ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / As part of Morgan’s iNET development, the Mixed Cellular and Mobile Ad hoc Network (MCMN) architecture has been 1proposed to provide coverage to over-the horizon test articles. Nodes in MCMN are assigned to one of three possible modes- Ad hoc, Cellular or Gateway. We present architecture for the proposed MCMN and some performance analysis to characterize the network. The problem of organizing nodes in this mixed network with optimal configuration is significant. This configuration gives nodes ability to know the best mode to operate and communicate with other nodes. Node organization is critical to the performance of the mixed network and to improve communication. The configuration of nodes required to optimally organize nodes in MCMN is demonstrated. The problem of evaluating configuration parameters for nodes in a mixed network is a nonlinear and complex one. This is due to the various components like the number of nodes, geographical location, signal strength, mobility, connectivity and others that are involved. Clustering techniques and algorithms have been used in literature to partition networks into clusters to support routing and network management. A clustering technique is employed to dynamically partition the aggregate network into Cluster Cells (CCs). A gateway node is selected for each CC which relays traffic from the cellular to the Ad hoc and vice versa. A trade-off analysis of the cellular boundary is presented using the maximum of the minimum data rate in the network. Numerical analysis and experiments are provided to show that the coverage can be extended to test articles in over-the-horizon region. It is also shown that, when the network is well organized, performance is improved.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper investigates the sum-rate capacity of a cognitive multiple access (MAC) sensor network. The multiple access network consists of K sensors communicating to a common base station. Outside of the network exists another user of the radio spectrum. Each sensor of the MAC network is aware (i.e. cognitive) of this user, denoted the primary user, and transmits in a manner to avoid any interference to this user. No interference transmission is achieved using the dirty-paper coding technique. The sum-rate capacity is the theoretical maximum of the sum of the simultaneously achievable rates of each sensor within the network. Using a recently derived iterative algorithm, we quantify the sum-rate capacity of this network and investigate its behavior as a function of the number of sensors, cognitive signal-to-noise ratio (CSNR) and primary SNR (PSNR) in a Rayleigh fading environment. We also derive bounds and scaling results for the ergodic sum-rate capacity.

The vast majority of the research efforts in finite capacity scheduling over the past several years has focused on the generation of precise and almost exact measures for the working schedule presupposing complete information and a deterministic environment. During execution, however, production may be the subject of considerable variability, which may lead to frequent schedule interruptions. Production scheduling mechanisms are developed based on centralised control architecture in which all of the knowledge base and databases are modelled at the same location. This control architecture has difficulty in handling complex manufacturing systems that require knowledge and data at different locations. Adopting biological control principles refers to the process where a schedule is developed prior to the start of the processing after considering all the parameters involved at a resource involved and updated accordingly as the process executes. This research reviews the best practices in gene transcription and translation control methods and adopts these principles in the development of an autonomous finite capacity scheduling control logic aimed at reducing excessive use of manual input in planning tasks. With autonomous decision-making functionality, finite capacity scheduling will as much as practicably possible be able to respond autonomously to schedule disruptions by deployment of proactive scheduling procedures that may be used to revise or re-optimize the schedule when unexpected events occur. The novelty of this work is the ability of production resources to autonomously take decisions and the same way decisions are taken by autonomous entities in the process of gene transcription and translation. The idea has been implemented by the integration of simulation and modelling techniques with Taguchi analysis to investigate the contributions of finite capacity scheduling factors, and determination of the ‘what if’ scenarios encountered due to the existence of variability in production processes. The control logic adopts the induction rules as used in gene expression control mechanisms, studied in biological systems. Scheduling factors are identified to that effect and are investigated to find their effects on selected performance measurements for each resource in used. How they are used to deal with variability in the process is one major objective for this research as it is because of the variability that autonomous decision making becomes of interest. Although different scheduling techniques have been applied and are successful in production planning and control, the results obtained from the inclusion of the autonomous finite capacity scheduling control logic has proved that significant improvement can still be achieved.

International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / In this paper, we investigate high-capacity fiber-optic networks for real-time telemetry applications. The network topologies and related network components are analyzed for telemetry fiber-optic Local Area Network (LAN) and Metropolitan Area Network (MAN) as well as MAN internetworking with LANs. Two types of multiplexing techniques, namely, Wavelength Division Multiplexing and Time Division Multiplexing, are proposed to support real-time high-capacity telemetry applications, and the perspective of such networks is also considered. Finally, the optical modulation technique and the choice of optical devices are discussed, which are based on improving the reliability of fiber-optic LANs and MANs.

The ability of firms to innovate has become a cornerstone in the economy of many developed and developing countries. The performance of firms is not exclusively linked to their internal capability. Other external factors, such as technology, globalisation of the market, knowledge, and evolving approaches to value offering, force them to constantly change their approaches to wealth creation. Innovation is vital for firms’ competitive advantage. Hence, a firm with higher innovation prosperity compared to its rivals has a crucial advantage that enables it to compete in local and global markets. However, innovation is a complex phenomenon, and a holistic view is required for a deep understanding of the factors that influence firms’ innovation performance. Day after day, markets are becoming more dynamic, increasing the necessity to understand how such momentum affects innovation performance. With a focus on how they develop strategic routines that enhance their assessment of opportunities and resource-configuration capabilities, firms may better align their products and services with market demands. Using state-of-the-art dynamic-capability theory, this research highlights the routines of firms that influence their abilities to acquire and multiply knowledge and technology consistent with market status, leading to more novel and successful innovative products and processes as well as better economic advantage. This research aims to provide a framework that comprises factors that may influence Saudi firms’ innovation performance. Furthermore, the research aim attempts to understand the impact of information technology on firms’ innovation performance. The research is based on survey data from 203 Saudi firms registered at the Riyadh Chamber of Commerce and Industry. The empirical results suggest that firms may enhance their ability to acquire, assimilate, transform, and exploit knowledge by increasing their breadth of knowledge sources and by internationalizing their searching activities for knowledge and skills. Moreover, both explorative and exploitative innovation strategies, although paradoxes, are significant to increasing firms’ overall innovative performance. Mutually, information technology (IT) plays a critical role in complementing firms’ dynamic capabilities through better provision of IT infrastructure, while IT effectiveness and IT flexibility are vital to increasing firms’ abilities to maintain both long-term and short-term competitiveness.

Lichens are poikilohydric and cannot control water uptake and loss, water relations could therefore impact their distribution. This study examines if morphological, anatomical, and water storage traits could explain distribution of epiphytic species in the lichen genus Usnea. Seven species from oceanic (Norway) and continental areas (Sweden) were studied. Total, internal, and external water holding capacity (WHC, mg H2O cm-2) along with relative water content (WC) were recorded by spraying the thalli with water and measuring mass after shaking and blotting. The specific thallus mass (STM, mg cm-2 - main driver of WHC) was calculated from images of wet thalli. Thickness of anatomical layers (cortex, medulla, and axis) was also measured. Pendent species had lower STM and water storage than shrubby species, most probably an adaptation to water uptake from humid air. Total, internal, and external WHC were higher in the shrubby species than in the pendent ones. The pendent species had the same internal WHC as earlier reports on Bryoria and Alectoria. External water storage decreased for all species as biomass increased. The ratio between total and internal water was twice as high as reported in foliose lichens. Variation in branch diameter was much higher in shrubby than in pendent species. The interspecific differences in water storage reflect regional differences in water sources – oceanic species had higher water storage than pendent continental species, but lower than the shrubby U. hirta. I conclude that both internal and external water storage help to explain distribution of Usnea in Norway and Sweden.

The study aims to provide information on efficiency opportunities on SCA's northbound cassettes. It has been made by examining the capacity utilization rate on the northbound cassettes on SCA's vessels for a period of two weeks. The cargo loaded in the ports of Rotterdam and Sheerness consists of external cargo of varying shape. The cargo is shipped northbound to Holmsund and Sundsvall. Measurements have been made on the cargo to the final destinations Sundsvall, Holmsund and Finland. The measurements have been used in a mathematical optimization model created to optimize the loading of the cassettes. The model is based on placing boxes in a grid where the boxes that are placed representing the cargo and the grids representing the cassettes. The aim of the model is to reduce the number of cassettes and thereby increase the capacity utilization rate. The study resulted in an increase in capacity utilization rate for both area and volume to all destinations. The overall improvement for all cassettes examined resulted in an increase in the area capacity utilization rate by 9.02 percentage points and 5.72 percentage points for the volume capacity utilization rate. It also resulted in a decrease of 22 cassettes in total on the four voyages that were examined which indicate that there are opportunities to improve the capacity utilization rate. The study also shows that the model can be used as a basis for similar problems.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Low-Density Parity-Check (LDPC) codes are powerful codes capable of nearly achieving the Shannon channel capacity. This paper presents a tutorial introduction to LDPC codes, with a detailed description of the decoding algorithm. The algorithm propagates information about bit and check probabilities through a tree obtained from the Tanner graph for the code. This paper may be useful as a supplement in a course on error-control coding or digital communication.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / To correctly demodulate a signal sent through a multiple-input multiple-output (MIMO) channel, a receiver may use training to learn the channel parameters. The choice of training parameters can significantly impact system performance. Training too often yields low throughput while training infrequently produces poor channel estimates and increased transmission errors. Previous work on optimal training parameters has focused on the block fading Rayleigh model. This work examines a more general case; finding the training parameters that maximize throughput for a continuously varying channel. Training parameters that maximize a lower bound on channel capacity are determined via simulation, and general guidelines are presented for selecting optimal training parameters.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / In the iNET community, communications between Test Articles (TA) and Ground Station (GS) can be over a long distance course that places a TA at ranges where they are sometimes beyond line-of-sight (LoS) or over-the-horizon communications with the GS. In other cases, the TA moves out of the LoS communications range of GS. There is a need to provide communications to these TA at these over-the-horizon locations. The Cellular and Mobile Ad Hoc Network (MANET) have attracted a lot of attention recently and the field continues to grow daily. The cellular network offers high capacity but limited in coverage due to its fixed base infrastructure. MANET on the other hand has a wide range of coverage and also high data rates, but its throughput performance is reduced at high capacity. The MANET cellular mixture network (MCMN) has been proposed to provide an extensive communications between the TA and GS in the iNET environment. This work presents a performance evaluation and analysis of the two different networks with respect to the performance needs of iNET environment which include coverage and throughput.