• Title/Summary/Keyword: Data Cleaning

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Discussions on Availability of Weather Information Data and Painting Effect of Existing 8,600 TEU Container Ship Using Ship Performance Analysis Program

  • Shin, Myung-Soo;Ki, Min Suk;Lee, Gyeong Joong;Park, Beom Jin;Lee, Yeong Yeon;Kim, Yeongseon;Lee, Sang Bong
    • Journal of Ocean Engineering and Technology
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    • v.34 no.6
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    • pp.377-386
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    • 2020
  • This paper discusses the effectiveness of onboard measurements and data extracted from weather information for speed-power analysis. Furthermore, validation results of hull and propeller cleaning and painting during dry-docking are discussed. Wind and wave information can be obtained from onboard measurements or weather information from the National Oceanic and Atmospheric Administration (NOAA). The weather information of a specified position and time is extracted from NOAA weather data and compared with onboard measurements. In addition, to validate the effects of hull cleaning and painting during dry-docking, speed-power analysis results of before and after dry-docking are compared. The results show that both onboard measurements and weather information show acceptable reliability when added resistance and speed-power analysis results are compared with each other. Moreover, the ship performance analysis (SPA) software clearly shows the effects of hull cleaning and painting, and it can provide reliable analysis results with either onboard measurements or weather information. In conclusion, it is confirmed that the analysis method and SPA software used in this study are effective in analyzing the ship's speed-power performance.

Flash Memory Shadow Paging Scheme Using Deferred Cleaning List for Portable Databases (휴대용 데이터베이스를 위한 지연된 소거 리스트를 이용하는 플래시 메모리 쉐도우 페이징 기법)

  • Byun Si-Woo
    • Journal of Information Technology Applications and Management
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    • v.13 no.2
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    • pp.115-126
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    • 2006
  • Recently, flash memories are one of best media to support portable computer's storages in mobile computing environment. We propose a new transaction recovery scheme for a flash memory database environment which is based on a flash media file system. We improved traditional shadow paging schemes by reusing old data pages which are supposed to be invalidated in the course of writing a new data page in the flash file system environment. In order to reuse these data pages, we exploit deferred cleaning list structure in our flash memory shadow paging (FMSP) scheme. FMSP scheme removes the additional storage overhead for keeping shadow pages and minimizes the I/O performance degradation caused by data page distribution phenomena of traditional shadow paging schemes. We also propose a simulation model to show the performance of FMSP. Based on the results of the performance evaluation, we conclude that FMSP outperforms the traditional scheme.

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Estimation of the Effect of Clean Road System on the $PM_{10}$ Concentration at a Heavy Traffic Roadside - A Case study for Daegu City - (클린로드 시스템 가동이 도로변 $PM_{10}$ 농도에 미치는 영향 분석- 대구지역의 사례연구 -)

  • Jo, Byung-Yoon;Baek, Sung-Ok
    • Particle and aerosol research
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    • v.8 no.3
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    • pp.111-120
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    • 2012
  • In Daegu, a road cleaning system was constructed in the central part of the city and has been operated from April, 2011. We evaluated the effect of the system on the concentration of $PM_{10}$ at a roadside monitoring site. The ambient $PM_{10}$ concentration data were logged every 1 min for a period of 20 weeks from May to October, 2011, by means of light scattering method, and then every 5 min data were used in the statistical analysis. The measured data were verified by comparing them with beta-ray data obtained at the same site. Correlation coefficient between the two groups was highly significant (r=0.79), though the absolute levels of light scattering data appeared to be approximately 2.8 times higher than the beta-ray data. Diurnal, daily, weekly, and monthly variations of $PM_{10}$ data did not show any evidence of decreasing effect owing to the clean road system. A comparison of roadside $PM_{10}$ data with non-roadside data also revealed very similar pattern, implying the variation of the $PM_{10}$ concentrations is mainly affected by the traffic conditions near the monitoring site. However, if the operating conditions of the clean road system can be improved, i.e. increasing the frequency and duration of water cleaning, the road cleaning effect may improve the air quality indirectly by means of removing the resuspended particles from the road.

A Segment Space Recycling Scheme for Optimizing Write Performance of LFS (LFS의 쓰기 성능 최적화를 위한 세그먼트 공간 재활용 기법)

  • Oh, Yong-Seok;Kim, Eun-Sam;Choi, Jong-Moo;Lee, Dong-Hee;Noh, Sam-H.
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.12
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    • pp.963-967
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    • 2009
  • The Log-structured File System (LFS) collects all modified data into a memory buffer and writes them sequentially to a segment on disk. Therefore, it has the potential to utilize the maximum bandwidth of storage devices where sequential writes are much faster than random writes. However, as disk space is finite, LFS has to conduct cleaning to produce free segments. This cleaning operation is the main reason LFS performance deteriorates when file system utilization is high. To overcome painful cleaning and reduced performance of LFS, we propose the segment space recycling (SSR) scheme that directly writes modified data to invalid areas of the segments and describe the classification method of data and segment to consider locality of reference for optimizing SSR scheme. We implement U-LFS, which employs our segment space recycling scheme in LFS, and experimental results show that SSR scheme increases performance of WOLF by up to 1.9 times in HDD and 1.6 times in SSD when file system utilization is high.

Stress Analysis of a Window Cleaning Robot using 3D Modeling and Improvement Plan (3D 모델링을 통한 유리창 청소로봇의 응력해석 및 설계 개선방안 도출)

  • Kim, Kyoon-Tai;Jun, Young-Hun
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.2
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    • pp.161-168
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    • 2018
  • Recently, a prototype of a guide rail type window cleaning robot was developed, and is currently undergoing field testing. The size and the load of the robot have not yet been optimized. In this study, a stress analysis was performed to derive quantitative data to improve the current window cleaning robot and secure its structural safety. Through the analysis of its own weight, resistance to wind speed, and other factors, it was found that the robot can be improved in terms of the drooping caused by its own weight and the drag force against wind pressure. The analysis results obtained will be directly applied to improve the design of the window cleaning robot, and it is expected that this will advance the completeness of the robot's design.

An Assessment of Genotoxicity on Organic Solvent Workers by $^{32}$P-postlabelling Method ($^{32}$P-postlabelling법을 이용한 유기용제 작업장 근로자의 유전독성 평가)

  • 홍대용;김장락;이장호;문중갑;이한우;김동일;박성학;정주화;이홍근
    • Environmental Analysis Health and Toxicology
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    • v.9 no.1_2
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    • pp.37-51
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    • 1994
  • To evaluate the genotoxicities of workers exposed to glue and glue cleaning solution, ambient air monitoring of working place, animal study and human monitoring were carried out. By GC-MS analysis, air samples collected from shoesmaking plant were found to be toluene, xylene, cyclohexane, n-hexane, methyl ethyl ketone, trichloroethylene, butylacetate, isopropyl alcohol. Glue and glue cleaning solution from shoesmaking plant were applicated topically to the CD-1 mice. DNA was isolated from skin 24 hr following the application and analysed for DNA-adducts using the nuclease $P_1$version of $^{32}$P-postlabelling assay. RAL (Relative Adduct Labelling, adducts$10^8$ nucleotides) was significantly increased in a dose-dependent manner in the glue cleaning solution treated mice skin. Peripheral blood DNA-adducts of workers exposed to glue and glue cleaning solution were also analysed by the same method, but there were not significant differences in the peripheral blood DNA-adducts level between exposed and control workers. In addition, glue cleaning solution from shoes factory was evaluated for mutagenicity in the Salmonella plate incorporation assay using strains TA 100 and TA 1535 in the presence and absence of Arochlor 1254-induced rat liver S$_{9}$. There was evident mutagenicity for cleaning solution in TA 100 regardless of $S_9$, but TA 1535 showed positive only in the absence of $S_9$when predicted by Stead model of mutagenicity prediction (p=0.0000). The urine concentrates from workers and controls were also assayed for mutagenicity towards strain TA 100 of Salmonella typhimurium in the presence of $S_9$ using Kado's microsuspension assay, but their mutagenic activities were not found to be significant. These data suggest that shoesmaking workers are exposed to genotoxic compounds and need to be monitored by testing the mutagenicity of human urines. However, $^{32}$P-postlabelling application requires further validation for the routine monitoring of human exposure.osure.

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Hydraulic Characteristics of the Non-power Soil Cleaning and Keeping System by the Large-Scale Model Test at the Dike Gate (배수문에서 실내모형실험에 의한 무동력 토사제거시스템의 수리 특성)

  • Park, Chan Keun;Oh, Beom Hwan;Lee, Dal Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.5
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    • pp.67-75
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    • 2014
  • In this study, the large-scale hydraulic model test was performed to investigate the hydraulic characteristics for development of the non-power soil cleaning and keeping system at the dike gate. The outlet height, outflow number, outflow discharge, and outflow cycle were compared and analyzed. The non-power soil cleaning and keeping system was most effective at 11.2 mm in the outlet height. And then the mean outflow cycle was 1.09 sec, and the mean outflow discharge was $0.00164m^3/s$. The total outflow number increased gradually as the water level of a water tank increased, and the outlet height decreased. As a level of water tank decreased, the mean outflow cycle was lengthened, and the unit outflow discharge increased. This result showed this system was most effective. To remove the silty clay deposited in facilities, the methods of excavation, dredging, high pressure washing, etc have been applied to the tidal facilities such as land reclamation, a small size fishing port, and a harbor for maintenance. However, this is extremely cost-ineffective, whereas the non-power soil cleaning and keeping system will bring about an enormously positive economic effect. In addition, when the non-power soil cleaning and keeping system is applied to the dike gate of land reclamation, a thorough examination of the local tidal data and the careful system planning are required to prevent the disaster damage caused by flooding.

Bonding effects of cleaning protocols and time-point of acid etching on dentin impregnated with endodontic sealer

  • Tatiane Miranda Manzoli;Joissi Ferrari Zaniboni;Joao Felipe Besegato;Flavia Angelica Guiotti;Andrea Abi Rached Dantas;Milton Carlos Kuga
    • Restorative Dentistry and Endodontics
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    • v.47 no.2
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    • pp.21.1-21.11
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    • 2022
  • Objectives: This study aimed to investigate the bonding effects of cleaning protocols on dentin impregnated with endodontic sealer residues using ethanol (E) or xylol (X). The effects of dentin acid etching immediately (I) or 7 days (P) after cleaning were also evaluated. For bonding to dentin, universal adhesive (Scotchbond Universal; 3M ESPE) was used. The persistence of sealer residues, hybrid layer formation and microshear bond strength were the performed analysis. Materials and Methods: One hundred and twenty bovine dentin specimens were allocated into 4 groups (n = 10): G1 (E+I); G2 (X+I); G3 (E+P); and G4 (X+P). The persistence of sealer residues was evaluated by SEM. Confocal laser scanning microscopy images were taken to measure the formed hybrid layer using the Image J program. For microshear bond strength, 4 resin composite cylinders were placed over the dentin after the cleaning protocols. ANOVA followed by Tukey test and Kruskal-Wallis followed by Dunn test were used for parametric and non-parametric data, respectively (α = 5%). Results: G2 and G4 groups showed a lower persistence of residues (p < 0.05) and thicker hybrid layer than the other groups (p < 0.05). No bond strength differences among all groups were observed (p > 0.05). Conclusions: Dentin cleaning using xylol, regardless of the time-point of acid etching, provided lower persistence of residues over the surface and thicker hybrid layer. However, the bond strength of the universal adhesive system in etch-and-rinse strategy was not influenced by the cleaning protocols or time-point of acid etching.

Influence of access cavity design on calcium hydroxide removal using different cleaning protocols: a confocal laser scanning microscopy study

  • Seda Falakaloglu;Merve Yeniceri Ozata;Betul Gunes;Emmanuel Joao Nogueira Leal Silva;Mustafa Gundogar;Burcu Gucyetmez Topal
    • Restorative Dentistry and Endodontics
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    • v.48 no.3
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    • pp.25.1-25.13
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    • 2023
  • Objectives: The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex. Materials and Methods: Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC. Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%. Results: The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05). Conclusions: The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.