• The KIPS Transactions:PartA
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• v.19A no.1
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• pp.1-8
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• 2012

Network-based intelligent robot is connected with network system, provides interactions with humans, and carries out its own roles on ubiquitous computing environments. URC (Ubiquitous Robot Companion) robot has been proposed to develop network-based robot by applying distributed computing techniques. On URC robot, it is possible to save the computing power of robot client by environments, has been proposed to develop robot software using service-oriented architecture on server-client computing environments. The SOMAR client robot consists of two layers - device service layer and robot service layer. The device service controls physical devices, and the robot service abstracts robot's services, which are newly defined and generated by combining many device services. RSEL (Robot Service Executing Language) is defined in this paper to represent relations and connections between device services and robot services. A RESL document, including robot services by combining several device services, is translated to a programming language for robot client system using RSEL translator, then the translated source program is compiled and uploaded to robot client system with RPC (Remote Procedure Call) command. A SOMAR client system is easy to be applied to embedded systems of host/target architecture. Moreover it is possible to produce a light-weight URC client robot by reducing workload of RSEL processing engine.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.6-9
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• 2010

URC 로봇 클라이언트는 원가 절감 및 하드웨어 경량화를 위해 최소한의 요소로 구성되며, 필요한 기능을 외부 디바이스와의 연동 또는 서버를 통해 전송받아 작업을 수행하게 된다. 기존의 URC 로봇 시스템은 이기종간의 제약 없는 서비스를 제공하기 위해서 웹 서비스를 사용하고, 워크플로우 표준 언어인 BPEL 을 기반으로 한 워크플로우 엔진을 사용하고 있다. 로봇 클라이언트의 제한 된 자원으로 인해 대부분의 URC 로봇 시스템은 서버에서 BPEL 엔진을 동작시키고, 네트워크를 통해서 클라이언트의 서비스를 호출하는 구조를 가지게 된다. 이에따라 기존 로봇 시스템은 클라이언트 서비스 호출로 인한 네트워크 부하가 발생하는 문제가 있다. 본 논문에서는 경량화 된 B2J 시스템을 이용하여 로봇 클라이언트에서 BPEL의 실행을 수행하는 DBRS를 제안한다. 기존의 B2J는 BPEL 문서를 Java 코드로 변환, 컴파일, 실행하는 과정을 같은 환경에서 수행했으나 DBRS에서 사용되는 경량화 된 B2J 는 변환자와 실행자를 분리함으로써 요구사항을 낮추고 로봇의 제한된 자원을 절약한다. DBRS 는 다른 BPEL 엔진을 사용하는 로봇 시스템에 비해 클라이언트의 제한된 자원을 절약하고, 로봇 서비스 호출에 의해 발생하는 네트워크 부하가 감소한다.

• Journal of Convergence for Information Technology
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• v.12 no.1
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• pp.7-14
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• 2022

Unlike general maps, the underground geospatial Information is a system made to view underground information in a 3D shape. This system is managed by a tile maps to lighten the data. But there are various underground structures in the basement, and the structures are made of 3D data, so the data size is large. Therefore, when a client mobile program requests a tile map, the service server fetches the requested tile map from the DB server and transmits ti to the client, but there is a transmission delay time problem. In this paper, we design the tile cache method to improve the request response speed for the tile map data provided to the client in the mobile underground geospatial information system. We propose a method in which a service server predicts and prefetchs the next tile map while the client is viewing tile map, and stores the prefetching data in the memory of client mobile terminal. Then, the transmission delay time problem can be solved.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.6
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• pp.63-71
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• 2006

In this paper, we propose a secure solution for user authentication by using fingerprint verification on the sensor-client-server model, even with the client that is not necessarily trusted by the sensor holder or the server. To protect possible attacks launched at the untrusted client, our solution makes the fingerprint sensor validate the result computed by the client for the feature extraction. However, the validation should be simple so that the resource-constrained fingerprint sensor can validate it in real-time. To solve this problem, we separate the feature extraction into binarization and minutiae extraction, and assign the time-consuming binarization to the client. After receiving the result of binarization from the client, the sensor conducts a simple validation to check the result, performs the minutiae extraction with the received binary image from the client, and then sends the extracted minutiae to the server. Based on the experimental results, the proposed solution for fingerprint verification can be performed on the sensor-client-server model securely and in real-time with the aid of an untrusted client.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.251-252
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• 2012

모바일 환경에서의 모니터링 시스템은 경량 디바이스의 특징을 고려하여 설계 및 구현해야 한다. 이에 적합한 기법이 서비스 기반의 모바일 응용 기술이다. 대부분의 기능을 서버에 두고 클라이언트에서 호출하여 사용하는 구조이다. 이 논문에서는 안드로이드 기반의 스마트폰을 연동한 모니터링 시스템의 구조를 설계한다. 또한 서버와 클라이언트의 구현 내용을 기술한다. 서버는 JAVA로 구현하고, 클라이언트는 안드로이드를 이용하여 구현하는 내용을 제시한다.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.509-520
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• 2009

The advancement of network & application technology causes a major change for the use of IT(Information Technology) equipment, including computer and mobile system. In the process from beginning with main frame in the 1960s and 70's, through the server-client paradigm in the 1980s and toward the development of network computer since 90's, computer systems are now evolutioning from isolated physical system to complementary network based virtual system[1][2]. In network based computer system, application and data required for operation are stored at not client as local system, but at server[1]. User can use application & data on a server as if those are on a local client, and a client is now toward a developing thin and network friendly system. In this paper, we discuss possible ways for the efficient implementation of thin-client. For the use of remote application & data as if in local environment, we make use of X protocol. Unlike formal simple Client - Server paradigm, we design a Proxy for middle-tier server for the improvement of QoS and session persistence. X server, Xvfb(X virtual frame buffer) are implemented on thin client and Server, respectively and we applied XSMP(X Session Management Protocol) to our framework for session management. In the end, beyond simple transfer of server display, we suggest thin client framework for the transfter of remote server application over internet.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.245-253
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• 2007

In this paper, we propose an effective web service software platform for remote monitoring and control. We removed the servlet container for better web service performance so as to improve the gSOAP processing which is an essential element of web service implementation. Furthermore, we designed the web service server/client software platform which can be applied to robot or ubiquitous sensor applications. For validation of this study we tested it by manufacturing robot hardware for monitoring control which combined tanks and sensors on a LDS4000 engine board mounted with a PXA270 processor. The practical excellence and the efficiency of the result of this study was validated by the comparison of gSOAP message exchange load between the web service client application and the conventional remote monitoring control technique through a web server.

• Convergence Security Journal
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• v.20 no.4
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• pp.209-215
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• 2020

The environment of the Internet provides an efficient communication of the things which are connected. While internet and online service provide us many valuable benefits, online services offered and accessed remotely through internet also exposes us to many different types of security threats. Most security threats were just related to information leakage and the loss of authentication on client-server environment. In 2016, Ahmed et al. proposed an efficient lightweight remote user authentication protocol. However, Kang et al. show that it's scheme still unstable and inefficient. It cannot resist offline identity guessing attack and cannot provide session key confirmation property. Moreover, there is some risk of biometric information's recognition error. In this paper, we propose an improved scheme to overcome these security weaknesses by storing secret data in device. In addition, our proposed scheme should provide not only security, but also efficiency since we only use hash function and XOR operation.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1135-1138
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• 2001

본 논문에서는 클라이언트/서버 환경에서의 온실 환경 자원을 원격지에서 제어하는 실시간 모니터링 방법을 제안하고 구현하였다. 자바의 JApplet과 자바의 경량 컴포넌트로 구현된 본 시스템은 웹을 사용하여 관리자의 인증을 거친 후 직접적으로 제어를 담당하는 서버에게 제어 명령을 하게 된다. 제어 서버는 자바 확장 팩키지 JFC와 Commutation API를 이용하였고, 클라이언트는 JApplet과 JFC를 이용하였으며 서버는 IIS 5.0과 ASP를 이용하여 웹 서비스를 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1571-1574
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• 2010

최근 자료 송수신을 위한 분산 컴퓨팅 시스템들이 다양하게 연구되고 있다. 특히 센서를 이용하는 임베디드 어플리케이션들을 위한 분산 시스템들은 다양한 방면으로 연구되고 있다. 그 중 분산 미들웨어는 다양한 하드웨어 시스템과 응용 시스템 중간에 존재하며 유기적인 연결을 돕는 역할을 해왔다. 분산 미들웨어는 크게 원격 객체 관리를 위한 서버-클라이언트 모델, 메시지 패싱을 목적으로 하는 메시지 패싱 모델, 자료 분배를 목적으로 하는 출반-구독 모델로 나눌 수 있다. 이중출판-구독 모델은 원하는 데이터를 선택하여 다양한 수신 단말에 전송하기에 최적화된 구조를 지닌다. 본 논문에서는 대표적인 출판-구독 모델인 Data Distribution Service 를 소개하고 특정 상황에서 발생할 수 있는 네트워크 집중화를 막기 위해 오버레이 네트워크를 이용하는 기법을 제시한다.