A New Method of Construction of Robust Second Order Rotatable Designs Using Balanced Incomplete Block Designs

The following article has been retracted due to the investigation of complaints received against it. Title: A New Method of Construction of Robust Second Order Rotatable Designs Using Balanced Incomplete Block Designs Authors: Bejjam Re. Victorbabu, Kottapalli Rajyalakshmi. The above paper is a copy of Dr. Rabindra Nath Das’s former article, entitled '“Robust second order rotatable designs (Part I)”. The scientific community takes a very strong view on this matter and we solemnly withdrawn?the paper from the journal OJS. This paper published in OJS Vol.2 No.1, 39-47, 2012, has been retracted.

Comment on ＂Comparison of 45-degree Kelman and 45-degree balanced phaco tip designs in torsional microcoaxial phacoemulsification＂

Dear Editor,We read with interest the article ＂Comparison of 45-degree Kelman and 45-degree balanced phaco tip designs in torsional microcoaxial phacoemulsification＂ by Demircan et al. The authors describe the intraoperative and post-operative outcomes of phacoemulsification in terms of cumulative dissipated energy （CDE）, total ultrasound （US） time, torsional US time, total fluid use, percentage change in central corneal thickness and endothelial cell count in the two groups. A comparative evaluation has been made between the two groups involving the Kelman mini-flared tip and the Intrepid balanced phaco tip using the Infiniti Ozil IP Vision system （Alton Laboratories Inc., Fort Worth, TX, USA） as hasbeen explicitly mentioned in the article under the ＂Methods＂ section. However,

Optimal Design of Deforming Regulation for Compact Continuous Rolling Mill with Balanced Load

If the draught of each mill stand is limited by forced bite condition for compact continuous mill,the rolling load difference between one mill stand and another is very big.If deforming regulation of relative load for each mill stand is approximate to the same,the productive capacity of compact continuous mill can be brought into full play,and also the safety running and the smooth rolling of mill can be ensured.

EXISTENCE OF OPTIMAL STRONG PARTIALLY BALANCED DESIGNS

A strong partially balanced design SPBD（v, b, k; λ,0） whose b is the maximum number of blocks in all SPBD（v, b, k; λ, 0）, as an optimal strong partially balanced design, briefly OSPBD（v, k, λ） is studied. In investigation of authentication codes it has been found that the strong partially balanced design can be used to construct authentication codes. This note investigates the existence of optimal strong partially balanced design OSPBD（v, k, 1） for k = 3 and 4, and shows that there exists an OSPBD（v, k, 1） for any v ≥ k.

U-Type Designs via New Generalized Partially Balanced Incomplete Block Designs with <i>m</i>= 4, 5 and 7 Associated Classes

The traditional combinatorial designs can be used as basic designs for constructing designs of computer experiments which have been used successfully till now in various domains such as engineering, pharmaceutical industry, etc. In this paper, a new series of generalized partially balanced incomplete blocks PBIB designs with m associated classes (m = 4, 5 and 7) based on new generalized association schemes with number of treatments v arranged in w arrays of n rows and l columns (w ≥ 2, n ≥ 2, l ≥ 2) is defined. Some construction methods of these new PBIB are given and their parameters are specified using the Combinatory Method (s). For n or l even and s divisor of n or l, the obtained PBIB designs are resolvable PBIB designs. So the Fang RBIBD method is applied to obtain a series of particular U-type designs U (wnl;) (r is the repetition number of each treatment in our resolvable PBIB design).

Splitting Balanced Incomplete Block Designs with Block Size 2×k

This paper investigated the existence of splitting balanced incomplete block designs with blck size 2× k .The necessary conditions for such a design are λ(v-1) ≡0(mod k ),and λv(v- 1)≡0(mod 2 k 2).It will show that the above necessary conditions are also sufficient for k =3 with the definite exception( v,λ )=(10,1) and with several possible exceptions.

CONSTRUCTION OF NONSYSTEMATIC LOW-DENSITY PARITY-CHECK CODES BASED ON SYMMETRIC BALANCED INCOMPLETE BLOCK DESIGN

This paper studies the nonsystematic Low-Density Parity-Check(LDPC)codes based onSymmetric Balanced Incomplete Block Design(SBIBD).First,it is concluded that the performancedegradation of nonsystematic linear block codes is bounded by the average row weight of generalizedinverses of their generator matrices and code rate.Then a class of nonsystematic LDPC codes con-structed based on SBIBD is presented.Their characteristics include:both generator matrices andparity-check matrices are sparse and cyclic,which are simple to encode and decode;and almost arbi-trary rate codes can be easily constructed,so they are rate-compatible codes.Because there aresparse generalized inverses of generator matrices,the performance of the proposed codes is only0.15dB away from that of the traditional systematic LDPC codes.

ON BALANCED n-ARY t-DESIGNS

A t-(v,k,λ)design(X,B)is a set X of points,of cardinality v,and a collection B of k-subsets of X called blocks,with the property that every t-subset of X is contained in precisely λ blocks.A t-design is a t-(v,k,λ) design for some v,k,γ.In this paper,we give a generalization of t-design called balanced n-ary t-design,and obtain some properties of the new combinatorial structure.

Balance between education and game-play— A case study of design and optimization of the mini-game book classification

Purpose： Based on our experience of designing and testing a computer-based game for teaching undergraduate students information literacy （IL） concepts and skills, this paper summarizes the basic strategies for striking a balance between education and entertainment for the designers of quality IL games. Design/methodology/approach： The project team recruited 10 college students to play the game and post-game group interviews revealed problems and optimization priorities. The optimized game was tested among 50 college students. Based on a comparison of testing results of the two versions of the game, basic strategies for designing quality 1L games were summarized. Findings： The following 5 basic strategies can effectively promote combination of education and entertainment： l） using adventure games to enhance gaming experience, 2） plotting an intriguing story to attract players, 3） motivating players to engage in game play with game components such as challenge, curiosity, fantasy and control, 4） presenting learning materials through game props, and 5） assigning players tasks to be completed with subject knowledge. Research limitations： The 5 basic strategies have been tested only in the development process of one game, and the book classification knowledge in the mini-game is limited to the 22 major categories of the Chinese Library Classification. Practical implications： University libraries may refer to our experience to design and utilize educational games to promote the IL education for college students. Originality value： Few empirical studies tested and summarized strategies for combining learning and fun in the design of IL games for university students. The 5 strategies, which are summarized in the process of design and optimization of the mini-game book classification, are valuable for other designers of IL games.

Some Construction Methods of A-Optimum Chemical Balance Weighing Designs

Some new construction methods of the optimum chemical balance weighing designs and pairwise efficiency and variance balanced designs are proposed, which are based on the incidence matrices of the known symmetric balanced incomplete block designs. Also the conditions under which the constructed chemical balance weighing designs become A-optimal are also been given.

Some Construction Methods of Optimum Chemical Balance Weighing Designs III

Methods of constructing the optimum chemical balance weighing designs from symmetric balanced incomplete block designs are proposed with illustration. As a by-product pairwise efficiency and variance balanced designs are also obtained.

Dynamic Balancing Structure Optimal Design for the Rotating Arc Sensor

Rotating arc sensor is a key device for automation welding. The vibration has a big influence on signal's correct collection and reliable automatic welding. In order to solve the vibration problem and the dynamic balancing design with the restricted space,a bearing force analysis based dynamic balancing structure optimal design is proposed and implemented with the help of Pro/Engineer( PROE) and automatic dynamic analysis of mechanical systems( ADAMS) virtual prototype technology, in which three parameters of the counterbalance are considered. The method is suitable for the practical online adjustment. The simulation result shows that optimal design based counterbalance structure and parameters can satisfy the space requirement with lower vibration. The methodology provides a new idea for dynamic balancing design and adjustment of rotating arc sensor with adjustable rotation radius.

35 kV高压直挂大容量电池储能系统

为推动35 kV高压直挂电池储能系统(battery energy storage system,BESS)的实际应用,系统研究了35 kV高压直挂BESS的主电路参数设计、控制策略及相关控制参数的设计方法;并在MATLAB/Simulink中搭建了35 kV/10 MW/10 MWh系统的仿真模型,以验证所提设计方法及控制策略的正确性。研究结果表明:35 kV高压直挂BESS单机容量大,功率响应速度快,可对内部电池簇进行主动荷电状态均衡及故障冗余控制,系统效率和可靠性更高,能适应未来新能源大规模发展需求。

超弹性形状记忆合金自恢复与耗能平衡设计理念

超弹性形状记忆合金具有优越的自恢复性能,在工程抗震应用中能够赋予结构完美的自复位性能,但由于其超弹性旗帜形本构关系,自身耗能能力十分有限,致使其难以满足结构地震下的抗震需求。探求在保留形状记忆合金自恢复性能的前提下,尝试将超弹性形状记忆合金与摩擦阻尼器组合应用,以使形状记忆合金系统的耗能能力最大化。首先,对超弹性形状记忆合金自恢复耗能平衡设计理念进行深入研究,引入系统平衡参数的概念,提出相应的配比设计公式;随后,通过开展形状记忆合金超弹性性能试验、简易摩擦阻尼器试验以及组合张拉试验,证明上述平衡设计理念的实用性以及平衡设计公式的可行性。平衡设计理念的提出以及其验证能够推进并指导形状记忆合金在工程抗震中的应用。

平衡车车架拓扑优化设计与仿真分析

目的本研究以平衡车车架为研究对象,旨在满足模型强度与刚度约束条件的前提下,通过拓扑优化设计实现车架质量的减轻,从而为平衡车车架的轻量化设计提供参考。方法首先,通过SolidWorks软件建立车架的三维模型,然后利用ANSYS Workbench对原始车架进行静力学分析,以获取车架的应力分布情况。在此基础上,采用AltairInspire软件对原模型进行拓扑优化,优化目标是减少车架的质量。结果经过拓扑优化设计,得到了优化后的重构模型。与原始车架相比,优化后的车架质量减少了约54.0%。虽然优化后的车架在满足使用规范的前提下,米塞斯应力有所上升,但仍小于材料的屈服强度,确保了车架的安全性和稳定性。结论本研究通过拓扑优化方法有效地减少了平衡车车架的质量,同时保持了必要的结构强度和刚度。尽管优化后车架的应力有所增加,但仍在材料允许范围内,证明了拓扑优化在车架轻量化设计中的可行性。该方法为未来平衡车车架部件的设计和改进提供了新的思路和参考。

基于热平衡法生成同时发生设计日的方法研究

提出了基于热平衡法生成同时发生设计日的方法.首先基于热平衡法计算某城市的历年逐时动态冷负荷,以历年平均不保证50 h为依据确定理论设计负荷,采用综合聚类法挑选同时发生设计日.用热平衡法计算同时发生设计日、传统设计日的峰值负荷,确定为同时发生设计负荷和传统设计负荷.分别对比了哈尔滨、北京、长沙和广州样本房间的同时发生设计负荷、传统设计负荷与理论设计负荷的差异率.结果显示,各城市同时发生设计负荷与理论设计负荷的差异率偏差范围都远小于传统设计负荷与理论设计负荷的差异率.说明依据同时发生设计日的气象参数进行空调系统设计负荷计算是更加合理、准确的,基于热平衡法可以准确生成适合工程应用的同时发生设计日.

基于现代试验设计的风洞天平校准方法

风洞天平的校准精度直接决定了风洞试验的气动载荷测量精度,为了提升天平校准的质量和效率,以BCS-100天平校准系统为研究对象,基于现代试验设计方法(modern design of experiments,MDOE)开展了风洞天平校准研究。针对单因子变量法(one factor at a time,OFAT)天平校准中存在系统误差与响应量耦合的问题,采用MDOE的随机、重复和分块策略控制校准的系统误差,并选定响应面理论的中心复合设计方法生成校准矩阵。校准矩阵共计86个样本点,包括64个分级因子点、12个轴向因子点和10个中心因子点,其中所有样本点的加载顺序做随机化处理,并作为一个样本块在短时间内集中完成加载,中心因子点则用于满足重复原则。最后开展了OFAT和MDOE的对比校准,拟合载荷的残差正态概率分布显示MDOE校准中横侧向分量的样本点独立性更强,样本点残差最高可降低84%;检验载荷显示MDOE和OFAT两种方法中天平所有分量的综合加载重复性持平,MDOE校准中横侧向分量的综合加载误差最高可降低54%。研究表明MDOE能够有效降低校准的系统误差,提升横侧向小量的预测能力。

面向光栅刻划机的负刚度结构隔振性能优化

大面积光栅刻划机实验室存在的复杂振动因素,会对它的运行及刻画精度造成影响,针对光栅刻划机设计一种正负刚度并联的被动隔振结构,改善仅有空气弹簧时对低频隔振无效的现象,拓宽隔振频带。为模拟隔振器隔振性能,建立系统的动力学模型和动力学方程,使用仿真软件MATLAB进行仿真,为磁致负刚度弹簧进行尺寸结构设计,对比并联磁致负刚度弹簧前后的隔振效果。仿真结果表明采用空气弹簧和磁致负刚度结构并联后能够有效的隔离低频振动,并且磁吸致负刚度和磁斥致负刚度进行组合能够有效的改善单一磁吸致负刚度或磁斥致负刚度结构的非线性。

数控机床主轴动平衡设计

随着高速高精机加工行业的发展和对高效率的追求,数控机床主轴不断朝高精度、高效率、高速方向发展,尤其是对主轴转速的要求越来越高。主轴组件在设计、加工、装配等过程中,由于结构不对称、材质不均匀、装配间隙等原因,会引起主轴组件质心偏离旋转中心,严重影响主轴动平衡,在高速旋转时产生发热、噪声、振动等现象。针对主轴组件质心偏离旋转中心而影响动平衡的问题,结合数控机床主轴特点,进行主轴动平衡设计,并在高速车削中心主轴上进行计算验证。

磁平衡法压力计量方法与装置

活塞式压力计量中,微量的压力变化需要依赖微小砝码,无法实现连续压力变化输出,且自动化存在一定困难。鉴于此,提出了一种基于光机电设计的磁平衡法压力计量方法并进行装置研究,以探索电磁平衡法实现压力计量的可行性。在该装置中,原本用于平衡的砝码重力计量用电子天平代替,无需人为手动加减砝码,直接由天平称量平衡力;另一方面,通过磁斥力方式,调节磁铁对的间距以连续输出计量所需压力,此方法可将手动放置砝码达到平衡的过程转变为天平实时连续读取力值最终实现平衡的过程。在装置设计中,实验分析论证了磁铁对电子天平的示数影响,并通过压力输出测试实验与分析,获得了磁铁间距与磁力输出的精确关系,证明了本文提出并搭建的磁平衡法压力计量方法与装置是有效的,以电磁平衡法替代活塞式压力计中的微小砝码是可行的。