• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.395-403
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• 2007

The purpose of this study is to investigate the main factors that affect turnover of Dental Hygienists so that it leads to preventing high turnover and long-term service in their position. Data were obtained from 112 dental hygienists who are currently working for dental clinics from September 17th 2007 to October 16th 2007 via questionnaires. For this study, the demographic factors and unique characteristics of Dental Hygienists are considered as well as all the variables of statistic. The results derived from using SPSS 11.0 are as follows: 1. The average of job related factors is 2.55 point, the average of job satisfaction is 2.59 point, the average of salary related factor is 2.24 point and the average of changing their occupation is 2.85 point. 2. The difference between the factors related to age and changing their occupation shows the highest level on job related factors.(pM0.033) in the age between 26 and 30. 3. Dental Hygienists who are in their occupation for 6years to 9 years answer that salary would be the main reason to change their jobs. 4. For married dental hygienists, salary related factor is the main reason to make them change their occupation.(pM0.002)

• Journal of Ecology and Environment
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• v.40 no.1
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• pp.34-44
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• 2016

Background: Little is known about how chemical water quality is associated with ecological stream health in relation to landuse patterns in a watershed. We evaluated spatial characteristics of water quality characteristics and the ecological health of Dongjin-River basin, Korea in relation to regional landuse pattern. The ecological health was assessed by the multi-metric model of Index of Biological Integrity (IBI), and the water chemistry data were compared with values obtained from the health model. Results: Nutrient and organic matter pollution in Dongjin-River basin, Korea was influenced by land use pattern and the major point sources, so nutrients of TN and TP increased abruptly in Site 4 (Jeongeup Stream), which is directly influenced by wastewater treatment plants along with values of electric conductivity (EC), bacterial number, and sestonic chlorophyll-a. Similar results are shown in the downstream (S7) of Dongjin River. The degradation of chemical water quality in the downstream resulted in greater impairment of the ecological health, and these were also closely associated with the landuse pattern. Forest region had low nutrients (N, P), organic matter, and ionic content (as the EC), whereas urban and agricultural regions had opposite in the parameters. Linear regression analysis of the landuse (arable land; $A_L$) on chemicals indicated that values of $A_L$ had positive linear relations with TP ($R^2=0.643$, p < 0.01), TN ($R^2=0.502$, p < 0.05), BOD ($R^2=0.739$, p < 0.01), and suspended solids (SS; ($R^2=0.866$, p < 0.01), and a negative relation with TDN:TDP ratios ($R^2=0.719$, p < 0.01). Conclusions: Chemical factors were closely associated with land use pattern in the watershed, and these factors influenced the ecological health, based on the multimetric fish IBI model. Overall, the impairments of water chemistry and the ecological health in Dongjin-River basin were mainly attributes to point-sources and land-use patterns.

• Journal of the Korean Society of School Health
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• v.6 no.1
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• pp.58-68
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• 1993

This study was designed to grasp the knowledge and practice the level about visual impairment protective care of the primary school students and also analyse the state of visual impairment. The subjects of this study ware 347 students composed of 456 boys and 391 girls in primary school students. The data were collected by questionaire developed for the purpose of this study which has been made through studying references. These were carried out from the 10th to 30th of June 1992. Analysis of the data was done utilizing SPSS for percentage, mean, S.D., T-test., ANOVA and Pearson's Correlation Coefficient. The major results obtained from this study were as follows: 1. The level of the knowledge about visual impairment protective care was in intermediate range (mean on 20 point scale of 12.34, with O=definitely no), but low in aspects of preventive care for overwork of eye (mean on 5 point scale of 2.67). 2. The level of the practice about visual impairment protective care was intermediate range (mean on 20 point scale of 12.34, with O=definitely no), but low in aspects of preventive care for overwork of eye (mean on 5 point scale of 2.58). 3. Significant variables influencing knowledge of visual impairment protective care were sex (p<0.01) and grade (p<0.001). 4. Significant variables influencing practice of visual impairment protective care was living area (p<0.01). 5. Correlation between knowledge and practice: Those who have more knowledge score have more practice score (p<0.001). 6. vision impairment state 1) Student with subnormal in 0.9 or less were 26.3% in left eye and 28.4% in right eye. 2) Student with subnormal in 0.6 or less were 11.9% in left eye and 10.9% in right eye. 7. Vision impairment programs 1) Males are slightly higher in the degree of visual impairment than females. 2) Visual impairment were increased in accordance with the increase of grade. 3) Urban students are higher in the degree of visual impairment than rural students, but these seem to have no statistical meaning.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.2
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• pp.380-389
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• 2005

The Goldschmidt iterative algorithm for a floating point divide calculates it by performing a fixed number of multiplications. In this paper, a variable latency Goldschmidt's divide algorithm is proposed, that performs multiplications a variable number of times until the error becomes smaller than a given value. To calculate a floating point divide '$\frac{N}{F}$', multifly '$T=\frac{1}{F}+e_t$' to the denominator and the nominator, then it becomes ’$\frac{TN}{TF}=\frac{N_0}{F_0}$'. And the algorithm repeats the following operations: ’$R_i=(2-e_r-F_i),\;N_{i+1}=N_i{\ast}R_i,\;F_{i+1}=F_i{\ast}R_i$, i$\in${0,1,...n-1}'. The bits to the right of p fractional bits in intermediate multiplication results are truncated, and this truncation error is less than ‘$e_r=2^{-p}$'. The value of p is 29 for the single precision floating point, and 59 for the double precision floating point. Let ’$F_i=1+e_i$', there is $F_{i+1}=1-e_{i+1},\;e_{i+1}',\;where\;e_{i+1}, If '$[F_i-1]<2^{\frac{-p+3}{2}}$ is true, ’$e_{i+1}<16e_r$' is less than the smallest number which is representable by floating point number. So, ‘$N_{i+1}$ is approximate to ‘$\frac{N}{F}$'. Since the number of multiplications performed by the proposed algorithm is dependent on the input values, the average number of multiplications per an operation is derived from many reciprocal tables ($T=\frac{1}{F}+e_t$) with varying sizes. 1'he superiority of this algorithm is proved by comparing this average number with the fixed number of multiplications of the conventional algorithm. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a divider. Also, it can be used to construct optimized approximate reciprocal tables. The results of this paper can be applied to many areas that utilize floating point numbers, such as digital signal processing, computer graphics, multimedia, scientific computing, etc

• Journal of Korean Academy of Fundamentals of Nursing
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• v.20 no.3
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• pp.259-268
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• 2013

Purpose: The purpose of this study was to identify factors influencing job satisfaction among nurses working in college health centers in order to enhance their role functions and to increase their work capabilities. Method: In this study a cross-sectional survey was used to collect data from 106 nurses working in college health centers. Collected data were analyzed using frequency, Pearson correlation coefficients, independent t-test, one-way ANOVA and multiple regression with the SPSS 20.0. Results: Mean scores for self-efficacy, job stress and job satisfaction for the participants were 3.86 (5-point scale), 2.51 (5-point scale) and 3.37 (5-point scale) respectively. There was a negative correlation between self-efficacy and job satisfaction (r=-.653, p<.001). Factors influencing job satisfaction were job stress (${\beta}$=-.58, p=<.001), level of perception among the nurses that they were contributing to the health promotion of students (${\beta}$=-.21, p=.005) and marital status (${\beta}$=.17, p=.029). These 3 elements accounted for 47.7% of the variance in job satisfaction. Conclusions: The results indicate that reduction in job stress and increase in the perception that nurses are contributing to the promotion of students' health are important to reinforce the role function of nurses and to increase their work capabilities.

• Journal of Environmental Science International
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• v.26 no.4
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• pp.467-481
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• 2017

This study sought to determine the changes in weather conditions in urban streets, along with conditions of traffic and roads in urban areas. The variations in weather conditions depending on traffic differed according to distance. First, the temperature difference measured by traffic results is as follows: T1 point $1.03^{\circ}C$, T2 point $1.04^{\circ}C$, T3 point $0.9^{\circ}C$, T4 point $1.01^{\circ}C$, and T5 point $0.31^{\circ}C$. The average difference between the measured temperatures by the point of measurement was $0.86^{\circ}C$. The changes in wind velocity according to traffic volume results of the measurements is T1 point 1.32 m/s, T2 point 0.80 m/s, T3 point 0.29 m/s, T4 point 0.04 m/s, and T5 point 0.09 m/s. The difference between the average wind speeds was 0.51 m/s and traffic jams caused substantial differences in distance. The relative humidity tended to be inversely proportional to temperature. The measurements results ares T1 point 2.29%, T2 point 2.67%, T3 point 2.47%, T4 point 2.16%, and T5 point 0.91% The difference between the average relative humidity was 7.3%. In case of independent sampling T test according to traffic volume, changes in wind velocity and temperature were directly proportional to the level of statistical significance(p<0.01). On the other hand, relative humidity tended to be inversely proportional; however, there was no statistical significance.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.457-463
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• 2011

Introduction: This study evaluate the soft tissue changes to the upper lip and nose after Le Fort I maxillary posterosuperior rotational movement. Materials and Methods: Twenty Skeletal class III patients, who had undergone bimaxillary surgery with a maxillary Le Fort I osteotomy and bilateral sagittal split ramus osteotomy, were included in the study. The surgical plan for maxilla was posterosuperior rotational movement, with the rotation center in the anterior nasal spine (ANS) of maxilla. Soft and hard tissue changes were measured by evaluating the lateral cephalograms obtained prior to surgery and at least 6 months after surgery. For cephalometric analysis, four hard tissue landmarks ANS, posterior nasal spine [PNS], A point, U1 tip), and five soft tissue landmarks (pronasale [Pn], subnasale [Sn], A' Point, upper lip [UL], stomion superius [StmS]) were marked. A paired t test, Pearson's correlation analysis and linear regression analysis were used to evaluate the soft and hard tissue changes and assess the correlation. A P value <0.05 was considered significant. Results: The U1 tip moved $2.52{\pm}1.54$ mm posteriorly in the horizontal plane (P<0.05). Among the soft tissue landmarks, Pn moved $0.97{\pm}1.1$ mm downward (P<0.05), UL moved $1.98{\pm}1.58$ mm posteriorly (P<0.05) and $1.18{\pm}1.85$ mm inferiorly (P<0.05), and StmS moved $1.68{\pm}1.48$ mm posteriorly (P<0.05) and $1.06{\pm}1.29$ mm inferiorly (P<0.05). The ratios of horizontal soft tissue movement to the hard tissue were 1:0.47 for the A point and A' point, and 1:0.74 for the U1 tip and UL. Vertically, the movement ratio between the A point and A' point was 1:0.38, between U1 tip and UL was 1:0.83, and between U1 tip and StmS was 1:0.79. Conclusion: Posterosuperior rotational movement of the maxilla in Le Fort I osteotomy results in posterior and inferior movement of UL. In addition, nasolabial angle was increased. Nasal tip and base of the nose showed a tendency to move downward and showed significant horizontal movement. The soft tissue changes in the upper lip and nasal area are believed to be induced by posterior movement at the UL area.

• Journal of Korean Society of Forest Science
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• v.9 no.1
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• pp.75-80
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• 1969

Traced observations were carried out for efficiency and behavior of Camellia japonica L in bloom stage by employing $p^{32}$-labeled phosphorus, growing in Southern Korea, and the results were as follows. 1) The percentage of phosphorus contained in flowerbud was double the value of the other parts, and the root and the stem were the same patterns in the course of the times. 2) The circulation of the phosphorus in the plant seems to occur within 24 hours, the proportions of the phosphorus at the growing-point and flowerbud had a half of the total phosphorus contained in other parts. 3) Specific activities of each part were notable on the growing-point where, after 24 hours it took more than 80 percent. On the other hand, the efficiency rate which derived from the phosphorus was shown as about 19 percents.

• Communications for Statistical Applications and Methods
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• v.3 no.2
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• pp.275-282
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• 1996

A life distribution F with survival function $\overline{F}$=1-F, finite mean $\mu$ and mean residual life m(t) is said to be NBUE(NWUE) if m(t)$\leq$($\geq$) .$\mu$ for t$\geq$0. This NBUE property can equivalently be characterized by the fact that $\varphi$(u)$\geq$($\leq$)u for 0$\leq$u$\leq$1, where $\varphi$(u) is the scaled total-time-on test transform of F. A generalization of the NBUE properties is that there is a value of p such that $\varphi$(u)\geq.u$ for 0$\leq$u$\leq$p and $\varphi$(u)\leq$$\leq$u$\leq$1, or vice versa. This means that we have a trend change in the NBUE property. In this paper we point out an error of Klefsjo's paper (1988). He erroneously takes advantage of trend change point of failure rate to calculate the empirical test size and power in lognormal distribution. We solves the trend change point of mean residual lifetime and recalculate the empirical test size and power of Klefsjo (1988) in mocensoring case.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.4
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• pp.249-256
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• 2021

Objectives: The purpose of this study was to evaluate the postoperative anteroposterior stability and improvements in facial asymmetry after performing LeFort I osteotomy in the maxilla, sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) in the mandible, and lateral corticectomy on the IVRO side. Materials and Methods: From July 2009 to October 2018, a retrospective analysis was performed on 11 subjects. Lateral cephalometric radiograph was performed preoperatively (T0), postoperatively (T1), and at 12 months of follow-up (T2), and the B point distance was measured. Posteroanterior cephalometric radiograph was performed preoperatively (S0) and at 12 months of follow-up (S1) and was used to measure five indicators (Ag angle, M-Ag, Co-Ag, Co-Me, and Ag-Me) of facial asymmetry. Results: The B point distances for T0 and T1 were significantly different (P=0.007), whereas those for T1 and T2 were not significantly different (P=0.1). In addition, there was a significant difference between the B point distances of T2 and T0 (P=0.026). Comparison of the facial asymmetry indicators before and after surgery showed a significant difference for all indicators between S0 and S1: the P-values of Ag angle, M-Ag, Co-Ag, Co-Me, and Ag-Me were 0.003, 0.003, 0.008, 0.006, and 0.004, respectively. The Z value was based on negative ranks. Conclusion: There was no significant difference in the B point distances from postoperation to the 12-month follow-up. However, there were significant differences in all five indicators related to facial asymmetry before and after surgery. The values for the five indicators of facial asymmetry all increased postoperatively.