Computing the Types of the Relationships Between Autonomous Systems

We investigate the problem of computing the types of the relationships between Internet Autonomous Systems. We refer to the model introduced by Gao [IEEE/ACM Transactions on Networking, 9(6):733-645, 2001] and Subramanian (IEEE Infocom, 2002) that bases the discovery of such relationships on the analysis of the AS paths extracted from the BGP routing tables. We characterize the time complexity of the above problem, showing both NP-completeness results and efficient algorithms for solving specific cases. Motivated by the hardness of the general problem, we propose approximation algorithms and heuristics based on a novel paradigm and show their effectiveness against publicly available data sets. The experiments provide evidence that our algorithms perform significantly better than state-of-the-art heuristics     

高清工业电视系统在白山发电厂智能化建设中的应用

本文介绍了针对白山发电厂工业电视现状进行的高清工业电视系统建设方案,并将原有其他类型的工业电视系统引入到新建系统中。     

Evapotranspiration estimates using NOAA AVHRR imagery in the Pampa region of Argentina

We used multiple regression analysis to relate evapotranspiration (ET), computed from a water balance technique, to both thermal infrared and normalized difference vegetation index data obtained from the Advanced Very High Resolution Radiometer (AVHRR) sensor on board on the National Oceanic and Atmospheric Administration (NOAA) satellite. This approach, based on only remotely sensed data, provided a reliable estimate of ET over the Pampas, the main agricultural region of Argentina. The relationship between spectral data and ET was more sensitive to the dates than to the sites used to generate the models.     

Providing multiple 'ways in' to expertise for learners with different backgrounds : When it works and what it suggests about adult cognitive development

The introduction of information technology into the workplace has changed the cognitive requirements for many categories of jobs. As a result, much emphasis has been placed on identifying the new basic skills and prerequisite knowledge for learning complex systems. In addition, because of the nature of the processes being controlled, some feel that a work history of shop floor experience may be more appropriate when decisions are made regarding who should use these information systems. However, these systems are notoriously difficult to learn for those who lack formal education. This study describes shop floor personnel successfully learning a management-oriented decision support technology while participating in an alternative educational workshop. The workshop itself and the follow-up evaluation of the participants suggest that identifying prerequisite knowledge may be unnecessary, or even beside the point, so long as the educational intervention is designed to accommodate multiple ‘entry points’ and permit constructive cognitive development rather than mere acquisition of procedures.     

Results of cemented metal-backed acetabular components: a 10-year-average follow-up study

We have developed a computer program for the rapid assessment of the primary structure differences between a protein of unknown sequence and a homologous known protein. Both proteins are reduced, alkylated, and digested with the same hydrolytic agent. The unfractionated peptide mixtures are submitted to automatic sequence analysis. Based on the knowledge of the reference sequence, the program utilizes the analysis data to identify all the potential peptides present in the two mixtures, determining their primary structure, homology degree, and molecular weight calculated both as integer MH+ and average mass variables. These fingerprints allow the user to easily identify the structural differences between the two proteins and clarify possible doubts by a mass spectrometric analysis of the two mixtures. In order to verify the utility of the program, we provide an application example using the already reported data of two homologous proteins.     

Electrical and thermal transport behaviours of high-entropy perovskite thermoelectric oxides

Oxide-based ceramics could be promising thermoelectric materials because of their thermal and chemical stability at high temperature.However,their mediocre electrical conductivity or high thermal conductivity is still a challenge for the use in commercial devices.Here,we report significantly suppressed thermal conductivity in SrTiO₃-based thermoelectric ceramics via high-entropy strategy for the first time,and optimized electrical conductivity by defect engineering.In high-entropy(Ca_0.2Sr_0.2Ba_0.2Pb_0.2La_0.2)TiO₃bulks,the minimum thermal conductivity can be 1.17 W/(m·K)at 923 K,which should be ascribed to the large lattice distortion and the huge mass fluctuation effect.The power factor can reach about 295μW/(m·K²)by inducing oxygen vacancies.Finally,the ZT value of 0.2 can be realized at 873 K in this bulk sample.This approach proposed a new concept of high entropy into thermoelectric oxides,which could be generalized for designing high-performance thermoelectric oxides with low thermal conductivity.     

Integrated microstrip probe for phaseless near-field measurementson plane-polar geometry

An integrated probe performing phaseless near-field measurements on a polar surface is presented. The unknown near-field phase is computed by an interferometric technique used in conjunction with the minimisation of a suitable functional. A microstrip patch antenna for synthetic aperture radar (SAR) applications is considered to validate the method     

Enhanced properties of pure alumina ceramics by oscillatory pressure sintering

A novel oscillatory pressure sintering (OPS) process to consolidate high-quality pure alumina ceramics is reported. The microstructure of the ceramics prepared by OPS develops into a higher final density, a smaller and a narrower distribution of grain sizes compared with those prepared by conventional pressureless sintering (PS) and hot-pressing (HP) processes. Enhanced mechanical properties of alumina ceramics were investigated by OPS process. The bending strength, hardness and elastic modulus of the OPS specimen reached about 546 MPa, 19.1 GPa and 374 GPa, respectively, i.e values significantly higher than that of the specimens by PS and HP. XRD analysis indicates the strengthening of atomic bonds aided by oscillatory pressure. The results suggest OPS to be an effective technique for preparing high-quality pure alumina ceramics.     

阳离子表面活性剂对不同纤维吸附性能的研究

讨论了阳离子表面活性剂－双十八烷基二在氯化铵在棉的确良,尼龙和真丝等织物上的吸附量与ｐＨ,浓度,温度等因素条件下的研究,其吸附量顺序为真丝〉尼龙〉棉〉的确良。     

GB150-1998与ASMEⅧ-1的某些差异

本文以ASMEⅧ-1为基础,对GB150－1998与ASMEⅧ-1的差异提出分析,作为同行专家们的参考。