• 대한산업공학회지
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• 제24권1호
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• pp.115-126
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• 1998

A GDHS(Geothermal District Heating System) is a heating system supplying a group of districts with heat extracted from geothermal sources. Due to various advantages of GDHS including the saving of fuel consumption as well as the reduction of air pollution, a world-wide trend is to replace central/individual heating systems with GDH systems. The basic point of this paper is that a crash program mentality leads to inappropriate decisions about policy issues in large-scale research and development like the development of GDHS, R&D funding should be viewed as a sequential decision, not a once-and-for-all choice. Hence we develop on economic feasibility assessment model based on a continuous sequential decision process for the Chejoo Island GDHS Project by modifying Roberts's model.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.314-315
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• 2010

This paper presents the design and development of Web control algorithm of continuous process control system using torque controlled vector inverter. Web algorithm used tension control with the tension sensor, and it is to calculate diameter of motor speed with maintain Web tension. The performance of Web control in this paper is verified by experiment.

• Journal of Information Processing Systems
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• 제12권3호
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• pp.410-421
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• 2016

In this paper, we propose a framework that attempts to incorporate landmarks into a segment-based Mandarin speech recognition system. In this method, landmarks provide boundary information and phonetic class information, and the information is used to direct the decoding process. To prove the validity of this method, two kinds of landmarks that can be reliably detected are used to direct the decoding process of a segment model (SM) based Mandarin LVCSR (large vocabulary continuous speech recognition) system. The results of our experiment show that about 30% decoding time can be saved without an obvious decrease in recognition accuracy. Thus, the potential of our method is demonstrated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.584-589
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• 1994

A time-varying nonlinear mathematical model was derived to consider the effect of change in roll radius on tension varation during winding and unwinding. A variable-gain PID controller was designed for tension control at start and stop in a multi-span continuous process system. The controller gains are updated at every control loop as roll radii continuously change. Computer simulation was carried out by using the mathematical model and the controller developed for a typical operating condition including acceleration and deceleration. When the variable-gain PID controller was used, the tension control performance was improved compared with that of existing control method during start-up and stop.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.48-50
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• 2005

This paper presents the design and development of web control algorithm of continuous process control system using vector inverter. The Diameter of web is calculated, tension is controlled by PID control and the speed reference of motor is calculated at current diameter. The performance of web control in this paper is verified by experiment.

• 정보보호학회논문지
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• 제26권3호
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• pp.777-785
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• 2016

공학교육인증제는 공학 교육의 질적 향상을 통해 국제 경쟁력을 갖는 공학기술 인력의 양성을 목적으로, 공학교육인증 프로그램의 학생들이 졸업할 시점에 달성해야 하는 학습 성과를 프로그램의 교육목표에 맞게 설정하고 적합한 절차에 따라 성취도를 평가하도록 하고 있다. 본 논문에서는 호서대학교 정보보호학 프로그램에서 설정한 프로그램 학습성과를 달성하기 위해 수행 준거, 평가 체계, 문서 체계 및 순환형 자율개선 체계 등을 포함하는 성취도 평가 시스템과 이러한 평가체계에 따라 성취도를 측정한 사례에 대해 연구한다.

• 동력기계공학회지
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• 제8권3호
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• pp.30-35
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• 2004

In the steel making industries, the continuous casting process has been applied to the number of company because of its economical benefit. Casting rolls are utilized for frictional drive and transport of solidifying slap. Dimensional tolerances, mechanical stability and surface condition of the cast roll can affect both the surface and internal quality of the product being cast. To overcome these problems, the industry is accelerating on the rate of technology improvements. Samples were overlaid on the S45C steel by submerged arc welding process. And the hardness, wear, electrochemical corrosion and oxidation tests were carried out. Test results were that all these materials were satisfying basic requirements of caster rolls. By these results, the addition of 0.1%Nb and 0.15%V increase mechanical properties and tempering resistance by its superior carbide forming characteristics in low carbon $12{\sim}13%Cr$ martensitic stainless steels.

• 한국기계가공학회지
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• 제12권4호
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• pp.22-28
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• 2013

It is important to begin left ventricular assist device (LVAD) treatment at appropriate time for heart failure patients who expect cardiac recovery after the therapy. In order to predict the optimal timing of LVAD implantation, we predicted pumping efficacy of LVAD according to the severity of heart failure theoretically. We used LVAD-implanted cardiovascular system model which consist of 8 Windkessel compartments for the simulation study. The time-varying compliance theory was used to simulate ventricular pumping function in the model. The ventricular systolic dysfunction was implemented by increasing the end-systolic ventricular compliance. Using the mathematical model, we predicted cardiac responses such as left ventricular peak pressure, cardiac output, ejection fraction, and stroke work according to the severity of ventricular systolic dysfunction under the treatments of continuous and pulsatile LVAD. Left ventricular peak pressure, which indicates the ventricular loading condition, decreased maximally at the 1st level heart-failure under pulsatile LVAD therapy and 2nd level heart-failure under continuous LVAD therapy. We conclude that optimal timing for pulsatile LVAD treatment is 1st level heart-failure and for continuous LVAD treatment is 2nd level heart-failure when considering LVAD treatment as "bridge to recovery".

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.629-632
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• 2007

Communications Based Train Control(CBTC) is a continuous, automatic train control system utilizing high-resolution, train location determination independent of track circuits; continuous, high capacity, bi-directional train-to-wayside data communications; and trainborne and wayside processors capable of implementing vital functions. In this paper, we present a basic design of CBTC system based on ERTMS/ETCS specifications. The basic design is composed of system requirements analysis, system functional analysis, system architectural design, sub-system requirements analysis, sub-system functional analysis. Each deliverable has been produced according to a development process based on UML/SysML.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.91-94
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• 2005

With increasing demands for large-scale micro-optical components in the field of digital display, the establishment of large-scale fabrication technology fur polymeric patterns has become a priority. The starting point of any polymer replication process is the mold, and the mold often has flat surface. However, It is very hard to replicate large-scale micro patterns using the flat mold, because the cost of large-scale flat mold was very high, and some uniformity and releasing problems were often occurred in large scale flat molding process. In this study, a UV roll imprinting system to overcome the financial and fabrication issues of large-scale pattern replication process was designed and constructed. As a practical example of the system, a lenticular lens with radius of curvature of $223{\mu}m$ and pitch of $280{\mu}m$, which was used to provide wide viewing angle in projection TV, was designed and fabricated. The roll stamper was fabricated using direct machining process of aluminum roll base. Finally, the shape accuracy and uniformity of roll imprinted lenticular lens sheet were measured and analyzed.