• Journal of Energy Engineering
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• v.6 no.1
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• pp.41-51
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• 1997

A dynamic mathematical model of a thermal power plant with a single drum-type boiler is described with the base on modular concept. The present process model, which is including full scope of the components and high load changes, is based on physical approach through lumped parameters. The module, which means a component of the power plant and must essentially depict the characteristics of the component well, might be interconnected using pressure nodal method in a arrangement determined by users. With the results of the load changes of 75 MW to 95 MW and 95MW to 75 MW with the rate of 3 MW/min, the applicability of the process model is examined connecting to DCS(Dispersion Control System), which has a real running logic of 100 MW real power plant.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.703-713
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• 2015

The linking system between the control system and the field devices in the existing EMS/SCADA, in order to increase the reliability of the data, and access control through the separation of external network. Currently, There is a tendency that the need for connection to an external network that takes into account the economic aspect, systematic management and efficiency of operations is increasing. Such is evolved linkage section, is to have more security vulnerabilities than in the past, Eventually communication EMS/SCADA linkage section requires special management method. In this paper, taking into account the domestic environment, were presented the security Certification and Accreditation technology that was applied to serial DNP3 and TCP/IP based DNP3 that are mainly used in EMS/SCADA linkage section. Presented to security of Certification and Accreditation technology, divided into Resource Robustness Test and Malicious Packet Test for evaluate the safety. Each of the security requirements and evaluation method in proposed technology, is an attempt to present the differentiation of the existing Certification and Accreditation technology.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.6
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• pp.483-490
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• 2015

There are many software reliability models that are based on the times of occurrences of errors in the debugging of software. It is shown that it is possible to do likelihood inference for software reliability models based on finite failure model and non-homogeneous Poisson Processes (NHPP). For someone making a decision about when to market software, the conditional failure rate is an important variables. The infinite failure model are used in a wide variety of practical situations. Their use in characterization problems, detection of outlier, linear estimation, study of system reliability, life-testing, survival analysis, data compression and many other fields can be seen from the many study. Statistical process control (SPC) can monitor the forecasting of software failure and thereby contribute significantly to the improvement of software reliability. Control charts are widely used for software process control in the software industry. In this paper, proposed a control mechanism based on NHPP using mean value function of Musa-Okumo and Power law type property.

• Journal of Internet of Things and Convergence
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• v.1 no.1
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• pp.39-44
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• 2015

Organization is increasing the authorizing process to use public certificate and bio information. Certificate, has evolved to be able to parallel distributes the bio authentication and portable bio-authentication device. Authentication using an individual's PC and smart devices continue to generalize, while convenience for authentication is increased by comparison Study on cooperation with the security at the network level's a weak situation. If ask authentication method through the cooperation of the public certificate and bio information work with current network access control, there is a possibility to develop a more powerful security policy. by cooperation weaknesses against vulnerable personal authentication techniques on security token in a reliable and secure personal authentication techniques, such as bio-recognition, Bio Information for identification and to prevent exposing a methodology suggest to validate whether or not to carry out in this paper. In addition, organize the scenario that can work with the 802.1x network authentication method, and presented a proposal aimed at realization.

• Journal of KIISE:Information Networking
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• v.36 no.5
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• pp.456-469
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• 2009

We develop a new wireless link quality metric, ECOT(Estimated Channel Occupancy Time) that enables a high throughput route setup in wireless mesh networks. The key feature of ECOT is to be applicable to diverse mesh network environments where IEEE 802.11 MAC (Medium Access Control) variants are used. We take into account the exact operational features of 802.11 MAC protocols, such as 802.11 DCF(Distributed Coordination Function), 802.11e EDCA(Enhanced Distributed Channel Access) with BACK (Block Acknowledgement), and 802.11n A-MPDU(Aggregate MAC Protocol Data Unit), and derive the integrated link metric based on which a high throughput end-to-end path is established. Through extensive simulation in random-topology settings, we evaluate the performance of proposed link metric and present that ECOT shows 8.5 to 354.4% throughput gain over existing link metrics.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.4
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• pp.107-117
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• 2008

OBE(On Board Equipment) of IR(Infrared)/RF(Radio Frequence)-DSRC(Dedicated Short Range Communication) are set up 1.25 million cars because Korea Highway Cooperation supplied in HiPass(Domestic Electronic Toll Collection System). But this DSRC system has strength and weakness of service for BIS(Bus Information System) or UTIS(Urban Traffic Information System) because BIS and UTIS are required vary high communication's performance and management. In this paper, Efficiency of IR/RF-DSRC is analyzed performance of MAC(Medium Access Control) by computer simulation for services of BIS or UTIS, so Suggested to be commensurated with medium of there service. Specially, DSRC is needed high mobility and throughput in the vary short communication range, so Analysed the transmission rate of data in each communication medium over the specific character of the MAC frame.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.3-11
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• 2005

As the usage of Internet grows, we share many informations among the others and use more database systems for a various type of data. However, secure database system, which prevents the unauthorized users from modification, deletion, and access, is urgently required for sharing data in Internet. Conventional technologies of a data security are passive methods which depend on several steps with an access control, and these methods are vulnerable against the illegal attack because attacker can see the plain text that is private message. To prevent private data item for the special security from the malicious attack in web database, this paper is devoted to implement database system using steganography method, so we can protect the data item completely because attacker cannot know the secure message although he get the content of database.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.101-109
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• 2009

An encryption module is equipped basically at 8i version ideal of Oracle DBMS, encryption module, but a performance decrease is caused, and users are restrictive. We analyze problem of DB security by technology by circles at this paper whether or not there is an index search, object management disorder, a serious DB performance decrease by encryption, real-time data encryption beauty whether or not there is data approach control beauty circular-based IP. And presentation does the comprehensive security Frame Work which utilized the DB Masking technique that is an alternative means technical encryption in order to improve availability of DB security. We use a virtual account, and set up a DB Masking basis by security grades as alternatives, we check advance user authentication and SQL inquiry approvals and integrity after the fact through virtual accounts, utilize to method as collect by an auditing log that an officer was able to do safely DB.

• Journal of the Korea Society of Computer and Information
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• v.14 no.7
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• pp.105-112
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• 2009

Small and medium enterprises have more dependency on their information technology than large enterprises have. but they can't pay much for information technology and information security due to financial restrictions, limited resources, and lack of know-how. So there are many vulnerabilities in small and medium enterprises and these would make many security incidents. Security managers of small and medium enterprises think that information security in their company is simply equivalent to updating the antivirus solutions. managing firewall, and patching systems regularly. However, security policies, prevention of information theft. business continuity, access controls, and many other information security issues should be considered for mitigating security incidents. In this context, we redefined security countermeasures and strategies which are only appropriate to large enterprises. for making them appropriate on a secure operating for information system of small and medium enterprises, and we investigate information security issues in the four views of information system and company, and finally we present information security strategies for each view, in this paper.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.595-596
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• 2009

정보화의 발전에 비례하여 정보보호의 중요성도 높아지고 있다. 최근까지 정보보호에 대한 관심과 주요 연구의 흐름은 기술적인 보호조치(예: 암호화, 접근제어, 방화벽 등)와 관리적 관점의 행동연구였다. 최근에 들어서야 국내외적으로 정보보호 투자효과에 대한 연구가 활성화되기 시작했다. 정보보호 투자효과에 대한 계량적 산정이 필요한 이유는 정보보호의 중요성을 정확하게 인식할 수 있어 적정규모의 예산을 책정하고 효율적으로 예산을 투입할 수 있는 기초를 마련할 수 있기 때문이다. 정보보호 투자효과를 측정하기 위한 선행연구로 보안사고의 피해규모를 산정하는 연구가 필수적이다. 보안사고의 피해규모는 가시적 손실(피해복구, 생산성 저하, 손해배상 등)과, 비가시적 손실(고객 충성도 저하, 회사의 브랜드 이미지 하락 등) 규모의 합으로 구성된다. 그 동안 가시적 손실규모 측정에 관한 연구는 상대적으로 많았으나, 비가시적 손실규모 측정에 관한 연구는 상대적으로 미흡하였던 것이 사실이다. 이는 현실적으로 비가시적 손실규모를 측정할 수 있는 접근방법을 고안해내는 것이 어려웠기 때문이다. 이로 인해 막연히 비가시적 손실규모가 가시적 손실규모에 비해 대단히 클 것이라고 짐작해 올 수 밖에 없었다. 본 논문에서는 보안사고의 비가시적 손실규모를 측정하기 위해 대규모 개인정보 보안 사고가 발생한 기업의 매출액 증가율을 경쟁기업과 분석하는 연구방법을 제안한다. 매출액은 영업이익 및 순이익과는 달리 회사 내부적인 회계방침에 의해 규모의 조절이 불가능한 재무요소이면서 회사가 고객 충성도 저하와 회사의 브랜드 이미지 하락으로 인해 받게 되는 영향을 가장 정확하게 반영하는 재무요소이기도 하다. 연구방법에 따라 2008년 대규모 개인정보 보안사고가 발생한 국내기업을 선정하고 그 경쟁사와 매출액 변화추이를 비교 분석하였다. 분석결과 보안사고가 발생한 기업의 평균 매출액 증가율이 경쟁사 평균 매출액 증가율 보다 0.0225% 높다는 사실을 발견했다. 이 결과는 국내의 보안 사고가 기업 가치에 미치는 비가시적 영향이 거의 없거나 또는 발생하더라도 그 영향력이 미미하여 가격정책 및 광고 홍보를 통해 충분히 극복할 수 있다는 점을 대변한다. 본 논문의 결과는 역설적으로 국내 보안사고의 피해규모를 측정하는데 있어 가시적 손실규모의 정확한 측정이 무엇보다 중요함을 의미한다.