• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.92-99
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• 2021

The ever-growing demand for enhanced competitiveness of engineered systems require designing in quality strategies that can efficiently incorporate multiple design attributes into a system. In a robust design, there must be consideration for any uncontrollable factors that should not be disregarded in the design process. Studies on multi-attribute design challenges usually assume mutual utility independence amongst the design attributes. However, mutual utility independence does not exist in every design situation. In this study, a new robust design methodology that has two utility-dependent attributes are presented. The proposed method was then compared with a traditional robust design that utilizes a wave soldering process design. The results of this case study indicate that the proposed method yields a better solution than the traditional method.

• Journal of Distribution Science
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• v.16 no.12
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• pp.57-68
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• 2018

Purpose - The development of technologies lead the volume of sale on online market increase but an off-line shopping center is still a core component in the omni-channel strategy. It is generally thought that high-level retailtainment on brick and mortar store affects purchase intentions positively, but some previous studies dispute that and have reported that retailtainment does not affect purchase intentions. So we have studied the additional factors' effect - the nature of purchase and utility - with retailtainment. Research design, data, and methodology - There are 8 treatment groups which were assigned by the method of retailtainment (high vs. low), nature of purchase (essential vs. non-essential), and utility (acquisition vs. transaction). A total of 240 subjects (office workers = 163, 68%; undergraduates = 77, 32%; average age = 30s; female = 39%) were divided into groups and exposed to one of the eight scenarios. Participant's purchase intention was the dependent, and ANOVA and L-matrix were used to analyze for main and interactive effects between factors. Results - First, the main effect and interactive effect between retailtainment and the nature of purchase are significant. We also found that the contrast between essential and non-essential at low-level retailtainment is higher than that of high-level retailtainment. Second, in the case of retailtainment and utility, transaction utility under high-level retailtainment affects purchase intentions positively. Third, between the nature of the purchase and utility, the main effect of the nature of purchase and the interactive effect is significant, but the main effect of utility is not significant. In the case of non-essential goods, the purchase intention was high when transaction utility was provided but in the case of essential goods, acquisition utility increased purchase intentions. Finally, when transaction utility is given, purchase intentions of essential goods increase under low retailtainment, and the purchase intentions of non-essential goods increase under high retailtainment. Conclusions - When customers buy essential goods, discounts decrease purchase intentions. During the season for bargain sales, purchase intentions increase when retailtainment of essential goods is low, and retailtainment of non-essential goods is high.

• Journal of the Korean Home Economics Association
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• v.42 no.5
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• pp.107-126
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• 2004

As the information society matures, an analysis on possible outputs of internet usage is needed. Thus, this study was peformed in order to understand the utility cognition and negative outputs of internet users. The method used in this study was a web-based questionnaire that was administered to the internet users. Five hundred married men and women were analyzed with a factor and a multiple regression analysis. Results were as follows: First, many kinds of internet usages - information searching, internet shopping, electronic mail, instant messaging, and decision-making dependent on internet information - were differentiated with age. Second, the altitude about the internet was an important explanatory variable in the types of internet usage. Third, negative outputs of internet usage were great in terms of information resource management and unbalanced scheduling in daily time spent. Fourth, utility cognition was affected by qualitative elements on internet usage more than the quantitative ones.

• The Journal of Society for e-Business Studies
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• v.26 no.2
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• pp.1-17
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• 2021

This paper elucidates the effect of characteristics of service quality on continuance usage intention of digital healthcare service using mediating factors of user expectation and user utility. First, we classified independent factors into three types such as service system characteristics, user characteristics, and healthcare service characteristics from the previous studies, and investigated the effect of three independent factors on continuance usage intention of digital healthcare service. Second, we analyzed the impact of two mediating factors, user expectation and user utility, on the continuance usage intention. We developed a research model that includes three types of independent factors, mediated factors of user expectation and user utility, and a dependent factor of continuance usage intention. We surveyed a total of 357 samples from digital healthcare service users and analyzed the research model. The research results significantly show that Characteristics of Users is essential factor impacting a dependent factor of Continuance Usage Intention. The results indicate the followings: (1) Characteristics of Users including the variables of Innovation impacts User Expectation, and User Expectation affects Users Utility, and Users Utility also affects Continuance Usage Intention. (2) Characteristics of Service Systems including the variables of Functionality, Compatibility, and Convenience and Characteristics of users of Innovation variable impact the mediating factor of User Expectation, and User Expectation also affects the factor of Continuance Usage Intention. (3) Characteristics of Healthcare Services including the variables of Reliability, Ease of Operation, Safety, and Accuracy impact User Utility, and User Utility also affects Continuance Usage Intention.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.555-558
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• 2003

The Choquet-Stieltjes integral is defined. It is shown that the Choquet -Stieltjes integral is rep-resented by a Choquet integral. As an application of the theorem above, it is shown that Choquet expected utility model for decision under uncertainty and rank dependent utility model for decision under .risk are respectively same as their simplified version.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10A
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• pp.1023-1033
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• 2007

This study considers a joint congestion control, routing and power control for energy-constrained wireless networks. A mathematical model is introduced which includes maximization of network utility, maximization of network lifetime, and trade-off between network utility and network lifetime. The framework would maximize the overall throughput of the network where the overall throughput depends on the data flow rates which in turn is dependent on the link capacities. The link capacity on the other hand is a function of transmit power levels and link Signal-to-Interference-plus-Noise-Ratio (SINR) which makes the power allocation problem inherently difficult to solve. Using dual decomposition techniques, subgradient method, and logarithmic transformations, a joint algorithm for rate and power allocation problems was formulated. Numerical examples for each optimization problem were also provided.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.147-155
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• 2008

The economics of most chemical plants are heavily dependent upon the management of the utilities used in the plants. The utilities are supplied by the centralized utility system of the plant. Among the various utilities the steam is by far the most important energy source and the management of the electricity and the process water are greatly affected by the steam. Therefore it is necessary to educate students and new employees the basic concepts about the effective distribution of the utilities and the fundamental strategies to apply the concepts in actual plant operations. The OOUS (Optimal Operation of Utility System) is an GUI educational system designed to educate the effective generation of the steam and the optimal steam distribution schemes within short period. The OOUS deals with various utility equipments and processes and shows how to save operation costs by displaying the optimal operation conditions based on the process models and the operational knowledgebase.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.110-118
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• 2018

Due to recent earthquakes, there is a growing awareness that Korea is not a safe zone for earthquakes any more. Therefore, the review of various aspects of the seismic safety of the infrastructures are being carried out. Because of the characteristics of the underground structure buried in the ground, the electric power utility tunnels must be considered not only for the inertia and load capacity of the structure itself but also the characteristics of the surrounding soils. An extensive and accurate numerical analysis is inevitably required in order to consider the interaction with the ground, but it is difficult to apply the soil-structure interaction analyses, which generally requires high cost and extensive time, to all electric power utility tunnel structures. In this study, the major design variables including soil characteristics are considered as independent variables, and the seismic safety factor, which is the result of the numerical analysis, is considered as a dependent variable. Thus, a method is proposed to select vulnerable electric power utility tunnels with low seismic safety factor while excluding costly and time-consuming numerical analyses through the direct correlation analysis between independent and dependent variables. Equations of boundary limits were derived based on the distribution of the seismic safety factor and the cover depth and rebar amounts with high correlation relationship. Consequently, a very efficient and simple approach is proposed to select vulnerable electric power utility tunnels without intensive numerical analyses. Among the 108 electric power utility tunnels that were investigated in this paper, 30% were screened as fragile structures, and it is confirmed that the screening method is valid by checking the safety factors of the fragile structure. The approach is relatively very simple to use and easy to expand, and can be conveniently applied to additional data to be obtained in the future.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.498-509
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• 2023

Purpose: This paper proposes a method detecting the falling of a maintenance worker in the underground utility tunnel, by applying deep learning techniques using CCTV video, and evaluates the applicability of the proposed method to the worker monitoring of the utility tunnel. Method: Each rule was designed to detect the falling of a maintenance worker by using the inference results from pre-trained YOLOv5 and OpenPose models, respectively. The rules were then integrally applied to detect worker falls within the utility tunnel. Result: Although the worker presence and falling were detected by the proposed model, the inference results were dependent on both the distance between the worker and CCTV and the falling direction of the worker. Additionally, the falling detection system using YOLOv5 shows superior performance, due to its lower dependence on distance and fall direction, compared to the OpenPose-based. Consequently, results from the fall detection using the integrated dual deep learning model were dependent on the YOLOv5 detection performance. Conclusion: The proposed hybrid model shows detecting an abnormal worker in the utility tunnel but the improvement of the model was meaningless compared to the single model based YOLOv5 due to severe differences in detection performance between each deep learning model

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.4
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• pp.325-332
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• 2002

In the process of designing pareto optimal insurance contract, it is necessary to assume that insurance contract conditions are endogenous to build a model. The expected utility, the non-expected utility and the state-dependent utility function can be applied as a insurance decision making principle. The insurance costs may have the linear, convex, and concave ralationship with the indemnity schedule. However, the sunk cost and fixed cost must be recognized. The deductible which decides whether an insurance contract to be a full or partial insurance contract can exist in the forms of straight deductible or diminishing deductible. Indeciding the level of deductible, the types of the insurance and the risks to be insured should be the deciding factors. Especially for recall insurance, there is relatively high chance that the recalling company being bankrupt. Therefore, the possibility of bankrupcy should be the considering factor in deciding the policy limit. The existence of the incomplete market and uninsurable background risk should be understood as restricting conditions of the pareto-optimal insurance contract.