• Journal of The Korean Association For Science Education
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• v.27 no.1
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• pp.50-58
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• 2007

In this study, students' thoughts were searched according to the types of experiments related to the "law of definite proportions" in 9th grade science textbooks. The most common four types of experiments in textbooks were selected and analyzed for this study. It was found that the experiments needed various preconceptions and complex inferring process by students. But most of the students could not catch the concept understanding desired from the experiments. They just perceived simple observation from their senses. These phenomena were common regardless of types of experiments. These means that the level of preconceptions and inferring process for the interpretation of the experimental data did not match with students' level of thoughts. The goals of the experiments in science textbooks are to increase students' inquiry ability, and to acquire science concepts by themselves from the experiment results. But if the contents of experiments are not suitable to students' understanding level, the educational effects of the performance of these experiments were not positive. Therefore, these experiments need contents revisions for students to acquire the concept related to the "law of definite proportions" by themselves.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.919-929
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• 2007

Some Korean terminologies related to the structures of vascular tissues in plant morphology, written differently depending upon textbooks and dictionaries, were analysed to propose properly expressed Korean terminologies. A total of 14 university textbooks such as general biology, plant biology, and plant morphology were selected and investigated. The terminologies on the xylem structures, i.e., apotracheal parenchyma, paratracheal parenchyma, tylose, and tangential (longitudinal) section; and on the pit structures i.e., simple pit, bordered pit, aspirated bordered pit, and pit aperture; and on the stelar structures, i.e., haplostele, actinostele, plectostele, and solenostele were examined. The definition and etymology of the terminologies were traced in 4 textbooks of plant anatomy and 2 dictionaries of biology and botany written in English. And then reasonably expressed Korean terminologies, mostly written in Chinese characters, were suggested. The terminologies were compared with those that appeared in the Iwanami dictionary of biology published in Japan. It was expected that the results would contribute to promote mutual understanding between teachers and students in learning plant biology.

• Journal of The Korean Association For Science Education
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• v.26 no.1
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• pp.88-98
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• 2006

The purpose of this study was to analyze the process of scientists' science knowledge generation by employing four creative scientists as participants. Raw protocols were collected by an intensive interview method and then analyzed by a psychological modelling procedure. The present study showed that the process of knowledge generation divided into the processes of inductive, abductive, and deductive thinking. Furthermore, the inductive process in simple and operative observation was involved in the processes of generating a question, conjecture/prediction, designing an operational method, operation, and simple observation. Also, the abductive process had two components; question generation, and hypothesis generation which consisted of analyzing questions, searching explicans, and constructing hypothesis. Finally, the deductive process involved inventing abstract test methods, inventing abstract criteria, inventing concrete test methods, inventing concrete criteria, collecting results, and evaluating hypotheses and stating conclusions.

• Journal of Life Science
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• v.34 no.6
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• pp.377-384
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• 2024

Prodigiosin is a red pigment characterized by a common pyrrolylpyrromethane skeleton. It is produced by Serratia marcescens, Vibrio psychroerythrus, Hahella chejuensis, etc. Prodigiosin has been reported to possess anticancer, immunosuppressant, antifungal antimalarial, and algicidal activities. However, despite prodigiosin's diverse range of activities, its production rate is significantly low and biosynthesis conditions are difficult. Consequently, the selling price is high, and its usability is limited. This study aimed to increase the efficiency of prodigiosin production according to the culture conditions of Serratia. In this study, a bacterial strain PDGS¹²⁰⁹¹⁵ producing prodigiosin was isolated from lightly contaminated stream water in Busan and identified as a strain of Serratia sp. based on 16S rDNA gene sequence analysis and physiological characteristics. The reddish pigment from PDGS¹²⁰⁹¹⁵ was directly extracted using acidified ethanol, and a characterization analysis confirmed that it was a prodigiosin compound. The optimal conditions for pigment production were 25℃, pH 7, and 0% NaCl concentration for a duration of 14 hr. Furthermore, by treating carbon and nitrogen sources, such as fructose and beef extract, respectively, prodigiosin production increased approximately six-fold and four-fold. Among the minerals tested, 0.1% KCl was found to be the most effective for prodigiosin production. Moreover, casein was identified as the most suitable source for prodigiosin production.

• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.225-237
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• 2024

In the analysis of competing risks data, some of covariates may not be fully observed for some subjects. In such cases, excluding subjects with missing covariate values from the analysis may result in biased estimates and loss of efficiency. In this paper, we studied multiple imputation and the augmented inverse probability weighting method for regression parameter estimation in the cause-specific proportional hazards model with missing covariates. The performance of estimators obtained from multiple imputation and the augmented inverse probability weighting method is evaluated by simulation studies, which show that those methods perform well. Multiple imputation and the augmented inverse probability weighting method were applied to investigate significant risk factors for the risk of death from breast cancer and from other causes for breast cancer data with missing values for tumor size obtained from the Prostate, Lung, Colorectal, and Ovarian Cancer Screen Trial Study. Under the cause-specific proportional hazards model, the methods show that race, marital status, stage, grade, and tumor size are significant risk factors for breast cancer mortality, and stage has the greatest effect on increasing the risk of breast cancer death. Age at diagnosis and tumor size have significant effects on increasing the risk of other-cause death.

• Journal of Internet Computing and Services
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• v.25 no.1
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• pp.91-98
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• 2024

With the advancement of ICT (Information and Communication Technology), searching for judgments through the internet has become increasingly convenient. However, predicting sentencing based on judgments remains a challenging task for individuals. This is because sentencing involves a complex process of applying aggravating and mitigating factors within the framework of legal provisions, and it often depends on the subjective judgment of the judge. Therefore, this research aimed to develop a model for predicting sentencing using artificial intelligence by focusing on structuring the data from judgments, making it suitable for AI applications. Through theoretical and statistical analysis of previous studies, we identified variables with high explanatory power for predicting sentencing. Additionally, by analyzing 50 legal judgments related to serious crimes that are publicly available, we presented a framework for extracting essential information from judgments. This framework encompasses basic case information, sentencing details, reasons for sentencing, the reasons for the determination of the sentence, as well as information about offenders, victims, and accomplices evident within the specific content of the judgments. This research is expected to contribute to the development of artificial intelligence technologies in the field of law in the future.

• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.361-365
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• 2007

Aero-pulsation noise, generally caused by geometric asymmetry of a rotating device, is one of considerable sources of annoyance in passenger cars using the turbocharged diesel engine. Main source of this noise is the compressor wheel in the turbocharger system, and can be reduced by after-treatment devices such as silencers, but which may increase the manufacturing cost. More effective solution is to improve the geometric symmetry over all, or to control the quality of components by sorting out inferior ones. The latter is more simple and reasonable than the former in view of manufacturing. Thus, an appropriate discrimination method should be needed to evaluate aero-pulsation noise level at the production line. In this paper, we introduce the accurate method which can measure the noise level of aero-pulsation and also present its evaluation criteria. Besides verifying the reliability of a measurement system - a rig test system-, we analyze the correlation between the results from rig tests and those from vehicle tests. The gage R&R method is carried out to check the repeatability of measurements over 25 samples. From the result, we propose the standard specification which can discriminate inferior products from superior ones on the basis of aero-pulsation noise level.

• The Journal of Sustainable Design and Educational Environment Research
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• v.23 no.1
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• pp.1-11
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• 2024

Complex school facilities are being considered to meet increased public demands for culture and welfare in Korea, given the decreasing population. In this context, Gyeongi-do Hwaseong City's E-umteo is recognized as a relatively well-operated school complex. Therefore, this study considered seven E-umteo branches as case studies to examine the operations of educational programs and understand the techniques employed in the spatial configuration of E-umteo. To this end, field observations and interviews with facility operators were conducted. The case analysis results revealed that educational programs could be classified into three types: learning sharing , community communication, and lifelong learning. Furthermore, the learning sharing type was classified into education and physical education while the community communication type was classified into the community and convenience types. Meanwhile, lifelong learning was identified as the most actively used type by differentiating specialized programs. With regard to the spatial composition between the school and the "pitcher," only the connection and independent types were observed, and no integral type was discovered. Therefore, integrated future studies are mandated.

• Tunnel and Underground Space
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• v.34 no.3
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• pp.208-217
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• 2024

There is so much research effort for developing and implementing deep learning-based surveillance systems to manage health and safety issues in construction sites. Especially, the development of deep learning-based object detection in various environmental changes has been progressing because those affect decreasing searching performance of the model. Among the various environmental variables, the accuracy of the object detection model is significantly dropped under low illuminance, and consistent object detection accuracy cannot be secured even the model is trained using low-light images. Accordingly, there is a need of low-light enhancement to keep the performance under low illuminance. Therefore, this paper conducts a comparative study of various deep learning-based low-light image enhancement models (GLADNet, KinD, LLFlow, Zero-DCE) using the acquired construction site image data. The low-light enhanced image was visually verified, and it was quantitatively analyzed by adopting image quality evaluation metrics such as PSNR, SSIM, Delta-E. As a result of the experiment, the low-light image enhancement performance of GLADNet showed excellent results in quantitative and qualitative evaluation, and it was analyzed to be suitable as a low-light image enhancement model. If the low-light image enhancement technique is applied as an image preprocessing to the deep learning-based object detection model in the future, it is expected to secure consistent object detection performance in a low-light environment.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.237-244
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• 2024

We studied the effects on their academic achievement of chemistry II and advanced chemistry subjects of science high school students according to the type of class (face-to-face and non-face-to-face). The subjects of this study were 195 first-year students of G Science High School located in Gyeongnam. The average scores of Chemistry II and Advanced Chemistry in non-face-to-face classes in 2020 and face-to-face classes in 2021 were compared and analyzed. As a result of comparing and analyzing the academic achievement according to the class type, students' grades in Chemistry II and Advanced Chemistry were higher in non-face-to-face classes. In the comparison of academic achievement by level according to class type, Chemistry II showed higher average grades in non-face-to-face classes as the lower level were, and in advanced chemistry, the higher the upper grades in non-face-to-face classes. In addition, in terms of the effect of changes in class form on the upper and lower 10% levels of academic achievement of Chemistry II, the upper 10% showed high grades in face-to-face classes and the lower 10% in non-face-to-face classes. On the other hand, in advanced chemistry, the average grade of non-face-to-face classes was higher than that of face-to-face classes in the top 10%, and the average grade of face-to-face classes was higher than that of non-face-to-face classes in the bottom 10%. Through these results, it was found that in the teaching-learning of science high school students, instructors need to design and treat teaching-learning appropriate to the level of academic achievement.