Closed, oriented, connected 3-manifolds are subtle equivalence classes of plane graphs

A blink is a plane graph with an arbitrary bipartition of its edges. As a consequence of a recent result of Martelli, it is shown that the homeomorphisms classes of closed oriented 3-manifolds are in 1-1 correspondence with specific classes of blinks. In these classes, two blinks are equivalent if they are linked by a finite sequence of local moves, where each one appears in a concrete list of 64 moves: they are organized in 8 types, each being essentially the same move on 8 simply related configurations. The size of the list can be substantially decreased at the cost of loosing symmetry, just by keeping a very simple move type, the ribbon moves denoted [Formula: see text] (which are in principle redundant). The inclusion of [Formula: see text] implies that all the moves corresponding to plane duality (the starred moves), except for [Formula: see text] and [Formula: see text], are redundant and the coin calculus is reduced to 36 moves on 36 coins. A residual fraction link or a flink is a new object which generalizes blackboard-framed link. It plays an important role in this work. It is in the aegis of this work to find new important connections between 3-manifolds and plane graphs.

Understanding typology of residents living in disaster prone-area

Research about population immobility associated with disaster is very limited. This causes a lack of understanding about population immobility in disaster-prone areas. This research contributes to understanding population immobility by explaining the typology of residents who remain stay in disaster-prone areas. The survey was conducted among the residents of Kampong Tambak Lorok Semarang, which is prone to rob inundation (rob). The research sample was 235 heads of households selected using proportional sampling area technique. Data was collected using a questionnaire consisting of two parts: (1) demographic, social, and economic characteristics of people who did not move from disaster-prone areas; and (2) staying intention in disaster-prone areas. Data was analyse using descriptive analysis by using the table and graph of respondent characteristic and relation between respondent characteristics and the staying intention in the research area. Three (3) typologies have been identified, namely: Type-1 are residents who wish to stay; Type-2 are residents who still have not decided whether to stay or move; Type-3 are residents who do not want to stay. Each of these typologies is described by place of birth, age, length of stay, education, occupation, and income. Understanding the typology of residents living in disaster-prone areas is important for inputs for policy-makers, especially regarding the relocation of people from disaster-prone areas to be more effective.

Collaboration as Co-Constructed Discourse

This chapter presents a coding guide for the analysis of peer talk during educational information seeking. The guide is an outcome of a structuring content analysis of learners’ dialogues as they seek, evaluate, and use information on a collaborative basis. The analysis is informed by a language-based theory of learning and the sequential organization of spoken discourse. The generic steps of a structuring content analysis are described first; before each step, sequence, exchange, and move type identified in the dialogues are described. Illustrative examples of each unit and type of talk are provided, so as to aid in the precise and reliable assignment of the categories and codes in further studies. The chapter concludes with implications of the coding guide, and the broader study of which it is a part, for research in educational information seeking.