• Title/Summary/Keyword: Difference Means

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Change in Axial Rotation of Toric Soft Contact Lens according to Tear Volume (눈물양에 따른 토릭 소프트콘택트렌즈의 축 회전양 변화)

  • Seo, Woo Hyun;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.4
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    • pp.445-454
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    • 2015
  • Purpose: The present study was aimed to investigate the effect of tear volume on a change of axial rotation according to wearing time of toric soft contact lens and gaze directions. Method: Toric soft contact lenses with double thin zone design applied on 62 eyes. Then, changes in non invasive tear film break-up time and the rotational direction/amount of lens when changing gaze direction were respectively measured after 15 minutes and 6 hours of lens wear. Results: Lens rotation to temporal direction was more found when changing gaze direction after lens wear. However, its rotation was varied according to wearing time and the subjects' tear volume. Furthermore, the frequency of lens rotation to temporal direction was higher in dry eyes compared with normal eyes at nearly all gaze directions after 15 minutes and 6 hour of lens wear. The rotational amount of lens was generally greater in dry eyes after 15 minutes of lens wear. However, its difference between normal eyes and dry eyes was not great after 6 hours of lens wear. Conclusion: The present study revealed that axial rotation of toric soft contact lens was varied according to the wearer's tear volume and lens rotational patterns at the initial, and extending periods of lens wear were different. The change in rotational pattern of toric soft contact lens from these results means the possibility of visual change after extending lens wear, and the identification of its correlation with tear volume suggests the necessity of considering factors for choosing appropriate toric soft contact lens.

Characteristics of the Regional Rock Stress Field at Shallow Depth in the Kyungsang Basin with In-situ Rock Stress Measurement (현장 측정을 통한 경상분지의 천부 초기응력장 특성에 관한 연구)

  • Bae, Seong-Ho;Jeon, Seok-Won;Kim, Jae-Min;Kim, Jang-Soon
    • Tunnel and Underground Space
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    • v.18 no.2
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    • pp.149-161
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    • 2008
  • It is nearly impossible to estimate the exact state of the current rock stress of interest site by the theoretical and physical approaches except some specific geological situations. This means that in-situ stress measurement is a unique way to obtain reliable information on rock stress especially for civil and mining engineering related problems. Since late in the 90's, in-situ rock stress tests have been widely conducted to provide the quantitative information on the stress state of engineering site at the design stage of an underground rock structure in the Kyungsang Basin, Korea. The study area is the near surface regions at the depth less than 300 m in the Kyungsang Basin. It includes Yeosoo to the west and Busan to the east. Totally, 270 in-situ stress measurements were conducted in the surface test boreholes at the depth from 14 m to 300 m by hydraulic fracturing method. In this paper, based on the measurement data set, the overall characteristics of the current in-situ rock stress fields in the study area are briefly described. And also the investigation results on the difference between the stress distributions for the granitoid and the andesitic rock region are also introduced. Finally, the distributions of the regional horizontal stress directions in Busan and the Yangsan faults area are shown.

Study on the lead exposure of workers in a litharge making industry (모 일산화 연 제조 업체 근로자들의 연 폭로에 관한 연구)

  • Lim, Sang-Bok;Lim, Jung-Kyu;Lee, Sung-Soo;Ahn, Kyu-Dong;Lee, Byung-Kook
    • Journal of Preventive Medicine and Public Health
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    • v.28 no.4 s.51
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    • pp.875-884
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    • 1995
  • In order to investigate the level of lead exposure of workers in litharge making industry and to evaluate how lead exposure, personal habit such as smoking and drinking affect the prevalence of lead related symptoms and other study variables, we investigate 114 workers(24 office workers and 90 lead exposed workers) in a litharge making industry. Study variables chosen were blood lead(PbB), zinc protoporphyrin in whole blood(ZPP), Hemoglobin(Hb), hematocrit (Hct), SGOT and SGPT symptom questionnaires which had 15 lead exposure related symptoms were provided to all workers and filled up by themselves and reconfirmed by physician. The results obtained were as follows; 1. The mean value of PbB, ZPP and SGOT in lead exposed group were higher than those of non-exposed group, and there were no differences of means in other study variables. 2. The smoking and drinking rate of study subjects were 65.8% and 71.0% as a whole. Smoking rates were lower in non-exposed group than exposed group, but drinking rate were not. 3. There were no differences of mean values of study variables between smoker and non-smoker in non-exposed and exposed group, but there was a difference of mean value of SGOT between drinker and lion-drinker in lead exposed group. 4. While the symptom prevalence of lead exposed group were higher in neuromuscular category than non-exposed group, those of non-exposed group were higher or same with exposed group in gastrointestinal and general symptom category. 5. The symptom prevalence of smoker were higher than non-smoker regardless of exposure. 6. The symptom prevalence of drinker were only higher in gastrointestinal symptom category than non-drinker. 7. In multiple stepwise regression analysis of lead related symptoms as dependent variable and blood lead, smoking habit, drinking habit and work duration as independent variables, drinking habit contributed to the gastrointestinal symptom category, whereas blood lead and smoking contributed to the neuromuscular symptom category. For the total symptoms work duration and smoking habit contributed significantly.

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The change of mathematical representations and behavioral characteristics in the class using manipulative materials - Focused on teaching regular polytopes - (교구를 활용한 수업에서의 수학적 표현과 행동 특성의 변화 - 정다면체 지도를 중심으로 -)

  • Choi, Jeong-Seon;Park, Hye-Sook
    • The Mathematical Education
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    • v.48 no.3
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    • pp.303-328
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    • 2009
  • In this study, we developed the teaching methods using manipulative materials to teach regular polytopes, and applied these to first-year student of middle school who is attending the extra math class. In that class, we focused on the change of the mathematical representations -especially verval, visual and symbolic representations- and mathematical behavioral. By analyzing characterstics the students' work sheets, we obtained affirmative results as follows. First, manipulative materials played an important role on drawing a development figure of regular polyhtopes describing the verval representation definition of regular polytopes. Second, classes utilizing manipulative materials changed students verbalism level of representations the definition of regular polytopes. For example, in the first class about 60% of students are in the $0{\sim}2$ vervalism level, but in the third class, about 65% of students are in the $6{\sim}7$ level. Third, classes utilizing manipulative materials improved visual representation about development figure. After experiences making several development figures about regular octahedron directly, and discussion, students found out key points to be considered for draws development figure and this helped to draw development figures about other regular polytopes. Fourth, students were unaccustomed to make symbolic representations of regular polytopes. But, they obtained same improvement in symbolic representations, so in fifth the class some students try to make symbol about something in common of whole regular polytopes. Fifth, after the classes, we have significant differences in the students, especially behavioral characteristics in II items such as mind that want to study own fitness, interest, attachment, spirit of inquiry, continuously mathematics posthumously. This means that classes using manipulative materials. Specially, 'mind that want to study mathematics continuously' showed the biggest difference, and it may give positive influence to inculcates mathematics studying volition while suitable practical use of manipulative materials. To conclude, classes using manipulative materials may help students enhance the verbal, visual representation, and gestates symbol representation. Also, the class using manipulative materials may give positive influence in some part of mathematical behavioral characteristic. Therefore, if we use manipulative materials properly in the class, we have more positive effects on the students cognitive perspect and behavioral cteristics.

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Studies on the Preservation of Korean Chestnnt by Gamma Irradiation -Part 1. Radiation Effect of Low Oxygen Atmosphere- (방사선조사(放射線照査)에 의한 밤저장연구(貯藏硏究) -제1보 저산소상태(低酸素狀態)에서 방사선조사효과(放射線調査効果)-)

  • Park, Nou-Poung;Kim, Yun-Jin;Kim, Sung-Kih;Rhee, Chung-Ouk
    • Korean Journal of Food Science and Technology
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    • v.9 no.1
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    • pp.36-40
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    • 1977
  • Experiments were carried out to determine the optimum dose for the preservability of each Korean chestnut varieties by means of gamma-radiation. They were associated with control of spots in the edible portion of chestnut due to irradiation at the final stage of storage. With this result the following summary can be made. 1. In consideration of those factors such as rooting, sprouting, rotting and undesirable spots on the flesh, it was shown that the optimum radiation dose was checked to be 25-35 Krad though there are some difference among the varieties of chestnut. 2. Rotting and the spots on the flesh of chestnut were remarkably inhibited by low oxygen atmosphere during irradiation. This condition greatly contributed to inhibit sprouting with the low radiation dose(15 Krad). 3. The nuts irradiated had a marked increase in carbon dioxide evolution immediately after the irradiation. However on the day succeding the treatment, these increased curves gradually normalized as same as that of untreated.

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SURFACE ROUGHNESS AND MICROLEAKAGE OF CLASS V COMPOSITE RESTORATIONS : EFFECT OF SURFACE SEALING (치경부 5급 와동 수복물의 표면 거칠기와 미세누출에 관한 연구 : 표면 전색의 효과)

  • Kim, Min-Jeong;Lee, Mi-Jeong;Yu, Mi-Kyung;Park, Soo-Joung;Lee, Kwang-Won
    • Restorative Dentistry and Endodontics
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    • v.30 no.1
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    • pp.22-30
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    • 2005
  • The purpose of this study was to compare the effect of surface sealing materials on microleakage and surface roughness in Class V composite restorations. Twenty five standardized Class V cavity preparations were made on the facial surface of human premolars and were randomly assigned to 5 groups. The teeth were restored with Z-250 after applying Single Bond. Following 7 days storage in distilled water at $37^{\circ}C$, the restorations were sealed as following systems : No sealing ; Single Bond Adhesive ; Biscover ; Fortify ; Optiguard. Then, toothbrush abrasion test was conducted using a wear testing machine. Surface roughness was measured by means of profilometer before and after toothbrushing and the results were statistically analysed by using a paired t-test and ANOVA. The bonded interfaces and the changes of surface roughness were examined by SEM. For microleakage test, specimens were stained in a $2\%$ methylene blue solution, then longitudinally sectioned and analyzed for leakage at occlusal and cervical interfaces using stereomicroscope. The results were statistically analysed by using a Kruskal-Wallis and Mann-Whitney U test. Surface roughness was increasing in all groups after toothbrushing, but no statistically significant differences. In SEM observation, surface sealant was partially retained and partially detached in bonded interfaces. Especially, microgap was identified in cervical margins. In microleakage test, there was better seal in the enamel region and a significant difference between groups at occlusal margin. Control group and Single Bond group had significantly better marginal seal at enamel margin than cervical margin.

A Study on Synthesis Acrylic Polymer Resin and Mechanical Properties Containing Monoammonium Phosphate (Monoammonium phosphate를 포함한 아크릴 수지의 합성 및 물성에 관한 연구)

  • Lee, Joo-Youb;Kim, Ki-Jun
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.3
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    • pp.500-508
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    • 2014
  • For this research, synthesis acrylic resin by ethyl acrylate monomer(EAM) and prepared samples which set by difference amount of monoammonium phosphate solution in waterborne acrylic resin. Use these resins, analyzed mechanical properties and thermal stability by films and leather surface coated. The test of DSC experiment sample WAC-APS3 was $410^{\circ}C$ Tm values which means the highest content of monoammonium phosphate had highest thermal stability in acrylic resin. According to measure data for solvent resistance, all samples showed good property. As known in the results, increase of ammonium phosphate constant did not influence to big change of resin properties. In abrasion test WAC-APS3 was good abrasion properties(68.729 mg.loss). Test of tensile strength, as increase as monoammonium phosphate resin analyzed low properties $1.505kgf/mm^2$ to $1.275kgf/mm^2$. In elongation case, same as strength test result 425 % to 384 % by increase to monoammonium phosphate amount in acrylic resin.

Real-time Hand Region Detection based on Cascade using Depth Information (깊이정보를 이용한 케스케이드 방식의 실시간 손 영역 검출)

  • Joo, Sung Il;Weon, Sun Hee;Choi, Hyung Il
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.10
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    • pp.713-722
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    • 2013
  • This paper proposes a method of using depth information to detect the hand region in real-time based on the cascade method. In order to ensure stable and speedy detection of the hand region even under conditions of lighting changes in the test environment, this study uses only features based on depth information, and proposes a method of detecting the hand region by means of a classifier that uses boosting and cascading methods. First, in order to extract features using only depth information, we calculate the difference between the depth value at the center of the input image and the average of depth value within the segmented block, and to ensure that hand regions of all sizes will be detected, we use the central depth value and the second order linear model to predict the size of the hand region. The cascade method is applied to implement training and recognition by extracting features from the hand region. The classifier proposed in this paper maintains accuracy and enhances speed by composing each stage into a single weak classifier and obtaining the threshold value that satisfies the detection rate while exhibiting the lowest error rate to perform over-fitting training. The trained classifier is used to classify the hand region, and detects the final hand region in the final merger stage. Lastly, to verify performance, we perform quantitative and qualitative comparative analyses with various conventional AdaBoost algorithms to confirm the efficiency of the hand region detection algorithm proposed in this paper.

Effects of Different Sources of Dietary n-3 Fatty Acids on Immune Response and Eicosanoids Production (급원이 다른 n-3 지방산이 흰쥐에서 면역반응과 Prostaglandin $E_2$ 및 Leukotriene $B_4$ 생성에 미치는 영향)

  • 김우경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.4
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    • pp.697-703
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    • 1997
  • This study was planned to compare the effects of source of dietary n-3 fatty acids, i.e., tuna oil and perilla oil, on mitogenesis and production of prostaglandin E$_2$ and leukotriene B$_4$ in rats. Weaning male Sprague-Dawley rats were fed 3 different experimental diets for 4 weeks(Control: beef tallow 50% + sesame oil 50%, FO : beef tallow 50% + sesame oil 25% + tuna oil(27% docosahexaenoic acid) 25%, PO : beef tallow 50% + sesame oil 25% + perilla oil 25%). Food intakes were higher in FO group than in other groups, but body weight gains, food efficiency rates and weights of spleen were not different among groups. Proliferation of splenocyte to PWM(pokeweedmitogen) was higher in FO and PO group than control group. But there was no difference between FO and PO group. Response to ConA was not different among three groups. Serum PGE$_2$ levels were higher in control group than other groups. Serum LKB$_4$ levels were not different among groups. Therefore, it seemed that n-3 fatty acids increased the immune response by means of decreasing the PGE$_2$ production.

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Meta-analysis of the effects on family life education for couples in Korea (한국 부부교육 프로그램의 효과에 대한 메타분석)

  • Lee, Eun-yeong;Jang, Jin-Kyung
    • Journal of Family Relations
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    • v.22 no.4
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    • pp.181-204
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    • 2018
  • Objectives: The aim of this study is to integrate the results of the previous studies from 1900 to 2016 according to the types of dependent variables individually and statistically to obtain the results of the overall level of the marital education program I need to figure it out. In other words, the general and valid study on the overall effectiveness of the marriage education program will lead to more concluded conclusions and draw up an integrated and holistic conclusion about the effectiveness of the marriage education program. Method: The purpose of this study was to investigate the effect of married couples' education program on married couples' education program. The results of this study are as follows. First, Comprehensive Meta-Analysis. In other words, funnel plot, forest plot, and trim & fill were used to analyze all the variables related to the education of the couple, and homogeneity test After choosing an analytical model for the analysis, we calculated the 'standardized mean difference' effect size (d) that can compare different individual studies through the analytical model. The results of this study are as follows. Results: The purpose of this study was to investigate the overall effect size of domestic couples education programs after 1990, and to investigate the effect sizes of dependent variable types and program - related variables. First, the total effect size of the domestic marriage education program was close to the level of the large effect size and had a substantial and preventive effect. Self-esteem, communication, marital adjustment, emotion, and self control have a substantial and prophylactically significant change depending on the type of subordinate variables related to the marital education program But there was no change in origin family and life satisfaction. Third, as a result of the categorization of the dependent variable categorization of the Korean couple education program, it was found that the marital relations of the participant in the individual inner and the marital relations The effect was significant enough to change. Fourth, Korean couple education program was most effective when mixed age couples were participated in various family life cycle. Conclusions: Based on the results of this study, it is necessary to study more deeply about marital education program effect of marriage education for various special groups such as married couples who are in a crisis of divorce, . It also means that the results of the research for the last 30 years from 1900 to 2016 were comprehensively and systematically summarized through meta - analysis. The results of this study provide information on how to provide the most effective couples education programs for practitioners in the field. The result of this study will be the data of judgment about how to organize the marital education program for people of any ages and characteristics in the future.