• Proceedings of the Korean Society of Laser Processing Conference
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• 2005.11a
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• pp.37-41
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• 2005

When screen size of the Flat Panel Display (FPD) becomes larger, the traditional photo-lithography using photomasks and UV lamps might not be possible to make patterns on Photo Resist (PR) material due to limitation of the mask size. Though the maskless photo-lithography using UV lasers and scanners had been developed to implement large screen display, it was very slow to apply the process for mass-production systems. The laser exposure system using 405 nm semi-conductor lasers and Digital Micromirror Devices (DMD) has been developed to overcome above-mentioned problems and make more than 100 inches FPD devices. It makes very fine patterns for full HD display and exposes them very fast. The optical engines which contain DMD, Micro Lens Array (MLA) and projection lenses are designed for 10 to 50 ${\mu}m$ bitmap pattern resolutions. The test patterns for LCD and PDP displays are exposed on PR and Dry Film Resists (DFR) which are coated or laminated on some specific substrates and developed. The fabricated edges of the sample patterns are well-defined and the results are satisfied with tight manufacturing requirements.

• Journal of the Semiconductor & Display Technology
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• v.5 no.4 s.17
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• pp.1-4
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• 2006

Recently, with rapid development of digital media like semiconductor and large flat panel display, the manufacturing equipment is required to have high precision over large travel range. Moreover it should have high product throughput. To achieve high product throughput, a controller should perform fast point-to-point motion and high precision positioning after settling in spite of external disturbances or residual vibrations. We proposed a new mode switching control algorithm with an application to dual stage for long range and high precision positioning. The proposed algorithm uses a proximate time-optimal servomechanism for the fast settling and a time-delay controller for the high precision positioning. Experimental results show that the proposed method enables smooth mode switching and improves the settling time and the precision accuracy after settling by over than 33% and 45%, respectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.109-115
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• 2005

In the study, Methods for operating measures in equipment security to find out dangerousness timely in the system and to need for the prevention and measures. The method for analyzing and reconstructing the causes of accident of equipment in site, and try to save the information of site in real-time and to analyze the state of equipment to look for the factors of accidents. By this analysis, one plan for efficiency of production, Equipment Fault Diagnosis Management and security is integrating and building module of using the Fuzzy Inference based on fuzzy theory. The case study is applied to the industrial electric motors that are necessarily used to all manufacturing equipment. Using the sensor for temperature is attached to gain the site information in real time and to design the hardware module for signal processing. In software, realize the system supervising and automatically saving to management data base by the algorithm based in fuzzy theory from the existing manual input system

• Management Science and Financial Engineering
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• v.19 no.1
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• pp.29-36
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• 2013

This paper considers common due-date assignment and scheduling on parallel machines. The main decisions are: (a) deter-mining the common due-date; (b) allocating jobs to machines; and (c) sequencing the jobs assigned to each machine. The objective is to minimize the sum of the penalties associated with common due-date assignment, earliness and tardiness. As an extension of the existing studies on the problem, we consider sequence-dependent setup times that depend on the type of job just completed and on the job to be processed. The sequence-dependent setups, commonly found in various manufacturing systems, make the problem much more complicated. To represent the problem more clearly, a mixed integer programming model is suggested, and due to the complexity of the problem, two heuristics, one with individual sequence-dependent setup times and the other with aggregated sequence-dependent setup times, are suggested after analyzing the characteristics of the problem. Computational experiments were done on a number of test instances and the results are reported.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.63-71
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• 2014

As power consumption increases, more power utilities are required to satisfy the demand and consequently results in tremendous cost to build the utilities. Another issue in construction of power utilities to meet the peak demand is an inefficiency caused by surplus power during non-peak time. Therefore, most power company considers power demand management with time-based electricity rate policy which applies different rate over time. This paper considers an optimal machine operation problem under the time-based electricity rates. In TOC (Theory of Constraints), the production capacities of all machines are limited to one of the bottleneck machine to minimize the WIP (work in process). In the situation, other machines except the bottleneck are able to stop their operations without any throughput loss of the whole manufacturing line for saving power utility cost. To consider this problem three integer programming models are introduced. The three models include (1) line shutdown, (2) block shutdown, and (3) individual machine shutdown. We demonstrate the effectiveness of the proposed IP models through diverse experiments, by comparing with a TOC-based machine operation planning considered as a current model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.174-183
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• 2018

In the industrial fields, the process capability index has been using to evaluate the variation of quality in the process. The traditional process capability indices such as $C_p$, $C_{pk}$, $C_{pm}$ and $C^+_{pm}$ have been applied in the industrial fields. These traditional process capability indices are mainly applied in the univariate analysis. However, the main streams in the recent industry are the multivariate manufacturing process and the multiple quality characteristics are corrected each other. Therefore, the multivariate statistical method should be used in the process capability analysis. The multivariate process indices need to be enhanced with more useful information and extensive application in the recent industrial fields. Hence, the purpose of the study is to develop a more effective multivariate process index ($MC_{pI}$) using the multivariate inverted normal loss function. The multivariate inverted normal loss function has the flexibility for the any type of the symmetrical and asymmetrical loss functions as well as the economic information. Especially, the proposed modeling method for the multivariate inverted normal loss function (MINLF) and the expected loss from MINLF in this paper can be applied to the any type of the symmetrical and asymmetrical loss functions. And this modeling method can be easily expanded from a bivariate case to a multivariate case.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.152-161
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• 2015

Until a recent date, Toyota Production System (called TPS) was introduced by many domestic companies to remove waste and reduce manufacturing cost. However, cases of substantial and effective improvement after the introduction are not much. Even though many companies have actively conducted TPS during that time, the outcome is not satisfactory. In this paper, we show the problems and core contents to consider in applying of TPS as follows. First, the innovative organizational culture formed by active participation of employees and leadership of the CEO is very important for a successful introduction of TPS above all. Second, it is necessary to prepare various training programs optimized for the field in order to continuously improve the competency of employees in each class, and to train skilled personnel through that programs. Third, it is necessary to improve the maturity level of TPS application through the construction of correct evaluation system on accomplishment of the production system. In addition, the problems that occur should be solved through the continuous improvement activities. These results will help to TPS introduction of the domestic small-medium companies. Therefore, this study will contribute to strengthen and improve the global competitiveness in the related industries.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.44-51
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• 2015

When manufacturing die casting mold, generally, the casting layout design should be considered based on the relations of injection system, casting condition, gate system, and cooling system. According to the various relations of the conditions, the location of product defects was differentiated. High-qualified products can be manufactured as those defects are controlled by the proper modifications of die casting mold with keeping the same conditions. In this research, Computer Aided Engineering (CAE) simulation was performed with the several layout designs in order to optimize the casting layout design of an automotive part (Housing). In order to apply them into the production die-casting mold, the simulation results were analyzed and compared carefully. With the filling process, internal porosities caused by air entrapments were predicted and also compared with the modification of the gate system and overflow. With the solidification analysis, internal porosities occurring during the solidification process were predicted and also compared with the modified gate system. The simulation results were also applied into the production die-casting mold in order to compare the results and verify them with the real casting samples.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.1
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• pp.41-50
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• 2010

본 논문에서는 수명이 다한 제품이나 소비자가 더 이상 사용하지 않는 폐기품을 다시 재사용하거나 폐기하는데 필요한 일련의 활동을 위한 역방향 로지스틱스에서의 수거망 설계 문제를 다루고 있다. 수거망 설계 문제는 수거지점의 위치와 수요지의 폐기품을 수거 지점에 할당하는 것을 결정하는 문제로 정의할 수 있으며 수거지점은 재활용품이나 폐기품이 위치한 지점 근처에 위치하고 주어진 잠재적인 위치를 중에서 결정하게 된다. 여기서, 각 수거지점은 용량제약이 있어 수거 지점에 할당되는 폐기품의 양에는 제한이 있다. 본 논문에서 다루는 수거망 설계문제에서는 수거지점을 설치하는데 필요한 고정비용과 수요지와 수거지점간의 수송비용의 합을 최소화하는 것을 목적으로 한다. 또한 대상문제를 보다 명확히 설명하기 위하여 징수계획법을 이용한 수리적 모형을 제안하였으며 문제의 복잡도 인하여 타부 서치와 시뮬레이티드 어닐링 두 가지 형태의 탐색기법을 제안하였다. 이들 탐색기법에 대하여 최대 500개의 잠재적 위치를 가지는 문제에 대하여 실험을 수행하였고 실험결과를 제시하였다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.477-482
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• 2016

Airtight containers have been widely used in many industries and household. They need a packing for sealing between the inside and outside. Previous packing materials have some drawbacks like stench, stickiness, and difficulty of applying to automated manufacturing systems. So, a new packing material which is harmless and suitable for automation is needed. This study performed a hot plate welding process of thermoplastic elastomer (TPE) as the packing material. The hot plate welding process included a phase change process of solidification and melting. The porosity-enthalpy method was adopted in order to simulate phase change problems. The TPE showed non-Newtonian fluid characteristics during the melting process. Since properties of SEBS are not well-defined, we established TPE properties by observing the melting behavior of TPE. In order to find an optimized condition, a parametric study including packing thickness, shapes, hot plate temperature, and thermal resistance, was conducted.