• Natural Product Sciences
• /
• v.12 no.1
• /
• pp.1-7
• /
• 2006

We have screened the cytoprotective effect on ${\gamma}-ray$ radiation induced oxidative stress from forty one Korean plant extracts. Carpinus laxiflora (caulis), Quercus salicina (caulis), and Castanopsis cuspidata (caulis) were found to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and intracellular reactive oxygen species (ROS). As a result, extracts of three plants reduced cell death of Chinese hamster lung fibroblast (V79-4) cells induced by $H_2O_2$ treatment. In addition, these extracts protected cell death of V79-4 cells damaged by ${\gamma}-ray$ radiation. In addition, these extracts scavenged ROS generated by radiation. Taken together, the results suggest that Carpinus laxiflora, Quercus salicina, and Castanopsis cuspidata protect V79-4 cells against oxidative damage by radiation through scavenging ROS.

• Toxicological Research
• /
• v.21 no.4
• /
• pp.279-284
• /
• 2005

We have screened the cytoprotective effect against $H_2O_2$ and $\gamma-ray$ radiation induced oxidative stress from 32 Korean plants. Betula ermani var.saitoana (caulis, leaves), Rosa wichuraiana (caulis), Sorbus commixta (caulis), Weigela florida (leaves), Cirsium rhinoceros (whole plant), and Viburnum erosum (caulis) were found to scavenge 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and intracellular reactive oxygen species (ROS). As a result, extracts of six plants reduced cell death of Chinese hamster lung fibroblast (V79-4) cells induced by $H_2O_2$ treatment. In addition, these extracts protected cell death of V79-4 cells damaged by $\gamma-ray$ radiation. In addition, these extracts scavenged ROS generated by radiation. Taken together, the results suggest that Betula ermani var. saitoana, Rosa wichuraiana, Sorbus commixta, Weigela florida, Cirsium rhinoceros, and Vibumum erosum protect V79-4 cells against oxidative damage by radiation through scavenging ROS.

• Korean Journal of Ichthyology
• /
• v.9 no.1
• /
• pp.5-14
• /
• 1997

The fish fauna was investigated on summer (from July 28 to Aug. 2) and winter (December, 1994) at the Munsom in Cheju-do. As a result of this study, the fishes identified in these areas were classified into 79 species involved in 35 families. And seven species unrecorded in Korea were found, i.e. Halicampus boothae, Cirrhitichthys aprinus, Stegastus altus, Parupeneus sp., Pomacentrus sp., Pomacentrus sp., and Pomacentridae sp. In this region large number species of family Pomacentridae (12 species), family Labridae (9 species), Scorpaeinidae(6 species) and Blennidae (5 species) were observed in summer.

• Korean Journal of Veterinary Research
• /
• v.29 no.3
• /
• pp.333-342
• /
• 1989

Effect of raising types and environmental conditions on the infection of Toxoplasma in the swine, the cat and the man were studied in Cheju Island from Sept. 1987 to Aug. 1988. Blood samples were taken from 214 conventionally raised swine in 6 villages and 506 swine raised in swine specialized farms, 122 cats raised under free moving or restraned conditions in 8 locations, 113 butchers, and 210 villagers. Toxoplasma antibody values of the blood sera were determined using the enzymelinked immunosorbent assay (ELISA). The eating type of viscera was also investigated by using questionaires 1. When ELISA method was used, the percentage of Toxoplasma infected swine among the conventionally raised and of those raised in swine specialized farms were 60.7% and 21. 390, respectively. The respective mean of antibody values (${\pm}SD$) were 0.589 (${\pm}0.310$) and 0.385 (${\pm}0.237$) and differed very significantly (p<0.01). A significant difference was also found in antibody values among 6 villages (p<0.05). 2. The mean infection percentage of toxoplasma in the cat was 38.2%. the infection percentage for cats raised under free-moving and re~;trained condition were 37.0% and 38.2% respectively. The respective antibody values(${\pm}SD$) for toxoplasma were 0.600(${\pm}0.614$) and 0.637 (0.645), and did not difference significantly. 3. The infection percentage of toxoplasma in villagers and butchers were 26.2 and 38.3% respectively. The respective antibody values (SD) for toxoplasma were 0.429(${\pm}0.195$) and 0.341 (${\pm}0.236$), and differed very significantly (p<0.01). There were also highly significant differences Pyo-sun and other village (p<0.01). 4. Analysis of the questionaires showed that 26.0% of 392 villages eated liver and some villagers eated other viscera.

• Ocean Science Journal
• /
• v.42 no.2
• /
• pp.117-127
• /
• 2007

The dynamics of phytoplankton abundance with seasonal variation in physicochemical conditions were investigated monthly at 10 stations around the Chagwi-do off the west coast of Jeju Island, Korea, including inshore, middle shore, and offshore in the marine ranching are a from September 2004 to November 2005. Water temperature varied from 12.1 to $28.9^{\circ}C$ (average $18.8^{\circ}C$), and salinity from 28.9 to 34.9 psu (average 33.7 psu). The chlorophyll a concentration was $0.02-2.05\;{\mu}g\;L^{-1}$ (average $0.70\;{\mu}g\;L^{-1}$), and the maximum concentration occurred in the bottom layer in April. A total of 294 phytoplankton species belonging to 10 families was identified: 182 Bacillariophyceae, 52 Dinophyceae, 9 Chlorophyceae, 12 Cryptophyceae, 6 Chrysophyceae, 4 Dictyophyceae, 13 Euglenophyceae, 6 Prymnesiophyceae, 5 Prasinophyceae, and 5 Raphidophyceae. The standing crop was $2.21-48.69\times10^4\;cells\;L^{-1}$ (average $9.23\times10^4\;cells\;L^{-1}$), and the maximum occurred in the bottom layer in April. Diatoms were most abundant throughout the year, followed by dinoflagellates and phytoflagellates. A phytoplankton bloom occurred twice: once in spring, peaking in April, and once in autumn, peaking in November. The spring bloom was represented by four Chaetoceros species and Skeletonema costatum; each contributed 10-20% of the total phytoplankton abundance. The autumn bloom comprised dinoflagellates, diatoms, and phytoflagellates, of which dinoflagellates were predominant. Gymnodinium conicum, Prorocentrum micans, and P. triestinum each contributed over 10% of the total phytoplankton abundance.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.7-10
• /
• 2005

Ad hoc MAC protocols using directional antennas can be used to improve the network capacity. Directional antennas have a Deafness problem and decrease throughput of the network caused by increasing backoff duration. Dual channel protocols have been proposed to mitigate the Deafness and hidden node problems. In this paper, we propose a dual channel MAC protocol using a directional antenna to mitigate the Deafness problem and increase the network capacity. The performance of the proposed Ad hoc MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.57-58
• /
• 2006

Ad hoc MAC protocols using directional antennas can be used to improve the network capacity by improving spatial reuse. But, the directional MAC protocols have the problem of deafness and have a poor throughput performance. The dual-channel DMAC protocol has been proposed to mitigate deafness and improve spatial reuse. In this paper, we propose a dual-channel DMAC protocol using the omnidirectional antenna for an out-of-band tone and directional antennas for control/data channels. In the proposed MAC protocol, an omnidirectional out-of-band tone mitigates deafness and directional antennas used in control/data channels improve spatial reuse and reduce interference packets. The throughput performance of the proposed MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.

• Proceedings of the KAIS Fall Conference
• /
• 2008.05a
• /
• pp.282-285
• /
• 2008

최근 실시간 상황 정보를 제공할 뿐만 아니라 상황 정보를 파악하여 필요한 행위를 제안하거나 수행하는 서비스가 필요하다. 특히 대중 시설에서 긴급한 상황이 발생할 경우 사람들에게 위험 상황을 알리거나 대처 행위를 위한 안내가 요구된다. 이에 본 논문에서는 고립된 다층 건물에서 화재 발생 시 최대한 빠른 탈출 경로를 제시하고 3차원 대피 유도 방안을 설계하고 구현한다. 이를 위하여 건물의 정보를 입력할 수 있는 건물 층 정보 입력 모듈, 건물 내부의 유도등, 비상구등을 표시하는 건물 노드입력 모듈, 이 노드 간 연결 정보를 생성하는 연결 정보 생성 모듈을 설계하고 구현한다. 제시한 3차원 대피 유도 방안으로 건물 어느 층에서나 현재 건물의 상태 정보를 알아내어 최종 탈출구로의 올바른 유도 경로를 표시 할 수 있다.

• Journal of Preventive Medicine and Public Health
• /
• v.21 no.1 s.23
• /
• pp.5-9
• /
• 1988

• Proceedings of the Korean Society of Environment and Ecology Conference
• /
• 2004.04a
• /
• pp.101-105
• /
• 2004