• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.9
• /
• pp.3610-3614
• /
• 2010

Taxonomic compositions and species diversities of the planktonic micro algae communities were investigated 8 times during the period from May, 2006 to November, 2007 in Saemangeum water regions. Total of 191 taxa were observed; 94 diatoms, 31 chlorophytes, 24 dinoflagellates, 24 cyanophytes, 11 euglenophytes, 3 silicoflagellates, 1 cryptophyte and 3 unidentified microflagellates. During the period of this study, diversity indices of the community were changed spatio-temporally and fluctuated irregularly. It was surmised that artificial factors to the water condition such as open and lock of the dike stressed to the planktonic micro algal groups.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.11 no.1
• /
• pp.40-47
• /
• 1986

In this paper, the principles of cascade realization of 3-3CLC(3input-3out put Conservative Logic Circuit)using magnetic bubble are exlpored and the problem of realizing arbitary 3-3lofic circuit with minimal number of logic elements is handled. The five primitives classes 5, 15, 21, 24 and 29 are selected to realize all of the 3 equivatlent class by cascading only two of them. The crossoreres of lines are permitted in this realization and the upper bound of crossorers is three. The composition results are computed in MV 4000 minicomputer.

• Animal Systematics, Evolution and Diversity
• /
• v.19 no.2
• /
• pp.167-176
• /
• 2003

This study sought to observe systematic relationships through taximetrical analyses by morphological characters among the 10 species, on three species in the virilis section (D. virilis, D. tsigana and D. lacertosa) and seven species in the quinaria section (D. angularis, D. brachvnephros, D. curvispina, D. kuntzei, D. nigromaculata, D. takadai and D. unispina) of the subgenus Drosophila. In the cluster and the cladistic analysis among the members of subgenus Drosophila, 10 species was divided into the 1st group of D. virilis, D. tsigana, and D. lacertosa and the 2nd group of D. angularis, D. brachynephros, D. curvispina, D. kuntzei, D. nigromaculata, D. takadai, and D. unispina. In cluster analysis, the 2nd group had three sister groups; one sister group that clustered D. angularis and D. brachynephros then D. unispina was clustered to them, another sister group clustered D, curvispina and D. takadai then D. kuntzei was clustered to them and the other sister group of D. nigromaculata. In the 10 species, D. virilis and D. lacertosa were the first to be divided and then D. tsigana. Although 1st group which D. virilis was belonged can be determined as more primitive than the 2nd group, it seemed that this group was not the direct ancestor of the 2nd group, rather there should be another ancestor. Among the quinaria species group, D. nigromaculata was the first to be divided and D. kuntzei was the most recent species to be divided.

• The Korean Journal of Pesticide Science
• /
• v.12 no.4
• /
• pp.382-390
• /
• 2008

This study was performed to evaluate the acute toxicity and residual toxicity of the 69 kinds of agrochemicals (41 insecticides, 18 fungicides, and 10 acaricides) against honeybee, Apis mellifera and bumblebee, Bombus terrestris. According to the IOBC standard, the toxicity showed below 30% was classified as non-toxic. Among 41 insecticides, five insecticides (acetamiprid, chlorfenapyr, thiacloprid, milbemectin, and buprofezin+amitraz) against the honeybee; eight insecticides (methomyl, thiodicarb, acetamiprid, chlorfenapyr, thiacloprid, abamectin, spino sad, buprofezin+amitraz) against the bumblebee did not show any toxic effect. Therefore, it thought to being safe. Other 18 fungicides and 10 acaricides were safe against the honeybee and bumblebee. In residual toxicity against the honeybee, eight insecticides (dichlorvos, methomyl, imidachlorprid, emamectin benzoate, spinosad, cartap hydrochloride, chlorfenapyr, and endosulfan) among 41 insecticides tested were safe at three days after treatment; however, sixteen insecticides (dimethoate, fenitrothion, fenthion, methidathion, phenthoate, pyraclofos, fenpropathrin, clothianidin, dinotefuran, thiamethoxam, abamectin, acetamiprid+ethofenprox, acetamiprid+indoxacarb, bifenthrin+imidacloprid, ethofenprox+phenthoate, imidacloprid+methiocarb) still remain high toxicity at eleven days after treatment. Against the bumblebee, residual toxicity showed as safe in seven insecticides (dimethoate, methidation, a-cypermethion, ethofenprox, indoxcarb, chlorpyrifos+a-cypennethrin, esfenvalerate+fenitrochion) at three days after treatment; however, eight insecticides (fenitrothion, pyraclofos, clothianidin, fipronil, acetamiprid+ethofenprox, chlorpyrifos+bifenthrin, ethofenprox+phenthoate, imidacloprid+methiocarb) still showed high toxicity at seven days after treatment. From above results, it will be useful information to select insecticides being safe and effective against the honeybee and bumblebee.

• Korean Journal of Environment and Ecology
• /
• v.3 no.1
• /
• pp.28-41
• /
• 1989

A survey of Hongryu-Dong and Chi-in district. Gaya National Park, was conducted using 40 sample sites of 500$m^2$ size. TWINSPAN classification confirmed a complex pattern of both local and geographical variation in the vegetation: Dry and wet community types. Within dry community types, two floristic assocation of Pinus densiflora were defined according to local variation. Within wet community types. two floristic association were defined according to altitude. Those associations can be further subdivided floristically into eight subassociation. The vegetation pattern presented by DCA ordination corresponds to one of TWINSPAN at the first two division. The DCA ordination was successful in separating Pinus densiflora from broad leaf forest. Ordination of samples produced arrangements reflectly environmental gradient of soil. The correlation between the first axe of DCA and soil moisture, soil acid, altitude, maximum species diversity and species diversity was significantly negative. The similarity index between each community was very low level.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.2 no.2
• /
• pp.101-109
• /
• 1997

The present study was carried out to investigate the temporal and spatial changes in species composition and abundance of polychaetes in Lake Shihwa. Macrobenthic fauna were collected from eight sampling surveys performed in March, June, September and December of 1994, March and October of 1995, February and August of 1996, using a modified van Veen grab with 0.1 $m^2$ coverage area. Polychaete worms, the most abundant macrofaunal group, comprised of 1~22 species at each investigation; number of species continuously decreased during the survey period. The mean density of polychaete was $794{\pm}1,275\;indiv.{\cdot}m^{-2}$ and showed a large fluctuation over time. The variation in abundance was mainly coupled with the domination of Polydora ligni occupying 83% in total density. The next dominant species were Pseudopolydora kempi (mean density of 31 $indiv.{\cdot}m^{-2}$) and Capitella capitata (mean density of 23 $indiv.{\cdot}m^{-2}$). Abundant polychaetes in Lake Shihwa are known to be tolerant to sediment pollution. Ecological indices such as diversity (H') and dominance (D) also indicated that the number of species significantly decreased and a few species predominated in Lake Shihwa after the dike construction. The azoic zone were extended from the upper reach of Lake Shihwa to the vicinity of the dike over time. The reduced number of species, predominance of pollution indicator species and development of an azoic zone reflect severe deterioration of benthic environments in Lake Shihwa.

• Korean Journal of Environmental Agriculture
• /
• v.28 no.2
• /
• pp.194-201
• /
• 2009

To evaluate the exposure of non-point source pesticide pollution in agricultural watershed and to investigate pesticide distribution and runoff from agricultural land, paddy field, upland and orchard, this experiment was carry out during crop growing seasons. The pesticide were detected twenty pesticides fungicide 4, insecticide 10, herbicide 6) in water of Neungchon agricultural watershed and detection concentrations were range 0.008${\sim}$7.59 ppb. Most of the detection pesticides were using pesticides to rice paddy fields to control fungi, insects, weeds. During the crop cultivation, the pesticide were detected total thirty pesticides by pepper field soil 6, orchard soil 4, sesame field soil 3 and rice paddy field soil 5, and pesticide concentrations were range 0.001${\sim}$0.109 ppm. Especially the herbicides were detected mainly in May and June in the stream water. The pesticide were detected thirty pesticides by fungicide 2, insecticide 6, herbicide 5 in water of Jungam Koseong agricultural watershed and detection concentrations were range 0.01${\sim}$7.21 ppb. In regard to the detected pesticides, the concentration of individual pesticides measured in surface water of the study areas never exceeded guidelines for agriculture chemicals concerning water quality-effluent from paddy fields in Japan (Katayama, 2003). Runoff rate of pesticides was range 0.07${\sim}$3.06 % from Kongju agricultural land to watershed after applied pesticides.

• The Korean Journal of Zoology
• /
• v.20 no.1
• /
• pp.29-40
• /
• 1977

The authors examined fresh-water gammarid materials which were collected from streams in 20 localities of South Korea during the period from 1965 to 1977. As the results of the observation, the authors have concluded as follows: 1. These fresh-water gammarids belong to Gammarus pulex-group and are distributed widely in mountain-streams of mainland and surrounding islands of South Korea. 2. The present specimens are different from the subspecies, G. pulex koreanus Ueno, 1940 which was described originally from North Korea. In the latter, the pulmose setae of third uropod are limited only to the outer margin of both rami. The peduncle and flagellum of second antenna are fringed with a few short setae and the flagellum is provided with calceoli. In the former, both margins of inner ramus and outer margin of outer ramus of third uropod are fringed with long pulmose setae. The peduncle and flagellum of second antenna have abundant relatively long setase and the flagellum is not provided with calceoli. 3. The present specimens are different from the subspecies, G. pulex sobaegensis Ueno, 1966 which was described originally from South Korea. The latter dwells in cave, while the former dwells in mountain-stream. In the former, the arrangements of pulmose setae of third uropod and the setation of second antenna are similar to those of the latter. But they are quite different from each other in several characters such as shape of upper lip, shape of fifth article of second gnathopod and numbers of incisions on front distal margins of coxal plates 1-3. The former has spines on surface of coxal plates 1-3, but the latter has not. In females, the former has four pairs of marsupial plates, while the latter has three pairs. 4. The present materials show local variations. Therefore, they could be divided into 3 local groups. The first group (specimens from Mt. Odae and Mt. Sogeumgang) has pulmose setae on the both margins of both rami of third uropod and second article of outer ramus is relatively long. In general, this group has setae sparsely on the both rami and especially a few setae on the outer margin of outer ramus. The second group, which are widely distributed in South Korea, has pulmose setae on the both margins of inner ramus and on the outer margin of outer ramus of third uropod. In the third group (specimens from Mt. Soyo), the pulmose setation of third uropod is similar to that of the first group, but the second article of outer ramus is very small.

• Animal Systematics, Evolution and Diversity
• /
• v.2 no.2
• /
• pp.53-58
• /
• 1986

한국에서 발견된 갈르와벌레의 세 번째 신종을 기재하였따. 세계적으로 희귀한 본 속은 지금까지 우리나라에서 2종 [Galloisiana biryongensis Namkung, 1974 (비룡갈르와벌레) 및 Galloisiana kosuensis Namkung, 1974(고수갈르와 벌레)]이 보고된 바 있고 , 이 신종 [Galloisiana magnus, n.sp.(동대갈르와벌레)]을 추가함으로서 한국산 갈르와벌레는 3 종이 된다. 본 신종은 미지의 어느것보다도 대형종이며 그 형태적면에서 비룡갈르와벌레와 비슷한 점이 많으나 , 제 10 복절배판(supra-anal plate) 및 주교속돌기(principal couplatory sclerite)의 모양 등엣 뚜렷한 차이가 있다. 본 종의 한국명은 동대 동굴탐험연구회의 다년간에 걸친 동굴 탐험연구의 업적을 기념하기 위하여 \" 동대갈르와벌레\" 로 명명하였다.; 로 명명하였다.

• Korean Journal of Ichthyology
• /
• v.5 no.1
• /
• pp.113-121
• /
• 1993

Cytogenetic studies and hybridization experiment using two populations of Oryzias latipes from Korea were conducted in order to examine their systematic positions. In the chromosome number of specimens examined. O. sinensis had 46 with a pair of large metacentrics and O. latipes had 48 chromosomes without a pair of large metacentrics. However, the diploid chromosome number of the hybrid between O. latipes and O. sinensis was 47 and they had a large metarcentric chromosome in their karyotype. In the $F_2$ hybrids, distribution of chromosome number was variable among individuals. Hatching rates showed little difference between control and hybrids. However, hatchiabilties of $F_2$ hybrids were decreased by 83.3% as compared with $F_1$ offspring. Incidence of abnormal larvae was increased by 15.3% as compared with their parents. These results indicate that the two karyotype populations formerly regarded as two subspecies would be two distinct allopatric sibling species O. sinensis, and O. latipes.