• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.181-204
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• 1974

The study has been carried out to investigate the occurrence, damage, host range, transmission and control of rice stripe virus in Korea since 1965. 1 Disease occur「once and damage : The virus infection during the seedling stage ranged from 1.3 to $8\%$. More symptom expression was found in regrowth of clipped rice than infected intact plants, and the greater infection took place in early seasonal culture than in ordinary seasonal culture. A higher incidence of the disease was found on the rows close to the bank, and gradually decreased toward the centre of the rice paddy. Disease occurrence and plant maturity was highly correlated in that the most japonica rice types were diseased when they were inoculated within 3 to 7 leaf stage, and$50\%$, $20\%$ and no diseaseb were found if they were inoculated at 9, 11 and 13 leaf stages, respectively. Symptom expression required 7-15 days when the plants were inoculated during 3-7 leaf stages, while it was 15-30days in the plants inoculated during 9-15 leaf stages. On Tongil variety the per cent disease was relatively higher when the plants were infected within 1.5-5 leaf stages than those at 9 leaf stage, and no disease was found on the plants infected after 15 leaf stage. The disease resulted in lowered growth rates, maturity and sterility of Tongil variety although the variety is known as tolerant to the virus. 2. Host range: Thirty five species of crops, pasture grasses and weeds were tested for their susceptibility to the virus. Twenty one out of 35 species tested were found to be susceptible. and 3 of them, Cyperus amuricus Maximowics var. laxus, Purcereus sanguinolentus Nees and Eriocaulon robustius Makino, were found as new hosts of the virus. 3. Transmission: The vector of the virus, Laodelphax striatellus, produces 5 generations a year. The peak of second generation adults occurred at June 20th and those of third was at about July 30th in Suweon area. In Jinju area the peak of second generation adult proceeded the peak at Suweon by 5-7 days. The peaak of third generation adult was higher than the second at Jinju, but at Suweon the reverse was true. The occurrence of viruliferous Laodelphax striatellus was 10-15, 9, 17, 8 and about $10\%$ from overwintered nymph, 1st generation nymph, 2nd generation adult, End generation nymph and the remaining generations, respectively. More viruliferous L. striatellus were found in the southern area than in the central area of Korea. The occurrence of viruliferous L. striatellus depended on the circumstances of the year. The per cent viruliferous vectors gin 2nd and 3rd generation adult, however, was consistantly higher than that of other generations. Matings of viruliferous L. striatellus resulted in $90\%$ viruliferous progenies, and the 3rd, 4th and 5th instars of the vector had higher infectiviey than the rest of the vector stages. The virus acquisition rate of non-viruliferous L. striatellus was $7-9\%$, These viruliferous L. striatellus, however, could not transmit the virus for more than 3 serial times. The optimum temperature for the transmission of the viru3 was $25-30^{\circ}C$, while rare transmission occurred when the temperature was below $15^{\circ}C$. The per cent of L. striatellus parasitization by Haplogonatopus atratus were $5-48\%$ during the period from June to the end of August, and the maximum parasitization was $32-48\%$ at around July 10. 4. Control: 1) Cultural practices; The deeper the depth of transplanting more the disease occurrence was found. The higher infection rate, $1.5-3.5\%$, was observed during the late stages of seedling beds, and the rate became lower, $1.0-2.0\%$, in the early period of paddy field in southern area. Early transplanting resulted in more infection than early seasonal culture, and the ordinary seasonal culture showed the lowest infection. The disease also was favored by earlier transplanting even under tile ordinary seasonal culture. The higher the nitrogen fertilizer level the more the disease occurrence was found in the paddy field. 2) Resistant varieties; Tongil varieties shelved the resistant reaction to the virus in greenhouse tests. In the tests for resistance on 955 varieties most japonica types shelved susceptible reactions, while the resistant varieties were found mostly from introduced varietal groups. 3) Chemical control; Earlier applications of chemicals, Disyston and Diazinon, showed better results when the test was made 4 days after inoculation in the greenhouse even though none of the insecticides shelved the complete control of the disease. Three serial applications of chemicals on June 14, June 20 and June 28 showed bettor results than one or two applications at any other dates under field conditions.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.2
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• pp.163-186
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• 2009

The missile technology and its development in south Korea have been restrained to the limit of 180 km by America which instead provided to Korea with security protection. In the same vein, America pressured South Korea to abort its nuclear weapons program so as to prevent another possible military encounter that can easily develop into a war between South and North Korea. This restraint was a bit relaxed when South Korea joined the Missile Technology Control Regime (MTCR) in 2001 whereby the limit was 300 km. The situation of South Korea is in much contrast with its neighbor, North Korea, which has fired Taepo Dong 1 and Taepo Dong 2 to put its alleged satellite respectively into the Earth orbit. The range of this rocket believed to be reaching more than 5,500 km, a range of the intercontinental ballistic missile, without any rein. South Korea that has just geared its full powers for its outer space industry, with the current space projects of putting its satellites into the low Earth orbit, will in future put its satellite into the geostationary orbit, 36,000 km above the Earth. To do so, such restraint had better be resolved. Korean space industry, as it is alike in other countries, started with putting and manufacturing sounding rockets, producing satellites but relying on foreign launching facilities, and learning launching capacities. Experiencing three time launchings of KITSAT, the current satellite projects of Korea are undertaken as follows: - Koreasat - STSAT - Komsat - MBSAT - COMS (Communication, Ocean, and Meteorological Satellite) Koreans waked up to the things of outer space in 2008 with the first Korean astronaut Li So-yeon, a lady bio systems engineer. Although the first Korean made rocket in cooperation with a Russian company to fire last August 2009 was a failure, it should be considered as an inevitable process for future endeavors. There are currently three outer space related laws of Korea: Aerospace Industry Development Promotion Act 1987, Outer Space Development Promotions Act 2005, and Space Damage Compensation Act 2008. The first two stemming from the two different ministries are, however, overlapping in many aspects and have some shortcomings to be improved.

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.87-93
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• 2003

This study was conducted to investigate the effects of embryo development by fusion condition on the nuclear transfer with brindle coated cow's ear cells. Ear cells were transferred into an enucleated oocyte and fused with cytoplasm in the fusion condition with 1.9kv/cm, 2.0kv/cm, 2.1kv/cm each 10 and 20ug duration Nuclear transfer embryo were activeted with a combination of 5ug/ml and 1.9mM 6-DMAP (4min, 4h). Fusion rate was 51∼68% range among fusion condition (1.9, 2.0, 2.1kv/cm; 10, 20us). But, cytoplasm lysis rate was increased by higher electric condition (0∼51.8% range). Each parameter's cleavage and blastocyst formation rate were 1.9kv/cm for 10us (75.8 and 19.5%), 20us (69.8 and 48.6%), 2.0kv/cm for 10us (76.9 and 20.0%), 20 us (68.5 and 40.9%), 2.1kv/cm for 10us (70.5 and 44.2%), 20 us (68.5 and 27.0%). We compared the effectiveness of cloning for between brindle coated cow's ear cells and Hanwoo fetal fibroblast cells. There was no significant differences in the fusion rate and developmental rate to the blastocyst stage. After transfer of blastocysts derived from nuclear transfer embryos, pregnancy rates of the Hanwoo fetal fibroblast cells and brindle coated cow's ear cells were checked pregnant on day 60 as assessed by ultrasonography, 40% (2/5) and 15.8% (3/19), respectively. This studies conclude that brindle coated cow's ear cells have the developmental potentiality to term by nuclear transfer. These results demonstrate that the increased the field strength was to be profitable for development of blastocyst or reduce of cytoplasm's damage than increasing the pulse duration.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.571-578
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• 2001

To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.445-456
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• 2001

In the 1990s, Cochlodinium polykikoides red tide has been annually occurred in the southern coast of Korea and caused the mass damage to the fisheries with a huge amount of economic loss. The present study was done to establish the biological foundation for the elucidation of the mechanism of C. polykikoiaes red tide. The growth response of C. polykikoides to physico-chemical factors such as temperature, salinity, pH, and light intensity were examined using axenic cultures to evaluate the relative importance of these factors on the dynamics of natural populations, It was found that the highest growth conditions were $25^{\circ}C,\;40\%_{\circ}$, pH 7.5, and 7,500 lux, respectively. The tolerable salinity range of growth was relatively wide at an optimum temperature and was reduced to a much narrower range at a sub-optimum temperature. These findings indicate that C. polykikoides is an eurythermal and euryhaline organism. The organism demanded higher light intensity and oceanic pH narrow in its growth. C. polykikoides utilize inorganic nutrients, such as nitrate and ammonium as N, and phosphate as P. The nutritional requirements of C. polykikoides were $40{\mu}M$ for nitrate, $50{\mu}M$ for ammonium, and $5{\mu}M$ for phosphate. The half saturation constant (Ks) for growth was $2.10{\mu}M$ for nitrate, $1.03{\mu}M$ for ammonium, and $0.57{\mu}M$ for phosphate. These values were comparatively smaller than those of other dinoflagellates reported previously. We confirmed that the organism is characterized as an eutrophic species. However, ammonium Ks value is smaller than that of other eutrophic species, This result indicates that C. polykikoides red tide may outbreak in the waters which eutrophication is in progress rather than eutrophicated waters. C. polykikoides preferred ammonium better than nitrate as a nitrogen source when in a growth stage, Therefore, our results indicate that ammonium is more important nutrient on the growth of the organism in comparison with other inorganic nutrients and C. polykikoides red tide is related with the increased ammonium concentration in the coastal waters.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.383-390
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• 2008

Purpose : This study was aimed to analyze the clinical characteristics of patients with acute interstitial pneumonia who had presented similar clinical patterns from March to June, 2006 and to describe our experience of treatment and to identify risk factors associated with prognosis. Methods : The clinical characteristics, radiologic and histopathologic findings and response to steroids of 15 patients (non-survival group [n=7] and survival group [control, n=8]) with acute interstitial pneumonia were investigated through the review of medical records. Results : The mean age of the patients was 26 (range: 3-48) months. Cough, cyanosis and fever were frequent symptoms. The most frequent radiologic findings on admission were pneumomediastium and extensive ground glass opacity. Surgical lung biopsy was performed on 8/15 (53.3%) patients and diffuse alveolar damage was found. Mechanical ventilation was applied for 9/15 (60.0%) patients for 40 (range: 1-99) days. Five patients in survival group received steroid treatment and 7 patients in non-survivial group (P=0.20). One patient in survival group received steroid pulse treatment and 4 patients in non-survival group (P=0.12). Seven patients died all of respiratory failure. The survival rate was 53.4%. Conclusion : The patients with acute interstitial pneumonia which occurred on spring 2006 showed high mortality because of rapidly and extensively progressing pulmonary fibrosis and air leakage. Therefore, we should consider surgical lung biopsy and steroid application earlier. We should recognize this acute interstitial pneumonia occurring on spring in domestics and need to investigate the cause and treatment in large scale.

• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.351-363
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• 2020

It is well known that alluvial sediment located in coastal region has been easily affected by geohazard like ground subsidence, marine or meteorological disasters which threaten invaluable lives and properties. The subsidence is a sinking of the ground due to underground material movement that mostly related to soil compaction by water extraction. Thus, continuous monitoring is essential to protect possible damage from the ground subsidence in the coastal region. Radar interferometric application has been widely used to estimate surface displacement from phase information of synthetic aperture radar (SAR). Thanks to advanced SAR technique like the Small BAseline Subset (SBAS), a time-series of surface displacement could be successfully calculated with a large amount of SAR observations (>20). Because the ALOS-2 PALSAR-2 L-band observations maintain higher coherence compared with other shorter wavelength like X- or C-band, it has been regarded as one of the best resources for Earth science. However, the number of ALOS-2 PALSAR-2 observations might be not enough for the SBAS application due to its global monitoring observation scenario. Unfortunately, the number of the ALOS-2 PALSAR-2 Stripmap images in area of our interest, Busan which located in the Southeastern Korea, is only 11 which is insufficient to apply the SBAS time-series analysis. Although it is common that the radar interferometry utilizes multiple SAR images collected from same acquisition mode, it has been reported that the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application could be possible under specific acquisition mode. In case that we can apply the Stripmap-ScanSAR interferometry with the other 18 ScanSAR observations over Busan, an enhanced time-series surface displacement with better temporal resolution could be estimated. In this study, we evaluated feasibility of the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application using Gamma software considering differences of chirp bandwidth and pulse repetition frequency (PRF) between two acquisition modes. In addition, we analyzed the interferograms with respect to spectral shift of radar carrier frequency and common band filtering. Even though it shows similar level of coherence regardless of spectral shift in the radar carrier frequency, we found periodic spectral noises in azimuth direction and significant degradation of coherence in azimuth direction after common band filtering. Therefore, the characteristics of spectral bandwidth in the range and azimuth direction should be considered cautiously for the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometry.

• Journal of Korean Society of Forest Science
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• v.4 no.1
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• pp.1-8
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• 1965

In this study, the present institution of reserved forests in Korea has been criticized through the analysis of the present situation of reserved forests in Korea, and mainly, on designation and cancellation of them because of this important institution thought as restriction of forest ownership. Reserved forest land in Korea as of the end of 1962 is 996,915 chungbo in area, or about 14.8% of the total forest land area, 6,750,324 chungbo in Korea, and we can find that the area of reserved forest land has increased remarkably since the Liberation in 1945, in comparison with about 180,000 chungbo-a little over 1% of the total forest land area, 16,000,000 chungbo, through Southern and Northern Korea till the Liberation in 1945. This fact clearly proves that Korean forests are extremely devastated since the Liberation in 1945, and in Korea we can find that reserved forest policy is very important in forest policy, consequently, reserved forest institution must be dealt with care. Moreover, the area of reserved forest land, 996,915 chungbo, which is divided into 43,820 chungbo of national forest land, 59,302 chungbo of public forest land, 893,793 chungbo of private forest land, and private forest land is excellently large, or about 89.7% of the total area of reserved forest land. In this number, we may understand the fact that reserved forests have the most influences on private forests, therefore, we may recognize that it is necessary for reserved forest constitution which is infringement of private right to be carried out carefully. From the first beginning, the institution of reserved forests is serious restriction to the forest ownership. Consequently, when the area of reserved forest land grows, it interferes seriously with the free forest management and the desire for forest own ership is decreased, at the same time, forest enterprise results in obstruction. Especially, Korean forests are destroyed extremely at present, so, intensification of reserved forest institution is unavoidable for completion of the national aim which forests have, but the author thinks that reserved forest institution must be as avoidable as possible, and we have to obtain good results by supervision of forest management which is regulated in the Forest Law. Consequently, designation of reserved forests must be minimized, and although forests were already designated as reserved forests they must be cancellated as fast as fast as possible and put them free in the owner's hands when they are in cancellation conditions. According to the provision of Article 18 of the Forest Law concrete cases designated as a reserved forest are enumerated for the purpose of maintaining the forest ownership and avoiding to give the forest authorities a free hand in order to protect forest owners from one-sided damage. Therefore, the forest authorities must not abuse the institution of reserved forests, and it is not good tendency to give only the authorities a free hand in eesignation and cancellation of reserved forests, and especially, when the forest owners object to that, establishing some legal organization like the reserved forest council in each province in order to hear about impartial opinions, and it is more suitable than administrative disposal by the same organization. The compensation of damages for reserved forests by the provision of Article 25 of the Forest Law is a different problem by forest policy, but the results of compensation of damages regulated in the Forest Law are wholly lacking up to now, the author thinks that this is caused to poor forest cover, the forest owner's unconcern and insincerity of administrative authorities. Therefore, the government must enlarge the range of compensation and minimize the forest owner's economic sacrifice, also, the government must mollify the conditions of the legal restrictions to reserved forests, and harmonize with functions of national conservation and economy. This means that it is necessary to modify the restrictive conditions for the effective utilization of forest resources within the range in which can be attained the purpose of designation, from permanent prohibition of cutting. Except the reserved forests of fish habitat, public sanitation, maintaining scenery and navigational mark ect., most of reserved forests are prohibited from cutting, and the present situation of forests in Korea are extremely devastated and those forests are not so expected in cancellation possibility in near future. Therefore, when the forest owners apply for national purchase of those reserved forests, the government had better nationalize them, protect and manage to reduce the forest owner's economic sacrifice.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.271-279
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• 2008

Purpose: To evaluate the efficacy of a belly-board device (BBD) in reducing the volume of small bowel during four-field pelvic irradiation. Materials and Methods: Twenty-two cancer patients (14 uterine cervical cancer, 6 rectal cancer, and 2 endometrial cancer) scheduled to receive pelvic irradiation were selected for this study. Two sets of CT images were taken with and without the belly-board device using the Siemens 16 channel CT scanner. All patients were set in the prone position. The CT images were transferred to a treatment planning system for dose calculation and volume measurements. The external surfaces of small bowel and the bladder were contoured on all CT scans and the 4-pelvic fields were added. The dose-volume-histogram of the bladder and small bowel, with and without the BBD, were plotted and analyzed. Results: In all patients, the total small bowel volume included in the irradiated fields was reduced when the BBD was used. The mean volume reduction was 35% (range, $1{\sim}79%$) and was statistically significant (p<0.001). The reduction in small bowel volume receiving $10{\sim}100%$ of the prescribed dose was statistically significant when the BBD was used in all cases. Almost no change in the total bladder volume involved was observed in the field (<8 cc, p=0.762). However, the bladder volume receiving 90% of the prescribed dose was 100% in 15/22 patients (68%) and $90{\sim}99%$ in 7/22 patients (32%) with the BBD. In comparison, the bladder volume receiving 90% of the prescribed dose was 100% in 10/22 patients (45%), $90{\sim}99%$ in 7/22 patients (32%), and $80{\sim}89%$ in 5/22 patients (23%) without the BBD. When the BBD was used, an increase in the bladder volume receiving a high dose range was observed Conclusion: This study shows that the use of a BBD for the treatment of cancer in the pelvic area significantly improves small bowel sparing. However, since the BBD pushed the bladder into the treatment field, the bladder volume receiving the high dose could increase. Therefore it is recommended to be considerate in using the BBD when bladder damage is of concern.

• The Korean Society of Law and Medicine
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• v.19 no.2
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• pp.139-171
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• 2018

The 「Act on Remedies for Injuries from Medical Malpractice and Mediation of Medical Disputes」(hereinafter referred to as 'the Act on Mediation of Medical Disputes') provides that the state should compensate the victims of medical accidents occurred irresistibly in childbirth despite that health and medical service personnel fulfilled their duty of care for their damage within the range of its budget(Article 46 of the Act on Mediation of Medical Disputes). Given that victims of medical accidents could expect demage recovery only through lawsuits thus far, this act can be said to be a groundbreaking act. However, However, as 30% of the costs for such medical accident compensation projects are borne by those who have records of childbirth among the founders of health and medical institutions (Article 21 of the Act on Mediation of Medical Disputes), there has been a question about whether doctors are held responsible despite that the accidents such as the deaths of mothers and newborn babies occurred irresistibly without doctors' fault. However, recently, the Constitutional Court ruled that 'the range of founders of health and medical institutions' and 'share ratios of finances for compensation' in Article 46 (3) of the Act on Mediation of Medical Disputes' related to the imposition of the share of costs are institutional (Constitutional Court ruling dated April 26, 2018, 2015Heonga13, hereinafter referred to as 'the ruling in the case'). Although the ruling in the case was made based on only the principle of statutory reservation and the principle of ban on comprehensive authorization, this paper added a practical judgment. This paper proved that the share of costs in this case has the nature of burden charges in pursuit of study and does not infringe on the property rights of the founders of health medical institutions even in light of the principle of proportionality because there is a legitimate reason for imposing the burden charge. The imposition of the share of costs in the system for compensation for medical accidents occurred irresistibly is against the principle of liability with fault in part. However, the medical accident compensation projects are rational a national policy for the victims of medical accidents and the medical world clearly gains some benefits from the effect to terminate medical disputes. The expansion of finances for compensation through the payments of the share of costs will reduce the suffering and misunderstanding of victims of medical accidents occurred in the process of childbirth and will be very helpful to the construction of stable treatment environments of medical workers by quickly establishing the medical accident compensation projects as such.