• 한국전기전자재료학회논문지
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• 제15권7호
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• pp.576-582
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• 2002

Nonvolatile semiconductor memory devices with reoxidized nitrided oxide(RONO) gate dielectrics were fabricated, and nitrogen distribution and bonding species which contribute to memory characteristics were analyzed. Also, memory characteristics of devices depending on the anneal temperatures were investigated. The devices were fabricated by retrograde twin well CMOS processes with $0.35\mu m$ design rule. The processes could be simple by in-situ process in growing dielectric. The nitrogen distribution and bonding states of gate dielectrics were investigated by Dynamic Secondary Ion Mass Spectrometry(D-SIMS), Time-of-Flight Secondary Ion Mass Spectrometry(ToF-SIMS), and X-ray Photoelectron Spectroscopy(XPS). As the nitridation temperature increased, nitrogen concentration increased linearly, and more time was required to form the same reoxidized layer thickness. ToF-SIMS results showed that SiON species were detected at the initial oxide interface which had formed after NO annealing and $Si_2NO$ species within the reoxidized layer formed after reoxidation. As the anneal temperatures increased, the device showed worse retention and degradation properties. It could be said that nitrogen concentration near initial interface is limited to a certain quantity, so the excess nitrogen is redistributed within reoxidized layer and contribute to electron trap generation.

• 한국정밀공학회지
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• 제24권8호통권197호
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• pp.58-66
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• 2007

In order to improve the recyclability and to reduce the recycling cost and time, the disassembly technology should be systemized because the worn out products can be reused or recycled after disassembly processes. This paper attempts to propose the integrated CATIA-based DfD (Design for Disassembly) support system to promote the disassemblability of products. The system is composed of two modules; evaluation of disassemblability, generation of DfD alternatives. The disassemblability of current vehicle is evaluated to identify the weak point in terms of disassembly using the DELMIA and developed evaluation system. Furthermore a new expert system is developed to propose the optimal redesign rule and principle for generating the DfD alternatives. In order to generate the DfD alternatives, a CATIA-based design support system is implemented. The system can provide quick results and ensure consistency and completeness of the redesign alternatives.

• 산업기술연구
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• 제3권
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• pp.69-74
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• 1983

For the determination of a reservoir capacity Rippl's mass-curve method has long been used with the past river flow data assuming the same flow records will be repeated in the future. This study aims to find out a better method for determining the reservoir capacity by employing the analytical theory based on the stochastic process. For the present study the synthetic generation methods of Thomas-Fiering type was used to synthetically generate 50 years of monthly river inflows to three single-purpose reservoirs and three multi-purpose reservoirs. The generated sequences of monthly flows were analyzed based on the range concept. With the optimum operation rule of the reservoirs as the one which maximizes the water-use downstream the waterrelease from the reservoir was determined and with due consideration to the mean inflows and the range of monthly flows the required reservoirs capacity was stochastically determined. It was possible to repersent the so-determined reservoir capacity in terms of the mean monthly inflows and the number of subseries in the determination of ranges. It is suggested that the result obtained in this study would be applied to approximately estimate, in the stage of preliminary design, the required capacity of a reservoir in question with the limited information such as the mean monthly inflow and the period of reservoir operation.

• 한국인터넷방송통신학회논문지
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• 제20권2호
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• pp.29-37
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• 2020

기존에 사용되던 방화벽들은 기본적으로 정책을 수동적으로 입력해 주는 방식으로 되어 있어 공격이 오는 즉시 대응하기 쉽지 않다. 왜냐하면 전문 보안 관리자가 이를 분석하고 해당 공격에 대한 방어 정책을 입력해 주어야하기 때문이다. 또한, 기존 방화벽 정책은 공격을 막기 위해 정상 접속까지 차단하는 경우가 많다. 패킷 자체는 정상적이지만 유입량이 많아 서비스 거부를 발생시키는 공격이 많기 때문이다. 본 논문에서는 방어 정책을 입력하는 부분을 인공지능으로 대체하여 정책을 자동으로 생성하고, 정상 접속 학습을 통해 생성된 화이트리스트 정책으로 정상 접속은 가능하면서 Flooding, Spoofing, Scanning과 같은 공격만을 차단하는 방법을 제안한다.

• Wind and Structures
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• 제18권6호
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• pp.599-618
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• 2014

In this study, a square rectangular tall building is considered to investigate the effects of turbulence integral length scale and turbulence intensity on the along-wind responses, across-wind responses and torsional responses of the tall building by Large Eddy Simulation (LES). A recently proposed inflow turbulence generator called the discretizing and synthesizing random flow generation (DSRFG) approach is applied to simulate turbulent flow fields. It has been proved that the approach is able to generate a fluctuating turbulent flow field satisfying any given spectrum, desired turbulence intensity and wind speed profiles. Five profiles of turbulence integral length scale and turbulence intensity are respectively generated for the inflow fields by the DSRFG approach for investigating the effects of turbulence integral length scale and turbulence intensity on the wind-induced responses of the tall building. The computational results indicate that turbulence integral length scale does not have significant effect on the along-wind (displacement, velocity and acceleration) responses, across-wind displacement and velocity responses, while the across-wind acceleration and torsional responses vary without a clear rule with the parameter. On the other hand, the along-wind, across-wind and torsional responses increase with the growth of turbulence intensity.

• Journal of Electrical Engineering and Technology
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• 제5권4호
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• pp.552-560
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• 2010

This paper presents an application of layered Artificial Neural Network controller to study load frequency control problem in power system. The objective of control scheme guarantees that steady state error of frequencies and inadvertent interchange of tie-lines are maintained in a given tolerance limitation. The proposed controller has been designed for a two-area interconnected power system. Only one artificial neural network controller (ANN), which controls the inputs of each area in the power system together, is considered. In this study, back propagation-through time algorithm is used as neural network learning rule. The performance of the power system is simulated by using conventional integral controller and ANN controller, separately. For the first time comparative study has been carried out between SMES and CES unit, all of the areas are included with SMES and CES unit separately. By comparing the results for both cases, the performance of ANN controller with CES unit is found to be better than conventional controllers with SMES, CES and ANN with SMES.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.14-18
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• 1997

In this paper, we suggested and made a classifier or qualitative and quantitative analysis in urine analysis system. Input variable number and fuzzy membership function was made from determination of standard sample, and the fuzzy rules were determined by the analysis of spectroscopic properties of pads in strip. Fuzzy classifier used in urine analysis system was evaluated or the standard samples in each items and degrees. Negative and positive response of urine test was classified in good property, but detail classification or quantitative analysis had 8% maximum error in each items. If fuzzy membership unction and generation of rule are supplemented, suggested fuzzy classifier can be applied to the clinical test.

• Journal of Information Processing Systems
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• 제16권5호
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• pp.1083-1094
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• 2020

Recognizing plant species based on leaf images is challenging because of the large inter-class variation and inter-class similarities among different plant species. The effective extraction of leaf descriptors constitutes the most important problem in plant leaf recognition. In this paper, a multi-scale angular description method is proposed for fast and accurate leaf recognition and retrieval tasks. The proposed method uses a novel scale-generation rule to develop an angular description of leaf contours. It is parameter-free and can capture leaf features from coarse to fine at multiple scales. A fast Fourier transform is used to make the descriptor compact and is effective in matching samples. Both support vector machine and k-nearest neighbors are used to classify leaves. Leaf recognition and retrieval experiments were conducted on three challenging datasets, namely Swedish leaf, Flavia leaf, and ImageCLEF2012 leaf. The results are evaluated with the widely used standard metrics and compared with several state-of-the-art methods. The results and comparisons show that the proposed method not only requires a low computational time, but also achieves good recognition and retrieval accuracies on challenging datasets.

• 한국지능시스템학회논문지
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• 제21권5호
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• pp.569-574
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• 2011

이 논문에서는 마이크로어레이 데이터에 대한 분석 문제로서 부공간 대조집단 식별 문제를 소개하고, 이를 해결하는 방법을 제안한다. 제안한 방법은 부공간에서 속성값이 대조적인 집단의 쌍들을 식별하기 위해, 먼저 각 속성에 대해서 분석자가 지정한 대조영역의 값을 갖는 두 개의 샘플집단을 선택한 다음, 연관규칙 마이닝과 유사한 형태의 방법으로 부공간의 차원을 점진적으로 확대해 가면서 대조집단을 추출한다. 마이크로어레이 데이터는 수천개 이상의 유전자에 대한 발현정보를 포함할 수 있는 다차원 데이터이기 때문에, 대조적인 발현특성을 갖는 유전자집합에 대한 샘플집단의 쌍을 모두 부차원에 대해서 질의를 통해 식별하는 것은 부담이 되지만, 제안한 방법을 사용하면 분석자가 지정한 대조영역 값의 범위를 기준으로 하여 모든 가능한 부공간에서의 대조집단을 효과적으로 추출할 수 있다.

• 전력전자학회논문지
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• 제21권2호
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• pp.182-189
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• 2016

A modeling method of electric power network inside a fishing boat less than 5 tons is proposed for its high-energy efficiency with renewable energy sources. The power network inside the fishing boat consists of a diesel engine, a starter motor, an alternator, battery packs, and electric loads, which are connected in parallel. To obtain proper power network model, the voltage -current characteristics of the electric components are considered to develop elaborate electrical models under several load conditions. Measured data of the battery and alternator current include noise. By using an average method, the AC components from the power network of the fishing boat can be reduced, which is verified by KCL rule. Using the proposed power network model, the power generation of the alternator and the reduction of diesel consumption in the boat's engine are predictable under various operating conditions. The validity of the proposed methodology is verified by comparing simulation results with experimental measurements using statistical inferences.