• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.6
• /
• pp.63-68
• /
• 2009

In the whole information technology area, the protection of information from hacking or tapping becomes a very serious issue. Therefore, the more effective, convenient and secure methods are required to make the safe operation. Encryption algorithms are known to be computationally intensive. They consume a significant amount of computing resources such as CPU time and memory. In this paper we propose the scalable encryption scheme with four criteria, the compression of plaintext, variable size of block, selectable round and software optimization. We have tested our scheme by c++. Experimental results show that our scheme achieves the faster execution speed of encryption/decryption.

• The Journal of Korean Association of Computer Education
• /
• v.10 no.1
• /
• pp.89-96
• /
• 2007

Two-way specification table for educational objectives proposed by B.S.Bloom, which is useful in reviewing and determining the objectives of instructions, is widely used in schools. However, differences in subject matters and school environments require various types of two-way specification table. Extensible markup language (XML) can be effectively applied for two-way specification table for educational objectives because it is well structured and the content of an XML document can be separated from its presentation. In this paper, the document type definition (DTD) for two-way specification table was designed. An example of XML document and XSL style sheet for the table were also presented. Furthermore, applications of the designed DTD were discussed. It is expected that the proposed DTD can be useful to various applications related to education assesment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.2B
• /
• pp.171-177
• /
• 2002

As speed and capacity of optical communication system increase dramatically, polarization-mode-dispersion compensation(PMDC) becomes a hot issue in these days. In this paper, we introduce a new state-of-polarization (SOP) tracking algorithm that can be used in a PMDC system. The new SOP tracking algorithm is also based on optical heterodyne coherent detection technique like the previous algorithm that we have reported before. However, unlike the previous algorithm, the new algorithm requires only three times of measurement in any circumstances to find the exact SOP information so that it can effectively be applied to PMDC system where very fast and stable operation is indispensible.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.6A
• /
• pp.864-870
• /
• 1999

A key difference between a tactical military and commercial satcom system is that the military system is expected to provide a service in the presence of ECM threats such as jamming. In this paper, we analyzed the three different type of link system applicable to the military satellite and directly compared to each system in order to find system performance according to the maximum jammer power. For the analysis, we modeled and simulated the SHF satellite system based on uplink jamming. From the results, it is found for each different type of link the maximum jammer power that can be tolerated with link operating at its suggested nominal rate. Also, we studied to the survivability level against the jamming condition through the performance comparison in shipborne and portable terminal consistent with frequency.

• Convergence Security Journal
• /
• v.12 no.6
• /
• pp.77-84
• /
• 2012

Recent Security Programs are widely used to improve the security of Client Systems in the Web authentication. Security Program is provide the function of the Keyboard Security and Certificate Management, Vaccines, Firewall. in particular, This Security Program has been used Financial Institutions and Government Agencies, and some private corporate Home Page. and ActiveX is used to install the Security Program. but Security Programs caused by several security vulnerabilities and problems as they appear, are threat to the stability of the Client System. Therefore, This paper will be analyzed through Case Studies and Experiments to the Vulnerabilities and Problems of Security Program and This Is expected to be utilized to further improve the performance of the Security Program and the building of a new Certification Scheme for material in the future.

• The Journal of Information Technology
• /
• v.2 no.2
• /
• pp.145-161
• /
• 1999

This paper proposes a high speed back propagation neural networks which uses the residue number system. making the high speed operation possible without carry propagation Consisting of MAC(Multiplication and Accumulation) operator unit using Residue number system and sigmoid function operator unit using Mixed Residue Conversion is designed, The Designed circuits are descripted by VHDL and synthesized by Compass tools. Result of simulations shows that critical path delay time is about 19nsec and the size can be reduced to 40% compared to the neural networks implemented by the real number operation unit. The proposed design circuits can be implemented in parallel distributed processing system with desired real time processing.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.13 no.1
• /
• pp.16-22
• /
• 1976

Broadband operation of Y-junction microstrip circulator withlnonreciprocal device is predicteg by Rosenbaum using Bosma's Green function analysis. The anslysis has been modified to enable the scattering matrix and therefore the circulator bandwidth, to be found. The width of the coupling transmission lines is found to be a significant design parameter${\psi}$. A comparison of experimental and theoretical results for the 3-port junction shows that wide lines and a smaller 7.5U than usual disk radius can be used to obtain broadband operation. Circulator operates in the frequency band 5-11 GHz. The obtained maximum insertion loss is 0.5dB and the isolation is more than 15dB.

• Journal of Korea Game Society
• /
• v.15 no.5
• /
• pp.153-162
• /
• 2015

This study explores the social sides of games by investigating the relationship between cooperative games and psychological factors determining social relationships (i.e., self-disclosure, intimacy) and how such psycosocial factors influence offline social participations. Utilizing both online and offline surveys, the results indicated that the amount of time spending on cooperative games have a positive impact on self-disclosure and intimacy. The results also showed that users' self-disclosure and intimacy influence offline social participation.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2003.05a
• /
• pp.87-91
• /
• 2003

포항제철소는 제품의 선적 및 하역업무를 위래 13기의 하역기를 운영 중에 있다. 제품하역기의 운전실태는 1명의 작업자가 탑승하여 제품이 놓여질 선박 내 location을 관리한다. 특히, 중량물을 다루는 만큼 안전사고 방지를 위산 고도의 주의를 요하는 작업이다. 그러나 운전실의 위치가 지상 $13\~24m$에 위치해 있어, 하방 관측을 위해 장시간 머리를 구부려야 하므로 작업피로는 물론 요통 발생 가능성이 높다. 또한, 13기 하역기의 제작사 및 제작 시기에 차이가 있어, User Interfare가 각기 다르다. 주기적으로 하역기를 바꿔 탑승하는 작업자로서는 오조작 가능성이 있어 문제점으로 지적되고 있다. 근본적으로는 이동통로 폭의 협소함에 따른 진$\cdot$출입의 문제, 전장품의 부적절한 배치에 따른 작업자 충돌 문제 등, 기본적인 인간공학적 원칙이 반영되지 않은 운전실설계로 제품하역기 작업자의 업무부하가 가중되고 있는 실정이다. 본 연구에서는 인간공학적 설계원칙을 반영하여 제품하역기 운전실을 가상환경으로 제작해보고, 3차원 인제 모형을 실제로 탑승시켜 주요 설계 제약조건의 검증을 실시하였다. 3차원 가상환경 및 인체모형의 제작은 상용 3D Tool인 3ds Max 5와 Anthropos Ergomax라는 프로그램을 이용하였다. 이와같은 방법을 통해, 실제 공사 후에 발견될 문제점에 대한 사전 도출이 가능함은 물론, 보다 인간공학적인 운전실 설계가 이뤄질 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.4
• /
• pp.84-92
• /
• 2002

As today's field programmable gate arrays have very large logic capacity as well as relatively fast operation speed, they're widely used in many application areas. However, debugging the design implemented in FPGA's is very time-consuming and painful as the internal signal probing usually requires large number of FPGA re-compilations, which take tremendously long time. In this paper, we analyze the problems in FPGA debugging and propose a new powerful debugging solution. With the proposed FPGA debugging solution, we can guarantee not only to provide 100% internal signal visibility without FPGA re-compilation for the design in FPGA's, but also to identify at least one design bug per FPGA compilation. An experimental result has clearly shown the proposed approach to FPGA debugging very powerful and practical.