Comparing the terrain reversal effect in satellite images and in shaded relief maps: an examination of the effects of color and texture on 3D shape perception from shading     

Arzu Çöltekin  Julien Biland 《International Journal of Digital Earth》2019,12(4):442-459

Terrain reversal effect (TRE) causes reversed 3D shape perception in satellite images and shaded relief maps (SRMs), and introduces difficulties in identifying landforms such as valleys and ridges. With this paper, in a controlled laboratory experiment, we compare how well 27 participants could identify valleys and ridges over 33 locations using SRMs, color satellite images and grayscale satellite images. The main depth cue is shadow both in vertical-view images and SRMs. However, the presence of texture and color in images also affect 3D shape perception. All our participants experience the illusion strongly: with the SRMs, it is very severe (2% accuracy), with grayscale images low but considerably better than SRMs (17.6% accuracy), and slightly worse with color imagery (15.3% accuracy). These differences between SRMs and imagery suggest that the participants who are able to bypass the illusion consciously or subconsciously interpret the photographic information. We support this observation further with a cue-strength analysis. Furthermore, we provide exploratory analyses of the effects of expertise, global convexity bias, and bistable perception. Our original empirical observations serve towards a better understanding of this visual illusion, and contribute towards nuanced and appropriate solutions to correcting for TRE differently for satellite images and SRMs.  相似文献   

Numerical study of effect of fluke inclination on behavior of drag anchor in clay with linearly increasing shear strength under unidirectional and combined loading     

《Applied Ocean Research》2019

Drag anchor is a widely used anchor type in offshore engineering for the mooring system. The prediction of the anchor trajectory installation and the final position is important for anchor selection in design. The existing method using yield envelope method for trajectory prediction ignored the shallow anchor behavior but applied the deep yield envelope from a deeply embedded horizontal fluke in uniform clay for the whole drag-in installation process. However, the anchor fluke embedment depth and inclination angle change continually during installation in clay with linearly increasing shear strength soil profile in practice. Studies on the effect of fluke inclination angle on the anchor behavior in clay with such non-uniform soil profile under unidirectional and combined loading are important and necessary for the improvement of the yield envelope method to ensure a reasonable prediction. The current 2D finite element studies investigate the anchor behavior for inclined fluke in clay with linearly increasing shear strength under unidirectional vertical, horizontal and rotational loadings first. Then the effects of the fluke inclination angle, soil non-homogeneity and embedment depth ratio on the shallow yield envelopes are investigated. It is found that the effect of fluke inclination angle on the vertical capacity factors for anchor in clay with non-uniform and uniform soil profile is largely different. The resultant large impact on the yield envelopes shown here illustrates the importance of considering the fluke inclination angle and soil non-homogeneity in the prediction of anchor trajectory using yield envelope method.  相似文献   

The sustainable development goals: A case study     

《Marine Policy》2017

The Sustainable Development Goals or SDGs [44] are an ambitious step towards sustainable development, taking a much broader view of sustainability than ever achieved previously, yet practical challenges remain, including how to implement change. The aims of this research were to determine how an influential aquaculture company in Australia - Tassal, Tasmania's largest salmon aquaculture company - perceived the SDGs, and to ascertain the motivations and barriers for Tassal to work towards implementing the goals. Interviews were conducted with leaders, employees and external business partners. Tassal was not aware of the SDGs prior to this project, but were open to considering implementing them in their current sustainability practices. The survey responses were analysed using the Values-Rules-Knowledge (vrk) framework of decision making. Key findings were: 1) corporate and personal values were the key component driving Tassal's positive responses to the SDGs; 2) awareness of the SDGs resulted in Tassal recognising the potential gains from engaging with some of the seemingly less aquaculture-related goals (such as health and wellbeing). These findings demonstrate that businesses can fruitfully engage with the SDGs, even without government requirements or societal expectations, if they are prepared to broaden their interpretation of business sustainability and be reflective about their values. The vrk model is a potentially useful addition to current SDG and sustainability tools, such as those of the UN Global Compact, as a way to diagnose organisational barriers to adopting practices aligned with the SDGs. An emerging area of importance to social, economic and environmental sustainability – social license – was also identified as implicit in many, but not explicit in any of the SDGs.  相似文献   

健脾益气方调控间隙连接蛋白43防治PD大鼠腹膜损伤的作用机制研究          下载免费PDF全文

孟立锋  杨端云  史伟 《应用海洋学学报》2020,36(7):157

目的：研究健脾益气方通过调控间隙连接蛋白（Cx）43干预腹膜透析大鼠腹膜间皮细胞转分化的作用机制。方法：将75只大鼠随机分为5组,即空白组、模型组、中药高剂量组、中药低剂量组、西药组,除空白组大鼠外,其余各组均采用5/6肾切除联合腹腔注射4.25％腹透液复制慢性肾衰竭腹膜纤维化大鼠模型。造模成功后,中药高、低剂量组给予健脾益气方,西药组给予阿托伐他汀钙,模型组给予0.9%氯化钠注射液,空白组不做任何处理。每天灌胃1次,连续4周。干预后光镜观察各组大鼠腹膜结构变化,测量腹膜致密层厚度;免疫组化法及蛋白质印迹法检测Cx43、蛋白激酶B/哺乳动物雷帕霉素靶蛋白（AKt/mTOR）通路和腹膜间皮细胞转分化（EMT）标志蛋白表达。结果：各组大鼠腹膜厚度及Cx43、pAKt、pmTOR、α平滑肌肌动蛋白（α-SMA）、E-钙黏附蛋白（E-cadherin）阳性面积比,空白组与模型组比较,中药高、低剂量组及西药组与模型组比较,中药高剂量组与西药组、中药低剂量组比较,差异均有统计学意义（P<0.05）。各组大鼠腹膜组织Cx43、pAKt、pmTOR、α-SMA、E-cadherin蛋白表达,空白组与模型组比较,中药高剂量组与西药组比较,差异均有统计学意义（P<0.05）。结论：健脾益气方可能通过调控Cx43表达,干预Akt/mTOR信号通路介导的腹膜间皮细胞EMT进程,从而发挥保护腹膜间皮细胞、防治腹膜损伤的作用。  相似文献   

四磨汤口服液SD大鼠长期毒性实验研究          下载免费PDF全文

刘正清  孔卫青  杨华 《应用海洋学学报》2020,36(8):163

目的：观察SD大鼠灌胃四磨汤口服液的长期毒性反应。方法：将120只SD大鼠随机分为四磨汤口服液高、中、低3 个剂量组和辅料对照组,连续灌胃给药13周,恢复期4周,观察各组大鼠实验过程中症状发生情况、体质量、血细胞计数[包括白细胞（WBC）、红细胞（RBC）、血红蛋白（HGB）、红细胞压积（HCT）、平均红细胞体积（MCV）、平均红细胞血红蛋白（MCH）、平均红细胞血红蛋白浓度（MCHC）]、血液生化指标[包括丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、总蛋白（TP）、白蛋白（ALB）、白蛋白/球蛋白（A/G）、直接胆红素（TBil）、尿素氮（BUN）、肌酐（Cre）、总胆固醇（CHO）、三酰甘油（TG）]的变化,并观察停药后各指标的恢复情况。结果：四磨汤口服液高、中、低剂量组实验期间均未出现异常症状。与同期同性别辅料对照组相比,末次给药后次日高剂量组雌性大鼠RBC和HGB指标降低（P<0.05）,其他指标和时间点差异均无统计学意义（P＞0.05）。由于RBC和HGB变化幅度较小,均在正常参考值范围内波动,其他红细胞相关指标也未见异常改变,故认为该变化无重要的毒理学意义。各剂量组雄性大鼠血细胞计数指标均未见统计学差异（P＞0.05）。与同期同性别辅料对照组相比,末次给药后次日,高剂量组雄性大鼠BUN、雌性大鼠Cre降低,雄性大鼠CHO升高;与同期同性别辅料对照组相比,末次给药后次日,中剂量组雄性大鼠CHO升高;恢复期结束后,雄性大鼠TBil升高;与辅料对照组相比,恢复期结束后,雌性动物TG降低;上述指标差异均有统计学意义（P<0.05）。以上指标中,CHO、TBil的升高未见明显的剂量-反应关系,且在正常参考值范围内波动,认为无重要的毒理学意义。BUN、Cre、TG的降低无重要的毒理学意义。结论：本实验未见明显不良反应的剂量为45 g/kg,表明四磨汤口服液安全性高。  相似文献   

中国各省市区开放型经济水平比较研究     

陈子曦 《地域研究与开发》2010,29(5)

改革开放以来,中国不断深化发展开放型经济。十七大报告明确提出"拓展对外开放广度和深度,提高开放型经济水平"。由于受地缘、人缘、政府宏观调控、跨国公司产业配置、国际分工、生产要素全球流动等因素影响,各省市区开放型经济水平存在差异。在前人研究的基础上设计了评价国内各省市区开放型经济水平的指标体系,并采用2004—2008年连续5年的相关数据,用主成分分析法测算出我国各省市区开放型经济水平。最后,对计算结果进行综合评价和分类比较得出若干结论。  相似文献   

我国主体功能区划研究进展与展望     

马随随  朱传耿  仇方道 《世界地理研究》2010,19(4):91-97

主体功能区划是对我国经济社会发展和环境保护空间框架的约束性重构,是以经济增长、人口发展和制度公平三者之间的有机协调为基本诉求的包容性增长战略在空间上的体现。通过从理论基础、方法论和管治3个方面系统总结与分析我国主体功能区划研究现状及存在问题,认为,加强主体功能区划空间定位、主体功能区划过程相对标准化、主体功能区划动态调整机制、主体功能区外部效应等方面研究,是今后我国主体功能区划研究的重点领域和趋势。  相似文献   

Northward-shift of temperature zones in China’s eco-geographical study under future climate scenario     

WU Shaohong  ZHENG Du  YIN Yunhe  LIN Erda  XU Yinlong 《地理学报》2010,20(5):643-651

Despite the well-documented effects of global climate change on terrestrial species’ ranges, eco-geographical regions as the regional scale of ecosystems have been poorly studied especially in China with diverse climate and ecosystems. Here we analyse the shift of temperature zones in eco-geographical study over China using projected future climate scenario. Projected climate data with high resolution during 1961–2080 were simulated using regional climate model of PRECIS. The number of days with mean daily temperature above 10℃ and the mean temperature of January are usually regarded as the principal criteria to indicate temperature zones, which are sensitive to climate change. Shifts due to future climate change were calculated by comparing the latitude of grid cells for the future borderline of one temperature zone with that for baseline period (1961–1990). Results indicated that the ranges of Tropical, Subtropical, Warm Temperate and Plateau Temperate Zones would be enlarged and the ranges of Cold Temperate, Temperate and Plateau Sub-cold Zones would be reduced. Cold Temperate Zone would probably disappear at late this century. North borderlines of temperature zones would shift northward under projected future climate change, especially in East China. Farthest shifts of the north boundaries of Plateau Temperate, Subtropical and Warm Temperate Zones would be 3.1°, 5.3° and 6.6° latitude respectively. Moreover, northward shift would be more notably in northern China as future temperature increased.  相似文献   

钢管混凝土桥墩抗震性能试验研究   总被引：1，自引：0，他引：1  

臧华  刘钊  李红英  涂永明 《地震学刊》2010,(4):442-446,451

为研究钢管混凝土桥墩的抗震性能,对钢管混凝土桥墩和钢筋混凝土桥墩进行了拟静力对比试验研究。根据试件的破坏发展过程以及各试件的滞回曲线和骨架曲线,分析了其滞回性能、耗能能力、延性、强度退化及刚度退化等抗震性能。试验结果表明,钢管混凝土桥墩的抗震性能明显好于钢筋混凝土桥墩。在含钢率和轴力相同的情况下,钢管混凝土桥墩的滞回曲线比钢筋混凝土桥墩丰满得多,前者的耗能能力约为后者的4.46倍,钢管混凝土桥墩的延性大于钢筋混凝土桥墩;随着轴压比的增大,钢管混凝土桥墩延性有所下降,强度退化加快,但对其刚度退化的影响不大。  相似文献   

雪峰山隧道砂板岩各向异性力学特性的试验研究   总被引：4，自引：0，他引：4  

高春玉  徐进  李忠洪  邓建辉 《岩土力学》2011,32(5):1360-1364

利用MTS815 Flex GT岩石力学试验系统,对雪峰山隧道围岩中的砂板岩开展单轴和三轴试验,研究这种砂板岩中的细微层理对岩石变形特性、强度特性及其参数的影响,结果表明：岩石力学特性的各向异性特征显著。层理面与轴向力夹角0°时应力-应变曲线呈不稳定破裂特征,破坏面沿层理面方向发育;夹角90°时曲线呈峰后迅速软化特征,破坏面为对角贯通性剪切破坏。单轴试验中夹角0°的抗压强度比夹角90°高出约20%,弹性模量和变形模量比夹角90°分别约大50%和80%。三轴试验中2种夹角情况破坏时主应力差 相近,夹角0°的弹性模量和变形模量分别比夹角90°时约大6%和20%,围压对砂板岩的各向异性特征有弱化效应。这些结论揭示了该砂板岩各向异性的力学特性,对解决工程实际问题有重要的参考价值  相似文献