• Asia pacific journal of information systems
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• 제6권2호
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• pp.171-200
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• 1996

Information Systems(IS) departments face many challenges in today's rapidly changing environment. One approach to understanding the challenges by IS departments is to survey IS managers in order to elicit their key issues. The study compares and contrasts the major findings of key information systems management issues in Korea and United States. It examines the key concerns of IS managers on these areas focusing on identifying and explaining regional similarities and differences. IS managers in Korea and United States show a reasonable level of agreement on the most critical issues they face. In some of the issues the differences are found and possible reasons for these differences are discussed. The study concludes by suggesting an evolution model that can explain the changing nature of the IS issues across time and nations.

• Journal of Mechanical Science and Technology
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• 제18권9호
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• pp.1565-1571
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• 2004

Ride characteristics of a vehicle moving on a rough ground with changing travel velocity are analyzed in this paper. The solution is difficult due to the non-stationary characteristics of the problem. Hence a new technique has been proposed to overcome this difficulty. This new technique is employed in the analysis of ride characteristics of a vehicle with changing velocity in the time/frequency domain. It is found that the proposed technique gives successful results in modelling non-stationary responses in terms of a series of stationary responses.

• Asia pacific journal of information systems
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• 제26권3호
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• pp.427-448
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• 2016

The stochastic phenomena of traffic network condition, such as traffic speed and density, are affected not only by exogenous traffic control but also by endogenous changes in service time during congestion. In this paper, we propose a mixed M/G/1 queuing model by introducing a condition-varying parameter of traffic congestion to reflect structural changes in the traffic network. We also develop congestion indices to evaluate network efficiency in terms of traffic flow and economic cost in traffic operating system using structure-changing queuing model, and perform scenario analysis according to various traffic network improvement policies. Empirical analysis using Korean highway traffic operating system shows that our suggested model better captures structural changes in the traffic queue. The scenario analysis also shows that occasional reversible lane operation during peak times can be more efficient and feasible than regular lane extension in Korea.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.201-208
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• 2002

In this paper, the control strategy of ratio changing system for a metal belt CVT adopting primary pressure regulation is developed, and the shirting performance of pressure regulating type CVT with the suggested control strategy is investigated. The control strategy suggested in this study is composed of 2 feedback loop, one is speed ratio feedback and the other is primary pressure feedback. The pressure feedback is adopted to ensure prohibiting a belt slip during transient period in a fast downshift mode. Simulation results show that the system with suggested control strategy gives appropriate response time and tracking Performance for upshift and also gives a proper primary pressure which can prohibit the belt slip. In addition, it is fecund that the given system has an acceptable servo property in tracking the target speed ratio and robustness for the disturbance of line pressure.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.179-187
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• 2001

In this paper, a primary pressure regulating type ratio control system is developed for a metal belt CVT, and the CVT ratio changing characteristics are investigated by simulation and experiment. The hydraulic part of the ratio control system has a simple structure with one 3-way spool valve as a main ratio control valve and one bleed type variable force solenoid as a pilot valve. The mathematical modelling of the CVT hydraulic system is derived by considering the CVT shift dynamics. Simulation results of CVT speed ratio and the primary pressure agree with the experimental results demonstrating the validity of the dynamic models. It is found from the simulation and experimental results that the response time of speed ratio and primary pressure can be shortened by increasing the ratio control valve port area, and the size of feedback orifice of ratio control valve gives a damping effect on the primary pressure oscillation.

• 교육시설
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• 제15권1호
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• pp.44-52
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• 2008

Amid the rapidly changing constructional business conditions, the volume of BTL business sectors has expanded largely during two or three years. Especially, construction works fur educational facilities of elementary, middle and high schools has been performed by the mid-sized construction companies who are not capable of doing effective and systematic quality management while the requirements of the customers are getting higher and higher. In order to have a flexible deal with the rapidly changing business conditions and also to enhance the quality level, it is the high time to reorganize the effective quality management systeme by doing the overall analysis about the quality defects in construction site. Accordingly through the investigation about the quality defects in the construction sites of domestic educational facilities, this study will focus on what kind of quality defects show. It is aimed at providing the preliminary data for the establishment of quality management fur the construction site of the domestic educational facilities by analysing the investigation results.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.37-38
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• 2006

Conjugated diacetylene supramolecules are interesting biomimetic materials in view of application to chemical and label-free biological sensors. These supramolecules are unique in changing color from blue to red upon specific binding events. Various binding events including viruses, toxins, glucose, and ionic interactions have been reported detectible. Here, we focus on fabrication of polydiacetylene supramolecule dot array patterns on solid substrates by using a conventional microarrayer. Each dot is found to possess the color-changing property as well as the fluorescence self-emission. This technique allows us, for the first time, to fabricate biochips based on polydiacetylene supramolecules. Label-free detection of small molecules and biological targets will be discussed.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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• pp.323-329
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• 1998

In Pusan port, the studies, which analysis container cargo volumes by using forecasting methods and research about container logistics system, etc., have been continuously performed. But, in Pusan port, this study on an evaluation of traffic congestion has been scarcely performed until now. Especially, when changing and extending a berth, and constructing a new port, it is very important to examine this field. And it should be considered. Thus, this paper aims to analysis the effect of ship traffic condition in 2011, to evaluate marine traffic congestion, according to changing ship traffic volumes in Pusan port. To analysis it, we used simulation method and examined the results

• 한국디지털건축인테리어학회논문집
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• 제4권1호
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• pp.17-25
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• 2004

The architectural space is the involuntary place where man lives and experiences, and as a 3 dimensional space through the continuous experience with the concept of 4th dimension of time, it provides the observers with the dramatic space imagery. These kinds of space experiences are experienced mentally and perceptively through the physical elements of inner and outer space of the architectural buildings, and this space imagery is created here by all the space composing elemensts of the building. These space experiences are caused by the changing processes of the space characteristics, and the observers perceive the changes in space characteristics. These changing processes of inner and outer space, space versus space, and unit space, which are perceived by the observer, could be called as 'the transition' and thd changes of the space characteristics as 'the transition characteristics'.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.851-856
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• 2003

This paper proposes a single-mode Lamb-wave generation and detection system using a pulsed laser as a generator and an air-coupled transducer combined with the wavelet transform analysis, as the detector. The laser source with arrayed linear slits was used to generate Lamb-wave which is able to control the wavelength of Lamb-wave to be generated by changing the slits separation. An ari-coupled transducer was used to receive Lamb-wave, which can selectably receive a single mode of leaky Lamb wave by changing the oblique angle of transducer, since the leaky Lamb-wave has unique leaky-angle according to the mode. Also, the received signal was processed by wavelet transform for the analysis in domain of time-frequency. The theoretical dipersion curve and the experimetal result was compared to show good agreement.