• Journal of electromagnetic engineering and science
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• v.11 no.3
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• pp.220-226
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• 2011

We have proposed a new method to accurately predict the resonance of Fabry-Perot Cavity (FPC) antennas enclosed with conducting side walls. When lateral directions of an FPC antenna are not blocked with metallic walls, the conventional technique is accurate enough to predict the resonance of the FPC antenna. However, when the FPC antenna has side walls, especially for case with only a short distance between the walls, the conventional prediction method yields an inaccurate result, inevitably requiring a tedious, time-consuming tuning process to determine the correct resonant height to provide the maximum antenna gain in a target frequency band using three-dimensional full-wave computer simulations. To solve that problem, we have proposed a new resonance prediction method to provide a more accurate resonant height calculation of FPC antennas by using the well-known resonance behavior of a rectangular resonant cavity. For a more physically insightful explanation of the new prediction formula, we have reinvestigated our proposal using a wave propagation characteristic in a hollow rectangular waveguide, which clearly confirms our approach. By applying the proposed technique to an FPC antenna covered with a partially reflecting superstrate consisting of continuously tapered meander loops, we have proved that our method is very accurate and readily applicable to various types of FPC antennas with lateral walls. Experimental result confirms the validness of our approach.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.9
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• pp.750-757
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• 2002

A new lateral trench LTEIGBT with p+ diverter was proposed to suppress latch-up of LTIGBT The p+ diverter was placed between the anode and cathode electrode. The latch-up of LTEICBT with a p+ diverter was effectively suppressed to sustain an anode voltage of 8.7V and a current density of 1453A/$\textrm{cm}^2$ while in the conventional LTIGBT, latch-up occured at an anode current density of 540A/$\textrm{cm}^2$. In addition, the forward blocking voltage of the proposed LTEIGBT with a p+ diverter was about 140V. The forward blocking voltage of the conventional LTIGBT of the same size was no more than 105V, We fabricated the proposed LTEIGBT with a p+ diverter after the device and process simulation was finished. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT with a p+ diverter and the conventional LIGBT are 90㎃ and 70㎃, respectively, at the same breakdown voltage of 150V.

• Bulletin of the Society of Naval Architects of Korea
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• v.17 no.1
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• pp.1-10
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• 1980

The nonlinear analysis of ship plating with flat bar stiffners has been carried out by the finite element method based on the load incremental approach. The large deflection analysis has been done by using the Lagrangian description. The elastoplastic analysis has been performed by adopting the flow theory of plasticity and the von Mises yield condition. The layered elements are used to show the process of yielding through the plate thickness in the elasto-plastic analysis. The following results are obtained; 1) According to the large deflection analysis, it is shown that the small deflection theory to the plate is applicable in the range of the lateral deflection-the thickness ratio $w/h{\leqq}0.3$ and ship plating in the range of $w/h{\leqq}0.5$. 2) By means of the elasto-plastic analysis, it is found that the maximum load-carrying capacity of the plate increases as much as 1.8 times of the initial yield load in the case of the simply supported condition and 2.2 times in the clamped condition. It is also shown that the maximum load-carrying capacity of ship plating increase as much as 4.3 times in the simply supported condition and 4.2 times in the clamped condition. This method would be applied and extended to solve combined nonlinear problems which involve both material nonlinearity and geometric nonlinearity.

• The Journal of Information Systems
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• v.14 no.3
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• pp.89-96
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• 2005

Though studies on negotiations have actively been conducted in the field of e-Commerce so far, some problems have yet to be solved and many application fields of negotiation systems exist. Currently, many businesses shift from various fields to e-Commerce market, due to recent social changes and expansion of e-Commerce market; however, we need to develop the study of automated agents to resolve the issue of negotiation, which is an essential element in the e-Commerce, by minimizing human interference under the e-Commerce environment. In this study, we intend to propose a new negotiation protocol considering the negotiation alternatives through continuous negotiation rounds in relation to an automated negotiation issue whose participants are one to N (seller to buyers). We also present an agent-facilitated negotiation methodology by which negotiation alternative generation process is automated, in consideration of buyer's negotiation attributes and strategies in the negotiation system.

• Proceedings of the Korean Magnestics Society Conference
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• 2011.12a
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• pp.29-30
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• 2011

We have demonstrated the fabrication of sub 30 nm MTJ pillars with PMA characteristics. The multi-step IBE process performed at $45^{\circ}$ and $30^{\circ}$, using NER resulted in almost vertical side profiles. There deposition on the sidewalls of the NER prevented lateral etching of the resist hard mask allowing vertical MTJ side profile formation without any reduction in the lithographically defined resist lateral dimensions. For the 28nm STT-MTJ pillars, the measured TMR ratio was 13 % with resistance of 1 $k{\Omega}$, which was due to remaining redeposition layers less than 0.1 nm thick. With further optimization in multi-step IBE conditions, it will be possible to fabricate fully operating sub 30 nm perpendicular STT-MTJ structures for application to future non-volatile memories.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.211-214
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• 2011

In the present work, a computational study was conducted to investigate characteristic of lateral force on the flow fields inside the propulsion nozzle with step. The unsteady, compressible, axisymmetric, Navier-Stocks equations with SST k-${\omega}$ turbulence model are solved using a fully implicit finite volume scheme. In order to simulate the shut-down process of the engine, NPR is varied from 100.0 to 10.0. It is observed that the separation point and Mach-disk strongly depend on the variation of NPR, and adjusting the step lead to significantly different characteristics in the lateral forces.

• Structural Engineering and Mechanics
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• v.35 no.4
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• pp.459-478
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• 2010

This paper contains detailed descriptions of a dynamic time-history modal analysis to calculate deflection, inter-storey drift and storey shear demand in single-storey and multi-storey buildings using an EXCEL spreadsheet. The developed spreadsheets can be used to obtain estimates of the dynamic response parameters with minimum input information, and is therefore ideal for supporting the conceptual design of tall building structures, or any other structures, in the early stages of the design process. No commercial packages, when customised, could compete with spreadsheets in terms of simplicity, portability, versatility and transparency. An innovative method for developing the stiffness matrix for the lateral load resistant elements in medium-rise and high-rise buildings is also introduced. The method involves minimal use of memory space and computational time, and yet allows for variations in the sectional properties of the lateral load resisting elements up the height of the building and the coupling of moment frames with structural walls by diaphragm action. Numerical examples are used throughout the paper to illustrate the development and use of the spreadsheet programs.

• Journal of Species Research
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• v.8 no.3
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• pp.288-293
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• 2019

Herein, we report a new record of Arna bipunctapex (Hampson) and a new species, Euproctis fulvatus sp. nov. in Korea; both are Lymantriine moths. Arna bipunctapex is distinguished by a relatively large wingspan with two black dots and a small dot between these black dots in the apical region of a yellowish forewing. The male genitalia of A. bipunctapex can be distinguished by the lack of a process on the sacculus of valva while the female genitalia can be distinguished by an antrum that is basally flat with two lateral digitate arms. Euproctis fulvatus is distinguished by yellowish wings with a medially curved central fascia of the forewing. The male genitalia can be distinguished by the bifid, digitate uncus and the simple, square-shaped valva with a distal strong invaginated margin. The female genitalia can be distinguished by the long, medially twisted, ductus dursae with simple antrum posteriorly strongly sclerotized and ovate corpus bursae without signum. Larvae of E. fulvatus are distinguished by a black head with a pair of long, black, lateral tufts, dorsum with 10-11 white intersegmental dots and bright red setal warts on T2-A8, and bright red glands on A6 and A7.

• Clinics in Orthopedic Surgery
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• v.10 no.4
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• pp.508-512
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• 2018

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5-S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a $30^{\circ}$ arthroscope to enable foraminal decompression at the L5-S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5-S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a $30^{\circ}$ arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5-S1 level that preserves facet stability and provides symptomatic relief.

• Structural Engineering and Mechanics
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• v.81 no.4
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• pp.395-409
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• 2022

The presence of infill generally neglected in design despite the fact that infill contribution significantly increase the lateral stiffness and strength of the reinforced concrete frame structure. Several experimental studies and computational models have been proposed to capture the rational response of infill-frame interaction at global level. However, limited studies are available on explicit finite element modelling to study the local behavior due to high computation and convergence issues in numerical modelling. In the current study, the computational modelling of RC frames is done with various configurations of infill masonry in terms of types of blocks, lateral loading and reinforcement detailing employed with material nonlinearities, interface contact issues and bond-slip phenomenon particularly near the beam-column joints. To this end, extensive computational modelling of five variant characteristics test specimens extracted from the detailed experimental program available in literature and process through nonlinear static analysis in FEM code, ATENA generally used to capture the nonlinear response of reinforced concrete structures. Results are presented in terms of damage patterns and capacity curves by employing the finest possible detail provided in the experimental program. Comparative analysis shows that good correlation amongst the experimental and numerical simulated results both in terms of capacity and crack patterns.