• Journal of Information Processing Systems
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• v.13 no.3
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• pp.546-558
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• 2017

The amount of multimedia traffic over the Internet has been increasing because of the development of networks and mobile devices. Accordingly, studies on multicast, which is used to provide efficient multimedia and video services, have been conducted. In particular, studies on centralized multicast tree construction have attracted attention with the advent of software-defined networking. Among the centralized multicast tree construction algorithms, the group Takahashi and Matsuyama (GTM) algorithm is the most commonly used in multiple multicast tree construction. However, the GTM algorithm considers only the network-cost overhead when constructing multicast trees; it does not consider the temporary service disruption that arises from a link change for users receiving an existing service. Therefore, in this study, we propose a multiple multicast tree construction algorithm that can reduce network cost while avoiding considerable degradation of service quality to users. This is accomplished by considering both network-cost and link-change overhead of users. Experimental results reveal that, compared to the GTM algorithm, the proposed algorithm significantly improves the user-experienced quality of service by substantially reducing the number of linkchanged users while only slightly adding to the network-cost overhead.

• The Journal of Korean Academic Society of Nursing Education
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• v.22 no.4
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• pp.559-566
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• 2016

Purpose: This study aimed to examine the communication styles and nursing service satisfaction of clinical research nurses perceived by clinical subjects. Methods: The data were collected with self-administrated questionnaires after receiving consents from 200 clinical trial subjects. The data were analysed with descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients and stepwise multiple regression analysis using SPSS 21.0 statistic program. Result: Clinical subjects perceived that clinical research nurses used the informative, affective, and non-authoritative communication styles. The study identified factors influencing the nursing service satisfaction, and they were the informative communication styles (${\beta}$=.34, p<.001) and affective communication styles (${\beta}$=.35, p<.001, $R^2$=37%) by multiple linear regression. Conclusion: If educational programs on communication are developed to help clinical research nurses use the informative and affective communication styles according to the characteristics of subjects and applied to the field of practice, they will be able to increase the nursing service satisfaction and contribute to the higher quality of clinical trials.

• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.75-83
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• 2005

The purpose of this study was to investigate the antibiotic resistance pattern of E. coli and Salmonella spp. isolated from chicken feces. One hundred and forty-seven E. coli isolates showed resistance to tetracycline (95.2%), erythromycin (89.2%), ampicillin (70.1%), streptomycin (59.2%), cephalothin (56.5%), sulfamethoxazole/trimethoprim (53.7%), ciprofloxacin (57.1%), enrofloxacin (59.2%) and norfloxacin (57.1%). The multiple resistance was seen in 144 isolates (97.9%) and the rate of five, six and seven drugs resistance pattern were 20.4%, 18.4% and 16.3%, respectively. Also, the multiple resistance of E. coli to twelve drugs were seen in 1 isolates (0.7%). Fourteen Salmonella spp. showed resistance to ampicillin (50.0%), streptomycin (57.1%), erythromycin (64.3%) and tetracycline (57.1%) and the rate of two and three drugs resistance pattern were 4 isolates (28.6%), respectively. The prevalence of resistant organisms in Korea probably reflects lack of proper antibiotic policy resulting in prolonged and indiscriminate use of antimicrobial agents.

• Journal of Communications and Networks
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• v.13 no.2
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• pp.160-166
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• 2011

In u-healthcare services based on wireless body sensor networks, reliable connection is very important as many types of information, including vital signals, are transmitted through the networks. The transmit power requirements are very stringent in the case of in-body networks for implant communication. Furthermore, the wireless link in an in-body environment has a high degree of path loss (e.g., the path loss exponent is around 6.2 for deep tissue). Because of such inherently bad settings of the communication nodes, a multi-hop network topology is preferred in order to meet the transmit power requirements and to increase the battery lifetime of sensor nodes. This will ensure that the live body of a patient receiving the healthcare service has a reduced level of specific absorption ratio (SAR) when exposed to long-lasting radiation. We propose an efficientmethod for delivering delay-intolerant data packets over multiple hops. We consider forward error correction (FEC) in an erasure correction mode and develop a mathematical formulation for packet-level scheduling of delay-intolerant FEC packets over multiple hops. The proposed method can be used as a simple guideline for applications to setting up a topology for a medical body sensor network of each individual patient, which is connected to a remote server for u-healthcare service applications.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.6
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• pp.659-664
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• 2006

The Context-Aware system is the core technology in the Ubiquitous Computing Environment. Recently, the practical use of a sensor is magnified and the application fields of it are gradually extended in order to collect necessary context information. Context-Aware service integrates the context information which is collected by sensors, and then provides, a suitable service to a user through the process of analysis and reasoning. This service is studied in a variety of fields such as marketing, medical treatment, education and so on. In this paper, we analyze the method of recognizing surrounding context and the result of the awareness by using differential and structural property of multiple valued logic function; propose the model that provides appropriate service depending on the change of surrounding contort; confirm the applicability of the Context-aware system by showing the example of application.

• Journal of Korean Critical Care Nursing
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• v.14 no.3
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• pp.50-61
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• 2021

Purpose : This study aimed to identify the moderating and mediating effects of resilience on the relationship between role conflict and job satisfaction among nurses working in a comprehensive nursing care service ward. Methods : Participants were 130 comprehensive nursing care service ward nurses from four hospitals. Data were collected using structured questionnaires and analyzed by t-test, ANOVA, Scheffe test, Pearson correlation coefficients, and hierarchical multiple regression analysis, using SPSS 25.0. The mediating effect of resilience on the relationship between role conflict and job satisfaction was analyzed using multiple regression analysis according to Baron and Kenny's procedure. Results : Statistically significant negative correlations were found between role conflict and resilience (r=-.25, p<.007) and between role conflict and job satisfaction (r=-.38, p<.001). A significant positive correlation was found between resilience and job satisfaction (r=.54, p<.001). A partial mediating effect of resilience was found between role conflict and job satisfaction (Z=-2.53, p=.012) but no moderating effect was found. Conclusion : To improve the job satisfaction of comprehensive nursing care service ward nurses, interventions for alleviating role conflict and improving resilience as well as evaluations of the two variables are necessary.

• Asia-Pacific Journal of Business
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• v.12 no.1
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• pp.87-100
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• 2021

Purpose - This study aims to examine the antecedents of willingness to pay in the domain of duty free shop. Design/methodology/approach - This study chooses willingness to pay as explained variable. The candidates of explanatory variables are price fairness, brand awareness, employee service, product diversity, and crowding. This study uses survey to explore the linear relation between variables. This research collected data using online panel data collection service. The number of valid observation is 265. The research targe is Lotte duty free store. Statistical analysis was for statistical inference. To attain the information of survey respondents, frequency analysis is employed. Next, this study implemented exploratory factor analysis and reliability to ensure both validity and reliability of measurement items. This study executed multiple regression analysis to test research hypotheses Findings - Regrading results, brand awareness, employee service, and product diversity are positively associated with willingness to pay of duty free shop product. Moreover, the results of regression analysis suggest the inverted-U shape association between crowding and willingness to pay. However, price fairness appeared as non-significant variable to account for willingness to pay in the multiple regression analysis. Originality - This study contributes to the literature by examining duty free shop customers more.

• Journal of Communications and Networks
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• v.8 no.4
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• pp.401-409
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• 2006

Orthogonal frequency division multiplexing (OFDM) and multiple input multiple output (MIMO) technologies provide additional dimensions of freedom with spectral and spatial resources for radio resource management. Multi-dimensional radio resource management has recently been identified to exploit the full dimensions of freedom for more flexible and efficient utilization of scarce radio spectrum while provide diverse quality of service (QoS) guarantees. In this work, a multi-dimensional radio resource scheduling scheme is proposed to achieve above goals in hybrid orthogonal frequency division multiple access (OFDMA) and space division multiple access (SDMA) systems. Cochannel interference (CCI) introduced by frequency reuse under SDMA is eliminated by frequency division and time division between highly interfered users. This scheme maximizes system throughput subjected to the minimum data rate guarantee. for heterogeneous users and transmit power constraint. By numerical examples, system throughput and fairness superiority of the our scheduling scheme are verified.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.1-8
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• 2006

In ubiquitous environments, recommendation service based on multiple contexts is required. The total amount of information is larger due to the greater number of contexts in multiple context environments. This paper proposes a new effective recommendation method adaptive to multiple contexts in ubiquitous environments. A new method of recommendations in multiple context environments is suggested that uses user's preferences and behavior as a weighting factor. This paper describes the recommendation method, scenario and the experimental results. The results verify that the proposed method's recommendation performance is better than other existing method.

• Korean journal of food and cookery science
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• v.29 no.5
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• pp.605-616
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• 2013

A multistage approach for service recovery enables restaurant managers to do the most effective recovery strategies to reduce customer dissatisfaction and lead to positive behavioral intentions. The purpose of this study was to identify the most effective service recovery strategies in terms of service stage and examine the relationship between service strategies and behavioral intentions. A total of 227 diners examined the customer perceptions to recovery strategies (tangible strategy and intangible strategy) following service failures in each of the four stages:1) reservation and parking, 2) seating and ordering, 3) meal consumption, and 4) payment and exit. The one-way ANOVA showed that intangible strategies were relatively more effective than tangible strategies regardless of service stages. Free meal or free dessert were most effective in service stage 1 and stage 2 whereas correct the failure and reperformance of service found to be the most effective service recovery strategy. Regarding the association between service recovery strategies and behavioral intentions, multiple regression analysis showed that intangible strategies influenced diners' likelihood of positive behavioral intentions whereas tangible strategies lead to diners' willingness to positive behavioral intentions only in service stage 1. The findings enable restaurant practitioners to improve service recovery activities from a service stage perspective.