Integral sliding mode design for robust filtering and control of linear stochastic time‐delay systems

This paper presents an integral sliding mode technique robustifying the optimal controller for linear stochastic systems with input and observation delays, which is based on integral sliding mode compen‐sation of disturbances. The general principles of the integral sliding mode compensator design are modified to yield the basic control algorithm oriented to time‐delay systems, which is then applied to robustify the optimal controller. As a result, two integral sliding mode control compensators are designed to suppress disturbances in state and observation equations, respectively, from the initial time moment. Moreover, it is shown that if certain matching conditions hold, the designed compensator in the state equation can simultaneously suppress observation disturbances, as well as the designed compensator in the observation equation can simultaneously suppress state disturbances. The obtained robust control algorithm is verified by simulations in the illustrative example, where the compensator in the observation equation provides simultaneous suppression of state and observation disturbances. Copyright © 2005 John Wiley & Sons, Ltd.     

Tree Induction for Probability-Based Ranking

Tree induction is one of the most effective and widely used methods for building classification models. However, many applications require cases to be ranked by the probability of class membership. Probability estimation trees (PETs) have the same attractive features as classification trees (e.g., comprehensibility, accuracy and efficiency in high dimensions and on large data sets). Unfortunately, decision trees have been found to provide poor probability estimates. Several techniques have been proposed to build more accurate PETs, but, to our knowledge, there has not been a systematic experimental analysis of which techniques actually improve the probability-based rankings, and by how much. In this paper we first discuss why the decision-tree representation is not intrinsically inadequate for probability estimation. Inaccurate probabilities are partially the result of decision-tree induction algorithms that focus on maximizing classification accuracy and minimizing tree size (for example via reduced-error pruning). Larger trees can be better for probability estimation, even if the extra size is superfluous for accuracy maximization. We then present the results of a comprehensive set of experiments, testing some straightforward methods for improving probability-based rankings. We show that using a simple, common smoothing method—the Laplace correction—uniformly improves probability-based rankings. In addition, bagging substantially improves the rankings, and is even more effective for this purpose than for improving accuracy. We conclude that PETs, with these simple modifications, should be considered when rankings based on class-membership probability are required.     

Programming by Demonstration Using Version Space Algebra

Programming by demonstration enables users to easily personalize their applications, automating repetitive tasks simply by executing a few examples. We formalize programming by demonstration as a machine learning problem: given the changes in the application state that result from the user's demonstrated actions, learn the general program that maps from one application state to the next. We present a methodology for learning in this space of complex functions. First we extend version spaces to learn arbitrary functions, not just concepts. Then we introduce the version space algebra, a method for composing simpler version spaces to construct more complex spaces. Finally, we apply our version space algebra to the text-editing domain and describe an implemented system called SMARTedit that learns repetitive text-editing procedures by example. We evaluate our approach by measuring the number of examples required for the system to learn a procedure thatworks on the remainder of examples, and by an informal user study measuring the effort users spend using our system versus performing the task by hand. The results show that SMARTedit is capable of generalizing correctly from as few as one or two examples, and that users generally save a significant amount of effort when completing tasks with SMARTedit's help.     

Preparation of polyclonal antibodies specific for wine proteins

Immunology is an expanding area of research with potentially important applications in the analysis of many biological molecules. Polyclonal antibodies were raised in rabbits against specific proteins as well as against the total protein from a Portuguese wine. FPLC cation exchange chromatography was used to isolate the total protein fraction and, when in combination with denaturing electrophoresis, to purify individual wine polypeptides. To obtain a high titre, an injection of each antigen followed by three boosters were given in the immunisation of each rabbit. The titre of the antisera was measured by the ELISA technique and the specificity of the antibodies detected by immunoblotting. The antibodies produced were shown to be highly specific for the corresponding antigens. However, antibodies obtained specifically against a highly purified wine polypeptide seem to recognize the other major wine polypeptides, raising the possibility of structure similarity between different wine proteins. Neither the anti‐total wine protein antibodies not the anti‐specific wine protein antibodies originated a signal when used to probe thaumatin or chitinase. © 1999 Society of Chemical Industry     

Prediction of gas hold-up and liquid velocity in airlift reactors using two-phase flow friction coefficients

The overall friction coefficient (K_f) of airlift reactors was estimated using equivalent lengths (L_eq) and friction factors ( f ). The friction factor was calculated taking into account the riser liquid velocity profile corresponding to the two-phase flow and using classical one-phase equations. A previously described model was used to obtain simultaneously both gas hold-up and liquid circulation velocity. The model simulates experimental data obtained in a wide range of configurations of internal (2 and 30 dm³ volume) and external (from 8 to 600 dm³ volume) airlift reactors with Newtonian (water and alcohol solutions) and non-Newtonian (carboxymethylcellulose (CMC) solutions) systems. Com-parison with other models from the literature yielded similar results.     

甘蔗糖厂联产燃料酒精及全面降低能耗--可获取最大的经济效益

近年来,由于生物量电能的价格较高,更为有利可图,糖厂进行联产发电(糖厂利用蔗渣发电,并将多余的电量出售给糖厂以外的用户)的需求越来越大.本文论述为获得最大联产效果而重新设计糖厂的主要措施,例如,工艺用汽的用量降低,采用高压锅炉,以及冷凝式和部分背压式透平机,全部工序用电动机操作.措施也包括把甘蔗中糖量的5 0%用于产糖,其余用于酒精生产.为了提高糖厂的联产潜力,在酒精生产的蒸馏过程中尽量减少蒸汽消耗显得很有必要.在蒸馏车间采用中压蒸汽和多抽用汁汽,这比传统普遍使用的方法降低约4 3%的汽耗,可使联产的糖厂减少乏汽的用量,并可增加高压蒸汽入冷凝式透平机.糖厂和酒精厂重新设计组合能获得最大的联产效果,生产能力从目前的12.8 kW·h/t提高到82.6 kW·h/t,这种联产的经济效益十分显著.特别是像巴西、危地马拉、毛里求斯,甚至印度等这些地区可在甘蔗生产季节中以相当可观的电价出售大量的电能.     

Pathogenesis of Penile Squamous Cell Carcinoma: Molecular Update and Systematic Review

Penile squamous cell carcinoma (PSCC) is a rare but aggressive neoplasm with dual pathogenesis (human papillomavirus (HPV)-associated and HPV-independent). The development of targeted treatment is hindered by poor knowledge of the molecular landscape of PSCC. We performed a thorough review of genetic alterations of PSCC focused on somatic mutations and/or copy number alterations. A total of seven articles have been identified which, overall, include 268 PSCC. However, the series are heterogeneous regarding methodologies employed for DNA sequencing and HPV detection together with HPV prevalence, and include, in general, a limited number of cases, which results in markedly different findings. Reported top-ranked mutations involve TP53, CDKN2A, FAT1, NOTCH-1 and PIK3CA. Numerical alterations involve gains in MYC and EGFR, as well as amplifications in HPV integration loci. A few genes including TP53, CDKN2A, PIK3CA and CCND1 harbor both somatic mutations and copy number alterations. Notch, RTK-RAS and Hippo pathways are frequently deregulated. Nevertheless, the relevance of the identified alterations, their role in signaling pathways or their association with HPV status remain elusive. Combined targeting of different pathways might represent a valid therapeutic approach in PSCC. This work calls for large-scale sequencing studies with robust HPV testing to improve the genomic understanding of PSCC.     

Bicyclic O,P Ligands for Catalytic Asymmetric 1,4‐Addition to α,β‐Unsaturated Ketones

A new class of bicyclic O,P ligands has been prepared and evaluated in the 1,4‐addition to α,β‐unsaturated ketones. The best results with the bicyclic ligand were obtained using a lower catalyst loading than what has been reported with similar ligands when adding a Grignard reagent to 2‐cyclohexenone.