Mining Precedence Relations among Lecture Videos in MOOCs via Concept Prerequisite Learning

In recent years, MOOC has gradually become an important way for people to learn knowledge. But the knowledge background of different people is quite different. Moreover, the precedence relations between lecture videos in a MOOC are often not clearly explained. As a result, some people may encounter obstacles due to lack of background knowledge when learning a MOOC. In this paper, we proposed an approach for mining precedence relations between lecture videos in a MOOC automatically. First, we extracted main concepts from video captions automatically. And then, an LSTM-based neural network model was used to measure prerequisite relations among the main concepts. Finally, the precedence relations between lecture videos were identified based on concept prerequisite relations. Experiments showed that our concept prerequisite learning method outperforms the existing methods and helps accurately identify the precedence relations between lecture videos in a MOOC.

Geminate blockage in Logoori harmony with no added machinery

Following the demise of the SPE theory of phonology, little attention was paid to how rules should be formulated. Instead, there was a general trend to minimize the language-specific component of a grammar, to factor out recurring patterns and state them as independent constraints or parameters. The richer representations of autose­gmental phonology additionally led to uncertainty in rule formulation, primarily because of questions about what the correct representations are, but also because specifying dominance and precedence relations is more complex than just specifying precedence relations. This paper discusses a vowel harmony rule in the Bantu language Logoori, which is blocked by an intervening gemi­nate consonant. It is typologically surprising that an intervening geminate has an effect on harmony, and there is no clear model for how such an effect in a rule should be encoded. It is shown that the effect follows naturally from correctly formalizing the rule, with attention to how rule and representational substrings are matched, and no rule-external conditions on the rule are necessary.

Preprocessing the Discrete Time-Cost Tradeoff Problem with Generalized Precedence Relations

This study investigates the deadline of the discrete time-cost tradeoff problem (DTCTP-D) with generalized precedence relations (GPRs). This problem requires modes to be assigned to the activities of a project such that the total cost is minimized and the total completion time and the precedence constraints are satisfied. Anomalies under GPRs are irreconcilable with many current theories and methods. We propose a preprocessing technology, an equivalent simplification approach, which is an effective method for solving large-scale complex problems. We first study a way to deal with the anomalies under GPRs, such as the reduce (increase) in project completion as a consequence of prolonging (shortening) an activity, and discover relationships between time floats and path lengths. Then, based on the theories, we transform the simplification into a time float problem and design a polynomial algorithm. We perform the simplification and improve the efficiency of the solution by deleting redundant calculation objects.

Labeling for linearization

The primary goal of the present paper is to argue for the hypothesis that labeling is required for linearization, which is called Labeling for Linearization (LfL). To achieve this goal, it is first argued that labels are not necessary for semantic interpretation. It is then proposed that labels are necessary for linearization at the PF-interface in that they serve as a device to encode structural asymmetries that are employed to determine precedence relations, which are asymmetric as well. It is also shown that LfL can remove several problems of the original labeling framework. Building on the idea that Spell-Out applies to the whole phase but not its subpart, it is illustrated that the LfL-based analysis can solve the problem concerning the variable ways of applying Spell-Out, which arises in the standard phase theory. Extending the LfL-based framework to Japanese, a novel analysis of particle-stranding ellipsis is also proposed. Incorporating some insights of recent approaches that particle-stranding ellipsis arises through a PF-deletion process, it is shown that the proposed analysis based on LfL offers a theoretically more suitable characterization of the PF-deletion process. In this way, the present article contributes to not only sharpening the core theoretical notions regarding structure building and linearization in terms of labeling but also deepening our understanding of the structure of Japanese.

Syntactic relations and syntactic constraints

This chapter continues the discussion of the formal architecture of LFG and of ways to describe and constrain constituent structures and functional structures. The chapter introduces additional relations and constraints on structures, and discusses concepts fundamental to our formal theory, including regular expressions (Section 6.1); sets (Section 6.3); off-path constraints (Section 6.6); templates (Section 6.7); relations between f-structures such as f-command, subsumption, and restriction (Section 6.9); c-structure/f-structure constraints including empty nod rules (Section 6.10); and precedence relations (Section 6.11). For most readers, this chapter best serves as a reference to be consulted for definition and discussion of concepts and relations that are used in the analyses presented in the remainder of the book.