• Title/Summary/Keyword: Fundamental Factors

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Field Intercomparison and Calibration of Net Radiometers (순복사계의 야외 상호 비교 및 보정)

  • Byung-Kwan Moon;Sang-Boom Ryoo;Yong-Hoon Youn;Jonghwan Lim;Joon Kim
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.5 no.2
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    • pp.128-137
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    • 2003
  • Net radiation (Rn) is one of the most fundamental components in surface energy budget. For an accurate measurement of Rn, periodic and consistent calibrations of net radiometers are required. With a 4-month time interval, two field experiments were conducted to inter-compare and calibrate two types of net radiometers (the Q-7.1 and the CNR1), widely used in flux measurements. Differences between the Q-7.1 and the CNR1 net radiometers were within 7.7%, and the errors after calibration against the standard net radiometer were <3.2%. Radiometric responses and calibration factors appeared to have changed with sky renditions, especially temperature difference with season's progress. We concluded that the periodically calibrated Q-7.1 can replace more expensive, more accurate CNR1 net radiometer for long-term field measurements, providing that field calibrations of net radiometers are performed every 4-6 months interval.

THE VIRIAL RELATION AND INTRINSIC SHAPE OF EARLY-TYPE GALAXIES

  • TRIPPE, SASCHA
    • Journal of The Korean Astronomical Society
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    • v.49 no.5
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    • pp.193-198
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    • 2016
  • Early-type galaxies (ETGs) are supposed to follow the virial relation $M=k_e{\sigma}^2R_e/G$, with M being the mass, σ* being the stellar velocity dispersion, Re being the effective radius, G being Newton's constant, and ke being the virial factor, a geometry factor of order unity. Applying this relation to (a) the ATLAS3D sample of Cappellari et al. (2013) and (b) the sample of Saglia et al. (2016) gives ensemble-averaged factors 〈ke〉 = 5.15 ± 0.09 and 〈ke〉 = 4.01 ± 0.18, respectively, with the difference arising from different definitions of effective velocity dispersions. The two datasets reveal a statistically significant tilt of the empirical relation relative to the theoretical virial relation such that $M{\propto}({\sigma}^2_*R_e)^{0.92}$. This tilt disappears when replacing Re with the semi-major axis of the projected half-light ellipse, a. All best-fit scaling relations show zero intrinsic scatter, implying that the mass plane of ETGs is fully determined by the virial relation. Whenever a comparison is possible, my results are consistent with, and confirm, the results by Cappellari et al. (2013). The difference between the relations using either a or Re arises from a known lack of highly elliptical high-mass galaxies; this leads to a scaling (1 - ϵ ) ∝ M0.12, with ϵ being the ellipticity and $R_e=a\sqrt[]{1-{\epsilon}}$. Accordingly, a, not Re, is the correct proxy for the scale radius of ETGs. By geometry, this implies that early-type galaxies are axisymmetric and oblate in general, in agreement with published results from modeling based on kinematics and light distributions.

A Study on the Measurement and Shape of Lower Body of Sportmen (슬랙스 설계를 위한 스포츠전공 남자대학생의 하반신 체형 연구)

  • Lee Hyun-Min;Kim Soo-A;Choi Hei-Sun
    • Journal of the Korean Society of Costume
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    • v.54 no.8
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    • pp.1-14
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    • 2004
  • The aim of this study is to provide fundamental data on the development of ready-to-wear clothing appropriate for the lower body types of male students who play sports in college. The study was conducted by means of targeting 151 male sports majors between $18{\sim}27$ years of age. Characteristics of the respondents were ascertained by means of questionnaires and an evaluation of a total of 36 lower body features. The results of the study are as follows. 1. A comparison of anthropometric measurements with the National Anthropometric Survey of Korea (1997) revealed that the main characteristics of the lower somatotypes of male sports college students are large circumferences and developed muscles of the lower body. 2. Sports were classified into the following five categories : soccer, bodybuilding, wrestling, judo, and taekwondo. In particular, bodybuilding students demonstrated a somatotype with an increased circumference, depth, and width of the thigh and lower body. 3. Somatotypes were classified into 3 types by means of a cluster analysis employing S factors. Type 1 somatotype exhibits a large circumference in the lower body. Type 2 is a lower somatotype of a middle size. Finally, Type 3 encompasses a smaller group in weight and circumference with a developed calf and ankle. 4. Each group was evaluated using a discriminatory analysis as a check to see if the groups had been discriminated with accuracy. The total accuracy rate was 96.0%.

Changes of Hydraulic Conductivity During Desalmization of Reclaimed Tidelands (간척지 토양의 제염과정중 수리전도도의 변화)

  • 구자웅;은종호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.4
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    • pp.85-93
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    • 1988
  • This laboratory study was carried out in order to produce fundamental data for analyzing salt movement and desalinization effects, using samples of silt loam soil collected in Gyehwado and Daeho reclaimed tidelans, and samples of silty clay loam soil collected in Kimie tideland. Desalinization experiments with gypsum treatment were performed to analyze changes of the hydraulicc conductivity with changes of the soil property and the salt concentration during the desalinization of reclaimed tideland soils by leaching through the subsufface drainage, and correlations between factors infl uencing the reclamation of salt affected soils were analyzed by the statistical method. The results were summarized as follows: 1. The reclaimed tideland soils used in this study were saline-sodic soils with the high exchangeable sodium percentage and the high electrical conductivity. 2. Changes of the hydraulic conductivity with the amount of leaching water and the leaching time elapsed were affected by the amount of gypsum except exchangeable sodium and clay contents. The regression equation between the depth of water leached per unit depth of soil (Dw / Ds : X) or the square root of the leaching time elapsed (T $^1$ $^2$ : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a . bx. 3. The more exchangeable sodium and clay contents regardless of the amount of gypsum, the more the leaching time was required until a given volume of water was leached through the soil profile. The regression analysis showed that the relationship between the depth of water leached per unit depth of soil(Dw /Ds:X) and the square root of the leaching time elapsed(T$^1$$^2$ :Y) could be described by Y=a . Xb. 4. The hydraulic conductivity was influenced to a major degree by the salt concentration provided that the electrical conductivity was below 10 mmhos / cm during the desalinization of reclaimed tideland soils. The regression equation between the relative electrical conductivity ( ECr : X) and the relative hydraulic conductivity (HCr:Y) could be expressed in Y=a + b . X-$^1$. 5. In conclusion, the hydraulic conductivity, leaching requirements and the leaching time elapsed can be estimated when the salt concentration decreases to a certain level during the desalinization of reclaimed tidelands, and the results may be applied to the analysis of salt movement and desalinization effects.

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Development of the Light Guide Lamp for Lighting Image Enhancement Using Retro Reflection Principle (재귀반사 원리를 이용한 점등이미지 향상 LIGHT GUIDE 개발)

  • Kim, Hyeongseon;Choi, Sungwuk;Jin, Gunsoo
    • Journal of Auto-vehicle Safety Association
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    • v.11 no.4
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    • pp.16-21
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    • 2019
  • In recent years, most automobile manufacturers have been using slim light source images to imprint their own brand image and identity. A light guide type lamp is widely used for making these kinds of a slim light source image. A light guide lamp means using a light emitting diode light source at one end of a long cylindrical pipe. The light from the light emitting diode source moves through the pipe by total reflection principle. Moving light is sent forward by various optic structures which is applied in the cylindrical pipe. However, the light guide lamp has a problem that the image of the light differs depending on the viewing direction, and in some cases there is dark section. It means light guide has low quality about lighting image. In this paper, trying to improve the fundamental problems of the light guide mentioned above by using various triz methods. Through functional modeling, estimating the factors affecting the light in the light guide lamp and make various ideas to improve the lighting image using the chain effect cause analysis, function oriented search scientific database techniques. Using these kinds of various TRIZ methods, finally find solutions that can improve the brightness and lighting uniformity of the light guide lamp. The ideas obtained in this paper were applied to actual vehicle development, and several patents achievements were obtained. In conclusion, it is proved that TRIZ method is useful for making ideas in actual automobile industrial field and is also a useful method for acquiring patent.

3-D Kinematic Analysis According to Stance Patterns During Forehand Stroke in Tennis (테니스 포핸드 스트로크 동안 스탠스 조건에 따른 3차원 운동학적 분석)

  • Choi, Ji Young
    • Korean Journal of Applied Biomechanics
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    • v.15 no.4
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    • pp.105-115
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    • 2005
  • Recently among several tennis techniques forehand stroke has been greatly changed in the aspect of spin, grip and stance. The most fundamental factor among the three factors is the stance which consists of open, square and closed stance. The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle according to open, close, and square stance patterns during forehand stroke in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head angle were defined. In conclusion, the first hypothesis, "In three dimensional maximum linear velocity of racket head would be significant difference among the stance patterns during forehand stroke in tennis" was rejected. The second hypothesis, "In three dimensional anatomical angular displacement of trunk would be significant difference among the stance patterns during forehand stroke in tennis" was rejected and the result showed that the internal-external rotation showed most important role among the three dimensional anatomical angular displacement of trunk The third hypothesis, "In three dimensional anatomical angular displacement of upperlimb would be significant difference among the stance patterns during forehand stroke in tennis" was rejected and the result showed that The three dimensional anatomical angular displacement of shoulder joint showed most important role in forehand stroke. Flexion-extension and internal-external rotation the open stance showed the largest angular displacement and is follwed by square stance and closed stance. The fourth hypothesis, "In three dimensional anatomical angular velocity of upperlimb would be significant difference among the stance patterns during forehand stroke in tennis" was rejected and the result showed that X-axis angular velocity and Z-axis angular velocity the square stance showed the largest angular velocity of the trunk and X-axis angular velocity and Y-axis angular velocity the closed stance showed the largest angular velocity of the shoulder joint.

Snowboard Injury (스노우보드 손상)

  • Seo Joong-Bae;Lee Sung-Cheol;Park Jin-Young
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.3 no.1
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    • pp.22-24
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    • 2004
  • Snowboarding has become one of the premier alpine sports. The past decade has seen the popularity of snowboarding increase dramatically and the recent Winter Olympic Game showcased the strong visual appeal of the sport and the youth-oriented lifestyle and culture that accompanies it. The injury profile of the sport has also undergone change along with technological advances in boot and binding systems and the changing demographics of the sports participants. Central to the development of injury-prevention strategies is knowledge of the profile of injuries that occur, understanding those who are at particular risk and, if possible, the biomechanical factors involved in each injury type. Snowboarding was initially considered a dangerous, uncontrolled, alpine sport - an opinion based on little or no scientific evidence. That evidence has rapidly grown over the past decade and we now know that snowboard injury rates are no different to those in skiing; however, the injury profile is different. The purpose of this review is to give some perspective to the current snowboard injury literature. It discusses not only the demographic profile of those injured and the type of injuries that occur, but also gives some insight into the progress that has occurred in determining the impact of specific prevention strategies, such as splints to prevent injuries to the wrist/forearm. As the literature indicates, however, some things will not change, e.g. injuries are more likely to occur in beginners and lessons need to be reinforced as a fundamental aspect of any injury-prevention strategy.

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Fundamental study on the evapo-transpiration requirements of paddy rice plant (수도용수량계획상의 엽면증발량 및 주간수면증발량에 관한 기초적인 연구)

  • 김철기
    • Journal of the Korean Professional Engineers Association
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    • v.2 no.6_7
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    • pp.12-23
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    • 1969
  • The purpose of this study is to find out the reasonable amount of evapo-transpiration required for the paddy rice plant during the whole growing season. So, on the basis of the 3year experimental data concerning the evapo-transpiration from 1966 to 1968, the author obtained the following results. 1) The leaf area index in the densely planted plot is generally higher than that in the conventionally planted one during the first half of growing season. So, the coefficient of transpiration in the former plot is some what higher than in the latter, and the coefficient of water surface evaporation under the plant cover has the inverse relation between both plots. 2) It is unreasonable that coefficient of evapo-transpiration is applied to the calculation of the evapo-transpiration requirments of each growing stage, because a certain degree of variation in meteorological factors and in the thickness of the plant growth is involved in it. 3) It is most reasonable that the rate of transpiration and of the water surface evaporation is applied to the calculation of the transpirated amount and evaporated one in each growing stage because it shows almost constant value in spite of any meteorological conditions in so far as the variety of rice, planted density and control of applying fertilizer are same and the disease and blight are negligible. 4) The ratio of the amount of transpiration to the weight of the whole air dried yields has the tendency of decreasing as that of the yields increase, having almost constant value despite the amount of pan evaporation; and the value is about 210 when the weight of root parts is included to that of the yields. 5) Although the required amount of transpiration during the whole growing season can be calculated with the above ratio, fig. 7 showing the relation between the amount of transpiration and the weight of the yields is more reasonable and will be convinient to find it. And the requirements of water surface evaporation during the same season can also be directly found with the weight of air dried straw refering to fig.8.

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Synetheses and Surface Active Properties of Amphoteric Surfactant Derivatives(7);Detergency Performance of Amphoteric Surfactants Derived from Imidazoline (양쪽성계면활성제의 유도체합성 및 계면성에 관한 연구(제 7보);이미다졸린으로부터 유도된 양쪽성계면활성제의 세정성)

  • Ro, Y.C.;Kim, T.Y.;Nam, K.D.
    • Journal of the Korean Applied Science and Technology
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    • v.12 no.1
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    • pp.47-54
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    • 1995
  • Water pollution, which is caused by surfactants, is increased by insolubility and excessive uses of detergents. The detergency properties of nine kinds of amphoteric surfactants derived from imidazoline were investigated and compared with sodium lauryl sulfats(SLS) of petrochemical surfactant by using detergent formulations. Several physico-chemical properties were measured to investigate the effective factors on detergency. From the comparision of these compounds with SLS, it was found that 1-(2-hydroxyethyl)-1- (3-sulfonatedpropyl)-2-undecyl-2-imidazolinum [IV] has the most outstnading characteristics of detergency and various fundamental properties. Therefore, this result is expected to do its environmental stability as a nonpolluting detergent. Detergency process of surfactants were discussed in relation to physico-chemical treatments. Performance improvement on detergency is made work of adhesion to soil as small as possible. Therefore these results show that contamination is easily removed and industrial applications may be respected.

Economics During Global Recession: Sharia-Economics as a Post COVID-19 Agenda

  • ARFAH, Aryati;OLILINGO, Fahruddin Zain;SYAIFUDDIN, S.;DAHLIAH, D.;NURMIATI, N.;PUTRA, Aditya Halim Perdana Kusuma
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.1077-1085
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    • 2020
  • This research is a literacy study regarding the implementation and management of the economic role of haria as a new strategy in overcoming the problem of the global financial crisis that has hit the middle of the COVID-19 pandemic. The research method comes from previous studies to compare the capitalist, socialist, and sharia economic systems. In response to various economic uncertainties, both internal and external, the ability to seize opportunities and transform has become the key to economic resilience. Islamic economics can be an alternative in responding to the dynamics of the global and national economy. Several things need to be taken into consideration in fulfilling the sharia economy and the primary strategy chosen must come from the inputs given by the stakeholders, including business actors, associations, regulators as well as experts, and academicians. The primary strategy in implementing the sharia economy also requires the support of various parties in order to develop sustainability. Strengthening regulation and governance is one of the fundamental factors. Optimization of the sharia economy based social sector such as Zakat, Infaq, Sadaqah, and Waqaf can be optimized both for collection and distribution so that the concept of sharing can certainly support the development and the economy both nationally and globally.