On large sets of disjoint steiner triple systems III

AbstractTo construct large sets of disjoint STS(3n) (i.e., LTS(3n)), we introduce a new kind of combinatorial designs. Let S be a set of n elements. If x ∈ S, we denote an n × n square array on S by Ax, if for every w ∈ S\{x} the following conditions are satisfied: Ax = [ayz(x)](y, z ∈ S), axx(x) = x, aww(x) ≠ w, axw(x) = axw(x) = x, and {awz(x) | z ∈ S} = {ayw(x) | y ∈ S} = S. Let j ∈ {1, 2&}, Aj = {ayz[j](y, z ∈ S) be a Latin square of order n based on S with n parallel transversals including the diagonal one. Two squares Ax and Ax′ on the same S are called disjoint, if ayz(x) ≠ ayz(x′) whenever y, z ∈ S\{x, x′}; two squares Ax and Aj on the same S are called disjoint, if ayz(x) ≠ ayz[j] whenever y, z ∈ S\ {x}; and two squares A1 and A2 on the same S are called disjoint, if ayz[1] ≠ ayz[2] whenever y ≠ez. It is a set of n + 2 pairwise disjoint squares Ax (x runs over S), A1 and A2 on S as mentioned above that is very useful to construct LTS(3n), and such a set we denote by LDS(n). The essence in the relation between LDS(n) and LTS(3n) is the following theorem which is established in the Section 2:Theorem. If there exist both an LDS(n) and an LTS(n + 2), then there exists an LTS(3n) also.The set of integers n for which LDS(n) exist is denoted by D. In the other parts of this paper, the following results are given: 1.(1) If n ∈ D, and q = 2α (α is an integer greater than 1), or q ∈ {;5, 7, 11, 19}, then qn ∈ D.2.(2) If pα is a prime power, p > 2 and pα ∈ D, then 3pα ∈ D.3.(3) If q is a prime power greater than 4 and 1 + n ∈ D, then 1 + qn ∈ D.4.(4) If t is a nonnegative integer, then 7 + 12t ∈ D and 5 + 8t ∈ D

Should I Stay or Should I Go: Two Features to Help People Stop An Exploratory Search Wisely

poster abstractAs information becomes more ubiquitously available, many information users tend to experience a sense of anxiety due to the “information overload”. Few studies have systematically examined searchers’ stopping behavior, i.e., how users recognize how much information is enough to terminate a search. Bad decisions on a stopping point will lead to either insufficient information or unnecessary waste of time and effort without much additional information gain. Understanding searchers’ stopping behavior is extremely important to assist in thorough search result evaluation and to prevent a premature or a too-late search stopping. In this study, we present the design and implementation of two search techniques: Result Preview (RP) and History Review (HR), to help people make right decisions about when to terminate a search and how to consume information efficiently when facing an overwhelming amount of information. The basic idea of RP is to visualize the distribution of newly retrieved and re-retrieved documents to users, and that of HR is to display the previous search activities for searchers to review what has been done to help define the next steps. Both features are aiming at guiding searchers through the process of problem solving and decision making about whether to stay or leave during the search process. To implement the two techniques, we developed the search system on Bing Search API. The Bing search results were brought back to the search interface using AJAX and PHP. A formal user experiment with 24 participants is also proposed to evaluate the benefits and limitations, and also inform the future RP and HR design

Financing Capture Ready Coal-Fired Power Plants in China by Issuing Capture Options

‘Capture Ready’ is a design concept enabling fossil fuel plants to be retrofitted more economically with carbon dioxide capture and storage (CCS) technologies, however financing the cost of capture ready can be problematic, especially in the developing world. We propose that fossil fuel plants issue tradable Capture Options to acquire financing. The Capture Option concept could move CCS forward politically in countries such as China, speed up CCS technology development, help Capture Ready investors diversify risk, and offer global warming investors an alternative investment opportunity. As a detailed case study, we assess the value of a Capture Option and Capture Ready plant for a 600 MW supercritical pulverized coal power plant in China, using a cash flow model with Monte-Carlo simulations. The gross value of Capture Ready varies from CNY3m ($0.4m) to CNY633m ($84.4m) at an 8% discount rate and the Capture Option is valued at CNY113m ($15.1m) to CNY1255m ($167.3m) for two of the four scenarios analyzed