• Journal of Korea Technology Innovation Society
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• v.14 no.3
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• pp.622-646
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• 2011

This paper analyses the effects of mobile telecommunications market's interconnection charge on consumer welfare between 2000 and 2010 by estimating price elasticity of demand with using log linear model and augmented Alexander et al(2000)'s model. The results show that consumer welfare is about 6 trillion won in 2009 and an upward trend. In the 2nd analysis, the decline in interconnection charge raise consumer welfare but, asymmetric interconnection and current TD-BU LRIC system have negative(-) relation with consumer welfare. Hence we need to revise interconnection policy frame.

• Electronics and Telecommunications Trends
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• v.31 no.2
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• pp.28-40
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• 2016

Software Defined Network(SDN)/Network Function Virtualization(NFV) 기술은 기존 하드웨어 기반의 경직된 네트워크의 구조를 소프트웨어, 가상화 기반의 유연한 네트워크 구조로 전환함으로써 미래의 다양한 융 복합 산업과 4차 산업혁명에 대응할 수 있는 네트워크 아키텍처 기술로 주목받고 있다. 현재 SDN/NFV기술이 네트워크 산업에서 주요 이슈가 되고, 이를 활용하여 성과가 소개되면서 네트워크장비 벤더들은 다양한 SDN/NFV 제품 및 솔루션을 출시하고 있다. 시장정체에 고심하던 통신사들도 SDN/NFV를 활용한 네트워크 인프라 전환을 모색하고 있다. 이에 본고는 주요 SDN/NFV 장비 벤더들의 동향과 SDN/NFV 도입사례를 살펴보고자 한다.

• Electronics and Telecommunications Trends
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• v.37 no.3
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• pp.52-63
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• 2022

Immersive media, also known as spatial media, has become essential with the decrease in face-to-face activities in the COVID-19 pandemic era. Teleconference, metaverse, and digital twin have been developed with high expectations as immersive media services, and the demand for hyper-realistic media is increasing. Under these circumstances, MPEG-I Immersive Media is being standardized as a technologies of navigable virtual reality, which is expected to be launched in the first half of 2024, and the Audio Group is working to standardize the immersive audio technology. Following this trend, this article introduces the trend in MPEG-I immersive audio standardization. Further, it describes the features of the immersive audio rendering technology, focusing on the structure and function of the RM0 base technology, which was chosen after evaluating all the technologies proposed in the January 2022 "MPEG Audio Meeting."

• ETRI Journal
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• v.33 no.6
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• pp.871-879
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• 2011

Because a wide variety of multimedia services are provided through personal wireless communication devices, the demand for efficient bandwidth utilization becomes stronger. This demand naturally results in the introduction of the variable bitrate speech coding concept. One exemplary work is the selectable mode vocoder (SMV) that supports speech/music classification. However, because it has severe limitations in its classification performance, a couple of works to improve speech/music classification by introducing support vector machines (SVMs) have been proposed. While these approaches significantly improved classification accuracy, they did not consider correlations commonly found in speech and music frames. In this paper, we propose a novel and orthogonal approach to improve the speech/music classification of SMV codec by adaptively tuning SVMs based on interframe correlations. According to the experimental results, the proposed algorithm yields improved results in classifying speech and music within the SMV framework.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.137-145
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• 2010

The objective of this paper is to evaluate the equilibrium price between PSTN and VoIP telephony services in the case of non-linear utility function. Currently there are two types of wired phone services we are known PSTN (Public Switched Telephone Network) and VoIP (Voice over Internet Protocol). The PSTN telephony which provide high quality service and VoIP which provides relatively low quality service form a vertically differentiated oligopoly. Therefore, the evaluation of the equilibrium price between PSTN and VoIP services is very important to wired phone service providers. The equilibrium price depends on the state of the service cost function has been proved different value. This paper was evaluated each equilibrium price for the state of the linear cost function and non-linear cost function. Subsequently, this paper analyzed the demand of both services and the equilibrium profit which can maximize the profit of both service providers.

• ETRI Journal
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• v.30 no.4
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• pp.587-596
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• 2008

Facility-based competition (FBC) in the telecommunications market is considered to have lower static efficiency in the short term and higher dynamic efficiency in the long term. Under service-based competition (SBC), the entrant can reduce its setup costs by leasing network facilities from the incumbent, which makes the entrant viable, pushes the market price down and promotes static efficiency. This paper attempts to measure static efficiency by comparing the profits of the incumbent and entrant in terms of consumer surplus and social welfare under each competition type by extending the Stackelberg model. The results, assuming a linear demand function and variation in regulatory level, show that FBC results in higher social welfare than SBC on the whole. However, SBC accompanied by strong regulation is also shown to have the potential to be superior over FBC. It is also revealed that FBC exhibits a higher producer surplus (particularly, the incumbent's producer surplus) and is, therefore, more desirable in terms of dynamic efficiency. When the entrant's cost is high in FBC, social welfare is shown to be lowered, implying that cost competitiveness is a necessary condition for social welfare.

• ETRI Journal
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• v.40 no.2
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• pp.227-236
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• 2018

Ultra-dense small cell networks (UD-SCNs) have been identified as a promising scheme for next-generation wireless networks capable of meeting the ever-increasing demand for higher transmission rates and better quality of service. However, UD-SCNs will inevitably suffer from severe interference among the small cell base stations, which will lower their spectral efficiency. In this paper, we propose a software-defined networking (SDN)-based hierarchical agglomerative clustering (SDN-HAC) framework, which leverages SDN to centrally control all sub-channels in the network, and decides on cluster merging using a similarity criterion based on a suitability function. We evaluate the proposed algorithm through simulation. The obtained results show that the proposed algorithm performs well and improves system payoff by 18.19% and 436.34% when compared with the traditional network architecture algorithms and non-cooperative scenarios, respectively.

• Proceedings of the Korea Technology Innovation Society Conference
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• 1999.05a
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• pp.117-149
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• 1999

This paper is to examine the effect of the receiver pays principle (RPP) on the calling price, social welfare and interconnection charge. A significant trouble with introducing this system in telecommunications pricing is the possibility that the receiving party may refuse to receive a call if the charge he has to bear is very high. We find the condition for no calls to be refused and show that the profit maximizing prices charged to the calling party and the receiving party must satisfy this condition. We demonstrate that the calling price under RPP must be lower than the price under the caller pays principle (CPP), that the profit of a firm will be increased under RPP, but that the consumer surplus will not necessarily be increased under RPP despite the lowered calling price. Also, we show that, if the demand function is linear, the reciprocal interconnection charge under RPP is higher than that under CPP.

• Journal of IKEEE
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• v.3 no.2 s.5
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• pp.204-214
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• 1999

The user authentication service can be used to prevent telecommunications piracy and to demand reliable payment from subscriber. Over the last few years several of the cryptographic systems being used by the IS-41 North American Mobile telephones have been broken. These algorithms included ORYX, CMEA and CAVE. The process of replacing these algorithms is already underway. In this paper we designed a hash function and applied it to the authentication algorithm of IS-95A authentication system. We also analyzed the randomness properties of designed algorithm using statistical analysis and simulated the validity of this algorithm using C programming language.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1481-1492
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• 1999

As Internet is popularized by the advent of Web concept having characteristics such as open network, user-friendly, and easy-usage, there are many changes in Information systems providing various information. Web is rapidly transferred traditional Information systems to Web-based Information systems, because it provides not only text information but also multimedia information including image, audio, video, and etc. Also, as information contents were changed from text-based simple abstract information to full-text information, there was appeared various document formats processing Full-text information. But, as they naturally demand large systems memory, long processing time, broader transmission bandwidth, and etc, estimating of these factors is necessary when constructing information systems. This paper focuses on how to design and construct information system processing full-text information and providing function of an integrated document. Primarily, we should review standard document format which is used or developed, and any document format is appropriate to process full-text information in review with viewpoint of information system. Also, practically we should construct information system providing full-text information based on PDF document.