• Journal of the Korean Society for Precision Engineering
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• 제29권3호
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• pp.319-323
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• 2012

Transmission is one of the important pars to transmit power from engine to wheels. Mass reduction gears can make the engine power requirement reduce, and can make dynamic performance and fuel efficiency of vehicle improve. Transmission gears are modified for mass reduction without changing their tooth shapes, face widths, and modules by using shape optimization and re-check process. Also structural stability is verified by FEA.

• Korean Journal of Computational Design and Engineering
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• 제3권1호
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• pp.22-30
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• 1998

The deflection yoke (DY) controls the direction of the electron beam that falls on the screen of the television monitor. Its quality depends on the shape and density of coils wound around the DY coil separator. Winding frames are used to make these coils, and therefore, their shapes are essential in making quality coils. A reverse engineering(RE) is applied to create the 3D model of the winding frame. It considerably shortens the design verification time and shows the level of accuracy that is feasible in the production mode. The paper explains each step of the reverse engineering process in detail.

• IE interfaces
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• 제24권4호
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• pp.428-434
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• 2011

In these days, mobile technology such as smart phone and GPS have an effect on business processes of many companies especially a transportation company. The purpose of this paper is to present the development processes of real time vehicles tracking and intelligent TMS (Transportation Management System) using smart phone applications. The objective of this study is two-fold. The first is to redesign business process of the transportation company. Using BPR (business process re-engineering), we analyze current processes to find opportunities for improvement redefining processes after adopting mobile technology precisely. The second is to develop the real time vehicles tracking and intelligent TMS. Proposed system consists of four parts : (1) intelligent TMS(web system) (2) real time vehicle tracking application for TMS (3) real time tracking application for customer (4) salesman supporting application. Developed system was tested at the transportation company and was found to be an useful system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제13권1호
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• pp.45-51
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• 2014

Generally, marine transmissions contain straight shafts and helical gears, meaning that enginerooms require more space. In order to guarantee a levelengine space for conical involute gears or beveloid gears, both of which are important machine parts, a conical gear was used to replace the traditional cylinder gear. Owing to weak points such as the point contact phenomenon of the teeth, a limitation of the width of each tooth in terms of the addendum, the variational modification coefficient,and the difficulty of processing, research about conical involute gears remains at a standstill. Along with the increasing number of applications of conical involute gears, research on conical gear design technology is necessary. In this paper, in an effort to enhance conical gear design technology, research on the 3D modeling and stress analyses of helical conical involute gears were done.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제13권1호
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• pp.85-91
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• 2014

The rotation of a spindle unit must be accurate for high-quality machining and to improve the quality of the machine tools. Therefore, the proper measurement of the rotation accuracy and ensuring a proper analysis are very important. Separate processes are necessary because spindle errors and roundness errors associated with the test balls can both factor into the measured rotation error values. We used three methods to discern test ball errors and analyzed which could be deemed as the most proper technique in a test of the rotation accuracy of the main spindle of a machine tool.

• Transactions on Electrical and Electronic Materials
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• 제15권1호
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• pp.32-36
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• 2014

In this study, the etching characteristics of titanium dioxide ($TiO_2$) thin films were investigated with the addition of $N_2$ to CF4/Ar plasma. The crystal structure of the $TiO_2$ was amorphous. A maximum etch rate of 111.7 nm/min and selectivity of 0.37 were obtained in an $N_2/CF_4/Ar$ (= 6:16:4 sccm) gas mixture. The RF power was maintained at 700 W, the DC-bias voltage was - 150 V, and the process pressure was 2 Pa. In addition, the etch rate was measured as functions of the etching parameters, such as the gas mixture, RF power, DC-bias voltage, and process pressure. We used X-ray photoelectron spectroscopy to investigate the chemical state on the surface of the etched $TiO_2$ thin films. To determine the re-deposition and reorganization of residues on the surface, atomic force microscopy was used to examine the surface morphology and roughness of $TiO_2$ thin films.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제25권1호
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• pp.14-20
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• 2016

This paper describes a green stripping process to effectively strip the remaining DFR layer on a non-alkali-based ITO glass surface after an etching process. A stripper, water-soluble amine compound, is used to investigate the characteristics of stripping ability and to suggest a valid method for the green process. Increasing the composition (5-30% concentration) of the ethanol amine-based stripper was found to greatly reduce the stripping time applied in the dipping method. The composition (30%) achieved an excellent stripping effect and free-residue impurities. Additionally, it was possible to obtain the effect of stripping in a way to sustain the release before generating DFR sludge from the ITO glass surface by using dipping condition (stripping time) in the composition. An Additional stripping process (buffering) out of dipping can realize productivity improvement and cost reduction because of the higher proportion of re-use of the stripping solution used in the DFR removal step.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2206-2214
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• 2023

The existing wet reconversion processes for the recovery of scraps generated in manufacturing of nuclear fuel are complex and require several unit operation steps. In this study, it is attempted to simplify the recovery process of high-quality fuel-grade UO₂ powder. A novel wet reconversion process for uranyl nitrate hexahydrate solution is suggested by using a newly developed pulsed fluidized bed reactor, and the resultant chemical characteristics are evaluated for the intermediate ammonium uranate hydrate product and subsequently converted UO₂ powder, as well as the compliance with nuclear fuel specifications and advantages over existing wet processes. The UO₂ powder obtained by the suggested process improved fuel pellet properties compared to those derived from the existing wet conversion processes. Powder performance tests revealed that the produced UO₂ powder satisfies all specifications required for fuel pellets, including the sintered density, increase in re-sintered density, and grain size. Therefore, the processes described herein can aid realizing a simplified manufacturing process for nuclear-grade UO₂ powders that can be used for nuclear power generation.

• Journal of Ocean Engineering and Technology
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• 제31권4호
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• pp.315-323
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• 2017

This paper presents an integrated navigation system that combines ultra-short baseline (USBL), Doppler velocity log (DVL), and heading measurements for a deep-sea remotely operated vehicle, Hemire. A navigation model is introduced based on the kinematic relation of the position and velocity. The system states are predicted using the navigation model and corrected with the USBL, DVL, and heading measurements using the Kalman filter. The performance of the navigation system was confirmed through re-navigation simulations with the measured data at the Southern Mariana Arc submarine volcanoes. Based on the characteristics of the measurements, the design process for the parameters of the system modeling error covariance, measurement error covariance, and initial error covariance are presented. This paper reviews the influence of the outliers and blackout of the USBL and DVL measurements, and proposes an outlier rejection algorithm that is robust to USBL blackout. The effectiveness of the method is demonstrated with re-navigation for the data that includes USBL blackouts.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.476-479
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• 2004

In the process of industrialization of our country in 1970's, Korea's housing strategy has focused on housing supply. Rapid completion and supply of apartment house buildings have caused a problem of their early deterioration due to their poor quality. In 1987 Housing Construction Promotion Act, therefore, included new regulations on housing re-construction. In July 2001, other new regulations on remodeling apartment buildings were also included in the Act. Reconstruction and remodeling have been considered to deal with such problems. This study suggests an appraisal criteria if they can select reconstruction or remodeling method in conducting their apartment building project. At first, evaluation items should be selected by the criteria of function31ity and economical efficiency. Second, the selected item is screened by AHP and multi-criteria decision-making methods. The result of study shows that the owners of apartment units will be able to select reasonable alternatives through the suggested appraisal method