• 산업기술연구
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• 제15권
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• pp.5-13
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• 1995

Natural gas, which is getting more important as a fuel, should be liquefied and shipped in a special tank. During transportation, a spill of liquefied natural gas(LNG) could occur by a collision or even an accident. As a result, violent explosion called the superheat-limit explosion(SLE) can take place in some cases, unexpectedly. Such explosion may result from the formation of a superheated liquid which has attained the superheat-limit temperature when hot(water) and cold(LNG) liquids come into contact. Natural gas mixtures can be considered as discrete light components plus continuous heavy fractions where several continuous distribution function can be adopted. This work is aiming at prediction of the superheat-limit explosion condition by suing continuous thermodynamics development of algorithm to predict.

• 소성∙가공
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• 제8권3호
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• pp.237-244
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• 1999

The purpose of this research is for the development of a new type forging equipment. H.C.G.(Hyundai Continuous Grain-Flow), by using two virtual build-up tools, rigid viscoplastic FEM and downsized plasticine experiment. This forging method consists of only vertical pressuree. Therefore, high quality crankshafts can be forged with this method as it can maintain a continuous grain flow. The factors considered in the development of equipment are die geometry for flawless deformed shape, die reaction forces, stress/strain distributions and continuous material flow. We carried out several numerical simulations and downsized plasticine experiments for the proper design of the forging equipment. The validity of those simulation results is confirmed by checking with the actual test results. Based on these simulation results, the proper design of the H.C.G. forging equipment is enabled.

• 한국군사과학기술학회지
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• 제17권1호
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• pp.82-89
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• 2014

The damage in germanium (Ge) optical window irradiated by a near-infrared continuous wave (CW) laser was studied. Laser-induced heating and melting process were surveyed, and the specific laser power and the irradiance time to melt were estimated by numerical simulation. The experiments were also carried out to investigate the macro and micro structure change on Ge window. Results showed that the surface deformation was formed by melting and resolidification process, the damaged surface had a polycrystalline phase, and the transmittance as an optical performance factor in mid-infrared region was decreased. We confirmed that an abnormal polycrystalline phase and surface deformation effect such as hillock formation and roughness increase reduced the transmittance of Ge window and were the damage mechanism of CW laser induced damage on Ge window.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.8-13
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• 2003

For continuous improvement of the railway customer satisfaction service, more objective evaluation and development system for software and hardware shall be built. The entire activity of railway customer is the interface between the customer and software/hardware services. Customer's activity was investigated by participating observation and objective observation, and considering the connection of all the activities, it was divided into 9 categories and 43 items. Although the detailed activity of customer would vary per item, they show more than 430 different activities under general condition. Also, the customer's activity varies according to the numerous variants such as physical, mental, environmental and cultural features. Especially, as lots of changes, diversification and high-quality of railway industry are expected according to the middle and long term plan on railway industry development, it is necessary for experts in various fields to perform cooperative research aggressively to improve the customer satisfaction service continuously based on continuous customer activity research.

• Asia pacific journal of information systems
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• 제32권2호
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• pp.354-380
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• 2022

This study proposed a novel model to investigate influential factors affecting the intention to continue using increasingly popular food delivery apps (FDAs). The proposed theoretical model is developed and validated to extend traditional technology acceptance and adoption theories by identifying several determinant factors that capture the unique context of FDAs continuous usage. Hypotheses were tested using a partial least square structural equation modeling approach (PLS-SEM) on data collected from 331 actual FDAs users during the COVID-19 pandemic. The results reveal that convenience, perceived compatibility, delivery experience, and online reviews significantly influence the continuous usage of FDAs. The findings also confirm the importance of continuous intention on the actual use of FDAs. The research model of this study explains 65% of variance in continuous intention and 47% in actual use. The insights provided by this study suggest fruitful directions for future research. They can also help FDAs companies, developers and marketers with strategies and tips for further development and growth by ensuring users' continuous usage of these platforms.

• 한국환경농학회지
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• 제29권4호
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• pp.374-380
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• 2010

본 연구에서는 농촌진흥청에서 개발한 LED Chamber System을 이용하여 명기시간 동안 광질과 광조사 방법 제어가 단절단엽의 국화 배양소식물체(Dendranthema grandiflorum L., cv. 'Cheonsu')의 생장에 미치는 영향을 검토하였다. 실험은 청색, 적색 및 녹색의 단일광질 또는 청색+적색, 청색+녹색 및 적색+녹색의 혼합광질 조건하에서 이들 광질을 명기 16시간 동안 연속적으로 또는 초당 50회 간격과 분당 20초간격으로 간헐적으로 제어하면서 42일간 수행하였다. 총 일장을 4시간 단축한 분당 20초 간격의 간헐조사는 관행의 형광등 연속조사에 비해 국화의 절간길이 신장에 의한 신초신장을 촉진하였으나, 배양소식물체의 양적생장은 연속광 처리에 의해 유의하게 증가하였다. 한편, 명기동안 녹색광을 초당 50회 간격으로 간헐제어한 경우 연속조사에 비해 건물중이나 엽면적 증대와 같은 양적생장은 억제되었으나 형태적인 면에서의 절간신장은 촉진되었다. 따라서, LED Chamber System을 이용한 광질이나 광조사 방법의 제어는 관행의 형광등 이용 연속조사에 비해 명기시간 단축에 의한 전력소모량 감소 및 기내 배양소식물체의 생장이나 형태제어에 효과적인 배양기술로 이용 가능할 것으로 판단된다.

• 대한조선학회 특별논문집
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• 대한조선학회 2011년도 특별논문집
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• pp.101-105
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• 2011

In most shipbuilding company, cutting procedure is proceed by cutting machine which run by CNC(Computer Numerical Code) data. In our cutting process, all CNC data is created by our nesting post processor system automatically. Among them, in case that cutting piece in the remnant plate, our system creates only one piece CNC data. Because remnant plate is not typical shape, and ship designers don't know remnant plate shape and quantity. In can happen some merit and good point if we modify 1:1 piece NC data by shorten cutting path, reducing cutting time or re-arrangement piece. For modifying cutting data, outside workers have to call to ship designer or have to go to NC control room where control the CNC system and cutting machine. It makes stop work process, and it waste time. In this paper, we introduce a program that can modify and replace 1:1 NC data with continuous or common NC data automatically.

• 농촌지도와개발
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• 제28권1호
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• pp.53-68
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• 2021

This study aimis to identify policy priorities for promoting youth activities through the Importance-Performance Analysis (IPA). IPA is used to identify policy priorities for promoting local youth activities. The IPA tabulated result is presented in a two-dimensional grid to showing for promoting local youth activities, The require concentrate support part is divided into 3 parts. Problem solve supporting at work development of leisure activities programs, leisure activities programs developing and development of leisure-related professionals. And leisure-related professionals developing. The next parts that require continuous management were divided into four parts. The next parts that require continuous management is divided into four parts. Creating rental housing for young people, support for housing expenses supporting, loans supporting, and Holiday guaranteed. Based on the factors that support youth activities that make up the IPA matrix, the implications of revitalizing local youth activities is presented as below. First, ensuring employment of local youth and efforts to create sustainable jobs. Second, continuous efforts to improve the housing conditions of local youth, and third, policy support is needed for local youth to do various leisure activities.

• International Journal of Aeronautical and Space Sciences
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• 제16권2호
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• pp.148-156
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• 2015

A continuous type side jet controller which has four nozzles with thrust control devices was considered. It is deployed to a missile for high maneuverability and fast controllability in the terminal guidance phase. However, it causes more complex aerodynamic jet interactions between the side jet and the supersonic free stream than does the conventional impulse type side jet with a small single thruster. In this paper, a numerical investigation of the jet interference effects for the missile equipped with a continuous type side jet thruster is presented. A three-dimensional flow field was simulated by using a commercial unstructured-based CFD solver. The numerical simulation method was validated through comparison with wind tunnel test results for the single jet. The method of defining jet direction for this type of side jet control to minimize simulation cases was also introduced. Flow fields investigation and jet interaction effects for various flow conditions, jet pressure ratios and defined jet direction conditions were performed. From the numerical simulation for the continuous type side jet, extensive aerodynamic interference data were obtained to construct an aerodynamic coefficients database for precise missile control.

• 한국가스학회지
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• 제9권3호
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• pp.15-20
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• 2005

최근에 환경안전관리는 효과성, 효율성, 우수성이라는 측면에서 사고의 손실비용을 줄이기 위하여 다양하게 접근을 하고 있다. 대부분의 기업은 산업화시대의 대량생산적인 측면에서의 생산성향상보다는 기업을 건전하게 성장시킬 수 있는 손실을 감소시키는데 초점을 맞추고 있다. 본 연구는 석유화학산업에서 기본적으로 운영하고 있는 ISO14001, OHSAS18001, PSM, Responsible Care의 기본적인 요구사항과 지속적 발전을 위하여 요구되는 사항을 분석하여, 손실을 지속적으로 관리할 수 있는 석유화학공장에서의 지속적 발전을 위한 손실관리시스템(LCMCI; the Loss Control Management system for Continuous Improvement of the Petrochemical Industries)를 개발하였다.