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Development of heat exchanger for underground water heat. II - Design and manufacture for heat exchanger of underground water - (지하수 이용을 위한 열교환기 개발. II - 지하수이용 냉·난방기 설계제작 -)

  • Lee, W.Y.;Ahn, D.H.;Kim, S.C.;Park, W.P.;Kang, Y.G.;Kim, S.B.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.4 no.1
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    • pp.128-137
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    • 2002
  • This study was conducted to develop the heat exchanger by utilizing the heat energy of underground water(15℃), which might be used for cooling and heating system of the agricultural facilities. We developed the heat exchanger by using the parallel type plat fin tube made of Aluminum(Al 6063), which was named Aloo-Heat(No. 0247164, offered by Korean Intellectual property Office). The trial manufactures were made from Aloo-heat which was 600mm, 700mm length respectively, and It were welded to the end "U" type in order to direct flow of the underground water. The performance test was carried out under the condition of open space and room temperature with the change of flow rate of the underground water and air. The results are as follows. 1. The trial manufactures had convection heat value from 33 to 156 W/m2℃, and It was coincided with design assumption. 2. The amount of energy transfer was increased with the increment of the area of heat transfer, the air flow, the gap of temperature inlet & outlet the underground water and the air. 3. The heat value was 6,825W when the air flow was 6,000m3/h and the gap of temperature between inlet and outlet of the underground water was 6℃, and It dropped from 25.8℃ to 23.2℃(-2.6℃ difference). The convection heat value was 88.5W/m2℃. 4. The heat value was 2.625W when the air flow was 4,000m3/h and the gap of temperature between inlet and outlet the underground water was 2℃, and It dropped from 27℃ to 22.5℃(-4.5℃ difference). The convection heat value was 33.6W/m2℃. 5. Correlation values(R2) of the testing heat values of the trial manufacture type I, II, and III were 0.9141, 0.8935, and 0.9323 respectively, and correlation values(R2) of the amount of the air flow 6,000m3/h, 5,000m3/h, 4,000m3/h were 0.9513, 0.9414, and 0.9003 respectively.

Korean Buddhist Pictures and Performances-Focused on Ttangseolbeop performed at Samcheok Anjeongsa Temple (한국의 불교그림과 공연 - 삼척 안정사에서 연행되는 땅설법을 중심으로 -)

  • Kim, Hyung-Kun
    • (The) Research of the performance art and culture
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    • no.41
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    • pp.219-255
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    • 2020
  • This article was triggered by Victor H. Mair's book 'Painting and performance'. The book explained that Buddhist paintings are common in the area where Buddhism was spread, and there are also performances using them. And although it has nothing to do with Buddhism, it has been shown that this form of performance can be global. However, the problem was not 'Korea'. It was because there was no record or transmission of the corresponding performance soon. In this situation, the landing method of Samcheok stable temple was announced in 2018. On the one hand, the academic community is very pleased, but on the other hand, it is troubled. The worries are summed up as 'synchronic and diachronic universality'. Is the landing method inherited from the Samcheok stable temple a unique type of temple? Otherwise, it is a question of whether it has been passed down or is it universal at the national level. However, prior to this essential question, we do not yet know the full picture of the stable landing method. So this article was prepared to show the overall outline of the stable landing method. There is a 'picture' in common throughout the landing method, and understanding how to operate it in various ways is the first step in understanding the landing method. There are five repertoires (which are called main halls) that are considered important, and more than that. What these repertoires have in common is the narrative structure of a Buddhist character. In this narrative, the most important thing is the revised figure, and it was the earthly method to inform the contents of the revised figure in various ways. In the case of Byeonsangdo, which serves as a clue to the narrative, there was a problem that could not be seen in the evening without light, which required special design. It is the way of shadow play and Yeongdeung. In other words, there are three types of performances in the landing method. The first is the method of using reparation, and the second is the method of using shadow. The third is the way of eternity. This method is not a selection based on the contents of the repertoire, but a selection based on the performance environment. If there is light and you can see the picture, use reparation. However, in the evening, it was impossible to see it dark (when there was no electricity in the past). The use of the visual method as a tool in this method is to confirm the transition to a visual culture that is a step further from the level of culture. Moreover, unlike the epic narrative, the power of the implied image provided an opportunity for viewers to experience the mystery of Buddhism through emotional stimulation.

Correlation and Combining Ability related to the Growth Characteristics in F1 Hybrids by Diallel Cross of Viola tricolor (팬지의 일대 잡종에서 생육관련 형질의 상관관계 및 조합능력)

  • Song, C.Y.;Hong, K.H.;Kang, Y.K.;Lee, K.H.;Kim, J.C.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.4 no.1
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    • pp.70-79
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    • 2002
  • This study was conducted to determine correlations and combining abilities of leaf lengths, leaf widths, petiole lengths, number of branches, number of leaves, leaf areas, fresh weights, dry weights and number of flowers in F1 crosses made with the partial seven-parent diallel cross in Viola tricolor. Leaf lengths and leaf widths showed highly positive correlation with petiole length and negative correlation with number of branches, number of leaves and number of flowers. There was positive correlation between the number of leaves and flowers as well as between leaf area and fresh weight. Mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for all the parameters. Variance component values of SCA were greater than those of GCA for all the parameters except leaf length, implying preponderance of non-additive gene actions for these characters. The lines C and G for leaf lengths and widths, the lines A and F for number of leaves, the lines A, B and G for leaf areas, and the lines B and F for number of flowers showed relatively high GCA effects. The crosses of A×B and B×D exhibited high SCA effects on increasing leaf lengths, leaf widths, number of leaves, fresh weights and number of flowers. And also the crosses of B×E and D×G exhibited high SCA effects on decreasing leaf lengths, leaf areas and fresh weights as well as increasing number of flowers. The broad sense heritabilities of most characters were high compared with the narrow sense one. Those of leaf length, leaf width, petiole length and number of leaves were high in both the broad and narrow sense heritabilities.

The Transmission Activities and characteristic of the Naeseo Traditional Folk art Conservation Association in Masan (마산 내서전통민속문화예술보존회의 전승 활동과 특징)

  • Choi, Ja-Un
    • (The) Research of the performance art and culture
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    • no.43
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    • pp.121-143
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    • 2021
  • The Aim of the this paper is to figure out impetus of the Naeseo Traditional Folk art Conservation Association. This Preservation Society derived from Hogaeri farmers' band. Through aging and hollowing out Hogaeri farmers' band got into a period of stagnation. In order to overcome slump villager and people of a township organized a conservation society in 1994. Members restored and directed folk song which from age to age for performance. are designated as cultural asset in 2017. Sutguldeong song is only song in inland area. This song are worthy of notice in . which is consist of various agricultural work songs experienced two changes. Rice-planting songs are characteristic. Especially, Executive playing a central role harden foundation of the Preservation Society. The mainspring of activity is the sense of responsibility. Preservation Society laying emphasis on recruiting new members. Preservation Society is planning to develop curriculum for Jurisdiction elementary and middle school students. This Preservation Society is made up of First generation members and Second generation members. First generation members who are born and bred in Hogaeri have been good friends both in joy and in sorrow Early days of Preservation Society. So, They has a strong family bond. In order to induce membership Members are practicing Nongak, popular folk songs, dancing program. Second generation members are not conversant with a folk song. Nonetheless They have a strong mind on a member line.

Performance Activities and Social Role of the Theater in Ulsan during the Japanese Colonial Period (일제강점기 울산지역 극장의 공연활동과 사회적 역할)

  • Kim, Joung-Ho
    • (The) Research of the performance art and culture
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    • no.42
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    • pp.107-146
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    • 2021
  • This article examined the current status of performance activities in the theaters in Ulsan during the Japanese colonial period, and examined the characteristics and social roles of performance culture at that time.,The cultural space during the Japanese colonial period can be divided into theater space and semi-theater space.,The theater spaces in Ulsan include Daejeonggwan, Sangbanggwan, and Ulsan Theater. The semi-theater spaces include Ulsan Youth Center, Ulsan Youth Alliance Hall, Barrack Youth Hall, Eonyang Youth Alliance Hall, Eonyang Christian Hall, Eonyang Christian Hall, Eonyang Inn, Eonyang Public Inn, Eonyang Public Normal School, Seosaeng School, Ulsan Public Aid Auditorium, Night school.,These spaces not only held events or performances for a specific purpose, but also played a role as public spaces producing local discourse. The theater was a complex cultural space where performances are performed along with movie performances, and artists and audiences meet.,Furthermore, the theater provided a special experience of producing and consuming various issues such as colonial modernization, modern city formation, and the emergence of new popular culture beyond the meaning of stage space.,The theaters in Ulsan also functioned as a space to represent the foreign culture acceptance, leisure activities, the performance and viewing of cultural contents, and the artistic skills of local artists in accordance with the purpose of establishing local theaters.,It was a base space for local discourse production and enjoyment activities by holding political rallies, meetings, lecture activities, and various conferences.,Political rallies were also concerts, enlightenment activities were also accompanied by film screenings, and music performances were associated with dance performances and charity gatherings.,In particular, Ulsan Theater, which is the first theater in Ulsan, and the role of the public hall, held a lecture, debate, and oratory for public enlightenment along with performances such as musical drama, children's song contest, fairy tale contest, small-sized play performance,, It was widely used as a large-scale rallying place, and served as a public hall, such as a place to visit outside theaters. Thus, the theater and semi-theater space in Ulsan during the Japanese colonial period improved the cultural level of the region, fulfilling the aesthetic needs of the local people and faithfully fulfilling the social role as a public sphere leading the public opinion and agenda.,And it was also positioned as an alternative public area of ​​modern society and also played a role as a public institution.

Scenario-Based Analysis on the Effects of Green Areas on the Improvement of Urban Thermal Environment (녹지 조성 시나리오에 따른 도시 열환경 개선 효과 분석)

  • Min, Jin-Kyu;Eum, Jeong-Hee;Sung, Uk-Je;Son, Jeong-Min;Kim, Ju-Eun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.6
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    • pp.1-14
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    • 2022
  • To alleviate the urban heat island phenomenon, this study aims to quantitatively analyze the effects of neighborhood green spaces on the improvement of the thermal environment based on detailed scenarios of five types of green spaces, including parks, pocket parks, parking lot greening, roadside planting, and rooftop-wall greening. The ENVI-met 4.4.6v model, a microclimate simulation program, was used to analyze the effects of green spaces. As a result, it was found that the air temperature decreased as the planting density of the park increased, but the thermal comfort index PET, which is the degree of heat sensation felt by humans, was not directly proportional to temperature. The establishment of a pocket park reduced air temperature up to a radius of 56m, while the range of temperature reduction increased by about 12.5% when three additional pocket parks were established at 250m intervals. Unlike the air temperature, PET was only affected in the vicinity of the planted area, so there was no significant difference in the thermal comfort of the surrounding environment due to the construction of pocket parks. Changing the surface pavement from asphalt to lawn blocks and implementing rooftop or wall greening did not directly act as solar shading but positively affected air temperature reduction; PET showed no significant difference. Roadside planting showed a higher air temperature reduction effect as the planting interval was narrower, but PET was not directly proportional to tree density. In the case of shrub planting under trees, it did not significantly affect the air temperature reduction but positively affected the improvement of thermal comfort. This study can outline strategies for constructing neighborhood green spaces to solve the urban heat island phenomena and establish detailed strategies for efficient thermal environment improvements.

Analysis of Changes in Tree Height-Diameter Allometry for Major Tree Species in South Korea (우리나라 주요 수종의 수고-직경 상대생장 변화 분석)

  • Moonil Kim;Taejin Park;Youngjin Ko;Go-Mi Choi;Soonchul Son;Yejun Kang;Jaehee Yoo;Minkyeong Kim;Hyeonji Park;Woo-Kyun Lee
    • Journal of Korean Society of Forest Science
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    • v.112 no.1
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    • pp.71-82
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    • 2023
  • Forest biomass is used as a representative indicator of forest size, maturity, and productivity. Therefore, quantitative evaluation is important for management and harvest as well as the evaluation of ecosystem functions and services including CO2 absorption. The allometric equation is a widely used method for estimating the value of each component through the relative growth rate of plants. Recently, studies indicated that the relative growth of trees is changing because of the increased CO2 concentration in the atmosphere and the resulting climate change, raising the need to review the previously developed relative growth models and coefficients. In this study, the height-diameter at breast height (DBH) relationships of four major tree species in Korea [(Pinus densiflora (PD), Larix kaempferi (LK), Quercus variabilis (QV), and Quercus mongolica (QM)] were analyzed using the 5th-7th National Forest Inventory (NFI) data. Furthermore, these results were compared with the present yield table from the National Institute for Forest Science. This analysis revealed that the expected height for the same DBH increased as the NFI progressed. For example, in model analysis, the expected heights for PD, LK, QV, and QM for DBH of 25 cm were 12.48, 19.17, 14.47, and 13.19 m, respectively, in the 5th NFI data. In the 7th NFI data, these values were estimated as 13.61 (+9.1%), 21.58 (+12.7%), 15.76 (+8.9%), and 13.93 m (+5.6%), respectively. These results indicate that the major tree species in South Korean forests currently are more vigorous in height growth than in diameter growth when compared to the height-DBH development trends by tree species identified through past survey data.

Feasibility of Environmental DNA Metabarcoding for Invasive Species Detection According to Taxa (분류군별 외래생물 탐지를 위한 환경 DNA 메타바코딩 활용 가능성)

  • Yujin Kang;Jeongeun Jeon;Seungwoo Han;Suyeon Won;Youngkeun Song
    • Journal of Environmental Impact Assessment
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    • v.32 no.2
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    • pp.94-111
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    • 2023
  • In order to establish an effective management strategy for invasive species early detection and regular monitoring are required to assess their introduction or dispersal. Environmental DNA (eDNA) is actively applied to evaluate the fauna including the presence of invasive species as it has high detection sensitivity and can detect multiple species simultaneously. In Korea, the applicability evaluation of metabarcoding is being conducted mainly on fish, and research on other taxa is insufficient. Therefore, this study identified the feasibility of detecting invasive species in Korea using eDNA metabarcoding. In addition, to confirm the possibility of detection by taxa, the detection of target species was evaluated using four universal primers (MiFish, MiMammal, Mibird, Amp16S) designed for fish, mammals, birds, and amphibians. As a result, target species (Trachemys scripta, 3 sites; Cervus nippon, 3 sites; Micropterus salmoides, 7 sites; Rana catesbeiana, 4 sites) were detected in 17 of the total 55 sites. Even in the selection of dense sampling sites within the study area, there was a difference in the detection result by reflecting the ecological characteristics of the target species. A comparison of community structures (species richness, abundance and diversity) based on the presence of invasive species focused on M.salmoides and T.scripta, showed higher diversity at the point where invasive species were detected. Also, 1 to 4 more species were detected and abundance was also up to 1.7 times higher. The results of invasive species detection through metabarcoding and the comparison of community structures indicate that the accumulation of large amounts of monitoring data through eDNA can be efficiently utilized for multidimensional ecosystem evaluation. In addition, it suggested that eDNA can be used as major data for evaluation and prediction, such as tracking biological changes caused by artificial and natural factors and environmental impact assessment.

Evaluation of estuary reservoir management based on robust decision making considering water use-flood control-water quality under Climate Change (이수-치수-수질을 고려한 기후변화 대응 로버스트 기반 담수호 관리 평가)

  • Kim, Seokhyeon;Hwang, Soonho;Kim, Sinae;Lee, Hyunji;Kwak, Jihye;Kim, Jihye;Kang, Moonseong
    • Journal of Korea Water Resources Association
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    • v.56 no.6
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    • pp.419-429
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    • 2023
  • The objective of this study was to determine the management water level of an estuary reservoir considering three aspects: the water use, flood control and water quality, and to use a robust decision-making to consider uncertainty due to climate change. The watershed-reservoir linkage model was used to simulate changes in inflow due to climate change, and changes in reservoir water level and water quality. Five management level alternatives ranging from -1.7 El.m to 0.2 El.m were evaluated under the SSP1, 2, 3, and 5 scenariosof the ACCESS-CM2 Global Climate Model. Performance indicators based on period-reliability were calculated for robust decision-making considering the three aspects, and regret was used as a decision indicator to identify the alternatives with the minimum maximum regret. Flood control failure increased as the management level increased, while the probability of water use failure increased as the management level decreased. The highest number of failures occurred under the SSP5 scenario. In the water quality sector, the change in water quality was relatively small with an increase in the management level due to the increase in reservoir volume. Conversely, a decrease in the management level resulted in a more significant change in water quality. In the study area, the estuary reservoir was found to be problematic when the change in water quality was small, resulting in more failures.

Behaviors of Soft Bangkok Clay behind Diaphragm Wall Under Unloading Compression Triaxial Test (삼축압축 하에서 지중연속벽 주변 방콕 연약 점토의 거동)

  • Le, Nghia Trong;Teparaksa, Wanchai;Mitachi, Toshiyuki;Kawaguchi, Takayuki
    • Journal of the Korean Geotechnical Society
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    • v.23 no.9
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    • pp.5-16
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    • 2007
  • The simple linear elastic-perfectly plastic model with soil parameters $s_u,\;E_u$ and n of undrained condition is usually applied to predict the displacement of a constructed diaphragm wall(DW) on soft soils during excavation. However, the application of this soil model for finite element analysis could not interpret the continued increment of the lateral displacement of the DW for the large and deep excavation area both during the elapsed time without activity of excavation and after finishing excavation. To study the characteristic behaviors of soil behind the DW during the periods without excavation, a series of tests on soft Bangkok clay samples are simulated in the same manner as stress condition of soil elements happening behind diaphragm wall by triaxial tests. Three kinds of triaxial tests are carried out in this research: $K_0$ consolidated undrained compression($CK_0U_C$) and $K_0$ consolidated drained/undrained unloading compression with periodic decrement of horizontal pressure($CK_0DUC$ and $CK_0UUC$). The study shows that the shear strength of series $CK_0DUC$ tests is equal to the residual strength of $CK_0UC$ tests. The Young's modulus determined at each decrement step of the horizontal pressure of soil specimen on $CK_0DUC$ tests decreases with increase in the deviator stress. In addition, the slope of Critical State Line of both $CK_0UC$ and $CK_0DUC$ tests is equal. Moreover, the axial and radial strain rates of each decrement of horizontal pressure step of $CK_0DUC$ tests are established with the function of time, a slope of critical state line and a ratio of deviator and mean effective stress. This study shows that the results of the unloading compression triaxial tests can be used to predict the diaphragm wall deflection during excavation.