2014, 3(4):1-9. DOI: 10.12146/j.issn.2095-3135.201404001
Abstract:Benchmarks are important tools to evaluate the performance of a variety of computing systems. However, benchmarks for big data systems are lacking as big data is relatively new and researchers are interested in understanding how big data systems including hardware and software work but do not have data. In this paper, an approach to develop big data benchmarks was devised at first. Then a big data benchmark suite named SIAT-Bench, which contains five representative workloads from Shenzhen urban transportation system, was presented. To this end, the program behavior was characterized and the impact of input data sets was qualified by observing metrics from multiple levels such as microarchitecture, OS and application layer. Then statistical techniques such as Principal Component Analysis (PCA) and Clustering were employed to perform similarity analysis between different workload-input pairs. Finally, we built SIATBench by selecting representative workloads and associated input sets according to the clustering results. Experimental results show that SIAT-Bench properly satisfies the requirements of a benchmark suite.
2014, 3(4):10-17. DOI: 10.12146/j.issn.2095-3135.201404002
Abstract:Because CFCs deplete the ozone layer and HFCs have high global warming potentials, many countries have been reinvestigating low GWP refrigerants as alternatives in household air conditioners, one of which is R290 as the alternative for R22. But the most important problem is how to choose the suitable lubricant for refrigerant R290. In this paper, the design method of lubricant was proposed through analyzing the lubrication in rotate compressor of household air conditioners and studying on properties of several oils in R290 refrigerant.
2014, 3(4):18-30. DOI: 10.12146/j.issn.2095-3135.201404003
Abstract:Volume, variety and velocity are the three challenges that the big data computing must be faced with, which cannot be dealt with by traditional IT technologies. Benefiting from numerous domestic and overseas Internet companies’ practical applications and continuous code contributions, the Apache Hadoop has become a mature software stack and the de facto standard of the PetaByte scale data processing. Furthermore, around different types of data processing requirements, different software ecosystems have been established. In the big data system field, three research works of data placement, index construction and compression and decompression hardware acceleration, i.e. RCFile, CCIndex and SwiftFS respectively, effectively solving the storage space and query performance issues, were introduced in this paper. The above research achievements have been already integrated into the Golaxy big data engine software stack in the form of key technologies, and directly supported multiple practical applications of Taobao Inc. and Tencent Inc.
2014, 3(4):31-37. DOI: 10.12146/j.issn.2095-3135.201404004
Abstract:Linux application sandbox is designed for providing an independent, secure operating environment for untrusted applications. The sandbox has its own independent working directory, and the operation of applications in the sandbox has no impact on the host. The sandbox provides filesystem isolation, system resources isolation, physical resources isolation, capabilities limits and mandatory access control (MAC) policies, adding memory protection policies like address randomization and non-executable memory page protection. The sandbox increases several security mechanisms relative to existing sandboxes, improving the system security and protecting the system and user’s personal privacy.
2014, 3(4):38-43. DOI: 10.12146/j.issn.2095-3135.201404005
Abstract:An oil-soluble polyether ester was synthesized according to the actual working conditions of the refrigerator, and the basic physical and chemical properties of synthetic esters were detected by national standards. To obtain the viscosity of pentaerythritol esters and polyether esters under various pressure of propane (R290), a laboratory-made lubricants-refrigerant online viscosity measurement system has been employed to measure the viscosity of the liquid fraction. Stability under practical conditions was tested by a sealed tube. It shows that the overall performance of polyether ester is better than the reference oil. Properties of the tribology have been tested by the four-ball wear tester. The results show that the wear amount of the polyether ester is less than the mineral oil and polyol esters, and polyether esters have better viscosity characteristics. The cooling efficiency is increased by 1.7% compared to mineral oil in the propane refrigeration system.
2014, 3(4):44-49. DOI: 10.12146/j.issn.2095-3135.201404006
Abstract:With the development of network applications, the network security assessment has become an important subject of researches on network security. In order to overcome the defects of traditional network security evaluation models, the network security assessment model based on the comprehensive grey relational analysis, which is the organic combination of grey relation analysis and the analytic hierarchy process (AHP), was proposed in this paper. Firstly, the proposed model used the Delphi method to construct the network security assessment index system. Secondly, it utilized AHP to work out the specific weight of each index. Finally, the comprehensive grey relational degree was calculated to evaluate the network security. By means of simulating a campus network with MATLAB, the research results show that the evaluation is more accurate and the proposed assessment method is an efficient, accurate and practical network security assessment method.
2014, 3(4):50-57. DOI: 10.12146/j.issn.2095-3135.201404007
Abstract:By the IP locating associated with network attributes acquisition, an internet “resource and object” spatial database was established in this paper in order to combine the cyberspace and realspace together. Then it was layered and partitioned, and projected into the three-dimensional coordinate system of digital earth. Functions such as positioning, query, analysis and visualization for 3D CyberGIS virtual-reality integration were implemented, which could effectively expand the GIS management capabilities to the virtual space elements.
2014, 3(4):58-66. DOI: 10.12146/j.issn.2095-3135.201404008
Abstract:Protein misfolding leads to many diseases, such as Alzhemizer disease and polyQ diseases, etc. Protein folding is vital for the mechanism study of folding-related diseases. In this paper, several aspects in protein folding were reviewed, including the side chain ordering, computational algorithms for protein folding, folding diseases, molecular dynamics simulation and structure prediction.
2014, 3(4):67-74. DOI: 10.12146/j.issn.2095-3135.201404009
Abstract:The Hash function with high speed and efficiency has been a hotspot of security. In this paper, a new Hash function based on cellular neural network was proposed. The parameters of the cellular neural network were produced by a unique system which combined the Logistic map with the Chebyshev map. The function can handle the plaintext by the block, and the final 128 Hash value is the xor of every block’s Hash value. The experimental data and simulated analysis show that the proposed algorithm can satisfy the requirements of a secure hash function, and it has some good properties such as diffusion, confusion, weak collision and sensitivity to initial conditions. What’s more, the construction of the scheme can be achieved easily.
2014, 3(4):75-80. DOI: 10.12146/j.issn.2095-3135.201404010
Abstract:It is feasible to implement the indoor localization techniques using wireless received signal strengths(RSSs) on the mobile devices since the RSSs indicate the information of distance between a transmitter and a receiver. However, the variation of RSSs severely reduces the localization accuracy due to the multipath effect and the unpredictable change of indoor environments. On this basis, a fingerprint-based indoor localization algorithm was designed leveraging the theory of sparse representation. In our approach, the variations were separated from the feature fingerprints using the sparse dictionary. Experiments were conducted for evaluating the performance of the algorithm in the real scenarios. Compared to traditional algorithms in indoor localization, the average localization error is reduced by 20%.
2014, 3(4):81-87. DOI: 10.12146/j.issn.2095-3135.201404011
Abstract:In this paper, a semi-physical simulation platform of the master-slave robot control simulation system was built based on the analysis on functional requirements of the PHANToM OMNI robot system. Based on differential transformation method, the real-time master-slave control was executed by using Jacobian matrix and proportionalderivative( PD) close-loop control algorithm, and the digital filter was designed to eliminate effects of surgeons’ hand lowfrequency tremors on the precision of the master-slave control. The simulation experimental results demonstrate that the slave robot can follow precisely and quickly movements of the master robot and eliminate hand tremors.
2014, 3(4):88-93. DOI: 10.12146/j.issn.2095-3135.201404012
Abstract:The abnormal detection of cardiac markers is an important diagnostic index of acute myocardial infarction. Monitoring the cardiac markers can directly affect the clinical diagnosis, risk stratification, treatment options and prognosis of the patients with cardiovascular disease. The procedures, including sampling, pre-treatment, separation and detection, can be combined in one set by microfluidic chips. The microfluidic chip is an ideal platform for the detection of cardiac markers with several remarkable characteristics, such as the demand for less sample, portable and rapid detection. The review will focus on recent research developments of microfluidic platform for the detection of cardiac markers, which are detected by optical and electrical method. More detection methods can be used with the development of the sensor technology. It is necessary to timely summarize the existing technologies and approaches, so that the development of the microfluidic chips in the field of point-of-care-test of cardiac markers will be promoted.