Problem Definition. 1.1.1 The Nature of Energy Flows Energy flows are distinctly different from the manner in which the energy commodity is purchased, sold, and ultimately scheduled. In the current practice of “contract path” scheduling, schedules identify a source point for generation of energy, a series of wheeling agreements being utilized to transport that energy, and a specific sink point where that energy is being consumed by a load. However, due to the electrical characteristics of the Eastern Interconnection, energy flows are more dispersed than what is described within that schedule. This disconnect becomes of concern when there is a need to take actions on contract-path schedules to effect changes on the physical system (for example, the curtailment of schedules to relieve transmission constraints). In the Eastern Interconnection, much of this concern has been addressed through the use of the North American Electric Reliability Corporation (NERC) and/or North American Energy Standards Board (NAESB) TLR process. Through this process, Reliability Coordinators utilize the IDC to determine appropriate actions to provide that relief. The IDC bases its calculations on the use of transaction tags: electronic documents that specify a source and a sink, which can be used to estimate real power flows through the use of a network model. In order to change flows, the IDC is given a particular constraint and a desired change in flows. The IDC returns back all source to sink transactions that contribute to that constraint and specifies schedule changes to be made that will effect that change in flows. In other parts of the Eastern Interconnection, however, the use of centralized economic dispatch results in a solution that does not focus on changing entire transactions (effectively redispatching through the use of imbalance energy), but rather redispatch itself. In this procedure, the party attempting to provide relief does not need to know that a balanced source to sink transaction should be adjusted; rather, they are aware of a net generation to load balance and the impacts of different generators on various constraints. Bid-based security constrained central dispatch based on Locational Marginal Pricing is a regional implementation of this practice. Currently, these two practices are somewhat incompatible. Due to the electrical characteristics of the Interconnection and geographic scope of the regions, this incompatibility has been of limited concern. However, regional market ...
Problem Definition. The following standard problem definitions will apply to the performance of Member Youth Services under this Service Level Agreement. Priority Problem Status Impact Priority 1 Mission critical Serious service, and/or financial impact Priority 2 Extremely urgent Significant service and/or financial impact Priority 3 Urgent Medium service and/or financial impact Priority 4 Medium priority Minimal service and/or financial impact Priority 5 Low Priority No service and/or financial impact
Problem Definition. To assist in expeditiously resolving Customer’s problem, the Customer should record the following information for reference and should provide the information to Alchemy: (a) error messages and indications that Customer received when the malfunction occurred,
Problem Definition. Customer shall record the following information for reference and provide it to Upland: (a) error messages and indications that Customer received when the malfunction occurred; (b) what the user was doing when the malfunction occurred; (c) what steps Customer has taken to reproduce the malfunction; (d) what steps Customer may have already taken to solve the problem; and (e) system logging Severity Impact 1 Production system Defect that prevents business critical work from being done, no Workaround exists, and Defect impacts most Users; or Defect causes a material loss of Customer Data in production system; or Security-related Defect. 2 Production system Defect that prevents business critical work from being done and a Workaround exists; or Defect violates the material specifications in the Documentation and impacts Customer’s production system. 3 All other Defects.
Problem Definition. Agreeing on a given piece of information is a clas- sical coordination problem in distributed computing. The Two Generals’ Agreement Problem, formulated by Xxx Xxxx to illustrate the two-phase commit protocol in distributed database systems [4], is often used to explain the challenges when attempting to coordinate an action by communicating over a faulty channel, and can be described as follows. Two battalions are encamped near a city, ready to launch the final attack. Because of the redoubtable fortifications, the attack must be carried out by both battallions at the same time in order to succeed. Hence, the generals of the two armies need to agree on the time of the attack, and their only way to communicate is to send messengers through the valley. The latter is occupied by the city’s defenders, and a messenger can be captured and its message lost, i.e., the communication Fig. 1. n-way handshake between nodes S and R. Fig. 2. Enhanced n-way handshake between nodes S and R using redundancy: the last ACK message is transmitted k times. channel is unreliable. Since each general must be aware that the other general has agreed on the attack plan, messengers are used also to exchange acknowledgements. However, because the acknowledgement of a message receipt can be lost as easily as the original message, a potentially infinite series of messages is required to reach an agreement1.
Problem Definition. The processes in the group are periodically agreeing on a value. Each period is called an agreement instance. The outcome of an agreement instance is that every process decides a value, with the following properties: 1)
Problem Definition. The Village of Lake Placid and the Town of North Xxxx are looking to increase public awareness of and promote increased transparency within public meetings through the incorporation of technology. Lake Placid/North Xxxx wants to focus on public awareness within the government and improve access and streaming capabilities of public hearings.
Problem Definition. A. Previous work Co-design is used in systems having interplay among various domains, and targeted to meet the system requirements in the presence of complex domain dependencies. Co-design approaches have been used in control systems in the context of networked control systems (see, [2]-[11]), embedded control systems [12-13], hardware, and software [14], electrical and mechanical design [15], embedded systems [16-18] among others. In a recent research survey on co-design approaches for networked control systems- X. Xxx et al. [11] commented that the co-design tool should deal with complex dependencies among different domains. Finding rational abstractions that allow (control) system requirements, and assumptions alongside platform constraints to be communicated across the domains was identified as the key issue in such a design. Further, it was also commented that the co-design approach not only leads to optimal design but also gives less conservative results that could be used for design of NCSs. To our knowledge, the use of co-design approach for NAS has not been investigated in the literature. Further, the concept of rational abstractions has not been answered and not many results are available in this direction. Motivated by these gaps, we study NAS co-design for the functional requirement of reliable control in the presence of timing imperfections. We try to answer the questions about suitable rational abstractions in the context of NAS by studying the timing imperfections that affect the control performance. In [19], design contract has been used as tool for defining interface among software and control domain in the context of CPS. The main idea is to extend the idea of design contracts to NAS wherein the contracts specify the timing requirement and, provide interface among the domains. Contract based design was proposed by X. Xxxxx [51] in the context of the programming language Eiffel. Contract based design has been used for designing closed loop controllers for hybrid systems [52], embedded systems, Simulink control diagrams [53], robotic systems, heterogeneous systems to mention a few. In all the above cases, contracts have been used as an interface for inter-domain communication and/or negotiation. Recently, the concept of contract based design has been studied in the context of CPS in and various design contracts have been proposed. Further, the investigation also outlines some open problems, they are:
Problem Definition. The following standard problem definitions will apply to the services provided under the terms of this agreement by National Office to Member Youth Services. Priority Problem Status Impact Priority 1 Mission critical Serious service and/or financial impact Priority 2 Extremely urgent Significant service and/or financial impact Priority 3 Urgent Medium service and/or financial impact Priority 4 Medium priority Minimal service and/or financial impact Priority 5 Low Priority No service and/or financial impact The following standard problem definitions will apply to the performance of Member Youth Services under this Service Level Agreement. Priority Problem Status Impact Priority 1 Mission critical Serious service and/or financial impact Priority 2 Extremely urgent Significant service and/or financial impact Priority 3 Urgent Medium service and/or financial impact Priority 4 Medium priority Minimal service and/or financial impact Priority 5 Low Priority No service and/or financial impact
Problem Definition. In this section we propose a key agreement scheme for secure home networks that would:
