Modified stiffness formulation of unbalanced anisotropic sandwich plates

An approximate formulation is presented for the analysis of sandwich plates consisting of an orthotropic core and two unequal thickness anisotropic face plates. The method uncouples the membrane and bending actions, thereby significantly reducing the effort involved in accurately predicting displacements and stresses. Defining modified stiffnesses, the formulation is valid for relatively thick anisotropic laminated face plates and can be combined with a variety of analysis techniques. Using a series solution, results are generated herein for simply supported sandwich plates with unbalanced cross-ply and angle-ply faces.     

Tuning PI controllers for stable processes with specifications on gain and phase margins

In industrial practice, controller designs are performed based on an approximate model of the actual process. It is essential to design a control system which will exhibit a robust performance because the physical systems can vary with operating conditions and time. Gain and phase margins are well known parameters for evaluating the robustness of a control system. This paper presents a tuning algorithm to design and tune PI controllers for stable processes with a small dead time while meeting specified gain and phase margins. Simulation examples are given to demonstrate that the proposed design method can result, in a closed-loop system, in better performances than existing design methods which are also based on user-specified gain and phase margins.     

Quality evaluation model using loss function for multiple S-type quality characteristics

Most of the studies of quality system or product-quality assessment deal with a single quality characteristic to determine the quality loss. Products are often assessed on more than one quality characteristic. For this reason, different multivariate quality loss functions have been proposed. However, these loss functions only consider the nominal-the-best quality characteristics (N-type); they do not consider the condition when the quality characteristics are of the smaller-the-better (S-type). In this article, we present a quality evaluation model using loss function for multiple S-type quality characteristics. A numerical example is illustrated showing that using inappropriate loss functions will lead to inaccurate results that give either an underestimate or overestimate of the expected quality costs.     

哈萨克语基本名词短语自动识别研究与实现

以哈萨克语基本名词短语识别为目标,实现了哈萨克语基本名词短语自动识别系统。采用基于规则自动识别及人工标注的方法建立基本名词短语标注语料库,在此基础上,采用统计和规则相结合的识别方法,利用互信息进行基本名词短语边界预测,然后根据哈萨克语基本名词短语构成规则对预测边界进行调整,加入标注符,得到最终的识别结果。实验结果表明,两种方法封闭测试的识别精确率分别为80.2%和82.5%。     

高寒草原地区安格斯和西门塔尔母牛血液及肌内脂肪酸组成特性

随机采集48 月龄安格斯和西门塔尔母牛各37 头血液样品以及用于肉质分析的各5 头母牛背最长肌肉样。样品经过前处理和甲酯化后,利用气相色谱-质谱联用仪测定脂肪酸组成和含量,对血液和肌内脂肪酸组成特性进行分析。结果表明：安格斯和西门塔尔母牛血液和肌内脂肪中均测得36 种脂肪酸,样品中均含有51%以上的高含量饱和脂肪酸（saturated fatty acids,SFA）,且具有以棕榈酸和硬脂酸为主的组成特点,二者总含量分别约占血液和肌内脂肪SFA的92%和89%;不饱和脂肪酸（unsaturated fatty acids,UFA）中油酸相对含量最高,其次为亚油酸;血液和肌内脂肪的油酸含量均约占单不饱和脂肪酸总量的87%,UFA中各主要脂肪酸组成在血液中有显著性差异,而在肌内脂肪中无显著性差异;血液和肌内脂肪中n-6/n-3 PUFA均符合联合国粮农组织（United Nations Food Agriculture Organization,FAO）推荐比例（5～10）,血液中P/S高于世界卫生组织（World Health Organization,WHO）推荐标准（≥0.4）。综上所述,高寒草原饲养的纯种安格斯和西门塔尔母牛血液和肌内脂肪酸组成特性相似,UFA符合FAO和WHO理想比值及推荐标准,具有较高的营养价值。     

响应面法优化红柳枝烟熏液制备工艺及其理化特性分析

以红柳枝为实验材料,在高温下干馏（厌氧热解）得到烟熏液,通过单因素试验和响应面设计法,研究干馏温度、干馏时间和木材厚度对红柳枝烟熏液产率、酚含量、羰基化合物含量的影响,进而确定红柳枝烟熏液制备工艺参数的最优组合。在最佳制备工艺参数的基础上,探究干馏温度对红柳枝烟熏液色泽的影响和吸附精制处理对红柳枝烟熏液理化性质的影响。结果表明：最优参数组合为干馏温度402.22 ℃、干馏时间75.66 min、木材厚度0.627 cm,该条件下制备烟熏液的酚含量为10.066 mg/mL、羰基化合物含量为14.35 g/100 mL、烟熏液产率为33.082%;烟熏液的亮度值（L*）随干馏温度的增大而降低,黄度值（b*）、色度值和色调随干馏温度的增大变化趋势与L*相似,但红度值（a*）的变化趋势与L*相反（P＜0.05）,随干馏温度的升高,红柳枝烟熏液总色泽的变化趋势由淡黄色至棕褐色,当干馏温度为380 ℃时,总色差（ΔE）最小,红柳枝烟熏液的色泽鲜艳、与商业烟熏液最接近;大孔树脂与核桃壳吸附精制对烟熏液pH值没有影响,但降低苯并(a)芘含量、酚含量、羰基化合物含量和烟熏液产率（P＜0.05）,苯并(a)芘含量远低于国标限量（0.5 μg/kg）。     

An Indexing Method for Answering Queries on Moving Objects

We consider the problem of indexing a set of objects moving in d-dimensional spaces along linear trajectories. A simple external-memory indexing scheme is proposed to efficiently answer general range queries. The following are examples of the queries that can be answered by the proposed method: report all moving objects that will (i) pass between two given points within a specified time interval; (ii) become within a given distance from some or all of a given set of other moving objects. Our scheme is based on mapping the objects to a dual space, where queries about moving objects are transformed into polyhedral queries concerning their speeds and initial locations. We then present a simple method for answering such polyhedral queries, based on partitioning the space into disjoint regions and using a B+-tree to index the points in each region. By appropriately selecting the boundaries of each region, we guarantee an average search time that matches a known lower bound for the problem. Specifically, for a fixed d, if the coordinates of a given set of N points are statistically independent, the proposed technique answers polyhedral queries, on the average, in O((N/B)^1−1/d⋅(log _B N)^1/d+K/B) I/O's using O(N/B) space, where B is the block size, and K is the number of reported points. Our approach is novel in that, while it provides a theoretical upper bound on the average query time, it avoids the use of complicated data structures, making it an effective candidate for practical applications. The proposed index is also dynamic in the sense that it allows object insertion and deletion in an amortized update cost of log _B(N) I/O's. Experimental results are presented to show the superiority of the proposed index over other methods based on R-trees. recommend Ahmed Elmagarmid