• Communications for Statistical Applications and Methods
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• v.21 no.4
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• pp.335-347
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• 2014

This paper employs dynamic conditional correlation (DCC) model to examine time-varying comovement in the Korean stock market with a focus on the financial industry. Analyzing the daily returns of KOSPI 200 eight sector indices from January 2008 to December 2013, we find that stock market correlations significantly increased during the GFC period. The Financial Sector had the highest correlation between the Constructions-Machinery Sector; however, the Consumer Discretionary and Consumer Staples sectors indicated a relatively lower correlation between the Financial Sector. In terms of model fitting, the DCC with t distribution model concludes as the best among the four alternatives based on BIC, and the estimated shape parameter of t distribution is less than 10, implicating a strong tail dependence between the sectors. We report little asymmetric effect in correlation dynamics between sectors; however, we find strong asymmetric effect in volatility dynamics for each sector return.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.2
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• pp.53-55
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• 2011

The printed wide band monopole antenna having characteristics of dipole by modified coplanar wave guide(CPW) ground plane is presented. We are called a slot-arm printed monopole antenna and investigated the effect of the surface currents of the radiator on ground plane. The proposed antenna is treated as two asymmetric dipoles with the included angle of $90^{\circ}$ degrees which lie along Z-direction symmetrically. It is observed that the effect of the surface currents on the radiation patterns is similar to that of the corresponding dipole. The length and width of the ground plane correspond the radius and length of the dipole respectively. This approach is also valid to general printed monopole antennas. The simulation impedance bandwidth of the proposed antenna the range of 2.4 to 4.6 [GHz] for a voltage stand wave ratio (VSWR)${\leq}$2 and got pick gain of 6 [dBi]. So the proposed antenna is satisfied the requirement of the industry science medical (ISM) band operation.

• Wind and Structures
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• v.5 no.2_3_4
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• pp.359-368
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• 2002

This paper describes a CFD investigation into the flow over the cab of a bluff-fronted lorry. Several different simulations were undertaken, using the commercial codes: CFX, Fluent and PowerFLOW. Using the $k-{\varepsilon}$ turbulence model, the flow over the cab was symmetric, however, using more accurate turbulence models such as the RNG $k-{\varepsilon}$ model or the Reynolds Stress Model, the flow was asymmetric. The paper discusses whether this phenomenon is a real effect or whether it is a solver artefact and the study is supported by experimental evidence. The findings are preliminary, but suggest that it has a physical origin and that it may be aspect ratio-dependent.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.576-580
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• 2013

We investigate the enhanced effects of asymmetry ratio variations of the source and drain area in silicon (Si) field-effect transistor (FET). Photoresponse according to the variation of asymmetry difference between the width of source and drain are obtained by using the plasmonic terahertz (THz) wave detector simulation based on technology computer-aided design (TCAD) with the quasi-plasma 2DEG model. The simulation results demonstrate the potential of Si FETs with asymmetric source and drain structures as the promising plasmonic THz detectors.

• Proceedings of the Korean Magnestics Society Conference
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• 1999.04a
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• pp.86-87
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• 1999

• Proceedings of the Membrane Society of Korea Conference
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• 1999.04a
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• pp.53-55
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• 1999

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.93-94
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• 1999

• Journal of Digital Convergence
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• v.20 no.4
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• pp.215-224
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• 2022

This study tried to examine the effect of cost asymmetry on food service companies and what characteristics affect such cost behavior. This study analyses cost behavior for cost of good sold, selling, general and administrative cost over the 2019-2020 period. Also, the rate of change in activity level was measured using change in sales. This study measures the behavior of cost using the research model of [1]. As a result of the analysis, it was found that food service companies exhibited cost asymmetric behavior as their sales level decreased. In addition, the cost asymmetric behavior has been strengthened since the corona virus, and the shorter the operating cycle. Lastly, the shorter the inventory holding period and the collection period of accounts receivable, which are components of the operating cycle, more strengthen asymmetric behavior of costs. These results seem to be meaningful in examining the cost structure and factors that may affect the structure for food service industry. This has approached the cost aspect of the situation faced by service food companies due to COVID-19, and it can be suggested that this pandemic can lead to cost reduction due to a decrease in corporate sales.

• Journal of Aerospace System Engineering
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• v.10 no.3
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• pp.39-43
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• 2016

In this paper, a wind-tunnel test is accomplished to investigate the roll characteristics of a variable-span wing flying inside a channel. The factors that affect the roll characteristics of the wing were identified by analyzing the measured data; accordingly, when the wing is flying without both the ground and sidewall effects, the asymmetric wing extension causes the roll moment. Both the ground and the sidewall can increase the roll moment, but when the wing is affected by both the ground and the sidewall, the roll moment does not increase as much as the case where the wing is only affected by the ground. Also, the aerodynamic characteristics of the flying wing inside a channel are the nonlinear function of the wing height and the gap between the wingtip and the sidewall, both of which should be considered in a study of the stability and the flight control of the wing-in-ground effect of the vehicle flying inside a channel.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.342-343
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• 2012

We studied the Drain-Induced-Barrier-Lowering (DIBL) effect by different drain engineering. One other drain engineering is symmetric source-drain n-channel MOSFETs (SSD NMOSs), the other drain engineering is asymmetric source-drain n-channel MOSFETs (ASD NMOSs). Devices were fabricated using state of art 40 nm dynamic-random-access-memory (DRAM) technology. These devices have different modes which are deep drain junction mode in SSD NMOSs and shallow drain junction mode in ASD NMOSs. The shallow drain junction mode means that drain is only Lightly-Doped-Drain (LDD). The deep drain junction mode means that drain have same process with source. The threshold voltage gap between low drain voltage ($V_D$=0.05V) and high drain voltage ($V_D$=3V) is 0.088V in shallow drain junction mode and 0.615V in deep drain junction mode at $0.16{\mu}m$ of gate length. The DIBL coefficients are 26.5 mV/V in shallow drain junction mode and 205.7 mV/V in deep drain junction mode. These experimental results present that DIBL effect is higher in deep drain junction mode than shallow drain junction mode. These results are caused that ASD NMOSs have low drain doping level and low lateral electric field.