The Irreducible Spine(s) of Undirected Networks

Using closure concepts, we show that within every undirected network, or graph, there is a unique irreducible subgraph which we call its "spine". The chordless cycles which comprise this irreducible core effectively characterize the connectivity structure of the network as a whole. In particular, it is shown that the center of the network, whether defined by distance or betweenness centrality, is effectively contained in this spine. By counting the number of cycles of length 3 <= k <= max_length, we can also create a kind of signature that can be used to identify the network. Performance is analyzed, and the concepts we develop are illurstrated by means of a relatively small running sample network of about 400 nodes.Comment: Submitted to WISE 201

Estimating Cost Savings when Implementing a Product Platform Approach

Many market forces are driving companies to improve their targeting of increasingly small market niches. To accomplish this efficiently, products are organized into product families that typically share common platforms. To reorganize the current product offerings or new products into a product family, using a platform approach, requires estimating the savings for such a modification. One of the problems encountered in estimating development and design cost is the lack of availability of hard information during the initial design phases. The purpose of this paper is to estimate the design and development cost, when moving towards a platform approach, using simple models. The activity based product family cost models are developed from existing single product design activities, which are modified and extended to reflect activities related to development of product platform and subsequent product family members supported by the platform. Uncertainty related to cost associated with activities are included in the model, which is solved using Monte Carlo simulation. The approach is demonstrated using a hard disk drive spindle motor platform development for a family of hard disks.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Mathematical Continuity in Dynamic Social Networks

Abstract. A rigorous concept of continuity for dynamic networks is developed. It is based on closed, rather than open, sets. It is local in nature, in that if the network change is discontinuous it will be so at a single point and the discontinuity will be apparent in that point’s immediate neighborhood. Necessary and sufficient criteria for continuity are provided when the change involves only the addition or deletion of individual nodes or connections (edges). Finally, we show that an effective network process to reduce large networks to their fundamental cycles is continuous.

Supporting data intensive applications with medium grained parallelism

ADAMS is an ambitious effort to provide new database access paradigms for the kinds of scientific applications that require massively parallel access to very large data sets in order to be effective. Many of the Grand Challenge Problems fall into this category, as well as those kinds of scientific research which depend on widely distributed shared sets of disparate data. The essence of the ADAMS approach is to view data purely in functional terms, rather than the more traditional structural view in which multiple data items are aggregated into records or tuples of flat files. Further, ADAMS has been implemented as an embedded interface so that scientists can develop applications in the host programming language of their choice, often Fortran, Pascal, or C, and still access shared data generated in other environments. The syntax and semantics of ADAMS is essentially complete. The functional nature of the ADAMS data interface paradigm simplifies its implementation in a distributed environment, e.g., the Mentat run-time system, because one must only distribute functional servers, not pieces of data structures. However, this only opens up the possibility of effective parallel database processing; to realize this potential far more work must be done in the areas of data dependence, intra-statement parallelism, parallel query optimization, and maintaining consistency and reliability in concurrent systems. Discovering how to make effective parallel data access an actually in real scientific applications is the point of this research

Scoping Persistent Name Spaces in ADAMS

: ADAMS is based on five primitive concepts: Attribute, co-domain, element, map, and set. Each instance of these primitives is a named entity to which user references resolve. Thus, the concept of naming and name resolution is crucial to the effective management of data in ADAMS. This paper describes the hierarchical name space proposed for the adams database environment. The reasons for choosing a hierarchical model are examined and the difficulties engendered by this choice are explored. This research was supported in part by JPL Contract #957721 1. Introduction The concept of naming is essential to the process of communicating ideas and information. But what is a &quot;name&quot;? We should be able to agree that a name is a sequence of symbols drawn from some alphabet, a word, or more simply a string. But with this we may have reached the limit of communal consensus. The real issue is &quot;what is the function of names in communication ?&quot;. This must be resolved before we can develop a meaningf..