• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.246-251
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• 1989

A medicinal legume crop, Cassia tora L., was grown with four different seeding dates in 1986 field condition to find the flowering and pod setting characteristics. Initial flowering date and flowering duration were almost same between plants sown from April 20 to May 30, but those of plants seeded at June 20 were significantly delayed and shortened. Last flowering date, however, was not different between plants sown from April 20 to June 20. C. tora plants showed indeterminate flowering habit, and bloomed vigorously from fourth date after initial flowering. Numbers of flowers, ovules and pods per plant were decreased along with delaying seeding date, and ovule to flower ratio and pod to flower ratio were greatly decreased in June 20 seeding plot. Flowers bloomed on second week from initial flowering showed the highest number of ovules and pods, and flowers bloomed after early September did not develop to matured pods. Maximum values of pod length, number of seeds per pod and 1000-grain weight were obtained from flowers bloomed on second week from initial flowering of plants sown from April 20 to May 30, and first week in June 20 seeding plot.

• Korean journal of applied entomology
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• v.30 no.3
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• pp.169-173
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• 1991

These studies were conducted to investigate overwintering forms and adult population fluctuation in field condition, and life cycle in field-cage condition of diamondback moth, Plutella xylostella (L.). Plutella xylostella overwintered as all the stages of eggs, larvae, pupae and adults in southern region of Korea. The occurrence which adult moths were attracted by light trap at 5-day intervals, reached their peaks in May, mid-June to mid-July, and late September to early November, and fell in late July to mid-September. Under field-cage condition, they occurred 10-11 generations a year and the period of adult emergence from egg was 11-18 days in July and August, 19-23 days in June and September, 28-34 days in April, May and October, and about 50-100 days in other months. And the longevities of adults were 4-11 days in summer, 7-17 days in spring and fall. A number of eggs laid by individual female ranged from 50 to 240. The females laid more eggs in spring and fall than they did in summer. The period of developmental stages under field-cage conditions was 2-3 days for eggs, 7-8 days for larvae and 4-6 days for pupae in July and August; 4-5 days for eggs, 3-12 days for larvae and 6-8 days for pupae in June and September; 6-18 days for eggs, 13-20 days for larvae and 8-14 days for pupae in March, April, May and October; and 12-40 days for eggs, 50-100 days for larvae, and about 20 days for pupae in winter.

• 한국해양학회지
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• v.1
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• pp.37-48
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• 1971

Observations of water temperature, salinity, pH and transparency of the Ko-ri sea area were made between May 1969 and April 1970. A seasonal thermocline was well defined in August, strongly isolating the warm serface water(19-22$^{\circ}C$) from the cold bottom water (14-17.5$^{\circ}C$) introducing from the open sea. In February the coldest isothermal water (11$^{\circ}C$) occurred. In the warm months(May- September), the salinity patterns show great variations with the coastal run-off During the cold months(December-April) the highest isohaline water (35 ) occurred. Annual ranges of surface and bottom pH values were 7.8-8.4(averaging 8.27) and 7.9-8.4(averaging 8.26), respectively. The transparency was greatest (6.0-7.0m) during winter and spring months and least (1.2-2.5m) during summer months.

• The Korean Journal of Malacology
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• v.23 no.2
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• pp.165-172
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• 2007

Gonadal development, reproductive cycle and sex ratio of the purplish Washington clam, Saxidomus purpuratus were investigated monthly by histological observations. Samples were collected from May 2006 to April 2007 in the Gangjin Bay of Namhea, Gyeongsangnam-do, Korea. The clams are dioecious. The gonads consist of a number of oogenic follicle and acinus. Monthly changes in the gonad index reached a maximum in April and a minimum in July. Monthly changes in the condition index reached a maximum in June and a minimum in November. The reproductive cycle of this species can be divided into five successive stages: the recovery and resting stage (June to December), early active stage (January to April), late active stage (February to July), ripe stage (March to October), spent stage (April to October). The main spawning of the clam occurred in July and September in Gangjin Bay. The sex ratio of female to male was not significantly different from 1:1.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1953-1957
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• 2007

전 세계적으로 지구 온난화 등의 영향으로 인해 이상기후의 발생이 증가하고 있는 추세에 있다. 특히 엘니뇨 현상은 세계적으로 발생하는 홍수, 가뭄 등과 같은 재해와 많은 관련이 있음이 연구를 통해 확인되었다. 이러한 엘니뇨 현상을 판단하기 위해서는 다양한 자료들이 사용되고 있으며, 그 중 관측 인자의 하나로서 태평양 해수면 온도 자료 (Pacific sea surface temperature)를 많이 사용하고 있다. 본 연구에서는 우리나라 강수량 자료와 태평양 해수면 온도의 원격상관 (Teleconnection) 관계를 분석하였다. 강수량 자료로는 우리나라 20개 기상관측소의 월강수량 자료를 사용하였으며, 태평양 해수면 온도 자료로는 Nino1+2 $(0-10^{\circ}S,\;90^{\circ}W-80^{\circ}W)$, Nino3 ($5^{\circ}N-5^{\circ}S$, $150^{\circ}W-90^{\circ}W)$, Nino4 ($5^{\circ}N-5^{\circ}S$, $160^{\circ}E-150^{\circ}W$) 그리고 Nino3.4 ($5^{\circ}N-5^{\circ}S$, $170^{\circ}W-120^{\circ}W$) 관측 지역의 해수면 온도 자료를 사용하였다. 우리나라 강수량의 경우 계절에 따라 큰 변동성을 보이고 있다. 따라서 자료의 계절적 영향을 파악하기 위해 봄 (3월, 4월, 5월), 여름 (6월, 7월, 8월), 가을 (9월, 10월, 11월) 그리고 겨울 (12월, 1월, 2월)의 4계절로 구분하여, 초과확률 등을 이용한 분석을 실시하였다. 분석 결과 Warm ENSO episode의 경우 강수량 증가와 유의한 상관관계를 나타냈으며, Cold ENSO episode의 경우 강수량 감소와 유의한 상관관계를 나타내었다. 이러한 분석 결과는 최근 들어 우리나라에 발생하고 있는 이상기후발생과 관련된 연구에 유용한 정보를 제공해 줄 수 있을 것으로 판단된다.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.46-54
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• 2002

We observed zooplankton community to understand variations in the species composition and abundance in Gangjin Bay. Samples were collected bimonthly from February to November 1999 at 10 stations in Gangjin Bay of the southern part of Korea. Zooplankton communities consisted to nine taxa and mean biomass was 2,028 indiv. $m^{-3}$. The maximum abundance was observed to be 5,496 indiv. $m^{-3}$ in February and the minimum in November, 78 indiv. $m^{-3}$. Copepods dominated and most diverse in Gangjin Bay. Seasonal fluctuation in the copepod abundance varied between 42 and 4,159 indiv. $m^{-3}$. Dominant species are Acartia omorii, Centrophages abdominalis, Paracalanus indicus and A. steueri. Cladoceran also dominated and the maximum abundance was 765 indiv. $m^{-3}$ in April. A. omorii and Oithona davisae dominated in February, A. omorii, Eurytemora pacifica, Evadne nordmanni and Podon polyphemoides in April, Tortanus dextrilobatus and decapod nauplius in June, Paracalanus indicus, E. tergestina and Penitia avirostris in August and A. erythraea and P. indicus in October. In November, P. indicus and Sagitta crassa dominated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.102-105
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• 2004

희토류원소를 이용하여 전주-완주지역에서의 지표수와 지하수의 연계성을 밝혀내기 위해 8개 지역을 선정한 후, 기반암시료와 더불어 2002년 4월, 2003년 6월, 2003년 8월 그리고 2003년 11월의 4차례에 걸쳐 현장분석과 더불어 지표수와 지하수시료를 채취하였다. PAAS(Post Archean Australian Shale)로 규격화한 희토류원소분포도에 의하면, 갈수기인 2002년 4월과 2003년 11월의 지표수와 지하수는 대체적으로 중희토류가 부화되었고, 아울러 강한 Eu의 정(＋)의 이상과 Ce의 부(-)의 이상이 관찰된다. 그러나 갈수기가 끝난 2003년 6월과 장마가 끝난 직후인 2003년 8월의 시료에서는 대부분의 지표수와 지하수 시료가 Eu의 강한 부(-)의 이상을 보여준다. 그리고 일부 시료에서는 Ce의 부(-)의 이상도 관찰되었다. 이와 같은 희토류원소 분포 및 Ce과 Eu의 변화는 산화-환원작용의 영향을 받은 산화수(즉 Ce$^{3+}$ 와 Ce$^{4+}$ , Eu$^{2+}$와 Eu$^{3+}$ )의 변화에 의한 것으로 해석할 수가 있다. 뿐만 아니라, 본 연구결과에 의하면, 전주-완주 지역에서의 지표수와 지하수는 매우 밀접한 연관성을 갖고 있으며, 그 순환속도 또한 비교적 빠른 편으로 나타났다. 그리고 본 연구결과, 희토류원소는 지표수와 지하수의 연계성을 밝혀내는 데 있으며 매우 유용한 지시자임을 확인하였다.

• Korean Journal of Ichthyology
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• v.25 no.4
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• pp.216-221
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• 2013

Histological study and gonadosomatic index (GSI) to investigate an exact reproductive cycle of Korean loach Kichulchoia multifasciata, were conducted throughout a year from December 2011 to December 2012. The stage of ovarian and testicular development was divided into four phases: a growing phase (November to March the following year), a spawning phase (April~May), a degeneration phase (May~June), a resting phase (June to November). The peak of the spawning period in male and female appears between April to May, having water temperature $12.7^{\circ}C$ and day length over 13 hours. These results were consistent well with a histological study.

• Journal of Aquaculture
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• v.6 no.3
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• pp.133-146
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• 1993

Monthly variation of fatness index of the shortnecked clam was investigated at Moonhangri in Namhaedo of the southern coast of Korea from April 1991 to March 1992. The standing crops of umbo stage larvae and spats of this bivalve were also investigated. The results are as follows: The ranges of a monthly average water temperature and salinity were $6.9\~23.5^{\circ}C$ and $29.6\~33.1%o$ during the investigation period. Fatness index of the shortnecked clam decreased suddenly from June to September, which seemed to be spawning season. The umbo stage larvae of the clam were observed from May to November. The standing crops of the larvae were $883\;inds./m^3$ in August and$68\;inds./m^3$ in November. The observed number per ~ of the spats varied with the month and the different exposure time zones. The highest density $(1,508\;inds./m^3)$ was observed 1 hour exposure zone in August, and the lowest one $(28 inds./m^3)$ at 1 hour exposure station in April. Even the observed number of the spats below 4 mm in shell length were high in 1 and 3 hour exposure zones, the spats above 4 mm in shell length were observed mainly at 3 hour exposure zone.

• Journal of Aquaculture
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• v.10 no.2
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• pp.133-141
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• 1997

Gonadal maturation and annual reproductive cycle of the cultured scallop, Patinopecten yessoensis from eastern waters near of Kangwon-do province, Korea were studied on the basis of monthly variation of gonadosomatic indices (GSI) and histological observations of gonadal tissue. During the experimental period, water temperature at the depth of 20m and sunshine duration per day were ranged from $5.3^{\circ}C\;to\;18.0^{\circ}C$ and 9.4 to 14.6 hours, respectively. GSI values of femal were in a wide range from $2.8\pm0.37(August)\;to\;22.66\pm4.38(April)$. GSI values began to increase in March and reached the maxium in April, then decreased repidly. GSI values of male were in a range from $2.04\pm0.80(August)\;to\;20.46\pm1.49(April)$ and were same tendency with female's. Digestive diverticula indices (DDI) of both sex reached the maximum values in December, then deceased gradually until September. Contrary to GSI, adductor muscle indices (AMI) of both sex were the minium values in April, but began to increase rapidly until July and reached $47.71\pm3.17(female)\;and\;48.70\pm3.55(male)$. In the scallp collected hermaphroditic gonads were found. Monthly changes of oocyte diameter were in a range from 11.3 um(October) to 73.3um (April) and nuclear diameters were in a range from 8.3um (September) to 35.3um (April), similar tendency with each other. The changes in number of ovarian tubules were reciprocal tendency with those of oocyte diameter and monthly number of ovarian tubules per $\textrm{mm}^2$ in the tissue perpatation was in a range from 51 (April) to 175 (August). As the results, the annual reproductive cycle of the cultured scallolp from eastern waters of Korea could be classified into five successive stages : multiplicative (October), growing (November to February), mature (March and April), spawning (April to June) and recovery (July to September) in female ; multiplicative (October and November), growing (December and January), mature (February to April), spawning (April to June) and recovery (July to September) in male.