• Title/Summary/Keyword: Field Study

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A Practical Method to Quantify Very Low Fluxes of Nitrous Oxide from a Rice Paddy (벼논에서 미량 아산화질소 플럭스의 정량을 위한 실용적 방법)

  • Okjung, Ju;Namgoo, Kang;Hoseup, Soh;Jung-Soo, Park
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.24 no.4
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    • pp.285-294
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    • 2022
  • In order to accurately calculate greenhouse gas emissions in the agricultural field, Korea has been developing national-specific emission factors through direct measurement of gas fluxes using the closed-chamber method. In the rice paddy, only national-specific emission factors for methane (CH4) have been developed. It is thus necessary to develop those for nitrous oxide (N2O) affected by the application of nitrogen fertilizer. However, since the concentration of N2O emission from rice cultivation is very low, the QA/QC methods such as method detection and practical quantification limits are important. In this study, N2O emission from a rice paddy was evaluated affected by the amount of nitrogen fertilizer, by taking into account both method detection and practical quantification limits for N2O concentration. The N2O emission from a rice paddy soils affected by the nitrogen fertilizer application was estimated in the following order. The method detection limit (MDL) of N2O concentration was calculated at 95% confidence level based on the pooled standard deviation of concentration data sets using a standard gas with 98 nmol mol-1 N2O 10 times for 3 days. The practical quantification limit (PQL) of the N2O concentration is estimated by multiplying 10 to the pooled standard deviation. For the N2O flux data measured during the rice cultivation period in 2021, the MDL and PQL of N2O concentration were 18 nmol mol-1 and 87 nmol mol-1, respectively. The measured values above the PQL were merely about 12% of the total data. The cumulative N2O emission estimated based on the MDL and PQL was higher than the cumulative emission without nitrogen fertilizer application. This research would contribute to improving the reliability in quantification of the N2O flux data for accurate estimates of greenhouse gas emissions and uncertainties.

Effects for Growth and Chlorophyll in Old-barley and New-barley Seed exposed by X-ray (X-선이 묵은보리 씨앗과 햇보리 씨앗의 생장과 클로로필 농도에 미치는 영향)

  • Sang-Bok, Jeong;Sun-Cheol, Jeong;Mo-Kwon, Lee;Yun-Ho, Choi;Kang-Un, Byun;Su-Ah, Yu;Sang-Eun, Han;Jun-Beom, Heo;Wan-Sik, Shin;Won-Jeong, Lee
    • Journal of the Korean Society of Radiology
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    • v.17 no.1
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    • pp.149-156
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    • 2023
  • The purpose of this study is to compare of growth and chlorophyl between old-barley seed (OBS, 2019) and New-barley seed (NBS, 2020) exposed by X-ray. After germination the OBS and NBS, experimental group was exposed by 30 Gy X-ray using linear accelerator (Clinac IS, VERIAN, USA), by 6 MV X-ray, SSD 100 cm, 18 × 10 cm2, 600 MU/min. Length was measured every day until 9th day, and chlorophyl was analyzed using spectrophotometer(uv-1800, shimadzu, japan) after measuring weight in 9th day. Data analysis was performed the Independent T-test using SPSS ver 26.0(Chicago, IL, USA). NBS grow more faster than OBS in control group, but OBS grow more faster than NBS in experimental group. Length of control group was longer significantly every day than that of experimental group in OBS. NBS weighted more than OBS in control group, but OBS weighted more than NBS in experimental group. In comparing chlorophyl density, NBS high more than OBS in control group as well as experimental group. Growth and weight of OBS was effected more those than NBS by X-ray, but NBS in chlorophyl by X-ray. It is expected to be used as basic data for future X-ray research in barley seed.

Improvement in Calculating Engineer Standard Wage Rate and Its Appropriate Level Computation (엔지니어링 노임단가 산출기준 개선방안과 적정 노임단가 추정)

  • Lee, Jae Yul;Lee, Hae Kyung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.6
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    • pp.853-860
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    • 2022
  • The purpose of this study is to suggest an improvement plan for the calculation method of the engineer standard wage rate (ESWR) and to compute a reasonable ESWR. To this end, an adequacy review of theESWR calculation criteria was conducted along with an extensive engineering industry survey. The survey results were analyzed using an effective response sample of 748 companies out of 1,000 survey samples extracted by stratifying the 5,879 survey population. The main results were as follows. ①When calculating the engineering service fee, the prime contractor's engineer wage is suitable for the ESWR. The ESWR can be estimated by the formula 'average wage÷[1-proportion of subcontract orders×(1-subcontract rate)].' ② The field survey showed that the number of monthly working days was 20.35-20.54 days at 99 % confidence interval, which was significantly different from the current standard (22 days). In addition, as a result of a legal review of the ESWR criteria, it was found that the number of working days should be calculated in accordance with the Labor Standards Act after 2022. ③ Applying government guidelines, the time difference between the wage survey and the ESWR application can be corrected by the past ESWR increase rate for a specific period. ④ Using modeling based on the analysis above, the current ESWR was 13.5-14.5 % lower than the appropriate level. A lower ESWR was driven by the non-reflection of subcontract structure (4.1 %), overestimation of monthly work days (6.8-7.8 %), and application of past wage (2.6 %). The proposed model is expected to be widely used in policy making, as it can provide a useful framework for calculating the standard wage rate in similar industries as well as calculating appropriate engineering fees.

Floristic Characteristics of Vascular Plants in the Goyangsan Mtn.(Jeongseon-gun) and Munraesan Mtn.(Jeongseon-gun) Area (고양산(1,152.3m, 정선군)과 문래산(1,082.5m, 정선군) 일원의 관속식물)

  • Kim, Young-Chul;Chae, Hyun-Hee;Park, You-Cheol;Lee, Seon-Mi
    • Korean Journal of Environment and Ecology
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    • v.36 no.3
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    • pp.220-256
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    • 2022
  • The most important thing for conserving plant diversity in an area is to make an overall inventory of the plant species inhabiting the area. In particular, limestone areas are known for their high plant diversity and distribution of specific plants. Despite that, only a few have been designated as protected areas. This study investigated the vascular plants distributed in Goyangsan Mtn. and Munraesan Mtn., located in limestone areas of the central part of the Korean Peninsula. A field survey was conducted eight times from April to October 2021. As a result, we identified a total of 654 taxa comprising 113 families, 357 genera, 592 species, 15 subspecies, 44 varieties, and 3 formulas. They included four endangered wild plant species: Astilboides tabularis, Eleutherococcus senticosus, Cypripedium macranthos, and Epilobium hirsutum. Endemic plants in Korea were identified as 32 taxa. Floristic target plants were identified as 168 taxa, specifically 5 taxa of grade V, 41 taxa of grade IV, and 36 taxa of grade III. The red data plants included 2 taxa as "Endangered (EN)", 7 taxa as "Vulnerable (VU)", and 7 taxa as "Near threatened (NT)". A total of 41 taxa of naturalized plants were identified, and 4 of them were invasive alien plants. The surveyed vicinity of Goyangsan Mtn. and Munraesan Mtn. showed high plant diversity and contained core habitats for distribution of an endangered wild plant, Astilboides tabularis,in the limestone area. Moreover, both mountains contained a small population of Cotoneaster integerrimus. These findings confirm that the area has conservation values. Therefore, we propose to identify areas with high plant diversity and designate them as special protected areas.

A Plan for Activating Elderly Sports to Promote Health in the COVID-19 Era (코로나19 시대 건강증진을 위한 노인체육 활성화 방안)

  • Cho, Kyoung-Hwan
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.7
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    • pp.141-160
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    • 2020
  • The purpose of this study was to devise a specific plan for activating sports to promote health in old age against the prolonged COVID-19 pandemic. Through literature review, it also analyzed the association between health status and COVID-19 in old age, suggested health promotion policies and projects for elderly people, and presented a plan for activating sport to promote health in old age against COVID-19 era. First, it is necessary to revise the relevant laws, including the Sport Promotion Act and the Elderly Welfare Act, partially or entirely, make developmental and convergent legislations for elderly health and sports, and establish an institutional device as needed. Second, it is necessary to build an integrated digital platform for the elderly and make a supporting system that links facilities, programs, information, and job creation as part of a New Deal program in the field of sports on the basis of the Korean New Deal. Third, it is necessary to train elderly welfare professionals. Efforts should be made to establish more departments related to elderly sports in universities and make it compulsory to place elderly sports instructors at elderly leisure and welfare facilities. Fourth, it is necessary to develop contents related to health in old age. This means performing diverse movements by manipulating them through a virtual reality (VR) simulation. Fifth, it is necessary to make a greater investment in research and development related to elderly sports and relevant fields. This means the need to conduct constant research on healthy and active aging in a systematic and practical way through multidisciplinary cooperation. Sixth, it is necessary to establish and operate an elderly management agency (elderly health agency) under the influence of the Office of the Prime Minister. This means the need to secure independence in implementing the functions related to health promotion in old age and make comprehensive operation, which involves all the issues of health promotion in old age, daily function maintenance and rehabilitation, social adjustment, and long-term care, by establishing an elderly management agency in an effort to give lifelong health management to the elderly and cope with the untact, New Normal age.

The Direction of Physical Training for Actor in Post-Drama Era, "Empty" (포스트드라마 시대에 따른 배우의 몸 훈련의 방향성,'비우기(empty)')

  • Ra, Kyung-Min
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.8
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    • pp.77-90
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    • 2020
  • Today, the transition to the era of "post-drama" brought a change in the position of text, which was considered the center of the play, and the expansion of the role of actors. After entering the post-drama era, the actor no longer transforms himself into "delivering" the fixed meaning of text, but "producing" the valid meaning of "now, here" meeting the audience. In other words, actors in the post-drama era have expanded their roles as "performers" who can become the subject of narratives themselves and create various theatrical languages. Despite the expansion of the actor's role, verbal-centered actor training through text, which still forms the basis of acting education, does not satisfy the newly changing contemporary theatricality and creates a gap between education and the field. Therefore, the researcher argued that non-verbal-centered acting education needs to be discussed, and highlighted the actors' physical training on the "empty" side. The researchers first compare and analyze the characteristics of modern theater people's training methods from an "empty" perspective. Based on this, researchers about the meaning and direction of the training "empty". Furthermore, the study concludes with an emphasis on the direction of acting education in the post-drama era, which is free from language that can respond to stimuli and interact freely.

Learning Curve of the Direct Anterior Approach for Hip Arthroplasty (직접전방 접근법을 통한 인공 고관절 치환술의 학습곡선)

  • Ham, Dong Hun;Chung, Woo Chull;Choi, Byeong Yeol;Choi, Jong Eun
    • Journal of the Korean Orthopaedic Association
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    • v.55 no.2
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    • pp.143-153
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    • 2020
  • Purpose: To evaluate the timing of the improvement in surgical skills of the direct anterior approach for hip arthroplasty through an analysis of the clinical features and learning curve in 58 cases. Materials and Methods: From November 2016 to November 2018, 58 patients, who were divided into an early half and late half, and underwent hip arthroplasty by the direct anterior approach, were enrolled in this retrospective study. The operation time and complications (fracture, lateral femoral cutaneous nerve injury, heterotopic ossification, infection, and dislocation) were assessed using a chi-square test, paired t-test, and cumulative sum (CUSUM) test. Results: The mean operation times in total hip arthroplasty (26 cases) and bipolar hemi-arthroplasty were 132.1 minutes and 79.7 minutes, respectively, demonstrating a significant difference between the two groups. CUSUM analysis based on the results revealed breakthrough points of the operation time, decreasing to less than the mean operation time because of the 16th case in total hip arthroplasty and 14th case in bipolar hemiarthroplasty. Complications were encountered in the early phase and late phase: five cases of fractures in the early phase, no case in the late phase; eight and two cases of lateral femoral cutaneous nerve injury, respectively; three and two cases of heterotopic ossification, respectively; and one case of dislocation, one case of infection and three cases of others in the early phase. The CUSUM chart for the fracture rate during operation in the early phase revealed the following: five cases fracture (17.2%) in the early phase and no case in the late phase (0%). This highlights the learning curve and the need for monitoring the inadequacy of operation based on the complications. Conclusion: Hip arthroplasty performed by the direct anterior approach based on an anatomical understanding makes it difficult to observe the surgical field and requires a learning curve of at least 30 cases.

Germination Responses to Mixtures Seeding Rate and Sowing Method of Kentucky Bluegrass and White Clover (캔터키블루그래스와 토끼풀의 파종방법 및 혼파비율에 따른 종자발아 반응)

  • Park, Sun-Yeong;Lee, Sun-Yeong;Yoon, Yong-Han;Ju, Jin-Hee
    • Korean Journal of Organic Agriculture
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    • v.29 no.4
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    • pp.601-612
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    • 2021
  • This study was conducted to evaluate the appropriate sowing method and mixture seeding rate on germination of Kentucky bluegrass (Poa pratensis L.) and white clover (Trifolium repens L.). The experimental design includes two sowing methods and six mixed seeding per each method: BT1:BP0 (broadcast seeding; B, Trifolium repens; T, Poa pratensis; P), BT1:BP2, BT1:BP3, BT3:BT1, BT2:BP1, BT0:BP1 and ST1:SP0 (spot seeding; S), ST1:SP2, ST1:SP3, ST3:ST1, ST2:SP1, ST0:SP1. The germination was the highest for both species when the seeding rate was higher than other species. In overall, the germination of white clover was higher and faster than Kentucky bluegrass. Two plots, BT2:BP1, ST1:ST2, were retained the balanced proportion of the germination rate. Therefore, It was suggested, for maintaining the balanced field, it is better to seed white clover twice Kentucky bluegrass on broadcast seeding and Kentucky bluegrass twice white clover on spot seeding. In regard of sowing method, broadcast seeding is better than spot seeding in terms of increasing the germination. It is necessary to supplement the result for real application by long-term monitoring.

Analysis of Thermal Environment Improving Effects of Green Curtain in Summer (Green Curtain 형식의 벽면녹화시스템을 통한 여름철 건물 실내 열환경 비교 분석)

  • Lee, Sunyoung;Jo, Sangman;Park, Sookuk
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.5
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    • pp.80-89
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    • 2022
  • In order to solve the limitations of horizontal thermal environment improvement, this study compared the thermal environment of the indoor and outdoor of a building in summer according to the presence or absence of a green curtain, a vertical greening method. In the summer of 2021, the air temperature, relative humidity, wind speed, and shortwave and longwave radiation were measured at a central point inside a building and the grass field outside of the building to determine the human thermal sensation index, PET and UTCI. As a result, the green curtain showed an average 1.6℃ cooler air temperature during the daytime, but it did not have an effect at night. For relative humidity, it showed higher humidity indoors by an average of 5.6% and 1.0% during the daytime and at night, respectively. Wind speed was 1.4-1.8 ms-1 and 1.4-1.5 ms-1 higher outdoors on average during the daytime and at night, respectively, showing a high value outdoors regardless of whether a green curtain was installed. The green curtain showed an average indoor mean radiant temperature reduction effect of 4.7℃ during the daytime, but it did not have an effect at night. In PET and UTCI, the green curtain reduced the indoor PET by about a 1/3 level, an average of 2.1℃, and the indoor UTCI by about a 1/6 level, an average of 1.1℃, during the daytime. However, no effects appeared in PET and UTCI at night. For landscape planning, a green curtain can effectively modify the thermal environment during the daytime in summer.

Efficacy of Three Antiviral Agents and Resistant Cultivars on Tomato Yellow Leaf Curl Virus in Tomato (토마토황화잎말림바이러스병에 대한 저항성 품종과 항바이러스 활성 물질 3종의 효과 검증)

  • Kwon, Yongnam;Cha, Byeongjin;Kim, Mikyeong
    • Research in Plant Disease
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    • v.28 no.2
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    • pp.82-91
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    • 2022
  • Recently, several in vitro studies have reported antiviral activity of agents of systemic acquired resistance against plant virus infection, but the approach has not been applied in a wide range of agricultural fields. The objective of this study was to evaluate the inhibitory effect of the exogenous application of salicylic acid (SA), chitosan (CH), or eugenol (EG) in tomato yellow leaf curl virus (TYLCV) infection of greenhouse-grown tomato plants. In vitro, the initial time of symptom was observed in TYLCV-infected plants (VP) of the resistant cultivar 'Superdotaerang' at 12 days post inoculation (dpi) after application of antiviral agents. At 32 dpi, the disease rate of TYLCV in the CHT+VP (0.1% chitosan and virus infected control) treated plants was 87.5%, lower than that of the other treatment. However, the virus content in the CHT+VP treated plants was higher than those of the other treatments, and SA, EG, and CH did not show significant effect on plant height or shoot and root fresh weight. Our results from summer-cultivated greenhouse-grown tomatoes show that none of the tested agents had an inhibitory activity on viral infection or yield of tomato 'Dotaerangsola'cultivar. In contrast, all treated 'TY Giants' cultivars that possessed TYLCV resistance genes Ty-1 and Ty-3a did not show typical symptoms and the virus content was remarkably lower than those in the TYLCV treated plants in 'Superdotaerang'. The results of this research indicated that the planting of resistant tomato cultivars was effective method instead of using SA, EG, and CH (known as resistance-inducing factors for control) of TYLCV in the field.