• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1194-1196
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• 2003

Variations in soil physical and chemical properties can affect agricultural productivity and the environmental implications of crop production. These variations are present and may be important at regional, field, and sub-field (precision agriculture) scales. Because traditional measurements are time-consuming and expensive, reflectance-based estimates of soil properties such as texture, organic matter content, water content, and nutrient status are attractive. Soil properties have been related to reflectance measured with laboratory, in-field, airborne, and satellite sensors. Both multispectral and hyperspectral instruments have been used, with both natural and artificial illumination. Varying levels of accuracy have been obtained, with the best results (r > 0.95) using hyperspectral reflectance data to estimate soil organic matter and water content.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.5
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• pp.114-124
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• 2000

The method to estimate agricultural organic matter flow on the regional scale was established and applied to a rural area in Chongwon-gun, Chungbok in 1996. The study area is of about 67$\textrm{km}^2$ and its population is about 7,000. The stocks and flows of organic matter are represented in dry weight per unit area and dry weight per unit area per year, respectively. the amount of inflow of organic matter indicates a possibility to cause environmental pollution. the amount of animal waste 767 kg/ha/yr account for 42 percent of total amount of organic waste 1,834 kg/ha/yr and therefore the environment in study area is greatly influenced by livestock. The decrease in recycling rate of animal waste form 100% to 70% has greatly increased the amount of disposal waste nearly twice, i.e., from 267 kg/ha/yr to 497kg/ha/yr . The results of this study demonstrate that appropriate animal population, increase in recycling of animal waste and preservation of agricultural land are necessary for environmental conservation of the study area.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.393-399
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• 2013

To control organic matters, it needs to manage not only biodegradable organic matters but also refractory organic matters. Refractory organic matters from municipal wastewater, industrial wastewater, non-point sources and etc., have been continuously discharged to the near watersheds. It is estimated that the refractory organic matter ratios are continuously increased in waterbody. In watersheds of the Total Maximum Daily Loads (TMDLs), it was investigated that COD/BOD ratios increased in many unit watersheds of the 4 major river basins. The portions COD/BOD ratios increased were found to be a 97% of Geum River unit watersheds, a 81% of Yeongsan/Seumjin River unit watersheds, a 78% of Nakdong River unit watersheds, a 70% of Han River unit watersheds, respectively. Therefore, it has become important for establishment of effective management strategies to control refractory organic matter in watersheds of the Total Maximum Daily Loads (TMDLs). In order to properly manage organic matters including refractory organic matters, the present organic indicator (BOD) has to be converted to TOC (or COD). Compared to COD and BOD, TOC, as a organic matter indicator, is evaluated more appropriate.

• Transactions of Materials Processing
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• v.33 no.4
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• pp.270-276
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• 2024

In order to improve the performance of the PM (Particulate Matter) filter, the TPMS structure was used as a flow controller to control the flow entering the filter. Among various TPMS structures, a primitive structure that is easy to utilize 3D printing technique was selected and the effect of unit cell size was analyzed. In addition, numerical analysis was performed and swirl ratio was analyzed to confirm changes in filter inlet flow characteristics that affect changes in filter performance. Unit cell size is closely related to filter performance, and both PM collection efficiency and pressure drop increase as unit cell size decreases. Through quality factor (QF) comparison, which comprehensively evaluate collection efficiency and pressure drop, it was confirmed that when the unit cell size is 5 mm, PM collection efficiency increases, but the flow controller actually reduces filter performance. QF values are similar for unit cell sizes of 10 and 20 mm, and it is advantageous to select the unit cell size among these two considering collection efficiency and operating costs. The filter's collection performance increases due to the increase in swirl flow caused by the primitive structure, and the filter's collection efficiency increases due to the swirl flow that increases throughout the flow field as the unit cell size becomes smaller.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.158-164
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• 1988

The growth characteristics and yield per unit area of two cropping systems, corn monoculture and 'wrnsoybean intercropping, were compared and the obtained results were as follows; 1.The two cultivation systems were not significantly different in leaf length, leaf width and length of internode at harvesting time. 2.The weight of stalk and the leaves of a plant were decreased with maturity, while the weight of ear was markedly increased. The patterns of relative ratio of each components were essentialy same in each cultivation systems. In corn monoculture, the percentages of stalk, leaf, and ear at final harvesting stage were 22.9, 13.7, and 63.4 and in corn-soybean intercropping, they were 21.8, 10.9, and 67.3 respectively. 3.Dry matter yield per unit area (kg/lOa) of intercropped corn at yellow stage was similar to that of monocultured corn (1, 483 kg/ 10a vs 1, 509 kg/ 10a). At ripe stage, however, the dry matter yield of intercropped plant was more than that of monocultured (1, 679 vs 1, 660 kg/ 10a). 4.The same pattern was observed in organic matter yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.1
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• pp.47-54
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• 1988

The growth characteristics and yield per unit area of two cultivation systems of forage, corn (Zea mays L.) monoculture and corn-cowpea (Vigna sinesis King) inter-cropping were compared and obtained follow results. 1. The two cultivation systems were not significantly different in leaf length, leaf width and length of internode with harvesting time. 2. The weight of stalk and leaves of a plant were decreased with maturity, while weight of ear was markedly increased. The patterns of relative ratio of each components was essentially same in each cultivation system. In corn monocrop., the percentages of stalk, leaf and ear at final harvesting stage were 22.9, 13.7 and 63.4, respectively. 3. Dry matter yield per unit area (33kgIlOa) of intercropped corn at yellow stage was similar to that of monocropped corn ( l,482.8kg/ 10a vs 1 ,SO8.9kg/ 10a). At ripe stage, however, the DM yield of intercrop. was higher than that of monocrop. (1,810.4kg/lOa vs 1,660.4 kg/ 1 Oa). 4. The same pattern was observed in organic matter yield.

• Journal of Korean Elementary Science Education
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• v.19 no.1
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• pp.101-112
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• 2000

The purpose of this study was to develop the modular multimedia instructional materials emphasizing the particulate nature on the realm of matter in elementary science classes. Features of the material are as follows: 1 To be in focus on particulate model named 'phenomenal magnifying glasses' in order to change the student's belief system of continuous matter into the belief system of particulate matter . The 'phenomenal magnifying glasses' is a new instructional strategy designed to change into the view of particulate matter through facilitating the reflective thinking resulted from the simultaneous consideration of experimental phenomena(macroscopic world) and particulate model(microscopic world). 2. To introduce modular system into the instructional materials, which was consisted of 14 subunits according to the sequential instruction unit of 'molecule and molecular motion'. Each subunit was composed of 5 types of modules(module 1: motivation, module 2: experimental result, module 3: discussion, module 4: phenomenal magnifying glasses, module 5: related experiment) 3. The multimedia program was composed of 36 kinds of experimental animation and 59 kinds of computer animation materials combined with text resources, photographic materials and sounds.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.474-478
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• 2001

Eighteen Murrah male buffalo calves were allotted into three groups of six each. The calves in group I (control) were fed with whole milk, skim milk, calf starter and green maize fodder. The calves in group II (high butyric acid) and group III (low butyric acid) were fed with the same diet as control along with 24 ml and 12 ml of butyric acid/calf/day for 120 days, respectively for 120 days. Dry matter intake was higher in group II and III as compared with group I. Digestibility of dry matter, organic matter, crude protein, crude fibre, ether extract, neutral detergent fibre, acid detergent fibre, cellulose and hemicellulose was the highest in group II followed by group III and the control group. Body weight gain and conversion efficiency of dry matter, digestible crude protein and total digestible nutrients were better in group II. Cost of feed for per unit of live weight gain was the lowest in group II. It was concluded that dietary addition of butyric acid (24 ml/day) was economical and had positive effect on the performance of Murrah buffalo calves.

• International Journal of Contents
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• v.17 no.3
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• pp.67-73
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• 2021

Dark matter is barely known because it cannot be explained using the Standard Model. In addition, dark matter has not been detected yet. It is currently being explored through various ways. In this paper, we studied dark matter in an electron-positron collider using MadGraph5. The signal channel is e⁺e^- → 𝜇⁺𝜇^-A' where A' decays to dimuon. We studied the cross-section by increasing the center-of-mass energy. Central processing unit (CPU) time of simulation was compared with that using a local Linux machine and a KISTI-5 supercomputer (Knight Landing and Skylake). Furthermore, one or more cores were used for comparing CPU time among machines. Results of this study will enable the exploration of dark matter in electron-positron experiments. This study also serves as a reference for optimizing high-energy physics simulation toolkits.

• Journal of Korean Home Economics Education Association
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• v.8 no.2
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• pp.65-79
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• 1996

This study proposes a model curriculum for Vocational Home Economics High School in the 7th Curriculum Revision. The model in the study is first drawn from the assumptions that reflect ever changing demands of industrial society for Home Economics education. Another perspective employed in the study is historical analysis that focuses on the evolution of the Vocational Home Economics Curricula from the 1st through the 6th revision. This study also employes comparative research tools for the national level comparison such as USA, Japan, Taiwan, and Korea. The proposed model curriculum in this study is concluded from those step-by-step studies as follows：1) Problem definition and design in current curriculum for Vocational Home Economics high school； 2) Needs and roles analysis of Vocational Home Economics high school for the future； and 3)Historical analysis of our curriculum revisions in the past and coparative analysis with other countries. Authors conducted this research project for 3 month period from June 15, 1996 to September 15, 1996. During this period, authors collected the data and information through those method as an extensive literature review, survey and interview, and curriculum specialist conference. The key and critical features of the proposed curriculum in the study are as follows：1) In the numbers of department, a proposed model curriculum offers 8 as opposed to 6 in the 6th revision, reflecting two additional departments of “Elderly Welfare”and “Cosmotology”. 2) In the statement of educational objectives, a model curriculum emphasizes a more concrete statement to each specific skills according to the changing societal needs. 3) In the numbers of total subject matters, there would be 40 in the new as opposed to 23 in the current curriculum. Among these changes, 17 would occurr in the newly introduced subject matters, while 11 would simply change the subject matter name. Among 40 subject matter, “Introduction to Computer” and “Home Economics in Vocational Education”would be required subject matter. 4) In the total numbers of required unit for graduation in three years, a model offers 86∼132 unit. A maximum unit for each subject matter would be 12.