AAA gunnermodel based on observer theory

The Luenberger observer theory is used to develop a predictive model of a gunner's tracking response in antiaircraft artillery systems. This model is composed of an observer, a feedback controller and a remnant element. An important feature of the model is that the structure is simple, hence a computer simulation requires only a short execution time. A parameter identification program based on the least squares curve fitting method and the Gauss Newton gradient algorithm is developed to determine the parameter values of the gunner model. Thus, a systematic procedure exists for identifying model parameters for a given antiaircraft tracking task. Model predictions of tracking errors are compared with human tracking data obtained from manned simulation experiments. Model predictions are in excellent agreement with the empirical data for several flyby and maneuvering target trajectories

User benefits and funding strategies

The justification, economic and technological benefits of NASA Space Programs (aside from pure scientific objectives), in improving the quality of life in the United States is discussed and outlined. Specifically, a three-step, systematic method is described for selecting relevant and highly beneficial payloads and instruments for the Interim Upper Stage (IUS) that will be used with the space shuttle until the space tug becomes available. Viable Government and private industry cost-sharing strategies which would maximize the number of IUS payloads, and the benefits obtainable under a limited NASA budget were also determined. Charts are shown which list the payload instruments, and their relevance in contributing to such areas as earth resources management, agriculture, weather forecasting, and many others

Serving children: the impact of poverty on children's experiences of services

This study arose from the identification of a gap in knowledge and corresponding need for the development of a better contemporary understanding of children's experiences of poverty. Focusing on children aged 10 - 14 years, the study aimed to provide a perspective on the lives of children and young people affected by poverty in Scotland through comparing the experiences of children living in poverty with those more economically advantaged

Stochastic Models for Replication Origin Spacings in Eukaryotic DNA Replication

We consider eukaryotic DNA replication and in particular the role of replication origins in this process. We focus on origins which are `active' - that is, trigger themselves in the process before being read by the replication forks of other origins. We initially consider the spacings of these active replication origins in comparison to certain probability distributions of spacings taken from random matrix theory. We see how the spacings between neighbouring eigenvalues from certain collections of random matrices has some potential for modelling the spacing between active origins. This suitability can be further augmented with the use of uniform thinning which acts as a continuous deformation between correlated eigenvalue spacings and exponential (Poissonian) spacings. We model the process as a modified 2D Poisson process with an added exclusion rule to identify active points based on their position on the chromosome and trigger time relative to other origins. We see how this can be reduced to a stochastic geometry problem and show analytically that two active origins are unlikely to be close together, regardless of how many non-active points are between them. In particular, we see how these active origins repel linearly. We then see how data from various DNA datasets match with simulations from our model. We see that whilst there is variety in the DNA data, comparing the data with the model provides insight into the replication origin distribution of various organisms.Comment: 18 pages, 26 figure

Solar-heated new technology house (1993)

In 1980, the College of Agriculture completed construction of a solar-heated home on a University farm near Columbia. It's called a New Technology House because it incorporates the latest technology available for home construction. The major emphasis is on energy conservation and solar heating.Reviewed October 1993

Total scattering descriptions of local and cooperative distortions in the oxide spinel (Mg,Cu)Cr2O4 with dilute Jahn-Teller ions

The normal spinel oxide MgCr2O4 is cubic at room temperature while the normal spinel CuCr2O4 is tetragonal as a consequence of the Jahn-Teller nature of Cu2+ on the tetrahedral sites. Despite different end-member structures, complete solid solutions of Mg_{1-x}Cu_xCr2O4 can be prepared that display a first-order structural transition with composition x = 0.43 at room temperature. Reverse Monte Carlo analysis of total neutron scattering on data acquired between 300 K and 15 K on samples with x = 0.10, 0.20, and 0.43 provides unbiased local and average structure descriptions of the samples, including an understanding of the transition from local Jahn-Teller distortions in the cubic phase to cooperative distortions that result in a tetragonal structure. Distributions of continuous symmetry measures help to understand and distinguish distorted and undistorted coordination around the tetrahedral site in the solid solutions. Magnetic exchange bias is observed in field-cooled hysteresis loops of samples with dilute Cu2+ concentration and in samples with tetragonal--cubic phase coexistence around 300 K.Comment: 10 pages, 14 figure

Partnership practice as collaborative knowledge work: Overcoming common dilemmas through an augmented view of professional expertise

Purpose - The purpose of this paper is to shed new light on how partnership practices that build resilience in families work. Two broad questions are explored: first, what are the forms of expertise required in practices that effectively build resilience through partnership; and second, how can some of the challenges practitioners experience when working in partnership be addressed Design/methodology/approach - A theoretical approach is taken, framing partnership as collaborative knowledge work between practitioners and clients. Concepts of relational expertise, common knowledge and relational agency are explored as means to understand the forms of expertise involved in partnership. An empirical example is provided from practices guided by The Family Partnership Model, an approach that has been widely implemented. Findings - These concepts help to address three key challenges experienced by practitioners: client readiness for change, maintaining focus and purpose and using specialist expertise in partnership. This approach elucidates features of partnership practice that distinguish it from expert-led models, while highlighting diverse forms of expertise in play. Originality/value - The framework presented in this paper is distinctive and can be used to identify how practitioners can avoid common dilemmas, even in challenging circumstances with vulnerable families where practitioner-client relationships may be perceived as fragile. It counters the idea that partnership work dilutes professional expertise. Instead, an enriched and augmented view of professional expertise is presented

Universality of residence-time distributions in non-adiabatic stochastic resonance

We present mathematically rigorous expressions for the residence-time and first-passage-time distributions of a periodically forced Brownian particle in a bistable potential. For a broad range of forcing frequencies and amplitudes, the distributions are close to periodically modulated exponential ones. Remarkably, the periodic modulations are governed by universal functions, depending on a single parameter related to the forcing period. The behaviour of the distributions and their moments is analysed, in particular in the low- and high-frequency limits.Comment: 8 pages, 1 figure New version includes distinction between first-passage-time and residence-time distribution

Thermopower as a Possible Probe of Non-Abelian Quasiparticle Statistics in Fractional Quantum Hall Liquids

We show in this paper that thermopower is enhanced in non-Abelian quantum Hall liquids under appropriate conditions. This is because thermopower measures entropy per electron in the clean limit, while the degeneracy and entropy associated with non-Abelian quasiparticles enhance entropy when they are present. Thus thermopower can potentially probe non-Abelian nature of the quasiparticles, and measure their quantum dimension.Comment: 5 pages. Minor revisions in response to referee comments. Published versio

Imaginary companions in childhood: Relations to imagination skills and autobiographical memory in adults

The presence of a childhood imaginary companion (IC) has been proposed to reflect heightened imaginative abilities. This study hypothesized that adults who reported having a childhood IC would score higher on a task requiring the imaginative construction of visual scenes. Additionally, it was proposed that individuals who produced more vivid and detailed scenes would also report richer autobiographical memories, due to a shared reliance on imaginative abilities in construction and recollection. Sixty participants (20 with an IC), completed an adapted scene construction procedure and an autobiographical memory questionnaire. Participants reporting a childhood IC scored significantly higher on scene construction and rated themselves as more imaginative. Scene construction scores were also moderately related to the richness of autobiographical memories, although this was almost entirely due to scores on the thought/emotion/action component of scene construction. Autobiographical memory was unrelated to the presence of an IC. Implications for overlapping and dissociable aspects of imagination and memory are discussed