• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3300-3305
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• 2007

Ignition delay of second injection of HSDI diesel engine was usually much shorter than that of first injection. It is due to the interaction between radicals generated during the combustion process, and mixed gas of second injection. In this paper, To analyze combustion phenomena of multiple injection mode in HSDI diesel engine effectively, two-dimensional flamelet combustion model was modified. To reduce calculation time, two-dimensional flamelet equations were only applied near stoichiometric region. If this region was ignited, species and temperature of other region were changed to the steady-state solutions of one dimensional flamelet equations. By this method calculation time for solving flamelet equations was reduced to 20 percents, thought the results were almost same. Modified flamelet combustion model was coupled to commercial CFD code interactively using user subroutine.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.415-420
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• 1999

본 연구의 목적은 SEA모델링 기법을 이용하여 시스템 응답 특성을 예측 하는데 있어서 연견 손실 계수(coupling loss factor). 내부 손실 계수(internal loss factor)와 같은 주요 변수의 값을 압전 지능 구조물을 이용하여 도출 하는 .것이다. 관심 주파수 대역에서 임피던스(impedance) 해석기를 이용해 압전 지능 구조물의 임피던스를 측정하고 랜덤 가진 시 압전 지능 구조물의 부하전압을 측정, 시스템에 가해지는 전기적 파워를 구하였다. 이 값을 전기-기계적 연결 계수(electro-mechanical coupling coefficient)를 이용 기계적 파워로 상사 시키고 이때 시스템에 저장되는 에너지를 가속도계를 이용해 측정 하였다. 이 결과 값을 이용하여 연결 손실 계수와 내부 손실 계수를 구하여 보았다. 또한 이론식을 이용하여 얻은 이론 값과 기존의 가진기(shaker)를 이용하여 얻은 실험 값과 비교 분석 하였다.

• Journal of the Korean Geosynthetics Society
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• v.4 no.2
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• pp.19-28
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• 2005

This paper presents a laboratory investigation on the failure mechanism of geosynthetic reinforced slopes using 1/5-scale reduced model. The components of the model were selected with due consideration of the similitude law and the step-by-step actual wall construction procedure was closely simulated. The model tests successfully replicated the failure mechanism with relative density, slope and vertical spacing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.90-95
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• 2014

In order to investigate low frequency swishing noise of wind turbines, singularity in circular motion with large radius is introduced as a noise source model. By employing Lowson's acoustic analogy, simple exact solution is obtained. The solution shows that time histories of acoustic pressure at receiver points varied significantly according to receiver's directional location, even when the retarded time distributions are similar. However, the corresponding spectra of sound pressure for the receiver locations where the retarded time distributions are almost the same are not significantly different. It can be inferred from these results that the time-averaged sound pressure spectra which cannot take into account the detailed difference in the time-variation of wind turbine noise may not represent the sound quality of wind turbines due to its swishing.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1756-1762
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• 1991

본 연구에서는 막냉각되는 터빈블레이드에서의 열전달 계수를 측정하기 위하 여 열전달과 물질전달의 상사관계를 이용하였다.터빈블레이드의 선단을 다른 연구 에서와 마찬가지로 원봉으로 모사하였고, 원봉의 표면에 위치하고 있는 1열의 분사홀 로부터 제트가 분사될 때 분사홀 근처 및 그 하류에서의 물질 전달계수를 측정하기 위 해 나프탈렌승화법을 이용하였다. 분사홀 열의 위치를 정체점에서 하류방향으로 이 동시키면서, 물질전달계수의 변화를 연구하였고, 분사율(M=.rho.$_{j}$ U$_{j}$ /.rho.$_{\infty}$ U$_{\infty}$)의 영향도 고찰하였다.

• Journal of Arbitration Studies
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• v.13 no.2
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• pp.489-517
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• 2004

The resolution of the 1993 Uruguay Round and the opening of Korea's construction market in '97 marked the beginning of the globalization of Korea's domestic construction market. Consequently, the process led to changes in contracting procedures, as well as disputes in construction management. With globalization came a rapid realization of reasonable values, which forced the hierarchical vertical relationship between the owners, constructors, and subcontractors into a more equal, horizontal relationship. Once the hierarchical relationship was altered, the late 1990's witnessed a dramatic increase in managerial disagreements, in addition to escalating legal disputes and expenditures. The horizontal relationship was a new concept and brought forth many complexities. Unfortunately, because all of this was new, management of construction disputes was elementary at best. Anticipation of disputes is the key to effective dispute management. This includes thorough reviews of contract documents, document management, construction records, and checklists. Also necessary is the education of owners and contractors with pertinent knowledge concerning dispute management. The following paper focuses on the importance of observing construction disputes in order to facilitate management thereof.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2047-2054
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• 2015

The purpose of this study was to define the relationship between job stress contents and smoking habits of manufacturing male workers. The 872 male workers were observed the general characteristics, smoking habits and job stress contents from the JCQ, during the period from February 1st to April 30st, 2012, using the self-administered questionnaires. As a results, the smoking rate of study subjects was 53.0%, and in terms of smoking status by general characteristics, the smoking group was higher in the group of age, job position and job career than their respective counterparts. In terms of smoking status by job stress contents, the smoking group was higher in the group of job demand and supervisor support than their respective counterparts. Based on the results of logistic regression adjusted age, job position and job career, the odds ratio of smoking was significantly increase in the high group of job demand than that of low group, but it was significantly decrease in the low group of supervisor support than that of high group. Above results suggested that the smoking related with the job demand and the supervisor support among the job stress contents.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.199-208
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• 2007

The Employment instability of current employees should be related to uncertainty of switching job for experienced ones. Therefore, the researcher would like to look into the influence which is taken by Job Insecurity after verifying Job Instability Recognition through employees and identification of the level into Trust in organization, In particular, for the employee who is working in a catering department and expected to be ranked highly among tourist companies concerning Job Instability Recognition. According to the result of a tentative theory that Job Insecurity will effect negatively to Trust, conversely, it does not give any considerable effects both Trust in colleague and company. It just turned out that the risky factor of their dismissal could come to a substantial consequence to Trust in Superior. In this regard, a study shows that there isn't any relation to Trust in colleague even though there Is the cause of being fired. In this sense, employees can assume that a work evaluation or relationship with their superior, who work together in the field, is related to the risky factor regarding their dismissal. In other words, it turned out that there was no difference between regular employee and non-regular employee in the matter of Job-Instability-Recognition.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.2
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• pp.75-92
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• 2018

This study investigates the effects of family-friendly corporate policies on employees' job satisfaction, quality of life, organizational commitment, and turnover intention. Data was collected using a self-administered questionnaire from medium sized manufacturing company during the summer of 2017 and received 295 useful responses. The data was analyzed using the multiple and simple regressions. The results showed that the effects of family-friendly corporate policies were significantly positive from the employee's perspective. The employees' awareness of the family-friendly policy was positively correlated with their job satisfaction, quality of life, and organizational commitment, but it was negatively associated with turnover intention. It should be noted that the boss' support at work showed the insignificant effect on the family friendly policy awareness and this result was very different from the previous study. The study concludes that companies as well as employees benefit from family-friendly policies. The study that in order to create a family-friendly corporate culture, the company should not only introduce the policy to employees but also provide the support and atmosphere for the employees to utilize the family-friendly policy easily, and to establish a companywide support policy, organizational practitioners should find the way family-friendly policies to be rooted in the organization.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.12
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• pp.1108-1115
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• 2015

In this study, correlation equations were arranged about mass flow rates of oxygen and volume flow rates of helium using a mouthpiece method. The mouthpiece method can reduce examination cost by using similar empirical formula. Instead of liquid oxygen, in the mouthpiece method, gas helium can be measured in order to determine the leakage amount of liquid oxygen conveniently. Experiment was conducted and compared to understand leakage amount relation between the helium and the oxygen for prototype item under a room and a cryogenic temperature conditions. The leakage volume flow rate [$A.m{\ell}/s$] of the helium was 174 times higher than mass flow rate [g/s] of the oxygen leakage at liquid state. The derived correlation equations were verified using data from the National Institute of Standards and Technology (NIST).