• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.155-160
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• 2000

In this paper, we investigated quality properties for the expansive of the CaO-$CaSO_4$ family which used to compensate dry-shrinkage in the floor mortar of On-Dol heating System. This experimental study established the mix condition with quantity of the expansive and is to investigate the relativity between the compress strength and the length change and the relativity between the chemical properties and the length change with the analysis of the physical and chemical properties. As a result of the study, the expansive is controlled by more the CaO than the $CaSO_4$. The relativity between the compress strength and the length change is expressed by exponential function, showing that if the expansive performance is increased, the compress strength is decreased. And the relativity between the chemical properties and the length change is only relative the quantity of the F-CaO among the chemical properties, is expressed by the second order function, showing that if the F-CaO is increased, the expansive performance is increased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6810-6814
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• 2014

The concept of IFS (Iterated Function System) was applied to compress and transmit image data efficiently. To compress the image data with IFS, self-similarity was used to search a similar block. To improve the coding performance for the iterated function system with natural images, the image will be formed of properly transformed parts of itself to minimize the coding error. The simulation results using the proposed IFS represent high PSNR performance and improved compression efficiency with the coefficient of a recursive function.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.902-908
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• 2013

This paper suggests to compress data selectively for improvement of data compression efficiency, not to perform unconditional compression on data. Whether to compress or not is determined by selective data distinction. By doing so, we can avoid unnecessary compression in the case of low compression efficiency. Cutting down the unnecessary compression, we can improve the performance of the pre-compression algorithm. Especially, the data algorithm which was already compressed could not be compressed efficiently in many cases, even if apply compression algorithm again. Even in these cases, we don't have to compress data unnecessarily. We implemented the proposed function actually and performed experiments with implementation. The experimental results showed normal operation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.2949-2963
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• 2019

A novel distributed compress-and-forward (CF) system based on multi-relay network is presented. In this system, as the direct link between the source and destination is invalid due to some reasons, such as the limited power, special working environment, or even economic factors, relays are employed to receive analog signals and carry on distributed compressed encoding. Subsequently, the digital signals are transmitted to the destination via wireless channel. Moreover, a theoretical analysis for the system is provided by utilizing the Chief Executive Officer (CEO) theory and Shannon channel capacity theory, and the rate-distortion function as well as the connection between the transmission rate and the channel capacity are constructed. In addition, an optimal signal-to-noise ratio (SNR) -based power allocation method is proposed to maximize the quantization SNR under the limited total power. Simulation result shows that the proposed CF system outperforms the amplify-and-forward (AF) system versus the SNR performance.

• ETRI Journal
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• v.33 no.4
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• pp.652-655
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• 2011

In this letter, we propose a new compression method for a high dimensional support vector machine (SVM). We used singular value decomposition (SVD) to compress the norm part of a radial basis function SVM. By deleting the least significant vectors that are extracted from the decomposition, we can compress each vector with minimized energy loss. We select the compressed vector dimension according to the predefined threshold which can limit the energy loss to design criteria. We verified the proposed vector compressed SVM (VCSVM) for conventional datasets. Experimental results show that VCSVM can reduce computational complexity and memory by more than 40% without reduction in accuracy when classifying a 20,958 dimension dataset.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.2
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• pp.97-122
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• 2011

Fluid dynamics driven by pumping without valves (valveless pumping) shows interesting physics. Especially, the driving function to generate valveless pump mechanism is one of important factors. We consider a closed system of valveless pump which consists of flexible tube part and stiffer part. Fluid and structure (elastic tube) interaction motions are generated by the periodic compress-and-release actions on an asymmetric location of the elastic loop of tubing. In this work, we demonstrate how important the driving forcing function affects a net flow in the valveless circulatory system and investigate which parameter set of the system gives a more efficient net flow around the loop.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.6
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• pp.127-134
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• 2001

At PKC\`98, SangUk Shin et al. proposed a new hash function based on advantages of SHA-1, RIPEMD-160, and HAVAL. They claimed that the Boolean functions of the hash function have good properties including the SAC(Strict Avalanche Criterion). In this paper, we first show that some of Boolean functions which are used in Shin\`s hash function does not satisfy the SAC, and then argue that satisfying the SAC may not be a good property of Boolean functions, when it is used for constructing compress functions of a hash function.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.788-795
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• 1996

In this paper, and optimum profile of a cam being used in a VTR Deck mechanism is designed by the response surface analysis. The objective function of the design is to reduce driving torque of the pinch roller system that is used to compress video tape to the capstan motor axia. The pinch roller system that will be designed is modeled using the general purpopse mechanism analysis program DADS. The computer model is compared with the physical system for reliability. A model function to represent relationship between design variables and the objective function is estimated by the response surface analysis. Once the model function is reliably estimated the optimal design is carried out using the model function and each design variable's boundaries. To verify improvement of the pinch roller system, a prototype for the pinch rooler system is made and tested. From the test result, an optimum cam profile to resuce driving torque of the pinch roller system is verified.

• Journal of Computing Science and Engineering
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• v.10 no.1
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• pp.21-31
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• 2016

With the application and development of biomedical techniques such as next-generation sequencing, mass spectrometry, and medical imaging, the amount of biomedical data have been growing explosively. In terms of processing such data, we face the problems surrounding big data, highly intensive computation, and high dimensionality data. Fortunately, cloud computing represents significant advantages of resource allocation, data storage, computation, and sharing and offers a solution to solve big data problems of biomedical research. In order to improve the efficiency of resource management in cloud computing, this paper proposes a clustering method and adopts Radial Basis Function in order to compress comprehensive data sets found in biology and medicine in high quality, and stores these data with resource management in cloud computing. Experiments have validated that with such a data-compression-based resource management in cloud computing, one can store large data sets from biology and medicine in fewer capacities. Furthermore, with reverse operation of the Radial Basis Function, these compressed data can be reconstructed with high accuracy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1846-1863
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• 2016

High dynamic range (HDR) images can present the perfect real scene and rich color information. A commonly encountered problem in practical applications is how to well visualize HDR images on standard display devices. In this paper, we propose a multi-scale decomposition method using guided filtering for HDR image tone mapping. In our algorithm, HDR images are directly decomposed into three layers：base layer, coarse scale detail layer and fine detail layer. We propose an effective function to compress the base layer and the coarse scale detail layer. An adaptive function is also proposed for detail adjustment. Experimental results show that the proposed algorithm effectively accomplishes dynamic range compression and maintains good global contrast as well as local contrast. It also presents more image details and keeps high color saturation.