基于超宽带测距技术的土方运输车工作量计数系统

提出一种基于超宽带测距技术的土方运输车工作量计数系统。通过挖掘机上的超宽带接收器去感知固定在运输车车厢底部的超宽带RFID标签所发射的信号,测出挖掘机与运输车之间的距离,并通过超宽带信号中的标识号来唯一识别运输车。通过分析挖掘机和运输车的距离,判断运输车是否进入装载区域以及判断是否离开。通过LTE网络将计数信息发往网络服务器;用户可通过手机或者PC终端实时查询土方运输车工作量。实现了土方运输车工作量的自动计数,计数客观准确,可靠性高。

仓库货物自动计数和警报装置

在商业部门储存、中转等仓库工作中,需要对进出仓的货物进行计数,比较简单常用的是用人工方法计数,也有用机械计数器的。但如果仓库进出的商品数量较大时,人工计数就难以胜任了。另外机械计数器也因是接触式的,不够可靠。可见,如用上述二种方法,有时不免会产生差错,甚至还会造成经济损失。为此,我们自行设计,试制了一台自动计数和报警器,用于出仓货物的计数工作,也可用于生产车间的流水线上,和其它一些需要对商品作累加工作的场所。整机有计数和报警两部分。

An integrated approach to study of strata behaviour and gas flow dynamics and its application

This paper presents an advanced and integrated research approach to longwall mining-induced strata move- ment, stress changes, fractures, and gas flow dynamics with actual examples of its application from recent studies for coextraction of coal and methane development at Huainan Mining Group in China, in a deep and multi-seam mining environment. The advanced approach takes advantage of the latest techniques in Australia for mine scale geotechnical characterisation, field measurement, monitoring and numerical modelling. Key techniques described in this paper include coal mine site 3D geotechnical characterisation methods, surface deep downhole multi-point extensometers and piezometers for overburden displacement and pore pressure measurements during mining, tracer gas tests for goal gas flow patterns, and advanced numerical modelling codes for coupled coal mine strata, water and gas simulations, and longwall goaf gas ttow investigations. This integrated approach has resulted in significant insights into the complex dynamic imeraction between strata, groundwater, and gas during mining at Huainan Mining Group in recent years. Based on the lindings from the extensive field monitoring and numerical modelling studies, a three-dimensional annular-shaped over-lying zone along the perimeter of the longwall panel was identified for optimal methane drainage during mining.

再入飞行器电子类单机的贮存期估计

基于元器件非工作计数法能够实现对再入飞行器电子类单机的贮存,并通过对贮存寿命的估计,说明该方法可行,可作为再入飞行器电子类单机贮存期试验研究与工程评定的辅助手段。

Medline-based bibliometric analysis of gastroenterology journals between 2001 and 2007

AIM: To analyze the MEDLINE-indexed publications in gastroenterology specialty journals from 2001 to 2007. Special attention was paid to specific types of articles, the number of publications for individual authors and the author count in each journal. METHODS: The bibliographic entries of papers belonging to journals listed under the subject heading of "gastroenterology" were downloaded from MEDLINE on the PubMed web site. The analysis was limited to journal articles published between January 1, 2001 and December 31, 2007. The analytical dimensions of an article included journal, publication year, publication type, and author name (the last name and initials). RESULTS: According to MEDLINE, 81 561 articles were published in 91 gastroenterology journals from 2001 to 2007. The number of articles increased from 9447 in 2001 to 13 340 in 2007. Only 12 journals had more than 2000 articles indexed in MEDLINE. The "World Journal of Gastroenterology" had the largest number of publications (5684 articles), followed by "Hepato-Gastroenterology" (3036) and "Gastrointestinal Endoscopy" (3005). Of all the articles published, reviews accounted for 17.2% and case reports for 15.4%. Only 3739 randomized controlled trials (4.6% of all articles) were published and their annual number increased from 442 in 2001 to 572 in 2007. Among 141 741 author names appearing in the articles of gastroenterology journals, 92 429 had published only in one journal, 22 585 in two journals, 9996 in three journals, and 16 731 in more than three journals. The "World Journal of Gastroenterology " had the greatest number of authors (17 838),followed by "Gastroenterology " (12 770), "Digestive Diseases and Sciences" (11 395), "American Journal of Gastroenterology" (10 889), and "Hepatology" (10 588). CONCLUSION: Global gastroenterology publications displayed a continuous growth in the new millennium. The change was most striking in certain journals. Regular bibliometric analyses on the trends and specific topics would help researchers publish more efficiently and allow editors to adjust the policy more accurately.

SS-SERA:An improved framework for architectural level soft error reliability analysis

Integrated with an improved architectural vulnerability factor （AVF） computing model, a new architectural level soft error reliability analysis framework, SS-SERA （soft error reliability analysis based on SimpleScalar）, was developed. SS-SERA was used to estimate the AVFs for various on-chip structures accurately. Experimental results show that the AVFs of issue queue （IQ）, register update units （RUU）, load store queue （LSQ） and functional unit （FU） are 38.11%, 22.17%, 23.05% and 24.43%, respectively. For address-based structures, i.e., levell data cache （LID）, DTLB, level2 unified cache （L2U）, levell instruction cache （LII） and ITLB, AVFs of their data arrays are 22.86%, 27.57%, 14.80%, 8.25% and 12.58%, lower than their tag arrays＇ AVFs which are 30.01%, 28.89%, 17.69%, 10.26% and 13.84%, respectively. Furthermore, using the AVF values obtained with SS-SERA, a qualitative and quantitative analysis of the AVF variation and predictability was performed for the structures studied. Experimental results show that the AVF exhibits significant variations across different structures and workloads, and is influenced by multiple microarchitectural metrics and their interactions. Besides, AVFs of SPEC2K floating point programs exhibit better predictability than SPEC2K integer programs.

Reliability evaluation method and algorithm for electromechanical product

The reliability of electromechanical product is usually determined by the fault number and working time traditionally. The shortcoming of this method is that the product must be in service. To design and enhance the reliability of the electromechanical product, the reliability evaluation method must be feasible and correct. Reliability evaluation method and algorithm were proposed. The reliability of product can be calculated by the reliability of subsystems which can be gained by experiment or historical data. The reliability of the machining center was evaluated by the method and algorithm as one example. The calculation result shows that the solution accuracy of mean time between failures is 97.4% calculated by the method proposed in this article compared by the traditional method. The method and algorithm can be used to evaluate the reliability of electromechanical product before it is in service.

Using Transformation Thought to Simplify Reciprocal Function Derivatives

Derivatives are the foundation of mathematical calculations,however,for some functions, using the rules of finding a derivative may lead to cumbersome steps. Therefore, this paper provides a simple way using transformation thought for the reciprocal function derivative.

Numerical Analysis of Natural Smoke Ventilation Design System under External Wind Effect in Factory Compartment

This study applied the numerical simulator tool FDS （fire dynamics simulator）, Version 5.53, and focused on the simulation of the natural smoke flow ventilation design system, an innovative ventilation design using the parallel processing technology MPI （message passing interface）. The design was then compared with the exhaust efficiency of a typical natural smoke vent. The natural smoke flow ventilation design system was located at the top of the factory, where smoke streams effectively converged. Therefore, the source of fire was designed to be 2 MW, which has a better exhaust efficiency than typical natural smoke vent with same area. The simulation discovered that the exhaust efficiency of the natural smoke ventilation design systems is higher than that of typical natural smoke vent with 2 times the opening area and that was not affected by external wind speed, Instead, external wind speed can help to enhance the exhaust efficiency. Smoke exhaust of typical natural smoke vents was affected by external wind speed, even leading them to become air inlets which would disturb the flow of air indoors, leading to smoke accumulation within the factory.

The Experimental Research on a New Multiple Curved Surfaces Compound Focus Solar Trough Collector

A new trough imaging solar collector with multiple compounding curved surfaces has been designed. Its working principle and design parameters have been introduced. The experimental curve of temperature rising of the system with time under the real weather has been given. The system efficiency and the relation between efficiency and temperature have been calculated. The test result shows that the system has the advantages of high collecting temperature and not obvious variety of the collecting efficiency with the operating temperature. Therefore, this collector is a quite ideal medium temperature solar collector.

A Comparative Study of Workplace Environment against Industrialization Stage and Income Level

This paper explores the improvement of the workplace environment in the context of industrialization evolution by comparing statistics from China, the U.S., Japan and other nations at various levels of economic development. The study reveals that, compared either with the U.S. and Japan at similar stages of industrialization or many developing and developed nations at different income levels, China has certain advantages when it comes to the improvement of its workplace environment. This report concludes that China is not a country with low labor standards, as is widely accepted.

Optimizing Geothermal Energy Resource

Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.

THE RESEARCH OF MANUFACTURING TOOLS(FIXTURES) PLANNING FOR ARMOURED FLEXIBLE CONVEYOR (AFC) USING CAD TECHNIQUE

The deepth and width of CAD application in coal mining equipments need promote furtherly. The information stream method is applied as the main clue to deal with the related technology and problems in research of manufacturing tools (Fixtures) planning for AFC (mining scraper bars conveyor) using CAD technique.

CONTINUOUS AUXILIARY COVARIATE IN ADDITIVE HAZARDS REGRESSION FOR SURVIVAL DATA

This paper considers the additive hazards iliary covariate information to improve the efficiency regression analysis by utilizing continuous aux- of the statistical inference when the primary covariate is ascertained only for a randomly selected subsample. The authors construct a martingale based estimating equation for the regression parameter and establish the asymptotic consistency and normality of the resultant estimators. Simulation study shows that the proposed method can greatly improve the efficiency compared with the estimator which discards the auxiliary covariate information in a variety of settings. A real example is also provided as an illustration.