• Title/Summary/Keyword: research fields

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A Research on the Relations between Mathematics/statistics and Software/Hardware Tracks (소프트웨어 및 하드웨어분야의 트랙과 수학/통계와의 연관성 정도 파악)

  • Lee, Seung-Woo
    • The Mathematical Education
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    • v.47 no.4
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    • pp.505-517
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    • 2008
  • This paper studies on the necessity of mathematics/statistics in software and hardware fields. First, this research analyzes the contents of mathematics/statistics among subjects in software and hardware fields. Secondly, this research explores the relationship and connectivity between mathematics/statistics and major tracks of software and hardware fields. This connectivity between mathematics/statistics and majors in software and hardware fields would certainly contribute to creating pragmatic and professional knowledge.

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Relationship between the Population of Ralstonia solanacearum in Soil and the Incidence of Bacterial Wilt in the Naturally Infested Tobacco Fields

  • Chung, Yun-Hwa;Yu, Yun-Hyun;Kang, Yue-Gyu
    • The Plant Pathology Journal
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    • v.20 no.4
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    • pp.289-292
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    • 2004
  • The population of Ralstonia solanacearum (Rs) in soil is very important as a primary inoculum source of bacterial wilt in tobacco fields. To investigate the population of Rs, physical properties and chemical components during the tobacco growing season, soil samples were taken from the fifteen fields which were located in the flue-cured tobacco growing area, Ansung, Kyunggi province and Wonju, Kangwon province. Two fields of the fifteen were bacterial wilt free. Six fields had less than 10% plants being diseased and seven over 10%. The Rs population level determined by using SMSA medium generally showed an up-and-down pattern being low in May, high in Jun and July and low in August. The soil population in May and June showed a positive correlation with the incidence of bacterial wilt (r=0.571$^*$, r=0.688$^{**}$), but P$_2O_5$, content of soil was negatively correlated with the disease incidence (r=-0.539$^*$). These results suggest that Rs population in soil examined in May or in June, and the P$_2O_5$ content in soil should be key factors to determine the bacterial wilt potential of tobacco fields.

Contribution of Journals to Academic Disciplines

  • Lee, Hye-Young
    • Journal of Information Science Theory and Practice
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    • v.3 no.1
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    • pp.66-76
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    • 2015
  • This research uses a new approach to analyze the extent of influence journal papers have on the progress of varied research fields by estimation of subject-based influence on research other than impact factor that relies on citation index. It is initiated with the hypothesis that earlier established citation relations between journal and citing paper, which reveals the research field that contains the highest citation index and hence has received the greatest contribution from a particular journal, would have inconsistent contribution to the research field over the year of journal publication. The target research is primarily 128 journal papers and 4,123 citing papers from Information Systems Research published in the years 2001, 2004, 2007, and 2010. The characteristics of citation history and hallmarks of research field of citing papers were studied and analysis on significant distinction between citing fields based on the year of publication was performed. The analysis results show the order of citation rate to be highest from Computer Science (2,221 cases), Business & Economics (2,191 cases), and Information Science & Library Science (1,901 cases). The citation history of the journal, nonetheless, indicates increase in citation during 2-3 years after the earliest publication till it achieves constant citation. The statistical analysis shows significant variation in citing fields in accordance with the publication year; especially in 2010, journal contribution has increased in the fields of Business & Economics, Operations Research & Management Science, and Health Care Sciences & Services but, however, is reduced in Education & Educational Research and Social Sciences - Other Topics.

Effect of continuous maize cultivation on soil condition and yield in Northern Laos

  • Fujisao, Kazuhiko;Khanthavong, Phanthasin;Oudthachit, Saythong;Matsumoto, Naruo;Homma, Koki;Asai, Hidetoshi;Shiraiwa, Tatsuhiko
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.346-346
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    • 2017
  • In Northern Laos, maize is cultivated in continuous cropping without fertilizer, fallowing nor any other soil conservation practice. It is expected that this inadequate management in maize cultivation will degrade soil and decrease yield. However, there is limited information about the change of soil condition and yield under continuous maize cultivation. We tried to evaluate the change of soil condition and yield under continuous maize cultivation in Northern Laos. Our study was conducted in farmer's flat and slope fields in Sainyabuli province where maize cultivation had been introduced earlier than the other provinces of Northern Laos. Our study was conducted in 21 fields in 2014, and in 19 fields in 2015. We analyzed grain yield and soil characteristic (total carbon (TC), total nitrogen (TN), available phosphorus (Av-P), exchangeable cation, pH, soil texture) at 3 places in each field. The 3 places were set at different elevation level (lower position, middle position, upper position) in slope fields. Further, the period of continuous maize cultivation and crop management practice were investigated. Then, by evaluating the relation between the period of continuous maize cultivation and yield and the soil characteristics, the effect of maize cultivation was estimated. Crop management practices were similar among the investigated fields. Maize was cultivated in rain season. Grain seed and cob were harvested on September or October, but shoot was left on the fields. No crop was cultivated during dry season. Fertilization and fallowing has never been conducted under continuous maize cultivation. On the other hand, the period of maize cultivation was different among the fields, and ranged from 2 years to 30 years. In the slope fields, as the period of continuous maize cultivation was longer, the contents of TC and TN were lower at all 3 positions, Av-P content was lower at the upper position, exchangeable potassium (Ex-K) content was lower at the middle and the upper positions. The other soil characteristics weren't related with the period of maize cultivation in the slope fields. In contrast, soil characteristics weren't related with the period of maize cultivation in the flat fields. Yield was lower as the period of maize cultivation was longer at the upper position of the slope fields. At middle position of slope fields, yield tended to be low with increase of the period of maize cultivation. In contrast, yield wasn't related with the period of continuous maize cultivation in flat fields. From the results about crop management, it was presumed that the period of maize cultivation was one of the main factors causing the difference of yield and soil characteristics among the fields. Therefore, from the result of yield and soil condition, it was considered that the continuous maize cultivation decreased soil productivity in the slope fields with decline of TC, TN, Av-P, Ex-K and yield at upper position of slope fields, and decline of TC and TN in the other positions in Sainyabuli province.

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Evolution of Coronal Magnetic Fields Consisting of Flux Ropes and Overlying Fields

  • Jun, Hongdal;Yi, Sibaek;Choe, G.S.
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.69.1-69.1
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    • 2019
  • A series of numerical MHD simulations are performed to investigate the evolution of coronal magnetic fields consisting of two flux ropes and an overlying field. Depending on the directions of the axial current and the axial field, two co-helicity cases and two counter-helicity cases are addressed. In Case 1, in which both the axial currents and the axial fields are parallel, flux rope merging bears a huge flux rope with a large winding number. This flux rope naturally erupts, but the whole evolutionary process is rather slow. In Case 2, in which the axial currents are parallel while the axial fields are antiparallel, a self-closed structure is formed and it drives eruption. In Case 3, in which the axial currents are antiparallel and the axial fields are parallel, each flux rope erupts independently and the presence of the other flux rope does not affect the eruption of one flux rope. In Case 4, in which both the axial currents and the axial fields are antiparallel, interaction of the flux ropes and the overlying field effects a breakout reconnection creating an apple-like CME configuration. Our study tells what kind of eruption mechanisms are involved for different eruption features observed.

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A Three-Dimensional Calculation of the Reactor Impedance for Planar-Type Cylindrical Inductively Coupled Plasma Sources

  • Kwon, Deuk-Chul;Yoon, Nam-Sik
    • Applied Science and Convergence Technology
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    • v.24 no.6
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    • pp.237-241
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    • 2015
  • The reactor impedance is calculated for a planar-type cylindrical inductively coupled plasma source by expanding the electromagnetic fields into their Fourier-Bessel series forms including the three-dimensional shape of the antenna. The mode excitation method is utilized to determine the electromagnetic fields based on a Poynting theorem-like relationship. From the obtained electromagnetic fields, a tractable form of the reactor impedance is obtained as a function of various plasma and geometrical parameters and applied to carry out a parametric study.

Effects of Integrated Soil Amelioration Techniques to Mature Newly Established Research Fields

  • Jung, Sug-Jae;Hyun, Byung-Keun;Sonn, Yeon-Kyu;Cho, Hyun-Jun;Choi, Jung-Won;Lee, Pyeong-Ho;Lim, Dong-Hyuk
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.2
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    • pp.208-217
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    • 2016
  • The Rural Development Administration moved to Jeonju for the balanced development of the land. This situation required establishment of new research fields with soils appropriate to cultivation. We applied a variety of amelioration techniques to mature soils of new research fields of the National Institute of Agricultural Science (NAS) and evaluated effects of the integrated amelioration techniques. The schedule of amelioration was following: 1) location of research fields was determined, 2) surface and subsoil samples were collected separately, 3) after aligning the top level of research fields, subsoil and surface soil were re-established with soil amendment, 4) the green manure crops were grown four seasons to improve the uniformity and increase the organic content of the research field, and 5) drainage canal and/or underdrainage were applied to poorly drained fields. The last green manure crop was rape in RDA fields and green barley in NAS fields. The average height, fresh weight, and dry matter weight of rape in good condition were 123 cm, $3,938kg\;10a^{-1}$, and $651kg\;10a^{-1}$, respectively. The height, fresh weight, and dry matter of green barley, on average, were 97 cm, $3,013kg\;10a^{-1}$, and $1,004kg\;10a^{-1}$, respectively. In the chemical properties of paddy field, pH and levels of silicate, calcium, magnesium, and potassium were in appropriate range but organic matter content of $16g\;kg^{-1}$ was less than the optimum level. In the chemical properties of upland field, pH and levels of phosphorus, calcium, magnesium, and potassium were appropriate range but organic matter content of $12g\;kg^{-1}$ was less than the optimum range. Evaluation of well-adapted soil was performed. The field in RDA was classified into the superior class with points ranging from 90 to 95 by the field evaluation test. The fields in NAS were mainly evaluated as the superior class with points greater than 85. However, some fields in NAS remained low quality with scores between 80 and 83. Further soil amelioration practices were suggested to fields with low soil quality.

A Study on the Usage of Hanbok Terms -Comparing Academic and Journalistic Fields- (한복 용어 출현 양상에 대한 연구 -학술연구분야와 언론분야의 비교를 중심으로-)

  • Joonyoung Shim
    • Journal of Fashion Business
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    • v.27 no.4
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    • pp.115-124
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    • 2023
  • This study reviewed hanbok terms emerging in academic research and media fields to conceptualize hanbok terms. Terms of hanbok were collected through RISS and Bigkinds by field. Results of textming using Textom were as follows. First, a total of 17 hanbok terms appeared in the field of academic research and a total of 41 hanbok terms appeared in the field of media, showing a difference. Fourteen terms, including hanbok, traditional hanbok, traditional clothing, daily hanbok, modernized hanbok, fashion hanbok, fusion hanbok, Shinhanbok, ready-made hanbok, luxury hanbok, women's hanbok, and children's hanbok, were hanbok terms that appeared in both academic and media fields. Second, the appearance of hanbok terms was examined based on five terms: traditional hanbok, daily hanbok, modernized hanbok, fusion hanbok, and Shinhanbok, which differed in the appearance of hanbok terms between academic research and media. Traditional hanbok and daily hanbok terms steadily appeared in both academic research and media, with modernized hanbok and fusion hanbok appearing mainly in the media and Shinhanbok in the academic research fields. Results of this studys confirmed that there were differences in terms of hanbok used between academic research and media fields.

CHARACTERISTICS OF THE KAERI NEUTRON REFERENCE FIELDS FOR THE CALIBRATION OF NEUTRON MONITORING INSTRUMENTS

  • Kim, Bong-Hwan;Kim, Jang-Lyul;Chang, Si-Young;Cho, Gyu-Seong
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.243-248
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    • 2001
  • Neutron reference fields of Korea Atomic Energy Research Institute (KAERI) for calibrating neutron measuring devices to be used in radiation workplace monitoring consist of two kinds of neutron spectra, the direct and the scattered neutron fields, which are produced by using radionuclide neutron sources, 252Cf and 241AmBe sources. Necessary parameters for calibration such as the anisotropy factor of each neutron source and the room-scattered fraction of some neutron surveymeters in the KAERI calibration facility were determined by calculation or measurement. Spectral measurement of scattered neutron fields were performed at each reference calibration point using a Bonner Multi-sphere Spectrometer (BMS) and the dosimetric quantities for calibration also estimated from the neutron energy spectra which were unfolded using the BUNKI code.

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The Mysterious Universe in High and Low Gravity Fields (고중력·저중력장의 불가사의한 세계)

  • Kwon, Soon-Ik
    • Journal of the Korean Society of Industry Convergence
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    • v.3 no.4
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    • pp.293-296
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    • 2000
  • We have accumulated the knowledge of the phenomena of external nature under the gravity fields of the earth, but have not the data of the natural phenomena under the high or low gravity fields. It is necessary to research the phenomena of the combustion, heat transfer and the behavior of the living animals under the high or low gravity fields. This paper introduces the mysterious universe in high and low gravity fields from the experimental study by Arai et al.

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