Regression with respect to sensing actions and partial states

In this paper, we present a state-based regression function for planning domains where an agent does not have complete information and may have sensing actions. We consider binary domains and employ the 0-approximation [Son & Baral 2001] to define the regression function. In binary domains, the use of 0-approximation means using 3-valued states. Although planning using this approach is incomplete with respect to the full semantics, we adopt it to have a lower complexity. We prove the soundness and completeness of our regression formulation with respect to the definition of progression. More specifically, we show that (i) a plan obtained through regression for a planning problem is indeed a progression solution of that planning problem, and that (ii) for each plan found through progression, using regression one obtains that plan or an equivalent one. We then develop a conditional planner that utilizes our regression function. We prove the soundness and completeness of our planning algorithm and present experimental results with respect to several well known planning problems in the literature.Comment: 38 page

The role of attitude, preference conflict, norms, and family identity in explaining intention/behavior toward fish consumption in Vietnamese families

The main objective of the thesis is to explore and test the roles of attitude, preference conflict, norms and family identity in explaining intention/behavior toward fish consumption in Vietnamese families. This study utilizes a theoretical framework based on the Theory of Planned Behavior, but more focused on some other variables (ambivalence, family conflict and identity) in an extended model. The study reveals that attitude, family conflict, and family identity influence intention, while family norms factor do not exhibit a direct relationship with the intention to consume fish in Vietnam. In addition, ambivalence was negatively correlated with attitude, while interpersonal conflict was unrelated to attitude. Moreover, although social variables seem to be of vital importance in predicting attitude, only family identity and attitude enjoy positive correlation with high statistical significance. Family norms have a low impact on attitude while family conflict has no significance in predicting attitude towards fish. Also, family norm and family conflicts were mutually related. Further, the result does not support the hypothesis that family identity represents a moderator in the family norm-intention relationship. Finally, intention to eat fish is highly positively correlated to behavior to consume. However, there is no direct relationship between family identity and fish consumption behavior. The results of this study will shed some light on discovering the role of attitude, preference conflict, family norms, and family identity in explaining intention/behavior toward fish consumption in Vietnamese families. It will allow academics to better understand the complication of social variables and further develop future research in this area. Keywords: Fish consumption; attitude; preference conflict; ambivalence; family norms; family identity

Computing Graph Roots Without Short Cycles

Graph G is the square of graph H if two vertices x, y have an edge in G if and only if x, y are of distance at most two in H. Given H it is easy to compute its square H2, however Motwani and Sudan proved that it is NP-complete to determine if a given graph G is the square of some graph H (of girth 3). In this paper we consider the characterization and recognition problems of graphs that are squares of graphs of small girth, i.e. to determine if G = H2 for some graph H of small girth. The main results are the following. - There is a graph theoretical characterization for graphs that are squares of some graph of girth at least 7. A corollary is that if a graph G has a square root H of girth at least 7 then H is unique up to isomorphism. - There is a polynomial time algorithm to recognize if G = H2 for some graph H of girth at least 6. - It is NP-complete to recognize if G = H2 for some graph H of girth 4. These results almost provide a dichotomy theorem for the complexity of the recognition problem in terms of girth of the square roots. The algorithmic and graph theoretical results generalize previous results on tree square roots, and provide polynomial time algorithms to compute a graph square root of small girth if it exists. Some open questions and conjectures will also be discussed