• Journal of KIISE:Databases
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• v.30 no.1
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• pp.95-107
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• 2003

The broadcast environment has asymmetric communication aspect that is typically much greater communication bandwidth available from server to clients than in the opposite direction. In addition, most of mobile computing systems allow mostly read-only transactions from mobile clients for retrieving different types of information such as stock data, traffic information and mews updates. Since previous concurrency control protocols, however, do not consider such a particular characteristics, the performance degradation occurs when previous schemes are applied to the broadcast environment. In this paper, we propose the efficient concurrency control for query transaction in broadcast environment. The following requirements are satisfied by adapting weak consistency that is the appropriate correctness criterion of read-only transactions: (1) the mutual consistency of data maintained by the server and read by clients (2) the currency of data read by clients. We also use the serialization graph scheme to check the weak consistency efficiently. As a result, we improved a performance by reducing unnecessary aborts and restarts of read-only transactions caused when global serializability was adopted.

• Journal of KIISE:Databases
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• v.29 no.6
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• pp.477-491
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• 2002

The broadcast environment has asymmetric communication aspect that is typically much greater communication bandwidth available from server to clients than in the opposite direction. In addition, mobile computing systems generate mostly read-only transactions from mobile clients for retrieving different types of information such as stock data, traffic information and news updates. Since previous concurrency control protocols, however, do not consider such a particular characteristics, the performance degradation occurs when previous schemes are applied to the broadcast environment. In this paper, we propose optimistic concurrency control based on timestamp interval for broadcast environment. The following requirements are satisfied by adapting weak consistency that is the appropriate correctness criterion of read-only transactions: (1) the mutual consistency of data maintained by the server and read by clients (2) the currency of data read by clients. We also adopt the timestamp Interval protocol to check the weak consistency efficiently. As a result, we improved a performance by reducing unnecessary aborts and restarts of read-only transactions caused when global serializability was adopted.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.825-833
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• 2013

An estimation of confidence intervals is essential to calculate uncertainty for greenhouse gases inventory. It is generally assumed that the population has a normal distribution for the confidence interval of parameters. However, in case data distribution is asymmetric, like nonnormal distribution or positively skewness distribution, the traditional estimation method of confidence intervals is not adequate. This study compares two estimation methods of confidence interval; parametric and non-parametric method for exponential distribution as an asymmetric distribution. In simulation study, coverage probability, confidence interval length, and relative bias for the evaluation of the computed confidence intervals. As a result, the chi-square method and the standardized t-bootstrap method are better methods in parametric methods and non-parametric methods respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.541-545
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• 2014

In this paper, the angle of the thighs that appear during walking condition to balance estimation to the left and right leg was occurred during normal walking. Get over to the limitations of gait analysis using image processing or foot pressure that was used a lot in the previous, the angle of the thigh were used for estimation of asymmetric gait. We implemented heathy five adult male to test targeting and gait and obtained cycle data from 10 times. For this research, Thigh-Angle measurement device were developed, and attached to in a position of $20^{\circ}$ for flexion and $15^{\circ}$ for extension to measure the angle of the thigh. Also, in order to verify the reliability of estimation of asymmetric gait using thigh-angle, it was compared with the result of asymmetric gait estimation using foot pressure. The results of this paper, using the thigh angle is the average of 16.84% higher than using pressure to accuracy of determine the gait imbalance.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.1185-1194
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• 2020

This study aims to test Voluntary Disclosure, Quality of Financial Reporting and Information Asymmetry as Moderation Variables. The Voluntary Disclosure variable is calculated using the Index Disclosure. This research uses quantitative methods and uses partial least square with EViews data analysis. The research sample consisted of 225 manufacturing companies listed on the Indonesian stock exchange for the period 2016-2018. The results of the study state that voluntary disclosure has a positive and significant effect on the quality of financial reporting through asymmetric information. The relationship between voluntary disclosure and asymmetric information has a negative effect on the quality of financial reporting, states that the disclosure of voluntary reports to companies can prevent information asymmetry, as well as the relationship of voluntary disclosure to information asymmetry states that companies that make voluntary disclosure will increase the interest of investors and other stakeholders. The quality of financial reporting states that if there is information asymmetry, the quality of financial reporting will also decline. The low value of relevance will affect the level of large or small information gaps between management and investors. The quality of financial reporting with increased relevance means that asymmetric information will have a negative impact on financial reporting.

• The Journal of the Acoustical Society of Korea
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• v.34 no.5
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• pp.343-350
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• 2015

In this paper, we perform a study on the directionality of broadband ship radiation noise, mainly resulting from propeller cavitation. By examining a few foreign studies for ship radiation noise and domestic data measured in Korean waters, it is reconfirmed that the asymmetric directionality of the ship radiation noise at bow and stern aspect is observed commonly. In order to explore the reason of this asymmetric directionality, a numerical analysis, based on the acoustic boundary element method, is applied into the geometric form equal to the commercial ship used in the domestic experiment. The numerical result demonstrates that the diffraction of the propeller cavitation noise by ship is a primary cause of the bow-stern asymmetry in the directionality of ship radiation noise.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.3
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• pp.25-32
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• 2018

Purpose : This study investigated the effects of different types of plank exercise on abdominal muscle thickness in subjects with asymmetric pelvic anterior tilt. Methods : Participants with a diagnosis of pelvic anterior tilt were divided into an experimental group (n=12) and a control group (n=13). The thicknesses of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles were measured using an ultrasound diagnostic apparatus. The data were analyzed using an SPSS (Ver. 21) program. Results : In the experimental group, there was a significant difference in the thicknesses of the left and right muscles in the standing and elbow plank exercises (p<.05). All the muscle thicknesses increased significantly during the plank exercises(elbow plank, right-side plank, and left-side plank) as compared with those in the standing position (p<.05). In addition, the side-plank exercise resulted in significantly higher muscle thickness of the supported side (p<.01, p<.001). Conclusion : These findings suggest that asymmetric exercise should be applied to the change of the left and right muscles of the abdominal when applying plank exercise according to pelvic anterior tilt.

• Journal of Ocean Engineering and Technology
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• v.25 no.3
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• pp.19-27
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• 2011

In case of constructing submerged breakwaters for the purpose of preventing coastal erosion, the number of submerged breakwaters, as well as their asymmetry is dependent on the field conditions. The aim of the present study was to examine the 3-D hydrodynamic characteristics (3-D wave field, wave height, mean water level, and mean flow) around the asymmetric submerged breakwaters using a 3-D numerical model, LES-WASS-3D, which was validated through a comparison with existing experimental data and showed fairly nice agreement. From the numerical results, the wave height, mean water level, and mean flow are discussed in relation with the variation in the breakwater length ratio.

• Fibers and Polymers
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• v.7 no.1
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• pp.42-50
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• 2006

In this paper, elasto-plastic constitutive equations for highly anisotropic and asymmetric materials are developed and their numerical implementation is presented. Some engineering materials such as fiber reinforced composites show different material behavior in the different material directions (anisotropy) as well as in tension and compression (asymmetry). Although these materials have mostly been analyzed using the anisotropic elastic constitutive equations, the necessity of consideration of plastic properties has been frequently reported in the previous works. In order to include both the anisotropic and asymmetric properties of composite materials, the Drucker-Prager yield criterion is modified by adding anisotropic parameters and initial components of translation. The implementation procedure for the developed theory and algorithms is presented based on the implicit finite element scheme. The measured data from the previous work are used to validate the present constitutive equations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1052-1057
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• 2006

The implement the adaptive partial response maximum likelihood (PRML) detector with tilt analyzer for asymmetric high-density optical storage system. For the estimation of disc tilt, we exploit spc patterns in each data frame. Because of using the ROM table to renew the coefficients of equalizer and reference values of branches, the complexity of the hardware is reduced. The proposed PRML has been designed and verified by VerilogHDL and synthesized by the Synopsys Design Compiler with Hynix $0.35{\mu}m$ STD cell library. In the result, the total gate count is 35K, and the maximum operating frequency is 140MHz.