• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.7-19
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• 2005

Mode choice Analysis is essential analysis stage in transportation demand forecasting process. Therefore, methods for calibration and forecasting of mode choice model in aspect of practical view need to be discussed in depth. Since 1980s, choice models, especially Logit model, are spread widely and rapidly over academic area, research institutes and consulting firms in Korea like other developed countries in the world. However, the process of calibration and parameter estimation for practical application was not clearly explained in previous papers and reports. This study tried to explain clearly the calibration process of mode choice step by step and suggested a forecasting mode choice model that can be applicable in real policy analysis by using household survey data of Pusan metropolitan are. The study also suggested a way of estimating attributes which was not observed during the household survey commonly such as travel time and cost of unchosen alternative modes. The study summarized the statistical results of model specification for four different Logit models as a process to upgrade model capability of explanation for real traveler's choice behaviors. By using the analysis results, it also calculated the value of travel time and compared them with the values of other previous studies to test reliability of the estimated model.

• Journal of Technology Innovation
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• v.19 no.2
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• pp.99-128
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• 2011

University-to-industry technology transfer has become an increasingly important issue in recent years. Studies on technology transfer and commercialization evolved to diverse knowledge transfer channels. Among them, university spin-off is not only known as the most direct and tangible method but also suitable for effectively transferring tacit knowledge. Much of the studies on university spin-offs are mostly focused on macro-level but studies using the individual professors as their unit of analysis need better understanding as well. This paper investigates why the speed of university spin-off formations differ among individual professors drawing on the resource-based view. Utilizing data of 149 professors in 25 universities who formed spin-offs, Cox regression results suggest that professors' technological research capabilities, academic research capabilities and financial resources promote university spin-off formations.

• Journal of Korea Water Resources Association
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• v.48 no.12
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• pp.1051-1064
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• 2015

Currently, the H purification plant determines the hourly water intake amount based on operator experience and skill. Therefore, inevitably, there are deviations among operators. While meeting time-varying demand and maintaining the proper water level in the clean water reservoir, the methodology for minimizing electricity cost, when dealing with different electricity rate time zones, is a very complicated problem, which is beyond an operator's capability. To solve this problem, a linear programming (LP) model is proposed, which can determine the optimal hourly water intake amount for minimizing the daily electricity cost. It is shown that an inaccurate estimate for the hourly water usage in the demand areas causes the water level constraint to be violated, which is the weak point of the proposed LP method. However, several examples with real-field data show that we can practically and safely solve this problem with safety margins. It is also shown that the safety margin method still works effectively whether the estimate is accurate or not. The operators need not attend the site at all times under the proposed LP method, and we can additionally expect reductions in labor costs.

• Journal of Korea Water Resources Association
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• v.34 no.4
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• pp.347-356
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• 2001

Even though the increase of greenhouse gases such as $CO_2$ is thought to be the main cause for global warming, its impact on global climate has not been revealed clearly in rather quantitative manners. However, researches using Genral Circulation Model(GCM) has shown that the accumulation of greenhouse gases increases the global mean temperature, which in turn impacts on the global water circulation pattern. A climate predictive capability is limited by lack of understanding of the different process governing the climate and hydrologic systems. The prediction of the complex responses of the fully coupled climate and hydrologic systems can be achieved only through development of models that adequately describe the relevant process at a wide range of spatial and temporal scales. These models must ultimately couple the atmospheres, oceans, and lad and will involve many submodels that properly represent the individual processes at work within the coupled components of systems. So far, there are no climate and related hydrologic models except local rainfall-runoff models in Korea. The purpose of this research is to predict the change of temperature in Korean Peninsula using regional scale model(IRSHAM96 model) and GCM data obtained from the increasing scenarios of $CO_2$ Korean Peninsula increased by $2.5^{\circ}C$ and the duration of Winter in $lxCO_2$ condition would be shorter the $2xCo_2$ condition due to global warming.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.611-625
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• 2007

The purpose of this study was to analyze dental hygienists' opinions on health promotion projects in public health and their needs for specialized education in the projects, so that it could help prepare specialized education program required for health promotion projects in the future. To meet the goals, total 364 dental hygienists working in public health were asked to join a questionnaire survey via e-mail in September 2007 for data analysis. As a result, this analysis came to the following conclusions: First, it was found that 29.9% of total respondents took in charge of health promotion projects, and 26.9% respondents considered it very necessary to be responsible for the health promotion projects(56.0% considered it necessary). Almost half respondents considered nonsmoking assistance most desirable task(48.4%) and foremost demanded(50.5%) out of all current health promotion projects, 39.8% respondents answered that they could carry on health promotion task, if assigned, after completing occupational training course. Second, it was found that 39.3% respondents acquired other licenses and qualifications than certificate of registered dental hygienist, and their medical licenses or qualifications included certificate of nursing assistant(18.7%) and certificate of social worker(11.8%) by category. Third, in terms of opinions on possible ways to facilitate health promotion projects, it was found that over half respondents considered it recommended to step up specialized education(56.9%) and prepare legal basis and administrative system(53.6%). Notably, 90.7% respondents considered it necessary to step up specialized education in health promotion. Fourth, in terms of opinions on participation in health promotion projects, it was found that almost half respondents(49.7%) considered it necessary and very positive for extending dental hygienists' works in the future. Moreover, in terms of reasons for sum positive answers, it was found that many respondents considered it helpful for appointment(41.8%) and contributing to capability development and job satisfaction(44.5%). In terms of opinions that sud, participation would be unnecessary, 29.7% respondents thought that nothing would be changed in their dental health projects even with reduced number of public health dentists, and 31.3% respondents thought that dental hygienists are professional manpower responsible only for dental health works. Finally, in terms of on-the-job training(OJT) related to health promotion, it was found that 92.9% respondents desired for OJT. In terms of experiences in OJT, 79.9% respondents answered that they never joined OJT course. In other words, only 20.1% respondents joined OJT courses for health promotion task, such as nonsmoking assistance(8.8%), health promotion FMTP training(2.2%), exercises(1.4%) and nutrition(0.6%).

• Journal of Science Education
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• v.36 no.1
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• pp.94-105
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• 2012

The purposes of this study is to identify the professional knowledge of the three elementary teachers for science-gifted students in teaching method. All teachers have received in-service program in gifted education, and have been recommended by their colleagues. Two teachers have instructed the gifted for more than five years, one teacher have instructed the gifted for one year and the general students for eleven years. For for this study, each teacher's lesson plans were collected, videotapes were recorded during lessons, and in-depth interview for each participant were conducted. All recoded data were transcribed and analyzed. Some unique characteristics of teaching method for the gifted were identified from the class instruction of participants. They had knowledge of teaching model for the gifted, especially Renzulli's three pod enrichment model. And they mainly used the materials developed by KEDI for the gifted. Also they had capability to be able to reconstruct them, but their lesson plans did not be realized well in their class. Some implications from findings of this study were suggested, such as teaching methods to improve the quality in the classes of the gifted in science.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.133-141
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• 2009

The main objective of water distribution system is to supply enough water to users with proper pressure. Hydraulic analysis of water distribution system can be divided into Demand Driven Analysis (DDA) and Pressure Driven Analysis (PDA). Demand-driven analysis can give unrealistic results such as negative pressures in nodes due to the assumption that nodal demands are always satisfied. Pressure-driven analysis which is often used as an alternative requires a Head-Outflow Relationship (HOR) to estimate the amount of possible water supply at a certain level of pressure. However, the lack of data causes difficulty to develop the relationship. In this study, effective supply, which is the possible amount of supply while meeting the pressure requirement in nodes, is proposed to estimate the serviceability and user's convenience of the network. The effective supply is used to calculate Subsystem Importance Index (SII) which indicates the effect of isolating a subsystem on the entire network. Harmony Search, a stochastic search algorithm, is linked with EPANET to maximize the effective supply. The proposed approach is applied in example networks to evaluate the capability of the network when a subsystem is isolated, which can also be utilized to prioritize the rehabilitation order or evaluate reliability of the network.

• Development and Reproduction
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• v.3 no.1
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• pp.45-51
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• 1999

It is crucial to remove trophectoderm (TE) cells of blastocysts for an efficient isolation of pluripotent embryonic stem (ES)-like cells from bovine blastocysts. We evaluated the effectiveness of chemosurgery using calcium ionophore A23l87 (CIPA) by investigating the viability and pluripotency of ES-like cell lines isolated from in vitro-produced bovine blastocysts after CIPA treatment. The blastocysts treated with 50 $\mu$M CIPA for 25 min colonized most efficiently (51% of blastocysts) and developed to ES-like cell lines through 10 passages (4.8% of blastocysts) among CIPA-treated groups with different concentration and duration. In comparison with CIPA-untreated blastocysts, the colonization rate and overall viability of the CIPA-treated blastocysts were five times higher, suggesting that CIPA treatment condition defined in this study was highly efficient for establishing ES-like cell lines without apparent toxicity of CIPA. We evaluated in vitro pluripotency of the established three ES-like cell lines by examining alkaline phosphatase (AP) activity, capability of embryoid body formation, and chromosomal euploidity of the cells. Our cells showed a heterogeneous AP activity similarly to other reports. The cells were able to form simple embryoid bodies during suspension culture and majority of them showed a normal chromosome number of 60, the euploid chromosomal complement of bovine Therefore, our data suggest that CIPA treatment can be safely used for an efficient isolation of ES-like cell lines from bovine blastocysts.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.107-117
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• 2017

Since South Korea started to apply Renewable Portfolio Standard (RPS) in 2012, there have been huge investment for deploying renewable technologies. Recently, the government determined to incentivize battery energy storage system(BESS) with renewable generations in order to induce the improvement of dispatching capability. In this paper, the annual pattern of PV generation based on actual generation data in South Korea is analyzed and the duration curve of capacity factor is proposed in order to provide the simplified analyzing methodology of present support policy for additional BESS installation for decision maker who is responsible for supply and demand planning. With suggested methodology, the range of appropriate BESS size with respect to the variation of system marginal price(SMP) and renewable energy certificate(REC) price can be derived briefly, and decision makers easily evaluate the effect of support scheme. Current policy for BESS installation support present additional BESS-related installation policy may give incentives to developers partially, however, the dependence between BESS size and benefit components (SMP and REC) can limit the deployment of the various portfolios of the BESS. Therefore, when improving the current policy in future, addressing the dependence between the technical aspects of battery size and the benefit components separately by the technical and economical parts is needed to set the suitable compensation rules for the renewable generation and BESS.

• Journal of Engineering Education Research
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• v.5 no.1
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• pp.34-49
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• 2002

The School of Electrical Engineering and School of Civil, Urban, and Geosystem Engineering of Seoul National University (SNU) have conducted alumni surveys to evaluate the importance and preparedness of the engineering outcomes that are demanded in the industry and to feedback the survey results to the establishment of educational objectives and student capability and the revision of curricula. In this paper, first we analyzed the collected data to see the distributions of the respondents in terms of graduation year, profession, final degree, and so on. Second we evaluated the importance and preparedness of the engineering outcomes and compared them with those obtained at the Department of Mechanical and Aerospace Engineering of UCLA. The above-mentioned three groups gave very similar evaluation of the importance of each item of engineering outcomes, showing that the industry-demanding engineering outcomes are very similar regardless of country or major. Investigating the difference between the importance and preparedness, SNU showed relatively low preparedness compared to UCLA, meaning that SNU is somewhat behind UCLA in engineering education. On the other hand, all the three groups showed considerably poor preparedness in the abilities to function on multi-disciplinary teams and to communicate effectively, indicating that is needed education to strengthen these abilities.