• Title/Summary/Keyword: Range of variation

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Study on Thermal Performance of Energy Textile in Tunnel (터널 지열 활용을 위한 에너지 텍스타일의 열교환 성능 연구)

  • Lee, Chulho;Park, Sangwoo;Sohn, Byonghu;Choi, Hangseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.5
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    • pp.1907-1914
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    • 2013
  • Textile-type heat exchangers installed on the tunnel walls for facilitating ground source heat pump systems, so called "energy textile", was installed in an abandoned railroad tunnel around Seocheon, South Korea. To evaluate thermal performance of the energy textile, a series of long-term monitoring was performed by artificially applying daily intermittent cooling and heating loads on the energy textile. In the course of the experimental measurement, the inlet and outlet fluid temperatures of the energy textile, pumping rate, temperature distribution in the ground, and air temperature inside the tunnel were continuously measured. From the long-term monitoring, the heat exchange rate was recorded as in the range of 57.6~143.5 W per one unit of the energy textile during heating operation and 362.3~558.4 W per one unit during cooling operation. In addition, the heat exchange rate of energy textile was highly sensitive to a change in air temperature inside the tunnel. The field measurements were verified by a 3D computational fluid dynamics analysis (FLUENT) with the consideration of air temperature variation inside the tunnel. The verified numerical model was used to evaluate parametrically the effect of drainage layer in the energy textile.

Genetic Relationship among Sedum Species Based on Morphological Characteristics and RAPD Analysis (한국산 Sedum속 식물의 형태적 특성과 RAPD에 의한 유연관계 분석)

  • Kwon, Soon Tae;Jeong, Jeong Hag
    • Horticultural Science & Technology
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    • v.17 no.4
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    • pp.489-493
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    • 1999
  • This study was conducted to investigate the potentiality of various Korean Sedum species as ornamental plants based on morphological characteristics and to analyze the genetic relationship among the Sedum species. S. kamtschaticum and S. takesimense possessing splendour flowercluster with yellow color could be suggested for garden plant, S. routundifolium having pink flower-clusters with round leaf shape for pot flower or garden plant and S. sarmentosum, S. polystichoides and S. oryzifolium with creeping stem and low plant height for ground cover plant or floral carpet. Eighteen oligonucleotide random primers were used to amplify genomic DNA of Sedum species using polymerase chain reaction (PCR). Ninety five polymorphic bands among 125 different DNA fragments in the range of 224 to 3,675 base pairs were obtained from RAPD analysis. Similarity matrix of RAPD profiles was generated by coefficient value of variation, and the data were subjected to be cluster analysis. Fifteen lines of Sedum species analyzed were classified into 3 groups with the similarity coefficient value of 0.418, and 12 groups with the value of 0.328. RAPD results showed similar trends as the morphological characteristics of the plants.

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The study of Si(111)Au surface by variation of RHEED spot intensity (Rheed 반점강도의 변화를 이용한 Si(111)-Ad 표면조사)

  • Kwak, Ho-Weon;Lee, Eui-Wan;Lee, Sang-Yun
    • Korean Journal of Materials Research
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    • v.4 no.6
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    • pp.638-643
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    • 1994
  • The Si(ll1) surface structures induced by deposition of Au atoms were investigated by RHEED system. When Au atoms were deposited on the Si(ll1) $7\times7$ surfade, the dependence of structures and phases on the substrate temperatures and coverages was drastic. For O.1ML to 0.4ML of coverage the $7\times7$ structure changes to $7\times7$ + $5\times2$ structure as temperature increases to $350^{\circ}C$-$750^{\circ}C$. Between 0.4M1 to 1.OML the phase changed to $5 \times 2,\alpha- \sqrt{3} \times \sqrt{3},\beta- \sqrt{3} \times \sqrt{3}$ structure according to the substrate temperature and coverages. When the coverages exceeds O.SML, the 6 x 6 structure appears at the substrate temperature range between $270^{\circ}C$-$370^{\circ}C$ and compeletely transforms to 6 x6 at 1,OML. The isothermal desorption of Au on Si(ll1) surface investigated by using AES in the $\alpha- \sqrt{3} \times \sqrt{3},5 \times 2$ structures shows that the desorption energys of $\alpha- \sqrt{3} \times \sqrt{3}$ and 5 x 2 were 79Kcal/mol and 82 Kcal/mol respectively.

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Performance of Northern Exposure Index in Reducing Estimation Error for Daily Maximum Temperature over a Rugged Terrain (북향개방지수가 복잡지형의 일 최고기온 추정오차 저감에 미치는 영향)

  • Chung, U-Ran;Lee, Kwang-Hoe;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.3
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    • pp.195-202
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    • 2007
  • The normalized difference in incident solar energy between a target surface and a level surface (overheating index, OHI) is useful in eliminating estimation error of site-specific maximum temperature in complex terrain. Due to the complexity in its calculation, however, an empirical proxy variable called northern exposure index (NEI) which combines slope and aspect has been used to estimate OHI based on empirical relationships between the two. An experiment with real-world landscape and temperature data was carried out to evaluate performance of the NEI - derived OHI (N-OHI) in reduction of spatial interpolation error for daily maximum temperature compared with that by the original OHI. We collected daily maximum temperature data from 7 sites in a mountainous watershed with a $149 km^2$ area and a 795m elevation range ($651{\sim}1,445m$) in Pyongchang, Kangwon province. Northern exposure index was calculated for the entire 166,050 grid cells constituting the watershed based on a 30-m digital elevation model. Daily OHI was calculated for the same watershed ana regressed to the variation of NEI. The regression equations were used to estimate N-OHI for 15th of each month. Deviations in daily maximum temperature at 7 sites from those measured at the nearby synoptic station were calculated from June 2006 to February 2007 and regressed to the N-OHI. The same procedure was repeated with the original OHI values. The ratio sum of square errors contributable by the N-OHI were 0.46 (winter), 0.24 (fall), and 0.01 (summer), while those by the original OHI were 0.52, 0.37 and 0.15, respectively.

Benthic Marine Algal Flora and Community Structure of Yongho-dong Area in Pusan, Korea (부산 용호동 일대의 저서 해조상 및 군집구조)

  • NAM Ki Wan;KIM Young Sik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.3
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    • pp.374-384
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    • 1999
  • Benthic marine algal flora and community structure of Yongho-dong area in Pusan, Korea were investigated seasonally in intertidal and subtidal zones by a quadrat method along 5 transect lines from July 1996 to April 1997. In this area, a total of 99 species including 3 blue-green, 13 green, 26 brown and 57 red algae was found. Among them, 33 taxa, together with dominant Ulva pertusa and Corallina pilulifera, occurred throughout the year. Enteromorpha spp. and Ulva spp. vertically distributed in upper and middle zone, while Simphyocladia latiuscula, Chondria crassicaulis, Corallina pilulifera and Sargassum sup. in lower zones. Biomass per unit area exhibited a wide range of variation, from 1,241 g/$m^2$(spring) to 1,648 g/$m^2$(summer) in fresh weight. Maximum and minimum species diversity were recorded in spring and autumn, respectively. Results of the UPGAM cluster analysis suggest that the examined 5 sites can be divided into two groups, sites exposed to open sea (transects 1, 2, 3) and comparatively sheltered sites (transects 4, 5) faced with the Pusan Harbor. The former group is represented by large brown algae, Sargassum and Hizikia, while Ulva pertusa and Lomentaria species are mainly found in the latter group. A calcareous alga, Corallina pilulifera occurred dominantly in both groups throughout the year. In conclusion, number of species in this area was remarkably reduced as compared to the previous data. This result may suggest probably more change of algal vegetation in future, considering the physical and chemical pollutions loaded in the coastal marine environment of this area.

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Study on the Body Temperature Measuring Time and Accuracy and Reliability of Tympanic Thermometer (체온측정시간 및 고막체온계의 정확도와 신뢰도에 관한 연구)

  • Jeong Ihn-Sook;Yoo Eun-Jung
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.4 no.1
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    • pp.19-30
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    • 1997
  • This study was to investigate the method for shortening the body temperature (BT) because it takes a long time and is impractical to measure axillary or oral BT with mercury thermometer, The first approach was to identify BT change according to the measuring time and determine the clinically not statistically avaiable and optimal BT measuring time. The second was to test the accuracy of tympanic thermometer. It can measure BT within a few seconds, so if it is approved accurate, we can save BT measuring time by substitute tympanic thermometer for mercury thermometer. This study was conducted from 1, to 30 June, 1996. The subjects were 12men students of medicalk college and 29 women students of nursing school. The results were as follows ; 1) The 3, 5, 7, 9, 11, 13minute-measured axillary BT and 3, 5, 7, minute-measured BT showed somewhat linear relationship with time. It was difficult to find the optimum measuring time which were clinically significant. 2) For axillary tempeiature, the measuring time which were not statistically different was 11 and 13minute. But the real BT difference between 3 and 13minute, or between 5 and 13minute were very small and was within the range of daily variation. 3) For oral temperature, there was no intervals which showed the statistically insignificant. But like as axillary temperature, the difference between 3 and 7, or 5 and 7 minute were trivial by $0.3^{\circ}C$ and by $0.1^{\circ}C$ respectively. 4) Tympanic temperatures were lower than oral BTs which were measured with mercury thermometer by $0.26^{\circ}C$ (with ear tug) and $0.15^{\circ}C$(without ear tug). 5) The reliability of repeated measure tympanic temperature was better than without ear tug. With above results, we can't determine the optimal and cilically significant oral and axillary measuring time using mercury thermometer. However, because the real differences between measuring times were very small, so we recommend further study for the aged, the infants and the febrile patients. And we can't sure the accuracy of tympanic temperature but the reliability was better with ear tug than without ear tug.

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Genetic Relationahips of the Two Morphorogical Types of Myzus persicae(Homoptera:Aphididae) Collected from Tobacco Plants Based on Random Amplified Polymorphic DNA(RAPD) (연초에서 발생하는 복숭아혹진딧물(Myzus persicae)형태형 2종의 Random Amplified Polymorphic DNA(RAPD)을 이용한 유전적 유연관계 분석)

  • 채순용;이기원;김상석;장영덕
    • Korean journal of applied entomology
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    • v.37 no.1
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    • pp.31-37
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    • 1998
  • Random amplified polymorphic DNA (RAPD) markers were used to analyze genetic similarity among 8 clones of apierous green peach aphid, two types (M. persicae Sulzer and M. nicotianae lack man) classified by their mo~hologi~cahla raters and host preference (Blackman, 1987), collected from tobacco plants. The genetic variation among these clones was evaluated by polymerase chain reaction amplification with 20 random primers. The higher GC contents of primers, the better in amplification efficiency of PCR reaction in general. The genetic similarities among eight aphid clones were analyzed from UPGMA (unweighted pair group average method) cluster analysis based on simple matching coefficient. The range of genetic similarity coefficients was 0.414 to 0.808. The most close relationship among the clones was similarity coefficient of 0.808 between the PG2 and the PG3 clone. The eight aphid clones analyzed were clustered into three groups by the genetic similarity coefficient. The first group, PG1, PG2, PG3 clone including in M. persicae type by their morphological characters and RED clone in M. nicotianae type was clustered at the genetic similarity coefficient of 0.643. The second group, GR1, GR2, BRN in M. nicotianae type was at the 0.636;and the third group was DBR clone in M. persicae type. The results did not indicate any correlation between m&-phological types (M. persicae and M. nicotianae) and RAPD polymorphism. We could not detect any obvious genetic relationships of the two morphological types of the green peach aphid collected from tobacco plants.

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Comparative Study on the Departure Area for a Day's Tour Trip in Due Consideration of the Circular Trip among Tourist Attractions - Focused on Geoje-si Tourist before and after the Opening of BG Fixed Link - (관광지간 회유(回遊)행동을 고려한 당일관광통행 출발권역 비교연구 - 거가대로 개통 전후 거제 방문관광객을 대상으로 -)

  • Song, Ki-Wook;Jung, Hun-Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1103-1110
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    • 2015
  • Ratio of a day's tour for Geoje-si, 22.6 percent, has increased to 48.6 percent since the opening of Busan-Geoje fixed link. Eight cities of Yeungnam area including Busan-Ulsan and Daegu-Gyeongbuk has been directly affected by the changed route from GJ Bridge to BG Bridge. In order to compare the range of departure area for a one-day trip in Geoje tourist attractions before and after the new fixed link, duration variation of visitors is described as individual difference by normal distribution function. One-day tour trip model based on a circular trip is also suggested under comparatively simple supposition. Since average area after the opening is equal to maximum area before as minimum area after is equal to average area before, the effect of access improvement by the new bridge is revealed definitely. In addition, the effect of cities located in the middle and long distance is greater. Although cities proximity to Geoje are not influenced significantly, every citizen is capable of taking a one-day trip anywhere.

The Profitability Analysis of BESS Installation with PV Generation under RPS (RPS 제도 하에서의 태양광발전 연계형 배터리시스템 수익분석 방법에 관한 연구)

  • Kim, Chang-Soo;Yoo, Tae-Hyun;Rhee, Chang-Ho
    • Journal of Energy Engineering
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    • v.26 no.4
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    • pp.107-117
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    • 2017
  • Since South Korea started to apply Renewable Portfolio Standard (RPS) in 2012, there have been huge investment for deploying renewable technologies. Recently, the government determined to incentivize battery energy storage system(BESS) with renewable generations in order to induce the improvement of dispatching capability. In this paper, the annual pattern of PV generation based on actual generation data in South Korea is analyzed and the duration curve of capacity factor is proposed in order to provide the simplified analyzing methodology of present support policy for additional BESS installation for decision maker who is responsible for supply and demand planning. With suggested methodology, the range of appropriate BESS size with respect to the variation of system marginal price(SMP) and renewable energy certificate(REC) price can be derived briefly, and decision makers easily evaluate the effect of support scheme. Current policy for BESS installation support present additional BESS-related installation policy may give incentives to developers partially, however, the dependence between BESS size and benefit components (SMP and REC) can limit the deployment of the various portfolios of the BESS. Therefore, when improving the current policy in future, addressing the dependence between the technical aspects of battery size and the benefit components separately by the technical and economical parts is needed to set the suitable compensation rules for the renewable generation and BESS.

Growth Characteristics and Search for Eligible Cultivation Area of Rhodiola sachalinensis A. Boriss. (홍경천의 생육특성검정 및 재배지역 탐색)

  • Hong, Eui-Yeon;Kim, Ik-Hwan;Yoon, Jong-Sun;Yoon, Tae;Lee, Chul-Hee
    • Korean Journal of Plant Resources
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    • v.16 no.3
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    • pp.212-217
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    • 2003
  • This study was conducted to search for possible cultivation area of Rhodiola sachalinensis as well as to obtain the basic information of growth characteristics. One­year old nursery plants of Rhodiola sachalinensis were collected from Yonbyeon Hongkyungcheon development society in China This expriment was evaluted in three areas according to sea level such as plain region in Cheongwon(50m at sea level), mid­mountainous region in Jecheon(350m at sea level) mountainous region in Banyans(650m at sea level). The growth status Rhodiola sachalinensis showed wide range of variation in there areas. Plant height showed from 8.1cm to 15.8cm, number of branch showed from 3.1 eachs to 4.6 eachs and rate of withering showed from 76% to 94%, respectively. It was increased rapidly at the early August caused by summer depression. Flowering period of Rhodiola sachalinensis was shown at around middle and late June, total duration of flowering showed from 12 to 13 days and flower colors were various as brown, dark purple, yellow green and brown red color.