Ledge Design of InGaP Emitter GaAs Based HBTs

A wide range of emitter composition, thickness, and doping is studied via dc current gain measurements on large area GaAs based heterojunction bipolar transistors (HBTs) at both room and elevated temperatures. InGaP emitters offer the widest thickness and doping design window in terms of dc peak current gain, as compared with AlGaAs emitters. Remarkably, a 50 Å InGaP emitter HBT retains 50% gain of a more standard 500 Å emitter device. For state-of-the-art HBTs, a degraded peak gain is argued to be caused by an increased reverse hole injection current (IRHI). In light of previously published results which implicate IRHI as a mechanism for materials limited HBT reliability, we suggest dc current gain measurements on large-area HBTs give meaningful insights into the long term reliability of the structure. Specifically, the wider emitter thickness and doping design window offered by an InGaP emitter HBT could apply to reliability as well as to the demonstrated gain stability

Color Inheritance and Sex Inheritance in Certain Aphids

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Reflections on a coaching pilot project in healthcare settings

This paper draws on personal reflection of coaching experiences and learning as a coach to consider the relevance of these approaches in a management context with a group of four healthcare staff who participated in a pilot coaching project. It explores their understanding of coaching techniques applied in management settings via their reflections on using coaching approaches and coaching applications as healthcare managers. Coaching approaches can enhance a manager’s skill portfolio and offer the potential benefits in terms of successful goal achievement, growth, mutual learning and development for both themselves and staff they work with in task focused scenarios

Exploiting Expertise through Knowledge Networks

The paper discusses the necessary capabilities of knowledge networks: categorizing (the ability to classify Web pages and other unstructured data automatically); hyperlinking (the ability to add to each item of information appropriate pointers to other relevant items of information); alerting (the automatic notification of users and agents to new information that might be of interest to them); and profiling (the construction of models of users and agents to describe their interests and expertise)

Consensus Ontologies: Reconciling the Semantics of Web Pages and Agents

As you build a Web site, it is worthwhile asking, Should I put my information where it belongs or where people are most likely to look for it? Our recent research into improving searching through ontologies is providing some interesting results to answer this question. The techniques developed by our research bring organization to the information received and reconcile the semantics of each document. Our goal is to help users retrieve dynamically generated information that is tailored to their individual needs and preferences. We believe that it is easier for individuals or small groups to develop their own ontologies, regardless of whether global ones are available, and that these can be automatically and ex-post-facto related. We are working to determine the efficacy of local annotation for Web sources, as well as performing reconciliation that is qualified by measures of semantic distance. If successful, this research will enable software agents to resolve the semantic misconceptions that inhibit successful interoperation with other agents and that limit the effectiveness of searching distributed information sources

Personal Ontologies

Corporations can suffer from too much information, and it is often inaccessible, inconsistent, and incomprehensible. The corporate solution entails knowledge management techniques and data warehouses. The paper discusses the use of the personal ontology. The promising approach is an organization scheme based on a model of an office and its information, an ontology, coupled with the proper tools for using it

Automating Supply Chains

A recent study found that supply-chain problems cost companies between 9 and 20 percent of their value over a six-month period (T.J. Becker, 2000). The problems range from part shortages to poorly utilized plant capacity. When you place this in the context of the overall business-to-business (B2B) market expected to reach US$7 trillion by 2004 (37 percent of which is projected to be e-commerce sales), it is easy to see that effective supply-chain management (SCM) tools could save companies billions of dollars. Attempts to automate solutions to these problems are complicated by the need for the different companies in a supply chain to maintain the integrity and confidentiality of their information systems and operations. The modeling technologies currently used within the manufacturing business-to-business standards communities, such as the Open Applications Group (http://www.openapplications.org) and RosettaNet (http://www.rosettanet.org) do a good job of capturing user requirements. Unfortunately, current technologies do not explicitly link the requirements to formal process models. This missing link is crucial to efficient SCM implementations

GaAs-based Self-Aligned Stripe Superluminescent Diodes Processed Normal to the Cleaved Facet

We demonstrate GaAs-based superluminescent diodes (SLDs) incorporating a window-like back facet in a self-aligned stripe. SLDs are realised with low spectral modulation depth (SMD) at high power spectral density, without application of anti-reflection coatings. Such application of a window-like facet reduces effective facet reflectivity in a broadband manner. We demonstrate 30mW output power in a narrow bandwidth with only 5% SMD, outline the design criteria for high power and low SMD, and describe the deviation from a linear dependence of SMD on output power as a result of Joule heating in SLDs under continuous wave current injection. Furthermore, SLDs processed normal to the facet demonstrate output powers as high as 20mW, offering improvements in beam quality, ease of packaging and use of real estate. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Time dependence of evanescent quantum waves

The time dependence of quantum evanescent waves generated by a point source with an infinite or a limited frequency band is analyzed. The evanescent wave is characterized by a forerunner (transient) related to the precise way the source is switched on. It is followed by an asymptotic, monochromatic wave which at long times reveals the oscillation frequency of the source. For a source with a sharp onset the forerunner is exponentially larger than the monochromatic solution and a transition from the transient regime to the asymtotic regime occurs only at asymptotically large times. In this case, the traversal time for tunneling plays already a role only in the transient regime. To enhance the monochromatic solution compared to the forerunner we investigate (a) frequency band limited sources and (b) the short time Fourier analysis (the spectrogram) corresponding to a detector which is frequency band limited. Neither of these two methods leads to a precise determination of the traversal time. However, if they are limited to determine the traversal time only with a precision of the traversal time itself both methods are successful: In this case the transient behavior of the evanescent waves is at a time of the order of the traversal time followed by a monochromatic wave which reveals the frequency of the source.Comment: 16 text pages and 9 postscript figure