• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.24 no.1
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• pp.11-18
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• 1996

A stability analysis in the geomagentotail is presented within MHD limit with a modified form ideal Ohm's law. Using the high ky approximation (ballooning limit), we derive the basic eigenmode equations which can be reduced to the ideal MHD limit. The incompressible limit is numerically solved for a number of model equilibria of tail by Kan [1973], and we have found no unstable Kan equilibrium. Also, an analytic theory is carried out for the case where Bkc is assumed to be constant along the field line, following the idea by Lee and Min [1996]. In that case, it is suggested that the tail stability to the incompressible antisymmetric mode is determined by the ideal MHD.

• Advances in nano research
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• v.8 no.2
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• pp.169-182
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• 2020

This study presents the hygro-thermo-electromagnetic mechanical vibration attributes of elastically restrained piezoelectric nanobeam considering effects of beam surface for various elastic non-ideal boundary conditions. The nonlocal Eringen theory besides the surface effects containing surface stress, surface elasticity and surface density are employed to incorporate size-dependent effects in the whole of the model and the corresponding governing equations are derived using Hamilton principle. The natural frequencies are derived with the help of differential transformation method (DTM) as a semi-analytical-numerical method. Some validations are presented between differential transform method results and peer-reviewed literature to show the accuracy and the convergence of this method. Finally, the effects of spring constants, changing nonlocal parameter, imposed electric potential, temperature rise, magnetic potential and moisture concentration are explored. These results can be beneficial to design nanostructures in diverse environments.

• Computers and Concrete
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• v.10 no.1
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• pp.19-33
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• 2012

The performance of a concrete is significantly influenced by its mixture proportion and the coating thickness on aggregate surface. The concrete in this study is designed by estimating the blending ratio of aggregate using a densified mixture design algorithm (DMDA) based on an ideal grading curve and estimating the paste volume as the sum of the amount of paste needed to provide an assigned coating paste thickness. So as to obtain appropriate concrete amount, and thus can accurately estimate the property of concrete. Deduction of this mix design formula is simple and easy understanding, and meanwhile to obtain result is fast. This estimation model of mix design is expected to reward to industry and effectively upgrade concrete quality.

• KDI Journal of Economic Policy
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• v.33 no.3
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• pp.121-161
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• 2011

We study incentive structures of public developers and land owners in the process of public expropriations using a sequential game model. In the model, we show that there is an incentive for the public developer to give more compensation than just compensation that are defined by law. Also the model shows that there is an incentive for the land owners to revolt strategically against the public expropriation. Then an ideal authority delegation model is introduced to resolve the problems, where an independent appraiser determines the compensation for the expropriation. In the real world, improving the independence of appraisal process is critical to make the system closer to the ideal authority delegation model. So this paper concludes by making a few policy suggestions to improve the current appraisal system.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.379-384
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• 2011

The critical micelle concentration (CMC) and the counter ion binding constant (B) for the mixed micellizations of DBS (sodium dodecylbenzenesulfonate), SDS (sodium dodecylsulfate), and Brij 30 (polyoxyethylene(4) lauryl ether) at $25^{\circ}C$ in pure water were determined by the use of electric conductivity and surface tension measuring methods. Various thermodynamic parameters ($X_i,\;{\gamma}i,\;C_i,\;a_i^M,\;{\beta}$, and ${\Delta}H_{mix}$) were calculated and compared with each other mixed surfactant system by means of the equations derived from the nonideal mixed micellar model. The results show that the SDS molecule interacts more strongly with Brij 30 molecule than DBS molecule and that the SDS/Brij 30 mixed surfactant system has the greatest negative deviation from the ideal mixed micellar model and the SDS/DBS mixed system has followed almost the ideal mixed micellar model.

• Archives of design research
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• v.13 no.1
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• pp.247-256
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• 2000

Recently, foreign tourists and car owners or motorists are increasing, so tourist sign boards are necessary to inform them. Unfortunately, tourist sign boards are difficult to understand because they are often written incorrectly. This paper has a thorough grasp of this problem and will present an ideal standard model which is precise and detailed. This paper includes research of tourist boards sign Seoul, Kyongju, Pusan, Kwangju, Yosu, Kwang reung in Korea. Also tourist sign boards in the U.K, France, Switzerland, Italy and Austria will be discussed. A survey was conducted of eight hundred people to determine tourist information is obtained. In conclusion, tourist sign board should convey accurate and useful information to people of all ages. Tourist information should be systematic and logical. An ideal standard model of tourist signs will render traveling easier for tourists all over the world. It will be more convenient for both kinds of tourist; domestic and foreign. Futhermore good tourist sign board will give an excellent and bright image.

• Journal of Convergence Society for SMB
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• v.1 no.1
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• pp.45-53
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• 2011

There are always many kinds of risks in software development such as frequent changes of requirements. Especially those risks related to the software characteristic of non-visibility can be threat to the project success. That lead us to the need of process implementation to reduce and minimize those risks. Although, most of the organization recognizes the importance of risk management, actual implementation requires professional knowledge in this area. CMMI, the de facto standard in process reference model, also emphasizes on risk management process area but only provides goals and practices to be implemented, not detail procedure and methods. In this paper, we developed Risk management implementation model based on IDEAL, the process improvement model based on CMMI. The proposed model will help the organizations to implement risk management process which is proper to their situation in the factor of organization size and project characteristics.

• Journal of Korea Game Society
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• v.3 no.2
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• pp.86-92
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• 2003

Today, the visual description of body is viewed in various categories, and the circumstance of computers is regarded as new type of communication beyond the circumstance of individual body. In cyber space, when existence and role of character in computer game constitute communication, the ideal body description of each character depicts dramatic beauty, which rises above reality. On this thesis, analyzing the body description and transition on visual in, I grope for a method to utilize in creating game character which is modeled from ideal human being. Although the progress of producing character has already come to limit, concluding that we have to create character model which has marked individuality and beauty by adding modem and future analysis to the golden ratio, which has established since ancient Greece, this paper suggests the method of creating character which has the image of ideal human body.

• Smart Structures and Systems
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• v.19 no.5
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• pp.487-497
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• 2017

Semi-active devices use the building's own motion to produce resistive forces and are thus strictly dissipative and require little power. Devices that independently control the binary open/closed valve state can enable novel device hysteresis loops that were not previously possible. However, some device hysteresis loops cannot be obtained without active analog valve control allowing slower, controlled release of stored energy, and is presents an ongoing limitation in obtaining the full range of possibilities offered by these devices. This in silico study develops a proportional-derivative feedback control law using a validated nonlinear device model to track an ideal diamond-shaped force-displacement response profile using active analog valve control. It is validated by comparison to the ideal shape for both sinusoidal and random seismic input motions. Structural application specific spectral analysis compares the performance for the non-linear, actively controlled case to those obtained with an ideal, linear model to validate that the potential performance will be retained when considering realistic nonlinear behaviour and the designed valve control approach. Results show tracking of the device force-displacement loop to within 3-5% of the desired ideal curve. Valve delay, rather than control law design, is the primary limiting factor, and analysis indicates a ratio of valve delay to structural period must be 1/10 or smaller to ensure adequate tracking, relating valve performance to structural period and overall device performance under control. Overall, the results show that active analog feedback control of energy release in these devices can significantly increase the range of resetable, valve-controlled semi-active device performance and hysteresis loops, in turn increasing their performance envelop and application space.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.2
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• pp.117-124
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• 2017

Densities of molten salt mixtures of eutectic LiCl-KCl with $UCl_3$, $CeCl_3$, or $LaCl_3$ at various concentrations (up to 13 wt%) were measured using a liquid surface displacement probe. Linear relationships between the mixture density and the concentration of the added salt were observed. For $LaCl_3$ and $CeCl_3$, the measured densities were significantly higher than those previously reported from Archimedes' method. In the case of $LiCl-KCl-UCl_3$, the data fit the ideal mixture density model very well. For the other salts, the measured densities exceeded the ideal model prediction by about 2%.