• Advances in concrete construction
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• v.5 no.6
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• pp.671-683
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• 2017

Commonly used concrete in general, consists of cement, fine aggregate, coarse aggregate and water. Natural river sand is the most commonly used material as fine aggregate in concrete. One of the important requirements of concrete is that it should be durable under certain conditions of exposure. The durability of concrete is defined as its ability to resist weathering action, chemical attack or any other process of deterioration. Durable concrete will retain its original form, quality and serviceability when exposed to its environment. Deterioration can occur in various forms such as alkali aggregate expansion, freeze-thaw expansion, salt scaling by de-icing salts, shrinkage, attack on the reinforcement due to carbonation, sulphate attack on exposure to ground water, sea water attack and corrosion caused by salts. Addition of admixtures may control these effects. In this paper, an attempt has been made to replace part of fine aggregate by tailing material and part of cement by fly ash to improve the durability of concrete. The various durability tests performed were chemical attack tests such as sulphate attack, chloride attack and acid attack test and water absorption test. The concrete blend with 35% Tailing Material (TM) in place of river sand and 20% Fly Ash (FA) in place of OPC, has exhibited higher durability characteristics.

• Structural Engineering and Mechanics
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• v.70 no.4
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• pp.395-405
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• 2019

In the present work, the effects of cutting parameters on surface roughness parameters (Ra), tool wear parameters (VBmax), tool vibration (Vy) and material removal rate (MRR) during hard turning of AISI 4140 steel using coated carbide tool have been evaluated. The relationships between machining parameters and output variables were modeled using response surface methodology (RSM). Analysis of variance (ANOVA) was performed to quantify the effect of cutting parameters on the studied machining parameters and to check the adequacy of the mathematical model. Additionally, Multi-objective optimization based desirability function was performed to find optimal cutting parameters to minimize surface roughness, and maximize productivity. The experiments were planned as Box Behnken Design (BBD). The results show that feed rate influenced the surface roughness; the cutting speed influenced the tool wear; the feed rate influenced the tool vibration predominantly. According to the microscopic imagery, it was observed that adhesion and abrasion as the major wear mechanism.

• Advances in concrete construction
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• v.11 no.2
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• pp.173-181
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• 2021

The main objective of this work is to contribute to the valorization of plastic and glass waste in the improvement of concrete properties. Waste glass after grinding was used as a partial replacement of the cement with a percentage of 15%. The plastic waste was cut and introduced as fibers with 1% by the total volume of the mixture. Mechanical and durability tests were conducted for various mixtures of concrete as compressive and flexural strengths, water absorption, ultrasonic pulse velocity, and acid attack. Also, other in-depth analyses were performed on samples of each variant such as X-ray diffraction (XRD), thermogravimetric analysis (DSC-TGA), and scanning electron microscope (SEM). The results show that the addition of glass powder or plastic fibers or a combination of both in concrete improved in the compression and flexural strengths in the long term. The highest compressive strength was obtained in the mix which combines the two wastes about 26.72% of increase compared to the control concrete. The flexural strength increased in the mixture containing the glass powder. Therefore, the mixture with two wastes exhibits better resistance to aggressive sulfuric acid attack, and incorporating glass powder improves the ultrasonic pulse velocity.

• Geomechanics and Engineering
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• v.34 no.3
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• pp.285-301
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• 2023

During the construction of E75 highway through Grdelica gorge in Serbia, a major failure occurred in the zone of reinforced rock slope. Excavation was performed in highly anisotropic Paleozoic schist rock formation. The reinforcement consisted of the two rows of micropile wall with pre-stressed anchors. Forces in anchors were monitored with load cells while benchmarks were installed for superficial displacement measurements. The aim of the study is to investigate possible causes of instability considering different probability distributions of the strength of discontinuities and anchor bond strength by applying different optimization techniques for finding the critical failure surface. Even though the deterministic safety factor value is close to unity, the probability of failure is governed by variability of shear strength of anisotropic planes and optimization method used for locating the critical sliding surface. The Cuckoo search technique produces higher failure probabilities compared to the others. Depending on the assigned statistical distribution of input parameters, various performance functions of the factor of safety are obtained. The probability of failure is insensitive to the variation of bond strength. Different sampling techniques should yield similar results considering that the sufficient number of safety factor evaluations is chosen to achieve converged solution.

• Coupled systems mechanics
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• v.12 no.5
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• pp.429-444
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• 2023

The comprehension and structural modeling of masonry constructions is fundamental to safeguard the integrity of built cultural assets and intervene through adequate actions, especially in earthquake-prone regions. Despite the availability of several modeling strategies and modern computing power, modeling masonry remains a great challenge because of still demanding computational efforts, constraints in performing destructive or semi-destructive in-situ tests, and material uncertainties. This paper investigates the shear behavior of masonry walls by applying a plane-stress FE continuum model with the Modified Masonry-like Material (MMLM). Epistemic uncertainty affecting input parameters of the MMLM is considered in a probabilistic framework. After appointing a suitable probability density function to input quantities according to prior engineering knowledge, uncertainties are propagated to outputs relying on gPCE-based surrogate models to considerably speed up the forward problem-solving. The sensitivity of the response to input parameters is evaluated through the computation of Sobol' indices pointing out the parameters more worthy to be further investigated, when dealing with the seismic assessment of masonry buildings. Finally, masonry mechanical properties are calibrated in a probabilistic setting with the Bayesian approach to the inverse problem based on the available measurements obtained from the experimental load-displacement curves provided by shear compression in-situ tests.

• Advances in nano research
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• v.16 no.5
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• pp.445-458
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• 2024

The objective of this paper is to present free vibration and static stability analyses of rotating composite beams reinforced with carbon nanotubes (CNTs) under uniform thermal loads. Beam structural equations and CNT-reinforced composite (CNTRC) beam formulations are derived based on Timoshenko beam theory (TBT). The temperature-dependent properties of the beam material, such as the elastic modulus, shear modulus, and material density, are assumed to vary over the thickness according to the rule of mixture. The beam material is modeled as a mixture of single-walled carbon nanotubes (SWCNTs) in an isotropic matrix. The SWCNTs are aligned and distributed in the isotropic matrix with different patterns of reinforcement, namely the UD (uniform), FG-O, FG-V, FG- Λ and FG-X distributions, where FG-V and FG- Λ are asymmetric patterns. Numerical examples are presented to illustrate the effects of several essential parameters, including the rotational speed, hub radius, effective material properties, slenderness ratio, boundary conditions, thermal force, and moments due to temperature variation. To the best of the authors' knowledge, this study represents the first attempt at the finite element modeling of rotating CNTRC Timoshenko beams under a thermal environment. The results are presented in tables and figures for both symmetric and asymmetric distribution patterns, and can be used as benchmarks for further validation.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.2
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• pp.142-150
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• 2024

Improving transportation accessibility on islands is closely related to regional development. Currently, the government is constructing Ulleung Airport as part of the 6th Airport Mid- to Long-term Development Plan. Similar to the case of Jeju Airport in 2016, severe congestion occurs at passenger terminals upon flight resumption after cancellations at airports on islands. Therefore, considering the cancellation rate at island airports is important. This study investigates the conditions leading to increased cancellation rates at Ulleung Airport, with the research results predicting frequent cancellations during the winter season. The research methodology involved examining airport construction plans, aircraft performance, airport de-icing capabilities, and also included consideration of weather conditions. Ulleung Island is a representative snowfall area, and sufficient snow removal capacity must be secured. However, the current plan's snow removal capacity is insufficient, leading to anticipated high cancellation rates. Therefore, measures to mitigate passenger inconvenience caused by increased cancellations and methods to reduce the cancellation rate are explored. With Ulleung Airport scheduled to open in 2027, there is ample time to implement supplementary measures to reduce the cancellation rate and minimize passenger inconvenience.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.100-107
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• 2007

People have spent lots of time inside building about 90% of these day. Industry has been developed rapidly after I960. Construction materials had changed from natural materials to chemical materials and confidentiality of building has been more higher than before by policy of saving energy. These have caused sick-building syndrome (SBS) for us. So people want environmental construction materials for their house. We designed a environmental loess (yellow soil) finishing material which was composed of loess, water, water-soluble resin, hardener and filler. The purposes of this study were that making an environmental loess finishing material with optimum ratio, evaluating the usability of loess finishing material for wall. Furthermore it was suitable for wall to evaluate mechanical properties that are impact test, cracking test, abrasion test and de-bonding test, environmental properties that were emission of VOCs, formaldehyde and far infrared radiation.

• Journal of Science of Art and Design
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• v.7
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• pp.5-63
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• 2005

Generally, the meanings of destruction are related in the meaning of demolition, breakdown, into fragments ... and so on, and the similar meanings are twist, crush, demolish, split, cut, into pieces , break up ... etc. Further, it has related in the cruelty and destructive heart which are linked with orgy, Sadism, Necrophilia and so on. The meanings are also expressed by the initial , which are deprivation, deface, defame, deform, degrade, delegitimize, denounce , deride, destroy, devalue, as well as debase, debunk, declaim, declassify, decry, delete, denigrate, deprecate, despise or detract ...and so on. Dario Gamboni has discussed the meaning in his book as two categories Iconoclasm and Vandalism. And the similar meanings could be found in the words which has the initial of , like abase, abate, abhor, abjure, abolish, abridge, abuse ...and so on. Even though the distinct meanings of Iconoclasm and Vandalism, it is not easy to distinguish clearly between the differences when the results are accomplished in contemporary paintings because of the similarity of the results. In korean vocabulary there are no similar words to distinguish between the meanings of destruction and deconstruction, and the deconstruction is not recorded in the general dictionaries. However the meaning of is diminishing, separation, contrast and so on. So the unification of the word as do-construction is not construct, minus construction, reverse construction. And Vincent Ditch explained that there are the meaning of destroy the text. From Jacques Derrida, the deconstruction strategy is to criticise the world of traditional metaphysics and logocentrism, and not to reconstruire the philosophical meaning of texts but $d\'{e}construire$ them. And Saussure emphasized that the signifers could have more meaning that there can be more signified in traditional texts in the art. as a result, deconstruction is explained that there are many signified meanings in a signifer. In this thesis , from using the meanings of destruction and deconstruction, to distinguish the expressive skills in contemporary art works are arising. Therefore, special methods which are linked in the destruction styles are selected. As a result, the two different purposes of destruction is arising, one is enmity destruction and the other is self destruction another word, auto destruction or destruction to create The enmity destruction can be distinguished by the two category Iconoclasm and Vandalism. They come from the moment of different historical aspect is arising and want to attack the Icon or masterpiece this concept is from the study of John Philips and especially iconoclasm is linked with religious and artistic heart, but Vandalism is come from the political attack. Sometime, this distinguish is not clearly arising, because the two aspects are co-related in the attack. As a result, firstly, the Iconoclastic controversy had arisen in the methods of Dadaism which has developed by Man Ray, Francis Picabia and Marcel Duchamp. They want to attack the pre-established master-pieces and painting spaces, and they had 'non-artistic attitude' not to be art. Since 1980, the German artist Anselm Kiefer adapted the methods and made them his special skills so he had tried to paint tough brush strokes and draw with hugh pallette image line and fire and water images , they can be the image attack as the Iconoclasm. secondly, the model of vandalism is to be done by hammer, drill, canon and so on. the method is to attack the content of painting. Further, the object of destruction is bound by cords and iron lings to demolish or to declare the authority of pre-statues; it symbolize the pre-authority is gone already. Self-destruction based paintings are clearly different in the purpose of approaching the art work. First of all, they can be auto-destruction, creative destruction and metamorphosis destruction, which is linked with the skill the material aspect and basic stature, and sign destruction or signifier destruction, which is link with the inner meaning destruction that is considered as the Semiotical destruction in post-modern paintings. Since 1960, the auto destruction is based on the method of firing, melting, grinding and similar skills, which is linked with Neo-Dada and reverse-assemblage. Metamorphosis destruction is strongly linked with the basic inner heart price and quality, so it can be resulted in the changedness of expectation and recognition. Tony Cragg has developed the skills to metamorphose the wood as stone or iron as cloth and stone as sponge and rubber and so on. The researcher has developed the same style in the series of since 2003. The other self-destructive methods are found in the skill of sign destruction. In the methods the meaning of the art is not fixed as one or two, but is developed multi-meaning and differ from original starting situation, so Jacques Derrida called the difference meaning in deconstruction. It is the destruction of textes. These methods are accomplished by David Salle, Francesco Clemente, and recently Tracy Emin, who has developed the attacking heart in the spectators' emotion. Sometime in the method of self-destruction, it is based on horror and shock, the method is explored by Demian Hirst and Jakes and Dinos Chapman. Their destructive styles stimulate ambivalent heart and destroy original sign of girl and animals.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.2 s.115
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• pp.80-98
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• 2006

This study originated from following questions. What can we understand the conception of deconstruction, which has been the core idea of new discourses developed in various ways since modernism? How can this question be interpreted in landscape design? What is the conceptional frame of integration the prominent hybrid post-genre movements and phenomena? The frame can be epitomized with the deconstruction phenomenon. 'Deconstruction' is the core conception appeared in late or post-modern ages in the embodiment of modernity and can be viewed as an integrating or a hybrid phenomenon between areas or genres in formative arts. Therefore, the author regards the hybrid movements widely witnessed in the post contemporary formative arts as one of the most important indicators of de-constructive signs. It is safe to say that the phenomenon of this integration or hybridism, of course, does not threaten the identity of landscape design but serves as an opportunity to extend the areas of landscape design. One of the consequences of this integration or hybridism is the voluntary participation of users who have been alienated in the production of the meanings of design works and hybrid landscape design with the hybridization of genres that is characterized with transformation in forms. This view is based on the distinction between hybridization of interactions between the designer (the subject) and the user (the object), and hybridization of synesthesia. Generally speaking, this is an act of destroying boundaries of the daily life and arts. At the same time, it corresponds to vanishing of modern aesthetics and emerging of post-contemporary aesthetics which is a new aesthetic category like sublimeness. This types of landscape design tries to restore humans' sensibility and perceptions restrained by rationality and recognition in previous approach and to express non-materialistic characteristics with precaution against excessive materialism in the modern era. In light of these backgrounds, the study aims to suggest the hybrid concept and to explorer a new landscape design approach with this concept, in order to change the design structure from 'completed' or 'closed' toward 'opened' and to understand the characteristics of interactions between users and designs. This new approach is expected to create an open-space integrating complexity and dynamics of users. At the same time, it emphasizes senses of user' body with synesthesia and non-determination. The focus is placed on user participation and sublimity rather than on aesthetic beauty, which kind of experience is called simulacre. By attaching importance to user participation, the work got free from the material characteristics, and acceptance from the old practice of simple perception and contemplation. The boundaries between the subject and object and the beautiful and ordinary, from the perspective of this approach, are vanished. Now everything ordinary can become an artistic work. Western dichotomy and discrimination is not effective any more. And there is 'de-construction' where there is perfect equality between ordinary daily life and beautiful arts. Thus today's landscape design pays attention to the user and uses newly perceived sensitivity by pursing obscure and unfamiliar things rather than aesthetic beauty. Space is accordingly defined to take place accidentally as happening and event, not as volume of shape. It's the true way to express spatiality of landscape design. That's an attempt to reject conventional concepts about forms and space, which served as the basis for landscape design, and to search for new things.