Geological adaptability matching design of disc cutter using multicriteria decision making approaches

Geological adaptability matching design of a disc cutter is the prerequisite of cutter head design for tunnel boring machines(TBMs)and plays an important role in improving the tunneling efficiency of TBMs.The main purpose of the cutter matching design is to evaluate the cutter performance and select the appropriate cutter size.In this paper,a novel evaluation method based on multicriteria decision making(MCDM)techniques was developed to help TBM designers in the process of determining the cutter size.The analytic hierarchy process(AHP)and matter element analysis were applied to obtaining the weights of the cutter evaluation criteria,and the fuzzy comprehensive evaluation and technique for order performance by similarity to ideal solution(TOPSIS)approaches were employed to determine the ranking of the cutters.A case application was offered to illustrate and validate the proposed method.The results of the project case demonstrate that this method is reasonable and feasible for disc cutter size selection in cutter head design.

REVERSE DESIGN APPROACH FOR MECHANISM TRAJECTORY BASED ON CODE-CHAINS MATCHING

Aiming at the problem of reverse-design of mechanism, a method based on the matching of trajectory code-chains is presented. The motion trajectory of mechanism is described with code-chain, which is normalized to simplify the operation of geometric transformation. The geometric transforma-tion formulas of scale, mirror and rotation for trajectory code-chain are defined, and the reverse de-sign for mechanism trajectory is realized through the analysis and solution of similarity matching between the desired trajectory and the predefined trajectory. The algorithm program and prototype system of reverse design for mechanism trajectory are developed. Application samples show that the method can break the restriction of trajectory patterns in matching, meet the demand of partial match-ing, and overcome the influence of geometric transformation of trajectory on the reverse design for mechanism.

BIMATCHING DESIGNS

A collection of k-matchings of bipartite graph Kn,n with the property thatevery pair of independent edges lies in exactly λ of the k-matchings is called aBIMATCH(n,k,λ)-design. Existences and constructions for various BIMATCH (n,k,λ)designs are given.

REQUIREMENTS AND DESIGN METHOD FOR MATCHING AIRCRAFT GUNS WITH THEIR SUPPORTING STRUCTURE

In aircraft structural dynamic design the matching of guns with their supporting structure is one of the most important tasks on which hinges the success or failure of the structural design. The design curves for matching guns with their supporting structure can be obtained from response calculations of the plate-spring system supporting the gun on the ground,the model structure tested on the ground and the actual structure.A set of matching curves is given for engineering application.Then,the matching design can be accomplished by means of impact load spectrograms so as to perform an optimal structural design and to make further improvements on dynamic design program.

Cumulative logit model in the analysis of endometrial cancer under a matched pair case-control design

Background: Binary as well as polytomous logistic models are widely used for estimating odds ratios when the exposure of prime interest assumes unordered multiple levels under matched pairs case-control design. In our previous studies, we have shown that the use of a polytomous logistic model for estimating cumulative odds ratios when the outcome (response) variable is ordinal (in addition to being polytomous) under matched pairs case-control design. The cumulative odds ratios were estimated based on separate fitting of the model at each of the cutpoint level as compared to less than equal to that level. In this paper we propose an alternative method of estimating the cumulative odds ratios and reanalyze the Los Angeles Endometrial Cancer data in the context of dose levels of conjugated oestrogen exposure and development of endometrial cancer under the matched pair case-control design. Methods: In the present study, the cumulative logit model is fitted using a single multinomial logit model for the data. For this, the full maximum likelihood estimation procedure is adopted. A test for equality of the cumulative odds ratios across the exposure levels is proposed. Results: The analysis revealed that there is a strong evidence of risk for developing endometrial cancer due to oestrogen exposure above each of the three dose level as compared to less than equal to that level. The estimated values at the three cutpoint levels were found to be 6.17, 3.60 and 5.16 respectively. Conclusions: The odds of developing endometrial cancer are very high for the users of any amount of oestrogen, even if it is the least dose, as compared to the non-users.

Shape design of the reinforcement for bending load-carrying capacity of under-matched butt joint under four-point bending load

To improve the bending load-carrying capacity （ BLCC） of under-matched butt joint under four-point bending load in the elastic stage, the shape design of the reinforcement is studied based on the theoretics of mechanics of materials. The concept, criterion, realization condition and design proposal of equal bending load-carrying capacity （EBLCC） are put forward. The theoretical analysis results have been verified by the finite element method. The simulation results are coincident basically with the ones of theoretical analysis. The research results show that the shape design of the reinforcement of EBLCC can improve BLCC of under-matched butt joint and the unilateral-side type reinforcement can replace double-side symmetry

基于MATLAB App Designer的电动汽车动力参数匹配

“节能发展,绿色环保”已成为当今社会最关切的主题,电动汽车因此迎来了发展热潮。电动汽车的动力参数匹配是设计开发中的关键环节,能够使电动汽车满足基本的动力性及经济性要求。文章参考某款电动汽车的整车参数和性能指标,基于MATLAB App Designer开发设计一款App,实现电动汽车的驱动电机、动力电池和传动比的关键参数匹配。该款App能够使电动汽车的参数匹配计算提供便利,也为后续应用程序开发及扩展提供参考。

基于Ansoft Designer的射频功放电路阻抗匹配优化设计

针对工作频率为433MHz 的射频功率放大电路中的阻抗匹配问题,提出了基于 EDA 软件——Ansoft designer 的阻抗匹配优化设计方法。运用 Ansoft designer 对射频功放电路进行了阻抗匹配优化设计,并对电路进行了仿真分析。仿真结果表明射频功放电路的增益得到了明显的提高,反射系数得到了显著的改善,达到了阻抗匹配优化设计的目的。

Component Matching Based on Low Bypass Ratio Mixed Exhaust Turbofan Engine

In order to study component matching which exists in off-design situation at the initial design stage of turbine engine,by establishing performance analysis model of low bypass ratio mixed flow turbofan engine and components characteristic data,and by applying Newton-Raphson method to solve the nonlinear equations of offdesign points in flying envelop,the factors which affect matching between engine components are studied.The results show that low pressure turbine(LPT)must not operate in a critical condition,and the partial derivative(slope)of pressure ratio to similitude mass flow ratio of working point in LPT characteristic map affects the stability of engine.The smaller the slope is,the more stable the engine is.In addition,the engine is more stable when the fan characteristic map is steep.

Design Analysis of DC-DC Converters Connected to a Photovoltaic Generator and Controlled by MPPT for Optimal Energy Transfer throughout a Clear Day

The DC-DC converters are widely used in photovoltaic generating systems as an interface between PV module and the load. These converters must be chosen to be able to match the maximum power point (MPP) of PV module when climatic conditions change with different resistive load values. So DC-DC converters must be used with MPPT controller in order to reduce losses in the global PV system. This article focuses on the effect of climatic conditions on design of two components (inductance, capacitance) for three topologies of DC-DC converters commonly used in PV systems. When climatic conditions change, the boundary of inductance and capacitance parameters of DC-DC converter will change. These two parameters must be properly sized to achieve optimal efficiency for each converter. The design optimization is based on two principles: 1) for a steady-state operation in a continuous conduction mode, the inductance value for all choppers must be greater than the maximum value of boundary inductance, and 2) in order to limit the output voltage ripple of DC-DC converter below a desired value, the filter capacitance must be larger than the maximum value of boundary capacitance.

数学对服装色彩的匹配与调和的影响

在服装设计中,色彩的选择主要依靠设计师的直觉与经验,带有一定的主观性与不确定性,但在科学技术的发展以及多学科交叉领域的不断发展下,运用数学可以在服装设计中进行合理的颜色匹配与调和,可以有效提升产品的品质。因此,针对数学对服装色彩的匹配与调和的影响展开探究,以期为服装设计师提供理论参考。

Error Searching System with Keyword Extraction and Keyword Fuzzy Matching

This paper has proposed an error searching method to search the solutions of errors that occurred in the unified commanding platform mix-deployed software (UCPMD). Because those errors belong to different stages or may be happened in different services, applications, IP ports, system software, or different versions of software, and those errors are also can be classified into different types. It is necessary to locate accurate reason that cause an error as well as find out its solution. The proposed error searching system applies Chinese keyword extraction and Chinese fuzzy matching between keywords, which considers the processed keywords as the index to find out the solutions of errors. Besides, the error searching system had made correspondence among errors, reasons, and solutions, and put them to different categories in terms of their characteristics, such that it is easy to manage, search, and use. Among others, we have added specialized thesaurus as the index of keywords, which enriches and completes the searching results. Because of the proposed error searching system evolves keyword extraction and keyword fuzzy matching technologies;it is more accurate to find out user-interested solutions.

Solving the Maximum Matching Problem on Bipartite Star123-Free Graphs in Linear Time

The bipartite Star123-free graphs were introduced by V. Lozin in [1] to generalize some already known classes of bipartite graphs. In this paper, we extend to bipartite Star123-free graphs a linear time algorithm of J. L. Fouquet, V. Giakoumakis and J. M. Vanherpe for finding a maximum matching in bipartite Star123, P7-free graphs presented in [2]. Our algorithm is a solution of Lozin’s conjecture.

Collaborative Design Theory and Related Key Technology Study Based on Cloud Computing

Analyzes the main way of product distribution for collaborative design. According to the requirement of manufacturing collaborative design, apply cloud computing in manufacturing collaborative design and come up the concept of product collaborative cloud design. Study the product collaborative design theory based on cloud computing and the general key technology of cloud computing, semantic web, intelligent matching selection algorithm, STEP and XML technology, version management and conflict resolution arithmetic and so on which related to this theory. The study object of this article is automotive product. Construct an automotive collaborative design system with the key technology to verify the feasibility and validity of the cloud basing collaborative design theory and related technology. This collaborative design system will overcome the weakness that resource and information can not be shared between different department in the same enterprise or different enterprises. Join up this system will help directly enterprise for collaborative design and the repetition construction of collaborative design platform of each enterprise will be avoid. It will reduce the investment of enterprises for constructing and managing collaborative design platform and further reduce the cost of product R&D with a better and more efficient design.

叶轮与导叶宽度匹配参数对LNG泵压力脉动特性的影响研究

应用CFD技术研究了叶轮和导叶宽度匹配设计对LNG潜液泵压力脉动特性影响,进行了宽度匹配设计,采用K-epsilon湍流模型进行了多工况数值模拟,引入无量纲参数R(导叶进口宽度/叶轮出口宽度)进行结果分析,分析验证了泵的外特性,得到了LNG泵的时、频域压力脉动特性等。结果表明:压力脉动主频为叶轮的叶频,次频为其倍频。时域峰值与监测点处的相对位置有关,相对于交界面越近,时域峰值越大。压力脉动幅值随R增加先减小后增大,存在最佳宽度匹配方案使得泵压力脉动峰值降低。

数智时代科技成果供需对接机制

为探究我国数智时代科技成果供需对接影响因素和机制作用,梳理我国科技成果供需对接模式及演变历程,构建科技成果供需对接影响因素概念模型,运用扎根理论和文献分析方法归纳出供方、需方、平台、政策、资金和技术因素等影响因素,运用DEMATEL方法分析影响因素之间的影响度。基于分析结果,提出我国科技成果供需对接机制为从应需引供模式转变为掘需育供模式,从上下游关系转变为共同体关系,从局域平台转变为广域平台,从信息化转变为智慧化,从单点服务转变为全链条服务,从技术发展转变为多要素融合发展。

125ksi超级马氏体油管成分-组织-性能-工艺综合控制技术

125ksi钢级15Cr超级马氏体不锈钢具有优良的高强度、高韧性匹配与耐CO_(2)腐蚀性能,是深度>7000 m深井油井管的候选材料。从成分设计、生产工艺、组织调控等方面,论述了15Cr超级马氏体不锈钢油管的高强高韧综合控制技术。成分控制方面,采用无δ铁素体成分设计,w[Cr]取15%,w[Ni]取6.5%~7%,w[C]取0.01%~0.03%,w[Cu]取1.25%~1.5%,Cr、Ni元素合理匹配是降低δ铁素体含量的主要因素,C、Cu含量的合理匹配是获得高强高韧力学性能的关键因素。冶炼工艺方面,研究了电弧炉钢杂质元素的影响,结果表明,V、N、Al杂质元素会增加15Cr钢的硬度,将回火温度提高至550~575℃,能够降低硬度保证韧性。热加工成型方面,通过热变形试验,获得了15Cr钢的动态再结晶规律,制定了无缝管热穿孔成型变形温度1100~1150℃,能够获得细小的再结晶晶粒。组织性能调控方面,通过热处理工艺研究,确定了正火温度采用950~980℃,即能保证晶粒尺寸不明显长大,又能获得高强度与高韧性的匹配。

新媒体背景下视觉传达设计中色彩发展趋势

探索新媒体时代视觉传达设计中色彩的发展趋势,提高设计中色彩的合理性。分析色彩在视觉传达领域的重要作用,引出新媒体大背景环境下色彩应用在视觉传达设计中的地位,并以动态海报设计、UI设计、标志设计的实际出发,分析色彩在其中的变化方法及原理。得到色彩在新媒体时代视觉传达设计中的发展趋势。无论是在什么时期,色彩在视觉传达设计中都是必不可少的元素,通过时代的变化,色彩应用于新媒体技术上,色彩表现方法与内容也更加丰富,但这更需要设计师时刻警醒自己运用好色彩,提升视觉传达设计在新媒体领域的潜力。

4~18 GHz超宽带行波管输能系统设计

为满足新一代电子对抗装备对跨频带超宽带行波管的需求,本文针对4~18 GHz超宽带大功率行波管输能系统开展了匹配优化设计和功率容量分析研究。从同轴窗、同轴输能结构及输能结构与高频结构匹配等几方面综合优化,设计出输入驻波比优于1.53、输出驻波比优于1.55的输能系统,与测试结果对比表明设计方法合理,输能系统和器件匹配成功;针对输出系统的功率容限问题,从峰值功率和平均功率两方面分析了输能窗的电可靠性和热可靠性,制管实测结果表明,该输能系统能够满足行波管应用要求。

X-band inverse class-F GaN internally-matched power amplifier

An X-band inverse class-F power amplifier is realized by a 1-mm Al Ga N/Ga N high electron mobility transistor（HEMT）.The intrinsic and parasitic components inside the transistor,especially output capacitor Cds,influence the harmonic impedance heavily at the X-band,so compensation design is used for meeting the harmonic condition of inverse class-F on the current source plane.Experiment results show that,in the continuous-wave mode,the power amplifier achieves 61.7% power added efficiency（PAE）,which is 16.3% higher than the class-AB power amplifier realized by the same kind of HEMT.To the best of our knowledge,this is the first inverse class-F Ga N internally-matched power amplifier,and the PAE is quite high at the X-band.