• Journal of Korean Ophthalmic Optics Society
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• v.10 no.4
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• pp.255-259
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• 2005

When we wear contact lenses for correcting astigmatism, we often experience the axis-rotation of contact lenses that is happened in case we could not fit the axis of lens exactly or by the eyelid used to blink. In this case, because the exact correcting state becomes in the wrongly correcting state, the asthenopia is led, and the decline of eyesight can be led. For this reason, we need to know axis-rotating degrees of contact lenses. If a contact lens rotated, a residual astigmatism may be detected in the refraction examination after wearing. Using this, we developed a program that calculates the axis-rotating amount of contact lenses.

• Journal of Welding and Joining
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• v.27 no.3
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• pp.60-66
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• 2009

The structures distorted by welding have to be corrected. Since the correcting work needs a lot of costs and time, it is very important to minimize the buckling distortion due to welding of thin plate structure. Therefore the aim of this study is to investigate the effect of single bead on plate welding and fillet welding on the buckling distortion. In the single bead on plate welding, it was found that the welding speed and welding sequence were the most dominant factors on distortion. In the fillet welding, there were four typical buckling modes observed, and the welding sequence was the most influential factor on the buckling distortion. However typical distortion measuring method is not considered for the distortion correcting process costs of each buckling modes, therefore, in this study, the measuring method is developed to classify the buckling modes for torsion of specimen and buckling distortion depend on nodal point for the bead on plate welding specimen and fillet welds.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.173-174
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• 2009

With the recent emergence of high rise buildings, this study was conducted in order to examine shortening, which has been used only in civil engineering structures, in such buildings. Examination of the shortening of vertical members is basically focused on deformations caused by load applied to concrete, material characteristics, etc. Shortening is analyzed through calculating parameters from the factors or characteristics of concrete, but analysis in the aspect of material tests has been somewhat unsatisfactory. Thus, this study purposed to analyze basic material test items for correcting the shortening of vertical members, namely, columns, to determine the reliability of material tests before parameter calculation for correcting shortening, and to examine the performance of material tests.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1626-1634
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• 1993

In this paper we propose a coding scheme which combines source codes and error correcting codes in order to be robus to channel noise. One of the coding schemes that take into account both the source and the channel is the channel optimized quantizer (COQ) which simultaneously minimizes quantization noise and the noise due to channel errors. This paper deals with the problem of combining channel optimized quantizers with ECC to build an improved system. To be specific, we computed the performance of an n bit COQ and that of an n-1 bit COQ followed by an (n-1)/n punctured convolutional code. From this result whether or not the ECC are selected is determined by the number of allocated bits and the channel bit error rate. These results are applied to the image trans-mission method using DCT, and the system performances are evaluated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3438-3454
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• 2018

In this paper, we propose a robust blind watermarking scheme for high-definition video. In the embedding process, luminance component of each frame is transformed by 2-dimensional fast Fourier transform (2D FFT). A secret key is used to generate a matrix of random numbers for the security of watermark information. The matrix is transformed by inverse steerable pyramid transform (SPT). We embed the watermark into the low and mid-frequency of 2D FFT coefficients with the transformed matrix. In the extraction process, the 2D FFT coefficients of each frame and the transformed matrix are transformed by SPT respectively, to produce two oriented sub-bands. We extract the watermark from each frame by cross-correlating two oriented sub-bands. If a video is degraded by some attacks, the watermarks of frames contain some errors. Thus, we use an ensemble position-based error correcting algorithm to estimate the errors and correct them. The experimental results show that the proposed watermarking algorithm is imperceptible and moreover is robust against various attacks. After embedding 64 bits of watermark into each frame, the average peak signal-to-noise ratio between original frames and embedded frames is 45.7 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1966-1973
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• 1999

In this paper, we introduce the concept of a HAPS(High Altitude Platform Station) system which is expected to be a next generation communication system and suggest several error correcting codes to provide high quality services. Since a HAPS system encounters serious signal attenuation due to rain and scattering in the air, concatenated codes which have a high coding gain is considered to be a proper error correcting method. In this paper, we provide performance analyses result of two candidate coding schemes for a HAPS. The first one is a conventional concatenated coding scheme, and the second one is a iterative decoding method known as Turbo Codes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.3
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• pp.323-330
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• 2009

The demand that we are monitoring security and crime of the urban facilities is increasing recently, but the using CCTV devices are expensive. In this research, we enlarge the angle of view using the Fish-eye Lens and the Photogrammetry, the efficiency of monitoring enhance. First, we carry out the calibration of the Fish-eye Lens indoors, we calculate the correction parameters, and then covert the original image-point to new image-point correcting distortion. Second, the correction program with the correction parameters can obtain the real-time correcting image. Lastly, for authorization the developed program we compare correcting-image with scanning-imge, it is showed the RMSE is 3.2pixel.

• Science of Emotion and Sensibility
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• v.4 no.2
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• pp.63-68
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• 2001

We purpose to evaluate the fatigue of the error correcting task on monitoring with color temperature 2700 K, 4000 K and 6500 K. Results of questionnaire on subjective feeling of visual fatigue, mental fatigue and concentration. Visual fatigue and mental fatigue level were the lowest, concentration level was the highest and working performance was the best at 2700 K. At 6500 K, mental fatigue level was the highest and concentration level is the lowest. At 4000 K, visual fatigue level was the highest and working performance shown the worst ratio of correcting answers. As results, color temperature 2700 K is the best condition of color temperature to perform the error correcting task on monitoring.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.2
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• pp.180-184
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• 2009

The memory is very sensitive to the soft error because the integration of the memory increases under low power environment. Error correcting codes (ECCs) are commonly used to protect against the soft errors. This paper proposes a new genetic ECC design method which reduces power consumption. Power is minimized using the degrees of freedom in selecting the parity check matrix of the ECCs. Therefore, the genetic algorithm which has the novel genetic operators tailored for this formulation is employed to solve the non-linear power optimization problem. Experiments are performed with Hamming code and Hsiao code to illustrate the performance of the proposed method.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.227-235
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• 2013

The quality of the part-of-speech (POS) annotation in a corpus plays an important role in developing POS taggers. There, however, are several kinds of errors in Korean POS-tagged corpora like Sejong Corpus. Such errors are likely to be various like annotation errors, spelling errors, insertion and/or deletion of unexpected characters. In this paper, we propose a method for detecting annotation errors using error patterns, and also develop a tool for effectively correcting them. Overall, based on the proposed method, we have hand-corrected annotation errors in Sejong POS Tagged Corpus using the developed tool. As the result, it is faster at least 9 times when compared without using any tools. Therefore we have observed that the proposed method is effective for correcting annotation errors in POS-tagged corpus.