• The Mathematical Education
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• v.39 no.2
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• pp.167-177
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• 2000

In this thesis we concerned with the degree of similarity in pairs of scores having a common mean and variance could express similarity in terms of the absolute difference between the standardized scores. We particulary discussed the distribution of absolute differences between pairs of T scores among many standardized scores and demonstrated the procedures for calculating the lower limit of Med(│d│) values i. e. the maximum possible similarity with medians and correlation coefficients of the equivalent form tests by using the folded normal distribution, although other researchers expressed the degree of similarity using only the standard normal distribution. We also described many cases how to use those techniques and to apply effectively them in real evaluation fields.

• Advances in Traditional Medicine
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• v.7 no.2
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• pp.171-181
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• 2007

Metal binding activity of the pectin samples with different physicochemical properties was studied. It was found that in vitro copper binding capacity of pectins is depending on the following factors: degree of esterification, content of non-methylated anhydrogalacturonic acid, and pH of solution. There was found that the maximum copper uptake capacity increases correspondingly to reduction of the degree of esterification of pectin, rise of the non-methylated anhydrogalacturnic acid content and the solution pH. It is proposed to use for standardization of pectin samples such parameters as the degree of esterification, content of anhydrogalacturonic acid, and intrinsic viscosity.

• Journal of Korean Academy of Nursing
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• v.15 no.3
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• pp.39-49
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• 1985

The study was carried out to measure the degree of work stress among clinical nurses, and to identify factors influencing the work stress. Data was collected from 215 staff nurses working in the Seoul National University Hospital from the end of February to first of march, 1984. The results and suggestion of study were: 1. Nurses perception of work stress. 1) Mean score of total work stress of nurses was 4.467, when maximum score was 6. High degree of work stress is evident among nurses. 2) The highest rank of stress factor was inter-personal relationship with physicians, night duty, heavy work load, inadequate working condition and payment were other stress factors. 2. Relationships between situational variables and degree of stress. There was significant correlation-ship between nurse's total work stress score and educational levels (r=0.153, p=0.032).

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.415-419
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• 2000

Multi-degree-of-freedom (MDOF) displacement measurement Is needed In many application fields: precision machine control, precision assembly, vibration analysis, and so on. This paper presents a new MDOF displacement measurement method using a laser diode (LD), two position-sensitive detectors (PSDs), and a conventional diffraction grating. It utilizes typical features of a diffraction grating to obtain the information of MDOF displacement. MDOF displacement is calculated from the independent coordinate values of the diffracted ray spots on the PSDs. Forward and inverse kinematic problems were solved to compute the MDOF displacement of a rigid body. Experimental results show maximum absolute errors of less than ${\pm}10$ micrometers in translation and ${\pm}30$ arcsecs in rotation.

• Journal of applied mathematics & informatics
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• v.26 no.5_6
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• pp.851-860
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• 2008

A countable locally finite triangulation is a strong triangulation if a representation of the graph contains no vertex- or edge-accumulation points. In this paper we exhibit the structure of an infinite strong triangulation and prove the existence of connected spanning subgraph with maximum degree 4 in such a graph

• Journal of the Korean Solar Energy Society
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• v.27 no.3
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• pp.1-6
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• 2007

In this study, we analyze the maximum power generation of photovoltaic(PV) module depending on constituent materials and incidence angle dependence of light. To verify characteristics of constituent materials, we made photovoltaic modules with 4 kinds of solar cells and textured glass according to fabrication method. To find the degree of the maximum power generation dependence on intensity of light, Solar Simulator is applied by changing angle of module and light intensity. Through this experiment, to obtain maximum power generation from limited PV modules, it is needed to fully understand constituent materials, fabrication method and dependence of incident light characteristics.

• Earthquakes and Structures
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• v.22 no.6
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• pp.571-584
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• 2022

The residual displacement ratio (RDRs) response spectra have been generally used as an important means to evaluate the post-earthquake repairability, and the ratios of residual to maximum inelastic displacement are considered to be more appropriate for development of the spectra. This methodology, however, assumes that the expected residual displacement can be computed as the product of the RDRs and maximum inelastic displacement, without considering the correlation between these two variables, which inevitably introduces potential systematic error. For providing an adequately accurate estimate of residual displacement, while accounting for the collapse resistance performance prior to the repairability evaluation, a probability-based procedure to estimate the residual displacement demands using the nonlinear static analysis (NSA) is developed for single-degree-of-freedom (SDOF) systems. To this end, the energy-based equivalent damping ratio used for NSA is revised to obtain the maximum displacement coincident with the nonlinear time history analysis (NTHA) results in the mean sense. Then, the possible systematic error resulted from RDRs spectra methodology is examined based on the NTHA results of SDOF systems. Finally, the statistical relation between the residual displacement and the NSA-based maximum displacement is established. The results indicate that the energy-based equivalent damping ratio will underestimate the damping for short period ranges, and overestimate the damping for longer period ranges. The RDRs spectra methodology generally leads to the results being non-conservative, depending on post-yield stiffness. The proposed approach emphasizes that the repairability evaluation should be based on the premise of no collapse, which matches with the current performance-based seismic assessment procedure.

• Journal of the Korea Society for Simulation
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• v.8 no.4
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• pp.25-31
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• 1999

To analyze the impulsive response of a motorcycle helmet, a simulation is performed using the finite element method. Based upon the simulation result, an equivalent one degree of freedom vibrational system is adapted, and transient impulsive responses are analysed to investigate the influence of engineering parameters such as damping, natural frequency, and impact velocity on the impulsive response of the helmet. Maximum gravitational acceleration reduces as the damping factor value increases. When the damping factor value is around 0.6 or larger, the maximum acceleration does not change. With respect to the natural frequency and the impact velocity, it increases linearly. The relationship between head injury criterion(HIC) and maximum gravitational acceleration is also presented. The scheme of this study is expected to be utilized to economize the design process of high quality motorcycle helmets.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.38-44
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• 1998

The modified maximum likelihood estimation method is used to estimate the nondimensional aerodynamic derivatives of a single turbo-prop aircraft at a specified flight condition for the best deduction of the dynamic characteristics. In wind axes the six degree of freedom equations are algebraically linearized so that the linear state equation contains aerodynamic derivatives in a state-space form and is used in the maximum likelihood method. The simulated data added with the measurement noise is used as a flight test data which is necessary to the estimation of nondimensional aerodynamic derivatives. It is obtained by implementing the 6-DOF nonlinear flight simulation. In the flight simulation, the effects of several control input types, control deflection amplitudes, and the turbulence intensities on the statistical convergence criteria are also examined and quantitative analysis of the results is discussed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.181-192
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• 1995

In this study, we introduce new types of planar 2 degree-of-freedom robot modules resembling the musculoskeletal structure of the human arm with actuation redundancy. First, for the given actuator sizes the performance analysis for the manipulator with redundant actuation and without redundant actuation is performed with respect to maximum load handling capacity, maximum hand velocity, and maximum hand acceleration. Secondly an algorithm which decides optimal actuator sizes for the given operational performances is introduced, and the optimal actuator sizes for a robot module with four redundant actuation are obtained. The algorithms employed in this paper will be useful to analyze the robot performances and to determine the actuator sizes for general robot manipulators.