• 한국통신학회논문지
• /
• 제34권4C호
• /
• pp.424-429
• /
• 2009

본 논문에서는 페이딩 채널 환경에서 훈련 신호을 이용하는 자기 상관 함수 기반의 반송파 주파수 오차 추정기를 제안한다. 제안된 주파수 동기화 기법은 기존의 자기 상관 함수 기반의 추정기와 비교하였을 때 자기 상관 함수 계산 과정에서 보다 낮은 계산 복잡도를 가진다. 실험 결과를 통하여 제안된 반송파 주파수 오차 추정기가 기존의 방식보다 향상된 성능을 가지며, 제안된 추정기의 성능이 CRLB(Cramor-Rao lower bound)에 근접함을 보인다.

• 대한전기학회논문지
• /
• 제37권5호
• /
• pp.272-281
• /
• 1988

The problem of optimal transmission system planning is to find the most economical locations and time of transmission line construction under the various constraints such as available rights-of-way, finances, the technical characteristics of power system, and the reliability criterion of power supply, and so on. In this paper the constraint of right-of-way is represented as a finite set of available rights-of-way. And the constructed for a unit period. The electrical constraints are represented in terms of line overload and steady state stability margin. And the reliability criterion is dealt with the suppression of failure cost and with single-contingency analysis. In general, the transmission planning problem requires integer solutions and its objective function is nonlinear. In this paper the objective function is defined as a sum of the present values of construction cost and the minimum operating cost of power system. The latter is represented as a sum of generation cost and failure cost considering the change of yearly load, economic dispatch, and the line contingency. For the calculation of operating cost linear programming is adopted on the base of DC load flow calculation, and for the optimization of main objective function nonlinear Branch-and-Bound algorithm is used. Finally, for improving the efficiency of B & B algorithm a new sensitivity analysis algorithm is proposed.

• 농업생명과학연구
• /
• 제46권6호
• /
• pp.197-205
• /
• 2012

이 논문은 한육우 사육두수 주기를 분석하고 이 주기를 기초로 한육우 사육두수를 예측하였다. 이를 위해 일정한 주기를 가지고 정점과 저점을 반복하는 싸인함수를 활용하였다. 과거 한육우 사육두수의 주기는 짧게는 5년부터 길게는 12년까지의 패턴을 보여주었고, 이러한 주기는 시간이 흐름에 따라 점차 길어지는 양상을 보여주고 있다. 싸인함수를 활용하여 한육우 사육두수를 추정한 결과, 모형의 적합도가 0.95로 매우 높게 나타났다. 이 모형을 이용하여 한육우 사육두수를 예측한 결과, 사육주기에 따라 약간의 차이가 나지만 저점의 사육두수는 160~180만두 정도이고 정점의 사육두수는 320만두~370만두 수준으로 예측되었다. 이러한 예측결과는 사육두수 불안정성에 따른 농가 소득 불안정성을 내포하고 있어 그에 따르는 적절한 정책이 필요함을 시사한다.

• 한국환경농학회지
• /
• 제10권2호
• /
• pp.149-157
• /
• 1991

Aging 기간의 증가에 따른 토양 중 TCAB의 추출불가 토양흡착 잔류물의 변화를 규명하기 위해 benzene ring에 $^{14}C$로 균일하게 표지된 $^{14}C-TCAB$를 토양(유기물 함량 : 1.8%)에 처리하고 $21{\pm}1^{\circ}C$의 incubator내에서 각각 3, 6, 9, 12, 15개월 동안 aging하였다. Aging기간중 $^{14}CO_2$에 방출량과 휘발된 량은 극히 적었으며, 3개월 aging시 7.55%이던 TCAB의 추출불가 토양흡착 잔류물의 량이 15개월 aging시 19.32%까지 지속적으로 증가하였다. 또한 토양 추출액의 partition결과 TCAB의 구조 중에 극성기(polar group)가 전혀 형성되지 않았음을 알 수 있었으며 토양흡착 잔류물의 대부분은 $humin(50.52{\sim}58.93%)$에 분포하였다. 한편 토양 중 미생물의 수가 모든 처리구에서 대조구에 비해 감소한 것은 TCAB의 추출불가 토양흡착 잔류물의 형성에 미생물의 영향이 없었음을 시사해준다. 따라서 aging기간이 증가함에 따라 TCAB의 추출불가 토양흡착 잔류물의 량이 증가하는 것은 trans-TCAB가 흡착력과 극성이 더 큰 cis-TCAB로 변환되었기 때문인 것으로 보인다.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
• /
• pp.349-352
• /
• 2004

In this literature, the selection of data set among the universe set is carried out with the fuzzy entropy function. By the definition of fuzzy entropy, we have proposed the fuzzy entropy function and the proposed fuzzy entropy function is proved through the definition. The proposed fuzzy entropy function calculate the certainty or uncertainty value of data set, hence we can choose the data set that satisfying certain bound or reference. Therefore the reliable data set can be obtained by the proposed fuzzy entropy function. With the simple example we verify that the proposed fuzzy entropy function select reliable data set.

• 한국지능시스템학회논문지
• /
• 제14권5호
• /
• pp.655-659
• /
• 2004

In this literature, the selection of data set among the universe set is carried out with the fuzzy entropy function. By the definition of fuzzy entropy, the fuzzy entropy function is proposed and the proposed fuzzy entropy function is proved through the definition. The proposed fuzzy entropy function calculate the certainty or uncertainty value of data set, hence we can choose the data set that satisfying certain bound or reference. Therefore the reliable data set can be obtained by the proposed fuzzy entropy function. With the simple example we verify that the proposed fuzzy entropy function select reliable data set.

• IMMUNE NETWORK
• /
• 제13권2호
• /
• pp.63-69
• /
• 2013

IL-12 is a secretory heterodimeric cytokine composed of p35 and p40 subunits. IL-12 p35 and p40 subunits are sometimes produced as monomers or homodimers. IL-12 is also produced as a membrane-bound form in some cases. In this study, we hypothesized that the membrane-bound form of IL-12 subunits may function as a costimulatory signal for selective activation of TAA-specific CTL through direct priming without involving antigen presenting cells and helper T cells. MethA fibrosarcoma cells were transfected with expression vectors of membrane-bound form of IL-12p35 (mbIL-12p35) or IL-12p40 subunit (mbIL-12p40) and were selected under G418-containing medium. The tumor cell clones were analyzed for the expression of mbIL-12p35 or p40 subunit and for their stimulatory effects on macrophages. The responsible T-cell subpopulation for antitumor activity of mbIL-12p35 expressing tumor clone was also analyzed in T cell subset-depleted mice. Expression of transfected membranebound form of IL-12 subunits was stable during more than 3 months of in vitro culture, and the chimeric molecules were not released into culture supernatants. Neither the mbIL-12p35-expressing tumor clones nor mbIL-12p40-expressing tumor clones activated macrophages to secrete TNF-${\alpha}$. Growth of mbIL-12p35-expressing tumor clones was more accelerated in the $CD8^+$ T cell-depleted mice than in $CD4^+$ T cell-depleted or normal mice. These results suggest that $CD8^+$ T cells could be responsible for the rejection of mbIL-12p35-expressing tumor clone, which may bypass activation of antigen presenting cells and $CD4^+$ helper T cells.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권8호
• /
• pp.3862-3888
• /
• 2017

In high diversity node situation, single-channel MAC protocols suffer from many collisions. To solve this problem, the research of multichannel MAC protocol has become a hotspot. And the cyclic quorum-based multichannel (CQM) MAC protocol outperformed others owing to its high frequency utilization. In addition, it can avoid the bottleneck that others suffered from and can be easily realized with only one transceiver. To obtain the accurate performance of CQM MAC protocol, a Markov chain model, which combines the channel hopping strategy of CQM protocol and IEEE 802.11 distributed coordination function (DCF), is proposed. The metrics (throughput and average packet transmission delay) are calculated in performance analysis, with respect to node number, packet rate, channel slot length and channel number. The results of numerical analysis show that the optimal performance of CQM protocol can be obtained in saturation bound situation. And then we obtain the saturation bound of CQM system by bird swarm algorithm (BSA). Finally, the Markov chain model and saturation bound are verified by Qualnet platform. And the simulation results show that the analytic and simulation results match very well.

• 대한수학회논문집
• /
• 제18권3호
• /
• pp.449-457
• /
• 2003

On the setting of the upper half-space of the Euclidean space $R^{n}$, we show that to each weighted harmonic Bergman function $u\;\epsilon\;b^p_{\alpha}$, there corresponds a unique conjugate system ($upsilon$_1,…, $upsilon_{n-1}$) of u satisfying $upsilon_j{\epsilon}\;b^p_{\alpha}$ with an appropriate norm bound.

• 대한수학회지
• /
• 제56권4호
• /
• pp.1001-1016
• /
• 2019

We are concerned with optimization methods for the $L^2$-Wasserstein least squares problem of Gaussian measures (alternatively the n-coupling problem). Based on its equivalent form on the convex cone of positive definite matrices of fixed size and the strict convexity of the variance function, we are able to present an implementable (accelerated) gradient method for finding the unique minimizer. Its global convergence rate analysis is provided according to the derived upper bound of Lipschitz constants of the gradient function.