• Journal of the Korean Society of Industry Convergence
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• v.23 no.5
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• pp.773-787
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• 2020

In the injection molding process, the controlling stability of products quality is a very important factor in terms of productivity. Even when the optimum process conditions for the desired product quality are applied, uncontrollable external factors such as ambient temperature and humidity cause inevitable changes in the state of the melt resin, mold temperature. etc. Therefore, it is very difficult to maintain prodcut quality. In this study, a system that learns the correlation between process variables and product weight through artificial neural networks and predicts process conditions for the target weight was established. Then, when a disturbance occurs in the injection molding process and fluctuations in the weight of the product occur, the stability control of the product quality was performed by ANN predicting a new process condition for the change of weight. In order to artificially generate disturbance in the injection molding process, controllable factors were selected and changed among factors not learned in the ANN model. Initially, injection molding was performed with a polypropylene having a melt flow index of 10 g/10min, and then the resin was replaced with a polypropylene having a melt floiw index of 33 g/10min to apply disturbance. As a result, when the disturbance occurred, the deviation of the weight was -0.57 g, resulting in an error of -1.37%. Using the control method proposed in the study, through a total of 11 control processes, 41.57 g with an error of 0.00% in the range of 0.5% deviation of the target weight was measured, and the weight was stably maintained with 0.15±0.07% error afterwards.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.71-78
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• 2010

The end shape of tube for automobile power steering system has influence on the ability of performance. In this case study, we attempted to optimize the forming process of a small tube using Taguchi experimental design methodology. A preliminary experiment was conducted and four main control factors were selected. The experiment was set up as an $L_9(3^4)$ orthogonal array, and determined the optimal levels of the four factors through the analysis of the experimental results. As a result, the performance characteristic(close adhesion power) of the product was improved about 36%. In addition, the process capability index $C_{pk}$ is enhanced from 0.94 to 6.85.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.4
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• pp.107-121
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• 2018

This study investigates the effects of the Kano model on the product quality and quality satisfaction on the FDM low cost 3D printer, which is used by consumer and makers. 3D printer product quality is analyzed in terms of functionality, usability, durability, reliability and safety based on the inherent quality of the product itself. This study were tested using Kano analysis to calculate the product detail characteristics and Timko coefficient to calculate the degree of satisfactory effects of the 3D printer. As a result, this study becomes product size, the output speed, durability against external impact as attractive quality and the safety part is regarded as One-dimensional quality. With the exception of surface resolution, the Timko customer satisfaction index was the same as the Kano model.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.3
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• pp.190-196
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• 2004

In this paper, we address a layout design problem, PTL[3], for determining an optimal 3-class-based dedicated linear storage layout in a class of unit load storage systems. Our objective is to minimize the expected single command travel time. We analyze PTL[3] to derive a fundamental property that an optimal solution to PTL[3] is one of the partitions based on the PAI(product activity index)-nonincreasing ordering. Using the property and partial enumeration, we construct an efficient exact algorithm with O $(n\;{\lceil}\;log\;n\;{\rceil}\;)$ for solving PTL[3].

• Industry Promotion Research
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• v.5 no.3
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• pp.45-51
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• 2020

This study analyzed the influence of investment and fostering support on gross regional product by utilizing big data using multiple regression analysis. Gross regional product (GRDP) is an index that intensively contains the production scale, expenditure level, income level, and industrial structure of each region, and is an important data used for regional economic analysis and national policy establishment. In order to properly carry out the country's major national tasks, it is necessary to accurately grasp the regional economy, and as a result, interest in regional gross domestic product is rapidly increasing. In particular, foreign investment has a significant impact on the economy of the host country, and many empirical analyzes are being conducted. In this study, correlation analysis and multiple regression analysis were conducted to examine the influence of foreign investment and domestic development support on gross regional product, and as a result, it was concluded that investment and support as a whole had a positive effect on gross regional product.

• Archives of design research
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• v.17 no.3
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• pp.111-122
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• 2004

The purpose of this study are two the first is to identify the positioning of product design and analyze its functional relationship with product development, manufacturing, marketing and sales in the comprehensive competitiveness evaluation model ; and the second is to estimate the determinants of QCI(quality competitiveness index), analyze the impact of product design on QCI, and compare the aforementioned results for the seven industrial sectors and the five product patterns. For this empirical analysis, this study surveyed 400 Korean manufacturing firms during August-October 2003. The major empirical findings are summarized as follows : First, the hypothesis on the positive effect of product design on QCI is accepted at a highly significant level (p < 0.001) for all : the manufacturing sector, seven industrial sectors, and five product categories. Second, the correlation analysis and factor analysis lead to the result that the effect of product design on QCI is estimated to be relatively very low, in comparison to those of product functionality and basic performance on QCI. These findings imply that Korean manufacturing sector has been still in the prematured stage at which product design has not played an important role yet. This study concludes that product design in line with other functions (product development, manufacturing, marketing, and sales) should make a good contribution to the improvement of QCI in the future.

• International Journal of Quality Innovation
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• v.2 no.2
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• pp.34-45
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• 2001

This study uses MATLAB as a programming tool and applies the bootstrap method to process capability analysis. The advantage of using MATLAB in bootstrap method is to make the bootstrap method much easier to implement and apply particularly in process capability analysis. An example is provided to further illustrate the easy use of MATLAB in bootstrap method.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.3
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• pp.222-229
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• 2003

In this paper, we address a layout design problem, PTN[2], for determining an appropriate 2-class-based dedicated storage layout in a class of unit load storage systems. Our strong conjecture is that PTNI2] is NP-hard. Restricting PTN[2], we provide three solvable cases of PTN[2] in which an optimal solution to the solvable cases is one of the partitions based on the PAI(product activity index)-nonincreasing ordering. However, we show with a counterexample that a solution based on the PAI-non increasing ordering does not always give an optimal solution to PTN[2]. Utilizing the derived properties, we construct an effective heuristic algorithm for solving PTN[2] based on a PAI-non increasing ordering with performance ratio bound. Our algorithm with O($n^2$) is effective in the sense that it guarantees a better class-based storage layout than a randomized storage layout in terms of the expected single command travel time.

• Journal of Venture Innovation
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• v.2 no.1
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• pp.23-31
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• 2019

The primary goal of this study is to develop proper indicators for evaluating and selecting an organization that contributes product safety in his industry. The indicators of product safety include input, process, and output in the sequences of product safety activities and systems. The indicators are proposed by the side of measurable and unmeasurable index. In detail, the indicators are consist of 3 parts - product safe management, efforts for product safety and the performance of product safety. The indicators are itemized by size of enterprise (large, medium and small size) due to the difference of their system and management capability of product safety. To get the indicators reasonably, the opinions of experts and VOC of the industrial field are considered. And the indicators are also divided by job position and level(an executive vs. worker). The items of indicators are 20 and the score is 200, that are the same whichever the case may be. The indicators are useful tools for selecting a person who serves the development of product safety in his industry.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.16-23
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• 2012

At present, the significance of a new manufacturing system that can shift from 'mass production' and consider life cycles of a product is pointed out and extremely expected. In such a situation, it is recognized that the modular design, often called 'unit design,' is the important design methodology which realizes the new production system enabling 'cost reduction,' 'flexible production of a multi-functional artifact,' 'settlement of an environmental issue,' and so on. A module (unit) of a product is generally defined as 'the parts group made into the sub-system from a certain specific viewpoint.' So far, there have been many researches related to the modular design. However, they are often limited to a certain viewpoint (objective). This paper proposes a simple but effective method for multi-objective modular design. In the proposed method, a new design metric, called similarity index, is proposed to evaluate the modular design candidates from the multiple viewpoints.