基于AHM和ABC分类法的多元过程能力指数

简要介绍了多元质量特性的过程能力指数(MPCI)的研究现状,并提出基于AHM(属性层次模型)和ABC分类法的多元过程能力指数。该方法充分考虑了各个质量特性的重要性差异和不同等级的质量特性的控制目标的不同。具体介绍了该方法的步骤,并通过实例分析证明了方法的有效性和实际性。     

A physics-based simulation approach for cooperative erection activities

Cooperative erection activities are critical to projects which involve the erection of heavy loads or the installation of special equipment. Detailed simulation on computer prior to construction can identify constructability problems, and subsequently avoided during actual erections. This paper describes an integrated approach for simulating the detailed motions of cranes. This research develops a physics-based model that follows the principle of closed-form forward kinematics and constraint-based dynamics to present the dual-crane mechanism mathematically — a non-trivial task. This model can be used to analyze the inputs from the users (i.e. virtual crane operators) and simultaneously compute the cables sway and reaction of collisions. We also implemented the model on computer and developed a simulation system, Erection Director, to render realistic cooperative erection activities. A demonstration of simulating two-crane lift has been built and three performance tests including a small building (840 elements), a medium building (1937 elements) and a large building (2682 elements) validate the feasibility of the proposed approach. The test results indicate that Erection Director can support real-time and physics-based visualization of cooperative erections.     

Amplifier linearization using compact microstrip resonant cell-theory and experiment

This paper presents a novel technique for reducing the intermodulation distortions (IMDs) in power amplifiers. In this method, both second- and third-harmonic components generated by the transistor are reflected back simultaneously by the compact microstrip resonant cell (CMRC) at the input port with proper phases to mix with the fundamental signal for the reduction of IMDs. A rigorous mathematical analysis on the effectiveness of multiharmonic reflections has been formulated and derived using the Volterra series. Moreover, the delay mismatch factor of the proposed method is analytically studied and the result shows that a better tolerance to the delay error can be achieved by using CMRC circuitry. Standard two-tone test measurements reveal 32- and 22-dB reductions for the third-order IMD and fifth-order IMD, respectively, without affecting the fundamental signal at 2.45 GHz. Meanwhile, the proposed approach gives a peak power added efficiency of 53% with 11.5 dB transducer gain and 15 dBm output power for a single-stage SiGe bipolar junction transistor. The adjacent channel power ratio (ACPR) is -55dBc for a data rate of 384-kb/s quadrature phase shift keyed modulated signal with 2-MHz spanning bandwidth, and this ACPR is maintained for a broad range of output power level.     

Unprecedented Homoleptic Bis‐Tridentate Iridium(III) Phosphors: Facile,Scaled‐Up Production,and Superior Chemical Stability

Bis‐tridentate Ir(III) metal complexes are expected to show great potential in organic light‐emitting diode (OLED) applications due to the anticipated, superb chemical and photochemical stability. Unfortunately, their exploitation has long been hampered by lack of adequate methodology and with inferior synthetic yields. This hurdle can be overcome by design of the first homoleptic, bis‐tridentate Ir(III) complex [Ir(pzpyph)(pz^Hpyph)] ( 1 ), for which the abbreviation (pzpyph)H (or pz^Hpyph) stands for the parent 2‐pyrazolyl‐6‐phenyl pyridine chelate. After that, methylation and double methylation of 1 afford the charge‐neutral Ir(III) complex [Ir(pzpyph)(pz^Mepyph)] ( 2 ) and cationic complex [Ir(pz^Mepyph)₂][PF₆] ( 3 ), while deprotonation of 1 gives formation of anionic [Ir(pzpyph)₂][NBu₄] ( 4 ), all in high yields. These bis‐tridentate Ir(III) complexes 2 – 4 are highly emitted in solution and solid states, while the charge‐neutral 2 and corresponding t ‐butyl substituted derivative [Ir(pzpy^Buph)(pz^Mepy^Buph)] ( 5 ) exhibit superior photostability versus the tris‐bidentate references [Ir(ppy)₂(acac)] and [Ir(ppy)₃] in toluene under argon, making them ideal OLED emitters. For the track record, phosphor 5 gives very small efficiency roll‐off and excellent overall efficiencies of 20.7%, 66.8 cd A^?1, and 52.8 lm W^?1 at high brightness of 1000 cd m^?2. These results are expected to inspire further studies on the bis‐tridentate Ir(III) complexes, which are judged to be more stable than their tris‐bidentate counterparts from the entropic point of view.     

Hydrogen‐Bonding‐Assisted Intermolecular Charge Transfer: A New Strategy to Design Single‐Component White‐Light‐Emitting Materials

This study reveals the mechanism of the dual‐emission properties for asymmetrical diphenylsulfone and diphenylketone derivatives. A series of asymmetrical diphenylketone and diphenylsulfone derivatives with dual‐emission properties are designed and synthesized. By single crystal structure analyses, various photophysical studies, and 2D ¹H–¹H NOSEY NMR studies, the lower energy emission bands in the dual‐emission spectra are successfully assigned to hydrogen‐bonding‐assisted intermolecular charge transfer emission. The emission properties of these compounds can easily be tuned in both solid state and solution state by destroying or strengthening the intermolecular hydrogen bonding. In addition, thermally activated delayed fluorescence characteristics for the intermolecular charge transfer emissions are also observed. The control of the intermolecular and intramolecular charge transfers serves as the basis for the generation of the white‐light emission. For compound CPzPO, nearly pure white‐light emission with CIE coordinates of (0.31, 0.32) is easily achieved by precipitation from dichloromethane and hexane mixed solvent system. These results clearly give an insight into the dual‐emission properties and provide a rational strategy for the design and synthesis of single‐component white‐light‐emitting materials and mechanoresponsive light‐emitting materials.     

WDM/FDM star coupler with gain using fibre amplifiers

An efficient amplified WDM/FDM star coupler is proposed. The size of the coupler can be increased by a factor of m using m fibre amplifiers. Furthermore, the complexity and cost of the proposed scheme are less than those of other configurations.<>     

Gate-leakage compensation scheme for programmable SI-DAC of ΣΔ modulator in deep sub-micron

A gate-leakage compensation scheme is proposed to solve the gate-leakage current issue caused by large-size current-source transistors in multi-bit switched-current (SI) DACs of the continuous-time ΣΔ modulator in deep sub-micron process without extra power consumption. To cover wide current range due to variable coefficients in different modes, the programmable SI-DAC architecture with 2-bit digital controlled unit cells is proposed. Implemented in 65 nm CMOS, the simulated results verify that the proposed scheme solves the gate-leakage issue and the modulator achieves tremendously high performance of 84.5 dB SQNDR and 94.6 dB SFDR with almost 14 and 19 dB improvement in SQNDR and SFDR, respectively.     

Utility-based power control for a two-cell CDMA data network

Power allocation across users in two adjacent cells is studied for a code-division multiple access (CDMA) data service. The forward link is considered and cells are modeled as one-dimensional with uniformly distributed users and orthogonal signatures within each cell. Each user is assumed to have a utility function that describes the user's received utility, or willingness to pay, for a received signal-to-interference-plus-noise ratio (SINR). The objective is to allocate the transmitted power to maximize the total utility summed over all users subject to power constraints in each cell. It is first shown that this optimization can be achieved by a pricing scheme in which each base station announces a price per unit transmitted power to the users, and each user requests power to maximize individual surplus (utility minus cost). Setting prices to maximize total revenue over both cells is also considered, and it is shown that, in general, the solution is different from the one obtained by maximizing total utility. Conditions are given for which independent optimization in each cell, which leads to a Nash equilibrium (NE), is globally optimal. It is shown that, in general, coordination between the two cells is needed to achieve the maximum utility or revenue.     

周期极化钽酸锂倍频窄谱线全光纤连续激光放大器特性

通过准相位匹配技术,采用1μm波段高功率窄谱线连续光纤激光放大器抽运高二次谐波转换效率周期性极化晶体,是实现高光束质量、小型化、高功率连续绿光激光器的一个非常有前途的方向。实验自主研发了高效率主振荡功率放大(MOPA)全光纤保偏放大模块,获得中心波长为1064.25nm,线宽为0.035nm的30 W连续线偏振激光,并以此作为基频光抽运国产周期极化钽酸锂(PPSLT)晶体进行了外腔单通倍频实验。保持PPSLT晶体的控制温度为145.6℃,在抽运光功率为21.5W时得到了2.1W的绿光输出。实验分析了温度、基频光功率密度和Boyd-Kleinman聚焦因子对倍频光转换效率的影响。实验过程中没有出现饱和现象,进一步提高抽运功率有望获得更高功率的绿光。     

复杂系统高效能仿真技术研究

首先给出了复杂系统高效能仿真技术的内涵和重要作用,并从复杂系统高端建模仿真及为海量用户按需提供云仿真服务两类应用需求的角度,讨论了发展复杂系统高效能仿真技术的技术需求及介绍了相关的国内外技术概况。接着,从高效能仿真建模技术、高效能仿真系统及支撑技术、高效能仿真应用工程技术等三个方面论述了当前复杂系统高效能仿真技术研究中值得关注的9类技术：1）复杂系统高效能仿真语言;2）复杂系统高效能仿真算法;3）高效能仿真系统体系结构;4）高效能仿真硬件优化技术;5）高效能仿真软件支撑技术;6）高效能云仿真技术;7）复杂系统高效能仿真系统VV＆A技术;8）海量数据管理技术;9）复杂系统仿真实验及结果分析与评估技术等技术,包括其研究内容和作者所在团队的研究成果与进一步的研究方向。最后给出几点结论与建议。