Closed loop identification and control loop reconfiguration: an industrial case study

The results of a joint university–industry collaborative project for control loop reconfiguration using closed loop experimental data from a fuel gas pressure control system are described in this paper. The fuel gas pressure was being regulated using a butane stream. For economic reasons, it was necessary to switch control to the ethane stream. Previous attempts at effecting this changeover had proved unsuccessful. In this study, a powerful system identification technique namely Canonical Variate Analysis (CVA) was employed to obtain the empirical plant models. A PI controller was then designed using the direct synthesis method. Acceptable closed loop behavior was obtained with little online tuning.     

螺旋状匹配搜索的块拼贴纹理合成

基于样图的纹理合成方法是继纹理映射、过程纹理合成等方法后发展起来的一种纹理拼贴方法。该文在Efros块拼贴算法和徐晓刚的螺旋状点匹配搜索算法基础上,提出了一种螺旋状匹配搜索的块拼贴算法。该算法利用纹理块的连惯性,在搜索待合成纹理块时,在已合成纹理块在样本图像中位置的邻域进行搜索,找到匹配纹理块后进行输出。该方法大大加快了纹理合成的速度,与Efros块拼贴算法相比,在合成质量不变的基础上,合成速度平均提高了10倍。对于不同的纹理进行实验,其结果也令人满意。     

一种面向并行实现的全局光照算法

提出了种适合于并行实现的全局光照算法。对真实感图象的实时生成和交互式性运行进行了有益的探索,算法主要由两个模块组成;粒子跟踪过程,网格优化与密度估计过程,在此进行了详细介绍。另外,给出算法实际运行得到的具有高度真实感的生成图象。     

模式识别技术对Al_2O_3-TiC-ZrO_2纳米复合材料制备工艺参数的优化和预报

利用燃烧合成 热压工艺制备Al2 O3 TiC ZrO2 纳米复合材料 ,利用计算机模式识别技术中的非线性映照对其工艺参数进行分析。以陶瓷的抗弯强度和断裂韧性作为判据 ,给出参数目标优化区域。采用非线性逆映照研究不同工艺参数对材料性能的影响趋势 ,并对工艺参数进行预报和设计 ,再用实验结果予以验证 ,克服了传统“炒菜式”合成方法的盲目性。     

Synthesis and characterisation of alumina pillared Texas montmorillonite and determination of the effective Keggin ion charge

Controlled calcination of Texas montmorillonite has allowed production of a range of materials of cation exchange capacity from 70 mequiv./100 g dry clay to virtually zero. Pillaring of these with Chlorhydrol precursor solution has then provided a family of materials of pillar density ranging from about one per six unit cells to zero. The analytical technique based on isomorphous metal dilution (IMD) that follows pillaring is validated. The results provide a consistent value for the precursor (Keggin) ion charge, in the conditions normally used, of 3.15±0.10 rather than the formal value of 7. An approach to the attainment of pillar densities consistent with the introduction of shape/size selectivity on pillared layered materials is outlined.     

Preparation of acidic or bifunctional catalysts by means of straightforward calcination of as-synthesized [Ga]-ZSM-5 zeolites obtained from alkali-free media. Propane aromatization

Propane aromatization (530°C, 1 atm) was used as a reaction model to evaluate the effect of the calcination temperature on the catalytic properties of an as-synthesized [Ga_1.3]-ZSM-5 zeolite obtained from alkali-free media and calcined at two different temperatures: 530°C (C-530) and 750°C (C-750). Results show that in spite of its lower acidity, C-750 is more active and selective toward aromatics than C-530. This is probably due to the fact that at higher temperature the decomposition of organic compounds used during the zeolite synthesis is accompanied by a partial degalliation of the zeolitic support leading to the production of a bifunctional xGa₂O₃ /H-[Ga_y-ZSM-5(2x+y=1.3)catalyst.     

Analysis of Written and Spoken Form of Hungarian Numbers for TTS Applications

Correct reading of numbers is an essential feature of today's text-to-speech systems (TTS). This article discusses the problems of converting numbers into letters for Hungarian speech synthesis. In the first part of the article, numbers as an organic part of the text are analyzed. Different representations of ordinals, cardinals, telephone numbers, and date and time formats are examined. Special characters, such as comma, period, and plus or minus sign, and various suffixes attached to the numbers may modify the written and spoken form of the number. Numerous conjugated forms are introduced, and examples are shown for these cases. Next, the prosody of spoken numbers is analyzed; intonation, word stress, and pause assignment rules are discussed. Last, implementation questions of number-to-letter (NTL) conversion are addressed with respect to application in TTS and number-to-speech systems.     

A MODIFIED METHOD FOR SUPERVISOR SPECIFICATION AND SYNTHESIS OF A CLASS OF DISCRETE EVENT SYSTEMS

In this paper, a model‐refining method is proposed to alleviate the complexity involved in specification interpretation of DES control problems. The legal constraint language is defined in terms of illegal states and events in contrast with constructing the automaton of the specification language. This method could provide a more intuitive view of the DES control problem and would be suitable for practical implementation. Two examples, which have commonly been used in the literature, are employed to show the efficiency of the proposed method. Further, under this framework, it is shown that the supremal controllable sublanguage can take a simpler form based on the concept of an illegal state set. A state‐based supervisor synthesis procedure is presented, and a simple example is provided.     

树枝状大分子催化剂的合成与应用研究进展

介绍了一类新型催化剂－树枝状大分子的合成方法。包括发散法，收敛法，高度核心和支化单体法及双倍指数混合生长法，同时介绍了新型催化剂的结构特点，重点论述了催化活性中心在核心和外围端基两类催化剂在加氢，Diels-Alder反应，Fischer-Tropsch反应，Heck反应，Kharasch加成反应等中的应用，展望了这类新型催化剂的发展前景。     

微波辐射四丁基溴化铵催化合成肉桂酸苄酯

研究了以肉桂酸钠和氯化苄为原料，四丁基溴化铵作催化剂，采用微波辐射技术，在常压下直接合成肉桂酸苄酯，以及催化剂用量、微波辐射功率和辐射时间对酯产率的影响。最适宜的反应条件为：当n(肉桂酸钠)／n(氯化苄)为1：1．2时，四丁基溴化铵的用量1．0g，微波功率300W，辐射25min，产率达83％以上。