• Journal of the Korea Institute of Building Construction
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• v.10 no.3
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• pp.57-64
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• 2010

This study is to analyze the effects of aluminum form surface coating material on surface quality of concrete. When observing the surface quality of concrete affected by the change of aluminum form surface coating material, in general, as the number of use of the coating material increased, the surface quality of concrete decreased and good surface quality was shown in plywood (hereinafter PW). For epoxy (hereinafter EP) resin, when applying form remover, good surface quality was shown. For the surface roughness of concrete by the application form oil of form remover and the number of use of the coating material, as the number of use increased, highest surface roughness value was shown which meant the leveling was bad, but the surface roughness value in EP and PW was the lowest. Just for EP, when applying form remover, surface roughness value was low. For the number of void for concrete by the application of form remover and the number of use of the coating material, In general, the number of void which was generated when applying form oil the remover decreased.

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.457-464
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• 2013

Traditionally, the material used for the form in reinforced concrete construction has been wood or steel. But recently, aluminum forms have been widely used in wall structures such as apartment buildings. Aluminum is light, easy to handle, and economically advantageous, but the hydrogen gas created due to its reaction with the alkali component in concrete gives rise to air pockets on the concrete's surface, and deteriorates the surface's finishability. In this research, to determine the influence of aluminum material on concrete, the cement paste W/C and its chemical reactivity in alkali and acid solution were analyzed. As a prevention plan, the influence of the number of applications of calcium hydroxide and various surface coating materials was analyzed. Through the analysis, it was found that the surface voids on the aluminum form are the result of the reaction of hydrogen gas with an alkali such as $Ca(OH)_2$. This can be prevented by the surface treatment of $Ca(OH)_2$, separating material and coating material. However, poor surface form and damages to the form are expected to cause quality degradation because of the aluminum-concrete interaction. Therefore, thorough surface treatment, rather than the type of separating material or coating material, is considered the most important target of management.

• The Journal of KAIRB
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• v.1 no.2
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• pp.30-42
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• 2019

In pharmaceutical clinical trials as human material research, the collection, use, storage and provision of human materials must be in accordance with the criteria stipulated in 「Bioethics and Safety Act」, except in the case that some criteria about it is in the law related to clinical trials such as 「Pharmaceutical Affairs Act」 and 「Enforcement Rule on Safety of Drugs, etc.」 so these take precedence over. Under 「Bioethics and Safety Act」, the core aspect of the legal standard for obtaining informed consent is the use of statutory form . The use of statutory form ensure that both those who obtain informed consent and those who give it can know the contents contained this form as well as recognize its importance. Thus, the person who has the right to informed consent can sign the statutory form after correct understanding of the contents. In reality, however, some researchers and IRB members determine that only the main informed consent form is to be used because most of contents on statutory from are included in the main informed consent form. Some other researchers and IRB members judge that the use of statutory form is not needed if human materials may only be used for laboratory testing and the rest will not be stored and provided for future use. Most of these determination and judgement is based on the interpretation of the Korea National Institute for Bioethics Policy(hereafter, KoNIBP) on IRB Information Portal Site. But, it is questionable whether the KoNIBP's interpretation is legally valid and the KoNIBP is the legal entity having authority to interpret existing statute. In some cased not only using the main informed consent form including enough information about the collection, use, storage and provision of human materials but also collecting necessary minimum human materials, and discarding the rest, unusing the statutory form may not cause the problem to respect and protect the research participant's rights. Therefore, the provision stipulating the criteria about the use of statutory form as the legal standard of obtaining informed consent that applies all human material research without exception should review to revise. At least, straighten out the confusion surrounding whether or not the statutory form is to be used, before the revision of related provision, considering the logical opinions of some researchers and IRB Members, the Ministry of Health and Welfare as the legal entity having authority to interpret existing statute should represent its opinion about permission of the acceptable exceptions.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.4
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• pp.57-63
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• 2003

Machining information such as form accuracy and surface roughness is an important factor for manufacturing precise parts. To this regard, OMM (On the Machine Measurement) has been researched for last several decades to alternate CMM (Coordinate Measurement Machine) process. In this research, the OMM system with a laser displacement sensor was developed for measuring form accuracy and surface roughness of the machined workpiece on the machine tool. The surface roughness was estimated comparing the sensory signal with the reference data measured from master specimen. Also, form accuracy was determined from the moving averaged raw data. In addition, the geometric error map constructed beforehand using the geometric errors of the machine tool was used to compensate the obtained form accuracy. The overall performance was compared with CMM result, and verified the feasibility of the measurement system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.150-151
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• 2014

A mold of free-form concrete segment can be used only one time. Thus, the construction duration and cost are increased. The materials of the mold such as wood and metal have limitations due to the implementation and reuse. The review of the material of the mold for free-form concrete segment is needed to reduce duration and production cost. Phase change material can be used both to implement free-shape by heating and to produce mold after cooling. After using Phase change material can be re-used to mold by heating. The scope of this study is many kind of phase change materials for molding. The aim of this study is to analyze the phase change materials for production of changable mold for free-form concrete segment. In this study, the paraffin wax that is melted at 64℃ was selected by considering both the energy efficiency and the weather of Korea.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.73-82
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• 2006

Nowadays, the general stripping work of form has brought some problems; increase of total constructing cost resulted from the man-dependent form work procedure and environmental issues by wasting the debonded form. In this study, to effectively reduce unnecessary cost and resolve the environmental problems caused by these kinds of reason, a permanent form method using stainless steel fiber was introduced then its material and structural characteristics were evaluated. In the case of material characteristic, the permanent form had a good ductile behavior in the result of flexural test of the permanent form panel and pull-out test of insert bolt which is installed in the permanent form and perfect bonding capacity with a field concrete. In the case of structural characteristic, compressive and tensile behavior of the permanent form was evaluated. It also showed a good structural behavior in the view of load-deflection relationship, crack patterns and additional strengthening effect.

• Structural Engineering and Mechanics
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• v.67 no.4
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• pp.417-425
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• 2018

The main aim of this paper is to investigate the bending of Euler-Bernouilli nano-beams made of bi-directional functionally graded materials (BDFGMs) using Eringen's non-local elasticity theory in the integral form with compare the differential form. To the best of the researchers' knowledge, in the literature, there is no study carried out into integral form of Eringen's non-local elasticity theory for bending analysis of BDFGM Euler-Bernoulli nano-beams with arbitrary functions. Material properties of nano-beam are assumed to change along the thickness and length directions according to arbitrary function. The approximate analytical solutions to the bending analysis of the BDFG nano-beam are derived by using the Rayleigh-Ritz method. The differential form of Eringen's non-local elasticity theory reveals with increasing size effect parameter, the flexibility of the nano-beam decreases, that this is unreasonable. This problem has been resolved in the integral form of the Eringen's model. For all boundary conditions, it is clearly seen that the integral form of Eringen's model predicts the softening effect of the non-local parameter as expected. Finally, the effects of changes of some important parameters such as material length scale, BDFG index on the values of deflection of nano-beam are studied.

• The Journal of Natural Sciences
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• v.4
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• pp.221-231
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• 1991

We have thought artistic charactics of modern form is abstract expression and purity and unity sight. Specially, modern sculpture form has strict geometrical form as showed in primitive art. In this circumstances, modern costume has stylized more artistic form in pure sight. Artistic characteristics showed in those collections are picturesque in material and sculpture in shillouette. Picturesque material pointed in decoretive function and simple shillouette pointed in sculpturesque body in modern costume.

• Design & Manufacturing
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• v.17 no.2
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• pp.15-21
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• 2023

In this study, a diamond turning machine and a laser-assisted machining module were utilized for the complex combined cutting of aspheric shapes and fine patterns on the surface of high-hardness brittle material, silicon. The analysis of material's form accuracy and corrective machining was conducted based on key factors such as laser output, rotational speed, feed rate, and cutting depth to achieve form accuracy below 1 ㎛ and surface roughness below 0.1 ㎛. The cutting condition and corrective machining methods were investigated to achieve the desired form accuracy and surface roughness. The rotational speed of the spindle and the linear feed rate of the diamond turning machine were varied in five stages for the cutting condition test. Surface roughness and form accuracy were measured using both a contact surface profilometer and a non-contact surface profilometer. The experimental results revealed a tendency of improved surface roughness with increased rotational speed of the workpiece, and the best surface roughness and form accuracy were observed at a feed rate of 5 mm/min. Furthermore, based on the cutting condition experiments, corrective machining was performed. The experimental results demonstrated an improvement in form accuracy from 0.94 ㎛ to 0.31 ㎛ and a significant reduction in the average value of the surface roughness curve from 0.234 ㎛ to 0.061 ㎛. This research serves as a foundation for future studies focusing on the machinability in relation to laser output parameters.

• Journal of the Korea Furniture Society
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• v.12 no.1
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• pp.69-79
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• 2001

The purpose of this study is to examine the characteristics of Arne Jacobsen's chair design. He was one of the few creators who inscribed his name in both the history of architecture and furniture design. His works reflected a form of "Regional Modernism" in which traditional techniques collide with functionalist beliefs. This grafting of ideas generated a person aesthetics which he used to establish a suitability of scale, detail an program for each design. In the material aspect, he had enjoyed using the plasticity of the plywood, polyurethane, tubular steel and in the formative aspect, organic form is combined with minimalization of material and simplicity. To sum up what is unique about Arne Jacobsen's chair design, it is that it is distinguished by a clear understanding and expression of beauty from nature, a complete understanding of the material used and the melding of traditional and functional techniques to generate organic form.anic form.