• 유공압시스템학회:학술대회논문집
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• 유공압시스템학회 2010년도 춘계학술대회
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• pp.66-69
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• 2010

A punched pipe in a muffler for an automobile has many important variables, like location of holes in the pipe and length of the pipe related to noise reduction of a diffuser. This pipe is cut depending on length of product and this process, generally workers cut pipes by hands. In this process, there are many errors and it relies on the skill of workers, so it can happen that cycle time for complete product gets long and productivity gets low. Therefore, we need a vision system to distinguish holes in the punched pipe and a transfer system to set the cutting position automatically by moving the pipe depending on forward and backward part of the holes. This paper explains the development of an automatic transfer device which will cause the beating pipe to be cut correctly, exactly the same length as the product.

• 한국안전학회지
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• 제3권2호
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• pp.5-16
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• 1988

This study is conducted to evaluate the explosion of tolune storage tank in the petrochemical plant by Fault Tree Analysis. The conclusions are as follows; 1) Fault Tree diagram and the required computer program for evaluation of explosion accident is developed. 2) The probability of the top event, explosion accident, is $1.5\;{\times}\;10^{-8}$ per year, so there is almost no possibility of explosion during the life cycle of tank. However, the probability of Gate 6 and Gate 7 is 8.8 per month, therefore, attention should be paid to them for accident prevention. 3) The number of minimal cut sets is 67 sets which are not calculated the probability of each set, because of the lack of computer capacity. All the minimal cut sets should be examined case by case. However, it is necessary to be paid attention to COM1, 126, 131, and COM4 in minimal cut sets, because the number of appearance is so high. 4) The number path sets is 70 sets which are not calculated the probability of each set, because of the lack of computer capacity. It is very useful to prepare safety checklist by using this minimal path sets. Also, the events which appear many times, 123, COM5, 139, 127 and 128, are very high in reliability.

• Kyungpook Mathematical Journal
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• 제54권2호
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• pp.197-201
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• 2014

In this paper, we study some properties of finite or infinite poset P determined by properties of the ideal based zero-divisor graph properties $G_J(P)$, for an ideal J of P.

• 기술발표회
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• 통권2006호
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• pp.279-291
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• 2006

This study shows decision-making process for selection of cutoff wall on a wastewater treatment project. There are 10 different cut-off wall methods So, we examine the site to gather information for find appropriate methods. After using that information, 10 cutoff wall methods are reviewed for analysis. Through brainstorming, four alternatives are selected for design VE item. Following the standard VE process, we established performance criteria and evaluated function score(F) using questionnaire. The questionnaires, brainstorming and AHP method for weighting on performance criteria and evaluate function score increased the reliability of this selection process. Water Jet method, one of four methods, has the best function score(F=92.71) and the lease construction cost(as cost index 1,000). The value score also highest as 92.7, so we select the method. The result is value innovation type In addition, the authors try to calculate the environmental burden in selection process using LCA. We cannot conduct the full LCA as defined ISO, so perform Simple LCA In LCA result, the cut-off grouting has the least environmental burden as index 9.09E+01 and Water Jet method has following as the second. To selection best method to specific area and purpose, design VE/LCG process used as useful tool and it is needed to develop integrated method that evaluate VEILCC and LCA as one-set process.

• 한국CDE학회논문집
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• 제16권5호
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• pp.351-360
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• 2011

Product systems are quickly and frequently changed because Product Life Cycle is continuously reduced and adopting new product is steadily fast. Thus, various studies are progressed using simulation which is one of digital manufacturing. The research that is concerning simulation of control verification for shorten the commissioning which has a lot of trial and error is in progress. Also, simulation of control verification has strength that it can catch the errors in advance. However, a control program in simulation needs virtual factory for representation of control information. For this reason, excessive time and energy is put into controlling the virtual factory. So, in this paper, we construct library which is using exist data, in order to overcome limitation of these problems. Furthermore, we suggest methodology which can model and verify the process more speedy using library. Especially, we give body to the BB/BR Line process which has many altering equipment and need high technology effectively using physical and logical modeling. We can set up a control simulation environment very rapidly, as well as cut process time down using our suggestion.

• 설비공학논문집
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• 제20권12호
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• pp.802-807
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• 2008

A Study on Typical Rates of Water-use for School Facilities has been carried out in this work. Water supply system is given much weight in school facilities. Therefore, it set up a basis efficiency using of water sources to calculate typical rates of water use. The results are summarized as follows; 1) On the whole, typical rates of water-use was founded out 15 L/stu. d in pirmary school, 10 L/stu. d in middle school and 30 L/stu. d in high school smaller than the existing it. It was rate of water-use change as season and Max. Rates of water-use was July. 2) I deem that school hours are 5 hour's in primary school, 7 hour's in middle school and 8 hour's in high school. It the concept of 1 hour that is lesson time 40 minutes and resting time 10 minutes in primary school, lesson time 45 minutes and resting time 10 minutes in middle school and lesson time 50 minutes and resting time 10 minutes in high school. 3) It is desired that we calculate the volume of pump and water tank throughout this concept and the size of water tank should be 1.5 times with taking peak load into consideration by this study on typical rate of water-use. 4) The amount of using water increases in gradually and I consider the life cycle of facilities is more than 10 years. As a result, I can forecast that the size will be insufficiency but I deem that if we devise a plan about parallel pumping on water tank space, we can cope with it. Also, it is expected that we can cut back the transport energy by controlling pump volume.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.510-515
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• 2007

A Study on Typical Rates of Water-use for School Facilities has been carried out in this work. Water supply system is given much weight in school facilities. Therefore, it set up a basis efficiency using of water sources to calculate typical rates of water use. The results are summarized as follows ; 1) On the whole, typical rates of water-use was founded out 15 L / stu. d in pirmary school, 10 L / stu. d in middle school and 30L / stu. d in high school smaller than the existing it. It was rate of water-use change as season and Max. Rates of water-use was July. 2) I deem that school hours are 5 hour's in primary school, 7 hour's in middle school and 8 hour's in high school. It the concept of 1 hour that is lesson time 40 minutes and resting time 10 minutes in primary school, lesson time 45 minutes and resting time 10 minutes in middle school and lesson time 50 minutes and resting time 10 minutes in high school. 3) It is desired that we calculate the volume of pump and water tank throughout this concept and the size of water tank should be 1.5 times with taking pick load into consideration by this study on typical rate of water-use. 4) The amount of using water increases in gradually and I consider the life cycle of facilities is more than 10 years. As a result, I can forecast that the size will be insufficiency but I deem that if we devise a plan about parallel pumping on water tank space, we can cope with it. Also, it is expected that we can cut back the transport energy by controlling pump volume.

• 대한환경공학회지
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• 제28권10호
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• pp.1009-1015
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• 2006

정수 슬러지의 감량화와 탈수장치의 성능향상을 위하여 필터프레스 탈수장치의 각 Plate 사이에 음극판과 양극판을 설치하여 케이크 층에 전기장을 투입하는 전기식 필터프레스 탈수장치(EDFP)를 구축하여 기존의 기계식 필터프레스 탈수장치(MDEF)와의 탈수성 비교, 그리고 EDFP의 탈수성 향상에 따른 경제적인 측면 등을 분석하였다. 동일조건에서 탈수실험을 수행한 결과 EDFP를 통해 배출된 여액량은 43.2 kg으로 MDFP에 비하여 증가하였으며, 케이크 무게는 4 kg으로 MDFP에 비해 2배 증가하였고 탈수 케이크의 함수율은 55 wt%로 MDFP에 비하여 약 20% 감소하였으며 탈수속도는 2.3 $kg/m^2{\cdot}cycle$로 약 30% 증가하였다. 즉 전기탈수(Electrodewatering)의 원리로 구축된 EDFP는 기계탈수(Mechanical Dewatering)에 의한 MDFP 비하여 여액배출량을 증가시키고 저함수율 탈수 케이크를 생산하며 탈수속도를 증가시키는 특성이 있다. EDFP의 소모된 전력량은 400 kwh/DS ton으로, 투입된 전력량과 저함수율 탈수 케이크 생산에 따른 부피 감소로 인한 처리경비 저하의 효과를 서로 고려하여 경제성을 분석한 결과 1 ton(Dry Solid base) 처리하는데 약 20,000원 경제적 절감 효과가 있었다. 이 외 탈수속도가 빨라진 부가적 이점을 감안하면, EDFP는 탈수 성능 면에서 우수할 뿐만 아니라 경제적 타당성이 있는 장치로 평가할 수 있다.

• 방사성폐기물학회지
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• 제6권3호
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• pp.171-178
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• 2008

중 저준위 방사성폐기물 유리화 실증시설의 고온필터(HTF)시스템에 금속필터를 도입하여 일련의 성능시험을 수행하였다. 고온필터시스템의 여과재는 총 19개의 필터 element로 구성되는데 필터로서 금속 재질별 특성을 알기 위해 316L, 904L, Inconel 600 등 3종의 element를 혼합하여 필터set를 구성하였다. 매 시험을 종료한 후에는 필터하우징에서 종류별로 필터 element를 꺼내어 육안으로 변화를 관찰하였다. 그 결과 일부 element 표면에서 어두운 색깔의 반점들이 관찰되었으며, 특히 AISI 316L 재질의 element에서 많은 반점들이 발견되었다. 이 반점들이 부식을 의미하는 것인지 확인하기 위해 두 가지 분석을 수행하였다. 첫째 재질별로 1개씩의 element를 절단하여 정상적인 곳과 반점이 있는 곳의 표면 및 단면을 SEM/EDS로 분석하였다. 그 결과 반점은 Na, S, Si 등 무기계 산화물이 집중적으로 침적되어 필터의 미세기공을 막고 있는 현상으로 밝혀졌으며, 이 침적물들은 폐기물 및 유리용탕으로 부터 휘발된 물질로 판단된다. 둘째, 재질별로 필터 element에 대해 ring tensile시험을 수행하였다. 그 결과 반점을 포함한 시험 필터 element의 인장강도 값이 규정값 이상으로 나타나서 필터에 부식이 없는 것으로 확인되었다. 앞서 두 가지 분석결과로 볼 때 시험한 금속필터 표면에 생성된 반점은 부식생성물이라기 보다는 필터 전단으로부터 유입된 무기산화물 필터기공을 막고 있는 현상으로 판단되며, 이 반점이 반점형태로 국부적 지점에만 나타나는 것은 시험 중단시기 필터에 응축된 수분과 관련이 있는 것으로 판단된다. 반점의 생성은 필터의 유효 여과면적이 줄어 결과적으로 필터에 걸리는 압력손실이 커지기 때문에 필터하우징의 상시보온을 통한 응축 방지가 필요할 것으로 판단된다. 아울러, 보다 장시간의 시험을 통해 필터 부식현상에 대한 검증 필요하다고 판단된다.