• The Transactions of the Korea Information Processing Society
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• v.2 no.4
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• pp.509-523
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• 1995

With the diversified and enlarged softwares, the issue of software maintenance became more complex and difficult consequently, the cost of software maintenance took up the highest portion in the software life cycle. At the same time, in order to develop or use software for general computers the development environment will be changed to incorporate user-friendly 4GL (Fourth generation Language). Therefore, it is required to take a closer look at the languages such as COBOL, C, FORTRAN, PASCAL which have source code comprised of 4GL and investigate the method of analysis and reuse for program understanding since a lot of research has been done with these languages in program maintenance. The purpose of this paper is to propose reverse engineering tool in 4GL and find an effective way of understanding and maintaining the program by transforming source code comprised of 4GL to meta language and designing and implementing Document Generator, Report Generator, Module Generator, Code Translator for program understanding.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.815-819
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• 2018

In this study, we investigate balance of a biped robot applying Foot Placement Estimator (FPE) in simulation. FPE method is used to determine a stable foot location for balancing the biped robot when an initial orientation of the robot body is statically unstable. In this case, the 6-DOF biped robot with point foot is modelled considering contact and friction between foot and the ground. For simulation, the mass of the robot is 1 kg assuming the center of robot mass (COM) is located at the center of the robot body. The height from the ground to the COM is 1 m. Robot balance is achieved applying stable foot locations calculated from FPE method using linear and angular velocities, and the height of the COM. The initially unstable angular postures, $5^{\circ}$ and $-5^{\circ}$, of the robot body are simulated. Simulation results confirm that the FPE method provides stable balance of the robot for all given unstable initial conditions.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.2
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• pp.123-128
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• 2020

A low phase noise phase locked loop (PLL) with negative feedback loop including frequency variation sensing circuit (FVSC) has been proposed. The FVSC senses the frequency variation of voltage controlled oscillator output signal and controls the volume of electric charge in loop filter capacitance. As the output frequency of the phase locked loop increases, the FVSC reduces the loop filter capacitor charge. This causes the loop filter output voltage to decrease, resulting in a phase locked loop output frequency decrease. The added negative feedback loop improves the phase noise characteristics of the proposed phase locked loop. The size of capacitance used in FVSC is much smaller than that of loop filter capacitance resulting in no effect in the size of the proposed PLL. The proposed low phase noise PLL with FVSC is designed with a supply voltage of 1.8V in a 0.18㎛ CMOS process. Simulation results show the jitter of 273fs and the locking time of 1.5㎲.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.16-26
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• 2010

The transmission valuation methodology we propose here captures the interaction between generation and transmission investment decisions recognizing that a transmission expansion can impact the profitability of new resources investment, so that a methodology should consider both the objectives of investors in resources and the transmission planner. In this perspective, this paper purports to develop the mixed-integer programming based transmission expansion planning optimization software, which is well designed to determine the construction time and place of new generators, transmission lines, and substations as well as their capacities to minimize total expenditures related to their investment and operations while meeting technical constraints such as capacity margin, constitution ratio of power resources, spinning reserves, energy and fuel constraints, transmission line outages and losses, pi-type branching, and so on. Finally, Garver's simple system is adopted to validate not simply the accuracy but the efficiency of the proposed model in this paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1333-1337
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• 2011

3D engines loading, and expansion of the usable capacity, next-generation smartphone game markets are rising briskly by the improvement in CPU processing speed of Phones (hardware of smartphone). Therefore, in creating 3D game characters, realistic and free-form animations in a small screen of a smartphone are becoming important. Through this paper, as a method of creating characters and operating for game characters to cause user's feeling, with NURBS data of MAYA, We completed a face in turns of eyes, a nose, and a mouth, and with Polygon Cube tool, modeled hands and feet. After dividing a cube into half and modeling it, through mirror copying We completed the whole body and modeled the low-polygon. Then to model realistic and free-form characters, We completed each detail with ZBrush and applied Divide level up to 4. Though they might look rough and exaggerated, We tried to express stuck-out parts and fallen-in parts effectively and smoothly with Smooth brush effect, map and design the low-polygon 3D characters.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.380-381
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• 2011

전력거래소는 2014년 나주본사이전 이후 1억kW 대용량 전력계통을 운영하기 위한 차기 계통운영시스템(이하 차기EMS) 구축을 계획하고 있다. EMS(Energy Management System)는 전국의 발, 변전소에서 계통정보를 실시간으로 취득하여 전력계통을 감시하며, 연료비 기반의 최적 경제점을 찾아 발전기를 제어하고, 전력계통을 수식화한 상태추정 결과를 기반으로 상정사고분석, 고장전류계산 등 전력계통운영을 위한 종합시스템이다. 국내 EMS의 역사는 1979년 미국의 L&N 시스템 도입을 시작으로 1988년 일본의 Toshiba EMS, 2001년 Alstom사의 NEMS를 구축하여 현재 운영중에 있다. 하지만, 외산 제품 도입에 따른 기술이전, 유지보수의 어려움을 타개하기 위해 2004년 한국형 EMS(이하 K-EMS) 연구개발계획을 수립하고 전력거래소를 주축으로 한 산학연을 구성하여 2010년 K-EMS 개발을 성공적으로 완료하였다. 차기 EMS는 국내 기술력으로 개발된 정부연구과제 성과물인 K-EMS를 기반으로 구축이 이루어지며, 총 3년간의 개발 및 시험과정을 거쳐 실계통운영을 담당할 예정이다. 차기EMS가 설치되어 운영예정인 급전소는 전력수급 균형유지와 발전소 운영 총괄 지휘 및 765kV, 345kV 송전망 운영역할을 담당할 나주급전소와 154kV 비수도권 송전망 운영을 담당할 천안급전소, 154kV 수도권 송전망 운영을 책임질 서울급전소 이상 3곳이다. 차기EMS는 발전 및 송, 변전 설비의 대형화, 다양한 FACTS 설비, 신재생에너지원으로 대표되는 분산전원의 등장과 같은 급변하는 전력계통 변화에 능동적인 역할을 성공적으로 수행할 것으로 기대하고 있다.

• Korean Journal of Human Ecology
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• v.15 no.4
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• pp.651-658
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• 2006

This study was performed to provide the analysis on their size and the structural factors required in the process of design and manufacture of school girls' shoes. 371 elementary school girls in Kyungin and Youngnam area were participated in the size measurement. 25 foot items and 6 main body items were measured directly or indirectly using a digital photography. The results of the study are as follows: first, by most of measured items, the range of their foot size was very wide from the size of toddlers to adults'. That shows that the change of school girls' foot size occurred with their growth is pretty big. Second, from the structural factor analysis on 25 foot items, five factors were extracted such as 'the size of the foot', 'the volume of the foot,' 'the height and inclination of the foot,' 'the shape of the foot,' and 'the inside and outside inclination of the foot'. Third, from the cluster analysis, three clusters were classified: Cluster 1 was the group of 10 to 11 year old girls who had big-sized feet. The elementary school girls in the fourth to sixth grade belonged to this group. Cluster 2 consisted of girls who had small-sized and big-volumed feet. Cluster 3 had medium-sized and slim-shaped feet. Most of 6 to 7 year old elementary school girls belonged to this group. The above-mentioned results imply that many continual researches are required on children's shoe production reflecting the change of elementary school girls' feet size owing to their growth. The quantitative data on elementary school girls' feet size in this study could be used as basic information for the development of children's shoe design and its production.

• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.759-767
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• 2000

In this study, the time dependent internal stress changes of a Concrete Filled Steel Tube(CFT) column during a fire test were quantitatively analyzed. The strain ratio of a CFT column on the different loads was measured by tensile strength tests in terms of yield strength, tensile strength average extensibility and elasticity modulus. To understand the internal material properties change of concrete in CFT column damaged due to a fire, the compressive strength and elastic modulus tests were measured on a core sample from the center of the steel tube after the fire test. The elastic modulus test measured the strain from the stress. To determine the fire temperature of the test material, a differential thermal analysis was done. From the tested result, the gained data were conducted and an analysis method was suggested. The purpose of this work is to suggest a basic data for structure regulation enactments of the internal fire design of CFT.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.80-87
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• 2020

The purpose of this study was to compare in antiseptic effect between povidone-iodine and chlorhexidine-ethanol for laparoscopic cholecystectomy on the port site. A total of 46 patients admitted to surgery at one university hospital in Seoul were included in the study. A study group was randomly assigned using a random number table. The antiseptic effect was evaluated and compared to povidone-iodine and chlorhexidine-ethanol by using a culture and identification of bacteria, measurement of the number of bacteria (CFU/ml) and incidence of surgical site infection. Our results show that povidone-iodine and chlorhexidine-ethanol have no statistically significant difference in the incidence rate of bacteria after 3 minutes of disinfection and before removal of the trocar and in the number of bacteria and the incidence of surgical site infection. Thus, in order to select an efficient and appropriate skin antiseptics, we suggest that it is necessary to consider not only the disinfectant effect but also cost and convenience. In this research, our results about effect and usage of skin antiseptics can be used as basic data and educational resource, and this is expected to improve comprehension of skin antiseptics.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.121-127
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• 2020

The small tracking radar targets the target in a real-time, fast-moving, fast-moving target against aircraft with a large RCS that is maneuvering at low speed and a small RCS aircraft maneuvering at high speed (fighters, drones, helicopters, etc.) It is a pulsed radar that detects and tracks. Performing a performance test on a tracking radar in a real environment is expensive, and it is difficult to quantitatively measure performance in a real environment. Describes the composition of the laboratory environment's comprehensive performance test facility and the main requirements and implementation of each configuration.Anechoic chambers to simulate the room environment, simulation target generator to simulate the signal of the room target, target It is composed of a horn antenna driving device to simulate the movement of a vehicle and a Flight Motion Simulatior (FMS) to simulate the flight environment of a tracking radar, and each design and implementation has been described.