• Journal of KIISE:Databases
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• v.36 no.4
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• pp.280-291
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• 2009

Skyline Query processing is important to wireless sensor applications in order to process multi-dimensional data efficiently. Most skyline researches about sensor network focus on minimizing the energy consumption due to the battery powered constraints. In order to reduce energy consumption, Filtering Method is proposed. Most existing researches have assumed a snapshot skyline query processing and do not consider continuous queries and use data generated in ancestor node. In this paper, we propose an energy efficient method called Bottom up filtering tuple selection for continuous skyline query processing. Past skyline data generated in child nodes are stored in each sensor node and is used when choosing filtering tuple. We also extend the algorithms, called Support filtering tuple(SFT) that is used when we choose the additional filtering tuple. There is a temporal correlation between previous sensing data and recent sensing data. Thus, Based on past data, we estimate current data. By considering this point, we reduce the unnecessary communication cost. The experimental results show that our method outperforms the existing methods in terms of both data reduction rate(DRR) and total communication cost.

• Journal of the Korean Society of School Health
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• v.11 no.1
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• pp.27-50
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• 1998

Adolescent health is considered to contribute to health promotion in the home and community in the near future as well as individual health. However, adolescent health has been neglected from education field because of competitive school education focused on the university entrance examination That's why I suggest in this study that we should pay much more attention to adolescent health condition and try to make It better, in terms of man-power development and life-health promotion for nation development The purposes of this study are as follows First, to look into a variety of adolescent health problems Second, to find out the situation and problems of current adolescent health promotion and school health education Third, to make an effort to find, based on the current situation, various developments of adolescent health promotion and school health education in terms of practical, political and environmental change There are used study methods as adolescent-related, school heath-related literature review and anlysis of statistical data The results and suggestions are as follows Teenagers have a great variey of health problems including most Important physical, mental and social developments Recently, chronic diseases, emotional problems, health-risk behaviors linked With adolescents are on increase The complicated disorders of physical, mental, social health rather than paricular aspects of health or health-behavior problems influence adolescent health problems adolescence is regarded as the period when most health-related behaviors are formed. Therefore, adolescent health promotion would he assured by developing the ability of controlling multi-dimensional health determinants in the early stage. Health promotion is a positive concept that each individual, family and community makes real efforts to improve their health To achive this, we need health educational, organizational, political and environmental supports. Adolescent health promotion in Korea has been systematically treated in the category of school health Current school health services have had lots of systemic, constitutional, administrative and educational flaws Accordingly, I'm concerned that we can afford to accept a variety of adolescent health needs However, I would say that if were not to make those flaws better, it's certain that Korean national competitive power and the quality of the lives of most Koreans Will he threatened someday We have to develop Comprehensive School Health Crriculum(CSHC) and set up its standards to Improve adolescent health. CSHC is an organizational and costant process. CSHC means an Important part of overall curriculums. In addition, I could say that it's an Important school health education acivity including current school health services-health care service and school health environment. In conclusion, in order to develop CSHC, we require school nurse's role changes, establishment and management of intergrated subject of health education, striking revision of school health law(or legislation of school health promotion law), reorganization of administration system, big changes in curriculum for school health educators.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1683-1688
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• 2012

Topology optimization is applied for the lightweight design of three main parts of a vertical articulated robot: a base frame, a lower and a upper frame. Design domains for optimization are set as large solid regions that completely embrace the original parts, which are discretized by using three-dimensional solid elements. Design variables are parameterized one-to-one to the material properties of each element by using the SIMP method. The objective of optimization is set as the multi-objective form combining the natural frequencies and mean compliances of a structure for which load steps of interest are selected from the multibody dynamics analysis of a robot. The obtained results of topology optimization are post-processed to designs favorable to manufacturability for casting process. The final optimized results are 11.0% (base frame), 12.0% (lower frame) and 10.0% (upper frame) lighter with similar or even higher static and dynamic stiffnesses than the original models.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.246-246
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• 2012

Smart catalyst design though novel catalyst preparation methods can improve catalytic activity of transition metals on reducible oxide supports such as titania by enhancement of metal oxide interface effects. In this work, we investigated Pt nanoparticles/titania catalysts under CO oxidation reaction by using novel preparation methods in order to enhance its catalytic activity by optimizing metal oxide interface. Arc plasma deposition (APD) and metal impregnation techniques are employed to achieve Pt metal deposition on titania supports which are prepared by multi-target sputtering and Sol-gel techniques. In order to tailor metal-support interface for catalytic CO oxidation reaction, Pt nanoparticles and thin films are deposited in varying surface coverages on sputtered titania films using APD. To assess the role of oxide support at the interface, APD-Pt is deposited on sputtered and Sol-gel prepared titania films. Lastly, characteristics of APD-Pt process are compared with Pt impregnation technique. Our results show that activity of Pt nanoparticles is improved when supported over Sol-Gel prepared titania than sputtered titania film. It is suggested that this enhanced activity can be partly ascribed to a very rough titania surface with the higher free metal surface area and higher number of sites at the interface between the metal and the support. Also, APD-Pt shows superior catalytic activity under CO oxidation as compared to Pt impregnation on sputtered titania support. XPS results show that bulk oxide is formed on Pt when deposited through impregnation and has higher proportion of oxidized Pt in the form of $Pt^{2+/4+}$ oxidation states than Pt metal. APD-Pt shows, however, mild oxidation with large proportion of active Pt metal. APD-Pt also shows trend of increasing CO oxidation activity with number of shots. The activity continues to increase with surface coverage beyond 100%, thus suggesting a very rough and porous Pt films with higher active surface metal sites due to an increased surface area available for the reactant CO and $O_2$ molecules. The results suggest a novel approach for systematic investigation into metal oxide interface by rational catalysts design which can be extended to other metal-support systems in the future.

• Management & Information Systems Review
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• v.35 no.2
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• pp.205-220
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• 2016

The purpose of this research was to figure out what impacts technology and market orientation have on technological cooperation and management performance by analyzing the factors of technological cooperation aimed at firm's product development. In addition, the research was purported to help CEO and policy makers make better decision about technological cooperation by means of the systematic examination on the impacts that different factors of technological cooperation have on the management performance. For this purpose, it was analyzed first what kind of technology or factors of market orientation might affect manufacturer's technological cooperation. From the analysis, it was found that technological cooperation is affected by the factors of market orientation, which means that a firm needs strategic technological cooperation by taking into account multi-dimensional factors of technology and market when the firm aims at developing technology and market orientation. Second, it was analyzed whether a firm's technological cooperation has an impact on its performance. The results indicated that the impact differs in the degree of process of technological cooperation, implying that managing firm's technological cooperation is important in order to improve the quality of management performance. Third, it was analyzed through what structural relations technology and market orientation could exercise impacts on management performance. It was discovered from the 1analysis that technology and market orientation have an impact on management performance. To improve management performance, it seems essential to determine the order of priority among technology and factors of market orientation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.719-727
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• 2013

Four-step travel-demand modeling based on a trip-level has been widely used over many decades. However, there has been a wide variance between forecasted- and real-travel demands, which leads less reliable on the model implications. A primary reason is that person's real travel behavior is not properly captured throughout the model developments. An activity-based modeling (ABM) approach was proposed and developed toward increasing the accuracy and reality of person's travel behavior in the U.S. since 1990', and stands as a good alternative to replace the existing trip-based approach. The paper contributes to the understanding of how the ABM approaches are dissimilar to the trip-based modeling approach in terms of estimation units, estimation process, their pros and cons and etc. We examined three activity-based travel demand model systems (DaySim, CT-Ramp, and CEMDAP) that are most commonly applied by many MPOs (Metropolitan Planning Organization). We found that the ABM approach can effectively explain multi-dimensional travel decision-makings and be expected to increase the predictive accuracy. Overall, the ABM approach can be a good substitute for the existing travel-demand methods having unreliable forecasts.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.1
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• pp.1-7
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• 2013

Structural design and analysis of a coiling arm unloading machine for submarine cable have been originally conducted in this study. Three-dimensional CAD modeling process is practically applied for the structural design in detail. Finite element method(FEM) and multi-body dynamics(MBD) analyses are also used to verify the safety and required motions of the designed coiling arm structure. The effective moving functions of the designed coiling arm with respect to rotational and radial motions are achieved by adopting bearing-roller mechanical parts and hydraulic system. Critical design loading conditions due to its self weight, carrying cables, offshore wind, and hydraulic system over operation conditions are considered for the present structural analyses. In addition, possible inclined ground conditions for the installation of the designed coiling arm are also considered to verify overturn stability. The present hydraulic type coiling arm system is originally designed and developed in this study. The developed coiling arm has been installed at a harbor, successfully tested its operational functions, and finished practical unloading mission of the submarine cable.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.80-90
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• 2002

Clustering is a useful technique for grouping data points such that points within a single group/cluster have similar characteristics. Many clustering algorithms have been developed and used in engineering applications including pattern recognition and image processing etc. Recently, it has drawn increasing attention as one of important techniques in data mining. However, clustering algorithms such as K-means and Fuzzy C-means suffer from difficulties. Those are the needs to determine the number of clusters apriori and the clustering results depending on the initial set of clusters which fails to gain desirable results. In this paper, we propose a new clustering algorithm, which solves mentioned problems. In our method we use evolutionary algorithm to solve the local optima problem that clustering converges to an undesirable state starting with an inappropriate set of clusters. We also adopt a new measure that represents how well data are clustered. The measure is determined in terms of both intra-cluster dispersion and inter-cluster separability. Using the measure, in our method the number of clusters is automatically determined as the result of optimization process. And also, we combine heuristic that is problem-specific knowledge with a evolutionary algorithm to speed evolutionary algorithm search. We have experimented our algorithm with several sets of multi-dimensional data and it has been shown that one algorithm outperforms the existing algorithms.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.265-271
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• 2006

According to globalization of world economy by extension of production, sales and distribution all around the world and international transportation system changed into a transport system that puts great importance on speediness and value-added services, international transport system is changing into a Multimodal Transport Routing centered system that systematically connects marine, air and rail transports. Due to such changes production, sales and distribution must be provided in time and Multimodal Transport Routing, which can provide multi-dimensional logistics services to customers of global network, is needed but information connection for international transport and connection system between transport modes are insufficient and can not be activated. Especially in Korea, selection standard of 3rd party logistics companies and transport companies is presented, but logistics exclusive companies, which plan and execute the transportation, can't present a systematic evaluation standard for international Multimodal Transport Routing, selection. Thus, this research surveys important previous studies about Multimodal Transport Routing, selection, derives an evaluation standard for Multimodal Transport Routing, selection through interview with company officials, and presents a theoretical basis for Multimodal Transport Routing, selection through systematic analysis of Multimodal Transport Routing, selection using Analytical Hierarchy Process (AHP).

• Information Systems Review
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• v.26 no.1
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• pp.315-335
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• 2024

This study analyzes the digital business environment in Korea and predicts the digital business trends to be noted in 2024. The study comprehensively reviews the domestic and international ICT market outlook and provides objective and in-depth analysis by compiling opinions from various experts. In particular, through a multi-dimensional approach, it derives practical trends applicable to the local business environment, provides strategic implications considering the characteristics of digital business in Korea, and suggests directions for Korean companies to adapt to the global business environment and strengthen their competitiveness. During the research process, 20 preliminary candidate trends were initially identified by collecting and analyzing reports from major domestic and international market research institutes. We then conducted in-depth interviews with 10 experts from industry and academia to select 15 shortlisted trends from these 20 trends and 10 trends selected from the previous year. Finally, we conducted a large-scale survey of 209 experts from academia and industry, and we selected 11 domestic digital business trends to focus on in 2024. This study, which presents an outlook of digital business trends suitable for the Korean business environment based on a variety of opinions scientifically gathered from Korean digital business leaders, will contribute to understanding IT trends in Korea from a business perspective and their differences from global trends.