• Journal of the Korean School Mathematics Society
• /
• v.10 no.3
• /
• pp.323-340
• /
• 2007

This study set out to analyze the learning types that most students were engaged in after school, to review the efficiency of private education through academic institutions or tutoring, and to examine the directions in the after-school learning in math under the current system. It also aimed to analyze the impacts of those after-school learning activities on school classes and to suggest some plans to help public education get back on the track. In the study the after-school learning activities in the math subject were categorized into taking classes at academic institutions, tutoring, and autonomous learning. The grades of the subject students were compared and analyzed for three semesters to find the directions right for the school classes.

• Structural Engineering and Mechanics
• /
• v.67 no.1
• /
• pp.9-20
• /
• 2018

In this paper, a framework is proposed for dynamic analysis of train-bridge systems with a damaged pier after barge collision. In simulating the barge-pier collision, the concrete pier is considered to be nonlinear-inelastic, and the barge-bow is modeled as elastic-plastic. The changes of dynamic properties and deformation of the damaged pier, and the additional unevenness of the track induced by the change of deck profile, are analyzed. The dynamic analysis model for train-bridge coupling system with a damaged pier is established. Based on the framework, an illustrative case study is carried out with a $5{\times}32m$ simply-supported PC box-girder bridge and the ICE3 high-speed train, to investigate the dynamic response of the bridge with a damaged pier after barge collision and its influence on the running safety of high-speed train. The results show that after collision by the barge, the vibration properties of the pier and the deck profile of bridge are changed, forming an additional unevenness of the track, by which the dynamic responses of the bridge and the car-body accelerations of the train are increased, and the running safety of high-speed train is affected.

• Archives of Plastic Surgery
• /
• v.48 no.3
• /
• pp.323-328
• /
• 2021

Background Lymphaticovenular anastomosis (LVA) is a minimally invasive surgical procedure used to treat lymphedema. Volumetric measurements and quality-of-life assessments are often performed to assess the effectiveness of LVA, but there is no method that provides information regarding postoperative morphological changes in lymphatic vessels and veins after LVA. Photoacoustic lymphangiography (PAL) is an optical imaging technique that visualizes the distribution of light-absorbing molecules, such as hemoglobin or indocyanine green (ICG), and provides three-dimensional images of superficial lymphatic vessels and the venous system simultaneously. In this study, we performed PAL in lymphedema patients before and after LVA and compared the images to evaluate the effect of LVA. Methods PAL was performed using the PAI-05 system in three patients (one man, two women) with lymphedema, including one primary case and two secondary cases, before LVA. ICG fluorescence lymphography was performed in all cases before PAL. Follow-up PAL was performed between 5 days and 5 months after LVA. Results PAL enabled the simultaneous visualization of clear lymphatic vessels that could not be accurately seen with ICG fluorescence lymphography and veins. We were also able to observe and analyze morphological changes such as the width and the number of lymphatic vessels and veins during the follow-up PAL after LVA. Conclusions By comparing preoperative and postoperative PAL images, it was possible to analyze the morphological changes in lymphatic vessels and veins that occurred after LVA. Our study suggests that PAL would be useful when assessing the effect of LVA surgery.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.10
• /
• pp.1518-1522
• /
• 2006

In the present study, it was observed how the phage-host system that is naturally reproduced in activated sludge is affected by the host inoculation. The system of Microlunatus phosphovorus and its phages was selected as the phage-host system native to an activated sludge system operated for 19 days under sequencing anaerobic-aerobic conditions with glutamate as the main carbon source. The phage-host system related to M. phosphovorus was monitored by plaque assay for the phages and by fluorescent in situ hybridization (FISH) for the bacterial host. In addition, the whole phage structure was also monitored by pulsed-field gel electrophoresis (PFGE). During the first 9 days, the phage-host system was more or less steady at approx. 9% (FISH/ DAPI) for M. phosphovorus and approx. 10,000 PFU/ml for its lytic phages. Microlunatus phosphovorus JCM9379 was inoculated into the activated sludge on day 10. Right after the inoculation, M. phosphovorus was approx. 24% (FISH/DAPI) whereas its lytic phages dropped down to approx. 500 PFU/ ml. After the host inoculation (within 9 days), however, the phage-host system eventually reverted to its original level in each population. On the other hand, the whole phage structure was not significantly changed by M. phosphovorus inoculation but stable throughout the process operation. Only the minor change that four phage groups gradually became abundant after the host inoculation was observed.

• Proceedings of the KACD Conference
• /
• 2003.11a
• /
• pp.577-577
• /
• 2003

Microcomputed tomography (MCT) made it possible to investigate the morphology of root canals more accurate. The aim of this study was to compare the effects of four root canal shaping methods, the profile system, the ProTaper system, a combination of these, and stainless steel K-files, in the shaping of the mesial root canals of extracted human mandibular first molars, three-dimensionally using MCT. Eight extracted mandibular first molars were scannde using MTC before and after the root cannals were instrumented. Two specimens were prepared using the Profile system and another two specimens were prepared using MCT before and after the root cannals were instrumented. Two specimens were prepared using the Profile system and another two specimens were prepared using the ProTaper system according to manufactures recommendation.(omitted)

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.2
• /
• pp.152-160
• /
• 2016

The market demand for diesel engine tends to increase in general passenger cars as well as commercial vehicles because of its advantages. However, to meet the vehicle emissions regulation which will be more stringent in the future, it is necessary to plurally apply all after-treatment technologies such as diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF), lean NOx trap (LNT) and selective catalytic reduction (SCR), and so on. Accordingly, the exhaust after-treatment system for diesel vehicle requires the technology of minimizing the numbers of catalysts by integrating every individual catalysts. The purposes of this study is to develop hybrid exhaust after-treatment device system which simultaneously uses LNT/DPF and SCR/DPF catalyst concurrently reducing NOx and particulate matter (PM). As the results, the hybrid system with $NH_3$ generated at LNT/DPF working as a reducing agent of SCR/DPF catalyst, improving NOx conversion rate, was found to be more excellent in de-NOx performance than that in LNT/DPF alone system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.11
• /
• pp.3144-3154
• /
• 2009

Recently, people seek to recognize organizationally and cross sectionally the period work of a company such as manufacturing, retail, distribution, accounting, and personnel management in order to maximize company profit. Also, the ERP system, which is used as a management concept for plan management designed to optimize the utilization of management resources in an enterprise like manner, has been introduced for the same purpose. This study has examined the ERP system, which has been currently set up, for the parent company, S. The study has evidentially analyzed the system efficiency and satisfaction level of customers by examining implementation effects after onsite application and by seeking ways of improvement after recognizing the difficulty linked with use discovered after onsite application of the system and rejection by customers by conducting a questionnaire survey.

• Journal of the Korean School Mathematics Society
• /
• v.17 no.1
• /
• pp.93-108
• /
• 2014

In this paper we carried out a survey targeting 185 elementary, middle and high school mathematics teachers to identify their conception, satisfaction, requirements of after-school mathematics education. The survey results show that we need to develop newer programs, reduce teachers' task, build a more effective system for supporting and researching after-school mathematics education, and so on. Using these survey results we understand the facts of existing after-school mathematics education and provide preliminary data for discussing how to invigorate and advance the after-school mathematics education.

• Korean Journal of Community Nutrition
• /
• v.24 no.1
• /
• pp.24-37
• /
• 2019

Objectives: The study purpose is to develop a content system for a healthy dietary education program for after-school care in lower grade in elementary school. Methods: The contents of healthy dietary education in the 2015 revised curriculum and textbooks and the major education programs related to dietary life that are currently used in elementary school education were analyzed. Focus group interviews were held with field experts related to lower grade in elementary care class. Accordingly, the structuring of the education area and the detailed education contents were systematized. Results: From the analysis results, the contents of curriculum, textbook, and administrative department were classified as hygiene safety, health, and culture. The goal of the educational content system was divided into three areas: nutritional dietary life, food hygiene and health, and food culture. The subjects consisted of dietary balance, healthy body weight, digestion and absorption, food hygiene, Korean agricultural products, traditional food, and table manners. The curriculum was composed of 12 content elements. Conclusions: In order to ensure that after-school care students can grow into healthy, growth-oriented and creative talents, the role of the caring guide is important, and associated guidelines are needed in the future.

• Journal of Korean Association for Spatial Structures
• /
• v.16 no.3
• /
• pp.89-97
• /
• 2016

With the recent trend to construct high-rise and large buildings, the steel structure system is widely used, but there are not enough studies on the vibration characteristics of the iFLASH system on the buildings. Therefore, in this study, we performed a vibration measurement of the natural frequency and damping ratio in the stage of iFLASH panel, composit, frame completion and cladding completion. The result findings suggest that the damping ratio after the cladding completion has a greater effect on the reduction of the damping ratio, than the stage after the frame completion.