Laser frequency stabilization using a molecular beam Final report, 1 Feb. - 31 Dec. 1969

Iodine molecular beam absorption resonance as long-term frequency reference for argon ion laser stabilizatio

A Molecular Beam Primary Reference for Long- Term Frequency Stabilization

Laser in molecular beam for feedback stabilizatio

Analytical and experimental investigations of low level acceleration measurement techniques

Construction techniques for accelerometer with low level threshold sensitivit

Balancing Vibrations at Harmonic Frequencies by Injecting Harmonic Balancing Signals into the Armature of a Linear Motor/Alternator Coupled to a Stirling Machine

Vibrations at harmonic frequencies are reduced by injecting harmonic balancing signals into the armature of a linear motor/alternator coupled to a Stirling machine. The vibrations are sensed to provide a signal representing the mechanical vibrations. A harmonic balancing signal is generated for selected harmonics of the operating frequency by processing the sensed vibration signal with adaptive filter algorithms of adaptive filters for each harmonic. Reference inputs for each harmonic are applied to the adaptive filter algorithms at the frequency of the selected harmonic. The harmonic balancing signals for all of the harmonics are summed with a principal control signal. The harmonic balancing signals modify the principal electrical drive voltage and drive the motor/alternator with a drive voltage component in opposition to the vibration at each harmonic

Driving an Active Vibration Balancer to Minimize Vibrations at the Fundamental and Harmonic Frequencies

Vibrations of a principal machine are reduced at the fundamental and harmonic frequencies by driving the drive motor of an active balancer with balancing signals at the fundamental and selected harmonics. Vibrations are sensed to provide a signal representing the mechanical vibrations. A balancing signal generator for the fundamental and for each selected harmonic processes the sensed vibration signal with adaptive filter algorithms of adaptive filters for each frequency to generate a balancing signal for each frequency. Reference inputs for each frequency are applied to the adaptive filter algorithms of each balancing signal generator at the frequency assigned to the generator. The harmonic balancing signals for all of the frequencies are summed and applied to drive the drive motor. The harmonic balancing signals drive the drive motor with a drive voltage component in opposition to the vibration at each frequency

Parallelizing Deadlock Resolution in Symbolic Synthesis of Distributed Programs

Previous work has shown that there are two major complexity barriers in the synthesis of fault-tolerant distributed programs: (1) generation of fault-span, the set of states reachable in the presence of faults, and (2) resolving deadlock states, from where the program has no outgoing transitions. Of these, the former closely resembles with model checking and, hence, techniques for efficient verification are directly applicable to it. Hence, we focus on expediting the latter with the use of multi-core technology. We present two approaches for parallelization by considering different design choices. The first approach is based on the computation of equivalence classes of program transitions (called group computation) that are needed due to the issue of distribution (i.e., inability of processes to atomically read and write all program variables). We show that in most cases the speedup of this approach is close to the ideal speedup and in some cases it is superlinear. The second approach uses traditional technique of partitioning deadlock states among multiple threads. However, our experiments show that the speedup for this approach is small. Consequently, our analysis demonstrates that a simple approach of parallelizing the group computation is likely to be the effective method for using multi-core computing in the context of deadlock resolution

Hong Kong SAR: Full Deposit Guarantee

Following a run on Hong Kong’s fifth-biggest bank in September 2008, the Hong Kong government announced that it would use its Exchange Fund to extend full insurance temporarily to depositors at approved banks. The existing Deposit Protection Scheme (DPS) would continue to insure the first 100,000 Hong Kong dollars (HKD; about USD 13,000) per depositor at each bank; the new program would cover the rest. It also covered a broader set of institutions. The Hong Kong Monetary Authority (HKMA) administered the program, overseen by the Hong Kong Deposit Protection Board (HKDPB); the HKMA was also responsible for managing the Exchange Fund, a standing reserve that was established in 1935. The Full Deposit Guarantee insured HKD 6 trillion during its operation. No claims were ever made. Upon its scheduled expiration on December 31, 2010, the government permanently replaced the existing DPS with an enhanced DPS, insuring deposits up to HKD 500,000

Internal position and limit sensor for free piston machines

A sensor for sensing the position of a reciprocating free piston in a free piston Stirling machine. The sensor has a disk mounted to an end face of the power piston coaxially with its cylinder and reciprocating with the piston The disk includes a rim around its outer perimeter formed of an electrically conductive material A coil is wound coaxially with the cylinder, spaced outwardly from the outer perimeter of the disk and mounted in fixed position relative to the pressure vessel, preferably on the exterior of the pressure vessel wall

Disability in Postsecondary STEM Learning Environments: What Faculty Focus Groups Reveal About Definitions and Obstacles to Effective Support

Students with disabilities lag behind their peers without disabilities in success outcomes related to access to, persistence within, and completion of postsecondary degree programs (National Center for Education Statistics [NCES], 2017). Faculty play a key role in shaping student success. To date, however, most of the work exploring faculty attitudes and behaviors has drawn from a broad sample (e.g., Buchanan, Charles, Rigler, & Hart, 2010; Kraska, 2003; Jensen, McCray, Krampe, & Cooper, 2004; Rao & Gartin, 2003), with only limited exploration of the attitudes and behaviors of science, technology, engineering, and mathematics [STEM] faculty (e.g., Milligan, 2010; Moon, Utschig, Todd, & Bozzorg, 2011). This study seeks to understand how STEM faculty think about and respond to students with disabilities in order to shape effective interventions. Data were collected through a series of four focus groups with 27 participants across 17 STEM majors including lecturers, pre- and post-tenure, and academic administrators. Key findings from the focus groups illuminated the impact of a formal accommodations process, individual approaches to providing support, and perceptions of the STEM climate towards students with disabilities. Recommendations for research and practice include strengthening support and training for faculty in STEM disciplines while continuing to explore these themes across institutional types