• Title/Summary/Keyword: Statistical test

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Bias Correction for GCM Long-term Prediction using Nonstationary Quantile Mapping (비정상성 분위사상법을 이용한 GCM 장기예측 편차보정)

  • Moon, Soojin;Kim, Jungjoong;Kang, Boosik
    • Journal of Korea Water Resources Association
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    • v.46 no.8
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    • pp.833-842
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    • 2013
  • The quantile mapping is utilized to reproduce reliable GCM(Global Climate Model) data by correct systematic biases included in the original data set. This scheme, in general, projects the Cumulative Distribution Function (CDF) of the underlying data set into the target CDF assuming that parameters of target distribution function is stationary. Therefore, the application of stationary quantile mapping for nonstationary long-term time series data of future precipitation scenario computed by GCM can show biased projection. In this research the Nonstationary Quantile Mapping (NSQM) scheme was suggested for bias correction of nonstationary long-term time series data. The proposed scheme uses the statistical parameters with nonstationary long-term trends. The Gamma distribution was assumed for the object and target probability distribution. As the climate change scenario, the 20C3M(baseline scenario) and SRES A2 scenario (projection scenario) of CGCM3.1/T63 model from CCCma (Canadian Centre for Climate modeling and analysis) were utilized. The precipitation data were collected from 10 rain gauge stations in the Han-river basin. In order to consider seasonal characteristics, the study was performed separately for the flood (June~October) and nonflood (November~May) seasons. The periods for baseline and projection scenario were set as 1973~2000 and 2011~2100, respectively. This study evaluated the performance of NSQM by experimenting various ways of setting parameters of target distribution. The projection scenarios were shown for 3 different periods of FF scenario (Foreseeable Future Scenario, 2011~2040 yr), MF scenario (Mid-term Future Scenario, 2041~2070 yr), LF scenario (Long-term Future Scenario, 2071~2100 yr). The trend test for the annual precipitation projection using NSQM shows 330.1 mm (25.2%), 564.5 mm (43.1%), and 634.3 mm (48.5%) increase for FF, MF, and LF scenarios, respectively. The application of stationary scheme shows overestimated projection for FF scenario and underestimated projection for LF scenario. This problem could be improved by applying nonstationary quantile mapping.

Measurement of thermal expansion characteristic of root canal filling materials : Gutta-percha and Resilon (수 종의 근관충전재의 열팽창 특성 측정 : Gutta-percha와 Resilon)

  • Jeon, Kyung-A;Lee, In-Bog;Bae, Kwang-Shik;Lee, Woo-Cheol;Baek, Seung-Ho
    • Restorative Dentistry and Endodontics
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    • v.31 no.5
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    • pp.344-351
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    • 2006
  • The purpose of this study was to evaluate the thermal expansion characteristics of injectable ther-moplasticized gutta-perchas and a Resilon. The materials investigated are Obtura gutta-percha, Diadent gutta-percha, E&Q Gutta-percha Bar and Epiphany (Resilon). The temperature at the heating chamber orifice of an Obtura II syringe and the extruded gutta-percha from the tip of both 23- and 20-gauge needle was determined using a Digital thermometer. A cylindrical ceramic mold was fabricated for thermal expansion test, which was 27 mm long, with an internal bore diameter of 3 mm and an outer diameter of 10 mm. The mold was filled with each experimental material and barrel ends were closed with two ceramic plunger. The samples in ceramic molds were heated in a dilatometer over the temperature range from $25^{\circ}C$ to $75^{\circ}C$. From the change of specimen length as a function of temperature, the coefficients of thermal expansion were deter-mined. There was no statistical difference between four materials in the thermal expansion in the range from $35^{\circ}C$ to $55^{\circ}C$ (p > 0.05). However, Obtura Gutta-percha showed smaller thermal expansion than Diadent and Metadent ones from $35^{\circ}C$ to $75^{\circ}C$ (p < 0.05). The thermal expansion of Epiphany was similar to those of the other gutta-percha groups.

Comparison of screw-in effect of three NiTi file systems used by undergraduates (학생들이 사용한 세 종류 NiTi file systems의 screw-in effect 비교)

  • Oh, Seung-Hei;Park, Jeong-Kil;Hur, Bock;Kim, Hyeon-Cheol
    • Restorative Dentistry and Endodontics
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    • v.31 no.6
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    • pp.477-484
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    • 2006
  • The purposes of this study were to compare the apical terminus width of simulated curved root canal prepared with three NiTi file systems used by undergraduates for evaluation the effects of flute angle and pitch or radial land on reducing screw-in effect and to determine more safe NiTi file system for inexperienced operators. Fifty inexperienced undergraduate students prepared 150 simulated curved root canals in resin blocks with three NiTi file systems ; ProFile$^{(R)}$, Hero Shaper$^{(R)}$, K3$^{TM}$. The electric motor set at a speed of 300 rpm and torque of 30 in a 16 : 1 reduction handpiece was used. The simulated root canal was prepared to ISO #25 sizes with each file system. The scanned images of pre- and post-instrumented canal of resin block were superimposed. To evaluate the screw-in effect of three NiTi file systems, apical terminus width of root canal was measured from superimposed images and statistical analysis was performed. There were significant differences in three NiTi flle systems. ProFile$^{(R)}$ had significantly smaller width than Hero Shaper$^{(R)}$ and K3$^{TM}$"" (P < 0.05), but no significant difference was observed between K3$^{TM}$ and Hero Shaper$^{(R)}$. Under the condition of this study, active file system (Hero SHaper$^{(R)}$, K3$^{TM}$) with variable pitch and helical angle had more screw-in effect than passive file system (ProFile$^{(R)}$) with constant pitch and helical angle. It seems that the radial lands play more important role in reducing screw-in effect.

BONDING OF RESIN INLAY TO GLASS-IONOMER BASE WITH VARIOUS TREATMENTS ON INLAY SURFACE (내표면 처리에 따른 레진 인레이와 글래스아이오노머 베이스간의 접착)

  • Jang, Byung-Sung;Kim, Sung-Kyo
    • Restorative Dentistry and Endodontics
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    • v.25 no.3
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    • pp.399-406
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    • 2000
  • The effect of inlay surface treatment on bonding was investigated when resin inlay was bonded to resin-modified glass-ionomer base with resin cement. For the preparation of glass-ionomer base, resin-modified glass-ionomer cement (Fuji II LC, GC Co., Japan) was filled in class I cavities of 7mm in diameter and 2mm in depth made in plastic molds. Eighty eight resin inlay specimens were made with Charisma$^{(R)}$ (Kulzer, Germany) and then randomly assigned to the four different surface treatment conditions: Group I, $50{\mu}m$ aluminium oxide sandblasting and silane treatment ; Group II, silane treatment alone ; Group III, sandblasting alone, and Group IV (control), no surface treatment. After a dentin bonding agent with primer (One-Step$^{TM}$, Bisco Inc., IL., U.S.A.) was applied to bonding surface of resin inlay and base, resin inlay were cemented to glass-ionomer base with a resin cement (Choice$^{TM}$, Bisco Inc., IL., U.S.A.). Shear bond strengths of each specimens were measured using Instron universal testing machine (4202 Instron, lnstron Co., U.S.A.) and fractured surfaces were examined under the stereoscope. Statistical analysis was done with one-way ANOVA and Dunkan's multiple range test. The results were as follows: 1. Sandblasting and silane treatment provided the greatest bond strength(10.56${\pm}$1.95 MPa), and showed a significantly greater bond strength than sandblasting alone or no treatment (p<0.05). 2. Silane treatment provided a significantly greater bond strength(9.77${\pm}$2.04 MPa) than sandblasting alone or no treatment (p<0.05). However, there was no significant difference in bond strength between sandblasting treatment and silane one (p>0.05). 3. Sandblasting alone provided no significant difference in bond strength from no treatment (p>0.05). 4. Stereoscopic examination of fractured surface showed that sandblasting and silane treatment or silane treatment alone had more cohesive failure mode than adhesive failure mode. 5. In relationship between shear bond strength and failure mode, cohesive failure occurred more frequently as bond strength increased.

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Association between Satisfaction with Assistive Technology Devices and Psychosocial Impact among Some Mentally or Physically Disabled Children (뇌병변 및 지체 장애아의 보조공학기기 사용 만족도와 심리사회적 영향의 관련성)

  • Jang, Kyoung-Lae;Ryu, So Yeon;Park, Jong;Han, Mi Ah
    • Journal of agricultural medicine and community health
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    • v.42 no.3
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    • pp.132-144
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    • 2017
  • Objectives: The purpose of this study was to identify the association between satisfaction with assistive technology devices and psychosocial impact among some mentally or physically disabled children. Methods: The study subjects were 120 disabled children and their primary caregivers who were using rental assistive technology devices in Gwangju and Jeollanam-Do. Data were collected by structured questionnaire composed of general characteristics of subjects, characteristics related with using assistive devices. Quebec User Evaluation of Satisfaction with assistive Technology 2.0 (QUEST 2.0) and Psychosocial Impact of Assistive Device Scale (PIADS). The statistical analysis were performed by descriptive statistics, t-test, ANOVA and Pearson's correlational analysis. Results: The total mean score for QUEST 2.0 was $4.08{\pm}0.66$ (satisfaction with devices, $4.01{\pm}0.70$; satisfaction with the assistive devices service, $4.14{\pm}0.90$) and the mean of PIADS was $1.00{\pm}0.75$ (ability, $0.99{\pm}0.78$; adaptability, $1.04{\pm}0.86$; self-respect, $0.99{\pm}0.74$). The scores of PIADS was statistically significant difference according to usage time of assistive devices. The PIADS was significantly positive correlated with QUEST 2.0 Conclusions: The mentally or physically disabled children reported that the higher level of satisfaction and the more positive impact of psychosocial aspect with assistive technology devices. It would be necessary to perform further studies for addressing the effects of assistive technology devices.

A Structural Model for Quality of Life in Women Having Hysterectomies (여성의 자궁절제술후 삶의 질 구조모형)

  • 김숙남
    • Journal of Korean Academy of Nursing
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    • v.29 no.1
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    • pp.161-173
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    • 1999
  • The purpose of this study was to develope and test the structural model for quality of life in women having hysterectomies. A hypothetical model was constructed on the basis of previous studies and a review of literature. The conceptual framework was built around eight constructs. Exogenous variables included in this model were marital intimacy, importance of uterus, professional support, positive coping behavior and pre-operative symptoms. Endogenous variables were spouse's support, sense of loss and quality of life. Empirical data for testing the hypothetical model was collected using a self-report questionnare from 203 women having hysterectomies at the outpatient clinics of four general hospitals and a mail survey in Pusan City. The Data was collected from December, 1997 to January, 1998. Reliability of the eight instruments was tested with Cronbach's alpha which ranged from 0.639-0.915. For the data analysis, SPSS 7.5 WIN Program and LISREL 8.12 WIN Program were used for descriptive statistics and covariance structural analysis. The results of covariance structure analysis were as follows : 1. Hypothetical model showed a good fit with the empirical data. [$\chi$$^2$=6.93(df=5, P=.23), GFI=.99, AGFI=.94, RMSR=.019, NNFI=.97, NFI=.98, CN=440, standardized residuals(-2.14-2.10)] 2. For the parsimony of model, a modified model was constructed by deleting 3 paths and adding 1 path according to the criteria of statistical significance and meaning. 3. The modified model also showed a good fit with the data. [$\chi$$^2$=5.26(df=7, P=.63), GFI=.99, AGFI=.97, RMSR=.014, NNFI=1.02, NFI=.99, CN=710, standardized residuals(-1.46-1.70)] Results of the testing of the hypothesis were as follows : 1. Marital intimacy(${\gamma}$11=.78, t=14.37) and professional support(${\gamma}$13=.12, t=2.12) had a significant direct effect on the spouse's support. 2. Pre-operative symptoms(${\gamma}$25=.32, t=3.12), importance of uterus(${\gamma}$22=.20, t=2.61) and spouse's support($\beta$2l=-.19, t=-2.43) had a significant direct effect on the sense of loss. 3. Sense of loss($\beta$32=-.66, t=-9.83) had a direct effect on the quality of life. Marital intimacy had a direct(${\gamma}$31=.19, t=3.33), indirect(${\gamma}$31=.14, t=2.52) and total effect(${\gamma}$31=.25, t=4.41) on the quality of life. Professional support had a direct effect(${\gamma}$33=.11, t=2.07) and total effect(${\gamma}$33=.13, t=2.31) on the quality of life. The direct effect of pre-operative symptoms(${\gamma}$35=-.36, t=4.02) and positive coping behavior(${\gamma}$34=.15, t=2.06) had the insignificant effect on the quality of life while, due to the idirect effect these variables had overall significant effect on the quality of life. The results of this study showed that the sense of loss had the most significant direct effect on the quality of life. Marital intimacy, pre -operative symptoms and spouse's support had a significant direct effect on this sense of loss. These four variables, the sense of loss, marital intimacy, pre-operative symptoms and spouse's support, were identified as relatively important variables. The results of this study suggested that there is needed to determine if nursing intervention would alleviate this sense of loss and promote a greater quality of life in women who have had hysterectomies.

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The Relationship between Anterior Disc Displacement without Reduction and Development of Anterior Open Bite (비정복성 관절원판변위와 전치부 개교합 발생간의 관계)

  • Hur, Yun-Kyung;Ko, Myung-Yun;Ahn, Yong-Woo
    • Journal of Oral Medicine and Pain
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    • v.32 no.3
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    • pp.293-303
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    • 2007
  • The purpose of this paper is to evaluate if there is a relationship between anterior disc displacement without reduction and development of anterior open bite, and a relation between occurrence of open bite and occlusal appliance therapy. In general, the statistically significant differences were found between the Group 1 and 2 and normal mean group. The variables that represent mandibular size and form, showed a statistical significance in all 3 groups. Also 3 groups patients had a smaller ANB, a larger FMA than normal mean group. When we compared the 3 groups with respect to all cephalometric measurements by One-way analysis of variance (ANOVA), group 1 and 2 patients had a larger FMA, a larger SN to mandibular plane angle, a larger maxillomandibular plane angle, a larger occlusal plane to mandibular plane angle, a smaller total posterior facial height/total anterior facial height(%), and a larger gonial angle than group 3. The statistically significant differences were not found between the Group 1 and 2, and skeletal patterns were similar. Thus, morphologic features of patients with vertical discrepancies may represent a risk factor for the development of anterior open bite with or without occlusal appliance treatment. In case of patients with vertical discrepancy, we may have to be more careful when inducing a change of the vertical dimension.

Comparison of the degree of conversion of light-cured resin cement in regard to porcelain laminate thickness, light source and curing time using FT-IR (도재 라미네이트 두께와 광원 및 광조사 시간에 따른 광중합형 레진 시멘트의 FT-IR을 이용한 중합도 비교)

  • Yuh, Chi-Sung;Kim, Jee-Hwan;Kim, Sun-Jai;Lee, Yong-Keun;Shim, June-Sung
    • The Journal of Korean Academy of Prosthodontics
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    • v.47 no.4
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    • pp.416-423
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    • 2009
  • Statement of problem: The degree of light attenuation at the time of cementation of the PLV restoration depends on characteristics such as thickness, opacity and shade of the restorations, which interfere with light transmittance and, as a result, may decrease the total energy reaching the luting cement. Purpose: The purpose of this study was to compare the degree of conversion of light-cured resin cements measuring by FT-IR in regard to different thickness, light devices and curing time. Material and methods: In the control group, a clear slide glass (1.0 mm) was positioned between the light cured resin cement and light source. The specimens of ceramics were made with IPS Empress Esthetic. The ceramics were fabricated with varying thicknesses-0.5, 1.0, 1.5 mm with shade ETC1. Rely $X^{TM}$ Veneer with shade A3, light-cured resin cement, was used. Light-activation was conducted through the ceramic using a quartz tungsten halogen curing unit, a light emitting diode curing unit and a plasma arc curing unit. The degree of conversion of the light-cured resin cement was evaluated using FT-IR and OMNIC. One-way ANOVA and Tukey HSD test were used for statistical analysis ($\alpha$< .05). Results: The degree of conversion (DC) of photopolymerization using QTH and LED was higher than results of using PAC in the control group. After polymerization using QTH and LED, the DC results from the different ceramic thickness- 0.5 mm, 1.0 mm, 1.5 mm- did not show a significant difference when compared with those of control group. However, the DC for polymerization using PAC in the 1.5mm ceramic group showed significantly lower DC than those of the control group and 0.5 mm ceramic group (P<.05). At 80s and 160s, the DC of light-cured resin cement beneath 1.0 mm ceramic using LED was significantly higher than at 20s (P<.05). Conclusion: Within the limitation of this study, when adhering PLV to porcelain with a thickness between 0.5-1.5 mm, the use of PAC curing units were not considered however, light cured resin cements were effective when cured for over 40 seconds with QTH or LED curing units. Also, when curing the light cured resin cements with LED, the degree of polymerization was not proportional with the curing time. Curing exceeding a certain curing time, did not significantly affect the degree of polymerization.

Analysis on the Effect of the Dental Health Characteristics of Adult on the Status of Recognition and Practical Application of Dental Hygiene Devices (성인의 구강건강 특성이 구강위생용품의 인지도와 사용 실태에 미치는 영향)

  • Lee, Eun-Ju;Lee, Mi-Oak
    • Journal of dental hygiene science
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    • v.10 no.4
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    • pp.241-250
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    • 2010
  • The purpose of this study, which was processed from March $22^{nd}$ to April $9^{th}$ of 2010, was to figure out recognition, well-formed instructions, and Practical application about dental hygiene devices based on the dental health characteristics of 350 adults who dwell in Busan and Gyeongnam regions. Also, this study recommended the adults to use dental hygiene devices and provided such devices to help individuals take care of their dental health at home. The collected data was statistically processed with a statistics SPSS (Statistical Packages for Social Science 14.0. SPSS Inc. USA) program. First of all, in order to demonstrate the characteristics of the sample population statistics and that of the descriptive data, frequency analysis was performed and to find out the relationship between variations of the dental health, Chi-squared test through Crosstabs was operated. According to the study, recognition and Practical application of dental hygiene devices were very low. Therefore, public announcement about necessity and effectiveness of such devices should be reinforced nationwide and instructions on choosing the right device and using of the dental hygiene devices based on patients' conditions by dental hygienic human efforts gathered from dental health organization should be carried out.

Plasma Transforming Growth Factor-$\beta$1 Levels of Cancer Patients (암 환자의 혈장 Transforming Growth Factor-$\beta$1 농도)

  • 전지현;이시은;이수진;박찬후;장정순;하우송;박순태;박병규
    • Biomedical Science Letters
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    • v.5 no.2
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    • pp.181-190
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    • 1999
  • To evaluate the usefulness of transforming growth factor-$\beta$1 (TGF-$\beta$1) as a new tumor marker, we determined the plasma TGF-$\beta$1 levels using sandwich ELISA assay in cancer patients. Patients with three most common adult cancers in Korea (stomach, liver and breast cancer) and children's cancers (leukemia and two kinds of solid tumor) were enrolled for the study. Furthermore, 39 individuals were subjected to age and sex-stratified plasma TGF-$\beta$1 analysis. No statistical difference was demonstrated with respect to age or sex. The mean plasma TGF-$\beta$1 level (16.0 ng/ ml) of stomach cancer patients was significantly higher than that (8.3 ng/ml) of controls. However, there was no difference among the mean plasma TGF-$\beta$1 levels of liver, breast cancer patients and controls. Seven of 16 patients (43.7%) with stomach cancer, one of 8 (12.5%) with liver cancer, and one of 7 (14.3%) with breast cancer showed higher TGF-$\beta$1 levels compared to controls. Plasma TGF-$\beta$1 concentrations of five leukemic children remained in the normal range regardless of the remission state. In contrast, initial high TGF-$\beta$1 levels from two children with solid tumors returned to normal range on surgical resection of tumors. From the above results, we could conclude that plasma TGF-$\beta$1 levels of apparently healthy individuals seem to be rather constant irrespective of difference in age or sex, and the plasma TGF-$\beta$1 has the limited value as a screening test for the diagnosis of aforementioned adult cancers because of its low sensitivity. Finally, additional studies need to be pursed for the large number of stomach cancer and pediatric solid tumor patients in order to reach a secure conclusion on the usefulness of plasma TGF-$\beta$1 as a tumor marker in these patients.

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