• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.345-358
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• 1982

1980.8-1982.8월까지 일광, 주문진, 돌산, 어청도 및 성산포에서 채집한 1,663미의 보라성게의 성장 및 산란에 관한 조사이다. 1세부터 5세까지의 평균각경은 가각 19, 32, 43, 51, 58mm로 추정됐으며 $l_\infty=84.4 mm,\;k=0.223,\;t_o=-0.187$의 성장식을 보였다. 가경에 대한 각고, 보대, 간보대, 위홍문부경 및 극 길이의 상관관계는 매우 높았다. 연령에 따른 가부분의 상대성장은차이가 없으나 극의 성장에서는 3세까지는 각경에 비례하여 성장하나 그 이후의 연령부터는 반비례하고 있다. 일광해역에서의 산란은 6-10월에 일어나며 주 산란은 8월로 사료한다. 연령에 따른 주 산란시기는 다르며 고연령군은 저연령군 보다 일찍 산란하고 있다. 제주산 보라성게는 8월 이전에 산란을 이미 마친 상태이며 여수산, 일광산은 주로 8월에, 주문진산, 어청도산은 8월 이후에 산란하는 것으로 판단된다.

• KOREAN POULTRY JOURNAL
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• v.43 no.10
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• pp.135-139
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• 2011

지난 8월 25~26일 이틀간 충북 충주시 소재 농협 수안보수련원에서 2011년 산란계자조금사업 일환으로 농가 및 관련종사자 150여명이 참석한 가운데 '계란산업 가치향상을 위한 심포지움'을 가졌다. 첫째 날은 계란 산업 정책방향(농림수산식품부 노수현 과장), 계란유통 선진국 사례와 농협 역할 및 선진화방안(농협중앙회 김삼수 팀장), 산란계 생산성 향상 방안(농협사료 엄재상 박사), 소비자가 원하는 사양관리(한국양계농협 오정길 조합장), 산란계자조금 거출 향상 방안(산란계자조금사무국 김종준 팀장)에 대한 발표가 있었으며 둘째 날은 국내 닭 전염병 발생동향 분석(농림수산검역검사 본부 권용국 박사), 산란계 강소농을 위한 제언(국립축산과학원 서옥석 과장), 산란계자조금사업 선진국 사례와 활성화 방안(한국자조금연구원 박영인 박사)에 대한 발표가 있었다. 계란산업 발전방안 및 정책건의 토론회 시간에는 안영기 산란계자조금관리위원장이 좌장을 맡은 가운데 오정길 조합장(한국양계농협), 김삼수 팀장(농협중앙회 가금팀), 엄재상 박사(농협사료)가 토론자로 나섰다. 본고는 이날 발표내용을 요약, 정리 하였다.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.447-450
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• 2002

음향수조 내에 일정한 간격으로 배열된 단순 모양의 산란체들로부터 획득된 후방산란 신호를 분석하여 산란체 간격(scatterer spacing)을 추측 할 수 있는 방법을 연구하였다. 수신신호의 산란특성을 켑스트럼 피크(cepstral peaks)를 이용하여 산란체 간격으로 해석하였다. 임펄스 응답신호를 이용한 수치계산으로 산란체 간격 추정방법을 검증한 후, 수조 실험으로 획득한 후방 산란 신호에 적용해 그 결과를 비교해 보았다.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.127-134
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• 2012

Microwave remote sensing can help monitor the land surface water cycle, crop growth and soil moisture. A ground-based polarimetric scatterometer has an advantage for continuous crop using multi-polarization and multi-frequencies and various incident angles have been used extensively in a frequency range expanding from L-band to Ka-band. In this study, we analyzed the relationships between L-, C- and X-band signatures and soil moisture content over the whole soybean growth period. Polarimetric backscatter data at L-, C- and X-bands were acquired every 10 minutes. L-band backscattering coefficients were higher than those observed using C- or X-band over the period. Backscattering coefficients for all frequencies and polarizations increased until Day Of Year (DOY) 271 and then decreased until harvesting stage (DOY 294). Time serious of soil moisture content was not a corresponding with backscattering over the whole growth stage, although it increased relatively until early August (R2, DOY 224). We conducted the relationship between the backscattering coefficients of each band and soil moisture content. Backscattering coefficients for all frequencies were not correlated with soil moisture content when considered over the entire stage ($r{\leq}0.50$). However, we found that L-band HH polarization was correlated with soil moisture content (r=0.90) when Leaf Area Index (LAI)<2. Retrieval equations were developed for estimating soil moisture content using L-band HH polarization. Relation between L-HH and soil moisture shows exponential pattern and highly related with soil moisture content ($R^2=0.92$). Results from this study show that backscattering coefficients of radar scatterometer appear effective to estimate soil moisture content.

• Korean Journal of Ichthyology
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• v.26 no.1
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• pp.11-16
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• 2014

The best spawning timing in a day and the first spawning position of Pseudopungtungia nigra was investigated at the Jujacheon stream in Jinan-gun Jeollabuk-do, Koera from May to July 2009. P. nigra spawned only at the nest of Coreoperca herzi from 7 May to 11 July, 2009. P. nigra spawned at 56 nests among 61 nests of C. herzi, and the spawning of P. nigra started on after 1st or 2nd day spawning of C. herzi. The spawning behavior was dominantly observed at around 06:00 to 07:00 AM, when parental C. herzi males are usually inactive in the territorial defence. The hatching rate of P. nigra eggs was closely related with the parental activity of the guarding C. herzi, and P. nigra deposit their eggs as close as possible to the egg clutches of C. herzi (normally at the perimeter of the clutch), likely to take much of the potential effects from fanning and guarding, as the hosts focus their care on the centre of the egg clutch.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.6
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• pp.425-438
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• 1990

Acoustic and ichthyoplankton data collected from Shelikof Strait in 1981, 1984 and 1985 were examined to determine spawning ground and period of walleye pollock, Theragra chalcogramma. Walleye pollock in the Gulf of Alaska migrated into Shelikof Strait for spawning during late winter and early spring. They entered Shelikof Strait via the warm and saline deep layer (continental slope water mass) in the southwestern channel, and major fish schools concentrated for spawning along the deep trough (250~300m) in the western part of the central strait. Peak spawning activity occurred there from late March to early April. Peak spawning time and area in Shelikof Strait varied little between years, despite difference in hydrography. Geographical advantages together with some oceanographic phenomena (reduced water transport and reduced mixed layer depth in spring) made that area an optimal spawning ground in the Gulf of Alaska during early April. After early April, spawning intensity decreased rapidly and the spawning area tended to expand to the northeast and southwest.

• Journal of Aquaculture
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• v.3 no.1
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• pp.1-11
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• 1990

To induce an early spawning, the adult red sea bream, Pagrus major, were exposed to predesignated condition of photoperiod and water temperature during February 21 to June 30, 1988. Spawning began from April 20, a month earlier than that in the natural condition, when the photoperiod and water temperature were controlled at 14L: l0D and $17.0^{\circ}C$, respectively, and the spawning continued until June 15, 1988. There were no particular differences between fish under the controlled condition and those in natural condition in terms of the fertilization rate, surface floating rate, the number of oil glouble and the hatching rate.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.207-216
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• 2005

Spawning behaviors of Squalidus gracilis majimae (Cyprinidae) were observed in the laboratory whose environmental factors such as light (D/L = 16 : 8), temperature ($20\;{\sim}\;24\;＾{\circ}C$), and dissolved oxygen (>8 mg $L^{-1}$) were quite regularly controlled. The behavioral patterns were categorized into three stages ofpre-spawning, spawning, and Post-spawning behaviors. In Particular, the pre-spawning stage was specified by 11 specific behavioral patterns of aggressive mating behaviors. During the spawning stage, the male and female performed four distinct spawning behaviors including sexual temptation, stimulation, egg spawning, and the separation, and randomly laid about 200 ${\sim}$ 300 eggs on the bottom substrates through the night. After finishing spawning, two adults separated toward their refuges and showed 3 types of post-spawning behaviors such as the resting, occasional eggs protecting, and the egg eating. The fish was identified as a partial-parental care species after the spawning.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.572-576
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• 2006

본 시험은 산란계에 생균제를 급여하였을 때 산란계의 산란능력과 계분내 유해가스 감소에 미치는 영향을 규명하기 위하여 실시하였다. 산란계용 사료에 생균제를 0.2%와 0.5%를 처리한 구와 무처리의 3개 처리구를 두고 처리당 6반복, 반복당 4수씩 총 72수의 갈색 산란계(36주령)를 공시하여 6주간(42일) 사양 시험을 실시하였다. 산란계 사료에 생균제의 참가량을 증가함에 따라 산란율은 증가하였으며, 사료 섭취량은 감소하였다. 한편 계란의 품질에서는 생균제의 첨가량을 증가함에 따라 난중, 농후난백고, HU 및 난항색도가 증가하였다. 산란계의 영양소 이용율에서는 가용무질소물을 제외하고 건물, 조단백질, 조지방 및 조섬유 이용율이 생균제를 첨가함에 따라 증가하였다. 계분내 유해가스 발생량에서는 암모니아, 황하수소 및 멜캅탄 가스의 감소에 효과가 있었으며, 특히 황화수소의 감소에 효과가 있었다. 이상의 시험결과를 종합해 볼 때 산란계에 첨가한 생균제는 산란율을 증가시킬 뿐만아니라 계란의 품질 향상에 효과가 있었다. 또한 영양소 이용율을 개선하고 계분내 유해가스를 감소시키는 효과가 있었다.

• The Journal of the Acoustical Society of Korea
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• v.40 no.1
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• pp.1-9
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• 2021

High-frequency bistatic sea surface scattering channels according to sea state were measured at an experimental site of Geoje bay in April 2020, and compared with predictions based on scattering theory. A linear frequency-modulated signal with a center frequency of 128 kHz and a bandwidth of 32 kHz was used for the acoustic measurements. Sea surface wavenumber spectrum was calculated from surface roughness data measured by a wave buoy, and bistatic scattering cross-section of Small Slope Approximation (SSA) based on the wavenumber spectrum was estimated. In addition, scattering from near-surface bubbles using wind speed measured during experiments was considered. Surface scattering channel intensity impulse responses were simulated using the scattering cross-section and the simulation results were compared and analyzed with the field data.