Using Natural Language as Knowledge Representation in an Intelligent Tutoring System

Knowledge used in an intelligent tutoring system to teach students is usually acquired from authors who are experts in the domain. A problem is that they cannot directly add and update knowledge if they don’t learn formal language used in the system. Using natural language to represent knowledge can allow authors to update knowledge easily. This thesis presents a new approach to use unconstrained natural language as knowledge representation for a physics tutoring system so that non-programmers can add knowledge without learning a new knowledge representation. This approach allows domain experts to add not only problem statements, but also background knowledge such as commonsense and domain knowledge including principles in natural language. Rather than translating into a formal language, natural language representation is directly used in inference so that domain experts can understand the internal process, detect knowledge bugs, and revise the knowledgebase easily. In authoring task studies with the new system based on this approach, it was shown that the size of added knowledge was small enough for a domain expert to add, and converged to near zero as more problems were added in one mental model test. After entering the no-new-knowledge state in the test, 5 out of 13 problems (38 percent) were automatically solved by the system without adding new knowledge

Mission-Market Tensions and Nonprofit Pricing

Private not-for-profit organizations combine characteristics of a public sector agency with those of a private, proprietary firm. In particular, nonprofits are required to address designated social missions while breaking even financially. This structure underlies the difficulty that nonprofit organizations face in making decisions with important resource implications. Specifically, choices that would achieve maximal mission impact may differ from choices that reward the organization in purely financial terms. As a result, nonprofit managers face a variety of trade-offs between mission responsive and financially rewarding actions. This paper considers some of these tradeoffs in the context of pricing decisions by nonprofit organizations. In particular, the paper draws on alternative theories of nonprofit pricing from the literature. In one theory, nonprofits are viewed as revenue maximizers, pricing their services to garner as much net revenue as possible to support their organizations. In an alternative theory, nonprofits are conceived as mission maximizers, pricing their services to achieve maximum mission impact within the constraint of financial solvency. The efficacy of these theories is explored through five case studies of organizations offering a variety of services within the context of a local social services federation. Evidence from these cases suggests that the forgoing theories apply in some combination for any given nonprofit organization. Several different behavioral patterns are found, including nonprofits seeking to balance financial and mission impacts in the pricing policies for each of their service offerings and others pursuing a strategic mix of pricing policies for profitable and mission-impacting services. It is clear from all cases observed that nonprofit managers struggle with mission-market tensions as they relate to pricing and that they can benefit from metrics to help them sort through these decisions in ways that resolve these tensions. Working Paper 08-0

Design Opportunities in Service-Product Combined Systems

This paper aims to examine recent research issues related to the integration of service and product in view of industrial design. Further, it attempts to identify new opportunities for further research regarding “product-servicization” vs. “service-productization”. In the continued efforts to provide the users with fuller experiences, one major trend is the blending of products and services. Much existing research seems to either present cases or propose frameworks regarding the ‘connection’, rather than ‘integration’ between products and services. Broadly, two major approaches seem to exist in this area: 1. product-servicization, 2. service-productization. The former generally indicates adding more services to existing products, whereas the latter generally refers to making services tangible and/or visible in the form of a product. However, findings of an extensive literature search conducted for this study suggest one important deficiency in dealing with service issues around the product: the ‘integration’ between the actual product design and service elements for supporting new service-product system. That is the rationale behind this research, an attempt to investigate the possibility for the integration of product design and service factors which could be embedded in the design of product itself in new service-product system. This paper is largely based on qualitative research. New design research opportunities are identified by qualitatively analyzing relevant literature, synthesizing the information and presenting some cases to support the main argument of the research. Design-led Service-Productization is not, and should not be re-arranging deck chairs on the Titanic. Rather, it should bring practical and tangible design issues related to new service-product system. Findings suggest that this approach could provide a new model of new product development integrated with a service scheme, which is a more proactive approach than “product-servicization”. Further development of this research could lead to establishing a framework for the Design-led Service-Product Integration. Keywords: Product-servicization; Industrial design; Service; Product; Integration</p

Searching for topological density wave insulators in multi-orbital square lattice systems

We study topological properties of density wave states with broken translational symmetry in two-dimensional multi-orbital systems with a particular focus on t$_{2g}$ orbitals in square lattice. Due to distinct symmetry properties of d-orbitals, a nodal charge or spin density wave state with Dirac points protected by lattice symmetries can be achieved. When an additional order parameter with opposite reflection symmetry is introduced to a nodal density wave state, the system can be fully gapped leading to a band insulator. Among those, topological density wave (TDW) insulators can be realized, when an effective staggered on-site potential generates a gap to a pair of Dirac points connected by the inversion symmetry which have the same topological winding numbers. We also present a mean-field phase diagram for various density wave states, and discuss experimental implications of our results.Comment: 15 pages, 10 figures, 7 table

Conditions for Generic Initial Ideals to be Almost Reverse Lexicographic

Let $I$ be a homogeneous Artinian ideal in a polynomial ring $R=k[x_1,...,x_n]$ over a field $k$ of characteristic 0. We study an equivalent condition for the generic initial ideal \gin(I) with respect to reverse lexicographic order to be almost reverse lexicographic. As a result, we show that Moreno-Socias conjecture implies Fr\"{o}berg conjecture. And for the case \Codim I \le 3, we show that $R/I$ has the strong Lefschetz property if and only if \gin(I) is almost reverse lexicographic. Finally for a monomial complete intersection Artinian ideal $I=(x_1^{d_1},...,x_n^{d_n})$, we prove that \gin(I) is almost reverse lexicographic if $d_i > \sum_{j=1}^{i-1} d_j - i + 1$ for each $i \ge 4$. Using this, we give a positive partial answer to Moreno-Socias conjecture, and to Fr\"{o}berg conjecture.Comment: 10 page

Empirical analysis of congestion spreading in Seoul traffic network

Understanding how local traffic congestion spreads in urban traffic networks is fundamental to solving congestion problems in cities. In this work, by analyzing the high resolution data of traffic velocity in Seoul, we empirically investigate the spreading patterns and cluster formation of traffic congestion in a real-world urban traffic network. To do this, we propose a congestion identification method suitable for various types of interacting traffic flows in urban traffic networks. Our method reveals that congestion spreading in Seoul may be characterized by a tree-like structure during the morning rush hour but a more persistent loop structure during the evening rush hour. Our findings suggest that diffusion and stacking processes of local congestion play a major role in the formation of urban traffic congestion.Comment: 10 pages, 7 figure