• KIEE International Transactions on Power Engineering
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• v.4A no.3
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• pp.134-140
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• 2004

This paper presents an improved group of energy functions reflecting generator damping effects for multi-machine power systems by using Center of Inertia (COI) formulation as an extension of the previous work. Since rotor angles at the Stable Equilibrium Point (SEP) of post-fault systems are generally calculated in COI, system transient energy can be found without assumption of infinite or slack bus, which is a crucial drawback of the absolute rotor angle frame approach. The developed energy functions have a structure preserving property with which it is very flexible to incorporate various models of power system components, especially various load and generator models. The proposed damping-reflected energy functions are applied to the Potential Energy Boundary Surface (PEBS) method, one of the direct methods. Numerical simulation of WSCC 9-bus shows that conservativeness of the PEBS method can be considerably reduced.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.676-683
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• 2008

It is developed in domestic and position Tilting train's Onboard Cabsignal system at the car of the train follows in the route which comes to be applied and application environment and the scope of function and application of equipment is different applied. The development direction of signal equipment at the domestic car must secure the maintenance conservativeness and a fundamental technique of hereafter. It will reach and to respect standardization of technical power it leads and must be applied development or. Consequently, Domestic it is developed tilting it investigates the application scope of the train. It investigates the development direction of signal equipment at the hereafter car. Currently it researches the signal equipment of top of head of a family enemy conditions grudge. Also, It was improved the scope of application function in following and it considered it researched the quality thing and the signal equipment at the car.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.4
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• pp.1-6
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• 2010

In this paper, we present a new delay-dependent and parameter-dependent robust stability condition for uncertain singular systems with polytopic parameter uncertainties and time-varying delay. The robust stability criterions based on parameter-dependent Lyapunov function are expressed as LMI (linear matrix inequality). Moreover, the proposed robust stability condition is a general algorithm for both singular systems and non-singular systems. Finally, numerical examples are presented to illustrate the feasibility and less conservativeness of the proposed method.

• Journal of Families and Better Life
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• v.17 no.4
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• pp.173-192
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• 1999

The differences of coping behaviors of professional and non-professional working mothers were assessed using data(n=704) from the working mothers with children under age 18. Professional working mothers' individual characters family and occupational conditions are more suitable than non-professionals for the coping behaviors. And such individual and situational aspects may relate to the differences of coping behaviors of he two groups. In general professional working mothers use coping behaviors more except the 'role reducation' and 'taking the support of fiends & neighbor' On the other hand the conservativeness and passive attitude in role strain coping is the same aspect of the two groups. Finally the relation of individual character family and occupational condition of working mothers to their coping behavios are slightly different in this two working mothers groups.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.71-78
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• 2003

In this study, the impact analysis for the steel fender system that designed for protection of collision between vessel and bridge was peformed. The size of objective collision vessel assumed as 3000 dead weight tonnage(DWT). The impact forces and the impact energies were estimated by formulas of several design codes, and the steel fender system was designed based on the estimated forces and energy. The bow of objective vessel was modeled as rigid body, and bridge substructure was modeled as fixed support. Since, the impact analysis have the dynamic nonlinear features, such as, material nonlinear, large deformation and contact, explicit structural analysis program was used. The analysis results presented that the impact forces formulas in codes have the sufficient conservativeness.

• Computers and Concrete
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• v.24 no.1
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• pp.85-94
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• 2019

The ACI building code is allowing for higher strength reinforcement and concrete compressive strengths. The nominal strength of high-strength concrete columns is over predicted by the current ACI 318 rectangular stress block and is increasingly unconservative as higher strength materials are used. Calibration of a rectangular stress block to address this condition leads to increased computational complexity. A triangular stress block, derived from the general shape of the stress-strain curve for high-strength concrete, provides a superior solution. The nominal flexural and axial strengths of 150 high-strength concrete columns tests are calculated using the proposed stress distribution and compared with the predicted strength using various design codes and proposals of other researchers. The proposed triangular stress model provides similar level of accuracy and conservativeness and is easily incorporated into current codes.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.896-903
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• 2001

This study investigates the use of mixed $H_2/H_{$\infty}$ and $\mu$-synthesis to construct a robust controller for the benchmark problem. The model treated in the problem is a coupled three-inertial system that reflects the dynamics of mechanical vibrations. This kind of problem requires to be satisfied the robust performance (both in the time and frequency-domain specifications). We, first, adopt the mixed $H_2/H_{$\infty}$ theory to design a feedback controller K(s). Next, $\mu$-synthesis method is applied to the overall system to make use of structured parametric uncertainty. This process permits higher levels of controller authority and reduces the conservativeness of the controller. Finally, the feedforward controller is also used to improve the transient response of the output. We confirm that all design specifications except a complementary sensitivity condition can be achieved.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.6
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• pp.918-927
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• 2008

The purpose of this research was to identify the dimensions of modesty and immodesty in dress and to examine the differences in female college students' perceptions, in various cultures, of modest and immodest clothes. The researchers selected South Korea and the United States for the cross-cultural comparison study because these two countries show distinctive cultural characteristics. This study was conducted through both qualitative and quantitative methods. According to the result of the preliminary study, 47 questions were developed. The 4 Likert type scales used in the questionnaire were written in both English and Korean. Pretests were performed simultaneously in both countries. 174 American and 208 Korean students completed the questionnaire. The data were analyzed using SPSS. According to the results of factor analysis, there were 4 factors identified for the modesty-immodesty concept, including 'Conservativeness', 'Body exposure', 'Social appropriateness', and 'Attracting attention from others'. Students answered that they liked to wear conservative and socially appropriate dress in both cultures and that they did not like to wear clothing which draws a great deal of attention to them. Cultural differences were also identified. Based on the results, American students dressed more conservatively than Korean students, while Korean students preferred to wear revealing dress. American students were more conservative and preferred modest clothing. Also Korean students were more open about their body exposure and had immodest clothing attitudes.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.239-245
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• 2010

There are 11,811 LWR spent fuels stored at reactor sites, as of 2009. Source terms based on reference spent fuel which represents entire spent fuels with bounding values in the aspect of source term has been applied to a design of nuclear installations, instead of those which are generated by weighting respective source term for each spent fuel. Simplified regression models to estimate total decay heat, radioactivity, and ingestion hazard index for spent fuel from Westinghouse-type reactors were developed in this study, because it can be used as a fundamental model for weighting source term for respective spent fuel to exclude conservativeness in source terms. It was found that the estimated source terms agreed with calculated value from ORIGEN-ARP within 5%. It was also found that the conservativeness could be excluded if the weight source terms were used as reference source term in the design. Therefore, it is expected that the developed regression model could be widely used in the conceptual design process of nuclear facilities related with storage and disposal of spent nuclear fuel.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.65-72
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• 2001

Generally, it is said that control of the inertia system is to track the reference input quickly while suppressing the vibration due to the system itself. In this case, the difficulty fur designing a controller is caused by modeling uncertainty and parameter variation. The purpose of this paper is to propose a design method to suppress the vibration of three-mass inertia system based on the LMI theory. That is, the generalized plant model by which we can cope with conservativeness of the existing H$_{*}$ theory is proposed and analyzed in terms of LMI. The results of simulation fur the three-mass inertia system show that the proposed design approach is quite effective under the given situations.