• Title/Summary/Keyword: Difference equation

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How about IRMA Curve (IRMA 법 Curve에 관하여)

  • Chang, Hyunyeong;Sin, Sunyoung;Lee, Hyunju;Woo, Jearyong;Lee, Hoyoung
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.156-161
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    • 2012
  • Purpose : IRMA method for the experimental reagents, as set out in the manual settings for doing and reporting the test results should, in principle. But many of the reagents allows for the setting of the plot does not have a lot of information. Depending on the angle setting of the table make a difference in test results and what settings are best suited to investigate. Materials and Methods : The hospital has Boramae DREAM10, Cobra, SR-300's using the Immunotech TSH reagents have been compared with the measurements. Since then there using EXCEL calculation of the equipment compared with the measurement. Results : In the comparison between each piece of equipment 1.SR-300: DREAM 10 y = 1.1376x - 0.046 (LOG-LOGIT), 2.SR-300: COBRA y = 1.0985x + 0.042 (LOG-LOG) 3.DREAM10: COBRA y = 0.965x + 0.0887 (LOG-LOG) was the result. In all charts the same X, Y axis, X values were good in general when you have. Linear-Logit value of Cobra Dream10 and Excel tends to match the calculated values provided. Conclusion : Is to guide the B / max, B / Total Logit Y axis of the chart is set to draw a look at the value equation when the X-axis LOG a high concentration are disadvantages rising urgently toward the slope. Linear-Logit plots close to the straight line has a curve. If you have a chart to guide on setting AS setting and therefore, set to guide the absence of information on the need to set up the experiment are thought to pass through.

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AC transport current loss analysis for a face-to-face stack of superconducting tapes

  • Yoo, Jaeun;Youm, Dojun;Oh, SangSoo
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.2
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    • pp.34-38
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    • 2013
  • AC Losses for face to face stacks of four identical coated conductors (CCs) were numerically calculated using the H-formulation combined with the E-J power law and the Kim model. The motive sample was the face to face stack of four 2 mm-wide CC tapes with 2 ${\mu}m$ thick superconducting layer of which the critical current density, $J_c$, was $2.16{\times}10^6A/cm^2$ on IBAD-MgO template, which was suggested for the mitigation of ac loss as a round shaped wire by Korea Electrotechnology Research Institute. For the calculation the cross section of the stack was simply modeled as vertically aligned 4 rectangles of superconducting (SC) layers with $E=E_o(J(x,y,t)/J_c(B))^n$ in x-y plane where $E_o$ was $10^{-6}$ V/cm, $J_c$(B) was the field dependence of current density and n was 21. The field dependence of the critical current of the sample measured in four-probe method was employed for $J_c$(B) in the equation. The model was implemented in the finite element method program by commercial software. The ac loss properties for the stacks were compared with those of single 4 cm-wide SC layers with the same critical current density or the same critical current. The constraint for the simulation was imposed in two different ways that the total current of the stack obtained by integrating J(x,y,t) over the cross sections was the same as that of the applied transport current: one is that one fourth of the external current was enforced to flow through each SC. In this case, the ac loss values for the stacks were lower than those of single wide SC layer. This mitigation of the loss is attributed to the reduction of the normal component of the magnetic field near the SC layers due to the strong expulsion of the magnetic field by the enforced transport current. On the contrary, for the other case of no such enforcement, the ac loss values were greater than those of single 4cm-wide SC layer and. In this case, the phase difference of the current flowing through the inner and the outer SC layers of the stack was observed as the transport current was increased, which was a cause of the abrupt increase of ac loss for higher transport current.

THE STUDY OF RELATIONSHIP BETWEEN SAGITTAL CONDYLAR GUIDE ANGLE AND INCISAL GUIDE ANGLE DURING MANDIBULAR PROTRUSION IN NORMAL KOREAN (정상 한국인의 하악 전방운동시 시상과로각과 절치로각에 관한 연구)

  • Kwon, Kung-Rock;Woo, Yi-Hyung;Choi, Dae-Gyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.27 no.2
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    • pp.11-36
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    • 1989
  • Mandibular movements are guided mainly by three determinants, namely the two posterior controls (the Temporomandibular joints) and the anterior control (the incisal guidance). The aim of this study was to evaluate the incisal guide angle in effort to reconcile a patient's condylar guide angle and incisu guide angle, to develop criteria for incisal guidance in clinical practice. 48 subjects (male 33, female 15) with intact intercuspation, without past history and symptoms of stomatognathic system, were selected for this study. All of the subjects had not anterior prostheses. The sagittal condylar guide angles and incisal guide angles were measured and estimated statistically by cephalogram and articulator (Whip-Mix 8500A). The results of this study were as follows: 1. Average of condylar guide angle was 43.33 degree by cephalogram, and was 35.18 degree by articulator. 95% confidence interval was from 40.43 to 46.23 degrees in cephalogram and was from 32.98 to 37.38 degrees in articulator. 2. Average of incisal guide angle was 51.51 degree by cephalogram, and was 44.11 degree by articulator. 95% confidence interval was from 49.12 to 54.95 degrees in cephalogram and was from 40.67 to 47.56 douses in articulator. 3. Difference between condylar and incisal guide angle was 8.18 degree by cephalogram, and was 8.94 degree by articulator. 95% confidence interval was from 4.61 to 11.74 degrees in cephalogram and was from 4.90 to 12.98 degrees in articulator. 4. In case of the incisal guide angle steeper than condylar guide angle, subjects were 69% (33 of 48) in cephatogram and 75% (36 of 48) in articulator. 5. By the multiple regression equation, condylar guide angle was more influenced by the anterior teeth. 6. When the mandible protrudes from the intercuspal position to the edge to edge position the incisal linear movement was 4.18mm (S.D.:1.30mm) and the condylar linear movement was 4.38mm (S.D.:1.26mm).

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Factors Influencing Entrepreneurs' Well-Being : Positive Psychological Capital and Antecedents (창업가의 웰빙에 미치는 영향요인 : 긍정심리자본과 선행요인)

  • Kim, Hyeong Min;Kim, Jin Soo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.5
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    • pp.203-220
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    • 2020
  • The purpose of this study is to examine the importance of entrepreneurs' well-being, and to propose several ways to improve it. First, the factors influencing entrepreneurs' well-being were explored via previous literature review, and positive psychological capital based on positive psychology was selected as the main factor. In addition, the hypotheses were formulated and the research model was constructed by selecting authentic leadership, mastery goal orientation, and social support as the antecedents predictably associated with positive psychological capital. To empirically analyze the proposed model, a questionnaire survey was conducted for the entrepreneurs who fulfilled the training/coaching/consulting programs offered by the Youth Startup Academy. By using the collected 133 responses, PLS-Structural Equation Analysis, PLS-Multi Group Analysis(MGA), and PLS-Importance-Performance Map Analysis(IPMA) were performed. As a result, it was found that positive psychological capital had a high causal relationship with the well-being of entrepreneurs; and authentic leadership and mastery goal orientation had a positive effect on positive psychological capital. However, the statistical significance of the impact of social support has not been verified. While differences in causality between early and growing stages of start-ups only acted as sub-factors of positive psychological capital, the aforementioned three antecedents showed a significant difference for hope and optimism, respectively. This study expanded the topic of entrepreneurship-related research, which mostly focuses on identifying the performance factors of start-ups. It is meaningful in that it empirically verified the causality model constructed by exploring the factors with respect to the mental well-being of entrepreneurs, which is a main theme in the entrepreneurship-related research. These results found in the current study will render practical insights to entrepreneurs, researchers, and educators.

Predictors of Positive Changes in Children with Divorced Parents: Focused on Moderating Effects of Family Incomes (이혼 가정 자녀의 긍정적 변화에 영향을 미치는 변인 분석: 가구 소득의 조절효과)

  • Choi, Hyo-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.465-475
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    • 2018
  • The purpose of this study was to explore predictors of positive changes in children with divorced parents and to demonstrate the structural path among the perceived experience of social discrimination, parenting difficulties, parent-child communication, and internet use of children that related to positive changes based on family incomes. The subjects for this study were 1,114 single parents from divorced families sourced from a study on the status of single-parent families in 2015. The results of this study by using the structural equation model of the moderating effect verification with family incomes and multi group analysis are as follows. First, single-parent's perceived experience of social discrimination turned had a significant positive effect on parenting difficulties( =.354) and children's internet use ( =.234). Single-parent's perceived parenting difficulties also had a significant positive effect on children's internet use ( =.440) but a significant negative effect on both parent-child communication( =.192) and positive changes of children( =.218). Interestingly, internet use of children demonstrated a significant negative effect on their positive changes. Second, parent-child communication, parenting difficulties, and children's internet use had a negative mediating effect with the relationship where single-parent's perceived experience of social discrimination had an effect on positive changes of children( =.167). Second, between the family groups based on family incomes, there was no statistically significant difference in the structural relationship. Based on these results, this study presented a practical proposal to help single parents not experience social discrimination and to help decrease the internet use of children to improve positive changes.

Elderly Caregiving and Health : Analysis of the mediate effect of social network and Satisfaction (노년기 수발 경험에 따른 건강 변화 : 사회적 관계망과 만족도의 매개효과 분석)

  • Lee, Seo-yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.642-651
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    • 2017
  • This study aimed to examine the changes in the health status, social network and satisfaction of caregivers as a result of caregiving using a structural equation model. As a result, it was found that caregiving increased the level of depression and decreased the subjective health status in both men and women. The social network and satisfaction were found to differ according to gender. For the women caregivers, caregiving affected their subjective health status and depression. In the case of the men caregivers, the total effect of caregiving on their subjective health was 1.087(p<.05), while the indirect effect was 0.546(p<.05). Also, caregiving affected the subjective health status of the male caregivers through the functional family network as a mediating factor(0.42, p<.01). The results suggest the necessity to take these gender differences into consideration when discussing the health of caregivers. Also, the functional family network needs to be strengthened to prevent the deterioration of the health status of male caregivers.

Varied Flow Analysis for Linear Drainage Channels (선형 배수로에 대한 부등류 해석)

  • Ku, Hye-Jin;Jun, Kyung-Soo
    • Journal of Korea Water Resources Association
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    • v.41 no.8
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    • pp.773-784
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    • 2008
  • The present study was carried out to examine flow properties in linear drainage channels such as road surface drainage facilities. The finite difference formulation for the varied flow analysis was solved for flow profiles in the channels. Starting the first step at the control section, the Newton-Raphson method was applied for producing numerical solutions of the equation. We considered two types of linear drainage channels, a channel with one outlet at downstream end and a channel with two outlets at both ends. Moreover, the flow analysis for various channel slopes was performed. However, we considered channels with the two outlets of slopes satisfying the condition that the both ends are the control section. The maximum of those slopes was decided from the relation between the channel slope and the location of control section. The flow of a channel with one outlet was calculated upward and downward from the control section existing in channel or upward from the control section at downstream end. The flow of a channel with two outlets at both ends were calculated for upstream and downstream channel segments divided by the water dividend, respectively and the flow analysis was completed when the water depth at the water dividend calculated from upstream end was equal to that calculated from downstream end. If the slope was larger than the critical slope, the channel with two outlets was likely to behave like the channel with one outlet. The maximum water depth was investigated and compared with that calculated additionally from the uniform flow analysis. The uniform flow analysis was likely to lead a excessive design of a drainage channel with mild slope.

Relationship between Total Body Fat and S/V Ratio and Body Cooling for Two Hours at $15^{\circ}C$ (한냉에 노출된 인체의 냉각과 총지방량 및 S/V 비율 사이의 관계)

  • Chung, Kwan-Ogg;Nam, Kee-Yong
    • The Korean Journal of Physiology
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    • v.3 no.1
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    • pp.19-28
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    • 1969
  • Skin temperatures on 10 sites and rectal temperature at every 10 minutes, oxygen consumption at every 20 minutes were measured on 18 male subjects (ages between 14 and 47 years) after exposure to cold air at $15^{\circ}C$ for two hours in a climatic room. Total body fat measured by means of a skinfold method and ratio of body surface area (S) to body volume (V), S/V, were utilized as basis of observations. Surface area was calculated after DuBois equation and body volume was calculated by our original formula. In influencing on the heat loss from the body core to the cold environment, % fat showed inverse relations, whereas, S/V ratio showed direct relations. Thus these two factors acted antagonistically on the body heat loss. Local skin temperatures showed negative correlations with skinfold thickness on the same site, nemaly, on chest, r=-.567; on back, r=-.507; and on upper arm, r=-.353. The other 7 skin sites showed low correlations with % fat. Minimum mean weighted skin temperature (MWST) showed a negative correlation (r=-.443) with % fat, and showed no correlation with S/V ratio. Oxygen consumption in the cold air at $15^{\circ}C$ increased from the first measurement at 20 minutes after exposure and maintained the same increasing trend up to 120 minutes. ${\Delta}T_R$ was greater in tile lean subjects who showed a greater % change in oxygen consumption. The antagonistic actions of % fat and S/V ratio on the heat loss were manifested by observations as follows: minimum rectal temperature was higher In fat subjects (r=.600) and lower in subjects with a greater S/V ratio (=-.582), ${\Delta}T_R$ was smaller in fat subjects (r=-.738) and greater in subjects with a greater S/V ratio (r=.618). Temperature difference between body core and skin surface (minimum rectal temperature minus minimum MWST) showed a positive correlation with % fat (r=.600) and a negative correlation with S/V ratio (r=-.881). Decrease in the mean body temperature and heat debt, respectively, showed negative correlations with % fat and positive correlations with S/V ratio.

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Evaluation of the Application on Distributed Inundation Routing Model (SIMOD) Using MDM and FWA Method (다중흐름방향법과 평수가정법을 이용한 분포형 침수추적모형(SIMOD)의 적용성 평가)

  • Kim, Jin Hyuck;Lee, Suk Ho;Kim, Byung Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.2
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    • pp.261-268
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    • 2018
  • The study used the simplified flooding analysis model, SIMOD, to distribute the total flood discharge by time, so research on flooding in urban areas can be conducted. The conventional flooding analysis models have limitations in constructing input data and take a long time for analysis. However, SIMOD is useful because it supports rapid decision-making process using quick modeling based on simple hydrological data, such as topography and inflow flood of the study area, to analyze submerged routes formed by flooding. Therefore, the study used the SIMOD model to analyze flooding in urban areas before conducting a comparative study with the outputs from FLO-2D, which is one of the conventional flooding analysis models, to identify the model's applicability. Seongseoje was selected as the study area, as it is located downstream the Geumho river where streams flow in the adjacent areas, and dikes are high enough to apply the "Overflow and Break" scenario for urban areas. With regard to topography, the study applied DEM data for the conventional flooding analysis and DSM data to represent urban building communities, distribution of roads, etc. Input flood discharge was calculated by applying the rectangular weir equation under the bank and break scenario through a 200-year return period of a design flood level. Comparative analysis was conducted in a flooded area with a simulation time of 1-24 hours. The time for the 24-hour simulation in SIMOD was less than 7 minutes. Compared with FLO-2D, the difference in flooded areas was less than 20%. Furthermore, the study identified the need for topography data using DSM for urban areas, as the analysis result that applies DSM showed the influence of roads and buildings.

Comparison of Physical Activity Level, Physical Activity Pattern and Energy Expenditure in Male and Female Elementary School Soccer Players using Accelerometer and Physical Activity Diary (가속도계와 신체활동일기를 이용한 초등학생 축구선수 남녀의 신체활동수준, 신체활동 패턴 및 에너지소비량 비교)

  • An, Hae-Sun;Choi, Su-Ji;Lee, Mo-Ran;Lee, Jung-Sook;Kim, Eun-Kyung
    • Korean Journal of Community Nutrition
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    • v.22 no.6
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    • pp.529-542
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    • 2017
  • Objectives: The purpose of this study was to compare the physical activity level (PAL), the physical activity pattern and the energy expenditure in male and female elementary school soccer players using the accelerometer and the physical activity diary. Methods: Twenty-five (male 11, female 14) elementary school soccer players (9-12 years) participated in this study. During their daily activities, they wore an accelerometer for seven days (five weekdays and two weekend days) and completed the physical activity diary for three days (two weekdays and one weekend day). PAL was calculated by using the physical activity diary and three equations (Pate Preschool, Freedson Children, and Freedson) were used to calculate the intensity of physical activity and energy expenditure from the counts of accelerometer. Results: The average of physical activity by day of the week, CPM (Counts Per Minute) and METs (Metabolic Equivalents) were significantly higher in males ($723.3{\pm}149.2CPM$, $2.07{\pm}0.18METs$) compared to females ($505.6{\pm}119.9CPM$, $1.79{\pm}0.20METs$), but there was no significant difference in PAEE (Physical Activity Energy Expenditure) between the two groups (males: $15.5{\pm}9.1kcal/day$, females: $11.5{\pm}6.0kcal/day$). During weekdays, physical activity intensity was significantly higher in males compared to females at lunch time and training time than at other times. In both genders, the PAL was higher during weekdays (males 1.98, females 1.89) compared to weekend (males 1.62, females 1.61) (p<0.05). Conclusions: Our study observations suggest the necessity to develop an accelerometer equation for accurately evaluating the physical activity of elementary school athletes.