• Title/Summary/Keyword: kolmogorov-smirnov test

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The effect of dentin desensitizers and Nd:YAG laser pre-treatment on microtensile bond strength of self-adhesive resin cement to dentin

  • Acar, Ozlem;Tuncer, Duygu;Yuzugullu, Bulem;Celik, Cigdem
    • The Journal of Advanced Prosthodontics
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    • v.6 no.2
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    • pp.88-95
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    • 2014
  • PURPOSE. The purpose of this study is to evaluate if pre-treatment with desensitizers have a negative effect on microtensile bond strength before cementing a restoration using recently introduced self-adhesive resin cement to dentin. MATERIALS AND METHODS. Thirty-five human molars' occlusal surfaces were ground to expose dentin; and were randomly grouped as (n=5); 1) Gluma-(Glutaraldehyde/HEMA) 2) Aqua-Prep F-(Fluoride), 3) Bisblock-(Oxalate), 4) Cervitec Plus-(Clorhexidine), 5) Smart protect-(Triclosan), 6) Nd:YAG laser, 7) No treatment (control). After applying the selected agent, RelyX U200 self-adhesive resin cement was used to bond composite resin blocks to dentin. All groups were subjected to thermocycling for 1000 cycles between $5-55^{\circ}C$. Each bonded specimen was sectioned to microbars ($6mm{\times}1mm{\times}1mm$) (n=20). Specimens were submitted to microtensile bond strength test at a crosshead speed of 0.5 mm/min. Kolmogorov-Smirnov, Levene's test, Kruskal-Wallis One-way Analysis of Variance, and Conover's nonparametric statistical analysis were used (P<.05). RESULTS. Gluma, Smart Protect and Nd:YAG laser treatments showed comparable microtensile bond strengths compared with the control group (P>.05). The microtensile bond strengths of Aqua-Prep F, and Cervitec Plus were similar to each other but significantly lower than the control group (P<.05). Bisblock showed the lowest microtensile bond strength among all groups (P<.001). Most groups showed adhesive failure. CONCLUSION. Within the limitation of this study, it is not recommended to use Aqua-prep F, Cervitec Plus and Bisblock on dentin when used with a self-adhesive resin cement due to the decrease they cause in bond strength. Beside, pre-treatment of dentin with Gluma, Smart protect, and Nd:YAG laser do not have a negative effect.

Changes in the Spinal Motor Neuron Excitability Depending on Postural Changes in Post Stoke Hemiplegics (뇌졸중 후 편마비 환자의 체위변화에 따른 척수운동신경원 흥분성 변화)

  • Park, Young-Hyun;Kim, Yong-Nam;Kim, Su-Hyon;Oh, Seok;Choi, Ji-Ho;Kim, Tae-Youl
    • The Journal of Korean Physical Therapy
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    • v.22 no.4
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    • pp.15-20
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    • 2010
  • Purpose: The purpose of this study was to measure changes in the H-reflex and V wave under loading conditions (e.g. prone and standing position) and to investigate whether postural change would affect the H-reflex and V wave in post stroke hemiplegic patients. Methods: Thirty persons with hemiplegia resulting from stroke (20 males, 10 females) participated in this study. Electromyography (EMG) was used to electrically stimulate and record the soleus H-reflexes and V waves under various loading conditions. The normality of the distribution of each variable (H latency, $H_{max}/M_{max}$ ratio, $V_{max}/M_{max}$ ratio) was tested using the Kolmogorov-Smirnov test. The means of normally distributed continuous data were assessed by independent t-test (${\alpha}$=0.05). Results: There were statistically significant differences in $H_{max}/M_{max}$ ratio (p<0.01), $V_{max}/M_{max}$ ratio (p<0.01), H latency (p<0.01) among the prone and standing position. Conclusion: We found that the H-reflex and V wave in standing position was more active to weight bearing load than prone position.

In-vitro development of a temporal abutment screw to protect osseointegration in immediate loaded implants

  • Garcia-Roncero, Herminio;Caballe-Serrano, Jordi;Cano-Batalla, Jordi;Cabratosa-Termes, Josep;Figueras-Alvarez, Oscar
    • The Journal of Advanced Prosthodontics
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    • v.7 no.2
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    • pp.160-165
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    • 2015
  • PURPOSE. In this study, a temporal abutment fixation screw, designed to fracture in a controlled way upon application of an occlusal force sufficient to produce critical micromotion was developed. The purpose of the screw was to protect the osseointegration of immediate loaded single implants. MATERIALS AND METHODS. Seven different screw prototypes were examined by fixing titanium abutments to 112 Mozo-Grau external hexagon implants (MG Osseous$^{(R)}$; Mozo-Grau, S.A., Valladolid, Spain). Fracture strength was tested at $30^{\circ}$ in two subgroups per screw: one under dynamic loading and the other without prior dynamic loading. Dynamic loading was performed in a single-axis chewing simulator using 150,000 load cycles at 50 N. After normal distribution of obtained data was verified by Kolmogorov-Smirnov test, fracture resistance between samples submitted and not submitted to dynamic loading was compared by the use of Student's t-test. Comparison of fracture resistance among different screw designs was performed by the use of one-way analysis of variance. Confidence interval was set at 95%. RESULTS. Fractures occurred in all screws, allowing easy retrieval. Screw Prototypes 2, 5 and 6 failed during dynamic loading and exhibited statistically significant differences from the other prototypes. CONCLUSION. Prototypes 2, 5 and 6 may offer a useful protective mechanism during occlusal overload in immediate loaded implants.

Comparisons for the Abnormality of Breathing Pattern, Kinesiophobia and Flexion Relaxation Phenomenon in Patients with Chronic Low Back Pain and Healthy Person during Flexion and Extension of the Trunk

  • Yoon, Junggyu
    • Journal of International Academy of Physical Therapy Research
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    • v.10 no.2
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    • pp.1750-1755
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    • 2019
  • Background: Most of the previous researches on the abnormality of breathing pattern have focused on the silence of functional movements owing to such abnormality, however, have not been clearly identified the relationship between the abnormal breathing pattern on one hand and kinesiophobia and flexion relaxation phenomenon (FRP) on the other hand. Objective: To compare patients with chronic low back pain (CLBP) and healthy person in the abnormality of breathing pattern, kinesiophobia, and FRP during flexion and extension of the trunk. Design: Case-control study. Methods: The research subjects consisted of a group of 15 healthy adults and another group of 15 patients with CLBP. Capnography was used to measure the endtidal $CO_2$ ($EtCO_2$) and respiratory quotient (RQ). The muscle activity of multifidus and erector spinae of the subjects was measured during flexion and extension of the trunk to identify their FRP. The Nijmegen Questionnaire (NQ) and Tampa Scale of Kinesiophobia (TSK) were utilized to measure their breathing patterns and kinesiophobia, respectively. The Kolmogorov-Smirnov (K-S) test was conducted in order to analyze the normal distribution of the measured data. Their general characteristics were identified by the descriptive statistics and the independent t-test was performed to identify the differences between the two groups in terms of abnormality of breathing pattern, kinesiophobia, and FRP. The level of significance was set at ${\alpha}=.05$. Results: The patients with CLBP had significantly less $EtCO_2$ and shorter breathing hold time (BHT) than normal healthy person (p<.05). The patient with CLBP also had significantly greater kinesiophobia than healthy person (p<.05), and had less FRP than the healthy person (p<.01). Conclusions: These results suggest that the CLBP had greater abnormality of breathing pattern and kinesiophobia with less FRP than healthy person.

Testing the Consistency of Unified Scheme of Seyfert Galaxies

  • Iyida, Evaristus U.;Eya, Innocent O.;Eze, Christian I.
    • Journal of Astronomy and Space Sciences
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    • v.39 no.2
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    • pp.43-50
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    • 2022
  • The unified scheme of Seyfert galaxies hypothesizes that the observed differences between the two categories of Seyfert galaxies, type 1 (Sy1) and type 2 (Sy2) are merely due to the difference in the orientation of the toroidal shape of the obscuring material in the active galactic nuclei. We used in this paper, a sample consisting of 120 Seyfert galaxies at 1.40 × 109 Hz in radio, 2.52 × 1017 Hz in X-ray and 2.52 × 1023 Hz in γ-ray luminosities observed by the Fermi Large Area Telescope (Fermi-LAT) in order to test the unified scheme of radio-quiet Seyfert galaxies. Our main results are as follows: (i) We found that the distributions of multiwave luminosities (Lradio, LX-ray, and Lγ-ray) of Sy1 and Sy2 are completely overlapped with up to a factor of 4. The principal component analysis result reveals that Sy1 and Sy2 also occupy the same parameter spaces, which agrees with the notion that Sy1 and Sy2 are the same class objects. A Kolmogorov-Smirnov test performed on the sub-samples indicates that the null hypothesis (both are from the same population) cannot be rejected with chance probability p ~ 0 and separation distance K = 0.013. This result supports the fact that there is no statistical difference between the properties of Sy1 and Sy2 (ii) We found that the coefficient of the best-fit linear regression equation between the common properties of Sy1 and Sy2 is significant (r > 0.50) which plausibly implies that Sy1 and Sy2 are the same type of objects observed at different viewing angle.

Evaluation of marginal and internal accuracy of provisional crowns manufactured using digital light processing three-dimensional printer (DLP 방식의 3D 프린터로 제작된 임시 보철물의 변연 및 내면 정확도 평가)

  • Noh, Mi-Jun;Lee, Ha-Bin;Kim, Ji-Hwan
    • Journal of Technologic Dentistry
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    • v.44 no.2
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    • pp.31-37
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    • 2022
  • Purpose: The aim of this study was to evaluate the accuracy of provisional crowns manufactured using a milling machine and a digital light processing (DLP) printer. Methods: A full-contour crown was designed using computer-aided design software. Provisional crowns of this design were manufactured using a milling machine and using a DLP three-dimensional (3D) printer (N=20). The provisional crowns were digitized with an extraoral scanner, and 3D deviation analysis was applied to the scanned data to confirm their accuracy. An independent t-test was performed to detect the significant differences, and the Kolmogorov-Smirnov test was used for analysis (α=0.05). Results: No significant differences were found among the precision of marginal surface between the printed and milled crowns (p=0.181). The trueness of marginal and internal surfaces of the milled crowns were statistically higher than those of the printed crowns (p=0.024, p=0.001; respectively). Conclusion: The accuracy of provisional crowns manufactured using a milling machine and a 3D printer differed significantly except with regards to the precision of the internal surface. However, all the crowns were clinically acceptable, regardless of the manufacturing method used.

A Study from a Highly Populated Country : Risk Factors Associated with Lower Back Pain in Middle-Aged Adults

  • Feda Anisah Makkiyah;Tasya Anggraini Sinaga; Namira Khairunnisa
    • Journal of Korean Neurosurgical Society
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    • v.66 no.2
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    • pp.190-198
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    • 2023
  • Objective : Low back pain (LBP) is a global health problem that affects the productivity of the patients. Several factors such as individual, occupational, and psychosocial factors increase the risk of LBP. However, only a few studies investigated those factors, especially in middle adulthood in Indonesia. Indonesia is a country with a young population that has been rapidly developing in recent years. This study was conducted to find out the factors associated with LBP in middle adulthood. Methods : This study is a cross-sectional observational analytic study using a convenience sampling method with a total sample of 3005 respondents. Data were collected using a questionnaire which was then analyzed using the chi-square test, Kolmogorov-smirnov, Spearman's Rank, and logistic regression test. Results : From the result of this study, it was found that the 12-month prevalence of LBP in middle-aged adults was 44,29%. Female (odds ratio [OR], 1.3; 95% confidence interval [Cl], 1.098-1.545; p=0.002), lack of physical exercises (OR, 0.87; 95% Cl, 0.794-0.959; p=0.005), high body mass index (OR, 1.09; 95% Cl, 1.009-1.187; p=0.002), stress level (OR, 1.26; 95% Cl, 1.088-1.458; p=0.002), and years of work experience (OR, 1.1; 95% Cl, 1.001-1.225; p=0.047) were determined as risk factors that significantly associated with LBP. Conclusion : LBP is quite common among middle-aged adults in Indonesia. Female gender, higher body mass index, lack of physical activity, stress level, and years of work experience were all potential risk factors for LBP in middle-aged adults. Middle-aged adults in Indonesia should be aware of LBP and avoid disabilities by identifying risk factors that may worsen LBP in the future.

Effect of various surface treatment methods of highly translucent zirconia on the shear bond strength with resin cement (고투명도 지르코니아의 다양한 표면처리 방법이 레진시멘트와의 전단결합강도에 미치는 영향)

  • Yu-Seong Kim;Jin-Woo Choi;Hee-Kyung Kim
    • The Journal of Korean Academy of Prosthodontics
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    • v.61 no.3
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    • pp.179-188
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    • 2023
  • Purpose. The purpose of this study was to evaluate the effect of surface treatments on the shear bond strength of two types of zirconia (3-TZP and 5Y-PSZ) with resin cement. Materials and methods. Two different types of zirconia specimens with a fully sintered size of 14.0×14.0×2.0 mm3 were prepared, polished with 400, 600, and 800 grit silicon carbide paper, and buried in epoxy resin. They were classified into four groups each control, sandblasting, primer, and sandblasting & primer. Cylindrical resin adhered to the surface-treated zirconia with resin cement. It was stored in distilled water (37℃) for 24 hours, and a shear bond strength test was performed. The normality of the experimental group was confirmed with the Kolmogorov-Smirnov & Shapiro-Wilk test. The interaction and statistical difference were analyzed using a two-way ANOVA. A post-hoc analysis was performed using Dunnett T3. Results. As a result of two-way ANOVA, there was no significant difference in shear bonding strength between zirconia types (P > .05), but there was a significant correlation in the sandblasting, primer, and alumina sandblasting & primer group (P < .05). Dunnett T3 post-test showed that, regardless of the type of zirconia, shear bonding strength was sandblasting & primer > Primer > sandblasting > control group (P < .05). Conclusion. There was no difference in shear bond strength between the types of zirconia. The highest shear bond strength was shown when the mechanical and chemical treatments of the zirconia surface was performed simultaneously.

A Study on the Optimal Aggregation Interval for Travel Time Estimation on the Rural Arterial Interrupted Traffic flow (지방부 간선도로 단속류 통행시간 추정을 위한 적정 집락간격 결정에 관한 연구)

  • Lim Houng-Seak;Lee Seung-Hwan;Lee Hyun-Jae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.3 no.2 s.5
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    • pp.129-140
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    • 2004
  • In this paper, we conduct the research about optimal aggregation interval of travel time data on interrupted traffic flow and verify the reliability of AVI collected data by using car plate matching method in RTMS for systematic collection and analysis of link travel time data on interrupted traffic flow rural arterial. We perform Kolmosorov-Smirnov test on AVT collected sample data and on entire population data, and conclude that the sample data does not represent pure random sampling and hence includes sample collection error. We suggest that additional review is necessary to investigate the effectiveness of AVI collected sample data as link representative data. We also develop statistical model by applying two estimation techniques namely point estimation and interval estimation for calculating optimal aggregation interval. We have implemented our model and determine that point estimate is preferable over interval estimate for exactly selecting and deciding optimal aggregation interval. Our final conclusion is that 5-minute aggregation interval is optimal to estimate travel time in RTMS, as is currently being used our investigation is based on AVI data collected from Yang-ji to Yong-in $42^{nd}$ National road.

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The Establishment of a High Resolution(1Km×1Km) Wind Energy Map Based on a Statistical Wind Field Model (통계적 바람장모형에의한 고해상도(1Km×1Km)풍력에너지지도 작성에 관한 연구)

  • Kim, Hea-Jung;Kim, Hyun-Sik;Choi, Young-Jean;Byon, Jae-Young
    • The Korean Journal of Applied Statistics
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    • v.23 no.6
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    • pp.1157-1167
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    • 2010
  • This paper details a method for establishing a wind energy map having($1Km{\times}1Km$) resolution. The map is essential for measurement and efficiency-testing of wind energy resources and wind site analysis. To this end, a statistical wind field model is estimated that covers 345,682 regions obtained by $1Km{\times}1Km$ lattices made over South Korea. The paper derives various characteristics of a regional wind energy resource under the statistical wind field model and estimates them to construct the wind energy map. Kolmogorov-Smirnov test, based on TMY(typical meteorological year) wind data of 76 weather station areas, shows that a Log-normal model is adequate for the statistical wind field model. The model is estimated by using the wind speed data of 345,682 regions provided by the National Institute of Meteorological Research(NIMR). Various wind energy statistics are studied under the Log-normal wind field model. As an application, the wind energy density(W$/m^2$) map of South Korea is constructed with a resolution of $1Km{\times}1Km$ and its utility for the wind site analysis is discussed.