육상으로부터 각종 오염물질이 유입되는 하구역은 오염관리에 주의를 기울일 필요가 있다. 본 연구에서는 석탄회 조립물과 하구의 오염 퇴적물을 혼합하여 저서 환경 개선 효과 및 저서 미생물의 군집 구조 변화를 조사하였다. 하구 퇴적물과 석탄회 조립물을 7:3 의 비율로 혼합하여 1개월 동안 반응시킨 후 환경 및 미생물 군집을 분석하였다. 퇴적물의 환경인자를 분석한 결과, 석탄회 조립물이 혼합된 실험구의 pH는 11까지 증가하였다. 실험구의 DIP 농도는 석탄회 조립물과의 반응을 통해 생성된 인산칼슘으로 인해 대조구 대비 30 % 감소하였다. 또한 대조구 대비 실험구에서 증가한 Gammaproteobacteria 강은 DIP 감소에 영향을 줄 수 있음을 확인하였다. DIN 농도는 대조구 대비 실험구에서 2배 이상 증가하였는데, 이는 높은 pH 및 석탄회 조립물에서 용출되는 NH4 +-N의 영향인 것으로 판단된다. 질소 순환과 관련된 미생물은 대조구 및 실험구 모두에서 확인되지 않았다. 따라서, 석탄회 조립물은 오염된 하구 퇴적물의 DIP 농도 감소에 효과적이며, 저서 미생물 군집이 인의 순환에 영향을 주는 것으로 나타났다.

The purpose of this study is to analyze the adequacy of production capacity of the assembly process system of mobile bath vehicle’s top box panel and process design through a simulation analysis. Towards this end, the layout of the facility designed with pre-verification job using a simulation modeling and an experiment, and facility, logistics process, and personnel input method were made into a simulation model, and the design system’s adequacy was evaluated through an experiment. To produce 120 mobile bath vehicles annually, it was analyzed that 14 general workers and seven skilled workers were adequate through the experiment. It was also identified that three painting process lines carried out through outsourcing were adequate. Production lead time was 201.7 hours on average and it was 230 hours maximum. To meet customer delivery service level of 95% within the deadline when establishing a customer order and vehicle delivery plan, it was analyzed that more than 215 hours of lead time is needed minimum. If the process cycle time is reduced to 85% upon system stabilization and skillfulness improvement, it was analyzed that annual output of 147 vehicles can be achieved without additional production line expansion.

Domestic as well as global automobile manufacturers are making greater efforts in cost reduction to strengthen the competitiveness. In this study, we developed a program to effectively manage standard time of automobile assembly line, and confirm based on A-automobile factory data. For the purpose, we develop the system which is possible to manage standard time as well as calculate man-hour for automobile assembly line.

본 논문에서는 ~1.5 μm의 기공 크기를 가지는 고투과도 알파 알루미나 지지체 위에 도포된 서스펜션의 증발유도 자기조립 현상을 이용하여 중간층을 형성하는 새로운 코팅 방식을 소개한다. 새로운 코팅 방법으로 만들어진 중간층은 일반 적으로 사용되는 담지법으로 코팅된 중간층과 비교하여 표면거칠기와 불균일도가 낮아 코팅에 적합하였다. 복합막 지지체로 서의 평가를 위해 제조된 지지체는 감마 알루미나 복합막 제조에 사용되었다. 메조 기공을 가지는 감마 알루미나 복합막은 반복코팅 없이도 매크로 기공 크기의 결함이 존재하지 않았으며 일반적으로 널리 사용되는 100~200 nm의 기공 크기를 가지 는 지지체로부터 만들어진 같은 두께의 복합막과 비교하여 2.3배 이상의 높은 질소투과도를 보였다.

본 논문에서는 조립트러스 매립형 합성보의 실험과 해석을 통하여 휨 및 전단의 구조적 거동을 분석한다. 본 합성보는 복부가 개방된 트러스를 콘크리트 속에 매입함으로써 콘크리트와의 맞물림작용 및 일체성이 뛰어남으로 휨재로서 완전합성 거동을 한다. 본 합성보에서는 콘크리트 단면의 복부를 가로지르는 외곽 2열의 강재 복재가 상, 하 접합부로 긴결되어 있어서 철근콘크리트 보의 스터럽(Stirrup)과 같은 전단보강재의 역할을 한다. 그러나 본 합성보에서는 복재 접합부의 강도에 따라서 전 단보강재인 경사재 및 수직재의 전단내력이 변화되므로 이에 맞는 구조적 안전성이 확보된 새로운 전단강도식을 제안한다. 실험 및 해석결과, 조립트러스 매립형 합성보의 모든 실험체는 휨강도에 대하여 강재앵커가 있는 완전합성보로 평가되며, 제안된 전단강도식은 구조적 안전성이 충분히 확보된 것으로 평가된다.

A manufacturing company should produce its products and make a profit to continue its management. With the adoption of a multi-category small-volume production system, manufacturers that produce concrete pump-cine products are carrying out improvement activities to increase their market share amid the business-to-customer business environment. However, the slump in the construction investment environment has led to a decline in sales of concrete pump trucks. The purpose of holding inventory is to prevent loss of sales opportunities with the rate of change in the sales plan, and reducing the rate of change in the product can reduce unnecessary inventory and, in order to realize this, the goal of reducing inventory can be achieved by reviewing the parts that can be designed for common use. Therefore, to reduce the inventory of concrete pump trucks, semi-finished publicization design is necessary. According to the analysis, the frame assembly process of the 32M model is common. Production capacity can be secured without loss of sales opportunity.

In this paper, the hybrid prefabricated retrofit method is suggested and examined. Six specimens were manufactured in order to evaluate their flexural performance of RC beams. Test parameters include the added beam depth, the thickness of bottom plate, the number of the steel plate with openings. The effects of these parameters on the flexural performance of reinforced concrete beams were examined. The load-deflection behavior and modes of cracks are presented from the test results. At the test result, the flexural capacity and the ductility of the hybrid prefabricated retrofit method was increased satbly. Also, comparing the flexural performance of RC beam and retrofitted RC beams, it was increased that the flexural strength is about 3.3 times, the ductility is about 2.55 times, and energy dissipation capacity is about 7.34 times.

In this paper, the hybrid prefabricated retrofit method that improve structural performance and reduce construction period was developed by using a finite element analysis. The hybrid prefabricated retrofit method consist of a Z-shaped side plate, a L-shaped lower plate, and a bottom plate containing an steel plate with openings. This shape has advantage that a retrofit method is possible regardless of the size of the beams and a follow-up process such as reinforcement bars placing are not required. The finite element analysis of hybrid Prefabricated retrofit method showed the most ideal stress distribution when the thickness of bottom plate was 10mm, the thickness of the L-shaped lower plate was 5mm, the thickness of the Z-shaped side plate was 2.5mm, and the bolt spacing was 200mm. The bending strength equation of Hybrid prefabricated retrofit method was proposed through the plastic stress distribution method in KDS 41 31 00. The result of Comparison the proposed equation with the finite element analysis, it is determined that the design of hybrid prefabricated retrofit method is possible through the KDS 41 31 00.