• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.91-93
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• 2004

인터넷의 정보가 많아짐에 따라 인터넷에서 원하는 정보를 얻어 효과적으로 사용하기는 더욱 힘들어지고 있다. 그러므로 관련된 정보에 쉽게 접근하기 위해 얻고자 하는 정보를 인터넷에서 자동적으로 전달해 주는 푸쉬 기술은 중요한 인터넷 기술로 주목받고 있다. 하지만 푸쉬 기술은 정보 전달 방식으로 인해 네트웍 대역폭을 너무 많이 소요하기 때문에 푸쉬 서버의 가용성이 급격히 떨어질 수 있다는 단점을 가지고 있다. 따라서 본 논문에서는 메시지 폭주로 인한 시스템 고장에 대처하고 부하를 분산시킬 수 있는 복제에 기반한 푸쉬 서버를 설계하고, Erlang/OTP로 구현하였다. 성능을 분석하기 위하여 단일 푸쉬 서버론 사용한 결과와 본 논문에서 제안된 구조를 사용한 결과론 비교.분석하였다.

• Communications of the Korean Mathematical Society
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• v.10 no.2
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• pp.443-460
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• 1995

We consider a G/M/1 vacation model where the vacation time has k-stages generalized Erlang distribution. By using the methods of the shift operator and supplementary variable, we explicitly obtain the limiting probabilities of the queue length at arrival time points and arbitrary time points simultaneously. Operational calculus technique is used for solving non-homogeneous difference equations.

• Venture DIGEST
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• s.115
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• pp.8-10
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• 2008

얼랑시스템(대표 박원구,www.erlang.co.kr)은 초고속 통신용 비메모리 반도체칩(ASIC) 설계업체로서 교환기, 네트워크 보안장비의 핵심 칩과 보드를 설계.제조한다. 여기서 개발한 교환기용 칩과 보드는 LG전자에 납품되어 최종 교환기로 완성된 후 KT, 데이콤, SK텔레콤, KTF등에 판매된다. 모범적인 상생경영을 통해 LG전자에 장영실상을 안겨준 장비인 MSR40의 핵심 비메모리칩을 개발한 얼랑시스템. 수요자 맞춤 설계로 시장의 어려움을 타개하고 세계 1위를 향해 발전하는 얼랑시스템의 박원구 대표를 만나본다.

• Journal of the Korean Operations Research and Management Science Society
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• v.21 no.2
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• pp.49-58
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• 1996

The generalized Erlang loss function, extensively studied in the literature, is revisited. We study the steady state loss probability in M/M/s/s + c queueing system and prove that it satisfies the first and second order properties in integral number of servers as well as integral queue capacities. Also we study the problem of allocating integral number of servers and queue capacities, and develop an algorithm to obtian an optimal allocation of them individually and jointly with the small number of computations.

• Proceedings of the Korean Reliability Society Conference
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• 2000.04a
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• pp.39-46
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• 2000

초고속, 대용량전송망 구축을 위해 설치, 운용되는 2.5Gbps 동기식 광전송장치에 대하여 MIL-HDBK-217의 부품고장율 산출방법을 기본으로 유니트별 예상 고장율을 산출한후 산출된 예상 고장율과 실제 년간 집계된 고장발생 데이타와 비교 분석하였다. 또한 서울망등 12개 통신망운용국에서 확보계획인 예비유니트수와 산출한 유니트별 예상고장율을 Erlang's Loss Fomula에 적용하여 산출한 수량과 비교분석을 실시한 후 투자계획에 따른 적정 예비 유니트를 선정, 산출하였다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.205-218
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• 1996

본 연구는 써버의 고장을 허용하는 단수써버 Queueing 시스템의 확률적 모델을 제시한 것으로, 써버는 N 제어 정책에 의하여 작동되며, 도착은 Stationary compound poisson에 의하여 이루어지고, 서비스 시간에 대한 분포는 Erlang에 의하여 발생하며, 수리시간에 대한 분포는 평균이 일정한 분포에 의하여 생성되는 경우를 고려하였다. 또한 고장간격 시간은 일정한 평균을 가진 임의의 분포를 가진 Renewal process에 의한다고 가정하였고, 완료 시간의 개념은 재생과정의 적용방법에 의하여 유도할 수 있으며, 시스템 크기의 확율 생성 함수의 값이 구해진다는 것을 제시하였다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.175-181
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• 1999

There are issues regarding how some of traffic parameters should be set so that ATM and non-ATM service parameters can be compatible. For example, policing method used by frame relay based on CIR(committed information rate) will not exactly match the ATM UPC(Usage Parameter Control) method. ATM and the frame relay have different transfer modes and traffic parameters. The cells and frames are police by their own traffic control schemes. For the same information, the real traffic of the ATM side takes greater bandwidth than that of the frame relay side caused by ATM cell format and AAL5 format. IN both networks this bandwidth than that of the frame relay side caused by ATM cell format and AAL5 format. In both networks this bandwidth ratio should be considered on traffic parameter mapping to maintain their QoS and to perform efficient network resource management. In this paper we describe traffic parameter mapping schemes between frame relay and ATM in ATM network and how to expect the bandwidth ratio to maintain FR QoS in ATM network. We assumed frame length distribution to Erlang or Exponential probability density function.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.4
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• pp.17-24
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• 2004

Call blocking probabilities of streaming data service in CDMA system with access point(AP) of WLAN are analyzed for different cell geometry of base station and AP and queuing is modeled. The considered system leads to successful handoffs between the APs of WLAN. Blocking probabilities are enumerated as a function for ratio of base station and AP sizes, their locations and the number of buffer in the queue. Results show that blocking probability is not influenced by base station and AP locations but mainly by ratio of their sizes. For CDMA system of radius 100m, 5 buffers in the queue and 7㏈ noise rise(NR), in order to obtain 1% call blocking probability, a cell with hot spot of radius 20m has more 0.6Erlang than that of radius 60m.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.310-315
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• 2014

Cellular retinol-binding protein II (CRBP II) belongs to the family of cellular retinol-binding proteins and plays a major role in absorption, transport, and metabolism of vitamin A. In addition, because vitamin A is correlated with reproductive performance, we measured CRBP II mRNA abundance in erlang mountainous chickens by real-time PCR using the relative quantification method. The expression of CRBP II showed a tissue-specific pattern and egg production rate-dependent changes. The expression was very high (p<0.05) in jejunum and liver, intermediate in kidney, ovary, and oviduct, and lowest (p<0.05) in heart, hypothalamus, and pituitary. In the hypothalamus, oviduct, ovary, and pituitary, CRBP II mRNA abundance were correlated to egg production rate, which increased from 12 wk to 32 wk, peaked at 32 wk relative to the other time points, and then decreased from 32 wk to 45 wk. In contrast, the expression of CRBP II mRNA in heart, jejunum, kidney, and liver was not different at any of the ages evaluated in this study. These data may help to understand the genetic basis of vitamin A metabolism, and suggest that CRBP II may be a candidate gene to affect egg production traits in chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.782-787
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• 2015

The myogenic regulatory factors is a family of transcription factors that play a key role in the development of skeletal muscle fibers, which are the main factors to affect the meat taste and texture. In the present study, we performed candidate gene analysis to identify single-nucleotide polymorphisms in the MyoD, Myf5, MyoG, and Mrf4 genes using polymerase chain reaction-single strand conformation polymorphism in 360 Erlang Mountain Chickens from three different housing systems (cage, pen, and free-range). The general linear model procedure was used to estimate the statistical significance of association between combined genotypes and muscle fiber traits of chickens. Two polymorphisms (g.39928301T>G and g.11579368C>T) were detected in the Mrf4 and MyoD gene, respectively. The diameters of thigh and pectoralis muscle fibers were higher in birds with the combined genotypes of GG-TT and TTCT (p<0.05). Moreover, the interaction between housing system and combined genotypes has no significant effect on the traits of muscle fiber (p>0.05). Our findings suggest that the combined genotypes of TT-CT and GG-TT might be advantageous for muscle fiber traits, and could be the potential genetic markers for breeding program in Erlang Mountain Chickens.