Cold performance of various biodiesel fuel blends at low temperature

This study examines the cold performance of biodiesel blends in a passenger car and a light duty truck at −16 °C and −20 °C. Six different types of biodiesels derived from soybean oil, waste cooking oil, rapeseed oil, cottonseed oil, palm oil and jatropha oil were blended with different volume ratios (B5 (5 vol. % biodiesel — 95 vol. % diesel), B10 and B20). The cold filter plugging point (CFPP) and the cloud point had an effect on the startability and driveability of both the passenger car and the light duty truck. The startability and driveability of the passenger car with all biodiesel blends (B5) were generally good at −20 °C. In the light duty truck, biodiesel blends (B10 and B20) of soybean, waste cooking, rapeseed and jatropha tended to be good at −20 °C in the startability and driveability tests than the biodiesel blends (B10 and B20) of cottonseed and palm. In particular, the palm biodiesel blend (B10) failed at −20 °C, and the palm biodiesel blend (B20) also failed at −16 °C in the startability test. The cold flow properties of biodiesel dictate that the length of the hydrocarbon chains and the presence of unsaturated structures significantly affect the low temperature properties of biodiesel.     

三维测量数据的钢结构虚拟装配过程仿真系统(英文)

The virtual erection simulation system was explained for a steel structure including ship and ocean plant blocks.The simulation system predicted the erection state to optimize any gap or overlap of blocks based on 3-D measurement data.The blocks were modified(cut) on the basis of the simulation result on the ground before erecting them by crane.The re-cutting process was not required and the blocks were erected into a mother ship speedily.Therefore,the erection time is reduced,increasing the dock turnover.     

Practically applicable devices for blocking the gap flow of a horn rudder to reduce rudder cavitation and their verification through numerical simulations

Rudder cavitation causes serious damage to the rudder and affects the safety and cost-effectiveness of a ship. In recent applications, a semicircular prismatic bar protruding beyond the concave surface of the horn facing the gap, located along the center-plane of the rudder, has been used to lessen the gap flow between the horn and the movable portion of the rudder system. Previous numerical studies with this single bar indicate that it can noticeably reduce rudder cavitation. In the present study, a pair of bars for blocking the vertical gaps, which are attached symmetrically to the center-plane on opposite convex surfaces of the movable portion, is suggested for circumventing the difficulties that arise in the practical application of single centre bars. Placed near the outer edges of the gap, the bars are are easily accessible at the maximum rudder angle to allow simple installation during routine ship maintenance. An additional blocking disk is inserted on top of the pintle block, blocking the horizontal gaps. Three-dimensional computations are conducted with these combined devices and the results show that the devices are remarkably efficacious in reducing rudder gap cavitation.     

In and out vision-based driver-interactive assistance system

The overall driving environment consists of the Traffic environment, vehicle and driver states (TVD). advanced driver assistance Systems (ADAS) must consider not only information on each of the TVD states but also their context. Recent research has focused on making more efficient and effective assistance systems by fusing all the information from the TVD states. Based on this research trend, this paper focuses on decision-level fusion to estimate the level of danger of a warning by using visual information of the traffic environment and the driver state. The driver state consists of the gazing region and the facial feature points that are obtained using the active appearance model (AAM). The traffic environment state consists of time to collision (TTC), time to lane Crossing (TLC), and lane color information, which are obtained from the environment in front of the vehicle, i.e., position of lanes and other vehicles. Warnings against lane-off, collision, and driver inattention are generated by fusing this vision-based information from inside and outside the vehicle. The experimental results prove that our vision-based interactive driver assistance system reduces most useless warnings.     

Isrss: Integrated side/rear safety system

As driver assistant systems (DAS) and active safety vehicles (ASV) with various functions become popular, it is not uncommon for multiple systems to be installed on a vehicle. If each function uses its own sensors and processing unit, it will make installation difficult and raise the cost of the vehicle. As a countermeasure, research integrating multiple functions into a single system has been pursued and is expected to make installation easier, decrease power consumption, and reduce vehicle pricing. This paper proposes a novel side/rear safety system using only one scanning laser radar, which is installed in the rear corner of the driver’s side. Our proposed system, ISRSS (integrated side/rear safety system), integrates and implements four system functions: BSD (blind spot detection), RCWS (rear collision warning system), semi-automatic perpendicular parking, and semi-automatic parallel parking. BSD and RCWS, which operate while the vehicle is running, share a common signal processing result. The target position designation for perpendicular parking and parallel parking situations is based on the same signal processing. Furthermore, as system functions during running and those during automatic parking operate in exclusive situations, they can share common sensors and processing units efficiently. BSD and RCWS system functions were proved with 13025 and 2319 frames, respectively. The target position designation for perpendicular and parallel parking situations was evaluated with 112 and 52 situations and shows a success rate of 98.2% and 92.3%, respectively.     

社区步行通达性对独栋住宅房价的效益评估--美国德克萨斯州奥斯丁市空间特征分析

通过分析美国德克萨斯州奥斯丁市2010—2012年独栋住宅的销售价格,以街道智慧步行指数(Street Smart Walk Score)和人行道密度(Sidewalk Density)作为衡量指标,研究社区步行通达性对房价的影响。使用Cliff-Ord空间特征模型(即广义空间模型,General Spatial Model,或者SAC)控制空间自相关影响。结果表明：在依赖小汽车的社区通过增加设施可达性来提升步行通达性的举措并不能提高房价;增加人行道也只能最小限度地提高房价。投资社区便利设施和人行道对适宜步行社区的房价提升效果比依赖小汽车的社区显著。     

Extended bottlenecks, the fundamental relationship, and capacity drop on freeways

This paper presents evidence that the commonly used point bottleneck model is too simplistic for freeway bottlenecks, the actual mechanism appears to occur over an extended distance. We find evidence of subtle flow limiting and speed reducing phenomena more than a mile downstream of a lane drop bottleneck. These phenomena impact the fundamental relationship, FD. Close to the lane drop the free flow regime appears to come from a “parabolic” FD, but further downstream the relationship straightens to a “triangular” FD and throughput increases. We develop a theory to explain the underlying mechanisms. These insights should help resolve the decades long debate about the shape of the FD. The phenomena also provide a mechanism that may contribute to the empirically observed capacity drop often seen at bottlenecks. Although we study a lane drop, this work should be transferable to other bottlenecks where the capacity restriction persists for an extended distance, e.g., a corridor with a fixed number of lanes and an on-ramp bottleneck.     

'Government preference' and its influence on the shipping industry in Korea

The author suggests the existence of 'government preference', which has changed the structure of the Korean economy from that of a light-goods industry to one of a heavy and chemical goods industry; and which has affected the formation of an export-dependent economy. 'Government preference' has also affected the shipping sector which was favoured as a foreign-exchange earner, not as an income generator. Korean shipping expanded through market forces in its earlier developmental stage where tonnage of the Korean fleet grew moderately and profitability was reasonably good; and by 'government preference' towards shipping externalities (balance-of-payments effect and support for export industry) which became a prime concern of the government in later years where the fleet expanded rapidly in spite of negative profitability. It follows that under circumstances of 'government preference' which is strong enough to work and which prefers shipping's external effect to value added generated by shipping. Korean shipping might well record a poor performance in terms of profitability. This means that Korean shipping companies' prime concern lies in 'survival' not in 'profit'.     

A combined land use-transportation model when zonal travel demand is endogenously determined

A combined transportation-land use model is proposed in this paper. Unlike other existing urban land use and transportation planning models in which a “fixed demand” for services is assumed to be known at the zonal level of an urban area, zonal travel demand is endogenously determined together with link congestion costs, optimal amounts of production and resulting efficient densities of land uses, once the transportation network is given. Some characteristics of alternative solutions are demonstrated. The proposed model represents progress over previous efforts in combining land use-transportation problems since the travel choice as to origin, destination and routes as well as amounts of goods to be produced at the optimal density of land uses are integrated into a consistent mathematical programming framework.