• Title/Summary/Keyword: Difference-In-Difference

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UNIFORMLY CONVERGENT NUMERICAL SCHEME FOR A SINGULARLY PERTURBED DIFFERENTIAL-DIFFERENCE EQUATIONS ARISING IN COMPUTATIONAL NEUROSCIENCE

  • DABA, IMIRU TAKELE;DURESSA, GEMECHIS FILE
    • Journal of applied mathematics & informatics
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    • v.39 no.5_6
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    • pp.655-676
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    • 2021
  • A parameter uniform numerical scheme is proposed for solving singularly perturbed parabolic partial differential-difference convection-diffusion equations with a small delay and advance parameters in reaction terms and spatial variable. Taylor's series expansion is applied to approximate problems with the delay and advance terms. The resulting singularly perturbed parabolic convection-diffusion equation is solved by utilizing the implicit Euler method for the temporal discretization and finite difference method for the spatial discretization on a uniform mesh. The proposed numerical scheme is shown to be an ε-uniformly convergent accurate of the first order in time and second-order in space directions. The efficiency of the scheme is proved by some numerical experiments and by comparing the results with other results. It has been found that the proposed numerical scheme gives a more accurate approximate solution than some available numerical methods in the literature.

Investigation Study on Gender Difference Based on Korean Data Related to Drug Use (의약품 사용 관련 국내 통계자료에 나타난 성별 차이 조사 연구)

  • Rhee, Su-Jin;Lee, Byung-Yo;Kwon, Kwang-Il
    • Korean Journal of Clinical Pharmacy
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    • v.23 no.2
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    • pp.114-122
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    • 2013
  • Background: Drugs should be evaluated in appropriate subjects representing potential population to take the drugs. This study focuses on gender factor and aims to make known the appropriateness of considering gender difference on clinical evaluation of drug with domestic data related to drug use. Methods: To understand gender difference shown in drug use, three types of domestic statistical data (prevalence of chronic disease, number of outpatient with major concerning disease, and consumption of medicine) were analyzed and compared according to gender. Results: Three of fifteen chronic diseases which were analyzed, showed significantly higher prevalence in women than in men, and three were vice versa. Meanwhile, the sex ratio of outpatients was significantly different in 22 major concerning diseases. Among the drug groups coded by Anatomical Therapeutic Chemical (ATC) Classification System, the consumption of most drug groups was generally higher in women than in men except for one group coded G (genito-urinary system and sex hormones). Conclusion: Gender difference should be considered in domestic clinical evaluation of drug and domestic guidance for reflecting gender difference should be established.

The Effect of Balance between General Walking Exercise and Power Walking Exercise

  • Kim, Shin Gyun;Kim, Chang Sook
    • Journal of International Academy of Physical Therapy Research
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    • v.4 no.2
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    • pp.566-572
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    • 2013
  • This study aims to compared effect of balance between general walking exercise and power walking exercise. Twenty subjects were classified into two groups, general walking exercise(n=10) and power walking exercise(n=10). As a result, two group showed difference within the group and there is significant difference between two groups. 1) In compared static balance of sway area at pre-post test to exercise group, general walking exercise group did not change significantly. however, power walking exercise group did change significantly. and At sway distance, two group showed significant changes. 2) In compared Static balance between the groups sway area and sway path at pre-post test, two group showed significant changes. 3) In compared dynamic balance of center distance at pre-post test to exercise group, general walking exercise group was no significant difference in all directions. power walking exercise group was significant difference in all directions. 4) In compared dynamic balance between the groups sway area and sway path at pre-post test, there was no significant difference in leftward, rightward, forward directions and was significant difference in backward, overall direction. Therefore, power walking exercise can be recommended promote balance.

Accident Proneness Prospect in Preschooler (학령전기 아동의 사고 경향 예측도)

  • 이자형;김신정;이정은
    • Journal of Korean Academy of Nursing
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    • v.28 no.3
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    • pp.662-675
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    • 1998
  • The purpose of this study was to provide basic data on preschool children for accident prevention and to improve their health through a sound, safe living environment with safety education established through more systematic methods. Data were collected from 516 preschoolers from 4 to 6 years old using APP paper test which consists of a question and drawing. The children's general characteristics and accident proneness prospect were investigated. The relationship between the children's general characteristics and the accident proneness prospect were analyzed. The findings of the study are as follows : 1. The institution which children attended had a significant difference in accordance with the living safety (p=.015) and behavioral character(p=.033). 2. The housing pattern in which children lived had a significant difference in accordance with the movement speed(p=.027). 3. The children's age had a significant difference in accordance with the living safety(p=.002), traffic safety(p=.001), the reasoning power(p=.000), movement speed(p=.00), movement stability(p=.000) and attentional power(p=.000). 4. The children's sex had a significant difference in accordance with the movement stability and behavioral character (p=.003, p=.008). 5. The children's past accidental experience had a significant difference in accordance with the behavioral character(p=.001). 6. General assessment of the APP test had a significant difference in accordance with the children's age(p=.000) and children's past accidental experience(p=.020).

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Analysis on Gender Difference Appearing in Middle School Students at Each Achievement Standard (성취기준 단위로 분석한 중학교 학생의 성차)

  • Jo, Yun Dong
    • School Mathematics
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    • v.18 no.2
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    • pp.231-256
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    • 2016
  • In this paper I will look into achievement standards which show gender difference. This work is based on the average of percentage of correct answer about items taken in National Assessment of Educational Achievement (2010~2014) at each male and female student of middle school. Achievement standard becomes the basic unit when teachers make study plans as the smallest unit that composes the curriculum. Study plans are expressed concretely according to lesson time numbers, and then lesson time numbers are determined by achievement standards. Therefore, objective informations about gender difference appearing in achievement standards will play an important role in embodiment of programs to obliterate gender difference when teachers make study plans. Also This research is expected to play a role as an indicator in studying on gender difference in mathematics education.

Characteristics of Thickness Sensation Observed through Sensory Evaluation and Psychophysical Method (관능검사법과 정신물리학적 방법론을 활용한 두께 감각 특성에 대한 고찰)

  • Kim, Soyoung;Hong, Kyunghi
    • Fashion & Textile Research Journal
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    • v.21 no.1
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    • pp.88-95
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    • 2019
  • The purpose of this study was to figure out the various characteristics of the thickness sensation among elements of tactile sensation using psychophysical method. Firstly, panel screening was processed to select sensitive thickness panel using the triangle test. As a result of discriminating the paper thickness difference from 1 to 4 pieces, the female students perceived the thickness difference more sensitively than the male students (p<.05). Secondly, JND (Just Noticeable Difference) was obtained at percentage of stimulus detection rate in order to detect the degree of thickness difference by psychophysical method. It was found that the difference threshold of the entire group was about 0.125mm, with male group being about 0.178mm and female group being about 0.095mm. Thirdly, Weber's law was used to find the minimum discrimination difference between the stimuli. The experiments were conducted by increasing the paper's base thickness from 1.950mm to 1.330mm, and it was found that the difference tendency increased when the size of the basic stimulus increased. At this time, the minimum discrimination difference increased, but the Weber' fraction was not proportional to the magnitude of the stimulus. The significance of this study was that sensory evaluation was applied to research in the fields of clothing science and it seems effective to further screen and train sensitive students as material discrimination experts.

Efficient 3D Acoustic Wave Propagation Modeling using a Cell-based Finite Difference Method (셀 기반 유한 차분법을 이용한 효율적인 3차원 음향파 파동 전파 모델링)

  • Park, Byeonggyeong;Ha, Wansoo
    • Geophysics and Geophysical Exploration
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    • v.22 no.2
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    • pp.56-61
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    • 2019
  • In this paper, we studied efficient modeling strategies when we simulate the 3D time-domain acoustic wave propagation using a cell-based finite difference method which can handle the variations of both P-wave velocity and density. The standard finite difference method assigns physical properties such as velocities of elastic waves and density to grid points; on the other hand, the cell-based finite difference method assigns physical properties to cells between grid points. The cell-based finite difference method uses average physical properties of adjacent cells to calculate the finite difference equation centered at a grid point. This feature increases the computational cost of the cell-based finite difference method compared to the standard finite different method. In this study, we used additional memory to mitigate the computational overburden and thus reduced the calculation time by more than 30 %. Furthermore, we were able to enhance the performance of the modeling on several media with limited density variations by using the cell-based and standard finite difference methods together.

Biomechanical Research of Soccer Footwear (축구화의 운동역학적 특성연구)

  • Jin, Young-Wan
    • Korean Journal of Applied Biomechanics
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    • v.15 no.2
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    • pp.31-39
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    • 2005
  • The Purpose of this study was to reveal the biomechanical difference of two soccer footwear(soft ground footwear and hard ground footwear). Secondly, the purpose of this study was to clarify how each type of soccer footwear effects soccer players, which will provide scientific data to coaches and players, to further prevent injuries and to improve each players capacity. The result of comparative analysis of two soccer footwear can be summarized as below. The comparison of the very first braking force at walking found distinctive factors in the statistical data(t=3.092, p<.05). Braking impulse of two difference footwear showed distinctive factors in the statistical data(t=2.542, p<.05). In comparing GRFz max(N), the result showed a statistically significant difference in the two soccer footwear at running(t=2.784, p<.05). In the maximum braking impulse(t=2.774, p<.05) and propulsive impulse for antero-posterior direction, there was a statistically significant difference between the two soccer footwear at running. In the maximum braking force(t=3.270, p<.05) and propulsive force(t=4.956, p<.05) for antero-posterior direction, there was a statistically significant difference between the two soccer footwear at running. Significant differences were not found in moment(rotational friction) with two difference soccer footwear(moment max; t=2.231, moment min; t=1.784).

Air Temperature Change by Vegetation Canopy in Urban Park (도시 공원 내 식생 수관에 의한 기온 변화)

  • Lee, Sang-Hwa;Lee, Kyoo-Seock;Zheng, Hai-Yan;Jin, Wen-Cheng
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.1
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    • pp.44-51
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    • 2009
  • In order to determine air temperature difference by canopy layer in the forest, air temperatures were observed at Seolleung Park, Gahngnam-ku, Seoul. from November 9, 2007 to November 8, 2008 by 10 minute interval. The data were analyzed in terms of diurnal variation based on annual and monthly temperature difference. Using calm, less cloudy and no rainy weather data, average air temperature difference between forest and grass was observed as $0.8^{\circ}C$. The maximum air temperature difference was observed at 22:10, 23:20, 23:30 and 23:40 by $2.13^{\circ}C$ and the minimum one observed at 13:00 by $-0.84^{\circ}C$ in diurnal variation. The maximum temperature difference occurred at 19 : 50 on September by $3.67^{\circ}C$, Overall the air temperature in the forest was higher than that of grass at night and lower in midday.

The Relationship between the Personality of Elementary School Students and the Safety Accidents in the School (초등학생의 성격특성과 학교안전사고)

  • Kim, Chang-Hee;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
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    • v.4
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    • pp.1-20
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    • 2003
  • This study was not intended to analyze out the realities of the safety accidents in school. The purpose of this study was to find out the personality of elementary school students in 6th grade and analyze the relationship between the personality of elementary school students and the safety accidents in the school. We made a visit 12 elementary school personally in the B city of Gyeonggi Province and gave out 552 questionaries in order to accomplish the purpose of this study. And we analyzed the 501 answer data except the unfittable data 51 sheets-in case of no answer or untruthfulness. The inspection of the personality used the Eysenck Personality Questionnaire(EPQ) and the questionnaires of the safety accidents in the school were reorganized of the questionnaires which were used in Chun-Ok, Joen(1997) and One-Yong, Kim(1999)'s study to correspond with our purpose of study. Answer sheets were gone through the t and x2 test by using the program of SPPS. First, elementary school students are in the formative period in the life of a man. So many students's personality was in the middle group rather than in high and low group. In regard of the distintion between the boy students and the girl students, the boy students had higher score in Psychoticism(P) but the girl students had higher score in Neutroticism(N). And Lie(L) was showing a little more score in the girl students. Second, there was significant difference in the investigation of safety accidents in school according to sex distinction. 1) Comparing the boy students and the girl students, the rate of accidents was higher in boy rather than girl. And there was significant difference. 2) Comparing the grade of the school, the rate of accidents was higher in upper grade than lower grade both girls and boys. 3) In the kind of accidents, the traumatic Injuries were very popular and the next were contusions. There was significant difference in the traumatic injury and nosebleed. 4) The results of injured parts showed that the injuries of foot, leg, hand, arm hold a large majority. And there was a significant difference in head, face, foot, leg and etc. 5) Most accidents broke out during the break time and then accidents happened after school were the next. The flowings were lunch time and class time. There was a significant difference in accidents happened during the class, break time and lunch time. 6) Comparing the subjects, the most accidents broke out in the class of physics. 7) Among the cause of accidents, one's own carelessness was showing the highest rate. There was a significant distintion in the fight and game. 8) The safety accidents took place most in playground, and there was a significant difference. 9) Being slight wound was showing almost in the degrees of damage. And there was a significant difference. Third, the boy students were not showing the significant difference in relation to the personality, the frequency of accidents and the degrees of damage. But the girl students were showing the significant difference in relation to the Extraversion-Introversion(E) and the frequency of accidents. And there were a significant difference between E and N. Also they were showing the intense damages.

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