• IE interfaces
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• v.12 no.1
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• pp.158-165
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• 1999

One solution to the estimation of product reliability during the development phase is to measure reliability improvement over time and compare this improvement to previous product development progress. This paper presents the reliability growth theory and applies it to some subsystems of vehicles during their design, development and prototype testing. The data presented illustrates explicitly the prediction of the reliability growth in the product development cycle. The application of these techniques is a part of the product assurance function that plays an important role in product reliability improvement.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.179-181
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• 1997

When grown the oxide single crystal including Li-ion, optimum oxygen condition is needed. Color and crack are caused in single crystal according too the change in the condition of the oxygen. LiTaO₃ crystals grown from off-composition of congruent melt composition under oxygen deficieny condition didn't generate any crack. LiNbO₃. LiTaO₃ crystals grown from congruent melt composition under optimum oxygen condition caused pale yellow color or colorless with no crack. Color gradually became colorless and generated cracks according to Oxygen excess.

• Journal of the Korean Geographical Society
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• v.40 no.1 s.106
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• pp.47-62
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• 2005

This paper aims at analyzing the economic effect of the public financial expenditure on the national industrial complexes. Since public finance support is indirectly supplied to the national industrial complexes, the economic effect of the public financial expenditure on the national industrial complexes may be analyzed indirectly and circuitously In this contort, this paper uses 3 stage analysis method. In the first stage, the economic effect that the public financial expenditure influence the allotment, production and employment of companies residing in the national industrial complexes is analyzed by multiple regression analysis. In the second stage, the economic effect that the investment on the national industrial complexes influence the national and regional economies is analyzed by multiple regression analysis. In the third stage, the economic effect of the public financial expenditure on the national industrial complexes is analyzed through the compromising the results of the first and second stage. The main results of this paper are as follows. Firstly, public financial expenditure on the infrastructure of national industrial complexes leaded to positive growth of the allotment of companies residing in the national industrial complexes. Additionally, growth of the allotment of companies leaded to the positive effect on the production and employment of companies. And secondly, growth of the allotment of companies leaded to the positive effect on the gross regional domestic production. Finally, financial expenditure on the infrastructure of national industrial complexes leaded to positive effect on the national and regional economic growth through the compromising the results of the first and second stage.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.34-41
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• 2018

This paper studied balanced regional development focused on employment in Korea, by analyzing regional disparity between regional and industrial employment. A Gini-coefficient decomposition method and Panel Granger causality test were conducted, using raw data of the Census on Establishments reported by the Statistics Korea. The regional and industrial disparity of employment, based on the Gini-coefficient decomposition method, have increased by year. However, the growth rates of disparity are on the decrease. Most of employment disparity occurred from regional disparity between SMA (Seoul Metropolitan Area) and Non-SMA. Industrial disparity are occurred mainly by the service industry. The amount of contribution to the whole disparity of inter/intra regional employment was differed by each industrial sector. Also the causal relationship between employment growth of manufacture and that of service industry was analyzed by Panel Granger causality test. In national level, the employment growth in manufacture industry has conduced that in service industry. On the other hand, in the Non-SMA, only the employment growth in manufacture industry has augmented that in service industry. In conclusion, to reduce employment disparity, the strategy for balanced regional development should be emphasized. Different strategies are needed across regions and industries. Basically creating new job in the Non-SMA is inevitable. In view of stable employment, manufacture industry is more desirable rather than service industry.

• Journal of Industrial Technology
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• v.23 no.A
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• pp.3-7
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• 2003

Effect of nitriding on fatigue crack initiation and growth rate has been studied on SNCM. Specimens were nitrided for 15 hr at $860^{\circ}C$. The fatigue limit of nitrided specimens was superior to that of annealed($860^{\circ}C$, 15 hr) specimens. Based on detailed observations of slip band and micro crack initiation, it is concluded that the excellent fatigue limit of nitrided specimens is attributed to improved slip initiation resistance by nitriding. The characteristic of fatigue crack growth rate of nitrided specimens was investigated and compared with those of annealed specimens. It was found that by nitriding the crack growth rate was markedly decreased and the threshold stress intensity factor range was improved. It is concluded that the excellent fatigue limit of nitrided specimens is also attributed to improved fatigue crack growth rate and threshold stress intensity factor range by nitriding.

• Journal of Applied Biological Chemistry
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• v.44 no.4
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• pp.185-189
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• 2001

Essential oils of 21 herb plant samples, using spectrophotometric and paper disc agar diffusion methods under anaerobic conditions, were tested in vitro for their growth-inhibiting activities against Bifidobacterium bifidum, B. longum, Lactobacillus casei, Clostridium perfringens, and Escherichia coli. The responses varied with bacterial strains and plant oils. At 10 mg/disk, all essential oils did not inhibit beneficial intestinal bacteria, except for the oil of Alpinia officinarum and Melaleuca alternifolia against L. casei. Due to their strong growth-inhibitory activities against C. perfringens, E. coli, and L. casei, the activites of nine oils were evaluated at low concentrations. In test with C. perfringens at 1 mg/disk, the oils of Amyris balsamifera, Curcuma longa, M. alternifolia, and Trachyspermum ammi showed moderate activities. Moderate activities against E. coli were observed with the oils of M. alternifolia and T. ammi. These results may be indications of at least one of the pharmacological actions of the four herb plants.

• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.962-971
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• 2002

The current study proposes a simple monodimensional model to estimate the linear growth rate of photosynthetic microorganisms in flat-plate photobioreactors (FPPBRs) during batch cultivation. As a model microorganism, Chlorella kessleri was cultivated photoautotrophically in FPPBRs using light-emitting diodes (LEDs) as the light sources to provide unidirectional irradiation in the photobioreactors. Various conditions were simulated by adjusting both the intensity of the light and the height of the culture. The validity of the proposed model was examined by comparing the linear growth rates measured with the predicted ones obtained from the proposed model. Accordingly, the value of $\frac{K\cdot\mu m}{\alpha\cdot L}log(I_0\cdot{I_s}^{\varepsilon 1)\cdot {I_c}^{-\varepsilon})$ was proposed as an approximate index for strategies to obtain the maximal lightn yield under light-limiting conditions for high-density algal cultures and as a control parameter to improve the photosynthetic productivity and efficiency.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.329-336
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• 2001

In this study, a series of fatigue tests are carried out in order to estimate quantitatively the characteristics of fatigue crack growth rate for high strength steels of SM570, POSTEN60, and POSTEN80 steel, that is, the influence on fatigue crack growth rate according to the welding line, the characteristics of fatigue crack growth according to the welding method and the kinds of steel, and the characteristics of fatigue crack growth for base metal, heat affected zone and weld metal. From the test results, in case that the notch if parallel to welding line, it knows that the retardations of fatigue crack growth rate in crack tip at early stage increase remarkably than in case that the notch is perpendicular to welding line due to compressive residual stress. And the characteristics of fatigue crack growth rate according to welding method are that the dispersion of fatigue crack growth rate in case of FCAW method is smaller than that of SAW method. Also, it knows that the fatigue crack growth rate converges in high stress intensity factor range.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.269-272
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• 2002

This study was carried out to investigate varietal differences on growth characteristics under the conditions of PE film-mulching and non-mulching in sesame. At maturing stage from 76 to 95 days after sowing, Yangbaeckkae, non-branching plant type, under non-mulching showed larger leaf area index (LAI) than that of film-mulching, while plant height and the number of capsules per plant were similar to those of film-mulching. LAI of Ahnsankkae, branching plant type, under non-mulching was similar to film-mulching, while plant height and the number of capsules per plant were smaller than those of film-mulching. Net assimilation rate (NAR) of two varieties under non-mulching was lower at seedling stage from 25 to 35 days after sowing but higher at flowering stage from 45 to 55 days after sowing. At maturing stage from 66 to 77 days after sowing, NAR and crop growth rate (CGR) of Yangbaeckkae under non-mulching were greater than those of film-mulching, whereas those of Ahnsankkae under non-mulching were lesser than those of film-mulching. Yield under non-mulching was decreased by 7 % in Yangbaeckkae and 33 % in Ahnsankkae compared with that of film-mulching, therefore Yangbaeckkae was more adaptable for non-mulching than Ahnsankkae. Main factors decreasing yield of Yangbaeckkae under non-mulching were small LAI, NAR, and CGR at the stage of young seedling, and small number of capsules at early maturing stage from first flowering to 20 days after first flowering.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.6
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• pp.555-567
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• 2014

Over 40 years, the domestic manufacturing industry of Korea played the vital role in creating national wealth, employment and innovation in its economy. In 2011, industrial products made up 99.7 percent of exports, and formed 31.2 percent of GDP. Given those facts, the research of manufacturing systems engineering for higher manufacturing efficiency and its industrial applications have been essential for Korea's economic growth. In this paper, for celebrating the 40th anniversary of the foundation of Korea institute of industrial engineers (KIIE), the research results and its industrial applications of KIIE are reviewed and summarized in the area of manufacturing systems engineering over past 40 years. Directions of future manufacturing system and the role of industrial engineers for our continuous economic growth are also mentioned.