Going Beyond Functionings to Capabilities : an Econometric Model to Explain and Estimate Capabilities

Any attempt to operationalise the capability approach necessitates an adequate framework for the measurement of the abstract unobservable multidimensional concept that the term human development stands for. One such attempt is the latent variable approach including principal components, factor analysis and MIMIC models. The first two models provide estimates of the latent variables but are silent on the factors influencing these variables (capabilities in our context). MIMIC models represent a step further in this direction as they include exogenous “causal” variables for the latent factors but the effects go only in one direction i.e. from the “causes” to the latent variables. We argue that some of these causal factors not only influence human development but they are also influenced by it and that unless this feedback mechanism is taken into account we do not have a complete picture of this complex phenomenon. In this paper we present a theoretical framework incorporating the above aspects into a coherent system of causes, effects and interactions, leading to an econometric model which represents a generalisation of existing latent variable models. Estimating the model will enable us to explain the level of capabilities, say how they can be best improved, test our theoretical hypotheses and derive estimators that reflect the actual capabilities rather than just the functionings.human development, capability approach, latent variables, qualitative response, simultaneous equations.

Self-stabilizing cluster routing in Manet using link-cluster architecture

We design a self-stabilizing cluster routing algorithm based on the link-cluster architecture of wireless ad hoc networks. The network is divided into clusters. Each cluster has a single special node, called a clusterhead that contains the routing information about inter and intra-cluster communication. A cluster is comprised of all nodes that choose the corresponding clusterhead as their leader. The algorithm consists of two main tasks. First, the set of special nodes (clusterheads) is elected such that it models the link-cluster architecture: any node belongs to a single cluster, it is within two hops of the clusterhead, it knows the direct neighbor on the shortest path towards the clusterhead, and there exist no two adjacent clusterheads. Second, the routing tables are maintained by the clusterheads to store information about nodes both within and outside the cluster. There are two advantages of maintaining routing tables only in the clusterheads. First, as no two neighboring nodes are clusterheads (as per the link-cluster architecture), there is no need to check the consistency of the routing tables. Second, since all other nodes have significantly less work (they only forward messages), they use much less power than the clusterheads. Therefore, if a clusterhead runs out of power, a neighboring node (that is not a clusterhead) can accept the role of a clusterhead. (Abstract shortened by UMI.)

Visualizing networked writing activity

In conjunction with the Honors Fellow program and two faculty advisors from both the English and Computer Science departments, another student and I have written software to visualize how participants collaborate on networked writing projects. Using Google Docs as a way to allow students to instantaneously interact with a document in real-time, this software captures data from Google's cloud service and displays it in a pair of visualizations. We used agile methods of software development to devise a way to implement their ideas in an appealing way. This document contains detailed instructions on where the latest iteration of the software can be located. It also details the process of making the system operational on a new machine, stating how the software works and where it should be placed in the file system. The document also explains how one can use the system to visualize writing collaboration. Finally, many failed iterations of the software have led to meaningful reflections on software development practices. The document serves as a technical report for the software, but also elaborates on the hardships of development, as well as provides insight on how this software may evolve toward richer experiences. Also included is an Author's Statement which reveals many of the learning experiences that arose throughout the development of this project.Honors CollegeThesis (B.?.

Automated Fixing of Programs with Contracts

This paper describes AutoFix, an automatic debugging technique that can fix faults in general-purpose software. To provide high-quality fix suggestions and to enable automation of the whole debugging process, AutoFix relies on the presence of simple specification elements in the form of contracts (such as pre- and postconditions). Using contracts enhances the precision of dynamic analysis techniques for fault detection and localization, and for validating fixes. The only required user input to the AutoFix supporting tool is then a faulty program annotated with contracts; the tool produces a collection of validated fixes for the fault ranked according to an estimate of their suitability. In an extensive experimental evaluation, we applied AutoFix to over 200 faults in four code bases of different maturity and quality (of implementation and of contracts). AutoFix successfully fixed 42% of the faults, producing, in the majority of cases, corrections of quality comparable to those competent programmers would write; the used computational resources were modest, with an average time per fix below 20 minutes on commodity hardware. These figures compare favorably to the state of the art in automated program fixing, and demonstrate that the AutoFix approach is successfully applicable to reduce the debugging burden in real-world scenarios.Comment: Minor changes after proofreadin