• Title/Summary/Keyword: Distribution of sample mean

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A Normality Test by Using the Simple Regression Analysis (단순(單純) 회귀분석(回歸分析)을 이용한 정규성검정(正規性檢定))

  • Lee, Chang-Ho;Han, Wang-Su
    • Journal of Korean Society for Quality Management
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    • v.13 no.1
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    • pp.77-83
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    • 1985
  • This paper deals with a normality test to determine whether the data are sampled from normal population or not. In this paper the property that the mean and variance are independently distributed only for the normal distribution is used as a basis for developing a new test using the simple regression analysis. Considering the redan and variance of a random sample as independent and dependent variables, if it has not the regression relationship we conclude that the data were sampled from the normal distribution. The Monte-Carlo power study shows that the new test using the simple regression analysis has good power property relative to 6 well-known test methods for 11 distributions.

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Study on the Community Structure of Meiofauna in Marian Cove, King George Island, Antarctica (남극 King George Islands, Marian Cove의 중형저서생물 군집 구조에 관한 연구)

  • Bang Hyun Woo;Kang Sung-Ho;Lee Wonchoel
    • Korean Journal of Environmental Biology
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    • v.23 no.2 s.58
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    • pp.191-199
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    • 2005
  • The community structure, vertical distribution and harpacticoids composition of the meiofauna community were observed from five stations in Marian Cove, King George Island and one station on the northeastern side of Nelson Island. Sample was taken by a free-fall corer in December 2002. Generally, 11 taxa of meiofauna were found, and meiofauna abundance ranged from 322 to 1575 indiv. $10cm^{-2}$ (mean 781 indiv. $10cm^{-2}$). Nematodes were the most dominant group, making up $89\%$ of total meiofauna, followed by harpacticoids $(6.8\%)$. Benthic harpacticoids appeared 19 species of nine families at all the stations, and most various taxa appeared at station B (13 species of seven families). For vertical distribution, more than $70\%$ of meiofauna was concentrated in the upper $0\~2cm$ sediment layers, and the density abruptly decreased with depth in all the stations. Total biomass of meiofauna varied between 41 and $360{\mu}gC\;10cm^{-2}$, and overall mean biomass was $205{\mu}gC\;10cm^{-2}$. Also nematodes had the highest percentage of total maiofauna biomass $(62.4\%)$. The analysis results of Canonical Correspondence Analysis between meiofauna community and sediment grain size showed that polychaets, oligochaets and cumaceans were influenced by silt&cray, and sand, granule and pebble had a influence on harpacticoids, kinorhynchs and ostracods respectively. But nematodes were not affected by sediment grain size.

Formation of Provitamin-$B_5$ Liquid Crystal with Hydrogenated Lecithin and Its Effectiveness of Moisturizing Activity (HL에 의한 프로비타민-$B_5$ 액정의 형성과 보습효과)

  • Kim, In-Young;Zhoh, Choon-Koo;Ryoo, Hee-Chang
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.2
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    • pp.101-109
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    • 2003
  • Provitamin $B_5$ liquid crystal ($PVB_5$-LC) was the new emulsion system to enhance moisturizing activity on the skin. In this study, it should be mentioned that PVB5-LC could be prepared with the main compound of hydrogenated lecithin (HL) in oil-in water (O/W) emulsion. The key ingredient of humectants was contained 2% of provitamin $B_5$ ($PVB_5$) into the $PVB_5$-LC. The best suitable compositions of $PVB_5$-LC were made from 4.0 wt% of HL, 4.0 wt% of cetostearyl alcohol (CSA) as emulsifier and gelling agent, 3.0 wt% of 1,3-butylene glycol (1,3-BG) and 2.0 wt% of glycerin as moisturizers, 3.0 wt% of cyclomethicone (CMC), 3.0 wt% of isononanoate (ININ), 3.0 wt% of capric/caprylic triglyceride (CCTG), 3.0 wt% of macadamia nut oil (MNO) as emollients. As the analytical result of $PVB_5$-LC, it could know that the distribution range of particle size was 0.14 to 12.37 m level (mean size 3.24 m). It was certified the multi lamellar phase around the droplet of liquid crystal when observed the droplet particles through a polarization microscope. And it clinically was tested the effectiveness of moisturizing activity (in-vivo) compared with control sample (O/W emulsion). The effectiveness of moisturizing activity of $PVB_5$-LC with Skincon-200EX after 6 hours went up 49.0% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 25.7% (p<005, n=20). Also, in case of Comeometer CM-825, the moisturizing activity of $PVB_5$-LC after 6 hours rose 36.6% (p<0.05, n=20) whereas the effectiveness of moisturizing activity of generally O/W emulsion cream was 10.8%. Therefore, it was known that the effectiveness moisturizing activity of $PVB_5$-LC with HL was remarkably superior compared with O/W emulsion cream.

An Analysis or the Medical problems of the Medical Aid Patients Registered in a Health Center in Seoul (Relationships Between the Findings Of the Routine Urinalysis and Hypertensive Symptoms) (1차진료기관(次診療機關) 이용환자(利用患者)의 질병양상(疾病樣相) 및 고혈압(高血壓)과 요검사소견(尿檢査所見)에 관(關)한 연구(硏究))

  • Park, Seung-Key
    • Journal of Preventive Medicine and Public Health
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    • v.17 no.1
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    • pp.259-268
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    • 1984
  • The Korean government launched the medicaid program for the poor people as a wing of the social development and welfare programs beginning in 1977 when the fourth 5-year national economic development program started. The charts of the medicaid recipients who visited Jonglo-Gu Health Center for the period from 1981 to 1983 were reviewed and analysed. Major findings from the analysis are as follows. 1. The medicaid recipients occupied 5.19% in 1981, 2.90% in 1982 and 2.00% among the total residents of Jonglo district in 1983, respectively. 2. The mean number of physician visits per person year of medicaid recipients who visited the Jonglo-Gu Health Center was 4.73 in 1981, 4.90 in 1982 and 4.41 in 1983, respectively. 3. The consultation/referral rate at the Jonglo-Gu Health Center was 2.65% in 1981, 1.77% in 1982 and 2.18% in 1983 while the rate at the department of family practice, Seoul National University Hospital was 3.18% in 1983. 4. Classifying into 17 major categories, the pattern of diseases of the poor outpatients who visited the Hallym College Medical Center both in 1981 and 1982 showed a statistically similar pattern of the 5,169 medicaid patients who visited the Jonglo-Gu Health Center in 1981 and 401 patients in 1983. 5. Classifying into 17 major categories, the disease of outpatient visits at the department of family practice, Seoul National University Hospital from 1st May, 1983 to 31s1 Oct., 1983 revealed statistically significant similarity with both the 5,169 medicaid patients in 1981 and the 401 patients sampled in 1983. 6. Classifying into 17 major categories, the diseases of community diagnosis at the Ihwa Dong, Jonglo-Gu also showed a statistically significant similarity with the 5,169 medicaid patients who visited the Jonglo-Gu Health Center in 1981. 7. Classifying into 17 major categories, the diseases of 5,169 medicaid patients at Jonglo-Gu Health Center in 1981 showed a statistically significant similar distribution with that of the 401 sampled medicaid patients at this center in 1983. 8. Among the medicaid patients who utilized the Jonglo-Gu Health Center in 1983, 401 sampled patients who are practicable routine urinalysis composed of 131 indigent group and 270 low-income group. The sample composed of 127 males and 274 females. There were more old patients than the young ones among the 401 sampled patients. 9. Age-adjusted prevalence rate of the hypertension computed by the direct method using estimated of midyear population of 1980 year as the standard is the highest in the Yonsei area and the lowest in the Shindongmyun. Furthermore age-adjusted prevalence rate was higher for males than that of females. 10. The group of hypertension patients using routine urinalysis profile composed of pyuria, hematuria, proteinuria and glycosuria is the most statistical significant, the pyuria alone is very significant, hematuria is significant and proteinuria is also significant.

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Seasonal Variation of PM2.5 Components Observed in an Industrial Area of Chiba Prefecture, Japan

  • Ichikawa, Yujiro;Naito, Suekazu;Ishii, Katsumi;Oohashi, Hideaki
    • Asian Journal of Atmospheric Environment
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    • v.9 no.1
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    • pp.66-77
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    • 2015
  • In order to survey the seasonal variation of the chemical composition of particulate matter of $2.5{\mu}m$ or less ($PM_{2.5}$), $PM_{2.5}$ was sampled from 8 February 2013 to 31 March 2014 in an industrial area of Chiba Prefecture, Japan. Chemical measurements of the sample included: ionic components ($Na^+$, $NH_4{^+}$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$), carbonaceous components - organic carbon (OC) and elemental carbon (EC), and water-soluble organic carbon (WSOC). Also, secondary organic carbon (SOC) was measured based using the EC tracer method, and char-EC and soot-EC were calculated from the analytical results. The data obtained were interpreted in terms of temporal variation. Of the overall mean value of $PM_{2.5}$ mass concentration obtained during the study period, ionic components, OC and EC accounted for 45.3%, 19.7%, and 8.0%, respectively. $NO_3{^-}$ showed a unique seasonal distribution pattern due to a dependence on temperature and absolute humidity. It was estimated that an approximate temperature of $14^{\circ}C$, and absolute humidity of $7g/m^3$ were critical for the reversible reaction of $NH_4NO_3(p){\leftrightharpoons}NH_3(g)+HNO_3(g)$. The amount of OC and EC contributing to the monthly $PM_{2.5}$ mass concentration was higher in autumn and winter compared to spring and summer. This result could be attributed to the impact of burning biomass, since WSOC and the ratio of char-EC/soot-EC showed a similar pattern during the corresponding period. From the comparison of monthly WSOC/OC values, a maximum ratio of 83% was obtained in August (summer). The WSOC and estimated SOC levels derived from the EC tracer method correlated (R=0.77) in summer. The high occurrence of WSOC during summer was mainly due to the formation of SOC by photochemical reactions. Through long-term observation of $PM_{2.5}$ chemical components, we established that the degree to which the above-mentioned factors influence $PM_{2.5}$ composition, fluctuates with seasonal changes.

ACCURACY OF TRI AUTO ZX® IN LOCATING APICAL FORAMEN WITH ROTARY FILE (전동 file을 장착한 Tri Auto ZX®의 치근단공 인지 정확도 평가)

  • Park, Jeong-Won
    • Restorative Dentistry and Endodontics
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    • v.24 no.4
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    • pp.578-584
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    • 1999
  • The purpose of this experiment was to determine: (1) the safe automatic apical reverse setting that prevents overinstrumentation of the root canal, using Tri Auto ZX$^{(R)}$ and (2) the effect of various irrigant on such instrumentation. The instrumentation was carried out with the automatic apical reverse setting of 0.5, 1.0, 1.5, and 2.0. The root canal irrigants used in usual manner were normal saline(0.9%), NaOCl(2.5%), and RC Prep$^{(R)}$. For each reverse setting and each irrigant, ten teeth were used with the total of 120 teeth. The distance between the file tip and the apical constriction was determined by stereomicroscope using the point that the file began to rotate in reverse direction. When the reverse setting mode was set to 0.5, 18 of 30 were overinstrumented. If these were discriminated by irrigant, 10 of 6 with 0.9% saline, 10 of 6 with NaOCl, and 10 of 6 with RC Prep$^{(R)}$ has the file tip located 0.57${\pm}$0.30mm, 0.73${\pm}$0.39mm, and 0.26${\pm}$0.25mm beyond the apical constriction respectively. In 1.0 setting 15 of 29 were over the apical constriction, and the distribution was 6 in saline, 5 in NaOCl, and 4 in RC Prep$^{(R)}$. The mean distance over the apical constriction was 0.28${\pm}$0.13mm with saline, 0.75${\pm}$0.61mm with NaOCl, and 0.25${\pm}$0.17mm with RC Prep$^{(R)}$. When the autoatic reverse mode was set to 1.5, and 2.0, 5, and 1 teeth were found to be overinstrumented in respective settings. But there were large variations in overinstrumented distances when an attempt was made to compare the effect of irrigants on this overinstrumentations and they were meaningless for the small sample size. When all of the autoreverse setting were combined to compare the number of overinstrumented teeth with each irrigant, there were no significant differences (14 for normal saline, 12 for NaOCl, 13 for RC Prep$^{(R)}$). When 0.5 or 1.0 automatic apical reverse setting mode was used the Tri Auto ZX$^{(R)}$ in clinical application, the possibility of overinstrumentation beyond the apical constriction exists in 55.9% of cases. Therefore 1.5 or 2.0 setting is safer for the preparation inside the canal but this type setting needs additional apical hand preparation of the root canal because the accuracy is lower than 0.5 or 1.0 setting.

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An Analysis of Current States and Curriculums of Interior Design Major at Vocational High Schools and Suggestions for Improvement (실업계 고등학교 실내디자인전공 활성화를 위한 교육현장의 실태와 교과내용 분석)

  • 김대년;오혜경;천진희
    • Journal of the Korean Home Economics Association
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    • v.39 no.12
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    • pp.1-14
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    • 2001
  • The purpose of this study was to analyze the current states of interior design as a major at vocational high schools and to suggest ways in which it can be improved. Three hundred and four students and twelve teachers of two vocational high schools comprised the sample population for this study. Data was collected using two methods, questionnaires and interviews. Frequency distribution, mean, and chi-square tests were used to analyze the data. The findings of this study are as follows: The student respondents were more interested in studying residential design, furniture design and making, drafting and perspective drawing than other areas of study. Most teachers had difficulties teaching the subject of residential design because they were not well educated with this area. Surprisingly most students hoped to extend their education to a university or college after graduation, not to enter the workforce. According to teachers'responses, almost ninety percentage of students entered university or college. And more than two thirds of the students desired to study an interior design related major at the university level. Among graduates having jobs, half of them were working in interior design fields. If the students had to choose their jobs, they would work in interior design fields. The variables differentiating several related careers after graduation were school, grade, and sex. The students viewed interior design, interior coordination, and CAD related work as fields likely to enter upon graduating from vocational high schools; however, teachers viewed furniture making, interior accessorizing, and home fashion as fields more appropriate to the students'level of training. The teacher respondents criticized the textbooks in four categories; suitability with the students'level was average or below average; students'interest level and students'understanding level were average or above average; and whether the book was easy or difficult to be utilized for the purposes of teaching was also average or above average. The criticism was a little diverse depending on each book or each chapter. The teachers pointed out several problems using those books, such as insufficient examples or explanation, lack of coherence between some chapters, and an incompatibility with the allotted time frame in class. The merits of the textbooks varied such as a well organized structure, ability to generate students'interest. This study revealed that the strategy for improving the interior design major at vocational high schools should invoke, 1) dividing students into two groups-one to enter a university; the other to have jobs after graduation to focus their interests. 2) improving textbooks more appropriate to the students. 3) providing present teachers the opportunities for in-service training and hiring new teachers with credentials more suitable to educate students who desire to be interior designers.

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Inelastic Time History Analysis of a Five-Story Steel Framed Structure Considering Rigidity of TSD Connection (TSD 접합부의 강성을 고려한 5층 철골골조구조물의 비탄성 시간이력해석)

  • Kang, Suk-Bong;Lee, Jae-Hwan
    • Journal of Korean Society of Steel Construction
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    • v.22 no.3
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    • pp.281-291
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    • 2010
  • In this study, a five-story steel frame was designed in accordance with KBC2005 to evaluate the effects of the beam-column connection on the structural behavior. The connections were designed as fully rigid and semi-rigid. The fiber model was used to describe the moment-curvature relationship of the steel beam and the column, the power model for the moment-rotation angle of the semi-rigid connection and the three-parameter model for the hysteretic behavior of the steel beam, column, and connection. The structure was idealized as separate 2-D frames and as connected 2-D frames. The peak ground accelerations of four earthquake records were modified in a time-history analysis for the levels of the mean return period and for the maximum base-shear force in a pushover analysis. The top story displacement, base-shear force, story drift, demanded ductility ratio for the semi-rigid connection, maximum bending moment of the column, beam, and connection, and distribution of the plastic hinge were examined in the time-history analysis. The frame with the semi-rigid connection yielded a lower base-shear force, less magnitude, and increasing ratio in the bending moment of the column, beam, and connection than the frame with a fully rigid connection. The TSD connection was deemed to have secured the economy and safety of the sample structure that was subjected to seismic excitation for the Korean design level.

Analysis of the Factors Influencing the Management Characteristics of Tech SMEs in Determination of High-growth Firms: Focusing on Fourth Industrial Revolution Related Businesses and General SMEs (기술 중소기업의 경영 특성에 대한 고성장 기업 결정 영향 요인분석: 4차 산업혁명기업과 일반 중소기업을 중심으로)

  • Yoon, Sun-jung;Seo, Jong-hyen
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.6
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    • pp.157-175
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    • 2021
  • This study categorized 3,214 companies out of the tech firms supported by the Korea Technology Finance Corporation's "technology guarantee scheme" through technology assessment from 2017 to 2019 into Fourth Industrial Revolution-related companies and general SMEs. The impact of the management characteristics of these 1,752 tech firms on the determination of high-growth firms was then empirically analyzed. This study used the OECD(2007) definition to define a "high-growth firm" as "an enterprise with average revenue growth greater than 20% per annum, over a two-year period." As the two sample groups showed non-normal distribution, this study conducted the Mann-Whitney U test, a nonparametric test, to analyze the mean differences and bivariate logistic regression in which the normality assumption is less stringent. The independent variables include fundamental characteristics; a regional dummy; a technological level dummy; and the capabilities of company representatives, human capital, and technological innovation. The corresponding sub-variables are representatives' level of education and experience in the same industry, full-time workers, research personnel, the extent of intellectual property rights, investment in research and development, firm age, total assets, region_metropolitan area, region_central region, technological level_high technology, and technological level_medium technology. As a result, the research hypothesis about representatives' level of experience in the same industry, full-time workers, total assets, and technological level_high technology was supported for the Fourth Industrial Revolution-related companies. For the general SMEs, the research hypothesis about representatives' level of experience in the same industry, research personnel, total assets, and region_metropolitan area was supported.

Association between Circulating Vitamin D, the Taq1 Vitamin D Receptor Gene Polymorphism and Colorectal Cancer Risk among Jordanians

  • Atoum, Manar Fayiz;Tchoporyan, Melya Nizar
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7337-7341
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    • 2014
  • Background: The physiological role of vitamin D extends beyond bone health and calcium-phosphate homeostasis to effects on cancer risk, mainly for colorectal cancer. Vitamin D may have an anticancer effect in colorectal cancer mediated by binding of the active form $1,25(OH)_2D$ to the vitamin D receptor (VDR). The Taq1 VDR gene polymorphism, a C-to-T base substitution (rs731236) in exon 9 may influence its expression and function. The aim of this study wass to determine the 25(OH)D vitamin D level and to investigate the association between circulating vitamin D level and Taq1VDR gene polymorphism among Jordanian colorectal cancer patients. Materials and Methods: This case control study enrolled ninety-three patients and one hundred and two healthy Jordanian volunteers from AL-Basheer Hospital/Amman (2012-2013). Ethical approval and signed consent forms were obtained from all participants before sample collection. 25(OH)D levels were determined by competitive immunoassay Elecsys (Roche Diagnostic, France). DNA was extracted (Promega, USA) and amplified by PCR followed by VDR Taq1 restriction enzyme digestion. The genotype distribution was evaluated by paired t-test and chi-square. Comparison between vitamin D levels among CRC and control were assessed by odds ratio with 95% confidence interval. Results: The vitamin D serum level was significantly lower among colorectal cancer patients (8.34 ng/ml) compared to the healthy control group (21.02ng/ml). Patients deficient in vitamin D (less than 10.0 ng/ml) had increased colorectal cancer risk 19.2 fold compared to control. Only 2.2% of CRC patients had optimal vitamin D compared to 23.5% among healthy control. TT, Tt and tt Taq1 genotype frequencies among CRC cases was 35.5%, 50.5% and 14% compared to 43.1%, 41.2% and 15.7% among healthy control; respectively. CRC patients had lower mean vitamin D level among TT ($8.91{\pm}4.31$) and Tt ($9.15{\pm}5.25$) genotypes compared to control ($21.3{\pm}8.31$) and ($19.3{\pm}7.68$); respectively. Conclusions: There is significant association between low 25(OH)D serum level and colorectal cancer risk. The VDRTaq1 polymorphism was associated with increased colorectal cancer risk among patient with VDRTaq1 TT and Tt genotypes. Understanding the functional mechanism of VDRTaq1 TT and Tt may provide a strategy for colorectal cancer prevention and treatment.