• Journal of Korean society of Dental Hygiene
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• v.24 no.3
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• pp.263-270
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• 2024

Objectives: The purpose of this study is to identify the effects of dental hygienists' cooperation and compensation satisfaction on job embeddedness through positive psychological capital, and to provide basic data on ways to improve the welfare of dental hygienists and the quality of medical services. Methods: From July 1 to 20, 2023, a questionnaire survey was administered to 206 dental hygienists via an online link. SPSS Statistics ver. 22.0 was used to conduct the frequency analysis, t-test, one-way ANOVA, Pearson's correlation coefficient, multiple regression analysis and hierarchical multiple regression. Results: Factors influencing dental hygienists' job embeddedness were type of compensation satisfaction (β=0.362, p<0.001), intangible compensation satisfaction (β=0.190, p<0.001), cooperation between dental hygienists (β=0.178, p<0.05), and age (β=0.112, p<0.05). Positive psychological capital was found to have a complete mediating effect on work cooperation in the effect of dental hygienists' job embeddedness (p>0.05), and partial mediating effect on compensation satisfaction (p<0.01). As a result of the Sobel test, it was confirmed that it was statistically significant as dental hygienist work cooperation (Z=2.339, p=0.019), dentist work cooperation (Z=1.985, p=0.047), intangible compensation satisfaction (Z=2.286, p=0.022), and type compensation satisfaction (Z=1.980, p=0.048). Conclusions: In order to improve the work environment of dental hygienists, develop programs to improve positive psychological capital, secure access to education, and various related studies are needed.

• Journal of the Korean Society for Railway
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• v.16 no.5
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• pp.386-393
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• 2013

In this study, the so-called repeated plate load bearing test (RPBT) used to get $E_{v2}$ values in order to check the degree of compaction of subgrade, and to get design parameters for determining the thickness of the trackbed foundation, is investigated. The test procedure of the RPBT method is scrutinized in detail. $E_{v2}$ values obtained from the field were verified in order to check the reliability of the test data. The $E_{v2}$ values obtained from high-speed rail construction sites were compared to converted modulus values obtained from resonant column (RC) test results. For these tests, medium-size samples composed of the same soils from the field were used after analyzing stress and strain levels existing in the soil below the repeated loading plates. Finite element analyses, using the PLAXIS and ABAQUS programs, were performed in order to investigate the impact of the strain influence coefficient. This was done by getting newly computed $I_z$ to get the precise strain level predicted on the subgrade surface in the full track structure; under wheel loading. It was verified that it is necessary to use precise loading steps to construct nonlinear load-settlement curves from RPBT in order to get correct $E_{v2}$ values at the proper strain levels.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.95-101
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• 1991

The results of relationships between colloidal stability and soil pH on three Hawaii's volcanic ash soils developed under the three different rainfall conditions can be summarized as follows: 1. The Hilo soil only revealed the increase of colloidal stability by becoming for from Z.P.C point to either side of pH. 2. Hilo and Kawaihae soils, however, showed the increase of colloidal stability only in the higher pH range than their Z.P.C. 3. $P_2O_5$ drying procers decreased colloidal stability kof these soils because of so called irreversible drying characteristics of amorphous materials and the decrement was in order of: Akaka>Hilo>Kawaihae expressing positive correlation with content of amorphous materials in them. 4. The difference of colloidal stability curves among three soils can easily be interpreted by DLVO theory considering 0.1N-HCl amount added to decrease their soil pH, respectively. The addition of large amount of 0.1N-HCl into Akaka and Kawaihae soils did not effectively develop the positive charge but resulted in the shrink of diffuse double layer thickness inducing large attraction forces among soil particles.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.125-132
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• 2001

The present study was conducted to investigate biological degradability of phosphamidon and profenfos. In the biodegradation test of two pesticides by the modified river die-away method from May 20 to July 29, 1999, the biodegradation rate was determined in Nakdong (A) and Kumho(B) River. The residual percentages of phosphamidon were 74.9%, 68.8% and 62.7% in control, A and B samples 7 days after applicaton, respectively. Biodegradation constants and half-lives of phosphamidon were 25.1%, 21.9% and 11.9% in control, A and B samples 7 days after application. Biodegradation constants and half-lives of profenofos were 0.0005 and 58.4 days in A, 0.0013 and 21.6 days in B, respectively. The biodegradation rates of phosphamidon and profenofos were higher in the Kumho River (B) than in the Nackdong River(A). The strains of microorganisms for the degradation of phosphamidon and profenofos were identified as Klebsiella pneumoniae, Aeromonas hydrophila and Acinetobacter calcoaceticus, all Gram-negative bacteria. In order to identify biodegradate products, the extracts of cultivates were analyzed by GC/MS. The mass spectra of biodegradate roducts of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the biodegradate metabolites of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.

• Korean Journal of Poultry Science
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• v.19 no.3
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• pp.113-123
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• 1992

This study was carried out to build up new synthetic egg Production lines which had sex linked gene for feather color sexing and had also superior combining ability for producing the best commercial chicks. In order to make autosexing layer line, the commercial layers which had Z$^{s}$ Z$^{s}$ and Z$^{s}$ W were mated. Among progeny, the chicks which had homozygote of silver gene and non-silver gene were selected for making dam and sire lines. Afterwards the closed flock breeding method was utilized to improve general performances of the each line. The performances of egg production in synthetic line were 161 day for age at sexual maturity, 219 eggs for total egg number to 60 weeks of age, 84% for hen-day egg production and 619 for average egg weight. There was no difference in egg production between new synthetic lines and imported breeds. In the analysis of genetic trends, the estimates of genetic parameter in the autosexing lines were similar to those of the general population of layer breeders. This results indicated the consistency of genetic variation from this selection.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.89-94
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• 1997

In order to reduce energy input in direct ethanol production from raw starch by co-immobilized Aspergillus awamori(A) and Zymomonas mobilis(Z), A-Z 36 culture system which was changed to anaerobic after 36 h of aerobic fermentation without sterilization was investigated. This immobilized cell system can not be carried out under unsterile conditions because of growth of microbial contaminants from original medium. Among some food additives such as sorbic acid, benzoic acid, dehydroacetic acid, p-hydroxybenzoic acid, Vantocil IB and Neupectin-L, Vantocil IB and Neupectin-L were a potent antibacterial agent in A-Z 36 culture cell system and were not affected in hydrolysis of substrate as compared with the case of control. Ethanol yield(6.9 g/l) in system of addition of 0.1% Neupectin-L was slightly higher than that in control(6.4 g/l). When 2% starch was fed five times in fed-batch culture with 0.1% Neupectin-L, ethanol yield and productivity were 34 g/l and 2.0 g/l/day, respectively.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.359-370
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• 2000

The purpose of this investigation was to observe the viscoelastic properties of five commercial flowable(Aeliteflo, Flow it, Revolution, Tetric flow, Compoglass flow), three conventional hybrid(Z-100, Z-250, P-60) and two condensable(Synergy compact, SureFil) resin composites. A dynamic oscillatory shear test was done to evaluate the storage shear modulus (G'), loss shear modulus(G"), loss tangent(tan ${\delta}$) and complex viscosity(${\eta}^*$) of the resin composites as a function of frequency - dynamic frequency sweep test from 0.01 to 100 rad/s at $25^{\circ}C$ - by using Advanced Rheometric Expansion System(ARES). To investigate the effect on the viscosity of resin composites of filler volume fraction, the filler weight % and volume % were measured by means of Archimedes' principle using a pyknometer. The results were as follows 1. The complex viscosity ${\eta}^*$ of flowable resins was lower than that of hybrid resins and significant differences were observed between brands. The complex viscosity ${\eta}^*$ of condensable resins was higher than that of hybrid resins. The order of complex viscosity ${\eta}^*$ at ${\omega}$=10 rad/s was as follows, Surefil, Synergy compact, P-60, Z-250, Z-100, Aeliteflo, Tetric flow, Compoglass flow, Flow it, Revolution. The relative complex viscosity of flowable resins compared to Z-100 was 0.04~0.56 but Surefil was 30.4 times higher than that of Z-100. 2. The storage shear modulus G' and the loss shear modulus G" of flowable resins were lower than those of hybrid resins but those of condensable resins were higher. The patterns of the change of loss tangent, tan ${\delta}$, of resin composites with increasing frequency were significantly different between brands. The phase angles, ${\delta}$, ranged from $30.2{\sim}78.1^{\circ}$ at ${\omega}$=10 rad/s. 3. All composite resins represent pseudoplastic nature with increasing shear rate. 4. The complex shear modulus $G^*$ and the phase angle ${\delta}$ was represented by the frequency domain phasor form, $G^*({\omega})=G^*e^{i{\delta}}=G^*{\angle}{\delta}$. The locus of frequency domain phasor plots in a complex plane was a valuable method that represent the viscoelastic properties of composite resins. 5. There was no direct linear correlationship but a weak positive relation was observed between filler volume % or weight % and the viscosity of the resin composites.

• Journal of Internet of Things and Convergence
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• v.7 no.4
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• pp.59-68
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• 2021

The purpose of this study is to develop a personality education tea culture therapy program to effectively improve juvenile delinquency prevention and social adaptation. In order to verify the effectiveness of the tea culture therapy program through social intervention, we analyzed whether there were significant differences in the scores of social characteristics such as self-efficacy, self-control, and interpersonal relationships of juvenile detention students before and after participating in the program. Ten juvenile detention students between the ages of 14 and 17 who were accommodated to a juvenile detention center in B city were selected as the experimental group for the study. The tea culture therapy program was conducted 10 times as a social intervention personality education for juvenile delinquents, and as a result, self-efficacy was found to have a pre-mean of 2.37 (SD 0.33) and a post-mean of 2.49 (SD 0.31), showing a significant difference (Z=-5.874. P=.000), self-control showed a significant difference with the pre-mean 2.06 (SD 0.20) and the post-mean of 2.16 (SD 0.19) (Z=-4.743, P=.001). The interpersonal relationship was found to have a significant difference, with a pre-mean of 1.90 (SD 0.32) and a post-mean of 2.15 (SD 0.21) (Z=-5.892, P=.000). The above results show that this program has a significant effect on improving social characteristics such as self-efficacy, self-control, and interpersonal relationships among juvenile detention students. Therefore, the tea culture therapy program developed in this study for personality education for juveniles can be used as a personality education program for various types of adolescents as well as in the field of correctional welfare in the future.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.45-48
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• 1993

High-order field gradients are useful for spatial localization of a volume of interest and dynamic range improvement of signal detection in NMR (Nuclear Magnetic Resonance) spectroscopy and imaging. This paper proposes a design method of shielded high-order gradient coils to reduce tile effect of eddy current on tile spectroscopy and imaging results. According to the experimental results, the shielded gradient coils produce less than 2 % eddy current compared to non-shielded coils. Two shielded $z^2$ gradient coils have been designed and constructed for 1.5 T whole-body and 3.0 T animal NMR imaging systems. Experimental results are in good agreement with the theoretically expected behavior and show the utility of the shielded high-order gradient coils.

• The Journal of Engineering Geology
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• v.27 no.1
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• pp.51-58
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• 2017

The purpose of this study was to quantitatively evaluate the state of rocks in load steps by using the low-frequency ultrasonic flaw detection method. The initial Vp-velocities measured with a CND tester were in the order of Z-axis < X-axis < Y-axis, with 1687.5 m/s along the X-axis, 1690.7 m/s along the Y-axis, 1548.3 m/s along the Z-axis, and an average of 1642.2 m/s. The overall average of the Q vlaues, measured with a Silver Schmidt hammer, was 62.6, which corresponds to a uniaxial compressive strength of ~105 MPa. The Vp-velocity, measured with a low-frequency ultrasonic flaw detector at load steps of 50%, 60%, 70%, and 80%, typically decreases in the order of X-axis < Y-axis < Z-axis with increasing load steps. This oder contrasts with that of the initial Vp-velocities. As the load step increases the factors that reduce the Vp-velocity in the X-axis direction are more influential than those in the Y-axis or Z-axis directions. This indicates that the initial state of rocks can vary and is dependent on the stress state.