• Journal of Applied Reliability
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• v.15 no.4
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• pp.248-255
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• 2015

Purpose : The purpose of this research is to develop the optimized method and process in the reliability-growth target setting, especially for complex and repairable system (or products) such as vehicle and airplane, construction equipment. Method : A reliability-growth test plan specifies a scenario to achieve the planned reliability value (or reliability target). The major elements in test planning are reliability-growth starting time and reliability level at that time, reliability-growth rate and reliability-growth target. All of them except a reliability target can be referred to the previous development data and reference researches. The reliability target level is directly influencing to test period (or time) which is related to test and warranty cost together. There are a few researches about the reliability target setting method and but showing the limitations to consider the views of engineering, business and customer together. There is no research how to handle the target setting process in detail. Result : We develop the optimized method and systematic process in reliability target setting with considering such views. This research also establish the new concept as production capability which means company (or supplier) capability to product its products. Conclusion : In this research result, we apply the new method to a few projects and can set the reasonable test planning. The developing results is showing the good balance between the developing cost and warranty cost at market.

• Design & Manufacturing
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• v.6 no.2
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• pp.17-23
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• 2012

In April 2010, the die and mould grand prix for university student was held in Osaka as a special event of Inter Mold Japan. The students from Korea, China, and Japan participated to demonstrate the design and manufacturing skill of die and mould. Based on the given product drawing of Test Work, progressive die should be designed and manufactured. Also, production of Test Work should be carried out. This study had been conducted to participate in the grand prix and to learn practical knowledge and experience from real die design and making. Test Work is made of SPCC and includes piercing, blanking, deep drawing and burring. From the analysis of product drawing, process planning and die design was carried out. Progressive die for Test Work was manufactured using CNC milling, grinding, wire-cutting and polishing. The production was successfully completed using mechanical press and product showed very good accuracy satisfying all dimensional tolerances.

• KDI Journal of Economic Policy
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• v.13 no.4
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• pp.117-140
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• 1991

The purpose of this paper is primarily to introduce a nonparametric statistical tool developed by Baek and Brock to detect a unidirectional causal ordering between two economic variables and apply it to interesting macroeconomic relationships among money, production and prices. It can be applied to any other causal structure, for instance, defense spending and economic performance, stock market index and market interest rates etc. A key building block of the test for nonlinear Granger causality used in this paper is the correlation. The main emphasis is put on nonlinear causal structure rather than a linear one because the conventional F-test provides high power against the linear causal relationship. Based on asymptotic normality of our test statistic, the nonlinear causality test is finally derived. Size of the test is reported for some parameters. When it is applied to a money, production and prices model, some evidences of nonlinear causality are found by the corrected size of the test. For instance, nonlinear causal relationships between production and prices are demonstrated in both directions, however, these results were ignored by the conventional F-test. A similar results between money and prices are obtained at high lag variables.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.3
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• pp.389-396
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• 2020

In order to obtain a good quality product, a proper verification of production/test facilities must be preceded before the quality conformity inspection of the product. Among the various production/test facilities, ATE is widely used in the civilian industry such as the automotive industry, aerospace industry, semiconductor industry today. In addition, ATE is actively used in the defense industry production and performance tests. This paper is the result of systematically verifying the Design Conformance of ATS which is ATE of military FM radio set using various methods. And It is expected to be a good reference at the present time when the design conformity verification procedure for ATE for military supplies is not documented.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.375-377
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• 2008

The KOMPSAT2 Terminal Polar Station was recently installed at near North Pole, Tromso, and Toulouse. The K2PS consists of one receiving station and two processing sites. The receiving station has been installed at SvalSat ($N78^{\circ}$, $E15^{\circ}$ ), and the two receiving sites have been installed at KSAT (Kongsberg Satellite Service AS), Tromso, Norway ($N69^{\circ}$ ,$E18^{\circ}$ ) and SISA, Toulouse, France ($N43^{\circ}$ ,$E1^{\circ}$ ). The products ofK2PS system can be classified to two categories: Level 1R product and Level 1G product. The Level 1R product is radiometric corrected product with RPC (Rational Polynomial Coefficients) and the Level 1G product is geometric corrected product with POD (Precise Orbit Data) and PAD (Precise Attitude Data) data based on Level 1R product. To meet a SISA (Spot Image SA)'s requirement, K2PS system has high performance product producing capability. This paper describes overall K2PS systems' production generation flow and the mass production test result of K2PS systems.

• Korean Management Science Review
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• v.25 no.3
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• pp.13-26
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• 2008

We investigate the effect of government and public sector R&D Investment at IT Industry on the amount of Production, export and nongovernment R&D Investment at IT Industry. We, firstly, examine the stationarity of each variable by the unit root t-test and perform the co-integration test for the pairs of variables. We use YECM(Vector Error Correction Model) according to the results of co-integration test for the examination of Granger-causality between variables. It is found that there exist an Granger-causality between public sector R&D Investment and nongovernment R&D investment and also between public sector R&D Investment and export. Secondly, we analyze the impulse response of government and public sector R&D Investment at IT Industry on the amount of production, export and nongovernment R&D investment at IT Industry based on VECM model. It is found that the response of the amount of production is highest at 3th period and is lowest at 8th period and that of export shows similar pattern.

• Journal of Korea Foundry Society
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• v.17 no.3
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• pp.286-291
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• 1997

Influence of Si contents on the mechanical properties and microstructure of austempered ductile iron was investigated. Four different Si contents between 2.0 and 2.9% were used. Austenitizing was performed at $890^{\circ}C$ for 2 hrs and austempering temperatures were both 340 and $380^{\circ}C$ for 0.5, 1, and 2 hrs. Nodule content was more than $300/mm^2$ and nodularity was more than 90%. Microstructure was revealed using nital and retained austenite was measured by x-ray diffractometer. Tensile test, no-notch Charpy impact test and wear test were performed. Tensile strength was improved as Si content increased and both elongation and impact toughness had peak at 2.6%Si. The specimen austempered at $380^{\circ}C$ showed lower tensile strength than that of $340^{\circ}C$, but showed higher elongation. However, austempering temperature of $380^{\circ}C$ was desirable because that of $340^{\circ}C$ was close to lower bainite transformation. As austempering time increased, tensile strength and elongation were improved and optimum condition was obtained for 2 hrs heat treatment.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.13-19
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• 2021

To provide empirical evidence on the impact of export instability on economic growth in developing countries, this study estimated the neoclassical production function using data of the Jordanian economy for the period 1995-2019. Real exports, real capital, and export instability were the independent variables in the production function. To determine the appropriate methodology for estimating the production function, the study conducted some preliminary tests, including the Augmented-Dickey Fuller (ADF), on the study data. The results of this test indicated that all study variables were stationary at first difference. Therefore, the Johanson cointegration test was applied to determine that there was cointegration between the study variables since the results of the former test indicated that there was one cointegration vector between these variables. The cointegration equation revealed a positive and statistically significant impact of real capital, real exports, and an indicator of export instability on economic growth. The most important policy implications for these results would be reducing the geographical concentration of exports through the expansion of free trade agreements (FTA) to enhance the positive impact of the instability of exports on economic growth. Moreover, the study recommends strengthening export-oriented actions to achieve higher levels of economic growth.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.3
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• pp.311-320
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• 2022

In this paper, we studied the optimal method of improving performance for aircraft having various variants within the same type. The study defined configuration of an entire fleet of aircraft being subject to a performance improvement program. And selected the most complicated aircraft configuration among them as a Standard Aircraft for modification by according to the proposed Aircraft Selection Process for developing an optimal Aircraft Performance Improvement Process. Based on the selected the Standard Aircraft, drew a system integration design result and carried out Evaluation Test and obtained Airworthiness Certification. Created the database with the design data of the Standard Aircraft, Evaluation Test, and Airworthiness Certification results, and applied it to variants of aircraft to complete the performance improvement program with optimized schedules and costs. By applying the proposed method to IFF performance improvement program, drew optimal system integration design and completed the program with minimized schedule.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.293-305
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• 2017

This experiment was conducted to evaluate the effect of leachate replacement frequency on solid state anaerobic digestion (SSAD) of dairy manure using 22 L volume lab-scale digesters at mesophilic temperature ($37^{\circ}C$) in batch mode. Three different leachate replacement strategies (no replacement, once every three days, and once every nine days) were applied and three digesters per each treatment were operated for 45 days. Results showed that leachate replacement test unit every nine days resulted in 1.6 times more methane production ($53.8N{\cdot}mL\;g^{-1}{\cdot}VS$) from SSAD compared to test unit every three days ($34.0N{\cdot}mL\;g^{-1}{\cdot}VS$). No leachate replacement strategy applied group showed slightly higher methane production ($56.3N{\cdot}mL\;g^{-1}{\cdot}VS$) than every nine days replaced one. When added the methane production potential of replaced leachate itself to the methane produced from digester, leachate replacement every nine days resulted in quite similar methane production ($56.5N{\cdot}mL\;g^{-1}{\cdot}VS$) to no leachate replacement group. Even though methane production potential of replaced leachate itself added to the methane produced from digester, every three days replacement showed only $34N{\cdot}mL$ methane production per gram of volatile solids. These results suggest that farmers do not need to replace leachate during SSAD of dairy manure and sawdust mixture in order to maximize methane production. If there are any concerns with accumulation of inhibiting substances in the digester, the 9-day cycle leachate replacement is appropriate.