• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.52-55
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• 1997

In this paper, both the generalization of one artificial variable technique to the general bound problem and the efficient implementation of the technique are suggested. When the steepest-edge method is used as a pricing rule in the simplex method, it is easy to update the reduced cost and the simplex multiplier every iteration. Therefore, one artificial variable technique is more efficient than Wolfe's method in which the reduced cost and simplex multiplier must be recalculated in every iteration. When implementing the one artificial variable technique on the LP problems with the general bound restraints on the variables, an arbitrary basic solution which satisfies the bound restraints is sought first, and the artificial column which adjusts the infeasibility is introduced. The phase one of the simplex method minimizes the one artificial variable. The efficient implementation technique includes the splitting, scaling, storage of the artificial column, and the cure of infeasibility problem.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.59.2-59.2
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• 2011

We have demonstrated ink-jet printed indium tin oxide (ITO) and indium tin zinc oxide (IZTO) electrodes for cost-efficient organic solar cells (OSCs). By ink-jetting of crystalline ITO nano-particles and performing a rapid thermal anneal at $450^{\circ}C$, we were able to obtain directly patterned-ITO electrodes with an average transmittance of 84.14% and a sheet resistance of 202.7 Ohm/square without using a conventional photolithography process. The OSCs fabricated on the directly patterned ITO electrodes by ink-jet printing showed an open circuit voltage of 0.57 V, short circuit current of 8.47 mA/cm2, fill factor of 44%, and power conversion efficiency of 2.13%. This indicates that the ITO directly-patterned by ink-jet printing is a viable alternative to sputter-grown ITO electrodes for cost-efficient printing of OSCs due to the absence of a photolithography process for patterning and more efficient ITO material usage.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.455-460
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• 2010

Recent increases in the road and rail infrastructure, but the urban traffic problems such as accidents, congestion are increasing. The reason is that the high cost and lack of accessibility of railway transportation, the low quality of road services, and efficient transport links, etc.. The developments of a variety of policy and technical means are being performed to solve these problems. Among them, the Bimodal Tram which is combined low-cost of bus and high service quality of railway transportation is attracting attention. In this paper, the development status of technology and efficient utilization of operational and infrastructure elements for the operational efficiency, safety and passenger comfort of Bimodal Tram is studied.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1523-1545
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• 2019

Cloud computing is now a widespread and economical option when data owners need to outsource or share their data. Designing secure and efficient data access control mechanism is one of the most challenging issues in cloud storage service. Anonymous broadcast encryption is a promising solution for its advantages in the respects of computation cost and communication overload. We bring forward an efficient anonymous identity-based broadcast encryption construction combined its application to the data access control mechanism in cloud storage service. The lengths for public parameters, user private key and ciphertext in the proposed scheme are all constant. Compared with the existing schemes, in terms of encrypting and decrypting computation cost, the construction of our scheme is more efficient. Furthermore, the proposed scheme is proved to achieve adaptive security against chosen-ciphertext attack adversaries in the standard model. Therefore, the proposed scheme is feasible for the system of data access control in cloud storage service.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.153-158
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• 2010

This study presents a single machine scheduling algorithm to minimize total cost(lateness cost, earliness cost and failure cost) by controlling machining speed. Generally, production scheduling uses the information of process planning and machining speed is not changed at production scheduling. And failure cost is not consider for scheduling algorithm. Therefore, the purpose of this study is to consider the change of machining speed for efficient production scheduling. And performance criteria for algorithm considers total cost. Especially, failure cost of product by increasing machining speed is considered.

• Communications for Statistical Applications and Methods
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• v.27 no.6
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• pp.689-699
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• 2020

This study investigates the effect of life settlement on the monopolistic insurance market. In particular, we consider liquidity cost, which is the cost incurred to the insurer to meet the request of surrender, and trading cost, which is the transaction cost of the policyholders for the settlement. We first show that the introduction of a life settlement can increase insurance demand and enhance consumer welfare even when the trading cost is higher than the liquidity cost. That is, even if the settlement market is less efficient than the insurance market, both insurance demand and consumer welfare can be increased. Second, the insurer's profit can also be increased when settlement is introduced because not only can the insurer save the liquidity cost but also the demand of insurance increases. Lastly, insurance demand does not always decrease when both costs increase. Depending on the population distribution over the liquidity risk, the demand of insurance can be increased or decreased.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.291-292
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• 2012

Progress in the construction project, the estimated cost of the measure is very important. Use preliminary estimate cost data for the prediction of construction cost. But, preliminary estimate cost data a clear calculation, there is no way. it is rely on the historical data and the past construction data. As a result, a significant difference in the actual construction cost and the predicted cost of the problem occurs. In this study, taking advantage of BIM Cost Prediction for efficient and rapid preliminary estimate BIM for building database through the study preliminary estimate cost data.

• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.143-153
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• 2006

This paper annually estimates the economies of density, scale and scope with the data of cost and output of 27 leading air carriers to suggest the political findings and strategies of raising the cost efficiency of our air transport industry. The estimation results and their implications are as follows. First, KAL and Aha would reduce their cost if they could increase international route density. Second, KAL and AAR would reduce their cost if they could expand the network but save their cost more effectively if they could increase international route density rather than expand the network. Third, the minimum efficient scale that minimize average cost of two national flag carriers which operate by the present output ratio among domestic passenger, international passenger and freight appears to be larger than each present output level of KAL and AAR. Meanwhile, it appears that minimum efficient scale of small size low cost carriers which operate domestic-oriented route is much smaller than minimum efficient scale of national flag carriers. Finally, it appears that there exists the diseconomies of scope between domestic passenger and the other outputs, that is, international passenger and freight and therefore save their cost if freight output ratio is higher and domestic passenger output ratio is lower than the Present level.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.2
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• pp.33-41
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• 2019

The purpose of this study is to provide a basic data for energy efficient apartment designs by analyzing electricity and gas usage according to horizontal locations of dwelling units in apartment buildings. The data for this research are collected from J-apartment complex, located at 'Wolbae' district in Daegu City. The data are sorted into several groups according to inner and outer locations, East-West locations, and the size of units. By the performance efficiency analysis, the study derives the result as follows: 1) generally inner units are more efficient than outer units. 2) West units are more efficient than East units. 3) The group that is most efficient in overall energy consumption is West-inner units (Group-D) and the least efficient group is East-outer units (Group-A1). 4) However, as units are getting bigger, inner units consumes more energy than outer units because of the gas usage patterns. The study also established cost analysis that shows the cost differences of usages for 30, 40, 50 years between each group. The result says Inner-outer location with East-West location affects a significant amount of the management costs. In terms of economic and social life of an apartment building, energy design standards need to be tuned and make the least efficient units perform as efficient as the most efficient units to optimize the social life of an apartment building.

• MALSORI
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• no.45
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• pp.107-115
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• 2003

An efficient method that compensates the HMM parameters for the noisy speech recognition is proposed. Instead of assuming some analytical approximations as in the PMC, the proposed method directly re-estimates the HMM parameters by the segmental k-means algorithm. The proposed method has shown improved results compared with the conventional PMC method at reduced computational cost.