43,881 research outputs found
“The Most Vivifying Influence:” Operation Delta in Preparing the Canadian Corps for the Hundred Days
Preparation and training for Operation Delta in May and June 1918 provided the Canadian Corps with vital experience for the types of operations conducted during the Hundred Days. Delta was a proposed attack on the southern portion of the Lys salient formed by the German April offensive in Flanders. The operation represented a clear break with the operational concepts employed in 1917 prior to Cambrai. It was a difference between seeing a play diagrammed on a blackboard and actually running it in conditions just short of combat. Having a concrete plan to prepare schemes against was an invaluable element in readying the corps for the strains of the Hundred Days. It helped in overcoming the challenges of ridding the corps of old thinking, mastering the new, and at an accelerated tempo. It was also a valuable rehearsal for the circumstances faced by the corps at Amiens. Finally, it demonstrated how the Canadian Corps differed from the British Army in creating and inculcating a corps level doctrine and the mechanisms used by the senior commanders and staff to disseminate, enforce, and practice it
Review of A Midnight Massacre: The Night Operation on the Passchendaele Ridge, 2 December 1917: The Forgotten Last Act of the Third Battle of Ypres by Michael LoCicero
Review of A Midnight Massacre: The Night Operation on the Passchendaele Ridge, 2 December 1917: The Forgotten Last Act of the Third Battle of Ypres by Michael LoCicero
A theoretical study of elastic X-ray scattering
Bragg X-ray scattering intensities are defined as scattering by the thermodynamic average electron-charge density. Purely elastic, kinematic X-ray scattering by a target in thermal equilibrium is always larger than Bragg scattering. At low temperatures, the elastic scattering becomes Bragg scattering. For large molecules, such as a crystal, at ordinary temperatures the elastic and Bragg scattering differ in a relative sense by O(N-1), where N is the number of vibrational degrees of freedom. For most practical cases the Bragg scattering is essentially the same as purely elastic scattering of X-rays
Food and Drug Administration Regulation of Food Safety
Food-borne illness remains a major public health challenge in the United States, causing an estimated 48 million illness episodes and 3000 deaths annually. The FDA Food Safety Modernization Act (FSMA), enacted in 2011, gives the Food and Drug Administration (FDA) new tools to regulate food safety. The act emphasizes prevention, enhanced recall authority, and oversight of imported food.
The FSMA brings the FDA’s food safety regulation in line with core tenets of public health by focusing on preventing outbreaks, rather than reacting to them, and differentiating between foods and food producers based on the degree of risk they pose. The FSMA also recognizes the increasing importance of imported food and enhances the ability of the FDA to safeguard the U.S. food supply from hazards originating abroad.
The act achieves its prevention objectives through requiring food production facilities to establish preventive control plans and by increasing inspection frequency—a shortcoming of the FDA in recent years. The act also enhances the FDA’s ability to respond to food safety problems when they occur. Through pilot projects on food tracing systems and an enhanced surveillance system, the FDA will be have better tools to determine the source of outbreaks. Additionally, the act gives the FDA new mandatory recall authority—a badly needed addition to its enforcement capabilities. In an increasingly globalized food environment, the FSMA gives the FDA new authority to regulate imported food. Among other provisions, the act allows FDA to inspect foreign facilities and to partner with foreign food regulatory agencies to help build capacity.
Through new tools and increased enforcement, the FSMA holds great promise for public health. The act, however, leaves several regulatory gaps, including keeping the food safety functions of the USDA and FDA separate. Additionally, the potential of the act to improve food safety may be thwarted by inadequate funding in the current budget environment.
The act includes numerous programs for building the capacity of domestic and foreign regulators and food producers. Such programs are essential to an improved food safety system, but require adequate funding from Congress to be fully implemented. In addition to national capacity building, FDA and Congress should fully engage partners in government and industry to improve global food safety at the international level
Space station
The history of American space flight indicates that a space station is the next logical step in the scientific pursuit of greater knowledge of the universe. The Space Station and its complement of space vehicles, developed by NASA, will add new dimensions to an already extensive space program in the United States. The Space Station offers extraordinary benefits for a comparatively modest investment (currently estimated at one-ninth the cost of the Apollo Program). The station will provide a permanent multipurpose facility in orbit necessary for the expansion of space science and technology. It will enable significant advancements in life sciences research, satellite communications, astronomy, and materials processing. Eventually, the station will function in support of the commercialization and industrialization of space. Also, as a prerequisite to manned interplanetary exploration, the long-duration space flights typical of Space Station missions will provide the essential life sciences research to allow progressively longer human staytime in space
Flight-testing of the self-repairing flight control system using the F-15 highly integrated digital electronic control flight research facility
Flight tests conducted with the self-repairing flight control system (SRFCS) installed on the NASA F-15 highly integrated digital electronic control aircraft are described. The development leading to the current SRFCS configuration is highlighted. Key objectives of the program are outlined: (1) to flight-evaluate a control reconfiguration strategy with three types of control surface failure; (2) to evaluate a cockpit display that will inform the pilot of the maneuvering capacity of the damage aircraft; and (3) to flight-evaluate the onboard expert system maintenance diagnostics process using representative faults set to occur only under maneuvering conditions. Preliminary flight results addressing the operation of the overall system, as well as the individual technologies, are included
A first order iteration process for simultaneous equations
First order iteration process for solutions of simultaneous equation
Project management techniques for highly integrated programs
The management and control of a representative, highly integrated high-technology project, in the X-29A aircraft flight test project is addressed. The X-29A research aircraft required the development and integration of eight distinct technologies in one aircraft. The project management system developed for the X-29A flight test program focuses on the dynamic interactions and the the intercommunication among components of the system. The insights gained from the new conceptual framework permitted subordination of departments to more functional units of decisionmaking, information processing, and communication networks. These processes were used to develop a project management system for the X-29A around the information flows that minimized the effects inherent in sampled-data systems and exploited the closed-loop multivariable nature of highly integrated projects
- …