Com

COM (Channel Operating Margin) was initially adopted in the IEEE802.3bj standard. The intent is to qualify a high speed serial channel in the context of a specification. The analysis is expected to be fast and efficient, utilizing transmitter and receiver specification parameters. This is in contrast to time-domain bit-by-bit simulations that require both high quality device models and a long running time. This paper focuses on the following six areas, with the emphasis on PAM4 signaling: (1) COM sampling time determination and its impact on channel margin (2) DFE tap coefficient impact on link error propagation and FEC CG (3) Jitter treatment and its impact on the accuracy in predicting COM (4) TX output signal level separation mismatch and how it is treated (5) CTLE implementation discussion and its implications for COM (6) COM margin computation and COM pass/fail criteria discussions The first goal of the paper is to provide the very basics for the beginners of COM. The second goal is to bring adequate attention to the COM community so that the computed results for PAM4 channels can be better interpreted and link margin assessment decisions can be more properly made without being too optimistic or too pessimistic for PAM4 systems in which FEC is mandatory.

A multi-purpose low-earth-orbit system of rings circling the earth - the "LEO ARCHIPELAGO" - is proposed as a means of solving or bypassing many major problems hindering man's quest to get into space. A fiber-optic ring about the earth would be an initial testing and developmental stage for the ring systems, while providing cash-flow through a LEO-based, high-band-width, world-wide communication system. A Low-Earth-Orbit-based space-elevator system, "Sling-on-a-Ring," is proposed as the crucial developmental stage of the LEO Archipelago. Being a LEO-based heavy-mass lifter, rather than earth- or GEO-based, it is much less massive and therefore less costly than other proposed space-elevators. With the advent of lower-cost, higher-mass transport to orbit, the options for further space development (e.g., communications, space solar power, radiation dampers, sun shades, and permanent LEO habitation) are greatly expanded. This paper provides an update of the Sling-on-a-Ring concept in terms of new materials, potential applications, and trade-offs associated with an earlier model. The impact of Colossal Carbon Tubes, CCT, a material with high tensile strength, extremely-low density, and other favorable properties and new technologies (e.g., solar-powered lasers, power beaming to near-space and earth, and thermal-control systems) on the development of associated LEO-Ring systems (e.g., "Solar-Shade Rings" and "Power Rings") is also explored. The material's effect on the timeline for the system development indicates the feasibility of near-term implementation of the system (possibly within the decade). The Sling-on-a-Ring can provide a less-expensive, environment-friendly, mode of access to space. This would pave the way (via eventual operation at >1000 tonnes per day by 2050) for large scale development of space-based technologies.

Abstract: - The Distributed object computing is a paradigm that allows objects to be distributed across a heterogeneous network, and allows each of the components to interoperate as a unified whole. This paper compares the layered architectures of various platforms such as COM/ ...

Vanicek N, Strike S, McNaughton L, Polman R. Postural responses to dynamic perturbations in amputee fallers versus nonfallers: a comparative study with able-bodied subjects.To quantify postural responses in amputee fallers versus nonfallers by using computerized dynamic posturography.All participants completed standard protocols on the Sensory Organization Test (SOT) and Motor Control Test (MCT) of the NeuroCom Equitest.Human performance laboratory in a university in the United Kingdom.Transtibial amputees (n=9) and able-bodied subjects (n=9) (all categorized into fallers and nonfallers according to their falls history in the previous 9mo).Not applicable.Equilibrium and strategy scores on the SOT. Postural response latency and weight distribution on the MCT.Equilibrium scores were highest when somatosensory information was accurate, but there were no differences between the groups. Strategy scores were lower when visual cues and somatosensory information were inaccurate, and the fallers and nonfallers used a combination of ankle and hip strategies to prevent a loss of balance. The amputee nonfallers indicated they had a greater reliance on visual input even when it was inaccurate compared with the amputee fallers, whereas the control fallers used the hip strategy significantly more compared with the control nonfallers (SOT condition 6: 56±22 vs 72±10, P=.01). Weight distribution symmetry showed that the amputee nonfallers bore significantly more weight through their intact limb compared with the amputee fallers during backward and forward translations (P<.05).The SOT and MCT appeared to be population specific and therefore did not reliably identify fallers among transtibial amputees or distinguish between community-dwelling control fallers and nonfallers. Amputee and control fallers can prevent a fall during challenging static and dynamic conditions by adapting their neuromuscular responses. The results from this study have important implications for amputee gait rehabilitation, falls prevention, and treatment programs.

One of the biggest challenges for future urban design is to cope with suburbia and sprawl. This paper investigates how sprawl can be compacted in terms of spatial morphology. New &apos;user-related &apos; loca-tion density measures, like spaciousness and compactness, are introduced that integrate floor area, axiality of pedestrian network, and public open space. These and &apos;administrative &apos; area density mea-sures are applied to two modernist suburbs in Stockholm, Björkhagen and Rågsved (1946-1957), and four strategic densification scenarios: &apos;New urbanism&apos;, &apos;New regularism&apos;, &apos;New conservatism&apos;, and &apos;New modernism&apos;. The results show that the suburbs can increase by 100 % in Floor Area Ratio in the first two and but only 20-40 % in the other two. Floor area accessibility, however, is influenced by network accessibility more than plot density. Public open space is needed to uphold spaciousness and compactness. To conclude, tree-like morp...

Abstract:-The Distributed object computing is a paradigm that allows objects to be distributed across a heterogeneous network, and allows each of the components to interoperate as a unified whole. This paper compares the layered architectures of various platforms such as COM/DCOM, RMI, CORBA, SOAP supporting distributed computing. While the fundamental structure of each is similar, there are differences that can profoundly impact an application developer or the administrator of a distributed simulation exercise.

sociolinguistics. To date, many models of politeness have been put forward in the literature. In this study, Brown and Levinson’s (1978, 1987) politeness model was used to carry out a comparative analysis. The compliment response behavior of native Persian speakers was compared with that of native speakers of American English to see if it can provide evidence for applicability of Brown and Levin-son’s universal model. The data were taken from a corpus of 50 hours of record-ing the live interviews from the Persian and English TV channels. The results show Persian and English speakers use different strategies and culture has an im-portant effect on speakers ’ speech act performance. The results also demonstrate the inapplicability of Brown and Levinson’s model for cross-cultural compari-sons.

Third order intermodulation products caused by two or more FM broadcasting radios transmitter on a site to inter modulate either within transmitters themselves or within a non-linear component on site and those intermodulation products due to non-linearity’s of passive circuits of transmitters sharing same radiating element have been the source of interference in Tanzania to aeronautical ground to air communication (COM) systems which are safety services due to its nature of safeguarding human life and properties. These intermodulation products have been found in frequencies used by COM systems. This research work focused on using of corner reflector antenna to mitigate interference caused by FM broadcasting radio stations to COM facilities which are used for ground to air communication between control tower and pilots in Tanzania. Through simulations it is observed that the corner reflector antenna provide sufficient front to back ratio which facilitate in reducing electric signal ...

This paper introduces a model of experiential learning to support teaching, research, and practice in library and information science (LIS). The concept we call Community Informatics (CI) Studio uses studio-based learning (SBL) to support enculturation into the field of CI. The SBL approach, closely related to John Dewey’s inquiry-based learn- ing, is rooted in the apprenticeship model of learning in which students study with master designers or artists to develop their craft. Our paper begins with a review of literature to frame our research before introducing our analysis of the CI Studio course. Using the first three semesters of the course as case studies, the goal of the paper was to present three related investigations that emerged from our overarching research question: How can the CI Studio be understood as a model of experiential learning to support LIS teaching, research, and practice?