• Title/Summary/Keyword: 이동 확산

Search Result 1,443, Processing Time 0.027 seconds

Spawning Density and Recruitment of Janpanese Anchovy, Engraulis japonica in the Southern Sea of Korea in 2007 (2007년 남해안 멸치의 산란밀도와 어장가입)

  • CHA, Byung Yul;Yang, Won Seok;Kim, Joo Il;Jang, Sun Ik;Chu, Eun Kyeong;Park, Ju Sam
    • Korean Journal of Ichthyology
    • /
    • v.20 no.3
    • /
    • pp.190-197
    • /
    • 2008
  • Spatio-temporal distribution of eggs and larvae of Japanese anchovy Engraulis japonica in the southern sea of Korea was determined using data obtained from icthyoplanktonic surveys and oceanographic observations between Goheung Peninsula and Goeje Island from May to August 2007. Commercial anchovy catch and size composition from four local fishery cooperative associations were also analyzed in relation to the geographic distribution of eggs and larvae. The abundance of anchovy eggs increased from May to July and was lowest in August. Eggs were mainly distributed between Namhae Island and Goeje Island, where water temperatures were $15{\sim}24^{\circ}C$ and salinities were 32~35‰. In 2007 anchovy landings between Namhae Island and Goeje Island were 11,409 tons at Tongyeong association, 4,137 tons at Masan association, and 2,487 tons at Sacheon association. However, landings between Goheung and Yeosu Peninsula were only 4,411 tons (at Yeosu association). The catch by anchovy tow net was high in the area where eggs were abundantly distributed. This indicates that the distribution of egg density was directly correlated with recruitment of E. japonica. All growth stages were abundant in the study area, indicating that this area is a major spawning and growing ground of E. japonica in Korean waters.

Regional Background Levels of Carbon Monoxide Observed in East Asia during 1991~2004 (1991~2004년 동아시아에서 관측한 일산화탄소의 지역적 배경 농도)

  • Kim, Hak-Sung;Chung, Yong-Seung
    • Journal of the Korean earth science society
    • /
    • v.27 no.6
    • /
    • pp.643-652
    • /
    • 2006
  • Data of the carbon monoxide concentration observed in Mt. Waliguan in China (WLG), Ulaan Uul in Mongolia (UUM), Tae-ahn Peninsula in Korea (TAP), and Ryori in Japan (RYO) were analyzed for a long period between 1991 and 2004. The annual average concentration of carbon monoxide was the highest at TAP $(233{\pm}41ppb)$ followed by $RYO(171{\pm}36ppb),\;UUM(155{\pm}26ppb),\;and\;WLG(135{\pm}22ppb)$. The seasonal variations being high in spring and low in summer were observed in other areas of Eastern Asia except WLG. TAP was high in carbon monoxide concentration in all seasons compared to WLG, UUM and RYO and shows wide distribution of concentration in the histogram, which is caused by the influence of large-scale air pollution due to its downwind location close to the East Asian continent, China in particular. Also, our data was compared with data measured at Mauna Loa (MLO) in Hawaii. According to the origin of the isentropic backward trajectory and its transport passage, carbon monoxide concentration observed in TAP was analyzed as follows: continental background airflows (CBG) were $216{\pm}47ppb$; regionally polluted continental airflows (RPC) were $316{\pm}56ppb$; Oceanic background airflows (OBG) were $108{\pm}41ppb$; and Partly perturbed oceanic airflows (PPO) were $161{\pm}6ppb$. The high concentration of carbon monoxide in TAP is due to the airflow from East Asian continent origin rather than that from the North Pacific origin. Especially, RPC which passes through the eastern China appeared to be the highest in concentration in spring, fall, and winter. However, OBG was affected by the North Pacific air mass with a low carbon monoxide concentration in summer. The NOAA satellite images and GEOS-CHEM model simulation confirmed a large-scale air pollution event that was in the course of expansion from southeastern China bound to the Korean Peninsula and the Korea East Sea by way of the Yellow Sea.

Study on the Measurement System for MIMO Channel Considering Urban Environment at Microwave Frequencies (도심 환경을 고려한 마이크로파 대역 MIMO 전파 채널 측정 시스템에 관한 연구)

  • Lim, Jae-Woo;Kwon, Se-Woong;Moon, Hyun-Wook;Park, Yoon-Hyun;Yoon, Young-Joong;Yook, Jong-Gwan;Jeong, Jin-Soub;Kim, Jong-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.18 no.10
    • /
    • pp.1142-1149
    • /
    • 2007
  • In this paper, the development of wideband MIMO channel sounder and a pilot measurement result is described for research on the multi antenna radio propagation characteristics considering urban environment at microwave frequencies. We developed $4{\times}4$ MIMO(BW:100 MHz) channel sounder using the high speed switching mechanism and periodic pseudo random binary signals method considering next generation mobile communication system. A pilot measurement campaign at the urban area of Bundang is presented for confirmation of system performance. From the analysis of measurement data, wideband path loss exponent of 3.7 and 8 GHz band is 1.79 and 1.76. Average RMS delay spread is 200 ns and 42 ns respectively. From the experiment results, operation of this measurement system is confirmed considering research for a coverage, SNR and channel capacity in urban environment at microwave frequencies.

A Cost-Benefit Analysis of Neonatal Screening Tests for Maple Syrup Urine Disease, Homocystinuria, Galactosemia, and Congenital Adrenal Hyperplasia (한국에서의 단풍당뇨증, 호모시스틴뇨증, 갈락토스혈증, 선천성 부신과형성증에 대한 신생아 선별검사의 경제성 분석)

  • Park, Shin-Young;Kim, Dong-Il;Lee, Dong-Hwan
    • Journal of Genetic Medicine
    • /
    • v.5 no.2
    • /
    • pp.111-118
    • /
    • 2008
  • Purpose: Neonatal screening tests are increasingly being used forearly diagnosis of inborn errors of metabolism (IEM) in the hope of avoiding the severe developmental delay, acute illness, and death that may result from these diseases. In this study, a cost-benefit analysis was performed on the neonatal screening of maple syrup urine disease, homocystinuria, galactosemia, and congenital adrenal hyperplasia in Korea. Materials and Methods: This study included 1,259,220 Korean newborns born between January 2005 to December 2007, who were screened for maple syrup urine disease, homocystinuria, galactosemia, and congenital adrenal hyperplasia. We calculated and compared the total costs in cases where these four screening tests were implemented, and those where they were not. Results: There were no benefits to screening for maple syrup urine disease or homocystinuria due to their low prevalence for these two tests, the costs exceeded the benefits at benefit:cost ratios of 0.5:1 and 0.6:1, respectively. In contrast, benefits far exceed costs at a ratio of 4.1:1 for galactosemia and 2.9:1 for congenital adrenal hyperplasia. The average benefit:cost ratio for all four tests was 2.0:1. Conclusion: Neonatal screening tests for maple syrup urine disease, homocystinuria, galactosemia, and congenital adrenal hyperplasia are financially viable.

  • PDF

Anti-invasive Activity of Human Breast Carcinoma Cells by Genistein through Modulation of Tight Junction Function (인체유방암세포의 tight junction 기능 조절을 통한 genistein의 암세포 침윤 억제 효과)

  • Kim, Sung-Ok;Jeang, Yang-Kee;Choi, Yung-Hyun
    • Journal of Life Science
    • /
    • v.19 no.9
    • /
    • pp.1200-1208
    • /
    • 2009
  • Tight junctions (TJs) that act as paracellular permeability barriers play an essential role in regulating the diffusion of fluid, electrolytes and macromolecules through the paracellular pathway. In this study, we investigated the correlation between the tightening of TJs, permeability and the invasive activity of genistein - a bioactive isoflavone of soybeans - in human breast carcinoma MCF-7 and MDA-MB-231 cells. The inhibitory effects of genistein on cell proliferation, motility and invasiveness were found to be associated with the increased tightness of the TJs, which was demonstrated by an increase in transepithelial electrical resistance and a decrease in paracellular permeability. Additionally, the immunoblotting results indicated that genistein repressed the levels of the proteins that comprise the major components of TJ, claudin-3 and claudin-4, which play a key role in the control and selectivity of paracellular transport. Furthermore, genistein decreased the metastasis-related gene expressions of insulin like growth factor-1 receptor and snail, while concurrently increasing that of thrombospondin-1 and E-cadherin. In addition, we demonstrated that claudins play an important role in the anti-motility and invasiveness of genistein using claudin-3 small interfering RNA. Taken together, our results indicate a possible role for genistein as an inhibitor of cancer cell invasion through the tightening of TJs, which may counteract the up-regulation of claudins. In addition, our results indicate that this may be beneficial for the inhibition of tumor metastasis.

Verification of Antibacterial Activities of Oriental Herbal Medicine Extracts (한약재 추출물의 항균활성 검증)

  • Lee, Chang-Eun;Jo, Jung-Kwon;Kim, Jae-Deok;Lee, Dong-Geun;Kim, Won-Seok;Lee, Sang-Hyeon
    • Journal of Life Science
    • /
    • v.27 no.6
    • /
    • pp.611-616
    • /
    • 2017
  • The antibacterial activities of nine oriental herbal medicine extracts were measured against seven kinds of bacteria known to cause food poisoning and disease. The extracts were prepared with distilled water using an autoclave ($121^{\circ}C$ for 30 min). The extraction yields of nine oriental herbal medicines were in the rage of 0.5%-33.4%. The antibacterial activities were evaluated using the paper-disc method. Extracts of Hwangryeon, Jiyu, and Ohbaeja showed antibacterial activities while the others did not. Extracts of Coptis japonica, Hwangryeon, and Sanguisorba officinalis, Jiyu showed antibacterial activities only against Clostridium perfringens and Listeria monocytogenes. Extracts of Rhus javanica, Ohbaeja showed the strongest antibacterial activities against all the bacteria tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of R. javanica extracts were in the range of 2.4~20 mg/ml for the bacteria tested. In conclusion, the extract of R. javanica showed superior antibacterial activities against the seven bacterial strains tested. The MIC and MBC values for each bacterium were represented as strain names (MIC, MBC), which were Bacillus cereus (11.2, 20), Clostridium perfringens (2.4, 4.7), Escherichia coli (9.1, 9.1), Listeria monocytogenes (11.1, 20), Salmonella typhi (4.7, 9.1), Staphylococcus aureus (2.4, 4.7), and Vibrio parahaemolyticus (2.4, 5.3). Further purification and study of this antibacterial material would be helpful for developing antibiotics or promoting synergistic effects with known antibiotics, producing antibacterial material for lengthening the shelf-life of food, and so on.

Design and Implementation of a Comparative Shopping Agent for E-Commerce (비교쇼핑 에이전트의 설계와 구현)

  • Choi, Moo-Jin;Hwang, Jin-Yeol
    • Information Systems Review
    • /
    • v.7 no.1
    • /
    • pp.97-113
    • /
    • 2005
  • This paper designed and implemented(programmed) a comparative shopping agent that helps consumers to shop at on-line shopping malls over Internet. At offline stores, as consumers usually tell a sales clerk about a manufacturer, functions and price range of an item they want to purchase, the sales clerk will show the products or relevant catalogues. Then the consumer will compare functions, design and prices of the product and buy it with the lowest price. PriceMeter, a comparative shopping agent, introduced in this paper, is designed best geared to this consumers' buying behavior. Basically, as consumers enter a manufacturer's name, price, features and etc. at a search window, PriceMeter will search the web and provide a list of product informations such as features and prices that meet the search conditions. Consumers can see the information in either a form of catalogue or a printing format. As consumers click specific items to examine closely, it will show prices and information about shopping malls that sell the requested items. Clicking a 'Buy' icon, the consumers will be transferred to the right web page at the linked shopping mall. The emergence of the comparative shopping agent will expedite a consumer-centered retailing economy in the age of e-commerce. As consumers are provided with a better set of product and shopping mall information, they can make better purchasing decisions and gain more bargaining power shifted from manufacturers(sellers). The presentation of this comparative shopping agent is intended to promote the consumer-centered B2C e-commerce.

Fe첨가에 따른 지르코늄의 재결정 현상

  • 김영석;권상철;주기남;안상복;김성수
    • Proceedings of the Korean Nuclear Society Conference
    • /
    • 1998.05b
    • /
    • pp.37-40
    • /
    • 1998
  • Fe량을 0 - 0.4 wt.%까지 변화시켜 Zr-Fe 이원계 합금을 진공아크용해로 제조한 후 1050 $^{\circ}C$에서 30분 균질화 처리 및 700 $^{\circ}C$에서의 열간압연, 그리고 2회의 걸친 냉간압연 및 열처리를 통하여 판재로 제조되었다. 중간 열처리 시 열처리 온도 및 시간을 조절하여 최종 냉간가공에 앞서 각 시편의 결정립 크기 및 경도 값이 같도록 조절하였다. 최종 냉간가공 시 냉간가공량을 60%로 동일하게 조절하였고, 최종열처리 시 열처리 온도 및 시간을 300-750 $^{\circ}C$, 5-3000분으로 각각 변화시켰다. 재결정 정도는 미세조직 관찰 및 경도 측정으로 평가되었으며, 석출물의 구조, 분포 및 형상 등도 TEM으로 분석되었다. 0.1 wt.% 정도까지의 Fe 첨가는 Fe를 첨가하지 않은 순수지르코늄에 비하여 지르코늄입자의 빠른 성장을 야기해, 조대한 재결정 지르코늄 입자들이 나타났다. 그러나 Fe 첨가량이 0.1wt.%이상 첨가되면, Zr$_3$Fe 석출물에 의한 입자성장 억제효과로 지르코늄 입자의 크기는 오히려 작아졌다. 결론적으로, Fe의 첨가는 지르코늄의 확산을 가속시켰다는 것을 보여준다. 한편, 750 $^{\circ}C$에서 열처리 시 이차 재결정현상으로 지르코늄 입자가 비정상적으로 매우 커졌으며, 동시에 annealing twining 현상이 관찰되었다. 이러한 annealing twining 현상은, 입자성장속도가 임계치 이상으로 갑자기 커진, Zr$_3$Fe 석출물이 거의 없는 합금에서만 나타났다. 이 결과를 토대로 annealing twining 현상은 입자의 빠른 이동이 필요 조건이라는 결론을 도출하였다. .Ar-4vol.%H$_2$ 분위기보다 H$_2$분위기에서 소결했을 때 밀도가 더 높았다. 그러나, 결정립은 $UO_2$$UO_2$-Li$_2$O의 경우, 수소분위기에서 소결했을 때, (U,Ce)O$_2$와 (U,Ce)O$_2$-Li$_2$O에서는 Ar-4vol.%H$_2$분위기에서 소결했을 때 더욱 성장하였다.설명해 줄 수 있다. 넷째, 불규칙적이며 종잡기 힘들고 단편적인 것으로만 보이던 중간언어도 일정한 체계 속에서 변화한다는 사실을 알 수 있다. 다섯째, 종전의 오류 분석에서는 지나치게 모국어의 영향만 강조하고 다른 요인들에 대해서는 다분히 추상적인 언급으로 끝났지만 이 분석을 통 해서 배경어, 목표어, 특히 중간규칙의 역할이 괄목할 만한 것임을 가시적으로 관찰할 수 있 다. 이와 같은 오류분석 방법은 학습자의 모국어 및 관련 외국어의 음운규칙만 알면 어느 학습대상 외국어에라도 적용할 수 있는 보편성을 지니는 것으로 사료된다.없다. 그렇다면 겹의문사를 [-wh]의리를 지 닌 의문사의 병렬로 분석할 수 없다. 예를 들어 누구누구를 [주구-이-ν가] [누구누구-이- ν가]로부터 생성되었다고 볼 수 없다. 그러므로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다. 즉, [+wh] 의미의 겹의문사는 동일한 구성요 소를 지닌 병렬적 합성어

  • PDF

Korean Demography 30 Years: Challenges and Prospects (한국인구학 30년: 도전과 과제)

  • Kim, Han-Gon;Cho, Young-Tae
    • Korea journal of population studies
    • /
    • v.30 no.3
    • /
    • pp.179-205
    • /
    • 2007
  • Demography has grown as an independent academic discipline in Korea during past 30 years by describing and examining changes of population components such as fertility, mortality, migration, and census, and the "Population Association of Korea" stands on the midst of the growth. High fertility of the 1960s and 70s, which was considered as a hurdle of economic growth, particularly boosted the prosper of demography in Korea by inviting a number of non-demographers as well as demographers to population-related research projects. However, as fertility gradually decreases and becomes no-threat anymore beginning the early 1990s, social interests in demography has withered to lose its academic soils in Korea. A recent phenomenon of the lowest low fertility has revived social need and interest in demography. Unfortunately, once curtailed capacity of Korean demography is not sufficient enough to provide academic and/or practical resources now. This research is conducted to cerebrate the 30th anniversary of "Population Association of Korea" and to seek ways to cultivate academic soils again and to rebuild the capacity of demography in Korea. To do this, this research examines the causes of current struggles of Korean demography by comparing its academic environments with that of America, and offers suggestions for its brighter future.

Vulnerability assessment on the location of industrial complex considering climate change -Focusing on physical and economic features of province·industrial complex - (산업단지의 입지적 요건을 고려한 기후변화 취약성 평가 - 지자체 및 산업단지의 물리적·경제적 특성에 집중하여 -)

  • Kim, Yoonjung;Lee, Dongkun;Seo, Changwan;Ryu, Jieun;Chae, Yeora;Baek, Gyounghye;Bae, Chae-Young
    • Journal of Environmental Impact Assessment
    • /
    • v.22 no.6
    • /
    • pp.627-637
    • /
    • 2013
  • 기후변화가 산업단지에 미치는 영향은 지자체에까지 확산될 수 있으며 물리적, 경제적인 영향이 미쳐지므로 어떠한 물리적, 경제적 변수에 의해 산업단지의 피해가 초래되는지 규명될 필요가 있다. 따라서 본 연구는 국가 산업단지를 대상으로 산업단지 및 입지 시군구의 물리적, 경제적 특성을 기반으로 한 기후변화 취약성 평가를 수행하고 산업단지 입지에 영향을 미치는 시간, 공간별 극한기후를 규명하고자 하였다. 산업단지의 극한기후에 의한 취약성은 IPCC에서 제안한 상향식 취약성 평가 방법을 따라 분석되었으며 전력요구도, 위험지역유무 등 단지의 물리적 입지조건과 입지 지자체의 기반시설 현황, 지자체와 산업단지의 경제적 특성 등이 평가 기준으로 연구되었다. 기후노출, 민감도, 적응 능력의 항목별 가중치와 항목내 변수들의 가중치 분석에 AHP가 적용되었다. 본 연구는 홍수, 가뭄, 혹서, 혹한, 해수면상승에 대해 취약 입지 시군구를 밝혔고 홍수와 가뭄, 혹서와 혹한별로 대비되는 취약성 결과가 나옴을 고찰하였다. 또한, 각 극한기후별로 적응능력 함양이 시급한 시군구를 밝혀 지자체 차원의 노력이 필요한 시군구를 규명하였다. 서울시 금천구는 산업단지 입지에 가장 취약한 지역으로 나타났으며 홍수, 혹한에서 높은 취약성을 보임이 분석되었다. 한편, 극한기후의 발생에도 불구하고 전반적으로 낮은 취약성을 보인 산업단지 입지 지자체는 광주광역시, 전라북도 익산, 제주시 등으로 분석되었다. 따라서 본 연구는 산업단지의 업종에 따라 적합하지 않은 입지 지역을 규명하였으며 향후 산업단지 입지의 잠재 기후변화 영향을 고려한 의사결정을 지원할 수 있다.