The purpose of this research is to develop a heuristic algorithm to minimize total costs in multi-commodity, multi-mode generalized networks with time windows problems. The proposed mathematical model incorporates features of the congestion of vehicle flows and time restriction of delivering commodities. The heuristic algorithm, HA, has two phases. Phase 1 provides lower and upper bounds based on Lagrangian relaxations with subgradient methods. Phase 2 applies two methods, early due date with overdue-date costs and total transportation costs, to search for an improved upper bound. Two application networks are used to test HA for small and medium-scale problems. A different number of commodities and various lengths of planning time periods are generated. Results show that HA can provide good feasible solutions within the reasonable range of optimal solutions. If optimal solutions are unknown, the average gap between lower and upper bounds is 0.0239. Minimal and maximal gaps are 0.0007 and 0.3330. If optimal solutions are known, the maximal gap between upper bounds and optimal solutions is less than 10% ranges of optimal solutions.

Cyber-Physical Systems(CPS) are a group of systems that are involved with both physical processes and computational processes. The interaction of physical components and computational components makes it difficult to analyze, design and verify this type of systems. The problem becomes more complex when certain input or decision of these systems must be initiated by human. Cyber-Physical Systems with human operator in the loop are called Embedded Human Systems(EHS). To ensure the safety of EHS such as traffic control systems, space shuttle control systems, nuclear power plant control systems and so on, it is critically important for human operators to fully understand both physical and computational processes. However, humans are usually easily overwhelmed by concurrent information, the situation becomes worse when it comes to complex EHS with timing constraints.This dissertation proposes a domain specific modeling language that takes advantage of hybrid system abstraction to retain important system behaviors and automatically generates self-configured system verification software. The verification software could effectively reduce the computation time with parallel scheduling algorithm, thus the computation process that violates the design protocol can be halted without wasting computation resources. The modeling environment also allows user to conveniently set design constraints to avoid flaws early in prototype phase and reuse the available model for a family of different platforms. Several verification results of different platforms are shown to demonstrate the efficiency and reusability of the modeling environment.

Component-based software engineering is becoming a prominent solution to the development of complex embedded systems. Since it allows a system to be built by reusable and independently developed components, component-based development substantially facilitates the development of a complex embedded system and allows its complexity to be better managed. Meanwhile, partitioning system behavior into multiple operational modes is also an effective approach to reducing system complexity. Combining the component-based approach with the multi-mode approach, we get a component-based multi-mode system, for which a key issue is its mode switch handling. The mode switch of such a system corresponds to the joint mode switches of many hierarchically organized components. Such a mode switch is not trivial as it amounts to coordinate the mode switches of different components that are independently developed. Since most existing approaches to mode switch handling assume that mode switch is a global event of the entire system, they cannot be easily applied to component-based multi-mode systems where both the mode switch of the system and each individual component must be considered, and where components cannot be assumed to have global knowledge of the system. In this thesis, we present a mechanism---the Mode Switch Logic (MSL)---which provides an effective solution to mode switch in component-based multi-mode systems. MSL enables a multi-mode system to be developed in a component-based manner, including (1) a mode-aware component model proposed to suit the multi-mode context; (2) a mode mapping mechanism for the seamless composition of multi-mode components and their mode switch guidance; (3) a mode switch runtime mechanism which coordinates the mode switches of all related components so that the mode switch can be correctly and efficiently performed at the system level; and (4) a timing analysis for mode switches realized by MSL. All the essential elements of MSL are additionally demonstrated by a case study. / ARROWS

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This thesis reports work extending the scope of a recently developed gas sensing technique, multi-mode absorption spectroscopy (MUMAS). The ability of MUMAS to simultaneously detect multiple species from a mixture is demonstrated for the first time. The technique is subsequently extended to mid-infrared wavelengths, realising large gains in sensitivity. A solid-state, multi-mode laser has been developed to provide a high-performance comb source for use with MUMAS. This in-house constructed, diode-pumped, Er/Yb:glass laser operates on 10 longitudinal modes, separated by 18 GHz and centred close to 1565 nm. The extensive development and prototyping work leading to this final laser design is described. Multi-species detection with MUMAS is reported for the first time, thus demonstrating the ability of this technique to perform multi-gas sensing using a single laser and simple detection scheme. The previously described Er/Yb multi-mode laser was used to record MUMAS signals from a sample containing CO, C₂H₂, and N₂O. The components of the mixture were detected simultaneously by identifying multiple transitions in each of the species. Temperature- and pressure-dependent modelled spectral fits to the data were used to determine the partial pressures of each species in the mixture with an uncertainty better than +/-2%. Multi-mode radiation has been successfully generated at 3.3 μm using quasi phase matched difference frequency generation (QPM-DFG). A mid-infrared laser comb was produced by optically mixing the near-infrared, multi-mode comb produced by the previously developed Er/Yb:glass laser with the single-mode output of a Nd:YAG laser operating at 1064 nm. This multi-frequency laser source was characterised to verify performance, and subsequently used to perform proof-of-principle MUMAS measurements on the strong transitions found in this spectral region. Spectra were recorded of NH₃ and CH₄ both individually and as components of a mixture. A minimum detection level for this system was determined to be 4.3 μbar m^-1 for CH₄, a sensitivity increase of 300 over similar measurements performed in the near-IR.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / Increasing gate counts in FPGA’s create an option of offering multiple waveform demodulation and modulation within a single transponder transceiver. Differing data rates, channel schemes, and network protocols can be addressed with the flexibility of software-based demodulation and modulation. Increased satellite longevity and reliability are benefits of software-based transceiver design. Newer packaging technology offers additional capability in reducing form factor and weight of a transponder. A review of the challenges in combining each of the above to produce the next generation of transponders is the subject of this paper.

In this thesis, three control methodologies are proposed for suppressing multi-mode vibration in flexible structures. Controllers developed using these methods are designed to (i) be able to cope with large and sudden changes in the system's parameters, (ii) be robust to unmodelled dynamics, and (iii) have a fast transient response. In addition, the controllers are designed to employ a minimum number of sensor-actuator pairs, and yet pose a minimum computational demand so as to allow real-time implementation. A cantilever beam with magnetically clamped loads is designed and constructed as the research vehicle for evaluation of the proposed controllers. Using this set-up, sudden and large dynamic variations of the beam loading can be tested, and the corresponding changes in the plant's parameters can be observed. Modal testing reveals that the first three modes of the plant are the most significant and need to be suppressed. It is also identified that the first and third modes are spaced more than a decade apart in frequency. The latter characteristic increases the difficulty of effectively controlling all three modes simultaneously using one controller. To overcome this problem, the resonant control method is chosen as the basis for the control methodologies discussed in this thesis. The key advantage of resonant control is that it can be tuned to provide specific attenuation only at and immediately close to the resonant frequency of concern. Consequently, it does not cause control spillover to other modes owing to unmodeled dynamics. Because of these properties, a resonant controller can be configured to form a parallel structure with the objective of targeting and cancelling multiple modes individually. This is possible regardless of the mode spacing. In addition, resonant control requires only a minimum number of collocated sensor-actuator pairs for multi-mode vibration cancellation. All these characteristics make resonant control a suitable candidate for multi-mode vibration cancellation of flexible structures. Since a resonant controller provides negligible attenuation away from the natural frequencies that it has been specifically designed for, it is very sensitive to changes of a system's natural frequencies and becomes ineffective when these mode frequencies change. Hence, for the case of a dynamically loaded structure with consequent variations in mode frequencies, the resonant control method must be modified to allow tracking of system parameter changes. This consideration forms the theme of this thesis, which is to allow adaptive multi-mode vibration control of dynamically-loaded flexible structures. Three controller design methodologies based on the resonant control principle are consequently proposed and evaluated. In the first approach, all possible loading conditions are assumed to be a priori known. Based on this assumption, a multi-model multi-mode resonant control (M4RC) method is proposed. The basis of the M4RC approach is that it comprises a bank of known loading models that are designed such that each model gives optimum attenuation for a particular loading condition. Conceptually, each model is implemented as a set of fixed-parameter controllers, one for each mode of concern. In reality, each mode controller is implemented as an adjustable resonant controller that is loaded with the fixed-model parameters of the corresponding mode. The M4RC method takes advantage of the highly frequency-sensitive nature of resonant control to allow simple and rapid selection of the optimum controller. Identification of the set of resonant frequencies is implemented using a bank of band-pass filters that correspond to the mode frequencies of the known models. At each time interval a supervisor scheme determines for each mode which model has the closest frequency to the observed vibration frequency and switches the corresponding model controller output to attenuate the mode. Selection is handled on a mode-by-mode basis, such that for each mode the closest model is selected. The proposed M4RC is relatively simple and less computationally complex compared to other multi-model methods reported in the literature. In particular, the M4RC uses a simple supervisor scheme and requires only a single controller per mode. Other multi-model methods use more complex supervision schemes and require one controller per model. The M4RC method is evaluated through both simulation and experimental studies. The results reveal that the proposed M4RC is very effective for controlling multi-mode vibration of a flexible structure with known loading conditions, but is ineffective for unmodeled loading conditions. In the second approach, the assumption that all loading conditions are a priori known is relaxed. An adaptive multi-mode resonant control (ARC) method is proposed to control the flexible structure for all possible (including unknown) loading conditions. On-line estimation of the structure's natural frequencies is used to update the adaptive resonant controller's parameters. The estimation of the natural frequencies is achieved using a parallel set of second-order recursive least-squares estimators, each of which is designed for a specific mode of concern. To optimise the estimation accuracy for each mode frequency, a different sampling rate suitable for that mode is used for the corresponding estimator. Simulation and experiment results show that the proposed adaptive method can achieve better performance, as measured by attenuation level, over its fixed-parameter counterpart for a range of unmodeled dynamics. The results also reveal that, for the same sequences of known loading changes, the transient responses of the ARC are slower than those of the M4RC. In the third approach, a hybrid multi-model and adaptive resonant control is utilized to improve the transient response of the ARC. The proposed multi-model multi-mode adaptive resonant control (M4ARC) method is designed as a combination of the M4RC and ARC methods. The basis of the proposed method is to use the M4RC fixed-parameter model scheme to deal with transient conditions while the ARC adaptive parameter estimator is still in a state of fluctuation. Then, once the estimator has reached the vicinity of its steady-state, the adaptive model is switched in place of the fixed model to achieve optimum control of the unforeseen loading condition. Whenever a loading change is experienced, the simple M4RC supervisor scheme is used to identify the closest model and to load the adjustable resonant controllers with the fixed parameters for that model. Meanwhile, the mode estimators developed for the ARC method are used to identify the exact plant parameters for the modes of concern. As soon as these parameters stop rapidly evolving and reach their steady-state, they are loaded into the respective adjustable controllers. The same process is repeated whenever a loading change occurs. Given the simplicity of the M4ARC method and its minimal computation demand, it is easily applicable for real-time implementation. Simulation and experiment results show that the proposed M4ARC outperforms both the ARC with respect to transient performance, and the M4RC with respect to unmodeled loading conditions. The outcomes of this thesis provide a basis for further development of the theory and application of active control for flexible structures with unforeseen configuration variations. Moreover, the basis for the proposed multi-model adaptive control can be used in other areas of control (not limited to vibration cancellation) where fast dynamic reconfiguration of the controller is necessary to accommodate structural changes and fluctuating external disturbances.

L'objet de cette thèse est la construction d'un outil graphique dans le cadre du projet mmi2 (a multi-mode intervade for man-machine interaction with knowledge based systems). Mmi2 est un projet esprit ii qui a pour objectif principal de construire une interface homme-machine intelligent intégrant plusieurs modes de communication: langue naturelle (anglais, français, espagnol), langage de commande, graphique et gestuel. Ce travail est le résultat d'une approche expérimentale de développement d'un outil de manipulation directe, baptisé outil de dessin, dans un environnement multi-mode. Dans ce contexte, notre démarche a consisté à utiliser des techniques de construction géométrique dans la conception d'une interface. Nous proposons pour cela un modèle fonde sur le concept de carte planaire. Il conduit à des structures de données de type représentation par frontières dont la notion de base est le brin, qui est une arête topologique orientée. Ce modèle permet de proposer un algorithme de saisie et de modification de cartes planaires qui, tout en contrôlant à chaque instant la planéité de la carte, est capable de détecter automatiquement la fermeture des contours. Par ailleurs, nous nous sommes intéressés à l'étude de la sémantique graphique, pour permettre l'intégration des différents modes de communication pour assurer un dialogue multi-mode entre l'utilisateur et l'ordinateur.

The objective of the proposed research is to develop novel, fully-packaged voltage controlled oscillators (VCOs), concurrent oscillators, and multi-mode filters using Liquid Crystalline Polymer (LCP) dielectric material that are directly applicable to simultaneous multi-band radio communication. Integrated wireless devices of the near-future will serve more diverse range of applications (computing, voice/video/data communication) and hence, will require more functionality. This research is focused on providing cost-effective and area-efficient solutions for multi-band/multi-mode oscillators and filters using system-on-package (SOP) design methodology. Silicon-based integrated circuits (ICs) provide an economical method of miniaturizing modules and hence, are attractive for multi-band applications. However, fully monolithic solutions are limited, by its high substrate losses, and marginal quality factors (Qs) of the passives, to low profile applications. Furthermore, the VCOs made on conventional packaging technologies are not very cost-effective. This thesis is directed towards developing highly optimized VCOs and filters using LCP substrate for use in multi-mode radio systems. The thesis investigates and characterizes lumped passive components on new LCP based technology feasible for VCO and filter design. The dissertation then investigates design techniques for optimizing both power consumption and the phase noise of the VCOs to be employed in commercial wireless systems. This work then investigates the temperature performance of LCP-based VCOs satisfying military standards. Another aspect of the thesis is the development of dual-band (multi-mode) oscillators. The approach is to employ existing multi-band theories to demonstrate one of the first prototypes of the oscillator. Finally, the design of multi-mode, lumped-element type filters was investigated.

In digital signal processing and multimedia applications, floating-point(FP) multiplication and addition are the most commonly used operations. In addition, FP multiplication operations are frequently followed by the FP addition operations. Therefore, in order to achieve high performance and low cost, multiplication and addition are usually combined into a single unit, known as the FP Multiply-Add Fused (MAF). On the other hand, the mobile devices nowadays are rapidly developing. For this kind of devices, performance and power sustainability have to become the major trend in the research area. As a result, the mechanisms to reduce energy consumption become more important. Therefore, we propose a multi-mode FP MAF based on the concept of iterative multiplication and truncated addition, to achieve different operating modes with different errors. This MAF, with a total of seven modes, includes three modes for the FP multiply-accumulate operations, two modes for single FP multiplication operation and single FP addition operation, respectively. FP multiply-accumulate operations provide three modes to user, and this three modes have 0%, 0.328% and 1.107% of error. The 0% error is the same with the standard IEEE754 single-precision FP Multiply-Add Fused operations. For FP multiplication and FP addition operations, the proposed MAF allows users to choose two kinds of error modes, which are 0%, 0.328% error for FP multiplication and 0%, 0.781% error for FP addition. The 0% error is the same with the standard IEEE754 single-precision floating-point operations. When compared with the standard IEEE754 single-precision FP MAF, the proposed multi-mode FP MAF architecture has 4.5% less area and increase about 22% delay to achieve the effect of multi-mode. To demonstrate the power efficiency of proposed FP MAF, it is used to perform the operations of FP MAF, FP multiplication, and FP addition in the application of RGB to YUV format conversion. Experimental results show that, the proposed multi-mode FP MAF can significantly reduce power consumption when the modes with error are adopted.