Methods of generating television test patterns.

Joint Operational Stocks (JOS) are used as a "revolving" inventory of end-use items available for loans to United States Special Operations Forces. The JOS items are administered by the United States Special Operations Command (USSOCOM) in Tampa, FL. By using a revolving inventory, USSOCOM reduces the total quantities of items that need to be stocked However, current stocks are inadequate to meet demand, and current funding is inadequate to fully stock all inventory items. Currently USSOCOM has no methodology to prioritize purchase decisions to provide the best support to Special Operations Forces, per dollar spent. This thesis provides a methodology to allocate limited financial resources in procuring additional JOS units of inventory to provide the greatest increase in mission support benefit to special operations forces. The methodology is applied to the current JOS inventory system, providing a recommended prioritized sequence of inventory purchases. This thesis is limited to those items in the JOS inventory that currently do not have adequate quantities to meet the current demand, yet have sufficient demand history to provide adequate data for analysis. The methodology developed, however, is generic in nature and can be applied again in the future as more data becomes availablehttp://www.archive.org/details/methodsofgenerat00hancU.S. Navy (U.S.N.) author

Search for Magnetic Field Induced Gap in a High-Tc Superconductor

Break junctions made of the optimally doped high temperature superconductor Bi2Sr2Ca2CuO8 with Tc of 90 K has been investigated in magnetic fields up to 12 T, at temperatures from 4.2 K to Tc. The junction resistance varied between 1kOhm and 300kOhm. The differential conductance at low biases did not exhibit a significant magnetic field dependence, indicating that a magnetic-field-induced gap (Krishana et al., Science 277 83 (1997)), if exists, must be smaller than 0.25 meV.Comment: 3 pages, 2 figure

Tunneling conductance of SIN junctions with different gap symmetries and non-magnetic impurities by direct solution of real-axis Eliashberg equations

We theoretically investigate the effect of various symmetries of the superconducting order parameter Delta(omega) on the normalized tunneling conductance of SIN junctions by directly solving the real-axis Eliashberg equations (EEs) for a half-filled infinite band, with the simplifying assumption mu*=0. We analyze six different symmetries of the order parameter: s, d, s+id, s+d, extended s and anisotropic s, by assuming that the spectral function alpha^{2}F(Omega) contains an isotropic part alpha^{2}F(Omega)_{is} and an anisotropic one, alpha^{2}F(Omega)_{an}, such that alpha^{2}F(Omega)_{an} = g alpha^{2}F(Omega)_{is}, where g is a constant. We compare the resulting conductance curves at T=2 K to those obtained by analytical continuation of the imaginary-axis solution of the EEs, and we show that the agreement is not equally good for all symmetries. Then, we discuss the effect of non-magnetic impurities on the theoretical tunneling conductance curves at T=4 K for all the symmetries considered. Finally, as an example, we apply our calculations to the case of optimally-doped high-T_{c} superconductors (HTSC). Surprisingly, although the possibility of explaining the very complex phenomenology of HTSC is probably beyond the limits of the Eliashberg theory, the comparison of the theoretical curves calculated at T=4 K with the experimental ones obtained in various optimally-doped copper-oxides gives fairly good results.Comment: 11 pages, 11 figures, 2 tables. References added, figs. 6,7,10 and 11 changed, text change

Predominantly Superconducting Origin of Large Energy Gaps in Underdoped Bi2Sr2CaCu2O8-d from Tunneling Spectroscopy

New tunneling data are reported in underdoped Bi2Sr2CaCu2O8-d using superconductor-insulator-superconductor break junctions. Energy gaps, Delta, of 51+2, 54+2 and 57+3 meV are observed for three crystals with Tc=77, 74, and 70 K respectively. These energy gaps are nearly three times larger than for overdoped crystals with similar Tc. Detailed examination of tunneling spectra over a wide doping range from underdoped to overdoped, including the Josephson IcRn product, indicate that these energy gaps are predominantly of superconducting origin.Comment: 10 pages, 4 figures, 1 tabl

Tunneling effect in the high-tc superconductors Bi2Sr2Ca1(Cu1-xMx)2O8: effect of temperature and partial substitutions

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Art militaire

Opgedragen aan Nicolaas I en Alexander II, tsaren van RuslandDe auteur was officier van de Burgerwacht te Gen