• Journal of KIISE:Software and Applications
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• v.33 no.12
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• pp.1031-1051
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• 2006

To develop a ubiquitous system, several researches have been tried to apply multi-agent models to design a system. Even though current multi-agent models provide many benefits with ubiquitous system developments, there are still some deficiencies in completely supporting the characteristics of ubiquitous systems such as dynamic formation and termination of mission-oriented organizations and interrelationship between organizations. In addition, existing agent-based models only concern aboutananalysis and design of a system, then place a burden of implementation on developers. Therefore, in this paper, we propose the high-level abstraction model of a multi-agent based ubiquitous system and the development process concerning implementation as well as design of systems. In addition, we implemented a development toolkit, called as CDTK(Community computing system Development Tool Kit), then developed a small community computing system using the CDTK.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.293-298
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• 2009

In this contribution, a 193-bit elliptic curve cryptography coprocessor was implemented on an FPGA board. Optimized algorithms and numerical expressions which had been verified through C program simulation, should be analyzed again with HDL (hardware description language) such as Verilog, so that the verified ones could be modified to be applied directly to hardware implementation. The reason is that the characteristics of C programming language design is intrinsically different from the hardware design structure. The hardware IP which was double-checked in view of hardware structure together with algoritunic verification, was implemented on the Altera CycloneII FPGA device equipped with ARM9 microprocessor core, to a real chip prototype, using Altera embedded system development tool kit. The implemented finite field calculation IPs can be used as library modules as Elliptic Curve Cryptography finite field operations which has more than 193 bit key length.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6A
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• pp.640-647
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• 2006

This paper describes a design of AES-based CCMP(Counter mode with CBC-MAC Protocol) core for IEEE 802.11i wireless LAN security. To maximize the performance of CCMP core, two AES cores are used, one is the counter mode for data confidentiality and the other is the CBC node for authentication and data integrity. The S-box that requires the largest hardware in ARS core is implemented using composite field arithmetic, and the gate count is reduced by about 27% compared with conventional LUT(Lookup Table)-based design. The CCMP core was verified using Excalibur SoC kit, and a MPW chip is fabricated using a 0.35-um CMOS standard cell technology. The test results show that all the function of the fabricated chip works correctly. The CCMP processor has 17,000 gates, and the estimated throughput is about 353-Mbps at 116-MHz@3.3V, satisfying 54-Mbps data rate of the IEEE 802.11a and 802.11g specifications.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.138-147
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• 2018

With the recent series of damage caused by earthquakes in Korea, such as Gyeongju and Pohang, we know that Korea is no longer a safe zone for earthquakes and that we need to be prepared for them. In addition, bridges built prior to the introduction of seismic design concepts remain without adequate seismic reinforcement measures, and earthquake reinforcement should be performed efficiently considering economic and structural safety. Preliminary assessment of seismic performance of existing bridges is divided into four seismic groups, taking into account seismicity, vulnerability and Impact, considering the magnitude of the existing bridge's seismic, and prioritization for further evaluation of seismic performance. In this study, unlike the existing anti-seismic reinforcement priority method, scores are calculated based on the seismic design criteria applied to bridges, importance coefficient of the bridge including the zone coefficient and the Importance, vulnerability index of the bridge including the soil condition and the elapsed years, detail coefficient of the bridge including the superstructure form, the span length, the width, the height, the design load, and the daily traffic volume. The calculated score items will be weighted and grouped according to the results. Using this, a simpler and more efficient algorithm was proposed to determine the priority of seismic reinforcement on a bridge.

• Journal of Power Electronics
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• v.13 no.2
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• pp.275-286
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• 2013

An explicit frequency-domain circuit model for the conventional coupled magnetic resonance system (CMRS) is newly proposed in this paper. Detail circuit parameters such as the leakage inductances, magnetizing inductances, turn-ratios, internal coil resistances, and source/load resistances are explicitly included in the model. Accurate overall system efficiency, DC gain, and key design parameters are deduced from the model in closed form equations, which were not available in previous works. It has been found that the CMRS can be simply described by an equivalent voltage source, resistances, and ideal transformers when it is resonated to a specified frequency in the steady state. It has been identified that the voltage gain of the CMRS was saturated to a specific value although the source side or the load side coils were strongly coupled. The phase differences between adjacent coils were ${\pi}/2$, which should be considered for the EMF cancellations. The analysis results were verified by simulations and experiments. A detailed circuit-parameter-based model was verified by experiments for 500 kHz by using a new experimental kit with a class-E inverter. The experiments showed a transfer of 1.38 W and a 40 % coil to coil efficiency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1317-1324
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• 2017

These days, a penetration of distributed generation(DG) has increased in power system. Due to increased penetration of DG, a whole system is forced to install the maximum hosting capacity of DG. Therefore analysis between the maximum hosting capacity of DG at the target bus and the whole system is important. If we know the maximum hosting capacity, it will be able to satisfy the demand of system planner and customer. In this paper, we use a genetic algorithm to calculate the hosting capacity with optimization program using Design Analysis Kit for Optimization and Terascale Applications(DAKOTA). To consider a real system, we establish constraints and use IEEE 34 node test system. In addition, through the correlation coefficient between the target bus and the other buses, when capacity of DG at the target bus increases, we analyze which capacity of DG at the other buses will be decreased.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.40-49
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• 2009

Recently, many methodologies and development environment to shorten embedded system development time and to satisfy customer requirement were proposed. In this paper, a method to shorten development time by improving cross development environment is proposed for embedded system development, This method was designed and implemented just for the environment using virtual prototyping development tools and embedded development kit. According to implementation and result analysis, the proposed method show the better performance the than existing method in the cross development environment which is required to modify more than once.

• Journal of Distribution Science
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• v.12 no.11
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• pp.25-34
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• 2014

Purpose - Considering that the governments' official statistics on the optimum scale of the domestic service industry will be crucial in future, this study's results will be used as an important benchmark to develop and verify the parameters in the government's official statistics. Research design, data, and methodology - To identify the appropriate scale of Korea's service industry and its adequacy, I have determined them through estimation using a regression method involving panel data analysis on the panel data of 30 OECD countries. Results - The regression coefficient provided indications of being non-linear. This means that a U-shaped curve relationship exists-that is, the level of the economic growth leverage decreases along with the service industry's growth up to the level of 70.9% in terms of the Korean service industry's adequacy; it increases along with the service industry's growth at a level higher than 70.9%. Conclusions - While the current proportion of the size of the service industry among all industries in Korea stands at 50.7%, its proper proportion estimated by a regression analysis was 70.9%.

• Asian Journal of Business Environment
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• v.7 no.3
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• pp.33-43
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• 2017

Purpose - It is necessary to identify the level of marketing activities of the businesses that are recognized and carried out by the small and midsize businesses that have been supported by the government's small-business policy Research design, data, and methodology - The method of data analysis of this study was conducted by the researcher's acquaintances and center staffs who visited small business owners in a small - scale company operating a business. Results - It is found that the financial support part of the support programs for the small business owners is not related to the center affection among the support programs for the small business owners of the government. This is a fact-finding process that can be regarded as a forming process that has a significant effect on. As a result of the analysis, both marketing activity and center attachment were found to be possible parameters which have significant influence on business performance. Conclusions - Developing a variety of contact and customer management programs with small business owners in the field has enabled the government's policies to effectively penetrate the site, and these efforts eventually resulted in more business results for small business owners.

• Journal of Distribution Science
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• v.15 no.5
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• pp.5-15
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• 2017

Purpose - This research identified the factors to be considered when CEOs establish small companies and improve their businesses by analyzing the effects of their entrepreneurship and marketing activities on the business performance of small companies and suggested measures to utilize them strategically. Research design, data, and methodology - The research conducted a survey for companies located in Busan, and Gyeongnam area in Korea. To verify the model and hypothesis mentioned above, relevant items were allocated to each variable. Results - the research found that the innovation of entrepreneurship negatively affects formalization and centralization along with the propensity for risk-taking which negatively affects all the characteristics of an organization's structure. It was also found that the pro-activeness which was rejected in the selection and verification of hypothesis is the CEOs characteristics which positively affect all of the organization type are contrary to the initial hypothesis. Conclusions - The results of these efforts will positively contribute toward developing a start-up strategy helpful for small companies CEOs, to change the business environment proactively, to operate their organization efficiently and to develop market-oriented marketing activities and objectives. This research found the role of market-oriented characteristics demanded by the CEO to overcome organizational structure, business innovation and bad business situations.