• Title/Summary/Keyword: probability.statistics

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A Study on Fire Data Analysis in Korea, Japan and USA(3) Deaths and Injuries Due to Fires (한국$\cdot$일본$\cdot$미국의 화재발생실태에 대한 비교분석(3) 화재로 인한 인명피해)

  • Lee Eui-Pyeong
    • Fire Science and Engineering
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    • v.19 no.1 s.57
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    • pp.1-19
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    • 2005
  • The following matters were confirmed through the analysis of casualties due to fires in Korea, Japan, and the U.S. in this paper. 1 Korean statistics are not the most detailed of the three countries about casualties due to fires, so we need to have detailed statistics of them on casualties more. 2. Korean deaths are the lowest by 10-11 people due to fires per one million of population. Those of Japan are 15-17 and about 12 people in the U.S.; decreased about 2/3 only for a quarter of a century. 3. Korean deaths are on the decrease about 1.5 people per 100 cases due to fires,3.5 in Japan and 0.2-0.3 in the U.S. Likewise, Korean injuries are on the decrease per 100 cases due to fires From 14.9 in 1977 to 5.1 in 2001 and 5.3 in 2002. In the U.S., the figure was 1.0-1.6. but after the year 1994, it was 1.2 or so. It tends to some increase to 2.6-2.8 in Japan. Therefore, when fires are happened, the death probability is the highest in Japan and 15 times higher than that of the U.S. The injury probability is the highest in Korea and 5 times higher than that of the U.S. 4. Fire deaths rate is the highest in the U.S. about $80\%$ due to home fires (including apartments) among all deaths. Japan tends to decrease of $55\%$. Recently, in case of Korea. it is similar level to that of Japan. 5. Korean aged people of 65 years old and over exceeded by $7\%$ in 2000 and entered an aging society, so It Is time to Investigate and take effect policies to reduce the death of the aged . Japan has ahead a super-aged society that exceeds $20\%$ of the people over the age 65, and many of them die of fire. Consequently, Japan has taken effect policies to reduce deaths from 10 years or more than before. Therefore, it is a good proposal to analyze the policies of Japan deeply and study introduction of them.

Features of sample concepts in the probability and statistics chapters of Korean mathematics textbooks of grades 1-12 (초.중.고등학교 확률과 통계 단원에 나타난 표본개념에 대한 분석)

  • Lee, Young-Ha;Shin, Sou-Yeong
    • Journal of Educational Research in Mathematics
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    • v.21 no.4
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    • pp.327-344
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    • 2011
  • This study is the first step for us toward improving high school students' capability of statistical inferences, such as obtaining and interpreting the confidence interval on the population mean that is currently learned in high school. We suggest 5 underlying concepts of 'discretion of contingency and inevitability', 'discretion of induction and deduction', 'likelihood principle', 'variability of a statistic' and 'statistical model', those are necessary to appreciate statistical inferences as a reliable arguing tools in spite of its occasional erroneous conclusions. We assume those 5 concepts above are to be gradually developing in their school periods and Korean mathematics textbooks of grades 1-12 were analyzed. Followings were found. For the right choice of solving methodology of the given problem, no elementary textbook but a few high school textbooks describe its difference between the contingent circumstance and the inevitable one. Formal definitions of population and sample are not introduced until high school grades, so that the developments of critical thoughts on the reliability of inductive reasoning could not be observed. On the contrary of it, strong emphasis lies on the calculation stuff of the sample data without any inference on the population prospective based upon the sample. Instead of the representative properties of a random sample, more emphasis lies on how to get a random sample. As a result of it, the fact that 'the random variability of the value of a statistic which is calculated from the sample ought to be inherited from the randomness of the sample' could neither be noticed nor be explained as well. No comparative descriptions on the statistical inferences against the mathematical(deductive) reasoning were found. Few explanations on the likelihood principle and its probabilistic applications in accordance with students' cognitive developmental growth were found. It was hard to find the explanation of a random variability of statistics and on the existence of its sampling distribution. It is worthwhile to explain it because, nevertheless obtaining the sampling distribution of a particular statistic, like a sample mean, is a very difficult job, mere noticing its existence may cause a drastic change of understanding in a statistical inference.

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Development of Conformal Radiotherapy with Respiratory Gate Device (호흡주기에 따른 방사선입체조형치료법의 개발)

  • Chu Sung Sil;Cho Kwang Hwan;Lee Chang Geol;Suh Chang Ok
    • Radiation Oncology Journal
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    • v.20 no.1
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    • pp.41-52
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    • 2002
  • Purpose : 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device (RGRD) for using during CT simulation, dose planning and beam delivery at identical breathing period conditions. Using RGRD, reducing the treatment margin for organ (thorax or abdomen) motion due to breathing and improve dose distribution for 3D conformal radiotherapy. Materials and Methods : The internal organ motion data for lung cancer patients were obtained by examining the diaphragm in the supine position to find the position dependency. We made a respiratory gating radiotherapy device (RGRD) that is composed of a strip band, drug sensor, micro switch, and a connected on-off switch in a LINAC control box. During same breathing period by RGRD, spiral CT scan, virtual simulation, and 3D dose planing for lung cancer patients were peformed, without an extended PTV margin for free breathing, and then the dose was delivered at the same positions. We calculated effective volumes and normal tissue complication probabilities (NTCP) using dose volume histograms for normal lung, and analyzed changes in doses associated with selected NTCP levels and tumor control probabilities (TCP) at these new dose levels. The effects of 3D conformal radiotherapy by RGRD were evaluated with DVH (Dose Volume Histogram), TCP, NTCP and dose statistics. Results : The average movement of a diaphragm was 1.5 cm in the supine position when patients breathed freely. Depending on the location of the tumor, the magnitude of the PTV margin needs to be extended from 1 cm to 3 cm, which can greatly increase normal tissue irradiation, and hence, results in increase of the normal tissue complications probabiliy. Simple and precise RGRD is very easy to setup on patients and is sensitive to length variation (+2 mm), it also delivers on-off information to patients and the LINAC machine. We evaluated the treatment plans of patients who had received conformal partial organ lung irradiation for the treatment of thorax malignancies. Using RGRD, the PTV margin by free breathing can be reduced about 2 cm for moving organs by breathing. TCP values are almost the same values $(4\~5\%\;increased)$ for lung cancer regardless of increasing the PTV margin to 2.0 cm but NTCP values are rapidly increased $(50\~70\%\;increased)$ for upon extending PTV margins by 2.0 cm. Conclusion : Internal organ motion due to breathing can be reduced effectively using our simple RGRD. This method can be used in clinical treatments to reduce organ motion induced margin, thereby reducing normal tissue irradiation. Using treatment planning software, the dose to normal tissues was analyzed by comparing dose statistics with and without RGRD. Potential benefits of radiotherapy derived from reduction or elimination of planning target volume (PTV) margins associated with patient breathing through the evaluation of the lung cancer patients treated with 3D conformal radiotherapy.

The Benefit of Individualized Custom Bolus in the Postmastectomy Radiation Therapy : Numerical Analysis with 3-D Treatment Planning (유방전절제술 후 방사선치료를 위한 조직보상체 개발 및 3차원 치료계획을 통한 유용성 분석)

  • Cho Jae Ho;Cho Kwang Hwan;Keum Kichang;Han Yongyih;Kim Yong Bae;Chu Sung Sil;Suh Chang Ok
    • Radiation Oncology Journal
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    • v.21 no.1
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    • pp.82-93
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    • 2003
  • Purpose : To reduce the Irradiation dose to the lungs and heart in the case of chest wail irradiation using an oppositional electron beam, we used an Individualized custom bolus, which was precisely designed to compensate for the differences In chest wall thickness. The benefits were evaluated by comparing the normal tissue complication probablilties (NTCPS) and dose statistics both with and without boluses. Materials and Methods : Boluses were made, and their effects evaluated in ten patients treated using the reverse hockey-stick technique. The electron beam energy was determined so as to administer 80% of the irradiation prescription dose to the deepest lung-chest wall border, which was usually located at the internal mammary lymph node chain. An individualized custom bolus was prepared to compensate for a chest wall thinner than the prescription depth by meticulously measuring the chest wall thickness at 1 emf intervals on the planning CT Images. A second planning CT was obtained overlying the individuailzed custom bolus for each patient's chest wall. 3-D treatment planning was peformed using ADAC-Pinnacle$^{3}$ for all patients with and without bolus. NTCPS based on 'the Lyman-Kutcher' model were analyzed and the mean, maximum, minimum doses, V$_{50}$ and V$_{95}$ for 4he heari and lungs were computed. Results .The average NTCPS in the ipsliateral lung showed a statistically significant reduction (p<0.01), from 80.2${\pm}$3.43% to 47.7${\pm}$4.61%, with the use of the individualized custom boluses. The mean lung irradiation dose to the ipsilateral iung was also significantly reduced by about 430 cGy, Trom 2757 cGy to 2,327 cGy (p<0.01). The V$_{50}$ and V$_{95}$ in the ipsilateral lung markedly decreased from the averages of 54.5 and 17.4% to 45.3 and 11.0%, respectively. The V$_{50}$ and V$_{95}$ In the heart also decreased from the averages of 16.8 and 6.1% to 9.8% and 2.2%, respectively. The NTCP In the contralateral lung and the heart were 0%, even for the cases with no bolus because of the small effective mean radiation volume values of 4.4 and 7.1%, respectively Conclusion : The use of an Individualized custom bolus in the radiotherapy of postrnastectorny chest wall reduced the NTCP of the ipsilateral lung by about 24.5 to 40.5%, which can improve the complication free cure probability of breast cancer patients.

Recommendation and current status in exposure assessment using monitoring data in ship building industry - focused on the similar exposure group(SEG) (조선업의 작업환경측정결과를 이용한 노출평가의 문제점과 해결방향 - 유사노출군을 중심으로 -)

  • Roh, Youngman;Yim, Hyeon Woo;Kim, Suk Il;Park, Hyo Man;Jung, Jae Yeol;Park, Sook Kyung;Kim, Hyun-Wook;Chung, Chee Kyung;Lee, Won Chul;Kim, Jung Man;Kim, Soo Keun;Koh, Sang Baek;Karl, Sieber;Kim, Euna;Choi, Jung Keun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.11 no.2
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    • pp.126-134
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    • 2001
  • Statistical approaches for analysis of data from the limited number of samples in ship building industry(SBI) collected by an industrial hygienist for checking compliance to an occupational standard were considered. Sampling for compliance usually has been guided by judgment selection, rather than true randomness, resulting in the creation of compliance samples which approximate a censored sample from the upper tail of the exposure distribution. Similar exposure groups(SEGs) including welding and painting process were established to assess representative values in each groups after reviewing the whole production line in SBI. For the convenient statistical approaches, the code has assigned to each SEGs. The descriptive statistics and probability plotting were used to yield the representative values in each SEGs. In the first step, SEGs of 558 were established from 5 ship building companies. The 38 SEGs showed the uncertainty are divided into each 5 companies and assessed the representative values again. The 44 SEGs in each companies was not showed the normal and lognormal distribution was analyzed each data. And also, recommendation was suggested to resolve the uncertainty in each groups.

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Medication Errors in Chemotherapy Preparation and Administration: a Survey Conducted among Oncology Nurses in Turkey

  • Ulas, Arife;Silay, Kamile;Akinci, Sema;Dede, Didem Sener;Akinci, Muhammed Bulent;Sendur, Mehmet Ali Nahit;Cubukcu, Erdem;Coskun, Hasan Senol;Degirmenci, Mustafa;Utkan, Gungor;Ozdemir, Nuriye;Isikdogan, Abdurrahman;Buyukcelik, Abdullah;Inanc, Mevlude;Bilici, Ahmet;Odabasi, Hatice;Cihan, Sener;Avci, Nilufer;Yalcin, Bulent
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1699-1705
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    • 2015
  • Background: Medication errors in oncology may cause severe clinical problems due to low therapeutic indices and high toxicity of chemotherapeutic agents. We aimed to investigate unintentional medication errors and underlying factors during chemotherapy preparation and administration based on a systematic survey conducted to reflect oncology nurses experience. Materials and Methods: This study was conducted in 18 adult chemotherapy units with volunteer participation of 206 nurses. A survey developed by primary investigators and medication errors (MAEs) defined preventable errors during prescription of medication, ordering, preparation or administration. The survey consisted of 4 parts: demographic features of nurses; workload of chemotherapy units; errors and their estimated monthly number during chemotherapy preparation and administration; and evaluation of the possible factors responsible from ME. The survey was conducted by face to face interview and data analyses were performed with descriptive statistics. Chi-square or Fisher exact tests were used for a comparative analysis of categorical data. Results: Some 83.4% of the 210 nurses reported one or more than one error during chemotherapy preparation and administration. Prescribing or ordering wrong doses by physicians (65.7%) and noncompliance with administration sequences during chemotherapy administration (50.5%) were the most common errors. The most common estimated average monthly error was not following the administration sequence of the chemotherapeutic agents (4.1 times/month, range 1-20). The most important underlying reasons for medication errors were heavy workload (49.7%) and insufficient number of staff (36.5%). Conclusions: Our findings suggest that the probability of medication error is very high during chemotherapy preparation and administration, the most common involving prescribing and ordering errors. Further studies must address the strategies to minimize medication error in chemotherapy receiving patients, determine sufficient protective measures and establishing multistep control mechanisms.

Improvements and Enhancements to the Direction of Current Elementary Mathematics Textbooks (현행 초등 수학 교과서에 대한 개선점과 개선 방향)

  • Ahn, Byoung Gon
    • Journal of Elementary Mathematics Education in Korea
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    • v.19 no.3
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    • pp.289-304
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    • 2015
  • In this study, connections between the NURI curriculum for 5 years old children and the contents of teacher's manual books according to it and the contents of elementary 1st grade mathematics curriculum and textbooks was analyzed to find the implications that can help to link the two curricula in the development of kindergarten and elementary school mathematics curriculum. The five following implications could be obtained from the analysis. First, it is necessary to connect the contents of the NURI curriculum for 5 years old children which were completed in that curriculum like 'spatial relation'in geometric figure domain and 'data collection'in probability and statistics domain to the contents of the 1st grade curriculum. Second, in the case of the contents not connected between the NURI curriculum for 5 years old children and the contents of elementary 1st grade mathematics curriculum but connected between the NURI curriculum for 5 years old children and the contents of elementary 2nd ~6th grade mathematics curriculum, it is necessary to re-adjust the hierarchy based on one of the curricula. Third, it is necessary to check whether $\ll$K-teacher's manual book$\gg$ obey the NURI curriculum for 5 years old children or not. Fourth, it is necessary to review the related elements of the NURI curriculum for 5 years old children and elementary 2nd ~6th grade mathematics curriculum in [activity] in $\ll$K-teacher's manual book$\gg$. Fifth, it is necessary to handle the mathematics contents explicitly and systematically in [activity] in $\ll$K-teacher's manual book$\gg$.

A study on the optimal variable transformation method to identify the correlation between ATP and APC (ATP와 APC 간의 관련성 규명을 위한 최적의 변수변환법에 관한 연구)

  • Moon, Hye-Kyung;Shin, Jae-Kyoung;Kim, Yang Sook
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.6
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    • pp.1465-1475
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    • 2016
  • In order to secure safe meals, the hazards of microorganisms associated with food poisoning accident should be monitored and controlled in real situations. It is necessary to determined the correlation between existing common bacteria number (aerobic plate count; APC) and RLU (relative light unit) in cookware. In this paper, we investigate the correlation between ATP (RUL) and APC (CFU) by using three types of transform (inverse, square root, log transforms) of raw data in two steps. Among these transforms, the log transform at the first step has been found to be optimal for the data of cutting board, knife, soup bowl (stainless), and tray (carbon). The square root-inverse and the square root-square root transform at the second step have been shown to be optimal respectively for the cup and for the soup bowl (carbon) data.

Comparison of Principal Component Regression and Nonparametric Multivariate Trend Test for Multivariate Linkage (다변량 형질의 유전연관성에 대한 주성분을 이용한 회귀방법와 다변량 비모수 추세검정법의 비교)

  • Kim, Su-Young;Song, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.21 no.1
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    • pp.19-33
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    • 2008
  • Linear regression method, proposed by Haseman and Elston(1972), for detecting linkage to a quantitative trait of sib pairs is a linkage testing method for a single locus and a single trait. However, multivariate methods for detecting linkage are needed, when information from each of several traits that are affected by the same major gene are available on each individual. Amos et al. (1990) extended the regression method of Haseman and Elston(1972) to incorporate observations of two or more traits by estimating the principal component linear function that results in the strongest correlation between the squared pair differences in the trait measurements and identity by descent at a marker locus. But, it is impossible to control the probability of type I errors with this method at present, since the exact distribution of the statistic that they use is yet unknown. In this paper, we propose a multivariate nonparametric trend test for detecting linkage to multiple traits. We compared with a simulation study the efficiencies of multivariate nonparametric trend test with those of the method developed by Amos et al. (1990) for quantitative traits data. For multivariate nonparametric trend test, the results of the simulation study reveal that the Type I error rates are close to the predetermined significance levels, and have in general high powers.

An Analysis of the Relationship Between Resettlement and Housing Redevelopment Characteristics (주택재개발사업 특성이 재입주에 미치는 영향)

  • Ko Duk Kyun;Kim Hong-Kyu
    • Journal of the Korean housing association
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    • v.16 no.3
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    • pp.101-107
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    • 2005
  • The reason that compulsory removals of a low-quality housing redevelopment such as involuntary or unintentional migration present a problem for urban communities is that whether involuntary movers adapt themselves to their new home has an influence on the urban communities that surround them. Moreover, involuntary emigrants have higher probability of choosing faulty residential areas than voluntary emigrants do. This gives rise to a problem of another residential migration for involuntary movers. In order to solve these problems, there is a need for a new housing policy that enables original residents to come back to their old community. However studies for resettlement had not conducted subjects about housing redevelopment characteristics which influences the involuntary movers directly. Instead personal microscopic characteristics such as statistics of resettlement, the moving distance, the reason of moving, improvement of living environment, had been main subjects of farmer studies. So the purpose of this study is to analyze an analysis of the relationship between resettlement and housing redevelopment characteristics. The data used in this study was obtained at 47 areas designated by Seoul (metropolis) since 1990 for redevelopment. Cluster Analysis Is used for dividing high rate of resettlement with low rate of resettlement and Regression Analysis is used for the analysis of the relationship between resettlement and housing redevelopment characteristics. The results of examining the effects of a redeveloped housing complex on returning residents at 47 areas designated by Seoul (metropolis) since 1990 fur redevelopment are as follows: First, A housing complex with a high returning rate (remove-in rate?) has no state/public land, unauthorized building owners who are in the low-income brackets, and few interested parties such as union members. This is the characteristic of a redeveloped housing complex with a short-period project span. On the contrary, a housing complex that has a low returning rate is crowded by state/public land, and numerous unauthorized building owners, and interested parties. Second, According to the linear regression analysis, among the factors that affect returning residents, 'physical properties(characteristics) of a region', 'population properties within a region', and 'properties of a project span' indicate a negative(-)influence whereas 'properties of a complex density' shows a positive(+) influence. In a nutshell, the more the physical properties, population properties, projectspan properties, the lower the returning rate and the more the complex density properties, the higher the returning rate. In detail, an area with many small land and new/large buildings, a high population, and a long project duration has a low returning rate of original residents while an area holding large capacity and buildings with many number of floors (multiple-storied building) has a high returning rate.