• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.7A
• /
• pp.649-658
• /
• 2006

Recently, Software Development was applied to new-approach methods as a various form : client-server system and web-programing, object-orient concept, distributed development with a network environments. On the other hand, it be concerned about the distributed development technology and increasing of object-oriented methodology. These technology is spread out the software quality and improve of software production, reduction of the software develop working. Futures, we considered about the distributed software development technique with a many workstation. In this paper, we discussed optimal release problem based on a stochastic differential equation model for the distributed Software development environments. In the past, the software reliability applied to quality a rough guess with a software development process and approach by the estimation of reliability for a test progress. But, in this paper, we decided to optimal release times two method: first, SRGM with an error counting model in fault detection phase by NHPP. Second, fault detection is change of continuous random variable by SDE(stochastic differential equation). Here, we decide to optimal release time as a minimum cost form the detected failure data and debugging fault data during the system test phase and operational phase. Especially, we discussed to limitation of reliability considering of total software cost probability distribution.

• Journal of KIISE:Information Networking
• /
• v.29 no.3
• /
• pp.286-298
• /
• 2002

The Remote Procedure Call(RPC) has been traditionally used for Inter Process Communication(IPC) among precesses in distributed computing environment. As distributed applications have been complicated more and more, the Mobile Agent paradigm for IPC is emerged. Because there are some paradigms for IPC, researches to evaluate and compare the performance of each paradigm are issued recently. But the performance models used in the previous research did not reflect real distributed computing environment correctly, because they did not consider the evacuation elements for providing security services. Since real distributed environment is open, it is very vulnerable to a variety of attacks. In order to execute applications securely in distributed computing environment, security services which protect applications and information against the attacks must be considered. In this paper, we evaluate and compare the performance of the Remote Procedure Call with that of the Mobile Agent in IPC paradigms. We examine security services to execute applications securely, and propose new performance models considering those services. We design performance models, which describe information retrieval system through N database services, using Petri Net. We compare the performance of two paradigms by assigning numerical values to parameters and measuring the execution time of two paradigms. In this paper, the comparison of two performance models with security services for secure communication shows the results that the execution time of the Remote Procedure Call performance model is sharply increased because of many communications with the high cryptography mechanism between hosts, and that the execution time of the Mobile Agent model is gradually increased because the Mobile Agent paradigm can reduce the quantity of the communications between hosts.

• Journal of architectural history
• /
• v.15 no.3
• /
• pp.43-57
• /
• 2006

The Villa Mairea (1937-39) designed by Alvar Aalto (1898-1976) has been studied by many researchers from various viewpoints. However, few studies have devoted their attention to the major issue raised by Aalto at the Yale University lecture and "Mairea" article in arkitekten in 1939. The issue is to fuse art with life in the living room with mobile partition walls that can function both as art exhibition walls and as art storage cabinets at the same time. Through this device, he maintained, the client can change displayed pictures easily according to the situation and so "painting and everyday life can evolve in a more direct manner." This paper argues that Aalto's concept originated from Japanese 'tokonoma' in Tetsuro Yoshida's Das japanische Wohnhaus (1935), which he referred to during the project. Differently from other Japanese features in the house, this tokonoma idea is more than formal, but more decisive than passing in driving the plan. And, whether coincidently or not, his idea exactly corresponds to Japanese aesthetes' and critics' own interpretation of the tononoma as the symbolic centre of Japanese people's everyday life. More importantly, however, this art display concept discloses secret strata of modern architecture during the time when the petrified rationalism was still at its power Even through the tokonoma motif alone, we see diverse trails in modern architecture: fusion of the East and the West, fusion of the traditional and the modern, to say nothing of fusion of art with life.

• Journal of KIISE
• /
• v.44 no.5
• /
• pp.545-552
• /
• 2017

Because of the explosive growth of mobile devices and development of network technologies, HTTP (Hypertext Transfer Protocol) adaptive streaming has become a new trend in video delivery to provide efficient multimedia streaming services. As interest in personalized broadcasting grows, the study of interactive multimedia has been actively pursued. The interactive multimedia service is a method of playing media according to a scenario selected by the user. Providing the interactive multimedia service with the existing HTTP adaptive streaming causes switching delay and buffer underflow according to the point in time when the user selects the scenario while the client streams the interactive multimedia and therefore decreases the user QoE (Quality of Experience). In this paper, we propose an adaptive streaming scheme for interactive multimedia service in HTTP adaptive streaming to provide seamless playback. We design the architecture and prefetching scheme for interactive multimedia streaming.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.9
• /
• pp.99-104
• /
• 2014

This paper presents a unified live-streaming method based on Hypertext Mark-up Language 5(HTML5) for an IP camera which is independent of browsers of clients and is implemented with open-source libraries. Currently, conventional security systems based on analog CCTV cameras are being modified to newer surveillance systems utilizing IP cameras. These cameras offer remote surveillance and monitoring regardless of the device being used at any time, from any location. However, this approach needs live-streaming protocols to be implemented in order to verify real-time video streams and surveillance is possible after installation of separate plug-ins or special software. Recently, live streaming is being conducted through HTML5 using two different standard protocols: HLS and DASH, that works with Apple and Android products respectively. This paper proposes a live-streaming approach that is linked on either of the two protocols which makes the system independent with the browser or OS. The client is possible to monitor real-time video streams without the need of any additional plug-ins. Moreover, by implementing open source libraries, development costs and time were economized. We verified usefulness of the proposed approach through mobile devices and extendability to other various applications of the system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.560-563
• /
• 2003

In this paper describes for use Authentication with the WPKI and Kerberos protocol. this paper is the security structure that defined in a WAP forum and security and watches all kinds of password related technology related to the existing authentication system. It looks up weakness point on security with a problem on the design that uses wireless public key-based structure and transmission hierarchical security back of a WAP forum, and a server-client holds for user authentication of an application level all and all, and it provides one counterproposal. Therefore, We offer authentication way solution that connected X.509 with using WIM for complement an authentication protocol Kerberos and its disadvantages.

• The KIPS Transactions:PartA
• /
• v.11A no.1
• /
• pp.37-48
• /
• 2004

The SyncML, the standard synchronization protocol, supports the synchronization of various application services between a client and a server such as an address book, a calendar. Even with this standard protocol, SyncML application developers usually spend a long time and efforts implementing service specific logics and databases. This paper designed and implemented the SDE(Service Development Environment) which is an integrated development environment for SyncML server developers to develop an application service rapidly and correctly. The SDE consists of two components i.e., the Sync Library and the SEG(Sync Engine Generator) tool. To prove the applicability of this study we implemented a SyncML server by using the SDE and also carried out the correctness tests and the performance test. We hope this system helps developers implement mobile application services more efficiently.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.6
• /
• pp.1416-1422
• /
• 2010

Various other platforms have appeared due to the abolishment of WIPI requirement and increased problems related with hacking and security. Since levels consisting of these platforms are composed of various APIs (Application Programming Interfaces) which are not standardized, other ways must be considered to protect data which are transferred using XML formats. Therefore, XML encryption API and XML digital signature API for data protection and certification, which are both responsible to define mark-up languages for XML encryption and digital signature respectively, were designed in this paper. The simulation system which played the role of the server and client between two terminal units was realized to validate the APIs.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.1
• /
• pp.147-154
• /
• 2017

This paper aims to build a home security system based on IoT to monitor a home on a mobile phone. The system consists of data gathering sensors, camera, gateway and Xively platform. The Raspberry Pi collects data from the three sensors and sends the data to Xively, and sends the video stream of home to a client in a smart phone through a internet. The servers are composed of Xively, socket server in Raspberry Pi and E-mail server in Google. The proposed system transmits e-mail, text message, and video stream when there are motion, fire, and gas leakage, and can control the gas valve through Raspberry Pi. The experimental results show that a user gets 'emergency E-mail' and text message and watches the video stream of the home through WIFI or LTE on a smart phone.

• Journal of Internet Computing and Services
• /
• v.19 no.5
• /
• pp.13-19
• /
• 2018

Although it's been nearly decade since the electronic notarization system enforced, the utilization is not high because of the troublesomeness of the client or his agent to visit the notarial office directly. Recently, the ministry of justice introduced e-notary based on audio-visual conference through amendament of the notarial law, and hence it will vitalize the usage of e-notary. In addition, due to the spread of smartphones, many people use SMS messages to express simple statements or promises. However, in case of legal disputes, the judgment of the court is different according to the case. The electronic notarization system can be used to prove of evidence of SMS messages, however, there is a hassle to convert SMS messages to electronic documents. To solve this problem, this paper proposes an SMS notarization system using smartphones. The proposed system uses reliable notarization server and it is divided into notarization system for message senders and notarization system for message receivers according to notary requestor.