• Computational Structural Engineering
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• v.4 no.3
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• pp.89-97
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• 1991

Conventional aseismic design methods of R/C frame all but disregard the state of damage over the entire building frame. This paper presents an automated damage-controlled design method for R/C frames which aims at an uniform energy dissipation rate throughout the building frame, so that the resulting damage is uniformly distributed as much as possible over all element. The accuracy of the basic hystertic model and the damage model for R/C members is verified by reproducing the experimental load-deformation curves of one-bay one-story frames. Application of this design method to various frame structures indicate that 1) regardless of the structural properties or input earthquake characteristics, damage-controlled frames generally survive more severe earthquake excitations and suffer less damage than conventionally designed frames, and 2) member yielding strength in the lower stories of damage-controlled frames is larger than that for conventionally designed frames, while the trend is opposite in the upper stories.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.757-766
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• 2015

This study was considered chances of additional income, if farmers raised silkworms in unused mulberry leaves, after harvesting mulberry, investigated yields of mulberry leaves in vinyl-house and optimal amount in raised silkworms, First, the results was investigated productions of mulberry leaves in the mulberry tree-shape of vinyl-house, T-shape harvested 7.07 kg, Y-shape was 6.55 kg, in comparison with convention of it was harvested 4.75 kg mulberry leaves/1 mulberry tree, was harvested 49%, 38% more each. Also, yields of mulberry leaves was used 302 kg when was raised 1box of silkworms in the mulberry tree-shape of vinyl-house. In other hand, yields of raising silkworms was analysed in the mulberry tree-shapes of vinyl-house, mulberry leaves of $1,000m^2$ vinyl-house mulberry tree was raised average of 3.74 boxs silkworms, in the concrete conventional-shape was 3.24 boxs, T-shape did 4.17 boxs and Y-shape was 3.83 boxs, Consequently, if the farmers of $1,000m^2$ vinyl-house mulberry tree raised silkworms with unused mulberry leaves, could get 1~1.2 million won additionally.

• Korean journal of communication and information
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• v.60
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• pp.172-192
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• 2012

Over the last ten years, media convergence and multiple platform expansion have affected the ways that people watch conventional television. In the post-TV era, the growing use of the Internet and mobile multi-media devices, such as smart phones, as well as the availability of abundant television content, allows television consumption to be more personalized, diversified, and linked with various media activities, especially social media uses. This study attempts to examine how television viewing experiences have been transformed with the development of the trans-media uses. Based on Walter J. Ong's concept of relation-ism, which posits that new media transform the meanings and relevance of old media rather than making old media obsolete, this study will pay particular attention to how the cultural meanings of television viewing have been redefined in the post-TV era. For the examination, this study has looked at concrete cases of the television viewing experiences of 29 young people in their twenties. Based on in-depth interview data, this study discusses the newly emerging characteristics of television viewing, its temporal and spatial experiences, and the significance of television as a medium and as a social place.

• Computers and Concrete
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• v.20 no.5
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• pp.539-544
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• 2017

Shear walls have high stiffness and strength; however, they lack energy dissipation and repairability. In this study, an innovative slotted shear wall featuring vertical slots and steel energy dissipation connectors was developed. The ductility and energy dissipation of the shear wall were improved, while sufficient bearing capacity and structural stiffness were retained. Furthermore, the slotted shear wall does not support vertical forces, and thus it does not have to be arranged continuously along the height of the structure, leading to a much free arrangement of the shear wall. A frame-slotted shear wall structure that combines the conventional frame structure and the innovative shear wall was developed. To investigate the ductility and hysteretic behavior of the slotted shear wall, finite element models of two walls with different steel connectors were built, and pushover and quasi-static analyses were conducted. Numerical analysis results indicated that the deformability and energy dissipation were guaranteed only if the steel connectors yielded before plastic hinges in the wall limbs were formed. Finally, a modified D-value method was proposed to estimate the bearing capacity and stiffness of the slotted shear wall. In this method, the wall limbs are analogous to columns and the connectors are analogous to beams. Results obtained from the modified D-value method were compared with those obtained from the finite element analysis. It was found that the internal force and stiffness estimated with the modified D-value method agreed well with those obtained from the finite element analysis.

• Steel and Composite Structures
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• v.23 no.2
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• pp.195-204
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• 2017

The effects of plaster on the behavior of single-story single-bay masonry-infilled steel frames under in-plane base accelerations have been experimentally investigated by a shake-table. Tested structures were made in a 1/3 scale, with realistic material properties and construction methods. Steel frames with high and low flexural rigidity of beams and columns were considered. Each type of frame was tested with three variants of masonry: (i) non-plastered masonry; (ii) masonry infill with conventional plaster on both sides; and (iii) masonry infill with a polyvinyl chloride (PVC) net reinforced plaster on both sides. Masonry bricks were made of lightweight cellular concrete. Each frame was firstly successively exposed to horizontal base accelerations of an artificial accelerogram, and afterwards, to horizontal base accelerations of a real earthquake. Characteristic displacements, strains and cracks in the masonry were established for each applied excitation. It has been concluded that plaster strengthens the infill and prevents damages in it, which results in more favorable behavior and increased bearing capacity of plastered masonry-infilled frames compared to non-plastered masonry-infilled frames. The load-bearing contribution of the adopted PVC net in the plaster was not noticeable for the tested specimens, probably due to relative small cross section area of fibers in the net. Behavior of masonry-infilled steel frames significantly depends on frame stiffness. Strong frames have smaller displacements than weak frames, which reduces deformations and damages of an infill.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.1
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• pp.23-31
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• 2003

Since the mid of 1990, permanent shotcrete tunnel linings such as Single-shell and NMT have been constructed in many countries for reducing the construction time and lowing construction costs instead of conventional in-situ concrete linings. Among essential technologies for successful application of permanent shotcrete linings, high performance shotcrete having high strength, high durability and better pumpability has to be developed in advance as an integral component. This paper presents the idea and first experimental attempts to increase early strength and bond strength of wet-mixed Steel Fiber Reinforced Shotcrete (SFRS) in spring water condition. In order to increase early behavior of SFRS, a new approach using high-early strength cement with alkali-free liquid accelerator has been investigated. From the test results, wet-mix SFRS with high-early strength cement and alkali-free accelerator exhibited excellent early compressive strength improvement compared to the ordinary portland cement and good bond strength even under spring water condition.

• Computers and Concrete
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• v.21 no.5
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• pp.495-504
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• 2018

The possibility of earthquakes in vulnerable regions indicates that efficient technique is required for seismic protection of buildings. During the recent decades, the concept is moving towards the insertion of base isolation on seismic prone buildings. So, investigation of structural behavior is a burning topic for buildings to be isolated in base level by bearing device. This study deals with the incorporation of base isolation system and focuses the changes of structural responses for different types of Lead Rubber Bearing (LRB) isolators. A number of sixteen model buildings have been simulated selecting twelve types of bearing systems as well as conventional fixed-base (FB) scheme. The superstructures of the high-rise buildings are represented by finite element assemblage adopting multi-degree of freedoms. Static and dynamic analyses are carried out for FB and base isolated (BI) buildings. The dynamic analysis in finite element package has been performed by the nonlinear time history analysis (THA) based on the site-specific seismic excitation and compared employing eminent earthquakes. The influence of the model type and the alteration in superstructure behavior of the isolated buildings have been duly assessed. The results of the 3D multistory structures show that the lateral forces, displacement, inertia and story accelerations of the superstructure of the seismic prone buildings are significantly reduced due to bearing insertion. The nonlinear dynamic analysis shows 12 to 40% lessening in base shear when LRB is incorporated leading to substantial allowance of horizontal displacement. It is revealed that the LRB isolators might be potential options to diminish the respective floor accelerations, inertia, displacements and base shear whatever the condition coincides. The isolators with lower force intercept but higher isolation period is found to be better for decreasing base shear, floor acceleration and inertia force leading to reduction of structural and non-structural damage. However, LRB with lower isolator period seems to be more effective in dropping displacement at bearing interface aimed at reducing horizontal shift of building structure.

• Journal of The Korean Association of Information Education
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• v.11 no.4
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• pp.461-470
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• 2007

Programming education can improve problem-solving skills and logical thinking required in a knowledge-based society. However, most conventional programming education spent more time to acquisition of command language and coding process rather than improvement of problem-solving skills and logical thinking, for using programming languages based on foreign language and learners have appeared to lost interest easily. To solve these problems in this paper, interest in programming study was enhanced by making it possible to verify the outcome of highly abstract programming process through a robot as a concrete object. In addition, the Hangul converter of robot programming language based on RCX that elementary school students can use easily was designed and developed. Furthermore, the developed tool was used for six months by students in after-school computer class and therefore learners showed a positive response.

• Resources Recycling
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• v.17 no.4
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• pp.30-36
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• 2008

The preparation of porous lightweight materials as well as the measurement of physical properties has been performed by using SSA(sewage sludge ash) as the raw material. For this aim, two types of lightweight filler, that is, perlite and silica sphere were employed respectively and bentonite was also used as an inorganic binder. The properties of lightweight specimen calcined at 1,000 were measured in terms of density, compressive strength, thermal conductivity and sound absorption to examine the effect of material composition as well as the preparation condition on the properties of lightweight material. As a result, the density of specimen prepared with perlite was ranged from 1.23 to $1.37g/cm^3$ and the compressive strength was ranged from 242.3 to $370.5kg/cm^2$. In case of specimen prepared with silica sphere, it was found that the compressive strength was less than $100kg/cm^2$ even though density was lower than that of specimen with perlite. As far as the thermal conductivity of specimen was concerned, it was ranged from 0.3 to $0.5W/m^{\circ}K$ depending on material composition so that the insulation effect was superior to conventional concrete.

• The Korean Society of Law and Medicine
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• v.15 no.1
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• pp.239-262
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• 2014

The conventional medical appraisal which was done in the process of medical lawsuit was requested from the court to the designated hospital and was delivered as a pattern of one question and one answer in each. However, the comprehensiveness of medical appraisal which was pursued, for example, in Korea Medical Dispute Mediation and Arbitration Agency, could be guaranteed in terms of in-depth medical analysis as well as the broader capacity of the causality estimation besides. The comprehensiveness of appraisal would also include how well organized hospital system of medical care is and how well correlated job system among medical staffs, when medical dispute was happened at the hospital. This comprehensiveness will exert a big contribution on making a demonstrative medical care to prevent from the medical dispute and it could achieve the national plan of building the patient safety net which is effective in restoring the worsened quality of contemporary medical service. Therefore, the comprehensiveness of medical appraisal has to be designed to go forward interdisciplinary fused speciality rather than one division of medicine, which is also aiming at the reliable and consistent appraisal with the supreme dignity from one window. In addition to that, the objective and concrete frame of comprehensive appraisal under the computed connection has to be deliberated to make itself possible in collaboration with positive participation of medical community. The comprehensiveness of medical appraisal would serve to expand not only the capacity of speciality but also the ability of influence on a restorative justice, so that it give effect to an increased number of mediation and arbitration rather than medical lawsuit as well as a decreased number of the social cost and social conflict.