• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.108-121
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• 2008

Dispatching rule for parallel machines with multi product is proposed in this paper, In current market,customer's request for higher quality is increasing, In accordance with such demand, manufacturers are focusingon improving the quality of the products. Such shift in production objective is risky. The possibility ofneglecting another important factor in customer satisfaction increases, namely due dates. From the aspect ofimproving quality, frequency of product assignment to limited number of high performance machines willincrease. This will lead to increased waiting time which can incur delays, In the case of due date orientedproduct dispatch, Products are assigned to machines without consideration for quality. Overall deterioration ofproduct quality is inevitable, In addition, Poor products will undergo rework process which can increase delays.The objective of this research is dispatching products to minimize due date delays while improving overallquality. Quality index is introduced to provide means of standardizing product quality. The index is used toassure predetermined quality level while minimizing product delays when dispatching products. Qualitystandardization method and dispatching algorithm is presented. And performance evaluation is performed withcomparison to various dispatching methods.

• IE interfaces
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• v.17 no.1
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• pp.93-103
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• 2004

Service importance has been growing increasingly as competition element of enterprises according to going on rapid softness, information and knowledge of industrial infrastructure recently. Quality management system that implemented in manufacturing sector have been spreading rapidly to service company, but the company performing pure engineering service only in construction fields performed mainly the evaluation on the operational aspect such as degree of implementation of the established system because it is difficult to objective evaluation on the activity of the established quality management system or quality assurance system. This study would like to make on offer the improvement points based on the evaluation of service quality and the itself evaluation result through the questionnaire on the service offerers and customers using the pre-qualified SERVQUAL model in establishment of the improvement goal of the company. According to the result of this study, it is analyzed a gap and required to establish a counter-plan to correct many gaps discovered between the real offered level and the expect level of custom.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.30-36
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• 2012

This study is aimed to show that an asymmetric load in the frontal plane leads to an increase in low back loading and fatigue in comparison with a symmetric load when workers lift an external weight by investigating previous studies and verifying the phenomenon with an experiment. Ten male subjects are required to lift and hold an given external load at 70cm height during 50sec, then the EMG amplitude and median frequency on bilateral low back muscle groups (Longissimus, Iliocostalis, and Multifidus) are recorded and analyzed. Independent variables are two-level load weight (13kg, 20kg) and three-level LCG (Center, 6.5cm to the right, and 13cm to the right), and dependent variables are EMG amplitude average, difference, and Fatigue Index (FI). Results show that load weight increases significantly amplitude average and FI, but LCG does significantly amplitude difference and FI significantly (P-value < 0.05). Also the correlation coefficient between amplitude difference and FI is over 0.99. These implies that trunk loading should be explained by not EMG amplitude but muscle fatigue aspect since the association between an external load and amplitude is linear, but the relationship between an external load and median frequency as muscle fatigue index is almost exponential.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.135-142
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• 2020

In this study, the case of brand IMC communication of LG Hausys' total interior solution brand Z:IN was dealt with. The target consumer of the Z:IN brand is a general end consumer and also shows the character of industrial goods. Accordingly, there should be a unique aspect that brand management and communication methods must be made from more angles. For many companies which are active in the industry, this case study should be significant. This case study was researched in terms of consumer's purchase decision-making process and consumer participation and experience. Brand Zi:in developed a brand communication strategy following the flow of the consumer purchasing decision process. And the brand actively induces consumer experience and participation so that consumers can communicate more closely with the brand. Brand communication from the perspective of consumer purchasing decision-making and consumer experience and participation is a crystal that fully considers LG Hausys' products, markets, and competitors, and will be an effective strategy to continue to preoccupy the market not only in the present but in the future.

• IE interfaces
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• v.22 no.2
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• pp.126-134
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• 2009

As product quality and yield are essential factors in semiconductor manufacturing, monitoring the main manufacturing steps is a critical task. For the purpose, FDC(Fault detection and classification) is used for diagnosing fault states in the processes by monitoring data stream collected by equipment sensors. This paper proposes an FDC model based on decision tree which provides if-then classification rules for causal analysis of the processing results. Unlike previous decision tree approaches, we reflect the structural aspect of the data stream to FDC. For this, we segment the data stream into multiple subregions, define structural features for each subregion, and select the features which have high relevance to results of the process and low redundancy to other features. As the result, we can construct simple, but highly accurate FDC model. Experiments using the data stream collected from etching process show that the proposed method is able to classify normal/abnormal states with high accuracy.

• Corrosion Science and Technology
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• v.17 no.6
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• pp.257-264
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• 2018

Anti-graffiti coatings have become more important. These layers must guarantee excellent corrosion protection properties, and graffiti must be easily removable, without reducing protection and aesthetic properties. In this study, anti-graffiti and corrosion behavior of two anti-graffiti polyurethane powder coatings were studied. These layers were deposited on aluminum substrate, with two different surface finishes, smooth, and wrinkled. The action of four different removers are investigated. Graffiti were drawn on coatings by means of red acrylic spray paint. Methyl-ethyl-ketone (MEK) and a "commercial" remover were the most effective solvents, in terms of graffiti removal capability, producing limited change in aesthetical surface aspect for smooth finishing. The wrinkled surface was less resistant. Corrosion protection properties, after removal action and contact with the remover, were evaluate by electrochemical impedance spectroscopy. After approximately 5 hours, coatings were no longer protective due to formation of defects. To simulate the weathering effect, UV-B cyclic test (4 hours of UV exposure followed by 4 hours of saturated humidity at $50^{\circ}C$) were performed for 2000 hours. Gloss and color changes were measured, and electrochemical impedance spectroscopy measurements were performed after aging and graffiti removal.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.263-271
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• 2023

In the (3,3) close combat model based on the Lanchester Square Law, this study proposes a plan to optimally allocate residual combat power after the battle to other battlefields. As soon as the two camps of three units can grasp each other's information and predict the battle pattern immediately after the battle began, the Time Zero Allocation of Force (TZAF) scenario was used to initially allocate combat power to readjust the combat model. It reflects travel time, which is a "field friction" in which physical distance exists from battlefields that support combat power to battlefields that are supported. By developing existing studies that try to examine the effect of travel time on the battlefield through the combat model, this study forms a (3,3) combat model, which is a large number of minimum units. In order to achieve the combat purpose, the principle of optimal combat force operation is presented by examining the aspect that support combat power is allocated to the two battlefields and the consequent battle results. Through this, various scenarios were set in consideration of the travel time and the situation of the units, and differentiated results were obtained. Although the most traditional, it can be used as the basic logic of the training or the commander's decision-making system using the actual war game model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.142-151
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• 2023

Sentiment analysis is a method used to comprehend feelings, opinions, and attitudes in text, and it is essential for evaluating consumer feedback and social media posts. However, creating sentiment dictionaries, which are necessary for this analysis, is complex and time-consuming because people express their emotions differently depending on the context and domain. In this study, we propose a new method for simplifying this procedure. We utilize syntax analysis of the Korean language to identify and extract sentiment words based on the Reason-Sentiment Pattern, which distinguishes between words expressing feelings and words explaining why those feelings are expressed, making it applicable in various contexts and domains. We also define sentiment words as those with clear polarity, even when used independently and exclude words whose polarity varies with context and domain. This approach enables the extraction of explicit sentiment expressions, enhancing the accuracy of sentiment analysis at the attribute level. Our methodology, validated using Korean cosmetics review datasets from Korean online shopping malls, demonstrates how a sentiment dictionary focused solely on clear polarity words can provide valuable insights for product planners. Understanding the polarity and reasons behind specific attributes enables improvement of product weaknesses and emphasis on strengths. This approach not only reduces dependency on extensive sentiment dictionaries but also offers high accuracy and applicability across various domains.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.133-141
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• 2023

Approximately 40,000 elevators are installed every year in Korea, and they are used as a convenient means of transportation in daily life. However, the continuous increase in elevators has a social problem of increased safety accidents behind the functional aspect of convenience. There is an emerging need to induce preemptive and active elevator safety management by elevator management entities by strengthening the management of poorly managed elevators. Therefore, this study examines domestic research cases related to the evaluation items of the elevator safety quality rating system conducted in previous studies, and develops a statistical model that can examine the effect of elevator maintenance quality as a result of the safety management of the elevator management entity. We review two types: odds ratio analysis and logistic regression analysis models.

• Steel and Composite Structures
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• v.26 no.4
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• pp.473-484
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• 2018

Free vibration of cross-ply laminated plates using a higher-order shear deformation theory is studied. The arbitrary number of layers is oriented in symmetric and anti-symmetric manners. The plate kinematics are based on higher-order shear deformation theory (HSDT) and the vibrational behaviour of multi-layered plates are analysed under simply supported boundary conditions. The differential equations are obtained in terms of displacement and rotational functions by substituting the stress-strain relations and strain-displacement relations in the governing equations and separable method is adopted for these functions to get a set of ordinary differential equations in term of single variable, which are coupled. These displacement and rotational functions are approximated using cubic and quantic splines which results in to the system of algebraic equations with unknown spline coefficients. Incurring the boundary conditions with the algebraic equations, a generalized eigen value problem is obtained. This eigen value problem is solved numerically to find the eigen frequency parameter and associated eigenvectors which are the spline coefficients.The material properties of Kevlar-49/epoxy, Graphite/Epoxy and E-glass epoxy are used to show the parametric effects of the plates aspect ratio, side-to-thickness ratio, stacking sequence, number of lamina and ply orientations on the frequency parameter of the plate. The current results are verified with those results obtained in the previous work and the new results are presented in tables and graphs.