• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.4
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• pp.335-341
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• 2017

In this paper, beam finite elements with higher-order derivatives' continuity are formulated and evaluated for various boundary conditions. All the beam elements are based on Euler-Bernoulli beam theory. These higher-order beam elements are often required to analyze structures by using newly developed higher-order beam theories and/or non-classical beam theories based on nonlocal elasticity. It is however rare to assess the performance of such elements in terms of boundary and loading conditions. To this end, two higher-order beam elements are formulated, in which $C^2$ and $C^3$ continuities of the deflection are enforced, respectively. Three different boundary conditions are then applied to solve beam structures, such as cantilever, simply-support and clamped-hinge conditions. In addition to conventional Euler-Bernoulli beam boundary conditions, the effect of higher-order boundary conditions is investigated. Depending on the boundary conditions, the oscillatory behavior of deflections is observed. Especially the geometric boundary conditions are problematic, which trigger unstable solutions when higher-order deflections are prescribed. It is expected that the results obtained herein serve as a guideline for higher-order derivatives' continuous finite elements.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.5
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• pp.23-32
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• 2007

The goal of this study is to perform several bending tests on a shape memory alloy bar and to analyze the characteristics of the bending behavior. The other goal is to verify the seismic performance of an SMA bar bending application. Single and double bending tests were conducted with varying loading speeds and maximum displacement. The loading and the unloading stiffness were estimated from the force-displacement curves and the equivalent damping ratio of each test was also assessed. In single bending, the SMA bar showed the stiffness hardening after the displacement of 32 mm. It is assumed that this phenomenon is due to the stress-induced-martensite hardening. The increasing loading speed did not influence on the stiffness of the single bending SMA bar. The stiffness of the double bending bar is about 5 times of that of the single bending. This study introduced a seismic application of SMA bending bars as seismic restrainers for bridges and showed its practicality. SMA bars in bending are used for seismic restrainers in a three-span-simply-supported bridge. They showed the effectiveness to reduce the responses of the bridge and the applicability for a seismic restrainer. The significance of this study is to provide basic knowledge of SMA bending and its seismic applications.

• Korean journal of applied entomology
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• v.27 no.2
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• pp.94-102
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• 1988

Studies were carried out to describe the structure and distribution of various sensilla on the antenna and mouthparts of the Oriental tobacco bud worm (H. assulta) larvae by light and scanning electron microscopy. The larval antenna has 3 segments. The second segment has 2 hairs and 3 pegs, while the third segment shows 3 regular pegs and a segmented peg (styloconicum type). Each mandible bears 2 aporous hairs on the lateral surface. The labrum bears 12 aporous hairs on its external surface. and 6 aporous hairs, 4 coeloconica-like sensilla and 2 campaniformia-like sensilla on its epipharynx. The stipes has 3 hairs, and the galea has 3 pegs. 2 papillae and 2 domes. The maxillary palpus has only a digitiform sensillum on its 1st segment but 11 sensilla of 4 different types on its 2nd segment. Maxillary sensilla represent almost 70% of total number of larval sensilla on the mouthparts. Labial pal pus has a single segment bearing a large segmented uniporous peg and a small peg. Finally their possible fun¬ctions were suggested.

• Journal of the Korean Society for Railway
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• v.17 no.4
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• pp.251-259
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• 2014

The transition zone between an earthwork and a bridge effect to the vehicle's running stability because support stiffness of the roadbed is suddenly changed. The design criteria for the transition structure on ballast track were not particular in the past. However with the introduction of concrete track is introduced, it requires there is a higher performance level required because of maintenance and running stability. In this present paper, a transition structure reinforced with geosynthetics is suggested to improve the performance of existing bridge-earthwork transition structures. The suggested transition structure, in which there is reinforcing of the approach block using high-tension geosynthetics, has a structure similar to that of earth reinforced abutments. The utilized backfill materials are cement treated soil and gravel. These materials are used to reduce water intrusion into the approach block and to increase the recycling of surplus earth materials. An experiment was performed under the same conditions in order to allow a comparison of this new structure with the existing transition structure. Evaluation items are elastic displacement, cumulative settlement, and earth pressure. As for the results of the real-scale accelerated testing, the suggested transition structure has excellent performance for the reduction of earth pressure and settlement. Above all, it has high resistance the variation of the water content.

• Food Science and Preservation
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• v.16 no.1
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• pp.33-39
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• 2009

To evaluate the quality of brown rice vinegar made by traditional fermentation in terms of Zymotechnic data and material content, vinegars prepared using a traditional leavening agent and yeast were compared. Amino acid, total nitrogen, free sugar, organic acid, and mineral levels were assessed, with vinegars made with initial brown rice contents of 12.36% (w/v). Vinegar made using Nuruk as fermenting agent (traditional fermentation, TF), with a brown rice content of 20% (w/v), and vinegar prepared using yeast for fermentation (control fermentation, CF), with a brown rice content of 12% (w/v) were compared. TF vinegar had a total nitrogen content about 2.0.4.6-fold that of CF vinegar. Total nitrogen in TF vinegar was 350.460 mg/100g, and in CF vinegar the level was 100.140 mg/100g. TF vinegar had more minerals, free sugars, and amino acids compared with CF vinegar. When free sugar was assessed, TF vinegar had a glucose level of 3.45 g/100g, double that of CF vinegar. Amino acid levels were five-fold higher in TF vinegar then in CF vinegar. When brown rice content was 36% (w/v), the amino acid level was $6088.22\;{\mu}g/mL$ in TF vinegar and $1194.05\;{\mu}g/mL$ in CF vinegar.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.140-146
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• 2011

As the demand of Variable Message Sign(VMS) has become pervasive in fulfilling the ITS policy, the costs of maintaining the Variable Message Sign operation have also increased. This paper proposes the U-curved figure, the C-curved figure and the ventilated figure type for aerodynamic drag reduction on Variable Message Sign and shows the analysis of aerodynamic drag effects using Flow Analysis. As a results of the flow analysis for right-angled, 45 degrees from side to side and 45 degrees from up or down, the C-curved figure and the ventilated figure type show about 30% aerodynamic drag reduction in all direction. And the U-curved figure type shows vivid aerodynamic drag reduction for right-angled and 45 degree from side to side, but trivial aerodynamic drag reduction for 45 degree from up or down. It is possible to reduce not only the damage on Variable Message Sign due to typhoon because of the aerodynamic drag reduction, but also installation constraints because of lighter Variable Message Sign support structure by appling the proposed structure and analysis in this paper.

• Korean journal of communication and information
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• v.25
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• pp.65-102
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• 2004

The purpose of this study was to examine the news attributes of the nuclear waste storage facility in Wido by conducting content analysis of two newspapers (Chosun Ilbo and Hangyoreh) and Ohmynews. Furthermore, this study measured the effects of news attributes on readers' attitude, opinion, and recognition of the event. The results of the content analysis indicated that all three newspapers focused on event-oriented coverage than issue-oriented one. Also, they only dealt with two issues-decision making process of the residents and rewards for residents-among a total of nine issues. That is, according to the hypothesis of the second-level agenda-setting theory, the media emphasize on a particular attribute while ignoring other attributes, which, in turn, make the particular attributes more salient. Based on the results of content analysis, this study conducted an experiment to measure the effects of media attributes on public recognition toward the attributes in terms of cognitive and of affective aspects. The results showed a significant relationship between media attributes and public attributes, which confirmed the effects of the second-level agenda setting. However, the transfer of attributes did not take place in affecting public opinion and public recognition of the event itself.

• Korean journal of communication and information
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• v.25
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• pp.41-64
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• 2004

This study examined the impact of newspaper scale on the use of local government's news releases by local newspapers. Thus, to see the impact, the four local newspapers and the local government's news releases were content-analyzed. Further, through a depth interview, this study tried to understand local journalists' thoughts on using the news releases published by local government. This study hypothesized a negative relationship between the newspaper scale and the degree of the use of news release, between the scale and the dependent rate on the news releases, and proposed a positive relationship between the scale and the writing styles(neutral, negative, neutral, positive). The research results supported the first two hypotheses, and the third partially. Thus, the greater the newspaper scale, the higher the degree of the use of news release by local newspaper. And the greater the scale, the higher the dependent rate on the news releases. In addition, the smaller newspaper in the scale showed more positive and negative writing styles than the larger did. On the other hand, the larger newspaper tend to have more neutral writing style than the smaller did. The interviewee also indicated, in terms of newspaper scale, there was diverse perspectives on the use of news release.

• Korean journal of communication and information
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• v.71
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• pp.116-154
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• 2015

Officially given a historical signifier as Gwangju Democratic Movement since 1987, far-right and conservative group have restated that $5{\cdot}18$ is a rebellion and a riot that was committed by rebellious elements who obeyed North Korea's command or who were connected with North Korea. As those who had been responsible for the rebellion, revolt and riot were rewarded, far-right and conservatives' collective narrative that a country was born where the pro-North Korea left became dominated aroused extreme hostility towards $5{\cdot}18$. Far-right and conservatives involved in many different fields such as political party, university, press and media and civil group carry out incendiary discourse politics with intention to reestablish history and memory of $5{\cdot}18$ in their own story. Many people at online sites such as Ilbe Storehouse who are considered 'young right wing' is a main route to spread the far-right groups' remarks on $5{\cdot}18$. Ilbe is a main channel to reconstitute and reproduce the far-right conservatives' remarks and information on $5{\cdot}18$. Ilbe is one of main area where remarks of disparagement and ridicule, hostility and hatred on $5{\cdot}18$ unfurl. This study collects $5{\cdot}18$-related remarks and stories unfolded at Ilbe and examines how these remarks and stories make significance as to $5{\cdot}18$ and how information resources which remarks are dependent upon are connected each other. In this process, this study intends to find implications of incendiary politics that echoed of remarks on $5{\cdot}18$ have which at the online site Ilbe and by the far-right conservatives.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.553-561
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• 2015

The exponential and power law functionally graded material(FGM) theory is reformulated considering the refined shear and normal deformation theory. This theory has ability to capture the both normal deformation effect and exponential and power law function in terms of the volume fraction of the constituents for material properties through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported plates on Pasternak elastic foundation. Numerical solutions of vibration analysis of FGM plates are presented using this theory to illustrate the effects of power law index and 3-D theory of exponential and power law function on natural frequency. The relations between 3-D and 2-D higher-order shear deformation theory are discussed by numerical results. Further, effects of (i) power law index, (ii) side-to-thickness ratio, and (iii) elastic foundation parameter on nondimensional natural frequency are studied. To validate the present solutions, the reference solutions are discussed.