• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.8
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• pp.744-751
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• 2004

This paper presents the implementation of the low cost and high speed RF ATE(Automatic Test Equipment) system, which can be a reasonable solution for reducing the test cost of RF devices. This paper suggests high speed and precise measurement capabilities which are realized by the 16 independent RF ports with high speed switching time and high accuracy digitizer using the industry standard Versus module eXtensions for Instrument(VXI) General Purpose Interface Bus(GPIB) interfaces. Also, the system has the capabilities of quad-site test which can dramatically increase the device throughput. This paper concludes with the demonstration of the implemented ATE system through the setup of RF Power Amplifier Module(PAM), which is under the most competitive market situation.

• The Journal of the Korea Contents Association
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• v.12 no.11
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• pp.39-48
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• 2012

It is well known that software testing amounts for a significant portion of software development cost. In order to reduce the cost of software testing. a lot of researches on automated test data generation have been performed. Sophisticated tools for performing symbolic execution or solving a system of path constraints are required to support automated test data generation. Developing or purchasing those tools leads to another factor of increasing the cost involving software testing. In this paper, we propose a dynamic test data generation approach that does not depend on symbolic execution or constraint solving at all. The proposed approach extends Korel's path-oriented method to satisfy the branch coverage criterion effectively. We conducted an experiment to evaluate the effectiveness of the proposed technique with a triangle classification program to show that branch coverage can be easily achieved.

• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.767-774
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• 1997

A procedure presented in this paper greerates test squences to check the conformity of an implementation wihh a protocol specification which is moedled as a determinstic fimite state machine(FSM).We proposed a tech-nique to determine a minium-cost tour of the transition graph of the FSM..The technique using Multiple UIO and Shortest Path(MUSP) sabes the cost 1-9% over MUIO and directly, derive a symertric test graph from an FSM graph From this fact, we proposed a tecuque using Multiple Sate Suganture(MUSS) to solve an open issue that the multiple UIO assignment may not minimize the lengy of the tour.In this paper, the proposed techique is also, applied to generate a synchronizable test wequence.And the result shows that the techique using MUSP anhd MUSS saves the cost 7-29% and 7-42% over the previous approach using MUIO, respect-ively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.149-151
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• 2012

Changes in the price of materials in construction projects is one of the important variables. Therefore, measures are necessary to respond to the demand and supply of materials and price instability. In previous studies, mainly of ready-mix concrete and steel beam analysis was carried out. However, a study of non-ferrous material prices are still insufficient. So, in this study, the researcher identified the causal relationship between the construction cost and non-ferrous materials prices. Construction Cost Index was selected as a proxy variable of construction cost.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.2
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• pp.17-26
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• 2008

The traveling salesman problem is to find tours through all cities at minimum cost ; simply visiting the cities only once that a salesman wants to visit. As such, the traveling salesman problem is a NP-complete problem ; an heuristic algorithm is preferred to an exact algorithm. In this paper, we suggest an effective cost relaxation using a candidate arc set which is obtained from a regression function for the traveling salesman problem. The proposed method sufficiently consider the characteristics of cost of arcs compared to existing methods that randomly choose the arcs for relaxation. For test beds, we used 31 instances over 100 cities existing from TSPLIB and randomly generated 100 instances from well-known instance generators. For almost every instances, the proposed method has found efficiently better solutions than the existing method.

• Steel and Composite Structures
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• v.27 no.5
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• pp.633-646
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• 2018

This study investigated the seismic performance of a hybrid damper composed of a steel slit plate and friction pads, and an optimum retrofit scheme was developed based on life cycle cost. A sample hybrid damper was tested under cyclic loading to confirm its validity as a damping device and to construct its nonlinear analysis model. The effectiveness of the optimum damper distribution schemes was investigated by comparing the seismic fragility and the life cycle costs of the model structure before and after the retrofit. The test results showed that the damper behaved stably throughout the loading history. Numerical analysis results showed that the slit-friction hybrid dampers optimally distributed based on life cycle cost proved to be effective in minimizing the failure probability and the repair cost after earthquakes.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.5
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• pp.220-225
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• 2000

As a competition is introduced in the electricity supply industry, a congestion problem arises in the transmission network. The congestion causes the transmission cost to increase. One way to decrease the congestion cost is to control the transmission flow through the installation of TCSC(Thyrister Controlled Series Capacitor). This paper deals with the optimal site of the TCSC for reducing the congestion cost using a shadow price which is one of the economic signals for the systems. Test results show that the site of the TCSC is optimal to minimize the congestion cost by the proposed algorithm.

• Progress in Superconductivity and Cryogenics
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• v.22 no.1
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• pp.17-23
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• 2020

Cryogenic insulation systems, with proper materials selection and execution, can offer the highest levels of thermal performance. Insulations are listed in order of increasing performance and, generally, in order of increasing cost. The specific insulation to be used for a particular application is determined through a compromise between cost, ease of application and the effectiveness of the insulation. Consequently, materials, representative test conditions, and engineering approach for the particular application are crucial to achieve the optimum result. The present work is based on energy cost balance for optimizing the thickness of insulated chambers, using foamed or multi layered cryogenic shell. The considered insulation is a uniformly applied outer layer whose thickness varies with the initial and boundary conditions of the studied vessel under steady-state radial heat transfer. An expression of the optimal insulation thickness derived from the total cost function and depending on the geometrical parameters of the container is presented.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.1
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• pp.9-16
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• 2003

In this paper, we propose a reliability evaluation method considering the momentary interruptions of power distribution systems. The results of research are concentrated on two parts. One is the analytic and probabilistic reliability evaluation of power distribution system considering the momentary interruptions and the other is the reliability cost evaluation that unifies the cost of sustained and momentary interruptions. This proposed reliability cost evaluation methodology is also divided into the analytic and probabilistic approach and the time sequential Monte Carlo method is used for the probabilistic method. The proposed methods are tested using the modified RBTS (Roy Billinton Test System) form and historical reliability data of KEPCO (Korea Electric Power Corporation) system. Through the case studies, it is verified that the proposed reliability evaluation and its cost/worth assessment methodologies can be applied to the actual reliability studies.

• ETRI Journal
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• v.43 no.4
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• pp.684-693
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• 2021

This paper presents a low-cost two-stage approximate multiplier for bfloat16 (brain floating-point) data processing. For cost-efficient approximate multiplication, the first stage implements Mitchell's algorithm that performs the approximate multiplication using only two adders. The second stage adopts the exact multiplication to compensate for the error from the first stage by multiplying error terms and adding its truncated result to the final output. In our design, the low-cost multiplications in both stages can reduce hardware costs significantly and provide low relative errors by compensating for the error from the first stage. We apply our approximate multiplier to the convolutional neural network (CNN) inferences, which shows small accuracy drops with well-known pre-trained models for the ImageNet database. Therefore, our design allows low-cost CNN inference systems with high test accuracy.