• Computers and Concrete
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• v.23 no.6
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• pp.445-457
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• 2019

Cracks are an important distress of concrete bridges, and may reduce the life and safety of bridges. However, the traditional manual crack detection means highly depend on the experience of inspectors. Furthermore, it is time-consuming, expensive, and often unsafe when inaccessible position of bridge is to be assessed, such as viaduct pier. To solve this question, the real-time automatic crack detecting system with unmanned aerial vehicle (UAV) become a choice. This paper designs a new automatic detection system based on real-time comprehensive image processing for bridge crack. It has small size, light weight, low power consumption and can be carried on a small UAV for real-time data acquisition and processing. The real-time comprehensive image processing algorithm used in this detection system combines the advantage of connected domain area, shape extremum, morphology and support vector data description (SVDD). The performance and validity of the proposed algorithm and system are verified. Compared with other detection method, the proposed system can effectively detect cracks with high detection accuracy and high speed. The designed system in this paper is suitable for practical engineering applications.

• Journal of Korean Academy of Dental Administration
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• v.7 no.1
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• pp.10-20
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• 2019

Korean dental hygienists perform more tasks in dental clinics than are described in the law. The purpose of this study was to investigate the actual work of Korean dental hygienists in dental clinics using an observational study design. Two dental hygienists observed and recorded the work performed in 1 day from the time of commencement to the time of leaving work by 18 dental hygienists working in the dental clinic in a single area. Data management, prevention of infection, counseling, calculus removal, radiography, assistance of fixed orthodontic treatment, assistance of fixed prosthetic treatment, and preparation for implant surgery were recorded. Among the tasks that take more than 1 min, the most time-consuming tasks were document management, infection control, consultation, calculus removal, preparation for implant surgery, assistance of orthodontic treatment, and assistance of fixed prosthetic treatment. Korean dental hygienists are performing various tasks, such as infection control, dental hospital/clinic management, oral disease prevention, and dental treatment assistants.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.121-127
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• 2021

Reverse offset printing is considering as an emerging technology for printed electronics owing to its environmentally friendliness and cost-effectiveness. In reverse offset printing, selecting the materials for cliché and blanket is critical because of its minimum resolution, registration errors, aspect ratio of reliefs, pattern area, and reusability. Various materials such as silicon, quartz, glass, electroplated nickel plates, and imprinted polymers on rigid substrates can be used for the reverse offset printing of cliché. However, when new structures are designed for specific applications, new clichés need to re-fabricated each time employing multiple time-consuming and costly processes. Therefore, by modifying the blanket materials containing the printing ink, several new structures can be easily created using the same cliché. In this study, we investigated various elastomeric materials and evaluated their applicability for designing a highly stretchable blanket with controlled elastic deformation to implement tunable reverse offset printing.

• Advances in materials Research
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• v.11 no.4
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• pp.251-277
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• 2022

Disposal of industrial waste in cities where municipal authorities permitting higher floor area ratio coupled with increasing living standards, a lot of demolition waste is being generated. Its disposal is a challenge particularly in megacities where no landfills are available. The ever-increasing cost of building construction materials also necessitates consuming demolition wastes in a useful manner to save fresh natural raw materials. In the present work, the crushed waste glass is used in high-strength concrete as a partial replacement of fine aggregate. The control concrete of grade M60 was proportioned following BIS 10262-2009. The crushed waste glass has been used as a partial replacement with varying percentages of 10, 20, 30, and 40% by weight of fine aggregate. Experimental tests were carried on the fresh and hardened state of the concrete. The effect of crushed waste glass on the workability of the concrete has been investigated. Non-destructive tests, acid attack tests, compressive strength, split tensile strength, and X-ray diffraction analysis was carried out for the control concrete and concrete containing crushed waste glass after 7, 28, and 270 days of normal curing. The results show that for the same w/c ratio, the workability of concrete increases with increasing replaced crushed waste glass content. However, the decrease in compressive strength of the concrete after 28 days of normal curing and further after 28 days of acid attacks, up to 30% replacement level of fine aggregate by the crushed waste glass is insignificant.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.316-322
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• 2009

The more repetitive, complex and objective the work, the more effective automation is. Code checking is an example of this. Checking building codes through a thick set of drawings is error-prone and time-consuming. In order to overcome this problem, several organizations have initiated efforts to automate building-code checking. Initiated study mainly focused on checking codes for invalidation, required size and crash, and then area of checkable codes have been expanding. But, it has not been considered for codes regarding anti-disaster/egress, which is also issued these days. This study is about how to automatically check codes for anti-disaster and egress based on Korea building codes. The codes can be categorized as five sections: egress way, material/capability, principals of evacuation, evacuation stairway and fire protection partition. To check automatically, there are problems, such as expression of codes for egress and limitation of extractable information from the BIM model. This paper shows what problems exist and assignments to be resolved. Also, current developing processes are presented, and suggestions are made about the direction for the work that remains.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.122-122
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• 2020

Urban flood simulation plays a vital role in national flood early warning, prevention and mitigation. In recent studies on 2-dimensional flood modeling, the integrated run-off inundation model is gaining grounds due to its ability to perform in greater computational efficiency. The adaptive quadtree shallow water numerical technique used in this model implements the adaptive mesh refinement (AMR) in this simulation, a procedure in which the grid resolution is refined automatically following the flood flow. The method discounts the necessity to create a whole domain mesh over a complex catchment area, which is one of the most time-consuming steps in flood simulation. This research applies the dynamic grid refinement method in simulating the recent extreme flood events in Metro Manila, Philippines. The rainfall events utilized were during Typhoon Ketsana 2009, and Southwest monsoon surges in 2012 and 2013. In order to much more visualize the urban flooding that incorporates the flow within buildings and high-elevation areas, Digital Surface Model (DSM) resolution of 5m was used in representing the ground elevation. Results were calibrated through the flood point validation data and compared to the present flood hazard maps used for policy making by the national government agency. The accuracy and efficiency of the method provides a strong front in making it commendable to use for early warning and flood inundation analysis for future similar flood events.

• Journal of The Korean Digital Architecture Interior Association
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• v.10 no.1
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• pp.39-47
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• 2010

The officetel introduced into Korea in the mid-1980s has thus far been in the limelight as the object of investment for the substitute for small-sized housing and for lease income. But to raise the possibility of succeeding in officetel investment in the future, it has been necessary to make a systematic analysis of the changed direction of the officetel market and the profitability and stability of investment. Accordingly, this study attempted to analyze demand for officetel with a focus on the possibility of increase in the households composed of one or two members, the major consuming bracket of small-sized housing. And it attempted to analyze the possibility of investment in officetel as the investment goods for lease income due to the entry of Korea into aging society. And past analysis of investment in officetel was confined to profitability analysis, but this study sought to develop the stability indicator of the officetel for the analytical purpose. As a result, it is predicted that demand for small-sized housing will increase due to the increase in 1-to 2-person households. Accordingly, it is predicted that demand for officetel as the place of residence will come to increase. And taking into consideration the more serious degree of sustained aging in the population, older people's preference for real estate and need for lease income, it is predicted that preference for officetel as the object of investment will increase. An attempt was made to analyze the profitability and stability of investment in the metropolitan area which the officetel has principally been supplied, in order to analyze the profitability and stability of officetels. For the purpose of this study, Yeoksam-dong in Kangnam-gu, Yeoui-dong in Youngdeungpo-gu, Bongcheon-dong in Kwanak-gu were selected in Seoul as the area for analysis. Jung-dong in Wonmi-gu, Bucheon, Seohyun-dong in Bundang-gu, Seongnam, Janghang-dong in Ilsan-gu, Koyang were selected in Kyonggi province as the area for analysis. As a result, it was found that the small-sized officetel had higher profitability and stability than the large-sized officetel. It was found that the area of Kyonggi Province had the larger deviation by size. That is, it was found that the small-sized officetel in the area of Kyonggi Province was significant as the object of investment for stable lease income.

• Korean Journal of Remote Sensing
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• v.34 no.6_4
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• pp.1519-1529
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• 2018

The volcanic ash can spread out over hundreds of kilometers in case of large volcanic eruption. The deposition of volcanic ash may induce damages in urban area and transportation facilities. In order to respond volcanic hazard, it is necessary to estimate efficiently the diffusion area of volcanic ash. The purpose of this study is to compare in-situ volcanic deposition and satellite images of the volcanic eruption case. In this study, we used Near-Infrared (NIR) channels 7 and 8 of Geostationary Ocean Color Imager (GOCI) images for Mt. Aso eruption in 16:40 (UTC) on October 7, 2016. To estimate deposit area clearly, we applied Principal Component Analysis (PCA) and a series of morphology filtering (Eroded, Opening, Dilation, and Closing), respectively. In addition, we compared the field data from the Japan Meteorological Agency (JMA) report about Aso volcano eruption in 2016. From the results, we could extract volcanic ash deposition area of about $380km^2$. In the traditional method, ash deposition area was estimated by human activity such as direct measurement and hearsay evidence, which are inefficient and time consuming effort. Our results inferred that satellite imagery is one of the powerful tools for surface change mapping in case of large volcanic eruption.

• Journal of the Korean Dietetic Association
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• v.11 no.1
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• pp.11-20
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• 2005

This study was conducted to investigate preference for convenience food and dietary attitude in college students in Seoul and Kyunggi-do area. This study used a questionnaires as instrument tool. Thequestionnaire consisted of socio-demographic characteristics of the subjects, the valuation of preference for convenience, the concern of nutrition, and the dietary attitude. The subject were 199 males and 137 females. The mean age of subjects was 22.4$\pm$2.3year. The results have been summarized as follows Male students preferred more convenience food than females. Male students liked chicken, ice cream, ramyeon, pizza·hamburgerandfemalestudentslikedchicken,pizza, ice cream, ramyeon·hamburger. The kinds of convenience foods for a substitute meal were ramyeon, hamburger, bread, potato in male group and female group had frequently ramyeon, hamburger, bread, rice cake for a substitute meal. Male students were more likely to eat ramyeon (p<0.01) and purchased sabalmyeon The subjects used to purchase sabalmyeon as main convenience food at convenient store The score of preference for convenience food in male group was higher than female group. The score of attitude toward balanced diet in female group was higher than male group(p<0.01). In scores of concern for nutrition information, balanced diet, and nutrition knowledge, Female group had higher scores of concern for nutrition information, balanced diet, and nutrition knowledge than that of male group (p<0.01).There was no significant difference in the degree of preference for packing types, however, Male group tended to prefer more micro wave type than female group. The persons to affect the consumption of convenience food were friends. There was no significant difference in the time of purchase convenience food, however, Male tended to purchase convenience food at the time of snack than female group. As a results, proper nutritional education and qualitative development of convenience food are required in order to improve the consuming attitude of consumers and their preference for convenience food.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.221-226
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• 2018

Special-purposed vehicles are customized according to the user's requirements. When these vehicles are out of oder, they are costly and time consuming to repair. In order to solve these problems, we want to remotely check whether the vehicle is abnormal and remotely identify the fault area, thereby shortening the repair cost and the repair period. In this study, the faulty part of the electric control part is automatically identified, and it is immediately grasped through the user's mobile phone application and an instant fault code is notified to the car manufacturer for quick and smooth fault repair. In order to realize this, we want to build a system that uses the technology of IoT to determine the fault area according to the items required in the field of the special purpose vehicle and notify the manufacturer of the fault on its own.