• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.149-155
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• 2005

We have proposed an objective evaluation method using ESNR as the measure of approximation by the visual model, which coincides with MOS, a subjective evaluation method. For two-value images, we have used five kinds of modulation methods: 1) ordered dither, 2) least mean error, 3) pulse density low division, 4) simple two-value, and 5) random dither methods. The purpose of this paper is to investigate the validity of ESNR, by comparing the proposed method together with the existing representative methods such as PSNR and WSNR, with the subjective method MOS. The results of a series of experiments show that the ranking by MOS coincides with ESNR, though does not coincides with PSNR and WSNR.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.163-164
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• 2023

The technical proposal bidding system emphasizes the evaluation of the construction company's technical capabilities, with the aim of improving the quality and cost-effectiveness of the construction. However, in the VE analysis and proposal process for technical proposal bidding, the ideas are often reused from similar past construction projects, and the application of new construction technologies/methods is often lacking. Therefore, this study proposes a methodology for managing VE proposal information by integrating it into a BIM model using parametric modeling. This research developed database based on the existing VE proposals and new construction technology/method information from the Korea Institute of Civil Engineering and Building Technology. And by using parametric modeling, the proposed method integrate the VE database with BIM model. The methodology proposed in this study is expected to improve the reliability and effectiveness of VE-related idea proposals in technical proposal bidding.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.74-82
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• 2022

Improving long-term performance in highway projects is an imperative goal for public administrations. Project delivery and procurement methods might provide an opportunity to align design and construction processes with this goal. Previous studies have explored whether project delivery methods impact the long-term performance of highway projects. However, these studies did not focus specifically on how core elements within the procurement might relate to long-term performance. Thus, this research aims to fill this gap by exploring to what extent and how long-term evaluation criteria are considered in design-build best-value procurement of highway projects. To this end, content analysis was conducted on 100 projects procured between 2009 and 2019 by 19 DOTs across the U.S. The analysis of 365 evaluation criteria found that (1) roughly 11% of them related to long-term performance. (2) The weight given to these criteria in the overall technical proposal was lower than 30%. (3) Sixty-five percent (65%) of long-term evaluation criteria focused on design while 15% related to materials and technology, respectively. The results of this study are a first steppingstone to initiate a deep exploration of the relationship between procurement practices and actual project performance. Currently, with sustainability and life cycle assessments being top concerns in infrastructure projects, this line of research might be of particular interest to DOTs and highway agencies across the U.S. and worldwide.

• Journal of Energy Engineering
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• v.14 no.3 s.43
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• pp.167-172
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• 2005

This paper presents a methodology to support decision making for distribution system planning based on value. To evaluate the reliability value, we employ valued-based distribution reliability assessment. To evaluate the harmonics value, we employ a marginal pricing method, and by using reliability cost, harmonics cost, and construction cost, we can make the most economic decision. By applying the method to the real system, we show this method can get the best result which meet reliability and harmonics level.

• Journal of Korean Society for Quality Management
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• v.24 no.1
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• pp.50-60
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• 1996

Though the quality characteristics within a specified tolerance are equally desired quality there is a difference in conformance between a specification limit and a target value. In this paper we propose a measure of process capability that takes into account the degree of conformance to a target value as well as the process variation.

• Information Systems Review
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• v.8 no.1
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• pp.265-285
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• 2006

The purpose of this research is to identify the major evaluation criteria of IT investment projects and establish the importance weights of criteria through AHP analysis. Seven evaluation criteria which have been drawn from prior studies and industry practices are direct costs, indirect costs, financial benefits, strategic value, risk, technical necessity, and political considerations. Data have been collected from 95 IT projects in 40 public organizations and private firms in Korea. After having applied the data reliability test, 79 projects have been selected. The results of AHP analysis show the importance weights and priorities of seven evaluation criteria as follows: financial benefits 25.2%, strategic value 22.36%, direct costs 14.34%, risk 12.10%, technical necessity 11.55%, political considerations 8.3%, and indirect costs 6.48%. And the weights of seven criteria shows considerable differences among three different IT project types such as transactional, informational, and infrastructural.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.5
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• pp.527-535
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• 2015

As a new technical approach, a hydraulic and magnetic clamp device was attempted to realize a magnetic clamp crane system that uses 8 simultaneously actuating individual hydraulic cylinders. Through this approach, a Sr type of ferritic permanent magnet ($SrO{\cdot}6Fe_2O_3$), not the previously employed electro-magnet, was utilized for the purpose of lifting and transporting the heavy weighted and oversized curved steel plates used for manufacturing the ships. This study is aimed at manufacturing and developing the hydraulic magnetic clamp prototype, which is composed of three main parts - the base frame, cylinder joint, and magnet joint - in order to safely transport such curved steel plates. Furthermore, this research was pursued to conduct a performance evaluation as to the prototype manufacture and acquire the planned quantity value and the development purpose items. The most significant item for a performance evaluation was estimated for the magnetic adhesive force (G) and in this process, a ferritic permanent magnet (Sr type) with 3700~4000 G of residual induction (Br) and 2640/2770 Oe of coercive force (Hc) was utilized. In addition, other relevant items such as hoist tension (kN), transportation time (sec), and the applied load (Kgf) exerted on the hydraulic cylinders were also evaluated in order to acquire the optimum quantity value. As a result of the evaluation, the relevant device turned out to be suitable for safely transporting the curved steel plates.

• Journal of radiological science and technology
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• v.44 no.4
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• pp.375-380
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• 2021

This study aim was quantitative assessment of MTFs of spectrum of the square wave chart images and Coltman chart images for 0°, 1.7°, 2.2°, 2.9°, 4.1° by using chart method. In general device was AccuRay-650 (DK Medical System, Korea) used, indirect flat panel detector(FPD) Aero (Konica, Japan) used and MATLAB R2019a (MathWorks, USA) used. The result of comparison for each angle of MTF the edge image was highest quantitatively value for MTF finding of showed the best value of 0.1 based on the frequency of 3.5 mm^-1, value of 0.1 based on the square wave was frequency of 3.0 mm^-1 and value of 0.1 based on the Coltman transform was frequency of 2.4 mm^-1. In this study it was significant that the methodology of the international Electro-technical Commission was applied mutandis by using the Fujita method within 2~3°.

• Journal of Ocean Engineering and Technology
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• v.32 no.6
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• pp.518-526
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• 2018

As a new technical approach, this paper introduces a method for improving an electrically propelled outboard motor in consideration of the driving system applied to an electric-propulsion boat with solar cell energy. The most efficient model for a drive shaft, propeller shaft, and bevel gear was suggested and examined with respect to the results of test operation in prototype mode. Furthermore, this research included a performance evaluation of the manufactured prototype to acquire the purposed quantity value and the development items. After manufacturing the desired prototype of an electrically propelled outboard motor, the maximum sail time, thrust force, noise, and weight were evaluated in a performance test. An additional test in relation to the maximum sail speed (knots) of the completed prototype was conducted using a sea trial evaluation to acquire the optimum quantity.

• Journal of Ocean Engineering and Technology
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• v.30 no.1
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• pp.57-67
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• 2016

As a new technical approach, an attempt was made to realize a photovoltaic system for an eco-environmental leisure ship by simultaneously actuating nine photovoltaic solar panels in association with the application of a sail-controlling system using wind energy. In this approach, the photovoltaic system consisted of a solar module, an inverter, a battery, and the relevant components, while the sail-controlling device was equipped with sail up/down and mast turning systems. The previously mentioned eco-environmental leisure ship utilizes a photovoltaic hybrid system that uses solar and wind energy as renewable energy sources. Furthermore, this research included a performance evaluation of the manufactured prototype, the acquisition of the purposed quantity values, and development of the purposed items. The significant items, including the sail up/down speed (seconds) and mast turning angle (degrees) were evaluated for a performance test. A wind direction sensitivity of 90% and maximum instant charging power of 900 W were also obtained in the process of the performance evaluation. In addition, the maximum sail time was also evaluated in order to acquire the optimum value. The performance evaluation showed that the prototype with a photovoltaic hybrid system was suitable for sailing an eco-environmental leisure ship using solar and wind energy.