• 한국양식학회지
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• 제19권1호
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• pp.52-56
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• 2006

This study was conducted to investigate the effects of three different concentrations (6%, 8% and 10% final volume) of dimethyl sulfoxide (DMSO) on cryopreserved sperm of grass carp (Ctenopharyngodon idellus). Grass carp sperm was suspended in Kurokura extender #2 and equilibrated at $4^{\circ}C$ for 10 min. French straws (0.25 ml) of sperm were frozen from $4^{\circ}C\;to\;-4^{\circ}C$ at a rate of $4^{\circ}C\;min^{-1}$ and then ken $-4^{\circ}C\;to\;-80^{\circ}C$ at a rate of $11^{\circ}C\;min^{-1}$. The straws were kept at $-80^{\circ}C$ for 10 min and finally stored in liquid nitrogen $(-196^{\circ}C)$. The cryopreserved sperm was thawed in a water bath at $40^{\circ}C$ for 30 sec and fertilization, hatching rate and larval malformation were compared with fresh sperm (control). The fertilization rate of post-thawed sperm was comparable (from 88.21% to 94.30%) to that of fresh sperm. However, hatching rate of all frozen sperm were significantly lower (P<0.05) than that of control. Additionally, the larval abnormality rate of frozen sperm was significantly higher than that of fresh sperm. The results indicate that DMSO could affect the quality of cryopreserved sperm of grass carp, and a freezing program and a proper extender composition should be further studied.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권3호
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• pp.477-493
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• 2011

The IEEE 802.16 mobile multi-hop relay (MMR) task group 'j' (TGj) has introduced the multi-hop relaying concept in the IEEE 802.16 Wireless MAN, wherein a relay station (RS) is employed to improve network coverage and capacity. Several RSs can be deployed between a base station and mobile stations, and configured to form a tree-like multi-hop topology. In such architecture, we consider the problem of a path selection through which the mobile station in and outside the coverage can communicate with the base station. In this paper, we propose a new path selection algorithm that ensures more efficient distribution of resources such as bandwidth among the relaying nodes for improving the overall performance of the network. Performance of our proposed scheme is compared with the path selection algorithms based on loss rate and the shortest path algorithm. Based on the simulation results using ns-2, we show our proposal significantly improves the performance on throughput, latency and bandwidth consumption.

• ETRI Journal
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• 제40권5호
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• pp.604-612
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• 2018

To solve the problem of unbalanced loads and the short network lifetime of heterogeneous wireless sensor networks, this paper proposes a node-selection algorithm based on energy balance and dynamic adjustment. The spacing and energy of the nodes are calculated according to the proximity to the network nodes and the characteristics of the link structure. The direction factor and the energy-adjustment factor are introduced to optimize the node-selection probability in order to realize the dynamic selection of network nodes. On this basis, the target path is selected by the relevance of the nodes, and nodes with insufficient energy values are excluded in real time by the establishment of the node-selection mechanism, which guarantees the normal operation of the network and a balanced energy consumption. Simulation results show that this algorithm can effectively extend the network lifetime, and it has better stability, higher accuracy, and an enhanced data-receiving rate in sufficient time.

• 제어로봇시스템학회논문지
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• 제19권12호
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• pp.1081-1088
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• 2013

Hyperspectral cameras acquire reflectance values at many different wavelength bands. Dimensions tend to increase because spectral information is stored in each pixel. Several attempts have been made to reduce dimensional problems such as the feature selection using Adaboost and dimension reduction using the Simulated Annealing technique. We propose a novel material detection method that consists of four steps: feature band selection, feature extraction, SVM (Support Vector Machine) learning, and target and specific region detection. It is a combination of the band ratio method and Simulated Annealing algorithm based on detection rate. The experimental results validate the effectiveness of the proposed feature selection and band ratio method.

• 한국수정란이식학회지
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• 제10권1호
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• pp.33-44
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• 1995

Genetic changes from improving female's reproductive rate through in vitro fertilization of large number of oocytes were studied. The breeding scheme employed was multiple ovulation and embryo transfer of juveniles and adults. Both balanced and unbalanced matings were examined for the four closed progeny population sizes, 10$^3$, 10$^4$, 105, 106. In balanced matings, all selected sires and dams were mated to each other(cross-classified mating) while unbalanced matings allowed selected dams and sires mated partially, eg. unbalanced matings allowed averages of .5 and .25 progeny per each mating. Various numbers of selected sires and dams were also examined in both balanced and unbalanced matings. In all mating schemes, selection of males and females was restricted to he one from each fullsib family to reduce the rate of inbreeding. The model calculations were deterministic and accounted for the effects of selection and inbreeding on loss of the genetic variation in succeeding generations. Balanced rectangular mating schemes, where more donors were selected than sires, resulted in larger selection responses than balanced square mating schemes, where equal numbers of sires and donors were selected, and unbalanced rectangular mating. The first round selection responses from the balanced rectangular matings of juvenile MOET, eg. number of progeny per mating equals 2 with 10 sires selected, were 1.192, 1.406, 1.580 and 1.735 times larger than the first round selection responses from the balanced square mating schemes for the given four progeny population sizes, 10$^3$, 10$^4$, 105 and 106, respectively. Similar results were obtained in adult MOET breeding schemes. However, balanced square matings gave greater selection responses than the unbalanced rectangular matings.

• 한국정보통신학회논문지
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• 제21권3호
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• pp.509-515
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• 2017

본 논문에서는 다수의 릴레이가 존재하는 협력 통신 환경에서 릴레이 노드들의 신뢰도 정보를 이용한 릴레이 선택 기법을 고려한다. 먼저, 신뢰도에 따라 릴레이 노드들이 송신단의 정보 전송을 도와주는 경우와 전송을 도와주지 않는 경우 모두를 고려한 정보 전송률의 기댓값을 유도한다. 다음으로 주어진 신뢰도 정보를 이용하여 수신단에서 달성 가능한 정보 전송률의 기댓값을 최대화하는 릴레이 선택 기법을 제안한다. 마지막으로 시뮬레이션을 통하여 제안하는 릴레이 선택 기법이 릴레이 노드의 신뢰도 정보를 이용하지 않는 기존의 릴레이 선택 기법과 비교하여 더 우수한 성능을 나타냄을 보인다.

• 한국정보통신학회논문지
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• 제17권11호
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• pp.2521-2526
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• 2013

본 논문에서는 공간변조 (Spatial Modulation, SM) 시스템에서 다중안테나 채널 용량을 고려한 송신 안테나 선택 기술을 제안하고 그 성능을 분석한다. 각 송신 안테나에서 수신안테나까지의 채널 벡터의 크기에 기반하여 안테나를 선택하는 기존 기술과 비교할 때, 제안하는 기술은 채널용량 자체를 계산하여 전체적인 공간변조 시스템의 용량 증가를 가져온다. 전체 안테나 중 사용할 안테나의 집합을 선택하는 모든 경우를 비교하여 최적의 안테나 집합을 선택하는 최적 방법 (Optimal)을 제시하고, 추가적으로 계산 복잡도를 줄이면서 최적 성능과 유사한 성능을 제공하는 Sub-Optimal 기술을 함께 제시한다. 시뮬레이션을 통하여 제안한 안테나 선택 방법이 기존의 안테나 선택 방법에 비하여 bit error rate(BER) 측면에서 월등한 성능을 제공함을 확인하였다.

• 지능정보연구
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• 제14권4호
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• pp.179-200
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• 2008

본 연구에서는 사례기반 추론 기법을 대상으로 효율성과 효과성을 함께 증진시킬 수 있는 속성선정 방법을 개발하였다. 기본적으로, 본 연구에서 개발한 속성선정 방법은 기존에 개발된 단변량 분석 방법과 LVF 알고리즘을 통합하는 것이다. 먼저, 단변량 분석 방법 중 선택효과를 사용하여 전체 속성 중에서 예측력이 우수하다고 판단되는 일부분의 속성들을 추려낸다. 이 속성들로부터 생성해낼 수 있는 모든 가능한 부분집합을 생성해낸 후에, LVF 알고리즘을 이용하여 이 부분집합들이 가지는 불일치 비율을 평가함으로써 최종적으로 속성 부분집합을 선정한다. 본 연구에서 개발한 속성선정 방법을 UCI에서 제공하는 데이터 집합들에 적용하여 성능을 측정한 후, 기존 기법의 성능들과 비교한 결과, 본 연구에서 개발된 속성선정 방법이 선정된 속성의 개수도 만족할만하고 적중률도 향상되어서, 효율성과 효과성 모두의 측면에서 우수함을 보였다.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제23권2호
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• pp.349-381
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• 2009

본 연구의 목적은 한 영재교육원의 초등수학영재의 선발 과정과 문항에 대한 심층적 분석을 통해 초등수학영재의 선발 과정에 대한 시사점을 얻고자 하는 것이다. 이를 위하여 1, 2, 3차 선발 시험별로 학생들의 반응을 바탕으로 정답률을 조사하였고, 2, 3차 선발 시험은 오류 유형을 파악하였다. 연구결과에 따르면 대체로 선다형보다는 단답형과 설명을 요구하는 서술형 문항에서 정답률이 낮았다. 그리고 수와 연산, 논리 영역에서의 성취도에 비해 다른 영역에서의 성취도가 상대적으로 낮다는 것을 알 수 있었다. 본 연구의 결과로부터 앞으로 프로젝트 과제나 프로그램과 연계한 영재 선발에 대한 연구가 필요하다는 결론을 얻을 수 있었다.

• 한국멀티미디어학회논문지
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• 제20권1호
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• pp.1-9
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• 2017

Explosive deployment of smart mobile devices such as smart phones, and tablets along with expansion of wireless internet bandwidth have enabled the deployment of mobile video streaming such that video traffic becomes the most important service in wireless networks. Recently, for more efficient video streaming services, the ISO MPEG group standardized a protocol called DASH (Dynamic Adaptive Streaming over HTTP) and the standard has been quickly adopted by many service providers such as YouTube and Netflix. Despite of the convenience of mobile streaming services, users also suffer from low QoE(Quality of Experience) due to dynamic channel fluctuations and unnecessary downloading due to high churning rates. This paper proposes a noble efficient video rate selection algorithm considering user buffer level, channel condition and churning rate. Computer simulation based performance study showed that the proposed algorithm improved the QoE significantly compared to a method that determines the video rate based on current channel conditions. Especially, the proposed method reduced the rebuffering rate, one of the most important performance factors of the QoE, to a nonnegligible level.