• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.26-34
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• 2018

In this paper, we propose a scheduling scheme that can efficiently serve I/O requests having deadlines in flash storage. The I/O requests with deadlines, namely, real-time requests, are assumed to be issued for streaming services of continuous media. Since a Web-based streaming server commonly supports downloads of HTMLs or images, we also aim to quickly process non-real-time I/O requests, together with real-time ones. For this purpose, we adopt the well-known rate-reservation EDF (RR-EDF) algorithm for determining scheduling priorities among mixed I/O requests. In fact, for the use of an EDF-style algorithm, overhead of task's switching should be low and predictable, as with its application of CPU scheduling. In other words, the EDF algorithm is inherently unsuitable for scheduling I/O requests in HDD storage because of highly varying latency times of HDD. Unlike HDD, time for reading a block in flash storage is almost uniform with respect to its physical location. This is because flash storage has no mechanical component, differently from HDD. By capitalizing on this uniform block read time, we compute bandwidth utilization rates of real-time requests from streams. Then, the RR-EDF algorithm is applied for determining how much storage bandwidth can be assigned to non-real-time requests, while meeting deadlines of real-time requests. From this, we can improve the service times of non-real-time requests, which are issued for downloads of static files. Because the proposed scheme can expand flexibly the scheduling periods of streams, it can provide a full usage of slack times, thereby improving the overall throughput of flash storage significantly.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.57-66
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• 2010

In this paper, we propose the reliability constrained resource allocation scheduling algorithm in cellular network for uplink transmission, where uplink transmission is supported via packet switching schemes without the dedicated uplink circuit links. We evaluate the performance of the proposed algorithm, and compared with the conventional works to identify the pros and cons. The proposed uplink scheduling algorithm is to satisfy the constraints requirements of the MTC services which is considered as the core technology for future mobile wireless networks. It is different to conventional works which target to maximize the link capacity. The proposed algorithm provides reliable uplink transmission independent to the location and the quality of the wireless link of the mobile terminal. Based on the performance evaluation results, we conclude that the proposed method provides enhanced reliability performance than conventional works.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.47-54
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• 2015

With the spread of smart technology, in the personal and office equipment, many of the products are equipped with smart features. These changes have opened the era that can enforce the user's operation from a remote location. In this study, we design and implement a smart multi-plug system to make a multi-plug installed in the home can be operated anytime and anywhere via wireless network technologies add smart feature to a multi-plug that can be seen easily around us, it is intended to complement the limitations of traditional multi-plugs. The smart multi-plug proposed in this paper, by operating the plug remotely from smart devices at anytime and from anywhere, is possible to provide services required for the weak users such as elderly and children, it is expected that the proposed system are widely used in the various areas requiring remote control of the power supply including u-Farming, terrarium, and smart home, and so on.

• Korean Journal of Clinical Pharmacy
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• v.24 no.4
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• pp.272-281
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• 2014

Objective: The provision of pharmaceutical care service in compliance with good pharmacy practice (GPP) standards is important, but there is lack of studies to investigate the barriers that significantly hinder community pharmacies in Korea from adhering to the standards. This study was aimed to identify the major barriers to provision of pharmaceutical care service in compliance with the proposed pharmacy practice standards which have been developed based on the GPP standards recommended jointly by WHO and FIP. Methods: Questionnaires reviewed by the expert committee were posted for 32 days on the website which is most frequently accessed by community pharmacists. The respondents completed them by checking the scores (Max=5, Min=1) for major barriers to provision of pharmaceutical care service focusing on patient information management and drug use review process in prescription fillings. The answered scores were automatically collected using online data processing. Mean differences between scored data were assessed by ANOVA. Results: Total 321 pharmacists participated in the survey. Results indicated that 'difficulty of diagnosis identification' (m=3.92, SD=1.21), 'lack of time' (m=3.48, SD=1.22) and 'lack of updated clinical information' (m=3.17, SD=1.10) were the major barriers to provision of pharmaceutical care service in patient information management. The main barriers to drug utilization review were 'lack of time' (m=3.32, SD=1.21), 'lack of updated clinical information' (m=3.11, SD=1.17), and 'negative feedbacks or refusals from prescribers' (m=3.00, SD=1.38). There were significant differences among the groups by location, employed number of pharmacists and acceptability to the proposed GPP standards. Conclusion: Difficulties in managing patient clinical information and lack of time were found to be the major barriers in providing pharmaceutical care services in community pharmacies in Korea. Further research is recommended to determine ways to reduce these barriers in order to provide quality pharmaceutical care service that is in compliance with the internationally recognized GPP guidelines.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.529-540
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• 2015

The NGN should support an ubiquitous environment in which users can use multiple devices. Especially, services should be provided to users in a seamless manner across multiple devices which are dynamically found in users' vicinity. Therefore, supporting service continuity is essential in the NGN. Currently the IMS, which is a session control layer for the NGN, deals with session control procedures in detail for service continuity. However, the IMS provides limited methods how users can find target terminals for transferring the session. The target terminals tend to be located near in user's physical location, and could be shared among different users. For providing better service experience in the NGN, The NGN needs to encompass methods to enable for users to use the dynamically-found terminals in users' vicinity seamlessly. In this paper, we introduce a novel registration method based on virtual ISIM by which the target terminals in user's vicinity can register themselves to the IMS, and also we discuss how service continuity is supported.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.411-413
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• 2010

The wireless AP positioning system is under active progress regarding research and commercialization due to its merit of being able to overcome the representing demerits of existing GPS positioning, which are signal distortion and poor signal reception. This system's feature is to collect AP information distributed throughout the real world, store it on database, and execute positioning by comparing with searched AP information. The positioning process uses collected data, whereas comparison of database data uses the fingerprinting method. The fingerprinting method is a probabilistic modeling method that acquires as much of the data collected from one location upon database composition, to store the value's average value and use it in positioning. Yet, using the average value may contain the probability of errors. Such errors are fatal weaknesses for services based on the background of accurate positioning. This paper deals with the characteristics and problems of the previously used wireless AP positioning system, and proposes measures of using AP information for outdoor positioning in order to solve the aforementioned problems.

• Journal of KIISE
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• v.42 no.5
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• pp.652-663
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• 2015

Due to the popularity of location-based services, the amount of generated spatial data in daily life has been dramatically increasing. Therefore, spatial database outsourcing has become popular for data owners to reduce the spatial database management cost. The most important consideration in database outsourcing is meeting the privacy requirements and guarantying the integrity of the query result. However, most of existing database transformation techniques do not support both of the data privacy and integrity of the query result. To solve this problem, we propose a spatial data transformation scheme that utilizes the shearing transformation with rotation shifting. In addition, we described the attack models to measure the data privacy of database transformation schemes. Finally, we demonstrated through the experimental evaluations that our scheme provides high level of data protection against different kinds of attack models, compared to the existing schemes, while guaranteeing the integrity of the query result sets.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.57-67
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• 2015

A large amount of work has been done in the areas of routing, MAC, QoS, capacity, location service, cooperative communication, fault tolerance, mobility models and various applications of mesh networks thanks to their merits of cost-effective way of deployment and flexibility in extending wireline services. Although multi-path routing protocols have been proposed to be used to provide QoS and fault-tolerance, there has not been any significant results discussed that support both in the literature to our best knowledge as they are often required in military and public safety applications. In this paper, we present a novel routing protocol for a mesh network based on the OFDM-TDMA collision-free MAC that discovers and maintains multiple paths that allows retransmitting and forwarding packets that have been blocked due to a link failure using an alternative next-hop node such that the delay-capacity tradeoff is reduced and the reliability is enhanced. Simulation results show that the proposed protocol performs well in terms of both the QoS and delivery ratio.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.31-37
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• 2021

Recently, in the market of home appliances, the technical differentiation of products using convergence technology has been receiving a lot of response to satisfy consumer demand. However, air-conditioner products are an area that requires research and development in the early stages of convergence technology. In this paper, it is developed that a non-contact bio-signal(respiration, movement) collection technology using IR-UWB(Impulse-Radio Ultra Wideband) technology, which controls the air-conditioner direction according to the user's location and also monitors sleep to provide an optimal sleep environment. In addition, emotional lighting and ASMR are developed to provide a comfortable and emotional place of life. Finally, based on the developed convergence technology, we develop intelligent smart air-conditioning services for the convenience of daily life and a comfortable resting space.

• Korea Journal of Hospital Management
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• v.23 no.4
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• pp.40-52
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• 2018

The purpose of this study is to identify medical consumers' hospital selection factors in response to the rapidly changing environment of medical industry. For that purpose this study classified consumers' hospital selection factors into three categories such that human factors including expertise, reliability, empathy; system factor including, convenience, differentiation, efficiency; and facility factor including tangibility, accessibility, and location, based on the previous studies and the results of a preliminary survey of the patients of a small private hospital. The nine factors were further divided into 23 more specific attributes. Then, an online survey was conducted to measure the perceptions of the 23 attributes by the medical consumers over the age of 20. The analysis of the survey data using Kano model and Timko model indicated that 14 of the 23 attributes were classified as attractive factors, eight attributes were or classified as, one-dimensional factors, and one attribute, doctors' educational background, was classified as indifference factor. Of the 14 attractive factors, "unique and differentiated services related to medical treatment" and "distance from home to hospital" had the highest customer satisfaction coefficients. Of the eight one-dimensional factors, "kind treatment," "providing adequate explanations," "accuracy of diagnosis," and "cleanness of facilities" had the highest customer satisfaction coefficients as well as the highest dissatisfaction coefficients. The findings indicate that these six attributes are the most basic and most impactful attributes that hospitals must manage strategically to improve their service quality and attract more medical consumers to their hospitals.