• Smart Structures and Systems
• /
• v.20 no.5
• /
• pp.583-593
• /
• 2017

This research deals with the nonlocal temperature-dependent dynamic buckling analysis of embedded sandwich micro plates reinforced by functionally graded carbon nanotubes (FG-CNTs). The material properties of structure are assumed viscoelastic based on Kelvin-Voigt model. The effective material properties of structure are considered based on mixture rule. The elastic medium is simulated by orthotropic visco-Pasternak medium. The motion equations are derived applying Sinusoidal shear deformation theory (SSDT) in which the size effects are considered using Eringen's nonlocal theory. The differential quadrature (DQ) method in conjunction with the Bolotin's methods is applied for calculating resonance frequency and dynamic instability region (DIR) of structure. The effects of different parameters such as volume percent of CNTs, distribution type of CNTs, temperature, nonlocal parameter and structural damping on the dynamic instability of visco-system are shown. The results are compared with other published works in the literature. Results indicate that the CNTs have an important role in dynamic stability of structure and FGX distribution type is the better choice.

• Korean Linguistics
• /
• v.48
• /
• pp.193-221
• /
• 2010

The goal of this paper is to reanalyze the structure of 'eumcikha(음직하)' in Korean. We have several important previous works for it. This paper argued against previous works and pointed outd their problems. At first, this paper regarded the construction of 'eumcikha' as one of the modality dependent noun constructions. In this paper I proposed some possibilities of new structure of 'eumcikha'. 1) The structure of 'eumcikha' is not regarded as the 'embedded sentence+upper sentence' construction. 2) It is not also considered as the 'main verb+auxiliary verb' construction. 3) It is not recognized as a morphological one unit, although they have lots of in common. In this paper, I proposed that the construction of 'eumcikha' has both syntactic property and morphological property. Owing to these properties, it is so difficult to determine the structure of it.

• Journal of the Korean GEO-environmental Society
• /
• v.24 no.7
• /
• pp.5-14
• /
• 2023

Recently, earthquakes have occurred frequently in worldwide. These earthquakes cause various forms of natural and physical damage. In particular, liquefaction in which the ground shows liquid-like behavior causes great damage to the structure. Accordingly, various liquefaction damage reduction methods are being studied and developed. Therefore, in this study, a method of reducing liquefaction damage in the event of an earthquake applicable to existing structures was studied using the sheet pile method. The 1-G Shaking table test was performed and the ground was constructed with Jumunjin standard sand. A two-story model structure was produced by applying the similitude law, and the input wave applied a sine wave with an acceleration level of 0.6 g and a frequency of 10 Hz. The effect of reducing structure damage according to various embedded depth ratio was analyzed. As a result of the study, the structure settlement when the ground is reinforced by applying the sheet pile method is decreased by about 71% compared to when the ground is not reinforced, and the EDR with minimum settlement is "1". In addition, as the embedded depth ratio is increased, the calculation of the pore water pressure in the ground tends to be delayed due to the sheet pile. Based on these results, the relationship with structural settlement according to the embedded depth ratio is proposed as a relational equation with the graph. The results of this study are expected to be used as basic data in developing sheet pile methods applicable to existing structures in the future.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.2C
• /
• pp.109-117
• /
• 2010

Gas hydrate dissociation can generate large amounts of gas and water in gas hydrate bearing sediments, which may eventually escape from a soil skeleton and form voids within the sediments. The loss of fine particles between coarse particles or collapse of cementation due to water flow during heavy or continuous rainfall may form large voids within soil structure. In this study, the effect of void formation resulting from gas hydrate dissociation or loss of some particles within soil structure on the strength of soil is examined. Glass beads with uniform gradation were used to simulate a gas hydrate bearing or washable soil structure. Glass beads were mixed with 2% cement ratio and 7% water content and then compacted into a cylindrical sample with five equal layers. Empty capsules for medicine are used to mimic large voids, which are bigger than soil particle, and embedded into the middle of five equal layers. The number, direction, and length of capsules embedded into each layer vary. After two days curing, a series of unconfined compression tests is performed on the capsule-embedded cemented glass beads. Unconfined compressive strength of cemented glass beads with capsules depends on the volume, direction and length of capsules. The volume and cross section formed by voids are most important factors in strength. An unconfined compressive strength of a specimen with large voids decreases up to 35% of a specimen without void. The results of this study can be used to predict the strength degradation of gas hydrate bearing sediments in the long term after dissociation and loss of fine particles within soil structure.

• Smart Media Journal
• /
• v.7 no.1
• /
• pp.37-44
• /
• 2018

Utilizing sequence control and numerical computing, embedded devices are used in a variety of automated systems, including those at industrial sites, in accordance with their control program. Since embedded devices are used as a control system in corporate industrial complexes, nuclear power plants and public transport infrastructure nowadays, deliberate attacks on them can cause significant economic and social damages. Most attacks aimed at embedded devices are data-coded, code-modulated, and control-programmed. The control programs for industry-automated embedded devices are designed to represent circuit structures, unlike common programming languages, and most industrial automation control programs are designed with a graphical language, LAD, which is difficult to process static analysis. Because of these characteristics, the vulnerability analysis and security related studies for industry automation control programs have only progressed up to the formal verification, real-time monitoring levels. Furthermore, the static analysis of industrial automation control programs, which can detect vulnerabilities in advance and prepare for attacks, stays poorly researched. Therefore, this study suggests a method to present a discussion on an industry automation control program designed to represent the circuit structure to increase the efficiency of static analysis of embedded industrial automation programs. It also proposes a medium term translation technology exploiting LLVM IR to comprehensively analyze the industrial automation control programs of various manufacturers. By using LLVM IR, it is possible to perform integrated analysis on dynamic analysis. In this study, a prototype program that converts to a logical expression type of medium language was developed with regards to the S company's control program in order to verify our method.

• Phonetics and Speech Sciences
• /
• v.12 no.3
• /
• pp.41-53
• /
• 2020

A wh-phrase in an embedded sentence may have either an embedded or a matrix scope. Interpretation of a wh-phrase with a matrix scope has tended to be syntactically unacceptable unless the sentence reads with a wh-intonation. Previous studies have found two differences in prosodic characteristics between sentences with matrix and embedded scopes. Firstly, peak F0s in wh-phrases produced with an F0 compression wh-intonation are higher than those in indirect questions, and peak F0s in matrix verbs are lower than those in sentences with embedded scope. Secondly, a substantial F0 drop is found at the end of embedded sentences in indirect questions, whereas no F0 reduction at the same point is noticed in sentences with a matrix scope produced with a high plateau wh-intonation. However, these characteristics were not found in our experiment. This showed that a more compelling difference exists in the values obtained from subtraction between the peak F0s of each word (or a word plus an ending or case marker) and the F0s at the end of the word. Specifically, the gap between the peak F0 in a word composed with an embedded verb and the F0 at the end of the word, which is a complementizer in Korean, is large in embedded wh-scope sentences and low in matrix wh-scope sentences.

• Multiscale and Multiphysics Mechanics
• /
• v.1 no.3
• /
• pp.225-231
• /
• 2016

The formation of silicon-on-nothing (SON) structure during an annealing process from the silicon substrate including the trench structures has been considered as an effective technique to construct the structure that has an empty space under the closed flat surface. Previous studies have demonstrated the mechanism of the formation of SON structure, which is based on the surface diffusion driven by the minimization of their surface energy. Also, it has been fragmentarily shown that the morphology of SON structure can be affected by the initial design of trench (e.g., size, number) and the annealing conditions (e.g., temperature, pressure). Based on the previous studies, here, we report a comprehensive study for the design of the cavity-embedded structure (i.e., SON structure). To do this, a dynamic model has been developed with the phase field approach. The simulation results represent that the morphology of SON structures could be detailedly designed, for example the position and thickness of cavity, the thickness of top and bottom layer, according to the design parameters. This study will give us an advantage in the effective design of SON structures.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2005.04a
• /
• pp.422-429
• /
• 2005

It is limited to decrease height or section even by system conversion to indeterminate structure - continuous beam - in existing PSC girder bridges. In this study, the movement of connection is analyzed through actual field test, by increasing stiffness of negative moment area in continuous PSC bridge and developing continuous PSC bridge with embedded steel plate, that can overcome the demerit of existing connection. As a result, it is confirmed that the body unification of the connection is being realized and maintained. Moreover, the height of a span is suggested in continuous PSC girder bridge with embedded steel plate by computational analysis

• IEMEK Journal of Embedded Systems and Applications
• /
• v.12 no.6
• /
• pp.413-424
• /
• 2017

In this paper, we show shortcomings of separate chaining scheme by way of experiments with NAND flash memory and improve the performance with merge chaining scheme which is proposed in this paper. We explain this merge chaining scheme and explain how to improve the performance of search operation. Merge chaining scheme shows better performance at insert and search operation compare to separate chaining scheme.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2001.11a
• /
• pp.21-27
• /
• 2001

Epoxy/BaTiO$_3$composite film type capacitors with excellent stability at room temperature, uniform thickness, and electrical properties over a large area were successfully fabricated. We fabricated composite capacitor films with good film formation capability and easy process ability, from ACF-resin as a matrix and two kinds of BaTiO$_3$powders as fillers to increase the dielectric constant of the composite film. The crystal structure of the powders and its effects on dielectric constant of the films were investigated by X-ray diffraction. DSC and dielectric properties tests were conducted to decide the right curing temperature and the optimum amount of the curing agent. As a result, the capacitors of $7{\mu}{\textrm}{m}$ thick film with 10nF/cm2 and low leakage current were successfully demonstrated.