THE U.S.-CANADA FREE TRADE AGREEMENT AND AGRICULTURE: ONE YEAR LATER

International Relations/Trade,

The Canadian Wheat Board: Government Guarantees and Hidden Subsidies?

The operations of the Canadian Wheat Board (CWB), a state trading enterprise, have generated controversy over the years, partly because of an alleged lack of transparency in its operations. This study examines one aspect of operations that is not well understood - the government guarantee of CWB borrowings and export credit sales. This special privilege allows the CWB to generate a "financial cushion", or non-market based revenue, that it can use to enhance returns to producers, discount export prices, or pay administrative expenses. Although recent WTO dispute settlement decisions concluded the CWB does not act inconsistently with some WTO rules, the July 31, 2004 WTO Doha Round framework agreement addresses these potential trade-distorting practices of the CWB.Canadian Wheat Board, financial cushion, state trading enterprise, World Trade Organization, International Relations/Trade,

Lessons Learned From the NAFTA: A U.S. Perspective

International Relations/Trade,

The WTO Agriculture Negotiations: Potential Implications for Cotton

International Relations/Trade,

Telephone multiline signaling using common signal pair

An operator can rapidly and automatically produce coded electrical signals by manipulating mechanical thumb wheel switches so as to instruct a service center to connect any number of telephone lines to the console thus enabling the operator to listen and/or talk over several lines simultaneously. The system includes an on-site console having several mechanically operated thumb wheel switches to which the desired lines to be connected can be dialed in. Electrical coded signals are fed to a number of banks of line AND gates representing units, tens and hundreds, a group of channel gates, and a command gate. These signals are gated out in a controlled manner to an encoder which generates tones that are transmitted over a single line to a communication service center

Formal Analysis of Pilot Error with Agent Safety Logic

In this paper, we show that modal logic is a valuable tool for the formal analysis of human errors in aviation safety. We develop a modal logic called Agent Safety Logic (ASL), based on epistemic logic, doxastic logic, and a safety logic grounded in a ight safety manual. We identify a class of human error that has contributed to several aviation incidents involving a specific kind of pilot knowledge failure, and formally analyze it. The use of ASL suggests how future avionics might increase aircraft safety

Design and Verification of a Distributed Communication Protocol

The safety of remotely operated vehicles depends on the correctness of the distributed protocol that facilitates the communication between the vehicle and the operator. A failure in this communication can result in catastrophic loss of the vehicle. To complicate matters, the communication system may be required to satisfy several, possibly conflicting, requirements. The design of protocols is typically an informal process based on successive iterations of a prototype implementation. Yet distributed protocols are notoriously difficult to get correct using such informal techniques. We present a formal specification of the design of a distributed protocol intended for use in a remotely operated vehicle, which is built from the composition of several simpler protocols. We demonstrate proof strategies that allow us to prove properties of each component protocol individually while ensuring that the property is preserved in the composition forming the entire system. Given that designs are likely to evolve as additional requirements emerge, we show how we have automated most of the repetitive proof steps to enable verification of rapidly changing designs

Compositional Verification of a Communication Protocol for a Remotely Operated Vehicle

This paper presents the specification and verification in the Prototype Verification System (PVS) of a protocol intended to facilitate communication in an experimental remotely operated vehicle used by NASA researchers. The protocol is defined as a stack-layered com- position of simpler protocols. It can be seen as the vertical composition of protocol layers, where each layer performs input and output message processing, and the horizontal composition of different processes concurrently inhabiting the same layer, where each process satisfies a distinct requirement. It is formally proven that the protocol components satisfy certain delivery guarantees. Compositional techniques are used to prove these guarantees also hold in the composed system. Although the protocol itself is not novel, the methodology employed in its verification extends existing techniques by automating the tedious and usually cumbersome part of the proof, thereby making the iterative design process of protocols feasible