• 한국멀티미디어학회논문지
• /
• 제2권3호
• /
• pp.243-251
• /
• 1999

본 논문에서는 MPEG 비디오 데이터들을 효율적으로 색인하고 검색하기 위한 키를 정의하는 새로운 방식 을 제안한다. 기존의 방법들은 추출된 Shot과 사용자의 질의 영상올 여러 가지 특정으로 패턴 매칭하므로 수행시간이 오래 걸린다, 이에 반해,제안하는PKey생성 방법은추출된PFrame의 영상을여러 가지 특징으로 영상을 특정한 비트로 코드화하여 저장하므로 색인과 검색시에 사용자가 질의한 영상의 PKey를 사용하여 수행속도를 높일 수 있다 사용자 질의에 대한 투명성을 위해 비구문 기반 서술에 대한 5가지의 특정을 PKey로서 정의하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1662-1667
• /
• 2005

In this paper, analysis, design, control and prototype construction of a wearable wire-driven haptic interface called HapticPen is discussed. This device can be considered as a wire driven parallel mechanism which three wires are attached to a pen-tip. Wire tensions are provided utilizing three DC servo motors which are attached to a solid frame on the user's body. This device is designed as input as well as output device for a wearable PC. User can write letters or figures on a virtual plate in space. Pen-tip trajectory in space is calculated using motor encoders and force feedback resulting from contact between pen and virtual plate is provided for constraining the pen-tip motion onto the virtual plane that can be easily setup by arbitrary non-collinear three points in space. In this paper kinematic model, workspace analysis, application analysis, control and prototype construction of this device are presented. Preliminary experiments on handwriting in space show feasibility of the proposed device in wearable environments.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제17권1호
• /
• pp.23-28
• /
• 2017

Non-volatile RAM (NVRAM) provides many opportunities to improve the performance of computing devices. In this paper, we present an approach that reduces the user-perceived latency of browsers by using NVRAM. To this end, we first analyze the browser launch process, and then employ several techniques that improve the performance of each step by using NVRAM. Specially, we focus on minimizing the launch time of browser by 1) prefetching the block sequence required for browser launch, 2) caching the web resources in the fast NVRAM, and 3) reusing the displayed bitmap data in the frame buffer. Through implementation, we show that our scheme significantly reduces the launch time of browsers.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1999년도 전력전자학술대회 논문집
• /
• pp.71-75
• /
• 1999

In this paper, we present the 3DOF force-reflecting interface which allows to acquire force of object within a virtual environment. This system is composed of device, virtual environment model, and force-reflecting rendering algorithm. We design a 3 DOF force-reflecting device using the parallel linkage, torque shared by wire, and the controller of system applied by impedance control algorithm. The force-reflecting behaviour implemented as a function position is equivalent to controlling the mechanical impedance felt by the user. Especially how force should be supplied to user, we know using a God-Object algorithm. As we experiment a system implemented by the interface of 3D virtual object and 3DOF force-reflecting interface, we can feel a contact, non-contact of 3D virtual object surface and sensing of push button model.

• Asia pacific journal of information systems
• /
• 제3권1호
• /
• pp.31-53
• /
• 1993

Computer Aided Software Engineering(CASE) tools are suggested as an automated method for the efficient development of softwares. This study are intended to measure the use level of CASE tools and to provide the meaningful information on the whole software development environment supported by CASE tools. Therefore, the results of a survey on CASE environment in Korea are empirically reported and analyzed. The use of CASE tools is measured; purposes purchasing CASE tools and achievement levels are investigated. Implications from the comparative analysis of the utilization of software engineering methodologies between the CASE user group and the non-user group are described. A proposition is suggested to check the request frequency for program change. Further studies on the reverse engineering, program reuse and the use of CASE tools under distributed processing systems such as client-server environments are suggested.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1999년도 추계 학술대회논문집
• /
• pp.145-151
• /
• 1999

An Interactive grid generation program(KGRID) with graphical user interface(GUI) has been improved. KGRID works on the UNLX environment and GUI has been implemented with OSF/Motif and X Toolkit and the graphics language is Open GL for visualization of the 3D objects. It supports more convenient user environment to generate 2D and 3D multi-block structured grid systems. It provides various useful field grid generation methods, which are the algebraic methods, the elliptic partial differential equations method and the predictor-corrector method. It also supports 3D surface grid generation with NURBS(Non-Uniform Rational B-Spline) and various stretching functions to control grid points distribution on curves and surfaces. And some menus are added to perform flexible management, for the objects. We generated surface and field grid system about full aircraft configuration using KGRID. The performance and stability of the KGRID is verified through the generation of the grid system about a complex shape.

• 한국컴퓨터산업학회논문지
• /
• 제2권9호
• /
• pp.1233-1238
• /
• 2001

전자상거래가 활성화되면서 상거래 기능과 거래되는 업무가 증가함에 따라 교환되는 메시지도 다양하게 되어, 개인정보, 결제정보(계좌번호, 카드번호, 비밀번호 등), 개인정보 등, 이러한 메시지에 대한 보안이 요구된다. 그래서 본 논문에서는 인터넷 환경 하에서 안전하게 메시지를 전송하기 위해 암호와 전자서명을 적용한 안전한 XML 메시징 시스템인 Secure-XML Messaging 시스템(S-XMS)은 위해 제안하였으며, 여러 보안 서비스 중 메시지 비밀보장 서비스, 사용자 인증 서비스, 메시지 무결성 서비스, 부인불능 서비스를 선정하여 구현하였다.

• 한국정보통신학회논문지
• /
• 제5권5호
• /
• pp.960-969
• /
• 2001

본 논문에서는 웹 페이지 제작을 위한 기본지식이 전혀 없는 초보자나 비전공자라 할지 라도 간단한 마우스 조작과 최소한의 필요정보 입력만으로 가상강의 홈페이지를 사용자의 요청에 따라 제작할 수 있고, 제작 완료한 홈페이지는 지정한 임의의 서버에 자동으로 설치할 수 있으며, 홈페이지의 운용과정에서 요구되는 홈페이지의 수정은 웹 페이지 소스를 직접 수정하지 않더라도 손쉽게 유지보수 할 수 있도록 하는 주문형 페이지 자동화 시스템과 이의 구현방법에 관해 연구하였다.

• 한국통신학회논문지
• /
• 제35권3A호
• /
• pp.260-268
• /
• 2010

Channel inversion is one of the simplest techniques for multiuser downlink systems with single-antenna users. In this paper, we extend the regularized channel inversion technique developed for the single-antenna user case to multiuser multiple-input multiple-output (MIMO) channels with multiple-antenna users. We first employ the multiuser preprocessing to project the multiuser signals near the null space of the unintended users based on the MMSE criterion, and then the single-user preprocessing is applied to the decomposed MIMO interference channels. In order to reduce the complexity, we focus on non-iterative solutions for the multiuser transmit beamforming and use a linear receiver based on an MMSE criterion. Simulation results show that the proposed scheme outperforms existing joint iterative algorithms in most multiuser configurations.

• Management Science and Financial Engineering
• /
• 제20권2호
• /
• pp.7-12
• /
• 2014

Content Delivery Network (CDN) has evolved to overcome a network bottleneck and improve user perceived Quality of Service (QoS). A CDN replicates contents from the origin server to replica servers to reduce the overload of the origin server. CDN providers would try to achieve an acceptable performance at the least cost including the storage space or processing power. In this paper, we introduce a new optimization model for the CDN design problem considering the user perceived QoS and single path (non-bifurcated) routing constraints and analyze the computational complexity for some special cases.