• Title/Summary/Keyword: Gap Statistic

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The Effects on Earth Science Concepts about Seasonal Changes by Generative Learning Strategy (발생학습 전략의 적용이 계절변화 관련 지구과학개념 변화에 미친 효과)

  • Jeong, Jin-Woo;Yoon, Sang-Wha;Lee, Hang-Ro
    • Journal of the Korean earth science society
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    • v.24 no.3
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    • pp.160-171
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    • 2003
  • This study was designed to analyze the types of concepts about earth science related to seasonal changes, so as to develop a generative learning model focused on dissolving cognitive conflicts between the aforementioned concepts through debates and using said debates to find out how effectively the model works. There are 100 types of earth science concepts concering seasonal changes, 66 of which are unscientific in nature, including misconceptions. Through a second field trial and a research and development (R&D) process, a test on these concepts was developed, consisting of 14 items. For the experimental group, a four-phase generative learning strategy that reflects the types of earth science concepts and cognitive conflicts between such concepts was developed through pre-analysis and discussion, respectively. On the other hand, a traditional teaching and teaming strategy was used for the control group. A meaningful statistic gap found between the two groups through a covariance analysis, the significance level of which was 0.05. This result may be interpreted to mean that the generative teaming strategy is a possible alternative for correcting misconceptions about scientific concepts of seasonal changes.

A Note for 1.5σ Shift of Six Sigma (식스시그마의 1.5σ 이동에 대한 소고)

  • Park, Jong Hun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.45 no.1
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    • pp.31-40
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    • 2022
  • Six Sigma is a philosophy and systematic methodology for quality improvement. It encourages continuous quality improvement efforts to achieve the ideal goal of 6σ. Sigma(σ) is a statistic representing the standard deviation of the normal distribution, and 6σ level means a level where the tolerance of the specification is six times the standard deviation of the process distribution. In terms of the defective rate, the 6σ level achieves the 0.002 defectives per one million units. However, in the field, the 6σ level is used in the sense of achieving 3.4 defects per one million opportunities, which shows a large gap from the 6σ level in the statistical viewpoint. This is because field practitioners accept a 1.5σ shift of the mean of process when calculating the defective rate under sigma level. It said that the acceptance of 1.5σ shift of the mean is from experience, but there is no research or theoretical explanation to support it logically. Although it is a non-scientific explanation based on experience, considering that there has been no objection to the 1.5σ shift for a long time and it is rather accepted, it is judged that there is a reasonable basis for the 1.5σ shift. Therefore, this study tries to find a reasonable explanation through detective power of control chart via the run-rules to the 1.5σ shift empirically recognized by practitioners.

High Incidence of Hiatal Hernia in Esophageal Atresia and Its Etiologic Factors (선천성 식도폐쇄 수술 후 열공탈장의 호발과 그 유발인자)

  • Son, Hai-Young;Chang, Eun-Young;Chang, Hye-Kyung;Oh, Jung-Tak;Han, Seok-Joo
    • Advances in pediatric surgery
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    • v.17 no.2
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    • pp.170-178
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    • 2011
  • Hiatal hernia is a very rare disease in the pediatric population. However information from our esophageal atresia postoperative follow-up program has hypotheses; "Hiatal hernia may more frequently occur in postoperative esophageal atresia patients (EA group) than in the general pediatric population (GP group)" and "The tension on the esophagus after esophageal anastomosis may be an important etiologic factor of hiatal hernia in EA group". To prove the first hypotheses, we compared the incidence of hiatal hernia in the GP group with the incidence in the EA group. The Incidence in the GP group was obtained from national statistic data from Statistics Korea and Health Insurance Review and Assessment Service of Korea. The incidence in the EA group was obtained from the medical record and the imaging studies of our esophageal atresia postoperative follow-up program. To prove the second hypothesis, the presumptive risk factors for the development of hiatal hernia in EA group, such as the type of esophageal atresia, degree of esophageal gap, the stage operation and the redo-operation with resection and re-anastomosis of esophagus were analyzed statistically. The total number of patients in the EA group was ninety-nine and there were 5 hiatus hernias. The incidence of EA group (5 %) is significantly higher than incidence of GP group (0.024 %). (p=0.0001) The statistical analysis of the presumptive risk factors for hiatal hernia development in EA group failed to show any evidence of correlation between postoperative esophageal tension and the hiatal hernia. This study shows that the postoperative patients with esophageal atresia have high occurrence of hiatal hernia and should be followed up carefully to detect hiatal hernia.

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Comparison of Health Promoting Behavior and Self-efficacy between New freshmen and University students before and after Health Education (보건교육 전·후 대학 신입생과 재학생 간 건강증진행위, 자기효능감 비교)

  • Kim, Sung-Soo;Lee, Hyun-Ju
    • Journal of Digital Convergence
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    • v.12 no.5
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    • pp.295-303
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    • 2014
  • This study has tried to find the gap of health promoting behavior and the lower level-health responsibility, physical activity, self-actualization, stress management and self-efficacy-between new freshmen and other university students in dormitories who have taken health education as an elective course through health education. With 105 students conducted self-answering survey. It was conducted from June 12 to June 13 of the year 2013. Analysis has been conducted into 5-point scale in every parts of health promoting behavior, 4-point scale in self-efficacy. As a result of the study, after health education, the increasing level of the score was bigger than general university students in preceding research before education; from this, we could interpret that the peers who live together lead positive competition. For before-and-after affects of education, after-education score increased statistically significantly higher from before-education score for both freshmen and other students on every item of the survey. Especially, self-efficacy and stress management, which are the lower level of health promoting behavior, have shown statistic significance of health education. When comparing freshmen and other students, the item that showed significant difference was 'self-efficacy,' and for both before and after health education, other students had higher score than freshmen. Based on the result of the analysis, for those who live together with group of people such as in-dorm students, group education is preferred to personal education; in addition, when selecting health education recipients, better achievement of education will be expected by primarily educating students who have lower level of self-efficacy and stress, especially freshmen who have lower self-efficacy level than other students in university.

A Study on Public Awareness of Landslide and Check Dam Using the Big Data Platform 'Hyean' (공공 빅데이터 플랫폼 '혜안'을 통한 산사태 및 사방댐 인식 분석)

  • Sohee Park;Min Jeng Kang;Song Eu
    • Journal of the Society of Disaster Information
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    • v.18 no.4
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    • pp.687-698
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    • 2022
  • Purpose: This study was conducted to understand the public awareness of landslide and check dams in 2015-2020 using the big data platform 'Hyean' and to confirm the utilization of this platform in disaster prevention areas. Method: The total amount, number of detection by period by media, and affirmative and negative trends of a search for 'landslide' and 'check dam' in 2015-2020 were analyzed using a keyword search of 'Hyean.' Result: There is significant lack of public awareness of check dam compared to landslide, and the trend is more noticeable in the conspicuous gap of data amount between the news and SNS media. The number and the timing of the search for 'landslide' coincided with the actual occurrence of landslide, while the detection of 'check dam' was less related to it. Relatively affirmative preception for the check dam is inferred, but it was difficult to confirm accurate statistical affirmative and negative trends in the disaster prevention field using 'Hyean.' Conclusion: Unlike the experts who expect positive public awareness of check dam, the statistic results show that the public awareness of the check dam as an effective countermeasure against landslide was extremely low. Active promotion of erosion control projects should be carried out first, and a balanced sample survey should accompany online and periodic field surveys. Since there is a limit to grasping the effective perception in the field of disaster prevention area using 'Hyean', it should be very cautious to establish local/governmental policies using it.

The Characteristics of Rural Population, Korea, 1960~1995: Population Composition and Internal Migration (농촌인구의 특성과 그 변화, 1960~1995: 인구구성 및 인구이동)

  • 김태헌
    • Korea journal of population studies
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    • v.19 no.2
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    • pp.77-105
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    • 1996
  • The rural problems which we are facing start from the extremely small sized population and the skewed population structure by age and sex. Thus we analyzed the change of the rural population. And we analyzed the recent return migration to the rural areas by comparing the recent in-migrants with out-migrants to rural areas. And by analyzing the rural village survey data which was to show the current characteristics of rural population, we found out the effects of the in-migrants to the rural areas and predicted the futures of rural villages by characteristics. The changes of rural population composition by age was very clear. As the out-migrants towards cities carried on, the population composition of young children aged 0~4 years was low and the aged became thick. The proportion of the population aged 0~4 years was 45.1% of the total population in 1970 and dropped down to 20.4% in 1995, which is predicted to become under 20% from now on. In the same period(1970~1995), the population aged 65 years and over rose from 4.2% to 11.9%. In 1960, before industrialization, the proportion of the population aged 0~4 years in rural areas was higher than that of cities. As the rural young population continuously moves to cities it became lower than that in urban areas from 1975 and the gap grew till 1990. But the proportion of rural population aged 0~4 years in 1995 became 6.2% and the gap reduced. We can say this is the change of the characteristics of in-migrants and out-migrants in the rural areas. Also considering the composition of the population by age group moving from urban to rural area in the late 1980s, 51.8% of the total migrants concentrates upon age group of 20~34 years and these people's educational level was higher than that of out-migrants to urban areas. This fact predicted the changes of the rural population, and the results will turn out as a change in the rural society. However, after comparing the population structure between the pure rural village of Boeun-gun and suburban village of Paju-gun which was agriculture centered village but recently changed rapidly, the recent change of the rural population structure which the in-migrants to rural areas becomes younger is just a phenomenon in the suburban rural areas, not the change of the total rural areas in general. From the characteristics of the population structure of rural village from the field survey on these villages, we can see that in the pure rural villages without any effects from cities the regidents are highly aged, while industrialization and urbanization are making a progress in suburban villages. Therefore, the recent partial change of the rural population structure and the change of characteristics of the in-migrants toward rural areas is effecting and being effected by the population change of areas like suburban rural villages. Although there are return migrants to rural areas to change their jobs into agriculture, this is too minor to appear as a statistic effect.

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Analysis of Image Distortion on Magnetic Resonance Diffusion Weighted Imaging

  • Cho, Ah Rang;Lee, Hae Kag;Yoo, Heung Joon;Park, Cheol-Soo
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.381-386
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    • 2015
  • The purpose of this study is to improve diagnostic efficiency of clinical study by setting up guidelines for more precise examination with a comparative analysis of signal intensity and image distortion depending on the location of X axial of object when performing magnetic resonance diffusion weighted imaging (MR DWI) examination. We arranged the self-produced phantom with a 45 mm of interval from the core of 44 regent bottles that have a 16 mm of external diameter and 55 mm of height, and were placed in 4 rows and 11 columns in an acrylic box. We also filled up water and margarine to portrait the fat. We used 3T Skyra and 18 Channel Body array coil. We also obtained the coronal image with the direction of RL (right to left) by using scan slice thinkness 3 mm, slice gap: 0mm, field of view (FOV): $450{\times}450mm^2$, repetition time (TR): 5000 ms, echo time (TE): 73/118 ms, Matrix: $126{\times}126$, slice number: 15, scan time: 9 min 45sec, number of excitations (NEX): 3, phase encoding as a diffusion-weighted imaging parameter. In order to scan, we set b-value to $0s/mm^2$, $400s/mm^2$, and $1,400s/mm^2$, and obtained T2 fat saturation image. Then we did a comparative analysis on the differences between image distortion and signal intensity depending on the location of X axial based on iso-center of patient's table. We used "Image J" as a comparative analysis programme, and used SPSS v18.0 as a statistic programme. There was not much difference between image distortion and signal intensity on fat and water from T2 fat saturation image. But, the average value depends on the location of X axial was statistically significant (p < 0.05). From DWI image, when b-value was 0 and 400, there was no significant difference up to $2^{nd}$ columns right to left from the core of patient's table, however, there was a decline in signal intensity and image distortion from the $3^{rd}$ columns and they started to decrease rapidly at the $4^{th}$ columns. When b-value was 1,400, there was not much difference between the $1^{st}$ row right to left from the core of patient's table, however, image distortion started to appear from the $2^{nd}$ columns with no change in signal intensity, the signal was getting decreased from the $3^{rd}$ columns, and both signal intensity and image distortion started to get decreased rapidly. At this moment, the reagent bottles from outside out of 11 reagent bottles were not verified from the image, and only 9 reagent bottles were verified. However, it was not possible to verify anything from the $5^{th}$ columns. But, the average value depends on the location of X axial was statistically significant. On T2 FS image, there was a significant decline in image distortion and signal intensity over 180mm from the core of patient's table. On diffusion-weighted image, there was a significant decline in image distortion and signal intensity over 90 mm, and they became unverifiable over 180 mm. Therefore, we should make an image that has a diagnostic value from examinations that are hard to locate patient's position.

Research on Factors Affecting Smartphone App Market Selection: App Market Platform Provider's Perspective (스마트폰 앱 마켓 선택에 영향을 미치는 요인에 관한 연구: 앱 마켓 플랫폼 사업자 관점으로)

  • Lee, Ho;Kim, Jae Sung;Kim, Kyung Kyu;Lee, Youngin
    • Journal of the Korea Knowledge Information Technology Society
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    • v.13 no.1
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    • pp.11-23
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    • 2018
  • This paper empirically investigates the factors that influence the consumer choice of an app market based on the rational choice theory. The app market is the only channel where a consumer can buy smartphone apps, which give various functional convenience and are considered to be a major contributor to the proliferation of smartphones. Analyses of 281 questionnaires show that usability and structural guarantees as benefit factors significantly influence the app market choice. From the cost perspectives, both monetary and non-monetary conversion costs are found to significantly influence the app market choice. On the other hand, customer trust, information quality, and market image were found to have no significant effect on app market selection. In particular, Korean app market platform providers (KT, LG U +) seem to be superior in terms of structural guarantees, such as customer center operation and damage compensation regulations, compared to overseas app market platform operators (Google). However, in the case of the Google App Market, it is pre-installed on all Android phones, so it is not inconvenient to install additional apps to use other app market. This is disadvantageous to domestic app market platform operators, and it is necessary to establish a policy solution point. In terms of operator costs, both monetary and non-monetary conversion costs have a significant impact on app market choice. In particular, non-monetary conversion costs have a negative impact on Korean app market platform operators. It can be explained that the service expectation level of the domestic app market is low and it is recognized that the time cost factor such as membership is large for new users to use. It seems to be necessary to improve the domestic app market business. Meanwhile, extant research on smartphone apps focuses on the purchase of apps themselves, but not on the selection of the app market itself. In order to fill in this gap, this study focuses on the determinants of app market selection, including the characteristics of an app market and the switching costs.