• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.932-935
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• 2015

This paper proposes a rectifier using bootstrapping and active body biasing in $0.11{\mu}m$ RF CMOS process. The proposed rectifier employs the full-wave rectifying structure with cross coupling and increases the power conversion efficiency by reducing the threshold voltage and leakage current using bootstrapping and active bias biasing. Also, it has been designed to be applied to a wide range of applications from 13.56 MHz used in wireless power transmission to 915 MHz used in RFID. As a measured result, 80 % of power conversion efficiency is obtained when the input power is 0 dBm at $10k{\Omega}$ load resistance and 13.56 MHz. Also 40 % of power conversion efficiency is shown in 915 MHz.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.6
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• pp.30-38
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• 1998

In this paper, a new CMOS current-mode integrator is proposed that can apply the basic building block of the low-voltage high frequency current-mode active filter. And tuning circuits that control the gain and unity gain frequency of them is designed. The proposed integrator is composed of the CMOS complementary circuit which can extend transconductance of an integrator. Therefore, the unity gain frequency which is determined transconductance and MOSFET gate capacitance can be expanded by the proposed integrator. The unity gain frequency of the proposed integrator is increased about two times larger than that of the conventional continuous-time integrator with NMOS-gm. And also, cut-off frequency and gain of the active filter can be controlled with the designed tuning circuit. From the result, we can reduce errors on fabrication. And then, 3rd-order low-pass active filter is designed as an application circuits. These results are verified by the small signal analysis and the 0.8$\mu\textrm{m}$ parameter HSPICE simulation.

• Journal of KIISE:Software and Applications
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• v.35 no.5
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• pp.306-312
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• 2008

In a goal-oriented dialogue, speaker's intention can be approximated by a semantic structure that consists of a pair of a speech act and a concept sequence. Therefore, it is very important to correctly identify the semantic structure of an utterance for implementing an intelligent dialogue system. In this paper, we propose a model to efficiently analyze the semantic structures based on an active teaming method. To reduce the burdens of high-level linguistic analysis, the proposed model only uses morphological features and previous semantic structures as input features. To improve the precisions of semantic structure analysis, the proposed model adopts CRFs(Conditional Random Fields), which show high performances in natural language processing, as an underlying statistical model. In the experiments in a schedule arrangement domain, we found that the proposed model shows similar performances(92.4% in speech act analysis and 89.8% in concept sequence analysis) to the previous models although it uses about a third of training data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1963-1970
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• 1998

In this paper, a two-dimensional slotline coupling structure is proposed for the planar active phased array antenna system with scanning the beam by coupled oscillators without phase shifters. The operating characteristics are analyzed and experimentally demonstrated. The proposed two-dimensional slotline coupling structure consists of $|{=}|$-type slotline in the ground plane for the coupling of E-plane and H-plane. From the simulation results of coupling strength with the variation of width, length and the number of slotlines, the optimal coupling structure is proposed and applied to $2{\times}5$ elements of planear phased array antenna. The experimental results show that the beamwidth of E-plane and H-pland are $42^{\circ}$ and $15^{\circ}$, respectivly, and the scanning range is from $-20^{\circ}$ to $15^{\circ}$ from the broadside. Therefore, it is shown the two-dimensional slotline coupling structure for oscillator-type active phased array antenna can be applied to the planar phased array antenna system.

• The Transactions of the Korea Information Processing Society
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• v.4 no.8
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• pp.1907-1920
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• 1997

In this paper, we present integrated model of postal business that would be newly organized. The integrated model is developed through four phase. First, postal business is analyzed by three parts;collection, transportation and delivery. Second, the modeling criteria are developed that will be used for designing integrated postal business model. Third, object-oriented concepts are used by the steps of postal business modeling criteria captured. Finally, methods applied to developed model are grouped according to their function. Also, active-based mechanisms such as trigger and constraints are developed, and knowledge-based mechanisms such as inference are developed. These selected methods and attributes are encapsulated into objects. These constitute an object-active-knowledge based database model. Finally, Operational Scenario and Service Scenario are composed for real application according to proposed O-A-K model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2163-2170
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• 2009

We present an automated, energy minimized-based method for Lung parenchyma segmenting Chest Computed Tomography(CT) datasets. Deformable model is used for energy minimized segmentation. Quantitative knowledge including expected volume, shape of Chest CT provides more feature constrain to diagnosis or surgery operation planning. Segmentation subdivides an lung image into its consistent regions or objects. Depends on energy-minimizing, the level detail image of subdivision is carried. Segmentation should stop when the objects or region of interest in an application have been detected. The deformable model that has attracted the most attention to date is popularly known as snakes. Snakes or deformable contour models represent a special case of the general multidimensional deformable model theory. This is used extensively in computer vision and image processing applications, particularly to locate object boundaries, in the mean time a new type of external force for deformable models, called gradient vector flow(GVF) was introduced by Xu. Our proposed algorithm of deformable model is new external energy of GVF for exact segmentation. In this paper, Clinical material for experiments shows better results of proposal algorithm in Lung parenchyma segmentation on Chest CT.

• Journal of KIISE
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• v.43 no.7
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• pp.795-800
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• 2016

In image classification, recent CNNs compete with human performance. However, there are limitations in more general recognition. Herein we deal with indoor images that contain too much information to be directly processed and require information reduction before recognition. To reduce the amount of data processing, typically variational inference or variational Bayesian methods are suggested for object detection. However, these methods suffer from the difficulty of marginalizing over the given space. In this study, we propose an image-text integrated recognition system using active vision based on Spatial Transformer Networks. The system attempts to efficiently sample a partial region of a given image for a given language information. Our experimental results demonstrate a significant improvement over traditional approaches. We also discuss the results of qualitative analysis of sampled images, model characteristics, and its limitations.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.141-147
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• 2006

부채널 정보를 이용한 공격이 제안된 이후, 스마트카드와 RFID와 같은 저 전력 정보보호 장치 내부의 암호 프로세서에서 소비되는 전력을 분석하여 암호 연산에 사용된 비밀 정보를 알아내는 공격 방법은 가장 위협적인 물리적 공격 방법으로 알려져 있다. 하지만 측정된 소비 전력 신호를 시간 영역에서 분석하는 기존의 분석 기법들은 암호 연산 시점이 시간 축 상에서 동일하여야 된다는 단점을 가지고 있다. 제안하는 주파수 분석 공격 방법은 공격이 적용되는 장치에서 측정된 시간 영역에서 정렬되지 않는 신호를 Fourier 변환을 하여 주파수 영역에서 분석함으로써 기존 전력 분석 공격이 시간 영역에서 정렬된 소비 전력 신호를 필요로 하는 문제점을 해결하였다. UC Berkeley에서 제작된 능동형 RFID 모듈에 국내 표준인 ARIA 알고리즘을 응용프로그램으로 탑재하여 기존 전력 분석 공격과 제안하는 주파수 분석 공격을 적용하여 결과를 분석 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.856-858
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• 2001

지적 재산권 보호 중에서 디지털 저작물 보호는 근래에 활발히 연구되고 있으며 법 과학 분야는 지문감식, 치아감정, DNA 등 많은 분야가 있다. 법과학 분야 중 법적용 컴퓨팅(Forensic Computing)에 관한 응용은 새로운 연구 과제이다. 그 중에서도 디지털 저작물에 대하여 증거를 보전 하고자 많은 연구가 진행되고 있지만 디지털 저작물에 관하여 네트워크를 통한 능동적 저작물 보호는 미약하다. 현재의 데이터 추출(Extraction), 발굴(Exploitation), 복구, 암호 해독, 패스워스 풀기(Defeat), 미러 이미징 등의 방법 가지고 해결 못하는 경우와 인터넷 상에서 온라인으로 이루어지는 불법 복제에서 결정적 기여(smoking gun)를 찾아내려고 하는 것이 본 논문에서 해결 하고자 하는 부분이다. 오프라인일 경우도 가능하며 분석된 결과는 변호사/대리인, 법인, 보험회사, 법집행관 등에게 온라인으로 제공한다. 진행 과정은 서버에서 파견시킨, 미션을 부여받은 에이전트가 저작물 불법 복제 상황을 트래킹 한 후, 네트워크를 통하여 정해진 시간별로 서버에 전달하면, 법 조항과 매핑시켜서 분석한 다음 서버의 지식베이스에 저장되어 사용자의 요구에 응하는 능동형 디지털 저작물 보호 관리 시스템이다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.111-118
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• 2008

RIA(Rich Internet Application) has the best User Interface and easy way to use. It is used in many Application System and Web Application. This Paper introduces a RIA technology for Implementation of u-Hospital Application. This System uses a history of customers in the hospital and question about diseases, so we can improve the satisfaction of service. This paper shows that the u-Hospital System using RIA is more fast and easy than HTML application. Because RIA has special features that data can be obtained from server without reloading entire page and every user interaction does not require web server response. The proposed technology can improve the efficient u-Hospital System because it can be extended to ubiquitous mobile application.