• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.310-318
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• 2015

In this paper, dual-port eFuse OTP (one-time programmable) memory cells with smaller cell sizes are used, a single VREF (reference voltage) is used in the designed eFuse OTP IP (intellectual property), and a BL (bit-line) sensing circuit using a S/A (sense amplifier) based D F/F is proposed. With this proposed sensing technique, the read current can be reduced to 3.887mA from 6.399mA. In addition, the sensing resistances of a programmed eFuse cell in the program-verify-read and read mode are also reduced to $9k{\Omega}$ and $5k{\Omega}$ due to the analog sensing. The layout size of the designed 32-bit eFuse OTP memory is $187.845{\mu}m{\times}113.180{\mu}m$ ($=0.0213{\mu}m2$), which is confirmed to be a small-area implementation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.56-61
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• 2011

The deign and lay-out of a combustion chamber test facility(CTF), a turbopump real propellant test facility(TPTF), a rocket engine test facility for 3rd stage engine(SReTF), a rocket engine ground/high altitude test facility(ReTF, HAReTF) and a propulsion system test complex(PSTC) for KSLV-II is briefly described. The development/qualification tests of engine component, 3rd stage engine system and 75ton-class liquid rocket engine system will be performed in CTF, TPTF, SReTF, ReTF and HAReTF and the development test of 1st/2nd/3rd propulsion systems for KSLV-II will be performed in PSTC. These propulsion test facilities will be built in NARO space center considering construction schedule, cost, safety distance and utility factor of propulsion test facilities.

• Journal of the Korean Society of Costume
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• v.57 no.6 s.115
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• pp.17-31
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• 2007

Fashion of one period is symbolic and figurative means of expression reflecting spirit, ideology, emotion and aesthetic values of that period. Designs of school uniforms fer girls also went through changes in various shapes along with changes in sociocultural and philosophical backgrounds in each period. Thus, in this study, in examining girls' school uniforms, how girls' school uniforms have evolved with what kind of design characteristics was observed along with process of historical changes, and investigation was made on realistic conditions of girls school uniforms since 1996 when active advancements in school uniform design were started. Also, through examination of girls' school uniform designs from homepage of large student uniform companies and catalogues, characteristics of girls' school uniforms after 1996 were observed. On the result, we could know that girl's school uniforms from 1996 to 2006 were designed in various forms compared to those of the past time and changing Arends of the era were reflected on the school uniform designs. Narrow waistline, shorter blouse, changes in the length of jacket and skirt showed that current school uniform designs pursue the fashionable and trendy designs unlike those of the past times that were uniform and strict. This study include organizing characteristics of girls' school uniform designs by each period, providing fundamental and realistic data for clothes manufacturing and marketing activities through analysis on designs of girls' school uniforms since 1996, and providing directions for future school uniform designs.

• The KSFM Journal of Fluid Machinery
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• v.18 no.2
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• pp.14-21
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• 2015

Design lifetime of a wind turbine is required to be at least 20 years. The most important step to ensure the deign is to evaluate the loads on the wind turbine as accurately as possible. In this study, extreme design load of a offshore wind turbine using Garrad Hassan (GH) Bladed and National Renewable Energy Laboratory (NREL) FAST codes are calculated considering structural dynamic loads. These wind turbine aeroelastic analysis codes are high efficiency for the rapid numerical analysis scheme. But, these codes are mainly based on the mathematical and semi-empirical theories such as unsteady blade element momentum (UBEM) theory, generalized dynamic wake (GDW), dynamic inflow model, dynamic stall model, and tower influence model. Thus, advanced CFD-dynamic coupling method is also applied to conduct cross verification with FAST and GH Bladed codes. If the unsteady characteristics of wind condition are strong, such as extreme design wind condition, it is possible to occur the error in analysis results. The NREL 5 MW offshore wind turbine model as a benchmark case is practically considered for the comparison of calculated designed loads. Computational analyses for typical design load conditions such as normal turbulence model (NTM), normal wind profile (NWP), extreme operation gust (EOG), and extreme direction change (EDC) have been conducted and those results are quantitatively compared with each other. It is importantly shown that there are somewhat differences as maximum amount of 18% among numerical tools depending on the design load cases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1749-1754
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• 2007

In this paper, we propose a new Intra-body communication system for bio-sensor which is one of applications in PAN(Personal Area Network) using body channel. The communication systems for bio-sensor network usually transmits a lot of data acquired in sensor to the receiver in wrist or waist. So we deign the intra-body modem with high data rate, low power, and small size which are achieved by baseband communication techniques. It is noted that the baseband transmission does not requires any analog IF and RF frontends, and can be operated in lower frequency than bandpass transmission. The proposed modem operates at 10MHz band according to the characteristics of intra-body channel, and shows the capability of 5Mbps data rate at distance of 20cm, with $BER=10^{-5}$. In addition, we implement the modem within $2{\times}2cm$ area.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.139-142
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• 2012

The deign and development status of a combustion chamber test facility(CTF), a turbopump real propellant test facility(TPTF), a rocket engine test facility for 3rd stage engine(SReTF), a rocket engine ground/high altitude test facility(ReTF, HAReTF) and a propulsion system test complex(PSTC) for KSLV-II is briefly described. The development/qualification tests of engine component, 3rd stage engine system and 75ton-class liquid rocket engine system will be performed in CTF, TPTF, SReTF, ReTF and HAReTF and the development test of $1^{st}/2^{nd}/3^{rd}$ propulsion systems for KSLV-II will be performed in PSTC. The CTF/TPTF are under construction such as ordering the long delivery items and the detailed design of ReTF/PSTC is being prepared.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.7
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• pp.539-547
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• 2021

Helicopter rotor blade is required to be designed by considering the interacting effects among aerodynamics, flexibility, and controllability. The reverse design allows the structural components to have common characteristics by using the configuration numerics and experimental results. This paper aims to design the composite rotor blade which will feature common characteristics with that of BO-105. The present engineering design procedure is done by dividing the rotor blade into a few sections and composite laminates across the cross section. For each section, variational asymptotic beam sectional analysis (VABS) program is used to evaluate its flapwise, lagwise, and torsion stiffnesses to have discrepancy smaller than certain tolerance. Finally, CAMRAD II is used to predict the stress acting on the rotor blade during the specific flight condition and to check whether the present deign is structurally valid.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1022-1027
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• 2003

The Motion controllers provide the sophisticated performance and enhanced capabilities we can see in the movements of robotic systems. Several types of motion controllers are available, some based on the kind of overall control system in use. PLC (Programmable Logic Controller)-based motion controllers still predominate. The many peoples use MCU (Micro Controller Unit)-based board level motion controllers and will continue to in the near-term future. These motion controllers control a variety motor system like robotic systems. Generally, They consist of large and complex circuits. PLC-based motion controller consists of high performance PLC, development tool, and application specific software. It can be cause to generate several problems that are large size and space, much cabling, and additional high coasts. MCU-based motion controller consists of memories like ROM and RAM, I/O interface ports, and decoder in order to operate MCU. Additionally, it needs DPRAM to communicate with host PC, counter to get position information of motor by using encoder signal, additional circuits to control servo, and application specific software to generate a various velocity profiles. It can be causes to generate several problems that are overall system complexity, large size and space, much cabling, large power consumption and additional high costs. Also, it needs much times to calculate velocity profile because of generating by software method and don't generate various velocity profiles like arbitrary velocity profile. Therefore, It is hard to generate expected various velocity profiles. And further, to embed real-time OS (Operating System) is considered for more reliable motion control. In this paper, the structure of chip-based precision motion controller is proposed to solve above-mentioned problems of control systems. This proposed motion controller is designed with a FPGA (Field Programmable Gate Arrays) by using the VHDL (Very high speed integrated circuit Hardware Description Language) and Handel-C that is program language for deign hardware. This motion controller consists of Velocity Profile Generator (VPG) part to generate expected various velocity profiles, PCI Interface part to communicate with host PC, Feedback Counter part to get position information by using encoder signal, Clock Generator to generate expected various clock signal, Controller part to control position of motor with generated velocity profile and position information, and Data Converter part to convert and transmit compatible data to D/A converter.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.283-294
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• 1996

To operate the automatic devices of manufacturing process more effectively and to solve the needs of the resource sharing, network technology is applied to the unit control devices located in common manufacturing zone and operated by connecting them. This paper introduces deign and test operation of cell system for the management of multivendor PLC by applying to wall paper process based on the manufacturing standardization of CIM. The analysis of designed multivendor PLC group is performed by selecting the parameters such as variation of data packet size and node number of PLC ladder logic program and variation by analyzing the corresponding variation values of token rotation time and waiting time for the system operation. For the method of the analysis,the equation is considering the overhead such as indicated packet service time and transmission safety margin for PLC network connection in M/G/1 queue model,and it is applied to the cell system and PLC group manage-ment for operation .Through the experiment,it is found that the realtime processing is possible with expanded and better result than the resuit obtained by Jayasumana.Browaka with PLC scan time considered,response lower limit of 10-20 msec. data packet size not more than 50 bytes.and the number of nodes less than 40.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.2
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• pp.217-225
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• 2010

Most of the steel bridges in Korea are being currently designed by the allowable stress design method that uses the conventional deterministic factors of safety. However the limit state design based on the concept of probability, statistics and reliability engineering is becoming very popular as a global standard deign method, leading the rational and economic bridge design. As part of the fundamental research to establish the load and resistance factor design(LRFD) of steel bridges considering domestic environmental conditions and regional characteristics, an experimental design is conducted by applying AASHTO-LRFD specification especially to a steel closed-box girder, which occupies relatively a large portion of steel bridges in Korea. Throughout the experimental design according to various sectional changes, some of the issues to be considered in the LRFD design of a composite steel closed-box girder bridge are examined. In this process, an Excel-based design verification program is developed for easy computation and prevention of errors. Quantitative reliability levels of the bridge sections designed by LRFD are also estimated using a reliability analysis method, and compared with the target reliability indexes applied in the LRFD design to verify the validity of the procedure and methodology used in this study.