• 대한안전경영과학회지
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• 제14권1호
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• pp.129-136
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• 2012

This study proposes a collaboration system framework on the web service in a supply chain to implement an efficient virtual supply chain and improve an ability to fulfill received orders over a supply chain. The system based on the framework proposed in this paper plays an important role for automatic order negotiation and placing/receiving an order noticed in web service by the main system. Furthermore, it can evaluate the fulfillment of received orders over a supply chain by using the transaction results from hierarchically related vendors and establish efficient manufacturing plans. In a word, this system is the automated system for creating manufacturing plans, placing and receiving orders. A little more important main function of this system is that it has a dynamic evaluation capability about fulfillment with received orders over a supply chain, and improves the evaluation method of fulfillment ability with received orders with related to direct dealing vendors, which is a main problem in existing system. As a result, this system is able to reduce the work load of the sales and purchasing materials, production control division, to manage accurate inventory promptly, to maintain the optimal inventory level by analyzing the information of fulfillment ability with received orders, and to enhance the level of service for customers.

• 대한안전경영과학회지
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• 제16권2호
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• pp.147-155
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• 2014

This paper suggests a specific model that could efficiently improve the interaction and the interface between WMS(Warehouse Management System) terminal and PDA terminal through real time processing in manufacturing shop. The proposed model shows that the new method can more efficiently perform to reduce processing time for shipping and receiving, compared with the current approach. As a result of the certain test among the main server, WMS system, and PDA terminal, it is noted in case of the new proposed system that the effects of proposed model are as follows: (a) While the receiving lead time for carrying by the current method was 2 hours, the receiving lead time by the new method was 20 minutes. (b) While the shipping lead time for carrying by the current method was 1 hours, the shipping lead time by the new method was 15 minutes. (c) While the inventory rate of accuracy by the current method was 85%, the inventory rate of accuracy by the new method was 98%.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.415-418
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• 2005

In recent years, Magnesium (Mg) and its alloys have become a center of special interest in the automotive industry. Due to their high specific mechanical properties, they offer a significant weight saving potential in modem vehicle constructions. Most Mg alloys show very good machinability and processability, and even the most complicated die casting parts can be easily produced. The die casting process is a fast production method capable of a high degree of automation for which certain Mg alloys are ideally suited. Although Mg alloys are fulfilling the demands for low specific weight materials with excellent machining and casting abilities, they are still not used in die casting process to the same extent as the competing material aluminium. One of the reasons is that effects of various forming variables for die casting process is not closely examined from the viewpoint of die design. In this study, step die and flowability tests for AM60 were performed by die casting process according to various combination of casting pressure and plunger velocity. Microstructure and Victors hardness tests were examined and performed for each specimen to verify effects of forming conditions.

• 한국국방경영분석학회지
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• 제28권2호
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• pp.85-94
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• 2002

Calculation of proper expenses on acquisition and purchasing defense product is matter of survival and weighing the morality for both defense industry and the national facilities. With this reason, both parties have been a big job to estimate the resonable cost. The cost are composed of many subordinated parts such as material cost, labor cost, and so on. In the compositions of that cost, the most important part in between companies and the government throughout the whole calculating process is to define the proper labor cost. When both parties calculate imported articles or overhead expenses, they can easily calculate and confirm by documented evidences or related materials. In other hand, the labor cost, which can be seen as two absolutely different numbers and opinions can be created, depends on analyzer's point of view. These interpretation and judgment of data cannot avoid analyzer's intention. In accordance with the above matters, defining the reasonable labor cost will be the top priority in order to analyze the proper expenses. This study will provide a method of proper labor cost estimation before starting the actual manufacturing to calculate the rational labor cost.

• 한국자원식물학회지
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• 제32권4호
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• pp.275-281
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• 2019

The pathological condition of excessive melanogenesis causing freckles, melasma, senile lentigo, pigmented acne scars, and cancer has a critical impact on the wellness of individuals. The mechanism of melanogenesis is related to the expression of melanogenic enzymes. Here, we evaluated the inhibitory effect of pine cone (Pinus densiflora) extracts on melanogenesis. P. densiflora, the Korean Red Pine, is the predominant tree species in the cool, temperate forests of northeast Asia, occurring in pure stands across Korea, Japan, and parts of northern China and Russia. P. densiflora leaves, pollen, and bark have been widely used for traditional medicine, or edible purposes. However, pine cones are rarely used as natural raw materials, although they contain many bioactive phytochemicals. The pine cone ethyl acetate fraction (PEF) showed no toxicity to B16F10 cells at a concentration of less than $100{\mu}g/mL$. PEF inhibited the expression of microphthalmiaassociated transcription factor (MITF), tyrosinase and tyrosinase-related factors in B16F10 cells treated with 3-Isobutyl1-methylxanthine (IBMX). These results suggest that pine cones can be used as an effective natural melanogenesis inhibitory agent.

• Elastomers and Composites
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• 제41권1호
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• pp.40-48
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• 2006

고무는 금속 및 플라스틱 재료와 달리 작은 하중에서도 큰 변형이 발생되며, 높은 변형 구간에서 탄성특성을 보이는 특징이 있다. 특히 충격흡수 특성이 금속 및 플라스틱보다 우수하므로 제진 및 충격 완충구조물로 널리 활용되고 있다. 충격하중을 받는 고무 구조물의 특성을 평가하기 위하여 자유 낙하형 충격시험기를 이용하여 충격실험을 실시하였으며, ABAQUS/Explicit를 이용하여 유한요소 해석을 수행하였다. 고무의 동강성은 충격펄스의 최대변형량과 충격지속시간으로부터 얻어진 진폭과 주파수를 적용하여 동특성 시험을 수행하고 WLF모델을 적용하여 높은 주파수 대역의 동강성을 예측하였다. 실험을 실시한 $0.3{\sim}l.5J$의 충격에너지 영역에서는 고무의 경도가 증가되면 충격흡수율이 감소되며, 충격에너지가 커질수록 충격흡수율은 감소하는 경향을 나타내었다.

• Design & Manufacturing
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• 제17권2호
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• pp.47-54
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• 2023

The research direction of the automobile industry worldwide is speeding up research to improve fuel efficiency through weight reduction as the weight of automobiles increases due to environmental problems, convenience demands, and safety problems. As a way to solve weight reduction, there is a method of improving mechanical properties by improving the development and manufacturing method of lightweight materials with replaceable mechanical properties. Therefore, research on the molding and processing technology of aluminum, which is a lightweight material, is being actively conducted. In this study, aluminum material was applied. By using Autoform S/W, a press forming analysis program, the blank holding force, mold die R, and bead restraint force were selected in three levels, respectively, and the results and optimization of formability and shape freezing were carried out. In this study, aluminum material was applied. By using Autoform S/W, a press molding analysis program, the blank holding force, mold die R, and bead restraint force were selected in three levels, respectively, and the results and optimization of formability and shape freezing were carried out. The optimized results were confirmed by comparative analysis of formability and Spring Back. As a result of the experiment, it was possible to confirm the result value of the Spring Back of the final product according to the tensile change of the material.

• Advances in nano research
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• 제16권1호
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• pp.81-90
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• 2024

In the oil and gas industry, composite materials should exhibit high flexibility and strength for offshore structures. Therefore, weak points in the composites should be improved, such as brittleness, moisture penetration, and diffusion of detrimental ions into nanometric pores. This study aimed to increase the strength, flexibility, and plugging of nanopores using single-layer graphene oxide (SGO) nanosheets. Therefore, SGO is added to unsaturated polyester resin at concentrations of 0.015 and 0.15 % with Normal Methyl Pyrrolidone (NMP) as a solvent for the formation of Nanographene Oxide Reinforced Polymer (NGORP). The mechanical properties of the prepared samples were tested using tensile testing (ASTM-D 638). It has been shown that incorporating SGO, approximately 0.015%, into the base resin resulted in enhanced properties such as rupture resistance forces increased by 745.61 N, applied stress tolerances increased by 4.1 MPa, longitude increased to 1.58 mm, elongation increased by about 2.38%, and rupture energy increased by about 204.51 J. Despite the decrease in tensile force strength properties in the manufactured nanocomposite with 0.15% SGO, it has exclusive flexibility properties such as a high required energy level for rupture of 5,576 times and a formability of 40% more than the base sample. It would be best to use NGORP manufactured from 0.015% nanosheets with exclusive properties rather than base samples for constructing parts and equipment, such as rebars, composite sheets, and transmission pipes, on offshore platforms.

• 접착 및 계면
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• 제11권3호
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• pp.120-125
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• 2010

UV-curable acrylic Pressure-sensitive adhesives (Acrylic PSAs) are used in many different parts in the world. A wafer manufacture process which is based on semiconductor industry is one thing. We have used acrylic PSAs whose thickness is different from $20{\mu}m$ to $30{\mu}m$ in wafer manufacture process so far. But as wafers become more thinner, acrylic PSAs are supposed to satisfy the requirements such as proper adhesion performance. The main purpose of this research is studying proper adhesion performance and UV-curing behavior of UV-curable acrylic PSAs with very thin thickness and then determining optimized conditions to raise the efficiency of thin wafer production. Acrylic PSAs contain 2-Ethylhexyl Acrylate (2-EHA), Acrylic Acid (AA) and Butyl Acrylate (BA). Ethyl acetate (EtAc) is used as solvent. The acrylic PSAs are obtained using solvent polymerization. Thickness of UV-curable acrylic PSAs is different from $10{\sim}30{\mu}m$. By peel strength and probe tack, adhesion performance and UV curing behavior of acrylic PSA are concerned.

• 한국지역지리학회지
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• 제3권1호
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• pp.183-198
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• 1997

본 연구는 구미공단 1단지내에 입주하고 있는 공장의 입지과정과 공간연계를 통하여 입지특성을 밝히고 공단내 공장의 전수를 방문하여 면담과 질문지에 의하여 조사하였다. 구미공업단지는 국가의 정책과 인접지역인 대구의 공업특성이 반영되어 전자공업과 섬유공업으로 특화되어 있으며 업종별로 단지가 양분되어 있다. 공장유치정책에 의한 유인효과로 소수의 대기업이 입지함으로써 관련되는 중소기업의 입지를 촉진시켰으며, 섬유공업은 대구에 본사를 둔 분공장이, 전자공업에서는 부품을 생산하는 단일공장이 다수를 정한다. 물자연계에 있어서 섬유공업은 원료구입은 대구와 제품판매는 수출중심으로 해외지역과 연계가 강하며, 전자공업은 원료구입은 타도시와 제품판매는 단지내와 연계가 강하다. 서비스연계도 업종에 따라 차이가 있으며, 고차서비스는 타지역과 저차서비스는 지역내와 연계하고 있다. 구미공단내의 공장은 하청관계가 탁월하여 지방소재 공업단지의 특성을 반영하고 있고 공간적인 관계는 섬유공업은 대구와 전자공업은 공단내의 대기업과 강한 연계관계를 맺고 있다.