• Title/Summary/Keyword: Probability and statistics

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Features of Patients Associated with Falls from Heights Admitted to Republican Research Center of Emergency Medicine (우즈베키스탄 국립응급병원에 내원한 낙상환자들의 임상적인 특성)

  • Khadjibaev, Abdukhakim Muminovich;Sultanov, Pulat Karimovich;Kim, Hoon
    • Journal of Trauma and Injury
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    • v.28 no.4
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    • pp.248-255
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    • 2015
  • Purpose: study of the mutual influence of the individual anatomical regions damage in patients associated with falls from heights. Methods: 561 medical reports of patients associated with falls from heights admitted to Republican Research Center of Emergency Medicine (RRCEM), in period of 2010-2013 yy, were analyzed retrospectively. Patient's age range was from 15 to 89. Treatment of these patients held in three stages: period of acute disorders of vital functions; relative stabilization period; stabilization of vital functions. The scope and content of medical diagnostic procedures performed on pre-hospital and intensive care stages. The severity of each injury was scored according to the AIS scale, the total severity of lesions was scored by points due to ISS. Digital material is treated by methods of mathematical statistics. Results: Falls from heights leads to associated injuries for 4 times more than isolated trauma, and increases according to height of fall and falling surface. Patients with TBI+chest trauma, are most serious contingent that has highest mortality and complications (36.8%). TBI+musculoskeletal system trauma are characterized by high blood loss, traumatic shock and fat embolism, forming a vicious circle. Conclusion: in patients associated with falls from heights clinical manifestations of injuries mutual aggravation syndrome will be seen. TBI leads to complication of chest trauma, delayed diagnostics of abdominal and chest trauma, aggravation of coma condition. Developing of high blood loss and fat embolism in musculoskeletal system trauma leads to shock and pulmonary embolism, which increases probability of death in the presence of abdominal or chest trauma, but abdominal trauma or chest trauma has no significant effect on the severity of the musculoskeletal system trauma.

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A Study on the Prediction of Power Consumption in the Air-Conditioning System by Using the Gaussian Process (정규 확률과정을 사용한 공조 시스템의 전력 소모량 예측에 관한 연구)

  • Lee, Chang-Yong;Song, Gensoo;Kim, Jinho
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.1
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    • pp.64-72
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    • 2016
  • In this paper, we utilize a Gaussian process to predict the power consumption in the air-conditioning system. As the power consumption in the air-conditioning system takes a form of a time-series and the prediction of the power consumption becomes very important from the perspective of the efficient energy management, it is worth to investigate the time-series model for the prediction of the power consumption. To this end, we apply the Gaussian process to predict the power consumption, in which the Gaussian process provides a prior probability to every possible function and higher probabilities are given to functions that are more likely consistent with the empirical data. We also discuss how to estimate the hyper-parameters, which are parameters in the covariance function of the Gaussian process model. We estimated the hyper-parameters with two different methods (marginal likelihood and leave-one-out cross validation) and obtained a model that pertinently describes the data and the results are more or less independent of the estimation method of hyper-parameters. We validated the prediction results by the error analysis of the mean relative error and the mean absolute error. The mean relative error analysis showed that about 3.4% of the predicted value came from the error, and the mean absolute error analysis confirmed that the error in within the standard deviation of the predicted value. We also adopt the non-parametric Wilcoxon's sign-rank test to assess the fitness of the proposed model and found that the null hypothesis of uniformity was accepted under the significance level of 5%. These results can be applied to a more elaborate control of the power consumption in the air-conditioning system.

Analysis of the Quantity and Quality of the Contents of Junior High School Mathematics Curriculum and Textbooks (중학교 수학 교육과정 및 교과서 내용의 양과 난이도 수준 분석)

  • 박경미
    • Journal of Educational Research in Mathematics
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    • v.10 no.1
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    • pp.35-55
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    • 2000
  • There seems to be a public consensus that the content of Korean mathematics textbooks is extensive and of a high level of difficulty. However, such judgment is the result of a generalization based on individual experience or on the results from comparisons of the international levels of achievement. Therefore, a more objective and stricter approach to the determination of the quantity and level of difficulty of mathematics content is necessary. For this purpose, this study has compared the content of Koreas 6th and 7th junior high school curriculums, and the Korean mathematics curriculum to textbooks of the United States, which has a considerable influence on the making of Korean mathematics textbooks. First of all, a comparison of Koreas 6th and 7th junior high school mathematics curriculums showed a slight reduction in the total quantity of content, as more content was deleted than was added in the 7th curriculum. However, given the fact that the number of hours of mathematics classes has been reduced, the reduction in content cannot be regarded as anything more than a simple reflection of the reduction in hours, proving that the 7th curriculum has not met its revision objective of reducing the content by 30%. Meanwhile, the comparison of the United States junior high school mathematics textbooks to Korea's 7th curriculum showed that the 7th grade content in the United States was much broader, encompassing content which in Korea ranged from the 2nd grade of elementary school to the 2nd year of junior high school. Therefore, on the surface, it may appear that the overall level of content in the American mathematics textbook is lower than that of the Korean. However, there are several cafes, such as statistics and probability, where certain content was more difficult and introduced at an earlier grade in the United States than in Korea. In fact, it can be said that Korea students tend to find content of the mathematics textbooks to be harder than they actually are because they are delivered as a mere aggregate of algorithms, with little consideration to its application in their everyday lives. In this respect, there is much room for improvement on the mathematics textbooks of Korea.

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An Analysis of the Gender Difference in National Assessment of Educational Achievement of Mathematics (수학과 국가수준 학업성취도 평가에서의 성별 차이 분석)

  • Ko, Jung-Hwa;Do, Jong-Hoon;Song, Mi-Young
    • Journal of Educational Research in Mathematics
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    • v.18 no.2
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    • pp.179-200
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    • 2008
  • In this paper, we analyzed the characteristics of the gender difference with the results of National Assessment of Educational Achievement(NAEA) from 2004 to 2006, which subjects are 3rd, 9th and 10th graders. First, we analyzed the characteristics of the achievement by the scale scores, according to years, achievement standards, grades. Second, we surveyed the number of items and ratio which male/female prevails and its characteristics according to grades, difference levels, content areas(i.e., numbers and operations, figures, measurement, probability and statistics, letters and formulas, patterns and function). Furthermore, we perform in-depth analysis of the items which gender difference in correct response proportion is more than 7% and analyze the cause of gender difference of achievement. This paper provides large valid data about gender difference by the results of NAEA. It can give suggestions with regard to policy making.

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Device Personalization Methods for Enhancing Packet Delay in Small-cells based Internet of Things (스몰셀 기반 사물인터넷에서 패킷 지연시간 향상을 위한 디바이스 개인화 방법)

  • Lee, ByungBog;Han, Wang Seok;Kim, Se-Jin
    • Journal of Internet Computing and Services
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    • v.17 no.6
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    • pp.25-31
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    • 2016
  • Recently, with greatly improving the wireless communication technology, new services are created using smart sensors, i.e., machine-to-machine (M2M) and Internet of Things (IoT). In this paper, we propose a novel IoT device (IoTD) personalization method that adopt Small-cell Access Points (SAPs) to control IoTDs using user equipments (UEs), e.g., smart phones and tablet PC, from service users. First, we introduce a system architecture that consists of UE, IoTD, and SAP and propose the IoTD personalization method with two procedures, i.e., IoTD profile registration procedure and IoTD control procedure. Finally, through simulations, we evaluated the system performance of the proposed scheme and it is shown that the proposed scheme outperforms the conventional scheme in terms of the packet delay, packet loss probability, and normalized throughput.

Quantification of future climate uncertainty over South Korea using eather generator and GCM

  • Tanveer, Muhammad Ejaz;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.154-154
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    • 2018
  • To interpret the climate projections for the future as well as present, recognition of the consequences of the climate internal variability and quantification its uncertainty play a vital role. The Korean Peninsula belongs to the Far East Asian Monsoon region and its rainfall characteristics are very complex from time and space perspective. Its internal variability is expected to be large, but this variability has not been completely investigated to date especially using models of high temporal resolutions. Due to coarse spatial and temporal resolutions of General Circulation Models (GCM) projections, several studies adopted dynamic and statistical downscaling approaches to infer meterological forcing from climate change projections at local spatial scales and fine temporal resolutions. In this study, stochastic downscaling methodology was adopted to downscale daily GCM resolutions to hourly time scale using an hourly weather generator, the Advanced WEather GENerator (AWE-GEN). After extracting factors of change from the GCM realizations, these were applied to the climatic statistics inferred from historical observations to re-evaluate parameters of the weather generator. The re-parameterized generator yields hourly time series which can be considered to be representative of future climate conditions. Further, 30 ensemble members of hourly precipitation were generated for each selected station to quantify uncertainty. Spatial map was generated to visualize as separated zones formed through K-means cluster algorithm which region is more inconsistent as compared to the climatological norm or in which region the probability of occurrence of the extremes event is high. The results showed that the stations located near the coastal regions are more uncertain as compared to inland regions. Such information will be ultimately helpful for planning future adaptation and mitigation measures against extreme events.

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Estimation of Attributes Affecting University Students to Select the Pizza Restaurant by Gender (성별에 따른 대학생의 피자전문점 선택에 영향을 미치는 속성 평가)

  • Kang, Jong-Heon;Jeong, In-Suk
    • Journal of the Korean Society of Food Culture
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    • v.21 no.1
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    • pp.57-64
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    • 2006
  • The purpose of this study was to measure the pizza purchasing behavioral characteristics of respondents and importances of factors affecting pizza purchase, to estimate the effects of attributes on pizza restaurant choice, and to predict probability of selecting a particular pizza restaurant. The questionnaire consisted of two parts: The paired experimental profiles, purchasing behavior and importances of factors affecting pizza purchase. This study generated profiles of 16 hypothetical pizza restaurant based on the seven attributes. The profiles comprised 16 discrete sets of variables, each of which had two levels. For this study, researcher randomly selected 150 students of university as respondents. Twenty students did not complete the survey instrument, resulting in a final sample size of 129. All estimations were carried out using frequencies, $X^2$, independent samples t-test, phreg procedure of SAS package. The results are as follows. Some purchasing behavioral characteristics and importances of factors affecting pizza purchase were significantly different by gender. Based on the estimated models developed for male student group and female student group, the Chi-square statistics were significant at p<0.001. The parameter estimate for late delivery time with male student group was highest, and the parameter estimate for price with female student group was highest. The pizza restaurant that charged \20,000, offered 100% discount on eleventh pizza, promised to deliver pizza in 40 mins, usually delivered the pizza as promised time, offered only 1 type of pizza crust, delivered warm pizza, offered the money-back guarantee was favored by each of male student group and female student group. The results from this study suggested that there was an opportunity to increase market share and profit by improving operations so that customers receive discount and money-back guarantee simultaneously, and by reducing price, delivery time.

Reproducibility of Hypothesis Testing and Confidence Interval (가설검정과 신뢰구간의 재현성)

  • Huh, Myung-Hoe
    • The Korean Journal of Applied Statistics
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    • v.27 no.4
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    • pp.645-653
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    • 2014
  • P-value is the probability of observing a current sample and possibly other samples departing equally or more extremely from the null hypothesis toward postulated alternative hypothesis. When p-value is less than a certain level called ${\alpha}$(= 0:05), researchers claim that the alternative hypothesis is supported empirically. Unfortunately, some findings discovered in that way are not reproducible, partly because the p-value itself is a statistic vulnerable to random variation. Boos and Stefanski (2011) suggests calculating the upper limit of p-value in hypothesis testing, using a bootstrap predictive distribution. To determine the sample size of a replication study, this study proposes thought experiments by simulating boosted bootstrap samples of different sizes from given observations. The method is illustrated for the cases of two-group comparison and multiple linear regression. This study also addresses the reproducibility of the points in the given 95% confidence interval. Numerical examples show that the center point is covered by 95% confidence intervals generated from bootstrap resamples. However, end points are covered with a 50% chance. Hence this study draws the graph of the reproducibility rate for each parameter in the confidence interval.

A Study of Service Quality and Identity on Professional Sports for Promoting Licensing Product Intentions (라이센스 제품의 구매 촉진을 위한 프로 스포츠 서비스 품질과 동일시에 관한 연구)

  • Park, Bae Jin;Park, Sun Young
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.11 no.3
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    • pp.189-197
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    • 2016
  • This study is aimed at providing basic data necessary for promoting consumption of professional sports licensing in the industry through service quality. Specifically, the current study examines the effects of service quality and licensing product intentions on professional sports and evaluates the moderating identity. For this study, we distributed a total of 480 questionnaires to those sampled through non-probability sampling from people living in small and medium cities including Seoul. Collected data were coded and entered into the computer, and statistically processed using SPSS Statistics 18 The results were as follow: First, service quality of professional sports significantly effect on licensing product intentions, but identity could not effect on licensing product intentions. Second, Identity as a moderating variable has significantly positive effect on the relationship between star player of service quality and Licensing Product Intentions. In conclusion, the companies that participate as title sponsors in professional sports were proven to promotion their licensing product intentions, as identified with sports fans through service quality of professional sports such as record, attractiveness, star player and locally affiliated.

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An Analysis on the Competence and the Methods of Problem Solving of Children at the Before of School Age in Four Operations Word Problems (학령 전 아이들의 사칙연산 문장제 해결 능력과 방법 분석)

  • Lee, Dae-Hyun
    • Journal of the Korean School Mathematics Society
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    • v.13 no.3
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    • pp.381-395
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    • 2010
  • The purpose of this paper is to examine the competence and the methods of problem solving in four operations word problems based on the informal knowledges by five-year-old children. The numbers which are contained in problems consist of the numbers bigger than 5 and smaller than 10. The subjects were 21 five-year-old children who didn't learn four operations. The interview with observation was used in this research. Researcher gave the various materials to children and permitted to use them for problem solving. And researcher read the word problems to children and children solved the problems. The results are as follows: five-year-old children have the competence of problem solving in four operations word problems. They used mental computation or counting all materials strategy in addition problem. The methods of problem solving were similar to that of addition in subtraction, multiplication and division, but the rate of success was different. Children performed poor1y in division word problems. According to this research, we know that kindergarten educators should be interested in children's informal knowledges of four operations including shapes, patterns, statistics and probability. For this, it is needed to developed the curriculum and programs for informal mathematical experiences.

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