1.A comparative study on the initial stability of different implants placed above the bone level using resonance frequency analysis.
In Ho KANG ; Chang Whe KIM ; Young Jun LIM ; Myung Joo KIM
The Journal of Advanced Prosthodontics 2011;3(4):190-195
PURPOSE: This study evaluated the initial stability of different implants placed above the bone level in different types of bone. MATERIALS AND METHODS: As described by Lekholm and Zarb, cortical layers of bovine bone specimens were trimmed to a thickness of 2 mm, 1 mm or totally removed to reproduce bone types II, III, and IV respectively. Three Implant system (Branemark System(R) Mk III TiUnite(TM), Straumann Standard Implant SLA(R), and Astra Tech Microthread(TM)-OsseoSpeed(TM)) were tested. Control group implants were placed in level with the bone, while test group implants were placed 1, 2, 3, and 4 mm above the bone level. Initial stability was evaluated by resonance frequency analysis. Data was statistically analyzed by one-way analysis of variance in confidence level of 95%. The effective implant length and the Implant Stability Quotient (ISQ) were compared using simple linear regression analysis. RESULTS: In the control group, there was a significant difference in the ISQ values of the 3 implants in bone types III and IV (P<.05). The ISQ values of each implant decreased with increased effective implant length in all types of bone. In type II bone, the decrease in ISQ value per 1-mm increase in effective implant length of the Branemark and Astra implants was less than that of the Straumann implant. In bone types III and IV, this value in the Astra implant was less than that in the other 2 implants. CONCLUSION: The initial stability was much affected by the implant design in bone types III, IV and the implant design such as the short pitch interval was beneficial to the initial stability of implants placed above the bone level.
Linear Models
2.Statistical notes for clinical researchers: simple linear regression 2 – evaluation of regression line.
Restorative Dentistry & Endodontics 2018;43(3):e34-
No abstract available.
Linear Models*
3.Statistical notes for clinical researchers: simple linear regression 3 – residual analysis
Restorative Dentistry & Endodontics 2019;44(1):e11-
No abstract available.
Linear Models
4.Statistical notes for clinical researchers: simple linear regression 1 – basic concepts.
Restorative Dentistry & Endodontics 2018;43(2):e21-
No abstract available.
Linear Models*
5.Effect of coloring agent on the color of zirconia.
Kwanghyun KIM ; Kwantae NOH ; Ahran PAE ; Yi Hyung WOO ; Hyeong Seob KIM
The Journal of Korean Academy of Prosthodontics 2017;55(1):18-25
PURPOSE: The aim of this study was to evaluate the effect of two types of coloring agents and the number of application on the color of zirconia. MATERIALS AND METHODS: Monolithic zirconia specimens (15.7 mm × 15.7 mm × 2.0 mm) (n = 33) was prepared and divided into 11 groups. Each experimental group was coded as a1-a5, w1-w5 according to the type of coloring agent and number of application. Specimens with no coloring agent applied were set as control group. The color difference of specimen was measured by using double-beam spectrophotometer, and calculated color difference (ΔE*(ab)), translucency parameter (TP). All data was analyzed with two-way ANOVA, multiple comparison Schéffe test, Pearson correlation and linear regression analysis. RESULTS: As the number of application increased, values of CIE L* was decreased, but values of CIE b* was increased in both coloring agents. However, there was no significant difference on values of translucency parameter. The color difference range of each group was 0.87 ΔE*(ab) to 9.43 ΔE*(ab). CONCLUSION: In this study, type of coloring agent and the number of application did not affect the color difference of zirconia.
Coloring Agents
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Linear Models
6.Overestimation of Vancomycin Clearance by the Linear Regression Formula in Rodvold's Report: Why?.
Infection and Chemotherapy 2014;46(1):62-63
No abstract available.
Linear Models*
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Vancomycin*
7.Analysis of binary classification repeated measurement data with GEE and GLMMs using SPSS software.
Shengli AN ; Yanhong ZHANG ; Zheng CHEN
Journal of Southern Medical University 2012;32(12):1777-1780
OBJECTIVETo analyze binary classification repeated measurement data with generalized estimating equations (GEE) and generalized linear mixed models (GLMMs) using SPSS19.0.
METHODSGEE and GLMMs models were tested using binary classification repeated measurement data sample using SPSS19.0.
RESULTS AND CONCLUSIONCompared with SAS, SPSS19.0 allowed convenient analysis of categorical repeated measurement data using GEE and GLMMs.
Linear Models ; Models, Statistical ; Software
8.Intraocular Pressure with the Mackay-Marg Electronic Applanation Tonometer in Normal Eyes.
Journal of the Korean Ophthalmological Society 1982;23(3):595-600
The measurement of the intraocular pressure were made with the Mackay-Marg electronic applanation tonometer, as compared with standard Goldmann tonometer and Schiotz tonometer in Korean 114 normal eyes. The results were as follows: 1. The mean intraocular pressure of 114 normal eyes was 16.61 +/- 3. 77 mmHg with a Mackay-Marg tonometer. 2. There was significant differances between the Mackay-Marg tonometer and Goldmann tonometric values(p<0.005). The corelation coefficent(r) was 0.975, the linear regression was Y = 1.37 + 1.06X. 3. The standard deviation for Mackay-Marg tonometer was greater thandoldmann readings, and it was about 1.37 mmHg higher than Goldmann's. 4. There was significant differances between the Mackay-Marg tonometer and Schiotz tonometric values(p<0.005). The corelation coefficent(r) was 0.938, the linear regression was Y = 0.82X - 0.07.
Intraocular Pressure*
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Linear Models
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Reading
9.Job Stress and Presenteeism of Clinical Nurses.
Mi Sook GUN ; Yeon Hee CHOI ; Kum Hwa PARK
Korean Journal of Occupational Health Nursing 2011;20(2):163-171
PURPOSE: This study is to investigate the job stress and presenteeism of nurses with work shift. METHODS: The data were collected through questionnaires from 281 clinical nurses working for a university hospital located in D city from 13 to 28 of February, 2009. The data were analyzed by descriptive statistics, t-test, ANOVA, Scheffe verification test, Pearson correlation coefficient and multiple linear regression using SPSS/WIN 16.0. RESULTS: The mean score of job stress was 3.47. Work overload and psychological burden scored the highest point as the sub-category of work stress factor. Work performance loss out of presenteeism showed 26.89 and perceived productivity, 79.79. Also 94.7% of respondents answered they had health problems. A significantly positive correlation was found among job stress, work performance loss and health issue. To determine the factors affecting persenteeism, work performance loss was associated with work overload and perceived productivity with interpersonal relationship conflict. CONCLUSION: Based on the findings of the study, job stress is positively correlated with work performance loss, and health problems. Therefore, health problems of nurses with work shift need to be considered and plans to manage their job stress affecting presenteeism need to be developed at an earlier stage.
Surveys and Questionnaires
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Efficiency
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Linear Models
10.Development of a Poikilocyte Measuring Method Using Image Analysis Software.
Jong Moon CHOI ; Woong Soo LEE
Laboratory Medicine Online 2013;3(1):6-14
BACKGROUND: To achieve consistency in poikilocytes grading in peripheral blood cell examinations, we made an image-based differential count (IDC) software to measure the degree of abnormalities in individual red blood cells (RBCs) and relative fractions of poikilocytes. METHODS: Thirty peripheral blood samples were analyzed. Smear slides were examined on a microscope with charge-coupled device (CCD) camera. To verify this program, we compared the IDC results with the results of manual differential counting (MDC). Relative fractions of schistocytes, echinocytes, and elliptocytes were measured by IDC and MDC. The error rate of IDC was measured by confirming the final processed images of IDC. Correlations of IDC and MDC results were compared using linear regression analysis and the time required for each test was measured. For presentation of the mathematical decision criteria of poikilocytes, IDC algorithms for recognizing schistocytes, echinocytes, and elliptocytes were made using simple geometrical or mathematical formulas. RESULTS: The error rate of IDC was 2.8%. For analysis of 1,000 RBCs, MDC took 7.3 minutes and IDC took 2.7 minutes. Linear regression coefficients were 0.776 (P<0.001) for schistocytes, 0.895 (P<0.001) for echinocytes, and 1.001 (P<0.001) for elliptocytes. CONCLUSIONS: It was possible to define poikilocytes with geometrical or mathematical formulas using image analysis programs. The IDC program would be helpful for consistent grading of poikilocytes.
Blood Cells
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Erythrocytes
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Linear Models