• Title/Summary/Keyword: Data dependence

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Development of spatial dependence formula of FORGEX method using rainfall data in Korea (우리나라 강우 자료를 이용한 FORGEX 기법의 공간상관식 개발)

  • Kim, Sunghun;Ahn, Hyunjun;Shin, Hongjoon;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.49 no.12
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    • pp.1007-1014
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    • 2016
  • The FORGEX (Focused Rainfall Growth Extension) method was developed to estimate rainfall quantiles in the United Kingdom. This method does not need any regional grouping and can estimate rainfall quantiles with relatively long return period. The spatial dependence formula (ln $N_e$) was derived to consider the distance from growth curve of proper population to the distributed network maximum (netmax) data using the UK rainfall data. For this reason, there is an inaccurate problem in rainfall quantiles when this formula is applied in Korea. In this study, the new formula was derived in order to improve such shortcomings using rainfall data of 64 sites from the Korea Meteorological Administration (KMA). A 42-year period (1973~2014) was taken as the reference period from rainfall data, then the formula was derived using three parameters such as rainfall duration, number of site, area of network. Then the new formula was applied to the FORGEX method for regional rainfall frequency analysis. In addition, rainfall quantiles were compared with those from the UK formula. As a result, the new formula shows more accurate results than the UK formula, in which the FORGEX method by the UK formula underestimates rainfall quantiles. Finally, the new improved formula may estimate accurate rainfall quantiles for long return period.

Locality-Conscious Nested-Loops Parallelization

  • Parsa, Saeed;Hamzei, Mohammad
    • ETRI Journal
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    • v.36 no.1
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    • pp.124-133
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    • 2014
  • To speed up data-intensive programs, two complementary techniques, namely nested loops parallelization and data locality optimization, should be considered. Effective parallelization techniques distribute the computation and necessary data across different processors, whereas data locality places data on the same processor. Therefore, locality and parallelization may demand different loop transformations. As such, an integrated approach that combines these two can generate much better results than each individual approach. This paper proposes a unified approach that integrates these two techniques to obtain an appropriate loop transformation. Applying this transformation results in coarse grain parallelism through exploiting the largest possible groups of outer permutable loops in addition to data locality through dependence satisfaction at inner loops. These groups can be further tiled to improve data locality through exploiting data reuse in multiple dimensions.

Spatial Variability Analysis of Paddy Rice Yield in Field (필지내 벼 수량의 공간변이 해석)

  • 이충근;우메다미키오;정인규;성제훈;김상철;박우풍;이용범
    • Journal of Biosystems Engineering
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    • v.29 no.3
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    • pp.267-274
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    • 2004
  • Using geo-statistical method, yield data of different fields were analyzed to examine their field variability according to examining year, analysis method. Semivariogram and Kriged maps of geo-statistical analysis were used to examine their spatial dependence within a filed. The results obtained were as follows. 1) Descriptive statistical results of the yield showed that the yield and the difference of yield ranged from 100 to 946kg/10a and from 272 to 653kg/10a, respectively within a field. The coefficient of variation also ranged from 5.9 to 22.4 %. 2) More than 90% of yield data were placed between 350 to 850kg/10a. e results indicated that the gram mass flow sensor should have the measuring range from 0.34 to 0.82kg/s considering the yields when 4 rows head-feeding combine with 0.8 m/s of working speed was utilized. 3) A high spatial dependence was found within paddy field. The Q values ranged from 0.20 to 0.97, and the range of spatial dependence was from 6.9 to 53.3m. From this result, the rational sampling interval for yield investigation was estimated 6.9m. 4) Yields within a field between observation years showed considerable variability even if the field was evenly cultivated and managed. To apply precision agriculture in a paddy field, the field test should be continued to build a solid data-base including meteorological data, blight damage and insect damage.

Determination of Dose Correction Factor for Energy and Directional Dependence of the MOSFET Dosimeter in an Anthropomorphic Phantom (인형 모의피폭체내 MOSFET 선량계의 에너지 및 방향 의존도를 고려하기 위한 선량보정인자 결정)

  • Cho, Sung-Koo;Choi, Sang-Hyoun;Na, Seong-Ho;Kim, Chan-Hyeong
    • Journal of Radiation Protection and Research
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    • v.31 no.2
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    • pp.97-104
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    • 2006
  • In recent years, the MOSFET dosimeter has been widely used in various medical applications such as dose verification in radiation therapeutic and diagnostic applications. The MOSFET dosimeter is, however, mainly made of silicon and shows some energy dependence for low energy Photons. Therefore, the MOSFET dosimeter tends to overestimate the dose for low energy scattered photons in a phantom. This study determines the correction factors to compensate these dependences of the MOSFET dosimeter in ATOM phantom. For this, we first constructed a computational model of the ATOM phantom based on the 3D CT image data of the phantom. The voxel phantom was then implemented in a Monte Carlo simulation code and used to calculate the energy spectrum of the photon field at each of the MOSFET dosimeter locations in the phantom. Finally, the correction factors were calculated based on the energy spectrum of the photon field at the dosimeter locations and the pre-determined energy and directional dependence of the MOSFET dosimeter. Our result for $^{60}Co$ and $^{137}Cs$ photon fields shows that the correction factors are distributed within the range of 0.89 and 0.97 considering all the MOSFET dosimeter locations in the phantom.

A Study on the Effect of Selection on Data Analytics by Auditor (감사인의 데이터 분석 기법 채택에 영향을 미치는 요인 연구)

  • Jung, Gwan Hoon;Lee, Jung Hoon;Kim, Da Som
    • Journal of Information Technology Applications and Management
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    • v.22 no.1
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    • pp.37-60
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    • 2015
  • As the dependence on information systems in enterprises has grown dramatically, the importance of implementing information systems in audit has been increased as well. However, there is a lact of about utilization of information system for audit process. Thus, this study is to investigate the factors that effect auditor's adopting Data Analytics to audit work. Through literature research and focus group interview, we added two factors that affect the behavioral intention to UTAUT model. We have selected performance expectancy, effort expectancy, social influence, facilitating conditions, anxiety, task fit, behavioral intention as variables and verified hypotheses based on survey questionnaires from auditors. As a result, it was found that performance expectations, social influence, task fit influenced the behavior intention. In Addition, we analyzed adding two variables, IT-related work experience and type of auditor as moderate variable. This study has an implication for companies to motivate implementation as well as activation of Data Analytics technique.

The study on dose variation due to exchange of Upper and Lower jaw in the linear accelerator (선형가속기에서 상위조리개와 하위조리개의 교환에 의한 선량 변화의 고찰)

  • Lim CK.;Kim HN.;Song KW.
    • The Journal of Korean Society for Radiation Therapy
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    • v.11 no.1
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    • pp.6-10
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    • 1999
  • The field size can be beam output, therefore MonitorUnit can be varied due to field size dependence The purpose of this study is to evaluate and compare the dose variation according to exchange of collimator The measurements were perfomed with Wellhofer dosimetry system(water phantom. ion chamber. electrometer. system controller. build up cap. etc)and two types of linear accerlerator (Mevatron KD, MevatronMX) Scatter can be affected to field size dependence and scatter correction is separated into collimator and phantom components, scatter components can affect by exchanging of collimator Measurements of collimator scatter factor(Sc) was done in air with build up cap. 1)Square field (5cm2 to 40cm2) was measured 2)and then keeping the upper jaw constant at loom and varing lower jaw from 5cm to 40cm, 3)keeping the lower jaw constant at 10cm and varing upper jaw from 5cm to 40cm Measurements of total scatter factor(Scp) was done in water at Dmax as the procedure of collimator scatter factor measurements in water Dmax The total scatter factors were obtained to the following equation(Sp=Scp/Sc) The measured data is normalized to the data of reference field size($10{\times}10$), rectangular field is inverted to equivalent field to compare three field size data As the collimator setting is varied, the output was changed In conclusion, the error was obtained small but it must be eliminated if we intend to reach the common stated goal of $5\%$ overall uncertainty in dose determination

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Dependence of solar proton events on their associated activities: CME parameters

  • Park, Jin-Hye;Moon, Yong-Jae
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.39.2-39.2
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    • 2011
  • In this study we have examined the occurrence probability of solar proton events (SEPs) and their peak fluxes depending two CME parameters, linear speed and angular width. For this we used the NOAA SPE events and their associated CME data from 1997 to 2006. As a result, the probability strongly depends on two parameters as follows. In the case of halo CME whose speed is equal to and faster than 1500km/s, 36.1% are associated with SPEs but in the case of partial halo CME ($120^{\circ}{\leq}AW$ < $359^{\circ}$) whose speed is $400{\leq}V$ < $1000km/s$, only 0.9% are associated with SPEs. When we consider only front-side CMEs, 45.3% are associated with SPEs in the first case and 1.8% are associated with them in the second case. Both of whole CME data group and front-side CME data group have similar tendencies. The probabilities are different as much as 4.9 to 23 times according to the CME speed and 1.6 to 6.5 times to the angular width. We have also examined the relationship between CME speed and proton peak flux as well as its dependence on angular width (partial halo CME and halo CME), longitude (east, center, and west) and direction parameter (< 0.4 and {\geq} 0.4). Our results show that the relationships strongly depend on longitude as well as direction parameter. In addition, the relationship using the radial CME speed based on a cone model has a higher correlation coefficient than that using the projected CME speed.

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Research on Spatial Dependence and Influencing Factors of Korean Intra-Industry Trade of Agricultural Products: From South Korea's Agricultural Trade Data

  • Lv, Hong-Qu;Huang, Chen-Yang
    • Journal of Korea Trade
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    • v.25 no.3
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    • pp.116-133
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    • 2021
  • Purpose - Intra-industry trade of agricultural products can eliminate the disadvantage of Korea's traditional agriculture and improve its lack of comparative advantage. The main purpose of this paper is to measure the level and index of intra-industry trade of Korean agricultural products and to explore the spatial dependence and spillover effect associated with this type of trade. The main factors influencing intra-agricultural trade are analyzed from two perspectives: the population and the classification of agricultural products. Design/methodology - First, the level of intra-industry trade of Korean agricultural products is measured. Second, to obtain a more accurate estimate of the influence of various factors, and based on two types of weight matrices, a spatial econometric model is constructed from two aspects: population and classification of agricultural products. The status and the factors influencing intra-industry trade are also studied. Findings - It is concluded that there is a positive spatial correlation between Korea's intra-industry trade in agricultural products and that of its trading partners. The spatial spillover effect of this type of trade is verified by using the spatial autoregressive model (SAR). Labor-intensive agricultural products are found to have a positive spillover effect on intra-industry trade, while land-intensive products do not have a significant effect. Originality/value - In this paper, the two types of agricultural products are meticulously distinguished, and the spatial effect of the intra-industry trade of agricultural products as well as the influence of various factors are analyzed. In addition, the accuracy of the estimation of the coefficients of the factors by using the spatial econometric model is higher than that of the ordinary panel data model.

Nicotine Dependence, Smoking-related Attitude, and Subjective Norms across the Stages of Change for Smoking Cessation among Adults Smokers in a Rural Area (일 농촌지역 성인흡연자의 금연변화단계별 니코틴의존도, 흡연태도, 및 주관적 규범)

  • Kim, Young-Hee;Seo, Nam-Sook;Kang, Hae-Young
    • Journal of Korean Academy of Nursing
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    • v.36 no.6
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    • pp.1023-1032
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    • 2006
  • Purpose: The purpose of this study was to identify nicotine dependence, smoking-related attitude, and subjective norms across the stages of change for smoking cessation among adult smokers in a rural area. Method: The subjects were 276 current smokers (male=243, female=33). There were 3 stages of change for smoking cessation: pre-contemplation, contemplation, and preparation stage. Data was collected by an interview or self-reporting from February 12th to March 5th 2004, and analyzed with frequency, percentage, $X^2-test$, Fisher's exact probability test, ANOVA, and Scheffe test using the SPSS-PC program. Result: According to the stages of change, 114(41.3%) current smokers were in pre-contemplation, 110(39.9%) in contemplation, and 52(18.8%) in the preparation stage. There was a higher percentage of males than females ($X^2-test$=8.99, p=.011) in the preparation stage. The mean score of the smoking-related attitude (F:7.43, p=.001) and subjective norm(F=27.41, p=.001) were both lowest in the pre-contemplation stage and increased positively during the stages of change for smoking cessation. Conclusion: Based on these findings, the authors recommend that community-based smoking cessation programs should be developed by considering the intention or motives of current smokers and should be initiated in the preparation stage and primarily for male groups.

The Influence of Adolescents' Temperament on Subjective Well-Being: the Mediating Effect of Perceived Parenting Affective Attitude (청소년의 기질이 주관적 안녕감에 미치는 영향 : 애정적 양육태도의 매개효과를 중심으로)

  • Yun, Kyoung-Hee;Lee, Sook
    • The Korean Journal of Community Living Science
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    • v.27 no.4
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    • pp.803-815
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    • 2016
  • The purpose of this study is to increase our understanding of subjective well-being in adolescents and to help improve it by investigating the relationship among adolescents' temperaments, perceived parenting affective attitude and subjective well-being. For this study, the subjects were 354 students from 4 different middle schools in Gwang-ju, Korea. The statistical analysis of the data was conducted by means of the SPSS 21.0 program using Pearson's correlations and hierarchical regression. The results are as follows: First, the temperament and perceived parenting affective attitude were correlated with subjective well-being. Among the temperament traits, novelty seeking and harm avoidance showed negative correlations with subjective well-being, whereas affection, reward dependence and persistence showed positive correlations with subjective well-being. Second, after the mediating effect of perceived affection on subjective well-being was confirmed, three temperament traits, viz. harm avoidance, reward dependence, and persistence, were identified as mediating factors. The conclusion of this study is that adolescents' temperament and perceived parenting affective attitude are related to their subjective well-being and can also predict their subjective well-being. Harm avoidance, reward dependence, and persistence, which are inborn temperaments, affect subjective well-being. Affection, which is a perceived parenting affective attitude trait, affects subjective well-being as a mediation variable. This study also suggests that it is more effective to influence perceived parenting affective attitude, which has growth potential, rather than temperaments which are hard to change.