• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2164-2169
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• 2005

SFFS(Solid Freeform Fabrication System) can quickly makes models and prototype parts from 3D computer-aided design (CAD) data. Three dimensional printing(3DP) is a kind of the solid freeform fabrication. The 3DP process slices the modeling data into the 50-200um along to z axis. And we pile the powder and make the manufactures. A manufacture is made by the SFFS has the precision of the 50um. Therefore the x-y table of SFFS to move a printhead must be the system that has a high speed and accuracy. So we proposed the SMCSPO algorithm for SFFS. The major contribution is the design of a robust observer for estimating the state and the perturbation of the timing belt system, which is combined with a robust controller. The control performance of the proposed algorithm is compared with PD control by the simulation and the experiment. The control algorithm of the SFFS is presented in the office environment. The system between control system and printhead for the SFFS is also integrated

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.555-556
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• 2006

In recent years, the higher flatness level in wafer shape has been strictly demanded with a high integration of the semiconductor devices. It has become difficult for a conventional wafer preparing process to satisfy those demands. In order to meet those demands, surface grinding with in-feed grinder is adopted. In an in-feed grinding method, a chuck table fur fixing a semiconductor wafrr rotates on its rotation axis with a slight tilt angle to the rotation axis of a cup shaped grinding wheel and the grinding wheel in rotation moves down to grind the wafer. So, stability of the grinder structure is very important to aquire a wafer of good quality. This paper describes the features of the in-feed grinder and some FEM analysis results of the grinder structure.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.06a
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• pp.121-147
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• 1996

Since 1980, the water quality of ultra-pure water has been rapidly improved, and presently ultra-pore water producing equipment for 64Mbit is in operation. Table 1 shows the degree of integration of DRM and required water quality exlmple. The requirements of the ultra-pure water for 64Mbit are resistivity: 18.2 MQ/cm or higher, number of particulates: 1 pc/ml or less (0.05 $\mu$m or larger). bacteria count: 0.1 pc/l or less. TOC (Total Organic Carbon, index of organic snbstance) : 1ppb or less, dissolved oxygen: 5ppb or less, silica: 0.5ppb or less, heavy metal ions: 5ppb or less. The effect of metals on the silicon wafer has been well known, and recently it has been reported that the existence of organic substance in ultra-pure water is closely related to the device defect, drawing attention. It is reported that if organic substance sticks to the natural oxidation film, the oxide film remaims on the organic substance attachment in the hydrofluoric acid treatment (removal of natural oxidation film). The organic substance forms film on the silicon wafer, and harmful elements such as metals and N.P.S., components contained in the organic substance and the bad effect due to the generatinn of silicon carbide cannot be forgotten. In order to remove various impurities in raw water, many technological develoments (membrane, ion exchange, TOC removal, piping material, microanalysis, etc.) have been made with ultra-pure water producing equipment and put to practical use. In this paper, technologies put to practical use in recent ultra-pure vater producing equimeut are introduced.

• Journal of Sensor Science and Technology
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• v.15 no.1
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• pp.40-46
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• 2006

This paper presents a novel fiber optic accelerometer system for monitoring vibration of large-size structures. The system is composed of one (or multiple) sensor head, a light control unit and a signal processing unit. The sensing mechanism of the sensor head is based on a novel integration of the moire fringe phenomenon with fiber optics to achieve a robust performance in addition to its immunity to EM interference, easy cabling, and low cost. In this paper, a prototype of the fiber optic accelerometer system has been developed successfully. A low-cost light control unit has been developed to drive the system's optic and electronic components. A unique algorithm has also been developed to derive the sensor's acceleration from the raw signals of the light control unit; it is implemented via a separate signal processing unit. Finally, the shaking table tests successfully demonstrate the performance and the potential of the moire fringe fiber optic sensor system to monitor the health of civil infrastructures.

• Journal of Distribution Science
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• v.17 no.3
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• pp.41-47
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• 2019

Purpose - Based on the analysis of Kazakhstan's experience of digital transformation, this study suggests a concept for digital solution to optimize organizational process, create trust networking between the center of state scholarships programs and recipients. In addition, the authors contribute to the current discussions of an effective digital transformation of state services. Research design, data, and methodology - Policy analysis is based on the combination of both primary and secondary materials collected during a Policy Research Project conducted in Kazakhstan in 2017. It involved semi-structured interviews with the state scholarship' recipients, ICT experts and findings from academic articles. Results - Findings are represented via Policy Development Matrix - a table with three options (status quo, partial change, total change) to deal with policy challenges. Authors suggest a concept for digital solution following the Customer Relationship Management (CRM) principles for optimizing core business processes, communication and networking strategies of the state scholarships program. Conclusions - At the time when digitalization becomes trending for states, the transformation of the state education policy is inevitable. The rapid development of digital technologies creates new opportunities for a single integration platform with key principles of Smart Remote Management in the state scholarships programs.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.05a
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• pp.70-74
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• 2003

Recently, many kinds of satellites are developed in many countries. The satellite contains various data, such as hardware status data attitude date an information, etc. And the ground station must check these data for successful operation These data is called as telemetry. Flight software is responsible for the telemetry processing. In KOMPSAT(Korea Multi-Purpose Satellite)-2, the telemetry processing logic takes the table-driven method to make satellite data flow efficient In this paper, the telemetry processing in KOMPSAT-2 is described Verification test and integration test are being carried out for the FSW of KOMPSAT-2.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.89-95
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• 2002

The purpose of this study is to assess the residential satisfaction of no-charge welfare facility for the elderly, and to examine the effect of the integration with pay-training institute on residential satisfaction. The data were collected from staffs and fifty one residents of welfare facility by interview and questionnaire. The statistical analysis was conducted to identify the residential satisfaction. A half of the elderly were aged over seventy five years old, eighty four percents of them were female, and seventy seven percents of them were non-educated. Forty two percents of the elderly considered themselves to be unhealthy, but the ADL data reveals that they are relatively healthy. The most of residents are highly satisfied with whole welfare facility. But, the level of satisfaction on the bathroom, the storing space, the cooking table and the benches were relatively low. These dissatisfactions can be solved by the expanding of the storing space, setting up of a common washing room and electric cooking stove, and the increasing of the number of benches. Also, it was recommended for the elderly to set up the Ondol-style rest room with the western style rest room. The level of satisfaction on the attached training institute with no-charge welfare facility for the elderly were high. This has positive effect on residential satisfaction of the elderly. Therefore, the community integrated welfare facility can be the alternative plan for the enhancement of residential satisfaction and quality of elderly life.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.4
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• pp.340-352
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• 1994

A numerical model of nonlinear stream function wave theory evolved from Dean's model (1965) is presented. The stream function theory has been evaluated to be an accurate and useful tool for engineering applications. Effects of damping coefficient employed in a linearized simultaneous equation and number of points in the numerical integration of model on numerical solutions are assessed. Most accurate wave characteristics calculated by the present model are tabulated using revised Dean's Table (Chaplin, 1980) input parameters. Since the well-known feature of nearly breaking waves that with increasing wave steepness the wave length as well as integral properties have a maximum prior to the limiting wave height is represented by the model, the accuracy of model can be proved.

• Journal of Biosystems Engineering
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• v.38 no.1
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• pp.25-32
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• 2013

Purpose: The objective of this study is to develop a data middleware for u-IT convergence in agricultural environment monitoring, which can support non-standard data interfaces and solve the compatibility problems of heterogenous sensor networks. Methods: Six factors with three different interfaces were chosen as target data among the environmental monitoring factors for crop cultivation. PostgresSQL and PostGIS were used for database and the data middleware was implemented by Python programming language. Based on hierarchical model design and key-value type table design, the data middleware was developed. For evaluation, 2,000 records of each data access interface were prepared. Results: Their execution times of File I/O interface, SQL interface and HTTP interface were 0.00951 s/record, 0.01967 s/record and 0.0401 s/record respectively. And there was no data loss. Conclusions: The data middleware integrated three heterogenous sensor networks with different data access interfaces.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.5
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• pp.537-544
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• 2019

In currently electronic systems, the speed of information integration has increased due to the development of electronic technology. However, due to the increase in the number of parts and groups, the product structure has become complicated. In this paper, a study was conducted to evaluate quantitatively the replacement of a small equipment. First, the level of the replacement was determined through the algorithm for the replacement level of parts. Next, we defined the ease of detail replacment, and the factors for each detail replacement. In order to calculate the weighting of the detail ease, we performed the analysis of the replacement process of subcomponents of communication exchanger and defined the evaluation criteria. Finally, the completion of the evaluation check sheet and the evaluation score table.