• Journal of the Korea Institute of Building Construction
• /
• v.15 no.3
• /
• pp.351-357
• /
• 2015

Fiber reinforced concrete (FRC) has been successfully used to enhance the flexural toughness of concrete. As fibers are randomly oriented in FRC, they sometimes produce clumps that reduce the mechanical performance, and a properly chosen mixing protocol can be a way to minimize this problem. In this research, the effects of mixing method on the mechanical properties of FRC were investigated. The compressive strength, flexural strength, and flexural toughness were measured using three different mixing methods. It was shown from the results that the compressive strength and peak flexural load were not affected by changes in mixing method. However, in terms of flexural toughness, the changes in mixing method clearly affected the flexural toughness of FRC. The truck-mixed FRC outperformed two pan-mixed FRCs.

• Journal of Digital Convergence
• /
• v.20 no.1
• /
• pp.87-94
• /
• 2022

The reform of the mixed ownership system of vocational colleges in China is an important driving force in the development of vocational education. The purpose of this study is to discuss the operation direction of the reorganization of the mixed ownership system of vocational colleges at this stage in accordance with the guidelines for vocational education reform in China. Therefore, this study analyzed the necessity and existing problems of reforming the mixed ownership system of vocational colleges using literature research methods. As a result of the study, it was found that the reform of the mixed ownership system of vocational colleges should be continuously developed by preparing measures in terms of legal support, providing incentives, and improving the evaluation system. This study has academic and practical significance in that it suggests the need to reform the mixed ownership system of Chinese vocational colleges, analyzes problems, and prepares policy measures.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2009.05c
• /
• pp.65-68
• /
• 2009

Recently, the knowledge access about concrete might be 2 methods. One is approach about advanced and new technical development through the institute journal, the other is construction technology which is using at construction fields. However, there is no research for the interrelationship between them. So, this paper investigates the demands on construction fields at the ready mixed concrete plants on the 4 cities, the characteristics of the products like the maximum size of coarse aggregate and slump, and the extension of market on the high strength and flow ability concrete in 2000 and 2008. Moreover, this study would like to propose the investigation about diversification of construction materials for the fine construction cultures and development of the ready mixed concrete to the engineers at the construction fields.

• Archives of Reconstructive Microsurgery
• /
• v.23 no.1
• /
• pp.1-7
• /
• 2014

Purpose: Recent studies have reported on application of fibrin glue composed of fibrinogen and thrombin to nerve anastomosis, which can be another candidate for vessel anastomosis. However, no research regarding the risk and effectiveness of thrombin in microvascular free tissue transfer has been reported. Therefore, the aim of study is to determine the risk and effectiveness of thrombin on microvascular free tissue transfer through clinical cases. Materials and Methods: Twenty-five patients underwent free flap reconstruction for soft tissue defect or bone exposure in our institute from March 2011 to February 2014. In the group using thrombin, dissolved powder thrombin (5,000 IU/amp) was mixed with 10 mL normal saline. Saline mixed with thrombin was applied on the flap, recipient, and around vessel anastomosis. In the control group, free flap was performed using the same method, except using thrombin. We analyzed the results between the two groups. Results: All flaps survived. The group using thrombin included 14 patients and the control group included 11 patients. Hematoma was found in two cases, respectively, in each group. The group using thrombin showed lower incidence of hematoma than the control group. No difference in survival rate of the flap was observed between the thrombin group and the control group. Conclusion: Results of this study showed that use of saline mixed with thrombin in free tissue transfer may be safe and effective for prevention of hematoma formation in the recipient site.

• International Journal of Highway Engineering
• /
• v.19 no.3
• /
• pp.65-70
• /
• 2017

PURPOSES : Pavement Management System contains the data that describe the condition of the road. Under limited budget, the data can be utilized for efficient plans. The objective of this research is to develop a mixed integer program model that maximizes remaining durable years (or Lane-Kilometer-Years) in road maintenance planning. METHODS : An optimization model based on a mixed integer program is developed. The model selects a cluster of sectors that are adjacent to each other according to the road condition. The model also considers constraints required by the Seoul Metropolitan Facilities Management Corporation. They select two lanes at most not to block the traffic and limit the number of sectors for one-time construction to finish the work in given time. We incorporate variable cost constraints. As the model selects more sectors, the unit cost of the construction becomes smaller. The optimal choice of the number of sectors is implemented using piecewise linear constraints. RESULTS : Data (SPI) collected from Pavement Management System managed by Seoul Metropolitan City are fed into the model. Based on the data and the model, the optimal maintenance plans are established. Some of the optimal plans cannot be generated directly in existing heuristic approach or by human intuition. CONCLUSIONS:The mathematical model using actual data generates the optimal maintenance plans.

• Imaging Science in Dentistry
• /
• v.48 no.4
• /
• pp.261-268
• /
• 2018

Purpose: To determine the impact of an image processing technique on diagnostic accuracy of digital panoramic radiographs for the assessment of anatomical structures in paediatric patients with mixed dentition. Materials and Methods: The study consisted of 50 digital panoramic radiographs of children aged from 6 to 12 years, which were later on processed using a dedicated image processing method. A modified clinical image quality evaluation chart was used to evaluate the diagnostic accuracy of anatomical structures in maxillary and mandibular anterior and maxillary premolar region of processed images. Results: A statistically significant difference was observed between pre and post-processed evaluation of anatomical structures(P<0.05) in the maxillary and mandibular anterior region. The anterior region was found to be more accurate in post-processed images. No significant difference was observed in the maxillary premolar region (P>0.05). The Inter-observer and intra-observer reliability of both pre and post processed images were excellent (>0.82) for anterior region and good (>0.63) for premolar region. Conclusion: The application of image processing technique in digital panoramic radiography can be considered a reliable method for improving the quality of anatomical structures in paediatric patients with mixed dentition.

• Animal Bioscience
• /
• v.35 no.11
• /
• pp.1725-1732
• /
• 2022

Objective: This study was conducted to investigate the effects of selenium benefits on the physiological responses, litter performance, blood profiles and milk composition of lactating sows and tissue concentration of their progeny when mixed form of selenium was provided in a lactation diet. Methods: A total of 45 multiparous sows (Yorkshire×Landrace) with similar body weight, backfat thickness, and parity were assigned to one of three treatments with 15 sows per treatment in a completely randomized design. Organic and inorganic selenium were mixed and added to the diet at 0.15 ppm and 0.25 ppm, respectively. A non-Se-fortified corn-soybean meal basal diet served as a negative control. Treatments were as follows: i) Control: corn-soybean meal based diet, ii) ISOS15: control+ inorganic Se 0.15 ppm+organic Se 0.15 ppm, iii) ISOS25: control+inorganic Se 0.25 ppm+organic Se 0.25 ppm. Results: Serum selenium concentrations of sows and piglets were increased by the supplemental Se mixture at 7 days of lactation compared with the control (p<0.01, respectively). The kidney and muscle selenium concentrations of piglets were increased by the supplemental Se mixture at 21 days of lactation compared with the control (p = 0.03; p = 0.04, respectively). Conclusion: Consequently, supplementation with mixed inorganic and organic selenium in a lactating diet could improve the selenium status of sows and piglets; no differences were observed among the mixing levels.

• Journal of Korean Biological Nursing Science
• /
• v.20 no.2
• /
• pp.92-102
• /
• 2018

Purpose: The purpose of this study was to analyze the current status of studies related to the learning methods of biological nursing subjects in Korea. Methods: Five databases (KoreaMed, KMbase, NDSL, KISS, KiSTi) and grey literature were searched prior to February 2018. A total 12 studies met the inclusion criteria including 11 articles and 1 proceeding. Results: We included five experimental studies, five non-experimental studies, and two mixed method studies. First, most of the studies that applied a learning method focused on the subject of human anatomy and physiology; team-based learning was the method that was utilized the most. Second, the necessity of well-designed research was confirmed because the quality of included studies was low. Third, the research variables identified were mainly concentrated on the affective domain, and included satisfaction, motivation, self-efficacy, self-directed learning, confidence, attitude. We confirmed the need to develop a learning program that can also improve the cognitive and psychomotor domain variables in future research. Conclusion: The results of this study suggest that further research should be conducted with consideration the domain of research variables evenly. In addition, future studies should apply various learning methods and included randomized controlled trials.

• Child Health Nursing Research
• /
• v.26 no.2
• /
• pp.140-153
• /
• 2020

Purpose: This mixed-methods study was conducted to compare and analyze the perceptions of children and their parents regarding the meaning of the children's life. Methods: First, children's and parents' perceptions of the meaning of life were analyzed using a quantitative approach, and the cognitive differences between children and parents were then confirmed through a qualitative approach. We integrated the collected data comprehensively. Results: Ten significant differences (awareness of strong points, recognizing oneself as a precious being, relationships with friends, happy memories, liking people, experiencing difficulty, dreams and goals, experiencing love, appreciating life, helping people who are poorer than me) were identified between children and parents. The results of the content analysis of the qualitative data were divided into two variables: children's experiences of the meaning of life (78 significant statements, 32 sub-themes, and 10 themes) and parents' perceptions of the meaning of life of their children (89 significant statements, 36 sub-themes, and 10 themes). Conclusion: Based on these results, we propose developing meaning-centered intervention programs for children and parents and applying them for educational purposes. By doing so, we expect that meaning-centered education for elementary school students will become more active.

• Child Health Nursing Research
• /
• v.26 no.1
• /
• pp.72-81
• /
• 2020

Purpose: This study was conducted to investigate nurses' perceptions and performance of family-centered care (FCC) at a children's hospital in Sri Lanka and to explore the feasibility of implementing FCC in the context of the Sri Lankan healthcare system. Methods: A convergent, parallel, mixed-methods design was applied to understand Sri Lankan nurses' perspectives on FCC. In total, 157 nurses working at a large teritagy children's hospital responded to a self-report survey and 18 nurses participated in focus group interviews. Results: Of the factors of FCC, family participation in caring for children received the highest score (4.09±0.51) for perceptions, and information-sharing received the highest score (3.54±0.55) for performance. The qualitative data revealed the following five themes: (a) importance of the family in caring for children; (b) helping families during children's hospitalization; (c) taking steps to implement FCC, even with imperfect knowledge; (d) barriers in the current situation; and (e) suggested strategies to promote FCC. Conclusion: Participants endorsed the concept of FCC and demonstrated some aspects of it in their day-to-day practice. The results indicate a clear knowledge deficit and several challenges, which need to be addressed to effectively implement FCC.