• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.687-692
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• 2016

When turbochargers are applied to engines, the temperature of the engine becomes high, making the cooling of pistons very important. To solve this problem, an oil jet is used. The oil jet provides oil to the underside of piston for cooling. When an oil jet is used, oil pump size-up and oil cooler are needed because of the increased oil flow rate and higher oil temperature. On the other hand, these increase the friction torque of the engine. This study examined how much the friction torque of an engine increases by an oil jet, oil cooler, and oil pump size-up. In addition, the proportions of the friction torque of the engine increased by each part were measured by changing the engine assembly condition. At low speed, the oil pump and oil cooler had a larger effect on the friction torque than the other factors. At high speed, oil cooler had a larger effect than the other factors.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1989.11a
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• pp.16-40
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• 1989

엔진오일 첨가제는 오일 전체의 성질에 영향을 주는 것과 윤활 부품의 표명 성질에 영향을 미치는 것으로 크게 구분할 수 있다. 표면 작용용 첨가제 들의 상호작용은 기대이하의 성능을 발휘하는 경우가 있고 그 원인은 첨가제의 상호작용에 의한 것으로 볼 수 있으므로 가능한 범위내에서 실험적으로 살펴보기로 한다. 현대자동차의 엔진과 변속기에 요구되는 윤활유 성능 특성을 만족시키기 위해서는 기유에 요구되는 적당한 성능을 발휘하기 위한 특수한 첨가제를 넣어주어야만 한다. 그러나 첨가제를 개발하는 과정에서 한가지 첨가제의 특성은 그 자체를 실험한 경우와 매우 상이한 결과가 완전히 혼합된 오일에서 나타남을 경험하게 된다. 이것은 첨가제들 자체의 상호작용에 의한 원인으로 암시되지만 이들에 관련된 연구나 지식은 상당히 제한되어 있다. 따라서 첨가제으 상호작용에 관한 실례를 찾아보고 관련자료를 검토해 보는 것은 의미있는 일이라 생각된다. 윤활오일 첨가제가 오일 자체의 성질에 영향을 주는 것으로 점도 시수향상제, 산화 방지제 같은 것이 있고 마찰 표면 특성에 영향을 미치는 내마모성 첨가제, 극압첨가제, 청정제, 분산제, 마찰 계수 감소제 등으로 크게 구분된다. 오일자체에 영향을 미치는 첨가제는 서로 별개로 작용하지만 그래도 상호 반응을 할 수 있다. 예를 들면 자유기 억제제와 과산화물 분해형식의 산화억제제의 혼합물은 산화억제 성능을 최대화 시켜준다.

• Tribology and Lubricants
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• v.6 no.1
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• pp.24-35
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• 1990

엔진 오일 첨가제는 오일 전체의 성질에 영향을 주는 것과 윤활 부품의 표면성질에 영향을 미치는 것으로 구분할 수 있다. 표면 작용용 첨가제들의 상호작용은 기대 이하의 성능을 발휘하는 경우가 있고, 그 원인은 첨가제의 상호작용에 의한 것으로 볼 수 있으므로 가능한 범위내에서 실험적으로 살펴보기로 한다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.105-116
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• 2019

Oil adsorption during hair or body washing is responsible for the hair conditioning. In this study, we established a method to extract oil from a substrate, and to determine amount of adsorbed oil upon substrate using a conventional absorption spectroscopy. We controlled the mole fraction of a surfactant in a mixture of anionic and amphoteric surfactants because that it induces the coacervate that regulates amount of adsorbed oil through the alteration of oil viscosity. Based on this, we established the optimized condition for adsorption and extraction for oil. UV absorbance were employed to estimate the amount of adsorbed oil using optical absorbance after extraction via adsorption. The estimation was confirmed by comparing with a mass analysis in HPLC and an adhesive energy in AFM. It has been proved that this method can be applied to all cases of oil adsorption from the results with various cationic polymers and a complex system of the polymers which regulate the oil adsorption.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.527-530
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• 2011

최근 저출산 고령화 등의 사회문제와 글로벌 환경문제가 심각하게 대두됨에 따라 스마트워크와 모바일 오피스 등 새로운 개념의 근무형태에 대한 중요성과 관심이 커지고 있다. 하지만 이러한 중요성에도 불구하고 대부분의 기존 연구는 스마트워크 또는 모바일 오피스의 도입 효과에 대해서만 논하고 있으며 실질적인 활용과 업무 만족도 향상 등 활성화를 위한 구체적인 방안에 관한 연구는 미비하다. 따라서 본 연구는 모바일 오피스 활성화를 위해 필요한 조직적 측면의 지원에 대해 분석하고자 한다. 이를 위해 모바일 오피스 사용자 172명을 대상으로 설문을 실시하여 조직에서 제공하는 물리적, 금전적, 업무적 차원의 지원이 모바일 오피스에 대한 사용자들의 인식과 활용, 그리고 만족감에 미치는 영향을 실증적으로 분석하였다. 분석 결과 조직지원은 시스템품질이나 정보품질과 같이 사용자들이 모바일 오피스에 대해 인식하는 품질을 통해 모바일 오피스 활용 및 만족도에 유의한 영향을 미치는 것으로 나타났다. 이러한 연구 결과는 모바일 오피스 활성화를 위한 구체적인 민관의 지원방안과 시사점을 제공했다는 점에서 의의가 있으며, 모바일 오피스 관련 정책 및 전략 수립의 가이드라인으로 작용할 것이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.644-654
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• 2013

It is required for enterprises to construct the proper information management system in order to cope with the volatile business situations. The mobile office system is introduced from the needs to provide organization members smart information and mobility. By setting the model, hence, we intend to scrutinize the impact of the task-technology fit model and organizational characteristics of the mobile office system on the job performance. As a result, system quality, information quality and mobility are revealed to affect positively the task-technology fitness and the fitness also affects the job performance positively. Organization characteristics affects the job performance positively through the task-technology fitness, too. Therefore the organization which plans to introduce the mobile office system should consider the task-technology fitness and exert organizational-level efforts to adopt and use the mobile office system in the workplace.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.29-38
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• 2008

In Seoul, the volume of office market has been expanding rapidly and the currency will be maintained. Many researches have looked at determinants of the office rent, we still cannot have adequate and accurate information of the impacts of traffic congestions around office buildings on the office rents. To gauge the effect of traffic conditions surrounding an office building on the office rent, a hedonic price model was estimated. The regression analysis estimates the values or implicit prices of the individual rent determinants; these parameters in turn allow for a detailed examination of the variables that impact office rents. The result shows that traffic conditions of office buildings play an important role in determining the office rental rate. Since a number of adjacent streets provided excellent opportunities to connect with the neighborhood, it pulls up the rental rate. Similarly, traffic congestions depreciates the value of an office buildings restricting the accessibility to the office building. We also provide evidence of the existence of spatial submarkets and find that market takes different spatial forms depending on the local context.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.4
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• pp.18-25
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• 1991

디젤엔진에서 윤활오일의 소모량이 점진적으로 증가하는 것은 비정상적인 시린더 마모 때문이다. 시린더 라이너의 작동기구를 L-link 피스톤운동 측정장치로 조사하여 피스톤 top-land의 탄소분 축적이 비정상시린더 마모의 주요 원인임이 증명되었다. 또 피스톤 top-land의 축소는 마모 방지의 유용한 방법인 것으로 이론과 실제에서 입증되었다. 오일 소모와 시린더 마모에 영향을 미치는 다른 요소들에 관해서도 살펴보았다.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.159-174
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• 2017

The long-term imbalances between supply and demand in office market can weaken urban growth since excessive supply of offices led to office market instability and excessive demand of offices weakens growth of urban industry. Recently, there have been a lot of new large-scale supplies, which increased volatility in Seoul office market. Nevertheless, new supply of Seoul office has not been fully examined. Given this, the focus of this article was on confirming the influences of profitability, replacement cost, and demand on new office supplies in Seoul. In examining those influences, another focus was on their relative influences over time. For these purposes, we analyzed quarterly data of Seoul office market between 2003 and 2015 using a vector error correction model (VECM). As a result, in terms of the influences on the current new supply, the impact of supply before the first quarter was negative, while that of office employment before the first quarter was positive. Also, that of interest rate before the second quarter was positive, while those of cap rate before the first quarter and cap rate before the second quarter were negative. Based on the findings, it is suggested that prediction models on Seoul offices need to be developed considering the influences of profitability, replacement cost, and demand on new office supplies in Seoul.

• Economic and Environmental Geology
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• v.47 no.3
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• pp.247-254
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• 2014

The compressibility of fracture in naturally fractured reservoir is larger than the compressibility of matrix in rock, although the compressibility of a typical rock is very small. The effective compressibility including the fracture compressibility should be considered to predict oil recovery correctly. It is hard to quantify changes of fracture aperture and pore volume in reservoir without the effective compressibility. In this study, oil recovery is analyzed by commercial simulator concerning the fracture compressibility based on fracture properties. We found that the effective compressibility affects oil recovery with change of polymer flooding factors such as polymer molar weight, concentration and injection rate. The estimated cumulative oil production is smaller with the effective compressibility than without it. Also, bottomhole pressure decreases rapidly without considering effective fracture compressibility.