• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.600-619
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• 2015

We propose a cost-efficient hybrid algorithm for online location updates that efficiently combines feature point detection with the online trajectory-based sampling algorithm. Our algorithm is designed to minimize the average trajectory error with the minimal number of sample points. The algorithm is composed of 3 steps. First, we choose corner points from the map as sample points because they will most likely cause fewer trajectory errors. By employing the online trajectory sampling algorithm as the second step, our algorithm detects several missing and important sample points to prevent unwanted trajectory errors. The final step improves cost efficiency by eliminating redundant sample points on straight paths. We evaluate the proposed algorithm with real GPS trajectory data for various bus routes and compare our algorithm with the existing one. Simulation results show that our algorithm decreases the average trajectory error 28% compared to the existing one. In terms of cost efficiency, simulation results show that our algorithm is 29% more cost efficient than the existing one with real GPS trajectory data.

• International Journal of Aeronautical and Space Sciences
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• 제17권2호
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• pp.222-231
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• 2016

This paper proposes a new method achieving computationally efficient attitude reference system for low cost strapdown sensors and microprocessor platform. The main idea in this method is to define and compare velocity differential vectors, geometrically computed from INS and GPS data with different update rate, for generating attitude error measurements which is further used for filter construction. A quaternion based Kalman filter configuration is applied for the attitude estimation with the adapted measurement model of differential vector comparison. Linearized model for Extended Kalman Filter and low pass filtered characteristics of measurement greatly extend the affordability of the proposed algorithm to the field of simple low cost embedded systems. For performance verification, experiment are done employing a practical low cost MEMS IMU and GPS receiver specification. Performance comparison with a high grade navigation system demonstrated good estimation result.

• Journal of Communications and Networks
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• 제18권2호
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• pp.162-172
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• 2016

The placement of the complete baseband processing in a centralized pool results in high data rate requirement and inflexibility of the fronthaul network, which challenges the energy and cost effectiveness of the cloud radio access network (C-RAN). Recently, redesign of the C-RAN through functional split in the baseband processing chain has been proposed to overcome these challenges. This paper evaluates, by mathematical and simulation methods, different splits with respect to network level energy and cost efficiency having in the mind the expected quality of service. The proposed mathematical model quantifies the multiplexing gains and the trade-offs between centralization and decentralization concerning the cost of the pool, fronthaul network capacity and resource utilization. The event-based simulation captures the influence of the traffic load dynamics and traffic type variation on designing an efficient fronthaul network. Based on the obtained results, we derive a principle for fronthaul dimensioning based on the traffic profile. This principle allows for efficient radio access network with respect to multiplexing gains while achieving the expected users' quality of service.

• 대한안전경영과학회지
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• 제13권1호
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• pp.189-193
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• 2011

The current standard cost for recycling applied under the Extended Producer Responsibility(EPR) institution, is not coping with continuously increased number of obligatory subject items as well as a variety of variable cost changing factors regarding the recycling treatment cost caused by price fluctuation such as increased material and labor cost entirely across the society; changes in recycling treatment process following the developing technologies; and changes in the required work forces and equipments followed by the trends of automated facilities. Despite such various cost fluctuation factors, the current EPR is not coping with the trends, making the re-calculation process difficult, which causes differences between the real treatment cost for recycling. In this study, the analysis was made on main factors affecting on the related cost and the related price changing index was calculated, by conducting the influence evaluation on the standard cost factors of the current standard cost for recycling. Through theses results, more objective standard will be set for the re-calculation of standard cost for recycling to greatly contribute to setting up the midterm and long-term strategies in the future towards efficient institution.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.607-612
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• 2007

사업 초기 단계에서의 정확한 공사비 예측은 각각의 대안을 비교하여 향후 공사비에 대한 정보를 제공함으로써 효율적인 예산수립을 가능하게 한다. 하지만 사업 초기 단계에는 공사비 산정 기준이 모호하고 가용 정보가 부족함에 따라 공사비 예측에 한계가 나타난다. 더욱이 현행 공사비 산정모델이 단위 길이당 공사비를 활용한 선형적이고 단순한 모델을 활용함에 따라 예측의 정확도에 한계를 가지고 있다. 따라서 본 연구에서는 기존 공사비 산정모델의 한계를 개선하고 사업 초기 단계에서 가용한 데이터를 활용할 수 있는 공사비 산정 모델의 Framework를 구축하고자 한다. 이를 위하여 본 연구에서는 국내외 개략공사비 산정 모델을 분석하였으며, 기존 도로공사의 공사비 분석자료를 토대로 노선선정 등 사업초기 단계에서 활용 가능한 도로공사 개략공사비 산정모델의 Framework를 제시하였다.

• 한국해양공학회지
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• 제23권3호
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• pp.1-5
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• 2009

It is necessary to develop an efficient optimization technique to optimize engineering structures that have given design spaces, discrete design values, and several design goals. In this study, an optimum algorithm based on the genetic algorithm was applied to the multi-object problem to obtain an optimum solution that simultaneously minimizes the structural weight and construction cost of panel blocks in ship structures. The cost model was used in this study, which includes the cost of adjusting the weld-induced deformation and applying the deformation control methods, in addition to the cost of the material and the welding cost usually included in the normal cost model. By using the proposed cost model, more realistic optimum design results can be expected.

• 품질경영학회지
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• 제22권4호
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• pp.132-151
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• 1994

Quality is a critical competitive factor in today's environment because of the impact of quality on market share, productivity and costs. Especially in Korean companies, the importance of quality is heightened as they are losing price competitiveness compared to the new industrialized countries. The traditional approach to quality improvement has been focused on workers. The primary means to achieving acceptable outgoing quality has been to inspect quality by adding more inspectors and inspection stations. This is an example of quality cost that can be reduced through the preventive actions against bad quality. Quality cost is best viewed as a measure of costs specifically associated with the achievement or nonachievement of product/service quality required by customers. This paper examines the concept of quality cost, provides guidance to implementing a quality cost system, and identifies the limitations of quality cost information. These limitations are the target for future research for an efficient and effective implementation of quality cost system.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권6호
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• pp.294-300
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• 1999

There is a growing interest in hybrid electric vehicles due to environmental concerns. Recent efforts are directed toward developing an improved main component systems for the hybrid electric vehicle applications. Soon after the introduction of electric starter for internal combustion engine early this century, despite being energy efficient and nonpolluting, electric vehicle lost the battle completly to internal combustion engine due to its limited range and inferior performance. Hybrid Electric vehicles offer the most promising solutions to reduce the emission of vehicles. This paper describes a method for cost reduction estimation of parallel hybrid electric vehicle. We used a cost reduction structure that consisted of five major subsystems (three-type and two-type motor) for parallel hybrid electric vehicle. Especially, we estimated the potential for cost reductions in parallel hybrid electric vehicle as a function of time using the learning curve. Also, we estimated the potentials of cost by depreciation.

• 한국국방경영분석학회지
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• 제30권2호
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• pp.13-31
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• 2004

This paper aims at efficient determining the economic life of weapon systems. Specifically, the procedure to estimate the life cycle cost at initial acquisition state or at development state using the PRICE model is proposed. The PRICE model is a parametric cost estimation which is widely used in the field of national defense. The model includes the estimation of the cost in life cycle of weapon systems such as research and development, acquisition, operation and support. Using this model, economic life of weapon systems can be determined. Based on an equivalent annual cost (EAC) method which sums the capital recovery with return (CR) and the equivalence cost (EC), the economic life will be calculated. A case study is accomplished to illustrate the proposed procedure.

• 산업경영시스템학회지
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• 제26권4호
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• pp.56-62
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• 2003

Recently, in order to stay at predominance in the global infinity competition, most of companies have been reducing the cost in many fields of industry First of all, the reduction of the logistics cost have been recognized greatly as the company value rises. But, the current situation of domestic logistics cost is very weak compared with Japan, U.S.A., etc. A rate of logistics cost out of GDP is still high compared with the competitors. The reduction of the transportation cost from overall logistics cost is most urgent subject. One of the methods to make a domestic transportation system efficient is the consolidation. In this paper. we try to compare the consolidated transportation model for a cost reduction with individual case. We also analyze the efficiency of consolidated transportation using simulation program with Arena of System Modeling Company.