• Parasites, Hosts and Diseases
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• 제43권3호
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• pp.75-92
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• 2005

Extensive previous studies on taxonomy, behavior/bionomics and control of Anopheles sinensis are reviewed and summarized. Recent molecular identification revealed that the population of An. sinensis complex includes An. sinensis, An. pullus, An. lesteri and at least two new species, and An. yatsushiroensis is synonmy of An. pullus. An. sinensis is the main vector specie of vivax malaria in Korea. Larvae of An. sinensis breed in wide range of habitats which are naturally-made clean water, stagnant or flowing; main habitats include rice fields, ditches, streams, irrigation cannals, marshes, ponds, ground pools, etc. Their host preferences are highly zoophilic. Human blood rate is very low ($0.7-1.7\%$); nevertheless An. sinensis readily feeds on man when domestic animals are not found near by. They feed on hosts throughout the night from dusk to dawn with a peak period of 02:00-04:00 hours; they are slightly more exophagic (biting outdoors); much larger numbers come into the room when light is on. Main resting places are outdoors such as grasses, vegetable fields and rice fields. A mark-release-recapture study resulted that $37.1\%$ was recaptured within 1 km, $29.4\%$ at 1-3 km, $21.1\%$ at 3-6 km, $10.3\%$ at 6-9 km and $2.1\%$ at 9-12 km distance. An. sinensis hibernate outdoors (mostly under part of dense grasses) during October-March. At the end of the hibernation period (March-April) they feed on cows at daytime. Until today any single measure to effectively control An. sinensis population has not been found. Indoor residual spray with a long-lasting insecticide can not reduce vector population densities, but shorten their life spans in some degree, so contributes to malaria control.

• 대한수학회논문집
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• 제35권3호
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• pp.1019-1035
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• 2020

In this paper, we introduce the deformed-Sasaki metric on the tangent bundle TM over an m-dimensional Riemannian manifold (M, g), as a new natural metric on TM. We establish a necessary and sufficient conditions under which a vector field is harmonic with respect to the deformed-Sasaki Metric. We also construct some examples of harmonic vector fields.

• Journal of the Korean Statistical Society
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• 제1권1호
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• pp.18-24
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• 1973

Study on convexity has been improved in many statistical fields, such as linear programming, stochastic inverntory problems and decision theory. In proof of main theorem in Section 3, M. Loeve already proved this theorem with the $r$-th absolute moments on page 160 in [1]. Main consideration is given to prove this theorem using convex theorems with the generalized $t$-th mean when some convex properties hold on a real linear vector space $R_N$, which satisfies all properties of finite dimensional Hilbert space. Throughout this paper $\b{x}_j, \b{y}_j$ where $j = 1,2,......,k,.....,N$, denotes the vectors on $R_N$, and $C_N$ also denotes a subspace of $R_N$.

• 충청수학회지
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• 제21권1호
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• pp.29-48
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• 2008

We deal with the classification problem of real hypersurfaces in a complex hyperbolic space. In order to classify real hypersurfaces in a complex hyperbolic space we characterize a real hypersurface M in $H_n(\mathbb{C})$ whose structure vector field is not principal. We also construct extrinsically homogeneous real hypersurfaces with four distinct curvatures and their structure vector fields are not principal.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제24권4호
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• pp.211-226
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• 2017

In this paper, machine learning models employed in various fields are discussed and applied to KOSPI200 stock index return forecasting. The results of hyperparameter analysis of the machine learning models are also reported and practical methods for each model are presented. As a result of the analysis, Support Vector Machine and Artificial Neural Network showed a better performance than k-Nearest Neighbor and Random Forest.

• Kyungpook Mathematical Journal
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• 제61권1호
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• pp.191-203
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• 2021

Let M be an almost Kenmotsu manifold of dimension 2n + 1 having non-vanishing ��-sectional curvature such that trℓ > -2n - 2. We prove that any second order parallel tensor on M is a constant multiple of the associated metric tensor and obtained some consequences of this. Vector fields keeping curvature tensor invariant are characterized on M.

• Kyungpook Mathematical Journal
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• 제62권2호
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• pp.333-345
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• 2022

We study *-Ricci solitons on non-cosymplectic (κ, µ)-acs (almost cosymplectic) manifolds M. We find *-solitons that are steady, and such that both the scalar curvature and the divergence of the potential field is negative. Further, we study concurrent, concircular, torse forming and torqued vector fields on M admitting Ricci and *-Ricci solitons. Also, we provide some examples.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.62-64
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• 1996

Two current approaches for modeling the vector magnetic hysteretic process are the vector Preisach models and those models based on a system of noninteracting pseudo-particles. The pseudo-particles are intended to mimic the average behavior of real media particles. The simplest switching mechanisms of pseudoparticles is the Stoner-Wholfarth model. The Preisach models are quite precise in specifying the experimental input to the models. The vector properties of the Preisach models are, however, inadequate. This is partly because of the questionable assumptions used in coupling the various vector hysteresis components. Also these models do not include reversible magnetization changes. Unlike Preisach counterpart, the Stoner-Wholfarth model is inherently vector in nature. This is because spatial distribution and switching mechanisms are imposed on the system of pseudo-particles, so they come closer to representing the physical reality. The lack of interaction between pseudo-particles exclude the usefulness of the Stoner-Wholfarth model for small fields when the medium is traversing minor loops. The present work is an attempt at combining the advantages of above two models into one composite model, including the effect of particle interaction.

• 대한수학회논문집
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• 제29권2호
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• pp.319-329
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• 2014

In this paper we study the properties of conformally recurrent pseudo Riemannian manifolds admitting a proper conformal vector field with respect to the scalar field ${\sigma}$, focusing particularly on the 4-dimensional Lorentzian case. Some general properties already proven by one of the present authors for pseudo conformally symmetric manifolds endowed with a conformal vector field are proven also in the case, and some new others are stated. Moreover interesting results are pointed out; for example, it is proven that the Ricci tensor under certain conditions is Weyl compatible: this notion was recently introduced and investigated by one of the present authors. Further we study conformally recurrent 4-dimensional Lorentzian manifolds (space-times) admitting a conformal vector field: it is proven that the covector ${\sigma}_j$ is null and unique up to scaling; moreover it is shown that the same vector is an eigenvector of the Ricci tensor. Finally, it is stated that such space-time is of Petrov type N with respect to ${\sigma}_j$.

• 한국전자파학회논문지
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• 제25권4호
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• pp.476-482
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• 2014

본 연구에서는 위성 SAR 영상을 이용한 초목층 정보 예측을 위해 옥수수의 생육에 따른 후방 산란 계수 변화를 분석한다. 이를 위하여 지상형 산란계 시스템을 이용하여 옥수수 밭의 후방 산란 계수를 측정하였으며, 지표면 정보를 입력변수로 한 1차 VRT(Vector Radiative Transfer) 기법을 이용하여 후방 산란 계수를 계산하여 측정값과 비교/분석한다. 그 결과, 생육 초기에는 옥수수보다 토양에서의 산란이 지배적이었으며, 옥수수의 밀도가 증가하면서 잎의 분포의 영향으로 입사각이 증가하면서 후방 산란 계수가 점차 상승하는 특징을 보였다. 측정 데이터와 1차 VRT 계산 오차는 평균 RMSE (Root Mean Square Error)가 VV-편파에서 1.32 dB이었고, HH-편파에서 0.99 dB이었다. 또한, 1차 VRT 계산을 통해 LAI (Leaf Area Index) 변화에 따른 작물과 토양에서의 산란 영향을 분석하였다.