• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.61-67
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• 2018

This study covers the results obtained after three years of development work of real - time gas safety monitoring app. In order to reduce the risk of accidents in the gas workplace, it is essential to provide information so that operators can recognize the location of dangerous substances, dangerous facilities, safety procedures, and the temperature and humidity of the workplace. Therefore, this study was conducted to develop a monitoring app that allows the main system to efficiently receive the information in the field where the information is continuously updated. As a result of quantitative and qualitative research and analysis on app scenarios based on the research done in the past and web screen of the main system, it was modified and improved in terms of ease of use, readability, and intuitiveness. Especially, we made many improvements at low depth, which is a sub-area of ease of use. As a result of conducting a user satisfaction survey on the finally derived app scenarios, the average score of 98.5 was obtained in terms of functionality, convenience and readability.

• Journal of Korea Multimedia Society
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• v.7 no.11
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• pp.1610-1619
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• 2004

While researches and studies on short distance wireless communications have been actively carried out, studies on many applications of short distance wireless communications focusing on user-oriented Mobile device are also in progress. Since Bluetooth has several advantages that existing short distance communication does not have, studies on standardization have been carried out focusing on SIG, and IEEE has also jointly studied on this. Bluetooth is a short distance wireless communication technology that can be usefully applied to various kinds of applications. In this regard, this thesis presents payment system using Bluetooth, out of several application technologies of Bluetooth. This payment system is based on the scenario in which secure piconet is formed focusing on the user, the user gets in the car, fill up the gas at the gas station using his own Mobile device and pay The secure payment system presented in this thesis is designed to complement the weakness of existing Bluetooth in terms of security and to secure several requirements of security required for payment using short distance wireless communication.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.481-488
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• 2002

Guarantee of the data integrity is important to the Virtual Private Network (VPN) which can be improved cost decreasing and effective work by applying on Internet as the private network. Thus, the integrity function in the VPN must be maintained and the security manager must be check it occasionally. In this paper we propose the VPN Integrity Evaluation System (VIES) which is collecting, and evaluating automatically the vulnerable data of VPN against current hacking mechanisms in information security system. And this VIES obtain to the results which have objectivity and fairness of evaluation by driving off the evaluation scenario based on Common Criteria (CC), and general users or non-specialist can utilize easy the security evaluation of organization.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.30-36
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• 2011

The current test methods are insufficient to evaluate and ensure the safety and reliability of vehicle system for all possible dynamic situation including the worst case such as rollover, spin-out and so on. Although the known NHTSA Sine with dwell steering maneuvers are applied for the vehicle performance assessment, they aren't enough to estimate other possible worst case scenarios. Therefore, it is crucial for us to verify the various worst cases including the existing severe steering maneuvers. This paper includes useful worst case based upon the existing worst case scenarios mentioned above and worst case evaluation for vehicle dynamic controller in simulation basis and UCC HILS. The only human steering angle is selected as a design parameter here and optimized to maximize the index function to be expressed in terms of both yaw rate and side slip angle. The obtained scenarios were enough to generate the worst case to meet NHTSA worst case definition. It has been concluded that the new procedure in this paper is adequate to create other feasible worst case scenarios for a vehicle dynamic control system.

• Journal of Korean Society of Disaster and Security
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• v.10 no.1
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• pp.19-27
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• 2017

In recent years, ground subsidence has been frequently occurred by underground cavities due to the excessive groundwater inflow, caused by poor construction and management, during tunnel excavation and underground structure construction. In this study, a numerical model (SEEFLOW3D) was developed to estimate groundwater fluctuations for saturated-unsaturated poros media, evaluates the impact on ground excavation with open cut and non-open cut scenarios. In addition, the visual MODFLOW was applied to demonstrate the verification of the model compared with both results. Our results indicated that the RMSE and NRMSE was obtained to range over -3.95~5.7% and 0.56~4.62%, respectively. The developed model was expected to estimate groundwater discharges and apply analysis tool for optimum design of waterproof wall in future.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.577-583
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• 2011

Radar performance test is one of the major steps for radar system design. However, it is restricted by time and cost when radar performance tests are performed with opportunity targets. So various simulated target generators are developed and used to evaluate radar performance. To simulate the target's range, most of simulated target generators are developed with optical line or DRFM(Digital RF Memory) technique but there are many restrictions such as limit of range imitation and test scenario because of their original usage. In this paper, DDL(Digital Delay Line) module for development of simulated target generator is designed with precise range simulation and easily embodiment feature. And pulse recognition and delay gap detection technique are used to simulate the time delay without distortions. Developed DDL module performances are verified through their performance tests and test results are described in this paper.

• Journal of the Korean Institute of Educational Facilities
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• v.25 no.4
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• pp.19-30
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• 2018

The school classroom is a common living place where students spend 7 to 14 hours a day to prepare for their careers. Therefore, if the ventilation of the classroom is not properly performed, it may lead to the deterioration of learning ability due to the unclear air. The concentration of carbon dioxide in the classroom is reported to be high, and the increase in carbon dioxide concentration has a negative effect on the learner's academic performance. In this context, the purpose of this study is to propose a methodology for intelligent and responsive window opening-closing operation process that can reduce the concentration of $CO_2$ in the classroom in order to build a support space that can create an effective teaching-learning environment for adolescents. The specific objectives are as follows. First of all, we define the concept of window opening-closing operation. Secondly, twe develop the operation process of window opening-closing. Thirdly, we develop an algorithm for real-time window opening and closing (process) (Window Opening-Closing Operation Process). Finally, we verify the intelligent responsive window opening-closing operation process through developing examples of window opening-closing operation process using the parametric design program. This study is a preliminary study to develop algorithms necessary for window opening-closing operation. Based on the first-order algorithm, We simulated window opening-closing operations according to a hypothetical scenario. As a result, This study can show that the window is open and close depending on the $CO_2$ concentration, but the $CO_2$ concentration in the room is higher than outdoors. Consequentially, we suggest that it is necessary to develop an algorithm to supplement these results because window is often not working when the temperature difference between indoor and outdoor in winter is large.

• Journal of Distribution Science
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• v.14 no.9
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• pp.111-120
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• 2016

Purpose - This study aimed to investigate the effects of customer relationship quality and perceived power on complaint behaviors in a context of service failures in a restaurant. Two different types of complaint behaviors were employed: personal complaining that disappointed customers directly approach to a service manager and public complaining that customers ask for related institutions, like consumer protection organization, for help. This study also examined the moderation effects of brand reputation on the relationships between customer perceived power and two types of complaint behaviors. Research design, data, and methodology - The author developed a structural model in which customer relationship quality is proposed to affect customer perceived power, thus influencing personal and public complaint behaviors. The model also includes the moderating role of brand reputation; the effect of customer perceived power on two types of complaint behaviors becomes stronger when brand reputation is high. To analyze the research model, a survey based on a scenario regarding the contexts of service failures in a restaurant was conducted toward 126 female college students. SPSS 22.0 and AMOS 21.0 were utilized to test the hypotheses. Results - The findings are as follows. First, customers who had positive relationships with a restaurant are more likely to perceive that they have strong power to influence the service provider. Second, customer perceived power had a significant and positive effect on both personal and public complaint behaviors. Finally, when the brand reputation for a restaurant is high, dissatisfied customers who think they can exercise influence to the restaurant complain more actively toward the service provider. Conclusions - The findings of this study are against the traditional viewpoint on customer loyalty that loyal customers compared respond more generously to the mistakes of a company, but consistent with the 'love becomes hate' effect proposed by Grégoire, Tripp, and Legoux(2009). In complaining contexts, companies should manage customers with positive and strong relationship more carefully and strategically to prevent the expansion of economic and social risks from customers' complaining behaviors. This is more significant for companies with strong brand reputations.

• Journal of Distribution Science
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• v.18 no.8
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• pp.113-125
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• 2020

Purpose: The purpose of this paper is to investigate the effect of interaction between product category (fresh vs. indulgent product) and shopping options (shipping charge and delivery time) on customer satisfaction and purchase intent in an e-commerce context. When ordering groceries online, consumers begin to allocate a larger share of their grocery budget toward product categories that generally contain healthier items at the expense of product categories that generally contain more indulgent products. Moreover, customers are extremely sensitive to shipping options such as shipping charges and delivery time. Therefore, this research investigates the issue at a more segmented level to focus on the impact that one dimension of logistics service quality - product category, shipping charge, and delivery time have on customer satisfaction and purchase intent. Research design, data, and methodology: To test the theoretically derived priori hypotheses concerning product category, shipping charges, delivery time, satisfaction, and purchase intent, this research presented a scenario-based experiment. Eight treatment groups were assigned by the method of product category (fresh produce vs. indulgent product), shipping charge (free vs. paid), and delivery time (one-day vs. two to three days). A total of 240 subjects were divided into groups and exposed to one of the eight scenarios. Participant's purchase intention was the dependent variable, and ANOVA and L-matrix were used to analyze for main and interactive effects between factors. Conclusions: Results indicated that in tests 1 and 2, free shipping and fast delivery time increased consumer satisfaction as well as purchase intent, and fast delivery moderated the impact of free shipping on consumer satisfaction and purchase intent. Test 3 showed that the effect of free shipping on consumer satisfaction and purchase intent moderated by fast delivery for indulgent products. In contrast, fast delivery for fresh products moderated the effect of paid shipping on consumer satisfaction and purchase intent. Consistent with this proposed mechanism, the relative importance of fresh produce versus indulgent products highlights the effect of shipping options on consumer satisfaction and purchase intent when ordering the target product in an e-commerce context. We conclude with a discussion of the theoretical and practical implications of our findings.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.89-94
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• 2014

It empirically studied the effects of customer status, truth of messages, and involvement on loyalty when customer experience demotion in loyalty program. A scenario based 2(customer demotion: highest status customer/middle status customer) ${\times}$ 2(truth of messages: high/low) ${\times}$ 2(involvement: high/low) between-subjects factorial design experiments are conducted for the hypotheses. According to the result of ANCOVA, highest status customer's loyalty and middle status customer's loyalty decrease when they experience demotion. But middle status customer's loyalty less decreases than the highest status customer. Loyalty of the group who feel high truth of message less decreases than those of other groups. And loyalty of the low-involvement group's loyalty less decreases than those of other groups. Moreover it test three way interactions among customer status, truth of messages, and involvement. The result indicates that loyalty of the group who feel high truth of message and low-involvement less decreases than those of other groups.