• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.117-118
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• 2023

Estimating the construction period at the initial stage of the project and determining whether it is appropriate is very important for the developer's decision-making and the success of the construction company's business. Existing researchers have conducted various studies to calculate the appropriate construction period, but there is no study on the influencing factors and methodology for the construction period of beam-column PC apartment building frame construction. The purpose of this study is to calculate the PC member assembly time using the mathematical algorithm of PC member assembly. The results of this study can be used as basic data to calculate the construction date of the standard floor of PC construction.

• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1277-1287
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• 2009

For stratifying skewed populations, the Lavall$\acute{e}$e-Hidiroglou(LH) algorithm is often considered to have a take-all stratum with the largest units and some take-some strata with the middle-size and small units. Related to its iterative nature have been reported some numerical difficulties such as the dependency of the ultimate stratum boundaries to a choice of initial boundaries and the slow convergence to locally-optimum boundaries. The geometric stratification has been recently proposed to provide initial boundaries that can avoid such numerical difficulties in implementing the LH algorithm. Since the geometric stratification does not pursuit the optimization but the equalization of the stratum CVs, the corresponding stratum boundaries may not be (near) optimal. This paper revisits these issues concerning convergence and near-optimality of optimal stratification algorithms using artificial numerical examples. We also discuss the formation of the strata and the sample allocation under the optimization process and some aspects related to discontinuity arisen from the finiteness of both population and sample as well.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.1
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• pp.19-25
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• 2010

In this paper, digital watermarking method using quad-tree algorithm is proposed. The proposed algorithm searches the significant coefficient of the watermark by using quad-tree algorithm and inserts the watermark by the Cox's algorithm. The simulation for performance analysis of the proposed algorithm is implemented about the effect of quad-tree algorithm in wavelet domain and that of embedding watermark in each subband coefficient (HH, LH, HL) and each DWT level, and that of embedding in the lowest frequency band (LL). As a simulation result, digital watermarking using quad-tree algorithm improves the watermarking performance in comparison with inserting watermark in the significant coefficients of fixed frequency band. The watermarking performance of simultaneously embedding in HH, LH, and HL band of DWT(6 level) is better than that of different cases. In addition, insertion the watermark to the LL band about 30~60% of all watermarks improves the correlation value while PSNR performance decreases 1~3dB.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.254-257
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• 2009

In this paper, we propose a learning-based super-resolution algorithm. In the proposed algorithm, a multi-resolution wavelet approach is adopted to perform the synthesis of local high-frequency features. To obtain a high-resolution image, wavelet coefficients of two dominant LH- and HL-bands are estimated based on wavelet frames. In order to prepare more efficient training sets, the proposed algorithm utilizes the LH-band and transposed HL-band. The training sets are then used for the estimation of wavelet coefficients for both LH- and HL-bands. Using the estimated high frequency bands, a high resolution image is reconstructed via the wavelet transform. Experimental results demonstrate that the proposed scheme can synthesize high-quality images.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.310-319
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• 2010

In this paper, digital watermarking method using wavelet transform and quad-tree algorithm is proposed. The proposed algorithm transforms the input image by DWT(Discrete Wavelet Transform) and AWPT(Adaptive Wavelet Packet Transform), inserts the watermark by quad-tree algorithm and the Cox's algorithm. The simulation for performance analysis of the proposed algorithm is implemented about the effect of embedding watermark in each subband coefficient (HH, LH, HL) of DWT, each DWT level, and each AWPT level. The simulation result by using DWT is compared with that using AWPT in the proposed algorithm. In addition, the effect of embedding watermark in the lowest frequency band (LL) is simulated. As a simulation result using DWT, the watermarking performance of simultaneously embedding in HH, LH, and HL band of DWT(6 level) is better than that of different cases. The result of AWPT(3 level) improves the correlation value compared to that of DWT(3 level). In addition, insertion the watermark to the LL band about 30~60% of all watermarks improves the correlation value while PSNR performance decreases 1~2dB.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.2027-2032
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• 2007

In this paper, digital watermarking method using quad-tree algorithm and the lowest frequency band is proposed. The proposed algorithm searches the coefficient of the watermark by using quad-tree algorithm and inserts the watermark by the Cox's algorithm. The simulation of the proposed algorithm is implemented about the effect of various weight factors in Cox's algorithm, that of embedding watermark in each subband coefficient (HH, LH, HL), and that of embedding in the lowest frequency band (LL). As a simulation result, the bigger weight factors in Cox's algorithm show strong to noise. The watermarking performance of simultaneously embedding in HH, LH, and HL band is better than that of different cases. In addition, insertion the watermark to the LL band about $30{\sim}60%$ of all watermarks improves the watermarking performance in comparison with the case of not using the LL band.

• The Korean Journal of Applied Statistics
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• v.31 no.5
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• pp.621-636
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• 2018

Research on the application of informative sampling technique has been conducted in order to reduce the influence of non-response. Chung and Shin (Korean Journal of Applied Statistics, 30, 993-1004, 2017) showed that the estimation accuracy improved when using exponential response rate information for the parameter estimation if the distribution of errors included in the super population model follows normal distribution. However this method divides the stratum into equally spaced substrata to obtain the sample weight of the informative sampling technique and shows that the accuracy of the estimation improves as the number of substrata increases. In this study, with the given number of total sample size, the optimal substratum boundary points are calculated using equal space, quantile, and LH algorithm; consequently, the results using those methods are compared through simulation. We also studied the criteria to determine the number of substrata and substratum boundaries that can be used in practice with various types of auxiliary variable distributions.

• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.85-94
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• 2009

This paper investigates the intonation patterns of Korean spontaneous speech through an analysis of four dialogues in the domain of travel planning. The speech corpus, which is a subset of spontaneous speech database recorded and distributed by ETRI, is labeled in APs and IPs based on K-ToBI system using Momel, an intonation stylization algorithm. It was found that unlike in English, a significant number of APs and IPs include hesitation lengthening, which is known to be a disfluency phenomenon due to speech planning. This paper also claims that the hesitation lengthening is different from the IP-final lengthening and that it should be categorized as a new category, as it greatly affects the intonation patterns of the language. Except for the fact that 19.09% of APs show hesitation lengthening, the spontaneous speech shows the same AP patterns as in read speech with higher frequency of falling patterns such as LHL in comparison with read speech which show more LH and LHLH patterns. The IP boundary tones of spontaneous speech, showing the same five patterns such as L%, HL%, LHL%, H%, LH% as in read speech, show higher frequency of rising patterns (H% and LH%) and contour tones (HL%, LH%, LHL%) while read speech on the contrary shows higher frequency of falling patterns and simple tones at the end of IPs.

• Journal of the Korea Computer Industry Society
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• v.3 no.7
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• pp.871-880
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• 2002

In this paper, I proposed the adaptive watermarking based on the discrete wavelet transform for the very robust watermarking against intentional distortion which attacks on image. A watermark is an binary image such as document(sign), and such watermark image is embedded in the LH and HL band of wavelet transformed domain for copyright protection of image data. To evaluate robustness of the proposed method, we applied some basic algorithm of image processing such as brightening, darkening, sharpening, blurring, cropping, histogram equalizing and lossy compression(JPEG, gif). As a result of experiment, the proposed method has the good image quality and the high perceptibility of watermark. It was demonstrated by experiments that the proposed algorithm can provide an excellent protection under various attacks.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.214-217
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• 2003

In this paper, we proposed an efficient blind watermarking algorithm using wavelet transform. The proposed algorithm inserts watermark into the high frequency subbands that were transformed by 1-level wavelet transform of original image. Watermark insertion is achieved by exchanging each the corresponding coefficients in the HL, LH, HH subbands according to be inserted watermark value. And watermark is extracted by the relation of wavelet coefficients without original image. Experimental results demonstrate that watermarked image has a good quality not to be able to be perceptible and is robust various attacks such as JEPG lossy compression, clipping and sharpening.