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Evaluation of Transverse Markings as a Speed Transition Zone Countermeasures in Small, Rural Communities

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Journal of Transportation Technologies 2021年第1期11卷 61-77页

作者： Shauna Hallmark Neal Hawkins skylar Knickerbocker Institute for Transportation at Iowa State University Ames USA

Small rural communities located along major state or county roadways typically find most of the traffic along their main thoroughfares is pass-through rather than local traffic. Unfortunately, drivers passing through these communities often enter at high rates of speeds, which are often significantly higher than the speed limit of the local segment. Speed management in rural areas requires different considerations compared to urban areas and, within the US, rural speed management is not as advanced with little experience or guidance for agencies to draw on. This paper summarizes the results of a study that evaluated, in part, several different types of transverse pavement markings within the speed transition zones in small rural communities. Three different countermeasures were evaluated: converging chevrons, transverse lane markings, and optical speed bars.

关键词： Community Entrance Converging Chevrons Optical Speed Bars Pedestrian Safety Speed Transitions Traffic Calming Traffic Safety Speed Management

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从建立到现在:FORTRAN三十年

计算机科学 1989年第5期16卷 73-75页

作者： Jim skylar 向隆万周范

1957年是轿车和软件的好年头。雪佛兰(chevrolet)公司推出了注定要成为美国街头典型的小汽车,而美国国际商用机器公司(IBM)则发表了第一组代表软件的计算机卡片,它是用一种新的计算机语言FORTRAN书写的。以计算机硬件的变化速度来衡量,... 详细信息

1957年是轿车和软件的好年头。雪佛兰(chevrolet)公司推出了注定要成为美国街头典型的小汽车,而美国国际商用机器公司(IBM)则发表了第一组代表软件的计算机卡片,它是用一种新的计算机语言FORTRAN书写的。以计算机硬件的变化速度来衡量,三十年似乎是不朽的。

关键词：程序设计语言 FORTRAN语言

Traffic Incident Management Performance Measures: Ranking Agencies on Roadway Clearance Time

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Journal of Transportation Technologies 2023年第3期13卷 353-368页

作者： Maroa Mumtarin skylar Knickerbocker Theresa Litteral Jonathan S. Wood Department of Civil Construction and Environmental Engineering Iowa State University Ames USA

This study develops a procedure to rank agencies based on their incident responses using roadway clearance times for crashes. This analysis is not intended to grade agencies but to assist in identifying agencies requiring more training or resources for incident management. Previous NCHRP reports discussed usage of different factors including incident severity, roadway characteristics, number of lanes involved and time of incident separately for estimating the performance. However, it does not tell us how to incorporate all the factors at the same time. Thus, this study aims to account for multiple factors to ensure fair comparisons. This study used 149,174 crashes from Iowa that occurred from 2018 to 2021. A Tobit regression model was used to find the effect of different variables on roadway clearance time. Variables that cannot be controlled directly by agencies such as crash severity, roadway type, weather conditions, lighting conditions, etc., were included in the analysis as it helps to reduce bias in the ranking procedure. Then clearance time of each crash is normalized into a base condition using the regression coefficients. The normalization makes the process more efficient as the effect of uncontrollable factors has already been mitigated. Finally, the agencies were ranked by their average normalized roadway clearance time. This ranking process allows agencies to track their performance of previous crashes, can be used in identifying low performing agencies that could use additional resources and training, and can be used to identify high performing agencies to recognize for their efforts and performance.

关键词： Traffic Incident Management Roadway Clearance Time Performance Measures and Ranking Agency Performance Evaluation Tobit Regression Model

An Integrated Framework for Regional Assessment of Water, Energy, and Nutrients from Food Loss of Selected Crops in the Lower Fraser Valley, Canada

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Agricultural Sciences 2022年第5期13卷 633-657页

作者： Ana Reinesch Lewis Fausak Anne Joseph skylar Kylstra Les Lavkulich Faculty of Land and Food Systems University of British Columbia Vancouver Canada

Although there is no global shortage of food or water, food security has not been achieved, as human activity has turned these vital resources into “waste”. Wasted food not only loses valuable water resources but embedded calories of human energy and nutrients for healthy human populations. The Food and Agricultural Organization of the United Nations, in addressing these concerns, focuses on a global scale largely on an economic estimate of individual components of energy or water or nutrient loss. It is suggested that more information is required through local or regional assessments to provide better estimates, incorporating regional factors of the losses along the food supply chain. To address this suggestion, this study focused on an intensive agricultural and rapidly urbanizing region of Canada, the Lower Fraser Valley of British Columbia. Seven selected crops, including annual crops such as green peas, sweet corn and potato, and perennial crops that included three berry crops were assessed for their water, both constituent and virtual, as well as embedded energy, protein, and Vitamin C. Annual virtual water losses were higher for sprinkler than drip irrigation, ranging from 82 × 106 kg of water for strawberry to 7570 × 106 kg for blueberry. These high virtual water losses estimated along the food chain confirm the significance of food loss impacts on local water resources. Estimates of losses of food in kg were highest at the consumer level along the food chain and it was estimated that wasted food from the seven crops selected would have supplied the protein and caloric energy of over 33,000 men per year and Vitamin C of about 240,000 men per year. This assessment increases the awareness of food loss impacts from a regional perspective and provides a framework for future research on both environmental and nutritional implications of wasted food.

关键词： Food Loss Food Waste Crop Water Demand Virtual Water Nutrition

Evaluation of Driver Behavior in Response to Stop Sign Beacons

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Journal of Transportation Technologies 2022年第2期12卷 245-257页

作者： Shauna Hallmark skylar Knickerbocker Neal Hawkins Raju Thapa Theresa Litteral Institute for Transportation Iowa State University Ames USA Louisiana Transportation Research Center Louisiana State University Baton Rouge USA

Crashes at rural intersections are frequently a result of failure to yield. As a result, agencies attempt to find countermeasures that encourage drivers to stop and yield appropriately. A number of countermeasures have been utilized to reduce crashes and improve intersection safety. However, some treatments have been shown to have mixed results, while for others only limited information about effectiveness is available. Because even low-cost treatments require some maintenance, it is important for agencies to have good information about the effectiveness of the various treatments before investments are made. Stop sign beacons are one such low-cost measure. This paper discusses results of research which evaluated stop sign beacons. Stop sign beacons were installed at 10 stop-controlled approaches in the US state of Iowa. The beacons were set to activate only when an approaching driver was traveling over a set speed threshold which was set based on whether a driver would be able to stop. Video data were collected before, at 1-month, and at 12-month after installation. Type of stop (i.e., rolling, no-stop), stop location in reference to the stop bar, and location of initial brake application were reduced from the video data. The percentage of drivers who began braking before or after 350 feet were compared. This threshold indicates the point at which drivers would need to engage in hard braking based on approach speed and stopping sight distance. At one month, 6 of the 9 intersections experienced an increase in the percentage of vehicles braking at 350 feet or before. At 12-month, drivers at more than half of the approaches were braking sooner than the before period. Results also indicate stopping behavior improved after installation of the beacons. Most of the approaches (70%) showed an increase in the percentage of drivers who came to a full stop at 1-month compared to the period before installation. At 12-month, 71% of approaches showed an increase in drivers who ca

关键词： Stop-Sign Mounted Beacons Safety Analysis Stopping Behavior Rural Intersection Countermeasures

Irrigation Water Demand Model as a Comparative Tool for Assessing Effects of Land Use Changes for Agricultural Crops in Fraser Valley, Canada

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Agricultural Sciences 2021年第8期12卷 888-906页

作者： skylar Kylstra Autumn D. Watkinson Lewis Fausak Leslie M. Lavkulich Faculty of Land and Food Systems University of British Columbia Vancouver Canada

Available water for human needs and agriculture is a growing global concern. Agriculture uses approximately 70% of global freshwater, mainly for irrigation. The Lower Fraser Valley (LFV), British Columbia, is one of the most productive agricultural regions in Canada, supporting livestock production and a wide variety of crops. Water scarcity is a growing concern that threatens the long-term productivity, sustainability, and economic viability of the LFV’s agriculture. We used the BC Agriculture Water Demand Model as a tool to determine how crop choice, irrigation system, and land-use changes can affect predicted water requirements under these different conditions, which can aid stakeholders to formulate better management decisions. We conducted a comparative assessment of the irrigation water demand of seven major commercial crops, by distinct soil management groups, at nineteen representative sites, that use both sprinkler vs drip irrigation. Drip irrigation was consistently more water-efficient than sprinkler irrigation for all crops. Of the major commercial crops assessed, raspberries were the most efficient in irrigation water demand, while forage and pasture had the highest calculated irrigation water demand. Significant reductions in total irrigation water demand (up to 57%) can be made by switching irrigation systems and/or crops. This assessment can aid LFV growers in their land-use choices and could contribute to the selection of water management decisions and agricultural policies.

关键词： Drip Irrigation Sprinkler Irrigation Water Management Water Resources Agricultural Water Demand Model

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恐鸟灭绝,凶手真的是人类

求知导刊 2014年第4期 24-25页

作者： skylar Tsai

几百万年以来,九种不会飞的大型鸟类在新西兰繁荣发展,它们统称“恐鸟”（Dinormthiformes）.然后,大约600年以前,它们突然灭绝,恰好赶在13世纪人类第一次到达新西兰的时候.长期以来科学家们想知道,在恐鸟衰亡过程中,智人的猎捕扮演着... 详细信息

几百万年以来,九种不会飞的大型鸟类在新西兰繁荣发展,它们统称“恐鸟”（Dinormthiformes）.然后,大约600年以前,它们突然灭绝,恰好赶在13世纪人类第一次到达新西兰的时候.长期以来科学家们想知道,在恐鸟衰亡过程中,智人的猎捕扮演着什么样的角色.我们的存在是导致这些巨型鸟类陷入绝境的唯一原因吗？又或者说,由于疾病和火山爆发,它们已经走上了灭亡的道路呢？

关键词：鸟类灭绝人类火山爆发新西兰科学家智人

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四维打印——造物自造

疯狂英语（初中天地） 2014年第2期 20-21页

作者： skylar Tibbits Stephanie

科技发展之神速，似乎用日新月异都不足以表达。这不，3D打印似乎还在凤靡，科学家们却已经有了新的点子。且听麻省理工学院的研究员斯凯拉·蒂比茨向我们展示其4D打印的实验，让我们窥探一个可能进行自我装配的未来。

关键词：打印造物四维麻省理工学院科技发展科学家研究员装配

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非周期脊椎V2.0

城市环境设计 2009年第10期 59-60+58页

作者： Marc Fornes skylar Tibbits Jared Laucks

THEVERYMANY位于纽约。创始人是Marc Fornes,主要成员有skylar Tibbits,Mat Staudt,Jared Laucks,Brandon Kruysman,Jon Proto。Marc Fornes曾在SOM,Ross Lovegrove及Zaha Hadid的建筑事务所担任项目建筑师。他策划了美国2007年的Scripted by purpose以及2008年北京双年展的欧洲部分。项目名称:非周期脊椎V2.0(APERIODIC VERTEBRAE V2.0)展览地点:德国法兰克福展览时间:2008年设计:Marc Fornes,skylarTibbits,Jared Laucks明确&编码协议:Rhinoscripting、Marc Fornes材料:聚乙烯板(4.7625mm厚)+丙烯酸连接(4.7625mm)+拉接固定构建装配:24小时+2人+2台笔记本电脑来(重新)集合360个面板和320个节点赞助商:象限资源增值计划美国公司(材料),Continental Signs(数控切割),Dick Dunlop(激光切割)

关键词：非周期 Marc 脊椎