• Journal of Aquaculture
• /
• v.8 no.1
• /
• pp.31-46
• /
• 1995

Gonadal maturation and annual reproductive cycle in ovoviviparous oblong rockfish, Sebastes oblangus on the basis of monthly gonadosomatic indices (GSI), hepatosomatic indices (HSI) and histological observations of gonadal tissues. GSI values of female were in a wide range from $0.l5\pm0.0l\;(July)\;to\;58.54\pm3.86$ (December) and began to increase in August and reached the maxium in December, then decreased rapidly thereafter. Male GSI values were in a range from $0.08\pm0.03$ (July) to $1.55\pm0.27$ (September) and began to increase rapidly in July and reached the maximum in September, then decreased gradually, thereafter. Female HSI was in a range from $0.89\pm0.12$ (December) to $3.73\pm0.15$ (October), and male's was from $2.09\pm0.76$ (October) to $3.62\pm0.48$ (August). HSI reached the maximum values one or two months before GSI reached their maxium values in both sex, and then decreased rapidly thereafter. Mature oocytes began to appear in late October as being oocytes began to mature in August, and the type of oocyte development is categorized in the roup-synchronous oocyte development'. Ovulation and fertilization of ripe oocytes occurred in November, and hatched larvae were born from December to January. Maturation of testis was progressed in short term from August to October and spermatozoa were released in October. Sperm balls consisted of many spermatozoa were preserved in ovarian cavity of female after copulation. These results may suggest that the annual reproductive cycle of oblong rockfish could be divided into the following successive stages: growing (August and September), mature (September and October), gestation (November and December), parturition (December and January) and resting (February to July) in female, and growing (August and September), mature (September and October), copulation (October) and resting (November to July) in male.

• Journal of Aquaculture
• /
• v.21 no.4
• /
• pp.252-258
• /
• 2008

Gonadal development and reproductive cycle of the ark shell Scarpharca subcrenata were investigated by histological observations. Samples were collected monthly from March 2007 to February 2008 in the Yeoja Bay, Yeosu, Jeollanam-do, Korea. S. subcrenata was dioecious. The gonads consist of a number of oogenic follicle and acinus. Monthly changes in the gonad index reached a maximum in June and a minimum in September. Monthly changes in the condition index reached a maximum in April and a minimum in September. The reproductive cycle of this species can be divided into five successive stages: early active stage (January to April), late active stage (March to June), ripe stage (May to August), spent stage (July to September) and recovery and resting stage (September to March). The main spawning of S. subcrenata occurred in July and August in Yeoja Bay. The sex ratio of female to male was not significantly different from 1:1.

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

• Korean Journal of Ecology and Environment
• /
• v.38 no.3 s.113
• /
• pp.382-392
• /
• 2005

Data were collected in Lake Daecheong from March 1997 to October 2002 and used to understand an annual change of water environmental factors and trophic states. The surface water temperature was ranged from $3.2^{\circ}C$ to $33.1^{\circ}C$ In the middle of February, water temperature was the lowest. Turbidity was ranged from 0.1 to 203.5 NTU, but the values of above 30 NTU were only measured at site 1. The total mean values of COD and Chl a were $3.6{\pm}1.4\;mg\;O_2\;L^{-1}$, $9.3{\pm}12.8\;{\mu}g\;L^{-1}$respectively. The concentrations of TP and TN were ranged from 0.14 to 5.09 mg N $L^{-1}$, 1 to $247\;{\mu}g\;P\;L^{-1}$ respectively. The total mean value of TN/TP ratio was $98.7{\pm}56.2$. The trophic states were ranged from mesotrophic to eutrophic in Lake Daecheong.

• Korean journal of applied entomology
• /
• v.33 no.3
• /
• pp.173-177
• /
• 1994

his study was conducted to Investigate the occurrence of small brown planthopper (SBPH), LaodeIpahx striatellus Fallen, and the ind~cence 01 rice virus diseases by d~fferent seeding dates in dryseeded rice. The occurrerlce of SBPH was the highest an nce seeded in May 11, followed byMay 1, May 21 and May 31. However. SBPH dld not occur on the rice seeded in June 10 duelo the rice was emerged after peak occurrence of first generailon adult of SBPH. The occurrenceof the first generation adult of SBPH was May 11 and it was 3-day earlier than that of infantnce transplanting. The ~nd~cencofe rice vlrus diseases, rice stripe vilus (RSV) and rice black-streakeddwarf virus (RBSDV), was the most severe at seeding date May 11. and then followed by May1, May 21 and May 31 Thus the incidence of "ce virus diseases was closely related with thedensity of the first generat~on adult of SBPH Rice yield was decreased by later seeding dates, although rice yield from May 1 to May 21 was relatively stable and hqii compared with laterseeding dates. Accordingly, there was slgniilcant relatlonsh~p between rice yield and seeding datesice yield and seeding dates

• 주택과사람들
• /
• s.16
• /
• pp.28-31
• /
• 1991

1. 2/4분기중 전국의 건축허가면적은 전년동기에 비하여 6.4$\%$가 감소하여, 1/4분기에 전년동기대비 12.3$\%$증가한 것에 비해 현저한 감소현상을 나타낸 바, 이는 건축허가제한 강화조치에 기인하는 것으로 보인다. 건축허가면적은 1월과 2월에 전년동기대비 각각 28.9$\%$, 18.4$\%$의 증가를 나타내었으나, 3월들어 1.1$\%$가 감소하면서 감소세로 돌아선 이후, 4월, 5월, 6월에 각각 0.2$\%$, 16.4$\%$, 0.6$\%$의 감소를 나타내면서 지속적 감소추세를 보이고 있다. 특히 6월의 경우 감소추세가 둔화된 사유는 ''90.5.15 건축허가제한조치에 따라 ''90년의 허가면적 자체가 대폭 감소한 데 기인한다. 2. 2/4분기중 허가면적을 용도별로 보면 주거용 건축이 5.6$\%$ 감소하였으며, 상업용은 17.1$\%$의 감소를 보였으나, 공업용은 제조업 분야의 시설투자활성화 영향으로 13.6$\%$의 증가율을 나타내고 있다. 3. 이와 같은 허가면적의 감소추세는 허가제한 강화조치에 따라 하반기에도 지속될 것으로 보인다.

• Journal of Bio-Environment Control
• /
• v.16 no.3
• /
• pp.269-273
• /
• 2007

Freezing hardiness of winter bud and branch according to dormancy level and low temperature, in persimmon (Diospyros kaki) cultivars, was investigated by electrolyte leaching rate, triphenyltetrazolium chloride (TTC) test, and sprouting. Electrolyte leaching rate was lowest in branch of 20th January and was highest in the 20th March. The electrolyte leaching rate of 'Fuyu' and 'Cheongdobansi' was high in the 20th January and was low in the 20th February, but 'Uenishiwase' and 'Nishimurawase' was opposed to that. 'Hachiva' was the middle level in the cultivars. Absence rate by TTC test was highest in the 20th January and was low in the others. The 20th March had a great decrease in $-10^{\circ}C$ treatment. The absence rate of 'Fuyu' and 'Uenishiwase' was low in the 20th January and March and was high in the 20th February. 'Nishimurawase' and 'Hachiya' had a high level irrespective of dormancy level. Sprouting was highest in the 20th February and was lowest in 20th March. Most cultivars were not sprout in $-20^{\circ}C$ treatment and 'Fuyu', 'Nishimurawase' and 'Cheongdobansi' was a little high level irrespective of dormancy level. 'Hachiya' was only high in the 20th January. Thus, freezing hardiness of persimmon was very weak low temperature after dormancy breaking and was not different between astringent and non-astringent persimmon.

• 전기산업
• /
• v.1 no.1
• /
• pp.83-84
• /
• 1990

• 전기산업
• /
• v.6 no.1
• /
• pp.110-115
• /
• 1995

• Defense and Technology
• /
• no.1 s.263
• /
• pp.42-51
• /
• 2001

전자파특화연구센터는 우리 나라 국방분야의 기초연구를 강화하기 위한 Plan에 의해서 1994년 12월 국방부 위촉으로 포항공대에 설립되어 현재 1994년 12월부터 1997년 12월까지 1단계 연구를 완료하고, 1998년 1월부터 2000년 12월까지 2단계의 연구가 완료된 시점에 와있다. 2001년부터는 3단계 연구가 계획되어 있어서 우리 나라 전자파분야 국방연구의 중추적인 역할을 담당하고 있다. 이 글에서는 본 센터의 설립취지, 역할, 연구내용 등에 관한 간략한 소개를 드리고자 한다.