• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2113-2120
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• 2011

In this paper, so as to improve spectral efficiency for cell-boundary users, we introduce a coordinated multi-point (CoMP) system, which is one of inter-cell cooperative transmission strategies studied in 3GPP long-term evolution-advanced (LTE-A) systems, and develop a system-level simulator to evaluate performance. To identify performance improvement of the system with inter-cell cooperative transmission, we select a 3GPP LTE system as a reference, which shows the highest performance among the existing mobile communication systems, and conduct a performance comparison. System-level simulation is performed based on widely-used OPNET tool. We implement modules including central unit (CU), CoMP eNodeB (CeNB), user equipment (UE), and multiple-input multiple-output (MIMO) channel model, while designing the inter-cell cooperative transmission system. Under WINNER wireless channel model and international telecommunication union (ITU) network model environments, we then evaluate the performance of edge users who belong to the lower 5% in terms of spectral efficiency. It is finally shown that throughput of the proposed CoMP system gets improved up to 2.5 times compared to that of the 3GPP LTE reference system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.611-616
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• 2018

With the recent increase in awareness of the diversification of patterns of warfare and security, technological evolution is occurring in the field of autonomous defense robots. As defense science and technology develops with the development of the concept of military utilization focusing on human lives and economic operation, the importance of autonomous robots in the effect-oriented future battlefield is increasing. The major developed countries have developed core technologies, investment strategies, priorities, data securing strategies and infrastructure development related to the field of autonomous defense robots, and research activities such as technology planning and policy strategy for autonomous defense robots in Korea have already begun. In addition, the field of autonomous defense robots encompasses technologies that represent the fourth industrial revolution, such as artificial intelligence, big data, and virtual reality, and so the expectations for this future area of technology are very high. It is difficult to predict the path of technological development due to the increase in the demand for new rather than existing technology. Moreover, the selection and concentration of strategic R&D is required due to resource constraints. It is thought that a preemptive response is needed. This study attempts to derive 6 new technologies that will shape the future of autonomous defense robots and to obtain meaningful results through an empirical study.

• Journal of the Korean Home Economics Association
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• v.17 no.4
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• pp.117-127
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• 1979

This study attempts to shed additional light on the national diffusion process and interaction of welfare services for children and mothers. The central hypothesis examined is the following : In general, the implant of social welfare system is first considered on the characteristics of their own socio-economics , and diffusion prodess of welfare services tends to occur faster in countries with open sicieties than in countries where entry barriers are high and society ranking rigid. The scope of the study is limited in several ways. Attention is concentrated on the agency of woman in the belief that an in-depth case study of one field can yield more insight than a less detailed investigation embracing a number of social welfare systems. The angency of woman is selected for several reasons. a) It is important the agency of woman alone produce more effective than services affecting both the child welfare and women's libertion bradually. Moreover, these services will form the heart of mother's welfare. b) The services of women's agency is gradually wide spread, since a role of government is still negligible before a full realization of economic income. c) The services of women agency is a prime example of a social welfare. d) statistical data and other information are more readily available. One of major findings of our study is the existence of the barriers inhibiting child welfare form " motherhood cult". Despite all the distinct advantages for mother and child , social attitudes appear to be some resistant on child welfare system among men and women even the agenices of women. What is surprised is the extent of the awareness that strategies of women's agency to liberate woman and to increate activities of women involve the strategies to liberate child. The conviction that solving application problems for child welfare in line with the activities of agency by women offer greater freedom and more advantage to mother are not apparent on the data collected from 18 of multi-functional agencies in our country. there are little sign that such agencies cooperate toward attainment of common goals. The intensive early focus of the movement on consciousness raising is a necessary beginning and such efforts by women's organizations would help both in the continuous evolution of women and child. Some of the agencies offer a variety of services to women and children, others are specialized in that they offer fewer services or even only one. Social welfare agenices giving service to children and their families are identified by various names usually women service and child welfare from govern , mental agency and voluntary public agency to foreign aided. What is totally missing , however, is an integrated synthesis of child welfare program Through women's agency. Social changes to occur, but delineation of appropriate and comprehensive social policy is also necessary at this point at this point since efforts, social changes and polices must be well coordianted and focused, as well as mutually supprotive and reinforcing.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.253-261
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• 2004

Game theory is mathematical analysis developed to study involved in making decisions. In 1928, Von Neumann proved that every two-person, zero-sum game with finitely many pure strategies for each player is deterministic. As well, in the early 50's, Nash presented another concept as the basis for a generalization of Von Neumann's theorem. Another central achievement of game theory is the introduction of evolutionary game theory, by which agents can play optimal strategies in the absence of rationality. Not the rationality but through the process of Darwinian selection, a population of agents can evolve to an Evolutionary Stable Strategy (ESS) introduced by Maynard Smith. Keeping pace with these game theoretical studies, the first computer simulation of co-evolution was tried out by Hillis in 1991. Moreover, Kauffman proposed NK model to analyze co-evolutionary dynamics between different species. He showed how co-evolutionary phenomenon reaches static states and that these states are Nash equilibrium or ESS introduced in game theory. Since the studies about co-evolutionary phenomenon were started, however many other researchers have developed co-evolutionary algorithms, in this paper we propose Game theory based Co-Evolutionary Algorithm (GCEA) and confirm that this algorithm can be a solution of evolutionary problems by searching the ESS.To evaluate newly designed GCEA approach, we solve several test Multi-objective Optimization Problems (MOPs). From the results of these evaluations, we confirm that evolutionary game can be embodied by co-evolutionary algorithm and analyze optimization performance of GCEA by comparing experimental results using GCEA with the results using other evolutionary optimization algorithms.

• Journal of Korea Port Economic Association
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• v.28 no.1
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• pp.159-178
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• 2012

Recently, Global network expansion strategy of GTOs(Global Terminal Operator) coupled with each country's port policy, plays huge role for the evolution of modern container port. The Chinese ports can be regarded as the major markets to the GTOs. However, there are scant of researches for finding the key success factors of GTOs' strategies when they consider to invest in overseas. In this respect, the aims of this study were to draw out the evaluation variables for successful investment strategies of GTOs, and to calculate the selected target ports. The 14 variables are selected including the variable named 'development potentiality of a port' through literature reviews. Using the Factor Analysis (FA) based on selected variables, four principal factors were extracted such as 'ability for port operating and cargo generating', 'the trade route and volume', 'the calling potentiality for large vessels' and 'the possibility of utilization of existing infrastructure'. In addition, the weights of factors and variables are evaluated through Fuzzy AHP method. As a result, 'ability for port operating and cargo generating' is chosen as the most important factor among principal factors as scored 0.343, and 'the development potentiality of a port' (0.107) is represented as the most important variable among 14 detailed variables. In overall, from the Global Terminal Operator's point of view, Shanghai is ranked as most suitable port for operating new terminal among the top 5 Chinese ports.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.143-154
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• 2022

Plant secondary metabolites play an important role in insect-plant interactions. Herbivorous insects have various strategies to cope with the plant defensive compounds. Polyphagous insects feed on a wide variety of plant species, and their detoxification mechanisms are more complex since they tend to respond to a large array of different plant-derived chemicals. Alternatively, oligophagous insects specialize on only a few related plant species and may be expected to have a more efficient form of adaptation. This adaptation could involve either the production of large quantities of enzymes to detoxify their defensive compounds or the sequestration of the compounds or their metabolites. The oriental tobacco budworm, Helicoverpa assulta, is a specialist herbivore, feeding on a few plants of Solanaceae, such as tobacco and hot pepper. Understanding its host-plant adaptation not provides an important insight on physiology, ecology and evolution of specialist herbivores, but also gives a clue to develop management strategies of the pest species such as H. assulta. This paper briefly reviews the specialist, H. assulta, focusing on its host range, larval associations with the host plants, and detoxification mechanisms to nicotine and capsaicin, two characteristic defensive compounds derived from its two major host plants, tobacco and hot pepper, respectively. It summarizes the relevant research over the last half century and provides a future perspective on this subject.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.440-440
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• 2012

Nanomaterials have emerged as new building blocks to construct light energy harvesting assemblies. Size dependent properties provide the basis for developing new and effective systems with semiconductor nanoparticles, quantized charging effects in metal nanoparticle or their combinations in 2 and 3 dimensions for expanding the possibility of developing new strategies for photovoltaic system. As top-down approach, we developed a simple and effective method for the large scale formation of self-assembled Cu(In,Ga)$Se_2$ (CIGS) nanostructures by ion beam irradiation. The compositional changes and morphological evolution were observed as a function of the irradiation time. As the ion irradiation time increased, the nano-dots were transformed into a nano-ridge structure due to the difference in the sputtering yields and diffusion rates of each element and the competition between sputtering and diffusion processes during irradiation. As bottom-up approach, we developed the growth of CIGS nanowires using thermal-chemical vapor deposition (CVD) method. Vapor-phase synthesis is probably the most extensively explored approach to the formation of 1D nanostructures such as whiskers, nanorods, and nanowires. However, unlike binary or ternary chalcogenides, the synthesis of quaternary CIGS nanostructures is challenging because of the difficulty in controlling the stoichiometry and phase structure. We introduced a method for synthesis of the single crystalline CIGS nanowires in the form of chalcopyrite using thermal-CVD without catalyst. It was confirmed that the CIGS nanowires are epitaxially grown on a sapphire substrate, having a length ranged from 3 to 100 micrometers and a diameter from 30 to 500 nm.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.97-104
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• 2018

Regarding seaport operation, a higher quality performance and increasing competitiveness are main goals to adapt to the evolution of international trade. This paper discusses about the competition among Southern Vietnam seaports concerning the strategic positioning analysis, by applying BCG method. This technique describes the performance of business based on two variables such as relative market share and average growth rate. The finding shows up different performances of 21 seaports and how the strategic positioning of each port changes in the period 2007-2016. After analyzing, this research pointed out the growth in strategic positioning of ports in Cai Mep-Thi Vai complex, gradually replacing Ho Chi Minh City-Dong Nai-Binh Duong and becoming the transportation hub of Southern Vietnam. Also, The results obtained would be helpful for port administrators and operators to establish short and long-term strategies to improve competitiveness in the future.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.96-96
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• 2016

Nanotechnology mostly employs nano-materials and nano-structures with distinctive properties based on their size, structure, and composition. It is quite difficult to produce nano-materials and nano-structures with identical sizes, structures, and compositions in large quantities, because of spatiotemporal fluctuation of production processes. In other words, fluctuation is the bottleneck in nanotechnology. We propose three strategies to suppress such fluctuations: employing 1) difference between linear and nonlinear phenomena, 2) difference in time constants, and 3) nucleation as a bottleneck phenomenon. We are also developing nano- and micro-scale guided assembly using plasmas as a plasma nanofabrication.1-5) We manipulate nano- and micro-objects using electrostatic, electromagnetic, ion drag, neutral drag, and optical forces. The accuracy of positioning the objects depends on fluctuation of position and energy of an object in plasmas. Here we evaluate such fluctuations and discuss the mechanism behind them. We conducted in-situ evaluation of local plasma potential fluctuation using tracking analysis of fine particles (=objects) in plasmas. Experiments were carried out with a radio frequency low-pressure plasma reactor, where we set two quartz windows at the top and bottom of the reactor. Ar plasmas were generated at 200 Pa by applying 13.56MHz, 450V peak-to-peak voltage. The injected fine particles were monodisperse methyl methacrylate-polymer spheres of $10{\mu}m$ in diameter. Fine particles were injected into the reactor and were suspended around the plasma/sheath boundary near the powered electrode. We observed binary collision of fine particles with a high-speed camera. The frame rate was 1000-10000 fps. Time evolution of their distance from the center of mass was measured by tracking analysis of the two particles. Kinetic energy during the collision was obtained from the result. Potential energy formed between the two particles was deduced by assuming the potential energy plus the kinetic energy is constant. The interaction potential is fluctuated during the collision. Maximum amplitude of the fluctuation is 25eV, and the average is 8eV. The fluctuation can be caused by neutral molecule collisions, ion collisions, and fluctuation of electrostatic force. Among theses possible causes, fluctuation of electrostatic force may be main one, because the fine particle has a large negative charge of -17000e and the corresponding electrostatic force is large compared to other forces.

• Journal of Cadastre & Land InformatiX
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• v.44 no.1
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• pp.1-15
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• 2014

This paper, at first, intends to develop a conceptual model of spatial information eco-system based on the related literature reviews. The basic requirements in constructing the model are also specified. Next, the functional roles and interrelationships among the actors constituting the eco-system are analyzed to investigate the major reasons of inefficient and unsmooth flows of value-added process of Korean spatial information industry. Especially, the Korea Cadastral Survery Corp.(KCSC), which has dual organizational characteristics of public and private entity, is analyzed to be positioned as the most dominant actors in the eco-system. However, the KCSC needs to be changed and challenged to re-establish the missions and institutional roles for upcoming network societies. Here, we proposed 4 future-oriented development strategies and action plans to promote the Korean spatial information industry and to activate the eco-system.