• Journal of The Korean Association For Science Education
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• v.37 no.6
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• pp.971-980
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• 2017

In this study, we explored the characteristics of instrumental genesis in high school students' scientific inquiries. Twenty-three 10th to 11th graders in a science research club participated in this study. The students in 6 groups autonomously planned and performed their own scientific inquiries for one semester. Their activities were videotaped and recorded. Semi-structured interviews were conducted. Material request papers and group worksheets were also collected for analysis. The results of the study suggested that students' practices were categorized as instrument genesis. When instrument genesis did not occur, the cases at the beginning of and during the practice were described respectively. Instrumental genesis was found to appear in three categories: instrumentation; instrumentation and instrumentalization; and instrumentalization. The characteristics and details of case represented in each category were described and discussed related to affordance as the results of the study. On the bases of the results, the implications for the reconsideration of the instruments in school science inquiries are discussed.

• The KSFM Journal of Fluid Machinery
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• v.2 no.3 s.4
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• pp.59-66
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• 1999

In this study the effects of nozzle diameter on the performance characteristics for the tangential impeller-type water meter are studied experimentally. The nozzle is cut along the tangential direction of the inner case in the water meter. The nozzle shape is round and the number of nozzles used for the experimental study are 8. The performance characteristics are discussed for various nozzle diameters such as 3.1, 3.3, 3.5, 4.0, 4.5 and 5.0 mm. Among the tangential impeller-type water meters, the water meter with the nozzle diameter of 5.0 mm shows the least pressure loss and the instrumental error compared to the Korean Standards.

• Korean Journal of Food Science and Technology
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• v.7 no.3
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• pp.168-180
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• 1975

Analogs and extenders should have mouthfeel and chewing characteristics that are similar to the food they are replacing or extending. Instrumental methods can measure some of the physical properties that constitute 'texture' but only sensory methods can provide a complete description and quantification of the textural properties of a food. Instrumental methods and sensory methods for measuring texture are reviewed.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.1-7
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• 1980

Less-volatile organic components in leaves from aromatic tobaccos of different varieties, both Oriental and Korean types were isolated and concentrated using a simple apparatus with fewer manipulations. Each less-volatile concentrate was then subjected to spectrophotometric recording in the visible range, to thin-layer chromatographic group separation, and high-performance liquid chromatographic profile analysis. The methods allow detection of significant quantitative differences in visible absorption spectra, TLC patterns, and high resolution HPLC profiles among varieties.

• Nuclear Engineering and Technology
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• v.37 no.5
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• pp.503-510
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• 2005

An instrumental neutron activation analysis was used to measure the concentrations of about 24 elements associated with airborne particulates (PM10) that were collected in the most polluted urban region of Daejeon city, Korea from 2000 to 2002. Using the measurement data for various elements, both the extent of elemental pollution in the study area and the seasonality in their distribution characteristics were examined. Examinations of their distribution patterns indicated that most elements with crustal origin tend to exhibit seasonal peaks during spring, while most elements with anthropogenic origin tend to exhibit seasonal peaks during fall or winter. In order to explain the factors regulating their mobilization properties, the data were processed by a factor analysis. Results of the factor analysis suggested competing roles of both industrial and natural source processes, despite that the study site is located at a downwind position of the industrial complex. Based on the overall results of this study, it is concluded that the site may be strongly impacted by man-made sources but the general patterns of elemental distributions in the study area inspected over a seasonal scale are quite consistent with those typically observed from natural environment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.688-693
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• 2002

Identification method is formulated to evaluate the dynamic characteristics of air bearings under NFR(Near Field Recording) sliders. Impulse responses and frequency response functions of NFR sliders are obtained on numerical non-linear models including rigid motion of slider and fluid motion of air bearing under the slider. Modal parameters and system parameters are identified by modal analysis method and instrumental variable method. The parameters of sliders are utilized to evaluate the dynamic characteristics of air bearings. Also, this study shows the difference between the dynamic characteristics of NFR and HDD slides, and squeeze effect of air bearings.

• Korean journal of food and cookery science
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• v.20 no.2
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• pp.170-179
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• 2004

The purpose of this study was to investigate the instrumental and sensory characteristics of coffee-sulgi(rice cake) with different ratios of the ingredients; coffee(30$m\ell$, 40$m\ell$ and 50$m\ell$ of espresso and instant coffee) and sugar (50g and 75g). A commercial scheme for coffee-sulgi was also investigated. The optimal mixing ratios of coffee-sulgi with added espresso were rice flour 500g, salt 5g, espresso 40$m\ell$ and sugar 75g. Those of coffee-sulgi with added instant coffee were the same. As the sensory intensities of coffee aroma, coffee taste, sweetness, moistness, elasticity, color acceptance for coffee-sulgi and overall acceptance for quality were enhanced, the overall preference for coffee-sulgi was increased. In addition, overall preference was positively correlated with adhesiveness and a-value of instrumental characteristics, but negatively correlated with cohesiveness and L-value. In coffee-sulgi with added espresso, intensities of coffee aroma, browniness, coffee taste, color acceptance for coffee-sulgi, overall acceptance for quality and overall preference were higher than those of coffee-sulgi with added instant coffee. In this point, gourmet coffee-sulgi with added espresso and universal coffee-sulgi with added instant coffee could be differentiated in the coffee-sulgi markets. In conclusion, this study of coffee-sulgi and the differential scheme for the market will be useful to expand rice processing, enhance the intake of rice cakes and provide a reference for the commercialization of rice cakes.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.303-308
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• 1984

Instrumental and sensory characteristics of chewing gums were measured at each masticatory stage, and the correlations between the characteristics were analyzed. In instrumental characteristics, similarities were proved between initial puncture work and puncture force, intermediate hardness and penetration work, final hardness and penetration work, and adhesion work and adhesion force. Final hardness correlated highly with yield force and the slope of force-distance curve of penetration test, and the slope also correlated significantly with springiness and adhesion force. In sensory characteristics, the correlations of the same parameter between trained panel and consumer were extremely high. Initial stiffness correlated significantly with both intermediate and final firmness by consumer. Highly significant correlations were obtained between final firmness and stiffness and between lift and cohesion by trained panel, whereas firmness correlated with adhesion negatively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.677-684
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• 2004

This paper describes a method for identifying the dynamic characteristics of air foil bearings for high speed turbomachinerys with the LS/IV method. In fact identifying the characteristics of air foil bearings is very difficult work, and it is tried to identify it. Experiments were conducted to determine the structural dynamic and hydrodynamic characteristics of air foil bearings. Numerical predictions compare the static and dynamic force performances. The housing of the bearing on the journal was driven by the impact hammer which were used to simulate impact force acting on air foil bearings. The characteristics of air foil bearings were extracted from the frequency response function (FRF) by LS(Least Square) method and IV(Instrumental Variable) method. The experiment was tested at 0 rpm and $10000\sim16000rpm$. And the test results were introduced about the dynamic characteristics of air foil bearings, and also compared with theoritical results.

• Korean Journal of Occupational Health Nursing
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• v.24 no.4
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• pp.352-362
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• 2015

Purpose: The purpose of this study was to investigate the effects of job stress and support from supervisors on depression of care givers in elderly care facilities. Methods: Subjects were 191 care givers working in elderly care facilities in K-Province in Korea. Data were collected from self-administered questionnaires. Descriptive statistics, ${\chi}^2$ test, t-test, F-test, Pearson's and Spearman's correlation coefficients, and hierarchical multiple logistic regression with dummy variables were used for statistical analysis of data. Results: Job stress measured with Korean Occupational Stress Scale was $56.16{\pm}5.88$. Emotional and instrumental support from supervisors were $37.05{\pm}7.30$ and $32.39{\pm}7.34$, respectively. After controlling for general characteristics, job stress was significantly related to depression (OR: 1.07, 95% CI: 1.01~1.14). However, job stress became non-significant in the model that included instrumental support from supervisors. Not emotional but instrumental support from supervisors was significantly related to depression of care givers (OR: 0.93, 95% CI: 0.88~0.99). Conclusion: Results of this study suggest that job stress has negative effects and instrumental support from supervisors has protective effects on depression of care givers in elderly care facilities. Therefore, measures to increase instrumental support by supervisors should be developed to improve psychological health of care givers in elderly care facilities.