• Title/Summary/Keyword: Depth of Field

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Development of Correction Formulas for KMA AAOS Soil Moisture Observation Data (기상청 농업기상관측망 토양수분 관측자료 보정식 개발)

  • Choi, Sung-Won;Park, Juhan;Kang, Minseok;Kim, Jongho;Sohn, Seungwon;Cho, Sungsik;Chun, Hyenchung;Jung, Ki-Yuol
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.24 no.1
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    • pp.13-34
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    • 2022
  • Soil moisture data have been collected at 11 agrometeorological stations operated by The Korea Meteorological Administration (KMA). This study aimed to verify the accuracy of soil moisture data of KMA and develop a correction formula to be applied to improve their quality. The soil of the observation field was sampled to analyze its physical properties that affect soil water content. Soil texture was classified to be sandy loam and loamy sand at most sites. The bulk density of the soil samples was about 1.5 g/cm3 on average. The content of silt and clay was also closely related to bulk density and water holding capacity. The EnviroSCAN model, which was used as a reference sensor, was calibrated using the self-manufactured "reference soil moisture observation system". Comparison between the calibrated reference sensor and the field sensor of KMA was conducted at least three times at each of the 11 sites. Overall, the trend of fluctuations over time in the measured values of the two sensors appeared similar. Still, there were sites where the latter had relatively lower soil moisture values than the former. A linear correction formula was derived for each site and depth using the range and average of the observed data for the given period. This correction formula resulted in an improvement in agreement between sensor values at the Suwon site. In addition, the detailed approach was developed to estimate the correction value for the period in which a correction formula was not calculated. In summary, the correction of soil moisture data at a regular time interval, e.g., twice a year, would be recommended for all observation sites to improve the quality of soil moisture observation data.

Study on the Interpretation of the Features Affacting to the N-supplying Capability of Field Soils to Corn in Pennsylvania (Pennsylvania주 옥수수재배지(栽培地) 토양(土壤)의 질소공급능력(窒素供給能力)에 영향(影響)을 미치는 요인분석(要因分析))

  • Hong, Soon-Dal
    • Korean Journal of Soil Science and Fertilizer
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    • v.25 no.1
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    • pp.26-37
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    • 1992
  • Fifty-five field experiments were conducted in order to find out some useful indices for the prediction of N-supplying capability(NSC) of soils under cultivation of corn in Pennsylvania over 3 years from 1986. Contents of $NO_3-N$, absorbance at 200 nm of the extract from soil with 0.01M $NaHCO_3$ were identified to be used as indices before planting. Methods for the estimation of organic nitrogen available later in the growing season(KCLA-N, PBBA-N, UV260 nm absorbance of $NaHCO_3$ extract) were not to be used as good indices individually, but when those are combined together with inorganic $NO_3-N$ showed a highly significant correlationship with the NSC. The year of an even distribution of rainfall, 1987, gave the highest significant correlationship between NSC and the indices. For soils of the same texture with slightly different physical properties, combined indices obtained from physico-chemical factors improved the degree of predictability when the grades of soil slope, depth of Ap were considered at the same time. More futher researches such as this need to be done before any conclusive result can be drawn.

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Nutrient Solute Transport during the Course of Freezing and Thawing of Soils in Korea (동결(凍結)과 해빙(解氷) 기간(期間)중 토양내(土壤內) 양분(養分) 용질(溶質)의 이동(移動))

  • Ha, Sng-Keun;Jung, Yeong-Sang;Lim, Hyung-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.28 no.2
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    • pp.135-144
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    • 1995
  • Understanding on nutrient solute movement during the course of freezing and thawing was attempted through laboratory and field obsevations. Small sectioned tubes with 5cm inner diameter, 0.2cm thick and 1cm long were connected to 30cm long soil columns for laboratory study. The columns were filled with soil, and treated with 20mmol/kg $KNO_3$ for upper 5cm. The upper end was set in the freezing section, and the lower end was set in the refrigerating section of a refrigerator. Temperature was controlled at $-7({\pm}1)^{\circ}C$ and $1.5({\pm}1)^{\circ}C$, respectively. After top 5cm soil was frozen, the columns were sectioned, and analyzed for $NO_3^-$, $NH_4^+$ and $K^+$. For field study, the 20cm inner diameter and lm long soil columns were installed in Chuncheon and Daegwanryung, where the altitude was 74m and 840m, respectively. The soils used were silt loam and clay loam. The top 20cm soils were treated with 50mmol/kg as $KNO_3$. The soil columns were taken during winter freezing and after thawing. By laboratiry study, upward movement of $NO_3^-$ and $K^+$ during the course of freezing was confirmed. The upward movement of $K^+$ was, however, one fifth to one tenth of $NO_3^-$. The upward movement of inorganic nitrogen as well as laboratory during the course of freezing, but large amount of nitrogen was lost from the profile after thawing in early spring. Leached nitrogen from the upper 20cm to lower part was 17 to 24 percents. The maximum depth of leaching during the experiment was 50cm for all soils. The net loss of inorganic nitrogen from the whole profile ranged 8.7 to 39.5 percents. The net loss was greater in Daegwanryung where temperature was lower and snowfall was larger than Chuncheon, and the loss was greater from the silt loam soil than clay loam soil of which percolation rate was small. The results implied that reasons for nitrogen loss during the winter might include surface washing by snow melt as well as leaching and denitrification.

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A Study on the Effects of ESG Entrepreneurship Education and Participatory Learning Method on Creative Problem-Solving and Social Value Recognition (ESG기업가정신교육과 참여적 학습 방식이 '창의적 문제해결' 및 '사회적 가치 인식'에 미치는 영향에 관한 연구)

  • Lee Sunyoung;Kim Seungchul
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.2
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    • pp.201-219
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    • 2023
  • ESG (Environment, Social, Governance) is becoming the core of the interest of today's entrepreneurs concerning about the earth crisis. Numerous studies are going on these days about the importance of ESG, but most of them seem confined to the introductory level. This study concentrates on "ESG education" that will teach the learners how to put various ESG ideas into practice, knowing that the earth crisis would not be overcome without actual practice of those ideas. First, elementary and junior·senior high school, professors in university and educational consultants in the field designed educational programs and related content materials under "ESG entrepreneurship education" integrated with ESG and Entrepreneurship education, which have been implemented previously. Participatory learning methods are converged with the program. The researcher analyzed the learning effects in depth after implementing the programs in the education field. Thus, this study first examined the effects of key variables of ESG educational program i.e., ESG entrepreneurship education, student participatory learning, and team-based learning on creative problem-solving and social value recognition with an essential variant of ESG educational programs and identified the relations to creative problem-solving and social value recognition. Besides, this study investigated the moderating effects of school atmosphere, and teachers' enthusiasm, regarding traits of educational programs and social value recognition. Findings indicate that sub variants of the traits of educational programs i.e., ESG entrepreneurship education, student participatory learning, and team-based learning significantly affect creative problem-solving skills and social value recognition and that creative problem-solving impacts social value recognition. In addition, teachers' enthusiasm has moderating effects between traits of educational programs and social value recognition. This study provides content-program learning methods that can be practically applied in education, emphasizing practice in ESG in elementary and junior·senior high school education. Implications suggest that ESG entrepreneurship education and active participatory learning affect social value recognition and that teachers' enthusiasm plays a significant role in education.

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Reproductive Growth of Seeds and Overwintered Stump of Bulrush (Scirpus juncoides Roxb.) (올챙고랭이(Scirpus juncoides Roxb.) 종실(種實) 및 월동주기부(越冬株基部)의 번식생장(繁殖生長)에 관한 연구(硏究))

  • Huh, S.M.;Guh, J.O.
    • Korean Journal of Weed Science
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    • v.7 no.1
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    • pp.35-44
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    • 1987
  • Differing in water conditions, the dry matter weight per plant was highest at 0 cm flooding depth, and was decreased at above 2 cm flooding depths. The shoot and spikes per pot developed best at flooding depths of 0 and 2 cm, but worst at -5cm or above 4cm flooding depths. The dry matter weight of shoots was linearly increased, but the weight of roots was sharply decreased according to high temperature after flower initation. The shoots and spikes per pot developed more effectively at 25$^{\circ}C$ than at 35 or 15$^{\circ}C$. The number of shoot and spike per pot were decreased according to higher shading. The effects of shading of 25-45% were not significantly small. The natural white and yellow spectra were the most effective to increase dry matter weight, shoots and spikes per pot. The dry matter weights of shoot and root per plant were not significantly different among at: 50 and 75% clay. The number of shoots were best and continuously increased at 75% clay, and the increments at 0 and 100% clays showed the lag period at early stage. The pattern of spikes was similar to shoots with less difference in various clay composition. The dry matter weight per plant in paddy field and upland field was basically similar. The numbers of shoot and spike were increased in response to increased fertilizer levels up to 20Kg per 10a of each component.

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Mechanisms of Cold Injury and Cultural Practices for Reducing Damage of Rice (벼 냉해발성 기작과 피해 경감대책)

  • Lee, Moon-Hee;Park, Nam-Kyu;Park, Suk-Hong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.s02
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    • pp.34-44
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    • 1989
  • The stability of rice cultivation in Korea is largely depended on climatic conditions, especially, low temperature at the period of early growth stage and after heading. The improvement of cold tolerant varieties and appropriate cultural practices in rice are very effective to minimize the cold damage. This paper is summarized the mechanism and counterplans of cold injury of rice plants. The paddy area having commonly cold injury in Korea is approximately 15, 522ha in 1,709 sites on the national scale. The cold damage at seedling stage in nursery bed appeared to poor germination, leaf discoloration, dead seedlings and seedling rot ect.. At the vegetative stage, the decreased tiller number due to poor rooting and the delayed heading caused by slow growth and panicle differentiation are commonly showed. The cold injury at early reproductive stage appeared to the degeneration of spikelets and rachis - branches, while that at meiosis stage showed to increased sterility due to poor development of pollen and shortened panicle length with delaying heading, therefore the grain yield is largely decreased. The cold damage at heading and ripening stages showed to poor pollination and fertilization, low panicle exsertion, poor grain filling and finally grain quality became low. To minimize the cold injury to rice plants by low temperature, following counterplans would be recommonded ; Improvement of the cold toelrant rice varieties for the regions of midmountains and alpines. Raising healthy seedlings at upland nursery beds and by using of growth regulators such as ABA, Fuchiwang and Tachiace. Soil improvement and organic matter application to reduce cold damage by increasing water and fertilizer holding capacities in the paddy field having commonly cold water and in the place where cold damage is regularly occurred. Appropriate fertilization for raising healthy rice plants to tolerate under low temperature condition. Water management to increase water temperature in the paddy such as depth watering, round channels and polyethylene tubes around the field. Establishment of the optimum cultivation time of rice based on minimum, mean and maximum temperatures at different regions with appropriate rice varieties.

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A study to analyze the satisfaction of theological education curriculum in order to restructure the theological college curriculum (신학교육과정 재구조화를 위한 신학대학 교육과정 운영 만족도 분석 연구)

  • Sunwoo Nam
    • Journal of Christian Education in Korea
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    • v.77
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    • pp.63-84
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    • 2024
  • Research Objective : The study aimed to investigate the satisfaction with the operation of theological university curricula from the perspective of learners experiencing the theological education curriculum in the field. The goal is to provide a basis for reflective introspection on the current theological education curriculum and for restructuring it to have influential impacts within the church and society. Content and Methodology : A survey was conducted with 80 learners currently enrolled in undergraduate, graduate, master's, and doctoral programs at a theological university to analyze satisfaction with current theological education programs. To interpret the survey results progressively, in-depth interviews were conducted with a randomly selected group of 6 participants. Survey Results : First, the satisfaction with the current theological education programs was found to be 60%, indicating a high level of satisfaction. Second, while 77.5% recognized the need for practical pastoral education, only 45.5% reported that practical pastoral education is currently provided in theological education programs, indicating a lower percentage than the perceived need. Third, 73.7% responded negatively regarding whether the current theological education programs can enhance pastoral competence for future society. Lastly, the areas identified as urgently requiring change for the restructuring of theological education programs were theological education content, methodology, and objectives, in that order. Conclusion and Recommendations : In an era of great transformation, our society is changing rapidly. In the face of this wave of change, the theological education curriculum also requires adaptation to suit the new era. Traditional theological education courses have primarily focused on imparting theory-centered knowledge. However, theological education in the new era necessitates a curriculum that enhances the pastoral capacity of churches and pastors to dynamically navigate through this era of significant transition. To achieve this, it is imperative to restructure the curriculum to one that is more closely related to the pastoral field. This involves offering a variety of constructivist-based, learner-centered teaching and learning methods within a theory-centered curriculum and methodology. Additionally, it entails establishing a practice-oriented theological school that can actively address the evolving pastoral landscape in this era of great transition. Restructuring of the process is essential to meet these goals.

Phenology and Population Dynamics of Scirpus fluviatilis (Torr.) A. Gray in the Littoral Zone of the Upo Wetland (우포늪 연안대에서 매자기의 화력학과 개체군 변화)

  • Seo, Hye-Ran;Park, Sang-Yong;Oh, Kyung-Hwan
    • Journal of Wetlands Research
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    • v.11 no.3
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    • pp.49-59
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    • 2009
  • Seasonal changes of the growth characteristics and biomass of Scirpus fluviatilis, a aquatic emergent vascular plant, were investigated to reveal the phenology and the population dynamics and to provide the fundamental resources for the restoration counterplan of the wetland vegetation in the littoral zone of the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from March 2006 to November 2006. Scirpus fluviatilis was distributed commonly in Upo, Mokpo, Sajipo, Jokjibyeol, and Topyeongcheon upstream and downstream of Upo wetland, and the density was highest in Mokpo. Distribution range for the water depth was 9~49cm, and the highest shoot density in 26~49cm, and the mean shoot density was $119/m^2$, and the mean shoot length was 122.3cm on May 28. The number of the tuber was $104.5/0.25m^2$, and the living tubers were 84.2%. The mean fresh biomass of the living tubers was 3.0g, and those of 1~4g was most as 57.9%. Germination rates of the living tubers was 43.8%, and the maximum rate was in 7~9g and more than 10g. In the pot cultivation, the shoot density of the germinated tubers and the dormant tubers were highest as 13.5 and 9.7, respectively in early August. In the field study, the shoot density had few change before typhoon damage, while the density increased abruptly in November after flooding accompanied with the typhoon 'Ewiniar'. The shoot length in the pot cultivation and in the field study were 100~116cm and 60~170cm, respectively in the growth-end. Biomass allocation rates into the stem, leaf, flower, and underground parts were 8.9%, 6.6%, 0%, and 84.5%, respectively in the pot cultivation of the germinated tubers, and those of the dormant tubers were 7.1%, 7.1%, 0%, and 85.8%, respectively. The tuber number increased to 1.4~4.1 times by the growth-end, so it is concluded that Scirpus fluviatilis is mostly propagated by the vegetative reproduction.

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Development of 2.5D Electron Dose Calculation Algorithm (2.5D 전자선 선량계산 알고리즘 개발)

  • 조병철;고영은;오도훈;배훈식
    • Progress in Medical Physics
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    • v.10 no.3
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    • pp.133-140
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    • 1999
  • In this paper, as a preliminary study for developing a full 3D electron dose calculation algorithm, We developed 2.5D electron dose calculation algorithm by extending 2D pencil-beam model to consider three dimensional geometry such as air-gap and obliquity appropriately. The dose calculation algorithm was implemented using the IDL5.2(Research Systems Inc., USA), For calculation of the Hogstrom's pencil-beam algorithm, the measured data of the central-axis depth-dose for 12 MeV(Siemens M6740) and the linear stopping power and the linear scattering power of water and air from ICRU report 35 was used. To evaluate the accuracy of the implemented program, we compared the calculated dose distribution with the film measurements in the three situations; the normal incident beam, the 45$^{\circ}$ oblique incident beam, and the beam incident on the pit-shaped phantom. As results, about 120 seconds had been required on the PC (Pentium III 450MHz) to calculate dose distribution of a single beam. It needs some optimizing methods to speed up the dose calculation. For the accuracy of dose calculation, in the case of the normal incident beam of the regular and irregular shaped field, at the rapid dose gradient region of penumbra, the errors were within $\pm$3 mm and the dose profiles were agreed within 5%. However, the discrepancy between the calculation and the measurement were about 10% for the oblique incident beam and the beam incident on the pit-shaped phantom. In conclusions, we expended 2D pencil-beam algorithm to take into account the three dimensional geometry of the patient. And also, as well as the dose calculation of irregular field, the irregular shaped body contour and the air-gap could be considered appropriately in the implemented program. In the near future, the more accurate algorithm will be implemented considering inhomogeneity correction using CT, and at that time, the program can be used as a tool for educational and research purpose. This study was supported by a grant (#HMP-98-G-1-016) of the HAN(Highly Advanced National) Project, Ministry of Health & Welfare, R.O.K.

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Partial transmission block production for real efficient method of block and MLC (Partial transmission block 제작 시 real block과 MLC를 이용한 방법 중 효율적인 방법에 대한 고찰)

  • Choi JiMin;Park JuYoung;Ju SangGyu;Ahn JongHo
    • The Journal of Korean Society for Radiation Therapy
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    • v.16 no.2
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    • pp.19-24
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    • 2004
  • Introduction : The Vaginal, the urethra, the vulva and anal cancer avoid the many dose to femur head and the additional treatment is necessary in inguinal LN. The partial transmission block to use inguinal LN addition there is to a method which it treats and produce partial transmission block a method and the MLC which to it analyzes. Material & Methode : The Inguinal the LN treatment patient partial transmission it used block and the MLC in the object and with solid water phantom with the patient it reappeared the same depth. In order to analyze the error of the junction the EDR2 (Extended dose range, the Kodak and the U.S) it used the Film and it got film scanner it got the beam profile. The partial transmission block and the MLC bias characteristic, accuracy and stability of production for, it shared at hour and comparison it analyzed. Result : The partial the transmission block compares in the MLC and the block production is difficult and production hour also above 1 hours. The custom the block the place where it revises the error of the junction is a difficult problem. If use of the MLC the fabrication will be break and only the periodical calibration of the MLC it will do and it will be able to use easily. Conclusion : The Inguinal there is to LN treatment and partial transmission block and the MLC there is efficiency of each one but there is a place where the junction of block for partial transmission block the production hour is caught long and it fixes and a point where the control of the block is difficult. like this problem it transfers with the MLC and if it treats, it means the effective treatment will be possible.

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