Novel Packet Switching for Green IP Networks

A green technology for reducing energy consumption has become a critical factor in ICT industries. However, for the telecommunications sector in particular, most network elements are not usually optimized for power efficiency. Here, we propose a novel energy‐efficient packet switching method for use in an IP network for reducing unnecessary energy consumption. As a green networking approach, we first classify the network nodes into either header or member nodes. The member nodes then put the routing‐related module at layer 3 to sleep under the assumption that the layer in the OSI model can operate independently. The entire set of network nodes is then partitioned into clusters consisting of one header node and multiple member nodes. Then, only the header node in a cluster conducts IP routing and its member nodes conduct packet switching using a specially designed identifier, a tag. To investigate the impact of the proposed scheme, we conducted a number of simulations using well‐known real network topologies and achieved a more energy‐ efficient performance than that achieved in previous studies.     

Scattering and absorption of turbid materials determined from reflection measurements. 2: measuring method and calibration

A new experimental method has been developed to determine the scattering and absorption characteristics of a turbid material. Existing methods usually require transmission and reflection measurements carried out on a thin slab of the material under study; this method is based on reflection measurements carried out on bulk material. This will be of great advantage in many applications. This paper describes the measuring system and indicates the area of application of the method. Calibration measurements have been carried out to substantiate the approach.     

Composition ofO-alkyl andO-alk-1-enyl moieties in the glycerolipids of the human adrenal

A comparison of human adult and fetal adrenals with respect to their levels of glyceryl ether lipids and other lipid components is reported. Fetal glands contained significantly lower levels of alk-1-enyl phosphoglycerides and of cholesterol. Neutral glyceryl ether diesters, and ethanolamine and choline phosphoglycerides were isolated from adult adrenal tissue. The composition of theO-alkyl glycerol groups in these lipid fractions was obtained by means of gas chromatography of the trimethylsilyl ethers and diacetyl derivatives;O-alk-1-enyl glycerols were analyzed as their diacetates. About one-half of the alkyl and alk-1-enyl glycerol moieties present in glyceryl ether diesters contained hydrocarbon side chains with 20, 22, or 24 carbon atoms. Long hydrocarbon chains (C_19–24) were also found in theO-alkyl glycerol moieties present in the total lipids of fetal adrenals.     

Ultrasonic relaxation studies of poly(isobutylene) in m-xylene

Ultrasonic measurements are reported on solutions of two different samples of poly(isobutylene), one relatively regularCH₂C(CH₃)₂(Vistanex L80) and one with considerable structural irregularity such as chain branching (Vistanex L140). Measurements were carried out from 303–353K in m-xylene over a frequency range 1–100 MHz. A low frequency normal mode (viscoelastic) and a higher frequency conformational absorption are observed. The temperature dependence of the conformational absorption reveals a pseudo helix-coil transition at around 323K. Above this temperature, the two polymers show temperature coefficients of different sign. This phenomenon is explained in terms of a lower energy difference between conformational states in the branched chain polymer.     

Online decentralized information gathering with spatial–temporal constraints

We are interested in coordinating a team of autonomous mobile sensor agents in performing a cooperative information gathering task while satisfying mission-critical spatial–temporal constraints. In particular, we present a novel set of constraint formulations that address inter-agent collisions, collisions with static obstacles, network connectivity maintenance, and temporal-coverage in a resource-efficient manner. These constraints are considered in the context of the target search problem, where the team plans trajectories that maximize the probability of target detection. We model constraints continuously along the agents’ trajectories and integrate these constraint models into decentralized team planning using a computationally efficient solution method based on the Lagrangian formulation and decentralized optimization. We validate our approach in simulation with five UAVs performing search, and through hardware experiments with four indoor mobile robots. Our results demonstrate team planning with spatial–temporal constraints that preserves the performance of unconstrained information gathering and is feasible to implement with reasonable computational and communication resources.     

Energy conservation in wireless sensor networks: a rule-based approach

The research reported in this paper addresses the problem of energy conservation in wireless sensor networks (WSNs). It proposes concepts and techniques to extract environmental information that are useful for controlling sensor operations, in order to enable sensor nodes to conserve their energy, and consequently prolong the network lifetime. These concepts and techniques are consolidated in a generic framework we term CASE: Context Awareness in Sensing Environments framework. CASE targets energy conservation at the network level. A subset framework of CASE, we term CASE Compact, targets energy conservation at the sensor node level. In this paper, we elaborate on these two frameworks, elucidate the requirements for them to operate together within a WSN and evaluate the applications they can be applied to for energy conservation.     

A manufacturing-oriented approach for multi-platforming product family design with modified genetic algorithm

With highly fragmented market and increased competition, platform-based product family design has been recognized as an effective method to construct a product line that satisfies diverse customer’s demands while aiming to keep design and production cost-effective. The success of the resulting product family often relies on properly resolving the inherent tradeoff between commonality across the family and performance loss. In this paper, a systematic multi-platforming product family approach is proposed to design a scale-based product family. In the light of the basic premise that increased commonality implies enhanced manufacturing efficiency, we present an effective platform decision strategy to quantify family design configuration using a commonality index that couples design varieties with production variation. Meanwhile, unlike many existing methods that assume a single given platform configuration, the proposed method addresses the multi-platforming configuration across the family, and can generate alternative product family solutions with different levels of commonality. A modified genetic algorithm is developed to solve the aggregated multiobjective optimization problem and an industrial example of a planetary gear train for drills is given to demonstrate the proposed method.     

JOINT: Java ontology integrated toolkit

In the past few years, the use of ontologies for creating more intelligent and effective application has increased considerably. This growth is due to the fact that ontologies attempt to provide semantics to the data consumed by machines so that they can reason about this data. However, developing complex ontology-based applications is still difficult and time-consuming because the existing tools do not provide a simple and unified environment for developers. Most of these tools only provide data manipulation using RDF triples, complicating the development of applications that need to work with the object orientation paradigm. Furthermore, tools that provide instances manipulation via object orientation do not support features such as manipulating ontologies, reasoning over rules or querying data with SPARQL. In this context, this work proposes a framework and a tool for supporting the efficient development of ontology-based applications through the integration of existing technologies. Furthermore, we also define a methodology to use this tool efficiently. In order to evaluate the benefits of our work, a controlled experiment with eight developers (unfamiliar with ontologies) was performed to compare the proposed tool, JOINT, with another one, Jastor/Jena, frequently used by the community. The results suggest that our tool helps novice developers to create ontology-based applications faster and with few errors in the code. In addition, a real educational application with 10 ontologies, more than 200 ontology concepts (classes) and more than a million triples is already using the proposed tool successfully.     

基于有效性函数的聚类算法

聚类作为一种无监督的学习方法,通常需要人为地提供聚类的簇数。在先验知识缺乏的情况下,通过人为指定聚类参数是不合实际的。近年来研究的聚类有效性函数（Cluster Validity Index） 用于估计簇的数目及聚类效果的优劣。本文提出了一种新的基于有效性指数的聚类算法,无需提供聚类的参数。算法每步合并两个簇,使有效性指数值增加最大或减小最少。本文运用引力模型度量相似度,对可能出现的异常点情况作均匀化的处理。实验表明,本文的算法能正确发现特定数据的簇个数,和其它聚类方法比较,聚类结果具有较低的错误率,并在效率上优于一般的基于有效性指数的聚类算法。     

A modified architecture used for input matching in CMOS low-noise amplifiers

An architecture used for input matching in CMOS low-noise amplifiers (LNAs) is investigated in this paper. In the proposed architecture, gate and source inductors, which are essential in the traditional source inductive degeneration CMOS LNAs, are either reduced or removed. The architecture is finally verified by a narrow-band LNA and a wide-band LNA operating at 2.4-2.5 and 5.1-5.9 GHz, respectively. The narrow-band LNA has measured power gain of 24-dB, noise figure (NF) of 2.6-2.8 dB, and power consumption of 15 mW. The wide-band LNA provides 22.6-24.6-dB power gain and 2.85-3.5-dB NF while drawing 6 mA current from a 1.5-V voltage supply. Compared with their traditional counterparts, the proposed LNAs consume less chip area and present better gain performance.