• Title/Summary/Keyword: 병진

Search Result 1,247, Processing Time 0.025 seconds

Evaluation of Pollutant Characteristics in Yeongsan River Using Multivariate Analysis (영산강 수계 오염특성 파악을 위한 다변량 통계분석법의 적용)

  • Jung, Soojung;Lee, Dongjin;Hwang, Kyungsup;Lee, Kyounghee;Choi, Kyoungchuk;Im, Sangsun;Lee, Yunhee;Lee, Jaeyoung;Lim, Byoungjin
    • Korean Journal of Ecology and Environment
    • /
    • v.45 no.4
    • /
    • pp.368-377
    • /
    • 2012
  • This study evaluated the water quality of Yeongsan River by multivariate analysis using the data collected during 2001~2010. Water quality in Yeongsan River could be explained up to 75.2% by four factors, which were included in loading of nutrients (32.021%) and organic matters (17.453%), seasonal variation (14.775%) and microbes (10.951%). The results of cluster analysis were classified into three groups by factor 1 and 2, which has different water quality characteristics. Group 1 included sampling stations located in the upper stream and estuary dyke of Yeongsan River, group 2 included Gwangju 1 and Gwangsan affected by domestic sewage of Gwangju-cheon, and group 3 included sampling stations located in the midstream around the livestock farm and farmland.

Factors Affecting the Survival Rates of Frozen-Thawed Spermatozoa in Jindo Dog by Monosaccharides and Freezing Rate (진도개 정액 동결 시 단당류 및 동결 속도가 생존율에 미치는 영향)

  • Choi, Sun-Ho;Kim, Sung-Jae;Cho, Sang-Rae;Choe, Chang-Yong;Son, Jun-Kyu;Kim, Jong-Suk;Oh, Suk-Il;Park, Byung-Jin;Kim, Sang-Hyun
    • Journal of Embryo Transfer
    • /
    • v.25 no.3
    • /
    • pp.195-199
    • /
    • 2010
  • This studies were conducted to investigate the survival rate of frozen-thawed spermatozoa of Jindo Dog by monosaccharide and freezing rates. Experimental animals were prepared 12 males within 1~8 year's old and collected once in a couple of weeks by digital manuplation methods. Collected semen was diluted 1:1 with Tris-egg yolk extender and added 4, 6 or 8% of glycerol and none, 4 mM glucose or 4 mM fructose as cryoprotectant and was equilibrated for 2 hrs in $4^{\circ}C$. In monosaccharide groups, the freezing rate was 5 cm-5 min. above $LN_2$. The survival rates without monosaccharide were $50.7{\pm}19.0%$, $58.6{\pm}18.0%$, $40.0{\pm}10.0%$ in 4, 6 or 8% glycerol, respectively. In addition of glucose, the survival rates were $43.1{\pm}14.7%$, $38.1{\pm}16.5%$, $33.3{\pm}4.0%$ in 4, 6 or 8% glycerol, respectively and in fructose, were $47.9{\pm}21.1%$, $61.3{\pm}6.2%$, $34.3{\pm}12.6%$ in 4, 6 or 8% glycerol, respectively. There showed significantly different between glycerol groups and monosaccharides groups (p<0.05). The survival rates of freezing rate in 5 cm-5 min. group was $64.5{\pm}15.8%$, $51.9{\pm}27.6%$, $29.7{\pm}24.8%$ and in 10 cm-10 min. group was $62.5{\pm}20.3%$, $64.9{\pm}23.6%$, $34.5{\pm}27.4%$ in 4, 6 or 8% glycerol, respectively. There were significantly different between freezing rates (p<0.05). These results suggest that the addition of fructose with 6%-glycerol and slow freezing improve the survival of frozen-thawed sperm in Jindo Dog.

Influence of Environmental Factors on Conidial Germination of Alternaria dauci (당근 검은잎마름병원균 Alternaria dauci의 포자 발아에 미치는 환경인자의 영향)

  • Park, Kyeong-Hun;Yun, Hye-Jeong;Ryu, Kyoung-Yul;Yun, Jeong-Chul;Kim, Se-Ri;Kim, Won-Il;Kim, Doo-Ho;Kwon, Young-Seok;Cha, Byeong-Jin
    • Research in Plant Disease
    • /
    • v.17 no.3
    • /
    • pp.381-385
    • /
    • 2011
  • Effects of temperatures, relative humidity, pH, and dry periods on conidial germination of Alternaria dauci were evaluated under in vitro conditions. Conidial germination was accelerated at over 95% relative humidity in $15^{\circ}C$ to $25^{\circ}C$ condition. Conidial germination was rapidly reduced at 5 regardless of relative humidity conditions. More than 50% of the conidial germination were initiated within 2 h at $25^{\circ}C$ through pH 5 to 7. The highest conidial germination of A. dauci was on 0.2% of carrot leaf extract. Conidia could survive longer than 12 h, even though its germination decreased. After a 12 h dry period, around 10% of conidia revived and germinated when conidia were hydrated again. These results could be used as the useful information on conidial germination of A. dauci and ecology of Alternaria leaf blight.

Survey on Virus Infection for Commercial Nursery Trees of Major Apple Cultivars in Korea (국내 유통 주요 사과나무 묘목의 바이러스 감염 실태)

  • Lee, Sung-Hee;Kwon, Yeuseok;Shin, Hyunman;Nam, Sang-Yeong;Hong, Eui Yon;Kim, Byeongkwan;Kim, Daeil;Cha, Byeongjin;Cha, Jae-Soon
    • Research in Plant Disease
    • /
    • v.23 no.4
    • /
    • pp.355-362
    • /
    • 2017
  • The 4 viruses, the Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), and Apple mosaic virus (ApMV) and 1 viroid, Apple scar skin viroid (ASSVd) are known major viral pathogens of apple trees in Korea. Infection degree of the 5 viral pathogens in the commercial nursery trees of major apple cultivars, 'Hongro', 'Fuji' and bud mutation of 'Fuji' was investigated. Infection ratio of the ACLSV, ASPV and ASGV for scion of an apple cultivar 'Hongro' were 100%, 81.3% and 100%, respectively. On the other hand, no infection for either ApMV and ASSVd detected. For the root stock of the cultivar, infection ratio of ACLSV, ASPV and ASGV showed 87.5%, 81.3% and 100% as well as ApMV and ASSVd were 12.5% and 6.3%, respectively. From the scion of apple cultivars 'Fuji' and bud mutation of 'Fuji', infection ratio of ACLSV, ASPV and ASGV showed 86.7%, 86.7% and 100%, respectively. Whereas, no infection for either ApMV or ASSVd detected. From the root stock of the cultivars, infection ratio of ACLSV, ASPV and ASGV showed 86.7%, 93.3% and 93.3% as well as ApMV and ASSVd were 12.5% and 6.3%, respectively. Result of our study indicates that most of commercial nursery apple trees were supplied with multiple infections by apple viruses causing potential losses for apple growers and, henceforth, agricultural policy for supply of the virus-free trees should be employed as soon as possible.

Enhancing Robustness of Floor Vibration Control by Using Asymmetric Tuned Mass Damper (비대칭 동조질량감쇠기를 활용한 바닥진동제어의 강건성 향상 방안)

  • Ko, A Ra;Lee, Cheol Ho;Kim, Sung Yong
    • Journal of Korean Society of Steel Construction
    • /
    • v.26 no.3
    • /
    • pp.177-189
    • /
    • 2014
  • When floor vibration problems occur in existing buildings, TMD (tuned mass damper) can be a viable alternative to resolving the problem. Only when TMD has been exactly tuned to the natural frequency of the floor, it can control the vibration as intended in design. However, TMD gets inefficient in the situation where the natural frequency changes as a result of the uncontrollable variation of the floor mass weight. This physical phenomenon is often called as TMD-off-tuning. This study proposes asymmetric TMD for enhancing the robustness of floor vibration control against uncertain natural frequencies. The proposed TMD features two asymmetric linear springs such that the floor vibrational energy can be dissipated through both the translational and rotational motion. An easy-to-use graphical optimization method was developed in this study. The asymmetric TMD proposed outperformed in vibration control by 28% compared to that of conventional TMD. The robustness of asymmetric TMD of this study was two times higher than that of conventional TMD.

Fish Compositions and Distribution Characteristics in the Upstream and Downstream Region of Seungchon Weir (승촌보의 상류구간 및 하류구간에서 어류 종 조성 및 분포특성)

  • Park, Chan-Seo;Choi, Ji-Woong;Lee, Jae Hoon;Lim, Byung Jin;Park, Jong-Hwan;An, Kwang-Guk
    • Journal of Korean Society on Water Environment
    • /
    • v.29 no.2
    • /
    • pp.196-203
    • /
    • 2013
  • Seungchon Weir was constructed in 2010 on the downstream region of Yeongsan River watershed for four major river projects. The purpose of our study was to determine whether fish compositions and distributions differ between the upper ($U_w$) and lower regions ($L_w$) of Seungchon Weir during May - December 2011 along with hydroacoustic fish surveys using Eco-Sounder monitoring ($E_SM$) technique. Total number of fish species sampled by conventional fish sampling at all sites was 29, and 21 and 24 species occurred in the $U_w$ and $L_w$, respectively. Most dominant species was Hemiculter eigenmanni (43%) in the $U_w$ and Opsaiichthys uncirostris amurensis (21%) in the $L_w$, indicating a distinct differences of the species composition. According to hydroacoustic approach of ESM, fish density was significantly higher (p < 0.05) in the $L_w$ section of 250 m than any other sections, This outcome indicates that fishes moving toward the upstream were blocked by weir construction. According to analysis of tolerance guilds, tolerant species (TS) were made of 88% and 79% in the $U_w$ and $L_w$ region, respectively, while the proportions of sensitive species were < 0.1% of the total in the both regions. Trophic guild analysis showed that the proportion of omnivore species were 58% and 40% in the $U_w$ and $L_w$ region, respectively, while insectivores were made of 16% and 21% in the $U_w$ and $L_w$ region, respectively. Both analyses of tolerance guilds and trophic guilds indicate the biological degradation of the waterbody. Fish community structure analysis, based on species diversity, dominance, and evenness indices, showed higher community stability in the $L_w$ region than $U_w$ region. Exotic species of largemouth bass were largely increased in this survey (14%), compared to the past (< 1%), indicating a modification of fish trophic structure.

Mirror Manipulator with Independent Adjustability Using an External Spherical Joint (외부 구형관절을 이용한 조정 독립형 거울조정기)

  • 길계환;김창균;나승유;이재민;윤화식;윤무현;백성기
    • Journal of the Korean Vacuum Society
    • /
    • v.10 no.2
    • /
    • pp.145-154
    • /
    • 2001
  • A new type of modular mirror manipulator with independent adjustability was developed for the EPU6 beamline under construction at the Pohang Accelerator Laboratory. The mirror manipulator was designed so that the angular displacements of roll and pitch rotations do not introduce translational displacements and are independent with each other by positioning the mirror center to the center of a newly devised spherical joint. Manipulating its roll and pitch micrometers, the rotation angles of a dummy mirror were measured at an accuracy of 5 $\mu$rad using a gravity-referenced inclinometer. While the designed angular resolution was 3.937 $\mu$rad/$\mu\textrm{m}$, measured angular resolutions were 3.94 $\mu$rad/$\mu\textrm{m}$ for roll rotation and 3.85 $\mu$rad/$\mu\textrm{m}$ for pitch rotation. The effect of roll rotation on pitch angles was measured to be -3.18% and the effect of pitch rotation on roll angles was measured to be -5.21%. As the mirror manipulator was designed with emphases on independent adjustability and standardization, it results in eases of manufacturing, installation and adjustment as well as reductions of development period and design cost of mirror manipulators for various types of mirrors.

  • PDF

Trend Analysis of Extreme Precipitation Using Quantile Regression (Quantile 회귀분석을 이용한 극대강수량 자료의 경향성 분석)

  • So, Byung-Jin;Kwon, Hyun-Han;An, Jung-Hee
    • Journal of Korea Water Resources Association
    • /
    • v.45 no.8
    • /
    • pp.815-826
    • /
    • 2012
  • The underestimating trend using existing ordinary regression (OR) based trend analysis has been a well-known problem. The existing OR method based on least squares approximate the conditional mean of the response variable given certain values of the time t, and the usual assumption of the OR method is normality, that is the distribution of data are not dissimilar form a normal distribution. In this regard, this study proposed a quantile regression that aims at estimating either the conditional median or other quantiles of the response variable. This study assess trend in annual daily maximum rainfall series over 64 weather stations through both in OR and QR approach. The QR method indicates that 47 stations out of 67 weather stations are a strong upward trend at 5% significance level while OR method identifies a significant trend only at 13 stations. This is mainly because the OR method is estimating the condition mean of the response variable. Unlike the OR method, the QR method allows us flexibly to detect the trends since the OR is designed to estimate conditional quantiles of the response variable. The proposed QR method can be effectively applied to estimate hydrologic trend for either non-normal data or skewed data.

The Applicability of Analysis Scheme for Spatio-Temporal Droughts Using Mass Moment Concept (질량모멘트 개념을 이용한 시공간적 가뭄해석기법의 적용성 분석)

  • Yoo, Ji Young;So, Byung Jin;Kim, Tae Woong;Kwon, Hyun Han
    • Journal of Korea Water Resources Association
    • /
    • v.45 no.10
    • /
    • pp.1069-1079
    • /
    • 2012
  • In this study, to analyze travelling route and transition characteristics which is a spatial time interpretation method now actively progressed in domestic as well as abroad, it was intended to develop new drought interpretation technique which can decide the centroid and orbit of drought through assuming ellipse using Mass Moment concept. First of all, after estimating Standard Precipitation Index (SPI) per different precipitation observatory station to extract drought events, by selecting precipitation sites where drought starting and end point are same, these were categorized as CASE. As a results, with various CASE selections falling in specific duration for monthly drought analysis, it is possible to find out drought area that additionally occurred, and drought reliving process could be confirmed more definitely. Therefore, if the research methods adopted in this study for drought monitoring are utilized, not only accurate spatio-temporal drought analysis is possible, also pattern of drought centroid movement can be analyzed by establishing statistically significant spatial characteristics data after separating all the drought events that occurred sporadically in Korea Peninsula.

A Study on the Development of North Korea's Economic Development Zones through Development Cooperation between South and North Korea (남북 개발협력을 통한 북한 경제개발구 개발 연구)

  • Kwon, Ki Chul
    • Land and Housing Review
    • /
    • v.6 no.2
    • /
    • pp.49-60
    • /
    • 2015
  • North Korean leader Kim Jong Un decided to open 19 Economic Development Zones which are located in all over the country, as a new economic development strategy. The strategy is estimated for accepting change from socialistic planning economic system into socialistic market economic system gradually. South Korean government is busy preparing for reunification between South and North Korea. Recently, many forums and seminars for the issue, 'reunification' are held by public side as well as private sector. This study is focused on making practical strategy for developing 13 Economic Development Zones which were established in 2013 in concurrence with South and North Korea. The study assessed investment potential of the 13 zones in terms of locational, economic and legal competency from the investor's perspective of south koreans. 5 E.D.Zs, Songrim, Hyungdong, Heungnam, Chungjin, Waudo were chosen to be developed on the preferential basis. Development cooperation between South and North Korea on the 13 E.D.Zs will increase the income of north koreans in rural areas by creating jobs, contribute to boost North Korea's economic growth, and bring forward economic integration between South and North Korea.