Today, Nicky spoke on a few approaches to higher K-theory. Let C be a pointed ∞-category with finite colimits (as in Lurie’s approach) or a category with cofibrations and weak equivalences satisfying certain axioms (as in Waldhausen’s approach). Recall that K0(C) was defined to be the free abelian group on isomorphism classes of objects of C modulo [X] = [X′] + [X′′] whenever we have a pushout ...

The goal of this chapter is to discuss pushouts in the category of algebraic spaces. This can be done with varying assumptions. A fairly general pushout construction is given in [TT13]: one of the morphisms is affine and the other is a closed immersion. We discuss a particular case of this in Section 2 where we assume one of the morphisms is affine and the other is a thickening, a situation tha...

Abstract We consider two preorder-enriched categories of ordered partial combinatory algebras: OPCA, where the arrows are functional (i.e., projective) morphisms, and OPCA † , applicative morphisms. show that has small products finite biproducts, coproducts, all in a suitable 2-categorical sense. On other hand, lacks nontrivial binary products. deduce from this pushout, over Set, realizability ...

This paper presents a Di€erentiated Services (Di€serv or DS) architecture for multimedia streaming applications. Speci®cally, we de®ne two types of services in the context of Assured Forwarding (AF) per hop behavior (PHB) that are di€erentiated in terms of reliability of packet delivery: the High Reliable (HR) service and the Less Assured (LA) service. We propose a novel node mechanism called S...

In a shared buffer packet switch, a good buffer management scheme is needed to reduce the overall packet loss probability and improve the fairness between different users. In this paper, a novel buffer control scheme called partial sharing and partial partitioning (PSPP) is proposed. The PSPP is an adaptive scheme that can be dynamically adjusted to the changing traffic conditions while simple ...

We address the problem of cyclic termgraph rewriting. We propose a new framework where rewrite rules are tuples of the form (L,R, τ, σ) such that L and R are termgraphs representing the left-hand and the right-hand sides of the rule, τ is a mapping from the nodes of L to those of R and σ is a partial function from nodes of R to nodes of L. τ describes how incident edges of the nodes in L are co...

The coordination language Reo defines circuit-like connectors to steer the collaboration of independent components. In this paper, we present a framework for the modeling of distributed, self-reconfigurable connectors based on algebraic graph transformations. Reconfiguring a connector that is composed with others, may involve a change of shared interfaces and may therefore require a reconfigura...

As the Internet transforms from the traditional best-effort service network into QoS-capable multi-service network, it is essential to have new architectural design and appropriate traffic control algorithms in place. This paper presents a network node architecture and several traffic management mechanisms that are capable of achieving QoS provisioning for the guaranteed service (GS), the contr...

The interfacial structure/property relationships of a representative composite system consisting of SIC (SCS-6) fibers in a T&Al + Nb intermetallic alloy have been investigated. Two samples were fabricated at 1040°C with different exposure times in order to vary the amount of fiber-matrix reaction. This resulted in samples with reaction zone thicknesses (S) of 1.1 and 1.7pm, while ensuring roug...

For uniform traffic, ATM switches employing shared buffering have lower cell loss probability and better buffer utilization than other buffering strategies. However, the performance of shared-buffer switches degrades dramatically under non-uniform traffic. Traffic nonuniformity is inherent in telecommunications, and is likely to be present in ATM networks because of the different characteristic...