Unsupervised learning of human motion

An unsupervised learning algorithm that can obtain a probabilistic model of an object composed of a collection of parts (a moving human body in our examples) automatically from unlabeled training data is presented. The training data include both useful "foreground" features as well as features that arise from irrelevant background clutter - the correspondence between parts and detected features is unknown. The joint probability density function of the parts is represented by a mixture of decomposable triangulated graphs which allow for fast detection. To learn the model structure as well as model parameters, an EM-like algorithm is developed where the labeling of the data (part assignments) is treated as hidden variables. The unsupervised learning technique is not limited to decomposable triangulated graphs. The efficiency and effectiveness of our algorithm is demonstrated by applying it to generate models of human motion automatically from unlabeled image sequences, and testing the learned models on a variety of sequences

Early Quantitative Assessment of Non-Functional Requirements

Non-functional requirements (NFRs) of software systems are a well known source of uncertainty in effort estimation. Yet, quantitatively approaching NFR early in a project is hard. This paper makes a step towards reducing the impact of uncertainty due to NRF. It offers a solution that incorporates NFRs into the functional size quantification process. The merits of our solution are twofold: first, it lets us quantitatively assess the NFR modeling process early in the project, and second, it lets us generate test cases for NFR verification purposes. We chose the NFR framework as a vehicle to integrate NFRs into the requirements modeling process and to apply quantitative assessment procedures. Our solution proposal also rests on the functional size measurement method, COSMIC-FFP, adopted in 2003 as the ISO/IEC 19761 standard. We extend its use for NFR testing purposes, which is an essential step for improving NFR development and testing effort estimates, and consequently for managing the scope of NFRs. We discuss the advantages of our approach and the open questions related to its design as well

DESIGNING INTERACTIVE USER INTERFACES: DIALOG CHARTS AND AN ASSESSMENT OF THEIR USE IN SPECIFYING CONCEPTUAL MODELS OF DIALOGS

The conceptual design of user interfaces focuses on arriving at a specification of the structure of the dialog, independent of any particular implementation approach. There is common agreement as to the importance of this activity to both IS professionals and end-users, but few -- if any -- modeling methods were developed to specifically support the process of conceptual design, and the usefulness of such methods has not been adequately addressed. This paper introduces the Dialog Charts (DCs), and documents a preliminary examination of their perceived usefulness by designers of user/system interaction who actually used them. The DCs yield high level dialog schemas that are abstract enough to support the conceptual design of dialog control structures. In a uniform diagramming framework they combine the concept of dialog independence, distinguish between the dialog parties, provide for hierarchical decomposition and enforce a structured control flow. The usefulness of the DCs has been studied empirically in a qualitative inquiry. Recalled experiences of designers were captured and analyzed to ascertain the concept of usability, as well as assess the usability of the DCs. Usability has emerged from this study as a set of 38 concerns that operationalizes the broader aspects of purpose of use, design stage, impact on product structure, impact on design process, and attitudinal patterns. In general, the Dialog Charts were found by these dialog designers to be a useful, exhibiting the essential attributes of tools for conceptual modeling.Information Systems Working Papers Serie

Language design for a personal learning environment design language

Approaching technology-enhanced learning from the perspective of a learner, we foster the idea of learning environment design, learner interactions, and tool interoperability. In this paper, we shortly summarize the motivation for our personal learning environment approach and describe the development of a domain-specific language for this purpose as well as its realization in practice. Consequently, we examine our learning environment design language according to its lexis and syntax, the semantics behind it, and pragmatical aspects within a first prototypic implementation. Finally, we discuss strengths, problematic aspects, and open issues of our approach

Opciones de políticas para la paliación de la pobreza

(Disponible en idioma inglés únicamente) Este trabajo se fundamenta en investigaciones anteriores para desarrollar una metodología que simplifique la identificación de las mejores opciones de políticas para paliar la pobreza en un país dado. Cuando se puede dividir una población en subgrupos según alguna característica fácilmente identificable, se puede entender el problema del alivio de la pobreza mediante un mecanismo dirigido a sectores específicos como una elección entre tres opciones: i) provocar un cambio marginal en el ingreso promedio de ciertos subgrupos; ii) modificar la distribución de ingresos dentro de subgrupos marginales y iii) generar un cambio marginal en las diferencias entre los subgrupos. Se aplican datos recientes de México.

Exploiting a Goal-Decomposition Technique to Prioritize Non-functional Requirements

Business stakeholders need to have clear and realistic goals if they want to meet commitments in application development. As a consequence, at early stages they prioritize requirements. However, requirements do change. The effect of change forces the stakeholders to balance alternatives and reprioritize requirements accordingly. In this paper we discuss the problem of priorities to non-functional requirements subjected to change. We, then, propose an approach to help smooth the impact of such changes. Our approach favors the translation of nonoperational specifications into operational definitions that can be evaluated once the system is developed. It uses the goal-question-metric method as the major support to decompose non-operational specifications into operational ones. We claim that the effort invested in operationalizing NFRs helps dealing with changing requirements during system development. Based on\ud this transformation and in our experience, we provide guidelines to prioritize volatile non-functional requirements

Agricultural Growth and Rural Performance: A Philippine Perspective

Usual indicators of intertemporal rural performance are technically flawed mainly because of the “shifting” of the physical area of the rural sector as population grows and/or economic activity expands. This problem is illustrated here using Philippine recovery data. Also shown is the fact that Green Revolution has not substantially alleviated rural poverty in the Philippines.poverty alleviation, agriculture sector, investment, poverty, road

CHALLENGES IN THE SECOND LANGUAGE ACQUISITION OF DERIVATIONAL MORPHOLOGY: FROM THEORY TO PRACTICE

The three studies in this dissertation bring together quantitative and qualitative methods in order to understand L2 learning of derivational morphology. By using measures of derivational knowledge developed from L1 research, Study 1 provides a foundation for in-class research by assessing what L2 learners know and do not know about derivational morphology in comparison to adult native English speakers and how factors such as L1 background and L2 proficiency shape L2 knowledge of derivational morphology. Results show that L2 learners have poor knowledge of derivational morphology regardless of L1 background or L2 proficiency.Study 2 follows from these results and investigates the effects of input-processing versus pushed output instruction on the development of productive and receptive morphological abilities. The results of this study support the hypothesis that instruction is beneficial for L2 derivational learning; however, results do not support the hypothesis that pushed output instruction leads to better immediate and long-term learning than the input-processing condition. In fact, results suggest that equivalent learning occurs between the two conditions across all measures of derivational knowledge.Finally, Study 3 was a qualitative investigation of learners' attitudes, actions, and motivations towards the learning of derivational morphology over the course of Study 2. Using activity theory, this study describes how students' initial actions, which were not aligned with the goal of morphological learning, were transformed over the course of the study as students came to realize the importance of derivational morphology for their success in English. The results of this study are also important because they offer an alternative explanation for why the hypotheses in Study 2 regarding the effectiveness of output were not supported. Specifically, many participants in this study became aware of derivational morphology for the first time as a result of this study; therefore, a "novelty effect" (cf. Tulving & Kroll, 1995) may have overridden any potential benefit of the output treatment over the input treatment