United States Coast Guard Cutter Research Articles

A MultiScale Framework for Nonintrusive Load Identification

Nonintrusive load monitoring, i.e., the process of identifying individual load information from aggregate electrical measurements, is useful for a variety of smart grid applications including energy scorekeeping, condition monitoring, and activity tracking. Numerous load disaggregation algorithms have been used for nonintrusive monitoring. Many of these perform well only on certain datasets or load types, because transient electrical events can occur on vastly different time-scales and operating schedules with significantly different regularities. This paper presents a nonintrusive load monitoring framework that allows multiple algorithms to be used across multiple time-scales, with their outputs combined to enhance load recognition. Results are demonstrated with power system data from a United States Coast Guard Cutter (USCGC), demonstrating the utility of the framework for developing applications for condition-based maintenance, among other applications.

Enzyme-linked immunoelectrotransfer blot analysis of a cryptosporidiosis outbreak on a United States Coast Guard cutter.

Symptoms consistent with an outbreak of cryptosporidiosis (diarrhea, vomiting, nausea, and abdominal cramps) occurred on a U.S. Coast Guard cutter within 0-18 days after the cutter filled its tanks with Milwaukee, Wisconsin city water in March 1993. At three-weeks postdocking (PD), the suspected water was removed, and serum samples and stool specimens were collected from 47 of the 58 crew members, as well as questionnaire data on their water consumption and symptoms aboard the cutter. At 10-weeks PD and/or at 28-weeks PD, additional serum specimens were collected. Intensitometric data from enzyme-linked immunoelectrotransfer blot (EITB) were obtained on IgA responses to a 17-kD antigen group, IgM responses to a 27-kD antigen group, and IgG responses to 27-, 17-, and 15-kD antigen groups extracted from oocysts. In addition, IgG responses to crude oocyst antigens were obtained by ELISA. Based on reported symptoms, EITB results, and stool examination, the crew members were classified as confirmed (10), probable (10), suspected (22), and noncases (16). Of the 10 confirmed cases (all symptomatic) and the 10 probable cases (eight symptomatic) whose stools were positive and negative, respectively, for Cryptosporidium oocysts by microscopy, all showed changes in EITB intensities to the antigen groups and were considered EITB positive. The remaining 38 crew members, 22 suspected cases (all symptomatic), and 16 noncases (all asymptomatic), if tested, had negative stool examinations and were considered EITB negative. Of the 10 confirmed cases, only four showed a significant change in IgG responses (P < 0.05) between three-weeks PD and follow-up serum specimens by ELISA. Crew members considered confirmed cases consumed significantly more water (P < or = 0.005) aboard the cutter than noncases. Crew members considered EITB positive consumed more water (P < or = 0.04) than crew members considered EITB negative while there was no significant difference in water consumption (P > or = 0.19) between crew members considered ELISA positive and ELISA negative. Using the EITB, the observation of changes in intensity of IgA responses to the 17-kD antigen group, IgM responses to the 27-kD antigen group, and IgG responses to the 27- 17-, and 15-kD antigen groups from C. parvum oocysts between acute and convalescent serum specimens appears useful for immunodiagnosis of Cryptosporidium infection and for prospective epidemiologic studies designed to monitor infection risk.

The Northeast Water Polynya as an atmospheric CO2 sink: A seasonal rectification hypothesis

During the multidisciplinary ‘NEW92’ cruise of the United States Coast Guard Cutter (USCGC) Polar Sea to the recurrent Northeast Water (NEW) Polynya (77–81°N, 6–17°W; July–August 1992), total dissolved inorganic carbon and total alkalinity in the water column were measured with high precision to determine the quantitative impact of biological processes on the regional air‐sea flux of carbon. Biological processes depleted the total inorganic carbon of summer surface waters by up to 2 mol C m−2 or about 3%. On a regional basis this depletion correlated with depth‐integrated values of chlorophyll a, particulate organic carbon, and the inorganic nitrogen deficit. Replacement of this carbon through exchange with the atmosphere was stalled owing to the low wind speeds during the month of the cruise, although model calculations indicate that the depletion could be replenished by a few weeks of strong winds before ice forms in the autumn. These measurements and observations allowed formulation of a new hypothesis whereby seasonally ice‐covered regions like the NEW Polynya promote a unique biologically and physically mediated “rectification” of the typical (ice free, low latitude) seasonal cycle of air‐sea CO2 flux. The resulting carbon sink is consistent with other productivity estimates and represents an export of biologically cycled carbon either to local sediments or offshore. If this scenario is representative of seasonally ice‐covered Arctic shelves, then the rectification process could provide a small, negative feedback to excess atmospheric CO2.

Measurements of the summer surface heat budget of the Northeast Water Polynya in 1992

A research cruise of the United States Coast Guard Cutter Polar Sea to the Northeast Water Polynya (NEWP), off the eastern coast of Greenland (77–81°N, 6–17°W), was made from mid‐July to mid‐August of 1992 (NEWP '92) as the first field component of the multidisciplinary study of a high‐Arctic polynya. Instruments to measure the components of the surface heat budget of the polynya were installed on a foremast at the bow of the ship. Measurements of apparent wind speed and direction, air temperature and humidity, long‐ and short‐wave downwelling radiation were made, together with sea surface temperature. The surface heat budget of the polynya derived from these measurements is presented and is shown to be dominated by the net radiation, with a mean value of 133 W m−2, when calculated over the duration of the cruise. The short‐wave insolation was high during the days with clear skies, reaching over 500 W m−2 at noon and dropping to about 75 W m−2 during the sunlit, polar night, with a mean value of 197 W m−2. In comparison, the mean value of the incident long‐wave radiation is 267 W m−2. In general, the turbulent fluxes were negligible. The measured heat budget is compatible with the observed thermal structure in the surface layers of the polynya and the presumed ice melt during the summer season.

Preliminary results of a binational research cruise in the Western Arctic Ocean1

Abstract This paper is a condensed version of a report on the preliminary results of a research cruise under the direction of the U. S. Geological Survey, on board the United States Coast Guard Cutter Polar Star to Northwind Ridge and Canada Basin of the Western Arctic Ocean, during the period August 16‐September 15, 1993. Major objectives of the cruise were to: survey the geology of the North‐wind Ridge and Canada Basin; determine whether radionuclide contamination from disposal of solid and liquid nuclear wastes by the former Soviet Union in the Kara and Barents seas had penetrated the North American Arctic; acquire sediment cores in support of research on the history of glaciation in the region; and gain a better understanding of water structure and currents, sea‐ice physics, and sediment and nutrient transport.

Shipboard rest, sleep, and seasickness: Evidence of interaction

Sea‐keeping trials of a United States Coast Guard cutter included a human factors engineering evaluation having particular regard to problems of seasickness in certain work stations. Some motion sickness incidence and related data, and the derivation of human factors engineering principles therefrom, were reported in 1985 [A. C. Bittner, Jr. and J. C. Guignard, Nav. Eng. J. 97 (4), 207–213; 97 (5), 107–111]. Further analysis [A. C. Bittner, Jr. and J. C. Guignard, in Trends in Ergonomics/Human Factors V, edited by F. Aghazadeh (Elsevier, New York, 1988), pp. 529–539] showed that, contrary to traditional assumptions, seasickness is characterized by at least two functionally independent factors, identified as F1 (symptomatic general motion illness) and F2 (retching‐vomiting). It was shown that the validity of future sea trials requires: (a) multiple‐score scaling of motion sickness (e.g., using F1 and F2); (b) control of subject crew activity and movements about the ship during periods of observation; and (c) avoidance of steaming patterns that induce extraneous carryover effects. The present paper draws attention to an incidental finding concerning the influence of brief sleep and rest (lying down in the bunk) upon motion sickness susceptibility and recovery in the shipboard environment. Analyses of questionnaire data including amount and subjective quality of sleep showed that these were affected by the passage of time in an adverse (nauseogenic) motion environment, as has been observed generally in naval operations. An apparent ameliorative effect of unscheduled rest periods and naps upon susceptibility to adverse motion effects was incidentally detected and is commented upon in this report. [Observations made while the authors were at the Naval Biodynamics Laboratory, New Orleans.]