing HMIP Extension for Mobile Networks (ROHMIP) scheme for nested nubile networks support which introduces HMIP concept with relation information between MNNs behind a MR and the MR in order to localize handoff, to optimize routing and especially reduce handoff signal overhead. With ROHMIP, a mobile network node (MNN) behind a MR performs route optimization with a correspondent node (CN) as the MR sends a binding update message (BU) to mobility anchor point (MAP) via root-MR on behalf of all active MNNs when the mobile network moves. This paper describes the new mechanisms and provides simulation results which indicate that our proposal reduces transmission delay, handoff latency and signaling overhead.

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Study of Multi Perforated Propellant Performance Analysis and Design using Configuration Variables (형상 변수를 사용한 다공형 추진제 성능 해석 및 설계 연구)

  • Oh, Seok-Hwan;Jang, Jin-sung;Park, Min-Su;Roh, Tae-Seong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.5
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    • pp.71-77
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    • 2015
  • Internal ballistics is a phenomenon happened in tens of milliseconds during the gun firing. The configuration variables of the solid propellant are important factors which have influences on the performance of the gun system. In this study, the performance analysis of the 7-perforated propellant has been conducted using the numerical program for the interior ballistics. The effect of the configuration variables on the gun system performance has been analyzed. The propellant design has been conducted for the satisfaction of the performance requirements. As results, the relationship between the configuration variables and the performance has been obtained and the basic design concept of the multi-perforated propellant has been provided.

The Sociocultural Value Research of Man Image and Make-up in Media (미디어에 나타난 남성의 이미지와 메이크업의 사회문화적 가치 분석)

  • Kim, Hye-Kyun;Park, Myung-Hee
    • Journal of Digital Convergence
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    • v.11 no.4
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    • pp.449-457
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    • 2013
  • This study seeks to find the sociocultural value which influences the man image and make-up in media. It helps to gain the effective data that suggest the application of male make-up in promoting development of market. The man emphasizes the practical value which is the technical and instrumental value to express the man image rationally, aesthetic value to pursue aesthetic purely and symbolic value which is a volitional and intentional value experienced in the history and society to express preferring man images as the society is changed. As analysing the man image based on sociocultural value, the practical value of men's make-up is to maximize the utility vale in order to deliver a clear image considering their activity range, environment, and situation. Second, the aesthetical value of men's make-up is to emphasize femininity through women's make-up technic. Third, the symbolic value of men's make-up is to deliver a concept or intentionally create an image by maximizing overall characteristic image. It will be hopefully valuable as a basic data for developing make-up products and setting trend for men as well as for future studies.