• 제목/요약/키워드: Byungki Kim

검색결과 33건 처리시간 0.023초

Dissolution Characteristics of Liquid Carbon Dioxide Injected at the Intermediate Depth of the Ocean

  • Namjin Kim, Jaeyong-Lee;Byungki Hur;Taebeom Seo;Kim, Chongbo
    • Journal of Mechanical Science and Technology
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    • 제14권11호
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    • pp.1276-1285
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    • 2000
  • The solubility, the surface concentration and the dissolution behavior of carbon dioxide in deep sea were numerically investigated. Base on the calculations the relations between the surface concentration of liquid carbon dioxide droplet with the hydrate film and the solubility and those between the ambient carbon dioxide concentration in the plume and the dissolution rate were obtained. The result show that a carbon dioxide droplet is released both at 1000 m in depth with the initial droplet diameter of 0.011 m or less and at 1500 m in depth with a diameter of 0.015 m or less, and the droplet is completely dissolved below 500 m in depth. The hydrate film acts as a resistant layer for the dissolution of liquid carbon dioxide, and the effect of the hydrate film on the dissolution of liquid carbon dioxide depended upon the depth.

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개선된 k-Nearest Neighbor를 이용한 물체 인식 (Object Recognition using Improved k-Nearest Neighbor)

  • 정병수;위승정;김종혁;김병기
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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    • pp.799-801
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    • 2005
  • 모델 영상내의 각각의 물체의 대표 값을 만든 후에 실험 영상을 물체 공간에 투영 시켜서 나온 성분과 대표 값의 거리를 비교하여 인식하게 된다. 그러나 단순히 기존의 방법인 Point to Point 방식인 단순 거리 계산은 오차가 많기 때문에 된 논문에서는 개선된 Class to Class방식인 k-Nearest Neighbor를 이용하여 몇 개의 연속적인 입력영상에 대해 각각의 모델영상들을 인식의 단위로 이용하였다.

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1960-70년대 뉴욕의 한국작가: 이주, 망명, 디아스포라의 미술 (Art of Dislocation, Exile, and Diaspora: Korean Artists in New York in the 1960s and 1970s)

  • 양은희
    • 미술이론과 현장
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    • 제16호
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    • pp.107-137
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    • 2013
  • This paper examines a number of Korean artists-Whanki Kim, Po Kim, Byungki Kim, Lim Choong-Sup, Min Byung-Ok and etc-working in New York in the 1960s and 1970s, focusing on their motivations to head for the U.S. and their life and activity in the newly-emerged city of international art. The thesis was conceived based upon the fact that New York has been one of the major venues for Korean artists in which to live, study, travel and stay after the Korean War. Moreover, the United States, since 1945, has had a tremendous influence upon Korea politically, socially, economically, and, above all, culturally. This study is divided into three major sections. The first one attends to the reasons that these artists moved out of Korea while including in this discussion, the long-standing yearning of the Korean intelligentsia to experience more modernized cultures, and American postwar cultural policies that stimulated them to envision life beyond their national parameters, in a country heavily entrenched in Cold War ideology. The second part examines these artists' pursuit of abstraction in New York where it was already losing its avant-garde status as opposed to the style's cutting edge cache in Korea. While their turn to abstraction was outdated from New York's critical perspective, it was seen to be de rigueur for Koreans that had developed through phases from Art Informel in the 1960s to Dansaekhwa (monochromatic paintings) in the 1970s. The third part focuses on the artists' struggle while caught between a dualistic framework such as Korea/U.S, East/West, center/margin, traditional/modern, and abstraction/figuration. Despite such dichotomic frames, they identified abstract art as the epitome of pure, absolute art, which revealed their beliefs inherited from western modernism during the colonial period before 1910-1945. In fact, their reality as immigrants in America put them in a diasporic space where they oscillated between the fixed, essentialist Korean identity and the floating, transforming identity as international artists in New York or Korean-American artists. Thus their abstract and semi-abstract art reflect the in-between identity from the diasporic space while demonstrating their yearning for a land of political freedom, intellectual fulfillment and the continuity of modern art's legacy imposed upon them over the course of Korea's tumultuous history in the twentieth century and making the artists as precursor of transnational, transcultural art of the global age in the twenty-first century.

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연료전지 자동차용 TMS 히터 개발 (Development of Thermal Management System Heater for Fuel Cell Vehicles)

  • 한수동;김성균;김치명;박용선;안병기
    • 한국수소및신에너지학회논문집
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    • 제23권5호
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    • pp.484-492
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    • 2012
  • The TMS(Thermal Management System) heater in a fuel cell vehicle has been developed to prevent a decline of fuel cell durability and cold start durability. Main functions of the COD(Cathode Oxygen Depletion) heater are depletion of oxygen in a cathode as heat energy and consumption of electric power for rapid warming up of a fuel cell stack. This paper covers subjects including the design specification of a heater, heater controller for detection of overheat and reliability assessment including coolant pressure cycle test of a heater. To verify the design concept, burst pressure and deformation analysis of plastic housing were carried out. Also, temperature distribution analysis of heater surface and coolant inside of housing were carried out to verify the design concept. By designing the plastic housing instead of a steel housing, the 30% weight lightening and 50% cost reduction were attained. A module-based design of a TMS system including a heater or reducing the watt density of a heater is a problem to be solved in the near future work.

자동차 외판 강성의 고객 감성 영향 분석 : 승용차의 후드 및 도어를 중심으로 (Effect of Automobile Exterior Panel Stiffness on Customers' Affect : Focused on Hood and Door of Mid-Size Passenger Cars)

  • 류태범;김원준;진병기;윤명환
    • 대한산업공학회지
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    • 제42권5호
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    • pp.360-369
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    • 2016
  • This study attempted to identify the effect of the panel stiffness on the customers' affect, which was not addressed in the research field of affective engineering. For this, this study derived four affects related to the panel stiffness from literature and pre-experiment : hardness, deform consistency, thickness and satisfaction and prepared a questionnaire to evaluate the affects of the panel. In the experiment, 54 adults in the age of 20~50 participated and evaluated the affects of hood, front and rear door for nine full size and luxury sedans by pressing the panels with their hands. As results, participants' affect for the panels were significantly different depending on the force-deflection curves of them, and the subjects' satisfaction of the panels increased as the slope of the curve (stiffness) increases. In addition, it was found that the subjects evaluated the panel with the pressing force up to 14kgf. The findings of the study can be used to increase and control the affective quality of exterior panels on passenger cars.

팀워크 바탕으로 애자일 개발방법의 개선연구 (Research And Improve Agile Development Methods Based On Teamwork)

  • ;김병기
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제2권5호
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    • pp.303-310
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    • 2013
  • 애자일 소프트웨어 개발 방법은 경량 소프트웨어 개발 방법으로 소프트웨어 개발에서 팀워크가 중요한 역할을 한다. 본 논문에서는 애자일 개발에서 공동 작업을 할 때 팀워크, 팀 관리, 프로젝트 관리를 효율적으로 수행할 수 있는 작업과 인적자원을 분배하는 방안을 제시한다. 제안모델은 작업과 인적자원 분배를 위한 수학적 모델을 재시하고 6-시그마의 우선순위를 적용해서 작업에 가장 합당한 인력을 할당한다. 그리고 개발인력 관계모델을 이용하여 작업에 할당된 인력의 적절성을 검증한다. 제안된 방법은 인원배치의 효율성을 통한 팀워크를 개선함으로써 SW개발 생산성을 높였다.

PRODUCTIVITY PREDICTION MODEL BASED ON PRODUCTIVION INFLUENCING FACTORS: FOCUSED ON FORMWORK OF RESIDENTIAL BUILDING

  • Byungki Kwon;Hyun-soo Lee;Moonseo Park;Hyunsoo Kim
    • 국제학술발표논문집
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    • The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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    • pp.58-65
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    • 2011
  • Construction Productivity is one of the most important elements in construction management. It is used in construction process scheduling and cost management, which are significant sector in construction management. It is important to make appropriate schedule and monitor how works are done within schedule. But construction project contains uncertainty and inexactitude, modifying construction schedule is being an issue to manage construction works well. Even though prediction and monitoring of productivity can be principal activity, it is hard to predict productivity with manager's experience and a standard of estimate. A large number of factors influencing productivity, such as drawing, construction method, weather, labor, material, equipment, etc. But current calculation of productivity depends on empirical probability, not consider difference of each influencing factor. In this research, the aim is to present a productivity predicting regression model of form work, which includes effectiveness of influences factors. 5 variables existed inside form work are selected by interview and site research based on literature review of existed various productivity influencing factors. The effectiveness and correlation of productivity influencing factors are analyzed by statistical approach, and it is used to make productivity regression model. The finding of this research will improves monitoring and controlling of project schedule in construction phase.

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PV PHIL-시뮬레이터의 성능 개선을 위한 최적의 운영제어 알고리즘 연구 (A study on advanced PV operation algorithm to improve the PV Power-Hardware-In-Loop Simulator)

  • 김대진;김병기;고희상;장문석;유경상
    • 한국산학기술학회논문지
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    • 제18권9호
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    • pp.444-453
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    • 2017
  • 기존 RTDS를 이용한 PV PHIL(Power-Hardware-In-Loop) Simulator는 확장성과 유연성의 문제로 인하여 일반 DC Amplifier를 이용한 많은 연구가 진행되었으나, PV Inverter와 연계할 경우에 과도 상태의 출력이 발생하여 안정성과 PV Inverter의 성능 개선이 불가능하였다. 따라서, 이러한 문제점을 해결하기 위하여 본 논문에서는 PV PHILS의 출력 성능 향상과 안정적인 운영이 이루어질 수 있는 제어 알고리즘을 제안한다. 즉, 이 제어 알고리즘은 DC Amplifier의 전기적 출력 특성을 극복하기 위해 정전압(CV), 정전류(CC) 상태에 따라 전압, 전류의 목표 값을 제어하고 각 장치별 특성 고려한 Multi-rate 기반의 특성을 갖는다. 먼저, PV Array의 수학적인 모델링과 DC Amplifier 그리고 DC 전력측정용 Isolated 장치와 통합하여 실시간 처리 기반의 장치로 구성하였고, 제안한 알고리즘이 적용된 PV PHILS와 실제 계통에 연계된 PV Inverter를 이용한 성능시험을 통해서, 그 결과가 기존 방법에 대비해 우수성 및 유용성을 입증하였다.

태양광전원 계통연계시험장치에 의한 수용가 전력품질특성에 관한 연구 (Analysis of Customer Power Quality Characteristics Using PV Test Devices)

  • 김병목;김병기;박재범;노대석
    • 한국융합학회논문지
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    • 제2권4호
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    • pp.21-27
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    • 2011
  • 현재 신 재생에너지 보급사업에 의해 설치되고 있는 태양광전원설비가 전력계통과 연계 운영될 경우 배전계통의 전력품질 요소에 어떠한 영향을 미치고 있는지를 모의시험을 통해 정확히 측정 분석하여 향후 분산형전원의 확대 보급에 따른 가이드라인의 구축과 기술적인 연계지침이 필요한 상황이다. 따라서 본 논문에서는 태양광이 연계되는 위치에 따른 선로임피던스($R{\pm}jX$)에 의하여 생기는 전압상승 및 하강에 의한 전력품질[Sag/Swell] 저하 현상에 대하여 태양광전원용 LabVIEW 프로그램을 통해 전력품질 시험을 수행하여 그 특성을 분석한다.

공기 중 SO2에 의한 고분자전해질 연료전지의 성능 감소 (Decrease of PEMFC Performance by SO2 in Air)

  • 이호;송진훈;김기중;김세훈;안병기;임태원;박권필
    • Korean Chemical Engineering Research
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    • 제48권3호
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    • pp.311-315
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    • 2010
  • 공기 오염에 의해 $SO_2$가 포함된 공기가 PEMFC cathode에 유입되어 전극 성능에 미치는 영향에 대해 연구하였다. 오염된 공기 접촉 후 저하된 성능회복을 위해 청정공기 유입, 순환전압측정법(cycle voltammetry, CV), 고전압 체류법(high voltage holding)을 사용하였다. 공기에 혼합된 $SO_2$농도 범위는 20 ppb~1.3 ppm이었다. 성능 감소 및 회복 측정은 일정전류에서 전압변화를 측정하는 방법, I-V 분극곡선 측정법, 임피던스측정법을 이용하였다. 20 ppb 농도로 $SO_2$를 200시간 주입 후 전지 전압은 주입 전보다 17 mV 감소하였다. 청정공기 주입, CV, 고전압체류방법에 의해 S가 Pt로부터 탈착되어 전지성능은 일부 회복되었다.