Differential representation of a general class of linear systems

In this paper it is shown that it is possible to derive a differential equation from an explicit form evolution equation that was introduced in a previously published paper to describe a very general class of ( in general infinite-dimensional) linear systems. The theory is developed for the case of Hilbert-space-valued inputs and outputs, instead of scalar-valued as in the previous article.     

Assessment of chitosan and extracts of lemon and sage as natural antimicrobial agents during Fior di latte cheesemaking

The use of antimicrobial active compounds (chitosan, lemon and sage extract) in Fior di latte cheesemaking was assessed. The three agents were added at different concentrations during processing cow’s milk. Control cheese was also made without active compounds. All cheese samples were kept at 4°C for 7 days and investigated for sensory and microbiological properties. Results clearly showed that the addition of lemon extract and chitosan increased cheese shelf life. In particular, the highest increase (129%) was recorded by adding 1000 mg/kg of lemon. In contrast, the addition of sage extract negatively affected the sensory properties, thus making the cheese unacceptable.     

Improved Emulsifying and Foaming of Whey Proteins after Enzymic Fat Hydrolysis

In an effort to improve emulsifying and foaming of sweet whey and whey protein concentrate, we studied the hydrolysis of the residual fat in these preparations with a sn 1,3 specific lipase. This enzymatic lipolysis would convert almost all triglycerides into mono- and diglycerides which have strong surface-active properties. Therefore, the emulsifying and foaming capacities of such modified whey products should be increased in comparison with native products, as shown by results presented at both neutral pH and those similar to a salad dressing emulsion. It was also demonstrated that emulsions and foams formed with lipasetreated whey preparations were more shelf-stable.     

两种补偿动态摩擦力的先进控制策略1)

在小型DC伺服电机中，静摩擦力和库仑摩擦力的影响是相当明显的. 本文提出了改善系统响应特性的两种控制策略. 第一种基于摩擦力模型的在线补偿， 适用于变化信号的跟踪. 第二种基于自学习原理的重复控制，适用于周期信号的跟踪. 两种控制策略均已实施在计算机控制的伺服系统中. 给出了与常规控制结果的对比.     

MULTI-AGENT INFRASTRUCTURES FOR OBJECTIVE AND SUBJECTIVE COORDINATION

Coordination in multi-agented systems (MAS) can be conceived as either an agent activity (the subjective viewpoint) or an activity over agents (the objective viewpoint). The two viewpoints have generated two diverging and often contrasting lines of research, as well as different and noncompatible technologies, however, their integration is mandatory for modeling and engineering complex MAS. In this paper, we explore the issue of integration at both the model and the technology levels.

First, by taking FIPA agents and coordination artifacts as reference notions for subjective and objective approaches, respectively, we sketch a framework where agent interactions with coordination artifacts are modeled as physical acts, deliberated and executed by agents analogously to communicative actions. Then, we show how the JADE infrastructure for FIPA-compliant agents, and the TuCSoN infrastructure providing agents with coordination artifacts can be integrated at the technology level, allowing JADE agents to access TuCSoN tuple centers through JADE services.     

Optimal H2 and H∞ LQ stochastic feedforward control

This paper deals with the solution of the discrete-time LQ stochastic tracking and servo problems for a general system configuration. It is shown that the resultant solution is in the form of a three-degree-of-freedom controller when the vector of the exogeneous signal is extended to include accessible disturbances. In particular, it is shown that a separation property between feedback, reference and accessible disturbance feedforward actions, proved for a two-degree-of-freedom optimal LQ stochastic control scheme, also holds true for the general system configuration here addressed. Further, this separation property can be suitably extended, when a linear control law is assumed, to the minimax LQ stochastic tracking and servo problems.     

Multisource remotely sensed data,field checks and seismicity for the definition of active tectonics in Ecuadorian Andes

Abstract

The active tectonics of the Ecuadorian Andes were analysed by the correlation of remotely sensed features, and microtectonic and seismological data. Landsat and radar imagery, and airborne stereophotos, were employed to investigate the fault pattern of scarcely accessible areas, with special reference to those lineaments showing young morphology, linear continuity and dragging effect on streams of post-glacial age. Some NNE-SSW long lineaments characterized by right-lateral strike-slip motions, were identified in the eastern Andes as probably very recent faults. Field microtectonic analysis was guided by remotely sensed data and allowed the reconstruction of the active tectonic compressional stress field characterized by a WSW-ENE trending σ. It also confirmed the recent motions along the NNE-SSW set. These data are consistent with published focal mechanism solutions in the same area. The seismicity is explained by a kinematic model of the upper crust, in which west dipping oblique thrusts and strike-slip faults coexist in the eastern Andes. Following the remotely sensed data and the available literature this model is extended southwards to complete the regional geodynamic framework.     

Exact augmented lagrangian approach to multilevel optimization of large-scale systems

An approach based on the exact augmented lagrangian function is developed for the optimization of large-scale systems composed of interconnected units. The decomposition and coordination strategies are examined and various schemes of upper-level coordination are proposed, all of which are formulated as unconstrained quadratic minimization problems. Convergence analysis is performed exploiting an analogy with minimization by relaxation methods. Numerical examples are reported.     

Glottal closure instant and voice source analysis using time-scale lines of maximum amplitude

¹Time-scale representation of voiced speech is applied to voice quality analysis, by introducing the Line of Maximum Amplitude (LoMA) method. This representation takes advantage of the tree patterns observed for voiced speech periods in the time-scale domain. For each period, the optimal LoMA is computed by linking amplitude maxima at each scale of a wavelet transform, using a dynamic programming algorithm. A time-scale analysis of the linear acoustic model of speech production shows several interesting properties. The LoMA points to the glottal closure instants. The LoMA phase delay is linked to the voice open quotient. The cumulated amplitude along the LoMA is related to voicing amplitude. The LoMA spectral centre of gravity is an indication of voice spectral tilt. Following these theoretical considerations, experimental results are reported. Comparative evaluation demonstrates that the LoMA is an effective method for the detection of Glottal Closure Instants (GCI). The effectiveness of LoMA analysis for open quotient, amplitude and spectral tilt estimations is also discussed with the help of some examples.