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        검색결과 298

        225.
        2000.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A baffle system for an airglow photometer, which will be on board the Korea Sounding Rocket-III(KSR-III), has been designed to suppress strong solar scattered lights from the atmosphere below the earth limb. Basic principles for designing a baffle system, such as determination of baffle dimensions, arrangement of vanes inside a baffle tube, and coating of surfaces, have been reviewed from the literature. By considering the constraints of the payload size of the KSR-III and the incident angle of solar light scattered from the earth limb, we first determined dimensions of a two-stage baffle tube for the airglow photometer. We then calculated positions and heights of vanes to prohibit diffusely reflected lights inside the baffle tube from entering into the photometer. In order to evaluate performance of the designed baffle system, we have developed a ray tracing program using a Monte Carlo method. The program computed attenuation factors of the baffle system on the order of 10 -6 for angles larger than 10°, which satisfies the requirements of the KSR-III airglow experiment. We have also measured the attenuation factors for an engineering model of the baffle system with a simple collimating beam apparatus, and confirmed the attenuation factors up to about 10 -4. Limitation of the apparatus does not allow to make more accurate measurements of the attenuation factors.
        4,000원
        226.
        2021.10 KCI 등재 서비스 종료(열람 제한)
        While there a growing interest in Voluntary Carbon Disclosure (VCD), comparatively little is discussed whether the improved quality of voluntary carbon disclosure can lead to subsequent changes in a company’s carbon reduction performance. Drawing on companies under the Korean Emission Trading Scheme (ETS) with the contents analysis of their sustainable reports, the present research seeks to address the existing knowledge gaps in the current literature on environmental disclosure. Findings empirically show that an increase in the voluntary carbon disclosure score is positively transformed into changes in carbon performance and further develop that the effect of voluntary carbon disclosure on carbon performance varies depending on changes in management capability with the moderation effect.
        227.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        We performed high-resolution three-dimensional global magnetohydrodynamic (MHD) simulations to study the interaction between the Earth’s magnetosphere and a prolonged steady southward interplanetary magnetic field (IMF) (Bz = –2nT) and slow solar wind. The simulation results show that dayside magnetic reconnection continuously occurs at the subsolar region where the magnetosheath magnetic field is antiparallel to the geomagnetic field. The plasmoid developed on closed plasma sheet field lines. We found that the vortex was generated at the magnetic equator such as (X, Y) = (7.6, 8.9) RE due to the viscous-like interaction, which was strengthened by dayside reconnection. The magnetic field and plasma properties clearly showed quasiperiodic variations with a period of 8–10 min across the vortex. Additionally, double twin parallel vorticity in the polar region was clearly seen. The peak value of the cross-polar cap potential fluctuated between 17 and 20 kV during the tail reconnection.
        228.
        2018.08 KCI 등재 서비스 종료(열람 제한)
        Paddy-upland rotation system is one of the important cropping system for improving soil quality and crop productivity. we conducted to investigate the effect of paddy-upland rotation system on soil properties and crop productivity in reclaimed tidal land. The paddy-upland rotation could be effective to conserve soil water contents and prevent from salt damage when cultivating upland crops. The first two years of maize cultivation after rice cultivation could be effective to secure stable production. However, in case of soybean crop, the rotation effect might be lower than that of maize. In the first year, the yield of soybean was 214 kg/10a. In the second and third year, the yields of soybean decreased consecutively to 152, 123 kg/10a respectively. In this paper, it would be suggested that maize be cultivated for up to two years and soybean be cultivated for one year after rice crop grown in reclaimed tidal land. This study could be provide basic data of the physico-chemical properties applicable to paddy-upland rotation system at reclaimed tidal lands.
        229.
        2018.05 KCI 등재 서비스 종료(열람 제한)
        지금까지 추진해 오던 제외지 중심의 하천복원에서 벗어나 최근에는 제내지까지 복원하고자 하는 노력이 시도되고 있다. 이의 일환으로 구하도의 복원이 추진되고 있으나 이로 인한 수리적 연결성 및 생태적 연결성 향상을 정량적으로 평가할 적합한 모형의 개발은 미진한 상태이다. 본 연구에서는 구하도 복원을 통한 생태적 연결성 회복을 평가할 수 있는 격자기반의 수리해석 모형을 개발하였다. 본 모형의 적용성을 검토하기 위하여 노탑리 일원의 청미천 하천복원 사업지를 대상으로 수리생태적 연결성을 평가하였다. 본 모형으로 수리 및 생태적 특성의 시 ․ 공간적 분포를 신속하고 간단하게 해석할 수 있었으며 향후 수리적 생태적 연결성을 평가하는 적절한 도구로 활용될 수 있을 것으로 판단된다.
        230.
        2017.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker (~7.4 nT) than that of MCs (~10.6 nT). Also, the average duration time and expansion speed of SMFRs are ~2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of ~10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.
        231.
        2017.11 KCI 등재 서비스 종료(열람 제한)
        베트남 북부 산악지형에 거주하는 소수 부족민들의 생계개선이 베트남 정부의 정책적인 지원 사업에도 불구하고 현 재까지 뚜렷한 성과를 내지 못하는 것으로 알려져 왔다. 특히 지속가능한 개발 및 인적자원개발을 목표로 하고 있는 베트남 경제사회개발정책(2011~2020)의 하위전략인 신농촌 개발정책(New Rural Development)에 의한 사업들이 적절히 수행되고 있는지 의문이 대두되었다. 한편, 베트남 라오까이성 행복프로그램은 한국 코이카 재원으로 새마을운동 경험과 정신을 바탕으로 설계되었으며 심각한 빈곤상태에 있는 성내 8개 소수부족민 마을에 마을특성과 주민 의견이 반영된 개발계획을 수립하고 계획실행의 주체인 마을주민들과 현장 공무원에게 다양한 훈련 사업들을 제공하였다. 본 연구는 생계개선에 대한 이론 고찰 과 함께 한국 및 베트남의 농촌개발 경험사례 분석을 바탕으로 프로그램의 다양한 역량강화 사업들이 8개 소수부족 주민들 의 의식변화와 생계자산 향상에 어떠한 영향을 끼쳤는지 알아보았다. 본 연구결과는 프로그램에서 제공한 다양한 역량강화 훈 련들이 주민의식의 긍정적인 변화와 소수 부족민들의 생계자산에 대하여 상당한 만족도를 가져왔는바, 신농촌 개발정책은 직접자재 위주의 지원을 줄이는 대신 주민들의 자신감 고취를 위한 주민의식 교육과 주민들의 생계활동 능력향상을 위한 다양한 훈련 사업을 확대해야 함을 보여준다.
        232.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to investigate the current situations of farms in South Korea which provide care farming activities in order to develop and settle care farms. A questionnaire that includes 60 questions about resources, clients, management, background of establishment, budget, manpower, organization, etc. was developed by the researchers. The survey was conducted by email and phone interview in the period of July to August, 2016. Five farms were participated in this study. As the results, each farm had a different size of land, about 744 – 39,670 m2. The farms were classified by different types of farming activities such as cultivating horticultural crops or cultivating horticultural crops and raising animals. The background of farmers was health, special education, social welfare or professional farmer. The income sources were from care farming programs, educational program, and crop production. The participants in the care farm were children with or without disability, adolescents, adolescents with behavior problem, adults, adults with mental disability or developmental disability, mental illness, dementia, addict, etc. The major activities in care farms were plant cultivating, harvesting, garden maintenance, cooking by using harvest, crop processing, waling in the farm, caring for animals, dealing with farm work equipment, and farming activity with local residents, etc. The participation duration was 25% for one-day experience, less than two weeks in a week, and more than six months, respectively. To settle and develop care farming of South Korea, the concept, clients, operation, professional manpower, policy, support, etc. should be established.
        233.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        This experiment was conducted to establish a cultivation system for sorghum in reclaimed soils. Pot experiments were used to test the effects on seedling establishment of sowing depth, soil water content, and soil salinity using seeds of Nampungchal-susu and Hwanggeumchal-susu in reclaimed soil. Field experiments were also conducted to examine differences in growth characteristics and yield production, by sowing time, and planting distance. The result of the pot experiment, examining seedling establishment at various sowing depths revealed that, it was the highest 76.7% when the seeds were sown at a depth of 3 cm. Seedling establishment did not differ with soil water content between 10~30 kpa and at 51~70 kpa. No effects of seed moisture absorption before sowing were observed. Seedling establishment showed no differences with soil salinity below 3.2 dS m-1, but decreased with Salinity above 4.8 dS m-1. In field experiments to assess the effects on seedling establishment ratio of sowing time, Nampungchal-susu was revealed to have a high seedling establishment ratio following sowing on June 15. Hwanggeumchal-susu did not exhibits effects of sowing time, on seedling establishment ratio but exhibited higher seedling establishment when in low soil salinity conditions than when sown in high soil salinity conditions. With respect to yield, the yield of the seeds sown on June 15 was higher by 13% for Nampungchal-susu and by 29% for the Hwanggeumchal-susu than that those sown on June 25. With respect to soil salinity, the yield at a soil salinity of 3.2 dS m-1 was lower by 23% than that at 1.6 dS m-1 or lower for Nampungchal-susu, and was lower by 30% Hwanggeumchal-susu. With respect to planting density, both breeds showed the highest yield at 60×10 cm. These results suggest that a sowing time of June 15 and a seeding distance of 60×10 cm are appropriate for sorghum in reclaimed land.
        234.
        2017.05 서비스 종료(열람 제한)
        Background : Ginseng is a perennial plant and damaged by various diseases and insect pests. The damage lowers harvest and quality. Accordingly, a chemical control system was made with the aim of effectively control gray mold, anthrax, and spotting disease which occur during growth period. fungicide resistance of gray mold rot was examined to find out whether the chemical control system can be used over the long term. Methods and Results : This experiment was conducted in three areas including Geumsan-gun, Yesan-gun, and Sejong city. The chemical control system was done to the plants of two years old or older. As for the order of the treatment, from the end of April to May Fludioxonil (A) and Pyraclostrobin (B) were used; from the mid-May to the end of July of growth stages Difenoconazole (C), Iminoctadinetris (albesilate) (D), Cyprodinil (E), Metconazole (F), Fluazinam (G) and Pyrimethanil (H); from August to September nonresidualizing polyoxinB + mancozeb (K); in November of hibernating period, Fenhexamid (I) and Carbendazim/diethofencarb (J) were used. As for the interval, from the end of April to the end of July the interval was 10 days, in August and September once a month, and twice in every ten days in November. The isolation of Botrytis cinerea for examination into mycelial growth inhibition rate was conducted to 4-year old ginseng in Geumsan, 5-year old in Yesan, and 3-year old in Sejong. In Geumsan, the mycelial growth inhibition rate to Botrytis cinerea was 75.5% - 100%. Every fungicides showed good rate of mycelial growth inhibition. The lowest rate was seen in fungicide B at 75.5%. K showed the prevention rate at 76.8%, D at 82.7%, and I at 82.2%, and other fungicides at 100%. In Sejong area, the hyphal prevention rate of Botrytis cinerea was 71.0% - 100%, indicating all fungicides show good rate of mycelial growth inhibition. The lowest rate was recorded by fungicide B at 71.1%, D at 81.1%, K at 85.4%, and I at 95.4%. Yesan area also showed similar results to those of Geumsan and Sejong. Conclusion : Botrytis cinerea was isolated from ginseng and mycelial growth inhibition effect was examined in concentration of 11 kinds of fungicides. In all three areas where chemical control system were applied, resistance was not found, suggesting that the chemical control system can be applied to control diseases of ginseng.
        235.
        2017.05 서비스 종료(열람 제한)
        Background : Ginseng is a perennial plant and damaged by various diseases and insect pests. The damage lowers harvest and quality. In particular, gray mold rot occurs to plants of every year, growth duration, and hibernating stage, and decays leaves, stems, and roots, lowering the amount of harvest. This experiment was conducted with the aim of effectively preventing gray mold rot, and other major diseases such as anthrax and spotting disease, and establishing chemical control system. Methods and Results : This experiment was conducted in three areas including Geunsan-gun, Yesan-gun, and Sejong city. As for the procedure of medical treatment, from the end of April to early May of germination period, Fludioxonil and Pyraclostrobin were used. From the mid-May to the end of July of growth period, Difenoconazole, Iminoctadine tris (albesilate), Cyprodinil, Metconazole, Fluazinam, and Pyrimethanil were used. From August to September, non residualizing polyoxinB + mancozeb was used. In November of hibernating stage, Fenhexamid and Carbendazim/diethofencarb were used. As for the interval, from the end of April to the end of July the interval was 10 days, in August and September once a month, and twice in every ten days in November. The chemical control system effect was compared with conventional prevention. When chemical control system was used, stem spotting disease occurred at a lower rate of 0.34% than 1.2% of the conventional method. Leaf spotting disease occurred at a lower rate of 1.4% compared with 7.1% of the conventional method, and anthrax occurred at a lower rate by more than 10% than the conventional method. Stem gray mold rot occurred at a rate of 4.1% when the conventional method was used, but the rate stood at 5.3% in Geumsan, 8.9% in Yesan, 2.3% in Sejong when the prevention method was used, which suggest the chemical control system was effective. Conclusion : When chemical control system was applied to prevent major diseases of ginseng, spotting disease, anthrax, and gray mold occurred at lower rates compared with the case where the conventional method was used. The finding is that the chemical control system can be utilized to prevent major diseases of ginseng.
        236.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng is a perennial, and damage occurs due to various diseases and pests. As a result, yield decreases and quality deteriorates. In particular, it is impossible to be repeatedly cultivated due to root rot, soil-borne disease. For this, in order to control root rot and repeatedly cultivate ginseng by using soil fumigation from virgin soil, this experiment was conducted. Methods and Results : This experiment was performed in ginseng farm field, Geumsan-gun, Chungnam province. And total area was 3ha. And the experiment was conducted in soil where apple trees had been grown. Apple trees were rooted up in 2006. And soil was fumigated in May 2007. With regard to soil fumigant, soil was treated with Basamid of 40kg/10a. After soil fumigation, 5 ton/10a of cattle manure fermented for 1 year was put in the soil in June, and then the soil was cared for by being plowed and rotary-tilled as occasion. Ginseng seeds were sowed in the soil cared for in October 2007. And 4-year-old ginseng was harvested in 2011. The soil from which ginseng was harvested was fumigated by the same method in May 2012, and then ginseng seeds were sowed in 1.5ha in October 2012 and in 1.5ha in October 2013. In October 2013, 3-year-old and 4-year-old ginseng was harvested. And ginseng growth characteristics and root rot incidence was examined. It was shown that 4-year-old ginseng yield after the fumigation of virgin soil was nearly 2 times as high as that of conventional virgin soil cultivation. And root rot didn't occur. After that time, the soil was fumigated again. And when ginseng was cultivated, 3-year-old and 4-year-old ginseng yield was 650kg and 960kg per 10a. And it was shown that root rot incidence was 1.3% and 15.3% in 3-year-old and 4-year-old ginseng respectively. Conclusion : This study showed the results where ginseng can be cultivated repeatedly if soil was fumigated again after ginseng was harvested following the soil fumigation from virgin soil so as to control the ginseng root rot and cultivate ginseng repeatedly.
        237.
        2016.10 서비스 종료(열람 제한)
        Background : Ancanthopanax senticosus Fruits Extracts were studied in order to develop as functional pigment. The extracts were evaluated for physicochemical properties and biological activity. Methods and Results : Ancanthopanax senticosus fruits extracts were extracted by the rate of ethanol and distilled water in 1% citric acid. The extracts were evaluated for physicochemical properties by chromaticity, total sugar content, free sugar content, acidity, total anthocyanin contents. Total sugar and acidity were 0.10 brix and 0.44% respectively. Fructose and glucose were 1.54% and 0.36% respectively. The 60% ethanol extracts showed the highest extraction yield and total anthocyanin content. The α-glucosidase inhibitory activity of 60% and 80% ethanol extracts higher than other extracts. Conclusion : These results suggest that Ancanthopanax senticosus fruits extracts may be useful purple pigment for anti-diabetes activity.
        238.
        2016.10 서비스 종료(열람 제한)
        Background : Aerial parts of Angelica gigas were studied in order to develop as functional pigment. The extracts were evaluated for physicochemical properties and biological activity. Methods and Results : Aerial parts of Angelica gigas were extracted by the rate of ethanol and distilled water. The extracts were evaluated for physicochemical properties by chromaticity, total sugar content, free sugar content, acidity, chlorophyll and carotenoids contents. Total sugar and acidity were 0.90 brix and 2.84% respectively. Chlorophyll and carotenoids contents were 0.24 and 0.04% respectively. The extracts were evaluated for biological activity by anti-inflammatory and anti-diabetes activity. Cell viabilities were measured by MTT assay. Effect of extracts on nitric oxide (NO) production from RAW264.7 cells was accessed by Griess reagent assay. Extracts to RAW 264.7 cells reduced amounts of nitrite by 76.0%. Conclusion : These results suggest that aerial parts of Angelica gigas Nakai may be useful pigment for anti-inflammatory and anti-diabetes activity.
        239.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        This experiment was conducted to identify the variations in inorganic nutrients and plant growth in millet (Panicum miliaceum L.) due to soil salinity. The soil series was Munpo and soil texture was silt loam. The experimental soil was amended so that the soil had salinities of 0.8 dS m-1, 1.6 dS m-1, 3.2 dS m-1 and 4.8 dS m-1. Millet was transplanted 15 days after sowing. As soil salinity increased, the degree of reduced growth was in the order of seed production > root dry matter > plant dry matter > culm length > tiller number > stem thickness > Panicle length. Seed production was decreased to 18.9% in soil salinity of 1.6 dS m-1, 36.9% in of 3.2 dS m-1, and 50.7% in EC of 4.8 dS m-1. Root dry matter decreased to 35.8% in EC of 3.2 dS m-1, and to 40.5% in EC of 4.8 dS m-1. As soil salinity increased, Total nitrogen content increased in all aboveground parts, roots and seeds. However, There was no difference in CaO, P2O5, K2O and, MgO in soils of different salinity. On the other hand, Na2O content was higher in the order roots> shoots> seed, and in the case of roots, Na2O content increased to 1.02% in soil salinity of 4.8 dS m-1. However, up to soil salinity of 1.6 dS m-1, the Na2O content of the seed was similar to that in plant grown in the Control conditions(0.8 dS m-1). In conclusion, taking into consideration economic factors, millet could be cultivated in soil with salinities of up to approximately 1.6 dS m-1, and seed produced from reclaimedland would be suitable for human consumption.
        240.
        2015.07 서비스 종료(열람 제한)
        In Brassica as matter of seedling manner, they have the bilocular ovary and 20~28 seeds per silique after fertilization. Rarely some of B. juncea and yellow sarson (Brassica rapa ssp, tricolaris) have multilocular ovary. In this stdudy, the LP8 (YS-033, CGN06835) is shown tetralocular ovary as well as high seed yields. As microscope study for the different size of immature bud sections and we have known the floral meristem with already four locules in immature buds less size than 1mm of LP8. To identify of determining of tetralocular ovary formation, RNA-seq was carried out on the isolated RNA from less than 1mm and from 1mm of bud size respectively. By contrast tetralocular ovay and bilocular ovary, Chiifu is used. A total of 994 differentially expressed genes(DEGs) are detected in only LP8. Among the DEGs, we identify 18 DEGs in only immature buds of less size than 1mm. The expression patterns of 18 DEGs are validated by real time quantitative PCR and these genes are cloned and the sequence analyzed. At present, 12 candidated gene are analyzed by sequencing and there are detected by large fragment insertion as well as SNPs in sequence comparison to Chiifu. We will perform the genetic transformation of these DEG genes in Arabidopsis for relation between genes and tetralocular ovary. Our results will be helpful in understanding for mechanisms of tetraovular ovary in Brassica rapa.