Microsized optical parametric oscillator in a photonic crystal

In this paper, we study optically parametric oscillation in a doubly resonant microsized cavity in a lithium niobate photonic crystal. Maxwell's equations are solved directly using the finite-difference time-domain scheme to compute stationary solutions and to obtain the bifurcation diagrams for different pump detunings. The results are compared to predictions from a mean-field approach.     

Quasi-one-dimensional photonic crystal as a compact building-block for refractometric optical sensors

We report the fabrication and the characterization of the refractometric and thermo-optical properties of a quasi-one-dimensional waveguide photonic crystal-a strong, 76-/spl mu/m-long Bragg grating. The transmission spectra (around 660 nm) of the structure have been measured as a function of both the cladding refractive index and the temperature. The transmission stopband was found to shift by 0.8-nm wavelength for either a cladding refractive index change of 0.05 or a temperature change of 120 K. The steep stopband edges provide a sensitive detection method for this band shift, by monitoring the transmitted output power.     

A correlation concept for the energy cost: a case study in Egypt

This paper presents two factors for the correlation of energy cost. The first factor is based on the process of accounting and the cycle of recording the readings of consumption in order to control the exact cost of energy. A sample for the domestic customers in Egypt within 20 years has been included in the investigation and analyzed. The mathematical analysis is deduced. Another sample for the load curves in Port Said City is inserted and investigated. The statistical performance for the readings of the presented load curves is deduced and the results are discussed. A second correlation factor for pricing the energy is proposed to cover the engineering effect in the technical process of operation. It correlates the automatic random variation in loads of customers and the load curves on the statistical base. The mathematical analysis for either average price of consumed energy or the statistical average loads, with the variation of load curves characteristics, are presented.     

Dynamic control over optical solitons in a resonant photonic crystal

When a defect associated with a weak linear excitation or incoherent pump inside a resonant photonic crystal is created, dynamics of light propagation in a gap soliton regime undergo a considerable modification. We show that dynamic control of such a defect can be used to convert coherently a propagating optical pulse into a stationary excitation trapped inside the photonic crystal. This can also impose changes onto a pulse interaction with each other, thus facilitating possible applications in optical switching, signal processing, and quantum computing.     

A holonic control system based on a universal learning network

A new control method is presented using the holonic concept on a universal learning network (ULN). The holonic concept was proposed by Arthur Koestler in 1905. Its aim is to harmonize entire systems with partial systems that have hierarchal structures. On the other hand, a ULN that models and controls large-scale complicated systems such as industrial plants and, economic, social, and life phenomena is proposed. In this paper, a holonic control system based on the holonic concept and ULN is presented. From simulation results from a nonlinear crane system, it has been proved that holonic control can harmonize the system rather than optimize it, which used to be the conventional method in control engineering.     

A model for advanced in-house industrial training: a case study onintelligent system technology transfer using a project-oriented approach

Petroleo Brasileiro SA (PETROBRAS) in conjunction with Synergetics Science and Technology Inc. has developed a comprehensive graduate level educational program in intelligent system design technology. The primary goals of this program are: training professionals to apply artificial intelligence (AI) and neural networks (NN) techniques to managerial and technological problem solving, and to do this in a manner that is both time- and cost-effective. This particular program has been centered around two distinct areas of specialization: symbolic AI and the connectionist approach (NNs). The AI section of the course is titled CAVIAR. The NN section of the course is titled CERN. Short courses and seminars were also part of the program. For this paper, our focus has been to deal with the special needs of graduate-level education in large companies as part of employee professional training. We also explore the nuances of, and the various needs associated with teaching intelligent system design technologies to such a diverse group, as is found in large companies like PETROBRAS. This paper also describes the needs that led to the development of such a broad-based program, the goals and structures of the various courses, the student profiles, educational facilities (libraries and computer laboratories), and the lessons learned. Finally, the conclusion offers recommendations     

A system for in-vivo cardiac optical mapping

Optical mapping of cardiac electrical activity is a valuable technique for studying arrhythmias, particularly the effects of defibrillation shocks. This technique has been exclusively applied to in-vitro preparations of hearts or tissues removed from an animal. But verification of experimental results and hypotheses is ideally performed in vivo on the heart as it remains in place in the animal. However, in-vitro optical mapping instrumentation and techniques cannot be easily applied in vivo. This article describes a system the authors developed to address this problem     

A hyperspectral imaging system for in vivo optical diagnostics

This paper details the basic principles and instrumental systems as well as applications of hyperspectral imaging system in the biomedical field. The development of an HSI system that combines recent advances in several photonic technologies, including an AOTF, a 2-D CCD detector, and imaging fiber optics. The integration of these technologies leads to a versatile and powerful imaging system that can rapidly record spectral images of samples. This imaging system could find useful applications in medical diagnostics applications where rapid in vivo detection of complex samples is required. The HSI technique has the potential for in site optical diagnosis on tissue and it can be use for guidance of surgical intervention and treatment. The optical diagnostic approaches may either be an imaging modality or a spectroscopic modality. The spectroscopic diagnostics may also provide real-time assessment of tissue response to therapy.     

通用的发电厂继电保护整定计算及管理软件

开发了一套通用性较好的发电厂继电保护整定计算及管理软件。该软件以通用性为开发原则,针对不同厂家生产的同一原理的保护在名称和整定计算方法上的差别造成的通用性问题,采用V isual Basic 6.0与SQL Server结合的方法,提高了软件的通用性,并介绍了软件各模块的功能和特点。     

通用的发电厂继电保护整定计算及管理软件

开发了一套通用性较好的发电厂继电保护整定计算及管理软件.该软件以通用性为开发原则,针对不同厂家生产的同一原理的保护在名称和整定计算方法上的差别造成的通用性问题,采用Visual Basic 6.0与SQL Server结合的方法,提高了软件的通用性,并介绍了软件各模块的功能和特点.     

Optical MEMS for photonic switching-compact and stable optical crossconnect switches for simple, fast, and flexible wavelength applications in recent photonic networks

We review the development trends and state-of-the-art technologies of large-port-count optical switches over the past decade. Practical implementation of optical switch fabrics is discussed in terms of optical switch architectures, optical configurations, port counts, switch elements, and so on. We describe compact and stable optical crossconnect three-dimensional microelectromechanical systems (3-D-MEMS) switches that are a key technology in recent photonic networks. To show how these enable simple, fast, and flexible wavelength applications in the photonic layer, we discuss the fast and stable MEMS switching by novel comb actuator and V-shaped torsion bar, compact optical configuration with roof-type mirror, stable switch housing with cubic structure, packaging techniques by tolerance expansion and simple procedures of the component assembly, MEMS mirror controller with fast and low power digital notch circuit, reliability by shock absorption, and field trials. In addition, we discuss the impact of these switches on system integration for recent metropolitan area networks and enterprise networks.     

Computer integrated manufacturing: a case study in the cementindustry

Efforts by California Portland Cement (CPC) to decrease manufacturing costs and increase productivity throughout the cement division are discussed. One aspect of these efforts has involved the planning for and the application of computer integrated manufacturing (CIM) to provide managers at all levels with the tools and information they need to achieve these goals. The CIM effort has been directed at both corporate and plant functions and includes both manufacturing and support personnel. The breadth of the hardware installation has ranged from new distributed control systems to corporatewide data communications networks and individual personal computers and workstations. Applications software has ranged from typical motor control logic and direct digital control algorithms to distributed databases and expert systems. A generic CIM model is used to summarize work to date in three cement plants constructed or modernized over the last 25 years. Directions for the future are also highlighted. Special emphasis is placed on identifying the areas of highest return for CIM in the cement industry, and the practical and political pitfalls of implementing CIM in any manufacturing environment are discussed     

An ultra-low material loss ellipse core-based photonic crystal fiber for terahertz wave guiding: design and analysis

In this research work, we report a new design model of quasi-shaped cladding areas with rotated-hexa-based elliptical shaped core areas in photonic crystal fiber (Q-PCF) for terahertz waves of communication signals. Here, we present a six-layer circular air hole in the quasi-shape of cladding regions with two layers of rotated-hexa-based elliptical shaped air holes in the core regions of the Q-PCF for analysis of communication networks in the terahertz regime. Additionally, perfectly matched layers and the finite element method based on the COMSOL software are used to design this Q-PCF. For short- and wideband communication sectors, our proposed Q-PCF is highly useful, as it reduces ultralow effective material loss (EML), confinement loss, and scattering loss in the terahertz regime. After analysis of the numerical results, our suggested Q-PCF shows an ultralow EML of 0.0159 cm^?1, power fraction in the core area of 74%, large effective area of 5.49?×?10^–8 m², confinement loss of 3.22?×?10^–12 cm^?1, and scattering loss of 1.23?×?10^–10 at 1 THz frequency. Moreover, our proposed Q-PCF demonstrates single-mode propagation by the graphical results of the V-parameter over a frequency range of 0.80–3 THz. Our results suggest, we can clearly say that the reported Q-PCF may be highly appropriate for terahertz wave propagation for many communication networks.

     

基于图论理论的通用化操作票微机生成系统

介绍了一个基于Windows平台的新型可视化操作票自动生成系统,以图论为基础,提出了主接线图拓扑结构的邻接矩阵表示法和保护配置的关联矩阵表示法,使通用性成为可能。该系统具备良好通用性和用户可维护性,具有操作票模拟演示和模拟培训功能。     

DSP for practicing engineers: a case study in Internet course delivery

With the explosion of the Internet and the desire of many institutions to disseminate courses across the world, many students look to online education with promise. However, institutions planning to provide distance learning opportunities may wish to have a model to analyze before venturing forth. There are many factors that ultimately influence the methods of delivery, content, length, and technical support for an online course. This paper presents the design, implementation, and evaluation of an online course titled DSP for Practicing Engineers at the Georgia Institute of Technology, Atlanta, and analyzes feedback from students who have taken the course and the staff who administered it. Different aspects of course development are discussed at length, including curriculum and media type.     

Total in situ etching and regrowth in an MBE system: application toburied heterostructure lasers

A new chlorine-based chemical beam etching technique (CBET) has been combined with molecular beam epitaxy (MBE) technology to prepare InP-InGaAsP buried heterostructures in a total in situ etching and regrowth process for the first time. This novel processing technology, combining two techniques in the same MBE growth chamber, is very attractive for the realization of high-performance discrete or integrated optoelectronic devices. The different aspects of the etching process optimization are reviewed in the case of InP-InGaAsP heterostructures, and a first application to buried heterostructure laser fabrication is presented. The results obtained for buried ridge stripe (BRS) lasers are very promising and compare favorably to the state-of-the-art lasers. This first device application passes a milestone in the development of this new technology and demonstrates its potential for further applications to the fabrication of optoelectronic devices     

A case study of wind energy conversion systems in an electric utility system

The potential of wind energy conversion systems (WECS) in a regional electric utility system was investigated. The Kansas Gas and Electric Company (KG&E) with 1800 MW generating capacity served as the case study subject.The general methodologies utilized to conduct a case study of this nature are outlined and then applied to investigate the impacts of WECS on the specific electric utility system selected for this study. Five years of concurrent wind/load data were used to simulate 15 years of KG&E system operation without and with WECS. The KG&E system simulation computer programs were used to model hour-by-hour operation and to generate fuel requirements, production costs, and other reports. The “loss-of-load probability” (LOLP) index was also calculated for the system without and with WECS, from whcih the effective capacity of WECS was determined. Economic analysis was performed to assess the value of WECS in the KG&E system, and breakeven WECS costs were calculated by considering WECS as “fuel saver”, plus extra tax credit and capacity credit.     

Market power implication on congested power system: A case study of financial withheld strategy

Market power refers to the ability of generators in influencing the energy prices above competitive level to obtain more profits. It may be the cause of transmission congestion that limits transfer capability in an interconnected area. Hence an independent system operator (ISO) must be able to detect the conditions in which market power has been practiced to guarantee a secure competition and economical operation of the electricity market. To cope up with transmission congestion to assess market power, an optimal power flow (OPF) based on shift-factor methodology to find out a new indicator, called congestion-based dynamic dispatch index has been proposed. One of the beneficial feature of the proposed method is the ability to recognise accurately the most potential generator to exercise the market power. A generator bidding scheme represented by financial withheld strategy is then utilised to investigate the dynamic condition of power market. An analysis on the power market performance to identify potential generators in exercising market power is also presented. The results show that transmission congestion condition may be created unnaturally by this particular bidding strategy. It prevents some cheap generators to supply their outputs and allows all more expensive generators within the congested zone to gain more profits at the cost of other market participants.     

The setting-up of an optical remote sensing system for targetidentification: a laboratory experiment

The construction of an optical system for vibration measurement using laser doppler velocimetry (LDV) is presented, the basis of which can be used as a laboratory experiment for the classroom. LDV is an optical technique that can be used to determine an object's velocity by analyzing the frequency content of coherent light reflected from it. It can be used for vibration measurement, target identification, covert surveillance or studying the flow of fluids. The setting up of such a system in the laboratory can sometimes be difficult if it is performed in a nonsystematic way. This paper describes an approach to configuring a free-space optical system and also demonstrates the optical equivalence of cochannel and multipath interference