Landsat Satellite Image Segmentation Using the Fuzzy ARTMAP Neural Network

This application illustrates how the fuzzy ARTMAP neural network can be used to monitor environmental changes. A benchmark problem seeks to classify regions of a Landsat image into six soil and crop classes based on images from four spectral sensors. Simulations show that fuzzy ARTMAP outperforms fourteen other neural network and machine learning algorithms. Only the k-Nearest-Neighbor algorithm shows better performance (91% vs. 89%) but without any code compression, while fuzzy ARTMAP achieves a code compression ratio of 6:1. Even with a code compression ratio of 50:1 fuzzy ARTMAP still maintains good performance (83%). This example shows how fuzzy ARTMAP can combine accuracy and code compression in real-world applications.Office of Naval Research (N00014-92-J-401J, N00014-91-J-4100, N00014-92-J-4015); National Science Foundation (IRI 90-00530

Landsat Satellite Image Segmentation Using the Fuzzy ARTMAP Neural Network

This application illustrates how the fuzzy ARTMAP neural network can be used to monitor environmental changes. A benchmark problem seeks to classify regions of a Landsat image into six soil and crop classes based on images from four spectral sensors. Simulations show that fuzzy ARTMAP outperforms fourteen other neural network and machine learning algorithms. Only the k-Nearest-Neighbor algorithm shows better performance (91% vs. 89%) but without any code compression, while fuzzy ARTMAP achieves a code compression ratio of 6:1. Even with a code compression ratio of 50:1 fuzzy ARTMAP still maintains good performance (83%). This example shows how fuzzy ARTMAP can combine accuracy and code compression in real-world applications.Office of Naval Research (N00014-92-J-401J, N00014-91-J-4100, N00014-92-J-4015); National Science Foundation (IRI 90-00530

Fusion Artmap: A Neural Network Architecture for Multi-Channel Data Fusion and Classification

Fusion ARTMAP is a self-organizing neural network architecture for multi-channel, or multi-sensor, data fusion. Single-channel Fusion ARTMAP is functionally equivalent to Fuzzy ART during unsupervised learning and to Fuzzy ARTMAP during supervised learning. The network has a symmetric organization such that each channel can be dynamically configured to serve as either a data input or a teaching input to the system. An ART module forms a compressed recognition code within each channel. These codes, in turn, become inputs to a single ART system that organizes the global recognition code. When a predictive error occurs, a process called paraellel match tracking simultaneously raises vigilances in multiple ART modules until reset is triggered in one of them. Parallel match tracking hereby resets only that portion of the recognition code with the poorest match, or minimum predictive confidence. This internally controlled selective reset process is a type of credit assignment that creates a parsimoniously connected learned network. Fusion ARTMAP's multi-channel coding is illustrated by simulations of the Quadruped Mammal database.Defense Advanced Research Projects Agency (ONR N0014-92-J-401J, AFOSR 90-0083, ONR N00014-92-J-4015); National Science Foundation (IRI-90-00530, IRI-90-24877, Graduate Fellowship); Office of Naval Research (N00014-91-J-4100); British Petroleum (89-A-1204); Air Force Office of Scientific Research (F49620-92-J-0334

Fusion ARTMAP: An Adaptive Fuzzy Network for Multi-Channel Classification

Fusion ARTMAP is a self-organizing neural network architecture for multi-channel, or multi-sensor, data fusion. Fusion ARTMAP generalizes the fuzzy ARTMAP architecture in order to adaptively classify multi-channel data. The network has a symmetric organization such that each channel can be dynamically configured to serve as either a data input or a teaching input to the system. An ART module forms a compressed recognition code within each channel. These codes, in turn, beco1ne inputs to a single ART system that organizes the global recognition code. When a predictive error occurs, a process called parallel match tracking simultaneously raises vigilances in multiple ART modules until reset is triggered in one of thmn. Parallel match tracking hereby resets only that portion of the recognition code with the poorest match, or minimum predictive confidence. This internally controlled selective reset process is a type of credit assignment that creates a parsimoniously connected learned network.Advanced Research Projects Agency (ONR N00014-92-J-401J, ONR N00014-92-J-4015); National Science Foundation (IRI-90-00530, IRI-90-24877, Graduate Fellowship); Office of Naval Research (N00014-91-J-4100); British Petroleum (89-A-1204); Air Force Office of Scientific Research (F49620-92-J-0334

Corridors of Clarity: Four Principles to Overcome Uncertainty Paralysis in the Anthropocene

Global environmental change challenges humanity because of its broad scale, long-lasting, and potentially irreversible consequences. Key to an effective response is to use an appropriate scientific lens to peer through the mist of uncertainty that threatens timely and appropriate decisions surrounding these complex issues. Identifying such corridors of clarity could help understanding critical phenomena or causal pathways sufficiently well to justify taking policy action. To this end, we suggest four principles: Follow the strongest and most direct path between policy decisions on outcomes, focus on finding sufficient evidence for policy purpose, prioritize no-regrets policies by avoiding options with controversial, uncertain, or immeasurable benefits, aim for getting the big picture roughly right rather than focusing on details

Exit time as a measure of ecological resilience

Ecological resilience is the magnitude of the largest perturbation from which a system can still recover to its original state. However, a transition into another state may often be invoked by a series of minor synergistic perturbations rather than a single big one. We show how resilience can be estimated in terms of average life expectancy, accounting for this natural regime of variability. We use time series to fit a model that captures the stochastic as well as the deterministic components. The model is then used to estimate the mean exit time from the basin of attraction. This approach offers a fresh angle to anticipating the chance of a critical transition at a time when high-resolution time series are becoming increasingly available.</p

Nonpoint pollution of surface waters with phosphorus and nitrogen

Agriculture and urban activities are major sources of phosphorus and nitrogen to aquatic ecosystems. Atmospheric deposition further contributes as a source of N. These nonpoint inputs of nutrients are difficult to measure and regulate because they derive from activities dispersed over wide areas of land and are variable in time due to effects of weather. In aquatic ecosystems, these nutrients cause diverse problems such as toxic algal blooms, loss of oxygen, fish kills, loss of biodiversity (including species important for commerce and recreation), loss of aquatic plant beds and coral reefs, and other problems. Nutrient enrichment seriously degrades aquatic ecosystems and impairs the use of water for drinking, industry, agriculture, recreation, and other purposes. Based on our review of the scientific literature, we are certain that (1) eutrophication is a widespread problem in rivers, lakes, estuaries, and coastal oceans, caused by overenrichment with P and N; (2) nonpoint pollution, a major source of P and N to surface waters of the United States, results primarily from agriculture and urban activity, including industry; (3) inputs of P and N to agriculture in the form of fertilizers exceed outputs in produce in the United States and many other nations; (4) nutrient flows to aquatic ecosystems are directly related to animal stocking densities, and under high livestock densities, manure production exceeds the needs of crops to which the manure is applied; (5) excess fertilization and manure production cause a P surplus to accumulate in soil, some of which is transported to aquatic ecosystems; and (6) excess fertilization and manure production on agricultural lands create surplus N, which is mobile in many soils and often leaches to downstream aquatic ecosystems, and which can also volatilize to the atmosphere, redepositing elsewhere and eventually reaching aquatic ecosystems. If current practices continue, nonpoint pollution of surface waters is virtually certain to increase in the future. Such an outcome is not inevitable, however, because a number of technologies, land use practices, and conservation measures are capable of decreasing the flow of nonpoint P and N into surface waters. From our review of the available scientific information, we are confident that: (1) nonpoint pollution of surface waters with P and N could be reduced by reducing surplus nutrient flows in agricultural systems and processes, reducing agricultural and urban runoff by diverse methods, and reducing N emissions from fossil fuel burning; and (2) eutrophication can be reversed by decreasing input rates of P and N to aquatic ecosystems, but rates of recovery are highly variable among water bodies. Often, the eutrophic state is persistent, and recovery is slow

Testing a Novel Manual Communication System for Mechanically Ventilated ICU Patients

Introduction: Available communication methods for intubated patients in the ICU are insufficient to meet patient needs. Both ICU patients and their care providers report broadly unsuccessful communication attempts, resulting in less effective medical care and undue stress1,2. Use of existing methods - including letter boards, writing, and mouthing words - for mechanically ventilated (MV) patients has led to a consensus that new methods are required3. We report on the testing of a new system designed to address the communication needs of MV patients that is currently being tested in a low- to medium- acuity surgical ICU4. Methods: We have developed several generations of prototypes designed to address patient communication needs. Design of this device has focused on ICU-specific communication needs, including ICU-specific content, infection control, simple design, and capitalizing on motor movements that can be easily performed by most ICU patients. Initial testing, starting with non-MV patients able to give more detailed feedback, has begun in a low- to medium- acuity surgical ICU. Recently developed prototypes combine custom-built tablet software, focusing on the needs that nurses believe patients wish to express in the ICU setting, with a newly designed manually operated access device. The system produces visual and auditory output to allow patients to answer basic questions and effectively convey information. Results: Initial patient impressions are encouraging, particularly among patients who have recently experienced mechanical ventilation. Many patients are unfamiliar with tablet software or struggle with manual dexterity required to access the tablet screen directly, further indicating the need for an external access method as part of the system. The content suggested by nurses via a previously conducted survey has been confirmed by patients as relevant to their experience. Conclusions: A novel manually operated communication system has elicited both positive reviews and helpful feedback from patients

Principles of Augmentative and Alternative Communication System Design in the ICU Setting

Introduction: The ICU as a technology design setting requires specific and thoughtful awareness of patient-, caregiver-, and environment-related constraints. Designing an ICU-specific communication system involves an even deeper understanding of patient needs and desires, building on existing work exploring available technologies for use in this setting1,2. We report our initial experience from a pilot study with a novel communication device engineered specifically to allow mechanically ventilated ICU patients to communicate with caregivers3. Methods: We used a validated survey for nurses about communication purposes to explore relevant beliefs, attitudes, and desires of nurses4. Existing technologies available for communication assistance in the ICU – e.g., letter boards, writing on paper, and mouthing words – were analyzed. Suggestions about the content for an eventual communication system were collected. ICU-specific design requirements were noted, including adherence to infection control standards, accessibility to restrained patients, and availability to patients with motor weakness, contractures, edema, tremor, and/or neuropathy. In addition, the system must include a minimal learning curve, Results: Initial testing in the ICU has revealed additional considerations for technology design. For instance, many patients have visual impairments, so displays should be large and high-contrast. Furthermore, patients benefit from a very short teaching/demo process due to their short attention span. Additionally, leveraging interfaces with significant similarities to everyday systems appears to reduce confusion. Nurses also mentioned that the system should be accessible to at least some non-English-speaking patients. Finally, physical deficits that ICU patients experience require that manually operated devices be as flexible as possible in terms of type of manipulation required. Conclusions: ICU patients are in significant need of communication systems that meet their unique needs. Building such a system requires awareness of many different constraints, including both general heterogeneity of patient needs and capabilities and the constraints of the ICU setting itself