• JSTS:Journal of Semiconductor Technology and Science
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• 제13권3호
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• pp.213-223
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• 2013

A unified channel thermal noise model valid in all operation regions is presented for short channel MOS transistors. It is based on smooth interpolation between weak and strong inversion models and consistent physical model including velocity saturation, channel length modulation, and carrier heating. From testing for noise benchmark and comparing with published noise data, it is shown that the proposed noise model could be useful in simulating the MOSFET channel thermal noise in all operation regions.

• 교육시설 논문지
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• 제25권4호
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• pp.3-9
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• 2018

In recent years, schools in the urban areas are also showing their interest in the integrated school and considering adapting the actual operation method. That is why decline of the school-age population is not limited to rural areas any more, and decreasing number of students in urban schools is raised as a social issue to reconsider the continuation of schools. To solve the problems of the small-scale schools in the urban area, the integrated school is being considered as an alternative. Furthermore, the newly built schools in the urban development areas are also planned as the integrated school. Accordingly, the purpose of this study is to examine the cases of integrated schools in urban area of developed countries and to analyze their architectural planning considerations in practice.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.790-799
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• 2018

This paper proposes a single-phase unified power quality conditioner (S-UPQC) for maintaining power quality issues in a microgrid. The S-UPQC can compensate the voltage and current harmonics, voltage sag, and swell as a dynamic voltage restorer (DVR), regardless of variations in the grid frequency. Odd harmonics are treated as even-order harmonics in a rotating frame to implement the harmonic compensators with only one repetitive controller (RC) without any harmonic extractor. The dynamic performance is improved and the delay time is reduced in the RC. The S-UPQC control scheme is designed to maintain accurate and stable operation under deviations of the grid frequency by using the Lagrange interpolation-based finite-impulse-response (LIFIR) filter approximation method. The proposed control schemes were validated through a simulation and experiment.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.354-361
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• 2014

The Unified Power Flow Controller (UPFC) can flexibly manage power flow and maintain line voltage. The UPFC consists of two inverters in parallel side and series side. In parallel side, the reactive power can be compensated to improve the power factor. In series side, the voltage drop can be compensated to maintain proper line voltage. It is necessary for the operation in both sides to output the current and the voltage quickly and accurately. As the method for the UPFC control, the deadbeat control with state observer is applied. The deadbeat control is able to realize a quick response of the current and voltage control for only a sampling period compared with the general PI control. A principle and simulation results are presented in this paper.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권3호
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• pp.162-168
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• 2011

In this paper, we propose a new Verilog-A current-voltage model for multi-level-cell PCRAMs. This model can describe the PCRAM operation not only in full SET and RESET states but also in the partial resistance states. And, 3 PCRAM operating regions of SET-RESET, Negative Differential Resistance, and strong-ON are unified into one equation in this model thereby any discontinuity that may introduce a convergence problem cannot be found in the new PCRAM model. The percentage error between the measured data and this model is as small as 7.4% on average compared to 60.1% of the previous piecewise model. The parameter extraction which is embedded in the Verilog-A code can be done automatically.

• 교육시설 논문지
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• 제19권3호
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• pp.21-31
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• 2012

According to the decrease in birth rate and reduction of population in rural area, primary schools have brought about many problems for decrease of number of student, and environment of education have became deteriorated. Accordingly, primary schools be required improvement, and it should be altered placement of schools because it change number of student, distance and time of attending school, and formation of school zone are changed by alternating of human and physical environment. Merger and abolition of primary school is inevitable for change of placement standard to primary school and qualitative improvement of environment of education in rural area. This study suggests the effective space planning methods for unified school and appropriate utilization alternatives for closed school following after the merger and abolition of small rural schools. In doing so, it explores the present models of merger and abolition through analysis of all sort of actual condition and the possibilities for various utilizations of the abolished schools. It proposes a classroom-operation type fused the comprehensive class and departmental class system for merged primary schools in rural area. It also suggests the re-use methods of closed school facilities for students and community. Finally, it emphasizes that in order to success the policy of the merger and abolition of small schools, it be attributed to the social-cultural environment based on local residents and community and required provision of a variety of utilization plans reflecting local specifics and guarantee of local residents' participation and selection.

• 전기전자학회논문지
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• 제19권3호
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• pp.392-399
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• 2015

본 논문에서는 HEVC와 VP9 코덱의 계수 변환 (Transform)을 수행하는 통합형 아키텍쳐를 제안하여 하드웨어 크기를 줄이고자 한다. 제안하는 아키텍쳐는 HEVC $4{\times}4$ IDCT, HEVC $4{\times}4$ IDST, VP9 $4{\times}4$ IDCT, VP9 $4{\times}4$ IADST를 통합 하드웨어에서 처리가 가능하다. HEVC $4{\times}4$ IDCT와 VP9 $4{\times}4$ IDCT는 계수의 스케일만 다를 뿐 동일한 IDCT 연산을 사용하며, 마찬가지로 HEVC $4{\times}4$ IDST와 VP9 $4{\times}4$ IADST도 계수의 스케일만 다를 뿐 동일한 IDST 연산을 사용한다. 더욱이 IDCT 연산과 IDST 연산에는 상당히 많은 유사점이 있어 일부 하드웨어를 공동으로 사용할 수 있다. 따라서 제안하는 하드웨어는 4가지 연산에 대해 곱셈기의 계수는 각각 다르지만 버터플라이 덧셈기등은 공통으로 사용하여 통합적으로 수행한다. 0.18um 공정에서 합성했을 때 게이트 수가 약 6,679 게이트로 기존 아키텍처 대비 25.3% 감소함을 확인하였다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2009년도 춘계학술발표회
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• pp.9-15
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• 2009

유출사고의 환경적 경제적 등의 천문학적 피해는 사고현장의 총괄지위자의 신속한 판단이 더욱 중요할 수 밖에 없다. 우리나라 경우, 관계행정기관 간 상호협조적인 범국가적 대응을 이루고 있으나, 협조간의 의사소통이 신속히 이뤄지지 못해 업무의 공백 및 중이 발생하게 되고, 오히려 신속한 방제활동을 방해하고 있다. 미국 등 해양선진국에서는 유출사고 해당지역만으로 대응할 수 없는 재난적 유류유출사고에 대비해 정부뿐만 아니라 오염행위자 등이 통합지휘센터(Unified Command Center)로 편성되어 유류유출사고에 더욱 적극적으로 방제활동을 펼친다. 재난적 유류 유출사고로 인한 피해를 더욱 줄이기 위하여 방제주도기관인 해양경찰청의 명목상의 방치활동 뿐만 아니라, 정부 관련 기관과 각 정유업체 및 민간방제업체 등이 방제활동을 보다 적극적으로 펼칠 수 있는 통합명령체계(KUCS, the Korea Unified Command System)가 갖춰줘야 할 것이다.

• 전자공학회논문지
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• 제50권1호
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• pp.86-96
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• 2013

통합 음성/오디오 부호화기 (Unified Speech and Audio Coding, USAC)는 2011년 MPEG에서 FDIS (Final Draft International Standard)를 승인받은 최고 성능의 통합 음성/오디오 부호화기이다. 전통적으로 MPEG에서는 복호화기 기술만 표준화하므로 인코더 기술에 대한 고찰이 쉽지 않을 뿐 아니라, 예제로 공개하는 인코더 (Reference Model, RM)의 경우에도 기본 아이디어만을 포함하고 있기 때문에 이를 사용할 경우 성능 저하가 매우 심각하다. 성능 열화는 매우 심각하다. 이러한 문제를 최소화하기 위해 오픈 소스 기반으로 진행되고 있는 프로젝트 JAME에서는 USAC에 적용된 핵심 인코더 기술의 성능을 최대화 할 수 있는 방법을 제안하고 있다. 본 논문에서는 입력 신호에 따라 두 코더가 선택적으로 동작되게 하는 신호 분류기와 심리 음향 모델을 기반으로 하는 주파수 부호화 기술, 그리고 전이 윈도우 기술 등의 주요 인코더 기술들에 대하여 소개한다. 또한 FDIS를 위한 verification test 결과와 Common Encoder의 성능 평가를 덧붙인다.

• Journal of Information Processing Systems
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• 제18권1호
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• pp.59-74
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• 2022

During the last decade, the security of digital images has received considerable attention in various multimedia transmission schemes. However, many current cryptosystems tend to adopt a single-layer permutation or diffusion algorithm, resulting in inadequate security. A hierarchical bilateral diffusion architecture for color image encryption is proposed in response to this issue, based on a hyperchaotic system and DNA sequence operation. Primarily, two hyperchaotic systems are adopted and combined with cipher matrixes generation algorithm to overcome exhaustive attacks. Further, the proposed architecture involves designing pixelpermutation, pixel-diffusion, and DNA (deoxyribonucleic acid) based block-diffusion algorithm, considering system security and transmission efficiency. The pixel-permutation aims to reduce the correlation of adjacent pixels and provide excellent initial conditions for subsequent diffusion procedures, while the diffusion architecture confuses the image matrix in a bilateral direction with ultra-low power consumption. The proposed system achieves preferable number of pixel change rate (NPCR) and unified average changing intensity (UACI) of 99.61% and 33.46%, and a lower encryption time of 3.30 seconds, which performs better than some current image encryption algorithms. The simulated results and security analysis demonstrate that the proposed mechanism can resist various potential attacks with comparatively low computational time consumption.