• Journal of the Korean Geotechnical Society
• /
• v.24 no.5
• /
• pp.129-137
• /
• 2008

An active application of concrete track is being expected far the future constructions of Korean railroad. In comparison with the existing ballasted tract, a concrete track is very susceptible for the settlement, since its rehabilitation requires much time and cost. When a concrete track is constructed on fine-grained subgrade soil, excessive cumulative plastic settlements due to repetitive train road may occur. In this case, the settlement of the concrete track may be effectively reduced by installing a small number of small-diameter piles beneath the track. This paper presents the effect of pile installation on the reduction of cumulative plastic settlement of concrete track. A method combining experiential equation and numerical method is proposed. Using an existing experiential equation and the estimated earth pressure distribution, the cumulative plastic strain was calculated. From the results, it is verified that the effects of the pile installation is significant to effectively reduce the cumulative plastic settlement of concrete track. The reduction effects of the cumulative plastic settlement according to the pile number and pile arrangement are presented.

• Korean journal of applied entomology
• /
• v.62 no.2
• /
• pp.69-78
• /
• 2023

The currently implemented Positive List System, sales manager training, and pesticide sales record systems focus on the safety of determined pesticide use, but the proposed agrochemical pharmacist (AP) system aims accurate diagnosis and reasonable prescription. In this study, 81% of famers claimed expert assistance for purchasing and applying pesticides, and 42~86% of sales managers insisted on the strengthening expertise in diagnosis and prescription. In the institutionalization of AP, a special implementation guideline is essential to embrace the present sales managers with long experience. Sales managers of commercial and agricultural cooperatives recognize the qualifications of agrochemical pharmacists as a strategy to differentiate themselves from competitors, and increase sales through market positioning of "pesticides prescribed by trustworthy agrochemical pharmacists", not sales managers anymore.

• Journal of Convergence for Information Technology
• /
• v.12 no.3
• /
• pp.186-192
• /
• 2022

This study investigated 110 contractual industries to identify the effects of curriculum development and educational environment improvement through Ulsan College LINC+ Program on job education and training. As a result of the study, core competency and job competency were 5.73 points each in field practice and educational environment, and job performance was significant with OJT 5.58 points and 5.74 points for educational environment(p<0.05). The relationship between suitability of the curriculum, educational environment, and recruitment performance was significant with 5.73 points for OJT, 5.74 points for field training during the education and training period, and 5.79 points for educational environment, and job reeducation/training expense was significant with 5.73 points for OJT and 5.79 points for educational environment(p<0.05). Also, students who completed the LINC+business curriculum shortened their job period by 1 to 6 months in 86.3% of the respondents, and responded that the education expense for new employees was reduced. Therefore, it was identified that the LINC+ Program of Ulsan College has the effect of shortening the job adaptation period and reducing education expenses for new employees by operating the curriculum reflecting the needs of the industry and improving the same educational environment as the industrial field.

• The Journal of Korean Society for School & Community Health Education
• /
• v.24 no.1
• /
• pp.17-31
• /
• 2023

Objectives: The purpose of this study is to identify differences in fear of COVID-19 according to types of positive mental health in college students, and to verify the moderating effect of mental well-being in the relationship between mental disorders and fear of COVID-19. Methods: The results of 1,542 college students' responses to the COVID-19 Fear Scale, Korean Mental Disorder Scale, and Korean Mental Health Scale were analyzed. According to the presence of mental disorders and the level of mental well-being (high, medium, and low) of the participants which were assessed by the Korean Mental Disorder Scale and the Korean Mental Health Scale, participants were classified into five mental health groups. And the difference in fear of COVID-19 between groups was identified by one-way ANOVA. In addition, it was identified whether the moderating effect of mental well-being was significant in the relationship between mental disorders and fear of COVID-19 using hierarchical regression analysis. Results: When participants were classified by positive mental health types, the flourish group had significantly lower fear of COVID-19 than the moderate mental health group and the languishing group. The moderating effect of mental well-being was significant in the relationship between mental disorder and fear of COVID-19. Additionally, the reducing effect of mental well-being upon fear of COVID-19 was greater when the severity of mental disorder was lower. Conclusions: Basically, in the case of groups with mental disorders, efforts to reduce mental disorders should be given first and foremost. In contrast, for groups without mental disorders, psychological interventions to raise levels of mental well-being are likely to help reduce fear of COVID-19.

• Journal of the Korean Society for Library and Information Science
• /
• v.57 no.2
• /
• pp.179-198
• /
• 2023

The purpose of this study is to verify the role of teacher librarians by examining the cases of media and information literacy(MIL) classes in the joint curriculum of high school credit system research school. The classes were two 34th classes joint curriculum established by two teacher librarians at the high school credit system research school. Individual students set their own inquiry problems integrated with their careers or subjects, and teacher librarians guide the process of solving them based on the process of using MIL. The participants were 22 high school students in Daegu who filled out the questionnaire before and after completing the course. The effect of the classes was analyzed through a questionnaire consisting of 42 questions for the 3 factors of access, evaluation, and creation, which are the components of MIL announced by UNESCO. As a result, all 3 factors and 25 of the sub-42 survey items showed a statistically significant difference before and after class, It was investigated that literacy of students improved through MIL education of teacher librarians. Through this study, it will be possible to expand the awareness of the effect of the educational role of teacher librarians in the flow of future curriculum.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2020.08a
• /
• pp.40-40
• /
• 2020

들깨(Perilla frutescens L.)는 꿀풀과 1년생 초본으로 한국, 중국 등의 동부 아시아가 원산지로 식용, 약용 및 공업용 등 다양한 용도로 이용되고 있다 들깨는 우리나라에서 오랜시간 재배해 왔으나 체계적인 연구기간이 짧아, 다른 유료작물에 비해 육성품종이 적고 유전자원의 체계적인 수집평가가 이루어지지 않았다. 특히 외국에서는 들깨와 근연종을 이용하여 색소 및 정유성분에 대한 연구를 하는데 비해 우리나라에서는 주로 식용으로만 연구가 진행되고 있다. 들깨 육종에 있어서 중요한 것은 유전자원 확보와 이를 정리 보존하여 우량한 육종재료를 효율적으로 이용하는 것이다. 본 연구에서는 국내에서 수집한 들깨 44자원의 형태적 특성을 조사하여 품종 육성을 위한 기초자료를 제공하고자 하였다. 본 연구에 사용된 들깨 자원은 경북 수집 10자원으로 가장 많았으며 전북 8자원, 경남 7자원, 강원과 경기에서 각각 6자원, 충남 3자원, 전남과 충북에서 각각 2자원이었다. 화색은 들깨 44자원 모두 흰색이었으며 줄기색은 연녹색이 29자원, 녹색 9자원, 자주색 4자원으로 조사되었다. 잎의 앞면은 녹색 27자원, 연녹색 10자원, 진녹색 7자원이었으며 뒷면색은 녹색 26자원, 연녹색 18자원으로 조사되었다. 잎의 모양은 장타원형 21자원, 피침형 15자원, 심장형 7자원이었으며 잎의 모용은 23자원이 적음, 14자원이 보통, 6자원이 많게 조사되었다. 잎의 길이는 35자원이 15.1cm이상으로 조사되었고 잎넓이는 11.1cm이상인 자원이 37자원으로 조사되었다. 종피색은 갈색이 28자원, 회색이 6자원, 암갈색이 3자원 순으로 조사되었다. 본 실험에서 조사된 들깨 유전자원의 형태적 특성은 들깨 선발에 있어 기초 정보로 활용 가능할 것이며 추가적으로 농업형질, 기능성 물질 분석등의 들깨 육종 프로그램을 위한 다양한 평가 및 선발이 필요할 것이다.

• Journal of The Korean Association For Science Education
• /
• v.29 no.8
• /
• pp.934-950
• /
• 2009

This study attempts to identify the relationship between students' images of science and science learning, and their career choices. A total of 163 students (seventh graders) from three different middle schools participated in this study. Students' images of science and science learning were investigated using the Draw-A-Scientist Test (DAST) and the Draw-A-Science-Learner Test (DASLT), respectively. Then, students' drawings were analyzed using the Draw-A-Scientist Test Checklist (DAST-C) and the Draw-A-Science-Learner Test Checklist (DASLT-C). The relationship between each element composing the students' images and their career choices were analyzed. Among several elements constituting the students' image of science, 'expression,' 'lab coat,' 'oddity,' 'knowledge symbol,' 'technology symbol,' 'co-work,' 'danger,' and 'STS' showed significant differences between students who chose a science-related career and students who did not. It was also revealed that the following elements - 'expression,' 'learning type,' 'inquiry symbol,' and 'learning place' - were more significantly associated with a science-related career choice compared to other elements consisting of an image of science learning.

• Journal of the Korea Computer Graphics Society
• /
• v.30 no.3
• /
• pp.9-22
• /
• 2024

Mobility data is important to understand social phenomena and problem. Previous studies have utilized Origin-Destination (OD) visualization methods to represent human's mobility. However, the effectiveness of visualization tools as a method for understanding social phenomena remains unexplored. Therefore, in this study, we developed a visualization tool called SeoulOD-Vis to facilitate understanding social issues. It included three different modules: map visualization, condition selection, and detailed information presentation. We recruited 28 participants to evaluate the SeoulOD-Vis and compared it with a publicly available visualization tool. The results suggested that the SeoulOD-Vis had higher usability and problem-solving performances. Interview results suggested that it attributed to its 'condition selection' and 'detailed information presentation' modules. Our results will contribute to develop visualization tools to solve social problems using mobility data.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.2
• /
• pp.101-111
• /
• 2016

It is possible that aggregates add on to geopolymer based fly ash to mix mortar and concrete like cement. This is necessary to evaluate mineral composition, particle shape, surface, size distribution, density and absorption ratio for fine aggregates due to few detailed research to examine influence of fine aggregates properties on unhardened geopolymer concrete. In this research, used two different fine aggregates, Jumunjin sand(having quartz, mica, feldspar, pyroxene in mineral composition, more than 96% of total size between -0.60 and +0.30mm, angular shape and rough surface) and ISO sand(having almost all quartz in mineral composition, more than 51% size between -1.40 and +0.60mm, simultaneously varied size distribution, spherical shape and smooth surface). After an experimental result of the varied ratio of Si/Al=1.0-4.1 geopolymer paste, mix proportion respectively applied Si/Al=1.5 having the highest compressive strength to mortar and Si/Al=3.5 having the highest consistency to concrete. Geopolymer mortar by mixing with Jumunjin and ISO sand in varied range of 20-50wt.% showed flow size increase between 69.5 and 112.0mm, between 70.5 and 126.0mm respectively. Geopolymer concrete at an addition of 77wt.% of total aggregates ratio showed that average compressive strength was 32MPa and the consistency was favorable to molding. Since ISO sand observing varied size distribution, spherical shape, smooth surface, low absorption ratio resulted in advantageous properties on consistency of geopolymer, geopolymer concrete can be suitable for using the fine aggregates similar to ISO sand.

• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.3
• /
• pp.234-240
• /
• 2007

Purpose: In this study we propose a block-iterative method for reconstructing Compton scattered data. This study shows that the well-known expectation maximization (EM) approach along with its accelerated version based on the ordered subsets principle can be applied to the problem of image reconstruction for Compton camera. This study also compares several methods of constructing subsets for optimal performance of our algorithms. Materials and Methods: Three reconstruction algorithms were implemented; simple backprojection (SBP), EM, and ordered subset EM (OSEM). For OSEM, the projection data were grouped into subsets in a predefined order. Three different schemes for choosing nonoverlapping subsets were considered; scatter angle-based subsets, detector position-based subsets, and both scatter angle- and detector position-based subsets. EM and OSEM with 16 subsets were performed with 64 and 4 iterations, respectively. The performance of each algorithm was evaluated in terms of computation time and normalized mean-squared error. Results: Both EM and OSEM clearly outperformed SBP in all aspects of accuracy. The OSEM with 16 subsets and 4 iterations, which is equivalent to the standard EM with 64 iterations, was approximately 14 times faster in computation time than the standard EM. In OSEM, all of the three schemes for choosing subsets yielded similar results in computation time as well as normalized mean-squared error. Conclusion: Our results show that the OSEM algorithm, which have proven useful in emission tomography, can also be applied to the problem of image reconstruction for Compton camera. With properly chosen subset construction methods and moderate numbers of subsets, our OSEM algorithm significantly improves the computational efficiency while keeping the original quality of the standard EM reconstruction. The OSEM algorithm with scatter angle- and detector position-based subsets is most available.