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Long-term Investigation of Soil Chemical Properties in Paddy Fields Located in Different Topographic Areas of Jeonbuk Province

  • Ahn, Byung-Koo;Ko, Do-Young;Lee, Chang-Kyu;Kim, Jin-Ho;Song, Young-Ju;Lee, Jin-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.3
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    • pp.275-281
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    • 2016
  • The aim of this study was to examine the selected soil chemical properties of paddy fields in different topographic areas to efficiently manage nutrient valances of the paddy fields in Jeonbuk Province. Three-hundred soil sampling sites in paddy fields were selected from the different topographic areas in Jeonbuk Province. The soil samples were collected every four years from 1999 to 2015. Soil pH and exchangeable K and Mg concentrations declined during the experimental periods. However, almost all the chemical properties were within the proper levels for paddy soil, except exchangeable Mg concentration. Distributed areas of the paddy fields with soil pH below 5.5 continuously increased, but the paddy fields with lower concentrations of soil organic matter and available $P_2O_5$ than the proper levels declined after 2007. In addition, the paddy fields with available $SiO_2$ below the proper concentration decreased from 83.3% of the total paddy fields studied in 1999 to 61.0% of the total fields investigated in 2015. The paddy fields with lower exchangeable K and Mg than the proper levels increased after 2003 whereas the fields with lower exchangeable Ca concentration decreased. Dominant landform of coastal and plain areas was fluvio-marine plains that was distributed in 53.7% and 40.9%, respectively. Local valley and fans was a dominant landform of mountainous and middle-mountainous areas, which was 51.8% and 67.6%, respectively. Dominant soil textures distributed in coastal and plain areas were silty loam and loam. Those in mountainous and middle-mountainous areas were sandy loam and loam, respectively. Soil pH was relatively higher in coastal area and the comparatively higher content of soil organic matter was found in costal area than other areas. The concentrations of available $P_2O_5$, exchangeable Ca, and exchangeable Mg were generally higher in mountainous, coastal, plain areas, respectively, but available $SiO_2$ and exchangeable K concentrations were not significantly different among the different topographic areas.

A Study on Constructing the Multiple-Valued Logic Systems over Finite Fields using by the Decision Diagram (결정도(決定圖)에 기초(基礎)한 유한체상(有限體上)의 다치논리(多値論理)시스템구성(構成)에 관한 연구(硏究))

  • Park, Chun-Myoung
    • Journal of IKEEE
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    • v.3 no.2 s.5
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    • pp.295-304
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    • 1999
  • This paper presents a method of constructing the Multiple-Valued Logic Systems(MVLS) over Finite Fields(FF) using by Decision Diagram(DD) that is based on Graph Theory. The proposed method is as following. First, we derivate the Ordered Multiple-Valued Logic Decision Diagram(OMVLDD) based on the multiple-valued Shannon's expansion theorem and we execute function decomposition using by sub-graph. Next, we propose the variable selecting algorithm and simplification algorithm after apply the each isomorphism and reodering vertex. Also we propose MVLS design method.

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Study on minimizing Extremely-Low-Frequency magnetic fields around power cables and busbars (송전선과 분전반 모선으로부터 발생하는 극저주파 자기장 저감을 위한 연구)

  • Lou, Ming;Jeung, Gi-Woo;Kim, Dong-Hun
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.88-90
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    • 2009
  • Extremely-Low-Frequency(ELF) magnetic fields are generated around power cables and bus bars in power systems. Such the stray fields may cause disturbances to nearby electronic apparatus and affect even human health. In order to seeking out a proper way to reducing the fields, the first thing to do is to accurately predict field distribution around analysis models of interest. Then, optimization techniques should be applied for finding a more improved design than the initial one. To achieve this goal, commercial electromagnetic software, MagNet, is combined with evolution strategy algorithm. For verification of the proposed method, three-phase power line cables and busbar systems have been tested.

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A Study on the baffle effect in a stirred mixer using simultaneous measurement of velocity/concentration fields (속도/농도 동시측정에 의한 회전교반기 내부 유동의 baffle 효과에 관한 연구)

  • Kim Yun Gi;Min Young Uk;Kim Kyung Chun
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.35-38
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    • 2003
  • Simultaneous measurement of velocity and concentration fields in a stirred mixer flow using a combined Stereo-PIV/Planar-LIF technique is carried out. Instantaneous velocity fields and concentration fields represent the local flow characteristics. A baffle is perpendicularly attached to the Wall to remove inactive region which shows very slow dispersion. It is found that the baffle produces tip vortex and breaking the divided streamline, so that mixing efficiency could be increases significantly.

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A Study on the Optimum Velocity Fields in Precision Forging (정밀단조 해석을 위한 최적 속도장에 관한 연구)

  • 이종헌;김영호;김진욱
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.837-841
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    • 1997
  • An upper bound elemental technique(UBET) program has been developed to analyze forging load, die-cavity filling and optimum kinematically admissible velocity fields for flashless forging. The simulation for flashless forgings are applied plane and axisymmetric closed-die forging with rib-web type cavity. The kinematically admissible velocity fields for inverse triangular and inverse trapezoidal elements, are used to analyze flashless forging. Experiments have been carried out with pure plasticine billets at room temperature. Theoretical predictions of the forging load in plane-strain and axisymmetric forging are in good agreement with experimental results.

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Analyzing the Multidisciplinarity and Interdisciplinarity of Humanities and Social Science Journals in KCI: Focusing on General and Miscellaneous Fields (KCI 인문학과 사회과학 학술지의 다학문성과 학제성 분석: 일반 및 기타 분야를 중심으로)

  • Lee, Jae Yun
    • Journal of the Korean Society for information Management
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    • v.38 no.2
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    • pp.227-250
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    • 2021
  • This study analyzed humanities and social science (HSS) journals of KCI to examine the multidisciplinarity and interdisciplinarity in the general and miscellaneous fields (hereinafter referred to as 'GM fields'), The multidisciplinarity and interdisciplinarity identified in this study will be a foundation to improve classification of KCI journals in GM fields. Each journal's multidisciplinarity and interdisciplinarity were measured by journal-level entropy and document-level entropy, respectively, in the citation relationships. According to the analysis, GM field journals have wide ranges of multidisciplinarity and interdisciplinarity. To improve classification quality of journals in GM fields, the general humanities should be considered as a new classification class for the multidisciplinary and interdisciplinary journals in the humanities. Furthermore, this study proposes a strategy to reclassify GM field journals of HSS according to their multidisciplinarity and interdisciplinarity.

A Comparative Study on the Trend of Technological Convergence (기술융합의 세계적 추세와 한국의 현황 비교분석)

  • Lee, June Young;Kim, Dohyun;Ahn, Sejung;Kwon, Oh-Jin;Moon, Yeong-Ho
    • Journal of Korean Institute of Industrial Engineers
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    • v.39 no.3
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    • pp.222-232
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    • 2013
  • In recent years, 'technological fusion or convergence' has drawn a lot of attention of innovation researchers and governmental policy makers as the driving force of technological innovation and industrial growth. There are, however, few studies on the analysis of longitudinal trends of technological convergence and its comparison between global and national level. In this study, with the citation data of about 18 million articles, we analyzed 1) the growth of representative convergence research areas, 2) the convergence of citing patterns between research fields, and 3) the changing trend of diversity index of all research fields. We conclude that technological convergence in korea shows the relatively strong orientation to the combination of neighboring fields than that of heterogenous fields in comparison to global trend. In particular, the relatively weak activity of cognitive science and the low level of mutual exchange between arts/humanities/social sciences and natural/engineering sciences in Korea are emphasized.

Analysis on the Contents of Digital-related Studies in the Field of Costume (복식분야 디지털 관련 연구 논문의 내용 분석)

  • Eum, Jungsun;Kim, Yunhee;Yoo, Youngsun
    • Journal of the Korean Society of Costume
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    • v.66 no.6
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    • pp.135-148
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    • 2016
  • This study aimed to understand whether or not academic outcomes in digital studies shown in detailed field of costume were generated appropriately according to the development of digital technology by analyzing contents of studies in the digital-related studies, which were conducted with a background of the digital age. First, as a result of frequency of digital-related theses by the age of 'Internet Age(1994-2000)', 'Digital Age(2000-2009)', and 'Smart Life Age(After 2010)', which were classified according to the digital environmental changes, the number of theses increased drastically based on the transition point of each age. Second, representative keywords that appeared in each age included 'digital' and 'Internet' in the Internet Age, and 'digital', 'smart', 'Internet', '3D', and 'wearable' were shown in the 'Digital Age' and 'Smart Life Age'. Third, results of analysis according to the field of costume show that relevant studies were conducted in three fields of marketing/information, clothing construction and fashion design in the Internet Age, whereas the Digital Age produced relevant studies in all fields, and Smart Life Age was characterized by increase in studies in the field of fashion design and clothing construction. Fourth, results of analysis according to the contents of study show that relevant studies in the Internet Age were shown only in two subjects of 'preliminary study and trend of study' and 'studies using technical programs', and 'preliminary study and trend of study' decreased, but relevant studies in other fields of subject increased in the Smart Life Age. As shown above, relevant studies appeared as various subjects in many different detailed fields of costume in costume studies according to the stream of the Smart Life Age, which is growing fast recently, and is considered an inspiring result for development of studies in the field of costume according to the environment of the age.

A Study on the Biofouling Control in Membrane Processes Using High Voltage Impulse (고전압 임펄스를 적용한 막분리 공정에서의 생물막 오염 제어에 관한 연구)

  • Lee, Ju-Hun;Kim, Jun-Young;Yi, Chin-Woo;Lee, June-Ho;Chang, In-Soung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.10
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    • pp.67-75
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    • 2011
  • Although membrane technologies are widely applied to the water and wastewater treatment processes, strategy for the control of membrane biofouling is strongly required. In this study, a possibility of control of membrane biofouling using HVI(High Voltage Impulse) was verified based on the inactivation of microorganisms by the HVI. The HVI system was consisted of power supply, voltage amplifier, impulse generator and disinfection chamber and the model microorganism was E. coli. When 15[kV/cm] of electric fields was applied to the E. coli solution, inactivation of the microorganism was found. A possibility of the control of membrane biofouling using HVI was verified with experiments of membrane filtration with and without exposure of the HVI to biomass solution. Another membrane filtration experiments with the contaminated membranes by E. coli solution were carried out and indicate that the HVI could be used as an alternative method for membrane biofouling control. A series of simulation of the electric fields between electrodes and microorganisms was carried out for the visualization of the disinfection that showed where the electric fields are formed.

Public Perceptions of Scientists and Engineers in Korea: Focusing on the Effects of Generation, Gender, and Class Fields (한국인의 과학기술자에 대한 인식분석: 세대, 성, 전공계열의 영향을 중심으로)

  • Park, Hui-Je
    • Journal of Technology Innovation
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    • v.13 no.1
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    • pp.169-191
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    • 2005
  • By analyzing a national survey of public understanding of science and technology, this paper attempts to examine public perceptions of scientists and engineers in Korea. A special attention is given to the gap in the view of scientists and engineers across generation, gender, and class fields (or major fields). This paper shows that generation has the strongest effect on public perceptions of scientists and engineers among all the socio-demographic factors examined in this study. Those over 50 are more likely to have the conventional idealized images of scientists and the stereotypical negative images of scientists simultaneously, while the 20s are less likely to accept the idealized image of scientists. The survey result thus may suggest that the younger generation began to depart from a patriotic and moral description of scientists and engineers-for the younger generation, science and engineering is losing moral respect but becomes perceived as an ordinary occupation. Contrary to the popular belief, however, gender has little effect on public perceptions of scientists and engineers. This finding questions the assertion that female students possess more negative attitudes toward scientists and engineers than male students, and thus are reluctant to develop careers related to science and engineering. By uncovering that class fields (or major areas) have no effect on the image of scientists, this study also call into question the assertion in the science wars that the inadequate appreciation of science particularly among those who do not major in science and engineering is responsible for inadequate support for science and technology.

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