Recent Advances in Declarative Networking

Declarative networking is a programming methodology that enables developers to concisely specify network protocols and services, and directly compile these specifications into a dataflow framework for execution. This paper describes recent advances in declarative networking, tracing its evolution from a rapid prototyping framework towards a platform that serves as an important bridge connecting formal theories for reasoning about protocol correctness and actual implementations. In particular, the paper focuses on the use of declarative networking for addressing four main challenges in the distributed systems development cycle: the generation of safe routing implementations, debugging, security and privacy, and optimizing distributed systems

PUMA: Policy-Based Unified Multi-radio Architecture for Agile Mesh Networking

This paper presents the design and implementation of PUMA, a declarative constraint-solving platform for policy-based routing and channel selection in multi-radio wireless mesh networks. In PUMA, users formulate channel selection policies as optimization goals and constraints that are concisely declared using the PawLog declarative language. To efficiently execute PawLog programs in a distributed setting, PUMA integrates a high performance constraint solver with a declarative networking engine. We demonstrate the capabilities of PUMA in defining distributed protocols that cross-optimize across channel selection and routing. We have developed a prototype of the PUMA system that we extensively evaluated in simulations and on the ORBIT testbed. Our experimental results demonstrate that PUMA can flexibly and efficiently implement a variety of centralized and distributed channel selection protocols that result in significantly higher throughput compared to single channel and identical channel assignment solutions

A Policy-based Constraint-solving Platform Towards Extensible Wireless Channel Selection and Routing

This paper presents PUMA, a novel declarative constraintsolving platform that achieves efficient policy-based channel selection and routing for multi-radio wireless mesh networks. PUMA is based on declarative networking, a databaseinspired extensible infrastructure using query languages to specify behavior. In PUMA, users specify high-level declarative policies that dictate their channel selection constraints and routing protocol behavior. We demonstrate that channel selection can be expressed in a compact fashion and implemented efficiently. We have developed a PUMA prototype based on the RapidNet declarative networking engine with enhancements to handle multi-channel communication and integration with an open-source constraint solver. We perform preliminary evaluation of PUMA using the emerging ns-3 network simulator, and describe our ongoing research in ORBIT testbed deployment, distributed channel selection protocols, and distributed optimizations that combine routing and channel selection. 1

Globalization and socialization in China

The end of the Cold War has marked the rise of globalization as one of the contending issues in international relations. As a dominant wave of world transition, globalization requires the states to coordinate their behavior and align their policies and standards to a generalized principle of conduct or to certain suggested directions. While some states have actively and positively responded to these changes, a few others have struggled to retard the influence of globalization, viewing it as a threat to social stability, state sovereignty, and national and cultural identity. However, China shows a dual response to this challenge. It welcomes globalization as a way to enrich national competitiveness, and it confines the impact of globalization exclusively within the economic field only, lest its regime stability be shaken. Hence, this paper argues that the impact of globalization on Chinese international behavior falls short of a fundamental change in Chinese worldview. To prove this argument, this paper explores the Chinese characteristics of globalization and China's domestic impediments to limit socialization.

Glasses and Glass-Ceramics Prepared by Sol–Gel

[EN] This review presents an insight on the advances in the Sol–gel route for preparation of glasses and glass-ceramics, considering the physical and chemical aspects governing the process. An overview of the most important developments and applications including Sol–gel coatings, appearing as the main technique used in optical as well as protective or photocatalytic applications. Biomaterials prepared by Sol–gel are also highlighted