• 제목/요약/키워드: handling condition

검색결과 306건 처리시간 0.026초

Evaluation of Logistics Infrastructure of Container Terminals in Northern Vietnam

  • Nguyen, Minh Duc;Kim, Sung-June;Jeong, Jung Sik
    • 한국항해항만학회지
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    • 제40권5호
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    • pp.305-310
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    • 2016
  • The sea-port in Northern Vietnam accounts for around one third of the total country's cargo throughput and for many decades has been playing an important role in the logistics system of the country. 11 container terminals currently operate in Northern Vietnam, concentrating in Haiphong city and Quang Ninh province. Despite the increasing demand, the competition among these container terminals has become increasingly more critical. In recent years, massive investments from both government and operators have been made to improve the capability of the local sea-port's logistics infrastructure. This critically needed comprehensive research evaluates the impact of the current logistics infrastructure condition on the competitiveness of terminals and quantitatively compares the competencies of these terminals. In order to meet such requirements, the paper first summarizes the indicators of the logistics infrastructures of the sea ports before developing and testing hypotheses to reveal the correlation between the given factors and the annual throughput of container terminals in the region. Factor analysis will then be applied to score the logistics infrastructure competency of each container terminal. A significant gap between logistics infrastructures among all container terminals was not observed and the competitiveness between container terminals is mostly driven by traditional activities including cargo handling and storage. According to the results, strategic thinking will be needed to contribute to related organizations for better decisions in investment, management, and operation.

$\cdot$ 대용량 인버터용 IGBT 병렬 운전 연구 (The Study on Parallel operation of IGBT for the Medium SE the Large capacity Inverter)

  • 박건태;윤재학;정명길;김두식
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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    • pp.430-433
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    • 2003
  • IGBTS are widely used for the industrial inverters in the mid power range at low voltage (440V$\~$660V) application. Advantageous features of the device are simple gate drive and high speed switching capability. Due to these advantages the application of IGBTS is enlarging into the high power application. However, to increase the power handling capacity at lower input voltage level, the current rating in each bridge arm must be enlarged. Therefore the parallel operation of IGBT devices is essentially needed. This paper describes the feasible parallel structures of the power circuit for the mid & the high power inverters and introduces the important design condition for the parallel operation of IGBT devices. To verify feasibility of the IGBT parallel operation, the feature of several IGBT devices (EUPEC, SEMIKRON's IGBT) are investigated and the power stacks are implemented and tested with these devices. The experimental results show the good characteristics for the parallel operation of IGBTS.

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유연매체의 거동해석: II. 공기의 영향을 고려한 해석 (Analysis of Flexible Media: II. Including Aerodynamic Effect)

  • 지중근;장용훈;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.1335-1340
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    • 2007
  • The media transport systems, such as printers, copy machines, facsimiles, ATMs, cameras, etc. have been widely used and being developed rapidly. In the development of those sheet-handling machineries, it is important to predict the static and dynamic behavior of the sheet with a high degree of reliability because the sheets are fed and stacked at such a high speed. Flexible media are very thin, light and flexible, so they behave in geometric nonlinearity with large displacement and large rotation but small strain. In the flexible media analysis, aerodynamic effect from the surrounding air must be included because any small force can make large deformation. In this paper, surrounding air was modeled by incompressible Navier-Stokes flow and an arbitrary Lagranigan-Eulerian(ALE) finite element method with automatic mesh-updating technique was formulated for large domain changes. In the numerical simulations, the results with consideration of the air fast decayed and converged into static results while the results without considering air oscillated continuously.

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추가성토에 의한 성토체 하부에서의 연직응력 산정 (Estimation of Vertical Stress Developed in Subsurface due to Additional Embankment)

  • 이승현;한진태
    • 한국산학기술학회논문지
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    • 제12권5호
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    • pp.2410-2415
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    • 2011
  • 매년 증가하는 교통량과 물동량으로 인해 기존 도로의 성토폭을 넓혀야 하는 경우가 빈번하게 발생한다. 본 연구에서는 추가 성토로 인해 기존 성토체 하부지반에 전달되는 연직응력 산정식을 유도하고자 하였다. 유도과정을 통해 평면변형률 지반조건에 대한 이론적 배경을 검토하여 보았다. 해석에서 고려한 응력함수는 적합조건 및 경계조건을 만족함을 알 수 있었다. 유도된 연직응력 산정식을 적용함에 있어 주의점을 살펴보았고 계산예를 통해 산정식의 신뢰성을 확인하였다.

저소득층 노인의 유헬스 서비스 이용경험 (Low-income Elders' Experiences in Using u-Health (Ubiquitous Healthcare) Services)

  • 최한나;김정은
    • 지역사회간호학회지
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    • 제25권4호
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    • pp.270-281
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    • 2014
  • Purpose: The purpose of the study was to understand low-income elders' experiences of community-based u-Health services. Methods: Qualitative data were collected from 11 participants. All interviews were recorded and transcribed verbatim. The transcribed data were analyzed using qualitative content analysis. Results: Three themes and eight sub-themes emerged as a result of analysis. The three main themes were 'recovered confidence and health condition,' 'trial and error in change,' and 'hope.'The eight sub-themes were 'the burden and efforts to overcome it in using bio-signal device,' 'ambivalence due to changing lifestyle,' 'increase of care time, decrease of pressure', 'conflict under environmental constraints,' 'difficulty in prioritizing health management,' 'discouragement in handling new devices,' 'desire not to be a burden to their children-gradual fulfillment of learning needs,' and 'long for broadening coverage range of services.' Conclusion: The findings of this study demonstrate that low-income elders among the participants have different needs in using u-Health services. Therefore, health professionals need to give personalized education to deal with their conflicts and requirements, especially emotional and environmental support in order for them to successfully accept the u-Health services for self-care.

소규모 건축공사 중점안전관리항목에 관한 연구 (A Study on the Intensive Safety Management Items of Small-Sized Construction Sites)

  • 고성석;송도흠;장윤라
    • 한국안전학회지
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    • 제28권5호
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    • pp.27-34
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    • 2013
  • Almost accidents in construction sites are occurred by unsafe work conditions and failure making safe environment. As recent construction projects become more complex, various and diversified, So the potential of construction-related accidents is increased as well. Comparing the frequency of construction-related accidents in large-sized construction sites, small-sized construction sites are more vulnerable because of lack of workforce and less effective technology system. Furthermore, the absence of safety committee, poor financial condition leads to lack of safety education, installation of safety facilities, and provision of individual protective equipment, which indicates difficulties handling even basic safety management. Therefore, in order to lower the hazard rate at small-Sized construction sites, it is necessary to proceed with more structural and thorough actions for preventing accidents. In other words, it is necessary to analyze the causes of the accidents at small-sized construction sites, set criteria for safety management, and suggest safety management items according to work classification by evaluating the relative importance of the items.

Hierarchical Cluster Analysis on Competitiveness of Container Terminals in Northern Vietnam

  • Nguyen, Minh-Duc;Kim, Sung-June;Jeong, Jung-Sik
    • 한국항해항만학회지
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    • 제40권2호
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    • pp.67-72
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    • 2016
  • Vietnam's sea-port industry has experienced a significant development in recent years. Especially in Northern Vietnam, both the demand and supply of handling services for containerized cargoes have increased at a considerable rates. Accompany with such movement, the competition among container terminals in the area becomes fiercer. In this paper, Hierarchical Cluster Analysis is employed to classify all 11 container terminals in Northern Vietnam by collecting data concerning terminal competitiveness. After the classification, each group will be discussed in order to reveal more details about their competitive characteristics. The paper consists of five sections. Section 1 is the general introduction. Section 2 provides a general literature review about competitiveness and factors to evaluate competitiveness. Section 3 explains variables and methodology applied to do the analysis. Section 4 presents the results with linkage to the current condition. Section 5 summarizes the analysis results. It is shown that container terminals in Northern Vietnam should not only pay attention to their service qualities but also have to find out an appropriate mechanism to avoid unhealthy competition. The paper is expected to contribute a background for further researches in container terminals' competition in the region as well as hints for operators in planning and making decisions.

유조선 화물취급구역내 동력환기특성에 관한 연구 (A Study on Mechanical Ventilation Characteristics in Cargo Handling Area of Tanker)

  • 조대환
    • 해양환경안전학회지
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    • 제7권1호
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    • pp.15-23
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    • 2001
  • In regulation of IGC code 12.1 mechanical ventilation should be arranged to ensure sufficient air movement through the space to avoid the accumulation of flammable or toxic vapours and ensure a safe working environment, but in no case should the ventilation system have a capacity of less than 30 changes of air per hour baed upon the total volume of the space. In this study, a scaled mode chamber was constructed to investigate the ventilation characteristics and stagnation area in the hood room of LNG carrier and pump room in tanker. An experimental study was performed on the model by using visualization equipment with a laser apparatus and an image intensifier CCD camera. Twelve different kinds of measuring areas were selected as the experimental condition. Instant simultaneous velocity vectors in the whole fields were measured by a 2-D PIV system A three-dimensional numerical simulation was also carried out for three different Reynolds numbers. Then the CFD predictions were discussed with the experimental results. The results show the spiral L-shape flow that moves from the opening on the left wall diagonally to the upper right part dominates the ventilation structure. The stationary area of hood room in the velcoity distributions was located in the upper left stern part.

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사수(邪祟)에 대한 의학적 인식의 변화 (Change of Perception on Sasu(邪祟), Evil-Spirit(鬼邪) Related Disease)

  • 홍세영
    • 대한한의학원전학회지
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    • 제27권2호
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    • pp.97-107
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    • 2014
  • Objectives : This study aims at exposing interaction between socio-cultural influence on medicine, and the strong quest for rational explanation concerning the evil-spirit(鬼邪) related disease, namely Sasu(邪祟), in medical history. Methods : In order to apprehend the change of perception, Chinese medical classics referring directly to Sasu(邪祟), as well as Korean medical classics from Joseon dynasty were reviewed. Results : In Chinese medical texts, discriminating pseudo-sasu(類似邪祟) from evil-spirit related sasu had been one of the main concerns. And Chinese were more inclined to specify treatment plan for pseudo-sasu than handling evil spirits. On the contrary, Korean medical texts show common interests in eliminating evil spirits throughout Joseon dynasty. Conclusions : Since medicine is under the influence of socio-cultural condition, it cannot escape from the epistemology of corresponding society. Evil-spirit related disease therefore could remain within the sphere of medical discussion until very recently. If we observe the disease under the frame of culture, we not only can obtain broader view on dynamic nature of medical conceptions, but also gain better insight to understand medical classics.

SDB와 전기화학적 식각정지에 의한 벌크 마이크로머신용 3차원 미세구조물 제작 (Fabrication of 3-Dimensional Microstructures for Bulk Micromachining by SDB and Electrochemical Etch-Stop)

  • 정귀상;김재민;윤석진
    • 한국전기전자재료학회논문지
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    • 제15권11호
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    • pp.958-962
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    • 2002
  • This paper reports on the fabrication of free-standing microstructures by DRIE (deep reactive ion etching). SOI (Si-on-insulator) structures with buried cavities are fabricated by SDB (Si-wafer direct bonding) technology and electrochemical etch-stop. The cavity was formed the upper handling wafer by Si anisotropic etch technique. SDB process was performed to seal the formed cavity under vacuum condition at -760 mmHg. In the SDB process, captured air and moisture inside of the cavities were removed by making channels towards outside. After annealing (100$0^{\circ}C$, 60 min.), the SDB SOI structure with a accurate thickness and a good roughness was thinned by electrochemical etch-stop in TMAH solution. Finally, it was fabricated free-standing microstructures by DRIE. This result indicates that the fabrication technology of free-standing microstructures by combination SDB, electrochemical etch-stop and DRIE provides a powerful and versatile alternative process for high-performance bulk micromachining in MEMS fields.