• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.452-464
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• 2015

This paper proposes a DC microgrid operational strategy and control method for improved service reliability. The objective is to supply power to as many non-critical loads as possible, while providing an uninterrupted power supply to critical loads. The DC bus signaling method, in which DC voltage is an information carrier, is employed to implement the operational strategy in a decentralized manner. During grid-connected operation, a grid-tied converter balances the power of the microgrid by controlling the DC voltage. All loads are connected to the microgrid, and operate normally. During islanded operation, distributed generators (DGs), a backup generator, or an energy storage system balances the power. However, some non-critical loads may be disconnected from the microgrid to ensure the uninterrupted power supply to critical loads. For enhanced service reliability, disconnected loads can be automatically reconnected if certain conditions are satisfied. Control rules are proposed for all devices, and detailed microgrid operational modes and transition conditions are then discussed. Additionally, methods to determine control parameter settings are proposed. PSCAD/EMTDC simulation results demonstrate the performance and effectiveness of the proposed operational strategy and control method.

• Fire Science and Engineering
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• v.17 no.1
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• pp.68-75
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• 2003

Temporary constructions are defined as constructions for temporary use, but frequently they are used long like permanent constructions and connected with main constructions. In this case, fire hazardousness increase. But there is no way to control this hazard in our system. This study include investigation of present related law survey about sample complex, collection of related lawsuit result and estimation of hazardousness of each contemporary construction type. The conclusion is that the article that specify distance between main construction and temporary one should be created in the architectural law. Or to apply fire service law to area of temporary construction, fire service law should be changed properly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.854-861
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• 2003

In this paper, we proposed the fuzzy control algorithm for efficient buffer control about traffic that is connected in ATM networks. The proposed Fuzzy control algorithm has total traffic arrival ratio, buffer occupancy ratio and Fuzzy set to search for dynamic service rates in server. That is, is based on Fuzzy logic according to the arrival ratio of total traffic and buffer occupancy ratio that is happened and reasoning. Then, made reasoning result control service rates in server about traffic that is connected with defuzzification value. Performance analysis result: it was confirmed that with the proposed scheme, performance improves at cell loss rate, when compared with the existing PBS scheme.

• Healthcare Informatics Research
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• v.24 no.4
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• pp.387-393
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• 2018

Objectives: This paper describes an experience of implementing seamless service trials online and offline by adopting Internet of Things (IoT) technology based on near-field communication (NFC) tags and Bluetooth low-energy (BLE) beacons. The services were provided for both patients and health professionals. Methods: The pilot services were implemented to enhance healthcare service quality, improve patient safety, and provide an effective business process to health professionals in a tertiary hospital in Seoul, Korea. The services to enhance healthcare service quality include healing tours, cancer information/education, psychological assessments, indoor navigation, and exercise volume checking. The services to improve patient safety are monitoring of high-risk inpatients and delivery of real-time health information in emergency situations. In addition, the services to provide an effective business process to health professionals include surveys and web services for patient management. Results: Considering the sustainability of the pilot services, we decided to pause navigation and patient monitoring services until the interference problem could be completely resolved because beacon signal interference significantly influences the quality of services. On the other hand, we had to continue to provide new wearable beacons to high-risk patients because of hygiene issues, so the cost increased over time and was much higher than expected. Conclusions: To make the smart connected hospital services sustainable, technical feasibility (e.g., beacon signal interference), economic feasibility (e.g., continuous provision of new necklace beacons), and organizational commitment and support (e.g., renewal of new alternative medical devices and infrastructure) are required.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.590-598
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• 2016

It comes into the spotlight as the new Blue Ocean in which the connected car industry in which the car and mobile communication technology is convergence. All sorts of infortainments services connecting with the portable electronic device(Smart phone, tablet PC, and MP3 player) and car are rapidly grown. The Connected car emphasizes the vehicle connectivity with the concept that the car has communication with the around on a real time basis and it provides the safety and expedience to the operator and using the thing of Internet (IoT) in the car and supports the application, presently, the entertainment service including the real-time Navigation, parking assistant function, not only the remote vehicle control and management service but also Email, multimedia streaming service, SNS and with the platform. Intelligent vehicle network is studied as the kind according to MANET(Mobile Ad Hoc Network) for the safety operation of the cars of the road and improving the efficiency of the driving.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.211-215
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• 2015

It comes into the spotlight as the new Blue Ocean in which the connected car industry in which the car and mobile communication technology is convergence. All sorts of infortainments services connecting with the portable electronic device(Smart phone, tablet PC, and MP3 player) and car are rapidly grown. The Connected car emphasizes the vehicle connectivity with the concept that the car has communication with the around on a real time basis and it provides the safety and expedience to the operator and using the thing of Internet (IoT) in the car and supports the application, presently, the entertainment service including the real-time Navigation, parking assistant function, not only the remote vehicle control and management service but also Email, multimedia streaming service, SNS and with the platform. Intelligent vehicle network is studied as the kind according to MANET(Mobile Ad Hoc Network) for the safety operation of the cars of the road and improving the efficiency of the driving. The intelligent vehicle network is comprised for the driving information offering changing rapidly of the communication(V2V: Vehicle to Vehicle) between the car and the car, communication(V2I : Vehicle to Infrastructure) between the infrastructure and the car, and V2X (Vehicle to Nomadic).

• Journal of the Korean Society of Food Culture
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• v.22 no.5
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• pp.544-555
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• 2007

The purpose of this study is to provide useful information for establishing efficient marketing direction of globalization and commercialization of Korean foods by investigating the performance(satisfaction) and importance of food-coordinators' role. The results of the survey are summarized as follows: The most influential improvement variable of Korean food for globalization was 'hygiene'(23.6%) followed by 'taste', 'price', and 'shape and color'. Interest degree about food-coordinators showed 3.68 points in 5 points, and necessity of food-coordinators' job and education was 4.15 points. Food-coordinators' quality for globalization of Korean food was "a skill should be excellent"(4.51 points), "it must be original troubleshooting ability."(4.43 points) and "It must be professional ethics consciousness."(3.99 points) in the order. They were highly important of "freshness of food"(4.75 points) and "cleanliness of food and tableware" (4.65 points) in terms of the quality of korean food for globalization. The role importance of food-coordinators for globalization of Korean food was 'ability of development of Korean dish and Korean menu'(4.22 points), 'coordinate ability for various Korean special diet'(4.14 points) and 'knowledge for wann welcome service that consider table manners, service method and other person(4.12 points) in the order. The most influential unsatisfied variable of food coordinators' role was 'consulting ability connected with management of Korean restaurant' followed by 'ability of presenting concept connected with restaurant development of Korean style' and 'production ability for banquet party plan and representation in a Korean style'. In terms of IPA analysis on food-coordinators' role for globalization of korean food, it was noteworthy that items with high importance but low performance included "ability of development of Korean dish and Korean menu", "event coordinate ability connected with a Korean-style dish", and "production ability for banquet party plan and representation in a Korean style".

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.1
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• pp.74-87
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• 2011

This paper tried to research the relationship among the passenger's satisfaction and expectation of in-flight service quality, overall satisfaction and passenger's Loyalty by emphasizing on two groups of passengers and cabin crews from K-airline to find out which service quality area should be focused on for pursuing premium in-flight service. Such six service quality areas as in-flight equipment, food&beverage, duty-free sales, service ability, service image and specialized service were conceived and survey questions were made based on relevant previous researches. The analysis has used the data of 281 passengers and 336 cabin crews from K-airline. According to the analysis, in physical service factors, passengers perceive satisfaction from duty-free sales contributes to overall service satisfaction. However, cabin crews believed in-flight equipment and food&beverage are important to overall service satisfaction. In human service factors, both groups seemed to agree service ability and service image have a positive impact on overall service satisfaction. Among service satisfaction factors, the customer's satisfaction from cabin crew's service ability(service response, professional knowledge and foreign language skill) is also proven to be directly connected to customer loyalty.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1710-1716
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• 2016

In general, software upgrade technique is needed to add new features or fix bug of software on a network devices. However, the problem is that the software must be upgraded after the termination of networking service to replace new package. An ISSU(In-Service Software Upgrade) technique is used to solve such the problem. ISSU is a technology to upgrade the software without interrupting the network service or an offline network equipment. In this paper, to provide a seamless networking service, we design and implement an architecture to apply ISSU technique to a network operating system. In this paper, we use high-availability feature in N2OS which has been developed by ETRI. In addition, in order to verify that the implemented ISSU function is operation properly, we proceed to test using a test environment based on a virtual machine.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.3-13
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• 2014

This study as an exploratory study, investigates personal cloud service use which has been developed and distributed rapidly. Focusing on the user's characteristics and use behaviors, the influences of connected uses of platform and contents are empirically figured out. The results show that the contents which need small-data capacity like pictures and musics have been used very frequently in a cloud service. Second, 'platform-connected use' has been found out as the most influential factor in cloud service. SNS, e-mail, and personal innovativeness are also proved as significant factors. As a leading study analyzing theoretically the personal cloud service, it implies that it is necessary to consider the user's characteristics and use behaviors in developing cloud service in the market and making policy for promoting relevant industry.