• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.75-77
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• 2021

전력 생산의 효율을 높이고 지속적인 공정관리를 위해 전력 설비 데이터의 패턴을 분석하고 원인이 되는 주요 변수를 찾는 것이 중요하다. 따라서, 본 연구에서는 전력 설비 데이터의 패턴을 분석하기 위해 데이터를 군집화하고 연구 방법으로 Decision Tree, Random Forest와 ResNet을 이용하여 패턴을 분류하였다. Class Activation Map을 이용하여 설비데이터의 원인이 되는 주요 변수를 확인하였다. 본 연구를 통해 전력 설비 데이터의 분류 및 원인 분석이 가능한 통합적 솔루션을 제시하고자 한다.

• 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.

• Management Science and Financial Engineering
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• v.17 no.2
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• pp.23-37
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• 2011

In this paper, we address a layout design problem for determining an optimal 4-class-based dedicated linear storage layout in a class of unit load storage systems. Assuming that space requirement for a class is the sum of the maximum inventory levels of products assigned to the class, and that one-way travel time is a linear function of storage index, we formulate a 4-class-based dedicated linear storage problem PTL[4] and provide an exact splitting algorithm with $O(n{\lceil}logn{\rceil})$. Our algorithms could be applied to more than a 4-class-based dedicated storage layout problem with slight modification in order to reduce computational execution time.

• Journal of Korean society of Dental Hygiene
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• v.21 no.6
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• pp.813-820
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• 2021

Objectives: This study was conducted to verify the effectiveness of the VR-applied head and neck anatomy class and to be used as basic data for the development of a teaching method using VR in the basic dental hygiene field. Methods: A convenience sample was extracted from 128 students and graduates who completed the head and neck anatomy class at the department of dental hygiene at a university in Gwangju. From June 1 to July 31, 2021, an online survey was conducted on class attitude and satisfaction, and statistical analysis was performed using frequency analysis and independent sample t-test. Results: Class attitude (3.79), interest (3.64), attention (3.88), learning motivation (3.80), and achievement motivation (3.84) were all high in the head and neck anatomy VR application group (p<0.01). Satisfaction (3.99), relevance of class content (4.06) and class achievement (3.96) were high in the head and neck anatomy VR application group (p<0.01). The suitability of class attitude (3.65) and class content (sub-item of class satisfaction) (4.13) was high in the group with the 4th industrial revolution education experience (p<0.05). Conclusions: The effect of VR application in the head and neck anatomy class was confirmed to increase students' class attitude and satisfaction. In the basic dental hygiene curriculum, it will be necessary to develop and utilize teaching methods related to the 4th industrial revolution and VR application classes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.286-296
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• 2007

In this paper, we have proposed on the Matching Table of 'Type of If Business - Class of IT Techniques' to train If manpower as an educational-industrial cooperation. The Type of If Business(TITB) are classified according to ${\triangle}$IT Services, ${\triangle}$IT Devices, and ${\triangle}$Software & Computer related Services which are guided by KAIT(Korea Association of Information & Telecommunication). The Class of IT Techniques(CITT) are brought from IITA(Institute for Information Technology Advancement). We have suggested on the element techniques from the Class of If Techniques(CITT) according to the Type of IT Business(TITB) and proposed an educational-industrial cooperation program to line up 'Type of IT Business(TITB) - Class of IT Techniques(CITT) - University(Department/Major)'. The deduction process of the core education program is presented to show the educational-industrial cooperation between company(Type of IT Business : Digital Contents Development Service) and university(Major of Multimedia & Contents) in the Busan area. The Matching Table of 'Type of IT Business(TITB) - Class of IT Techniques(CITT)' varies as the way of classification according to IT Business and IT Techniques. The research on the real and exact Matching Table of 'Type of IT Business(TITB) - Class of IT Techniques(CITT)' is necessary for educational-industrial cooperation by the trends of techniques and the changes of IT market share.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.2
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• pp.146-152
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• 2022

Objectives: The purpose of this study is to confirm whether there is a factor to affect the evaluation of fit test of a 2nd class half masks using a OPC test method. Methods: Total 34 adults including Males and Females were tested using OPC-based fit testing equipment while wearing a 2nd class half filtered mask. Results: 1. The result of measuring face dimensions using different tools such as a 3D scanner and digital calipers revealed that the variation of lip width was not statistically significant because there was only a difference of about 4 mm. However, it showed that a difference in face length was statistically significant enough with 10 mm(p<0.000). 2. The fit factor for each exercise stage according to gender was the highest at 124.54(p<0.001) in Step 3, and the fit factor was the lowest at 73.75 in Step 1. 3. In the evaluation of the degree of fit factor according to gender, female passed 67.44%, which was higher than the value in male(p<0.038). 4. The acceptance rate of the group having a face length of shorter than 110 mm was 91.67%. On the other hand, the acceptance rate of the group with a face length of longer than 110 mm was 47.27%(p<0.000). 5. The fit test was possible because the fit factor with 2nd class half masks corresponding to FFP1(Filtering Face Piece 1) was passed 55% or more. Conclusions: The test results showed that using a 2nd class half filtered mask, it is important to wear a properly designed mask so that face size does not affect the fit factor.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.147-153
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• 2017

The mortality rate in industrial accidents in South Korea was 11 per 100,000 workers in 2015. It's five times higher than the OECD average. Economic losses due to industrial accidents continue to grow, reaching 19 trillion won much more than natural disaster losses equivalent to 1.1 trillion won. It requires fundamental changes according to industrial safety management. In this study, We classified the risk of accidents in industrial complex of Ulju-gun using spatial analytics and data mining. We collected 119 data on accident data, factory characteristics data, company information such as sales amount, capital stock, building information, weather information, official land price, etc. Through the pre-processing and data convergence process, the analysis dataset was constructed. Then we conducted geographically weighted regression with spatial factors affecting fire incidents and calculated the risk of fire accidents with analytical model for combining Boosting and CART (Classification and Regression Tree). We drew the main factors that affect the fire accident. The drawn main factors are deterioration of buildings, capital stock, employee number, officially assessed land price and height of building. Finally the predicted accident rates were divided into four class (risk category-alert, hazard, caution, and attention) with Jenks Natural Breaks Classification. It is divided by seeking to minimize each class's average deviation from the class mean, while maximizing each class's deviation from the means of the other groups. As the analysis results were also visualized on maps, the danger zone can be intuitively checked. It is judged to be available in different policy decisions for different types, such as those used by different types of risk ratings.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.4
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• pp.384-393
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• 2001

The performance of a double carousel system depends on its design and operation strategy. The two-class based assignment policy is expected to be an appropriate storage policy for its efficient operation, since it has two independently-moved carousels, lower and upper sub-carousels. This paper conducts a comparative analysis of the effects of the two-class based assignment policy and those of randomized assignment policy on the throughput of a double carousel system. We also show that, by allowing the sub-carousels not to be equal in size, a further improvement in the throughput can be obtained.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.133-138
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• 2002

In this paper, we model a two-server queueing system with priority, to which we put a restriction of the number of servers for each customer class. A group of customers is divided into two different classes. The class 1 customers has non -preemptive priority over class 2 customers. We use the method of PGF depending on the state of server We find the PGF of the number of customers in queue, server utilization, mean queue length and mean waiting time for each class of customers.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.83-90
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• 2002

Recent commercial systems are too large and too complex to restructure their design by hand without tools and cost too much time and effort. This thesis presents a restructuring approach using cohesion and coupling of classes to change object-oriented designs automatically. The matrix which represents the relation between methods is defined by distance between methods using cohesion and coupling, Class restructuring starts to isolate to dividing class, selects the class to have the lowest cohesion and combines the selected class with the closest class.