Effects of code growth and parsimony pressure on populations in genetic programming

Parsimony pressure, the explicit penalization of larger programs, has been increasingly used as a means of controlling code growth in genetic programming. However, in many cases parsimony pressure degrades the performance of the genetic program. In this paper we show that poor average results with parsimony pressure are a result of "failed" populations that overshadow the results of populations that incorporate parsimony pressure successfully. Additionally, we show that the effect of parsimony pressure can be measured by calculating the relationship between program size and performance within the population. This measure can be used as a partial indicator of success or failure for individual populations.     

High Activity Solid Base Catalysts for Alkenyl Aromatic Isomerisation

The isomerisation of allylbenzene, dimethoxyallylbenzene (4-allyl-1,2-dimethoxybenzene), eugenol (2-methoxy-4-(2-propenyl)phenol), and estragole (4-allylanisole) into their respective cis/trans internal alkenyl aromatics has been studied over a supported solid base catalysts (K₂CO₃/alumina). The catalyst was active at 305 K with conversions as high as 36%. However all reactants cause deactivation of the catalyst.     

Pantothenic acid, coenzyme A, and human chronic ulcerative and granulomatous colitis

To investigate further an apparent relationship between chronic ulcerative and granulomatous colitis and pantothenic acid deficiency, colonic tissues obtained at the time of colectomy in 29 patients with these disorders were assayed for pantothenic acid and for coenzyme A (CoA) activity. For comparison, normal colonic tissues free of pathological lesions were obtained from 31 patients having colectomy for carcinoma or diverticulitis. Plasma, red blood cells, and colonic mucosa were assayed microbiologically for free and total pantothenic acid. The activity of CoA in colonic mucosa was determined by assaying the acetylation of sulfanilamide. Concentrations of free, bound, and total pantothenic acid in blood and in colonic mucosa did not differ between the two groups of patients. Bound pantothenic acid increased linearly with total pantothenic acid. Colonic mucosa concentrated free pantothenic acid to about 50 times the level of blood, and pantothenic acid in red cells was similar to the concentration in plasma. Compared to normal gut mucosa, CoA activity was markedly low in mucosa from patients with chronic ulcerative or granulomatous disease despite the presence of normal amounts of free and bound pantothenic acid. A block in the conversion of bound pantothenic acid to CoA in diseased mucosa is suggested.     

Expressed emotion and attributions in the carers of patients with Alzheimer's disease: The effect on carer burden.

Burden of care, expressed emotion (EE), causal attributions, and salivary cortisol were assessed in 100 carers of patients with Alzheimer's disease. Forty-one carers were rated high EE, which was associated with higher scores of carer distress and strain, and greater reports of noncognitive features in the patient, but not with cortisol levels. High EE carers made more attributions personal to, and controllable by, the patient for negative events. Critical carers made more attributions of the patient's behavior that was idiosyncratic. Warmth toward the patient was associated with the opposite of this pattern. Overinvolved carers made attributions of the patient's behavior to causes external to the patient and internal to themselves. Cortisol levels were associated with self-reports of strain and distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Series Capacitor SF-6 Bypass Interrupter

Series capacitor banks on transmission lines ave two types of bypass switches; high-speed switches located on the insulated capacitor platforms for operation, and manually-operated line switches to isolate the bank for maintenance. Air break switches used for maintenance bypass on 345 kV series capacitors could not successfully transfer line current without heavy arcing. An SF-6 interrupter like that manufactured for transformer protection, was selected for a simple retrofit replacement.     

运行中可编程的增益控制

可能的最大值时,ADC 能提供最精确的数字输出。但当传感器输出的变化达到几个数量级或在许多数据采集系统中你不知道用户将使用何种信号连到该系统的情况下,如何使电压摆幅量最大化呢?动态范围的实质在信号调理方面,最受关注的问题是使系统的动态范围最大化。然而,在分析信号路径时,动态范围(DR)这一术语经常被采用甚至滥用。相反,信噪比(SNR)是明确的采用相同方法和处于同样环境下测量出的信号与噪声电平之比。在一个可编程的增益放大器(PGA)中,放大器中的噪声和最大信号电24 位的测量分辨率能为你解决什么问题?答案是有非常多的应用…     

Enhanced Ionic/Electronic Transport in Nano‐TiO2/Sheared CNT Composite Electrode for Na+ Insertion‐based Hybrid Ion‐Capacitors

Ion‐insertion capacitors show promise to bridge the gap between supercapacitors of high power densities and batteries of high energy densities. While research efforts have primarily focused on Li⁺‐based capacitors (LICs), Na⁺‐based capacitors (SICs) are theoretically cheaper and more sustainable. Owing to the larger size of Na⁺ compared to Li⁺, finding high‐rate anode materials for SICs has been challenging. Herein, an SIC anode architecture is reported consisting of TiO₂ nanoparticles anchored on a sheared‐carbon nanotubes backbone (TiO₂/SCNT). The SCNT architecture provides advantages over other carbon architectures commonly used, such as reduced graphene oxide and CNT. In a half‐cell, the TiO₂/SCNT electrode shows a capacity of 267 mAh g^?1 at a 1 C charge/discharge rate and a capacity of 136 mAh g^?1 at 10 C while maintaining 87% of initial capacity over 1000 cycles. When combined with activated carbon (AC) in a full cell, an energy density and power density of 54.9 Wh kg^?1 and 1410 W kg^?1, respectively, are achieved while retaining a 90% capacity retention over 5000 cycles. The favorable rate capability, energy and power density, and durability of the electrode is attributed to the enhanced electronic and Na⁺ conductivity of the TiO₂/SCNT architecture.     

A New Family of Proton‐Conducting Electrolytes for Reversible Solid Oxide Cells: BaHfxCe0.8−xY0.1Yb0.1O3−δ

Reversible solid oxide cells based on ceramic proton conductors have potential to be the most efficient system for large‐scale energy storage. The performance and long‐term durability of these systems, however, are often limited by the ionic conductivity or stability of the proton‐conducting electrolyte. Here new family of solid oxide electrolytes, BaHf_xCe_0.8?xY_0.1Yb_0.1O_3?δ (BHCYYb), which demonstrate a superior ionic conductivity to stability trade‐off than the state‐of‐the‐art proton conductors, BaZr_xCe_0.8?xY_0.1Yb_0.1O_3?δ (BZCYYb), at similar Zr/Hf concentrations, as confirmed by thermogravimetric analysis, Raman, and X‐ray diffraction analysis of samples over 500 h of testing are reported. The increase in performance is revealed through thermodynamic arguments and first‐principle calculations. In addition, lab scale full cells are fabricated, demonstrating high peak power densities of 1.1, 1.4, and 1.6 W cm^?2 at 600, 650, and 700 °C, respectively. Round‐trip efficiencies for steam electrolysis at 1 A cm^?2 are 78%, 72%, and 62% at 700, 650, and 600 °C, respectively. Finally, CO₂? H₂O electrolysis is carried out for over 700 h with no degradation.