• Advances in concrete construction
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• v.6 no.5
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• pp.423-463
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• 2018

This paper investigates the behavior of normal and self-compacted steel fiber reinforced concrete (SCC-SFRC) corbels rehabilitated by Basalt Fiber Mesh (BFM) and Basalt Fiber Fabric (BFF) for the first time in literature. The research objective is to study the effectiveness of BFM and BFF in the rehabilitation of damaged reinforced concrete corbels with and without epoxy injection. The experimental program includes two types of concrete: normal concrete, and self-compacted concrete. For normal concrete, 12 corbels were rehabilitated by BFM without injection epoxy in cracks, with two values of compressive strength, three ratios of steel fiber (SF), and two values of shear span. For self-compacted concrete, 48 corbels were rehabilitated with different parameters where 12 corbels were rehabilitated by BFM with and without epoxy injection, 18 heated corbels with three different high-temperature level were rehabilitated by repairing cracks only by epoxy injection, and 18 heated corbels with three different high-temperature level were rehabilitated by repairing cracks by epoxy and wrapping by BFF. All 48 corbels have two values of compressive strength, three values volumetric ratios of SF, and two values of the shear span. Test results indicate that RC corbels rehabilitated by BFM only without injection did not show any increase in the ultimate load capacity. Moreover, For RC corbels that were repaired by epoxy without basalt wrapping, the ultimate load capacities showed an increase depending on the mode of failure of corbels before the rehabilitation. However, the rehabilitation with only crack repairing by epoxy injection is more effective on medium strength corbels as compared to high strength ones. Finally, it can be concluded that use of BFF is an effective and powerful technique for the strengthening of damaged RC corbels.

• Structural Engineering and Mechanics
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• v.67 no.3
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• pp.233-244
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• 2018

This study aims at evaluating the performance of repairing technique with CFRPs in recovering cyclic performance of damaged columns in flexure in terms of structural response parameters such as strength, dissipated energy, stiffness degradation. A 2/3 scaled substandard reinforced concrete frame was constructed to represent the substandard RC buildings especially in developing countries. These substandard buildings have several structural deficiencies such as strong beam-weak column phenomenon, improper reinforcement detailing and poor material properties. Flexural plastic hinges occurred at the columns ends after testing the substandard specimen under both constant axial load and reversed cyclic lateral loading. Afterwards, the damaged columns were externally wrapped with CFRP sheets both in transverse and longitudinal directions and then retested under the same loading protocol. In addition, ambient vibration measurements were taken from the undamaged, damaged and the repaired specimens at each structural repair steps to identify the effectiveness of each repairing step by monitoring the change in the natural frequencies of the tested specimen. The ambient vibration test results showed that the applied repairing technique with external CFRP wrapping was proved to recover stiffness of the pre-damaged specimen. Moreover, the lateral load capacity of the pre-damaged substandard RC frame was restored with externally bonded CFRP sheets.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.419-422
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• 2010

This paper reports a simple and versatile technique for generating highly controllable sinusoidal nanostructures on the surface of poly-(dimethylsiloxane) (PDMS). The sinusoidal features were generated by oxidizing PDMS slabs with oxygen plasma, then stretching them by wrapping around a cylinderical surface, and finally allowing them to relax. The wavelength and amplitude could be finely controlled by varying the fabrication conditions such as duration of oxidation, diameter of the glass cylinder, duration of stretching, thickness of the PDMS slabs, and temperature during the second hardening process. The varied trends of the buckling patterns were characterized by using an atomic force microscope.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.6
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• pp.594-604
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• 2003

A State-of-art methodologies on implementing conventional piezoelectric and flexible PVDF elements for generating ultrasonic guided waves in a tubing are presented. Comb transducers with PVDF can be efficiently applied to selectively excite a guided wave mode by wrapping around any size pipe while a conventional immersion type piezo-elements can be also possibly used with a modification of transducer fabrication. Technical comparisons between the use of angle beam probe and comb one will be also discussed in detail. The presented technique can be easily applied to NDE for a long range inspection of tubular structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.365-370
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• 2001

The repairing technique of surface wrapping concrete structural members using fiber composite sheet have been widely used. The research efforts have been limited to studying relative strength increase of repaired concrete structures rather than ductility improvement based on composite material effect and the interface effect between composite and concrete. The compression tests of CFS(carbon fiber sheet) reinforced concrete specimens with various cross-sectional shapes and laminate angles have been peformed. FEM algorithm considering various parameters will be performed based on the obtained data. The results will be discussed in detail.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.130-132
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• 2003

1990년대 초반에 등장한 자바 언어는 빠른 속도로 프로그래머들 사이에 보급되었으며 인터넷의 등장과 더불어 이는 더욱 가속화되었다. 또한 무선 플랫폼 등과 같은 새로운 컴퓨팅 환경에 빠르게 대처함으로써 자바 언어의 끝을 예측하기는 쉽지 않은 상태이다. 초기 자바 어플리케이션들은 단일 티어(single-tier)로 개발되었으며 환경의 변화로 인해 이런 어플리케이션들을 네트워크로 연결할 필요성이 대두되고 있다. 자바 언어는 분산 컴퓨팅 환경의 솔루션으로 Enterprise JavaBean(EJB)［1］을 제시하고 있다. 본 논문에서는 기존에 개발된 자바 어플리케이션을 EJB로 래핑하기 위한 기법들을 제공한다. 핵심 비즈니스 로직을 가진 클래스들을 수작업을 통해 EJB로 변환할 수도 있지만 본 논문에서는 반자동화된 방법을 통해 변환 상의 효율을 증대시키고 변환 과정에서 발생할 수 있는 오류를 최소화하고자 한다. EJB 래핑 기법은 세션 빈(session bean)［1］래핑과 엔터티 빈(entity bean)［1］래핑으로 구성된다. 세션 빈 래핑은 자바 어플리케이션을 구성하는 클래스 가운데 질의문(query)을 가지지 않는 자바 클래스들을 래핑한다. 엔터티 빈은 질의문을 포함하는 자바 클래스를 래핑한다. EJB 래핑을 위해 리플렉션(reflection)［2］과 위임 (delegation) 장치를 사용한다.

• International Journal of Costume and Fashion
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• v.7 no.1
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• pp.11-21
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• 2007

In this study, we will analyze the artistic character of Jogakbo as a element of fashion art design. Korean traditional Jogakbo is a common homemade item made from clothing remnants and is a part of the culture of women�s quarters. Currently, Jogakbo is higly regarded for its artistic value and it finds a variety of uses in fashion. In particular, it is striking how its modern-style geometric lines and color composition are congruous with abstract art. In applying Jogakbo to fashion art design, we study the artistic expression of Jogakbo in 4 aspects; namely, line, color, material, and technique; and analyze the 4 artistic characteristics; beauty of naivety, simplicity, moderation and freedom. 8 dresses designed based on these 4 characteristics are presented as examples.

• Structural Engineering and Mechanics
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• v.72 no.6
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• pp.723-736
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• 2019

The efficacy of a technique for the rehabilitation and strengthening of RC beam-column connections damaged due to cyclic loading was investigated. The repair mainly uses epoxy resin infused under pressure into the damaged region to retrieved back the lost capacity and then strengthening using fiber reinforced polymer (FRP) sheets for capacity enhancement. Three common types of reduced scale RC exterior beam-column connections namely (a) beam-column connection with beam weak in flexure (BWF) (b) beam-column connections with beam weak in shear (BWS) and (c) beam-column connections with column weak in shear (CWS) subjected to reversed cyclic loading were considered for the experimental investigation. The rehabilitated and strengthened specimens were also subjected to similar cyclic displacement. Important parameters related to seismic capacity such as strength, stiffness degradation, energy dissipation, and ductility were evaluated. The rehabilitated connections exhibited equal or better performance and hence the adopted rehabilitation strategies could be considered as satisfactory. Confinement of damaged region using FRP sheet significantly enhanced the seismic capacity of the connections.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.230-233
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• 2009

본 논문은 볼륨 데이터를 입력받아 계층성을 지원하는 등밀도 표면을 재구성하는 방법을 제안한다. 제안된 방법은 먼저 입력 볼륨 데이터에서 볼륨 피라미드를 구성하고 해상도가 최저인 피라미드의 최상단 볼륨에서부터 셀경계표현 방법을 이용하여 조악한 초기 메쉬를 생성하며, 이 메쉬를 표면축소기법을 사용하여 반복적으로 변형하여 O(3)-인접성 조건하에서 추출한 등밀도점을 잘 근사할 수 있도록 한다. 제안된 방법은 생성되는 표면이 압축이나 점진적인 전송 등과 같은 다중 해상도 알고리즘에 활용될 수 있다는 장점이 있다.

• Journal of the Korean Society of Costume
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• v.53 no.3
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• pp.51-61
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• 2003

1. This study is to veri(y the characteristics of gauze fabrics focused on the them found at Sukga Pagoda. The remains researched are those of the Unified Shilla Dynasty around 8∼10 century. The found textile remains seem to be used as rugs or to be used for filling in spaces, wrapping silver reliquaries, equipments preserving relics of the Buddha, a gold-plated outermost reliquary, and so on. Since other remains found inside the Sukga Pagoda are national treasures, the textile remains can be considered as the fabrics of the highest quality. 2. Seven gauze fabrics, four non-designed gauzes and three designed gauzes, are found. They are all four-end complex gauze, weaved with the complex gauze technique. Two designed gauzes out of three designed gauzes are weaved in pattern by the clamp-resist dyeing technique and one is weaved in pattern by giving some changes in weaving. 3. In addition to the characteristics peculiar to gauze fabrics, such as thinness, fineness, and sparseness, another characteristic is found. That is, the difference in thickness between wefts and warps is over two times on the average in all of the seven gauze fabrics. Some of the gauze fabrics look like laces because of the huge difference in their thickness. 4. This research verified that with their transparency, are such materials that their beauty can easily be realized without adding various colors or patterns on the fabric by painting, embroidery, stitching old foil, or compound weaving technique.