Design and development of automotive blind spot detection radar system based on ROI pre-processing scheme

In the conventional 2D-FFT based target detection method, all range-Doppler cells are computed by FFT (Fast Fourier Transform) and scanned by CA-CFAR (Cell-Averaging Constant False Alarm Rate) detection. This results in high computational complexity and long processing time. In this paper, we developed an automotive 24 GHz BSD (Blind Spot Detection) FMCW (Frequency Modulated Continuous Wave) radar with a low complexity target detection architecture based on a ROI (Region Of Interest) pre-processing scheme. In the real BSD zone, because the number of cars to be detected is limited, the designed method only extracts their velocities corresponding to the range ROIs in which real targets exist. Moreover, the presence probability of vehicles with the same range-bin but different velocities is very low. Thus, in the designed method, some Doppler ROIs cells with a high magnitude are only applied for CA-CFAR detection. This architecture can dramatically reduce the amount of data to be processed compared to that of the conventional 2D FFT based method, resulting in enhanced processing time. We developed a 24 GHz FMCW radar system composed a transceiver, antennas, and signal processing module. The designed algorithm was implemented in a tiny micro-processor of the signal processing module. By implementing our proposed algorithm in the developed 24 GHz FMCW radar system in an anechoic chamber and a real road, we verified that the range and velocity of a car occupying the BSD zone were detected. Compared to that of the conventional method, the reduction ratio of the total processing time was measured to be 52.4 %.     

Design of a Stroke Dependent Damper for the Front Axle Suspension of a Truck Using Multibody System Dynamics and Numerical Optimization

Summary A stroke dependent damper is designed for the front axle suspension of a truck. The damper supplies extra damping for inward deflections rising above 4 cm. In this way the damper should reduce extreme suspension deflections without deteriorating the comfort of the truck. But the question is which stroke dependent damping curve yields the best compromise between suspension deflection working space and comfort. Therefore an optimization problem is defined to minimize the maximum inward suspension deflection subject to constraints on the chassis acceleration for three typical road undulations. The optimization problem is solved using sequential linear programming (SLP) and multibody dynamics simulation software. Several optimization runs have been carried out for a small two degree of freedom vehicle model and a large full-scale model of the truck semi-trailer combination. The results show that the stroke dependent damping can reduce large deflections at incidental road disturbances, but that the optimum stroke dependent damping curve is related to the acceleration bound. By means of vehicle model simulation and numerical optimization we have been able to quantify this trade-off between suspension deflection working space and truck comfort.     

Port regionalization: towards a new phase in port development

Logistics integration and network orientation in the port and maritime industry have redefined the functional role of ports in value chains and have generated new patterns of freight distribution and new approaches to port hierarchy. Existing models on the spatial and functional evolution of ports and port systems only partially fit into the new freight distribution paradigm. This paper aims to add to existing literature by introducing a port regionalization phase in port and port system development. It is demonstrated that the regionalization phase and associated hinterland concepts demand new approaches to port governance and a functional focus that goes beyond the traditional port perimeter.     

超细水泥预注浆在挪威隧道工程中的应用

造价为5.9亿美元的挪威Sandvika-Asker铁路工程项目,位于奥斯陆南部,业主为Jernbaneverket Utbygging(铁道部),其修建目的是为了将奥斯陆与德拉曼之间的铁路运输能力提高一倍.     

Dynamics of suprabenthos-zooplankton communities around the Balearic Islands (western Mediterranean): Influence of environmental variables and effects on the biological cycle of Aristeus antennatus

Dynamics of suprabenthos and zooplankton were analyzed in two areas located in the NW (off Sóller harbour) and S (off Cabrera Archipelago) of Mallorca (Balearic Islands, western Mediterranean) at depths ranging between 135–780 m. Four stations situated respectively at 150 m (shelf-slope break), and at bathyal depths of 350, 650 and 750 m were sampled at bi-monthly intervals during six cruises performed between August 2003 and June 2004. Suprabenthos showed maximum biomass in both areas from late spring to summer (April to August), while minimum biomass was found in autumn (September–November). Though variable, temporal dynamics of zooplankton showed peaks of biomass in late winter and summer (February and June), while minimals occurred in autumn (August–September) and, at bathyal depths, in April. Suprabenthos (abundance; MDS analyses) showed a sample aggregation as a function of depth (3 groups corresponding to the shelf-slope break, upper slope — over 350 m; and the middle, deeper part of the slope — over 650–750 m), without any separation of hauls by season. By contrast, zooplankton samples were separated by season and not by depth. There was evidence of three seasonal groups corresponding to summer (June 2004–August 2003), autumn–winter (September and November 2003, February 2004), and spring (April 2004), being especially well established off Sóller. In general, suprabenthos was significantly correlated with the sediment variables (e.g. total organic matter content (% OM), potential REDOX), whereas zooplankton was almost exclusively dependent on Chl a at the surface, which suggests two different food sources for suprabenthos and zooplankton. The increase of suprabenthos abundance in April–June was paralleled by a sharp increase (ca. 2.8 times) in the %OM on sediment during the same period, coupled ca. 1–2 months of delay with the peak of surface Chl a recorded in February–March (from satellite imagery data). Suprabenthos biomass was also correlated with salinity close to the bottom, suggesting a link between suprabenthos abundance and changes in the oceanographic condition of water masses close to the bottom. It is suggested that a higher suprabenthos biomass recorded off Sóller in comparison to that off Cabrera in June could, in turn, be related to a seasonal inflow of Levantine Intermediate Water (LIW) in April–June in this area at mid bathyal depths (350–650 m). This trend would be based on: 1) it was evident only at mid-slope depths between 350–750 m, coinciding with the LIW distribution, and 2) it was not recorded among zooplankton (collected throughout the water column). The possible effect of the fluctuations of suprabenthos and zooplankton on higher trophic levels has been explored studying the diet and food consumption rates of the red shrimp Aristeus antennatus, as indicator species by its dominance in bathyal communities. A. antennatus increased its food consumption from February to April–June 2004 off Sóller, which in the case of large (CL > 40 mm) specimens was found in both areas. In addition, there was a shift of diet from winter to spring–early summer. In this last period, A. antennatus preyed upon euphausiids and mesopelagic decapods and fish, while benthos (e.g. polychaetes and bivalves) decreased in the diet. This indicates an increase in the food consumption and probably in the caloric content of the diet in pre-spawning females in April–June 2004, which is synchronized with the period when gonad development begins in A. antennatus females (May–June). Anyway, macrozooplankton, and not suprabenthos, is crucial as a high energetic food source in the coupling between food intake and reproduction in the red shrimp.     

Confidence bounds on structural reliability estimations for offshore platforms

Second-order estimates to measure platform reliability are generated and used to provide an additional space to select safety margins appropriate to the owner's perception or for risk-averse managers. The aleatory and epistemic uncertainties in the parameters of an offshore platform are explicitly considered in the reliability analysis and the platform structural reliability becomes a random variable, assessing then the beneficial effects of a reduction on these uncertainties. One of these benefits is for risk-aversive managers who often demand additional room to make conservative decisions regarding reliability estimations. Proposed here is a procedure to generate the frequency diagram of platform reliability with the use of confidence bounds to support reliability and cost decisions based on percentiles instead of mean values. The concepts are illustrated through a typical offshore platform in Mexico. The frequency diagram of the platform reliability index is built for several alternative designs and three levels of epistemic uncertainty. The results may be applied for decision making on new designs and also on the assessment and optimal inspection, retrofit, and decommissioning of existing platforms.     

Late Holocene history of the rainfall in the NW Iberian peninsula—Evidence from a marine record

This study reconstructs climatic variability over the last 4700 yr in the NW Iberian Peninsula on the basis of lithological, sedimentological, biogeochemical, micropaleontological (diatoms and biosiliceous compounds) and AMS ¹⁴C analyses conducted in a gravity core retrieved from the Galician continental shelf. The core was recovered at the Galicia Mud Patch, a muddy sedimentary body highly influenced by the terrestrial supply of the Miño and Douro rivers, and thus controlled by the rainfall variations over the catchment area. River plume transports the lithogenic and continental-derived compounds to the shelf area allowing us to recognize several periods of terrestrial/marine influence. These periods are well correlated with the lithological units identified. Coarser sediments, high values of Ca/Al, low values of Fe, Al and lithogenic Si (LSi) are representative of the marine-influenced periods. These stages are related to dry conditions and winds coming from the NE under a NAO positive-like phase.Terrestrial-influenced stages are characterized by muddy sediments, with high content of Fe, Al and LSi, freshwater and benthic diatoms, continental-derived organisms (crysophycean cysts and phytoliths) and high amount of land-derived organic matter as reported by the C/N ratios. The influence of NAO positive- and NAO negative-like periods and solar activity are the two mechanisms quoted to explain the climatic variability during the last 4700 years.Proxies for the lithogenic input and terrigenous content (non-organic material) show an increase at around 2000–1800 cal. yr BP, linked to the warmer conditions and high precipitation patterns during the Roman Warm Period, and soil erosion due to forest degradation and other anthropic activities. A strong river flow event is recorded in shelf sediments during 800–500 cal. yr BP. A pervasive NAO negative-like period, and the high irradiance registered during the Grand Solar Maximum (GSM) controlled the precipitation and induced a high run-off and riverine influx during this event.     

湛蓝十年海事梦 船舶管理业绩丰——中国海事局建局十周年成就之船舶管理篇

船舶管理作为海事管理的一项重要工作,在稳定水上交通安全形势,促进航运经济健康发展,构建和谐社会等方面发挥了重要作用。近年来,中国海事局积极作为,在认真履行国际公约的同时,结合我国经济社会发展的实际,实行了政务公开,实现一个窗口对外,推行了“无休息日”工作制和“预约服务”承诺,以更好地服务地方经济。积极支持地方港口口岸对外开放，为地方政府出谋划策，并通过规范非开放码头临时接靠程序，直接服务港口经营生产，促进了地方外向型经济的发展。