• 한국경영과학회지
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• 제34권4호
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• pp.113-121
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• 2009

In this paper, we consider the departure process from the open and nested tandem Queueing network with population constraint and constant service times. It is known that the Queueing network can be transformed into a simple Queueing network which can be easy to analyze. Using this simple Queueing network, upper and lower bounds on the interdeparture time are obtained. We prove that the variance of the interdeparture time is bounded within these two bounds. Validation against simulation data is shown that how it works the variance of the interdeparture time within two bounds. These bounds can be applied to obtain the better variance of the interdeparture time using a suitable method.

• Journal of Advanced Marine Engineering and Technology
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• 제22권2호
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• pp.174-180
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• 1998

Robust stability of discrete-time regulators which utilize state predictors to compensate computation delays is considered. Novel expressions for the return difference matrices and the complementary sensitivity matrices at the input and the output of the regulator are found to obtain simple bounds for unstructured perturbations. Robust stability for pertubations of the system matrix and /or the gain matrix is also considered. under certain restriction on the nominal system simple bounds for the pertubations are obtained directly from the characteristic equation. It is shown that as far as the effect of the computation delays concerns these bounds have explicit relation to those for the unstructured pertubations.

• 한국통신학회논문지
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• 제34권11C호
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• pp.1025-1028
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• 2009

본 논문에서는 기존의 단순 한계와 Maximum Likelihood (ML) 추정 입력 출력 무게 분포를 사용하여 몇 개의 불규칙한 LDPC 부호의 ML 복호에 대한 성능의 상향 한계를 구하고 부호의 길이가 길어지면 Belief-Propagation (BP) 복호의 성능이 ML 복호 성능에 단순하게 근접해 간다는 일반적인 견해와는 상반되게 정점 성능 감쇠(Peak Degradation)에 다다르기 이전에는 부호의 길이가 길어지면 오히려 BP 복호의 성능이 ML 복호 성능으로부터 성능 감쇠 폭이 증가하고 정점 성능 감쇠를 지난 후에 일반적인 견해가 적용되는 것을 보인다.

• Communications for Statistical Applications and Methods
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• 제21권3호
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• pp.201-212
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• 2014

We provide a simple basic method to find bounds for higher order moments of unimodal distributions in terms of lower order moments when the random variable takes value in a given finite real interval. The bounds for moments in terms of the geometric mean of the distribution are also derived. Both continuous and discrete cases are considered. The bounds for the ratio and difference of moments are obtained. The special cases provide refinements of several well-known inequalities, such as Kantorovich inequality and Krasnosel'skii and Krein inequality.

• 한국통신학회논문지
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• 제33권11C호
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• pp.880-882
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• 2008

This paper presents LDPC codes' upper bounds over the waterfall SNR region. The previous researches have focused on the average bound or ensemble bound over the whole SNR region and showed the performance differences for the fixed block size. In this paper, the particular LDPC codes' upper bounds for various block sizes are calculated over the waterfall SNR region and are compared with BP decoding performance. For different block sizes the performance degradation of BP decoding is shown.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.556-559
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• 1996

In this paper, we suggest a H center .inf. generalized predictive control(H center GPC) which guarantees $H_{\infty}$-norm bounds. THe suggested control is obtained by solving the min-max problem in nonrecursive forms. The stability conditions of the suggested control are derived in a somewhat simple form and it is not required for the derived solution to be a saddle point solution. It is also shown that the suggested control guarantees the $H_{\infty}$-norm bounds under the same conditions of stability.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1991년도 추계종합학술발표회논문집
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• pp.145-149
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• 1991

In this paper, an algorithm is proposed to analyze the approximating reliability of the capacity considered communication networks. In the case ofthe former methods to evaluate the source-to-termianl node reliability, it is very difficult to contract and delete the jointed terms in the simple path group. Therefore, the reliability bounds are used and compared to the exact reliability by TURBO PROLOG, the natural lanquage of artficial intelligence. In the reliability bounds, the upper bound used the valid cutset that isthe group of simple path and the lower bound used the minimal cutset by complement operation and the esact reiability is compared to this reliability bounds.

• 산업경영시스템학회지
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• 제34권1호
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• pp.67-73
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• 2011

Using the known result of the expected busy period for a controllable M/G/1 queueing model operating under the triadic Max (N, T, D) policy, its upper and lower bounds are derived to approximate its corresponding actual value. Both bounds are represented in terms of the expected busy periods for the dyadic Min (N, T), Min (N, D) and Min (T, D) and simple N, T and D operating policies. All three input variables N, T and D are equally contributed to construct such bounds for better estimation.

• 산업경영시스템학회지
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• 제33권2호
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• pp.97-104
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• 2010

Using the known result of the expected busy period for the triadic Min (N, T, D) operating policy applied to a controllable M/G/1 queueing model, its upper and lower bounds are derived to approximate its corresponding actual value. Both bounds are represented in terms of the expected busy periods for the dyadic Min (N, T), Min (N, D) and Min (T, D) and simple N, T and D operating policies. All three input variables N, T and D are equally contributed to construct such bounds for better approximations.

• 산업경영시스템학회지
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• 제36권1호
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• pp.58-63
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• 2013

Using the known result of the expected busy period for the triadic Med (N, T, D) operating policies applied to a controllable M/G/1 queueing model, its upper and lower bounds are derived to approximate its corresponding actual values. Both bounds are represented in terms of the expected busy periods for the dyadic Min (N, T), Min (N, D) and Min (T, D) or Max (N, T), Max (N, D) and Max (T, D) with the simple N, T and D operating policies without using any other types of triadic operating policies such as Min (N, T, D) and Max (N, T, D) policies. All three input variables N, T and D are equally contributed to construct such bounds for estimation of the expected busy period.