• The KIPS Transactions:PartB
• /
• v.12B no.4 s.100
• /
• pp.429-436
• /
• 2005

A simple stereo matching algorithm using population-based incremental learning(PBIL) is proposed in this paper to decrease the general problem of genetic algorithms, such as memory consumption and inefficiency of search. PBIL is a variation of genetic algorithms using stochastic search and competitive teaming based on a probability vector. The structure of PBIL is simpler than that of other genetic algorithm families, such as serial and parallel ones, due to the use of a probability vector. The PBIL strategy is simplified and adapted for stereo matching circumstances. Thus, gene pool, chromosome crossover, and gene mutation we removed, while the evolution rule, that fitter chromosomes should have higher survival probabilities, is preserved. As a result, memory space is decreased, matching rules are simplified and computation cost is reduced. In addition, a scheme controlling the distance of neighbors for disparity smoothness is inserted to obtain a wide-area consistency of disparities, like a result of coarse-to-fine matchers. Because of this scheme, the proposed algorithm can produce a stable disparity map with a small fixed-size window. Finally, an alterative version of the proposed algorithm without using probability vector is also presented for simpler set-ups.

• Communications for Statistical Applications and Methods
• /
• v.5 no.2
• /
• pp.517-529
• /
• 1998

When the sample size is small the robust minimum Hellinger distance (HD) estimator can have substantially poor relative efficiency at the true model. Similarly, approximating the exact null distributions of the ordinary Hellinger distance tests with the limiting chi-square distributions can be quite inappropriate in small samples. To overcome these problems Harris and Basu (1994) and Basu et at. (1996) recommended using a modified HD called penalized Hellinger distance (PHD). Lindsay (1994) and Basu et al. (1997) showed that another density based distance, namely the negative exponential disparity (NED), is a major competitor to the Hellinger distance in producing an asymptotically fully efficient and robust estimator. In this paper we investigate the small sample performance of the estimates and tests based on the NED and penalized NED (PNED). Our results indicate that, in the settings considered here, the NED, unlike the HD, produces estimators that perform very well in small samples and penalizing the NED does not help. However, in testing of hypotheses, the deviance test based on a PNED appears to achieve the best small-sample level compared to tests based on the NED, HD and PHD.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.10
• /
• pp.1829-1834
• /
• 2006

In this raper in order to recover sharp object boundaries we propose a new efficient stereo matching algorithm in which window size is varied to the distance from the boundaries of object. To this end, the processing region is divided into small subregions with a same area and the disparities of the center pixels in the subregions are calculated using a area-based algorithm with multiple windows. From the this disparity map we can find the edges of the contracted objects. The disparities of original image are obtained using the gradient constraint that means the disparity of the center pixel is similar to the ones of the remaining pixels in the subregion. from the experimental results it is found that the proposed algorithm is very good for recovering sharp object boundaries compared to the similar different algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.7
• /
• pp.2464-2479
• /
• 2014

Multi-view video coding is an international encoding standard that attains good performance by fully utilizing temporal and inter-view correlations. However, it suffers from high computational complexity. This paper presents a fast encoder design to reduce the level of complexity. First, when the temporal correlation of a group of pictures is sufficiently strong, macroblock-based inter-view prediction is not employed for the non-anchor pictures of B-views. Second, when the disparity between two adjacent views is above some threshold, frame-based inter-view prediction is disabled. Third, inter-view prediction is not performed on boundary macroblocks in the auxiliary views, because the references for these blocks may not exist in neighboring views. Fourth, finer partitions of inter-view prediction are cancelled for macroblocks in static image areas. Finally, when estimating the disparity of a macroblock, the search range is adjusted according to the mode size distribution of the neighboring view. Compared with reference software, these techniques produce an average time reduction of 83.65%, while the bit-rate increase and peak signal-to-noise ratio loss are less than 0.54% and 0.05dB, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.3
• /
• pp.251-258
• /
• 2011

To investigate whether the rearing environmental factors (size heterogeneity, rearing density, and feeding frequency) affect the growth and cannibalism of fry in cultured puffer Takifugu obscurus, we conducted three experiments. To examine size effects, we used small (total length [TL] $26.0{\pm}0.5\;mm$, body weight [BW] $0.18{\pm}0.01\;g$), medium (TL $23.1{\pm}0.1\;mm$, BW $0.28{\pm}0.01\;g$), large (TL $26.0{\pm}0.2\;mm$, BW $0.48{\pm}0.01\;g$) and small-large size combination groups. For density, we used size-matched puffers (TL $25.0{\pm}0.5\;mm$, BW $0.53{\pm}0.03\;g$) and five density were examined ranging from 1.43 to 7.14 individuals/L. For the feeding frequency, we also used size-matched fry and feeding frequencies of three times/2 days, one time/day, two times/day, three times/day. We ran each experiment in triplicate and investigated the survival rate, daily food intake (DFI), feed efficiency (FE), and daily growth rate (DGR). The growth of the puffers increased with increasing size, density, and feeding frequency, while cannibalism increased with a greater size gap, density and lower feeding frequency. Therefore, we concluded that size, rearing density, and feeding frequency are major factors influencing growth and cannibalism of the puffer, T. obscurus.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.23 no.8
• /
• pp.1149-1160
• /
• 1999

In order to investigate the influence of being self-consciousness of one's body size on clothing behavior we measured body size of Korean female college students directly and examined by questionnaire the degree of being self-conciousness of their body size the aspired clothing behavior and the actual clothing behavior. In addition after classifying the subjects into groups according to the degree of obesity we also examined the difference in the actual clothing behavior among the groups./ The results are as follows: 1) On the item of girth of the body parts the subjects felt thicker in the proximal and lower part of the body than in the distal and upper part of the body. And with respect to the style which exposes body silhouette the disparity between the aspired and actual clothing behavior was greater in the parts that the subjects felt thick. 2) After investigating the relationship between the aspired and the actual clothing behavior we found out that the style which subjects wanted to put on but actually did not was the style that exposes body silhouette and the style which subjects didn't want to put on but actually did was the style covers the body silhouette. 3) There was significant correlation between the subjects' consciousness of their body size and their actual clothing behavior. The self-consciousness of body size on actual dressing tend to influence the clothing for lower body more than the other parts. 4) The subjects were classified into lean normal and obese groups. There were significant differences among the groups in the frequency of wearing the clothing that expose body silhouette. The obese group had a tendency to avoid this clothing style.

• Korean Chemical Engineering Research
• /
• v.47 no.2
• /
• pp.179-184
• /
• 2009

Recent evolution of computer technology enhances the effectiveness of CFD(Computational Fluid Dynamics) analysis for the 3-dimensional complex transport phenomena including turbulent flows. Cheaper and easier than laser and ultra-sonic methods, the windows simulator name by CAMSI(Computer-Aided Management of Stereo Images) has been developed in order to implement the 3-dimensional image using a disparity histogram extracted from left and right stereo images. In our program using the area-based method, the matching pixel finding methods consist of SSD(Sum of Squared Distance), SAD(Sum of Absolute Distance), NCC(Normalized Correlation Coefficient) and MPC(Matching Pixel Count). On performing the program, stereo images on different window sizes for various matching pixel finding methods are compared reasonably. When the image has a small noise, SSD on small window size is more effective. Whereas there is much noise, NCC or MPC is more effective than SSD. CAMSI from the present study will be much helpful to implement the complex objects and to analyze 3-dimensional CFD around them.

• Proceedings of the IEEK Conference
• /
• 2000.06d
• /
• pp.210-213
• /
• 2000

In the closed range space, the parallel two CCD cameras are used to acquire a pair of stereo image. The acquired stereo image are computed with Wavelet Transform repeatedly and including the low frequency component, the image size of those are reduced. It is the pyramid structure. The optimum matching point is searched to the pixel. Then appling the optimum matching point to DLT, it extract the three - dimensional surface coordinate from a stereo image. The direct linear transformation(DLT) method is used to calibrate the stereo camera compute the coordinate on a three dimensional space. To find the parameters for the DLT method, 30 control points which marked on the cylinder type object are used. To improve the matching algorithm, the paper select the pyramid structure for Wavelet Transform. The acquired disparity information is used to represent the really three-dimensional surface coordinate.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.2
• /
• pp.126-136
• /
• 1998

One of the central problems in sereo matching is the selectionof the optimal window sizes for comparing image regions. The window size must be large enough to include enough variation for reliable matching, but small enough to avoid the effect of projection distortion. This paper discusses these problems with some novel algorithm based on iterativediffusion process at different disparity hypotheses. Also this paper proposes four kinds of diffusion algorithms to preseve discontinuity in stereo matching. We present and discuss extensive empirical results of algorithms based on various sets of synthetic and real image.

• Korean Journal of Agricultural Science
• /
• v.32 no.2
• /
• pp.169-179
• /
• 2005

이 연구는 근래 한국 농가계층간에 경쟁력 수준의 격차가 확대되는 원인을 생산기술효율 측면에서 계측하고 비교분석하는 것을 목적으로 한다. 비모수적 접근방법을 사용하여 농지규모계층별 농가의 생산기술효율을 측정하고, 이는 다시 순수기술효율과 규모효율로 분리 계측되어 농가계층간 격차의 원인을 비교분석하였다. 1998-2002년 기간에 한국농가평균 순수기술효율은 0.54, 규모효율은 0.93으로 계측되었고, 대농층으로 갈수록 순수기술효율은 높은데 비해 규모효율은 낮게 나타났다. 그러나 5년(1998-2002년)기간 동안 대농층일수록 순수기술효율과 규모효율 모두 여타의 계층보다 빠르게 증가하는 추세를 보였으며, 이는 결과적으로 시간이 경과함에 따라서 대농층과 여타농과의 기술의 격차가 확대되고 있는 것으로 해석된다.