• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.529-530
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• 2007

The design of a measurement system to perform Harmonic State Estimation(HSE) is a very complex problem. In particular, the number of available harmonic analysis measurement instruments is always limited. Therefore, a systematic procedure is needed to design the optimal placement of measurement points. This paper presents an optimal algorithm of HSE which is based on an optimal placement of measurement points using PSO. This PSO-HSE has been applied to power system for the validation of an optimal algorithm of HSE. The study results have indicated an economical and effective method for optimal placement of measurement points using PSO in the HSE.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.521-530
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• 2014

In this paper, the glint effect of maritime target to a radar system was analyzed by simulation and field test with a barge and corner reflectors. From the experiment, we proposed a glint measurement method of a real maritime target and it was indicated that the glint effect between the simulation results and real measurement is similar. Also it was founded that the glint effect is related to the relative amount of RCS(Radar Cross Section) difference among major scattering point and minor scattering points. Finally, the experiment showed the glint effects of the rotating barge with some different combinations of scattering points.

• Speech Sciences
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• v.3
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• pp.156-166
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• 1998

In this paper, I would like to propose a dividing method by estimating the inflection points and the average magnitude energy in speech signals. The method proposed in this paper gave not only a satisfactory solution for the problems on dividing method by zero-crossing rate, but could estimate the feature of the transient period after dividing the starting point and transient period in speech signals before steady state. In the results of the experiment carried out with monosyllabic speech, it was found that even through speech samples indicated in D.C. level, the staring and ending point of the speech signals were exactly divided by the method. In addition to the results, I could compare with the features, such as the length of transient period, the short term energy, the frequency characteristics, in each speech signal.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.43-48
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• 2003

This study presents the detailed methods for university facilities mapping using GPS and totalstation. In the control survey by GPS network adjustment, the level of significance for the height value of fourth order triangulation stations was estimated about loom. The accuracy analysis of height determination by totalstation for the traverse points showed that the RMSE came out 9mm to the basis of direct leveling, so it indicated that trigonometric leveling by totalstation was correct comparatively. For GPS/RTK method, the result of accuracy analysis about traverse points showed that the RMSE came out 33㎜ in horizontal location to the basis of totalstation's outcome and 15㎜ in height value to the basis of direct leveling. In the construction survey, GPS/RTK surveying is quicker and more economical than totalstation surveying in the feasible areas of GPS surveying, but there were many impossible areas lot GPS/RTK surveying by the obstacles like a building.

• Environmental Engineering Research
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• v.23 no.4
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• pp.390-396
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• 2018

This study investigated the transformation of dissolved organic matter (DOM) in a free-water surface flow constructed wetland. Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) coupled with preparative high-performance liquid chromatography (prep-HPLC) was used to analyze the compositions of biopolymers (polysaccharides, amino sugars, proteins, polyhydroxy aromatics, lipids and lignin) in DOM according to the molecular size at three sampling points of the water flow: inflow, midflow, and outflow. The prep-HPLC results verified the decomposition of DOM through the decrease in the number of peaks from three to one in the chromatograms of the sampling points. The Py-GC/MS results for the degradable peaks indicated that biopolymers relating to polysaccharides and proteins gradually biodegraded with the water flow. On the other hand, the recalcitrant organic fraction (the remaining peak) in the outflow showed a relatively high concentration of aromatic compounds. Therefore, the ecological processes in the constructed wetland caused DOM to become more aromatic and homogeneous. This indicated that the constructed wetland can be an effective buffer area for releasing biochemically stable DOM, which has less influence on biological water quality indicators, e.g., biochemical oxygen demand, into an aquatic ecosystem.

• Journal of dental hygiene science
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• v.23 no.2
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• pp.93-102
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• 2023

Background: To investigate political participation by dental hygiene students and analyze the differences therein based on the learning efficacy of dental hygiene policy. Methods: A total of 239 dental hygiene students who were expected to graduate responded to the survey. The data were collected online using a structured questionnaire consisting of 6 items on general characteristics, 10 on political participation, and 15 on the learning efficacy of dental hygiene policy. Statistical analysis was performed using SPSS 23.0. Political participation based on the learning efficacy of dental hygiene policy was analyzed using independent t-tests, ANOVA, and multiple regression analysis (p<0.05). Results: Among the dental hygiene students, 60.7% voted in all three recent presidential, general, and local elections, and 14.2% did not. For political parties supported, 65.7% responded that they had "no supporting party," and 34.3% indicated that they had a "supporting party." In terms of the level of political participation of dental hygiene students (0~50 points), the average score was 25.8 points, with the average passive political participation (0~25 points) score at 15.6 points and the average active political participation (0~25 points) score at 10.2 points. With an increase in dental hygiene policy learning efficacy, both passive and active political participation showed higher scores (p<0.05). Conclusion: Dental hygiene students showed low political participation. The presence of a supporting party, higher voting participation, and higher learning efficacy of dental hygiene policy were associated with higher passive and active political participation. Therefore, to increase this population's interest in political participation, various opportunities for related learning need to be promoted and provided in academia, leading to the enhancement of their political capabilities. In this manner, dental hygienists should expand their capabilities in various roles such as advocates, policy makers, and leaders.

• Journal of the Korean Home Economics Association
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• v.45 no.1
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• pp.111-125
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• 2007

By examining the existing Galot products in the market, we aimed to discover areas for new development and lay out the foundational system for establishing a database(DB) of their pattern grading. For the analysis, the team focused mainly on Galot in forms of casual korean traditional clothes, since they have the largest market share. The main accomplishments from this research are as follows. First, because adult females are the largest segment to consider in deciding the size system for grading, we selected three sizes that have to be compatible with the KS Clothing Standardized Sizing. Second, for basic pattern grading, we applied the reference size indicated in KS Clothing Standardized Size, and also used half dart sloper and dartless sloper. Third, we categorized designs according to the presence or absence of a dart, the structure of closure, and the shape of the sleeve and neck. We indicated the grading points with numbers and body area in Korean to make it easier for the users to understand when using the computer system and doing manual work. To further increase the user convenience, we provided diagrams for categorized designs, pattern grading layout, and a table for calculated grading points variation.

• Journal of Korean society of Dental Hygiene
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• v.22 no.1
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• pp.47-54
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• 2022

Objectives: The purpose of this study was to examine the association between work environment and positive psychological capital on job embeddedness in dental hygienists. Methods: Data were collected from 263 dental hygienists in the dental institutions. It was then assessed by mean of descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and a stepwise multiple regression analysis. Results: The impact of work environment was 3.35±0.46 points, positive psychological capital was 3.30±0.40 points, and job embeddedness was 3.34±0.47 points. The result of the stepwise multiple regression analysis indicated that work environment, positive psychological capital and clinical career predicted 45.7% (F=7.35, p<0.001) of job embeddedness. Conclusions: Therefore, it is necessary to improve working environment and to strengthen positive psychological capital in order to increase the degree of work commitment in dental hygienists, and to encourage long-term service.

• The Journal of Korean Physical Therapy
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• v.22 no.1
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• pp.83-90
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• 2010

Purpose: This study aimed to determine the degree of job stress and self-esteem of physical therapists as well as the correlation between the two variables. Method: This study targeted 218 physical therapists of Busan City, and was carried out from July 16 to August 6, 2009 as survey research. A structured questionnaire referring to advance researches was used as a research tool. Job stress symptoms were measured one a 5 point scale, the higher the point total, the higher the job stress. Self-esteem was measured on a 4 point scale, the higher the point total, the lower the self-esteem. After data collection we determined descriptive statistics, and did reliability analysis, factor analysis, Spearman's correlation analysis, and regression analysis. Results: Reliability analysis indicated that reliability for the job stress questionnaire was 0.93 and for the self-esteem was 0.83. The average job stress score of physical therapists was 1.19 points which was not high. The average self-esteem score was 1.76 points, whichwas high. It appeared that the higher the self-esteem, the lower the job stress. Also, self-esteem had an influence on psychological symptoms among job stress factors. Conclusion: Job stress and self-esteem of physical therapists are well-correlated and influence each other. Accordingly, self-esteem can be used as a variable for adjusting job stress of physical therapists.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.147-157
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• 2017

This study investigated the characteristics of variations in carbon dioxide concentration and air temperature with the vertical change of surface in a grassplot. Field observations were carried out at a grassplot in Gyeongnam Science High School, over four days in August and November, 2015. Continuous observation equipment (GMP343, VAISALA) was installed at the LP (0.1 m from the surface) and UP (1.1 m from the surface) points, and the carbon dioxide concentration and air temperature were measured simultaneously at 1-min intervals. To summarize the results of the observation, August had higher than average concentrations of carbon dioxide, while November showed average air temperatures. Moreover, the concentration of carbon dioxide was higher at the UP point, while the air temperature was higher at the LP point. The correlation coefficient of carbon dioxide concentration between the UP and LP points was 0.80 in August across all the four days, while it was higher in November at 0.58-0.95. The results of the regression analysis of carbon dioxide concentration with air temperature changes for both August and November showed a distinct change at the LP point (R2=0.36-0.76), as compared to the UP point (R2=0.1-0.57). Between the UP and LP points, the carbon dioxide concentration and air temperature regression analysis results indicated that an active exchange was taking place between the two points.