• Proceedings of the KSME Conference
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• 2000.11a
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• pp.492-497
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• 2000

This paper focuses on the weight minimization of radial gate, as an extention of the previous work. Radial gates are commonly used to regulate the flow-rate of general purpose dams, due to its simplicity in manufacture and control. The present study identifies the optimum position of support point for 2 and 3 arm type radial gate, which guarantees the minimum weight satisfying strength constraint condition. These optimum designs are then compared with previously constructed radial gates. The results indicate that the weights of the optimized radial gates reduce by about 20%, compared to those of the conventionally designed radial gates.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.2
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• pp.100-106
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• 2010

The impact of surface quantization on device parameters of a Si metal oxide semiconductor (MOS) capacitor has been analyzed in the present work. Variation of conduction band bending, position of discrete energy states, variation of surface potential, and the variation of inversion carrier concentration at charge centroid have been analyzed for different gate voltages, substrate doping concentrations and oxide thicknesses. Oxide thickness calculated from the experimental C-V data of a MOS capacitor is different from the actual oxide thickness, since such data include the effect of surface quantization. A correction factor has been developed considering the effect of charge centroid in presence of surface quantization at strong inversion and it has been observed that the correction due to surface quantization is crucial for highly doped substrate with thinner gate oxide.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.114-122
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• 2013

This study introduces an optimization methodology for the determination of gate location that ensures the melt flow balance within a part cavity of injection mold. A new sequential direct-search scheme based on the recursive reduction of the designer-specified gate design area is developed, and it is integrated with a commercial flow simulation tool for optimization. To quantify the level of melt flow balance, we employ the maximum difference among the fill times for the melt fronts to reach the boundary elements of part cavity as objective function. The proposed methodology is successfully applied in the case study of melt flow balancing in molding of a bar code scanner model. The result shows that the melt flow balance at the optimized gate positions is significantly improved from that for the initial gate position.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.47-55
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• 2011

The optimum mold design and the optimum process condition were constructed upon executing process simulation of rubber injection molding with the commercial CAE program of MOLDFLOW (Ver. 5.2) in order to solve the process-problems of K company relating to cracks, which occurs at the inner cavity wall of C. V. joint boots. As a result it was confirmed that the real cracks occurs at the exactly same position of the cavity as exhibits the defects of weld and meld line and unsatisfactory curing according to the result of simulation. In order to prevent the occurrence of weld and meld line at the defect-position, the location of gate was altered to the optimum position of the cavity. Consequently the filling pattern was established to minimize the degree of the melt-fronts confronting or the melt-flows melding to prevent the occurrence of weld and meld line at the defect-position. It was observed that both gate-positions to maximize the degree of the formation of weld and meld line and air traps are located, respectively, in opposite direction each other with reference to the optimum gate position. In addition, the temperature of mold was raised by $10^{\circ}C$ and maintained at $170^{\circ}C$ for satisfactory curing.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.8
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• pp.987-996
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• 1999

An algorithm for modeling the filling of metal into a mold and solidification has been developed. This algorithm uses the implicit VOF method for a filling and a general implicit source-based method for solidification. The model for simultaneous filling and solidification is applied to the two-dimensional filling and solidification of a square cavity. The effects of the wall temperature and gate position on the solidification are examined. The mixed natural convection flow and residual flow resulting from the completion of a filling are included in this study to investigate the coupled effects of the filling and natural convection on solidification. Two different filling configurations (assisting flow and opposite flow due to the gate position) are analysed to study the effects of residual flow on solidification. The results clearly show the necessity to carry out a coupled filling and solidification analysis including the effect of natural convection.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.4
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• pp.85-94
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• 2021

The LPR system's trigger sensor makes problem occasionally due to the heave weight of vehicle or the obsolescence equipment. If we replace the hardware sensor to the deep-learning based software sensor in order to generate the trigger signal, LPR system maintenance would be a lot easier. In this paper we proposed the deep-learning sliding window based object detection and tracking algorithm for the LPR system's trigger signal generation. The gate passing vehicle's license plate recognition results are combined into the normal tracking algorithm to catch the position of the vehicle on the trigger line. The experimental results show that the deep learning sliding window based trigger signal generating performance was 100% for the gate passing vehicles including the 5.5% trigger signal position errors due to the minimum bounding box location errors in the vehicle detection process.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1254-1258
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• 2004

This paper presents of position control of Permanent Magnet Synchronous Motor (PMSM) the implementation with Field Programmable Gate Array (FPGA) is proposed. Cascade control with inner loop as a current control and an outer loop as a position control is chosen for simplicity and fast response. FPGA is a single chip (single processing unit), which will perform the following tasks: receive and convert control signal, create a reference current signal, control current and create switch signal and act as position controller in a addition of zero form. The 10 kHz sampling frequency and 25 bit of floating point data are defined in this implementation.The experimental results show that the performance of FPGA based position control is comparable with the hardware based position control, with the advantage of control algorithm flexibility

• Journal of Power Electronics
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• v.10 no.4
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• pp.342-350
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• 2010

Randomizing the switching frequency (RSF) to reduce the electromagnetic interference (EMI) of switching power converters is a well-known technique that has been previously discussed. The randomized pulse position (RPP) technique, in which the switching frequency is kept fixed while the pulse position (the delay from the starting of the switching cycle to the turn-on instant within the cycle) is randomized, has been previously addressed in the literature for the same purpose. This paper presents a double-hybrid technique (DHB) for EMI reduction in dc-dc switching regulators. The proposed technique employed both the RSF and the RPP techniques. To effectively spread the conducted-noise frequency spectrum and at the same time attain a satisfactory output voltage quality, two parameters (switching frequency and pulse position) were randomized, and a third parameter (the duty ratio) was controlled by a digital compensator. Implementation was achieved using field programmable gate array (FPGA) technology, which is increasingly being adopted in industrial electronic applications. To evaluate the contribution of the proposed DHB technique, investigations were carried out for each basic PWM, RPP, RSF, and DHB technique. Then a comparison was made of the performances achieved. The experimentally investigated features include the effect of each technique on the common-mode, differential-mode, and total conducted-noise characteristics, and their influence on the converter’s output ripple voltage.

• Journal of architectural history
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• v.26 no.5
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• pp.19-26
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• 2017

This paper aimed to identify the architectural characteristics of the chimi excavated from ancient ruins, especially middle gate remains of Bunhwangsa Temple in the Unified Silla period. Middle gate had planned $3{\times}2$ with 295mm measuring unit and gabled building. Detailed study of the shape of chimi of the middle gate restored by related field experts reveals as follows. 1) Height of chimi is 4.5(130.6cm) of Tang's system of measurement classified as large one. 2) The front and back side square hole is made for transverse timber placement. 3) Position of chimi is not the end of the ridge of roof, it moved toward the center. 4) Construction method of chimi is structured with smaller beam and center column. 5) Width and height of the ridge is less than 38cm and 54cm to be approximately, Width and height of the gabled ridge is less than 38cm and 50cm. 6) This chimi is considered to be very unique when compared to existing ancient restored chimis, it is designed to be advantageous to the chimi construction.

• Journal of IKEEE
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• v.27 no.4
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• pp.630-635
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• 2023

SiC is replacing the position of silicon in the power semiconductor field due to its superior resistance to adverse conditions such as high temperature and high voltage compared to silicon, which occupies the majority of existing industrial fields. In this paper, the gate of 4H-SiC Planar MOSFET, one of the power semiconductor devices, was formed with aluminium to make the contrast and parameter values consistent with polycrystalline Si gate, and the threshold voltage, breakdown voltage, and IV characteristics were studied by varying the channel doping concentration of SiC MOSFET.