Growth of crystals of the ternary sulfides Final technical report

Crystal growth of ternary sulfide

PLASIM: A computer code for simulating charge exchange plasma propagation

The propagation of the charge exchange plasma for an electrostatic ion thruster is crucial in determining the interaction of that plasma with the associated spacecraft. A model that describes this plasma and its propagation is described, together with a computer code based on this model. The structure and calling sequence of the code, named PLASIM, is described. An explanation of the program's input and output is included, together with samples of both. The code is written in ANSI Standard FORTRAN

Fundamental concepts of structural loading and load relief techniques for the space shuttle

The prediction of flight loads and their potential reduction, using various control system logics for the space shuttle vehicles, is discussed. Some factors not found on previous launch vehicles that increase the complexity are large lifting surfaces, unsymmetrical structure, unsymmetrical aerodynamics, trajectory control system coupling, and large aeroelastic effects. These load-producing factors and load-reducing techniques are analyzed

Using a Visually Adapted Repertory Grid Technique (VARGT) with people who stalk

Purpose: This manuscript aims to provide instructions on how to implement an adapted version of the standard Repertory Grid Technique (the VARGT). The purpose of which is to provide practitioners with a tool which enables active engagement by participants in research and clinical practice. This tool has been utilised effectively with people convicted of stalking offences. Approach: Repertory grids, developed from Kelly’s Personal Construct Theory (1955), had never been utilised with those who stalk, either clinically or in a research context. Visual and kinaesthetic adaptations were made to standard RGT procedures (see Grice, 2002; Tan and Hunter, 2002), for use in a mixed methods research study (see Wheatley, 2019, p. 77) due to expected challenges in engaging with this group. This manuscript presents theoretical underpinnings and step-by-step instructions for practical application. Findings: The VARGT is easy to administer and produces rich data, in both qualitative and quantitative formats. This adapted approach encourages active participation and an interpreted therapeutic collaboration (see Wheatley, Winder, and Kuss, in press). Originality/value: This novel technique has engaged men convicted of stalking offences collaboratively in research activities and showed potential for its use as a clinical tool. This instructional technical paper allows the technique to be replicated

Researcher-practitioner reflections: the therapeutic utility of the Visually Adapted Repertory Grid Technique (VARGT) with stalkers

Purpose: This paper outlines researcher-practitioner reflections on the use of a Visually Adapted Repertory Grid Technique (VARGT) with men convicted of stalking. It draws on and assimilates participant experiences of the VARGT as a research engagement tool. Further, it extends discussion to propose its value as a generic engagement tool for when personal insights and collaborative case formulations may otherwise be difficult to access. Approach: The repertory grid technique, developed from Kelly’s Personal Construct Theory (1955), was adapted for use in a mixed methods research study undertaken with those who commit stalking offences (see Wheatley, 2019, p. 77). Analytical and reflexivity processes within this original study highlighted rich and recurrent data across the sample pertaining to the positive participant experience of the VARGT, unrelated to its core research question. Findings: This paper presents reflections and psychological discussion for experiences of using the VARGT. Key features clustered around therapeutic alliance and engagement, enlightenment, and a motivation for positive change. Practice implications: This paper suggests the VARGT has value in participant-client engagement, particularly where sensitive topics are investigated and participants have difficulty directly articulating their psychosocial functioning. Originality/value: This novel technique offers potential as an engagement tool for use in research and clinical settings

Structural control interaction

The basic guidance and control concepts that lead to structural control interaction and structural dynamic loads are identified. Space vehicle ascent flight load sources and the load relieving mechanism are discussed, along with the the characteristics and special problems of both present and future space vehicles including launch vehicles, orbiting vehicles, and the Space Shuttle flyback vehicle. The special dynamics and control analyses and test problems apparent at this time are summarized

Quantum Dynamics of the Slow Rollover Transition in the Linear Delta Expansion

We apply the linear delta expansion to the quantum mechanical version of the slow rollover transition which is an important feature of inflationary models of the early universe. The method, which goes beyond the Gaussian approximation, gives results which stay close to the exact solution for longer than previous methods. It provides a promising basis for extension to a full field theoretic treatment.Comment: 12 pages, including 4 figure

Nearly optimal solutions for the Chow Parameters Problem and low-weight approximation of halfspaces

The \emph{Chow parameters} of a Boolean function $f: \{-1,1\}^n \to \{-1,1\}$ are its $n+1$ degree-0 and degree-1 Fourier coefficients. It has been known since 1961 (Chow, Tannenbaum) that the (exact values of the) Chow parameters of any linear threshold function $f$ uniquely specify $f$ within the space of all Boolean functions, but until recently (O'Donnell and Servedio) nothing was known about efficient algorithms for \emph{reconstructing} $f$ (exactly or approximately) from exact or approximate values of its Chow parameters. We refer to this reconstruction problem as the \emph{Chow Parameters Problem.} Our main result is a new algorithm for the Chow Parameters Problem which, given (sufficiently accurate approximations to) the Chow parameters of any linear threshold function $f$, runs in time \tilde{O}(n^2)\cdot (1/\eps)^{O(\log^2(1/\eps))} and with high probability outputs a representation of an LTF $f'$ that is \eps-close to $f$. The only previous algorithm (O'Donnell and Servedio) had running time \poly(n) \cdot 2^{2^{\tilde{O}(1/\eps^2)}}. As a byproduct of our approach, we show that for any linear threshold function $f$ over $\{-1,1\}^n$, there is a linear threshold function $f'$ which is \eps-close to $f$ and has all weights that are integers at most \sqrt{n} \cdot (1/\eps)^{O(\log^2(1/\eps))}. This significantly improves the best previous result of Diakonikolas and Servedio which gave a \poly(n) \cdot 2^{\tilde{O}(1/\eps^{2/3})} weight bound, and is close to the known lower bound of $\max\{\sqrt{n},$ (1/\eps)^{\Omega(\log \log (1/\eps))}\} (Goldberg, Servedio). Our techniques also yield improved algorithms for related problems in learning theory