• 교육녹색환경연구
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• 제8권2호
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• pp.12-21
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• 2009

The purpose of this study is to suggest a scheme to provide children safer and more comfortable walking circumstances by survey current walking circumstances of school zone ways. First, to avoid pedestrian roads being interrupted and to expand waiting space near school zone ways, several measures are needed including fixing roads, using schools' unemployed spaces and building additional gateway. Second, pedestrian crossings in front of school gate should be located at least 23.16m away from the left side of the gate. Third, on narrow path which cross main streets, the interval of pedestrian signal should be extended as against of the moment. And traffic calming facilities should be built on accurate position. Fourth, to secure pedestrians' safety and field of view, trees lining streets and any obstacles located within 10m from bus stop sign should be removed. Finally, education system about school zone ways should be improved to help children get used to more complicated roads' conditions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.543-544
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• 2006

Pentacene thin film transistors fabricated without photolithographic patterning were fabricated on the plastic substrates. Both the organic/inorganic thin films and metallic electrode were patterned by shifting the position of the shadow mask which accompanies the substrate throughout the deposition process. By using an optically transparent zirconium oxide ($ZrO_2$) as a gate insulator and octadecyltrimethoxysilane (OTMS) as an organic molecule for self-assembled monolayer (SAM) to increase the adhesion between the plastic substrate and gate insulator and the mobility with surface treatment, high-performance transistor with field effect mobility $.66\;cm^2$/V s and $I_{on}/I_{off}$>$10^5$ was formed on the plastic substrate. This technique will be applicable to all structure deposited at low temperature and suitable for an easy process for flexible display.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.505-506
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• 2006

This study is focused on the manufacturing technique of powder injection molding of watch case made from zirconia powder. A series of computer simulation processes were applied to the prediction of the flow pattern in the inside of the mould and defects as weld-line. The material properties of melted feedstock, including the PVT graph and thermal viscosity flowage properties were measured to obtain the input data to be used in a computer simulation. Also, a molding experiment was conducted and the results of the experiment showed a good agreement with the simulation results for flow pattern and weld line location. On the other hand, gravity and inertia effects have an influence on the velocity of the melt front because of the high density of ceramic powder particles during powder injection molding in comparison with polymer's injection molding process. In the experiment, the position of the melt front was compared with the upper gate and lower gate positions. The gravity and inertia effect could be confirmed in the experimental results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권11호
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• pp.3145-3162
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• 2023

As an important technology of the internetwork, wireless sensor network technique plays an important role in indoor localization. Non-line-of-sight (NLOS) problem has a large effect on indoor location accuracy. A location algorithm based on improved particle filter and directional probabilistic data association (IPF-DPDA) for WSN is proposed to solve NLOS issue in this paper. Firstly, the improved particle filter is proposed to reduce error of measuring distance. Then the hypothesis test is used to detect whether measurements are in LOS situations or NLOS situations for N different groups. When there are measurements in the validation gate, the corresponding association probabilities are applied to weight retained position estimate to gain final location estimation. We have improved the traditional data association and added directional information on the original basis. If the validation gate has no measured value, we make use of the Kalman prediction value to renew. Finally, simulation and experimental results show that compared with existing methods, the IPF-DPDA performance better.

• 소성∙가공
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• 제6권6호
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• pp.489-499
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• 1997

The injection molding process is analyzed to get the information on the mold design parameters and the optimum process conditions for automotive plastic front fender. The gate position, runner size and cooling channel are determined by the estimation of the flow balance, packing time, uniform cooling and shrinkage and warpage in the injection molding analyses. The procedure can be used in the mold design in the early stage when developing plastic parts.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1332-1341
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• 2023

Beam position measurement system can not only provide the beam position monitoring, but also be used for global orbit correction to reduce beam loss risk and maximize acceptance. The Beam Position Monitors (BPM) are installed along the synchrotron to acquire beam position with the front-end electronics and data acquisition system (DAQ). To realize high precision orbit measurement in the main heavy ion synchrotron and cooling storage ring of heavy-ion research facility in Lanzhou (HIRFL-CSRm), a series of alignment and calibration work has been implemented on the BPM and its DAQ system. This paper analyzed the tests performed in the laboratory as well as with beam based on the developed algorithms and hardware. Several filtering algorithms were designed and implemented on the acquired BPM raw data, then the beam position and resolution were calculated and analyzed. The results show that the position precision was significantly improved from more than 100 ㎛ to about 50 ㎛ by implementing the new designed filtering algorithm. According to the analyzation of the measurement results and upcoming physical requirements, further upgrade scheme for the BPM DAQ system of CSRm based on field programmable gate array (FPGA) technology was proposed and discussed.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.649-655
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• 2007

In this paper, a time-delayed controller for position control of humanoid robot arms is designed and implemented on a field programmable gate array(FPGA) chip. The time-delayed control algorithm is simple to implement, and robust to reject disturbances. The time-delayed control method uses the one sample time-delayed previous information to cancel out uncertainties in the system. Since the sampling time is so fast with the current hardware technology, the time-delayed controller can be implemented. However, inertia values should be correctly estimated to have the better performance. The position tracking tasks of humanoid robot arms are tested to compare performances of several control algorithms including the time-delayed controller.

• 전자공학회논문지C
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• 제35C권8호
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• pp.33-41
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• 1998

We have designed a high speed and low power 16bit-ELM adder with variable-sized cells uitlizing the fact that the logic depth of lower bit position is less than that of the higher bit position int he conventional ELM architecture. As a result of HSPICE simulation with 0.8.mu.m single-poly double-metal LG CMOS process parameter, out 16bit-ELM adder with variable-sized cells shows the reduction of power-delay-product, which is less than that of the conventional 16bit-ELM adder with reference-sized cells by 19.3%. We optimized the desin with various logic styles including static CMOs, pass-transistor logic and Wang's XOR/XNOR gate. Maximum delay path of an ELM adder depends on the implementation method of S cells and their logic style.

• Journal of Positioning, Navigation, and Timing
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• 제13권2호
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• pp.149-158
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• 2024

Global Navigation Satellite System (GNSS) receivers are becoming increasingly sophisticated, equipped with advanced features and precise specifications, thus demanding efficient and high-performance hardware platforms. This paper presents the design and implementation of a Field-Programmable Gate Array (FPGA)-based GNSS receiver development platform for multi-band signal processing. This platform utilizes a FPGA to provide a flexible and re-configurable hardware environment, enabling real-time signal processing, position determination, and handling of large-scale data. Integrated signal processing of L/S bands enhances the performance and functionality of GNSS receivers. Key components such as the RF frontend, signal processing modules, and power management are designed to ensure optimal signal reception and processing, supporting multiple GNSS. The developed hardware platform enables real-time signal processing and position determination, supporting multiple GNSS systems, thereby contributing to the advancement of GNSS development and research.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.951-954
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• 2005

본 논문은 BLCD 모터를 사용하여 복합연막탄 선회구동 장치를 정밀 제어하는 시스템 설계 및 알고리즘 개발을 그 목적으로 하고 있다. 복합연막탄은 적위협의 시계를 가리는 역할을 하므로 매우 짧은 시간 내에 적 위협을 감지하고 그에 대응해야 하므로 빠른 응답성을 갖도록 설계 되어야 한다. 따라서 300Hz ${\sim}$ 500Hz의 빠른 전류 응답성을 가지는 전류 제어기를 설계하였으며 기존에 많이 사용되던 공간벡터 PWM을 사용하지 않고 MIX-MAX PWM 방식을 사용하여 연산속도를 향상 시켰다. 연막탄이 정확히 발사되기 위한 정밀 위치제어기를 제안하였으며 PC기반의 모니터링 프로그램을 통해 전류, 전압, 위치, 속도 등의 파라메터를 그래프로 확인 가능하도록 구현하였다. 부동소숫점 방식의 고속 DSP인 TMS320VC33을 사용하여 제어기를 구성 하였으며 PWM발생부는 CPLD인 EPM7128을 사용하여 구현 하였다.