• The KIPS Transactions:PartA
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• 제11A권7호
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• pp.489-498
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• 2004

VLIW processor is considered to be an appropriate processor for the embedded system, provided with high performance and low power con-sumption due to its simple hardware structure. Unfortunately, the VLIW processor often suffers from high memory access latency due to the variable length of I-packets, which consist of independent instructions to be issued in parallel. It is because of the variable I-packet length that some I-packets must be placed over two cache blocks, which are called straddle I-packets, so that two cache accesses are required to fetch such I-packets. In this paper, an expansion buffer cache is proposed to improve not only the instruction fetch bandwidth, but also the power consumption of the I-cache with moderate hardware cost. The expansion buffer cache has a small expansion buffer containing a fraction of a straddle packet along with the main cache to reduce the additional cache accesses due to the straddle I-packets. With a great reduction in the cache accesses due to the straddle packets, the expansion buffer cache can achieve $5{\~}9{\%}$improvement over the conventional I-caches in the $Delay{\cdot}Power{\cdot}Area$ metric.

• Review of KIISC
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• 제26권4호
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• pp.41-46
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• 2016

전통적으로 바이오인식기술은 출입국심사(전자여권, 승무원 승객 신원확인), 출입통제(도어락, 출입통제 근태관리), 행정(무인민원발급, 전자조달), 사회복지(미아찾기, 복지기금관리), 의료(원격의료, 의료진 환자 신원확인), 정보통신(휴대폰 PC 인터넷 인증), 금융(온라인 뱅킹, ATM 현금인출) 등 다방면에서 폭넓게 보급되어 실생활에서 널리 활용되고 있다. [그림1]은 신체적 특징(Physiological biometrics)과 행동적 특징(Behavioral biometrics)을 이용한 사용자 인증기술인 바이오인식기술의 유형과 함께 각 기술별 보안취약점(괄호 안 빨강색글자)을 나타내고 있다. 최근 들어, 모바일 지급결제서비스 ATM 인출기 인터넷전문은행 등과 같은 핀테크 분야에서 비대면 인증기술로 바이오인식기술이 각광을 받기 시작했다. 한편, 가짜지문 등 기존의 신체적 특징을 이용한 바이오인식기술의 위변조 위협에 대한 우려 존재함에 따라 뇌파 심전도 근전도 맥박 등 살아있는 사람의 행동적(신체의 기능적) 특징을 이용한 생체신호를 이용하여 비대면 인증기술로서 활용하기 위하여 주요 선진국에서 차세대 바이오인식 기술개발이 가속화되고 있는 추세이다.[1] 또한, 이러한 생체신호는 최근에 삼성전자, LG전자, 애플 등에서 스마트워치를 통해 심장박동수를 측정하고 스마트폰을 통하여 모바일 지급결제, 헬스케어 등과 같은 IoT 모바일 융복합 응용서비스에 활용될 전망이다. 본고에서는 뇌파 심전도(심박수)와 같은 생체신호를 측정하는 스마트워치 밴드형 의복형 또는 패치형태의 웨어러블 디바이스와 같은 생체신호센서, 생체신호 인증기술 및 관련표준화 동향을 고찰해 보기로 한다. 국내외 관련기술과 표준화 동향을 면밀히 분석하여 지난 2015년 5월29일에 발족한 국내외 전문가그룹인 KISA"모바일 생체신호 인증기술 표준연구회"(이하 KISA 표준연구회)가 구심점이 되어 한국형 생체신호를 이용한 차세대 텔레바이오인식기술에 대한 연구개발과 국내외 표준화 추진에 박차를 가할 계획이다.

• Korean Chemical Engineering Research
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• 제54권6호
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• pp.775-780
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• 2016

Recently, photovoltaic industry needs a new design of Czochralski (Cz) process for higher productivity with reasonable energy consumption as well as solar cell's efficiency. If the process uses the large size reactor for increasing productivity, it is possible to produce a 12-inch, rather than the 8-inch. Also the continuous czochralski process method can be maximized to increase productivity. In this study, it was designed to improve the yield value of ingot with optimal condition which reduce consumption of electrical power. It has increased the productivity of the 12-inch ingot process condition by using CFD simulation. I have found optimal growth rate, by comparing each growth rate the interface shape, Temperature gradient, power consumption. As a result, the optimal process parameters of the growth furnace has been derived to improve for the productivity and to reduce energy. This study will contribute to the improvement of the productivity in the solar cell industry.

• Journal of Navigation and Port Research
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• 제42권3호
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• pp.207-216
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• 2018

If empty containers from multiple shipping liners are mixed together in the same bay, then the space utilization increases; however, the expected number of re-handles also increases. Formulas for estimating the expected number of re-handles are derived for various storage strategies and two types of handling equipment. The expected number of re-handles is compared, through numerical experiments, among those cases. The results of the numerical experiments are used to analyze the change in the number of expected re-handles according to the change in the retrieval ratio and repair ratio. The impacts of the change in the bay size and the distribution of the storage and retrieval ratio of containers among multiple vessel liners on the expected number of re-handles are analyzed. It is necessary to study efficient operational strategies considering the expected number of re-handles for empty containers.

• Journal of the Korea Society of Computer and Information
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• 제16권2호
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• pp.1-8
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• 2011

NAND type Flash memory has performing much researches for a hard disk substitution due to its low power consumption, cheap prices and a large storage. Especially, the NAND type flash memory is using general buffer systems of a cache memory for improving overall system performance, but this has shown a tendency to emphasize in terms of data. So, our research is to design a high performance instruction NAND type flash memory structure by using a buffer system. The proposed buffer system in a NAND flash memory consists of two parts, i.e., a fully associative temporal buffer for branch instruction and a fully associative spatial buffer for spatial locality. The spatial buffer with a large fetching size turns out to be effective serial instructions, and the temporal buffer with a small fetching size can achieve effective branch instructions. According to the simulation results, we can reduce average miss ratios by around 77% and the average memory access time can achieve a similar performance compared with the 2-way, victim and fully associative buffer with two or four sizes.

• Journal of Korea Multimedia Society
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• 제11권1호
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• pp.34-43
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• 2008

This paper presents a system for recognizing sunglasses and a mask of an ATM (Automatic Teller Machine) user. The proposed system extracts firstly facial contour, then from this extraction results it estimates the regions of eyes and mouth. Finally, it recognizes sunglasses and a mouth using Histogram Indexing based on those regions. We adopt a face shape model to be able to extract facial contour and to estimate the regions of eyes and mouth when those regions are occluded by sunglasses and a mask. To improve the fitting accuracy of the shame model, we adopt 2-step face detection method and conduct fitting several times by varying the initial position of the model instance. To achieve a good performance of the face detection method based on a background model, we enable the system to automatically update the background model. In experiment, we present some experiments on setting parameters of the system with images taken from in our laboratory, and demonstrate the results of recognizing sunglasses and a mask.

• Nuclear Engineering and Technology
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• 제23권4호
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• pp.426-437
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• 1991

The $He^{++}$ beam transport system of the SNU 1.5-MV Tandem Van de Graaff accelerator is analysed by ion optical approach. The program OPTRANS is developed to determine the optimum operating conditions of each ion optical component and to simulate ion beam transport. First order matrix formalism is used and the space charge effect is neglected. Optimum operating conditions for the transport of 0.5~3.0 MeV $He^{++}$ beam are determined by the use of the program OPTRANS. Initial ion beam omittance is assumed to be 0.5$\times$80.0 mm.mrad from the structure of the extraction electrode and the experiment of ion beam extraction. ion beam transport characteristics of each ion optical component according to the variation of the operating conditions are investigated, and operating conditions to minimize the beam size at each slit, stripping foil, and target are calculated. Optimum operating conditions obtained from the experiment of ion beam transport show a discrepancy of less than 15% compared with the calculated ones. From the simulation and experiment of ion beam trans-port, the validity of the calculated optimum operating conditions and the usefulness of the program OPTRANS are verified.

• Journal of Korean Society of Coastal and Ocean Engineers
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• 제30권1호
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• pp.29-38
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• 2018

In order to evaluate the performance of the floating wave power, which is an axisymmetric oscillating water column type, linearized free surface boundary condition considering the influence of PTO (power takeoff) was derived and a finite element numerical model was established. Numerical experiments were carried out by varying cylinder length, skirt length, and depth of water, which are design parameters that can change the resonance of water column in cylinder and heave resonance of the float, which is considered to affect the power generation efficiency. Finally, the basic data necessary for the optimum design of the power generation system were obtained. As a result, the efficiency of the power generation system is dominated by the heave motion resonance of the float rather than the water column resonance in the cylinder, and the resonance condition for the heave motion can be changed efficiently by attaching the skirt to the outside of the buoy.

• The Korean Journal of Nuclear Medicine
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• 제39권1호
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• pp.1-8
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• 2005

This paper is described on the development of KOTRON-13 and recent status of PET cyclotron by commercial cyclotron companies. KIRAMS has developed medical cyclotron which is KIRAMS-13. Samyoung Unitech produces KOTRON-13 with transfered technology by KIRAMS. As a part of Regional Cyclotron Installation Protect, KOTRON-13 cyclotrons and $[18F]FDG$ production modules are being installed at regional cyclotron centers in Korea. The medical concern with radiation technology has been growing for the last several years. Early cancer diagnosis through the cyclotron and PET-CT have been brought to public attention by commercial cyclotron models in the world. The new commercial cyclotron models are introduced compact low energy cyclotrons developed by CTI, GE, Sumitomo in recent. It produces different short-lived radioisotopes, such as $[^{18}F],\;[^{11}C],\;[^{13}N]\;and\;[^{15}O]$. For the better reliability acceleration particle is proton only. The characteristics of new model cyclotrons are changed to lower energy corresponding to less 13 MeV. New models have self-shielding and low power consumption. Design criteria for the different types of commercial cyclotrons are described with reference to hospital demands.

• Journal of Navigation and Port Research
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• 제43권3호
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• pp.197-208
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• 2019

This paper assessed the impacts of the specification of the yard, handling equipment, and operation approaches on the expected number of re-handles during the loading operation for empty containers. When the various types of empty containers from multiple shipping liners are placed in separate spaces from each other, then the storage space cannot be fully utilized. So as to increase the utilization of the storage space, empty containers from multiple vessel liners are stored together incurring additional re-handles during the loading operation. Several formulas are derived for the estimation of the expected number of handles, including re-handles, for empty container retrieval from a bay. Transfer cranes and top handlers are utilized as handling equipment and various retrieval strategies are examined. Numerical analysis was conducted to assess the effects of various designs and operational parameters of the container stacking yard on the expected number of handles.