• Title/Summary/Keyword: '소수'

Search Result 4,067, Processing Time 0.027 seconds

중국 소수민족 두식의 유형분석 : 쓰개를 중심으로

  • 박춘순;김일정
    • Proceedings of the Korea Society of Costume Conference
    • /
    • 2004.05a
    • /
    • pp.62-62
    • /
    • 2004
  • 본 논문의 목적은 첫째, 중국 소수민족이 현재 사용하고있는 쓰개를 4대지구와 성별로 구분하고 쓰개의 명칭과 형태에 대하여 고찰한 후 도식화를 한다. 둘째는 이를 종합하여 쓰개의 유형을 분석하고 쓰개에 나타나는 상징성을 살펴보며 올바르게 이해하는데 있다. (중략)

  • PDF

초등학교 6학년 학생들의 분수와 소수연산에 나타나는 오류 유형 분석

  • 권오남;김진숙;이경아
    • Education of Primary School Mathematics
    • /
    • v.1 no.1
    • /
    • pp.45-58
    • /
    • 1997
  • 초등학교 아동은 교육과정을 이수하면서 수 영역에서 자연수, 정수, 그리고 양의 유리수까지 학습하게 되어 있다(교육부, 1992). 초등학교에서의 유리수는 분수ㆍ소수를 의미하는 소박한 의미의 유리수를 의미한다. 여기서 유리수는 자연수와 정수를 포괄하는 수 체계적 의미로서 포함관계가 강조되지는 않는다.(중략)

  • PDF

Prediction of the Flow Pattern Changes using FLOW-3D Model in the Effluent Region of the Samcheonpo Thermal Power Plant (TPP) (소수력 발전소 건설에 의한 삼천포 화력발전소 방류수로 흐름변화 예측)

  • Cho, Hong-Yeon;Jeong, Shin-Taek;Kim, Jeong-Dae;Kang, Kem-Seok
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.18 no.4
    • /
    • pp.338-347
    • /
    • 2006
  • A small hydro-power plant using the seawater used as the cooling (circulated) water and discharged is under construction. The bigger size of the small hydro-power plant, the better in order to maximize the efficiency and the electric power. The optimal size, however, should be determined in the constraints of the channel un-disturbed range. The water level change should be checked in detail based on the hydraulic behaviour. In this study, the FLOW3D model, three-dimensional flow model, is setup using the flow measurement data in the effluent discharge channel and the flow pattern changes due to the small hydro-power plant construction are predicted by the model. The plant construction makes the increasing of the water level, and the water level in the upstream of the channel weir is increased 65 cm from 4.32 m to 4.97 m, in the condition of the design discharge $156m^3/s$ and the movable weir height of the hydro-power plant 3.8 m.

Growth, Development, and Morphological Characteristics of Echinochloa colona (Echinochloa colona의 생장(生長), 발육(發育) 및 형태적(形態的) 특징(特徵))

  • Chun, J.C.;Moody, K.
    • Korean Journal of Weed Science
    • /
    • v.6 no.1
    • /
    • pp.1-6
    • /
    • 1986
  • The growth, development, and morphological characteristics of Echinochtoa colons (L.) Link were determined through one life cycle. E. colons emerged 2 to 3 days after seeding (DAS) and reached the two leaf stage by 8 DAS. During the early growth stages, root length was greater than plant height, but the relationship was reversed from 4 weeks after seeding (WAS). Tillering started from the third leaf of the main culm as the sixth leaf on the main calm emerged. The unfolding of the leaves and tillering followed a regular pattern during the vegetative growth period. This resulted in the production of 19 tillers (5 primary, 12 secondary, 1 tertiary, and I nodal) at the 14-leaf stage. Shoot-root weight ratio was highest just before panicle initiation. The second spike from the top of the panicle was the shortest and produced the fewest seeds. Thereafter, spike length and the number of seeds per spike generally increased, the lower the position of the spike on the panicle. Seeds on the lower spikes weighed less and had lower germination ability than those from the upper spikes. Adventitious roots arose from the leaf sheath bases of a flowering stalk. The ability to produce adventitious roots was greater in a younger stalls than in an older stalk.

  • PDF

Sterilization Effects on Mulberries (Morus alba L.) Washed with Electrolyzed Water and Chlorine Dioxide (전해수와 이산화염소수 세척에 따른 뽕나무 오디(Morus alba L.)의 살균효과)

  • Teng, Hui;Lee, Sun-Ho;Lee, Won-Young
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.23 no.5
    • /
    • pp.654-661
    • /
    • 2013
  • The current research is designed to analyze sterilization effects on mulberries in terms of storage temperature and storage period after treating with tap water (TW), electrolyzed water (EW) and aqueous chlorine dioxide ($ClO_2$). The treated $ClO_2$ concentrations are 10, 50, 100 and 200 ppm. In each concentration, the mulberries are soaked for 30 seconds respectively. The sterilization effects are being compared at room temperature ($25^{\circ}C$) and at $4^{\circ}C$, respectively. And the enzyme activity related to quality is also being investigated and analyzed about for browning inhibition effects. Microbial sterilizing power increases more in treating plots with EW and $ClO_2$ than treating plot with TW. Futhermore sterilizing power of $ClO_2$ increased sharply on high concentration treatment plot as well. Sterilization effects of $ClO_2$ during storage time are better at cold temperature. Pictures taken from scanning electron microscope reveal that there are no microbes in sterilizing solutions treatment plots. From measurement of the enzyme activity, it is concluded that activities decrease more in sterilizing solutions treatment plots as comparing with TW treated plot during the time. The amount of total polyphenolics decrease with the time passing and EW and $ClO_2$ treatment shows less contents than TW treatment. Thus, EW and $ClO_2$ treatment of mulberris are considered as method to improve safety by reducing total plate count and to contribute to quality maintenance and to extend storage time.

Effect of Membrane Materials on Membrane Fouling and Membrane Washing (막의 재질에 따른 막오염 특성 및 물리·화학적 세척의 영향)

  • Shim, Hyun-Sool;Jung, Chul-Woo;Son, Hee-Jong;Sohn, In-Shik
    • Korean Chemical Engineering Research
    • /
    • v.45 no.5
    • /
    • pp.500-505
    • /
    • 2007
  • The objectives of this research were to (1) identify the membrane fouling potential due to different fractions of NOM (2) correlate the physicochemical properties of NOM and membranes with the adsorption of humic substances on membrane (4) find out the effect of membrane physical and chemical washing according to membrane material. The static adsorption test and adsorption test showed that hydrophobic organics adsorbed much more quickly than hydrophilic organics. In case of the effect of membrane properties on the adsorption of organic fractions, the adsorption rate ratio(a) of hydrophobic membrane (0.016, 0.077) was greater than that of hydrophilic membrane (0.010, 0.033) regardless of the kind of organic fractions. This suggests that the UF membrane fouling were occurred mainly by internal pore size decreasing due to adsorption of organic into pore surface for hydrophobic membrane, and by sieving of organics and forming a gel layer on the membrane surface for hydrophilic membrane. In conclusion, the decrease in the pore volume, which was caused by the organic adsorption into the internal pore, was greater with the hydrophobic membrane than with the hydrophilic membrane. In case of the effect of membrane properties on permeate flux, the rate of flux decline for the hydrophobic membrane was significantly greater than that for the hydrophilic membrane.

An Analysis And Criticism on Mathematics Terminologies Used in Elementary School Mathematics: Focused on Some Examples (우리나라 초등학교 수학용어의 분석과 비판: 몇 가지 예를 중심으로)

  • Park, Kyo Sik
    • Journal of Elementary Mathematics Education in Korea
    • /
    • v.17 no.1
    • /
    • pp.1-17
    • /
    • 2013
  • In this paper, firstly, 'value', 'vertices', 'height' are discussed, which are used in the multiple contexts. Then 'sketch', 'mental math', 'zero point oneth place/zero point zero oneth place/zero point zereo zero oneth place', 'number of place', 'natural number part/decimal part' are discussed, which are not used consistently. Finally, middle school mathematics terms 'distance', 'number line', 'the value of the expression' are discussed which are used in elementary school mathematics textbooks/workbooks. From these discussions, the following four suggestions are proposed as conclusions. First, as a mathematical term 'value' and 'distance' should be emphasized. As 'distance' is a middle school term, there is a need to consider the 'height' as 'the length of the line segment' instead of 'distance'. Second, 'number of place' which can be replaced with other suitable term, 'the value of the expression' including 'value of $20{\times}4$', 'natural number part/decimal part', 'vertex of pyramid/vertex of cone', 'mental math' should not be used. Third, there is a need to consider the use of 'mixed decimal' and 'proper decimal'. In addition, there is a need to expand the use of 'sketch'. Fourth, there is a need to consider the confirmation of 'number line' as an elementary school mathematics term. In addition, there is a need to consider to specify that 'decimal first place', 'decimal second place', 'decimal third place' can be used equivalently with 'zero point oneth place', 'zero point zero oneth place', 'zero point zereo zero oneth place' respectively.

  • PDF

Electronegativity and CMC Characteristics of Hydrophilic and Hydrophobic Group for Surfactants (계면활성제의 친수·소수성 그룹의 전기음성도와 CMC 특성)

  • Ha, Youn-Shick;Paek, U-Hyon;Chang, Yoon-Ho
    • Applied Chemistry for Engineering
    • /
    • v.8 no.6
    • /
    • pp.914-919
    • /
    • 1997
  • On the basis of theory of Bratsch's electronegativity equalization, the electronegativity equalization, the group electronegativities and the group partial charges for anionic and nonionic surfactants could be calculated by using Pauling's electronegativity parameters. From calculated results, we have investigated how CMC, hydrophilic and hydrophobic groups, group partial charge, electronegativity of hydrophilic and hydrophobic groups, structural stability of micelle for anionic and nonionic surfactants are related. It was fround that CMC depends upon group partial charge and group electronegativity of hydrophilic and hydrophobic groups of surfactants. For the anionic surfactants, negative partial charge in hydrophobic group is delocalized as the carbon number in hydrophobic group increase. So negative partial charge of hydrophilic group has very large electronegativity that is decreased. And CMC decreases as hydration ability of hydrophilic groups which decreases relatively. For the nonionic surfactant, partial charge and electronegativity in hydrophobic group increases with the increment of carbon number in hydrophobic group. And CMC decreases because electronegativity of hydrophilic group is decreased with the increment of electronegativity of hydrophilic group. However, with the increase of repeating units in hydrophilic group, the negative partial charge of hydrophilic group increases. So CMC increases because surfactants hydrate rather than form micelles in aqueous solution by the increase of hydration ability.

  • PDF

Reduction of Microbial Load on Radish (Raphanus sativus L.) Seeds by Aqueous Chlorine Dioxide and Hot Water Treatments (이산화염소수 및 열수처리에 따른 무(Raphanus sativus L.) 새싹 종자의 미생물 제어 효과)

  • Park, Kee-Jai;Lim, Jeong-Ho;Kim, Ji-Hye;Jeong, Jin-Woong;Jo, Jin-Ho;Jeong, Seong-Woong
    • Food Science and Preservation
    • /
    • v.14 no.5
    • /
    • pp.487-491
    • /
    • 2007
  • This study was conducted to investigate the effect of treatment with squeous chlorine dioxide and hot water on the germination of radish (Raphanus sativus L.) seeds, and reduction of microbial load on the seeds. Increases in treatment and the concentration of aqueous chlorine dioxide in water resulted in increasing reductions in the counts of total aerobic microbes. Seeds treated with aqueous chlorine dioxide (100 ppm/20min, 200ppm/20min) showed about a 10-fold decrease in microbial loads. Germination of seeds was not adversely affected by any treatment tested, although the germination rate of seeds in the group treated at $55^{\circ}C$ for 20 min was reduced by 10% compared to that of control. Combined treatment with hot water and aqueous chlorine dioxide yielded better out comes in both microbial reduction and seed germination rate than did single treatments. A combined treatment with 100 ppm aqueous chlorine dioxide and hot water($45^{\circ}C$ or $50^{\circ}C$) resulted in about a 100-fold decrease in microbial load whereas germination rate showed only a slight increase to $97.0{\sim}97.7%$. Total aerobic microbial counts in radish seeds were decreased by aqueous chlorine dioxide and hot water treatment in the order. aqueous $CIO_2$+ hot water > aqueous $CIO_2$ > chlorinated water > hot water > control.

Effect of Organic Melecular Weight and Functional Group on Membrane Fouling (막오염에 미치는 유기물 분자량 분포특성 및 화학적 구조특성)

  • Jung, Chul-Woo;Son, Hee-Jong;Shin, Hyun-Sool;Sohn, In-Shik
    • Korean Chemical Engineering Research
    • /
    • v.45 no.6
    • /
    • pp.669-676
    • /
    • 2007
  • The raw water was fractionated into hydrophobic (HPO), transphilic (TPI), and hydrophilic portions (HPI) using XAD resins. The raw water DOC contains 39% of hydrophilics, 43% of hydrophobics, and 18% of transphilics. When fractionated NOM (natural organic matter) was passed through hydrophilic membrane with 100 kDa, hydrophobic portion (HPO) caused the most fouling and hydrophilic portion (HPI) caused the least fouling. This could be related to size and adsorption capability of organics. Small sized organics would pass through membrane pores, but large sized organics would be attracted to either membrane pores or surface, which led to the fouling. An effect of membrane pore size on membrane fouling is related to the availability of organics at membrane pores. As the pore size became larger, the more organics were transported into the membrane pore. Some organics caused pore blocking, and others caused pore adsorption, which resulted in membrane fouling. Membrane material is also important for membrane fouling. More fouling occurred at hydrophobic membrane than hydrophilic membrane regardless of its pore size. Hydrophobic interaction caused more fouling at hydrophobic membrane.