• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.518-521
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• 2008

When constructing a high-speed railroad, the reduction of the distance between track centers and the width of track bed will save the construction cost. However the shortening the distance between track centers may cause the stability problems due to higher wind pressure. Therefore the extensive technical review and aerodynamical study should be performed to determine the adequate distance between track centers. In this study, the impact that the increase in wind pressure due to the change of aerodynamic phenomena with the change of the distance between track centers may have on two trains passing by each other was predicted, and the stability of train operation was analyzed in order to review the distance between track centers suitable to Honam HSR trains. And we estimated the aerodynamical effects by the results of the real train experiments by using KTX.

• Asia pacific journal of information systems
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• v.14 no.4
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• pp.23-47
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• 2004

This study was tried for the improvement of software process ability of the software firms, and analyzed empirically the impact that a software process infrastructure level influences on the software process level and process performance. The questionnaire were developed and data were collected from the process improvement correspondences or project quality managers of the 78 software firms. The result was shown that management-organization infrastructure was composed of software process improvement organization's role and activity, process standard and education, management system and supporting, management guides and procedures. And organization's standard development procedure or criteria, process asset, process support tools were included in technical infrastructure. This study provides that some components of software process infrastructure had an significant influence on the process level, process infrastructure management level, and software process performance.

• Asia-Pacific Journal of Business
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• v.4 no.2
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• pp.11-20
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• 2013

This study extends the extant scope of understanding investment decision, beyond the dominant 'technical' emphasis on the application of discounted cash flow techniques. The research methodology draws the positivist and interpretive research paradigms. It uses a deductive approach, survey strategy and principal component analysis for the analysis. Three key sets of factors emerged as important in the investment decision process in the hydropower sector. They are: group consensus (framing), influences on own judgment (heuristics), and application of knowledge & experience (intuition). The use of purposive and convenient sampling might have some unintended impact on the findings. Consequently, any generalizations of the findings to a wider population of organizations and managers need to be made with care. It is hoped that this paper will encourage other researchers to go beyond the analytic techniques of investment appraisal that have dominated investment decision research and seek to balance the emphasis by focusing on human involvement and behavioral aspects of investment decision.

• Journal of Information Processing Systems
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• v.11 no.1
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• pp.104-115
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• 2015

Along with the evolution of Internet and its new emerging services, the quantity and impact of attacks have been continuously increasing. Currently, the technical capability to attack has tended to decrease. On the contrary, performances of hacking tools are evolving, growing, simple, comprehensive, and accessible to the public. In this work, network penetration testing and auditing of the Redhat operating system (OS) are highlighted as one of the most popular OS for Internet applications. Some types of attacks are from a different side and new attack method have been attempted, such as: scanning for reconnaissance, guessing the password, gaining privileged access, and flooding the victim machine to decrease availability. Some analyses in network auditing and forensic from victim server are also presented in this paper. Our proposed system aims confirmed as hackable or not and we expect for it to be used as a reference for practitioners to protect their systems from cyber-attacks.

• Tribology and Lubricants
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• v.33 no.5
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• pp.187-201
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• 2017

This paper presents the impact of couple stress lubricant on performance of slot-entry hydrostatic/hybrid journal symmetric/asymmetric bearings. Reynolds Equation using Finite Element Technique has been solved for the flow of couple stress and Newtonian lubricants in bearings. The results have been computed for concentric design pressure ratio(${\beta}^{\ast}=0.5$), slot width ratio (SWR = 0.25) and chosen parameters of couple stress lubricant ${\bar{l}}=5$, 10, 15. It is observed that numerically simulated outcomes for slot-entry journal bearings, considering the influence of couple stress lubricant indicate a substantial improvement in the performance of the bearing.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.3
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• pp.45-49
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• 2007

A gearing system emits inconsistent noises from the impact of gear teeth when defects are present, but it is not easy for a noise inspector on a production line to distinguish defective products objectively. Since customers constantly complain about various noises from geared motors, it is desirable to devise an analytical technique to classify motors. However, it is difficult to separate inconsistent noises due to defective gears from the overall noise produced by a geared motor using a general signal processing method such as a FFT because low frequency impulse signals have a tendency not to appear in the frequency domain. In this paper, we propose a method that can be used to obtain more objective estimates and measurements of inconsistent noises from a gearing system. The proposed method makes use of the cepstrum domain with an applied autocorrelation and comb lifter, followed by a domain inversion.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.349-352
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• 2008

The most concerning issue in these days is the energy crisis by increasing threat of global warming and depletion of natural resources. In the situations, the Plug-in Hybrid Electric Vehicle (PHEV) is drawing attention from many countries for the next generation's car which has higher fuel efficiency and lower environmental impact. This paper presents simulation results about the limit capacity of central power-grid which doesn't have enough surplus electric power for charging PHEVs. Therefore, this paper also presents a smart charging system that can charge the PHEVs with a function of distributing demands of charging. The smart charging system is an agent facility between the government and consumer, which can recommend the best time to charge the battery of PHEVs by the lowest energy cost. This function of choosing time-slots is the technical system for the government which wants to control the consumption rate of electric power for PHEVs. Finally, this paper presents the economic feasibility of PHEVs from the two kinds of price system, midnight electric price and home electric price.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.25-39
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• 2008

As the amount of IT investment and the complexity of information systems in public agencies have been increased, efficient and structured management of IT systems is more emphasized. For the Korean government. ITA (Information Technology Architecture) is one of the core parts of the e-Government initiative. Also introducing and managing ITA in organizations is mandated by law in Korea. The objective of the paper is to study whether using ITA in public agencies is related with their IT capability and IT performance or not. A questionnaire had been designed for the purpose, and a survey had been performed on Korean public agencies. The survey results show that using ITA has influence on relation and technology capability. However, ITA does not influence on human capability and IT performance. The reason why using ITA is linked to relation and technology capability is that ITA includes relationship between both business and technology. Also ITA provides a technical reference model (TRM) and standard profile (SP), so it has influence on technology capability.

• Journal of the Korean Society for Library and Information Science
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• v.24
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• pp.263-288
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• 1993

The use of telematics, or of data communications, for the information services is a much debated issue currently in the information science. The purpose' of this study is to gain a general overview of the use of data communications in specialized information centers in order to find out the direction of development in furture. In this study, the state of the specialized information services by data communications in Korea was analysed from the following points of view: (1) What kind of role play the liberalization of telecommunication to help develope the specialized information services? (2) Which problems have happend to the specialized information services using data communications? (3) How are technical, economical, and methodical problems handled for the new services? The background research stems from interview with managers and researchers in 5 specialized information centers.

• Tuberculosis and Respiratory Diseases
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• v.81 no.2
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• pp.91-98
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• 2018

When it comes to the use in inhalers in the management of chronic obstructive pulmonary diseases, there are many options, considerations and challenges, which health care professionals need to address. Considerations for prescribing and dispensing, administering and following up, education, and adherence; all of these factors impact on treatment success and all are intrinsically linked to the device selected. This review brings together relevant evidence, real-life data and practice tools to assist health care professionals in making decisions about the use of inhalers in the management of chronic obstructive pulmonary diseases. It covers some of the key technical device issues to be considered, the evidence behind the role of inhalers in disease control, population studies which link behaviors and adherence to inhaler devices as well as practice advice on inhaler technique education and the advantages and disadvantages in selecting different inhaler devices. Finally, a list of key considerations to aid health care providers in successfully managing the use of inhaler devices are summarized.