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Parametric analysis of microwave and laser systems for communication and tracking - updated reference data for advanced space communication and tracking systems

Parametric analysis of microwave and laser systems for communication and tracking - updated reference data for advanced space communication and tracking systems

Parametric analysis of microwave and laser systems for communication and tracking - updated reference data for advanced space communication and tracking systems

The purpose of this program was to develop two advanced development model high power amplifier tubes specifically for troposcatter communication application. Varian Associates was awarded a single contract to develop a klystron model tube and a klystrode model tube. Critical elements of the specification for the two tubes were (a) power output l0xw, (b) 10 MHz electronics bandwidth, (c) 750-980 MHz tuning range and (d) efficiency 50%. The challenge for the klystron design was to be able to maintain efficiency in excess of 50% over the full 10 MHz bandwidth. This was accomplished with an eight cavity design. The klystrode challenge required designing a new grid shape that integrates a converging electron beam with a cavity with a minimal magnetic field focusing. Results of the program were that basically most of the performance specifications were demonstrated. However, the klystron showed a sharp drop-off in power at 840 MHz due to a second harmonic cavity mode. The klystrode has considerably less gain than the existing klystron and thus additional RF drive is required.

The purpose of this program was to develop two advanced development model high power amplifier tubes specifically for troposcatter communication application. Varian Associates was awarded a single contract to develop a klystron model tube and a klystrode model tube. Critical elements of the specification for the two tubes were (a) power output l0xw, (b) 10 MHz electronics bandwidth, (c) 750-980 MHz tuning range and (d) efficiency 50%. The challenge for the klystron design was to be able to maintain efficiency in excess of 50% over the full 10 MHz bandwidth. This was accomplished with an eight cavity design. The klystrode challenge required designing a new grid shape that integrates a converging electron beam with a cavity with a minimal magnetic field focusing. Results of the program were that basically most of the performance specifications were demonstrated. However, the klystron showed a sharp drop-off in power at 840 MHz due to a second harmonic cavity mode. The klystrode has considerably less gain than the existing klystron and thus additional RF drive is required.

The purpose of this program was to develop two advanced development model high power amplifier tubes specifically for troposcatter communication application. Varian Associates was awarded a single contract to develop a klystron model tube and a klystrode model tube. Critical elements of the specification for the two tubes were (a) power output l0xw, (b) 10 MHz electronics bandwidth, (c) 750-980 MHz tuning range and (d) efficiency 50%. The challenge for the klystron design was to be able to maintain efficiency in excess of 50% over the full 10 MHz bandwidth. This was accomplished with an eight cavity design. The klystrode challenge required designing a new grid shape that integrates a converging electron beam with a cavity with a minimal magnetic field focusing. Results of the program were that basically most of the performance specifications were demonstrated. However, the klystron showed a sharp drop-off in power at 840 MHz due to a second harmonic cavity mode. The klystrode has considerably less gain than the existing klystron and thus additional RF drive is required.

This paper addresses the design of a dedicated homophonic coding for a class of communication systems which, in order to provide both reliability and security, first encode the data before encrypting it, which is referred to as the encoding-encryption paradigm. The considered systems employ error-correction coding for reliability, a stream cipher for encryption, and homophonic coding to enhance the protection of the key used in the stream cipher, on which relies the security of all the system transmissions. This paper presents a security evaluation of such systems from a computational complexity point of view, which serves as a source for establishing dedicated homophonic code design criteria. The security evaluation shows that the computational complexity of recovering the secret key, given all the information an attacker could gather during passive attacks he can mount, is lower bounded by the complexity of the related LPN (Learning Parity in Noise) problem in both the average and worst case. This gives guidelines to construct a dedicated homophonic encoder which maximizes the complexity of the underlying LPN problem for a given encoding overhead. Finally, this paper proposes a generic homophonic coding strategy that fulfills the proposed design criteria and thus both enhances security while minimizing the induced overhead.

Analysis of the average binary error probabilities (ABEP) and average capacity (AC) of wireless communications systems over generalized fading channels have been considered separately in the past. This paper introduces a novel moment generating function (MGF)-based \emph{unified expression} for the ABEP and AC of single and multiple link communication with maximal ratio combining. In addition, this paper proposes the hyper-Fox's H fading model as a unified fading distribution of a majority of the well-known generalized fading models. As such, we offer a generic unified performance expression that can be easily calculated and that is applicable to a wide variety of fading scenarios. The mathematical formalism is illustrated with some selected numerical examples that validate the correctness of our newly derived results.

Recently, experiments showed that the spatial-mode states of entangled photons are more robust than their polarization-mode states in quantum communications. Here we construct a complete and deterministic protocol for analyzing the spatial Bell states using the interaction between a photon and an electron spin in a charged quantum dot inside a one-side micropillar microcavity. A quantum nondemolition detector (QND) for checking the parity of a two-photon system can be constructed with the giant optical Faraday rotation in this solid state system. With this parity-check QND, we present a complete and deterministic proposal for the analysis of the four spatial-mode Bell states. Moreover, we present a robust two-step quantum secure direct communication protocol based on the spatial-mode Bell states and the photonic spatial Bell-state analysis. Our analysis shows that our BSA proposal works in both the strong and the weak coupling regimes if the side leakage and cavity loss rate is small.

We study the problem of lossy joint source-channel coding in a single-user energy harvesting communication system with causal energy arrivals and the energy storage unit may have leakage. In particular, we investigate the achievable distortion in the transmission of a single source via an energy harvesting transmitter over a point-to-point channel. We consider an adaptive joint source-channel coding system, where the length of channel codewords varies based on the available battery charge. We first establish a lower bound on the achievable distortion. Then, as necessary conditions for local optimality, we obtain two coupled equations that determine the mismatch ratio between channel symbols and source symbols as well as the transmission power, both as functions of the battery charge. As examples of continuous and discrete sources, we consider Gaussian and binary sources respectively. For the Gaussian case, we obtain a closed-form expression for the mismatch factor in terms of the $Lambert W$ function, and show that an increasing transmission power policy results in a decreasing mismatch factor policy and vice versa. Finally, we numerically compare the performance of the adaptive mismatch factor scheme to the case of a constant mismatch factor.

We study the problem of lossy joint source-channel coding in a single-user energy harvesting communication system with causal energy arrivals and the energy storage unit may have leakage. In particular, we investigate the achievable distortion in the transmission of a single source via an energy harvesting transmitter over a point-to-point channel. We consider an adaptive joint source-channel coding system, where the length of channel codewords varies based on the available battery charge. We first establish a lower bound on the achievable distortion. Then, as necessary conditions for local optimality, we obtain two coupled equations that determine the mismatch ratio between channel symbols and source symbols as well as the transmission power, both as functions of the battery charge. As examples of continuous and discrete sources, we consider Gaussian and binary sources respectively. For the Gaussian case, we obtain a closed-form expression for the mismatch factor in terms of the $Lambert W$ function, and show that an increasing transmission power policy results in a decreasing mismatch factor policy and vice versa. Finally, we numerically compare the performance of the adaptive mismatch factor scheme to the case of a constant mismatch factor.

The computer-communication field is rich with extremely challenging problems for the queueing theorist. In this paper, we describe a number of computer-communication applications in wide-area networks, packet radio networks and local area networks. All of these involve sophisticated queueing theoretic models which have led to advanced applications of existing theory and in some cases, to new methods in queueing theory. A significant component in many of these applications is that of multi-access to a common resource (typically, a communication channel); we devote a significant portion of this paper to multi-access systems. In addition to identifying problems of interest to the queueing theorist. This paper summarizes the latest results for the mean response time of many current computer-communication applications.

Bell System Technical Journal, 51: 9. November 1972 pp 2013-2027. On Fast Start-Up Data Communication Systems Using Pseudo-Random Training Sequences. (Chang, R.W.; Ho, E.Y.)

There are many students and researchers who don’t deeply understand the practical operating principle of digital communication system. Hence, in this paper, the digital communication system is studied with brief implementation of each block diagrams. In the system kit development, text and audio inputs are taken and encrypted with different encryption techniques including additive cipher, multiplicative cipher and affine ciphers. The encrypted data is converted in to 8-bit binary data stream. Then, the channel is encoded with distinct channel coding techniques including linear block encoder, cyclic encoder and convolutional encoder. The line coded bits are band passed by digital modulation schemes after the channel coding. Finally, the developed software is tested with equivalent inputs of a digital TV broadcasting and the results have correctly matched according to the theoretical analysis of the digital communication systems. Hence, students can be easily benefited from this practical understanding of the digital communication systems.

Records of human movements and communication patterns are continuously being generated by the 4 billion mobile phone users around the world. In collaboration with mobile operators in dozens of countries, my colleagues and I are aggregating and analyzing this behavioral data from over 250 million people from North and South America, Europe, and Africa. This unprecedented volume of information about movement, purchasing decisions, and social networks has led to a novel set of research questions applicable to a wide range of academic disciplines. This data enables comparisons across cultures and continents, and may even lead to the identification of universal laws governing human behavior. I will discuss a selection of results related to the scaling of complex social systems; ranging from inferences about human relationships on a social network of 100 people, to the evolution of community structure on a national communication graph of 1 million people, to topological properties correlated with socioeconomic status on a communication graph representing over 100 million people. I believe the ultimate value of this research will be in its application to solving global social challenges. We are now in a position to incorporate insights gained from these data into the design and engineering of social systems in order to actively improve human lives; we have named this nascent field Engineering-Social Systems. Understanding the behavioral patterns of millions of people is of more than academic interest, and we believe the ultimate question is the engineering one: how can we put those insights to good use? To that end, I will provide a broad overview of upcoming projects using behavioral data related to public policy, urban planning, developmental economics, and computational epidemiology. ©2009 Microsoft Corporation. All rights reserved.

The last decade has witnessed substantial interest in protocols for transferring information on networks of quantum mechanical objects. A variety of control methods and network topologies have been proposed, on the basis that transfer with perfect fidelity --- i.e. deterministic and without information loss --- is impossible through unmodulated spin chains with more than a few particles. Solving the original problem formulated by Bose [Phys. Rev. Lett. 91, 207901 (2003)], we determine the exact number of qubits in unmodulated chains (with XY Hamiltonian) that permit the transfer with fidelity arbitrarily close to 1, a phenomenon called pretty good state transfer. We prove that this happens if and only if the number of nodes is n=p-1, 2p-1, where p is a prime, or n=2^{m}-1. The result highlights the potential of quantum spin system dynamics for reinterpreting questions about the arithmetic structure of integers, and, in this case, primality.

The last decade has witnessed substantial interest in protocols for transferring information on networks of quantum mechanical objects. A variety of control methods and network topologies have been proposed, on the basis that transfer with perfect fidelity --- i.e. deterministic and without information loss --- is impossible through unmodulated spin chains with more than a few particles. Solving the original problem formulated by Bose [Phys. Rev. Lett. 91, 207901 (2003)], we determine the exact number of qubits in unmodulated chains (with XY Hamiltonian) that permit the transfer with fidelity arbitrarily close to 1, a phenomenon called pretty good state transfer. We prove that this happens if and only if the number of nodes is n=p-1, 2p-1, where p is a prime, or n=2^{m}-1. The result highlights the potential of quantum spin system dynamics for reinterpreting questions about the arithmetic structure of integers, and, in this case, primality.

This paper presents the design and simulation of a hyperchaotic communication system based on four dimensions (4D) Lorenz generator. The synchronization technique that used between the master/transmitter and the slave/receiver is based on dynamic feedback modulation technique (DFM). The mismatch error between the master dynamics and slave dynamics are calculated continuously to maintain the sync process. The information signal (binary image) is masked (encrypted) by the hyperchaotic sample x of Lorenz generator. The design and simulation of the overall system are carried out using MATLAB Simulink software. The simulation results prove that the system is suitable for securing the plain-data, in particular the image data with a size of 128×128 pixels within 0.1 second required for encryption, and decryption in the presence of the channel noise. The decryption results for gray and colored images show that the system can accurately decipher the ciphered image, but with low level distortion in the image pixels due to the channel noise. These results make the proposed cryptosystem suitable for real time secure communications. 

Abstract — Cognitive radio is an eminent technology that has been deployed in multiple communication systems in recent times. As in case of any communication system, the performance can be analyzed purely on the basis of transmitter and receiver. But it can be further enhanced by introducing relay concepts into the system. In a primary network, the data transmission takes place through a licensed channel. But at times the spectrum is not properly utilized and at that instant the secondary network comes into the picture, which takes care such that the efficiency of the spectrum shouldn’t be wasted. The secondary network consists of ST (Secondary Transmitter), SD (Secondary Destination) and Eavesdroppers. Here in the endeavor the main focus lies on the secondary network operations. The throughput of the network can be abruptly increased by introducing relays. To increase the overall system ability MIMO and OFDM techniques were implemented. The comparative analysis of the system with the single, multiple relays and the traditional direct transmission schemes has been done in order to analyze the system’s performance.

Bell System Technical Journal, 52: 10. December 1973 pp 1867-1876. Dispersion and Equalization in Fiber Optic Communication Systems. (Henderson, D.M.)

This annual report summarizes project activity from September 29, 2005 through April 28, 2006. All deliverables for this project period were met: (1) PACS equipment became fully operational at all four community hospitals (Eupora, Pontotoc, West Point, and Iuka sites); (2) Radiology staff at all four sites were thoroughly training - Data collection and analysis continued with results reported; (3) Network vulnerability assessment and penetration tests were completed with results reported.

Whether you're a ham radio enthusiast, a first responder, or a business professional, our radios are designed to keep you connected when it matters most. Experience crystal-clear audio, rugged reliability, and unmatched support. Upgrade your communication game today! Ready to stay connected? Click below to explore our range of radios and join the BridgeCom community. Your connection starts here! For more information: 📞: 816-532-8451 📧: [email protected] Technical Support: https://bit.ly/bridgecom-support Follow us on social media and stay up to date on all the latest news and products! Facebook: https://bit.ly/bridgecom-facebook Instagram: https://bit.ly/bridgecom-instagram Twitter: https://bit.ly/bridgecom-twitter LinkedIn: https://bit.ly/bridgecom-linkedin

Tri 2 2018/2019

Using MMICs in phased-array applications above 20 GHz requires complex RF and control signal distribution systems. Conventional waveguide, coaxial cable, and microstrip methods are undesirable due to their high weight, high loss, limited mechanical flexibility and large volume. An attractive alternative to these transmission media, for RF and control signal distribution in MMIC phased-array antennas, is optical fiber. Presented are potential system architectures and their associated characteristics. The status of high frequency opto-electronic components needed to realize the potential system architectures is also discussed. It is concluded that an optical fiber network will reduce weight and complexity, and increase reliability and performance, but may require higher power.

Due to a shift in the interest in wireless applications, from outdoor to indoor environments. new modelling solutions had to be designed to account for the immense complexity of the latter. Essentially, two categories of indoor propagation models prevailed until the mid-90's: the Empirical and the Physical models. They both predicted important characteristics of a given confined environment like the coverage area, transmitted power requirements. number and location of base stations or access points. The implementation of wireless communications systems onboard naval assets is expected to offer numerous advantages and enhance the existing shipboard communications systems. That, in turn, calls for a reliable and cost-effective means of estimating the expected link budget in such environments, especially when the infrastructure in question is yet to be built, as is the case in a ship class under development. This thesis treats the problem of indoor propagation modeling using the Numerical Electromagnetic Code-Basic Scattering Code (NEC-BSC) and compares the predicted results obtained by this code with actual measurements performed inside a building at the Naval Postgraduate School. A number of important conclusions regarding the validity of NEC-BSC for indoor applications are being reached and some intriguing statistical results are being presented.

Accompanied with the development of the wireless communication technologies, the high data traffic is more necessary for civil and industrial applications than ever The concept of an intelligent reflective surface (IRS) has attracted considerable attention recently as a low-cost solution. As the main contribution, the dissertation creates new state-of-the-art and formulates a solid milestone for the IRS research field.

Accompanied with the development of the wireless communication technologies, the high data traffic is more necessary for civil and industrial applications than ever The concept of an intelligent reflective surface (IRS) has attracted considerable attention recently as a low-cost solution. As the main contribution, the dissertation creates new state-of-the-art and formulates a solid milestone for the IRS research field.

Accompanied with the development of the wireless communication technologies, the high data traffic is more necessary for civil and industrial applications than ever The concept of an intelligent reflective surface (IRS) has attracted considerable attention recently as a low-cost solution. As the main contribution, the dissertation creates new state-of-the-art and formulates a solid milestone for the IRS research field.

We describe two protocols for efficient data transmission using a single passive bus. Different types of interactions are obtained enabling deterministic transfer and teleportation of composite quantum systems for arbitrary subsystem dimension and for arbitrary numbers of subsystems. The subsystems may become entangled in the transmission in which case the protocols can serve generalized teleportation based information processing as well as storage and transmission functions. We explore the cases of two qubits and two qutrits in detail, obtaining a maximally entangling mapping of the composite systems and discuss the use of a continuous variable bus.

Includes bibliographical references and index

Case name: National Communication Systems, Inc. v. Michigan Public Service Commission Opinion filed: 1986-10-06 Docket No.: 86-138 Citations: • 479 U.S. 852

The Engineering Design Handbook Series of the US Army Materiel Command is a coordinated series of handbooks containing basic information and fundamental data. The handbooks are authoritative reference books of practical information and quantitative facts helpful in the design and development of materiel that will meet the tactical needs of the Armed Forces. The objectives of this handbook series are: (1) to collect diverse sources of information unique to the determination of the vulnerability to electronic warfare of all types of communication-electronic and electro-optical equipment/systems, exclusive of guided missiles, in order to conserve time, materials, and money in the successful design of new equipment; (2) to provide guidance in capsule form for new personnel, Armed Forces contractors, or experienced design engineers in other fields who require information about vehicle electrical systems; (3) to supply current fundamental information; and (4) t o place the reader in a position  to use new information generated subsequent to the publication of this handbook. T o meet these objectives, the handbook has been written to provide the necessary background regarding the vulnerability of military electromagnetic systems to electronic warfare (EW). 124 pg

The Engineering Design Handbook Series of the US Army Materiel Command is a coordinated series of handbooks containing basic information and fundamental data. The handbooks are authoritative reference books of practical information and quantitative facts helpful in the design and development of materiel that will meet the tactical needs of the Armed Forces. The objectives of this handbook series are: (1) to collect diverse sources of information unique to the determination of the vulnerability to electronic warfare of all types of communication-electronic and electro-optical equipment/systems, exclusive of guided missiles, in order to conserve time, materials, and money in the successful design of new equipment; (2) to provide guidance in capsule form for new personnel, Armed Forces contractors, or experienced design engineers in other fields who require information about vehicle electrical systems; (3) to supply current fundamental information; and (4) t o place the reader in a position  to use new information generated subsequent to the publication of this handbook. T o meet these objectives, the handbook has been written to provide the necessary background regarding the vulnerability of military electromagnetic systems to electronic warfare (EW). 124 pg

The Engineering Design Handbook Series of the US Army Materiel Command is a coordinated series of handbooks containing basic information and fundamental data. The handbooks are authoritative reference books of practical information and quantitative facts helpful in the design and development of materiel that will meet the tactical needs of the Armed Forces. The objectives of this handbook series are: (1) to collect diverse sources of information unique to the determination of the vulnerability to electronic warfare of all types of communication-electronic and electro-optical equipment/systems, exclusive of guided missiles, in order to conserve time, materials, and money in the successful design of new equipment; (2) to provide guidance in capsule form for new personnel, Armed Forces contractors, or experienced design engineers in other fields who require information about vehicle electrical systems; (3) to supply current fundamental information; and (4) t o place the reader in a position  to use new information generated subsequent to the publication of this handbook. T o meet these objectives, the handbook has been written to provide the necessary background regarding the vulnerability of military electromagnetic systems to electronic warfare (EW). 124 pg

The Engineering Design Handbook Series of the US Army Materiel Command is a coordinated series of handbooks containing basic information and fundamental data. The handbooks are authoritative reference books of practical information and quantitative facts helpful in the design and development of materiel that will meet the tactical needs of the Armed Forces. The objectives of this handbook series are: (1) to collect diverse sources of information unique to the determination of the vulnerability to electronic warfare of all types of communication-electronic and electro-optical equipment/systems, exclusive of guided missiles, in order to conserve time, materials, and money in the successful design of new equipment; (2) to provide guidance in capsule form for new personnel, Armed Forces contractors, or experienced design engineers in other fields who require information about vehicle electrical systems; (3) to supply current fundamental information; and (4) t o place the reader in a position  to use new information generated subsequent to the publication of this handbook. T o meet these objectives, the handbook has been written to provide the necessary background regarding the vulnerability of military electromagnetic systems to electronic warfare (EW). 124 pg

The objective of UPSHOT-KNOTHOLE Project 3.20 was to determine the effects of air burst nuclear weapons on selected items of signal communication equipment. Typical items of this equipment, such as would be found in a communications zone or field army area, were oriented in test groups at varying distances from GZ to obtain an anticipated damage spread from severe to negligible. Participation in Shot 9 consisted of 93 such test groups. Participation in Shot 10 was limited to 17 test groups because of shortage of funds, materiel, and labor. Photographic records of damage, and evaluations of the levels of damage, were made by project personnel. The anticipated spread from negligible to severe damage was obtained for the majority of the test groups. Recorded values, and predicted values (from TM23-200), for thermal flux, peak overpressures, and initial gamma radiation were in close agreement in both Shots 9 and 10. The damage from Shot 9 was about what was expected.

Word-intelligibility (psycho-acoustic), Articulation Index (electrical) and voice recognition tests were made on the Thule, Greenland, to Cape Dyer, Baffin Island, link of the DEWDROP tropos pheric-scatter communication system, and on the Gander, Newfoundland, to Harmon Air Force Base, Newfoundland, link of the POLEVAULT tropospheric scatter communication system, and compared against similar tests taken on a laboratory reference system. Harvard phonetically-balanced (PB) word-lists were used in the psycho-acoustic tests; an abbreviated octave-band form of the Articulation Index procedure (after Kryter) was the basis of the electrical tests. These two measures agreed in ranking the three systems in order of intelligibility from highest to lowest: laboratory, POLEVAULT and DEWDROP. It is concluded that the Articulation Index technique suitably modified, is feasibile and useful for voice-system performancuation and quality control testing. It is also concluded, tentatively, that system characteristics affecting intelligibility do not necessarily affect listeners' ability to recognize individual talkers.

This paper addresses the overview of the life cycle system acquisition for non-tactical communication systems (excluding air traffic control and satellite ground systems) based on the recent DODD 5000.1 and 5000.2, the draft AR 1000-1, and existing Army regulations. It will serve as a guide for the development, procurement and deployment of communication systems. It will be useful for new personnel who are not familiar with the overview of non-tactical communication systems acquisition. (Author)

This report considers the problem of monitoring digital communication systems. Possible monitoring techniques are reviewed and a group of different methods, which will completely define the system state, is chosen. A new format violation type indication is suggested and analyzed for the seven-level partial response/FM system. Four-level FM, seven-level partial response/FM and quadrature partial response types of modulation are reviewed and a group of eleven generic faults are chosen as representative malfunctions for communication links using such modulation methods. The response of each of six monitors to each of the generic faults is determined theoretically. Simulation studies are conducted for a seven-level partial response/FM system using three monitors and a selection of typical faults. A method for processing error rate monitor outputs to obtain a fault alarm is worked out and the results are verified with simulation studies. Recommendations are given for a group of five monitors for a seven-level partial response/FM system. Fault isolation cannot be accomplished as well for the four-level FM system because format violation monitors cannot be used. A similar result pertains to the QPR system, although some type of format violation monitor may be possible for this type system. Fault detection can be accomplished for FM and QPR in the same manner as for partial response systems.

This report presents a comprehensive review of the state of the art of direct-sequence communication systems. Although it is largely self-contained mathematically, the report presumes a thorough understanding of modern digital communications. To limit the report to approximately 200 pages. Only the most vital aspects of the theory are emphasized. but the cited references provide many details and minor topics.

Medical Research and Material Command, Office of Regulatory Compliance and Quality (MRMC RCQ) Review. The primary problem encountered was obtaining the RCQ review. The need for this step in the research process was part of the initial grant process. Additionally, the local Investigation Review Board (IRB) had already approved the protocol when the need for this step was communicated several months after the grant was awarded. The development and testing of the system progressed to the point of having potential patients test the system by entering baseline data, however, this progress was immediately stopped under guidance from the RCQ reviewer. The initial information was forwarded to RCQ in November of 2000, and all requested revisions were forwarded in early January of 2001. However, review is still pending at the time of this report, and therefore, the clinical trial of the system still awaits RCQ approval. This has made completion of the project unfeasible due to funding short falls given this unexpected and prolonged administrative delay.

Medical Research and Material Command, Office of Regulatory Compliance and Quality (MRMC RCQ) Review. The primary problem encountered was obtaining the RCQ review. The need for this step in the research process was part of the initial grant process. Additionally, the local Investigation Review Board (IRB) had already approved the protocol when the need for this step was communicated several months after the grant was awarded. The development and testing of the system progressed to the point of having potential patients test the system by entering baseline data, however, this progress was immediately stopped under guidance from the RCQ reviewer. The initial information was forwarded to RCQ in November of 2000, and all requested revisions were forwarded in early January of 2001. However, review is still pending at the time of this report, and therefore, the clinical trial of the system still awaits RCQ approval. This has made completion of the project unfeasible due to funding short falls given this unexpected and prolonged administrative delay.

Thesis advisors, Jovan Lebaric, James Luscombe

Visual impairment is the condition of someone who has a disorder or an obstacle in their vision. In this research, the implementation of light follower systems for visually impaired using visible light is proposed. This system can enable visually impaired people to determine orientation and support mobility, especially in an indoor situation, using visible light. The prototype of the visually impaired pathway was made as visible light communication (VLC) transmitter consisting of a 12 V power supply, light emitting diode (LED), MPEG-1 Layer-3 (MP3), and band pass filter (BPF) filter circuit. The VLC receiver is made a prototype of a blind stick consisting of a photodiode, amplifier, buzzer, timer, and 9 V battery. The measurement of this system uses acrylic and color filters with system accuracy taking into account the angle and conditions when the fluorescent lights are turned on and off. This result showed the system could transmit audio signals at a frequency of 3000 Hz. Furthermore, the comparison results showed that the quality of measurements without using a filter is better than using a filter. The output voltage value without using a filter with an angle of 700 degree is 7.19 Vp-p, meanwhile using a filter with an angle of 700 degree is 6.48 Vp-p.

Visual impairment is the condition of someone who has a disorder or an obstacle in their vision. In this research, the implementation of light follower systems for visually impaired using visible light is proposed. This system can enable visually impaired people to determine orientation and support mobility, especially in an indoor situation, using visible light. The prototype of the visually impaired pathway was made as visible light communication (VLC) transmitter consisting of a 12 V power supply, light emitting diode (LED), MPEG-1 Layer-3 (MP3), and band pass filter (BPF) filter circuit. The VLC receiver is made a prototype of a blind stick consisting of a photodiode, amplifier, buzzer, timer, and 9 V battery. The measurement of this system uses acrylic and color filters with system accuracy taking into account the angle and conditions when the fluorescent lights are turned on and off. This result showed the system could transmit audio signals at a frequency of 3000 Hz. Furthermore, the comparison results showed that the quality of measurements without using a filter is better than using a filter. The output voltage value without using a filter with an angle of 700 degree is 7.19 Vp-p, meanwhile using a filter with an angle of 700 degree is 6.48 Vp-p.

Periodic gain adjustment in plants of irreducible order, n, or for equalization of communications channels is effected in such a way that the plant (system) appears to be minimum phase by choosing a horizon time N greater then n of liftings in periodic input and output windows Pu and Py, respectively, where N is an integer chosen to define the extent (length) of each of the windows Pu and Py, and n is the order of an irreducible input/output plant. The plant may be an electrical, mechanical or chemical system, in which case output tracking (OT) is carried out for feedback control or a communication channel, in which case input tracking (IT) is carried out. Conditions for OT are distinct from IT in terms of zero annihilation, namely for OT and of IT, where the OT conditions are intended for gain adjustments in the control system, and IT conditions are intended for equalization for communication channels.

This document is a survey of publicly available information concerning serial communication architectures used, or proposed to be used, in aeronautic and aerospace applications. It focuses on serial communication architectures that are suitable for low-latency or real-time communication between physically distributed nodes in a system. Candidates for the study have either extensive deployment in the field, or appear to be viable for near-term deployment. Eleven different serial communication architectures are considered, and a brief description of each is given with the salient features summarized in a table in appendix A. This survey is a product of the Propulsion High Impact Avionics Technology (PHIAT) Project at NASA Marshall Space Flight Center (MSFC). PHIAT was originally funded under the Next Generation Launch Technology (NGLT) Program to develop avionics technologies for control of next generation reusable rocket engines. After the announcement of the Space Exploration Initiative, the scope of the project was expanded to include vehicle systems control for human and robotics missions. As such, a section is included presenting the rationale used for selection of a time-triggered architecture for implementation of the avionics demonstration hardware developed by the project team

This presentation describes an open architecture SDR (software defined radio) infrastructure, suitable for space-based radios and operations, entitled Space Telecommunications Radio System (STRS). SDR technologies will endow space and planetary exploration systems with dramatically increased capability, reduced power consumption, and less mass than conventional systems, at costs reduced by vigorous competition, hardware commonality, dense integration, minimizing the impact of parts obsolescence, improved interoperability, and software re-use. To advance the SDR architecture technology and demonstrate its applicability in space, NASA is developing a space experiment of multiple SDRs each with various waveforms to communicate with NASA s TDRSS satellite and ground networks, and the GPS constellation. An experiments program will investigate S-band and Ka-band communications, navigation, and networking technologies and operations.

Prepared by the Eurydice European Unit on the basis of data supplied by its national partners, this document analyzes national policies for education in information and communication technology (ICT). Highlights include: (1) national policy and official documents on the use of ICT; (2) national or official bodies responsible for supervising the national policy; (3) national projects for the introduction of technology are on the increase; (4) schedule for implementing the projects; (5) sharing responsibility for the purchase and maintenance of hardware; (6) expenditure on equipment predominates in specific budgets; (7) projects with a variety of aims; (8) many countries include ICT in the primary level curriculum; (9) the most common approach to ICT in primary education is to use it as a tool; (10) ICT is in almost all curricula at lower secondary level; (11) a variety of approaches to ICT coexist in lower secondary education; (12) ICT is in most curricula at general upper secondary level; (13) ICT is usually taught as a separate subject in general upper secondary education; (14) most specialist ICT teachers are found at the secondary level; and (15) in-service training is often available but rarely compulsory. A directory of the Eurydice network is included. (MES)

Rear projection systems and their requirements and limitations are discussed in the light of projection equipment, screens, the observer, and physical surroundings. Performance criteria for rear projection systems for use in the communication-lecture hall centers are revealed, based on an evaluation of nineteen different systems. Design recommendations and standards for the viewing of projected images, and selection of projection components are given. Various seating and equipment layout plans are included, along with environmental criteria, and a glossary, graphs, and drawings. (TG)