Predicting NOx sensor failure in heavy duty trucks using histogram-based random forests

Being able to accurately predict the impending failures of truck components is often associated with significant amount of cost savings, customer satisfaction and flexibility in maintenance service plans. However, because of the diversity in the way trucks typically are configured and their usage under different conditions, the creation of accurate prediction models is not an easy task. This paper describes an effort in creating such a prediction model for the NOx sensor, i.e., a component measuring the emitted level of nitrogen oxide in the exhaust of the engine. This component was chosen because it is vital for the truck to function properly, while at the same time being very fragile and costly to repair. As input to the model, technical specifications of trucks and their operational data are used. The process of collecting the data and making it ready for training the model via a slightly modified Random Forest learning algorithm is described along with various challenges encountered during this process. The operational data consists of features represented as histograms, posing an additional challenge for the data analysis task. In the study, a modified version of the random forest algorithm is employed, which exploits the fact that the individual bins in the histograms are related, in contrast to the standard approach that would consider the bins as independent features. Experiments are conducted using the updated random forest algorithm, and they clearly show that the modified version is indeed beneficial when compared to the standard random forest algorithm. The performance of the resulting prediction model for the NOx sensor is promising and may be adopted for the benefit of operators of heavy trucks

February 2000 Land use and planning report, no. 2

February 2000.Print version has series title: Agricultural and resource policy report.Includes bibliographical references

Patterns of Tree Mortality During an Uncontrolled Spruce Budworm Outbreak in Baxter State Park, 1983

A forest inventory of Baxter State Park, Maine, was done during the summer and fall of 1983 to study the patterns of mortality in balsam fir and in the red-black spruce complex during an uncontrolled spruce budworm outbreak. The volume of trees that died during the outbreak was estimated at 40% of the original quantity. Fir mortality was consistently greater than that of spruce. The percentage mortality of spruce was always greater in the higher elevation zone than in the lower elevation zone. Percentage mortality of fir and spruce showed inconsistent patterns in relation to the proportion of hardwood species basal area and to the proportion of fir basal area in a stand. However, those mortality patterns tended to be pronounced when the overall tree mortality was relatively high. Hypotheses on the mechanisms producing the tree mortality patterns during a budworm outbreak were summarized and observed tree mortality patterns were then interpreted according to those hypotheses. Most observed patterns could be explained by more than one hypothesis. It was suggested that complex processes were responsible for developing certain tree mortality patterns, and a deductive method based on the simple observations would not reveal the true mechanisms.https://digitalcommons.library.umaine.edu/aes_techbulletin/1081/thumbnail.jp

Patterns of Tree Mortality During an Uncontrolled Spruce Budworm Outbreak in Baxter State Park, 1983

A forest inventory of Baxter State Park, Maine, was done during the summer and fall of 1983 to study the patterns of mortality in balsam fir and in the red-black spruce complex during an uncontrolled spruce budworm outbreak. The volume of trees that died during the outbreak was estimated at 40% of the original quantity. Fir mortality was consistently greater than that of spruce. The percentage mortality of spruce was always greater in the higher elevation zone than in the lower elevation zone. Percentage mortality of fir and spruce showed inconsistent patterns in relation to the proportion of hardwood species basal area and to the proportion of fir basal area in a stand. However, those mortality patterns tended to be pronounced when the overall tree mortality was relatively high. Hypotheses on the mechanisms producing the tree mortality patterns during a budworm outbreak were summarized and observed tree mortality patterns were then interpreted according to those hypotheses. Most observed patterns could be explained by more than one hypothesis. It was suggested that complex processes were responsible for developing certain tree mortality patterns, and a deductive method based on the simple observations would not reveal the true mechanisms.https://digitalcommons.library.umaine.edu/aes_techbulletin/1081/thumbnail.jp

Spot The Bot: A Robust and Efficient Framework for the Evaluation of Conversational Dialogue Systems

The lack of time-efficient and reliable evaluation methods hamper the development of conversational dialogue systems (chatbots). Evaluations requiring humans to converse with chatbots are time and cost-intensive, put high cognitive demands on the human judges, and yield low-quality results. In this work, we introduce \emph{Spot The Bot}, a cost-efficient and robust evaluation framework that replaces human-bot conversations with conversations between bots. Human judges then only annotate for each entity in a conversation whether they think it is human or not (assuming there are humans participants in these conversations). These annotations then allow us to rank chatbots regarding their ability to mimic the conversational behavior of humans. Since we expect that all bots are eventually recognized as such, we incorporate a metric that measures which chatbot can uphold human-like behavior the longest, i.e., \emph{Survival Analysis}. This metric has the ability to correlate a bot's performance to certain of its characteristics (e.g., \ fluency or sensibleness), yielding interpretable results. The comparably low cost of our framework allows for frequent evaluations of chatbots during their evaluation cycle. We empirically validate our claims by applying \emph{Spot The Bot} to three domains, evaluating several state-of-the-art chatbots, and drawing comparisons to related work. The framework is released as a ready-to-use tool

Predicting Ecological Behavior in the Era of Climate Change

The most devastating effects of climate change may be avoided if humans reduce activities that produce greenhouse gases and engage instead in more sustainable ecological behaviors. The current mixed methods study of 279 undergraduate students explored whether environmental worldview, belief in climate change, knowledge of climate change, personal efficacy, and intention to address climate change influenced participants’ engagement in ecological behavior. Results indicated that those with a stronger intention to address climate change and a more ecocentric worldview reported significantly more ecological behavior. Next, the study examined whether participants’ intentions to address climate change mediated the relationship between their belief in climate change and engagement in ecological behavior and whether intentions mediated the relationship between efficacy and ecological behavior. Intentions to address climate change did not mediate the relationship between belief and ecological behavior but fully mediated the relationship between efficacy to address climate change and ecological behavior

Planning and the Paradox of Conscious Purpose

Since the discovery of fire, and in the past 7,000-10,000 years with the development of agriculture and the establishment of fixed settlements, the evolution of human culture has been the reverse of that of organic systems

On the Truly Noncooperative Game of Island Life: Introducing a Unified Theory of Value & Evolutionarily Stable Island Economic Development Strategy

This discourse offers a solution to The Problem of Sustainable Economic Development on islands. This hypothesis offers a foundational, sub-game solution to The Island Survival Game, a counterintuitive, dominant economic development strategy for ‘islands’ (and relatively insular states). This discourse also tables conceptual building blocks, prerequisite analytical tools, and a guiding principle for The Earth Island Survival Game, a bounded delay supergame which models The Problem of Sustainable Economic Development at the global level. We begin our exploration with an introduction to The Principle of Relative Insularity, a postulate which informs ESS for ‘island’ and ‘continental’ players alike. Next, we model ‘island’ economic development with two bio-geo-politico-economic models and respective strategies: The Mustique Co. Development Plan, and The Prince Edward Island Federal-Provincial Program for Social and Economic Advancement. These diametrically opposed strategies offer an extraordinary comparative study. One island serves as a highly descriptive model for The Problem of Sustainable Economic Development; the other model informs ESS. The Island Survival Game serves as a remarkable learning tool, offering lessons which promote Darwinian fitness, resource holding power, self-sufficiency, and cooperative behaviour, by illuminating the illusive path toward sustainable economic development.Non-cooperative games, evolutionary game theory, relative insularity, islands, tragedy of the commons, sustainable economic development, resource holding power, evolutionarily stable strategy, long distance dispersal

Crawl Space: Driving Over the Anthropocene in a Jeep

The automobile has long been directly and indirectly connected to human conceptions of nature, yet few studies linger with the act of driving as a practice that contributes to how nature is experienced. I argue that a more nuanced understanding of automobility is necessary for any scholars who study both social practices and environmental sustainability. Following the work of the human geographer Doreen Massey, I explore how relations between humans and non-humans, the social and the natural, ideology and practice work together to produce places specific to space and time. I also argue that American automobility is not simply transportation, but is in fact an ideology. As such, specific practices of automobility shift in relation to the ideology, framing how subjects respond to power or to other articulations of subjectivity, and ultimately, produce places. As an example of the work being done by humans, machines, and nature, I focus on the practice of four-wheeling done in Northern California along the Rubicon Trail, a historical, long unimproved road that is claimed to be the toughest in North America. Operating within the ideology of American automobility, four-wheelers have historically used the Rubicon Trail to make and reproduce a natural place that is connected to the use of machines. When such practices were threatened by environmental degradation, four-wheelers worked within environmentalist discourse, while maintaining a distinct subjectivity framed counter to that of an environmentalist, to ensure the continuation of use of the Rubicon Trail