• Journal of Communications and Networks
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• 제12권5호
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• pp.459-465
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• 2010

A new blind equalization algorithm that is based on maximizing the probability that the constant modulus errors concentrate near zero is proposed. The cost function of the proposed algorithm is to maximize the probability that the equalizer output power is equal to the constant modulus of the transmitted symbols. Two blind information-theoretic learning (ITL) algorithms based on constant modulus error signals are also introduced: One for minimizing the Euclidean probability density function distance and the other for minimizing the constant modulus error entropy. The relations between the algorithms and their characteristics are investigated, and their performance is compared and analyzed through simulations in multi-path channel environments. The proposed algorithm has a lower computational complexity and a faster convergence speed than the other ITL algorithms that are based on a constant modulus error. The error samples of the proposed blind algorithm exhibit more concentrated density functions and superior error rate performance in severe multi-path channel environments when compared with the other algorithms.

• 산업공학
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• 제7권3호
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• pp.171-180
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• 1994

Defined is a Multi-level Parallel Machine Flow-Shop (MPMFS) which reflects some real world manufacturing situations. Just-In-Time (JIT) philosophy is applied to the MPMFS scheduling in order to achieve lowering work-in-process inventory level as well as meeting due dates. A schedule generating simulator is developed. The latest start time of each operation is determined by a backward simulation followed by another forward simulation to analyze the schedule feasibility and actual inventory level. Reasonable schedules are available through adjusting some parameters for allowance factors such as set-up times of machines and other environmental changes. The SLAMSYSTEM under Window is employed for this processing with some input/output data handling processes devised under DOS.

• 한국재료학회지
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• 제19권9호
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• pp.462-467
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• 2009

The Charge Trap Flash (CTF) memory device is a replacement candidate for the NAND Flash device. In this study, Pt/$Al_2O_3/La_2O_3/SiO_2$/Si multilayer structures with lanthanum oxide charge trap layers were fabricated for nonvolatile memory device applications. Aluminum oxide films were used as blocking oxides for low power consumption in program/erase operations and reduced charge transports through blocking oxide layers. The thicknesses of $SiO_2$ were from 30 $\AA$ to 50 $\AA$. From the C-V measurement, the largest memory window of 1.3V was obtained in the 40 $\AA$ tunnel oxide specimen, and the 50 $\AA$ tunnel oxide specimen showed the smallest memory window. In the cycling test for reliability, the 30 $\AA$ tunnel oxide sample showed an abrupt memory window reduction due to a high electric field of 9$\sim$10MV/cm through the tunnel oxide while the other samples showed less than a 10% loss of memory window for $10^4$ cycles of program/erase operation. The I-V measurement data of the capacitor structures indicated leakage current values in the order of $10^{-4}A/cm^2$ at 1V. These values are small enough to be used in nonvolatile memory devices, and the sample with tunnel oxide formed at $850^{\circ}C$ showed superior memory characteristics compared to the sample with $750^{\circ}C$ tunnel oxide due to higher concentration of trap sites at the interface region originating from the rough interface.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.190-198
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• 2002

Full scale durability test in the laboratory is an essential of any fatigue life evaluation of components or structures of the automotive vehicle. Component testing is particularly important in today's highly competitive industries where the design to reduce weight and production costs must be balanced with the necessity to avoid expensive service failure. Generally, hydraulic road simulator is used to carry out the fatigue test and the vibration test. In this paper, the algorithm and software to realize the real road profile are developed. The operation software for simultaneously controlled multi-axial road simulator is developed and the input and output data are displayed window based PC controller in the real time. Futhermore, the software to generate the real road profile are developed. The validity of the software are verified by applying the belgian road, the city road, the highway, and the gravel road. The results of the above experiment show that the real road profiles are realized well after 10th iteration.

• 한국전자통신학회논문지
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• 제12권2호
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• pp.273-280
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• 2017

트랜지트터의 대용량 집적 기술이 발전함에 따라 다수의 CPU를 하나의 칩에 구현하게 되었으며, 시스템의 요구사항을 맞추기 위하여 클럭 주파수는 점점 더 빨라지고 있다. 그러나 클럭 주파수를 증가시키는 것은 클럭 동기화 같은 시스템의 오동작을 일으키는 문제들을 유발시킬 수 있으므로 디지털 칩 설계 시에 불안정 상태 문제를 피하는 것이 아주 중요하다. 본 논문에서는 80nm CMOS 공정으로 설계된 D-FF을 사용하여 온도, 전원, 전달 게이트의 크기에 따라 Hspice의 이분법을 사용하여 불안정상태 구간을 측정한다. 모의 실험 결과에서 불안정상태 구간은 온도와 전원 전압의 증가에 따라 조금 증가하였지만, 전달 게이트의 면적에 대해서는에 포물선 모양으로 비례하고 있으며, 전달 게이트의 P 형과 N 형 트랜지스터의 비율이 4:2 일 때 불안정상태 구간이 최소가 되는 것을 확인하였다.

• 한국통신학회논문지
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• 제41권7호
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• pp.783-788
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• 2016

본 논문은 비면허대역을 위한 LTE 통신 기술인 LAA(Licensed Assisted Access)가 복수의 주파수 채널을 사용해 하향링크 전송을 수행하기 위한 액세스 기법을 설명하고, 액세스 기법의 세부 동작 설계에 따른 Wi-Fi와의 공존 특성 및 각 통신 기술의 성능 변화를 시뮬레이션을 통해 보인다. 이를 위해 LAA의 채널 본딩 규칙 적용 여부, LBT(Listen Before Talk)를 수행하는 채널, LBT 채널을 동적으로 변경 시 CW(Contention Window)의 설정방법, 그리고 Wi-Fi의 대역폭 설정 방식과 CW 조절 방식을 고려한다. 각 요소를 변경하였을 때 상호 간의 성능 변동 경향을 확인하고, 이를 통해 두 기술의 공존을 위해 다양한 요소가 복합적으로 고려되어야 함을 보인다.

• 한국화재소방학회논문지
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• 제22권1호
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• pp.105-114
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• 2008

본 연구에서는 2006년 개정소방법의 시행에 따라 다중이용업소 및 고층건물에 피난설비 중 피난기구로 설치가 의무화 되고 있는 '완강기'의 현재 나타난 설치상의 문제점을 조사해보고, 제시된 문제점들을 각 항목별로 나누어 원인 분석 및 개선사항을 제시하였다. 설문조사를 통하여 총 367건의 문제점이 지적되었으며, 다음과 같이 설치실태의 문제점이 나타났다. 완강기를 이용한 탈출이 부적합한 창문(34%), 관련문구 미부착(23.7%), 부적합한 설치장소(20%) 및 완강기의 파손(20%) 등으로 조사되었다. 특히 완강기 설치상 문제점으로 완강기를 이용한 탈출에 부적합한 창문이라는 사항이 가장 많이 제시되었기에 탈출 시 필요한 유리의 파괴에 관한 응력해석을 수행한 결과 완강기가 설치된 곳의 유리두께는 3,6 mm로 규정되어야 할 것으로 나타났다. 또한 기존의 소방법에 따른 형식적인 설치가 아닌 화재발생 시 인명을 보호하는 피난도구로써의 완강기 설치 및 사용이 가능할 수 있는 실질적인 완강기 설치상의 개선대책을 제시했다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1633-1649
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• 2017

In remote sensing image processing, the traditional fusion algorithm is based on the Intensity-Hue-Saturation (IHS) transformation. This method does not take into account the texture or spectrum information, spatial resolution and statistical information of the photos adequately, which leads to spectrum distortion of the image. Although traditional solutions in such application combine manifold methods, the fusion procedure is rather complicated and not suitable for practical operation. In this paper, an improved IHS transformation fusion algorithm based on the local variance weighting scheme is proposed for remote sensing images. In our proposal, firstly, the local variance of the SPOT (which comes from French "Systeme Probatoire d'Observation dela Tarre" and means "earth observing system") image is calculated by using different sliding windows. The optimal window size is then selected with the images being normalized with the optimal window local variance. Secondly, the power exponent is chosen as the mapping function, and the local variance is used to obtain the weight of the I component and match SPOT images. Then we obtain the I' component with the weight, the I component and the matched SPOT images. Finally, the final fusion image is obtained by the inverse Intensity-Hue-Saturation transformation of the I', H and S components. The proposed algorithm has been tested and compared with some other image fusion methods well known in the literature. Simulation result indicates that the proposed algorithm could obtain a superior fused image based on quantitative fusion evaluation indices.

• 한국통신학회논문지
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• 제34권11C호
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• pp.1029-1039
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• 2009

본 논문에서는 기존의 변이 영상 획득 방법들에 비하여 시간 대비 정확도가 우수한 기법을 제안하고 H/W로 구현한다. 제안한 기법은 고속 연산이 가능한 화소 대 화소의 움직임 추정 기법을 이용한다. 움직임 추정 기법은 영상 내 텍스쳐의 분포 특성과 무관하게 정합 윈도우의 유사성에만 의존하기 때문에 추출된 변이정보의 정확도가 떨어진다. 이를 해결하기 위해서 영상의 국부 특성에 따른 가변 크기 윈도우 정합 기법을 도입하고, 영상 내 텍스쳐가 균일한 부분 및 물체의 윤곽선 부분에서도 높은 정확도를 얻는다. 제안한 기법은 고속 연산이 가능하도록 수행속도에 최적화된 하드웨어로 설계된다. 하드웨어는 Verilog-HDL로 설계하였고, Hynix $0.35{\mu}m$ CMOS 라이브러리를 사용하여 게이트수준으로 합성하였다. 구현한 하드웨어는 최대 120MHz의 클록 주파수에서 초당 15 프레임을 안정적으로 처리할 수 있었다.

• 복식
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• 제60권6호
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• pp.89-100
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• 2010

This study is intended to analyze current status of costume in the cultural industry and explore feasibility of integrating costume as important cultural contents in the digital era. Among the websites for contents as the cultural archetypes, some have strong foundations while others don't. First, as for various archetypal characters restored based on the Korean history, most of their clothes focus on shapes and colors but lack details. They should be produced in 3D to provide back views or textile patterns to users. To ease understanding of the history of costume, user-friendly services such as launch of a pop-up window when users click on specific contents in question should be available for detailed information. At least there should be a link to other related sites where users can conveniently find more details. Second, some sites have too much data under one subject, increasing complexity and undermining orderliness. As a result, it takes long time to identify the site map. In this case, it is required to rearrange the contents with Quick View by subject and related links for in-depth study. Third, each subject is important to develop the archetypes for a variety of purposes. Creation of design derived from them or their commercialization can be an example but these activities should not restrict imagination of users or degrade the value of the archetypes. Last, it is needed to adopt validation system to detect the needs for a regular update (renewal) and to fix errors. We found many servers whose operation is not stable in general. When these technical issues are addressed for stable operation, users will rely on the sites to utilize them for their purpose of developing the cultural archetypes. In conclusion, advancement of www.culturecontent.com is essential. Based on efficient management and operation of the system, the quality of contents would be increased and multi-faceted advertising campaigns focusing on needs should be launched, to promote application of the contents. This is the recommendation for the future of the cultural archetype industry in Korea.