• Restorative Dentistry and Endodontics
• /
• v.24 no.2
• /
• pp.381-391
• /
• 1999

A new 5th generation adhesive system(ONE-STEP) has been supplied which operators can apply to conditioned tooth surfaces by one simplified step. The purpose of this study was to determine whether different methods of adhesive application and various air drying duration after applying adhesive affect the shear bond strength of composite resin to dentin, and to evaluate the adhesive pattern of composite resin and dentin under SEM. Seventy-seven extracted human molar teeth were cleaned and mounted in palstic test tubes. The occlusal dentin surfaces were exposed with Diamond Wheel Saw and smoothed with Lapping and Polishing Machine (South Bay Technology Co., U.S.A.). Teeth were randomly divided into 7 groups (n=11), In experimental A group, adhesive was applied to dentin with agitation for 20 sec. In experimental N-A group, adhesive were continuously applied to dentin for 20 sec. Also control and experimental 1, 2, 3, 4 groups were dried for 10, 0, 5, 20, 30 seconds after applying adhesive, respectively, Adhesives were light cured for 10 sec. A gelatin capsule 5mm in diameter was filled with Aelitefil$^{TM}$ composite resin, placed on the treated dentin surface and light cured for 40 see, from three sides, All specimens were stored in distilled water at room temperature for 24 hours. The shear bond strengths were measured using a universal testing machine(AGS-1000 4D, Japan) at a crosshead speed of 5mm/min. An one-way ANOVA and LSD test were used for statistical analysis of the data. For SEM evaluation, seven specimens were made and sectioned. Representive postfracture and seven specimens were mounted on brass stubs, sputter-coated with gold and observed under SEM. The results were as follows : 1. The shear bond strength of experimental A group which adhesive were applied to dentin with agitation was higher than that of experimental N-A group (continuous application), and there was significant difference between two groups (p<0.01). 2. The interface between composite and dentin according to different application methods showed close adaptation in experimental A group and showed tinny gap in experimental N-A group. 3. The shear bond strength accoding to various air drying duration was the lowest value(7.57${\pm}$2.60 MPa) in experimental 1 group, so there was significant difference between experimental 1 group and other four groups (p<0.05). But there was no significant difference of shear bond strength between four groups (p>0.05). 4. The interface between composite and dentin according to various air drying duration showed close adaptation in control group and tinny gap in experimental 3 and 4 groups. But experimental 1 and 2 groups showed $30{\mu}$ and 6 - $10{\mu}m$ thick gaps, respectively.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.45 no.2
• /
• pp.68-75
• /
• 2017

Demand for dwarf mondo grass (DMG; Ophiopogon japonicus 'Nanus') as an ornamental garden plant is expected to grow in the future. The purpose of this study was to investigate the levels of shade tolerance and ground cover by growing DMG under a variety of shade conditions for 18 months (May 2015~October 2016). DMG plants grown in bare ground for 3 years in Jangheung-gun, Jeonnam were used for testing. In an experimental site created in Naju city in Jeonnam, the DMG was planted in planters ($70cm{\times}70cm{\times}24cm$) and covered with a shading curtain to block natural light. Shaded conditions were then arranged under different levels of shade (0%, 55% and 75%). When the plants were grown, growth (leaf size, the number of leaves, fresh weight and dry weight) and ground coverage of DMG were analyzed. According to the results, DMG growth in terms of leaf size and the number of leaves was statistically higher under zero shade (full sunlight), when compared to other shaded conditions. DMG's fresh and dry weights were significantly greater under 0% and 55% shade, compared to those under 75% shade. The degrees of shade tolerance required for normal growth of DMG were found in the range of 0~50%, meaning that more than 50% shade may decrease plant growth. There were no statistical differences in ground coverage rates of DMG under different levels of shade. When 220 tillers were planted per $1m^2$ of plot, up to 80% of the area was covered by DMG after 18 months. Since DMG requires nutrient-rich soil to grow, sufficient nitrogen fertilizers are proposed to accelerate the ground cover of DMG. As DMG remained alive over the winter in the experiments, this study also suggests that DMG can be planted in the southern temperate region.

• The Korean Journal of Applied Statistics
• /
• v.5 no.2
• /
• pp.243-254
• /
• 1992

In the present study two sets of unbalanced two-way cross-classification data with and without empty cell(s) were used to evaluate empirically the various sums of squares in the analysis of variance table. Searle(1977) and Searle et.al.(1981) developed a method of computing R($\alpha$\mid$\mu, \beta$) and R($\beta$\mid$\mu, \alpha$) by the use of partitioned matrix of X'X for the model of no interaction, interchanging the columns of X in order of $\alpha, \mu, \beta$ and accordingly the elements in b. An alternative way of computing R($\alpha$\mid$\mu, \beta$), R($\beta$\mid$\mu, \alpha$) and R($\gamma$\mid$\mu, \alpha, \beta$) without interchanging the columns of X has been found by means of,$(X'X)^-$ derived, using $W_2 = Z_2Z_2-Z_2Z_1(Z_1Z_1)^-Z_1Z_2$. It is true that $R(\alpha$\mid$\mu,\beta,\gamma)\Sigma = SSA_W and R(\beta$\mid$\mu,\alpha,\gamma)\Sigma = SSB_W$ where $SSA_W$ and means analysis and $R(\gamma$\mid$\mu,\alpha,\beta) = R(\gamma$\mid$\mu,\alpha,\beta)\Sigma$ for the data without empty cell, but not for the data with empty cell(s). It is also noticed that for the datd with empty cells under W - restrictions $R(\alpha$\mid$\mu,\beta,\gamma)_W = R(\mu,\alpha,\beta,\gamma)_W - R(\mu,\alpha,\beta,\gamma)_W = R(\alpha$\mid$\mu) and R(\beta$\mid$\mu,\alpha,\gamma)_W = R(\mu,\alpha,\beta,\gamma)_W - R(\mu,\alpha,\beta,\gamma)_W = R(\beta$\mid$\mu) but R(\gamma$\mid$\mu,\alpha,\beta)_W = R(\mu,\alpha,\beta,\gamma)_W - R(\mu,\alpha,\beta,\gamma)_W \neq R(\gamma$\mid$\mu,\alpha,\beta)$. The hypotheses $H_o : K' b = 0$ commonly tested were examined in the relation with the corresponding sums of squares for $R(\alpha$\mid$\mu), R(\beta$\mid$\mu), R(\alpha$\mid$\mu,\beta), R(\beta$\mid$\mu,\alpha), R(\alpha$\mid$\mu,\beta,\gamma), R(\beta$\mid$\mu,\alpha,\gamma), and R(\gamma$\mid$\mu,\alpha,\beta)$ under the restrictions.

• Journal of Korean Society of Transportation
• /
• v.24 no.5 s.91
• /
• pp.57-66
• /
• 2006

This paper presents new pedestrian signal timings considering pedestrian demand Pedestrian characteristics, and land use which were obtained by Pedestrian characteristics field survey and pedestrian signal operation survey. Pedestrian signal timings suggested were compared to the existing pedestrian signal timings by using real field data. pedestrian characteristics field survey was conducted to collect pedestrian crossing speed data and reaction time data. Sixteen areas in Seoul were selected for the data collection. The average pedestrian crossing speed was 1.30m/sec and the 15th Percentile speed was 1.11m/sec. The average reaction time was 2.24 seconds. Pedestrian crossing speed differs by land use, road width. pedestrian age, sex, and number of Pedestrians. Reaction time also differs by road width, pedestrian age, and number of pedestrians. Statistical testing was performed to secure reliability of the collected data.

• Journal of Veterinary Clinics
• /
• v.24 no.2
• /
• pp.77-81
• /
• 2007

Diagnostic performance of polymerase chain reaction (PCR) for detecting Dirofilaria immitis in dogs was evaluated when no gold standard test was employed. An enzyme-linked immunosorbent assay test kit (SnapTM, IDEXX, USA) with unknown parameters was also employed. The sensitivity and specificity of the PCR from two-population model were estimated by using both maximum likelihood using expectation-maximization (EM) algorithm and Bayesian method, assuming conditional independence between the two tests. A total of 266 samples, 133 samples in each trial, were randomly retrieved from the heartworm database records during the year 2002-2004 in a university animal hospital. These data originated from the test results of military dogs which were brought for routine medical check-up or testing for heartworm infection. When combined 2 trials, sensitivity and specificity of the PCR was 96.4-96.7% and 97.6-98.8% in EM and 94.4-94.8% and 97.1-98% in Bayesian. There were no statistical differences between estimates. This finding indicates that the PCR assay could be useful screening tool for detecting heartworm antigen in dogs. This study was provided further evidences that Bayesian approach is an alternative approach to draw better inference about the performance of a new diagnostic test in case when either gold test is not available.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.19 no.1
• /
• pp.44-50
• /
• 2015

Purpose Quality control used in laboratory help to sustain precision and accuracy consistently to ensure the Diagnostic and treatment for medical employee. To perform an evaluation in statistical manner, it is recommended to use different quality control material than calibrator from manufacturer, quality control material must include analyzed concentration perimeter, must use more than two different concentration materials and recommended to use materials to indicate the concentration in clinical use. However, currently used quality control material has limit of evaluation due to unconsidered concentration or improperly used to get clinical importance data. Therefore, we compared the value of quality control, DIACON Hormone Level 1, 2, 3 (Scantibodies, USA) and DIACON Tumor Level 1, 2, 3 which applied to clinical concentration range. Materials and Methods DIACON Hormone Level 1, 2, 3 (Scantibodies, USA) and DIACON Tumor Level 1, 2, 3 (Scantibodies, USA) that used materials and methods test to compare the result from five RIA testing institution and one institution that used Elecsys (ROCHE) and Architect (ABOTT) for each level. The reagent RIA kit that used in this experiment is followed by Table 2 and 3. Test has performed by instruction itself and follow by instruction. Results Among DIACON hormone result of twenty four items, level 1 have three items, level 2 have four items and level 3 have five items were out of manufacturer set up range based on the average value. Among DIACON tumor result of thirteen items, level 1 have three items, level 2 have four items and level 3 have five items were out of manufacturer set up range. Other result were inside of manufacturer range. Conclusion For quality control material, it is widely available in market, but it is limited for normal range which is only concerned in improper clinical value and difficult to evaluate important concentration area in terms of clinical analyze. In this experiment, we evaluate Hormone twenty three items and Tumor thirteen items with DIACON Hormone and Tumor (Scantibodies, USA) to resolve this limit and we could observe that it ca be substituted and used.

• Restorative Dentistry and Endodontics
• /
• v.23 no.1
• /
• pp.197-212
• /
• 1998

The purpose of this study was to evaluate the effects of fluoride application on the aspect of shear bond strength of three aesthetic restorative materials to dentin. One light-cured composite resin(Palfique Esterite) and two light-cured glass ionomer cements(Fuji II LC and Compoglass)were used in this study. 120 permanent molars were used for this study. The teeth were extracted due to the origin of periodontal disease. The crowns of all teeth were removed, and the remaining roots were embedded in epoxy resin. The mesial or distal surfaces of roots were ground flat to expose dentin and polished on wet 320-, 400-, and 600 grit SIC papers for a total of 120 prepared flat root dentin surfaces. The prepared samples were divided into six groups. Group 1, 3, and 5 were control groups and group 2, 4, and 6 were experimental groups. Sixty samples for experimental groups were treated with 2% NaF solution for 5 minutes. Group 1 and 2 were bonded with Plafique Esterite, group 3 and 4 were bonded with Fuji II LC, and group 5 and 6 were bonded with Compoglass. After 24 hours water storage at $37{\pm}1^{\circ}C$, all samples were subjected to a shear to fracture with Instron universal testing machine(No.4467) at 1.0 mm/min displacement rate. Dentin surfaces treated with each conditioners before bonding and interfacial layers between dentin and aesthetic restorative materials were observed under Scanning Electron Microscope(Hitachi S-2300) at 20Kvp. The data were evaluated statistically at the 95% confidence level with ANOVA test. The result were as follows; 1. Among the control groups, group 1 showed strongest bond strength and group 3 showed weakest. 2. Among the experimental groups, group 2 showed strongest bond strength and group 6 showed weakest. 3. Statistical analysis of the data showed that pretreatment of dentin with 2% NaF solution significantly decreased the bond strength of three aesthetic restorative materials to dentin(P<0.05). 4. SEM findings of fluoride treated dentin surfaces (2, 4, 6 group) demonstrated dentin surfaces covered with fluoridated reaction products. 5. Except group 4 and 6, resin tags were formed in all groups.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.12 no.4
• /
• pp.1-10
• /
• 2008

Shear wave velocity($V_S$), which can be obtained using various seismic tests, has been emphasized as representative geotechnical dynamic characteristic mainly for seismic design and seismic performance evaluation in the engineering field. For the application of conventional geotechnical site investigation techniques to geotechnical earthquake engineering, standard penetration tests(SPT) and piezocone penetration tests(CPTu) together with a variety of borehole seismic tests were performed at many sites in Korea. Through statistical modeling of the in-situ testing data, in this study, the correlations between $V_S$ and geotechnical in-situ penetrating data such as blow counts(N value) from SPT and piezocone penetrating data such as tip resistance ($q_t$), sleevefriction($f_s$), and pore pressure ratio($B_q$) were deduced and were suggested as an empirical method to determine $V_S$. Despite the incompatible strain levels of the conventional geotechnical penetration tests and the borehole seismic tests, it is shown that the suggested correlations in this study are applicable to the preliminary estimation of $V_S$ for Korean soil layers.

• Journal of Radiation Industry
• /
• v.9 no.2
• /
• pp.69-75
• /
• 2015

Purpose: The gonad shielding is used to minimize the impact of the exposure to gonads when Abdomen, Pevis and Hip X-ray inspections are conducted on radiation impressionable pediatric patients. By the way, the gonad is palpable difficult and impossible to check visually because it's a sensitive area, so tests are conducted with the approximate location of shielding, thereby appearing problems of not shielding gonads accurately. Accordingly, this study produced shields by age and gender of pediatric patients and studied the method of positioning shields with ASIS as a reference point without palpable sensitive areas, and tried to evaluate its usability. Materials and methods: The study surveyed 30 pediatric patients by gender and age, who came and got inspected in Department of Radiology, our hospital from February 2012 to January 2014 and obtained the value of tolerance by measuring the average size of the pelvis using the distance measurement function of Infinitt Piview with the images stored in the PACS and producing shields by age and gender of pediatric patients and specifying the areas at random for the comparative analysis of pre- and post-using. It calculated the technology statistics($mean{\pm}SD$) with the value of tolerance measured the length using SPSS 12.0 statistical program. Results: As for boys, differences in the tolerance range of pre- and post-using shields were 2.69 mm in case of 1 year old, 2.58 mm in 2 years, 2.37 mm in 3 years, 2.815 mm in 4~5 years, 2.043 mm in 7~10 years, and as for girls, 1.92 mm in 1~2 years, 1.75 mm in 3~4 years, 2.52 mm in 5~6 years and 1.93 mm in 7~10. After analyzing the pre- and post-using shields for all of boys and girls, there were statistically significant differences(P<0.050). Conclusions: It is considered that we can minimize the exposure to gonads and get a better video for diagnosis in testing high biological impressionable pediatric, if we use shields correctly with ASIS as a reference point considering its shape and size by age and gender in Abdomen, Pevis and Hip X-ray inspections.

• Journal of Sericultural and Entomological Science
• /
• v.3
• /
• pp.61-67
• /
• 1963

This report is prepared to find how the filament of cocoon bave size deviation relates with the raw silk made by them which are intensively cultured in this country. Three recommended hybrid varieties and two varieties under working at Suwon Sericultural Experiment Station were selected as specimens. The cocoons were reeled as an individual filament of every fifty meters long skein with a wrap reel to weigh the denier and to investigate the relationship of the above statement so that it may be used for the quality estimation before processing it into raw silk. The conclusions obtained are as follows. (1) The variation of Pk${\times}$Sn was found as best cocoon for 21 denier raw silk use, but the number of cocoon to make the denier has to be eight which might cause more labor cost. (2) Baektoo-Kumkang and Myohiang-Chongchon were found as economical varieties for 21 denier use. (3) Seulak-Soyang is a proper variety for the use of 14 or 28 denier silk use. (4) Myohiang-Chongchon did not confirm a good property from the aspect of denier deviation. (5) It was found that there was a fairly strong corelationship between the mean cocoon bave size deviation as indicated by Ono's report. (6) Three graphs were prepared to estimate the cocoon quality before processing into various sizes of raw silk using the mean cocoon bave size and the raw silk size to be prepared. (7) Mean time, the graph which is able to estimate the expectable grade of the raw silk size deviation was designed for the practical use. (8) The expectable grade of the varieties used in this report were found as following data. Notice (A......cocoon number to make raw silk (B......total cocoon bave size deviation (C......expectable silk grade (9) The result of the work concerning the expectable denier deviation on 21 denier silk was the same with the statistical actual testing result as 1.25 D while the distribution showed farther necessity of improvement in technically.