• Journal of the Korea Society for Simulation
• /
• v.20 no.3
• /
• pp.119-127
• /
• 2011

Overhaul and repair service means the sequential processes of disassembly, repair and reassembly for a product which has been used for a long time. Overhaul is required for the companies producing airplanes, ships, trains, military weapons and heavy industrial equipments which are very expensive and have a long life cycle. The most important performance measure of the overhaul repair shop is usually the lead time. Thus, how to design the manufacturing system to meet the delivery date is a major concern in overhaul repair shop. This paper introduces the case study of an overhaul repair shop producing military weapon systems with the 3D simulation tool, $QUEST^{TM}$. At first, the characteristics of overhaul shop and what should be considered for simulation modeling are explained. Then, various simulation scenarios including two types of disassembly systems, one is flow line system and the other is cell system, are discussed with the results of simulation experiments.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.3
• /
• pp.31-37
• /
• 2014

"The Law of purchasing policy for market support of small and medium business" was legislated to support small and medium industry by expanding purchase and revised consistently for the activation. And then the government made the public construction direct purchase compulsory about design items designated by president on small and medium business based on this law. However, secureing quality, tardiness and field material staff's heavy duty were arisen from approximately 120 direct market purchase items. The legislative intent of law is in accord with Win-Win growth between major company and small and medium business. However material staff who works in the field based on this law has difficulties with material securing quality, JIT(Just In Time), cost push. This study reclassified procurement items of "the direct market purchase system" reasonably and then suggested performance criteria for evaluation. The suggested result will contribute to vatalize the direct market purchase system.

• Proceedings of the KAIS Fall Conference
• /
• 2000.10a
• /
• pp.74-77
• /
• 2000

사출성형에 관한 연구는 오랜 역사를 가지고 있으며 공정 시뮬레이션을 위한 상용화된 CAE 프로그램을 포함하여 많은 연구가 진행되는 분야중의 하나이다. 그러나 다양한 고분자 재료의 성질, 금형의 복잡한 형상 및 성형조컨 둥의 변화로 인해 금형설계 및 제작 그리고 사출성형시 상당한 어려움을 겪게 된다. 사출성형 공정에서는 금형온도, 플라스틱 재료, 냉각수, 보압과 사출압 등의 여러 가지 공정변수가 있어 현장전문가의 경험에 의해 사출금형의 제작이 이루어지는 경우가 보통이다 이와 같은 경험에 의한 금형 제작은 상당한 납기지연과 노동집약적인 방식으로 흘러가게 된다. 금형 제작시 가장 고려해야 될 사항 중의 하나는 사출성형품의 수축이다. 사출성형에서 광음수지는 냉각, 고화하면서 수축하는데 성형품 치수를 유지하기 위해서는 수축하는만큼 금형의 치수를 보정하여야 한다. 이 수축률은 사용수지의 종류와 성형품 크기, 살두께 등에 따라 다르다. 또 동일한 수지일 경우에도 성형조건에 따라 변화하고 특히 배향성을 가진 수지는 유동방향에 따라서도 변화가 있다. 즉, 금형의 온도가 높으면 수축률은 증가하고 사출압력이 높으면 감소한다. 또한 살두께가 두껍고 길이가 길 때 수축률은 증가한다 방향성이 있는 수지는 유동방향에 대하여 지각방향에서 가장 적다. 특히 방향성이 현저한 HDP에서는 유동방향에 따라 수축차가 크므로 성형할 때 변형을 일으키는 경우가 많다. 일반적으로 PE, PP. PA와 같은 결정성 수지는 PS, SAM, ABS 등의 비결정성 수지보다 수축률이 크다. 본 연구에서는 한조산업사에서 제작한 '클랠프 척' 금형 제작과정에서 성형품의 수축으로 인한 금형의 치수보정에 있어서의 문제점을 유동해석 전용 CAE 프로그램인 C-mold를 사용하여 해석하고 평가하였다. 그리하여 현장 전문가가 경험적으로 여러 번의 시행착오를 거쳐 완성된 금형을 제작하던 기존의 방법보다 체계적이고 합리적이며 또한 신속하게 문제를 해결함으로써 궁극적으로 금형설계 및 제작기간을 단축하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.1B
• /
• pp.38-47
• /
• 2008

The system test was accomplished in delivery time for a suitable of various requirements at the software market. Especially, critical faults must be detected and removed for a close main functions and users against target system. In generally, proposed test methods are executed with a calendar time, not a competitive and effectiveness method as selective software testing. These methods are inapplicable to short term test or early system development stage. Moreover, it's accompanied by heavy cost. Overcoming of these problems, must attempted to new software test method role of core function in the system test. Selective software testing method is decided to mixing with the three-information such as a frequency, complexity of use scenario and fault impact. Using this information, searching a fatal error and usefully system test for an executed test scenario. In this paper, we have proposed new test method and verified testing results for the detection of critical faults or search a fatal errors with a system main function.

• KIISE Transactions on Computing Practices
• /
• v.21 no.11
• /
• pp.739-744
• /
• 2015

In this paper, we examine the project-based educational practice that is co-developing a solution to the local food inventory management system. This project is aimed at the practical business of IT distribution in small and medium industries, and is linked with the project course on undergraduate students of IT division. For the practical project of the IT distribution in small and medium industries, an employee in charge of the project participates as a mentor such that he presents the project subject and the students develop the system for the subject. This system emerges from existing theory and the necessity for a term project, and this course leads students to learn practical knowledge through discussion with the employee in charge. Through this course, the latest technology is shared mutually, and students have the opportunity to understand a domain of the IT distribution business. As students experience how to understand and solve cost, quality and delivery time for the project by themselves, they build confidence. Also, the company can save on costs for the development of prototypes, while creating an opportunity for students to experience working with seasoned staff.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.1
• /
• pp.33-40
• /
• 2019

This study focuses on a job-shop scheduling problem with the objective of minimizing total tardiness for the job orders that have different due dates and different process flows. We suggest the dispatching rule based scheduling algorithm to generate fast and efficient schedule. First, we show the delay schedule can be optimal for total tardiness measure in some cases. Based on this observation, we expand search space for selecting the job operation to explore the delay schedules. That means, not only all job operations waiting for process but also job operations not arrived at the machine yet are considered to be scheduled when a machine is available and it is need decision for the next operation to be processed. Assuming each job operation is assigned to the available machine, the expected total tardiness is estimated, and the job operation with the minimum expected total tardiness is selected to be processed in the machine. If this job is being processed in the other machine, then machine should wait until the job arrives at the machine. Simulation experiments are carried out to test the suggested algorithm and compare with the results of other well-known dispatching rules such as EDD, ATC and COVERT, etc. Results show that the proposed algorithm, MET, works better in terms of total tardiness of orders than existing rules without increasing the number of tardy jobs.

• Journal of the Korea Convergence Society
• /
• v.10 no.6
• /
• pp.1-6
• /
• 2019

This paper examines the complexity of recent SW development such as the 4th industry to apply the requirement engineering and redimimn application to the project to solve the difficulty of scope management during project management of medium and small businesses. These engineering techniques were applied to mid-sized and small-sized SW development projects. It was verified through supervision of 15 SW development projects. As a result, we observed about 30% reduction in related issues. In addition, Redmimn was introduced to SW development projects involving medium and small sized companies, and it proved that it has the effect of shortening delivery time through requirement management and tracking management. In order to secure the safety of the SW system development project, it is necessary to apply the required engineering techniques and tools, and it is necessary to continuously cultivate professional manpower to carry out this.

• The Journal of the Korea Contents Association
• /
• v.19 no.2
• /
• pp.170-185
• /
• 2019

This study is intended to look into the structural relationship between SCM activity, process innovation and quality performance in small and medium sized enterprisers(SMEs). To achieve this, a survey was empirically carried out to 354 SCM operating officers and managers who perform the SCM activities in small and medium sized manufacturing firms. The results are summarized as follows. Overall, the SCM activity and process innovation had a significant effect on the quality performance, having a structural relationship with the quality performance in SEMs. This implies that the strategic alliance of the SCM activities and competence concentration based on technology development in SEMs can organize the unity through organizational members' information sharing. In other words, when the information integration supports the compatibility and reliability of shared information system by raising technological competence through this, the process innovation can lead to non-financial cost reduction, product quality, delivery compliance and inventory cost reduction as quality performance of the structured process, management and distribution.

• Journal of Digital Convergence
• /
• v.16 no.12
• /
• pp.123-135
• /
• 2018

The objective of this paper is to investigate the issues related to the supply chain management in plant engineering industry, and propose the framework to improve the project efficiency. The preliminary case study shows that EPC's fragmented nature, lack of coordination and information sharing, and lack of proper risk and change management contribute to project delay and cost overrun. To examine the level of informatization and information sharing in supply chain, survey responses from the suppliers and subcontractors have been collected. The statistical results show that information sharing, early involvement in design process and awareness in SCM have influenced the level of collaboration, but supplier assessment and informatization have no impact on the collaboration. A conceptual model is proposed in order to facilitate the integration of design, procurement and construction functions. Implications from the study are also provided.

• Journal of Industrial Convergence
• /
• v.20 no.4
• /
• pp.1-6
• /
• 2022

In recent years, many global manufacturers such as Mercedes-Benz and BMW have been using augmented reality technology to spread it to various fields such as assembly process, after-sales service, sales stores, and consumer manuals. In this study, the application status of innovation in manufacturing using industrial augmented reality was identified, and the possibility of combining existing ERP and augmented reality was analyzed based on this. In addition, it was empirically analyzed that the selection of a dedicated content development engine is the most important factor in development productivity in the development of industrial augmented reality content. The same content developed with Unity3d was redeveloped with Vuforia Studio, and as a result of comparative analysis of development man-hours by field, the development lead time was shortened by 8 times. This study proves productivity by actually developing industrial augmented reality contents, and it is a study with a difference that is difficult to implement in practice.