• 한국조리학회지
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• 제20권5호
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• pp.101-105
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• 2014

The topics of leadership and culture have attracted substantial interest from both academics and practitioners. This study examines the effects of leadership styles and national culture on affective commitment in samples of the restaurant employees in US. In detail, this study examines how employees evaluate their leaders with different national cultures and the ways in which cultural similarity influences employees' affective commitment. The findings suggest that participative leadership style and supportive leadership style have effects on affective commitment but instrumental leadership style does not. In addition, the findings show that employees evaluate differently leaderships of their leaders with different national culture. Finally, in order to increase the employees' affective commitment, it is recommended for managers to employ supportive leadership style toward employees of different national cultures. Participative leadership style is more effective when a manager is familiar with his or her employees' national culture.

• 한국가구학회지
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• 제19권3호
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• pp.163-171
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• 2008

This Study has been conducted with many concerns about various teaching methods that attainable the substantial learning process of practical affair system in order to cope with the rapidly changing situation of the times and the educational environment in the field of design. Design Process Studying Method which utilizes 'Story Telling' as the process where the whole learning is achievable, in accordance with the educational target of the creative professional technician training that complies with the requirement of the times, and by progress of the integrated structure dividing as 1, 2, 3 stages, it doubles various studying effect, and it enables to expect the connection studying effect with other study-subject. Since the process of such program induces the positive participation of the student, it was known that a superior interchange of information is attainable, and due to its enthusiasm and interest on the study, the participating rate for study was appeared very highly.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권6호
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• pp.80-86
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• 2016

Earthquakes of M5.1, M5.8 and M4.5 occurred in September 12 and 19 respectively in Gyeongju, Gyeongbuk Province. Theses earthquakes inflated fears of people and highlighted necessity of detailed countermeasures because we have considered our country is safe to earthquakes. In the meanwhile, earthquake also impacts groundwater and thus it was recently reported that the Gyeongju Earthquakes affected groundwater there. This study evaluates daily groundwater data collected from five national groundwater monitoring stations (Geoncheon, Sannae, Oedong, Yangbuksin, Cheonbuk) in Gyeongju. The analysis revealed that only groundwater level of bedrock monitoring well hosted in andesite exhibited earthquake impact while no wells in the other four stations hosted in sedimentary rocks showed substantial responses to the earthquakes. This may be derived from the difference of seismic velocity of hosting rocks as well as epicenter distance. Special interest on groundwater monitoring is required to predict earthquakes as precursory phenomena.

• Communications for Statistical Applications and Methods
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• 제11권2호
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• pp.399-411
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• 2004

A common method of handling nonresponse in sample survey is to delete the cases, which may result in a substantial loss of cases. Thus in certain situation, it is of interest to create a complete set of sample values. In this case, a popular approach is to impute the missing values in the sample by the mean or the median of responders. The difficulty with this method which just replaces each missing value with a single imputed value is that inferences based on the completed dataset underestimate the precision of the inferential procedure. Various suggestions have been made to overcome the difficulty but they might not be appropriate for public-use files where the user has only limited information for about the reasons for nonresponse. In this note, a multiple imputation method is considered to create complete dataset which might be used for all possible inferential procedures without misleading or underestimating the precision.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.126-133
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• 2003

The aerodynamic characteristics of automobiles have received substantial interest recently. Detailed knowledge of the vehicle aerodynamics is essential to improve fuel efficiency and enhance stability at high-speed cruising. In this study, a numerical simulation has been carried out for three-dimensional turbulent flows around a commercial bus body. Also, the effect of rear-spoiler attached at rear end of bus body was investigated. The Wavier-Stokes equation is solved with SIMPLE method in general curvilinear coordinates system. RNG $k-\varepsilon$ turbulence model with the MARS scheme was used for the evaluating aerodynamic forces, velocity and pressure distribution. The results showed details of the three-dimensional wake flow in the immediate rear of bus body and the effect of rear-spoiler on the wake structure. A maximum of 14% reduction in drag coefficient was achieved for a model with a rear-spoiler.

• 한국환경보건학회지
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• 제36권3호
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• pp.171-181
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• 2010

Semivolatile aerosols exist as vapor and particles at the same time in room temperature and each phase has different intake and uptake mechanisms. This characteristic requires substantial consideration during exposure assessment of semivolatile aerosol. Some sampling methods for solid particles pose high possibility of evaporative loss during sampling. Therefore, when establishing sampling strategy for them, the factors affecting the phase distribution of semivolatile aerosol should be counted including semivolatile aerosol of interest and sampling methods used. Evaluation for phase distributions of semivolatile aerosols is also recommended. Metalworking fluids, pesticides, asphalt fumes, diesel exhaust, and environmental tobacco smoke are common health-related semivolatile aerosols in workplaces.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 춘계학술대회 논문집
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• pp.70-79
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• 1999

Importance Sampling (IS) has been applied to accelerate the occurrence of rare events. However, it has a drawback of effective biasing scheme to make the estimator from IS unbiased. Adaptive Importance Sampling (AIS) employs an estimated sampling distribution of IS to the systems of interest during the course of simulation. We propose Nonparametric Adaptive Importance Sampling (NAIS) technique which is nonparametrically modified version of AIS and test it to estimate a probability of rare event in M/M/1 queueing model. Comparing with classical Monte Carlo simulation, the computational efficiency and variance reductions gained via NAIS are substantial. A possible extension of NAIS regarding with random number generation is also discussed.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.141-144
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• 2004

Nowadays, there has been substantial interest in whether there is an association between electromagnetic field exposure and living environment. It is increased the demand that electromagnetic wave environment and its countermeasure. In the present study, we has applied the electromagnetic absorbent inorganic paint of 'I' corporations, and measured electromagnetic waves generated in new apartment before occupancy using the standard field electromagnetic wave generating device we developed. The measurement before occupancy was $100\~131V/m$, but the measurement after occupancy was $6.9\~8.0V/m$ less than 10V/m, the comprehensive electromagnetic wave limit allowed by TCO in Sweden. The implication is that domestic apartment are exposed to extremely poor electromagnetic wave environment. Nevertheless, there have been neither serious efforts to overcome this problem, nor its alternatives and related standards. Therefore, it is necessary to continue research of related fields to establish standards and plans to improve the situation.

• 한국시뮬레이션학회논문지
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• 제8권3호
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• pp.77-89
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• 1999

Simulating rare events, such as probability of cell loss in ATM networks, machine failure in highly reliable systems, requires huge simulation efforts due to the low chance of occurrence. Importance Sampling (IS) has been applied to accelerate the occurrence of rare events. However, it has a drawback of effective biasing scheme to make the estimator of IS unbiased. Adaptive Importance Sampling (AIS) employs an estimated sampling distribution of IS to the system of interest during the course of simulation. We propose Nonparametric Adaptive Importance Sampling (NAIS) technique which is nonparametrical version of AIS. We test NAIS to estimate a probability of rare event in M/M/1 queueing model. Comparing with classical Monte Carlo simulation, the computational efficiency and variance reductions gained via NAIS are substantial. A possible extension of NAIS regarding with random number generation is also discussed.

• 전자통신동향분석
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• 제33권6호
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• pp.139-153
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• 2018

The explosive interest in block chain, which was triggered by Bitcoin in 2009, is leading to substantial investment and the development of block chain technology. There is no dispute among experts that block chain will be the next generation of innovation. However, despite the high expectations for block chains, the related technology still has certain limitations. In addition to improving issues such as a low transaction throughput, inefficient agreement algorithms, and an inflexible governance structure, it is necessary to solve various problems for commercialization and full-scale spreading owing to the trilemma problem among the scalability, security, and decentralization. Under this situation, identification of the technology characteristics according to the generation is helpful for the development of the core technology requirements and commercialization blueprint in establishing an R&D direction. Therefore, in this article, the development of blockchain technology is divided into generations and analyzed in terms of the operational structure, consensus algorithm, governance, scalability, and security.