• Journal of Korean Society of Steel Construction
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• v.19 no.2
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• pp.139-146
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• 2007

The objective of the present study is to provide statistical resistance statistics for steel-concrete composite plate girder sections under positive and negative moments. Statistical properties on yield strength, tensile strength, elongation, and fracture toughness of domestic structural steel products, gathered from an analysis of over 16,000 samples, were evaluated. Using the steel samples for the plate girder, the bias factor and the coefficient of variation of the ultimate flexural resistance for representative composite plate girder sections under positive and negative flexures were presented. In calculating the ultimate flexural resistance of the composite section, the moment curvature relationships were developed using the incremental load approach considering material nonlinearity for the steel girder. The predicted statistics can be used in the future for the efficient calibration of LRFD code.

• Korean Journal of Community Nutrition
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• v.3 no.4
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• pp.642-654
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• 1998

In order to examine the television(TV)'s role of nutrition education and the nutritional interests and problems of the general public in the 1990s, a comtents analysis was done on two nutrition-related TV programs, a regular round-table talk show and a newscast. Broadcast from January 1993 to July 1997 and from January 1997 to July f1997, respectively. Nutrition-related information was classified into five categories. Food and nutrient(39.5%) and diseases(34.7%) were most frequently telecasted, which were followed by food habits and general health(13.0%), traditional dishes and cookery(8.2%), and food sanitation and safety(4.6%). In becoming the latest year, some trends in the issues displayed increased telecasts about disease, dish and cookery, and food safety, while the telecasting of food and nutrient decreased. The contents about the relations hip between life-style(including diet) and chronic degenerative diseases and the importance of balanced diets and regualr meals for health promotion became particularly emphasized. Overall, two TV programs provided the public with positive, practical, and sometimes practive nutrition education messages for improving eating life and health care. They also raised the public's awareness of the nutritional importance of Korean staple foods such as rice, kimchi, seaweed, and soysauce, and they sometimes satified the audience's curiosities by introducing Korean food culture or foods of Buddhist priests. When the accident of food toxicity occurred concrete information about how to manage it was rapidly given to the public. In addition they played a role in food balance policy by telecasting over-product foods such as garlic and onion. However some negative points appeared. Telecasts on milk and its products and diabetes mellitus showed the least frequently. These shows should be broadcast more often considering the present nutrition and health problems in Korea. Some functions or effects of foods were mostly explained by only physicians of Chinese medicine. Sometimes misinformed, unclear, overemphasized, biased, or unfair information was televised to the public. If these problems could be solved through the sincere cooperation between nutrition faculty and TV produces, become televison could a more complete and effective medium for educating the public about nutrition.

• Advances in concrete construction
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• v.8 no.3
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• pp.207-215
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• 2019

Application of nanotechnology can be used to tailor made cementitious composites owing to small dimension and physical behaviour of resulting hydration products. Because of high aspect ratio and extremely high strength, carbon nanotubes (CNTs) are perfect reinforcing materials. Hence, there is a great prospect to use CNTs in developing new generation cementitious materials. In the present paper, a parametric study has been conducted on cementitious composites reinforced by two types of multi walled carbon nanotubes (MWCNTs) designated as Type I CNT (10-20 nm outer dia.) and Type II CNT (30-50 nm outer dia.) with various concentrations ranging from 0.1% to 0.5% by weight of cement. To evaluate important properties such as flexural strength, strain to failure, elastic modulus and modulus of toughness of the CNT admixed specimens at different curing periods, flexural bending tests were performed. Results show that composites with Type II CNTs gave more strength as compared to Type I CNTs. The highest increase in strength (flexural and compressive) is of the order of 22% and 33%, respectively, compared to control samples. Modulus of toughness at 28 days showed highest improvement of 265% for Type II 0.3% CNT composites. It is obvious that an optimum percentage of CNT could exists for composites to achieve suitable reinforcement behaviour and desired strength properties. Based on the parametric study, a tentative optimum CNT concentration (0.3% by weight of cement) has been proposed. Scanning electron microscope image shows perfect crack bridging mechanism; several of the CNTs were shown to act as crack arrestors across fine cracks along with some CNTs breakage.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.216-222
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• 2021

This is an experiment to complement new ways of using concentrated water discharged from the seawater desalination plant. In this study, metakaolin, which has excellent chloride ion immobilization effect, was used as the main binder, and 10% and 20% of calcium oxide were substituted with the activator. In addition, tap-water(TW) and reverse osmosis brine water(RW) were used as mixed water. As a result of the experiment, the mixture using RW showed higher compressive strength than TW. It also showed low water absorption and high density. In the mixture using RW as mixed water, a hydration reaction substance called Friedel's salt could be observed. Considering the corrosion problem of steel, RW is considered to be applicable to products such as non-reinforced concrete, brick, and curb stone. Through this study, it is thought that it is meaningful to propose a new application method other than the ocean release of RW.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.267-276
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• 2018

The purpose of this study is to analyze the cultural needs of foreign tourists, to investigate the cultural service elements that can be provided in 'Gamcheon Culture Village', to suggest concrete policy to improve cultural services, and ultimately to cultivate excellent international tourism culture brands in 'Gamcheon Culture Village'. In order to find out the cultural needs of foreign tourists, we conducted a case study on 'Gamcheon Culture Village' among the places where the urban regeneration proceeded. The study period was four months, and basic data were collected from foreign tourists from six countries through literature reviews, interviews and participation observation. Analysis of data was based on urban regeneration, cultural desire and service design theory, and we conducted content analysis. This study presented five cultural service goals of 'Gamcheon Culture Village'. First, it displays and promotes local characteristic culture. Second, it develops and sells cultural products. Third, it brings up a good tourist image. Fourth, it provides an unusual food. Fifth, cultural experience optimization. Through this study, it is expected to help improve the cultural service of 'Gamcheon Culture Village'.

• Journal of the Korea Institute of Building Construction
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• v.19 no.1
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• pp.19-29
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• 2019

In this study, a revised oil leakage evaluation method for assessing oil leakage stability of asphalt mastics used in upper slabs of below-grade residential parking lots was developed and presented. In order to verify the reliability and reproducibility of leakage results, the parameters the revised evaluation was carried out for three products with actual leakage history, and it was confirmed the leaks could be reproduced whereas the existing methods could not. To quantitatively verify the reproducibility, the filler content of the leaked samples was derived and the maximum filler content was 64% lower than that of the normal sample. The same results was found with the samples from the actual leakage site, thus verifying the reliability of the revised evaluation method.

• Journal of the Korea Institute of Building Construction
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• v.19 no.2
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• pp.105-112
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• 2019

Fine aggregate made of ferronickel slag(FNS) is similar to natural fine aggregates and is used in concrete structures both domestically and abroad, but its applications and research areas are limited. In this research, in order to expand the availability of FNS and improve the performance of cement mortar products, the applicability of FNS on dry mortar for floor was examined. Experimental results show that FNS improves flow of cement mortar because it has low absorption rate, spherical shape, and glassy surface. Also, the high stiffness of the FNS aggregate itself is considered to contribute to the improvement of cement mortar quality such as crack reduction by improving the compressive strength and shrinkage reducing. In addition, when FNS fine aggregate is applied, it was possible to secure the impact sound insulation performance equal to or higher than that of mortar using natural fine aggregate.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.111-117
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• 2019

In this paper, we propose a mobile remicon quality management system to enable inspection and correspondence with a smart phone in the field check of remicon. We also proposed a real-time slump data processing part to digitize field inspection and XML formats for data exchange with the server. We used the smart phone to transmit real-time image about field inspection of remicon and judged the error at the same time. By doing this, we shared the situation of the remicon products in the field and the head office. Based on the actual results, the development technology is used to determine whether the product is abnormal or not, and to provide appropriate information to the company and the site. Based on the analysis of raw material quality data, it is possible to present real time optimal blending ratio according to raw material import with raw material management data, which is the biggest problem of the ready mixed concrete industry.

• Journal of the Korea Institute of Building Construction
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• v.19 no.5
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• pp.391-399
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• 2019

This study reviewed the possibility of recycling into exhausted aggregate resources in Korea as a means of utilizing coal gasification slag(CGS) from integrated gasification combined cycle(IGCC) while being commissioned in order to introduce the new system to Korea. In other words, in order to solve the problem of insufficient aggregate resources, CGS generated by IGCC as a residual aggregate for concrete secondary products, which is an empty mortar, was considered to replace CGS in the range of 0 to 100 % for mixed residual aggregate mixed with crushed sand A(CSa) of good quality and sea sand(SS) of deep particles, which are the most commonly used in the domestic construction industry. According to the study, replacing CGS with CSa or crushed sand B(CSb)+SS by 25 % to 50 % resulted in good results in the aspect of the granularity of the aggregate and the workability and compressive strength of cement mortar, which were found to be usable.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.50-56
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• 2019

This study aims to make artificial stone by recycling blast furnace slag powder, red mud and recycled aggregate, which are known as industrial waste. Recycled aggregate is a typical construction waste, and various recycled products such as concrete block are being sold. In this study, we tried to make artificial stone mixed with waste such as recycled aggregate, and experimented with the use of artificial stone and further study. As the red mud replacement ratio increased, the absorption ratio, fluidity and air content of the matrix were measured to be decreased, and the strength and density were found to increase. The fluidity and absorption ratio decreased with increasing the replacement ratio of recycled aggregate, and the air quantity, rate of aggregate on the surface, density and intensity increased to a certain level. Therefore, this study intends to make artificial stone using recycled resources and conducted basic experiments for further study.