• Journal of Radiation Protection and Research
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• v.38 no.1
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• pp.29-36
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• 2013

The aim of this study was to determine the correlation between exposure index (EI) and dose factors related to radiation dose optimization in digital radiography (DR) system. Two phantoms with built-in regional test object for quantitative assessment of images were used to produce image signals that acquired in chest radiography background. EI and entrane surface dose (ESD) increased proportionally with rise of radiation dose (kVp, mAs) in both DR and CR systems. Especially, DR detector was effective to form good contrast and hence, reached easily to improvement of image quality with minimal dose changes. It made operators possible to expect the accuracy of EI values deeply related to absorbed dose of the detector. The evaluation of images was obtained specially employed calculation of noise to signal ratio (NSR) and contrast to noise ratio (CNR). These measurements were performed for how exposure factors affect image quality. NSR was inversely proportional to kVp and mAs and low NSR represented high signal detection efficiency. Consequently, EI values was the measure of the amount of exposure received by the image receptor and it was proportional to exposure factors. Therefore the EI in a recommended range from manufacturer can offer optimal image quality. Also, continuous monitoring of EI values in the digital radiography can reduce the unnecessary patient dose and help the quality control of the system.

• Journal of Korean Theatre Studies Association
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• no.40
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• pp.307-344
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• 2010

Cultural Studies built on the critical mind of New Left exposes the relationship between culture and power, and investigates how this relationship develops the cultural convention. It has achieved the new perspective that could make us to think culture and art in terms of political correctness. However, the critical voices against the theoretical premises of Cultural Studies have been increased as its heyday in 1980s was nearly over. For instance, Terry Eagleton, a former Marxist literary critic, declared in 2003 that the golden age of cultural theory is long past. This essay, therefore, intends to show the weak foundations on which the approaches of cultural studies to theatre rest and to clarify the general problem of their introduction to theatre studies. The approach of cultural studies to theatre takes the form of 'top-down inquiry' as it applies a theory to a particular play or historical period. In other word, from the theory the writer moves to the particular case. The result is not an inquiry but rather a demonstration. This circularity can destroy the point of serious intellectual investigation as the theory dictates answers. The goal-oriented narrow viewpoint as a logical consequence of 'top-down inquiry' makes the researcher to favor the plays or the parts of a play that are proper to test a theory. As a result it loses the fair judgment on the artistic value of a play, and brings about the misinterpretation. The interpreter-oriented reading is the other defect of cultural studies as it disregards the inherent meaning of the text, distorting a play. The approach of cultural studies also consists of a conventionality as it arrives at a stereotyped interpretation by using certain conventions of reasoning and rhetoric. The cultural theories are fundamentally the 'outside theories' that seek to explain not theatre but the very broad features of society and politics. Consequently their application to theatre risks the destructive criticism, disregarding the inherent experience of theatre. Most of, if not all, cultural theories, furthermore, are proven to be lack of empirical basis. The alternative method to them is a 'cognitive science' that proves scientifically our mind being influenced by bodily experience. The application of cultural materialism to Shakespeare's is one of the cases that reveal the limits of cultural studies. Jonathan Dollimore and Water Cohen provide a kind of 'canonical study' in this application that is imitated by the succeeding researchers. As a result the interpretation of has been flooded with repetitive critical remarks, revealing the problem of 'top-down inquiry' and conventional reasoning. Cultural Studies is antipodal to theatre in some respect. It is interested chiefly in the social and political reality while theatre aims to create the fiction world. The theatre studies, therefore, may have to risk the danger of destroying its own base when it adopts cultural studies uncritically. The different stance between theatre and cultural theories also occurs from the opposition of humanism vs. antihumanism. We have to introduce cultural theories selectively and properly not to destroy the inherent experience and domain of theatre.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.229-235
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• 2018

In this study, recycled aggregate and natural aggregate were mixed in advance using an aggregate mixing facility that was developed to improve the quality of recycled aggregate concrete. Then the mixed aggregate was applied and concrete characteristics before and after a mix were considered. Based on the findings extracted, this study aimed to suggest a new direction for quality stabilization and application activation of recycled aggregate. The test results of change rates of mortars and coarse aggregates in fresh concrete mixed by a concrete mixer, before and after mixing aggregates showed that the variations of the mortars and coarse aggregates in the concrete mixed with the aggregates beforehand were decreased than those in the concrete before mixing them. The variation of compressive strength and the mean compressive strength at the ages of 3 and 7 days showed similar results before and after the aggregates were mixed, and the strength at the age of 28 days before and after mixing them showed larger deviation than that at the ages of 3 and 7 days. The use of the mixed aggregates after mixing aggregates beforehand reduced the variation in strength and is believed that it is advantageous for long-age strength development. The above results show that the variations of coarse aggregates and compressive strength in the concrete using the mixed aggregates produced by mixing recycled aggregates and natural aggregates beforehand are reduced so it will be possible to produce the homogeneous concrete by mixing aggregates beforehand.

• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.88-94
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• 2011

This study was conducted to provide on a basic information for maintenance of roadside trees and identify the links between environmental pollution and tree damages (Ginkgo biloba, Platanus occidentalis) in Daejeon City by analyzing photosynthetic characteristics, water use efficiency, chlorophyll fluorescence and chlorophyll contents by the regions and plants. The investigations were conducted at Chungnam national university(CNU) considered as the least air-polluted area compared to other study sites, Daedeok science town(DS) which a new road with little traffic recently was built around, Daehwa industry complex(DIC) and Daejeon station(DS) which an old road with heavy is located around. The photosynthetic capacity of the two species were highest in CNU and lowest in the DS. However the water use efficiency was highest on the contrary to the photosynthetic capacity in DS. Chlorophyll fluorescence and chlorophyll contents were highest in CNU and lowest in DS as the photosynthetic capacity. On all of the test, Ginkgo biloba shows the more favorable physiological responses than Platanus occidentalis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.129-137
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• 2020

In performing the structural analysis, the foundation is considered to be a fixed end as a plastic hinge model. In this study, the displacements of the foundation, pier, and shoe were compared when the foundation modeled as a fixed end, a shallow foundation constructed on bedrock of 2m depth, and a pile foundation constructed in the 10m to 20m depth of bedrock. The shear force was also compared, and the probability of damage was calculated and compared for the critical condition. When calculated as a fixed end, the displacement of the foundation converged to 0mm, but the shallow foundation built on the bedrock with a depth of 2m caused relatively displacement, and the pile foundation constructed to contact the bedrock with a depth of 18m caused a larger displacement. In addition, it was analyzed that the displacement of the foundation, which is the lower structure, affects the displacement of the super structure, but the difference in shear force applied to the foundation was insignificant in the three cases. There was no difference between the shallow foundation and the pile foundation in the influence on the displacement of the top of the pier, but there was a big difference from the analysis assuming as a fixed end.

• Journal of the Korean Geotechnical Society
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• v.36 no.11
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• pp.61-70
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• 2020

In dynamic centrifuge tests, equivalent shear beam (ESB) container minimizes the boundary effect between the soil model and the wall of the container so as to effectively simulate the boundary conditions of real field state. The ESB container at KAIST was evaluated to be performing properly by Lee et al. (2013). However, it is necessary to re-evaluate the performance of ESB container since the ESB container may have deteriorated over time. Thus, the performance of eight-year-old ESB container was re-evaluated through dynamic centrifuge tests. Firstly, the natural period of the empty ESB container was compared with the results of Lee et al. (2013). Then the boundary effect of sand-filled ESB container was evaluated. Results show that the dynamic behavior of the sand-filled ESB container was similar to that of the ground, despite a decrease in the natural period of the empty ESB container over time. In addition, the dynamic response of the ground built in the ESB container and the same ground simulated through numerical analysis with free-field boundary conditions were similar. Therefore, it was found that the boundary effect of the ESB container due to the decrease in the natural period was not significant.

• The Journal of Engineering Geology
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• v.15 no.2 s.42
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• pp.201-212
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• 2005

A photogrammetric camera system and a software have been built for capturing planned stereo images. To evaluate the system,25 planar data from a constructed rock slope were measured using both geological compass and photo system. Comparison of the data groups from both system showed matching relationship that falls within the error range of $5.25\pm4.53$ in strike and $3.18\pm3.17$ in dip angles, when the 2 standard deviation error distributions were considered. To evaluate the errors of the Photo matching and non planarity of the surface, orientations of the same plane were repeatedly measured 20times. These measurements showed error ranges of $8.2\pm3.4$in strike and $6.6\pm3.4$ in dip angle, considering the same error distributions. Measured strikes and dips were compared with the corresponding compass measurements in 5 constructed. slopes to test the system. Stereonet plots showed that the photo system measured data coincided well with the compass measurements. With these evaluations, the photo system can measure the planar structure in inaccessible locations with reliable accuracy at the same time reducing the data gathering period therefore resulting to an efficient geological survey.

• Korean Journal of Cognitive Science
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• v.22 no.3
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• pp.271-298
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• 2011

The lexical semantic system should be built to grasp lexical semantic information more clearly. In this paper, we studied a semantic clustering of predicates that is one of the steps in building the lexical semantic system. Unlike previous studies that used argument of subcategorization(subject and object), selectional restrictions and interaction information of adverb, we used sense tagged definition in dictionary for the semantic clustering of predicate, and also attempted hierarchical clustering of predicate using the relationship between the generic concept and the specific concept. Most of the predicates in the dictionary were used for clustering. Total of 106,501 predicates(85,754 verbs, 20,747 adjectives) were used for the test. We got results of clustering which is 2,748 clusters of predicate and 130 recursive definition clusters and 261 sub-clusters. The maximum depth of cluster was 16 depth. We compared results of clustering with the Sejong semantic classes for evaluation. The results showed 70.14% of the cohesion.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.2
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• pp.135-146
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• 2020

To define an interface in a conventional level-set method, an analytical function must be revealed for an interfacial geometry. However, it is not always possible to define a functional form of level sets when interfaces become complex in a Cartesian coordinate system. To overcome this difficulty, we have developed a new level-set formalism that discriminates the interior from the exterior of a CAD modeled interface by parameterizing the stereolithography (STL) file format. The work outlined here confirms the accuracy and scalability of the hydrodynamic reactive solver that utilizes the new level set concept through a series of tests. In particular, the complex interaction between shock and geometrical confinements towards deflagration-to-detonation transition is numerically investigated. Also, a process of flame spreading and damages caused by point source detonation in a real-sized plant facility have been simulated to confirm the validity of the new method built for reactive hydrodynamic simulation in any complex three-dimensional geometries.

• Child Health Nursing Research
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• v.7 no.3
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• pp.280-297
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• 2001

The purpose of the study was to develop and test the model for the quality of life in mothers of children with nephrotic syndrome. A hypothetical model was constructed on the basis of previous studies and a review of literature. The conceptual framework was built around ten constructs. Exogenous variables included in this model were mother's health, father's health, marital intimacy, mother's attitude on children, economic state, side effect of steroid, severity of illness and social support. Endogenous variables were mother's burden and quality of life. Empirical data for testing the hypothetical model were collected by using a self-report questionnaire from 152 mothers of children with nephrotic syndrom at the outpatient clinics and in the hospital. The data was collected from May, 1999 to August, 1999.Reliability of the seven instruments was tested with Cronbach's alpha which ranged from 0.71 - 0.92.For the data analysis, SPSS 8.0 WIN program and LISREL 8.20 WIN program were used for descriptive statistics and covariance structural analysis. The results of covariance structural analysis were as follow :1. The hypothetical model showed a good fit with the empirical data. [x2 = .56, df = 3, p = .90(p>.05 ), GFI = .99, AGFI = .99, RMSR = .005.] 2. For the parsimony of model, a modified model was constructed by deleting 1 variable and excluding 2 paths according to the criteria of statistical significance and meaning.3. The modified model also showed a good fit with the data[x2 = 2.83, df = 7, p = .90( p>.05 ), GFI = 1.00, AGFI = .97, RMSR = .011].The result of the testing of the hypothesis were as follows : 1. Mother's health(γ21 = .26, t = 4.16), father's health(γ22 = .19, t = 2.92), marital intimacy(γ23 = .26, t = 4.13) and social support(γ28 = .12, t = 2.03) had a significant direct effect on the quality of life.2. Mother's burden(β21 = -.20, t = -3.10) had a significant negative direct effect on the quality of life.3. Mother's attitude on children(γ14 = -.34, t = .-4.57), mother's health(γ11 = -.22, t = -2.96) and side effect of steroid (γ16 = -.23, t = .-2.69) had a significant direct negative effect on the burden. The result of this study showed that mother's health, marital intimacy, mother's burden, father's health, and social support had a significant direct effect on the quality of life. Mother's attitude on children, mother's health, and side effect of steroid had a significant direct effect on mother's burden. These six variables, mother's health, marital intimacy, father's health, social support, mother's attitude on children and side effect of steroid were identified as relatively important variables. The results of this study suggest, it needed to determine the nursing intervention will alleviate mother's burden and promote a greater quality of life in mothers of children with nephrotic syndrom.