• Advances in nano research
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• v.12 no.3
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• pp.281-290
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• 2022

In the current research, the thermal buckling characteristics of the bi-directional functionally graded nano-scale tapered beam on the basis of a couple of nonlocal Eringen and classical beam theories are scrutinized. The nonlocal governing equation and associated nonlocal boundary conditions are constructed using the conservation energy principle, and the resulting equations are solved using the generalized differential quadrature method (GDQM). The mechanical characteristics of the produced material are altered along both the beam length and thickness direction, indicating that it is a two-dimensional functionally graded material (2D-FGM). It is thought that the nanostructures are defective because to the presence of porosity voids. Finally, the obtained results are used to design small-scale sensors and make an excellent panorama of developing the production of nanostructures.

• Steel and Composite Structures
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• v.46 no.6
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• pp.759-772
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• 2023

This manuscript presents a comprehensive mathematical model to investigate buckling stability and postbuckling response of bio-inspired composite beams with helicoidal orientations. The higher order shear deformation theory as well as the Timoshenko beam theories are exploited to include the shear influence. The equilibrium nonlinear integro-differential equations of helicoidal composite beams are derived in detail using the energy conservation principle. Differential integral quadrature method (DIQM) is employed to discretize the nonlinear system of differential equations and solve them via the Newton iterative method then obtain the response of helicoidal composite beam. Numerical calculations are carried out to check the validity of the present solution methodology and to quantify the effects of helicoidal rotation angle, elastic foundation constants, beam theories, geometric and material properties on buckling, postbuckling of bio-inspired helicoidal composite beams. The developed model can be employed in design and analysis of curved helicoidal composite beam used in aerospace and naval structures.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.287-301
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• 2019

Preservation of the original form is the principle for conservation, management and utilization of cultural heritages. Thus, non-destructive analysis of these samples are important field of the conservation science. In this study, examined the applicability of nondestructive surface X-ray diffraction analysis (ND-XRD) for cultural heritage by materials (rock specimen, jade stone, pigment painted specimen, earthen artifact, metal artifact). In result, all type of sample is recorded suitable X-ray diffraction patterns for identifying mineral composition in case of surface condition with adequate particle size and arrangement. And diffraction pattern is reflected surface information than matrix. Therefore, ND-XRD is thought to be applicable not only mineral identification but also interpretation of manufacturing technique and alteration trend about layered sample (in horizontally or vertically). Whereas some exceptional diffraction patterns were recorded due to overlapping information on specific crystal planes. It caused by skip the sample treatment (powdering and randomly orientation). It could be advantageously used for mineral identification, such as preferred orientation of clay minerals. In contrast, irregular diffraction pattern caused by single crystalline effect is required careful evaluation.

• Korean Journal of Heritage: History & Science
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• v.45 no.4
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• pp.126-139
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• 2012

Authenticity has emerged as an important condition which should be examined in setting out conservation and management principles of cultural heritage during the last half century. Compared that the concept has been internationally discussed developing it into the applicable framework such kind of effort has been relatively low within Asian context. This paper is the first half part the research on authenticity which aims at setting out conceptual framework of authenticity in Korean context and presenting a set of suggestion to make the Korean heritage-based concept of authenticity be workable in assessing heritage value in practice. It focused on the analytical review on two aspects: 1. the origin of the word and the development of the concept along with the implementation of World Heritage Convention, nt of related international charters; 2. Problems of the intrinsic nature of the concept and problems to be considered in defining the concept.

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.346-361
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• 2013

Since the Ming Castle located in Nanjing was designated by the Government of China as a cultural property in 1988, the Nanjing city government has been conserving the castle according to its plan and thus restoring the historical and cultural values of Nanjing. The project is still in progress, and in this regard, a series of logistics have formulated and a lot of discussions have taken place. Likewise, Korea has been carrying out multidirectional policies to conserve and utilize castles lying throughout the country, appreciating the historical and cultural resources of castles lying throughout the country, and at the same time gets down to designation as the World Heritage. This study focused on how Nanjing, not only a castle city but also a historical city, had established a principle and legal foundation regarding the protection of the Ming Castle, especially on how the problems, which might continually arise in a process where a scheme reached a working stage, had been solved. The problem-solving process is expected to have great implications for Korea in a similar situation. Hereat, this study analyzed the project plans formulated seasonally and gathered data on practical operation by conducting interviews with hands-on workers. The results showed that Nanjing had carried out policies to utilize the castles as tourism resources by harmonizing cityscape and ecological environment, but that it well conserved castles without damaging cultural assets. The stereoscopic protection system for the Ming Castle, based on the consideration of historical and cultural environments, may provide practical and useful data for Korea's administration mapping out for a castle conservation policy and designation as the UNESCO World Heritage.

• Korean Journal of Heritage: History & Science
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• v.49 no.1
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• pp.146-165
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• 2016

With the introduction of the system of recognizing masters of craft and performance skills in 1970, the principle of "preserving the original form," which was already in general use, was adopted as a legal principle in the Cultural Heritage Protection Act. While the concept "original form" can be related to tangible elements of heritage through the Act, the intangibility of craft and performance skills does not allow their pinpointing at a particular temporal period or the identification of a particular master from the past as the basis of an original form. Therefore, those craft or performance skills that are available at the point of recognition of relevant masters must serve as the basis of the original form for the intangible heritage concerned. This means that the principle of preserving the original form of intangible heritage has been implemented not based on a fundamental form of materiality, but rather on the craft or performance skills that may be held by a master at the time of his/her recognition as a "temporary original form." This principle has been observed through intangible heritage transmission and education policies for recognized masters and their trainees, contributing to establish an elitist transmission environment in which public were denied to join the education on intangible heritage. Even with policies guided by the principle of preserving the original form, designated craft and performance skills have been transformed contingent upon given social and environmental conditions, thus hindering the preservation of the original form. Despite the intrinsic limitations of the principle of preserving the original form when applied to intangible heritage, this principle has served as a practical guideline for protecting traditional Korean culture from external influences such as modernization and Westernization, and also as an ultimate goal for the safeguarding of intangible heritage, engendering actual policy effects. The Act on the Safeguarding and Promotion of Intangible Cultural Heritage that comes into effect in March 2016 takes the constantly evolving nature of intangible heritage into consideration and resultantly adopts a concept of "essential form" (jeonhyeong) in place of "original form" (wonhyeong). This new concept allows for any transformations that may take place in the environment surrounding the intangible heritage concerned, and is intended to mitigate the rigidity of the concept of "original form." However, it should be noted that "essential form," which is manifested as the unique significance, knowledge, and skills delivered by the intangible heritage concerned, should be maintained according to the guidelines and principles related to heritage conservation. Therefore, the new concept can be understood not as a rupture, but more as a continuum of the concept of "original form."

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.2
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• pp.38-45
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• 2018

Baekdudaegan is Korea's traditional geographic system which incorporates the mountains and water to constitute an organism. In this system, the mountain ranges of the Korean peninsula is categorized into one Daegan, one Jeonggan and thirteen Jeongmaek: a classification that follows the principle that 'a mountain range separates watercourse (山自分水嶺).' Among them, the scope of this study encompasses one Daegan and nine Jeongmaek which fall in South Korea. As for the methodology, this study interviewed the visitors to Baekdudaegan in South Korea and analyzed 2,519 responses. Among the interviewee, a very low proportion of 5.1% answered that they 'know' the traditional geographic system and those who 'know' Baekdudaegan were merely 39%. Only 11.8% said they 'know' Jeongmaek. Meanwhile, more than 60% answered that the natural environment of Baekdudaegan was 'well conserved,' and this can lead to the judgment that the environment is well conserved. Many answered that it was desirable to include Baekdudaegan in the curriculum, most effectively from the primary school, for promoting the awareness of Baekdudaegan. Currently, the traditional geological system is not included in the promulgated curriculum of the Ministry of Education. Therefore, the lessons from this study lead to a suggestion that the curriculum by the Ministry of Education shall allot courses on this traditional geological system. This policy will inculcate the identity of the Korean nationality and the fundamental concept of conservation by stimulating the affection to our territory and environment.

• Conservation and Restoration of Cultural Heritage
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• v.1 no.1
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• pp.39-48
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• 2012

The first twenty-five years of scientific study within Korea on Korean traditional ceramics has been characterized as a bridging effort to understand the rich field of artistic ceramic masterpieces on one hand with analytic results gained from mounds of broken shards and kiln wastes on the other. First shard pieces were collected directly from the waste mounds, but most of the analyzed shards were provided by art historians and museum staffs directly involved in systematic excavations. The scientific study is viewed as one of many complimentary ways in learning about the multi-faceted ceramics culture, ultimately connecting human spirits and endeavors from the past to the present to the future. About 1350 pieces of analyzed shards have been so far collected and organized according to the production location and time period. From the experimental results of the analysis, the compositional and microstructural characteristics of bodies and glazes have been deduced for many kiln sites of Goryeo and Joseon dynasties. Except for a few local kilns, porcelain stone was used as body material in both dynasties. The principle of mixing a clay component with a flux material was used in Korean glazes as was in China. The clay component different from body clay was often used early on. In Gangjin a porcelain material appropriate for whiteware body was mixed for celadon glaze, and in Joseon Gwangju kilns glaze stone was chief clay material. The use of wood ash persisted in Korea even in making buncheong glazes, but in Joseon whitewares burnt lime and eventually crushed lime were used as flux material.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.5
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• pp.1227-1236
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• 1993

In conventional thermodynamics, energy is regarded as a physical quantity transferring from one system to another, but in present study, the real energy is regarded as a physical quantity coming out from one interaction and absorbing into another interaction between two systems. To reconstruct thermodynamics with such a point of view, available work is distinguished from half work in conventional work concepts, and a special space named reversible world is proposed in which every process is reversible and the only measurable quantity is available work and just the equality between the intensities of two systems can be verified. As results, thermodynamic laws are arranged into two principles in the reversible world-conservations of energy elements and conservation of available energy. It means the exsistences of state properties corresponding to transferring energy elements and the available work. The former are extensive properties and the later is named potential work which is a property of the composite system and a kind of mathematical distance. The conventional available energy (exergy) and internal energy can be explained as the special cases of potential work, and the conventional first law of thermodynamics can be derived from the principle of the conservation of available energy. With these new concepts, the description of thermodynamic processes is more comprehensive. The second law of thermodynamics is no longer needed in the reversible world.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.89-104
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• 2011

This study was carried out to the development of ecological planting model to make up of coastal windbreak forest on the Suncheon-bay in Sucheon-si, Korea. Make up of coastal windbreak forest in this site was needed for appropriate bioresource, biodiversity and ecological structure, and for conservation of the eco-tour resource and protection of human life and property by the unforeseen disaster from the coast. Based on the plant-social principle, the planting model of windbreak forest was developed to facilitate growth of trees, considering planting locations. The ecological planting model for the coastal windbreak was composed of warm temperate evergreen and windbreak forest which is spreading around the inland area in Korea. The horizontal forest style was composed of forest edge community and inner forest community, and the vertical forest style was composed of upper, middle, low and ground planting class. The target of the present model was quasi-natural forest, and the species of tree were selected based on the adaptability to surroundings depending on a goal to create a forest and forest style. To achieve both functions of wind break forest and visual effect in short period of time, small trees and seedlings were planted with high-density of 40,000/ha in an expectation of easy natural maintenance in the future. The significance of the present study is a suggestion for a guideline to create ecological coastal windbreak forest in the Suncheon-bay in which the harmony of human life and the ecological conservation is of great importance. Also, the ecological coastal windbreak forest model should be developed further through the long term monitoring after construction of forest.