GMSK with limiter discriminator detection in satellite mobilechannel

Formulas are derived to find the error probability of partial-response frequency-shift keying with limiter discriminator detection, with and without decision feedback, for a satellite-mobile channel. The special cases of a Gaussian channel and a land-mobile channel are discussed. The formulas are applied to Gaussian minimum shift keying, and the error probability is computed as a function of energy-to-noise ratio, Gaussian filter bandwidth, Doppler frequency, maximum Doppler frequency, the ratio of powers in the specular and diffuse signal components, and the time delay between specular diffuse components     

Surface Modification of an Alumina‐Based Bioceramic for Cement Application

Biograde zirconia toughened alumina (ZTA) has found wide application in load bearing endoprosthetic implants due to high strength, fracture toughness, and wear resistance. In order to enhance bonding to acrylic bone cement (BC) for implants, fixation modification of ZTA with a thin layer of porous anodic alumina (PAA) was investigated. An Al‐layer of approximately 500 nm was sputtered on the ZTA substrate which subsequently was electrochemically oxidized by anodic polarization in H₂C₂O₄ or H₃PO₄ solution. PAA layers with a total porosity ranging from 11 to 30%, mean pore spacing of 90–200 nm and pore diameters of 30–110 nm were prepared. Compared to unmodified ZTA/BC interface (≈ 30 MPa), the PAA modified specimens (ZTA/PAA/BC) achieved a significantly higher interface bonding strength (≈ 60 MPa) measured by four point bending on composite beam specimens. While crack propagation in the unmodified ZTA/BC specimen was found to proceed along the interface, fracture analysis on the ZTA/PAA/BC specimens showed a mixed mode fracture with part of the fracture propagation localized along the PAA/BC interface and part through BC. Thus, pore structure controlled mechanical interlocking is expected to offer a high potential for applying PAA surface modification to improve biomaterial to BC bonding.     

Chromium exposure assessment of outdoor workers in Hudson County, NJ.

A large quantity of chromate chemical production waste, containing hexavalent chromium, has been used as fill at over 150 sites in Hudson County, New Jersey. One site is in a state park, and several other sites are adjacent to the park. Blood and urinary chromium levels were compared between 17 employees at the Hudson County park and 35 employees from two other state parks. A limited number of soil and personal air samples were also taken. Urinary and RBC chromium levels between the two groups were similar, even after adjusting for potentially confounding variables. The air sampling results demonstrated slightly higher chromium levels at Hudson County, but these were still very low level in nature (mean = 0.18 micrograms/m3). These results call into question the utility of chromium biomonitoring under environmental exposure conditions.     

Choice of parameters for explosive destruction of rock based on operational information on the composition of the rock

Nonferrous Metals Scientific Research Institute, Ust-Kamenogorsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 37–44, March–April, 1989.     

Host immune potentiation of drug responses to a murine mammary adenocarcinoma. II. Effect of melphalan therapy on the host immune system

The role of chemotherapy in influencing tumor-specific immunity to a mouse mammary adenocarcinoma was investigated. By studying different stages of tumor growth we were able to identify several factors important to drug-induced tumor regression: (1) antibody response, (2) delayed hypersensitivity, (3) sensitivity of tumor cells to immune attack and (4) tumor burden. The presence of tumor-specific delayed hypersensitivity and circulating antibody as well as specifically armed monocytes in the tumor mass characterize the T1699 adenocarcinoma. Successful chemotherapy had previously been shown to depend on prior establishment of the above immune responses. Treatment with alkylating agents was marked in all animals by abrogation of a humoral response to the tumor when drug was given early (day 7), and was associated with poor chemotherapeutic results. Later treatment (day 10) was associated with depression of antibody titers only in the minority of animals not responding to drug and prolongation of the delayed hypersensitivity response in all treated animals. Tumors recurring following initial drug-induced regression were marked by lack of delayed hypersensitivity in the host, lack of drug response and suppression of humoral immunity following treatment. Successive passage of cells from these resistant tumors led to decreasing sensitivity to chemotherapy despite established immunity on the part of the host. The selection of tumor cells resistant to immune destruction rather than drug resistance per se appeared to pay a role. Melphalan was thus able to affect both favorably and adversely the immune factors important to drug-induced regression.     

New,Faster Algorithms for Supervised Competitive Learning: Counterpropagation and Adaptive-Resonance Functionality

Hecht-Nielsen's counterpropagation networks often learn to associate input and output patterns more quickly than backpropagation networks. But simple competitive learning cannot separate closely spaced input patterns without adaptive-resonance-like (ART) functionality which prevents neighboring patterns from stealing each other's templates. We demonstrate pseudo-ART functionality with a new, simple, and very fast algorithm which requires no pattern normalization at all. Competition can be based on either Euclidean or L1-norm matching. In the latter case, the new algorithm emulates fuzzy ART. We apply the pseudo-ART scheme to several new types of counterpropagation networks, including one based on competition among combined input/output patterns, and discuss application with and without noise.     

Early desire

EARLY DESIRE (Direct Executing SImulation in REal time) is the first of a series of entirely new floating-point equation-language systems for interactive continuous-system simulation. DESIRE systems combine high computing speed (1.3 to 4 times faster that threaded FORTRAN) with immediate direct execution: no external compiler, linker, or loader is needed. DESIRE employs an interpreted job-control language (essentially an advanced BASIC dialect) for slower operations such as interactive program entry, editing, file manipulation, and for programming multi-run simulation studies. The ‘dynamic’ program segment containing differential equations in first-order form is entered just like the BASIC statements and can freely access the same named variables. The relative simplicity of the time-critical dynamic segment permits us to compile it practically instantaneously into efficient machine code, since a simple, super-fast compiler will do. DESIRE utilizes existing, precompiled FORTRAN integration routines; different integration rules can be switched as disk overlays while the program runs. EARLY DESIRE runs on PDP-11 or LSI-11 mini/microcomputers. Future DESIRE systems will download dynamic program segments into a variety of multiple execution processors.Thereafter rose Desire in the beginning; Desire, the primal germ and seed of Spirit.