• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.138-141
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• 1997

In this study, a simulation model is developed to analyze the effects of routing and scale-economy of transmission facilities on the traffic network topology and investment cost changes in a metropolitan telephone network. Computational experiments showed that the wide deployment of bifurcated routing in a dual-homing configuration reduces significantly the traffic network connectivity and the investment cost. Its enhanced version, when combined with the subscriber network cost model, can be used as a prototype cost proxy model for figuring out the access charges in a multi-operator environment.

• The Journal of the Acoustical Society of Korea
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• v.17 no.4E
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• pp.17-21
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• 1998

This paper presents an implementation of a multi-channel speech surveillance system over telephone lines using TMS320C31 DSP chips. The incoming speech into each telephone line are first compressed simultaneously in real-time by the popular vector-sum excited linear predictive (VSELP) speech coding algorithm at the rate of 8 Kbps. The compressed steech bit streams are then multiplexed with those of other users. The multiplexed speech bit streams are transferred to the system storage equipments with some other required information so that a system operator can later monitor the stored speech data whenever it is necessary. The host program runs under Microsoft Windows95 for an efficient man-machine interface and a future upgrade-ability. We have confirmed that the overall 64-channel system operates satisfactorily in realtime. We also have checked approximately up to 2,880 total hours of recording capability of the system on a playback module and two removable backup drives.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.53-58
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• 1998

Objectives : To compare the voice quality and voice problems of untrained professional voice user groups with that of normal control group without voice problem. Materials and Methods : The sustained vowel sounds of 13 male and 36 female teachers, 46 clergies and 15 telephone operators, and 40 normal male and 20 normal female persons were analyzed, using a videostroboscopy and acoustic analyzer. Together with these analyses, a questionnaire associated with risk factors for current and past voice problems was handed over to the patients. Results : The most common symptom in subjective groups was the voice fatigue. In stroboscopic examination, the professional voice user groups shelved functional voice disorder findings regardless of the Intensity of voice use. In the clergy and teacher using loud voice, vocal polyp, vocal nodule and hyperfunction of laryngeal muscle were frequently observed. In the clergy and telephone operator, jitter and shimmer were significantly increased. In the female teacher, the value of jitter, fundamental frequency variation and fundamental frequency were statiscally significant. However, the voice of male teacher showed no significant findings in the acoustic and aerodynamic studies. Conclusion : In the management of voice problems for untrained professional voice user groups, it is important to find the exact causes and patterns of voice problems, and to be individualized the management according to the causes.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.1
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• pp.17-21
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• 2001

Aims of study : The purpose of this study is to measure the chronic and daily voice burden of the professionals in their actual working places. These will be a valuable guideline for preventing and controlling the voice production of professionals. Material and method : Our study was selected to the 10 female telephone operators in the Asan Medical Center, ages ranging from 22 to 38 years old. The symptoms and acoustic analysis of both telephone operators and the controls were evaluated before and after their working. The symptoms were evaluated with questionaires, and the acoustic analysis was measured by using CSL (computerized speech laboratory) system. Results : The symptoms of the professional voice abusers are same as those symptoms in laryngeal fatigue. The acoustic analysis before their working were significantly increased in jitter and shimmer, in comparison with the data of the control. This shows that the experimental group is exposed to the chronic burden of voice production. The jitter, shimmer, and NHR after their working are significantly increased in comparison with the data of the acoustic analysis before their working. This also shows that the experimental group is exposed to the daily burden of voice production. Conclusion : The acoustic analysis of the professional voice overusers has objectively measured that there are chronic and daily overloading to the voice of operators, and these will be a valuable data for preventing and controlling the professionals that abuse their voice.

• Electronics and Telecommunications Trends
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• v.35 no.6
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• pp.68-77
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• 2020

Along the advancement of mobile networks, fixed telephone networks are gradually advancing from legacy networks based on copper and circuit-switches to optical cables and packet-switched IP networks. Incumbent fixed-line telephone operators are facilitating the introduction of IP networks and are gradually converting to IP-based facilities according to the investment plans for each operator. As the PSTN's IP conversion exceeds a certain level and VoIP; (an alternative service); is activated, some countries; such as Europe; are considering terminating the PSTN service, centering on operators. In this paper, trends in the procedure, timing, and major issues related to the termination of an overseas PSTN are examined. The domestic status is also examined.

• Journal of Technology Innovation
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• v.12 no.3
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• pp.73-96
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• 2004

This research began by recognizing the development of telecommunication skill in a short period of time as one achievement of launching the national research and development (R&D) project for the diversification of telephone service and for the solution of telephone holdup rate. Under this concern, this research is focusing on searching the influential elements on successful outcome by analyzing the case of Time Division Exchange R&D Project carried out by Korea. Those variables for analyzing the case is limited to 7 definite variables, which are "willingness of policy making organization", "participation of manufacturers and buyers", "support from research and development group", "economy of operating methods and selection of machinery", "rate of technology transfer", "support from Fixer", and "quality management". Summarizing the result of analysis, in order to bring about technological innovation, knowledge creation activity leading to upward efficiency through competition and cooperation making a harmony should be done in one mechanism. I.e., launching an innovative policy should be done in an arena of competition and cooperation, where stability of implementing system is achieved, the entity of "Fixer" is an adequate operator, and competition and cooperation is efficiently managed, among where agreement on purpose and professional opinions are reflected.

• Journal of Agricultural Extension & Community Development
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• v.28 no.1
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• pp.41-52
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• 2021

It is important to understand the factors that affect the business performance of insect farm for continuous insect farm management. The purpose of this study is to investigate factors influencing the business performance of insect farm. For this study, 1,577 questionnaires were collected through a telephone survey targeting insect farm owner. As a result of analysis using linear multiple regression analysis, the factors affecting total sales were gender, age, business experience, number of workers, and national and local government support projects. The factors affecting the net profit rate were age, business experience, number of workers, national and local government support projects, and education. When the gender of the business operator is male, it only affected the increase in total sales, and it was found that both the total sales amount and the net profit margin increased with the younger the business operator's age.

• Proceedings of the Korean Society for Language and Information Conference
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• 2002.02a
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• pp.271-280
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• 2002

A system to assist call routing task for telephone operators at the Directorate General of Telecommunications (DGT) in Taiwan is reported in this paper. The system was developed based on DGT organization profile with description of its six divisions instead of a corpus of recorded and transcribed call-routing dialogs. An acoustic module and an information retrieval module were built specifically for this task. The construction of IR module was based on term extraction and thesaurus discovery processes. By integrating acoustic and IR module, the system achieves satisfactory performance and provides a promising approach to call routing. Simulation results indicated that the proposed algorithm outperforms standard classification methods. A working system based on the proposed approach has been implemented and experimental results are presented.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.849-851
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• 2003

A location-based service or LBS in a cellular telephone network is a service provided to the subscriber based on his current geographic location. This position can be known by user entry or a GPS receiver that he carries with him, but most often the term implies the use of a function built into the cell network that uses the known geographic coordinates of the base stations through which the communication takes place. One implication is that knowledge of the coordinates is owned and controlled by the network operator, and not by the end user. Location utility service provides two kinds of functions, geocoder and reverse geocoder. Geocoder converts an address into a coordinate and reverse geocoder changes a coordinate into an address. Because location utility service is the first step to progress LBS, various servises such as directory, routing, presentation, and etc require to access that. In this paper, we will describe the architecture of LBS platform and the concept and the role of location utility service.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.239-242
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• 1997

Subscriber network investment cost is a main cost element among those constituting the access charges in telephone networks. The purpose of this paper to estimate the investment cost of installing a subscriber network in a typical metropolitan area and to develop a cost modeling framework. To this aim, a metropolitan area in Seoul was investigated. The main cost elements were identified and their relationships with the cable technology, geographical characteristics, and the number of subscribers were analyzed. The findings could be used to design an enhanced cost proxy models for estimating the access charges in a multi-operator environment.