• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.137-149
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• 1997

In this paper we propose a logdensity estimation based on a Fourier expansion. The basis functions consisting of trigonometric functions are determinded by stepwise addition and deletion and the Bayes Information Criterion, where the maximum likelihood method is used to estimate the parameters. Numericla examples using real data and simulated data are provided to show the performance of proposed method.

• Proceedings of the Korean Society for Information Management Conference
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• 2006.08a
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• pp.135-142
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• 2006

인용을 통한 연구성과 지표인 h-지수는 2005년에 제안된 이후 공식의 간단명료함, 용이한 산출 방법, 지수의 강건성 등이 인정되면서 계량정보학 분야를 비롯한 학술 공동체의 활발한 후속 논의가 이례적으로 신속하게 이어지고 있다. 후속 연구는 주로 h-지수의 타당성 검토, h-지수를 이용한 특정 분야의 개인성과 측정 시도, h-지수의 타 영역에의 응용, h-지수의 보완 등을 주제로 전개되고 있다. 이 연구에서는 우선 h-지수와 이를 보완한 g-지수를 비롯한 변형 지수에 대해서 현재까지 전개되고 있는 논의를 살펴보았다. 그리고 인용빈도가 높지 않은 경우를 고려하여 개선한 지수를 제안하고 실험적인 측정을 시도하였다.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.65-66
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• 2001

쌍끌이 중층망은 대형으로 양망시 네트드럼으로 양망해야 하므로 드럼용량이 커야하고, 드럼에 감긴 그물을 투망 할 때에 뜸에 그물코가 얽혀서 파망이나 안전사고를 유발하기도 한다. 또한, 망구 깊이를 주로 끌줄길이와 예망속도로서 제어하고 있으나, 어구저항이 커서 속도의 조절에 한계가 있다. 중층망의 이러한 결점을 보완하기 위하여 최근에는 뜸 대신 카이트(kite)의 사용에 대한 연구(권, 1995)가 있고, 유럽에서는 뜸 없는 무부자(無浮子) 어구를 개발하여 어구저항의 획기적인 감소를 도모하고 있다. (중략)

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.9-15
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• 2017

In this study we performed the experiment to detect the ERP using SVM with wavelet features. The EEG signal that is generated visual stimulated ERP database in SCCN applied for the experiment. The feature vectors for experiment are categorized frequency and continuous wavelet- based vectors. In experimental results, the detection rate of SVM with wavelet feature vectors improved above 10% comparing with frequency- based feature vector. Based on the experimental results we analyzed the relation between the activity degree of the ERP and the band split characteristics of the ERP by wavelet transform.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.2
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• pp.73-88
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• 2000

A series of analysis and experiment on the fishing gear and method of the existing midwater pair trawl net with 12,800mm of maximum mesh size is carried out to determine the most effective shape factor. As the first step of this study, the fishing gear and method for the existing net are analyzed to solve problems, such as being low of the net height by increasing the towing speed, twist of net pendant and twine, suspension of float between knots of mesh. etc. Standing on these results, the existing net are modified by very effective shape based on the theory and technology designing the fishing gear. Also, the model experiment is carried out to determine the most effective shape factor of the modified net in the circulation water channel. The obtained results can be summarized as follows : 1. On the length of net pendants(No.2 and No.3) connected with side line, opening efficiency of net with length 8.0cm of net pendant is the greatest and in the order of 11.5cm, 15.0cm. 2. On the number of the net pendant, opening efficiency of net with 4 lines of net pendant is the greatest and in the order of 3 lines, 2 lines. Center part of side panel is pushed out backward, and the pushed length is increasing by increasing flow speed. 3. On the sinking force, opening efficiency of the net is increasing by increasing sinking force. And opening efficiency shows almost the same when sinking force is greater about 1.5 times than that of the existing net in case of the net with 3 lines of net pendant, and about 1.6 ~ 1.7 times than that of the existing net in case of the net with 2 lines.

• Korean journal of applied entomology
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• v.41 no.1
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• pp.67-73
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• 2002

Studies were conducted to investigate the control effects of several insecticides on Apolygus(=Lygocoris) spinolae(Meyer-Dur) and to develop its management strategies in grapevine yards. Of insecticides which were applied by farmers in commercial grapevine yards, chlorpyrifos, parathion, fenvalerate, and esfenvalerate$.$fenitrothion showed good control effects against A. spinolae. In designed field experiments of fenitrothion and chlorpyrifos for the evaluation of A. spinolae control, both insecticides showed high control efficacy of 94.8 and 91.6%, respectively. The damage of A. spinolae was examined in a grapevine yard, where five different combinations of application timing and number were treated with fenitrothion to assess yield losses (average cluster weight) by A. spinolae. There were no significant differences among average cluster weights of sprayed vines; 466.0 g in sprayed vines on 2 to 3 leaves unfolded stage, 460.7g in sprayed vines on flower separating stage, 465.0 g in sprayed vines each on 2 to 3 leaves unfolded and flowers separating stage, and 487.4 g in sprayed vines each on 2 to 3 leaves unfolded, flowers separating and fruit set stage. Weights of fruit clusters of unsprayed vines was significantly lower than those of sprayed vines. Based on yield and spray cost, chemical control on 2 to 3 leaves unfolded stage produced higher net income than each spray on 2 to 3 leaves unfolded and flower separating stage (i.e., two times of spray), and produced similar net income as each spray on 2 to 3 leaves unfolded, flowers separating and fruit set stage (i.e., three times of spray). Thus, the 2 to 3 leaves unfolded stage was economical spray timing to controlA. spinolae in grapevine yards. Also, management strategies for A. spinolae were discussed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.2
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• pp.91-107
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• 2009

In order to compute linear wave transformation over a single step bottom, both variational approximation and eigenfunction expansion method are used. Both numerical results are in good agreement for reflection and transmission coefficients, surface displacement respectively. However x velocity profiles at the boundary of step are seen to be different to each other even though x velocity matching condition is used.

• Journal of Korea Multimedia Society
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• v.11 no.11
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• pp.1525-1535
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• 2008

High Altitude Platform (HAP) based networks deploy network infrastructures of Mobile Base Station (MBS) in a form of Unmanned Aerial Vehicle (UAV) at stratosphere in order to build network configuration. The ultimate goal of HAP based network is a wireless network service for wide area by deploying multiple MBS for such area. In this paper we assume multiple UAVs over designated area and solve the MBS placement and coverage problem by clustering the mobile ground nodes. For this study we assumed area around Cheju island and nearby naval area where multiple mobile and fixed nodes are deployed and requires HAP based networking service. By simulation, visual results of stratospheric MBS placement have been presented. These results include clustering, MBS placement and coverage as well as dynamic reclustering according to the movement of mobile ground nodes.

• The Korean Journal of Rheology
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• v.9 no.2
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• pp.81-87
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• 1997

비상용성 고분자는 그 계면의 특성에 의해서 복잡한 유변학적 거동을 갖는데 그러 한 거동을 해석하기 위해서 최근에 제안된 구성방정식을 토대로 소폭 진동 전단 흐름장에서 의 유변학적 물성과 몰폴로지 전개를 예측한 바 있다. Takahashi[2]등은 이런 흐름하에서의 계면은 거의 변하지 않음을 보여주었고 따라서 이경우는 상대적으로 쉬운편이었다. 본연구 에서는 정상전단흐름장하에서의 몰폴로지 전개에 대한 구성방정식을 간단한 형태로 표현함 으로써 실제 산업계에서 이용될수 있도록 하였다. 그러한 해석을 통하여 원래의 모델에서 제시되었던 3개의 실험변수를 2개로 줄일수 있었으며 계면의 특성을 잘 나타내 주는 새로운 변수($textsc{k}$)를 도입하였다. 계면의 특성을 잘 나타내 주는 이새로운 변수를 통하여 그 계면의 영향을 예측할수 있었다. 한편 분산상의 파괴, 변형, 합체 메카니즘을 모델에 제시되었던 변 수값들을 통하여 해석하였고 이를 실험적인 데이터와 비교해 보았다.

• Journal of Korea Water Resources Association
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• v.35 no.6
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• pp.677-684
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• 2002

In this study, a finite element model is employed to simulate the diffraction of waves caused by a change of water depths. The model is firstly applied to the estimation of reflection coefficients of monochromatic waves over a sinusoidally varying topography. Predicted coefficients are compared with those of the eigenfunction expansion method and laboratory measurements. A good agreement is observed. The model is then used to investigate effects of heights of bottom topography and number of ripples on variation of reflection coefficients of monocromatic water waves.