• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1193-1203
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• 2016

This paper proposes a droop control scheme to compensate the unbalanced line-to-line voltage of unbalanced 3-phase load which is coupled with two inverter-based distributed generations through unequal impedance lines. Unbalanced line-to-line load voltages occur due to using single-phase loads, which brings about bad effects on the coupled inverters and the distributed generations. In order to compensate the unbalanced line-to-line voltages, a positive sequence voltage control was used for sharing the active and reactive power and a negative sequence control was used for reducing the negative sequence voltage. The feasibility of the proposed scheme was first verified by computer simulations, and then experiments with a hardware set-up built in the lab. The experimental results were compared with the simulation results to confirm the feasibility of the proposed scheme.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.7
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• pp.1187-1192
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• 2008

This paper proposes a fast motion estimation using an adaptive search region and a new three step search. The proposed method improved in the quality of motion compensation image as $0.43dB{\sim}2.19dB$, according as it predict motion of current block from motion vector of neigher blocks, and adaptively set up search region using predicted motion information. We show that the proposed method applied a new three step search pattern is able to fast motion estimation, according as it reduce computational complexity per blocks as $1.3%{\sim}1.9%$ than conventional method.

• The Korean Society of Law and Medicine
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• v.13 no.2
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• pp.179-214
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• 2012

There are two opinions on the legal characteristics of damages for non-pecuniary loss, a private sanctions theory and complementary function of damages for non-pecuniary loss, briefly. There is a close connection between the legal characteristics and the function of damages for non-pecuniary loss. The functions of damages for non-pecuniary loss are consist of satisfaction, prevention( sanctions) and complementation. Several cases of medical injury relief reported to Korea Comsumer Agency are categorized as follows, 1) cases of death after having an operation, 2) diagnosed with disability after a medical accident, 3) extended damages happening related to delayed diagnosis, 4) et cetera(a plastic surgery, a treatment with oriental medicine), and the damages for non-pecuniary loss in respect to each cases are examined. In the case of occurring death or disability, Korea Comsumer Agency has set up guidelines for assessment of damages for non-pecuniary loss by classifying into major and collateral violation for a duty of care. Furthermore, the damages for non-pecuniary loss in the case of all sorts of cancers, are assessed in accordance with the degree of responsibility subsequent to dividing cancer into good and poor prognosis. When it comes to a complementary function of damages for non-pecuniary loss in the actual work, it is hard to assess the damages as it is difficult to objectify non-pecuniary loss, such as emotional distress. Though compensation for damages is major legal characteristics of consolation money, preventing a damage(private sanctions) through consolation for a victim or sanctions against an assailant also has great significance. Therefore, it is necessary to approach flexibly for mutual agreement by considering specialty( concrete facts) of individual issue thoroughly. If considering this aging society that limits the possible age for work to 60 years old, it is needed to have a complementary function of consolation money in mind not to make it less meaningful for victims due to small sum of consolation money.

• Journal of IKEEE
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• v.24 no.1
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• pp.319-325
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• 2020

In this paper, a discontinuous-conduction mode (DCM) DC-DC buck converter is presented for mobile device applications. The buck converter consists of compensator for stable operations, pulse-width modulation (PWM) logic, and power switches. In order to achieve small hardware form-factor, the number of off-chip components should be kept to be minimum, which can be realized with simple and efficient frequency compensation and digital soft start-up circuits. Burst-mode operation is included for preventing the efficiency from degrading under very light load condition. The DCM DC-DC buck converter is fabricated with 0.18-um BCDMOS process. Programmable output with external resistors is typically set to be 1.8V for the input voltage between 2.8 and 5.0V. With a switching frequency of 1MHz, measured maximum efficiency is 92.6% for a load current of 100mA.

• Journal of Environmental Policy
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• v.7 no.3
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• pp.89-120
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• 2008

With petroleum being a major source of energy in Korea, the quantity of petroleum transported via ocean routes is on its way up due to increased consumption. Due to the increase, more than 300 cases of pollution caused by petroleum occur annually. Moreover, the number of oil-spill accidents is also on the rise. Causes of such accidents, not including the disposal of waste oil on purpose, turn out to be human error during navigation or defects in the vessels, showing that most accidents are caused by humans. Therefore, to prevent future oil spills, it is imperative that navigation efficiency be enhanced by improving the quality of navigators and replacing old vessels with newer ones. Nevertheless, such improvements cannot occur overnight, so long- and mid-term efforts should be made to achieve it institutionally. As large-scale oil-spill accidents can happen at anytime along the coastal waters of Korea, it is necessary to set-up institutional devices which go beyond the compensation limit of 92FC. The current special law regarding this issue has its limits in that it prescribes compensation be supplemented solely by national taxes. Therefore, the setting-up of a new 'national fund' is recommended for consideration rather than to subscribe to the '2003 Convention for the Supplementary Fund'. It is strongly suggested that a National fund be created from fees collected from oil companies based on the risks involved in oil transportation and according to the profiteers pay principle. In addition, a public fund should be created to handle general environmental damage, such as the large-scale destruction of the ecosystem, which is distinct from the economic damage that harms the local people. The posterior responses to the large-scale oil spill have always been unsatisfactory because of the symbolic nature of the disasters included in such accidents. Oil-spills can be prevented in advance, because they are caused by human beings. But once they occur, they inflict long-term damage to both human life and the natural ecosystem. Therefore, the best response to future oil-spills is to work to prevent them.

• KIEAE Journal
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• v.12 no.4
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• pp.59-69
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• 2012

In order to create humanitarian living environment with sustainable ecological environment, urban regeneration project has been implemented recently seeking diverse methods for residents'participation stressing the process of communication with the residents changing from the existing one way planning by limited number of experts. Particularly, it is essential to develop systematic tools to promote the voluntary and positive participation of the residents because residents have to perform as the master of urban streetscape design project that requires sophisticated knowledge and experience and also because the residents have to function as sustainable maintainers and managers of their streetscape. This study intends to identify the organizational structure and major contents of design guideline as a tool to support the voluntary and positive participation of the residents in streetscape maintenance. For this purpose based on the structural system and characteristics of Chicago streetscape design guideline that was developed as tool for residents' participation, efforts were made to set up framework of design guideline for sustainable streetscape project with the users' participation with their overall understanding and trust. In detail, the author studied the resident participatory process for sustainable maintenance and management in a long term landscape project and the principle and theories of design planning for streetscape that supports the utilizing behaviors of the users, and how this information should be linked and organized to form the structure and contents of design guideline. As a tool supporting residents' participation and helping the residents perform the responsible function as sustainable maintainers and managers of their streetscape through social maturity with ontological sense of masters of their local community as they experience the gradual processes of their streetscape maintenance project, streetscape design guideline has its meaning in the efforts that tried to achieve deep participation of the residents through researches converging the two academic sectors of urban architecture and social psychology.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.11
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• pp.12-18
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• 1998

In non-geostationary orbit(NGSO) satellite communication links, satellite's elevation angle at terminal is changed continuously because of the satellite movement relative to earth surface. Therefore the characteristics of the fade-effected signal received by a terminal from a NGSO satellite is also varied continuously even if the terminal is operated at fixed location. In this paper, we determine a general statistic model for the fading characteristics over NGSO satellite communication links and set up the parameters of the fading model in terms of the elevation angle according to various propagation environment and find the parameter values using the data of fading margin for commercial NGSO mobile satellite communication systems. And the fading charateristics for each environment are analyzed using this model. These results can be applied to develop the compensation algorithm and to analyze the performance of the transmission schemes for NGSO mobile satellite communication systems.

• Journal of IKEEE
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• v.22 no.1
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• pp.174-179
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• 2018

In this paper, design of high-efficiency DC-DC converter is presented for low-power PMIC (power management integrated circuit). As PMIC technologies for IoT and wearable devices have been continuously improved, high-efficiency energy harvesting schemes should be essential. Since the supply voltage resulting from energy harvesting is low and widely variable, design techniques to achieve high efficiency over a wide input voltage range are required. To obtain a constant switching frequency for wide input voltage range, frequency compensation circuit using supply-voltage variation sensing circuit is included. In order to obtain high efficiency performance at very low-power condition, accurate burst-mode control circuit was adopted to control switching operations. In the proposed DC-DC buck converter, output voltage is set to be 0.9V at the input voltage of 0.95~3.3V and maximum measured efficiency is up to 78% for the load current of 180uA.

• Journal of the Korea Concrete Institute
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• v.27 no.5
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• pp.551-558
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• 2015

Lateral displacement in the most complex-shaped tall buildings is caused by eccentric gravity loads which are induced by the difference in location between a center of mass and a center of stiffness. The lateral displacements obtained from analysis, using conventional procedures, are prone to overestimate the actual values because much of realignment efforts made during construction phase are ignored. In construction sequence analysis, the self-leveling of slab and the verticality of columns/walls could be considered at each construction stage. Moreover, the displacement compensation can be achieved by manual process such as re-centering - locating to global coordinates through surveying. Because the lateral displacement increases with the building height, it is necessary to set up adjustment plan through construction stage analysis in advance in order to result in displacements less than the allowable limits. Because analytical solution includes lots of assumptions, the pre-adjusting displacement should be reasonably controlled with considerations for the uncertainty due to these assumptions.

• Information Systems Review
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• v.9 no.1
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• pp.259-282
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• 2007

This paper provides a case for the comprehensive performance management system in Public Procurement Service. Public Procurement Service set up the BSC system at the beginning of 2006 by improving and complementing the earliest performance management system and made it possible to automatically connet the performance measurement and evaluation of the departmental and person by using CSF and KPI, which result from their mission and strategic assignments. Therefore, the public service of the adminstration is able to offer better customer service, as the private corporations do, apply the incentive and disincentive policies to the personnel and reward administration and contribute to changing the administration into an organization of competition and performance compensation. The application of the BSC system enables the strengthening of the individual evaluation system in the departmental, integration of various evaluations into one, and the establishment of a monitering system of achievement rate in the objective management in the periodic results. Such a case study of Public Procurement Service will determine the course of establishment of the BSC in other public institutions and suggest many successful methods and ideas for the performance management system.