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        검색결과 3,109

        2681.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 일반촬영에서 자동노출제어장치를 이용하여 검사할 때 체내에 잔존하는 CT 조영제와 MRI 조영제가 면적선량에 미치는 영향에 대해 알아보고자 한다. 복부 두께의 파라핀 팬텀 중앙에 사각형의 홀을 만든 후 CT 조영제, MRI 조영제를 각각 식염수 대 조영제 희석 비율, 10:0, 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, 1:9, 0:10 %의 비율로 희석하였다. 각 실험은 KUB 촬영의 적정 조건인 78kVp, 320mA로 설정 후 자동노출제어장치를 이용하여 희석 비율 당 총 30회씩의 검사를 하였고, 각 조영제의 희석 비율에 따른 면적선량, 노출지수에 대해 평균 비교와 상관분석을 하였다. 그 결과, CT 조영제와 MRI 조영제는 희석 비율에 따라 면적선량이 다르게 나타났고(p<0.05), 희석 비율이 증가함에 따라 CT 조영제와 MRI 조영제는 면적선량이 증가하는 것으로 나타났다(p<0.05). 각 검사에서 노출지수는 제조사 권고 사항인 200-800 EI값을 나타냈으며, 노출지수와 면적선량은 면적선량이 증가할수록 노출지수도 증가하였다(p<0.05). 결론적으로 CT 조영제와 MRI 조영제는 모두 자동노출제어장치를 사용하는 일반촬영 검사에서 면적선량을 증가시키는 것을 확인하였다. 따라서 CT와 MRI 검사에서 조영제를 사용한 후 일반촬영 검사를 할 때에는 조영제가 충분히 배설된 후 시행하여야 할 것으로 사료된다.
        2682.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        Net primary productivity (NPP) is considered as an important indicator for forest ecosystem since the role of the forest is highlighted as a key sector for mitigating climate change. The objective of this research is to estimate changes on the net primary productivity of forest in South Korea under the different climate change scenarios. The G4M (Global Forest Model) was used to estimate current NPP and future NPP trends in different climate scenarios. As input data, we used detailed (1 km × 1 km) downscaled monthly precipitation and average temperature from Korea Meteorological Administration (KMA) for four RCP (Representative Concentration Pathway) scenarios (2.6/4.5/6.0/8.5). We used MODerate resolution Imaging Spectroradiometer (MODIS) NPP data for the model validation. Current NPP derived from G4M showed similar patterns with MODIS NPP data. Total NPP of forest increased in most of RCP scenarios except RCP 8.5 scenario because the average temperature increased by 5°C. In addition, the standard deviation of annual precipitation was the highest in RCP8.5 scenario. Precipitation change in wider range could cause water stress on vegetation that affects decrease of forest productivity. We calculated future NPP change in different climate change scenarios to estimate carbon sequestration in forest ecosystem. If there was no biome changes in the future NPP will be decreased up to 90%. On the other hand, if proper biome change will be conducted, future NPP will be increased 50% according to scenarios.
        2683.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        Three different transplanting dates for two rice cultivars grown in Daegu, Republic of Korea, were examined to identify the changes in growth, rice quality, and characteristics of amylopectin. An early transplanting date caused a reduction in the number of panicles in both rice cultivars compared to that in the optimal and late transplanting dates. The 1000-grain weight in the two rice cultivars was significantly increased in the late transplanting date. The rice cultivar tolerant to high temperatures, Donganbyeo, exhibited the lowest milky grain rate in the late transplanting date. The highest rate of head grain was observed in the late transplanting date in both rice cultivars. Regarding the pattern of pasting properties, peak viscosity increased with delayed transplanting dates. With respect to changes in the amylopectin branch-chain length distribution, the amylopectin structure of the translucent Dongan rice cultivar transplanted on April 25 was characterized by a significant increase in A chains with DP > 12, and a decrease in long chains DP ≥ 37 compared to that transplanted on June 25. In contrast, the amylopectin structure of the chalky Dongan rice cultivar transplanted on April 25 exhibited further decrease in 13 < DP < 19 than that transplanted on June 25. In the Ungwang rice cultivar, the amylopectin structure of the translucent Ungwang rice cultivar transplanted on April 25 and June 25 was characterized by a significant decrease in the lengths of total amylopectin chains. Furthermore, the amylopectin structure of the chalky Ungwangbyeo rice cultivar transplanted on April 25 was characterized by a significant increase in 7 < DP < 30, while a significant decrease was observed in that transplanted on June 25. These results indicate that the amylopectin structure is altered by different transplanting dates depending on the characteristics of the rice cultivar.
        2684.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        This research assessed the disparity in anion generation according to the vertical structure of a Zelkova Serrata tree for the purpose of creating a pleasant and green city environment. Measurements for the study were conducted between July and August of 2014 in Chung-ju in the central region of the Republic of Korea. The average anion generation of vertical structure trees during active photosynthesis periods was: L Section (839.0 ea/cm3) > M Section (664.6 ea/cm3) > U Section (472.0 ea/cm3). According to DMRT analysis, significant difference was found in the average between the L, or M Locations and the U Locations. During dormant photosynthesis periods, records showed that the anion production at the M Location (1,212.5 ea/cm3) > L Location (1,050.4 ea/cm3) > H Location (844.1 ea/cm3), According to DMRT analysis, the difference within each location was significant for α=0.05. In a comprehensive analysis of the weather factors in each vertical structure, anion generation during active photosynthesis periods showed a positive correlation with solar radiation and a negative correlation with wind speed. Dormant photosynthesis periods showed negative correlations with both solar radiation and temperature, and positive correlations with relative humidity and wind speed. Predictions from a multicenter retrospective study showed that during active photosynthesis periods, Y1 = 282.443X1 + 512.07, and Y2 = 314.337X1 + 16.913X2, while during dormant photosynthesis periods, Y1=391.009X1 + 840.043, and Y2=351.412X1 + 32.765X2.
        2685.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 움직이는 타깃을 대상으로 처방선량과 치료기법에 따른 흡수선량을 유리선량계를 이용하여 평가하였다. 타깃의 움직임에 따라 조사야에서 벗어나는 정도에 따른 선량을 MCNPX를 이용하여 모의모사하였으며 그 결과 조사야에서 이격하는 거리에 비례하여 감소하는 것으로 나타났다. 처방선량에 따른 흡수선량의 결과는 3D CRT의 경우 저선량에서 IMRT보다 흡수선량이 높은 것으로 나타났으며, 대선량에서는 IMRT가 더 높은 비율을 보였다. 치료기법에 따른 결과는 3D CRT가 가장 우수한 것으로 나타났으며, IMRT의 sliding window방식이 가장 낮은 것으로 나타났다. 본 연구를 통하여 3D CRT가 움직이는 타깃에 가장 높은 선량을 조사할 수 있는 기법으로 평가되었다. 하지만 정상조직의 보호효과와 환자의 상태 등을 고려한 적절한 치료기법의 선택으로 치료효과를 높일 수 있는 노력이 필요할 것이다.
        2686.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        The steady growth of seaborne trade has resulted in the further development of container ships, ports, and container terminals, and the operating efficiency of a container terminal is a decisive element for its competitive ability in international markets. The aim of this research is to evaluate the relative efficiency of Russian and South Korean container terminals. For this purpose, the output-oriented DEA was applied to 31 container terminals of Russian and South Korean seaports for the years from 2012 to 2014. The results indicate that Korean container terminals exhibited higher efficiency scores than their Russian counterparts.
        2687.
        2016.10 서비스 종료(열람 제한)
        Background : This study was carried out to select the medicinal crop having the superior antimicrobial activity against 5 microorganisms among 20 medicinal crops. Methods and Results : Dried plants were extracted by methanol. The extracts of each plant were evaporated under vacuum. The extracts were absorbed into 50㎕ of each extracts on paper disk and diameter of clear zone was confirmed around the colony. The results showed that diameter of the clear zone against Escherichia coli was the widest in Rhus javanica(R. javanica, 16mm), followed by Evening primrose(14.5mm), Chinaberry(13mm) and Giant knotweed(11mm). Also, diameter of the clear zone against Vibrio parahaemolyticu was the widest in R. javanica(26mm), followed by Evening primrose(21mm), chrysanthemum flower(19mm), Chinese pepper(16.5mm), Chidii rhizoma(11.5mm), Curly dock(11.5mm), Comfrey(11mm), Black nightshade(11mm) and Mustard(10mm). Likewise, diameter of the clear zone aginast Proteus mirabilis was the widest in R. javanica(11.5mm), followed by Chinaberry(11mm). Specially, diameter of the clear zone against Bacillus subtilis and Staphylococcus aureus was identified only in R. javanica(12mm and 11mm, respectively). Therefore, R. javanica showed the best excellent antimicrobial activity among 20 medicinal crops. Total phenolic and flavonoid contents of R. javanica were 2,725mg/100g and 30.2mg/100g respectively. DPPH and ABTS activity of R. javanica were 92.6% and 98.4%, respectively. Conclusion : These results suggest that R. javanica can be utilized as natural food additives and antioxidant materials because of its powerful antimicrobial action and the high antioxidant activity.
        2688.
        2016.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        We used the 4 m Discovery Channel Telescope (DCT) at Lowell observatory in 2014 to observe the Guitar Nebula, an Hα bow-shock nebula around the high-velocity radio pulsar B2224+65. Since the nebula's discovery in 1992, the structure of the bow-shock has undergone significant dynamical changes. We have observed the limb structure, targeting the “body” and “neck” of the guitar. Comparing the DCT observations to 1995 observations with the Palomar 200-inch Hale telescope, we found changes in both spatial structure and surface brightness in the tip, head, and body of the nebula.
        2689.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        This paper will examine Russia’s policy concerning Korea’s re-unification and Moscow’s likely responses to possible results of the unification process as a major and necessary element of peace-building in Northeast Asia. Since the middle of the 19th century Russia has had a keen interest in the situation on the Korean peninsula. History repeatedly proved that any aggravation of the situation on the peninsula caused serious concerns and made Russia to take additional steps to ensure her security. So both for security reasons and for smooth development of her Far Eastern region, Russia is vitally interested in maintaining peace and stability on the Korean peninsula. Emergence of the re-unified Korea, however, is likely to create a new situation in the region and make Russia to re-evaluate her policy in Northeast Asia. It is generally accepted notion that Russia will benefit, first of all, from liquidation of a long-time hot spot right next to her Far Eastern region and from founding the re-unified Korea, which is supposedly will maintain relations of friendship, good-neighborhood and cooperation with Russia and other neighboring states. Meanwhile, at the moment, better relations between North and South Korea, along with providing Russia with more favorable conditions for development of trade and economic cooperation with both parts of Korea, would also open new opportunities for economic development of the Russian Far East and for linking Russia’s economy to globalization and integration processes in the Asia-Pacific region. So both on security and economic reasons Moscow is vitally interested in reconciliation between North and South Korea and eventual emergence of a peaceful and neutral Korea.
        2690.
        2016.07 KCI 등재 서비스 종료(열람 제한)
        Purpose - The purpose of this research is to determine the impact of word of mouth on customer perceived value for restaurants in Malaysia. The objectives of this research include determining how word of mouth (WoM) factors - frequency of word of mouth messages, reputation of word of mouth messenger, richness of word of mouth message, dispersion of word of mouth conversations and manner of word of mouth delivery impact customer perceived value in Malaysian restaurant industry. Research Design, Data, and Methodology – The research follows causal / explanatory research method based on quantitative data. A sample of 150 restaurant customers in Kuala Lumpur, Malaysia was selected using convenience sampling technique. Likert scale questionnaire is used to collect data and data is analysed using regression analysis through SPSS 22. Results – The statistical analysis revealed that independent variable ‘manner of delivery’ significantly and positively impacts c ustomer perceived value for restaurants in Malaysia. Conclusions – To build strong positive customer perception, Malaysian restaurants can enhance word of mouth campaigns’ ‘manner of delivery’ by making them passionate, exciting and with high emotional appeal.
        2691.
        2016.05 서비스 종료(열람 제한)
        Background : Fruit picking is the most labor consuming procedure for Boxthorn (Lycium chinense Mill.) growers. Recently fruit harvesters were invented and improved in the efficiency to fulfill the expectation of farmers through field demonstration tests. Additionally, T-type hedge cultivation method harmonized well with fruit picking machine, but it also needed to be improved in its’ pruning methods for the efficiency of fruit collecting procedure. Methods and Results : In this experiment, ‘Cheong-un’ cultivar and local variety were grown in the rain shelter greenhouses for the tests. Plots were set by randomized block design. There were two types of previously developed harvesters. One vibrates it’s harvest rod right and left (A type) and the other shakes it’s rod back and forth (B type). Among two harvesters A type was superior to B type in efficiency and convenience in use and it was able to harvest eleven times more fruits than manual picking in simple comparison test. In field comparison test, A type harvester performed 4.6 to 5 times more fruits than manual fruit picking. T-type hedge cultivation method is the proper way of enhancing efficiency of harvester. In the test, wiry perpendicular branches formed by once pruning method hindered moving forward of fruit collector. However installing collecting net with velcro along the edge under the field increased the efficiency and handiness of fruit harvester and well harmonized with T-type hedge cultivation. Conclusion : From the above results, the newly developed fruit harvester could increase the annual income of Boxthorn growers by reducing fruit picking labor and time.
        2692.
        2016.05 서비스 종료(열람 제한)
        Background : Boxthorn has been cultivated by conventional fertilization and irrigation methods that can be characterized by applying a great deal of fertilizers and a small amount of water compared to the other crops. With increasing rain shelter greenhouses, there were significant needs for developing new fertigation and irrigation methods. In this study, several prescribed fertigation methods for balanced fertilizer application and a few irrigation start methods based on soil moisture tension has been tested to confirm the fruit quality and productivity for Boxthorn growers. Methods and Results : In the experiment, ‘Cheong-un’ cultivar was grown in the rain shelter greenhouses for the tests. Plots were set by randomized block design. According to the growth investigation on the ‘Cheong-un’ cultivar which is supplied with four different formulated fertigation, the formulation N 15 me/ℓ increased the size and weight of fruit leading to 17% increased yield than the others. Additionally, on the amount of annual supply of fertigation with the concentration of N 15 me/ℓ, the treatment applied with 10kg/10a during the cultivation period facilitated overall growth of ‘Cheong-un’ cultivar and increased the yield as well. In the irrigation experiment ‘Cheong-un’ cultivar was grown in the four differently planned treatments that start irrigation at –20, -40, -50 and -100kPa soil moisture tensions. According to the investigation, the irrigation treatment starting at -50kPa enhanced the number of fruit bearing and productivity of Boxthorn consistently during two years. Conclusion : Therefore, the newly developed fertigation and irrigation methods could enhance the annual income of Boxthorn growers by increasing growth and yield.
        2693.
        2016.05 서비스 종료(열람 제한)
        Background : Panax ginseng C.A.Meyer is a perennial herb and its growth potential keep relatively high at least for the early 3 years old. If the transplanted ginseng roots of 2 or 3 years old grow well, a period of cultivation and the disease management cost could be reduced for the production of 6 years old ginseng roots. Methods and Results : The rooting and growth of a transplanted ginseng root could be affected by the age of a transplant. Therefore, the experiments were conducted to examine the influences of the age factor on the rooting and growth of transplanted ginseng roots. The ginseng roots with different plant ages in growth years (1, 2, and 3 years old), used in this study, were obtained by raising in a seedling production field near the Punggi Ginseng Experiment Station. The transplants were continuously grown under the same conditions after transplanting. The number of lateral or branched roots at the root-growing period after transplanting was basically higher in originally older plant ages compared to younger plants: the numbers of secondary and tertiary branched roots of the 1 year-old transplants were 8, 12, respectably; 2 years old: 12, 20; 3 years old: 12, 28. Those did not show any difference in both overground and underground growing, in compared to conventional cultivations with roots of a year old. The plants grew well without anthracnose, spotting disease, and high temperature injury. Conclusion : The conventional cultivation period of above 5 or 6 years for the raw material of red ginseng might be shorten and also the cost of disease control could be decreased, by transplanting of 2 or 3 years old roots raised at a seedling nursing field.
        2694.
        2016.04 서비스 종료(열람 제한)
        In this study, strain properties of high strength concrete (HSC) have been evaluated at elevated temperature. To evaluate the strain behaviour of HSC at elevated temperatures, ø100 × 200 mm cylindrical specimens of HSC with compressive strengths of 80, 130 and 180 MPa concrete were heated to 700 °C at a rate of 1 °C/min. As a results, Total strain of HSC was showing shrinkage with compressive strength increasing.
        2695.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        Molecular targeting for the altered signaling pathways has been proven to be effective for the treatment of many types of human cancer, including colorectal cancer (CRC). The dual phosphatidylinositol-3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitor BEZ235 has shown to exhibit potent antitumor activity against solid tumors. Autophagy is a cellular lysosomal catabolic process to maintain metabolic homeostasis, which has been known to be induced in response to many therapeutic agents in cancer cells. This process is negatively regulated by mTOR and often acts as prosurvival or prodeath mechanism following cancer therapeutics. The current study was designed to investigate the antiproliferation activity of BEZ235 and to evaluate the role of autophagy induced by BEZ235 using HCT15 CRC cells bearing ras oncogene mutation. We found that BEZ235 decreases cell viability, which was mostly dependent on G1 arrest of cell cycle via suppression of cyclin A expression. BEZ235 affects PI3K/Akt/mTOR signaling pathway by increasing the phosphorylation of AKT at Ser473 and RAS/RAF/MEK/ERK pathway by decreasing the phosphorylation of ERK at Tyr204. BEZ235 also stimulated autophagy induction as evidenced by the increased expression of LC3-II and abundant acidic vesicular organelles (AVOs) in the cytoplasm. In addition, the combination of BEZ235 with autophagy inhibitor chloroquine, a known antagonist of autophagy, counteracted the antiproliferation effect of BEZ235. Thus, our study indicates that autophagy induced in response to BEZ235 treatment appears to act as cell death mechanism in HCT15 CRC cells.
        2698.
        2016.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Between 2010 and 2012, former Bank of Japan Governor Shirakawa argued, in series of speeches, that Japan’s economic performance, when compared to that of other G7 nations, was stronger after 1990 than appreciated by the critics. In May 2012, Nobel prize-winning economist and Princeton University professor Paul Krugman echoed a similar sentiment in a Financial Times interview. This analysis expands on these assertions and asks to what extent they are supported by cross-section data for the G7. As reviewed below, to date, no idiosyncratic explanation has arisen to explain the Japanese slowdown—perhaps this is the correct explanation: the slowdown in Japan, once adjusted for demographics, is less severe than in other G7 countries and, as recently noted by Eichengreen, Park, and Shin (2015), TFP growth in a number of other nations followed similar patterns. Focused on labor productivity, far from a laggard, Japan’s performance ranks near the best in the G7.
        2699.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        Purpose – The study aims to examine the students’ perspective (stream wise) of parameters affecting the undergraduate engineering education system present in a private technical institution in NCR, Haryana, India. Research design, data, and methodology – It is a descriptive type of research in nature. Questionnaire Based Survey has been used to collect the data. The sample size for the study is 500 comprising of the students respondents. The sample has been taken randomly and the questionnaire was filled by the students (pursuing B. Tech) chosen on the random basis from a private technical educational institution in NCR, Haryana, India. For data analysis and conclusion of the results of the survey, statistical tool like F test was performed with the help of high quality software; SPSS. Conclusion – Analysis of variance revealed statistically no difference between the mean number of the groups (stream wise) for the parameters "Selection", "Academic Excellence", "Infrastructure", "Personality Development and Industry Exposure" and "Management and Administration". While Analysis of variance revealed statistically difference between the mean numbers of the groups for the parameter "Placements".
        2700.
        2015.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The influence of different roasting temperatures, times and extraction methods on the quality characteristics of Omija (Schizandra chinensis) seed oils was investigated. Roasted Omija seeds were divided into five groups based on roasting temperature-time conditions: no roasting (Raw) and roasting [R11: 150℃, 10 min, R12: 150℃, 20 min, R21: 250℃, 10 min, R22: 250℃, 20 min (R22)]. Oils from each of the raw and roasted Omija seeds were obtained by solvent (n-hexane) and press (machine) extraction. The L* values decreased, but the a* and b* values increased with increasing the roasting temperature and time. The L* values were lower in the press-extracted oils than in the solvent-extracted oils. The peroxide value (POV) of Omija seed oils decreased with increasing the roasting temperature-time values. The POV value was higher in the press-extracted oils than in the solvent-extracted oils. ABTS (2, 2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical inhibition of Omija seed oils was higher in the solvent-extracted oils than in the press-extracted oils, but there were no significant differences between the two oils. The four major kinds of fatty acid methyl esters detected in Omija seed oils were methyl butyrate, methyl hexanoate, methyl arachidate, and methyl eicosanoate. In conclusion, Omija seed oils obtained by solvent extraction and at higher roasting temperature-time values were more effective antioxidants.