• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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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.

• 한국산학기술학회논문지
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• 제15권11호
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• pp.6810-6814
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• 2014

본 논문에서는 영상 데이터를 효율적으로 압축하고 전송하기 위해 IFS (반복함수시스템) 개념을 적용하였다. 영상 데이터 압축에 IFS를 적용하기 위해 자기유사도를 사용하여 동일한 영상에서 코딩하고자 하는 블록과 유사한 부분을 찾게 된다. 실제 영상에 대한 반복함수시스템 코딩의 정확도 향상을 위해서 영상의 각 세부 블록에 대해 에러를 최소화 하는 변환 블록을 적용하여 성능을 높였다. 제안한 IFS를 사용한 실험결과에서 높은 화질성능을 보였고 반복함수 계수만을 압축된 영상데이터로 사용함으로써 압축효율을 향상시킬 수 있다.

• 한국정보통신학회논문지
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• 제17권4호
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• pp.902-908
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• 2013

본 논문은 데이터 압축 효율 향상을 위하여 데이터에 대해서 무조건적인 압축을 시행하는 것이 아니라 선별적으로 데이타를 판별하여 압축을 하도록 한다. 선별적 데이터 판별을 통해서 압축 여부를 판단하게 된다. 이렇게 함으로써 압축 효율이 좋지 않은 경우에 대한 회피를 통해서 불필요한 압축을 하지 않을 수 있도록 한다. 불필요한 연산을 줄임으로써 압축 알고리즘의 성능 향상을 꾀할 수 있다. 특히, 이미 압축 알고리즘이 적용이 된 데이타의 경우에는 불필요한 압축을 하지 않도록 한다. 본 논문에서 제안하는 기능에 대해 실제 구현하고, 구현된 내용에 대해서 실험을 수행하였다. 본 논문에서 제시한 내용에 대해서 실험한 결과 정상적인 동작이 됨을 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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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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• 제33권4호
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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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• 제15권2호
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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.

• 정보보호학회논문지
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• 제11권6호
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• pp.127-134
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• 2001

PKC\`98에서 신 상욱 등은 SHA-1, RIPEMD-160, HAVAL의 장점을 이용한 새로운 해쉬함수를 제안하였다. 제안자들은 해쉬함수에 사용된 부울함수가 SAC(Strict Avalanche Criterion) 특성을 만족한다고 주장하였으나, 실제로는 SAC을 만족하지 않음을 알 수 있다. 본 논문에서는 PKC\`98에 제안된 해쉬함수에 사용된 부울함수가 SAC을 만족하는 경우의 충돌쌍을 찾음으로써, 일반적으로 암호학적으로 안전한 것으로 인식되는 논리를 사용하는 것이 오히려 안전성 저하 요인이 될 수도 있음을 지적한다.

• 대한기계학회논문집A
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• 제20권3호
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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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• 제10권1호
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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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• 제10권4호
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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.