• Proceedings of the KSR Conference
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• 1998.11a
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• pp.413-420
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• 1998

In this study, optimum design methodology for rail vehicle suspension characteristics is suggested. Three parameters, primary lateral/longitunal stiffness and secondary lateral stiffness, are selected as design parameters. critical speed, suspension stroke trade-off and derailment coefficient are selectee as performance constraints. The optimum parameters to maximize ride quality are evaluated under the constraints. Steady-state curiving model to be able to evaluate derailment coefficient is developed. The combined design procedure is developed to evaluate Three parameters at the same time.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.133-140
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• 2013

The purpose of this study is identifying the relationship among the business strategy, order receiving capability and leverage variables of a construction company using industry characteristic variables, in addition to the explanation variables used in the previous studies. The samples of this study were limited to the construction companies listed in Korean stock market. This study built multiple regression analysis models, which have been frequently used in traditional previous studies, in the explanation of company capital structure. Empirical analysis on Static Trade-off Theory and Pecking Order Theory was done by the built model. The study results suggested that the capital structure determination behavior of a construction company generally follows Static Trade-off Theory; however, profitability was found to follow Pecking Order Theory. The explanation variables used in the previous capital structure studies mostly produced significant results; however, the variables, which this study experimentally used, did not produce significant results. It is believed that it implies that additional studies are required in the selection of variables and study methodology. Consequently, a case that unconditionally supports a particular theory is scarce. It has been also found that a case can support both theories at the same time. Therefore, it is believed that development study methodology or introduction of new study methodology that can identify the dynamic characteristic of construction company capital structure formation is required.

• The Journal of Fisheries Business Administration
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• v.48 no.3
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• pp.61-74
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• 2017

This study is aimed to analyze the change of chinese fishing vessels' entry into the East Sea off North Korea and suggest directions for countermeasures. Based on the real landing data in China, Chinese fishing vessels' squid catch volume and value in the East Sea off North Korea are estimated. Results show that at least 205 thousand tons of squid was caught by Chinese fishing vessels in 2014. If the catch amount is calculated by the unit price per kilogram at the same year in Korea, it would be 556.3 billion KRW. As the UN sanctions become stricter with the recent resolution 2371 passed, Chinese fishing vessels' entry may increase in the future to compensate decreased seafood supply from North Korea. Even though there are not many options left for Korea to decrease the impact of Chinese depletive fishing, the study suggests countermeasures such as strengthening cooperative crack down on the Chinese illegal fishing vessels in Korean waters; increasing cooperation with UN member countries to incorporate banning the trade of fishing rights in the next UN sanctions; establishing regional fisheries management organization and managing migratory species with China and Japan cooperatively in the long term.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.15-27
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• 2007

Over the past decade, labor costs have increased relative to the cost of material hardware according to analysts in the construction industry. Therefore, the minimum weight design, which has been widely adopted in the literature for the optimal design of steel structures, is no longer the most economical construction approach. Presently, although connection- related costs is crucial in determining the most cost-effective steel structures, most studies on this subject focused on minimum-weight design or engaged in higher analysis. Therefore, in this study, we proposed a fabrication scheme for the most cost-effective moment-resisting steel frame structures that resist lateral loads without compromising overall stability. The proposed approach considers the cost of steel products, fabrication, and connections within the design process. The optimal design considered construction realities, with the optimal trade-off between the number of moment connections and total cost was achieved by reducing the number of moment connections and rearranging them using the combination of analysis that includes shear, displacement and interaction value based on the LRFD code and optimization scheme based on genetic algorithms. In this study, we have shown the applicability and efficiency in the examples that considered actual loading conditions.

• Health Policy and Management
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• v.17 no.4
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• pp.113-133
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• 2007

The present study was conducted to measure health-related utility for post-menopausal symptoms among Korean woman. A survey questionnaire was developed to measure utility based on visual analogue scale(VAS) and time trade-off method (TTO). From January 29 to February 3, 2007, a face-to-face interview was conducted with 274 women aged 45 to 60 to ask about their subjective utility for hypothetical health status of mild or severe post-menopausal symptoms. Among the participants, 160 were recruited from outpatient departments of 3 hospitals and 114 from 2 sports centers located in Seoul. For mild symptom, the average utility score of the respondents was $0.63{\pm}0.14$ based on VAS and $0.61{\pm}0.26$ based on ITO. For severe symptoms, the average utility was $0.39{\pm}0.16$(VAS) and $0.44{\pm}0.27$ (TTO). For severe symptom, a higher utility score was observed for TTO than for VAS, which is consistent with earlier studies and thus supports the validity of the utility measurement in this study. Overall, the severity of post-menopausal symptoms of the respondents themselves was not significantly associated with the utility score that the respondents answered for hypothetical health status. Multiple regression analysis results showed that the utility score was significantly higher among respondents with older age, higher education, higher family income, and from hospitals. It is expected that the utility score measured in this study will enhance the understanding of the quality of life of women after menopause and will be used to conduct cost-utility analysis of health care interventions to treat post-menopausal symptoms.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.716-717
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• 2015

A construction temporary work is main process and importance trade section. A technology system of construction temporary has very low availability of field works and needs improvements in Korea as construction site has a quick response about new requirements. This study reviews literature researches and can verify that changes to a comprehensive technology system for construction site. In addition, it suggests a breakdown structure of new standards for temporary construction technology based on views of construction site managers. Meanwhile, temporary construction technology in Korea has changed with a specification of construction temporary work which had been revised in 2014. However, the revision is merely dividing the design and building off of construction temporary technology. It is lacking in many ways to change this in a new standard system for temporary construction technology. Henceforth, it needs to develop a standard system for temporary construction technology and a professional system that is appropriate for different purposes by detail trade sections.

• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.2
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• pp.59-65
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• 1988

This paper discusses the problem of coordinating aggregate planning and production schedules, minimizing the combined set-up inventory and capacity costs. In this study, by using the relation of fixed production quantity and the number of set-up we develop a heuristirc procedure of solving the discrete demand, fixed production quantity, variable capacity problem. First, we obtain the trade-off between set-up cost and capacity cost, then search the point minimizing the combined inventory and capacity costs.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.201-204
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• 2006

In this paper, we propose efficient scheduling strategy for Multi-user MIMO systems that find advantageous trade off solution between multiuser diversity and spatial diversity, spatial multiplexing technique. Specifically, we suggest P-SFS(Pseudo-SNR Fair scheduling) algorithm that consider throughput and fairness problem. also we propose channel aware Antenna deployment that decide how to use assigned multiple antennas by the information of each user's channel condition.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.179-182
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• 2012

Effect of double post injections on diesel PCCI combustion with focus on HC emission was investigated in a single-cylinder direct-injection diesel engine. The ISFC, HC and CO emissions were reduced by single or double post injections. The application of double post injections could also improve the trade-off relationship between NOx and HC emissions under wide EGR rate range.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.943-946
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• 1999

In this paper, we present a new clock routing algorithm which minimizes total wirelength under any given path-length skew bound. The algorithm onstructs a bounded-skew tree(BST) in two steps:(ⅰ) a bottom-up phase to construct a binary tree of shortest-distance feasible regions which represent the loci of possible placements of clock entry points, and (ⅱ) a top-down phase to determine the exact locations of clock entry points. Experimental results show that our clock routing algorithm, named BST/DME, can produce a set of solutions with skew and wirelength trade-off.