• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.23 no.6
• /
• pp.1143-1156
• /
• 2013

Power control system like SCADA(Supervisory Control And Data Acquisition) is gathering information using RS232C and low-speed analog communication network. In general, these methods are known as secure because of the secure characteristics from the analog based communication network and serial communication. In this study, first we build DNP communication environment using commercial power control simulator and find some vulnerabilities by testing from the viewpoint of confidentiality, integrity and availability. Consequently, we see the necessity of a valid method for authentication and data encryption when gathering information, even though that is known as secure so far. Discussion of needs of DNP authentication and data encryption is started about several years ago, but there is still nowhere applied that on real environment because the current methods can not fully meet the security requirements of the real environment. This paper suggests a solution to the vulnerabilities, and propose some considerations for enhancing power control system's security level by applying DNP authentication and data encryption.

• Journal of Digital Contents Society
• /
• v.15 no.2
• /
• pp.263-270
• /
• 2014

This paper proposes a new metadata schema for effective mobile service of augmented reality technology, which is used in the convergence of media into a frame among the real world image and objects of virtual world. The proposed metadata schema is extended from JPSearch Core Metadata Schema (ISO/IEC 24800-2 International Standard) with analysis of the functionalities under industrial requirements, and enables to provide an effective application in the actual services. In addition, the proposed schema is available to organize the exchange of information between heterogeneous systems. With development of the prototype system, the proposed metadata schema is going to be submitted and verified under ISO/IEC JTC1 SC29 WG1 JPEG AR standard project.

• Journal of KIISE:Software and Applications
• /
• v.31 no.9
• /
• pp.1218-1225
• /
• 2004

S/KEY system was proposed to guard against intruder's password replay attack. But S/KEY system has vulnerability that if an attacker derive passphrase from his dictionary file, he can acquire one-time password required for user authentication. In this paper, we propose a correct S/KEY system mixed with EKE to solve the problem. Also, we specify a new S/KEY system with Casper and CSP, verify its secrecy and authentication requirements using FDR model checking tool.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.7
• /
• pp.1047-1054
• /
• 2002

To improve the fuel consumption and exhaust emission for gasoline engines, GDI(Gasoline Direct Injection) system was spotlighted to solve above requirements. Thus, many researchers have been studied to investigate the spray characteristics and the mixture formation of GDI injector. In this study, we tried to study the spray characteristics of a gasoline direct injector by using entropy analysis and PlV methods. The entropy analysis is based on the concept of statistical entropy, and it identifies the degree of homogeneity in the fuel concentration. The PlV method was adopted to determine the fluid dynamics information at the spray. From the applied results on a direct injection gasoline spray, we could find that the direct diffusion phenomena was a dominant factor in the formation of a homogeneous mixture at downstream of GDI spray especially under vaporizing ambient conditions, and mixing phenomena was also progressed by momentum exchange with induced air. In addition, the correlation between entropy and vorticity strength enabled to find their relation.

• Korean Journal of Construction Engineering and Management
• /
• v.5 no.3 s.19
• /
• pp.153-165
• /
• 2004

Most engineering tasks require collaboration between many users in major hospital construction projects that have many reconstructions. Loss and change orders occurred in factors such as information exchange, misunderstandings, advanced technology in hospital projects. Moreover, changes in context, costs, requirements, deadlines, etc. require negotiation of issues that may modify important project characteristics. The objective of this paper is to reduce reconstruction for the pre-construction process of hospital projects, reconstruction factors were analyzed in recent hospital construction project the system was established in order to solve reconstruction factors, and this system was validated through applying to the real project. Therefore it is a major challenge to make high level of communication and to have mutual understanding.

• Journal of Communications and Networks
• /
• v.15 no.1
• /
• pp.102-110
• /
• 2013

This paper considers a cooperative orthogonal frequency division multiple access (OFDMA)-based cognitive radio network where the primary system leases some of its subchannels to the secondary system for a fraction of time in exchange for the secondary users (SUs) assisting the transmission of primary users (PUs) as relays. Our aim is to determine the cooperation strategies among the primary and secondary systems so as to maximize the sum-rate of SUs while maintaining quality-of-service (QoS) requirements of PUs. We formulate a joint optimization problem of PU transmission mode selection, SU (or relay) selection, subcarrier assignment, power control, and time allocation. By applying dual method, this mixed integer programming problem is decomposed into parallel per-subcarrier subproblems, with each determining the cooperation strategy between one PU and one SU. We show that, on each leased subcarrier, the optimal strategy is to let a SU exclusively act as a relay or transmit for itself. This result is fundamentally different from the conventional spectrum leasing in single-channel systems where a SU must transmit a fraction of time for itself if it helps the PU's transmission. We then propose a subgradient-based algorithm to find the asymptotically optimal solution to the primal problem in polynomial time. Simulation results demonstrate that the proposed algorithm can significantly enhance the network performance.

• Journal of the Regional Association of Architectural Institute of Korea
• /
• v.21 no.6
• /
• pp.65-71
• /
• 2019

In Korea, there is a lack of adequate safety management for small-scale construction work, particularly when compared to large-scale construction projects. The number of construction disasters is also higher on small-scale construction sites. In this regard, this study aimed to develop the application prototype to support the safety management of small-scale construction projects. The major findings of the research are as follows. 1) About 60% of construction disasters and death occurred on small-scale construction sites over the last two years. In addition, institutional support and costs for safety management were found to be insufficient. 2) The items of the application for the small-scale construction safety management were constructed on the basis of the safety management of large-scale construction work. The contents of the application were confirmed based on a survey of small-scale construction project managers. 3) The application algorithm was developed with a focus on the roles of management subjects and information exchange. For transition from the application prototype presented in this study to a commercial product, further research needs to be conducted regarding the reflection of user requirements and application management subjects.

• International Journal of Computer Science & Network Security
• /
• v.24 no.3
• /
• pp.151-159
• /
• 2024

Twin clutch model enables the power-shifts as conventional planetary automatic transmission and eradicates the disadvantages of single clutch trans- mission. The automatic control of the dual clutches is a problem. Particularly to control the clutching component that engages when running in one direction of revolution and disengages when running the other direction, which exchange the torque smoothly during torque phase of the gearshifts on planetary-type automatic transmissions, seemed for quite a while hard to compensate through clutch control. Another problem is to skip gears during multiple gearshifts. However, the twin clutch gear control described in ["M Goetz, M C Levesley and D A Crolla. Dynamics and control of gearshifts on twin clutch transmissions, Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 2005"], a significant improvement in twin clutch gear control system is discussed. In this research our objective is to formally specify the twin clutch gear control system and verify it with the help of formal methods. Formal methods have a high potential to give correctness estimating techniques. We use UPPAAL for formal specification and verification. Our results show that the twin clutch gear control model partially fulfills its functional requirements.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.1
• /
• pp.55-61
• /
• 2010

As digital images combined with various types of information became popular, the development of transmission format standard for effective application of imageries is demanded. The purpose of the format standard is to provide a universal format that facilitates the exchange of images and related information. In this paper, we found optimal requirements of imagery transmission format standard after reviewing current state of both military and commercial products and studying functions of various types of format standards including NITF (National Imagery Transmission Format). In addition, future research direction of the imagery transmission format standard that complies with current trend of high-resolution and mass storage imagery data is proposed.

• Journal of the Korean Society for information Management
• /
• v.20 no.1
• /
• pp.301-320
• /
• 2003

The rapidly increasing use of the Internet and advancement of the communication network, the explosive growth of digital contents from personal home pages to professional information service the emerging file exchange service and the development of hacking techniques . these are some of the trends contributing to the spread of illegal reproduction and distribution of digital contents, thus threatening the exclusive copyrights of the creative works that should be legally protected Accordingly, there is urgent need for a digital copyright management system designed to provide centralized management while playing the role of bridge between the copyright owners and users for smooth trading of the rights to digital contents, reliable billing, security measures, and monitoring of illegal use. Therefore, in this study, I examined the requirements of laws and systems for the introduction of the centralized management system to support smooth distribution of digital contents, and also researched on the current status of domestic and international centralized management system for copyrights. Furthermore, 1 tried to provide basic materials for the standardization of digital contents copyright management information through the examination of the essential elements of the centralized digital contents management such as the system for unique identification the standardization for data elements, and the digital rights management (DHM) .