국내 자동차 개발기간 단축을 위한 쾌속 조형 기법(Rapid Prototyping)의 개발전략

박준영 동국대학교 산업기술환경대학원 1998 산업기술논총 Vol.4 No.-

본 연구에서는 쾌속 조형 기법이라고 불리우는 Rapid Prototyping의 국내 도입과 활용에 있어서 산업계의 현황을 고찰하고, 실제 적용 사례에서 부딪치는 애로 공정 및 기술을 도출하여 Rapid Prototyping기술을 이용한 신차 개발 기간 단축의 방안을 제시하고자 한다. 자동차 산업의 경우 시작차의 개발 기간 단축은 바로 기업의 사활이 달린 중대한 문제라고 할 수 있으므로 전체 개발 기간을 단축하기 위해 시작 부품을 신속히 제조할 수 있는 Rapid Prototyping기술이 국내·외에서 활발히 적용되고 있다. 최근에는 단순한 모형을 제조하는 Rapid Prototyping과 이보다 한 걸음 더 나아가 금형을 직접 제조하는 Rapid Tooling기술이 함께 개발되고 있는 추세이다. 따라서 본 연구에서는 국내·외의 RP기술의 적용 사례를 소개하며 국내 자동차 산업의 경쟁력 강화를 위해 필요한 RP분야에서의 요소 기술을 도출하려고 한다. In this research, we propose several approaches for the reduction of new car development period using RP(Rapid Prototyping) technologies. In the car industry, reduction of trial car development period is so crucial that many companies are using RP these days which enables to make prototype parts rapidly. This process eventually shortens the period of whole car development period. Recently, RP technology is further being applied to make tooling as well as to make simple prototypes. Therefore, in this research, we try to introduce the up to date technologies in RP area and identify future research topics which are necessary for the domestic car industry to be internationally competitive.

폴리옥시에틸렌 알킬아민계 비이온 계면활성제의 균염 효과에 관한 연구

한태성,성용길 동국대학교 산업기술환경대학원 1994 산업기술논총 Vol.2 No.-

Poly(oxyethylene) alkylamine type nonionic surfactants were used in order to investigate their retarding, migration, and reserving effects on silk fabrics which were dyed with milling type acid dyes. Three different alkylamines (stearylamine, oleylamine, and laurylamine) and different numbers(10, 15, 20, 30, 40 and 60) of ethylene oxide groups were used for this purpose. The poly(oxyethylene) stearylamine with 10 moles of ethylene oxide groups showed the best results in terms of retarding and reserving effects. The poly(oxyethylene) laurylamines with various numbers of ethylene oxide groups were also found to be unsuitable as a levelling agents for silk fabric due to its low retarding effect. Both poly(oxyethylene) stearylamine and poly(oxyethylene) oleylamine were found to be suitable as levelling agents for silk fabric due to their moderate adhesion with dyes.

다기준 의사결정 방법에 응용한 흐름생산방식에서의 작업순서

안춘수,조성구 동국대학교 산업기술환경대학원 1996 산업기술논총 Vol.3 No.-

In this paper, we propose a simple and efficient heuristic method to determine job sequencing in the flow-shop considering multiple criteria such as processing time, due date and cost. The proposed method is applicable to the flow-shop were the jobs are released simultaneously and their processing sequence is predetermined and not changed until the whole jobs are processed. To develop this method, we mixed and modified some well-known multi-attribute decision heuristics such as the simple linear weighting scheme, the lexicographic rule and the 'elimination by aspect' rule. Some computer simulations were conducted to test the efficiency of the proposed method and it has been compared with the SWPT(Shortest Working Processing Time) rule and EDD (Earliest Due Date) rule. The results show that our method is as effective as the traditional ones in terms of mean flow time, tardiness, makespan, cycle time, machine utilization, etc., and proved to be much simpler and more flexible to be used in real situations.

Numerical Analyses of Leachate Transport in Two Municipal Landfills

Jang, Yeon-Soo,Lee, Kwang-Yeol 동국대학교 산업기술환경대학원 1994 산업기술논총 Vol.2 No.-

The leachate transport through the subsurface of two representative domestic landfills called Nanji and Kimpo Landfill is analyzed using the finite element program of contaminant transport. In the case of Nanji landfill, verification of the model is performed using the available in-situ hydrogeologic data and the contaminant transport next 30 years is predicted. The results show that the contamination of Han River would reach the maximum 17 years after the start of waste disposal in 1992. The increase of leachate mounding in the landfill influences more than that of the dispersivity on the increase of concentration near Han River. In the case of Kimpo landfill the variation of the concentration of contaminant under the pheriperal embankment as well as the transport of leachate through the foundation of the embankment are investigated. The results show that the pervious layer located near the bottom of the embankment becomes a path of contaminant migration and increase in the concentration level at the toe of the embankment is significant.

실리콘 반도체 에칭기술개발 동향에 관한 조사연구

신영두,이진구 동국대학교 산업기술환경대학원 1994 산업기술논총 Vol.2 No.-

This paper describes investigation and analysis of Si wafer find-line processes from 1960's up to present based on U.S. Patent No. 4,941,941 entitled " METHOD OF ANISOTROPICALLY ETCHING SILICON WAFERS AND WAFER ETCHING SOLUTION". This study is intended to classify techniques on wet etchants from chemicals mainly used in the reference above and 9 patents, and also includes reviews on both physical and chemical features of wet etching and, further more, comparative explanation of wet and dry etching. The characteristics of low temperature and low speed, of the wet etching processes and some limitations of the informations, given in U.S. Patent No. 4,941,941 and 9 patents, are mainly investigated and analysed, and, then, the dry etching processes are simply discussed as a substitution for the fin-line Si processes. And, finally, future possible development of other kinds of chemical etchants is suggested.

고추 복합내병성 계통 선발에 관한 연구

김익준,이장수,김경제 동국대학교 산업기술환경대학원 1996 산업기술논총 Vol.3 No.-

The progenies of 108 combination crossed among Korean Lines and resistant lines introduced from Italy and Japan were tested with innoculation of p.capsici in order to select the multi-resistant lines to red pepper diseases 5 resistant lines to TMV, 7 resistant lines to PVY, 3 resistant lines to nematode and 10 resistant lines to p.capsici were selected among 241 lines introduced from Naples university in Italy 149 lines showed susceptibility to Japan race of p.capsici among the 241 line, 82 partial resistant lines and 10 resistant lines were selected in Tokuku seed company in Japan, respectively. The 11 combinations among 108 combinations crossed between Korea lines and the resistant 10 lines showed resistance to Korean p.capsici. The 12 combination with TMV resistance and p.capsici according to the result of immoculation test. Therefore, the possible result of improvement for the multi-resistant variety to PMV and p.capsici was obtained.

異常値를 探索하는 檢定方法들의 몬테카를로 시뮬레이션에 의한 效率性 比較

廉俊根,宋民求 동국대학교 산업기술환경대학원 1996 산업기술논총 Vol.3 No.-

We have discussed a number of outlier-detection methods from the literatures. In this paper, we compare to efficiency of utlier-detection methods, that is Box-plot. KS, ESD, SW, Dixon-typed by Monte-Carlo simulation. Some of these procedures are highly susceptible to either masking or swamping. Such outlier-detection procedures are not recommended. Other procedures not recommended require specific knowledge of the number and location of the outliers. The generalized ESD procedure performs especially well under each of the conditions. It is also relatively easy to compute and interpret. We recommend this procedure highly, from the results in <Table 1> and from conclusions reached in other studies. Alternatively, a Dixon-type test in sometimes useful for very small samples.

Air Stripping에 의한 트리할로메탄의 제거

임종주,이의수 동국대학교 산업기술환경대학원 1996 산업기술논총 Vol.3 No.-

The removal of trihalomethanes (THM) by air stripping was examined. Experimental variables studied for air stripping were air flow rate, initial THM concentration, and residence time. In batch aeration experiments, CHCl_3 rejection level was found to increase with an increase in air flow rate., residence time and temperature. In continuous aeration experiments, both rejection levels of CHCl_3 and CHBr_3 increased with an increase in air flow rate. For the maximum air flow rate used (air-to-water ratio=20), about 75% or the initial CHCl_3 was removed by aeration whereas only about 40% of the initial CHBr_3 was removed under the same experimental conditions. When doubling the residence time in each experiment, rejection levels of CHCl_3 and CHBr_3 were shown to be increased by a factor of 1.8 and 1.2 respectively. The CHCl_3 removal level was affected by its intial concentration and the effect was found to become more significant as higher air-to-water ratios were used during aeration. On the other hand, CHBr_3 removal was not greatly affected by the initial CHBr_3 concentration. Preliminary experimental results suggested that aeration could be an effective method for the removal of the more volatile THM component, CHCl_3 but some other method such as carbon adsorption must be accompanied in order to obtain a substantial removal of the less volatile THM component, CHBr_3.

導入 遺傳資源을 利用한 옥수수 新交雜種 育成

李明薰,金碩均 동국대학교 산업기술환경대학원 1994 산업기술논총 Vol.2 No.-

This study was conducted to develope elite, high adaptable corn hybrids using alien germplasm. We investigated yields, plant characters, and yield components of new 6 hybrids and 4 check hybrids. Hybrid CIM.A-21 × NC 246 which was late for days to tasseling, high for plant and ear heights showed the highest grain, stover, and total dry matter yields. Hybrid KS 8 × SC 12 which was a little lower total dry matter yield showed relatively high grain yield, early flowering, and good characters for plant and ear height. Horizontal plant type hybrids with big leaf angle had small leaf area index, were early matured varieties and high in yields. In yield components, KS 8 × SC 12, Suwon 19, and KS 7 × SC 12 were higher than the other hybrids. KS 8 × SC 12 might be the most effective material to develope corn hybrid. Leaf angle showed negative correlation coefficients with all of the characteristics of corn hybrid, except for ear height, stem diameter, and weight of 100 kernel. Expecially, it had negative correlation coefficients with plant height and number of kernels per row in 5% levels, and with grain yield, total dry matter in 1% levels.

木材 變色菌 및 表面汚染菌類에 對한 Streptomyces rimosus 代謝物質의 抗菌 效力

姜奎榮,金思翼,吳正壽 동국대학교 산업기술환경대학원 1994 산업기술논총 Vol.2 No.-

The objectives of this study were to evaluate the efficacy of metabolites produced by Streptomyces rimosus in protecting wood against wood staining and mold fungi. The following representative wood staining and mold fungi were selected for evaluate the antifungal activities of metabolites from Streptomyces rimosus : staining fungi - Ceratocystis pilifera, Ceratocystis piceae, Aureobasidium pullulans ; mold fungi - Trichoderma hazianum, Trichoderma viride, Penicillium citrinum, Aspergillus niger. The effect of medium concentration on development of antifungal metabolites from Streptomyces rimosus was examined in plate bioassay against spores of test fungi. The antifungal activity of these metabolites tested using plate bioassay. These results are summarized as follows ; 1. In the plate bioassay, the conidial germination of wood staining fungi was completely inhibited, leaving a clear zone around the paper disc treated with metabolites from Streptomyces rimosus. 2. The most effective antifungal activity showed in Aureobasidium pullulans. 3. The best result of different concentration of metabolites production medium was obtained with the ⅓×concentration in the largest clear-zone area around the paper disc. The next largest clear-zone area occurred with the ½×concentration.