• 제목/요약/키워드: variance to mean ratio

검색결과 156건 처리시간 0.03초

Simultaneous Tests with Combining Functions under Normality

  • Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • 제22권6호
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    • pp.639-646
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    • 2015
  • We propose simultaneous tests for mean and variance under the normality assumption. After formulating the null hypothesis and its alternative, we construct test statistics based on the individual p-values for the partial tests with combining functions and derive the null distributions for the combining functions. We then illustrate our procedure with industrial data and compare the efficiency among the combining functions with individual partial ones by obtaining empirical powers through a simulation study. A discussion then follows on the intersection-union test with a combining function and simultaneous confidence region as a simultaneous inference; in addition, we discuss weighted functions and applications to the statistical quality control. Finally we comment on nonparametric simultaneous tests.

Smile esthetics: Evaluation of long-term changes in the transverse dimension

  • Akyalcin, Sercan;Misner, Kenner;English, Jeryl D.;Alexander, Wick G.;Alexander, J. Moody;Gallerano, Ron
    • 대한치과교정학회지
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    • 제47권2호
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    • pp.100-107
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    • 2017
  • Objective: To analyze the long-term changes in maxillary arch widths and buccal corridor ratios in orthodontic patients treated with and without premolar extractions. Methods: The study included 53 patients who were divided into the extraction (n = 28) and nonextraction (n = 25) groups. These patients had complete orthodontic records from the pretreatment (T1), posttreatment (T2), and postretention (T3) periods. Their mean retention and postretention times were 4 years 2 months and 17 years 8 months, respectively. Dental models and smiling photographs from all three periods were digitized to compare the changes in three dental arch width measurements and three buccal corridor ratios over time between the extraction and nonextraction groups. Data were analyzed using analysis of variance tests. Post-hoc multiple comparisons were made using Bonferroni correction. Results: Soft-tissue extension during smiling increased with age in both groups. The maximum dental width to smile width ratio (MDW/SW) also showed a favorable increase with treatment in both groups (p < 0.05), and remained virtually stable at T3 (p > 0.05). According to the MDW/SW ratio, the mean difference in the buccal corridor space of the two groups was $2.4{\pm}0.2%$ at T3. Additionally, no significant group ${\times}$ time interaction was found for any of the buccal corridor ratios studied. Conclusions: Premolar extractions did not negatively affect transverse maxillary arch widths and buccal corridor ratios. The long-term outcome of orthodontic treatment was comparable between the study groups.

측방가압충전시 Heated Spreader 사용유무가 근관밀폐에 미치는 영향 (INFLUENCE OF HEATED SPREADER ON THE SEALING ABILITY OF LATERAL CONDENSATION)

  • 정원균;홍찬의
    • Restorative Dentistry and Endodontics
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    • 제24권1호
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    • pp.222-232
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    • 1999
  • The purpose of this study was to evaluate the effect of heated spreader on the sealing ability of lateral condensation, compared with regular cold spreader. Forty two extracted human teeth with single canal were randomly placed into 3 experimental groups, and four additional teeth were used as positive and negative controls. Each group was prepared with Ni-Ti Profile #40 using step-down technique and obturated with standardized colored gutta-percha cone by standard(cold) lateral condensation technique, warm lateral condensation technique with Endotec and hot spreader soaked in glass bead sterilizer, each with Sealapex sealer. Control groups were not obturated, but prepared. After 2 days in 2% methylene blue, the teeth were invested and made into transparent resin blocks. And then, each block was sectioned horizontally with microtome at 1, 2, 3, 4, 5 mm levels from the apex. The linear extent of dye penetration was examined with stereomicroscope at ${\times}$20 magnification. At each of 5 levels, ratio of the area of gutta-percha was obtained by calculating the area of gutta-percha to the total area of the canal. The data collected were then analyzed statistically using an analysis of variance(ANOVA) and Scheffe test. The results were as follows ; 1. All experimental groups produced the apical microleakage. 2. The mean leakage was 1.57${\pm}$0.76mm for cold spreader group, 0.86${\pm}$0.95mm for Endotec spreader group, and 0.64${\pm}$0.93mm for hot spreader group. The difference between hot spreader group and cold spreader group was statistically significant(p<0.05). 1. At the 1 mm level, the mean ratio of area of gutta-percha was 74.58${\pm}$13.15(%) for cold spreader group, 65.42${\pm}$14.62(%) for Endotec spreader group, and 80.72${\pm}$14.63(%) for hot spreader group. There was statistically significant difference between hot spreader group and Endotec spreader group(p<0.05). 2. At the 2mm level, the mean ratio of area of gutta-percha was 87.86${\pm}$11.22(%) for cold spreader group, 66.55${\pm}$14.02(%) for Endotec spreader group, and 92.93${\pm}$7.24(%) for hot spreader group. There was statistically significant difference between Endotec spreader group and other two spreader groups(p<0.05). 3. At the level 3, 4, 5 mm, there was no statistically significant difference between each group. Within the limits of the results of this experiment, warm lateral condensation technique with hot spreader soaked in a glass bead sterilizer demonstrated favorable apical sealing effect and improved density of gutta-percha mass. Thus, it is thought that this obturation technique is effective for clinical use and beneficial to reduce condensation forces, also economical and easy. Lateral condensation, Heated spreader, canal sealing, Microleakage.

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자궁적출술을 받은 부인과 자궁적출술을 받지 않은 부인의 성생활 만족 요인 분석 (Factors Influencing Sexual Satisfaction in Women who have had a Hysterectomy : A comparative group study)

  • 장순복
    • 대한간호학회지
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    • 제20권3호
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    • pp.357-367
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    • 1990
  • This descriptive study was done to identify factors influencing sexual satisfaction in women who had had a hysterectomy and to compare these with women who had not had a hysterectomy. The purpose was to contribute theoretical understanding on which to base nursing care planning. One group of subjects were 156 women who had had a hysterectomy, between one and 18 months post surgery, living with their spouse, having no complications, and menstruating before surgery. The other group of subjects were 282 healthy women who were living with their husbands and menstruating. The study tool consisted of 108 items including item concerning personal characteristics, characteristics related to the hysterectomy, husband's support, body image, emotions, attitude toward the sexual relationship, knowledge of sexuality, sexual behavior, and sexual satisfaction. Sexual satisfaction was measured by a tool based on Derogatis Sexual Function Inventory. The range of the internal level of the study tool was from. 5208 to .9462. Data collection was done during the period from June 20 to Aug.20, 1989. The same questionnaire was used of data collection for both groups, but a mail survey method was used for the women who had had a hysterectomy, and an interview method was used for the women who had not had a hysterectomy. Data analysis was done using frequency, ratio, mean and S.D. for the characterstics of the subjects and level of sexual satisfaction. t - test or ANOVA was used for the differences between the groups with regard to the general and hysterectomy related characteristics. The relationship between the score for sex life related factors and the level of sexual satisfaction was analyzed using the Pearson Correlation, and the influencing factors on sexual satisfaction were analyzed by stepwise multiple regression. The results of this study were as follows ; 1. Mean age and income level were the only general characteristics for the two groups that were significantly different. The mean age, and income level of the group who had had a hysterectomy were 45years, and 1,150,000 won respectively, and for those who had not had a hysterectomy, 41 years and 999,000 won. 2. There was no statistical difference of the sexual satisfaction score between the two groups. 3. There was differences in the factors influencing sexual satisfaction between the two groups. Factors influencing sexual satisfaction for the group who had had a hysterectomy were husband's support (R=.5793, P=.000) and the women's Knowledge of sexuality(R=.6670, P=.000) (total variance : 33.56). On the other hand, emotional status(R=.4294, P=.000), sexual behavior(R=.4294, P=.000), husband's support(R=.5274, P=.000) and attitude towards sexual relations (R=.5412, P=.000) (total variance : 54.12) were the factors influencing sexual satisfaction in the group who had not had a hysterectomy. Since husband's support and sexuality knowledge were identified as factors influencing sexual satisfaction of women who have had a hysterectomy, it can be concluded that, before a woman who has had a hysterectomy is discharged from hospital, nurses should include strategies in the nursing care plan that will promote husband's support and the women's knowledge of sexuality.

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Potential of the Quantitative Trait Loci Mapping Using Crossbred Population

  • Yang, Shulin;Zhu, Zhengmao;Li, Kui
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권12호
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    • pp.1675-1683
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    • 2005
  • In the process of crossbreeding, the linkage disequilibria between the quantitative trait loci (QTL) and their linked markers were reduced gradually with increasing generations. To study the potential of QTL mapping using the crossbred population, we presented a mixed effect model that treated the mean allelic value of the different founder populations as the fixed effect and the allelic deviation from the population mean as random effect. It was assumed that there were fifty QTLs having effect on the trait variation, the population mean and variance were divided to each QTL in founder generation in our model. Only the additive effect was considered in this model for simulation. Six schemes (S1-S6) of crossbreeding were studied. The selection index was used to evaluate the synthetic breeding value of two traits of the individual in the scheme of S2, S4 and S6, and the individuals with high selection index were chosen as the parents of the next generation. Random selection was used in the scheme of S1, S3 and S5. In this study, we premised a QTL explained 40% of the genetic variance was located in a region of 20 cM by the linkage analysis previously. The log likelihood ratio (log LR) was calculated to determine the presence of a QTL at the particular chromosomal position in each of the generations from the fourth to twentieth. The profiles of log LR and the number of the highest log LR located in the region of 5, 10 and 20 cM were compared between different generations and schemes. The profiles and the correct number reduced gradually with the generations increasing in the schemes of S2, S4 and S6, but both of them increased in the schemes of S1, S3 and S5. From the results, we concluded that the crossbreeding population undergoing random selection was suitable for improving the resolution of QTL mapping. Even experiencing index selection, there was still enough variation existing within the crossbred population before the fourteenth generation that could be used to refine the location of QTL in the chromosome region.

아산만 저어류 I. 적정 채집 방법 (The Demersal Fishes of Asan Bay -I. Optimal Sample Size-)

  • 이태원
    • 한국수산과학회지
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    • 제24권4호
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    • pp.248-254
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    • 1991
  • 1990년 8월 아산만에서 otter trawl을 이용하여 저어류를 채집하여 정점을 대표할 수 있는 저어류 군집 자료수집 방법을 추정하였다. 조사기간 중 총 17종, 957개체, 21,840g의 어류가 채집되었으며, 참서대 (Cynoglossus joyneri), 곤어리 (Thrissa koreana), 쥐노래미 (Hexagrammos otakii)와 민태 (Johnius belengerii)가 출현 빈도도 높고 개체수와 생체량에서 우점하였다. 주야 10회 반복 채집결과 종조성은 주야에 따라 유의한 차이를 보이지 않았으나, otter trawl 20분 예인의 개체수 자료는 우점종의 경우는 평균에 대하여 $2.2-385.1\%$, 전어종은 $52.2-162.0\%$의 넓은 변이를 보였다 채집면적을 늘려 갔을 때 누적종수는 예인 4회 자료 누적 이후에는 증가가 둔화되었고 종다양성지수는 3회 이후 거의 점관선에 도달하였다. 개체수의 평균에 대한 분산은 자료를 누적시켰을 때 감소하여 4회 이후에는 자료가 Poisson 분포 양상을 보였다. Otter trawl을 이용하여 아산만 저어류를 채집할 때 20분 예인 4회 이상의 자료를 합하면 정성, 정량적으로 한 조사정점을 대표할 수 있는 것으로 판단된다.

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Study on the fatty acid profile of phospholipid and neutral lipid in Hanwoo beef and their relationship to genetic variation

  • Beak, Seok-Hyeon;Lee, Yoonseok;Lee, Eun Bi;Kim, Kyoung Hoon;Kim, Jong Geun;Bok, Jin Duck;Kang, Sang-Kee
    • Journal of Animal Science and Technology
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    • 제61권2호
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    • pp.69-76
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    • 2019
  • Maize which has very high omega-6 fatty acid content has been used as a main feed grain for Hanwoo beef production to increase marbling, and thus omega-6 to omega-3 fatty acids ratio in Hanwoo beef is expected to be biased. To elucidate the current status of omega fatty acids ratio in Hanwoo beef, fatty acid profiles of neutral lipid and phospholipid fraction were analyzed separately using 55 Hanwoo steers' longissimus dorsi muscle slaughtered at Pyeongchang, Korea from Oct. to Nov. 2015. In addition, an association study was conducted to evaluate associations between single nucleotide polymorphism (SNP) markers from references and omega fatty acid profiles in phospholipid of Hanwoo beef samples using analysis of variance (ANOVA). In neutral lipid fraction, composition of saturated and monounsaturated fatty acids was higher and polyunsaturated fatty acids was lower compared to those in phospholipid fraction. The mean n-6/n-3 ratios of Hanwoo were $56.059{\pm}16.180$ and $26.811{\pm}6.668$ in phospholipid and neutral lipid, respectively. There were three SNPs showing statistically significant associations with omega fatty acid content. GA type of rs41919985 in fatty acid synthase (FASN) was significantly associated with the highest amount of C20:5 n-3 (p = 0.031). CC type of rs41729173 in fatty acid-binding protein 4 (FABP4) was significantly associated with the lowest amount of C22:2n-6 (p = 0.047). AG type of rs42187261 in FADS1 was significantly linked to the lowest concentration of C20:4 n-6 (p = 0.044). The total n-6/n-3 ratio of the steer which has all four SNP types in above loci (27.905) was much lower than the mean value of the total n-6/n-3 ratio in phospholipid of the 55 Hanwoo steers ($56.059{\pm}16.180$). It was found that phospholipid and neutral lipid of Hanwoo have very high n-6/n-3 ratios compared to the reported data from different cow breeds. Four SNPs in genes related with fatty acid metabolism showed significant associations with the fatty acid profile of phospholipid and may have potential as SNP markers to select Hanwoo steers in terms of n-6/n-3 balance in the future.

OFDM 통신 시스템에서 비선형 왜곡분석의 새로운 분석기법 (A New Method on the Nonlinear Distortion Analysis in the OFDM Communication System)

  • 이동훈;정기호;유흥균
    • 한국전자파학회논문지
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    • 제13권6호
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    • pp.538-545
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    • 2002
  • OFDM 통신 시스템에서는 피크전력 대 평균전력비(Peak to Average Power Ratio, PAPR)가 커짐에 따라 전력증폭기에서 비선형 왜곡이 발생되므로 이를 포함한 전송 성능평가가 중요하다. 본 논문에서는 전력증폭기에서 비선형 왜곡이 있는 OFDM 시스템의 성능을 평가하는 새로운 혼합 분석기법을 제안한다. 즉, 제안된 혼합 분석기법은 시뮬레이션을 이용하여 먼저 PAPR의 확률밀도함수와 비선형 잡음의 분산과 평균을 구하고, 이를 이용하여 해석적(analytical) 방법으로 전체 BER을 구하는 방법이다. QPSK 또는 16-QAM 변조방식의 OFDM 시스템에서, 반도체전력증폭기(Solid-State-Power Amplifier, SSPA)의 등가모델을 적용하고, PAPR을 파라미터로 사용하여 IBO 크기에 따른 BER을 분석한다. 제안 방법이 기존의 Monte-Carlo 시뮬레이션에 의한 BER과 거의 동일한 분석 결과를 보이고, 기존 방법보다 BER곡선을 얻는데 필요한 시간이 상당히 감소됨을 보인다

폐쇄성 수면무호흡증에서 지속적 상기도 양압술 시행이 교감신경계 활성도에 끼치는 영향 : 심전도 스펙트럼 분석 (Effects of Nasal Continuous Positive Airway Pressure Application on Sympathetic Activation : Power Spectrum Analysis of Electrocardiogram in Obstructive Sleep Apnea Syndrome)

  • 윤탁;박해정;김의중;정도언
    • 수면정신생리
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    • 제7권1호
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    • pp.43-50
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    • 2000
  • 목 적: 폐쇄성 수면무호흡증은 일반인구의 $2{\sim}5%$ 정도에서 발견될 정도로 흔한 질환이며, 특히 심혈관계 질환이 병발되는 경우가 많아 치료의 중요성이 점차 증가되고 있는 질환이다. 폐쇄성 수면무호흡증과 심혈관계 질환간의 관계는 명확하지 않으나 자율신경계가 매개 작용을 할 것으로 추정되고 있다. 폐쇄성 수면무호흡증에서의 교감신경계 활성도가 증가되어 있다는 연구들이 이를 뒷받침 해준다. 또한, 폐쇄성 수면무호흡증의 치료 방법인 지속적 상기도 양압술이 자율신경계를 변화시키는 것으로 알려져 있다. 그러나, 현재까지 폐쇄성 수면무호흡증 환자에서 지속적 상기도 양압술 치료 전후에 자율신경계의 변화를 측정한 연구는 많지 않으며, 결과도 일정하지 않다. 본 논문에서는 스펙트럼 분석 방법을 사용하여 폐쇄성 수면무호흡증의 환자의 심전도를 분석함으로써 지속적 상기도 양압술 전후의 자율신경계 변화를 고찰하였다. 방 법: 임상적으로 폐쇄성 수면무호흡증이 의심되어 수면 다원검사실에 의뢰된 환자들 중 병력청취, 이학적 / 신경학적검사와 야간 수면다원검사 시행결과 수면무호흡증으로 진단 된 17명을 연구대상으로 하였다. 기본 측정일과 지속적 상기도 양압술 시행일 모두 디지털 수면다원검사기로 기록을 저장하였으며, 양압술 시행일에는 무호흡 해소를 위한 처방압력을 결정하기 위한 목적으로 수면다원기록 시행 전 시간에 걸쳐 양압술을 시행하였다. 수면다원기록 판독은 국제판독기준에 따랐다. 그후 기본 측정일과 양압술 시행일 각각의 2단계 수면, 렘수면에서 잡음이 없는 300개의 연속된 심박동 기록을 선택하였다. 이를 대상으로 한 스펙트럼 분석에서 VLF(very low frequency) power, LF(low frequency) power, HF(high frequency) power, LHR(LF/HF ratio) 값을 산출하였다. 그리고, 심박동 변량(R-R variance)과 심박동 평균값도 산출하였다. 기본 측정일과 양압술 시행일 모두에서 수면다원기록과 동시에 혈중산소포화도($SaO_2$)도 측정하여 비교하였다. 제 변인의 값은 Wilcoxon signed ranks test로 통계 처리하였다. 결 과: 모든 대상군에서 양압술 시행으로 무호흡이 해소되었다. 양압술 시행일의 2단계 수면에서 기본 측정일의 2단계 수면에 비해 VLF power(p<0.05), LF power(p<0.01) 그리고 R-R variance(p<0.05)가 감소하였다. 렘수면의 LF power도 감소하였다(p<0.05). 최저 혈중산소포화도(p<0.01)와 평균 혈중산소포화도(p<0.01)의 증가도 관찰되었다. HF power, LHR, 심박동 변량 그리고 심박동 평균값의 유의한 차이는 없었다. 결 론: 본 연구에서는 처방압력 결정을 위한 양압술 시도 중에도 교감신경계 활성도가 즉각적으로 감소하는 것을 폐쇄성 수면무호흡증에서 관찰할 수 있었다. 부교감신경계의 활성도 변화는 유의하게 나타나지 않았으며, 이는 수면무호흡증에서 나타나는 혈동력학적인 변화가 교감신경계의 활성도의 증가와 관련이 있을 가능성을 시사해준다. 지속적 상기도 양압술을 처음 사용하는 날부터 폐쇄성 수면무호흡증 환자에서 즉각적이고 효율적으로 교감신경계 활성도가 감소하는 결과를 고려할 때, 임상적으로는 지속적 상기도 양얍술을 장기간 적용시 폐쇄성 수면무호흡증의 치료 뿐 만 아니라, 폐쇄성 수면무호흡증에서 병발하는 심혈관계 질환을 예방하고 치료에 도움을 줄 가능성도 시사된다.

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이면교잡에 의한 가잠 F1세대의 몇 가지 양적 형질에 관한 유전 분석 (Genetic Analysis by Diallel Crosses in F1 Generation of Silkworm, Bombyx mori)

  • 정원복;장권열
    • 한국잠사곤충학회지
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    • 제28권1호
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    • pp.24-29
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    • 1986
  • 가잠에 있어서 잡종세대의 우수한 계통을 생산할 수 있는 교배친의 선정과 교배친의 잡종세대의 유전 현상에 대한 기초 정보를 얻고자 7개 품종을 이면교잡하고 이를 F1세대에 대하여 유전자의 분포상태 및 우성 정도, 그리고 조합능력 등을 검정한 결과는 다음과 같다. 1. Vr-Wr graph 및 분산성분에서 단견종은 우성효과가 큰 초우성으로, 단층종과 단층비율은 상가적 효과가 큰 불완전우성으로 각각 추정되었다. 2. 조합능력은 전형질에서 유의적으로 작용하였고 일반조합능력이 특정조합능력보다 크게 평가되었다. 3. 조합능력의 효과 중 GCA 효과는 잠 107이 전 형질에서 가장 높았고, SCA 효과는 잠 113$\times$ 중 14의 조합이, 잠 107$\times$중 14의 조합이 크게 평가되어 주로 중 14가 교배부체일 때에 조합능력이 컸었다.

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