Experiment about Subjective Feeling of Presenting Traffic Attributes with Colors

摘要：本实验首先用对偶比较法逐一考察50名职业驾驶员对20种用10种色彩表征的交通属性的主观感受一致性,并依据Z分值得出交通属性强弱表征的色彩排序;然后,对50名被试的20种交通属性的实验数据予以处理,计算各种属性的色彩Z分值并汇总分析。实验结果表明:对于温度、胎压、音量、速度、瞬时油耗、车流速度、车流密度、交通拥堵状态、道路承重量、光照、长度、宽度、高度13种连续性属性,以及车辆设备状态、道路设施状态和系统安全状态3种两极性属性,色彩表征的主观感受一致性较高,并得到表征3种两极性属性的最佳色彩选配方案。 Abstract：The Paired-comparison method was adopted in this experiment to study fifty professional drivers&rsquo; subjective feelings about using 10 basic colors to present 20 kinds of traffic attributes. For the specific attributes, the ten basic colors were sorted according to the Z scores. An analysis on Z scores of different attribute colors was conducted based on the experiment data of twenty traffic attributes from the fifty professional drivers. The results show that the thirteen continuous traffic attributes, namely, temperature, tire pressure, sound volume, velocity, fuel consumption, traffic flow speed, density of traffic, illumination, length, width, traffic jam, hight and road&rsquo;s load-bearing, capacity as well as three bipolarity attributes: that is, equipment status of vehicle, state of road facilities and safety of traffic system, have high sorting consistency. Meanwhile, the best color combination for presenting the three bipolarity attributes was obtained.</p

Predation Strategies of Four Common Crabs on Sea Urchins Mesocentrotus nudus with Different Sizes

[Objectives] Mesocentrotus nudus is a key species in maintaining the stability of the kelp ecosystem and a valuable economic sea urchin species in northern China. However, little researches focus on its population ecology, and the factors impacting the population dynamics are still not clear. Gaetice depressus, Hemigrapsus sanguineus, Portunus trituberculatus and Charybdis japonica are four common crab species off the coast of China and are potential predators of M nudus. In order to explore the predation strategies and predation intensities of four crab species and the predation selectivities of C. japonica on different sizes of M. nudus, three different groups of body sizes of M nudus individuals, e.g., small sized (12 - 15 mm), medium sized (19-22 mm) and large sized (30 - 33 mm in diameter) were selected as the research objects. [Methods] Two sets of experiments were conducted in the laboratory. In the predation strategies and predation intensities experiment, each species of crabs was divided into two groups separately containing small and medium sized sea urchins, while the predation selective experiment contains a C. japonica and three sizes of urchins in a single experimental group. The data was analyzed using Excel and Spss16.0,and the significance was inspected using one-way ANOVA and Kruskal-Wallis in both sets of experiment, and Ivlev indexes were calculated to examine the predation selectivity of C. japonica on small and medium sized sea urchins. [Results] The results showed that four crab species could prey on the small sized sea urchin individuals, of which, the P. trituberculatus and C. japonica showed higher predation intensity on sea urchins (8.67 1.53 and 9.33 1.15, respectively, Table 2); whereas only P. trituberculatus and C. japonica consumed the medium sized sea urchins (Table 2). As for the predation strategies, four crab species presented diverse kinds of strategies on different sizes of sea urchins but showed similar predation behavior when encountering difficulties of crushing the urchins (Fig. 1). The predation and selection pattern of C. japonica belong to a kind of passive selection, and the selectivity was closely related to the size of its cheliped. Crabs with smaller cheliped had relatively high selective feeding index on small sized sea urchins (Fig. 2), while individuals with bigger cheliped showed no significant differencein predation rate for small and medium size sea urchins (one-way ANOVA, P > 0.05) (Fig. 2). [Conclusion] This study reveals that G. depressus, H. sanguineus, P. trituberculatus and C. japonica are all potential predator of sea urchin M. nudus. Moreover, they can adapt their hunting strategies according to the preys with different body size, predation capacity is a key factor to the prey selectivity of C. japonica