• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.8
• /
• pp.60-67
• /
• 1996

In this paper, we propose a new temporal interpolation method based on spatial filtering. Compared with the conventional method, the proposed one may use a few adjacent frames and apply temporal lowpass filtering. To develop this method, we follow the basic approach of sampling rate conversion. Additionally, we use some assumption of video sequence : moving object has constant velocity rigid translational motion. From them, spatial filtering for temporal sampling rate conversion is described. This method has a lot of noise immunity on a motion vector and doesn't make a great difference from the original frame. The interpolated frame shows moderate change even there is a great time difference. This method has exactly same description of motion adaptive spatial filter which has an efficient temporal band-limiting characteristics. It imposes the possibility to make video sequence with good pictural quality.

• Spatial Information Research
• /
• v.22 no.2
• /
• pp.45-52
• /
• 2014

In recent years, The importance of the river pollution management has increased and central and local governments are making constant effort to work out river pollution problems. Accordingly, this paper is to take a closer look at applications of spatial data and river pollution information(aerial photograph, parcel information, pollution source, GPS data et al.). More exactly, the purpose of the present paper is to offer an applications of spatial information for development of the river pollution management system. In order to provide a framework for more detailed consideration of the quantitative analysis of river pollution source and management plan by apply GPS and GIS. For that reason, this paper was to build pollution management system of river by spatial analysis. It is to be hoped that this paper will contribute to establish the management policy for urban stream pollution source preservation.

• The Journal of the Korea Contents Association
• /
• v.17 no.5
• /
• pp.90-99
• /
• 2017

Sports climbing requires repeated movements within a limited space, which may cause climbers to lose their constant interest in it. Furthermore, it is important that coaches should give lessons focusing on demonstrations to make sure that learners can understand the movements on their own, However, in traditional sports climbing lessons, they give instructions on almost every movement of learners' hands and feet. Hence, there have been constant calls for replacing these existing sports climbing lessons and presenting new methods to ensure that learners can observe their coaches' demonstrations in real time and emulate them. An introduction of the image training using spatial augmented reality techniques to solve these problems may have a positive effect on the improvement of learners' motor skills and attitudes toward lessons. This study aims to verify the effectiveness of the Climbing Character Animation (CCA) as a learning tool for sports climbing. To achieve this research objective, it applied it to actual sports climbing to verify its utility. As a result, it was shown that the lessons using spatial augmented reality-based CCA had a higher effectiveness than traditional sports climbing lessons in the degree of interest inducement, emersion and learning effects.

• Journal of Korean Association for Spatial Structures
• /
• v.20 no.4
• /
• pp.149-158
• /
• 2020

The governing equation for a dome-type shallow spatial truss subjected to a transverse load is expressed in the form of the Duffing equation, and it can be derived by considering geometrical non-linearity. When this model under constant load exceeds the critical level, unstable behavior is appeared. This phenomenon changes sensitively as the number of free-nodes increases or depends on the imperfection of the system. When the load is a periodic function, more complex behavior and low critical levels can be expected. Thus, the dynamic unstable behavior and the change in the critical point of the 3-free-nodes space truss system were analyzed in this work. The 4-th order Runge-Kutta method was used in the system analysis, while the change in the frequency domain was analyzed through FFT. The sinusoidal wave and the beating wave were utilized as the periodic load function. This unstable situation was observed by the case when all nodes had same load vector as well as by the case that the load vector had slight difference. The results showed the critical buckling level of the periodic load was lower than that of the constant load. The value is greatly influenced by the period of the load, while a lower critical point was observed when it was closer to the natural frequency in the case of a linear system. The beating wave, which is attributed to the interference of the two frequencies, exhibits slightly more behavior than the sinusoidal wave. And the changing of critical level could be observed even with slight changes in the load vector.

• Journal for History of Mathematics
• /
• v.13 no.2
• /
• pp.87-94
• /
• 2000

This paper investigates history and modern developments concerning spatial decay estimates for solutions in a semi-infinite cylinder or strip, in which model equations are defined with appropriate homogeneous lateral boundary conditions and initial conditions but left end boundary data are assumed. Our aim is to show this Saint-Venant type decay rate dependent critically on the Poincare constant resulting from characterizing variational principles.

• Environmental Engineering Research
• /
• v.23 no.1
• /
• pp.76-83
• /
• 2018

Spatial moment analysis has been performed on the concentration of the first species in a multispecies solute transport in porous media. Finite difference numerical technique was used in obtaining the solute concentration. A constant continuous source of contaminant was injected at the inlet of the domain. Results suggest that the decaying of solute mass increases as the magnitude of mean fluid velocity increases. The dispersion coefficient is highly time dependent under decaying of solutes with a complex behavior of mixing of solutes. The solute mobility and mixing varies non-linearly with time during its initial period, while the same ceases with higher decay rates of the first species much faster.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.721-725
• /
• 2004

Multiple-count problem is occurred when rectangle objects span across several buckets. The Cumulative Density (CD) histogram is a technique which solves multiple-count problem by keeping four sub-histograms corresponding to the four points of rectangle. Although it provides exact results with constant response time, there is still a considerable issue. Since it is based on a query window which aligns with a given grid, a number of errors may be occurred when it is applied to real applications. In this paper, we proposed selectivity estimation techniques using the generalized cumulative density histogram based on two probabilistic models: (1) probabilistic model which considers the query window area ratio, (2) probabilistic model which considers intersection area between a given grid and objects. In order to evaluate the proposed methods, we experimented with real dataset and experimental results showed that the proposed technique was superior to the existing selectivity estimation techniques. The proposed techniques can be used to accurately quantify the selectivity of the spatial range query on rectangle objects.

• Journal of Mechanical Science and Technology
• /
• v.14 no.10
• /
• pp.1041-1050
• /
• 2000

In this paper the effect of specimen thickness on fatigue crack growth with the spatial distribution of material properties is presented. Basically, the material resistance to fatigue crack growth is treated as a spatial stochastic process, which varies randomly on the crack surface. The theoretical autocorrelation functions of fatigue crack growth resistance with specimen thickness are discussed for several correlation lengths. Constant ${\Delta}K$ fatigue crack growth tests were also performed on CT type specimens with three different thicknesses of BS 4360 steel. Applying the proposed stochastic model and statistical analysis procedure, the experimental data were analyzed for different specimen thicknesses for determining the autocorrelation functions and probability distributions of the fatigue crack growth resistance.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.2
• /
• pp.81-90
• /
• 2017

This study aimed to construct an integrated database using the same spatio-temporal unit by employing various public-data types with different real-time information provision cycles and spatial units. Towards this end, three temporal interpolation methods (piecewise constant interpolation, linear interpolation, nonlinear interpolation) and a spatial matching method by district boundaries was proposed. The case study revealed that the linear interpolation is an excellent method, and the spatial matching method also showed good results. It is hoped that various prediction models and data analysis methods will be developed in the future using different types of data in the analysis database.

• Korean Journal of Remote Sensing
• /
• v.22 no.5
• /
• pp.451-456
• /
• 2006

Epipolar images have to be generated to stereo display aerial images or satellite images. Pushbroom sensor is used to acquire high resolution satellite images. These satellite images have curvilinear epipolar lines unlike the epipolar lines of frame images, which are straight lines. The aforementioned fact makes it difficult to generate epipolar images for pushbroom satellite images. If we assume a linear transition of the sensor having constant speed and attitude during image acquisition, we can generate epipolar images based on parallel projection model (20 Affine model). Recent high resolution images are provided with RPC values so that we can exploit these values to generate epipolar images without using ground control points and tie point. This paper provides a procedure based on the parallel projection model for generating epipolar images directly from a stereo IKONOS images, and experimental results.