• Journal of KIISE:Databases
• /
• v.29 no.4
• /
• pp.321-333
• /
• 2002

As web-based services are becoming more and more popular, concurrent updates of spatial data should be possible in the web-based environments in order to use the various services. Web-based GIS applications are characterized by large quantity of data providing and these data should be continuously updated according to various user's requirements. Faced with such an enormous data providing system, it is inefficient for a server to do all of the works of updating spatial data requested by clients. Besides, the HTTP protocol used in the web environment is established under the assumption of 'Connectionless'and 'Stateless'. Lots of problems may occur if the scheme of transaction processing based on the LAN environment is directly applied to the web environment. Especially for long transactions of updating spatial data, it is very difficult to control the concurrency among clients and to keep the consistency of the server data. This paper proposes a solution of keeping consistency during updating directly spatial data in the client-side by resolving the Dormancy Region Lock problem caused by the 'Connectionless'and 'Stateless'feature of the HTTP protocol. The RX(Region-eXclusive) lock and the periodically sending of ALIVE_CLIENTi messages can solve this problem. The protocol designed here is verified as effective enough through implementing in the main memory spatial database system, called CyberMap.

• Journal of Internet Computing and Services
• /
• v.23 no.1
• /
• pp.49-68
• /
• 2022

The operation system of a shipping company is still maintaining the mainframe based terminal access environment or the client/server based environment. Nowadays shipping companies that try to migrate it into a web-based environment are increasing. However, in the transition, if the design is processed by the old configuration and knowledge without considering the characteristics of the web-based environment and shipping business, various security vulnerabilities will be revealed at the actual system operation stage, and system maintenance costs to fix them will increase significantly. Therefore, in the transition to a web-based environment, a security design must be carried out from the design stage to ensure system safety and to reduce security-related maintenance costs in the future. This paper examines the characteristics of various threat modeling techniques, selects suitable modeling technique for the operation system of a shipping company, applies data flow diagram and STRIDE threat modeling technique to shipping business, derives possible security threats from each component of the data flow diagram in the attacker's point of view, validates the derived threats by mapping them with attack library items, represents the attack tree having various attack scenarios that attackers can attempt to achieve their final goals, organizes into the checklist that has security check items, associated threats and security requirements, and finally presents 23 security requirements that can respond to threats. Unlike the existing general security requirements, the security requirements presented in this paper reflect the characteristics of shipping business because they are derived by analyzing the actual business of a shipping company and applying threat modeling technique. Therefore, I think that the presented security requirements will be of great help in the security design of shipping companies that are trying to proceed with the transition to a web-based environment in the future.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.5 no.5
• /
• pp.471-479
• /
• 2015

This study was conducted to make use of Korea Meteorological Administration(KMA)'s Automatic Weather Station(AWS) data to operate smart green greenhouse. A Web-based KMA AWS data receiving system using JAVA and APM_SETUP 8 on windows 7 platform was developed. The system was composed of server and client. The server program was developed by a Java application to receive weather data from the KMA every 30 minutes and to send the weather data to smart greenhouse. The client program was developed by a Java applets to receive the KMA AWS data from the server every 30 minutes through communicating with the server so that smart greenhouse could recognize the KMA AWS data as the ambient weather information. This system was evaluated by comparing with local weather data measured by Inc. Ezfarm. In case of ambient air temperature, it showed some difference between virtual data and measured data. But, the average absolute deviation of the difference has a little difference as less than 2.24℃. Therefore, the virtual weather data of the developed system was considered available as the ambient weather information of the smart greenhouse.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.5
• /
• pp.935-940
• /
• 2023

Digital-twin technology is emerging as an innovative solution for all industries, including manufacturing and production lines. Therefore, this paper optimizes all the energy used in a biomass plant based on unused resources. We will then implement a digital-twin prototype for biomass plants and evaluate its performance in order to improve the efficiency of plant operations. The proposed digital-twin prototype applies a standard communication platform between the framework and the gateway and is implemented to enable real-time collaboration. and, define the message sequence between the client server and the gateway. Therefore, an interface is implemented to enable communication with the host server. In order to verify the performance of the proposed prototype, we set up a virtual environment to collect data from the server and perform a data collection evaluation. As a result, it was confirmed that the proposed framework can contribute to energy optimization and improvement of operational efficiency when applied to biomass plants.

• The KIPS Transactions:PartA
• /
• v.9A no.3
• /
• pp.327-332
• /
• 2002

Conventional proxy web cache, which is generally used to caching server, is a content-copy based system. This method focuses on speeding up the phase delivery not improving the webserver performance. However, if immense clients attempt to connect the webserver simultaneously, the proxy web cache cannot achieve the desired result. In this paper, we propose the web accelerator called the SCALA-AX, whitch improves web server performance by accelerating the delivery contents. The SCALA-AX is built in the Linux-based kernel as a kernel modulo and works in combination with the conventional webserver program. The SCALA-AX speeds up the processing rate of the webserver, because it processes the requests using the kernel thread. The SCALA-AX also applies the well-developed cache algorithm to the processing, and thus it obtains the advantage of the caching server without installing additional hardware. A banchmarking test demonstrates that the SCALA-AX improves webserver performance by up to 500％ for content delivery.

• Journal of the Korea Society of Computer and Information
• /
• v.15 no.6
• /
• pp.37-48
• /
• 2010

In general, an HTTP server sends information in response to requests from clients. Since it does not support active information delivery to clients, it can not efficiently provide the rapidly changing information to clients. Overcoming this shortcoming of the HTTP protocol, the technology known as server push enables the HTTP server to actively provide information to clients without explicit requests from clients. Adobe BlazeDS is a web server supporting the server push technology, helping users to develop web-based push applications. Unfortunately, since the BlaseDS server have no functions of filtering the information to be pushed according to various types of users, there are difficulties in developing push applications handling various situations in a efficient way. In this paper, to support effective development of push applications on BlazeDS we present the methods of adding a message filtering facility to BlazeDS and utilizing it. According to the filtering request of clients, the message filtering facility modifies information to be pushed, sending the modified information to the clients. The extended BlazeDS server with the message filtering facility provides environments to easily develop push services customized for various clients with their own situations.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.9
• /
• pp.574-584
• /
• 2006

Recently, ISO/IEC 23000 (also known as 'MPEG-A') has proposed a new file format called 'MAF(Multimedia Application File Format)[1]' which provides a capability of integrating/storing the widely-used compression standards for audio and video and the metadata in MPEG-7 form into a single file format. However, it is still very hard to verify the usefulness of MPEG-A in the real applications because there is still no real system that fully implements this standard. In this thesis, a design and implementation of a multimedia retrieval system based on MPEG-A standard on PC and mobile device is presented. Furthermore, an extension of MPEG-A for describing the metadata for video is also proposed. It is selected and defined as a subset of MPEG-7 MDS[4] and TV-anytime[5] for video that is useful and manageable in the mobile environments. In order to design the multimedia retrieval system based on MPEG-A, we define the system requirements in terms of portability, extensibility, compatibility, adaptability, efficiency. Based on these requirements, we design the system which composed of 3 layers: Application Layer, Middleware Layer, Platform Layer. The proposed system consists of two sub-parts, client-part and server-part. The client-part consists of MAF authoring tool, MAP player tool and MAF searching tool which allow users to create, play and search the MAF files, respectively. The server-part is composed of modules to store and manage the MAF files and metadata extracted from MAF files. We show the usefulness of the proposed system by implementing the client system both on MS-Windows platform on desk-top computer and WIPI platform on mobile phone, and validate whether it to satisfy all the system requirements. The proposed system can be used to verify the specification in the MPEG-A, and to proves the usefulness of MPEG-A in the real application.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2007.04a
• /
• pp.324-328
• /
• 2007

유비궈터스 헬스케어는 단일화된 서비스가 아니라 다양한 기술들이 복합적으로 결합되어 운용되는 서비스이다. 따라서 서비스의 형태가 고정적이지 않고 매우 다양하게 나타난다. 하지만 실제로 차이가 발생하는 부분은 서비스의 구현에 관한 세부적 내용에서 나타나고, 서비스 운용을 위한 기본 구성요소에 있어서는 큰 차이가 없이 유사한 형태를 가진다. 그 결과 유비쿼터스 헬스케어 서비스 개발 과정에서는 실제 서비스의 구현 외의 통신과 데이터베이스의 이용, 메시지 전달과 같은 중복되는 항목에 대한 고려가 매번 이루어져야 한다. 이것은 개발 과정에 있어 불필요한 비용의 증가를 불러온다. 본 논문에서는 이와 같은 불필요한 비용을 감소시키며 서비스의 개발과 운용이 가능한 유비쿼터스 헬스케어 서비스의 제공을 위한 아키텍처와 서비스 개발을 위한 프레임워크를 제안한다. 제안하는 서비스 제공 아키덱처는 크게 이용자 단말, 유비궈터스 헬스케어 서비스 센터, 외부 기관으로 구성된다. 서비스 개발 프레임워크는 서버와 클라이언트 프레임워크로 구분된다. 서비스 개발 프레임워크는 서비스를 제공하는 서버에서 필요한 유비쿼터스 헬스케어 서비스의 공통 구성요소를 가진다. 서비스의 개발을 위해 우선 프로세스에 대한 정의를 수행하고, 정의된 내용에 따라 필요한 코드 템플릿을 결합하여 서비스의 초기 형태를 만들어낸다. 여기에 각 서비스가 필요로 하는 세부 사항을 작성하는 것으로 서비스의 개발을 수행하게 된다. 제안된 서비스 제공 아키텍처와 서비스 개발 프레임워크를 실제 적용해보기 위해 전림선비대증 환자 진료를 위한 시스템을 설계하고 구현하였다.JSHOP2 계획수립기내에 구현하였다. 계획 실행 방법으로는 주어진 강건한 계획에 대하여 행위들이 직접 실행하수 있도록 한다.며 용량에 의존하는 양상을 보였다. $H_2O_2$에 의해 유발(誘發)된 DNA의 손상은 catalase와 deferoxamine에 의해 억제되었지만 DPPD는 억제시키지 못했다. 배기음(排氣飮)은 $H_2O_2$에 의해 유발(誘發)된 ATP의 소실을 회복시켰다. 이러한 실험결과 $H_2O_2$에 의해 유발(誘發)된 세포(細胞)의 손상(損傷)은 지질(脂質)의 과산화(過酸化)와는 다른 독립적인 기전에 의해 일어남을 나타낸다. 결론 : 이러한 결과들로 볼 때 Caco-2 세포(細胞)에서 배기음(排氣飮)이 항산화작용(亢酸化作用)보다는 다른 기전을 통하여 Caco-2 세포안에서 산화제(酸化劑)에 의해 유발(誘發)된 세포(細胞)의 사망(死亡)와 DNA의 손상(損傷)을 방지할 수 있다는 것을 가리킨다. 따라서 본 연구(硏究)는 배기음(排氣飮)이 반응성산소기(反應性酸素基)에 의해 매개된 인체(人體) 위장관질환(胃腸管疾患)의 치료(治療)에 사용할 수 있을 가능성(可能性)이 있음을 제시하고 있다.에 이를 이용하여 유가배양시 기질을 공급하는 공정변수로 사용하였다 [8]. 생물학적인 폐수처리장치인 활성 슬러지법에서 미생물의 활성을 측정하는 방법은 아직 그다지 개발되어있지 않다. 본 연구에서는 슬러지의 주 구성원이 미생물인 점에 착안하여 침전시 슬러지층과 상등액의 온도차를 측정하여 대사열량의 발생량을 측정하고 슬러지의 활성을 측정할 수 있는 방법을

• Journal of KIISE:Software and Applications
• /
• v.31 no.9
• /
• pp.1226-1232
• /
• 2004

Biometric authentication is rising technology for the security market of the next generation. But most of biometric systems are developed using only one of various biological features. Recently, there is a vigorous research for the standardization of various biometric systems. In this paper, we propose a web-based authentication system using three other verifiers based on functional, parametric, and structural approaches for one biometrics of handwritten signature, which is conformable to a specification of BioAPI introduced by BioAPI Consortium for a standardization of biometric technology. This system is developed with a client-server structure, and clients and servers consist of three layers according to the BioAPI structure. The proposed neb-based multiple authentication system of one biometrics can be used to highly increase confidence degree of authentication without additional several biological measurements, although rejection rate is a little increased. That is, the false accept rate(FAR) decreases on the scale of about 1:40,000, although false reject rate(FRR) increases about 2.7 times in the case of combining above three signature verifiers. So the proposed approach can be used as an effective identification method on the internet of an open network. Also, it can be easily extended to a security system using multimodal biometrics.

• Journal of Korea Multimedia Society
• /
• v.1 no.1
• /
• pp.45-55
• /
• 1998

In the tele-medical system, the broadband network for multimedia telecommunication and the multimedia terminal equipment for the remote access of the tele-medical information are essential. Especially, the tele-medical terminal equipment should provide the multimedia GUI environment in order to support the similar medical process by the tele-medical system. In this paper, we present a multimedia GUI (Graphic User Interface) for a Multimedia Tele-Medical System (TeleMedi_GUI) based on ATM/B-ISDN. In the tele-medical system, one workstation is used for the multimedia data server that is supporting multiple client terminals that are connected by the ATM network. The client terminals are based on Multimedia Personal Computers, and provide the remote access environment of the tele-medical database. We also developed the remote access protocols among the clients and the server to access multimedia medical information of the multimedia server. With using the TeleMedi_GUI, the doctors can examine and treat patients efficiently, using image data like X-ray/CT and voice data such as the S-ray diagnosis. The result of this paper can be applied to the following areas: 1) the implementation of the advanced medical service system interconnecting the small-scale health center and general hospitals, 2) the development of a fully computerized medical information system within the hospital.