• JSTS:Journal of Semiconductor Technology and Science
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• 제14권5호
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• pp.525-536
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• 2014

Recently, the first generation of mass production of FinFET-based microprocessors has begun, and scaling of FinFET transistors is ongoing. Traditional capacitance and resistance models cannot be applied to nonplanar-gate transistors like FinFETs. Although scaling of nanoscale FinFETs may alleviate electrostatic limitations, parasitic capacitances and resistances increase owing to the increasing proximity of the source/drain (S/D) region and metal contact. In this paper, we develop analytical models of parasitic components of FinFETs that employ the raised source/drain structure and metal contact. The accuracy of the proposed model is verified with the results of a 3-D field solver, Raphael. We also investigate the effects of layout changes on the parasitic components and the current-gain cutoff frequency ($f_T$). The optimal FinFET layout design for RF performance is predicted using the proposed analytical models. The proposed analytical model can be implemented as a compact model for accurate circuit simulations.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 추계학술대회
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• pp.31-38
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• 1994

This paper proposed signal decomposition and multiresolution representation through wavelet transform using wavelet orthonormal basis. And it suggested most appropriate filter for scaling function in multiresoltion representation and compared two compression method, arithmetic coding and Huffman coding. Results are as follows 1. Daub18 coefficient is most appropriate in computing time, energy compaction, image quality. 2. In case of image browsing that should be small in size and good for recognition, it is reasonable to decompose to 3 scale using pyramidal algorithm. 3. For the case of progressive transmittion where requires most grateful image reconstruction from least number of sampls or reconstruction at any target rate, I embedded the data in order of significance after scaling to 5 step. 4. Medical images such as information loss is fatal have to be compressed by lossless method. As a result from compressing 5 scaled data through arithmetic coding and Huffman coding, I obtained that arithmetic coding is better than huffman coding in processing time and compression ratio. And in case of arithmetic coding I could compress to 38% to original image data.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.395-400
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• 2011

강변저류지는 국내에서 천변저류지라는 이름으로 2000년 초반부터 관련 연구가 시작되었으며, 기존의 하천연안 저지대 및 홍수터를 활용하여 제방의 일부 구간에 취수부를 설치, 하천의 계획홍수를 초가하거나 일정수위 이상의 홍수가 발생할 때 초과하는 홍수량을 저류하여 하류의 첨두홍수를 저감시키는 소규모 수공구조물이다. 이러한 강변저류지는 off-line 형식으로 2차원적인 홍수량 분담을 통해 홍수량을 조절하여, 홍수조절효과가 확실하고 그 효과가 즉시 나타나는 특징이 있다. 또한 한 대상유역 내에 다수의 대상지역이 존재하게 된다. 하지만 이들 후 보지 전체에 강변저류지를 설치하는 것은 다수의 제약조건에 의해 불가능하며 대상유역의 어느 후보지에 강변저류지를 설치한다는 문제를 해결하기위해 기존에 수행되었던 연구들은 각각의 장단점이 있으며 이들 연구의 가장 큰 문제는 의사결정을 위해 사용되는 변수의 통합과정에서 발생될 수 있는 오류가 있다는 것이다. 본 연구에서는 다수의 기준과 변수에 의해 결정되어진 강변저류지의 설치 우선순위들을 다차원척도법(Multi-Dimensional Scaling)를 이용하여 최종적인 하나의 순위를 도출하는 것으로 기존에 수행되었던 연구결과의 장점을 포함하며, 보다 많은 변수를 고려할 수 있는 방안을 제시하고자 한다.

• 조명전기설비학회논문지
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• 제30권3호
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• pp.1-8
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• 2016

In this paper, we proposed a new driving scheme to reduce the motion blur and save the power for OLEDs(organic light emitting diodes). We adopted a DVS (dynamic voltage scaling) method to reduce power consumption and the division of TV field to improve motion blur. In the proposed scheme, BEW (Blur Edge Width) was decreased to the ratio of 1/4 compared to the conventional scheme under the optimal conditions. In this scheme, the gray levels to which the DVS method can be applied were divided into much smaller groups depending on the number of subfields. Therefore, our scheme does not guarantee less power consumption for every image compared to the conventional scheme. However, the new scheme can move the gray levels adopting the DVS to higher gray levels. Thus, we can save power even when having images at high gray levels.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.259-264
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• 2006

It is well known that the uncertainty of the covariance parameters of the process noise (Q) and the observation errors (R) has a significant impact on Kalman filtering performance. Q and R influence the weight that the filter applies between the existing process information and the latest measurements. Errors in any of them may result in the filter being suboptimal or even cause it to diverge. The conventional way of determining Q and R requires good a priori knowledge of the process noises and measurement errors, which normally comes from intensive empirical analysis. Many adaptive methods have been developed to overcome the conventional Kalman filter's limitations. Starting from covariance matching principles, an innovative adaptive process noise scaling algorithm has been proposed in this paper. Without artificial or empirical parameters to be set, the proposed adaptive mechanism drives the filter autonomously to the optimal mode. The proposed algorithm has been tested using road test data, showing significant improvements to filtering performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.2094-2112
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• 2019

Focusing on the issue that the conventional Kernel Correlation Filter (KCF) algorithm has poor performance in handling scale change and obscured objects, this paper proposes an anti-occlusion and scale adaptive tracking algorithm in the basis of KCF. The average Peak-to Correlation Energy and the peak value of correlation filtering response are used as the confidence indexes to determine whether the target is obscured. In the case of non-occlusion, we modify the searching scheme of the KCF. Instead of searching for a target with a fixed sample size, we search for the target area with multiple scales and then resize it into the sample size to compare with the learnt model. The scale factor with the maximum filter response is the best target scaling and is updated as the optimal scale for the following tracking. Once occlusion is detected, the model updating and scale updating are stopped. Experiments have been conducted on the OTB benchmark video sequences for compassion with other state-of-the-art tracking methods. The results demonstrate the proposed method can effectively improve the tracking success rate and the accuracy in the cases of scale change and occlusion, and meanwhile ensure a real-time performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.452-472
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• 2019

Most existing wavelet-based multiplicative watermarking methods are affected by geometric attacks to a certain extent. A serious limitation of wavelet-based multiplicative watermarking is its sensitivity to rotation, scaling, and translation. In this study, we propose an image watermarking method by using dual-tree complex wavelet transform with a multi-objective optimization approach. We embed the watermark information into an image region with a high entropy value via a multiplicative strategy. The major contribution of this work is that the trade-off between imperceptibility and robustness is simply solved by using the multi-objective optimization approach, which applies the watermark error probability and an image quality metric to establish a multi-objective optimization function. In this manner, the optimal embedding factor obtained by solving the multi-objective function effectively controls watermark strength. For watermark decoding, we adopt a maximum likelihood decision criterion. Finally, we evaluate the performance of the proposed method by conducting simulations on benchmark test images. Experiment results demonstrate the imperceptibility of the proposed method and its robustness against various attacks, including additive white Gaussian noise, JPEG compression, scaling, rotation, and combined attacks.

• 정보처리학회논문지B
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• 제9B권4호
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• pp.459-464
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• 2002

본 논문에서는 디지털 컨텐츠 저작권 보호를 위해서 웨이블릿 변환에 기초한 디지털 워터마킹 방법을 제안하였다. 이미지의 중요한 성분인 저주파 성분을 비롯한 각 대역의 가능한 모든 위치에 다양한 가중치와 임계값을 적용하는 워터마크 삽입방법을 통하여 손실압축, 고의적인 영상의 변형 등 각종 공격에 대하여 상반관계에 있는 비가시성과 강인성을 만족하는 워터마크 양에 대한 적정선과 삽입대역을 찾는 방법을 제안하였다. 제안한 방법이 적정한 워터마크 삽입영역과 적절한 워터마크양을 찾을 수 있음을 실험을 통하여 입증하였다.

• Journal of Welding and Joining
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• 제28권6호
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• pp.76-83
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• 2010

The purpose of this study is to propose a method to decide near-optimal settings of the constant current fuzzy control parameters using a controlled random search. This method tries to find the near-optimal settings of the constant current fuzzy control parameters through experiments. It has an advantage of being able to carry out searches in the search domain which includes some irregular points. The method suggested in this study was used to determine the fuzzy control parameters by which the desired welding current were formed during inverter DC resistance spot welding. The output variable was the ITAE (integral of time multiplied by the absolute error). This output variable was determined according to the input variables, which are the GE, GDE, and GDU. This study described how to obtained near-optimal welding current condition over a wide search space conducting a relatively small number of experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.501-503
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• 1999

In this paper, the design method of a hybrid fuzzy controller with an optimal auto-tuning method is proposed. The conventional PID controller becomes so sensitive to the control environments and the change of parameters that the efficiency of its utility for the complex and nonlinear plant has been questioned in transient state. In this paper, first, a hybrid fuzzy logic controller(HFLC) is proposed. The control input of the system in the HFLC is a convex combination by a fuzzy variable of the FLC's output in transient state and the PID's output in steady state. Second, a powerful auto-tuning algorithm is presented to automatically improve the Performance of controller, utilizing the improved complex method and the genetic algorithm. The algorithm estimates automatically the optimal values of scaling factors and PID coefficients. Controllers are applied to the plants with time-delay and the DC servo motor Computer simulations are conducted at the step input and the system performances are evaluated in the ITAE.