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1.
Data transformation is the core process in migrating database from relational database to NoSQL database such as column-oriented database. However,
there is no standard guideline for data transformation from relational database to
NoSQL database. A number of schema transformation techniques have been proposed to improve data transformation process and resulted better query processing
time when compared to the relational database query processing time. However,
these approaches produced redundant tables in the resulted schema that in turn
consume large unnecessary storage size and produce high query processing time
due to the generated schema with redundant column families in the transformed
column-oriented database. In this paper, an efficient data transformation technique
from relational database to column-oriented database is proposed. The proposed
schema transformation technique is based on the combination of denormalization
approach, data access pattern and multiple-nested schema. In order to validate the
proposed work, the proposed technique is implemented by transforming data from
MySQL database to HBase database. A benchmark transformation technique is
also performed in which the query processing time and the storage size are compared. Based on the experimental results, the proposed transformation technique
showed significant improvement in terms query processing time and storage space
usage due to the reduced number of column families in the column-oriented
database. 相似文献
2.
Iskandar Abdullaev Alexander Platonov Denis Sorokin 《The International journal of environmental studies》2013,70(1):151-168
Contemporary water management decisions use many sources and forms of data. The paper discusses the implementation results of data management activities in the water sector carried out in five countries of the Central Asia region. Geoinformation systems, remote sensing tools and databases have been applied worldwide for improving water resources management with differing levels of success. Water management organisations, equipped with data management tools will have better capacities to adapt their decision-making in the changing availability and scarcity of water resources. Application of data management tools for improving collection, storage and processing of data and information are a first step towards improved water governance. 相似文献
3.
Nawaf Labban Mounir Iskandar Jeffrey A. Platt Carl J. Andres John A. Levon Suteera Hovijitra 《Journal of Adhesion Science and Technology》2018,32(5):516-526
The aim of the study was to assess the effect of delayed photo-initiation on the polymerization contraction stress (PCS) and degree of conversion (DC) of a dual-cure resin-luting agent. Thirty-five disk (6 mm × 1 mm) samples (n = 10 each group) of dual cure resin luting agent for PCS assessment were fabricated and polymerized using two illuminated quartz rods. Based on the delay in photo-initiation, 30 disks were divided among six groups [group A-0 min (min) delay, group B-2 min, group C-4 min, group D-6 min, group E-8 min and group F-10 min]. A non-photoinitiated group (group G – chemical cure – n = 5) was included as control. The PCS for all specimens was assessed using a Tensometer. For DC evaluation thirty-five specimens were divided into seven groups with delays in photo-initiation (group H-0 min, group I-2 min, group J-4 min, group K-6 min, group L-8 min and group M-10 min, group N-chemical cure). DC was assessed using attenuated total reflectance spectroscopic technique. Statistical comparison among groups was performed using analysis of variance (α = 0.05). The maximum and minimum PCS and DC values with delayed photo-initiation was observed in group-C (3.34 MPa) & group-F (2.44 MPa); and group-M (0.78 MPa) and group-H (0.55 MPa) respectively. Chemically cured samples showed the least PCS (group-G, 1.94) and DC (group-N, 0.53) values in their respective categories. PCS significantly decreased with delayed photo-initiation. A significant increase in DC was noticed when photo-initiation was delayed in the dual cure resin luting agent. 相似文献
4.
The need to build and operate environmentally friendly plants has challenged the chemical industry to consider waste minimization or even elimination starting from the early stages of process development. A thorough waste minimization analysis requires specialized expertise and is laborious, time-consuming, expensive, and knowledge-intensive. This has caused a major technical barrier for implementing waste minimization programswithin the industry. Previously, we had reported a systematic methodology and a knowledge-based system, called ENVOPExpert, for identifying waste minimization opportunities in chemical processes. In this paper, we propose an integrated qualitative-quantitative methodology to identify waste minimization alternatives and assess their efficacy in terms of environmental impact and process economics. A qualitative analysis is first conducted to identify the sources of wastes and to propose alternatives for eliminating or minimizing them. Environmental impact of each alternative is then calculated by doing a quantitative pollutant balance. The capital expenditure required for implementing the alternative and the resulting plant operating costs are also calculated and used in the evaluation of the waste minimization alternatives. Through this, practical and cost-effective options can be identified. This methodology has been implemented as an integrated decision support system and tested using the hydrodealkylation process case study with satisfactory results. 相似文献
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6.
Nobuhiro Hagura W. Widiyastuti Ferry Iskandar Kikuo Okuyama 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2010,156(1):200-205
Described herein is the synthesis of individually silica-coated silver nanoparticles using a reverse micelle method followed by hydrolysis and condensation of tetraethoxysilane (TEOS). The size of a silica-coated silver nanoparticle can be controlled by changing the reaction time and the concentration of TEOS. By maintaining the size of a silver nanoparticle as a core particle at around 7 nm, the size of a silica-coated silver nanoparticle increased from 13 to 28 nm as the reaction time increased from 1 to 9 h due to an increase in silica thickness. The size of silica-coated silver nanoparticles also increased from 15 to 22 nm as the TEOS concentration increased from 7.8 to 40 mM. The size of a silica-coated silver nanoparticle can be accurately predicted using the rate of the hydrolysis reaction for TEOS. Neither the dispersion nor the film of silica-coated silver nanoparticles exhibited any peak shifting during surface plasmon resonance (SPR) at around 410 nm, whereas, without silica coating, the SPR peak of Ag film shifted to 466 nm. 相似文献
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9.
The dual specificity phosphatases M3/6 and MKP-3 are highly selective for inactivation of distinct mitogen-activated protein kinases 总被引:2,自引:0,他引:2
M Muda A Theodosiou N Rodrigues U Boschert M Camps C Gillieron K Davies A Ashworth S Arkinstall 《Canadian Metallurgical Quarterly》1996,271(44):27205-27208
The mitogen-activated protein (MAP) kinase family includes extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) and p38/RK/CSBP (p38) as structurally and functionally distinct enzyme classes. Here we describe two new dual specificity phosphatases of the CL100/MKP-1 family that are selective for inactivating ERK or JNK/SAPK and p38 MAP kinases when expressed in COS-7 cells. M3/6 is the first phosphatase of this family to display highly specific inactivation of JNK/SAPK and p38 MAP kinases. Although stress-induced activation of p54 SAPKbeta, p46 SAPKgamma (JNK1) or p38 MAP kinases is abolished upon co-transfection with increasing amounts of M3/6 plasmid, epidermal growth factor-stimulated ERK1 is remarkably insensitive even to the highest levels of M3/6 expression obtained. In contrast to M3/6, the dual specificity phosphatase MKP-3 is selective for inactivation of ERK family MAP kinases. Low level expression of MKP-3 blocks totally epidermal growth factor-stimulated ERK1, whereas stress-induced activation of p54 SAPKbeta and p38 MAP kinases is inhibited only partially under identical conditions. Selective regulation by M3/6 and MKP-3 was also observed upon chronic MAP kinase activation by constitutive p21(ras) GTPases. Hence, although M3/6 expression effectively blocked p54 SAPKbeta activation by p21(rac) (G12V), ERK1 activated by p21(ras) (G12V) was insensitive to this phosphatase. ERK1 activation by oncogenic p21(ras) was, however, blocked totally by co-expression of MKP-3. This is the first report demonstrating reciprocally selective inhibition of different MAP kinases by two distinct dual specificity phosphatases. 相似文献
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