New methods for compression of MP double array by compact management of suffixes

Minimal Prefix (MP) double array is an efficient data structure for a trie. However, its space efficiency is degraded by the non-compact management of suffixes. This paper presents three methods to compress the MP double array. The first two methods compress the MP double array by accommodating short suffixes inside the leaf nodes, and pruning leaf nodes corresponding to the end marker symbol. These methods achieve size reduction of up to 20%, making insertion and deletion faster at the same time while maintaining the retrieval time of O(1). The third method eliminates empty spaces in the array that holds suffixes, and improves the maximum size reduction further by about 5% at the cost of increased insertion time. Compared to a Ternary Search Tree, the key retrieval of the compressed MP double array is 50% faster and its size is 3–5 times smaller.     

Concordance of apolipoprotein B concentration with the Friedewald,Martin-Hopkins,and Sampson formulas for calculating LDL cholesterol

IntroductionTwo new formulas, the Martin-Hopkins and the Sampson formula, were recently developed to overcome shortcomings of the Friedewald formula for calculating LDL-cholesterol. We aimed to compare the concordance of the two formulas with apolipoprotein B (apoB), a surrogate marker of the number of LDL particles.Materials and methodsIn a study of serum lipid data of 1179 patients who consulted the AZ St-Jan Hospital Bruges for cardiovascular risk assessment, the correlation and concordance of the Friedewald, Martin-Hopkins and Sampson formulas with apoB concentration, measured by immunonephelometry, were determined and compared.ResultsThe Martin-Hopkins formula showed significantly higher correlation coefficient than the Friedewald formula with apoB in the entire dataset and in patients with low LDL-cholesterol < 1.8 mmol/L. Both Martin-Hopkins and Sampson formulas yielded > 70% concordance of LDL-cholesterol with regard to treatment group classification based on population-equivalent thresholds of apoB in hypertriglyceridemic patients (2-4.5 mmol/L), with the highest concordance (75.6%) obtained using Martin-Hopkins formula vs. 60.5% with Friedewald formula.ConclusionThe Martin-Hopkins (and, to a lesser extent, Sampson) formula is more closely associated with the number of LDL particles than Friedewald formula. This, in combination with literature evidence of lesser accuracy of the Friedewald formula, is an argument to switch from Friedewald to a modified, improved formula.     

Inverting microwell array chip for the cultivation of human induced pluripotent stem cells with controlled aggregate size and geometrical arrangement

We present a novel cell culture chip, namely, “inverting microwell array chip,” for cultivation of human induced pluripotent stem cells. The chip comprises a lower hydrogel microwell array and an upper polystyrene culture surface. We demonstrate the formation of uniform cellular aggregates in the microwell array, and after inversion, a culture with controlled aggregate size and geometrical arrangement on the polystyrene surface. Here, we report effects of cell concentrations on a cultivation sequence in the chip.     

Determination of railway wheel climb probability based on the derailment coefficient

The probability of wheel climb commencing is calculated using Nadal's formula as a basis. In particular, the functional form of Nadal's formula is maintained with normal probability density functions used to describe the two arguments in Nadal's formula, namely contact plane angle and coefficient of friction at the contact point. The theoretical value of the probability of wheel climb commencing for a given lateral/vertical force ratio value at the wheel flange–railhead interface is then compared with experimental results for positive angles of attack. Theoretical results for negative angles of attack are generated for several cases.     

On F-polynomials of thistles

A general formula is derived for the F-polynomial of thistles—a family of graphs obtained by attaching twigs (hinged edges) to all the nodes of a basic member. The formula involves a function which is identified explicitly for certain types of F-polynomials. The function is then used to partially characterize a special family of thistles.     

用正交设计方法求解非线性规划的区间约束最优化问题

给出了以正交设计原理为基础的两种方法———正交表法和加点正交表法,求解非线性规划的区间约束最优化问题。方法不要求目标函数可导,不依赖于初始点,计算速度快,算法简单,容易编成程序在计算机上执行。用检验考题对算法进行了验证,并进行了分析和探讨     

Onset of channeling during DNA electrophoresis in a sparse ordered post array

The “channeling hypothesis” of DNA electrophoresis in sparse, ordered arrays of posts predicts that the DNA will move through the array relatively unhindered if (i) the spacing between the posts is larger than the DNA coil and (ii) the electric field lines are straight. We tested this hypothesis by studying the electrophoretic separation of a small plasmid DNA (pUC19, 2686 base pairs) and a large, linear DNA (λ-DNA, 48 500 base pairs) in a hexagonal array of 1 μm diameter posts with a pitch of 7 μm. At low electric field strengths, these DNAs are separated due to the long-lived, rope-over-pulley collisions of λ-DNA with the posts. The resolution is lost as the electric field increases due to the onset of channeling by the λ-DNA. Using a diffusive model, we show that channeling arises at low electric fields due to the finite size of the array. This channeling is not intrinsic to the system and is attenuated by increasing the size of the array. Higher electric fields lead to intrinsic channeling, which is attributed to the disparate time scales for a rope-over-pulley collision and transverse diffusion between collisions. The onset of channeling is a gradual process, in agreement with extant Brownian dynamics simulation data. Even at weak electric fields, the electrophoretic mobility of λ-DNA in the array is considerably higher than would be expected if the DNA frequently collided with the posts.     

葱属粗根组5种材料的核型研究

 本文分析了葱属Allium粗根组Sect．Bromatorrhiza Ekberg五群材料的核型。多星韭Allium   wallichii Kunth有两个类型：第一类型是二倍体，染色体组公式为AA，核型公式为K(2n)=2X=   14=2m(SAT)+2m+10sm，属2A型；第二类型是同源四倍体，染色体组公式为AAAA,  核型公   式为K(2n)＝4X＝28＝2m(SAT)+6m十20sm,属2A型。宽叶韭Allium hookeri Thwaites有   三个类型：  第一类型是双基数同源异源三倍体，染色体组公式为AAB1,核型公式为  K(2n)＝2X+   x'＝22＝(12sm+2t)十(1m十45m+1st+2t)，  属3A型；  第二类型也是双基数同源异源三倍   体，能配对的两个染色体组染色体大小和形态与第一类型大体相似，不能配对的一个染色体组染色体   大小和形态与第一类型有明显区别，其中至少有两条染色体发生了罗伯逊易位，出现一条很大的染色体    和一条很小的染色体，染色体组公式为AAB2，核型公式为K(2n)=2x+x'＝22=(12sm+2t)+   (3m+1sm十2st+2t)，属3A型；第三类型相当于第一类型染色体的自然加倍，是双基数同源异源   六倍体，染色体组公式为AAAAB1B1，核型公式为K(2n)=4X十2x'＝44＝(24sm+4t)十(2m+   8sm十2st+4t)，属3A型。     

基于DEA无效改进的南通市建设用地结构预测

不同的经济社会发展水平需要不同的建设用地结构,只有以适应经济社会发展水平的建设用地规模作基数进行预测,才可能确保规划期内的建设用地供应规模不会超量,有利于控制建设用地规模的急速膨胀,促进建设用地的节约集约利用,保护耕地。本文采用南通市1996年-2008年土地利用变更调查数据及相关经济数据,运用数据包络分析法和灰色系统预测法,对南通市历年建设用地利用有效性进行分析,同时在对DEA表现相对无效的样本进行修正的基础上预测南通市2010和2020年建设用地结构规模。结论如下:①1996年-2005年11年间,有5年建设用地投入产出呈DEA相对无效,其余6年建设用地投入产出呈DEA相对有效;②至2020年,南通市建设用地总规模仍不断扩大,但各类建设用地变化趋势不同;③以进行DEA相对无效改进后的序列为基数预测的各类建设用地规模、年均变速均小于以原始序列为基数所预测的建设用地规模及变速。     

期刊质量权重在细化影响因子计算公式中的应用与探讨

[目的]细化期刊影响因子计算公式,研究了考虑引用期刊学术质量的影响因子计算公式。[方法]在计算期刊影响因子时细化期刊质量权重的计算方式,采用以(当年)期刊影响因子占所有期刊影响因子的比重作为期刊质量权重的计算方法的修正。并在原有的数据基础上,进行统计模拟计算和数据分析。[结果]采用细化期刊质量权重的影响因子计算结果较为精确。[结论]细化期刊质量权重计算方式将得到了比以往更为合理的影响因子计算公式,为期刊评价体系提供有益的参考。     

Investigation of array robustness to sensor failure

The presence of uncertainties in the array response, due to sensors operational malfunctions and environmental effects, results in a performance degradation often greater than the application requirements can afford. Various attempts have been made to measure the effect of the presence of uncertainties on the performance of direction-finding (DF) algorithms and, moreover, several methods have been developed to either detect or partly rectify the resulting defects in performance and hence improve the robustness of the array system. However, the impact of sensor response uncertainties on the ultimate array DF capabilities, as they are determined by the array manifold characteristics, has not been considered thoroughly. In this paper, the sensitivity of array DF capabilities to sensor response errors is first formulated and investigated. Robustness and reliability measures are then proposed. Such measures can be used as tools for the evaluation of each sensor's importance within the array geometry and as criteria for the comparison of a number of array geometries.     

氟化磷酸铟的合成与表征

以尿素与氯化胆碱的低共熔点液体同时兼做溶剂和模板传递剂,在离子热体系下合成了InF2 2(NH4)3.采用同样的低共熔点液体在水热条件下不能得到相同的产物.产物晶体参数如下:C2/c(No.15)空间群,a=13.799(3) ,b=5.091(2) ,c=16.094(3) , β=112.942(16)°,V=1041.2(5) 3 and Z=4; R1=0.0582,wR2=0.1589. 在产物结构中,In八面体与P四面体形成四员环,顶角相连形成链状结构.客体铵分子填充于链与链间的空穴中,通过氢键与骨架中的F原子,P—OH和 P O 基团作用,链与链间靠范德华力吸引进而形成层状结构.产物进一步通过粉末XR, EDX, IR, XPS和TG/DTA进行表征.     

Compression of double array structures for fixed length keywords

A trie is one of the data structures for keyword matching. It is used in natural language processing, IP address routing, and so on. It is represented by the matrix form, the link form, the double array, and LOUDS. The double array representation combines retrieval speed of the matrix form with compactness of the list form. LOUDS is a succinct data structure using bit-string. Retrieval speed of LOUDS is not faster than that of the double array, but its space usage is smaller. This paper proposes a compressed version of the double array by dividing the trie into multiple levels and removing the BASE array from the double array. Moreover, a retrieval algorithm and a construction algorithm are proposed. According to the presented experimental results for pseudo and real data sets, the retrieval speed of the presented method is almost the same as the double array, and its space usage is compressed to 66% comparing with LOUDS for a large set of keywords with fixed length.     

对VB数组大量数据初始化的方法及注意事项

VB数组在定义时没有提供数据初始化功能,这一点与C语言有较大差异。介绍了利用VB的ARRAY函数对大量数据初始化的处理方法。     

Tilted post arrays for separating long DNA

Recent simulations by Chen and Dorfman [Electrophoresis 35, 405–411 (2014)] suggested that “tilting” the electric field with respect to the lattice vectors of a hexagonal post array would lead to a substantial improvement in electrophoretic DNA separations therein. We constructed such an array where the electric field is applied at an angle equidistant between the two lattice vectors. This tilted array leads to (i) baseline resolution of 20 kbp DNA and λ DNA (48.5 kbp) in a 4 mm channel and (ii) measurable separation resolutions for electric fields up to 50 V/cm, both of which are improvements over untilted post arrays of the same post density. The predicted time required to reach a resolution of unity is approximately 5 min, independent of electric field. The separations are more reproducible at higher fields.     

共形相控阵天线的技术研究

相控阵天线技术在雷达、通信、电子战、导航等领域获得了广泛应用和高速发展,共形相控阵天线是相控阵天线发展的重点之一。文章介绍了共形相控阵天线国外发展现状,进而探讨了共形相控阵的天线阵型,方向图综合及波束形成技术体制等关键技术。     

Simulation of electrophoretic stretching of DNA in a microcontraction using an obstacle array for conformational preconditioning

Recently our group has reported experiments using an obstacle array to precondition the conformations of DNA molecules to facilitate their stretch in a microcontraction. Based upon previous successes simulating electrophoretic stretching in microcontractions without obstacles, we use our simulation model to study the deformation of DNA chains in a microcontraction preceded by an array of cylindrical obstacles. We compare our data to the experimental results and find good qualitative, and even quantitative, agreement concerning the behavior of the chains in the array; however, the simulations overpredict the mean stretch of the chains as they leave the contraction. We examine the amount of stretch gained between leaving the array and reaching the end of the contraction and speculate that the differences seen are caused by nonlinear electrokinetic effects that become important in the contraction due to a combination of field gradients and high field strengths.     

Dielectrophoretic spectra of translational velocity and critical frequency for a spheroid in traveling electric field

An analysis has been made of the dielectrophoretic (DEP) forces acting on a spheroidal particle in a traveling alternating electric field. The traveling field can be generated by application of alternating current signals to an octapair electrode array arranged in phase quadrature sequence. The frequency dependent force can be resolved into two orthogonal forces that are determined by the real and the imaginary parts of the Clausius–Mossotti factor. The former is determined by the gradient in the electric field and directs the particle either toward or away from the tip of the electrodes in the electrode array. The force determined by the imaginary component is in a direction along the track of the octapair interdigitated electrode array. The DEP forces are related to the dielectric properties of the particle. Experiments were conducted to determine the DEP forces in such an electrode arrangement using yeast cells (Saccharomyces cervisiate TISTR 5088) with media of various conductivities. Experimental data are presented for both viable and nonviable cells. The dielectric properties so obtained were similar to those previously reported in literature using other DEP techniques.     

日像仪干涉阵结构优化的加速压力算法

提出的加速压力算法是对Boone压力算法在解的质量和收敛速度两方面的改进,通过一次移动天线阵,可以完全消除阵元数目个uv采样点处的残差,使得每次迭代的uv分布修正量最大,从而不仅达到减小计算量的目的,而且使优化结果更加逼近理想模型.通过ALMA阵结构的优化与原有算法做了对比,验证了算法的有效性和高效性.最后,给出了中国国家天文台正在建设的日像仪干涉阵结构的仿真结果     

浅析超低音扬声器阵列的指向性控制

论述指向性超低音扬声器阵列的意义和实际应用价值,阐述三种常规超低音扬声器阵列的指向性基本原理,采用专用计算机软件进行模拟仿真,利用实际消声室实验对该基础理论以及计算机仿真结果进行验证及归纳总结;并针对侧墙对Front/Back阵列声辐射的影响进行探究,通过实验得出结论。