Identifying the practice components of youth councils: contributions of theory

Social workers are involved in numerous efforts to engage youth in programs, communities, and civic life. One potential strategy has focused on engagement and empowerment of youth through the form of youth councils. Multiple theoretical frames have characterized the scholarly literature. This has limited the conceptual coherence of the field. In this paper, we report empirical data on the operation of several youth councils. We analyze the data to identify the implicit frameworks in use and apply the data from our study to sort practice components within frameworks. This effort is designed to improve conceptualization of youth councils, to inform the development of councils, and eventually to improve outcomes of councils.Published versionAccepted manuscrip

Development of the ARIES parachute system

The design and testing of a two-stage parachute system to recover a space telescope weighing up to 2000 pounds is described. The system consists of a 15-ft dia ribbon parachute reefed to 50% for 10 seconds and a 73-ft dia paraform or cross second stage reefed to 10% for 10 seconds. The results of eight drop tests and one operational rocket launched flight and recovery are presented. A successful operational recovery of a 1600-lb NASA space telescope was conducted. The payload was launched by a second stage Minuteman rocket to an altitude of about 300 miles above sea level

Flexible Decision Control in an Autonomous Trading Agent

An autonomous trading agent is a complex piece of software that must operate in a competitive economic environment and support a research agenda. We describe the structure of decision processes in the MinneTAC trading agent, focusing on the use of evaluators – configurable, composable modules for data analysis and prediction that are chained together at runtime to support agent decision-making. Through a set of examples, we show how this structure supports sales and procurement decisions, and how those decision processes can be modified in useful ways by changing evaluator configurations. To put this work in context, we also report on results of an informal survey of agent design approaches among the competitors in the Trading Agent Competition for Supply Chain Management (TAC SCM).autonomous trading agent;decision processes

X-ray photoelectron spectroscopy investigation of the mixed anion GaSb/InAs heterointerface

X-ray photoelectron spectroscopy has been used to measure levels of anion cross-incorporation and to study interface formation for the mixed anion GaSb/lnAs heterojunction. Anion cross-incorporation was measured in 20 Å thick GaSb layers grown on lnAs, and 20 Å thick InAs layers grown on GaSb for cracked and uncracked sources. It was found that significantly less anion cross-incorporation occurs in structures grown with cracked sources. Interface formation was investigated by studying Sb soaks of InAs surfaces and As soaks of GaSb surfaces as a function of cracker power and soak time. Exchange of the group V surface atoms was found to be an increasing function of both cracker power and soak time. We find that further optimization of current growth parameters may be possible by modifying the soak time used at interfaces

Study of interface asymmetry in InAs–GaSb heterojunctions

We present reflection high energy electron diffraction, secondary ion mass spectroscopy, scanning tunneling microscopy and x‐ray photoelectron spectroscopy studies of the abruptness of InAs–GaSb interfaces. We find that the interface abruptness depends on growth order: InAs grown on GaSb is extended, while GaSb grown on InAs is more abrupt. We first present observations of the interfacial asymmetry, including measurements of band alignments as a function of growth order. We then examine more detailed studies of the InAs–GaSb interface to determine the mechanisms causing the extended interface. Our results show that Sb incorporation into the InAs overlayer and As exchange for Sb in the GaSb underlayer are the most likely causes of the interfacial asymmetry

Influence of convective transport on tropospheric ozone and its precursors in a chemistry-climate model

The impact of convection on tropospheric O₃ and its precursors has been examined in a coupled chemistry-climate model. There are two ways that convection affects O₃. First, convection affects O₃ by vertical mixing of O₃ itself. Convection lifts lower tropospheric air to regions where the O₃ lifetime is longer, whilst mass-balance subsidence mixes O₃-rich upper tropospheric (UT) air downwards to regions where the O₃ lifetime is shorter. This tends to decrease UT O₃ and the overall tropospheric column of O₃. Secondly, convection affects O₃ by vertical mixing of O₃ precursors. This affects O₃ chemical production and destruction. Convection transports isoprene and its degradation products to the UT where they interact with lightning NO_x to produce PAN, at the expense of NO_x. In our model, we find that convection reduces UT NO_x through this mechanism; convective down-mixing also flattens our imposed profile of lightning emissions, further reducing UT NO_x. Over tropical land, which has large lightning NO_x emissions in the UT, we find convective lofting of NO_x from surface sources appears relatively unimportant. Despite UT NO_x decreases, UT O₃ production increases as a result of UT HO_x increases driven by isoprene oxidation chemistry. However, UT O₃ tends to decrease, as the effect of convective overturning of O₃ itself dominates over changes in O₃ chemistry. Convective transport also reduces UT O₃ in the mid-latitudes resulting in a 13% decrease in the global tropospheric O₃ burden. These results contrast with an earlier study that uses a model of similar chemical complexity. Differences in convection schemes as well as chemistry schemes – in particular isoprene-driven changes are the most likely causes of such discrepancies. Further modelling studies are needed to constrain this uncertainty range

Next-to-leading order QCD corrections to single-inclusive hadron production in transversely polarized p-p and pbar-p collisions

We present a calculation of the next-to-leading order QCD corrections to the partonic cross sections contributing to single-inclusive high-p_T hadron production in collisions of transversely polarized hadrons. We use a recently developed projection technique for treating the phase space integrals in the presence of the cos(2Phi) azimuthal-angular dependence associated with transverse polarization. Our phenomenological results show that the double-spin asymmetry A_TT^pi for neutral-pion production is expected to be very small for polarized pp scattering at RHIC and could be much larger for the proposed experiments with an asymmetric pbar-p collider at the GSIComment: 7 pages, 5 figure

Real-time Tactical and Strategic Sales Management for Intelligent Agents Guided By Economic Regimes

Many enterprises that participate in dynamic markets need to make product pricing and inventory resource utilization decisions in real-time. We describe a family of statistical models that address these needs by combining characterization of the economic environment with the ability to predict future economic conditions to make tactical (short-term) decisions, such as product pricing, and strategic (long-term) decisions, such as level of finished goods inventories. Our models characterize economic conditions, called economic regimes, in the form of recurrent statistical patterns that have clear qualitative interpretations. We show how these models can be used to predict prices, price trends, and the probability of receiving a customer order at a given price. These “regime†models are developed using statistical analysis of historical data, and are used in real-time to characterize observed market conditions and predict the evolution of market conditions over multiple time scales. We evaluate our models using a testbed derived from the Trading Agent Competition for Supply Chain Management (TAC SCM), a supply chain environment characterized by competitive procurement and sales markets, and dynamic pricing. We show how regime models can be used to inform both short-term pricing decisions and longterm resource allocation decisions. Results show that our method outperforms more traditional shortand long-term predictive modeling approaches.dynamic pricing;trading agent competition;agent-mediated electronic commerce;dynamic markets;economic regimes;enabling technologies;price forecasting;supply-chain

Detecting and Forecasting Economic Regimes in Multi-Agent Automated Exchanges

We show how an autonomous agent can use observable market conditions to characterize the microeconomic situation of the market and predict future market trends. The agent can use this information to make both tactical decisions, such as pricing, and strategic decisions, such as product mix and production planning. We develop methods to learn dominant market conditions, such as over-supply or scarcity, from historical data using Gaussian mixture models to construct price density functions. We discuss how this model can be combined with real-time observable information to identify the current dominant market condition and to forecast market changes over a planning horizon. We forecast market changes via both a Markov correction-prediction process and an exponential smoother. Empirical analysis shows that the exponential smoother yields more accurate predictions for the current and the next day (supporting tactical decisions), while the Markov correction-prediction process is better for longer term predictions (supporting strategic decisions). Our approach offers more flexibility than traditional regression based approaches, since it does not assume a fixed functional relationship between dependent and independent variables. We validate our methods by presenting experimental results in a case study, the Trading Agent Competition for Supply Chain Management.dynamic pricing;machine learning;market forecasting;Trading agents

Mixed state Pauli channel parameter estimation

The accuracy of any physical scheme used to estimate the parameter describing the strength of a single qubit Pauli channel can be quantified using standard techniques from quantum estimation theory. It is known that the optimal estimation scheme, with m channel invocations, uses initial states for the systems which are pure and unentangled and provides an uncertainty of O[1/m^(1/2)]. This protocol is analogous to a classical repetition and averaging scheme. We consider estimation schemes where the initial states available are not pure and compare a protocol involving quantum correlated states to independent state protocols analogous to classical repetition schemes. We show, that unlike the pure state case, the quantum correlated state protocol can yield greater estimation accuracy than any independent state protocol. We show that these gains persist even when the system states are separable and, in some cases, when quantum discord is absent after channel invocation. We describe the relevance of these protocols to nuclear magnetic resonance measurements