• The Transactions of the Korea Information Processing Society
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• v.4 no.8
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• pp.2070-2079
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• 1997

In this paper, we proposed the FNCAC (fuzzy neural call admission control) scheme of the ATM networks which used the benefits of fuzzy logic controller and the learning abilities of the neural network to solve the call admission control problems. The new call in ATM networks is connected if QoS(quality of service) of the current calls is not affected due to the connection of a new call. The neural network CAC(call admission control) system is predictable system because the neural network is able to learn by the input/output pattern. We applied the fuzzy inference on the learning rate and momentum constant for improving the learning speed of the fuzzy neural network. The excellence of the proposed algorithm was verified using measurement of learning numbers in the traditional neural network method and fuzzy neural network method by simulation. We found that the learning speed of the FNCAC based on the fuzzy learning rules is 5 times faster than that of the CAC method based on the traditional neural network theory.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8800-8811
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• 2015

When the crucial role of the agent in communicating with the customer is acknowledged well enough to relieve the agent's stress, it will lead to the decrease of the agent's emotional labor and the improvement of the business organization's performance simultaneously. However, the research on the relationship between information system and the emotional labor has been scarcely conducted even though the importance of the emotional labor is actively researched and discussed these days. Therefore, much effort has been put in this study to fine out how the quality of airline call center information system affects expectations-conformation and how expectations-conformation and self-efficacy affect performance of Emotional Labors. Analysis of the results to target a call center agent 436 people, When you provide them with quality information systems, it increased satisfaction and pride in their job. This mechanisms subsequently reduces the strength of the emotion labor, which ultimately improves the service performance. The implications of this study can be summarized as following: First, this research presented practical guidelines to the organization's decision-makers related to the airline call center operations in order to introduce and expand successful call center information system. Second, this research suggested the possible method to inspect and diagnose the system by way of applying the measurement model mentioned in this research into the airline information system and analyzing it. Third, the performance-measuring model developed in order to measure the performance of the airline call center information system can also be used when we carry out the performance-measuring task in the similar information system as the basis of diagnosing the situation and presenting the driving directions.

• Journal of Korean Society for Quality Management
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• v.3 no.2
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• pp.16-22
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• 1969

• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.461-473
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• 2003

Multimedia applications are much more sensitive to QoS(Quality of Service) than text based ones due to their data continuity. In order to provide a fast moving MH(Mobil Host) using multimedia application with a consistent QoS,an efficient call admission mechanism is in need. This paper proposes the 2SCA(2-Step Call Admission) scheme based on cal admission scheme using pripority to guarantee the consistent QoS for mobile multimedia applications. A calls of MH are classified new calls, hand-off calls, and QoS upgrading calls. The 2SCA is composed of the basic call admission and advanced call admission; the former determines the call admission based on bandwidth available in each cell and the latter determines the call admission by applying DTT(Delay Tolerance Time), PQeueu(Priority Queue), and UpQueue(Upgrade Queue) algorithm according to the type of each call blocked at the basic call admission stage. In order to evaluate the performance of our mechanism, we measure the metrics such as the dropping probability of new calls, dropping probability of hand-off calls, and bandwidth utilization. The result shows that the performance of our mechanism is superior to that of existing mechanisms such as CSP(Complete Sharing Policy), GCP(Guard Channel Policy) and AGCP(Adaptive Guard Channel Policy).

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.927-934
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• 2002

In order to provide various multimedia services in a wireless network, the call admission control for wireless channels should be resolved at the time of call setup and handoff by moving mobile terminal. In this paper. we propose a reliable DCAC( Distributed Call Admission Control)scheme using virtual cluster concept. The proposed DCAC scheme considers the state of $1^{st}$ and $2^{nd}$ adjacent cells to provide a reliable call handling. The proposed scheme is analyzed by simulations and mathematical methods.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.4
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• pp.445-459
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• 2008

This paper addresses a call admission control(CAC) scheme giving handoff calls a priority over new calls for OFDMA wireless communication systems. The characteristics of OFDMA system and a variety of user QoS (Quality of Service) requirements are incorporated into the proposed CAC scheme which consists of several optimization modules for the system resource(subcarriers and power) allocations. The mathematical models and its solution methods for the embedded resource allocation problems are proposed. Some extensive computational experiments are conducted to illustrate the superiority of our CAC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1282-1289
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• 2000

In this paper we propose a Fractional Channel Reservation (FCS) scheme to satisfy a desired handoof dropping probability and to reduce the blocking probability of new calls using mobility characteristics and incoming handoff rate in mobile communication networks. When the ratio of the handoff call arrival rate is less then the ratio of the new call arrival rete, the proposed scheme is capable of determining the number of the guard channels which can guarantee the Quality of Service(QoS) in terms of the request handoff dropping probability and allocating dynamically the wireless channels the new calls according to the rest of the guard channels to reduce the new call blocking probability. Also we perform mathematical analysis and simulation to evaluate the performance of proposed scheme and compare to conventional guard channel scheme in terms of dropping probability blocking probability and the utilization efficiency of wireless channels.

• Journal of Korean Institute of Industrial Engineers
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• v.29 no.4
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• pp.312-320
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• 2003

Recently there is a growing interest in mobile cellular network providing multimedia service. However, the link bandwidth of mobile cellular network is not sufficient enough to provide satisfactory services to users. To overcome this problem, an adaptive framework has been proposed. In this study, we propose a new method of estimating DPR(Degradation Period Ratio) in an adaptive multimedia network where the bandwidth of ongoing call can be dynamically adjusted during its lifetime. DPR is a QoS(Quality of Service) parameter which represents the ratio of allocated bandwidth below a pre-defined target to the whole service time of a call. We improve estimation method of DPR using DTMC(Discrete Time Markov Chain) model by calculate mean degradation period, degradation probability more precisely than in existing studies. Under Threshold CAC(Call Admission Control) algorithm, we present analytically how to guarantee QoS to users and illustrate the method by numerical examples. The proposed method is expected to be used as one of CAC schemes in guaranteeing predefined QoS level of DPR.

• The Korean Journal of Emergency Medical Services
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• v.24 no.2
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• pp.67-77
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• 2020

Purpose: The study aims to improve the quality of emergency medical services by surveying the user's satisfaction of 119 emergency medical services nationwide. Methods: From December 21 to December 27 each year from 2015 to 2017 a total of 5,889 people were surveyed by phone call in fire station. Results: The average degree of satisfaction with the emergency medical services was 4.17±0.70, with 85.1% respondents reporting being 'satisfied'. Factors like being a patient, injuries, residential area, and scene arrival time affected satisfaction. From 2015 to 2017, the satisfaction degree decreased every year, with factors affecting this results including "first aid guidance of phone call" and "rapidity of emergency medical services." The highest satisfaction factors were 'friendly acting of emergency medical services' and 'appropriate offer of emergency medical services', while the lowest satisfaction factors were 'first aid guidance of phone call' and 'adequacy of emergency medical team'. Conclusion: The quality of emergency medical services needs to be improved by managing the quality of phone call first aid guidance and the assignment of adequate emergency medical teams to increase user satisfaction.

• Journal of Agricultural Extension & Community Development
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• v.15 no.3
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• pp.461-497
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• 2008

The objective of the study was to evaluate the impact of the Call System of agricultural extension services in Korea. The respondents were satisfied on the speedy solution (74.5%), consultation (88.4%), and accessibility (79.7%) of the call system. However, satisfaction of farmers on in-depth consultation was higher (74.3%) than the satisfaction rated by the public servants of RDA (48.9%). Both groups replied positively (70.4%) on the need for expansion of the call system. The analyses of the results leads to a conclusion that there is a need to increase marketing on the importance of RDA's Call System to customers of agricultural extension and to improve accessibility through expansion of the system in other areas. These could solve the decreasing number of extension professionals and improve the quality and efficiency of extension services. These analyses may be useful as bases for a nationwide Call System that connects the center with other districts and for planning a renovation of information-oriented agricultural extension services. The issue that needs improvement is to abandon the grounds of agricultural technology information provider and respond to the customers' needs efficiently by building an established Call System which can minimize the side effect of the trends of reforming and downsizing the organization. It is needed to develop a unified management Call System of agricultural technology information that could provide real-time information, and database the results simultaneously for use as feedback to the Rural Development Programs. Related laws and policies need to be improved to establish a nationwide information network that maximizes the current network in agricultural regions to spread information, to provide institutional support, and to encourage development of training system and research and development by concerned institutes.