• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.534-538
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• 2010

Efficient control of a marine engine requires an engine control unit (ECU) system that handles fast and precise signal processes for in-coming and out-going signals from fast running engines. In order to handle these roles, the sequential control has been adapted in the ECU system in small and medium size ship engines, which has caused high production cost and complexity of the system. Hence, this paper is focused on developing an distributed ECU system for high speed and high precision control of a marine engine by efficiently combining a CPLD chip and a microprocessor. By sharing load at the MCU with the designed CPLD chip, we could achieve in driving a marine engine with high speed and precise control so that the ECU board has been simplified and its production cost has been reduced.

• 전기의세계
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• v.26 no.1
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• pp.71-76
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• 1977

It has been expected that the 4th generation computers will be characterized for their problem adaptability. There are few techniques of implementing such a characteristic. One of the techniques that one have considered in this paper the user microprogrammable computer architecture. There are two different computer architectures that support user microprogramming. One uses the writeable control storage and another uses the main memory. The concept of utilizing writeable control storage for microprogramming was developed in 1950's and since then the most of the user microprogrammable computers produced belong to such category. The concept of utilizing the main memory for user microprogramming was first introduced by Thomas in 1973. This architecture has a strong advantage in the aspect of the system cost. In this paper, we have developed a user microprogrammable computer. The computer utilizes the main memory for user microprograms. It employs a 32 bit micro-instruction word in the form of the little encoded. The performance of the developed machine will be evaluated in the hard ware cost, programming easiness and the running time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.593-594
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• 2006

A novel thermal transfer method was developed to form the phosphor screen for VPT(Video Phone Tube). This method have advantages of simple process, clean environment, saving raw material and running-cost comparison of electrodeposition, spin coating of conventional methods. But now applying phosphor screen for thermal transfer method has been formed three layers (phosphor layer, ITO layer and thermal adhesive layer) on the PET film as substrate. This is complex process, run to waste of raw-material and require of high cost. Also ITO paste at present has been imported from Japan. To improve these problems, we have manufactured phosphor screen formed by two layers (phosphor layer and ITO layer). We have developed ITO paste that had both conductive and excellent thermal transfer abilities, made it of domestic raw-material.

• Journal of Korean Society for Quality Management
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• v.19 no.2
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• pp.117-124
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• 1991

In this paper, it is assumed that a system is composed of an essential unit and a nonessential unit. During the running of the system, an essential unit is replaced at periodic replacement time T or at nth failure of essential unit whichever occurs first. Nonessential unit is replaced at its failure and at the replacement of essential unit. This paper derive optimal replacement period which minmises the total expected cost for replacement. The unimodality of totoal maintenance cost function is proved under the assumption that hazard rate of each component is continuous and monotone increasing failure rate(IFR). Based on this condition, it is shown that the optimal replacement period is finite and unique.

• Journal of the Korea Society of Computer and Information
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• v.23 no.6
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• pp.59-66
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• 2018

Recently, the use of mobile payment, called "Pay" payment, is increasing such as 'KakaoPay' and 'SamsungPay'. In Korea, various mobile payment services are running and emerging. The purpose of this study is to examine the intention to switch from using existing credit cards or check card to mobile payment service based on the two-factor theory. We empirically examined the effect of the two factors, the factors that enable switching and the factors that inhibit switching. Therefore, the study use switching cost and switching benefit as parameters to confirm the effect on the switching intention. In addition, this study intends to analyze the differences between two subgroups by the degree of personal innovativeness. We survey smartphone users and credit card or check card users, and analyzed the Smart PLS 3.0 using structural equation model to verify the significance of the research hypothesis.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.3
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• pp.47-61
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• 2007

This paper presents two elimination methods of subtours, which is obtained by applying the Out-of-Kilter algorithm to the sequential ordering problem (SOP) to produce a feasible solution for the SOP. Since the SOP is a kind of asymmetric traveling salesman problem (ATSP) with precedence constraints, we can apply the Out-of-Kilter algorithm to the SOP by relaxing the precedence constraints. Instead of patching subtours, both of two elimination methods construct a feasible solution of the SOP by using arcs constructing the subtours, and they improve solution by running 3-opt and 4-opt at each iteration. We also use a perturbation method. cost relaxation to explore a global solution. Six cases from two elimination methods are presented and their experimental results are compared to each other. The proposed algorithm found 32 best known solutions out of the 34 instances from the TSPLIB in a reasonable time.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.217-221
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• 2001

Barber bogie and Y25 bogie is the main bogie of freight car which is used in the Korean railway. In case of Barber bogie and a mixed formation tile maximum speed limit of empty car is 70 km/h and that of loaded car is 90 km/t and also it runs a speed of 110 km/h in time of an exclusive formation of Y25 bogie. The car named as high speed freight car at present is Y25 bogie which modeled on the Y25 bogie or Europe developed in 1993, Y25 bogie has no problem about the running capacity up to the speed of 110 km/h, but it works as limiting factors to tile increasing cost of maintenance and repair expenses which caused by repair of bogie and the cost of materials. This study is going to describe the contents examined by analysis and tests, aimed at being used as an index of plan in the future through the strength test of high speed freight car which is used now.

• Wind and Structures
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• v.14 no.1
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• pp.71-80
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• 2011

This study presents a decision making process for installation of wind barrier which is used to reduce the wind speed applied to running vehicles on expressway. To determine whether it is needed to install wind barrier or not, cost and benefit from wind barrier are calculated during lifetime. In obtaining car accidental risk, probabilistic distribution of wind speed, daily traffic volume, mixture ratio in the volume, and duration time for wind speed range are considered. It is recommended to install wind barrier if benefit from the barrier installation exceed construction cost. In the numerical examples, case studies were shown for risk and benefit calculation and main risky regions on Korean highway were all evaluated to identify the number of installation sites.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.127-134
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• 2008

The purpose of this study is to propose the decision making technique in roof waterproofing method at the early construction stage. Selecting the suitable construction method is difficult because of the complex interrelationships between many factors of influencing the construction method selection. This study presents an example of selecting suitable method by analyzing LCC (Life Cycle Cost) in roof waterproofing work. In this study, roof waterproofing method is analyzed by LCC(Life Cycle Cost) which is consists of the initial costs, running costs, and removal costs. Sheet waterproofing, membrane waterproofing and asphalt waterproofing costs are compared to select the most economic method. The result of this study revealed that considering LCC is useful in selecting the proper method in the construction work.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.6 no.1
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• pp.29-39
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• 1992

In this paper, the basic idea of optimum electric system design by means of the forecasting of maximum demand is presented, and the load characteristics and practical operating conditions are based on the technical data. After reconstruction of th model plant by use of above method, power supply reliability, future extention, initial cost, and running cost saving effects are analyzed. As a result, it is verified that the systems wherein the power is supply to each load frm main transformer whose capacity is calculated by forecasting are economic rather than the systems wherein the power is supply to each electric feeders from each corresponding transformer.