• Journal of The Korean Association For Science Education
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• v.43 no.4
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• pp.389-402
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• 2023

The purpose of this study is to investigate the structural relationship between pedagogical content knowledge (PCK), grit, and teaching efficacy perceived by elementary school science teachers. Based on the results of the literature review, PCK was divided into knowledge domain and enactment domain, and these two domains were set as exogenous latent variables to investigate the structural relationship between PCK and teaching efficacy. In addition, teachers' grit was added to the structural equation model as an exogenous latent variable to investigate the effect of teachers' knowledge, enactment, and grit on teaching efficacy. Upon confirming the structural relationship between PCK and teaching efficacy, it was found that a high correlation between knowledge and enactment, and that knowledge had a greater effect on teaching efficacy than enactment. Furthermore, upon confirming the structural relationship between PCK, grit, and teaching efficacy, both knowledge and grit were found to have a statistically significant effect on teaching efficacy, while the relationship between enactment and teaching efficacy was not statistically significant. Based on the results of these studies, we discussed ways to strengthen teacher expertise and teaching efficacy in elementary school science classes and the meaning of grit in the field of teacher expertise.

• Korean Journal of Culture and Social Issue
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• v.22 no.1
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• pp.65-85
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• 2016

In this study, we examined the longitudinal change of multicultural acceptability, peer relationship, and teacher relationship using latent growth curve modeling. This study used data from the second, third, and fourth waves of the middle school student cohort (N=2,178) of the Korean Children-Youth Panel Survey (KCYPS). The dependent variable was multicultural acceptability. The independent variables were peer relationship and teacher relationship. The major longitudinal findings of this study are as follows: First, peer relationships, teacher relationships and multicultural acceptability increased with time. Second, peer relationship showed a significant effect on the multicultural acceptability over time. Finally, the teacher relationship showed a significant effect on the multicultural acceptability over time. These results show differentiation with previous cross-sectional studies of multicultural acceptability. Furthermore, it is expected that this study will provide educational implications for the cultivation of multicultural acceptability.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.78-83
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• 2013

The traffic culture index is used as a major index in evaluating the traffic safety services of local governments and also serve as important data for the planning and implementation of traffic safety services. However, as the traffic culture index gradually became a standard for comparison among local governments, in part, certain cases arose which questioned the grounds for selecting variables for the index and the validity of the index in terms of its influential relationship between evaluation items. This study analyzed the index's influential relationship by utilizing a PLS structural equation model based on the evaluation results of the 2011 traffic culture index. A variable-linking model was created which recognized the relativity taking into account of the indirect effects between latent variables and this model was proven to be a model suitable in explaining the traffic culture index with a 97.8% explanation power. It was found that traffic safety(0.530), driving behavior(0.527), pedestrian behavior(0.187) and vulnerable road users(0.147), in such order, had an effect on the traffic culture index. It was also found that human casualties due to traffic accidents under "traffic safety" and traffic light compliance rate under "driving behavior" had an important effect. The study showed that motor vehicle share in illegal parking in school zones did not have a valid explanation power regarding "vulnerable road users".

• Journal of Applied Reliability
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• v.15 no.4
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• pp.241-247
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• 2015

Purpose : The demand for higher fuel economy vehicles has helped develop fuel-efficient vehicles such as a CVVL called continuous variable valve lift. Existing CVVL has been applying DC type motor to control intake valve, but recently some car parts manufacturers have been developing a BLDC type CVVL motor for improvements of endurance performance. The purpose of this study is to find the potential failure mechanism of the CVVL BLDC moto in early stage of development based on the design properties and design the accelerated life test model. Methods : CVVL BLDC is consist of brushs, coil, magnetic, PCB, bearing and so on. Each component has a latent failure mechanism caused by temperature, humidity, vibration. By analysis result of the failure mechanism, thermal fatigue is the most important factor of a durability of CVVL BLDC motor. So, we designed a new accelerated life test model for guarantee of the CVVL BLDC motor. Results : A crack occurred on via hole in test using the conditions we designed, so we did change the design to avoid this failure. The via hole dimension is changed a little larger, as a result we achieve improvements in reliability of the CVVL BLDC motor. By applying various kinds and extreme level of stresses, we can find the operating limits of products. Conclusion : In thesis, We analyzed the failure mechanism of CVVL BLDC and designed an accelerated life test method to give a guarantee for reliability. Based on the test results, we could improve the reliability of developments by change of design.

• Atmosphere
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• v.29 no.4
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• pp.355-365
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• 2019

Based on in-situ monitoring data produced by National Institute of Meteorological Sciences, we evaluated the performance of Joint UK Land Environment Simulator (JULES) on the surface energy balance for rice-paddy and cropland in Korea with the operational ancillary data used for Unified Model (UM) Local Data Assimilation and Prediction System (LDAPS) (CTL) and the high-resolution ancillary data from external sources (EXP). For these experiments, we employed the one-year (March 2015~February 2016) observations of eddy-covariance fluxes and soil moisture contents from a double-cropping rice-paddy in BoSeong and a cropland in AnDong. On the rice-paddy site the model performed better in the CTL experiment except for the sensible heat flux, and the latent heat flux was underestimated in both of experiments which can be inferred that the model represents flood-irrigated surface poorly. On the cropland site the model performance of the EXP experiment was worse than that of CTL experiment related to unrealistic surface type fractions. The pattern of the modeled soil moisture was similar to the observation but more variable in time. Our results shed a light on that 1) the improvement of land scheme for the flood-irrigated rice-paddy and 2) the construction of appropriate high-resolution ancillary data should be considered in the future research.

• Journal of Korean Society of Transportation
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• v.24 no.6 s.92
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• pp.119-127
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• 2006

Recently. there are demanding a better sidewalk environment considering side of psychic as well as physical factors as the rapid growth of cities and improvement of traffic consciousness. Also. it needs to give a better sidewalk environment because those pedestrians evade a sidewalk space with minimum Physical design standards. So. we think very important that get a grip what makes Pedestrian feel a comfort and amenity in sidewalk above all. In this study, we carried out a cognition experiment of sidewalk environment on considering the human's psychic with Sensibility Ergonomics and the survey method using SD (Semantic Differential) scale. And we made a recognition evaluation model of sidewalk landscape and sensibility recognition model of sidewalk design factors using LISREL model that analysis sensibility recognition of sensibility adjective by SD scale. In results, we found out a possibility of the design with comfort and amenity in sidewalk environment as considering Sensibility Ergonomics, and an importance of harmonious green environment as a roadside tree etc. above all.

• Analytical Science and Technology
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• v.33 no.4
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• pp.197-207
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• 2020

The current comparison methods with scoring systems that are used to compare visualized latent fingerprints (LF) have disadvantages. Evaluators using these methods are prone to make errors and fail to discriminate LFs correctly to notice the differences among those LFs. Therefore, a comparative and quantitative evaluation method that is capable of obtaining more objective and quantitative results is needed. Densitometric image analysis (DIA) is used in other fields as a reliable semi-quantitative comparison method. To apply DIA to LFs, the potential variables that can occur during the DIA process were tested. The visualized ridges of LFs can be compared using the concentration of dots against the background to make it possible to analyze the ridges with DIA. The variables that can be present during the DIA process include the thickness of the analysis line, the number of ridges to be taken, the number of divided zones within each of the fingerprints, and the angles of the analysis line against the ridge lines that were selected. From the analysis of the inked fingerprints and circular lines that are similar to fingerprints, the angle of the analysis lines with the ridge line was the most significant variable. The preliminary test result was applied to the comparison of LFs that were developed with the powder method and then compared with the AFIS analysis. A similar trend was found, and a more detailed and semi-quantitative comparison of the visualized LFs was possible. In the future, it is necessary to check the evaluative ability of the DIA method by analyzing the visualized LFs with other various development methods. However, DIA is currently an option that can be used as an objective comparative evaluation method during fingerprint studies with supplementary role.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.483-489
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• 2010

An image analysis-based soft sensor is designed and applied to automatic quality classification of product appearance with color-textural characteristics. In this work, multiresolutional multivariate image analysis (MR-MIA) is used in order to analyze product images with color as well as texture. Fisher's discriminant analysis (FDA) is also used as a supervised learning method for automatic classification. The use of FDA, one of latent variable methods, enables us not only to classify products appearance into distinct classes, but also to numerically and consistently estimate product appearance with continuous variations and to analyze characteristics of appearance. This approach is successfully applied to automatic quality classification of intermediate and final products in industrial manufacturing of engineered stone countertops.

• Annals of Clinical Neurophysiology
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• v.4 no.1
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• pp.44-50
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• 2002

Introduction : Orthostatic tremor develops in the legs while standing up with no weakness, pain or imbalance in the leg and the tremor is characteristically not observed when walking. However there have been some confusions about orthostatic tremor in several aspects. For the past ten years, we have observed 4 patients with orthostatic tremor. In each case tests were performed to investigate the following three important areas of inquiry about orthostatic tremor. Firstly, whether this disorder is an independent diagnostic entity or a variant of essential tremor. Secondly, whether the progress of this disorder is specifically related with standing posture. Lastly, the nature of the pathophysiologic mechanism behind the appearance of the tremor when standing after the lapse of a certain latent period and its disappearance upon the commencement of walking. Methods : Our 4 cases of orthostatic tremor were studied clinically, electrophysiologically, and pharmacologically. Electrophysiological tests included tremor spectrum test and electromyography. Results : We observed the presence of this tremor in several other tonic postures, as well as its absence, in a vertically lifted position from all our cases. Our cases registered a variable tremor frequency between 5 and 12 Hz according to the tremor spectrum test and EMG. Furthermore all our 4 cases demonstrated patterns of both synchronous EMG activity and alternating EMG activity at various times in homologous muscles of both legs. Orthostatic tremor was improved significantly with propranolol as well as clonazepam. Conclusions : From the results of our study we drew the following conclusions. It is probable that orthostatic tremor is simply a variant of essential tremor rather than being an independent diagnostic entity and that in most cases its development is specifically related with muscle contraction rather than merely with the act of standing. Furthermore we discovered a clue in the previously described neural control mechanism that the nuclear bag fibers in the muscle spindle have lag time of several seconds in their response to muscle strength and that their baseline does not reset fully in rapidly moving muscle. This neural control mechanism could offer sufficient explanation for the phenomena of tremor appearance when standing and disappearance when walking in orthostatic tremor.

• Journal of Distribution Science
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• v.17 no.5
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• pp.103-111
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• 2019

Purpose - This paper aims to examine a spirituality's impact on the posttraumatic interpersonal relationships of family violence with a structural equation model(SEM). This article starts with the research idea that family violence experience bring about negative emotion in terms of interpersonal relationship leading to the distribution of negative affect in social relationship. The research question of this study pinpoints on how family violence experience affects interpersonal relationship problems and how spirituality affects interpersonal relations problems. Based on the idea, we attempts to deal with spirituality's impact as a driving factor of transforming the distribution of negative affect. Research design, data, and methodology - The structural equation modelling(SEM) is employed as a analysis method of this study. SEM provides a chiefly cross-sectional statistical modelling method, and moreover it allows multiple variables to be associated with a latent variable in this analysis. 300 samples from Seoul, Gyeonggy and Gangwon are selected in the survey. We chose available 271 among them. Results - The results verify that trauma have placed an negative impact on personal relations. The study results also shows that the more serious get the degree of family violence trauma, the worse become interpersonal relationship problems. What is more interesting is that the degree of trauma's impact on interpersonal relation problems in male is higher than that of trauma's impact in female. It is mainly attributed to the fact that women are superior to men in terms of empathy ability and interpersonal relationship orientation. It can be noted that the well-managed spirituality will be able to make a great contribution towards reducing the degree of trauma caused by interpersonal relationships. Conclusions - The study results demonstrates that family violence have negative impacts on spirituality, while spirituality have an positive impacts on reduction the problems of interpersonal relationship. It has been found out that family violence trauma may cause negative affectivity in personal relations, which can distribute negative impacts regarding interpersonal relationship in society. This study also supports that spirituality will be able to function well as a helper, which may reduce the distribution of negative affect in society.