• Title/Summary/Keyword: IMPACT FORCE

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Maturity model considering the interrelation between software project management areas (소프트웨어 프로젝트 관리영역의 상호영향을 고려한성숙도 모델)

  • Jeon, Soon-Cheon
    • Journal of Advanced Navigation Technology
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    • v.15 no.5
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    • pp.823-832
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    • 2011
  • Recently, as the project becomes larger and the number of project increases by the information system integration in the public and financial sectors, it is necessary to have a proper plan to manage the information system project. There have been many researches about the project management, success elements and failure elements, but the research on the interrelation between project management areas leaves much to be desired. This research deduces the scope, schedule, quality, work force and risk as the project management areas from the preceding research and the questionnaire and interview with PM developers, information system builders and data processing experts. And, it analyzes the interrelation and the relative importance between management areas, classifies the progress of the management areas under plan, implementation and completion stage and presents the frame to evaluate the accomplishment of each progress.

Analysis of Influencing Export Factors of Major Agricultural Products for ASEAN using Panel Gravity Model (패널중력모형을 이용한 동남아시아 대상 주요 수출 농산물 영향인자 분석)

  • Kim, Solhee;Son, Younghwan;Park, Jinseon;Kim, Taegon;Suh, Kyo
    • Journal of Korean Society of Rural Planning
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    • v.22 no.4
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    • pp.103-114
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    • 2016
  • The global trade partners have been diversified and mixed in agricultural market, which is expended the international agri-food market through the Regional Trade Agreement and World Trade Organization, etc. The aim of this study is to derive influential factors for exports increases of agricultural products targeting to Association of South-East Asian Nations (ASEAN). We set the equation for agricultural products exports referred to panel gravity model considering panel fixed effect for controlling endogeneity within variables. The results of this study are the follows; (1) Social economic distance considering international oil price negatively affects in the mushroom model; (2) Korean GDP affects (-) in a mushroom model and (+) in a vegetable model, however, ASEAN's per capita GDP indicates opposite influence in the same model; (3) Relative exchange rate shows negative impact in a vegetable model; (4) The entry status into WTO and the status in force of FTA have converse effects in mushroom and vegetable model, respectively.

Variation of the structural stability for the sonar dome window in a naval vessel according to the state of the drain valve (소나돔 충, 배수 밸브의 상태에 따른 함정용 소나돔 윈도우의 구조안정도 변화)

  • Han, HyungSuk;Lee, KyungHyun;Park, SeongHo;Lim, YongSoo
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.7
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    • pp.844-853
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    • 2014
  • Since the active sonar for a naval vessel is usually installed in a bulbous bow, GRP(Glass reinforced plastic) material with low density and high strength is used for the material of the sonar dome window in order to prohibit impact by slamming wave or foreign material in the sea. The structural safety of the sonar dome is varied according to the interior and exterior distributed pressure on the sonar dome. Therefore, the variation of the structural safety according to the pressure variation of the sonar dome window caused by the drain valve state is studied by CAE.

Fracture Behavior of Glass/Resin/Glass Sandwich Structures with Different Resin Thicknesses (서로 다른 레진 두께를 갖는 유리/레진/유리샌드위치 구조의 파괴거동)

  • Park, Jae-Hong;Lee, Eu-Gene;Kim, Tae-Woo;Yim, Hong-Jae;Lee, Kee-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.12
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    • pp.1849-1856
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    • 2010
  • Glass/resin/glass laminate structures are used in the automobile, biological, and display industries. The sandwich structures are used in the micro/nanoimprint process to fabricate a variety of functional components and devices in fields such as display, optics, MEMS, and bioindustry. In the process, micrometer- or nanometer-scale patterns are transferred onto the substrate using UV curing resins. The demodling process has an important impact on productivity. In this study, we investigated the fracture behavior of glass/resin/glass laminates fabricated via UV curing. We performed measurements of the adhesion force and the interfacial energy between the mold and resin materials using the four-point flexural test. The bending-test measurements and the load-displacement curves of the laminates indicate that the fracture behavior is influenced by the interfacial energy between the mold and resin and the resin thickness.

Analysis of Dynamic Characteristics of a Piston for a Linear Compressor Considering Changes in Groove Geometry (리니어 압축기에서 그루브 형상 변화에 따른피스톤의 동특성 해석)

  • Noh, Sangwan;Oh, Wonsik;Park, Kyeongbae;Rhim, Yoonchul
    • Tribology and Lubricants
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    • v.31 no.5
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    • pp.221-228
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    • 2015
  • It is possible to prevent a piston from contacting the cylinder by changing the shape of the piston or by applying micro-textures, such as micro-grooves or micro-holes, over the piston surface. Usually, the minimum radial clearance reaches its minimum value at the beginning of the suction stroke because the pressure around the piston is low and almost axisymmetric such that the net pressure force on the piston is not sufficiently high to support the piston from touching the cylinder. In this study, we apply a series of saw-tooth-shaped grooves on the piston surface, and numerically investigate the effects of groove depth, groove angle, and the number of grooves with radial clearance variations using a finite difference method. We conduct a dynamic analysis of the piston for various changes in groove geometries to obtain the minimum radial clearance variation for the entire compression cycle. The minimum radial clearance increases while friction loss decreases when we apply the series of saw-tooth-shaped grooves on the piston. In addition, we analyze the impact of the change in the groove shape variable due to changes in radial clearance. Leakage variations are relevant to radial clearance, but have almost no effect on the groove parameters.

Seymour's Fracture of the Base of the Distal Phalanx in a Child (소아 원위지골 기저부에서 발생한 Seymour씨 골절의 치험례)

  • Kim, Cheol Hann;Tark, Min Sung
    • Archives of Plastic Surgery
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    • v.33 no.6
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    • pp.776-779
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    • 2006
  • Purpose: Prior to closure of the epiphysis of the distal phalanx, fracture usually occurs through the growth plate, Salter-Harris type I or II, or through the juxtaepiphyseal region 1 to 2 mm distal to the growth plate. The terminal tendon of extensor inserts into the epiphysis only, while insertion site of the flexor digitorum profundus spans both the epiphysis and metaphysis. Because of the difference between these tendon insertions, this injury mimics a mallet deformity. But, this type of injury does not involve a tear or avulsion of the extensor, unlike mallet finger of adults. Seymour was the first to describe this type of injury in children and called after his name, Seymour's fracture. This fracture is prone to infection or remain the residual deformity unless adequate treatment. Methods: We report a case of Seymour's fracture. A 9-year-old boy presented a laceration of the nail matrix, with the nail lies degloved from the nail fold on the right middle finger gotten from an impact against a door. An X-ray examination showed the fracture line lying 1 mm distal to the growth plate. The injury was treated with debridement and the fracture was reduced by applying hyperextension force. Under the C-arm, a single 0.7 mm K-wire was used to immobilize the distal interphalangeal joint. Intravenous antibiotics were applied for 5 days after surgery. Results: The K-wire was removed in the 3rd week. No infection or significant deformity was found until follow-up of 12 months. Conclusions: Seymour's fracture may be at first classically mallet deformity by its appearance. But it is anatomically different and more problematic injury. If it isn't corrected at the time of injury, derangement of the extensor mechanism, and growth deformity of the distal phalanx may occur. The fracture site should be debrided, removed of any interposed soft tissue, and the patient should be given appropriate antibiotics. Reduction should be maintained by K-wire fixation. We experienced no infection or premature epiphyseal closure.

The influences of encircling gill net fishery on fish organisms (선자망어업이 어업생물에 미치는 영향)

  • HAN, Inwoo;YOON, Euna;OH, Wooseok;LEE, Kyounghoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.1
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    • pp.41-48
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    • 2017
  • Encircling gill net fishery is a kind of gill net which is generally used in shallow coastal waters. After the fish have been encircled by the gill net, noise stimulus such as a stone or sound is used to force them to gill or entangle themselves in the netting surrounding them. Although the fishing by a stone is a traditional fishing method, it is considered as an illegal fishing method by physical stimulus such as explosives and mechanical vibrator. However, this illegal fishing method has raised some problems to the fishing boat of other fisheries or many anglers due to disturb aggregating fish schools. This study is aimed to provide scientific base data to verify whether to impact the ecosystem caused by this encircling gill net. This study exhibited that the impulse noise by concrete sphere in the encircling gill net was $159dB/{\mu}Pa$, the ambient noise from ship engine was $160dB/{\mu}Pa$, and the maximum noise from continuous artificial vibrator was $175dB/{\mu}Pa$. These may be stimulus to the escape of fish distributed in a wide area in its natural state; it is not likely the cause of death due to catastrophic stress. Therefore, it needs to prepare the consideration of standard limit on fishing stimulus in fishing methods of the fishery laws and regulations, prevent fishermen form using illegal fishing gear (i.e. explosive sound standards: $200{\sim}220dB/{\mu}Pa$ and provide them with countermeasures.

Study of Determination in Measurement System for Safely Managing Debris-Flow (안전한 토석류 관리를 위한 계측기 선정에 관한 연구)

  • Min, Dae-Hong;Yoon, Hyung-Koo
    • Journal of the Korean Society of Safety
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    • v.32 no.3
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    • pp.41-47
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    • 2017
  • Recent studies have shown that there are various systems which can be used to monitor hazardous area in a debris flow location, but lack of methodological research on the exact location where each instrument should be installed has hindered the success of this systems. The objective of this study is to suggest the measurement system for monitoring debris-flow and propose the effective method to determine location of measurement system. Previously studied, from 1991 to 2015, were referred and the applied ratio of every instrument was investigated. The measurement information was divided into 8 categories including rainfall, debris-flow velocity, displacement, fluid pore pressure, ground vibration, image processing, impact force and peak flow depth. The result of this study revealed that the most applied instruments to be rain gauge and geophone for measuring average rainfall and ground vibration respectively. The Analytic Hierarchical Process (AHP) method was selected to determine installation location of instrument and the weighting factors were estimated through fine content, soil thickness, porosity, shear strength, elastic modulus, hydraulic conductivity and saturation. The soil thickness shows highest weights and the fine content relatively demonstrates lowest weights. The score of each position can be calculated through the weighting factors and the lowest score position can be judged as the weak point. The weak point denotes the easily affecting area and thus, the point is suitable for installing the measurement system. This study suggests a better method for safely managing the debris-flow through a precise location for installing measurement system.

A Preliminary Study on the Structural Performance of the Bumper-Beams for High-Strength Steel Applications (고장력강판 적용을 위한 자동차 범퍼빔 구조성능의 기초연구)

  • Kang, Jong-Su;Song, Myung-Hwan;Lim, Jae-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.6
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    • pp.78-84
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    • 2017
  • Consistent efforts have been made to reduce the weight of automotive parts by using lightweight materials. This has resulted in the replacement of conventional steels in car body structures with high-strength steels, and the current usage rate has reached 50%. This study examines the structural stiffness and energy absorption capability of bumper beams made of high-strength steels. New types of bumper beam cross sections are proposed.The structural stiffness and maximum bending force were computed via finite element analysis as about 25tons and 7.5tons/mm, and there were no significant differences among the proposedcross sections. Dynamic analysis was also carried out to investigate the energy absorption capabilities of the bumper beams, and the effects of materials and thickness reduction were analyzed. High-strength steel can be used to achieve weight reduction with comparable structural performance to conventional bumper beams.

Climate Change Concerns in Mongolia

  • Dagvadorj, D.;Gomboluudev, P.;Natsagdorj, L.
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.47-54
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    • 2003
  • Climate of Mongolia is a driven force on natural conditions as well as socio-economic development of the country. Due to the precariousness of climate conditions and traditional economic structure, natural disasters, specially disasters of meteorological and hydrological origin, have substantial effect upon the natural resources and socio-economic sectors of Mongolia. Mongolia's climate is characterized by high variability of weather parameters, and high frequency and magnitude of extreme climate and weather events. During the last few decades, climate of the country is changing significantly under the global warning. The annual mean air temperature for the whole territory of the country has increased by $1.56^{\circ}C$ during the last 60 years,. The winter temperature has increased by $1.56^{\circ}C$. These changes in temperature are spatially variable: winter warming is more pronounced in the high mountains and wide valleys between the mountains, and less so in the steppe and Gobi regions. There is a slight trend of increased precipitation during the last 60 years. The average precipitation rate is increased during 1940-1998 by 6%. This trend is not seasonally consistent: while summer precipitation increased by 11 %, spring precipitation decreased by 17. The climate change studies in Mongolia show that climate change will have a significant impact on natural resources such as water resources, natural rangeland, land use, snow cover, permafrost as well as major economic activities of arable farming, livestock, and society (i.e. human health, living standards, etc.) of Mongolia. Therefore, in new century, sustainable development of the country is defined by mitigating and adaptation policies of climate change. The objective of the presentation is to contribute one's idea in the how to reflect the changes in climate system and weather extreme events in the country's sustainable development concept.

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