• Information and Communications Magazine
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• v.20 no.3
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• pp.78-92
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• 2003

본 고에서는 차세대 통합 네트워크를 위한 프로토콜들 중 소프트스위치(MGC)와 미디어 게이트웨이를 중심으로 사용될 수 있는 BICC, SIPT, Megaco/H.248 프로토콜과 VoIP용 프로토콜인 H.323, SIP 프로토콜 등의 표준화 내용에 대해서 살펴보고 차세대 등합 네트워크로 진화하는 중간 단계에서 필수적으로 이루어져야 할 기존망들간의 연동 기술들에 대한 표준화 내용을 다루고자 한다. 그리고 마지막으로 연동기술 동향으로써 MSF(Multiservice Switching Forum)에서 주관하고 있는 장비 간 상호운용성 시험인 GMI(Global MSF Interoperability)에 대해서 기술하도록 한다.

• Electronics and Telecommunications Trends
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• v.19 no.6 s.90
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• pp.66-73
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• 2004

2004년도 정보통신부의 IT839 전략에 따르면 8대 신규 서비스로 인터넷 전화(VoIP)와 3대 첨단 인프라로 광대역 통합망(BcN)을 선정한 바 있다. 이에 본 고에서는 9대 신성장동력에서 공동으로 활용하기 위한 VoIP와 BcN을 연계한 기술 동향을 설명한다. SIP 와 H. 323에 의한 VoIP 서비스가 제공되면서 네트워크 구조 변화가 시작되었다. 유선 네트워크, 무선 이동통신 네트워크, 인터넷 등을 통합하는 유무선 통합네트워크(BcN)는 VoIP 기술로 구축될 것이다. 본 고의 구성으로는 VoIP 기술 특성을 설명하고, VoIP 표준 동향을 분석한 후에 앞으로 구축될 BcN VoIP 의 발전 방향에 대하여 설명한다. VoIP 기술은 회선 정합및 인터넷 정합 기술과 H. 323, SIP, MEGACO 등의 프로토콜 기술과 VoIP 품질을 결정하는 코덱 기술이있다. VoIP 표준은 IETF에서 제정한 SIP를 중심으로 네트워크 특성을 고려하여 3GPP, 3GPP2, ITU에서개발하고 있다. BcN VoIP 는 기존의 VoIP 기술을 발전시켜 음성 품질이 오디오 수준으로 향상되고, 유선과 무선, 방송이 통합되는 제어 기술과 연계하여 실시간 멀티미디어 서비스를 제공할 것이다.

• Environmental Engineering Research
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• v.17 no.3
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• pp.125-132
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• 2012

The removal of Cd(II) and Cu(II) from aqueous solution by an agricultural solid waste biomass prepared from Moringa oleifera bark (MOB) was investigated. The biosorbent was characterized by Fourier transform infrared spectroscopy and elemental analysis. Furthermore, the effect of initial pH, contact time, biosorbent dosage, initial metal ion concentration and temperature on the biosorption of Cd(II) and Cu(II) were studied using the batch sorption technique. Kinetic studies indicated that the biosorption process of the metal ions followed the pseudo-second order model. The biosorption data was analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. Based on the Langmuir isotherm, the maximum biosorption capacities for Cd(II) and Cu(II) onto MOB were 39.41 and 36.59 mg/g at 323 K, respectively. The thermodynamic parameters, Gibbs free energy (${\Delta}G^o$), enthalpy (${\Delta}H^o$), and entropy (${\Delta}S^o$) changes, were also calculated, and the values indicated that the biosorption process was endothermic, spontaneous and feasible in the temperature range of 303-323 K. It was concluded that MOB powder can be used as an effective, low cost, and environmentally friendly biosorbent for the removal of Cd(II) and Cu(II) ions from aqueous solution.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.323-327
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• 2006

In this study, we examined the changes in loaf weight, loaf volume and specific volume, moisture content and water absorption, pH and titrable acidity, shape, texture profile and sensory evaluation using sour dough instead of dough conditioner in bread making. The weight and volume of bread tended to increase in the sour dough bread, compared to the control. The pH of bread tended to be lower in the sour dough bread. The control bread had large irregular pores that were fewer in number, while the sour dough bread had small spots and was very dense and even throughout the whole surface. The texture profile of bread such as hardness, cohesiveness, chewiness and brittleness was lower in the sour dough bread. There were no significant differences in the sensory characteristics of the breads, except for the shape of bread. However, the sour dough A bread was better in color, texture, flavor, touch, moistness, taste and overall acceptability, and the sour dough B bread was better in flavor, touch and taste than the control.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.7-16
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• 2012

In this paper we describe a VoIP transcript system which is able to record call conversation between counselor and customer in an IP contact center based on IP telephony environment. The transcript system, designed and implemented in this paper, uses packet sniffering to capture packets without imposing network overhead on overall system. It can decode H.323 and SIP which are used to setup call sessions in VoIP environment and captures voice data and record without any loss of contents. Implemented transcript system can be integrated with CTI system in that it can manage and record call more effectively. It is designed generically so that it is implemented both on Windows and Linux environment.

• Journal of the Korean Chemical Society
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• v.9 no.4
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• pp.215-221
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• 1965

The significant liquid structure theory is extended to binary mixture, benzene-ethylenechloride system. The partition function, applicable throughout the temperature range in which Raoult's law is satisfied is derived. The thermodynamic quantities such as total and partial pressures, molar volumes and mixing entropies are calculated from the partition function at the temperatures $293.15^{\circ},\;323.14^{\circ}\;and\;357.15^{\circ}K.$ The theoretical values, thus calculated, are found to agree with the experimental data in the literatures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.331-334
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• 2002

According as internet service diffusion is popularized by internet user's increase, internet telehpony technology is becoming main issue of Internet Service Providers. Standardization issue about technologies related VoIP is discussed keeping in step on market's fast change and request in IETF. Specially, Standardizaiton is working through discussion on MMUSIC WG, SIP WG, SIPPING WG about SIP that is proposed by the alternative of ITU-T's H.323. Therefore in this Paper, introduce SIP standard that is established through several reconsideration revision works, and examine about IETF's trend for SIP based internet telephony service.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.323-323
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• 2007

Influence of $La_2O_3$ addition to $CaO-B_2O_3$-based glass on the water leaching resistance of the glass was first investigated. The optimized $La_2O_3-CaO-B_2O_3$(LCB) glass was ball milled for varying time, followed by mixing with $Al_2O_3$ crystalline phase to form $Al_2O_3$-LCB glass composites at $875^{\circ}C$ for 1h. Microwave dielectric properties of the composites were investigated as a function of the ball milling time of the LCB glass. Dielectric constant and quality factor of the composites were 6.31 and 13856 GHz, respectively, when the LCB glass was ball milled for 2h prior to mixing with $Al_2O_3$.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.403-405
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• 2001

한정된 대역폭의 통신망에서 다른 매체에 비해 자료량이 많은 화상의 압축은 중요한 문제로 떠올랐다. 대표적인 영상 압축방법으로 MPEG 시리즈와 H.26x 시리즈가 있다. 그중 H.263은 화상회의 표준안인 H.323와 최근 진행중인 차세대 이동통신이라 일컬어지는 IMT-2000에서 영상압축방법중의 하나로 채택되었다. 또한 현대에 이르러 Desktop상에서의 영상회의구축은 더 이상 불가능한 일이 아니며, 또 하나의 영상회의 활용분야로 급속히 떠오르고 있다. 이는 internet의 보급과 함께 internet방송, 다대다 화상회의, 원격 의료 진료 등, 수없이 많은 분야에 활용될 수 있는 계기가 마련되었다. 이에 본 논문에서는 H.261과 H.263, 그리고 H.263 version 2의 Desktop상에서의 실제적인 구현 및 비교를 기술한다.

• Korean Journal of Microbiology
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• v.28 no.4
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• pp.318-323
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• 1990

The bacterial secondary production was measured at 6 sites of Lake Soyang in October, 1989 by $^{3}$H-thymidine incorporation rate. Verfication for the method of bacterial secondary production measurement showed that $^{3}$H-thymidine incorporated into DNA, RNA and protein by average percentage of 38.45, 42.27 and 20.07%, respectively. THe more increased incoporated $^{3}$H-thymidine, the more increasde DNA fraction, but protein fraction was generally low. Incorporation of rate of /usp 3/H-thymidine. $^{3}$H-leucine into protein correlated with protein fraction of incorporated $^{3}$H-thymidine. Conversion factors were calculated as follows; $1.83*10 ^{20}$ cells/moles of thymidine incorporated/hr and 1.69*10$^{22}$ cells/moles of leucine incorporated/hr.