• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.49-60
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• 2003

In this paper, we study the joint design of sampling inspections and service capacities for multi-products. Products of different defect rates which are either deterministic or random variables are supplied in batches after sampling inspection and rework. When supplied, all defective products that have not been inspected in batches are uncovered through total inspection and returned to service. We identify the optimal inspection policies and service capacities for multi-products reflecting the relationships between inspection rework costs and service provision costs. We also develope a marginal allocation algorithm for the optimal allocation of the limited total service capacity to products as well as inspection quantities.

• Journal of Communications and Networks
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• v.11 no.1
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• pp.36-41
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• 2009

The IEEE 802.16 wireless metropolitan area network (WMAN) standard is designed to correct expensive communication costs in CDMA-based mobile communication systems and limited coverage problems in wireless LAN systems. Thus, the IEEE 802.16e standard can provide mobile high-speed packet access between mobile stations and the Internet service provider through the base station with cheap communication fees. To efficiently accommodate voice over IP (VoIP) services in IEEE 802.16 systems, an uplink quality of service packet-scheduling scheme is proposed, and its performance is evaluated with an NS-2 network simulator in this paper. Numerical results show that this proposed scheme can increase the system capacity by 100% more than in the unsolicited rand service (UGS) scheme and 30% more than the extended real-time polling service (ertPS) scheme, respectively.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.524-529
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• 1989

In this paper, an approximate sojourn time distribution is obtained for cyclic service systems. We consider symmetric and limited service systems in which each queue has an infinite capacity. The combined service time is defined which consists of the frame service time and server waiting time that is approximated by two cases of the uniform and exponential distributions. The approximate sojourn time distribution is obtained from the Pollaczek-Khinchine formula where the combined service time is used for the service time in the M/G/I model. And some numerical examples are given to validate the suggested approximate analysis.

• Fashion & Textile Research Journal
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• v.14 no.3
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• pp.413-422
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• 2012

This study is to verify the influence of salesperson's nonverbal communication on consumer emotions, and service quality in fashion shopping. This study sample is limited to Busan and Kyungnam Province's fashion shopping consumers. The responders included 239. Data were analyzed by frequency, factor analysis, and AMOS. As the results, kinesics, proxemics, paralanguage, and physical appearance are a major influence on positive consumer emotions that influence service quality. Kinesics and proxemics are a major influence on negative consumer emotions; however, paralanguage, and physical appearance are not a major determinant to influence negative consumer emotions; in addition, there is a direct link between negative consumer emotions and service quality. Also, consumer emotions mediated the relationship between nonverbal communication and service quality. Therefore, fashion firms should train employee manners to ensure that nonverbal communication is important in service encounters.

• Culinary science and hospitality research
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• v.3
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• pp.315-326
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• 1997

The school catering service has gained national attentions and has been expanding unto high schools after offering meals at elementary schools over years. This study is to identify problems and solutions in kitchen hardware areas to provide nutritiously balanced meals to schoolchildren through establishing standard menu planning. The survey analysis shows that 59.2% of dishes except for rice, Kimchi and soup are prepared by oil deep-fired or oil pan broiled. This indicates that school meals are so limited to serve baked or steamed dishes. Main reasons on the limited menu selection is that schools don't have equipment to prepare baking and steaming dishes mainly due to budget issues. All the dietitians who answered the surveys have been requesting to purchase Convotherm Ovens. Improvement solutions to the problems are: Publish the Revised Standard Equipment Layout that may allow to serve baked and steamed dishes. Establish Budget Support Program from the Government.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.262-267
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• 2001

In this study, the Reliability of degraded steam turbine blade was evaluated using the limited fatigue data. The statistical estimation of limited fatigue data implies that some unknown uncertainties which may be involved in fatigue reliability analysis. Therefore, an appropriate distribution in the fatigue strength was determined by the characteristic distribution - linear correlation coefficient, fatigue physics, error parameter. 3-parameter Weibull distribution is the most appropriate distribution to assume for infinite region. The load applied on the blade is mainly tensile. The maximum Von-Mises stress is 219.4 MPa at the steady state service condition. The failure probability($F_p$) derived from the strength-stress interference model using Monte carlo simulation under variable service condition is 0.25% at the 99.99% confidence level.

• Journal of the Korean Statistical Society
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• v.30 no.4
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• pp.661-666
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• 2001

In this paper we consider an M/G/1 queue where the server of the system has a vacation time and the service policy is limited-1. In this system, upon termination of a vacation the server returns to the queue and serves at most one message in the queue before taking another vacation. We consider two models. In the first, if the sever finds the queue empty at the end of a cacation, then the sever immediately takes another vacation. In the second model, if no message have arrived during a vacation, the sever waits for the first arrival to serve. The analysis of this system is particularly useful for a priority class polling system. We derive Laplace-Stieltjes transforms of the waiting time for both models, and compare their mean waiting times.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.10
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• pp.1733-1750
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• 2011

In the early stages of a software project, it is critical to understand the needs of the customers and elicit their customer requirements. Various requirements elicitation methods have been proposed. However, existing methods still have the limitations such as a limited number of target customers, limited expression of customers' opinions, and difficulty in collecting the customers' opinions continuously. A novel method for eliciting customer requirements is proposed by utilizing a social network service (SNS), which is a shared source of raw information of the customers' needs and opinions. The proposed method is validated to show its effectiveness in overcoming the limitations of existing methods.

• Journal of information and communication convergence engineering
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• v.13 no.1
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• pp.15-20
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• 2015

The limited battery power in the mobile environment, lack of sufficient wireless bandwidth, limited resources of mobile terminals, and frequent breakdowns of the wireless network have become major hurdles in the development of mobile cloud computing (MCC). In order to solve the abovementioned problems, This paper propose a proxy-based MCC framework by adding a proxy server between mobile devices and cloud services to optimize the access to cloud services by mobile devices on the network transmission, application support, and service mode levels. Finally, we verify the effectiveness of the developed framework through an experimental analysis. This framework can ensure that mobile users have efficient access to cloud services.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.4177-4190
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• 2015

Current research on Internet of Things (IoT) has primarily addressed the means to enhancing smart resource allocation, automatic network operation, and secure service provisioning. In particular, providing satisfactory security service in IoT systems is indispensable to its mission critical applications. However, limited resources prevent full security coverage at all times. Therefore, these limited resources must be deployed intelligently by considering differences in priorities of targets that require security coverage. In this study, we have developed a new application of Cognitive Radio (CR) technology for IoT systems and provide an appropriate security solution that will enable IoT to be more affordable and applicable than it is currently. To resolve the security-related resource allocation problem, game theory is a suitable and effective tool. Based on the Blotto game model, we propose a new strategic power allocation scheme to ensure secure CR communications. A simulation shows that our proposed scheme can effectively respond to current system conditions and perform more effectively than other existing schemes in dynamically changeable IoT environments.