检索结果-南通市图书馆

A New Tuning method for Two-Degree-of-Freedom Internal model Control under Parametric Uncertainty

Chinese Journal of Chemical Engineering 2013年第9期21卷 1030-1037页

作者： Juwari Purwo sutikno Badhrulhisham abdul aziz Chin Sim yee Rosbi mamat Process System Engineering Group Faculty of Chemical and Natural Resources-Engineering Universiti MalaysiaPahang Lebuhraya Tun Razak Gambang Kuantan 26300 Malaysia Process Design and Control Laboratory -Chemical Engineering Department Insfitut Teknologi Sepuluh NopemberSurabaya Kampus ITS Sukolilo Surabaya 60111 Indonesia Faculty of Elect)ical Engineering Universiti Teknologi Malaysia Skudai Johor 81310 Malaysia

Internal model control （ImC） yields very good performance for set point tracking, but gives sluggish response for disturbance rejection problem. A two-degree-of-freedom ImC （2DOF-ImC） has been developed to overcome the weakness. However, the setting of parameter becomes a complicated matter if there is an uncertainty model. The present study proposes a new tuning method for the controller. The proposed tuning method consists of three steps. Firstly, the worst case of the model uncertainty is determined. Secondly, the parameter of set point con- troller using maximum peak （mp） criteria is specified, and finally, the parameter of the disturbance rejection con- troller using gain margin （Gm） criteria is obtained. The proposed method is denoted as mp-Gm tuning method. The effectiveness of mp-Gm tuning method has evaluated and compared with ImC-controller tuning program （ImCTUNE） as bench mark. The evaluation and comparison have been done through the simulation on a number of first order plus dead time （FOPDT） and higher order processes. The FOPDT process tested includes processes with controllability ratio in the range 0.7 to 2.5. The higher processes include second order with underdarnped and third order with nonminimum phase processes. Although the two of higher order processes are considered as difficult processes, the proposed mp-Gm tuning method are able to obtain the good controller parameter even under process uncertainties.

关键词： tuning 2DOF-ImC model uncertainty dead time process mp-Gm tuning ImCTUNE

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adoption of Improved Rice Varieties in the Global South:A Review

引用

Rice science 2023年第3期30卷 186-206,I0021-I0034页

作者： Julia CHECCO Fathin Ayuni azizAN Jaquie mITCHELL Ammar abdul aziz School of Agriculture and Food Sciences The University of QueenslandGatton 4343QueenslandAustralia Department of Agrotechnology Faculty of Mechanical Engineering and TechnologyUniversiti Malaysia PerlisArau 02600PerlisMalaysia

Improved rice varieties(IRVs)play a significant role in establishing food security and improving livelihood in the Global South since its introduction in the ***,the adoption of new IRVs has remained relatively *** low adoption poses a challenge to rice-producing and consuming countries as they are increasingly threatened by production shortages,malnutrition,and poor rice *** empirical studies have attempted to identify the determinants influencing the adoption of IRVs by distinguishing the characteristics between adopters and *** review showed a consensus on the important determinants influencing the adoption of IRVs in the Global *** synthesized from 99 studies suggested that variables(farm size,education,information access and farm location)examined extensively are not necessarily the most important determinants of adoption when undertaking a weighted ***,source of seed and technology-related attributes(perceived yield,maturity,ease of use,marketability and technical efficiency)are more important determinants of adoption,with determinants changing according to adoption type(probability or intensity of adoption),variety type and *** recommendations for future adoption studies include:incorporating more technology-specific variables,increasing research for overlooked regions and variety types,shifting away from predominant static analysis by capturing the dynamics of the adoption process,and considering the potential biases in *** review will facilitate the development of targeted interventions and policies that promote IRV adoption in the Global South.

关键词： technology adoption improved rice variety systematic literature review the Global South

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Subspace Clustering in High-Dimensional Data Streams:A Systematic Literature Review

引用

Computers, materials & Continua 2023年第5期75卷 4649-4668页

作者： Nur Laila Ab Ghani Izzatdin abdul aziz Said Jadid abdulKadir Department of Computer and Information Sciences Universiti Teknologi PETRONASSeri Iskandar32610PerakMalaysia Centre for Research in Data Science(CeRDAS) Universiti Teknologi PETRONASSeri Iskandar32610PerakMalaysia

Clustering high dimensional data is challenging as data dimensionality increases the distance between data points,resulting in sparse regions that degrade clustering *** clustering is a common approach for processing high-dimensional data by finding relevant features for each cluster in the data *** clustering methods extend traditional clustering to account for the constraints imposed by data *** streams are not only high-dimensional,but also unbounded and *** necessitates the development of subspace clustering algorithms that can handle high dimensionality and adapt to the unique characteristics of data *** many articles have contributed to the literature review on data stream clustering,there is currently no specific review on subspace clustering algorithms in high-dimensional data ***,this article aims to systematically review the existing literature on subspace clustering of data streams in high-dimensional streaming *** review follows a systematic methodological approach and includes 18 articles for the final *** analysis focused on two research questions related to the general clustering process and dealing with the unbounded and evolving characteristics of data *** main findings relate to six elements:clustering process,cluster search,subspace search,synopsis structure,cluster maintenance,and evaluation *** algorithms use a two-phase clustering approach consisting of an initialization stage,a refinement stage,a cluster maintenance stage,and a final clustering *** density-based top-down subspace clustering approach is more widely used than the others because it is able to distinguish true clusters and outliers using projected *** algorithms implicitly adapt to the evolving nature of the data stream by using a time fading function that is sensitive to *** work can focus on the clustering framework,parameter optimiza

关键词： Clustering subspace clustering projected clustering data stream stream clustering high dimensionality evolving data stream concept drift

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ON THE COEFFICIENTS OF A POLYNOmIAL WITH RESTRICTED ZEROS

引用

Analysis in Theory and Applications 2009年第2期25卷 142-146页

作者： abdul aziz W. m. Shah Post Graduate Department of mathematics University of Kashmir Srinagar India Post Graduate Department of mathematics Govt.College BaramullaKashmir-193101 India

Let P（z）=anz^n＋an-1z^n-1＋…＋a0be a complex polynomial of degree n. There is a close connection between the coefficients and the zeros of P（z）. In this paper we prove some sharp inequalities concerning the coefficients of the polynomial P（z） with restricted zeros. We also establish a sufficient condition for the separation of zeros of P（z）.

关键词： polynomial inequality coefficient estimate separation of zeros

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Catalytic methanation reaction over alumina supported cobalt oxide doped noble metal oxides for the purification of simulated natural gas

引用

燃料化学学报 2012年第7期40卷 822-830页

作者： Wan Azelee Wan Abu Bakar Rusmidah Alil abdul aziz abdul Kadir Salmiah Jamal mat Rosid Nurul Shafeeqa mohammad Department of Chemistry Faculty of Science Universiti Teknologi Malaysia 81310 Skudai Johor Malaysia Faculty of Petroleum and Renewable Energy Engineering Universiti Teknologi Malaysia 81310 Skudai Johor Malaysia

A series of alumina supported cobalt oxide based catalysts doped with noble metals such as ruthenium and platinum were prepared by wet impregnation *** variables studied were difference ratio and calcination ***/Co(10∶90)/Al2O3 catalyst calcined at 700 ℃ was found to be the best catalyst which able to convert 70.10% of CO2 into methane with 47% of CH4 formation at maximum temperature studied of 400 ℃.X-ray diffraction analysis showed that this catalyst possessed the active site Co3O4 in face-centered cubic and PtO2 in the orthorhombic phase with Al2O3 existed in the cubic *** to the FESEm micrographs,both fresh and spent Pt/Co(10∶90)/Al2O3 catalysts displayed small particle size with undefined *** Adsorption analysis showed that 5.50% reduction of the total surface area for the spent Pt/Co(10∶90)/Al2O3 ***,Energy Dispersive X-ray analysis(EDX) indicated that Co and Pt were reduced by 0.74% and 0.14% respectively on the spent Pt/Co(10∶90)/*** using FT-IR and TGA-DTA analysis revealed the existence of residual nitrate and hydroxyl compounds on the Pt/Co(10∶90)/Al2O3 catalyst.

关键词： natural gas cobalt oxide noble metal catalyst methanation reaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

measuring powder flowability with a modified Warren Spring cohesion tester

引用

Particuology 2011年第2期9卷 148-154页

作者： Salam A.mohammed Ezzat C.abdullah Derek Geldart abdul aziz A.Raman Department of Chemical Engineering Faculty of EngineeringUniversity of Malaya Powder Research Ltd. Harrogate& University of Leeds

The measurement of powder flowability is a major concern for most industrial processes that deal with the handling of bulk solids as raw materials, intermediates, or products. The development of devices that measure the flowability of non-aerated powders has not progressed as rapidly as might have been hoped since most research activities have been based on various types of shear testers intended to aid the design of hoppers. A new flowability indicator named as weighted cohesion （WS） is established using newly improved version of direct cohesion texture. A cornerstone of the proposed technique is that the procedure is automated, using a digital Warren Spring tester called Warren Spring-University of malaya cohesion tester （WSUmCT）, thus making results operator-insensitive. Besides being a practical tool to diagnose the cohesion of experimental powders, the ratio between measured cohesion （using WSUmCT） and aerated density （using Hosokawa PT-S） provides us with a powerful technique to research fundamental particle internal cohesion forces directly and use these data to indicate the flowability. In this work, a series of fine （9.4μm） and coarse （60 μm） porous silica gel particle mixtures, and mixtures of fine （28μm） and coarse （72 μm） glass ballotini as well, were used as test powders. The results from these tests agree well with relative flowability determined on our newly driven indicator using WSUmCT. The validation of aerated weighted cohesion （WSA） as a flowability indicator was authenticated by comparing the conducted parameter with established measured Hausner ratio （HR） and angle of repose （AoR）.

关键词： Flowability Cohesion strength Hausner ratio Particle sizeAngle of reposeCohesive powder

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

measurement and correlation of physical properties of aqueous solutions of tetrabutylammonium hydroxide, piperazine and their aqueous blends

引用

Chinese Journal of Chemical Engineering 2015年第11期23卷 1811-1818页

作者： Rizwan Safdar abdul aziz Omar Lukman B.Ismail Arhama Bari Bhajan Lal Chemical Engineering Department Universiti Teknologi PETRONAS School of Engineering and Physical Science Heriot-Watt University Malaysia

The density,viscosity and refractive index of aqueous solutions of tetrabutylammonium hydroxide(TBAOH),piperazine(PZ) and their aqueous blends are determined at several temperatures(303.15 to 333.15 K).All these measured physicochemical properties decreases with an increase in *** density data is used to calculate the coefficient of thermal expansion and excess molar volume of all aqueous binary and ternary *** coefficient of thermal expansion increases with increase in temperatures and *** negativity of excess molar volume for all the aqueous solution decreased with increase in *** physical property is correlated with temperature by least square method and the corresponding coefficients for each property are *** prediction values from correlations for the physical properties are in good agreement with the experimental values.

关键词： Density ionic liquidsDensityViscosityRefractive index

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical investigation for a hyperbolic annular fin with temperature dependent thermal conductivity

引用

Propulsion and Power Research 2016年第1期5卷 55-62页

作者： m.T.Darvishi F.Khani abdul aziz Department of mathematics Razi UniversityKermanshah 67149Iran Department of mechanical Engineering School of Engineering and Applied ScienceGonzaga UniversitySpokaneWA 99258USA

An annular fin of hyperbolic profile with temperature dependent thermal conductivity is studied by pseudospectral *** illustrating the effect of fin dimensions,surface convection characteristics and the thermal conductivity parameter on the thermal performance of the fin are presented and discussed.A comparison of the obtained numerical results is made with the closed form analytical solution available in the literature for the case of constant themal *** comparison confirms the high accuracy of numerical *** the thermal conductivity increases with temperature,the effect is to elevate both the temperature distribution in the fin and the fin *** converse is true when the themal conductivity decreases with temperature.

关键词： Hyperbolic annular fin Thermal performance Pseudospectral method

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Development of a new connection for precast concrete walls subjected to cyclic loading

引用

Earthquake Engineering and Engineering Vibration 2017年第1期16卷 97-117页

作者： Ramin Vaghei Farzad Hejazi Hafez Taheri mohd Saleh Jaafar Farah Nora Aznieta abdul aziz Civil Department Engineering Faculty University Putra Malaysia Serdang Selangor 43400 Malaysia

The Industrialized Building System （IBS） was recently introduced to minimize the time and cost of project construction. Accordingly, ensuring the integration of the connection of precast components in IBS structures is an important factor that ensures stability of buildings subjected to dynamic loads from earthquakes, vehicles, and machineries. However, structural engineers still lack knowledge on the proper connection and detailed joints o fiBS structure construction. Therefore, this study proposes a special precast concrete wall-to-wall connection system for dynamic loads that resists multidirectional imposed loads and reduces vibration effects （PI2014701723）. This system is designed to connect two adjacent precast wall panels by using two steel U-shaped channels （i.e., male and female joints）. During casting, each joint is adapted for incorporation into a respective wall panel after considering the following conditions： one side of the steel channel opens into the thickness face of the panel; a U-shaped rubber is implemented between the two channels to dissipate the vibration effect; and bolts and nuts are used to create an extension between the two U-shaped male and female steel channels. The developed finite element model of the precast wall is subjected to cyclic loads to evaluate the performance of the proposed connection during an imposed dynamic load. Connection performance is then compared with conventional connections based on the energy dissipation, stress, deformation, and concrete damage in the plastic range. The proposed precast connection is capable of exceeding the energy absorption of precast walls subjected to dynamic load, thereby improving its resistance behavior in all principal directions.

关键词： industrial building system precast concrete structure precast wall connection finite element method nonlinear analysis energy dissipation concrete damage plasticity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Risk modification of colorectal cancer susceptibility by interleukin-8-251T>A polymorphism in malaysians

引用

World Journal of Gastroenterology 2012年第21期18卷 2668-2673页

作者： mohd Aminudin mustapha Siti Nurfatimah mohd Shahpudin Ahmad Aizat abdul aziz Ravindran Ankathil Human Genome Centre School of Medical Sciences Universiti Sains Malaysia Health CampusKubang KerianKelantan 16150 Malaysia

AIm: To investigate the allele and genotype frequencies and associated risk of interleukin (IL)-8-251T>A polymorphism on colorectal cancer (CRC) susceptibility risk. mETHODS: Peripheral blood samples of 255 normal controls and 255 clinically and histopathologically confirmed CRC patients were genotyped for IL-8-251T>A polymorphism employing allele-specific polymerase chain reaction. The relative association of variant allele and genotypes with CRC susceptibility risk was determined by calculating the odds ratios (ORs). Corresponding χ 2 tests on the CRC patients and controls were carried out and 95% confidence intervals (CIs) were determined using Fisher's exact test. The allele frequencies and its risk association were calculated using FAmHAP, haplotype association analysis software. RESULTS: On comparing the frequencies of genotypesof patients and controls, the homozygous variant AA was significantly higher in CRC patients (P = 0.002) compared to controls. Investigation on the association of the polymorphic genotypes with CRC susceptibility risk, showed that the homozygous variant IL-8 -251AA had a significantly increased risk with OR 3.600 (95% CI: 1.550-8.481, P = 0.001). In the case of allele frequencies, variant allele A of IL-8 -251 showed a significantly increased risk of CRC predisposition with OR 1.32 (95% CI: 1.03-1.69,P = 0.003). CONCLUSION: Variant allele and genotype of IL-8 (-251 T>A) was significantly associated with CRC susceptibility risk and could be considered as a high-risk variant for CRC predisposition.

关键词： Interleukin-8-251T〉A Polymorphism Colorectal cancer malaysians

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：