David M. Caditz, Ph.D.

Consider this.....

In 1900, 1/3 of cars produced in US were electric powered The 1908 Model T Ford got 25 miles per gallon The 2004 US passenger car average fuel economy was 22.4 miles per gallon Current production electric cars can travel up to 100 miles on a charge The average American drives less than 30 miles per day

 

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Saturday, May 19, 2012
Resume & Bibliography
Selected Publications & Abstracts
	HTTP Proxy Specification for Random Access Channels in Digital Satellite Communications, Caditz, D.  2004, Hokupa'a Technologies. ABSTRACT: This document discusses recent work regarding the so called Browser (IB) and Predictive Browser (PB). The emphasis of the work has been to develop methods to reduce data sent from an HTTP client (such as a web browser) to a server on the Internet via an ALOHA channel. I have not attempted to investigate data flow on the TDM channel (from server to client) other than to extract information needed from this return channel to perform further ALOHA channel optimization. In addition, the ideas discussed here apply to the HTTP protocol only. I do not attempt to discuss TCP/IP level traffic reduction or compression, although I believe that the IB/PB can accomplish improvements on that level as well. I have examined ways to reduce ALOHA traffic using several IB/PB schemes. I will discuss a scheme to minimize the number of HTTP request headers sent over the ALOHA channel by moving recursive requests by proxy to the PB at the server side of the channel. In addition, I propose a scheme to store and encode request headers on the PB for reuse. Finally, since HTTP request headers are plain text, it is possible that they may be compressed/decompressed at the IB/PB. Together, these schemes could reduce ALOHA channel traffic by a factor of 1000 or more. Demand Assigned Multiple Access Architecture for Digital Satellite Communications, Caditz, D. and Abramson, N. 2004, Hokupa'a Technologies. ABSTRACT: The Hokupa’a Technologies (HT) Proxy (AKA TCPIPlus) is designed to operate in a VSAT random access ALOHA or Slotted ALOHA networks. Such networks are known to be sensitive to saturation by high network data rates. The purpose of the HT Proxy is to reduce unnecessary network traffic in random access channels, thereby reducing the possibility of packet collisions and increasing channel throughput. HT Proxy operations include data compression, caching, tokenization and forms of ‘predictive’ behavior. While certain network protocols, such as HTTP, some forms of email, and DNS, are amenable to proxy operations, other network traffic may be resistant. Examples of resistant traffic include file transfer, voice, video or image data. This document discusses the possibility of sending such resistant network traffic via a separate demand assigned multiple access (DAMA) channel. Technology Assessment and Preliminary Design Study of Electromechanical Actuation Systems, Venkataramanan, G., and Caditz, D., 1999, successful Proposal to Montana Space Grant Consortium. ABSTRACT: This project is aimed at conducting a technology assessment and preliminary design study on electromechanical actuator systems for aerospace applications. Even though such actuators are known, in principle, to be superior to conventional hydraulic actuators, several technical challenges have prevented their widespread application in aerospace systems. Recently, there have been several technical breakthroughs relating to various subsystems which comprise an electromechanical actuator, in particular the development of smart inverters and an active spray cooling technology. As a result it is felt that an electromechanical actuator system can become a reality with a modest amount of research and developmental effort. The project activities include analytical and experimental investigations leading toward the preparation of a comprehensive research plan for further development of integrated electromechanical actuator systems. Solar Vehicle Design,  Caditz, D.,  1994, Successful Proposal to General Motors Corp. ABSTRACT: In the eighty-three years since the first Model "T" Ford rolled off of the assembly line, a total of 5 billion gasoline powered automobiles have been built. The impact of mass produced personal vehicles has been enormous, allowing almost unlimited freedom of mobility for millions of people worldwide. It has become increasingly clear, however, with declining fuel supplies and detrimental environmental effects of oil exploration, refining, and consumption, that the benefits of gasoline powered vehicles are transitory - we cannot continue to rely on combustion powered vehicles into the indefinite future. The record setting 1987 General Motors "Sunraycer" - a prototype solar powered vehicle - had impressive performance specifications in excess of its gasoline powered predecessor of 80 years ago: Ten horsepower, 0 to 50 in 25 seconds, maximum speed 82 miles per hour. The Sunraycer, like a small number of similar vehicles built by companies, schools, and backyard mechanics, uses sunlight as fuel, and produces zero pollution. Like the fastest gasoline powered race cars of the early century, these efficient, light weight solar racers may signify the dawn of a new era of clean, quiet, ultra-efficient, electric powered transportation. This year, Montana State University joins a small group of organizations who are building and racing solar cars. By summer of 1995, the Montana State University Solar Vehicle Project (MSUSVP) will be entering a world class solar racer into national and international competition. MSU's solar car is described in detail in this proposal. I encourage anyone interested to contact the MSUSVP for more details about the car or our project in general. The MSUSVP is an all volunteer project and we will be operating on a shoe-string budget. Montana's solar car will not be built without your help. We rely on the advice and generous donations of local and national businesses and interested individuals. While the technical problems associated with building a solar car are immense, raising funds to support the project presents an even greater challenge. We encourage you to consider your donation as an investment in environmentally clean transportation technologies. The MSU engineering students designing solar race cars today will be the engineers designing the efficient, quiet, emission free vehicles which we must be driving tomorrow. [see full article] Statistical and physical evolution of quasi-stellar objects, Caditz, D., and Petrosian, V. 1990, The Astrophysical Journal, 357, 326. ABSTRACT: The relationship between the physical evolution of discrete extragalactic sources, the statistical evolution of the observed population of sources, and the cosmological model are discussed. Three simple forms of statistical evolution - pure luminosity evolution (PLE), pure density evolution (PDE), and generalized luminosity evolution (GLE) are considered in detail together with what these forms imply about the physical evolution of individual sources. Two methods are used to analyze the statistical evolution of the observed distribution of QSOs from combined flux-limited samples. It is shown that both PLE and PDE are inconsistent with the data over the redshift range between 0.2 and 2.2 and that a more complicated form of evolution such as GLE is required, independent of the cosmological model. This result is important for physical models of AGN, and in particular, for the accretion disk model which recent results show may be inconsistent with PLE. Cosmological parameters and evolution of the galaxy luminosity function, Caditz, D., and Petrosian, V. 1989, The Astrophysical Journal, volume 337, part 2 (1989), page L65 ABSTRACT: The relationship between the observed distribution of discrete sources of a flux limited sample, the luminosity function of these sources, and the cosmological model is discussed. It is stressed that some assumptions about the form and evolution of the luminosity function must be made in order to determine the cosmological parameters from the observed distribution of sources. Presented is a method to test the validity of these assumptions using the observations. It is shown how, using higher moments of the observed distribution, one can determine, independently of the cosmological model, all parameters of the luminosity function except those describing evolution of the density and the luminosity of the luminosity function. These methods are applied to the sample of approximately 1000 galaxies recently used by Loh and Spillar to determine a value of the cosmological density parameter Omega approx = 1. It is shown that the assumptions made by Loh and Spillar about the luminosity function are inconsistent with the data, and that a self-consistent treatment of the data indicates a lower value of Omega approx = 0.2 and a flatter luminosity function. It should be noted, however, that incompleteness in the sample could cause a flattening of the luminosity function and lower the calculated value of Omega and that uncertainty in the values of these parameters due to random fluctuations is large.
Patents:
	Predictive Browser and Protocol Package - David Caditz & Norman Abramson (US patent #7904585) View ABSTRACT: TCP/IP is an almost universal protocol that was developed in the 1970's and is still used by nearly all Internet traffic. The TCP/IP protocol is no longer suitable for certain Internet applications. This is particularly true for wireless access channels, both satellite and terrestrial. These channels are assuming a greater role with the development of two-way VSAT access to the Internet and the introduction of 3G networks. In both cases, the cost of the access channel, usually some form of ALOHA channel, from the user to the network is the determining factor in any analysis of network costs. The inefficiencies introduced by the TCP in this class of channels translates directly to lower network capacity and lower revenue per channel. The replacement of TCP does not appear to be a feasible strategy despite TCP being ill suited to ALOHA access. Attempts to deal with the shortcomings of the combination of TCP and random access channels focus on the introduction of transparent proxies. This leaves the existing Internet protocol structure unchanged. A transparent proxy is simply a protocol translation entity acting dynamically on packets within the Internet so that its introduction is transparent to the Internet and to the user. Transparent proxies are commonly used to mask the effects of satellite delay in broadband VSAT Internet access. These transparent proxies may also be used in efficient transmission of trunking traffic within the Internet. However, in many applications for individual and small groups of users the paramount concern is the cost of the access channels, which is the dominant cost within the overall networks, rather than the cost of the Internet trunking channel that is the dominant cost for the backbone network provider. Needs exist for improved methods and tools for using random access channels. Needs exist for improved transparent proxies for random access channels. The present invention provides transparent proxies for random access channels. Client proxies and server proxies are provided at opposite ends of random access channels.The Predictive Browser (PB) of the present invention replicates many of the client browser functions at the Server Proxy in order to predict and encode the client traffic flowing in an ALOHA channel to the server.The replication moves the browser function away from the user into the Server Proxy on the other side of the random access channel. Several methods have been developed to reduce ALOHA channel HTTP traffic.These methods are Proxy Recursion and Page Caching, Request Tokenizing, Predictive Tokenizing and Request Compression. These methods, collectively integrated into the invention, reduce the amount of data required to be sent across the ALOHA channel.
Selected Designs:
	10 HP IGBT Motor Controller Solar Car Project Plan MSU Solar Car  Comet Camera
Press & Links:
	NASA/CERES Project A Systemic Approach to Improving K-12 Astronomy Education Using NASA's internet Resources. California Clean Air Race Solar Vehicle Project TangoMontana School of Dance tango.caditz.com "Changing Directions" by David Caditz
Photo Albums:
	Solar Powered Cars  Astronomy  Earth

hits: 1971