• The Journal of the Acoustical Society of Korea
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• v.40 no.3
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• pp.201-212
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• 2021

The present study was conducted as a pilot investigation to suggest the standards of acoustic performance for classrooms suitable for incomplete hearing people such as children under 9 years of age. Subjective evaluations such as questionnaire and speech intelligibility test were conducted to 264 students at two elementary schools in Cheong-ju in order to analyze the characteristics of the listening environment in the classrooms of the lower grades in elementary school. The survey was undertaken with a total of 264 students at two elementary schools in Cheong-ju, and investigated their satisfaction with the classroom listening environment. As a result, students responded that the most helpful information type for understanding class content is the voice of teacher. In addition, the volume of the current teacher's voice is normal, and the level of clarity is highly satisfactory. As for the acoustic performance of the classroom, the opinion that the noise was normal and the reverberation was very short was found to be dominant in overall satisfaction with the listening environment. Meanwhile, as a result of speech intelligibility test using the word list selected for the lower grade students of elementary school, it could be inferred that the longitudinal axis distance from the sound source in the case of 8-year-olds is a factor that affects speech recognition.

• Journal of Korea Water Resources Association
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• v.54 no.spc1
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• pp.1167-1181
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• 2021

In relation to the algae bloom, four types of blue-green algae that emit toxic substances are designated and managed as harmful Cyanobacteria, and prediction information using a physical model is being also published. However, as algae are living organisms, it is difficult to predict according to physical dynamics, and not easy to consider the effects of numerous factors such as weather, hydraulic, hydrology, and water quality. Therefore, a lot of researches on algal bloom prediction using machine learning have been recently conducted. In this study, the characteristic importance of water quality factors affecting the occurrence of Cyanobacteria harmful algal blooms (CyanoHABs) were analyzed using the random forest (RF) model for Bohyeonsan Dam and Yeongcheon Dam located in Yeongcheon-si, Gyeongsangbuk-do and also predicted the occurrence of harmful blue-green algae using the machine learning and deep learning models and evaluated their accuracy. The water temperature and total nitrogen (T-N) were found to be high in common, and the occurrence prediction of CyanoHABs using artificial neural network (ANN) also predicted the actual values closely, confirming that it can be used for the reservoirs that require the prediction of harmful cyanobacteria for algal management in the future.

• Journal of Advanced Technology Convergence
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• v.1 no.1
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• pp.15-24
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• 2022

This paper tried to investigate the moderating effect of chemyon sensitivity and usage situation in the relationship between self-presentation and brand preference. Data were collected from students of universities located in Chungnam. The analysis results can be summarized as follows. First of all, the effect of self-presentation on symbolic brand preference was not significant in both public and private use situations. On the other hand, the effect of self-presentation on functional brand preference was found to be significant in both situations. Second, the main effect of chemyon sensitivity was significant only when it had a negative effect on functional brand preference in public situations, but was not significant in other cases. Third, looking at the interaction effect of self-presentation and chemyon sensitivity, the brand preference did not show significant changes in those with relatively low chemyon sensitivity, regardless of the level of self-presentation, whether in public or private situations. This study is meaningful in that it reveals that chemyon sensitivity affects brand preference through interaction with self-presentation, whether the consumption situation is public or private.

• Journal of Korea Port Economic Association
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• v.38 no.2
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• pp.139-152
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• 2022

In this paper, samples are collected for individual companies and the factors affecting worker wages (average annual salary) are analyzed in depth. In addition to the average annual salary of workers in a company, we would like to conduct an in-depth analysis of the average annual salary of first-time employees. Specifically, we tried to explain the size of companies, the production structure of capital and labor, and the impact of business on the average annual salary of first-time, college, and graduate school graduates by educational background of first-time employees. The difference in average annual salary of first-time employees of logistics companies is a decisive factor in the main project on sales, and first-time graduates and college graduates provided high salaries in the overseas passenger cargo transportation, port operation, and unloading management, and low salaries in the land cargo and warehouse industries. n addition, Korean logistics companies had relationships between the location of the headquarters, the number of employees, the proportion of labor costs to sales, and the four characteristic factors of the main business on sales. This fact is that Seoul-based foreign passenger cargo transportation, corporate logistics agency, complex transportation, and international transportation relay are large companies, with a low proportion of labor costs and a higher proportion of capital, technology, and information-intensive investments.

• Journal of Industrial Convergence
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• v.20 no.5
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• pp.1-9
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• 2022

Today, apartment houses account for a very high proportion of the types of residence. This study analyzed the difference between the bidding construction cost using the long-term repair allowance and using the general repair cost, and analyzed the difference of factors affecting the amount of use of these two items. For this purpose, related data on apartment housing complexes located in seven representative districts of Busan from 2017 to 2021 were collected and analyzed from the apartment housing management information system. As a result of statistical analysis, the type of bidding variable had the greatest negative(-) effect on the bidding construction cost, and the next factor that affected was different between the amount of long-term repair allowance used and general repair cost used. In addition, there was a difference in statistical significance in the type of bidding by construction year for the number of bidding works between the case of using the long-term repair allowance and the case of using the general repair cost. The results of this analysis will help to find ways to reduce bidding construction costs. However, it is expected to find additional meaning by including more detailed variables such as technical ability.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.557-564
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• 2023

In this study, 3D printing technology was used to compensate for the shortcomings of the use of lead, which has proven to have excellent shielding performance, and to control unnecessary human exposure. 3D printers can implement three-dimensional shapes and can immediately apply individual ideas, which has great advantages in maintaining technology supplementation while reducing the cost and duration of prototyping. Among the various special 3D printers, the FDM method was adopted, and the filament used for output was manufactured using a research extruder by mixing two materials, PLA (Poly-Lactic-Acid) and tungsten. The purpose was to verify the validity through dose evaluation and to provide basic information on the production of chapezones of various materials. The mixed filament was implemented as a morphological shield. Filaments made of a research extruder by mixing PLA and tungsten were divided into 10 %, 20 %, 30 %, 40 %, and 50 % according to the tungsten content ratio. Through the process of 3D Modeling, STL File storage, G-code generation, and output, 10 cm × 10 cm × 0.5 cm was manufactured, respectively, and dose and shielding ability were evaluated under the conditions of tube voltages of 60 kVp, 80 kVp, 100 kVp, 120 kVp, and tube currents of 20 mAs and 40 mAs.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.408-408
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• 2022

환경부 홍수통제소의 경우는 전국단위의 강수량(지상, 레이더), 하천수위, 유사량 관측과 국부적으로 증발산량과 토양수분 관측이 이루어지고 있는 상황이며, 기상청 및 다른 공공기관도 각 목적에 맞게 수문기상관측이 이루어지나 유역(또는 지역) 단위의 물순환 과정(강우량, 유출량, 증발산량, 지하수함양량, 토양수분량 등 포함)을 규명하는 조사·연구는 매우 미비한 실정이다. 개별적인 물순환 성분별 수문조사에서 벗어난 전체적인 관점을 고려한 유역단위의 물순환 과정을 규명하는 것은 매우 중요하다. 즉 물순환 성분별 명확한 수문량 산정 결과는 수자원 개발과 물환경 보전에 중요한 정보를 제공할 수 있다. 따라서 물순환 성분별 명확한 분석을 위해서는 중·소규모 유역 단위를 대상으로 지속적이고 신뢰성 있는 자료의 획득과 축적이 중요하므로 중·소규모 유역 단위의 대표성 있는 시험유역의 운영은 매우 의미가 있다고 볼 수 있다. 본 논문에서는 한국건설기술연구원에서 운영하는 차탄천 유역(보막교 수위관측소 기준, 유역면적 88.17km², 유로연장 18.69km, 유로경사 1.62%, 경기도 연천군 소재)의 2021년 수문관측자료를 이용하여 지표수 물순환 성분인 강우량, 하천유출량, 증발산량의 자료를 산정하였다. 기본 관측자료인 강우량은 각 지점강우량의 관측자료의 비교·검토 등 품질관리를 통해 자료를 확정하고 유역평균강우량을 산정하였다. 하천수위는 기준수위표와의 검토를 통해 자료를 확정하였으며, 하천유출량은 기존 유량측정성과와 단면검토를 통해 수위-유량관계곡선식을 개발하고, 확정된 수위자료를 적용하여 산정하였다. 그리고 증발산량은 유역내의 기상관측자료와 유역인근 3개 관측소(동두천, 파주, 철원)의 기상자료를 이용하여 잠재증발산량을 산정하여 추정한 값이다. 각 물순환 성분별로 생성된 2021년의 차탄천 유역(보막교 수위관측소 기준)의 총강우량은 1,149.8mm이며, 하천유출량은 701.2mm(총강우량 대비 61.0%), 실제증발산량(잠재증발산량 추정값)은 381.3mm(33.2%)이며, 그 외는 유역 손실량이다. 이와 같이 산정된 물순환 성분별 자료는 유역의 물순환 과정 규명을 위한 기초자료로 매우 유용하게 활용될 수 있으며, 유역 물관리를 위한 의사결정 과정에 중요한 역할을 할 수 있을 것으로 기대된다.

• Journal of the Korean earth science society
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• v.43 no.6
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• pp.762-776
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• 2022

The purpose of this study was to determined the conceptual structure used by earth science teachers to classify metamorphic rocks as well as the criteria applied in the process of classifying metamorphic rocks. To this end, the researchers collected verbal data uttered in the process of classifying metamorphic rock using think-aloud from 21 earth science teachers in middle and high schools in Jeollabuk-do, Republic of Korea. The collected verbal data were analyzed using the semantic network analysis method, and the following results were obtained. First, in the process of classifying metamorphic rocks, earth science teachers classified them based on characteristics such as color, compositional minerals, and particle size, which can be generally observed in rocks, and foliation that appears in metamorphic rocks. Second, earth science teachers recognize the classification criteria for metamorphic rocks and focus on metamorphism such as contact metamorphism or regional metamorphism. However, there were cases where rocks were mistakenly classified through incorrect identification. Therefore, it is necessary to provide sufficient observational information about, and experience of, metamorphic rocks to enable earth science teachers to recognize and relate to the scientific process of identifying metamorphic rocks through the phenomena observed.

• Journal of Digital Convergence
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• v.20 no.1
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• pp.335-341
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• 2022

This is a descriptive research study to confirm the relationship between communication types, emotional labor, and job stress of nurses in small and medium-sized hospitals and to identify factors affecting job stress. The study was conducted on 192 nurses randomly selected from small and medium-sized hospitals located in G Metropolitan City. A structured questionnaire was used as a research tool for measuring communication types, emotional labor, and job stress, and the data were collected from August 20 to September 10, 2019. The results of the study are as follows. The subject's communication type averaged 3.55±0.31 points, emotional labor 3.21±0.59 points, and job stress 3.44±0.52 points. Job stress showed a statistically significant negative correlation with friendly communication among the types of communication, and a statistically significant positive correlation with emotional labor. Factors affecting job stress included gender, total clinical experience, and emotional labor, showing an explanatory power of 28.0%. It is considered that an efficient management strategy for emotional labor is needed to reduce the job stress of nurses in the future.

• Journal of Convergence for Information Technology
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• v.12 no.3
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• pp.158-170
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• 2022

The purpose of this study is to analyze class satisfaction with peer evaluation in Collaborative Learning-based classes. For collaborative learning-based classes, problem-based learning and project-based learning were selected. Educational implications were derived by designing Instructional procedures of Collaborative Learning-based classes, Peer evaluation types and questionnaire design, Peer evaluation progress of Collaborative Learning-based classes, Class satisfaction research and analysis In Collaborative Learning-based classes. The subjects of the study were participants in Collaborative Learning-based classes selected as problem-based learning and project-based classes. For class satisfaction with peer evaluation in Collaborative Learning-based classes, a survey was conducted on 168 participants A University in Korea. The research tool was designed as Learning procedures for peer evaluation Collaborative Learning-based classes is Team Building, Plan to the Task, To do Task, Mid-check on task, Task completion, Presentation & Evaluation, Reflection & Self-Evaluation. The content validity of items was confirmed by CVR of 12 experts. In the research results, the average class satisfaction of peer evaluation is 4.05(SD=91), followed by class concentration, diligence, voluntary, learning atmosphere. As a result of t-testing the difference in class type between collaborate learning-based classes, the satisfaction of PBL was higher than that of PjBL and a statistically significant difference was observed. The result of this study have significance in providing implications for class design and operation for the application and expansion of peer evaluation in higher education. However, there is a limit to generalization as a result of research using convenience.