• Computers and Concrete
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• v.30 no.4
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• pp.269-276
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• 2022

In this paper, frequency vibrations of double-walled carbon nanotubes (CNTs) has been investigated based upon nonlocal elastic theory. The inference of small scale is being perceived by establishing nonlocal Love shell model. The wave propagation approach has been operated to frame the governing equations as eigen value system. An innovational nonlocal model to examine the scale effect on vibrational behavior of armchair, zigzag and chiral of double-walled CNTs. An appropriate selection of material properties and nonlocal parameter has been considered. The influence of dimensionless nonlocal parameter has been studied in detail. The dominance of end condition via nonlocal parameter is explained graphically. The results generated furnish the evidence regarding applicability of nonlocal shell model and also verified by earlier published literature.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2761-2766
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• 2021

A method for preparing "reagent" for radioactive methyliodide vapors production using an isotopic exchange reaction has been developed. Based on the obtained data of the isotopic exchange efficiency and hydraulic resistance, white fused alumina (700-840 ㎛) was selected as the carrying agent material for "reagent" production. The radioiodine isotopic exchange dependences on such parameters as temperature, gas flow velocity, and the methyliodide concentration in it were determined. Optimal conditions have been selected to achieve 85% of the isotopic exchange rate in 1 h of the experiment. The obtained data allowed to develop an approach to the test of iodine filters for nuclear power plants and to determine their efficiency.

• Archives of Craniofacial Surgery
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• v.23 no.2
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• pp.53-58
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• 2022

Alveolar cleft belongs to the spectrum of cleft lip and/or palate, affecting 75% of cleft lip/palate patients. The goals of alveolar cleft treatment are stabilizing the maxillary arch, separating the nasal and oral cavities, and providing bony support for both erupting teeth and the nasal base via the piriform aperture. Secondary alveolar bone grafting is a well-established treatment option for alveolar cleft. Secondary alveolar bone grafting is performed during the period of mixed dentition using autologous bone from various donor sites. There are several issues relevant to maximizing the success of secondary alveolar bone grafting, including the surgical timing, graft material, and surgical technique. In this study, we reviewed issues related to surgical timing, graft materials, and evaluation methods in secondary alveolar bone grafting.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.11
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• pp.73-81
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• 1996

This paper presents a general procedure for the selection of the machining parameters for a given machine which provides the maximum material removal rate using a Genetic Algorithms(GAs). Some constraints were given in order to achieve desired surface integrity and cutting tool life conditions as wel as to protect machine tool. Such a constrained problem can be transformaed to unconstrained problem by associating a penalty with all constraint violations and the penalties are included in the function evaluation. Genetic Algorithms can be used for finding global optimum cutting conditions with respect to the above cost function transformed by pennalty function method. From the demonstration of the numerical results, it was found that the near optimal conditions could be obtained regardless of complex solution space such as cutting environment.

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.1-8
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• 1998

This paper presents an arificial neuro-fuzzy technique based prtial discharge (PD) pattern classifier to power system application. This may require a complicated analysis method employ -ing an experts system due to very complex progressing discharge form under exter-nal stress. After referring briefly to the developments of artificical neural network based PD measurements, the paper outlines how the introduction of new emerging technology has resulted in the design of a number of PD diagnostic systems for practical applicaton of residual lifetime prediction. The appropriate PD data base structure and selection of learning data size of PD pattern based on fractal dimentsional and 3-D PD-normalization, extraction of relevant characteristic fea-ture of PD recognition are discussed. Some practical aspects encountered with unknown stress in the neuro-fuzzy techniques based real time PD recognition are also addressed.

• Journal of Sensor Science and Technology
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• v.32 no.4
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• pp.213-218
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• 2023

Triboelectric nanogenerators (TENGs) have emerged as a highly promising energy harvesting technology capable of harnessing mechanical energy from various environmental vibrations. Their versatility in material selection and efficient conversion of mechanical energy into electric energy make them particularly attractive. TENGs can serve as a valuable technology for self-powered sensor operation in preparation for the IoT era. Additionally, they demonstrate potential for diverse applications, including energy sources for implanted medical devices (IMDs), neural therapy, and wound healing. In this review, we summarize the potential use of this universally applicable triboelectric energy harvesting technology in the disinfection and blocking of pathogens. By integrating triboelectric energy harvesting technology into human clothing, masks, and other accessories, we propose the possibility of blocking pathogens, along with technologies for removing airborne or waterborne infectious agents. Through this, we suggest that triboelectric energy harvesting technology could be an efficient alternative to existing pathogen removal technologies in the future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.199-200
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• 2023

This paper presents a study on the selection of optimal mix proportions for producing lightweight pre-foam concrete as a substitute for Autoclaved Lightweight Concrete (ALC) without the accelerated curing. The study was conducted using a rapid hardening binder made from by-products of the steel industry as the primary raw material. The experimental results established the optimal mix proportions, which included retarder content, water/binder ratio, foam content, and fiber inclusion amount, for the production of lightweight foam concrete. The optimal mix proportion was determined to have a retarder content at the minimum amount required to secure the working time, W/B of 35%, a foam content limited to 65% or less, and a fiber inclusion amount of 0.05% or less.

• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.425-435
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• 2016

In this paper, we propose a classification model by analyzing raw material images recorded using a color CCD camera to automatically classify good and defective agricultural products such as rice, coffee, and green tea, and raw materials. The current classifying agricultural products mainly depends on visual selection by skilled laborers. However, classification ability may drop owing to repeated labor for a long period of time. To resolve the problems of existing human dependant commercial products, we propose a vision based automatic raw material classification combining mean shift clustering and stepwise region merging algorithm. In this paper, the image is divided into N cluster regions by applying the mean-shift clustering algorithm to the foreground map image. Second, the representative regions among the N cluster regions are selected and stepwise region-merging method is applied to integrate similar cluster regions by comparing both color and positional proximity to neighboring regions. The merged raw material objects thereby are expressed in a 2D color distribution of RG, GB, and BR. Third, a threshold is used to detect good and defective products based on color distribution ellipse for merged material objects. From the results of carrying out an experiment with diverse raw material images using the proposed method, less artificial manipulation by the user is required compared to existing clustering and commercial methods, and classification accuracy on raw materials is improved.

• Journal of Korean Society of Rural Planning
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• v.14 no.2
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• pp.77-84
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• 2008

Amenity landscapes in rural areas are becoming increasingly important as a resource to enhance the (public) interest in rural landscapes and to vitalize the rural areas. Befitting the times, the objective of this project is to discover the amenity landscapes distributed throughout the rural areas and to produce material in the form of a publication for the promotion of the aforementioned landscapes. For such purposes, local autonomous bodies, rural amenity resource investigation team, and experts on landscape found rural amenity landscapes and entered them for a selection process, out of which the top 100 rural amenity landscapes were ultimately selected based both on the assessment system developed by the researchers and on the assessment process executed by the assessment committee. The following two categories of assessment criteria for the amenity landscapes were presented: village-related assessment criteria including value as resource and use value; landscape-resources-related assessment criteria, including aesthetic value, identity, adherence to traditionality, and sustainability. Assessment for each criteria item was made by applying a 5-point Likert scale throughout. The sum of the points for each landscape was then converted at a 100 point scale for ultimate use in selection of the top 100 landscapes. This paper is the outcome of such series of processes and systems.

• Journal of Conservation Science
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• v.26 no.1
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• pp.43-60
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• 2010

This study was investigated quantitative and objective making techniques for molding clay of Four-guardian statues in Songgwangsa temple. Also, basic data about the provenance of molding clay was acquired for the restoration using same materials when the conservation treatment is carried out. As a result, molding clay used the Four-guardian statues was identified the very similar soil regardless of layers and objects. But molding clay differed in particle sizes and contents of organic matters according to the first layer to finish layer in relatively thick parts. Also, it was used one kind of soil without the layer distinction in thin parts. The restoration soil was applied to genetically similar soil as molding clay of the Four-guardian statues, and showed a difference of careful selection degree according to the layers. As a result of the provenance interpretation, the soil distributing presumed provenance was confirmed the same origin as molding clay. Therefore, the soil is appropriate for the materials of conservation treatment. This result will contribute inorganic material research and conservation treatment for the clay molded Four-guardian statues in Korea.