• Title/Summary/Keyword: O$_2$

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Biocompatibility and Surface Characteristics of (Si,Mn)-HA Coated Ti-Alloy by Plasma Electrolytic Oxidation (PEO법으로 (Si,Mn)-HA 코팅된 치과 임플란트용 Ti 합금의 생체적합성 및 표면특성)

  • Gang, Jeong-In;Son, Mi-Gyeong;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.83-83
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    • 2017
  • 생체재료의 표면은 이식과 동시에 생체계면의 역할을 하게 되어, 일련의 생물학적 반응이 시작되고 진행되는 중요한 장소가 된다. 초기에 생체계면에서 일어나는 단백질 흡착이나 염증반응을 비롯한 생물학적 반응들은 궁극적으로 임플란트의 성패를 좌우할 만큼 중요하다. 골융합을 개선하기 위한 다른 방법으로 생체불활성의 타이타늄 (Ti)과 골조직의 능동적인 반응을 이루기 위해 생체활성 표면을 부여함으로서 계면에서의 골형성 반응을 증진시키는 방법이 이용된다. 생체불활성의 Ti과 Ti합금은 골조직과 직접적인 결합을 이루지 못하므로, 골조직과의 반응을 향상하기 위해 여러 종류의 생체활성 재료를 코팅하는 방법이 연구되어 왔고, 이 중 생체의 변화와 가장 유사한 하이드록시아파타이트 코팅이 가장 대중적인 방법으로 사용되었으며 이는 초기 골형성을 촉진하는 것으로 알려졌다. 치과용 임플란트의 표면형상과 화학조성이 골 융합에 영향을 미치는 가장 중요한 인자이므로 최근의 연구동향은 이들 두 가지 표면특성을 결합함으로서 결과적으로 최적의 골세포반응을 유도하고, 골융합 후 골조직과의 micromechanical interlocking에 의해 임플란트의 안정성에 중요한 역할을 하는 마이크론 단위의 표면조도와 표면 구조를 유지하면서, 부가적으로 골 조직 반응을 능동적으로 개선할 수 있는 생체활성 성분을 부여하여 골 융합에 상승효과를 이루기 위한 표면처리법에 관해 많은 연구가 요구되어지고 있다. 따라서 골을 구하는 원소인 망간과 실리콘으로 치환된 하이드록시아파타이트를 플라즈마 전해 산화법으로 코팅하여 세포와 잘 결합할 수 있는 표면을 제공함으로써 골 융합과 치유기간을 단축시킬 수 있을 것으로 사료된다. 실험방법은 시편은 치과 임플란트 제작 합금인 Ti-6Al-4V ELI disk (grade 5, Timet Co., USA; diameter, 10 mm, thickness, 3 mm)이며, calcium acetate monohydrate, calcium glycerophosphate, manganese(II) acetate tetrahydrate, sodium metasilicate을 설계조건에 따라 혼합 제조된 전해질 용액을 이용하여 플라즈마 전해 산화법으로 표면 코팅을 실시하였다. 각 시편의 플라즈마 전해시 전압은 280V로 인가하였고, 전류밀도는 70mA로 정전류를 공급하여 해당 인가전압 도달 후 3분 동안 정전압 방식을 유지하였다. 코팅된 피막 표면을 주사전자현미경과 X-선 회절분석을 통하여 미세구조 및 결정상을 관찰하였다. 또한 코팅된 표면의 생체활성 평가는 정량적으로 평가하기 위해 동전위시험과 AC 임피던스를 통하여 시행하였다. 분극거동을 확인하기 위해 potentiostat (Model PARSTAT 2273, EG&G, USA)을 이용하여 구강 내 환경과 유사한 $36.5{\pm}1^{\circ}C$의 0.9 wt.% NaCl에서 실시하였다. 전기화학적 부식 거동은 potentiodynamic 방법으로 조사하였고 인가전위는 -1500 mV에서 2000 mV까지 분당 1.67 mV/min 의 주사속도로 인가하여 시험을 수행하였다. 임피던스 측정은 potentiostat (Model PARSTAT 2273, EG&G, USA)을 이용하였으며, 측정에 사용한 주파수 영역은 10mHz ~ 100kHz 까지의 범위로 하여 조사하였고 ZSimWin(Princeton applied Research, USA) 소프트웨어를 사용하여 용액의 저항, 분극 저항 값을 산출하였다. 망간의 함량이 증가할수록 불규칙한 기공을 보였으며, 실리콘은 $TiO_2$ 산화막 형성을 저해하는 경향을 확인할 수 있었다. 단독으로 표면을 처리한 경우보다 두 가지 원소를 이용해 복합 표면처리를 시행한 경우가 내식성이 좋아 임플란트과의 골 유착에 긍정적인 영향을 미칠 것으로 사료된다.

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A Study on Development of Gas Accident Management System based on GIS (GIS 기반의 가스사고 관리시스템 개발에 대한 연구)

  • Kim, Kye-Hyun;Kim, Tae-Il
    • 한국지형공간정보학회:학술대회논문집
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    • 2002.03a
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    • pp.106-112
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    • 2002
  • 최근 급속한 도시의 팽창 및 신도시 건설과 산업의 발전으로 가스시설은 꾸준히 확대되고 있는 실정이다. 그리고 94년 아현동 도시가스사고와 95년 대구 도시가스사고 이후로 도시 가스 시설물의 대한 안전 대책 및 시설물 관리에 대한 국민들의 관심이 증대되었다. 이러한 흐름에 따라 가스회사들은 GIS 기술을 도입하여 기존에 수작업으로 관리되고 있는 가스시설 정보체계를 전산화하여 항상 최신의 현황을 유지하고, 사고 발생시 신속한 대처 방안 및 피해예측을 위한 시스템을 개발하기 위하여 많은 연구를 진행하고 있는 실정이다. 본 연구의 목적은 안전이 중요시되는 가스시설물에 대하여 가스사고 발생시 신속한 대처 및 처리방안을 제시할 수 있는 GIS 기반의 가스사고 관리시스템을 개발하는데 있다. GIS의 가스사고 관리시스템에서는 사고 발생시에 시설물 관리자가 사고 지점을 선택하여 우선적으로 공급을 중단해야 할 관로를 제시하고 사고지점을 검색하여 차단해야 할 밸브에 대한 정보를 신속히 제공하여 대응 방안을 제시 할 수 있도록 하였다. 아울러 가스공급이 중단되는 지역에 대한 정보를 추출하여 피해범위를 산정하여 효율적인 사고 관리를 지원하도록 구성되었으며, 이와 함께 잔존가스량을 구하여 사고후의 대처방안을 마련할 수 있는 기능을 제공하도록 하였다. 향후 연구과제로는 원격으로 가스 시설물을 감시하고 제어할 수 있는 원격감시/제어시스템(SCADA System)과 연계를 통하여 가스사고 후에 신속한 피해예측 및 피해를 최소화 할 수 있는 방안제시 및 GPS를 활용하여 신속한 사고처리를 할 수 있는 활용 방안을 연구하여 체계적이고 종합적인 가스사고의 관리가 필요하다고 사료된다. 또한, 사고 후의 긴급 대처방안 뿐만 아니라 잔존가스량을 이용하여 수용가에 가스의 신속한 재공급을 위한 정보의 제공까지 한 단계 발전된 시스템의 개발이 추진되어야 한다.남산지역에 대해 정사영상과 10m간격의 DEM을 제작하였으며 1:1000 수치지도를 통해 제작된 DEM과 비교한 결과 총 43990개 격자점의 표고 차이는 평균 5.98m였다.여재 높이 100 cm에서 원수를 하향류 및 상향류로 주입하면서 하향류 20, 40, 80, 100 cm, 상향류 20, 40, 60, 80, 100 cm에서 시료를 채취하여 분석한 결과 모두 원수가 주입되는 부근 여재 높이 20 cm에서 가장 많이 제거되었다. 상향류 보다 하향류로 원수를 주입했을 때 제거효율이 높았다. $Fe^{+++}$$Fe^{++}$로 환원하는 $O^{-}_{2}{\cdot}$의 작용을 대신할 수 있음을 증명하며 이와같은 ascorbate 의존적인 $OH{\cdot}$ 의 생성은 ascorbate가 조직손상에 관여할 가능성을 시사하였다.었다. 정확한 예측치를 얻기 위하여 불균질 조직이 조사야에 포함되는 경우 보정이 요구되며, 골반의 경우 골 조직의 보정이 중요한 요인임을 알 수 있었다. 이를 위하여 불균질 조직에 대한 정확한 정보가 요구되며, 이는 CT 영상을 이용하는 것이 크게 도움이 되리라 생각된다.전시 슬러지층과 상등액의 온도차를 측정하여 대사열량의 발생량을 측정하고 슬러지의 활성을 측정할 수 있는 방법을 개발하였다.enin과 Rhaponticin의 작용(作用)에 의(依)한 것이며, 이는 한의학(韓醫學) 방제(方劑) 원리(原理)인 군신좌사(君臣佐使) 이론(理論)에서 군약(君藥)이 주증(主症)에 주(主)로 작용(作用)하는 약물(藥物)이라는 것을 밝혀주는 것이라고 사료(思料)된다.일전 $13.447\;{\mu}g/hr/g$, 섭취 7일중 $8.123\;{\mu}g/hr/g$, 절식 14일후 $10.612

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Effects of Bangpoongtongsungsan on Adipose Tissue and Hyperlipidemia of 3T3-L1 Induced Rats (3T3-L1 cell에서 방풍통성산의 지방세포 분화 억제 효과 연구)

  • Lee, Jin-Yong;Kim, Deog-Gon;Lee, Kyung-Tae;Cha, Min-Kyung
    • The Journal of Pediatrics of Korean Medicine
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    • v.20 no.2
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    • pp.177-196
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    • 2006
  • Objective : This experimental study was designed to determine the effects of BPT on obesity in vivo and in vitro. Methods : in vitro, BPTn extracts of various concentration(50, 100, 200 ${\mu}g/m{\ell}$) were added in 3T3-L1 cell. Adipocyte differentiation was measured by Oil Red O staining and Morphological examination. The expression of $C/EBP{\alpha}$ and $PPAR{\gamma}$ receptor was measured by western blot assay and RT-PCR in vivo, Rats were orally administered BPT daily for consecutive four weeks before poloxamer-407 induced hyperlipidemic state. The rats were sacrificed 24 hrs later for poloxamer-407 treated and then serum triglyceride, total cholesterol were measured ; Rats were orally administered BPT daily for consecutive four weeks before triton WR-1339 induced hyperlipidemic state. The rats were sacrificed 40 hrs later for triton WR-1339 treated and then serum triglyceride, total cholesterol were measured ; Rats with obesity were induced by the high fat-diet for six weeks and then serum triglyceride, total cholesterol, LDL-cholesterol, triglyceride, HDL-cholesterol, hydroxy radical, superoxide dismuatse activity were measured. Results : In vitro, The 3T3-L1 cells' differentiation was significantly decreased by BPT. The expression of $C/EBP{\alpha}$ and $C/EBP{\beta}$ was decreased by BPT. In vivo, BPT significantly reduced serum triglyceride, total cholesterol contents in poloxamer-407 treated rat. BPT significantly reduced serum triglyceride contents in Triton WR-1339 treated rat. Total cholesterol also reduced but did not show a significant change. BPT significantly reduced body weight gain of rat and adipose tissue mass of rats and serum triglyceride, LDL-cholesterol contents and significantly increased HDL-cholesterol, HTR(HDL-cholesterol/Total-cholesterol) in rats with obesity induced by the high fat-diet. BPT reduced blood lipid peroxide, hydroxy radical and increased superoxide dismuatse(SOD) activity.

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Effect of Ilioinguinal-hypogastric Nerve Block and Caudal Block on Post-operative Pain after Orchiopexy and Herniorrhaphy in Pediatric Surgery (소아 고환고정술 및 탈장수술후 통증감소를 위한 장골서혜/장골하복 신경차단과 미추차단의 비교)

  • Moon, Sun-Ae;Lee, Hyun-Wha;Kim, Kun-Sik;Shin, Ok-Young;Kwon, Moo-Il
    • The Korean Journal of Pain
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    • v.9 no.1
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    • pp.145-150
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    • 1996
  • The purpose of this study was to evaluate and compare the effectiveness of ilioinguinal-hypogastric nerve blocks(IHNB) and caudal block in producing post-orchiopexy and post-heniorrhaphy analgesia in children. Forty consenting healthy children, ages 3~10yr, were randomly assigned to receive caudal bupitvacaine (0.125%, 0.5ml/kg), or IHNB bupivacaine (0.25%, 0.3 ml/kg). Blocks were performed following the induction of general anesthesia, be fore the operation. Pre-anesthetic medication in form of atropine 0.01 mg/kg, droperidol 0.05 mg/kg were given intramuscularly one hour before induction to 40 children. Children were induced with thiopental sodium 5 mg/kg and succinylcholine 1 mg/kg intravenously. Anesthesia was maintained with oxygen-nitrous oxide ($FiO_2$ 0.3) and ethrane. When the patients stabilized after induction. IHNB was done in the supine position and caudal block was done in the lateral position. The local anaesthetic was injected after negative aspiration. Postoperative pain was assessed with face pain rating scale (RPRS) at rest on discharge of recovery room, and 5 hours after discharge of recovery room, and the "red and white" visual analogue scale (VAS) at rest and mobilization from supine to sitting position on discharge of recovery room, and 5 hours after discharge of recovery room. Post-operative recovery was quiet and comfortable, without side effect. Relief of ain was complete in both IHNB group and caudal group. Surgeons, parents and recovery room personnel were satisfied. There were no surgical or anesthetic complications. In our study, the postpoerative pain scores were similar in both IHNB group and caudal group. IN conclusion, we found that both IHNB and caudal blocks before the start of surgery for orchiopexy & herniorrhaphy are safe and effective in controlling the postoperative pain of children.

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A Study of the Hierarchy of the Central Place and the Shopping Area in the Kyeong-ju Si Area (경주시지역 중심지계층과 생활권에 관한 연구)

  • Park, Tae-Hwa;Lee, Jae-Mok
    • Journal of the Korean Geographical Society
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    • v.31 no.3
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    • pp.508-528
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    • 1996
  • The purpose of this study is to analyze the classification of the hierarchy in terms of centrality and the demarcation of shopping areas in the context of goods-purchasing activity in the Kyeong-ju si area (The old Kyeong-ju city and Wol-song Kyn). The basic data for this study include mail questionnaire materials and sources by the on-the-sport survey. The main results of this study are as follows. (1) When forty-two centers within the wide Kyeong-ju area are classified into hierarchies in terms of the functional index and the number of central functions, it is confirmed that there are five hierarchies or classes. Hierachy A is the City of Kyeong-ju. Hierarchy B is the Up of An-gang. Hierarchy Cis made up of three Up of Kam-p'o, Oe-dong and Kon-ch' on. Hierachy D consist of seven Myons and two Ris. Hierarchy E is composed of one Myon and twenty-seven Ris. (2) Hierarchy A has five proper functions of the center. Hierarchy B holds eleven of them. Hierarchy C takes forty-one. Hierarchy D cherish twenty-seven. And hierarchy E has three. Therefor Hierachies C and D have the most functions of all. The threshold populations of the lowest central function is fifty-eight of miscellaneous stores in the central place of Hierarchy E (3) The purchase distance of the central functions of a center becomes farther in the order of barbers' and beauty salons, dental clinics, TV and refrigerator shops, and furniture stores. (4) When the shopping areas are classified according to goods purchase activity, they can be divided into four: the Myon, small Up, big Up, and City areas. Each shopping area can be classified into two categories: the independent areas and compoung areas. The Kyeong-ju city area is the largest city shopping areas of Po-hang and Ull-san are very small.

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An Interpretive Inquiry into the Guidance Experiences of Senior Elementary Teachers (초등학교 원로교사의 생활지도 경험에 관한 해석학적 탐구)

  • Lee, Jeong-Hee
    • The Korean Journal of Elementary Counseling
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    • v.7 no.1
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    • pp.111-133
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    • 2008
  • The purpose of this study was closely to explore the guidance experiences of senior elementary teachers who have had over 30 years of teaching experiences in elementary school based on interpretive(or hermeneutic) inquiry. The entry research question was 'What are the guidance experiences of senior elementary teachers like?' Seven senior elementary teachers working for O elementary School in G city participated in this study voluntarily. Each participant was interviewed twice in a consecutive manner. 14 periods of interview were completed all together and each period took about 40-60 minutes. In conclusion, this study conceptualized the guidance experiences of the senior elementary teachers(participants) as follows: First, the concepts of guidance held by the participants were conceptualized as 1) supporting and caring activity helping students to lead joyful school life, 2) assisting activity helping students to grow on good basic life habits, 3) character building activity helping students to lead integrative growth. Second, the fields and contents of guidance held by the participants were conceptualized as basic life habits, manners, and health & safety. Interestingly, these concepts were evolved in connection with their personal, practical teaching experiences rather than in-service teacher education. Third, the guidance methods frequently used by the participants were co-work with parents, exemplary storytelling, counselling, and praise. The participants applied these methods differently according to the grade, individual difference, and school curriculum policy to some degree. Fourth, the participants have experienced a lot of struggles with students, teachers, and parents in doing their guidance practices throughout the whole teaching career. Their guidance experiences commonly shifted from more teacher-centered or authoritative to more student-centered or relational way as their teaching years accumulated. Interestingly, all the participants more or less lived as lifelong learners to create their own right space as senior teachers in today's competitive and challenging landscape. This study strongly suggests that responsible teacher education can playa great role of enabling senior teachers to cope with guidance issues successfully. Compared with the speedy social change, the teacher education in Korea had been so authoritative, provider-based, subject-based until recently and it have not met the needs and wants of the elementary teachers in field. This trend has significantly hindered them from catching up with the needs of the speedy social change in terms of contemporary guidance issues. This study is limited in that the data is solely collected based on interview. So, an observational research is strongly suggested in order to uncover the situated understanding of the guidance experiences of elementary senior teachers.

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Lipase Inhibitory Mode of Dieckol Isolated from Eisenia bicyclis Ethanol Extract (Eisenia bicyclis 에탄올 추출물로부터 분리한 Dieckol의 Lipase 저해 Mode)

  • Jung, Seul-A;Kim, Koth-Bong-Woo-Ri;Kim, Dong-Hyun;Cho, Ji-Young;Kim, Tae-Wan;Ahn, Dong-Hyun
    • Microbiology and Biotechnology Letters
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    • v.41 no.1
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    • pp.112-118
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    • 2013
  • This study was performed to investigate the possible use of Eisenia bicyclis (EB) ethanol extract to inhibit activity against lipase. In tests, the lipase inhibitory activity of EB ethanol extract was noted as being 43, 27, and 24% at concentrations of 5, 2.5, and 1 mg/ml, respectively. Isolation was carried out by liquid and liquid extraction, silica-gel column chromatography, and HPLC. The results showed that the lipase inhibitory activity of the ethyl acetate (EA) fraction from EB ethanol extract exhibited the strongest lipase inhibitory activity with an $IC_{50}$ value of 1.31 mg/ml. The EA fraction was separated using silica-gel column chromatography and we obtained 22 sub-fractions. Amongst them, the EA1 fraction showed the highest lipase inhibitory activity with an $IC_{50}$ value of 0.54 mg/ml. Eight peaks were obtained from the EA1 fraction by HPLC. Fraction 5 also showed a strong lipase inhibitory activity with an $IC_{50}$ value of 0.37 mg/ml. The fraction 5 was identified as dieckol and the inhibition pattern analyzed from Lineweaver-Burk plots revealed a non-competitive inhibitor. These results suggest that EB has potential as a natural anti-obesity agent.

A Calculation Method of in vivo Energy Consumption in Estimation of Harvesting Date for High Potato Solids (고 고형분함량 감자의 수확시기 예측모형을 위한 식물체내 에너지 소모량 추정)

  • Jung, Jae-Youn;Suh, Sang-Gon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.4
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    • pp.284-291
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    • 2010
  • A simulation modeling for predicting the harvesting date with high potato solids consists of development of mathematical models. The mathematical model on potato growth and its development should be obtained by using agricultural elements which analyze relations of solar radiation quantity, temperature, photon quantity, carbon dioxide exchange rate, water stress and loss, relative humidity, light intensity, and wind etc. But more reliable way to predict harvesting date against climatic change employs in vivo energy consumption for growth and induction shape in a slight environmental adaptation. Therefore, to calculate in vivo energy loss, we take a concept of estimate of the amount of basal metabolism in each tuber on the basis of $Wm={\int}^m_tf(x)dt$ and $Tp=\frac{Tm{\cdot}Wm^{Tp}}{Wm^{Tm}}$. In the validation experiments, results of measuring solid accumulation of potato harvested at simulated date agreed fairly well with the actual measured values in each regional field during the growth period of 2005-2009. The calculation method could be used to predict an appropriate harvesting date for a production of high potato solids according to weather conditions.

An Ecological Analysis of Lichens Distributed in Rocks of Coast and Field in U-do by Molecular Technique (분자생물학적 기법에 의한 우도해안과 노지암석에 분포하는 지의류의 생태학적 분석)

  • Gang, Hyeong-Il;Yun, Byeong-Jun;Kim, Seong-Hyeon;Sin, Deok-Ja;Kim, Hyeon-U;Heo, Jae-Seon;Gang, Ui-Seong;O, Gye-Heon;Go, Yeong-Jin
    • Microbiology and Biotechnology Letters
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    • v.32 no.4
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    • pp.334-340
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    • 2004
  • This study was initially performed to obtain fundamental data on lichen distribution depending on environmental condiLichens distributed on coastal rocks atleast 20 m far away from the coast were also investigated. Analyof morphological characteristics and rDNA ITS clones revealed that lichens containing 9 families and 15 genera were distributed in coastal rocks of V-do, while lichens containing 10 families and 14 genera were in field rocks, demonstrating little difference of diversity between both sites. Foliose lichens such as PhaeophysPhyscia, Pyxine belonging to the family Physciaceae were representatives distributed in coastal rocks of V-do, along with Xanthoparmelia belonging to Parmeliaceae, fruticose lichens such as Ramalina to Ramaliand crustose lichen Lecanora to Lecanoraceae. In contrast, foliose lichen Cladonia belonging to the family Cladoniaceae, fruitcose lichen Stereocaulon to Streocaulaceae, and crustose lichen Porpidia to Porpidwere found only on the surface of field rocks. Crustose lichens containing genera Caloplaca, CanDirinaria, Graphis, Rhizocarpon, and Pertusaria were rarely distributed in coastal rocks, and most of them were also found in field rocks.

The Role of Universities and the Characteristics of Knowledge Networks in Three Regions (지역 대학의 역할과 지식 네트워크 특징에 대한 연구 : 3개 지역 비교를 중심으로)

  • Jeong, Dae-hyun;Kwon, O-Young;Jung, Yong-Nam
    • Journal of Korea Technology Innovation Society
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    • v.20 no.2
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    • pp.487-517
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    • 2017
  • In the context of an increased demand in universities' expansion of networks between other innovation actors, this research attempts to make a comparison on university-centered SCIE knowledge networks between regions. Using regional comparison, we have looked into these networks in regards to their characteristics, the importance of regional boundaries, and the effect of the regional industrial policy. As a result of this comparative analysis, we discovered that the point universities and research universities hold high centrality in regional knowledge networks, and that the characteristics of regions are reflected into this network. For instance, the Gyeonggi province had a preeminent level of industry-academy relationship, while for Daejeon it was public research institutions and academy, and Gangwon province it was between academy between academy. As a network analysis based on journals above SCIE levels, regional boundaries were not very clear in the network structures. However, within these boundaries, the impact of regional industrial policies were proven to be stronger in the Gang-won province where the academy-academy network was most prominent. The implication of this research outcome is that for regional innovation, government should more actively implement policies that can link academic institutes' knowledge to industry by expanding knowledge networks. In addition, we emphasize on the necessity of a regionally-appropriate policy, rather than a generalized industrial policy. And fundamentally, in regards to innovation, establishing a sound industrial infrastructure for regional development and efforts to link relevant actors are required.