• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.478-484
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• 2003

The electromagnetic wave scattering problems from inhomogeneous material bodies are considered. The formulation is made in terms of mixed potentials for the moment methods (MoM). The surfaces of a three-dimensional inhomogeneous scatterer of arbitrary shape are divide into triangular patches for descretization. Application of the boundary conditions leads to the coupled surface integral equations to be satisfied for the unknown surface equivalent electric and magnetic currents. The radar cross-section (RCS) for some structures is computed and the results are compared with the reported data.

• KOREAN POULTRY JOURNAL
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• v.23 no.7 s.261
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• pp.83-87
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• 1991

• KOREAN POULTRY JOURNAL
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• v.30 no.5 s.343
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• pp.84-92
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• 1998

• Korean journal of applied entomology
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• v.11 no.2
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• pp.61-68
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• 1972

This study has been carried out to investigate the varietal resistance of Tong-il rice variety (IR-667) at the seedling stage to the brown planthopper. Nilaparvata lugens STAL, and further to know the biological effects of the varieties to the insects. The results obtained were as followings; 1. Tong-il variety tested in this experiment was susceptible to the brown planthopper but it seemed to be a little more tolerable than the Japonica varieties which had been recommended in Korea. 2. Tong-il variety (Suwon 213, Suwon 213-1, Suwon 214, and Suwon 215) was highly prefered by brown planthopper for feeding to the Korean recommended varieties Paltal, Jinheung, Akibare, and Shin #2. 3, The resistant varieties Mudgo, Kayama MGL-2, and Karsamba ASD-7 which showed low feeding preference exhibited higher ovipositional preference than the susceptible varieties. Relatively greater number of eggs was recorded on the Tong-il variety (Suwon 213, Suwon 213-1, and Suwon 215) in comparison with the Korean recommended varieties, 4, When the female brown planthopper adults were caged on Tong-il variety (Suwon 214) and the resistant variety Karsamba ASD-7 separately, greater number of eggs were observed on Suwon 214 and less on Karsamba ASD-7, while when two varieties Suwon 214 and Karsamba ASD-7 were given together in the same cage, Karsamba ASD-7 was much more prefered for oviposition to Suwon 214. 5. There was no difference in e99 Periods and their hatchal\bility between the resistant and susceptible varieties, but nymphal periods, rate of adult emergence, longevity of the adult, and its fecundity were significantly different according to the varieties.

• 한국해양학회지
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• v.29 no.3
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• pp.287-295
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• 1994

The relationship between temperature profile and backscattering strength(S/SUB y/) computed by the ADCP data is studied in warm eddy of the southwestern parts of the East Sea of Korea in April, 1993. The result shows that S/SUB y/ with depth in N-S direction shows a symmetric shape that is almost the same as the warm eddy. But the profile of S/SUB y/ with depth in N-S direction shows a symmetric shape that is almost the same as the warm eddy. But the profile of S/SUB y/ in E-W direction shows asymmetric shape where the S/SUB y/ of the eastern parts is smaller than that of western parts. The asymmetric distribution may be due to the migration of a large number of scatterer(mainly zooplankton) carried by EKWC(East Korea Warm Current). Profile of the S/SUB y/ is similar to the temperature with depth in the ADCP data of CREAMS 93(Circulation Research of the East Asian Marginal Seas).

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.1
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• pp.69-79
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• 2001

A volume integral equation method(VIEM) is applied for the effective analysis of elastic wave scattering problems in unbounded solids containing general anisotropic inclusions. It should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only the Green's function for the unbounded isotropic matrix is Involved In their formulation for the analysis. nis new method can also be applied to general two-dimensional elastodynamic problems with arbitrary shapes and number of anisotropic inclusions. Through the analysis of plane elastodynamic problems in unbounded isotropic matrix with an orthotropic inclusion, it is established that this new method is very accurate and effective for solving plane elastic problems in unbounded solids containing general anisotropic inclusions.

• The Korean Journal of Malacology
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• v.13 no.1
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• pp.43-54
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• 1997

1994년 1월부터 12월까지 1년간에 걸쳐 우리 나라 서해안 비인만의 조간대에서 채집된 떡조개, Dosinorbis(Phacosoma) japonocus(Reeve)를 대상으로 성숙 및 산란시기를 규명하기 위해 생식소 여포지수(GFI)및 생식소지수(GI)의 월별변화, 생식주기, 월별 난경 조성 및 성비를 조사하였다. 본 종은 자웅이체이고, 생식소는 중장선 하부와 소화맹낭 그리고 섬유성 결체조직과 근섬유에 의해 치밀하게 구성된 외측 근섬유층 사이에 위치하고 있다. 산란기 추정을 위해 조사된 GFI와 GI의 월별변화 양상은 생식주기와 일치하는 경향을 보였다. 난경 55-65$\mu\textrm{m}$인 성숙란들은 젤라틴성 막에 의해 둘러싸여 있다. 본 종의 생식주기는 초기활성기 (12-2월), 후기활성기(2-5월), 성숙기(5-8월), 부분산란기(6-8월)그리고 퇴화 및 비활성기(8-12월)의 연속적인 5단계로 나눌 수 있었다. 산란기는 수온 및 먹이이용 가능성과 밀접하게 관련되어 있는 것으로 보이며, 산란은 수온이 2$0^{\circ}C$ 이상인 6월부커 8월까지 일어났고, 산란성기는 6월과 7월이었다. 산란기는 단지 그 해 하계에만 일어남으로써 1년에 1회의 산란기를 가지나 그 산란 빈도 횟수는 1년에 1회의 산란계절 중 2회 이상 일어나는 것으로 추정된다. 암.수 개체들의 성비는 통계 처리한 결과 1:1(x$^{2}$=0.08, P>0.05)로 나타나 암.수간 성비에 차이가 없었다.

• KOREAN POULTRY JOURNAL
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• v.43 no.10
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• pp.140-143
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• 2011

경기도 연천의 대표적인 산란계 농장인 안일농장(대표 안영기)은 연천군 내 산란계 사육수수의 50%를 차지하는 지역 선도농가로 알려져 있다. 전체 9만2,562$m^2$(2만8,000여 평)의 농장부지 중 연면적 5만6,198$m^2$(1만7,000여 평)에 육성사 2동, 성계사 10동, 자체 집하장과 액란가공공장을 갖추고 있는 안일농장은 산란계 25만수와 육성계 5만수 등 총 30만수를 사육하고 있으며 하루 12만개의 계란을 생산하고 있다.

• Proceedings of the KSRS Conference
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• 2000.04a
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• pp.137-142
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• 2000

본 논문에서는 풀밭으로 덮힌 지역의 초고주파 대역 편파별 후방 산란을 분석하는데 있어서 Radiative Transfer 이론의 첫 번째 해를 이용하였다. 풀밭지역에서의 잎은 사각형 형태의 resistive sheet 으로 모델화 시키고, 잎의 크기와 방향성은 불규칙적으로 흩어져 있다고 가정하였다. 땅에서의 흙의 수분 함유량과 표면 거칠기도 고려하였다. 이러한 지역에서의 후방 산란 계수는 풀밭 지역과 레이더 요소들에 따라 각각 다른 계산 결과를 나타낸다. 측정은 15 GHz 대역의 레이더 시스템을 사용하여 풀 층에서의 산란 계수를 측정하고 풀 층에서의 산란 모델을 이용하여 계산 결과와 측정값을 비교하였고 이 모델을 이용하여 Visual-Basic을 이용한 사용자 프로그램인 TSM(Total Scattering Model)을 제작하였다.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.224-230
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• 2010

Purpose: We designed the aft-multiple-slit (AMS) system to reduce scatter in cone-beam computed tomography (CBCT). As a preliminary study, we performed a Monte Carlo N-Particle Transport Code (MCNP) simulation to verify the effectiveness of this system. Materials and Methods: The MCNPX code was used to build the AMS geometry. An AMS is an equi-angled arc to consider beam divergence. The scatter-reduced projection images were compared with the primary images only and the primary plus scatter radiation images with and without AMS to evaluate the effectiveness of scatter reduction. To obtain the full 2 dimensional (2D) projection image, the whole AMS system was moved to obtain closed septa of the AMS after the first image acquisition. Results: The primary radiation with and without AMS is identical to all the slit widths, but the profiles of the primary plus scattered radiation varied according to the slit widths in the 2D projection image. The average scatter reduction factors were 29%, 15%, 9%, and 8% when the slit widths were 5 mm, 10 mm, 15 mm, and 20 mm, respectively. Conclusion: We have evaluated the scatter reduction effect of the AMS in CBCT imaging using the Monte Carlo (MC) simulations. A preliminary study based on the MCNP simulations showed a mount of scatter reduction with the proposed system.