• The Korean Journal of Archival Studies
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• no.55
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• pp.5-38
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• 2018

Trust in government agencies is closely related to accountability. The key strategy to increase public accountability is to document the processes and outcomes of their key tasks and policies adequately. The purpose of this study is to suggest a redesign of the records appraisal policy to enhance the accountability of government agencies. Applying the newly introduced concept of appraisal in ISO 15489-1: 2016, the relationship between accountability and appraisal is articulated and the problems of records appraisal systems in terms of accountability are analyzed. Based on this analysis, it suggests the principles for reforming the appraisal policies well as the redesign of the current disposition authorities as a key tool for appraisal, and the introduction of records disposal freeze system.

• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.96-113
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• 2013

The concept of disaster management of cultural heritage is not clearly established and the range and type of it is not organized yet. Also, there is an ever-present danger in the field control because there is no system that can provide safety of cultural heritage from various dangerous factors. Concretely, institutionally, the regulation of disaster management of cultural heritage remains limited and there are not enough reasonableness in installation and management of fire-fighting equipment and safety equipment. Also, we need to take an action to secure the safety of cultural heritage from its surroundings. In this research, we setup the concept, type and criteria for disaster management of cultural heritage to overcome limitations and problems of management of cultural heritage. In addition, in order to raise the level of disaster management of cultural heritage, this research proposes direction to reinforce the disaster management of cultural heritage by investigating and analyzing consciousness of security guards and fire-fighting officers.

• Korean Journal of Heritage: History & Science
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• v.45 no.4
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• pp.160-173
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• 2012

일본 문화청 소속의 정부조직이었던 나라국립문화재연구소가 국가조직의 행정개혁에 따라 현재의 독립행정법인 나라문화재연구소로 변혁하면서 나타나고 있는 여러가지 상황에 대해서 살펴보고자 한다. 나분켄은 동아시아에서도 잘 알려진 국보 호류지금당벽화의 소실이 문화재 분야의 큰 문제로 부각되면서 종합적이고 학술적인 문화재의 연구 보호 종합기관의 설립 필요성에 의해 만들어진 기관이었다. 연구분야에서 보면 초기에는 역사, 건축, 미술공예, 정원, 유적 등 다양한 분야에서 출발했으나 나라지역의 헤이조큐 유적보존 문제가 주요 이슈로 떠오르면서 매장문화재의 발굴 중심으로 그 역할이 강화되는 변화를 겪에 되었다. 그러나 선사고고학이 아닌 역사고고학이 중심이었기 때문에 건축사나 정원사, 보존과학 등 서로 다른 학문이 융합하여 연구할 수 있는 강점이 강화되어 설립목적은 견지하면서 변모하였다. 독립행정법인으로의 변화는 1999년의 제145차 통상국회에서 "독립행정법인통칙법"이 성립되면서 부터였다. 독립행정법인의 취지는 독립 운영하는 쪽이 효율적인 부분을 분리시켜 법인격을 가진 기관으로 바꾸면서 운영교부금을 주무관청으로부터 받아 사용처를 독자적 재량에 맡기면서 이윤을 올릴 수도 있게 한 것이다. 또한 조직과 인사의 자율성을 보장받는 장점도 있으나 평가시스템이 되입되는 정신적 부담도 공존하게 된다. 즉, 민간 방법의 도입에 따라 국가의 부담을 경감하고자하는 의미가 내재되어있다. 나분켄의 독립행정법인화는 동시에 도쿄문화재연구소의 통합을 수반하게 되었다. 도분켄은 원래 미술공예품을 중심으로한 동산문화재 연구와 보존과학부분에 충실한 조직이었으므로 부동산문화재 중심의 나분켄과 통합에 우려의 목소리가 있었다. 그러나 불행중 다행으로 다카마쓰즈카 고분벽화의 열화문제와 키토라 고분 벽화의 보존문제로 인하여 전무후무한 협업연구가 진행되고 양 연구소의 역량을 결집할 수 있는 계기가 되었다. 결론적으로 말하자면, 독립행정법인화는 매년 예산을 중기계획이나 연도계획과 정합성을 유지하면서 독자적인 판단을 통해 편성하는 등 극히 유연한 대응이 가능하다는 장점을 가지고 있는 반면, 문화재 보존을 위한 연구라는 공공적인 목적을 가진 조직이 정부의 의도대로 독자적으로 이윤을 올리는 사업을 확립하여 국가의 부담을 경감하는 방향으로 나아갈 수 있는가라는 부분에서는 의심할 여지가 남아 있다.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.5
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• pp.429-438
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• 2003

The effects of fiber orientation on acoustic emission(AE) characteristics have been studied for the unidirectional and satin-weave, continuous glass-fiber reinforced plastic(UD-GFRP and SW-GFRP) tensile specimens. Reflection and transmission optical microscopy was used for investigation of the damage zone of specimens. AE signals were classified as different types by using short time fourier transform(STFT) : AE signals with high intensity and high frequency band were due to fiber fracture, while weak AE signals with low frequency band were due to matrix and interfacial cracking. The feature in the rate of hit-events having high amplitudes showed a process of fiber breakages, which expressed the characteristic fracture processes of individual fiber-reinforced plastics with different fiber orientations and with different notching directions. As a consequence, the fracture behavior of the continuous GFRP could be monitored as nondestructive evaluation(NDE) through the AE technique.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.323-330
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• 2009

The objective of this research was to develop a practical integrated approach using extracted features from electrical resistance measurements and coupled electromechanical models of damage, for in-situ damage detection and sensing in carbon fiber reinforced plastic(CFRP) composites. To achieve this objective, we introduced specific known damage (in terms of type, size, and location) into CFRP laminates and established quantitative relationships with the electrical resistance measurements. For processing of numerous measurement data, an autonomous data acquisition system was devised. We also established a specimen preparation procedure and a method for electrode setup. Coupon and panel CFRP laminate specimens with several known damage were tested. Coupon specimens with various sizes of artificial delaminations obtained by inserting Teflon film were manufactured and the resistance was measured. The measurement results showed that increase of delamination size led to increase of resistance implying that it is possible to sense the existence and size of delamination. A quasi-isotropic panel was manufactured and electrical resistance was measured. Then three different sizes of holes were drilled at a chosen location. The panel was prepared using the established procedures with six electrode connections on each side making a total of twenty-four electrodes. Vertical, horizontal, and diagonal pairs of electrodes were chosen and the resistance was measured. The measurement results showed the possibility of the established measurement system for an in-situ damage detection method for CFRP composite structures.

• Composites Research
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• v.34 no.2
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• pp.77-81
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• 2021

Due to the high specific strength and stiffness of the composite materials, the composite materials have been extensively used in various industries. In particular, carbon fiber reinforced composites are widely used in many mechanical structures. In addition, since carbon fiber reinforced composites have anisotropic properties, to understand the fatigue behavior of composites with different fiber orientation is very important for the efficient structural design. Therefore, in this paper, the effect fiber orientation on the fatigue life of composite materials was experimentally evaluated. For this purpose, tensile and fatigue tests were performed on the off-axis specimens (0°, 10°, 30°, 45°, 60°, 90°) of the composite materials. As a result of the fatigue tests, the fatigue strength of the composites decreased significantly as the fatigue strength slightly deviated from 0 degrees. On the other hand, the more deviated, the less decreased. This is because the role of supporting the load of fibers decreased as the stacking angle increased. In addition, the fatigue behavior was analyzed by introducing a fatigue strength ratio (Ψ) that eliminates the fiber orientation dependence of the off-axis fatigue behaviors on the unidirectional composites. The off-axis fatigue S-N lines can be reduced to a single line regardless of the fiber orientation by using the fatigue strength ratio (Ψ). Using the fatigue Ψ-N line, it is possible to extract back to any off-axis fatigue S-N lines of the composites with different fiber orientations.

• Korean Journal of Materials Research
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• v.3 no.1
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• pp.84-94
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• 1993

This paper deals with the fatigue properties of chopped strand glass mat/polyester composite to understand the effect of water absorption on fatigue behavior of GFRP. The fatigue crack in the both no water and a water absorption materials initiated at the initial of cycle. Thereafter, it was divided with two regions that one decreased with the crack extension and the other increased with the crack extension. The absorption of distilled water degrades the bond strength between fiber and matrix, there, by the tendency of fiber pull-out is increased in perpendicular to crack growth deirection and the debonding of fibers increased to the place which is parallel to crack growth direction. Therefore, the reduction of fatigue strength was caused by these factors.

• Composites Research
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• v.33 no.1
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• pp.30-37
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• 2020

Stress distributions dependent on fiber arrangements are studied using the two-dimensional representative volume element (RVE) model for uni-directionally continuous fiber-reinforced composites subjected to transverse tensile loading. It is easily expected that the stresses around the fibers are concentrated mainly due to the stiffness mismatch between the fiber and matrix materials. In this presentation, it is shown that the stresses are not always increased although the distance between two fibers is shortened. The 2D RVE models, originally having a regular hexagonal fiber array, is utilized to study the effect of the fiber locations on the stress distributions. As the central fiber is relocated, the stress distributions around the fiber are obtained through finite element analysis. It is found that the stresses around the fiber are strongly dependent on the fiber distance as well as the angle between the loading direction and the line connecting two fibers.

• The Journal of the Korea Contents Association
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• v.21 no.9
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• pp.391-403
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• 2021

This study was studied to analyze the current early childhood education system based on elements of education publicness and to explore policy tasks for developing early childhood education policies. Qualitative literature analysis was conducted by collecting official government documents and reports from national research institutes, and the publicity level of early childhood education was evaluated based on the elements of publicity. As a result of the study, Korea's early childhood education policy has been promoted in the direction of strengthening the public nature of early childhood education, such as the introduction of the Nuri course. Quantitative expansion of public nature has been achieved, but now it is necessary to re-establish the policy direction focusing on the qualitative reinforcement of public nature and to supplement the system. This study suggests a direction for a review of early childhood education in general.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.861-867
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• 2015

The Compact Tension (CT) type test was performed in order to evaluate the fracture toughness performance of glass fiber-reinforced laminated timber. Glass fiber textile and sheet Glass fiber reinforced plastic were used as reinforcement. The reinforced laminated timber was formed by inserting and laminating the reinforcement between laminated woods. Compact tension samples are produced under ASTM D5045. The sample length was determined by taking account of the end distance of 7D, and bolt holes (12 mm, 16 mm, 20 mm) had been made at the end of artificial notches in advance. The fracture toughness load of sheet fiberglass reinforced plastic reinforced laminated timber was increased 33 % in comparison to unreinforced laminated timber while the glass fiber textile reinforced laminated timber was increased 152 %. According to Double Cantilever Beam theory, the stress intensity factor was 1.08~1.38 for sheet glass fiber reinforced plastic reinforced laminated timber and 1.38~1.86 for glass fiber textile reinforced laminated timber, respectively. That was because, for the glass fiber textile reinforced laminated timber, the fiber array direction of glass fiber and laminated wood orthogonal to each other suppressed the split propagation in the wood.