• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.14-15
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• 2020

The need for off-site construction has increased in the construction industry in Korea in recent years due to the enforcement of the 52-hour workweek, the increasing age of workers on construction sites, the deepening dependence on overseas workers, and the stagnation of productivity in the construction industry. Thus, studies on OSC started in April 2020. In addition, as a national policy study advocating the modular construction method, which is one of the OSC methods, was completed in the first half of 2019. 70 housing units in two complexes that satisfied the Housing Act requirements have been supplied to citizens. However, although modular construction methods have been recognized as a dramatic construction method that achieves shortened construction schedules and solves the issues of cost reduction and the shortage of technical workers on sites by combining the advantages of the manufacturing industry and applying the economies of scale, realistically it has issues due to the rising cost of steel and a low pre-fabrication ratio. Moreover, the construction time of core parts, such as those built by pouring concrete, has become a factor that hinders the shortening of construction times. Thus, this study aims to propose a precast concrete(PC) modular construction system, which fuses three-dimensional infill as an interior finish material and a three-surface PC module that can acts as a structure for a construction method that is economical and can shorten construction time.

• Journal of Veterinary Science
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• v.24 no.4
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• pp.58.1-58.25
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• 2023

Porcine epidemic diarrhea virus (PEDV) has posed significant financial threats to the domestic pig industry over the last three decades in South Korea. PEDV infection will mostly result in endemic persistence in the affected farrow-to-finish (FTF) herds, leading to endemic porcine epidemic diarrhea (PED) followed by year-round recurrent outbreaks. This review aims to encourage collaboration among swine producers, veterinarians, and researchers to offer answers that strengthen our understanding of PEDV in efforts to prevent and control endemic PED and to prepare for the next epidemics or pandemics. We found that collaboratively implementing a PED risk assessment and customized four-pillar-based control measures is vital to interrupt the chain of endemic PED in affected herds: the former can identify on-farm risk factors while the latter aims to compensate for or improve weaknesses via herd immunity stabilization and virus elimination. Under endemic PED, long-term virus survival in slurry and asymptomatically infected gilts ("Trojan Pigs") that can transmit the virus to farrowing houses are key challenges for PEDV eradication in FTF farms and highlight the necessity for active monitoring and surveillance of the virus in herds and their environments. This paper underlines the current knowledge of molecular epidemiology and commercially available vaccines, as well as the risk assessment and customized strategies to control PEDV. The intervention measures for stabilizing herd immunity and eliminating virus circulation may be the cornerstone of establishing regional or national PED eradication programs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.317-318
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• 2023

This study is part of the carbonation degree DB accumulation through quantitative analysis of carbonation depth, Ca(OH)₂ and CO₂ according to the type of finish and years of use of old concrete structures in order to predict the amount of CO₂ that can be absorbed through carbonation of concrete. To this end, the depth of carbonation of the concrete core specimen is measured using an indicator, and the dry amount of water combined with CO₂ in the sample is measured using a differential thermal gravimetric analyzer for samples in the carbonation area and non-carbonated area classified by the indicator, and the absorption compared to the weight of the sample. The amount of absorbed CO₂ was calculated. In addition, the degree of carbonation was calculated through quantitative comparison of Ca(OH)₂ in the carbonation section and non-carbonation section. In the future, we will continue to add the survey and analysis data of dismantled structures and use them as basic data for estimating the amount of carbon dioxide that can be absorbed according to the exposure conditions and years of use by concrete mix.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.47-56
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• 2023

The purpose of this study is the education applying Havruta's method for nursing students and to examine its effect on the communication competency, problem solving capability, and self-esteem. This study is the experimental group have take part in a Havruta's mathod course and the control group do a traditional course. Data is collect at begin and finish of semester in 2023 and analyzed using the SPSS 23.0 program. Result Problem solving capability and self-esteem of nursing students using the Havruta's method is significantly higher than those of the control group, but communication competency is not significan. Application of Havruta's method has to be extended to increase nursing students competencies and research applying various Havruta methods other than teaching friends and making problems should be conducted.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.801-809
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• 2023

Road construction projects have a long duration so cost overruns and schedule delays are occurred. However, performance assessment system that can manage and prepare for this in advance is insufficient. In addition, road construction are affected by many factors during under construction. Therefore it is necessary to conduct performance assessment considering the characteristics of roads and prepare for similar projects in the future. The purpose of this study is to provide a framework to evaluate construction phase performance and present a performance management plan using road construction information. Also, This study conducted time adjustment between the start and the finish of the project and developed performance metrics based on absolute and relative indicator. This study analyzed the cost, schedule, and changes of the road project construction process, showing the possibility of advancement of performance assessment and how to use it when planning new road construction projects.

• Tribology and Lubricants
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• v.40 no.2
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• pp.47-53
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• 2024

Surface topography plays a decisive role in determining the performance of several precision components. In particular, the surface roughness of semiconductor devices affects the precision of the circuit. In this regard, the surface topography of a given surface needs to be appropriately assessed. Typically, the average roughness is used as one of the main indicators of surface finish quality because it is influenced by both dynamic and static parameters. Owing to the increasing demand for such accurate and reliable surface measurement systems, studies are continuously being conducted to understand the parameters of surface roughness and measure the average roughness with high reliability. However, the differences in the measurement methods of surface roughness are not clearly understood. Hence, in this study, the surface roughness of the back of a silicon wafer was measured using both contact and noncontact methods. Subsequently, a comparative analysis was conducted according to various surface roughness parameters to identify the differences in surface roughness depending on the measurement method. When using a 3D laser confocal microscope, even smaller surface asperities can be measured compared with the use of a 3D profiler. The results are expected to improve the understanding of the surface roughness characteristics of precision components and be used as a useful guideline for selecting the measurement method for surface topography assessment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.114-122
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• 2007

In high strength bolted joints, the corrosion of base material causes the reduction of slip resistance of the joints. In this study, tensile tests on slip-critical joints utilizing Zn/Al metal spraying corrosion resistance method were carried out in order to prevent the corrosion and meet the required mechanical characteristics of joints. In addition, slip coefficient and surface roughness were calculated. The key parameters were surface finishing condition and thickness of coating with the identical geometry in all specimens. From the results, it is found that the slip coefficient of the joints with coated finish after sand blast treatment as well as those of non-coated joints with only sand blast treatment were similar or superior to 0.45, which is a specification criteria of slip coefficient in friction-typed joints.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.517-526
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• 2024

The purpose of this study is the education applying Havruta's method for nursing students and to examine its effect on the Communication Competency, Problem-Solving Capability, and Learning Satisfaction. This study is a one-group pre-post design is use and the subjects of this sutdy were the first-grade students of this study were the first grade students of C university the department of nursing, who Anatomy nursing courses. Data of study was collected at begin and finish of semester in 2023 using the SPSS 23.0 program. Result, Communicaton Competency (t=2.11, p=.036), Problem-Solving Capability (t=2.11, p<.001) and Learning Satisfaction (t=3.12, p=.002) of nursing students using Havruta's method is statistically significantly. As Havruta's method has shown results that improve nursing students' capabilities, various studies applying the havruta's method are suggested.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1112-1119
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• 2024

Addis Ababa, the capital of Ethiopia, has been lacking an adequate road network to ensure community access to social, political, and economic resources and to facilitate economic development. The road network coverage was about 22.5% in 2022, which is below the minimum international standard of 25%. To improve accessibility and mobility, the Addis Ababa City Roads Authority(AACRA) has engaged its own force crew (contractor), as well as local and foreign road contractors, in the construction of urban roads. However, these road construction projects are rarely completed within the estimated time and cost, along with a variety of other issues that also need to be addressed. This study aims to explore the application of lean construction for improving the performance of urban road construction projects in Addis Ababa City. A survey of road construction stakeholders was carried out to evaluate their perspectives on the importance of project performance indicators, with the goal of identifying key factors affecting road construction project performance. First, a list of performance indicators was prepared based on a review of lean construction literature, and a total of 38 identified factors were grouped into six performance indicator categories. Cross-tabulation analysis of the stakeholder perspectives was then carried out, and it was found that the indicators that affect the performance of urban road infrastructure projects (in descending order of importance) were: time, quality, cost, risk, safety, and sustainability. Through this analysis it was concluded that right-of-way issues, delay to finish, inflation, contractor capacity, and scope change with change order are also major factors that affect the performance of urban roads construction projects. Clarification of these factors will provide AACRA with useful information on what aspects of lean construction should be prioritized when evaluating future construction projects.

• Archives of design research
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• v.18 no.4 s.62
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• pp.257-266
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• 2005

The purpose of this study is to investigate the psychological reaction to the image of the worship space in the church buildings and to quantify its contribution of the stimulation elements causing such reaction, and finally to suggest basic data for realizing emotional worship space of the church architecture. For this, 143 christians were surveyed to analyze the relationship between 23 emotional expressions extracted from the worship space and 32 images of the worship space. The combined data was described with the two dimensional dispersion using the quantification theory III. The analysis found out that 'simplicity-complexity' of the image consisted of the horizontal axis (the x-axis) and 'creativity' of the image the vertical axis(the y-axis). In addition, to extract the causal relationship between the value of emotional reaction and its stimulation elements quantitatively, the author indicated 4 emotional word groups such as simple, sublime for x-axis and typical creative for y-axis based on its similarity by the cluster analysis, The quantification theory I was also used with total value of equivalent emotional words as the standard variance and the emotional stimulation elements of the worship space as the independent variance. 9 specific examples of the emotional stimulation elements were selected including colors and shapes of the wall and the ceiling, shapes and finish of the floor materials, window shapes, and the use of the symbolic elements. Furthermore, 31 subcategories were also chosen to analyse their contribution on the emotional reaction. As a result, the color and finish of the wall found to be the most effective element on the subjects' emotional reaction, while the symbolic elements and the color of the wall found to be the least effective. It is estimated that the present study would be helpful to increase the emotional satisfaction of the users and to approach a spatial design through satisfying the types and purposes of the space.