• Journal of Information Processing Systems
• /
• 제13권4호
• /
• pp.668-676
• /
• 2017

Recently, the importance of big data has been emphasized with the development of smartphone, web/SNS. As a result, MapReduce, which can efficiently process big data, is receiving worldwide attention because of its excellent scalability and stability. Since big data has a large amount, fast creation speed, and various properties, it is more efficient to process big data summary information than big data itself. Wavelet histogram, which is a typical data summary information generation technique, can generate optimal data summary information that does not cause loss of information of original data. Therefore, a system applying a wavelet histogram generation technique based on MapReduce has been actively studied. However, existing research has a disadvantage in that the generation speed is slow because the wavelet histogram is generated through one or more MapReduce Jobs. And there is a high possibility that the error of the data restored by the wavelet histogram becomes large. However, since the wavelet histogram generation system based on the MapReduce developed in this paper generates the wavelet histogram through one MapReduce Job, the generation speed can be greatly increased. In addition, since the wavelet histogram is generated by adjusting the error boundary specified by the user, the error of the restored data can be adjusted from the wavelet histogram. Finally, we verified the efficiency of the wavelet histogram generation system developed in this paper through performance evaluation.

• 한국전기전자재료학회논문지
• /
• 제35권2호
• /
• pp.172-177
• /
• 2022

The quench voltage of the second-generation superconducting wire is affected by the resistivity characteristics of the stabilization layer. The specific resistance of the stabilization layer can be changed by the deposition process using RF magnetron sputtering. In this paper, a thin film made of a homogeneous material (Ag) and a dissimilar material (Cu) was deposited on the stabilization layer of the second-generation superconducting wire through RF magnetron sputtering. We found that the specific resistance was reduced by increasing the thickness of the stabilization layer. The reduction in the resistivity of the stabilization layer led to a decrease in the quench voltage of the second-generation superconducting wire. We suggest that various characteristic changes of the second-generation superconducting wire can be expected through the successful change in the resistivity of the stabilization layer of the proposed deposition process.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.377-377
• /
• 2016

Under nanosecond-pulsed laser irradiation, light-absorbing thin films have been used for photoacoustic transmitters for ultrasound generation. Especially, nanostructured absorbers are attractive due to high optical absorption and efficient thermoacoustic energy conversion: for example, 2-dimensional (2-D) gold nanostructure array, synthetic gold nanoparticles, carbon nanotubes (CNTs), and reduced graphene oxides. Among them, CNT has been used to fabricate a composite film with polydimethylsiloxane (PDMS) that exhibits excellent photoacoustic conversion performance for high-frequency, high-amplitude ultrasound generation. Previously, CNT-PDMS nanocomposite films were made by using a high-temperature chemical vapor deposition (HTCVD) process for CNT growth. However, this approach is not suitable to fabricate large-area CNT films (>several cm2). This is because a chamber dimension of HTCVD is limited and also the process often causes nonuniform CNT growth when the film area increases. As an alternative approach, a solution-based process can be used to overcome these issues. We develop PDMS composite transmitters, based on the solution process, using several nanostructured light-absorbers such as CNTs, nanoink powders, and imprinted regular arrays of gold nanostructure. We compare fabrication processes of each composite transmitters and photoacoustic output performance.

• 펄프종이기술
• /
• 제37권3호
• /
• pp.59-65
• /
• 2005

There are accumulations of remained chemical additives and contaminants in the process water of semi-closed linerboard mill. High temperature of the process water aggravates the anaerobic digestion of contaminated process water and causes the generation of hazardous gases, which are from the biological reaction of varied additives and contaminants. The hydrogen sulfide in the gases easily combine with moisture in the air, and become sulfuric acid, which causes corrosion of paper machinery. This hydrogen sulfide is from the reduction of sulfate ions in the process water, and the sulfate ions are mostly from the alum. We changed the alum to PAC (Poly Aluminum Chloride). The results were preventing generation of hydrogen sulfide, and equivalent sizing effect by the use of PAC.

• 한국기록관리학회지
• /
• 제17권4호
• /
• pp.201-223
• /
• 2017

제 4차 산업혁명의 도래로 인한 신기술의 도입과 클라우드 업무환경으로의 변화 등의 기록관리 외부환경의 변화로 인해 기록의 생산 및 관리 환경의 변화가 예상되나 현재의 법제와 시스템 등이 이러한 외부 환경 변화에 유연하게 대응하기에는 부족한 상황이다. 기록관리 프로세스, 시스템, 인프라 영역의 제문제가 서로 얽혀있어 부분적인 개편으로는 외부환경 변화에 대응하기 어렵다. 이에 전면적인 재설계가 필요하며 이러한 전면적 개편을 '차세대 전자기록관리'로 명명하고 차세대 전자기록관리 체계 구축을 위해 전자기록관리 프로세스를 재설계할 때 고려해야 하는 주요한 이슈들과 개선방법에 대해 연구하였다.

• 한국CDE학회논문집
• /
• 제16권4호
• /
• pp.285-291
• /
• 2011

A pose estimation process from medical images is calculating locations and orientations of objects obtained from Computed Tomography (CT) volume data utilizing X-ray images from two directions. In this process, digitally reconstructed radiograph (DRR) images of spatially transformed objects are generated and compared to X-ray images repeatedly until reasonable transformation matrices of the objects are found. The DRR generation and image comparison take majority of the total time for this pose estimation. In this paper, a fast DRR generation technique based on GPU parallel computing is introduced. A volume ray-casting algorithm is explained with brief vector operations and a parallelization technique of the algorithm using Compute Unified Device Architecture (CUDA) is discussed. This paper also presents the implementation results and time measurements comparing to those from pure-CPU implementation and open source toolkit.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
• /
• pp.179-184
• /
• 2001

The mechanism of the aerosol generation consists of spin-off, splash, and evaporation/condensation. Most researchers showed some theoretical model for predicting the particulate size and generation rate without cutting in turning operation. These models were based on the spin-off mechanism and verified good for modeling the process. However, in real machining, the cutting tool destructs the spin-off process, and the majority of the mist is due to splash. In this paper, we show some experimental evidence the aerosol generation mechanism should be explained with splash model as well as spin-off.

• Journal of Ginseng Research
• /
• 제3권2호
• /
• pp.95-104
• /
• 1979

The effects of ginseng extracts on carbon dioxide generation, alcohol fermentation, and yeast cell production by Saccharomyces cerevisiae were investigated. The results are as follows. 1) In the process of fermentation, CO2 generation by yeast is faster in ginseng extracts media of 0.3%, 0. l% than in control. As the concentration of the extracts increases by 0.7% and 1.5%, CO2 generation is decreased. Among all these concentrations, CO2 generation is fastest in 0.3% of the extracts. 2) In the process of fermentation, the production of alcohol is larger in the order of 0.3%, 0.7% and 0.1% than in the control and least in 1.5%. 3) The number of yeast cell rapidly increased from 12 hours to 18 hours after cultivation and conspicuously increased in the order of 0.3%, 0.7%, 0.1%, control and 1.5%. 4) Dried yeast cell weight increased more in all the above concentration than control and among these it increased visibly in 0.3% of the extracts.

• 한국정밀공학회지
• /
• 제19권12호
• /
• pp.93-99
• /
• 2002

The mechanism of the aerosol generation generally consists of spin-off, splash, and evaporation/condensation. Most researchers showed some theoretical model for predicting the particulate size and generation rate without real cutting in turning operation. These models were based on the spin-off mechanism, and verified good for modeling the process. However, in real machining, the cutting tool destroys the spin-off process, and the majority of the mist is due to splash. In this paper, we show some experimental evidence that the aerosol generation mechanism in real machining should be explained with splash model as well as spin-off.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제12권1호
• /
• pp.15-19
• /
• 2012

A Domain Dictionary generation algorithm based on pseudo feedback model is presented in this paper. This algorithm can increase the precision of domain dictionary generation algorithm. The generation of Domain Dictionary is regarded as a domain term retrieval process: Assume that top N strings in the original retrieval result set are relevant to C, append these strings into the dictionary, retrieval again. Iterate the process until a predefined number of domain terms have been generated. Experiments upon corpus show that the precision of pseudo feedback model based algorithm is much higher than existing algorithms.