• YAKHAK HOEJI
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• v.44 no.1
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• pp.41-46
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• 2000

Phytochemical examination of the leaves of Alnus maximowiczii Call, one of the indigenous Alnus species grows in Korea, has led to the isolation of three flavonoids. Structure of these flavonoids were elucidated as quercetin-3-O-$\beta$-D-glucopyranoside (1) , quercetin-3-O-$\alpha$-L-rhamnopyranoside (2) and myricetin-3-O-$\alpha$-L-rhamnopyranoside (3) respectively by means of physico-chemical and spectral evidences.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.67-74
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• 2009

This paper presents a method of improving the service availability by distributing the traffic of voice/data calls over the multi-layer cells in a mobile communication network. The traffic model is described and the call handling performance is analyzed. In our method, a fast moving call is moved to and serviced in the upper layer cell. A call is also moved upward when an overflow occurs. But unlike other methods, the call that is moved upward in the overflow case is the one which has the longest sojourn time in the cell. Moreover, when the call that was moved upward due to overflow condition stays longer than a certain period of time in the upper layer cell, the system moves the call back to the lower layer in order to save the more expensive resources of the upper layer cell. Call handling performance of this method evaluated from M/M/C/K models shows clear improvement with respect to call blocking probability and forced termination probability.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.6
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• pp.361-361
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• 2000

In this paper, we propose a novel control signaling protocol that efficiently controls connection setup and increases the utilization of network resources. The proposed protocol, Separated Control Signaling Protocol(SCSP), separates bearer control from call control lot WDM optical networks. The main function of call control is to check the availability of network resources such as wavelengths and receivers at destination node. Bearer control is to reserve and assign wavelengths. The signaling architecture of this protocol consists of call controller and hearer controller The call controller handles call setup and release, activates the beater controller, and manages the status of call and bearer. The bearer controller reserves wavelengths, sets up bearer, tears down bearer. and notifies the status of beater to call controller. The state transition diagrams of each controller are designed. Using control messages and related primitives, the information flows for call setup and bearer setup, hearer teardown and call release, and reaction for setup failures are described to evaluate the performance. The simulation results show that the separated control signaling protocol is superior to conventional one in terms of call blocking probability and resource utilization.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.111-116
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• 2016

According to the Ministry of Science, ICT and Future Planning's survey of information gap, smartphone retention rate of disabled people stayed in one-third of non-disabled people, the situation is significantly less access to information for people with disabilities than non-disabled people. In this paper, we develop an application, CallHelper, that helps to be more convenient to use mobile voice calls to the auditory disabled people. CallHelper runs automatically when a call comes in, translates caller's voice to text output on the mobile screen, and displays the emotion reasoning from the caller's voice to visualize emoticons. It also saves voice, translated text, and emotion data that can be played back.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.1189-1192
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• 2003

초기 콜 센터는 단순히 고객에게 걸려오는 전화를 응대하는 서비스 수준으로 시작되었지만, 현재는 고객과 마주하는 최 접점으로 서비스 뿐만 아니라 마켓팅, 세일즈를 행하는 기업의 경쟁력을 유지하는데 있어 필수적인 요소로 자리잡아 가고 있다. 특히 개인고객을 많이 접하는 금융기관에서는 콜 센터를 대형화, 지방 분산화 및 백업체제 구축을 위한 Multi 센터를 구축하여 콜만 처리하는 센터로서가 아니라 다양한 채널[전화,email,fax,chating]를 통해 접속되는 고객요구 사항들을 통합된 인프라에서 One Stop 으로 처리하고자 한다. 하지만 회선 교환망을 이용하는 PBX기반 Voice 회선과 IP 환경의 DATA 를 처리하는 이원화된 구조로 Multi 콜 센터를 구축 할 경우, 타 센터의 상담원에게로 콜을 설정시 시간이 많이 소요되어 센터간 Call Load Balancing 및 상담원 Skill Based Routing 을 수행함이 어렵다는 단점이 있다. 본 논문에서는 이러한 단점을 개선할 수 있는 방안으로 Voice 와 Data 를 IP 기반 단일 망으로 구성하고 WAN상에서 음성을 전달할 때 적정한 MOS(Mean opinion score)를 측정 후 객관적으로 필요한 Bandwidth 를 검증하고 Muti 콜 센터에서 효과적인 콜 load Balancing 및 Routing을 할 수 있는 VOIP기반 Convereed Virtual Call Center Architecture 설계 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2184-2196
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• 1998

Admission control is one of the most important congestion control mechanism to be executed at the call set up phase by regulating traffic into a network in a preventive way. An efficient QOS evaluation or bandwidth estimation method is required for call admission to be decided in real time. In this paper, we spropose a computtionally simple approximation method of estimating cell loss probability and mean cell delay for admission control of both delay sensitive and loss sensitive calls. Mixed input queueing system, where a new call combines with the existing traffic, is used as a queueing model for QOS estimation. Also traffic parameters are suggested to characterize both a new call and existing traffic. Aggregate traffic is approximated by a renewal process with these traffic parameters and then mean delay and cell loss probability are detemined using appropriate approximation formulas. The accuracy of this approximation approach is examined by comparing their results with exact analysis or simulation results of vrious mixed unput queueing systems. Based on this QOS estimation method, call admission control scheme which is traffic independent and computable in yeal time are proposed.

• Journal of IKEEE
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• v.27 no.1
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• pp.93-102
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• 2023

As one of the techniques for analyzing malicious code, techniques creating a sequence or a graph of function call relationships in an executable program and then analyzing the result are proposed. Such methods generally study function calling in the executable program code through static analysis and organize function call relationships into a sequence or a graph. However, in the case of an obfuscated executable program, it is difficult to analyze the function call relationship only with static analysis because the structure/content of the executable program file is different from the standard structure/content. In this paper, we propose a dynamic analysis method to analyze the function call relationship of an obfuscated execution program. We suggest constructing a function call relationship as a graph using the proposed technique.

• ETRI Journal
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• v.25 no.1
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• pp.34-40
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• 2003

This paper considers a TMN-based management system for the management of public ATM switching networks using a four-level hierarchical structure consisting of one network management system, several element management systems, and several agent-ATM switch pairs. Using Jackson's queuing model, we analyze the effects of one TMN command on the performance of the component ATM switch in processing local calls. The TMN command considered is the permanent virtual call connection. We analyze four performance measures of ATM switches- utilization, mean queue length and mean waiting time for the processor directly interfacing with the subscriber lines and trunks, and the call setup delay of the ATM switch- and compare the results with those from Jackson's queuing model.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1533-1536
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• 2001

This paper considers the TMN system for management of public ATM switching network which has the four-level hierarchical structure consisting of one network management system, a few element management system and several agent-ATM switch pairs, respectively. The effects of one TMN command on the local call processing performance of the component ATM switch an analyzed using Jackson's queueing model. The TMN command considered is the permanent virtual call connection, and the performance measures of ATM switch are the utilization, mean queue length and mean waiting time for the processor interfacing the subscriber lines and trunks directly, and the call setup delay of the ATM switch.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.99-120
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• 2010

Due to the wide spread of customers' frequent access of non face-to-face services, there have been many attempts to improve customer satisfaction using huge amounts of data accumulated throughnon face-to-face channels. Usually, a call center is regarded to be one of the most representative non-faced channels. Therefore, it is important that a call center has enough agents to offer high level customer satisfaction. However, managing too many agents would increase the operational costs of a call center by increasing labor costs. Therefore, predicting and calculating the appropriate size of human resources of a call center is one of the most critical success factors of call center management. For this reason, most call centers are currently establishing a department of WFM(Work Force Management) to estimate the appropriate number of agents and to direct much effort to predict the volume of inbound calls. In real world applications, inbound call prediction is usually performed based on the intuition and experience of a domain expert. In other words, a domain expert usually predicts the volume of calls by calculating the average call of some periods and adjusting the average according tohis/her subjective estimation. However, this kind of approach has radical limitations in that the result of prediction might be strongly affected by the expert's personal experience and competence. It is often the case that a domain expert may predict inbound calls quite differently from anotherif the two experts have mutually different opinions on selecting influential variables and priorities among the variables. Moreover, it is almost impossible to logically clarify the process of expert's subjective prediction. Currently, to overcome the limitations of subjective call prediction, most call centers are adopting a WFMS(Workforce Management System) package in which expert's best practices are systemized. With WFMS, a user can predict the volume of calls by calculating the average call of each day of the week, excluding some eventful days. However, WFMS costs too much capital during the early stage of system establishment. Moreover, it is hard to reflect new information ontothe system when some factors affecting the amount of calls have been changed. In this paper, we attempt to devise a new model for predicting inbound calls that is not only based on theoretical background but also easily applicable to real world applications. Our model was mainly developed by the interactive decision tree technique, one of the most popular techniques in data mining. Therefore, we expect that our model can predict inbound calls automatically based on historical data, and it can utilize expert's domain knowledge during the process of tree construction. To analyze the accuracy of our model, we performed intensive experiments on a real case of one of the largest car insurance companies in Korea. In the case study, the prediction accuracy of the devised two models and traditional WFMS are analyzed with respect to the various error rates allowable. The experiments reveal that our data mining-based two models outperform WFMS in terms of predicting the amount of accident calls and fault calls in most experimental situations examined.