• 한국전자파학회논문지
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• 제30권5호
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• pp.407-417
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• 2019

탄도 미사일은 상공에서 자유 낙하하며 표적을 요격하기 때문에 탄도 미사일에 부착되는 탐색기는 높은 지표각에서 해상 클러터 영향을 받게 되며, 그 결과 탐색기의 탐지 성능이 급격히 낮아지게 된다. 이를 해결하기 위해서는 다양한 시나리오 기반의 시뮬레이션들을 통한 해상 표적 탐지 성능 분석이 반드시 필요하다. 따라서 본 논문에서는 실제와 유사한 높은 지표각의 해상 클러터 수신 신호를 모델링한 후, 이를 신호 대 클러터 비에 따라 해상 표적 수신 신호와 합성하여 2차원 레이다 영상을 생성한다. 이후, 레이다 영상에 2차원 CA-CFAR 탐지기를 적용하여 다양한 시나리오에서 해상표적 탐지 성능을 분석하였다. CAD 모델과 전자기 수치해석 도구를 사용한 시뮬레이션 결과, 지표각과 방위각에 따라 해상 표적의 탐지 여부가 다르게 나타남을 확인할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제7권4호
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• pp.555-561
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• 1994

This paper presents results from a study of the body composition and sensory characteristics of female weaner goat meat. A completely randomized $3{\times}3{\times}2$ factorial design was used. Factors were genotype (Thai native; TN, 75% TN $\times$ 25% Anglo-Nubian; AN and 50% TN $\times$ 50% AN), feeding {grazing only, low (1.0% BW/d) and high (1.5% BW/d) concentrate supplementation and parasite control (undrenched and drenched)}. It was shown that there was no effect of genotype on body components and dressing percentage. However, TN and 75% TN $\times$ 25% AN kids had significantly (p<0.05) higher muscle to bone ratios (4.20% and 4.20%, respectively) compared with 50% TN $\times$ 50% AN kids (3.88%). Kids on grazing only had significantly (p<0.01) higher muscle percentage (64.12%) than did kids in low (61.30%) and high (60.62%) supplementary feeding program, but there was no significant (p>0.05) difference between low and high supplementary feeding groups. Kids offered supplementary feeding had significantly (p<0.01) higher percentages of total fat, intermuscular fat, pelvic fat and kidney fat than those of grazing only. Kids offered supplementary feeding had significantly (p<0.05) higher muscle to bone ratios and significantly (p<0.01) higher muscle plus fat to bone ratios compared with those of grazing only. This may be due to significantly lower (p<0.01) bone contents (14.95, 14.17 and 16.8% for kids offered low and high supplementary feeding and grazing only, respectively. There was no significant difference in sensory characteristics of goat meat between genotypes or feeding groups.

• Asian-Australasian Journal of Animal Sciences
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• 제15권9호
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• pp.1300-1306
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• 2002

Fourteen non-descript zebu cattle calves of about 1 year and 6 months age and 111 kg average body weight were used in this experiment. Grazing (5 h daily) animals were supplemented with urea-molasses blocks with and without Yucca, while the control group was without any supplementation i.e. grazing only. The feeding trial continued for a period of 70 days (November to February). At the end of trial three animals per treatment were slaughtered to compare carcass traits. Group no. 1 was fed block with yucca, group no. 2 was fed block without yucca and group no. 3 was on grazing only. Block intake was found to be 724 g/h/d and 1,239 g/h/d for group no. 1 and group no. 2, respectively (p<0.05). Feed efficiency of blocks was found to be 2.71 kg and 4.86 kg for group no. 1 and group no. 2, respectively (p<0.05). Block intake per kg $BW^{0.75}$ was found to be 14.75 and 26.05 gram for group 1 and group 2, respectively (p<0.05). Average daily body weight gain was found to be 267 g/h/d, 255 g/h/d and 169 g/h/d for group 1, 2 and 3, respectively. Carcass traits among the three treatments were found to be statistically similar. Thus urea-molasses blocks supplementation improved body weight gain and addition of yucca in the blocks further improved body weight gain, feed efficiency and economics. Environment (ambient temperature, rainfall, wind and humidity) had no significant effect on three treatments.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.289-294
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• 1994

This report deals with the effect of levels of concentrate supplementary feeding (Nil, 0.25% BW and 0.75% BW) on the productivity of different genotypes (Thai native (TN), 25% Anglo-Nubian (AN), 50% AN and 75% AN) of female goats grazing newly established pasture in a tropical area. The major species of grass was Brachiaria mutica (33%) and of legumes was Centrosema pubescens (34%). There was no significant (p>0.05) difference between nil and 0.25% BW supplementary feeding for growth rate ($g/kg^{0.75}/d$). However, goats fed 0.75% BW supplementary feeding had significantly (p<0.01) higher growth rates than did other treatments. There was no significant (p>0.05) difference among genotypes and between age for growth rate. There was no interaction between feeding and genotype for growth rate.

• 디지털콘텐츠학회 논문지
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• 제18권5호
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• pp.889-894
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• 2017

본 논문은 방목형 축산관리의 효율성을 극대화하기 위해 무인비행체 기반의 자동항법과 근거리무선통신망 기술, 자동이착륙 시스템을 및 개체관리 운영 앱을 통하여 스마트팜 구현에 목적이 있다. 산지생태축산 활성화를 위하여 축산 ICT 융합 기술을 접목한 방목 목장 관리 시스템은 방목 가축의 생산성 향상과 우수품질을 생산하는 인프라 조성과 FTA에 대응하는 축산 경쟁력 확보에 기여할 것으로 예상된다. 축산업에 종사하는 부족한 인력을 대체하는 기술로 농가에 보급을 통해 경쟁력 향상에 기여할 것이다.

• The Journal of the Acoustical Society of Korea
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• 제15권2E호
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• pp.45-49
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• 1996

From the reverberation signals received in the shallower water, the surface scattered signals are identified by using the multipath eigneray model that provides launch angles, grazing angles and transmission loss from the high frequency directional source to and from the rough surface. For small scale surface waves, the perturbation method is used to compute the backscattering strength for various grazing angles and wind speeds. A scheme to inversely estimate the wind speed, by which the observed surface reverberation levels are produced, has been tested. In result, for low grazing angles the perturbation method can be used to predict the backscattering stregth, thereby the surface wind can be indirectly estimated.

• Asian-Australasian Journal of Animal Sciences
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• 제6권2호
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• pp.169-186
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• 1993

The grassland regions of Australia, the Pacific and Asia share common latitudes albeit in opposing hemispheres. However, the environmental and socio-cultural context of pasture development in the subtropical and tropical regions of Australia, the Pacific Islands and Asia differ greatly. Successful technology transfer for improved productivity of grazing livestock is beset by three broad challenges; technical, logistical and socio-cultural. The technical challenge of defining the grassland environment and adapting known technology to local conditions can be successfully addressed by local technicians supported by a reservoir of appropriate international expertise. Logistical difficulties that impede provision of infrastructure and continuity of support services are the responsibility of indigenous organizations. Socio-cultural factors are fundamentally pervasive. These challenges, though outwardly obvious, require careful consideration by both donors and recipients of pasture technology to ensure success with pasture development for viable grazing industries.

• ALGAE
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• 제32권3호
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• pp.199-222
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• 2017

Occurrence of Cochlodinium polykrikoides red tides have resulted in considerable economic losses in the aquaculture industry in many countries, and thus predicting the process of C. polykrikoides red tides is a critical step toward minimizing those losses. Models predicting red tide dynamics define mortality due to predation as one of the most important parameters. To investigate the roles of heterotrophic protists in red tide dynamics in the South Sea of Korea, the abundances of heterotrophic dinoflagellates (HTDs), tintinnid ciliates (TCs), and naked ciliates (NCs) were measured over one- or two-week intervals from May to Nov 2014. In addition, the grazing impacts of dominant heterotrophic protists on each red tide species were estimated by combining field data on red tide species abundances and dominant heterotrophic protist grazers with data obtained from the literature concerning ingestion rates of the grazers on red tide species. The abundances of HTDs, TCs, and NCs over the course of this study were high during or after red tides, with maximum abundances of 82, 49, and $35cells\;mL^{-1}$, respectively. In general, the dominant heterotrophic protists differed when different species caused red tides. The HTDs Polykrikos spp. and NCs were abundant during or after C. polykrikoides red tides. The mean and maximum calculated grazing coefficients of Polykrikos spp. and NCs on populations of co-occurring C. polykrikoides were $1.63d^{-1}$ and $12.92d^{-1}$, respectively. Moreover, during or after red tides dominated by the phototrophic dinoflagellates Prorocentrum donghaiense, Ceratium furca, and Alexandrium fraterculus, which formed serial red tides prior to the occurrence of C. polykrikoides red tides, the HTDs Gyrodinium spp., Polykrikos spp., and Gyrodinium spp., respectively were abundant. The maximum calculated grazing coefficients attributable to dominant heterotrophic protists on co-occurring P. donghaiense, C. furca, and A. fraterculus were 13.12, 4.13, and $2.00d^{-1}$, respectively. Thus, heterotrophic protists may sometimes have considerable potential grazing impacts on populations of these four red tide species in the study area.

• 한국초지조사료학회지
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• 제15권2호
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• pp.112-117
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• 1995

A field experiment was canied out to determine the effects of harvest time (grazing, soiling and hay stage) on the grass growth, dry matter (DM) yield, nutritive value, and weed development in reed canarygrass (Phalaris arundinacea L.) pasture. The cultivars of reed canarygrass used in this study were Palaton, Venture, Castor, and Frontier (control). The grass was harvested 3 times at hay stage, 4 times at soiling stage, and 6 times at grazing stage in 1992. The average plant height was 31-41cm at grazing, 47-59cm at soiling, and 76-86cm at hay stage. Similar DM yield was observed in Palaton(12,567 kglha), Venture(l2,435kg), and Frontier(12,762kg), and the yields of 3 cultivars were significantly higher than that of Castor(ll,025kg) (P<0.05). Total yields affected by harvest time were lO,O6 1, 1 1,832, and 14,699 kg/ha at grazing, soiling, and hay stage, respectively(P<0.05). The content of crude protein (CP) was not significantly different among cultivars. CP contents by harvest time were 21.6% at grazing, 19.3% at soiling, and 18.8% at hay stage, regardless of cultivm(P<0.05). The contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar among cultivars and harvest time. However, slightly higher NDF and ADF contents were found in Frontier. The contents of Ca, P, K, and Mg were not affected by cultivars and harvest time. The appearance of weeds was high in Castor, and low in Frontier. The weeds at grazing stage(33.3-60.0%) were remarkably higher than those at soiling and hay astage (ca 10%). In conclusion, it is suggested that 3-4 times (soiling and hay stage) of harvest was recommended for grass production, nutritive value, and weed control in reed canarygrass pasture, regradless of cultivars of Palation, Venture and Frontier, except Castor.

• 한국항공우주학회지
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• 제36권9호
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• pp.884-890
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• 2008

본 논문에서는 원형 목표구역에 무인 비행체가 도달할 때 비행체의 지향각, 즉 속도 벡터의 방향과 비행체와 목표점과의 시선이 이루는 사이 각을 제어할 수 있는 일반화된 중기 유도법칙을 제안한다. 유도법칙의 도출을 위해 비행체의 운동을 비선형 미분 방정식으로 모델링하고 거리함수 가중치를 갖는 제어 에너지 최소화 문제로 접근하여 최적제어이론을 적용하였다. 결과적으로 원형 목표구역 도달 시 지향각 구속조건을 만족시킬 수 있는 최적 해를 도출한다. 해의 수렴성을 비롯하여 제안한 유도법칙의 특성에 대해 고찰한다. 수치적인 시뮬 레이션을 통해 전형적인 시나리오에 대해 제안한 유도법칙의 성능을 시범적으로 보인다.