• Title/Summary/Keyword: concrete quality

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Determination and evaluation of dynamic properties for structures using UAV-based video and computer vision system

  • Rithy Prak;Ji Ho Park;Sanggi Jeong;Arum Jang;Min Jae Park;Thomas H.-K. Kang;Young K. Ju
    • Computers and Concrete
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    • v.31 no.5
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    • pp.457-468
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    • 2023
  • Buildings, bridges, and dams are examples of civil infrastructure that play an important role in public life. These structures are prone to structural variations over time as a result of external forces that might disrupt the operation of the structures, cause structural integrity issues, and raise safety concerns for the occupants. Therefore, monitoring the state of a structure, also known as structural health monitoring (SHM), is essential. Owing to the emergence of the fourth industrial revolution, next-generation sensors, such as wireless sensors, UAVs, and video cameras, have recently been utilized to improve the quality and efficiency of building forensics. This study presents a method that uses a target-based system to estimate the dynamic displacement and its corresponding dynamic properties of structures using UAV-based video. A laboratory experiment was performed to verify the tracking technique using a shaking table to excite an SDOF specimen and comparing the results between a laser distance sensor, accelerometer, and fixed camera. Then a field test was conducted to validate the proposed framework. One target marker is placed on the specimen, and another marker is attached to the ground, which serves as a stationary reference to account for the undesired UAV movement. The results from the UAV and stationary camera displayed a root mean square (RMS) error of 2.02% for the displacement, and after post-processing the displacement data using an OMA method, the identified natural frequency and damping ratio showed significant accuracy and similarities. The findings illustrate the capabilities and reliabilities of the methodology using UAV to evaluate the dynamic properties of structures.

Survey and Analysis of the Present State of Education in Regard to the Accreditation in Engineering Education (공학인증 관련 지방 사립 대학교 공학 교육 현황 조사와 분석)

  • Moon, Sangook
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.6 no.1
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    • pp.271-280
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    • 2016
  • In recent years, most domestic colleges of engineering are continuously trying to enhance the quality of education in engineering so as to meet the international requirement of education standards of this era. In consequence, the colleges are willing to acquire the accreditation of education by the ABEEK (Accreditation Board for Engineering Education of Korea) so that they can find the right way for the education of engineering and establish concrete educational programs in engineering. In this contribution, we exemplify a case of the College of Engineering in Mokwon University to survey and analyze the current state of education in engineering. We adopt the AS-IS and TO-BE analysis model to assess the system and try to figure out the right way for custom-designed education. The analysis helps understanding of the current situation of local private universities and consequently be used as important data for acquiring the engineering accreditation for global standard.

Current Status and Analysis of Durability for Buildings Long Neglected after Construction Discontinuation in Jeju (제주지역 공사중단 건축물의 현황조사 및 내구성 분석)

  • Han, In-Deok;Kim, Doo-Seong;Jang, Myunghoun
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.4
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    • pp.441-452
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    • 2023
  • Buildings that have been long neglected can suffer severe durability reduction due to factors such as rebar rust and concrete quality deterioration resulting from exposure to outside air. Furthermore, the issues associated with these suspended buildings, including safety accidents, social crimes, and environmental pollution, are becoming increasingly serious. This study investigates the current status of these buildings in the Jeju area, identifies the problems, and examines the durability of the structure in a specific location to assess the possibility of future use. Aesthetic surveys(visual and slope inspections) as well as non-destructive tests(compressive strength tests, neutralization tests, and rebar detection tests) were conducted to assess durability. The analysis revealed that the structure maintained satisfactory durability and the building's condition was good in comparison to the years of neglect.

A Basic Study to Prepare a Watertightness Evaluation Plan for Sealant Applied to Joints Between Members of PC Structures (PC 구조물 부재간 접합부에 적용되는 실링재의 수밀성 평가방안 마련을 위한 기초적 연구)

  • Kim, Tae-Ho;Kim, Yong-Ro;Ko, Hyo-Jin;Park, Jin-Sang;Kim, Dong-Bum;Lee, Sang-Wook
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.1
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    • pp.45-56
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    • 2023
  • This study was conducted to examine the feasibility of preparing a durability evaluation plan in watertightness for sealant applied to a PC structure. To this end, 5 types of sealant that equally satisfy the quality standards of the relevant KS standard were selected and tested. Through this testing, it was found that 3 of the 5 types of sealant showed deterioration in watertightness and durability, such as falling off and cracking from the substrate. For the remaining two types, a visual observation showed no significant changes, but additional analysis, confirmed that there was a large difference in the stress reduction rate of the material. Therefore, based on the above results, the need for a performance review in durability between sealant was confirmed, and based on this, the validity of the durability evaluation plan that can be used in product selection was quantitatively confirmed.

A Systematic Review of Eco-CMF Design Processes for Fashion Products (체계적 문헌 고찰을 통한 패션 제품의 친환경 CMF 디자인 프로세스 분석)

  • So Hyun Lee;Sukyung Kang;Sungjin Park;Young A Koh;Juyeon Park
    • Fashion & Textile Research Journal
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    • v.25 no.1
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    • pp.1-10
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    • 2023
  • An eco-CMF design process is vital to the sustainable development of fashion products concerning both emotional and physical quality factors, thus extending the use phase of the product life cycle. Life cycle assessment (LCA) is widely used in other fields to evaluate environmental impact; However, the method is rarely adopted in fashion. While cooperating with design, technology, and the users, reflecting the CMF design process is an excellent approach to the sustainable development of fashion products. Moreover, it is likely to evoke favorable reactions in users toward products. Therefore, this study aimed to review the sustainable design strategies associated with CMF in the fashion industry. Using a systematic review, 135 papers that met the inclusion criteria were examined from peer-reviewed journal articles published between 1990 and 2022. They contained specific design processes or tools relevant to eco-CMF design. The search used the Web of Science database. After a rigorous search, the final six peer-reviewed journal articles were selected and underwent thorough content reviews. Then, the CMF design tools and frameworks for eco-design featured in the articles were carefully reviewed and analyzed. Finally, we proposed practical guidelines for the sustainable development of eco-CMF design in the fashion industry. The study outcomes revealed the need for concrete eco-CMF design processes, particularly for fashion products. Furthermore, more active research involving eco-CMF design processes for the sustainable environmental impact of fashion products is required.

Improvement of the Architectural Environment by Applying Photocatalyst Building Materials and Ventilation Systems (광촉매 건축자재와 환기시스템 적용에 따른 건축 환경 개선 방안)

  • Yong Woo Song;Seong Eun Kim;Se Hyeon Lim;Sung Jin Sim
    • Land and Housing Review
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    • v.14 no.4
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    • pp.103-110
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    • 2023
  • People who spend most of their day indoors are continuously exposed to internally and externally generated indoor pollutants. According to a 2022 report from the World Health Organization (WHO), air pollution is the cause of more than 7 million deaths annually worldwide, emphasizing the seriousness of indoor air pollutants. Air pollutants include nitrogen oxides (NOx), formaldehyde (HCHO), and volatile organic compounds (VOCs), which have serious effects on the human body. Photocatalyst is a material that can remove these indoor air pollutants. Photocatalysts not only have the ability to remove dust precursors, but also have antibacterial, sterilizing, and deodorizing functions, making them effective in improving indoor air quality. This study suggests areas and methods in which photocatalysts can be applied to buildings. Fields of application include interior and exterior construction materials such as concrete, as well as organic paints and ventilation devices. If appropriate utilization plans are developed, it may be possible to improve the built environment through reduced indoor and outdoor pollutant levels.

Advantages and disadvantages of renewable energy-oil-environmental pollution-from the point of view of nanoscience

  • Shunzheng Jia;Xiuhong Niu;Fangting Jia;Tayebeh Mahmoudi
    • Advances in concrete construction
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    • v.16 no.1
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    • pp.69-78
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    • 2023
  • This investigation delves into the adverse repercussions stemming from the impact of arsenic on steel pipes concealed within soil designated for rice cultivation. Simultaneously, the study aims to ascertain effective techniques for detecting arsenic in the soil and to provide strategies for mitigating the corrosion of steel pipes. The realm of nanotechnology presents promising avenues for addressing the intricate intersection of renewable energy, oil, and environmental pollution from a novel perspective. Nanostructured materials, characterized by distinct chemical and physical attributes, unveil novel pathways for pioneering materials that exert a substantial impact across diverse realms of food production, storage, packaging, and quality control. Within the scope of the food industry, the scope of nanotechnology encompasses processes, storage methodologies, packaging paradigms, and safeguards to ensure the safety of consumables. Of particular note, silver nanoparticles, in addition to their commendable antibacterial efficacy, boast anti-fungal and anti-inflammatory prowess, environmental compatibility, minimal irritability and allergenicity, resilience to microbial antagonism, thermal stability, and robustness. Confronting the pressing issue of arsenic contamination within both environmental settings and the food supply is of paramount importance to preserve public health and ecological equilibrium. In response, this study introduces detection kits predicated upon silver nanoparticles, providing an expeditious and economically feasible avenue for identifying arsenic concentrations ranging from 0.5 to 3 ppm within rice. Subsequent quantification employs Hydride Atomic Absorption Spectroscopy (HG-AAS), which features a detection threshold of 0.05 ㎍/l. A salient advantage inherent in the HG-AAS methodology lies in its capacity to segregate analytes from the sample matrix, thereby significantly reducing instances of spectral interference. Importantly, the presence of arsenic in the soil beneath rice cultivation establishes a causative link to steel pipe corrosion, with potential consequences extending to food contamination-an intricate facet embedded within the broader tapestry of renewable energy, oil, and environmental pollution.

The Impact of Physical, Financial, and Psychological Factors on Elderly Life Satisfaction (신체적·재무적·심리적 요인이 고령자의 생활만족도에 미치는 영향)

  • Haerang Lee;Jihye Kim;Jong-Youn Rha
    • Human Ecology Research
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    • v.62 no.2
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    • pp.261-278
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    • 2024
  • This study aims to enhance the life satisfaction of the elderly population in South Korea by exploring their satisfaction levels and identifying influencing factors. Utilizing data from the 17th Korean Welfare Panel, which includes 6,260 individuals aged 65 and older, this study employs independent sample t-tests, one-way ANOVA, and hierarchical regression analysis. The results showed that, in general, the life satisfaction of the elderly population was somewhat lower than that of the general adult population in all areas, except for job satisfaction and satisfaction with housing. Key factors influencing life satisfaction among the elderly population include demographic characteristics (gender, age, economic activity, residence, education level), subjective health status factors, financial factors (disposable income, monthly living expenses), and psychological factors (depression, self-esteem). Notably, psychological factors, particularly self-esteem and depression, profoundly affect all life satisfaction domains. Enhancing life satisfaction necessitates fostering positive self-perception and capabilities in the elderly population, suggesting the need for programs focused on positive emotional experiences. Moreover, depression significantly reduces life satisfaction, underscoring the importance of policy interventions to address negative emotions in this demographic. This study is expected to provide basic data for establishing concrete and effective policies for improving the quality of life for the elderly population. Additionally, by highlighting the importance of positive psychological factors, it is anticipated that the study will offer a new direction for improving the life satisfaction of the elderly population.

A Study on Development of Health Care Service for the Elderly - Focus on Rural Community - (농촌지역 노인에 대한 보건의료서비스 개발을 위한 연구)

  • Hyun In-Sook
    • Journal of Korean Public Health Nursing
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    • v.11 no.2
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    • pp.57-72
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    • 1997
  • The objectives of this study are : 1) To understand self-care ability, living habits, utilization patterns of medical facililties for the elderly in Puk-Cheju county which has the highest percent age of senior citizens among Cheju rural community: 2) To identify factors which influence living quality and long life for the eldely 3) To develop health care service with a view to guaranteering living quality The eldely population of Puk-Cheju county was $10.8\%$ in 1995. It will be increasing and is projeted $23.0\%$ by 2030. The result indicated that utilizations rate by out-patient were 5.89 claims and utilizations rate by in-patient were 0.17 claims per person. The highest disease among respondents were disease of musculoskeletal system and connective tissue. A total of 310 elderlys were responded to analyze self-care ability and health behavior. The most important factors of long life were to have peaceful mind$(50.0\%)$. The common disease of acute and chronic disease was musculoskeletal system disease. $66.8\%$ of respondents went to hospital and local clinic when they got sick. The most needed health care service was home visiting service among public health center, representing $31.4\%$. The repondent's self-care ability and self-efficacy were relatively superiority. A total of 92 elderlys were conducted the intelligence test for the rate of dementia and their average age was 74.3. The result of Minimental State Scale indicated that 25% of respondents were suspected to be dementia. The followings are recommendations based on the survey result. 1) Concidering every conditions of self-care ability and health status for elderly. It is important to embody appopriate health care service. 2) Considering concrete method, it is necessary to establish health service, which match health status and self-care ability, and various planning for sepecial facilities for the elderly. 3) It is desiable to make actual programs for the elderly in each community level. 4) It must be develop the better use of volunteers and programs for prevention of dementia. Finally, Concerning the orgarnization of public health center, community health center need to be reorganized for health service for the elderly. It is important to develop and operate health promotion for the elderly, and it is necessary to form the foundation for the support of facilities equipments. This contribute to promote health status for the rural elderly.

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A Study on the Institutional System for Efficient-Sustainable Recycling of Construction Wastes (지속가능한 건설폐기물 재활용 활성화제도 개선에 관한 연구)

  • Park, Chan-Hyuk;Chung, Jae-Chun
    • Journal of the Korea Organic Resources Recycling Association
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    • v.12 no.1
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    • pp.94-103
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    • 2004
  • The generation of construction waste has increased continuously in the recent years, becoming an important social issue. In this paper, the generation and treatment of construction waste in Korea was reviewed and a comparative analysis was performed between Korea and developed countries to suggest some efficient recycling strategies. The generation of construction waste has increased 4 times from 10 million ton/yr in 1996 to 40.3 million ton/yr in 2002. Of the construction waste generated in 2002, concrete debris waste occupied 60.4%. Approximately 14.5% of the construction waste is landfilled, 2,0% incinerated and 83.4% recycled, then the recycling rate might be relatively high. However, there is room for increasing landfill diversion. It is somewhat important to strenghten incentives for the outstanding recycling business. It is also needed to improve the recycled aggregate quality standard and impurity content standard. It is desirable to toughen the facility standard for the recycling aggregate business and the quality standard for the intermediate treatment business. Also, market for the intermediate product of the recycled aggregate should be activated. Finally, more recycling-oriented regulations governing the construction waste has to be developed with the efficient public education program.

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