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Introduction: This paper seeks to identify which of three published formulas used for estimating the blood volume of normal human subjects correlates most closely with blood volumes measured in a published study where erythrocyte volume was determined by a method using 51Cr and a nonradioactive dye was used to determine the plasma volume. Methods: Blood volumes predicted by three published algorithms were compared with blood volume estimates from a study by Retzlaff et al. using the two-tailed Wilcoxon signed rank test and a robust version of the Bland–Altman test. Results: When applied to a sample of normal subjects selected from Mayo Clinic personnel and patients, the Nadler formula correlated more closely with blood volume measured using a radio nucleotide technique than did the Allen formula or one based on a saline haemodilution technique. Conclusions: The Nadler formula correlated more closely with blood volume measurements derived from Retzlaff's study than the other formulas for estimating blood volume in a population with height and weight distribution more consistent with that seen in North America. It should be used in preference to the Allen formula for estimating blood volume in adult patients currently undergoing cardiac surgical procedures. Saline haemodilution techniques used to measure blood volume require validation against more recently developed nuclear medicine techniques using statistical methods other than regression analysis. Until validated, they should be used with caution for estimating blood volume in adult patients currently undergoing cardiac surgical procedures. If a formula using height, weight and sex is used to estimate blood volume in the context of cardiac surgery, then it must be derived using a much more comprehensive sample of the population to which it is applied than has occurred to date. In particular, it should include broader distributions of height, weight and the presence or absence and type of significant valvular disease. [ABSTRACT FROM AUTHOR]

Beta-lactam allergy is reported in 5–10% of children in North America, but up to 94–97% of patients are deemed not allergic after allergist assessment. The utility of standardized skin testing for penicillin allergy in the pediatric population has been recently questioned. Oral drug challenges when appropriate, are preferred over skin testing, and can definitively rule out immediate, IgE-mediated drug allergy. To our knowledge, this is the only pediatric study to assess the reliability of a penicillin allergy stratification tool using a paper and electronic clinical algorithm. By using an electronic algorithm, we identified 61 patients (of 95 deemed not allergic by gold standard allergist decision) as low risk for penicillin allergy, with no false negatives and without the need for allergist assessment or skin testing. In this study, we demonstrate that an electronic algorithm can be used by various pediatric clinicians when evaluating possible penicillin allergy to reliably identify low risk patients. We identified the electronic algorithm was superior to the paper version, capturing an even higher percentage of low risk patients than the paper version. By developing an electronic algorithm to accurately assess penicillin allergy risk based on appropriate history, without the need for diagnostic testing or allergist assessment, we can empower non-allergist health care professionals to safely de-label low risk pediatric patients and assist in alleviating subspecialty wait times for penicillin allergy assessment. [ABSTRACT FROM AUTHOR]

This paper describes a new homogenization algorithm validation methodology, and its use to assess the skill of eight different algorithms, when applied to synthetic daily temperature time series. These algorithms were ACMANT, Climatol (in both daily and monthly configurations), DAP, HOM, MAC‐D, MASH and SpliDHOM. Algorithms were tested on benchmark data replicating daily temperature variability in four regions in North America: Wyoming, the South East, the North East and the South West. These benchmarks contained plausible spatial and temporal correlation, differing station densities and both abrupt and gradual inhomogeneities. Algorithm ability was assessed both according to detection of inhomogeneities and correction of their effects, investigating bias, root‐mean‐square error (RMSE), linear trend recovery, station extremes and variability recovery. Inhomogeneities with a magnitude greater than 1°C were those most commonly detected with smaller inhomogeneities, and those that were not constant over time, proving harder to identify. Regional RMSE was always reduced by all algorithms and regional bias was reduced in over half of the region/scenario pairs. Trend recovery was variable, but the correct sign of regional trends was retained by all algorithms. Areas for future algorithm improvement include working with autocorrelated data and correcting moments higher than the mean. The data are available from https://www.metoffice.gov.uk/hadobs/benchmarks and the validation code from https://github.com/RachelKillick/Daily%5fbenchmarks allowing the extension of this work and its application to new algorithms. [ABSTRACT FROM AUTHOR]

Maintaining an up-to-date repository of horizontal curve attributes is extremely important due to the role curves play in the safe operation of highways. Such attributes are typically collected using traditional surveying techniques which have been shown to be time-consuming, traffic disruptive, and potentially unsafe methods. This burden is further aggravated when the data collection is required on a large highway network across North America. To overcome this burden, this paper proposes a framework for network-level detection and extraction of horizontal curve elements from Light Detection and Ranging (LiDAR) data in a fully automated manner. The proposed technique was validated and then tested on LiDAR data collected on 242 km of highways in Alberta, Canada. The algorithm was successful in detecting all curves on the test highways and estimated their attributes with accuracies ranging from 96% to 100% demonstrating the robustness of the extraction method and the feasibility of performing the extraction on such a large scale. The proposed method is an alternative approach that could help transportation agencies maintain an updated inventory of horizontal alignment information on a large-scale. [ABSTRACT FROM AUTHOR]

Floating Catchment Area (FCA) methods are a popular tool to investigate accessibility to public facilities, in particular health care services. FCA approaches are attractive because, unlike other accessibility measures, they take into account the potential for congestion of facilities. This is done by 1) considering the population within the catchment area of a facility to calculate a variable that measures level of service, and then 2) aggregating the level of service by population centers subject to catchment area constraints. In this paper we discuss an effect of FCA approaches, an artifact that we term demand and level of service inflation. These artifacts are present in previous implementations of FCA methods. We argue that inflation makes interpretation of estimates of accessibility difficult, which has possible deleterious consequences for decision making. Next, we propose a simple and intuitive approach to proportionally allocate demandand and level of service in FCA calculations. The approach is based on a standardization of the impedance matrix, similar to approaches popular in the spatial statistics and econometrics literature. The result is a more intiuitive measure of accessibility that 1) provides a local version of the provider-to-population ratio; and 2) preserves the level of demand and the level of supply in a system. We illustrate the relevant issues with some examples, and then empirically by means of a case study of accessibility to family physicians in the Hamilton Census Metropolitan Area (CMA), in Ontario, Canada. Results indicate that demand and supply inflation/deflation affect the interpretation of accessibility analysis using existing FCA methods, and that the proposed adjustment can lead to more intuitive results. [ABSTRACT FROM AUTHOR]

Freely-available satellite data streams and the ability to process these data on cloud-computing platforms such as Google Earth Engine have made frequent, large-scale landcover mapping at high resolution a real possibility. In this paper we apply these technologies, along with machine learning, to the mapping of peatlands–a landcover class that is critical for preserving biodiversity, helping to address climate change impacts, and providing ecosystem services, e.g., carbon storage–in the Boreal Forest Natural Region of Alberta, Canada. We outline a data-driven, scientific framework that: compiles large amounts of Earth observation data sets (radar, optical, and LiDAR); examines the extracted variables for suitability in peatland modelling; optimizes model parameterization; and finally, predicts peatland occurrence across a large boreal area (397, 958 km2) of Alberta at 10 m spatial resolution (equalling 3.9 billion pixels across Alberta). The resulting peatland occurrence model shows an accuracy of 87% and a kappa statistic of 0.57 when compared to our validation data set. Differentiating peatlands from mineral wetlands achieved an accuracy of 69% and kappa statistic of 0.37. This data-driven approach is applicable at large geopolitical scales (e.g., provincial, national) for wetland and landcover inventories that support long-term, responsible resource management. [ABSTRACT FROM AUTHOR]

Model validation of power plant equipment is expected to be mandated imminently by the North American Electric Reliability Corporation. These standards will result in a great need for performing model validation for a large fleet of existing and future power plants. The historic approach to model validation of synchronous generators has typically been a battery of offline tests. In addition, the process of validation depends on a trial and error series of simulations, comparing the results of such simulations with measured test data, to gradually tend toward a validated model and its parameters. Such a method presents significant challenges for application on a large fleet of units. This paper documents a practical approach to model validation. The method is based on collecting online data from the generating unit, typically near or at base-load. Data are collected either from digital-fault recorders capturing system disturbances, or from digital excitation system for an imposed small voltage-reference step. The data are then used in a software tool to perform model validation using an automated optimization algorithm-–the entire process may be said to be semiautomated. The benefits are explained in the paper through actual examples of the application. [ABSTRACT FROM PUBLISHER]

Cellular location-based services need to use a variety of positioning methods to meet requirements on availability, response time, and accuracy. Due to the geometrical properties of the different positioning methods, the number of standardized reporting formats is large. Because the user requirements on the reporting formats are as scattered as the geometrical properties of the positioning methods, there is a need for shape conversion algorithms that transform between different formats. This paper discusses a case that transforms between a polygon and an ellipse while preserving the confidence between the two shapes. The transformation is required for emergency positioning outside North America, and when fingerprinting, localization is used in the Global System for Mobile Communications (GSM). The algorithm has a number of technically interesting properties, e.g., with regard to the selection of the optimization criterion and the fact that the solution is computed by an analytical solution of a cubic equation. [ABSTRACT FROM PUBLISHER]

The planned simultaneous availability of visible and near-IR observations from the geostationary platforms of Tropospheric Emissions: Monitoring of Pollution (TEMPO) and Geostationary Operational Environmental Satellites (GOES) 16/17 Advanced Base Imager (ABI) will present the opportunity of deriving an accurate aerosol product taking advantage of both ABI's high spatial resolution in the visible range and TEMPO's sensitivity to aerosol absorption in the near-UV range. Because the wavelengths of ABI are similar to those of the Moderate Resolution Imaging Spectroradiometer (MODIS), existing aerosol algorithms of MODIS can be applied to ABI observations. In this work, we evaluate three distinct aerosol algorithms of MODIS deriving aerosol optical thickness (AOT) over land surfaces using visible and near-IR observations. The Dark Target (DT), Deep Blue (DB), and Multiangle Implementation of Atmospheric Correction (MAIAC) algorithms are all applied to the radiance measurements of MODIS on board the Aqua satellite. We have evaluated each algorithm by comparing the satellite-retrieved AOT to space-time collocated ground-based sun photometer measurements of the same parameter at 171 sites of the Aerosol Robotic Network (AERONET) over North America (NA). A spatiotemporal scheme collocating the satellite retrievals with the ground-based measurements was applied consistently to all three retrieval datasets. We find that the statistical performance of all three algorithms is comparable over darker surfaces over eastern NA with the MAIAC algorithm providing relatively better comparison over western NA sites characterized by inhomogeneous elevation and bright surfaces. The higher spatial resolution of the MAIAC product (1 km) allows a substantially larger number of matchups than DB 10 km and DT 10 km (DT 3 km) products by 115 % and 120 % (86 %), respectively, over eastern NA and by 150 % and 220 % (197 %) over western NA. The characterization of the error in AOT for the three aerosol products as a function of bidirectional surface reflectance derived from both MAIAC and an independent MOD09 atmospheric correction shows a systematic positive bias in DT retrievals over brighter surfaces, whereas DB and MAIAC retrievals show no such bias throughout the wide range of surface brightness, with MAIAC offering the lowest spread in errors. The results reported here represent an objective, unbiased evaluation of existing over-land aerosol retrieval algorithms of MODIS. The detailed statistical evaluation of the performance of each of these three algorithms may be used as guidance in the development of inversion schemes to derive aerosol properties from ABI or other MODIS-like sensors. [ABSTRACT FROM AUTHOR]

Vehicular ad Hoc networks (VANETs) support a variety of applications ranging from critical safety applications to "infotainment" or "comfort" applications. In North America, 75 MHz of the spectrum in the 5.9 GHz band has been allocated for vehicular communication. Safety applications rely on event-driven "alert" messages as well as the periodic broadcast of Basic Safety Messages (BSMs) containing critical information, e.g., position, speed, and heading from participating vehicles. The limited channel capacity and high message rates needed to ensure an adequate level of awareness make the reliable delivery of BSMs a challenging problem for VANETs. In this paper, we propose a decentralized congestion control algorithm that uses variable transmission power levels to reduce the channel busy ratio while maintaining a high level of awareness for nearby vehicles. The simulation results indicate that the proposed approach is able to achieve a suitable balance between awareness and bandwidth usage. [ABSTRACT FROM AUTHOR]

Current fed parallel resonant electronic ballast (PREB) dominates the applications for the T8 fluorescent lamp in North America for its advantage of low cost, flexibility and high reliability. At fault condition, a PREB generates much heat externally, and it is difficult to provide fault protection with traditional approaches. In this paper, a digital solution is presented to detect universal fault condition in PREB without sacrificing its other advantages. Operational principal of PREB is explored to show that the load impedance disturbance in PREB leads to frequency perturbation of the inverter, which can be detected with a very simple and low cost digital device for fault detection. Experiments show that this frequency diagnostic provides very sensitive and reliable fault detection for PREB. With both end-of-life lamp and anti-arcing protections implemented with one algorithm, this technology provides a superior fault protection to one of the most widely used ballast topologies and extends the potential applications of PREB in modern lighting industry. [ABSTRACT FROM AUTHOR]

Allelic variation within individuals holds information regarding the relationships of organisms, which is expected to be particularly important for reconstructing the evolutionary history of closely related taxa. However, little effort has been committed to incorporate such information for reconstructing the phylogeny of organisms. Haplotype trees represent a solution when one nonrecombinant marker is considered, but there is no satisfying method when multiple genes are to be combined. In this paper, we propose an algorithm that converts a distance matrix of alleles to a distance matrix among organisms. This algorithm allows the incorporation of allelic variation for reconstructing the phylogeny of organisms from one or more genes. The method is applied to reconstruct the phylogeny of the seven native diploid species of Rosa sect. Cinnamomeae in North America. The glyceralgehyde 3-phosphate dehydrogenase ( GAPDH ), the triose phosphate isomerase ( TPI ), and the malate synthase ( MS ) genes were sequenced for 40 individuals from these species. The three genes had little genetic variation, and most species showed incomplete lineage sorting, suggesting these species have a recent origin. Despite these difficulties, the networks (NeighborNet) of organisms reconstructed from the matrix obtained with the algorithm recovered groups that more closely match taxonomic boundaries than did the haplotype trees. The combined network of individuals shows that species west of the Rocky Mountains, Rosa gymnocarpa and R. pisocarpa , form exclusive groups and that together they are distinct from eastern species. In the east, three groups were found to be exclusive: R. nitida – R. palustris , R. foliolosa , and R. blanda – R. woodsii . These groups are congruent with the morphology and the ecology of species. The method is also useful for representing hybrid individuals when the relationships are reconstructed using a phylogenetic network. [Allelic variation; gene tree–species tree; haplotype trees; hybridization; incomplete lineage sorting; phylogenetic networks; Rosa ; total evidence.] [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the influence of tropical sea surface temperature (SST) on the midlatitude circulation regime behavior in the Pacific–North American region. Toward this end, a cluster analysis has been applied to 55-member ensembles of winter seasonal simulations of the Center for Ocean–Land–Atmosphere Studies general circulation model for 18 winters. The ensemble members for each winter utilize the same prescribed, observed weekly varying SST for that winter. The cluster analysis includes all fluctuations with time scales longer than 10 days except for the ensemble mean seasonal cycle. Using a partitioning algorithm separately applied to each winter's ensemble, clusters are found in the 200-hPa height field that are signicant (vis-à-vis a suitable Gaussian background), reproducible (in half-length datasets), and consistent (with clusters obtained from the 200-hPa u wind) for all winters except the strong El Niño events of 1982/83, 1986/87, and 1997/98. One cluster found consistently in many winters, consisting of a strong ridge over the Alaskan region and a trough over central North America, is quite similar to the Alaskan pattern identified from observations as being particularly difficult to predict and that occurs preferentially during La Niña events. Two other clusters found in many winters have no observational counterparts. A regime that is very similar to the seasonal mean response to cold tropical Pacific SSTs is seen during several La Niña winters. A strong negative correlation between a measure of the strength of the clustering and the Niño-3 SST index is found. That this correlation is as strong as the correlation between the seasonal mean response and the same SST index indicates that the El Niño–Southern Oscillation–related SSTs affect the regime structure of intraseasonal flow as strongly as they do the mean state. [ABSTRACT FROM AUTHOR]

The tribe Plantagineae (Lamiales) is a group of plants with worldwide distribution, notorious for its complicated taxonomy and still unresolved natural history. We describe the result of a broadly sampled phylogenetic study of tribe. The expanded sampling dataset is based on the trnL-F spacer, rbcL, and ITS2 markers across all three included genera (Aragoa, Littorella and Plantago) and makes this the most comprehensive study to date. The other dataset uses five markers and provides remarkably good resolution throughout the tree, including support for all of the major clades. In addition to the molecular phylogeny, a morphology database of 114 binary characters was assembled to provide comparison with the molecular phylogeny and to develop a means to assign species not sampled in the molecular analysis to their most closely related species that were sampled. Based on the molecular phylogeny and the assignment algorithm to place unsampled species, a key to sections is presented, and a revised classification of the tribe is provided. We also include the description of new species from North America. [ABSTRACT FROM AUTHOR]

Satellite data from the Advanced Very High Resolution Radiometer (AVHRR) have been widely employed for fire monitoring around the world by virtue of the thermal emission in the middle-infrared (mid-IR) channel at 3.7 μm. This channel, however, receives both thermal emission and solar reflection. As far as fire detection is concerned, the solar reflection contaminates the fire emission signal, which can cause significant errors, especially over non-forest biomes. This study presents a method to detect and eliminate the significant contribution of solar reflection to the AVHRR mid-IR band so that the fire detection accuracy is improved. AVHRR data from April to November 2004 were analysed. Twenty-seven percent of commission errors, mainly located in the southwestern part of North America, were found to be caused by the strong solar reflection from the surface. We also found that the calculated solar reflection itself is an effective indicator of false detections for the AVHRR. Introducing a new test to take into account this effect leads to a considerable reduction in commission errors. The new filter can eliminate most commission errors at the expense of minor increases in omission errors. The total number of true fires is missed by 0.3%, and the total number of false fire detections is reduced by 27.1%. [ABSTRACT FROM AUTHOR]

1. Tracking insect migration at continental scales is intractable using exogenous markers because of tiny body size and high improbability of recapture. Naturally occurring endogenous isotopic markers, such as tissue δ2H and δ18O, are a means of assigning origins to both vertebrate and invertebrate populations, but the success depends upon derivation of a robust algorithm linking measured tissue isotope values with large-scale geospatial isotopic patterns (isoscapes) in the terrestrial hydrosphere. 2. We derived a North American dragonfly wing δ2H and δ18O isoscape from known-origin dragonflies of three species ( Aeshna interrupta, Aeshna umbrosa and Pachydiplax longipennis) obtained across North America. A strong relationship ( r2 = 0·75) was found between wing δ2H and hydrologic geospatial δ2H patterns, and between wing δ2H and δ18O ( r2 = 0·92). The strong coupling between emergent insect tissue and hydrologic spatial patterning suggested that this dragonfly isoscape may be applicable to other aquatic emergent migratory insects in North America and elsewhere. 3. As a proof of concept, we used the wing isoscape algorithm to map the probability of natal origin of Common Green Darners ( Anax junius) migrating through southern Texas. Results showed that these Texan dragonflies were a mix of local and far-distant migrant (e.g. northern United States) individuals. We suggest that this isoscape algorithm opens new opportunities to quantify the migration and natal origins of dragonflies and other aquatic emergent insects where conventional methods have failed. [ABSTRACT FROM AUTHOR]

Background: The Brown Marmorated Stink Bug (BMSB), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), native to Asia, is becoming an invasive species with a rapidly expanding range in North America and Europe. In the US, it is a household pest and also caused unprecedented damage to agriculture crops. Exploring its climatic limits and estimating its potential geographic distribution can provide critical information for management strategies. Methodology/Principals: We used direct climate comparisons to explore the climatic niche occupied by native and invasive populations of BMSB. Ecological niche modelings based on the native range were used to anticipate the potential distribution of BMSB worldwide. Conversely, niche models based on the introduced range were used to locate the original invasive propagates in Asia. Areas with high invasion potential were identified by two niche modeling algorithms (i.e., Maxent and GARP). Conclusions/Significance: Reduced dimensionality of environmental space improves native model transferability in the invade area. Projecting models from invasive population back to native distributional areas offers valuable information on the potential source regions of the invasive populations. Our models anticipated successfully the current disjunct distribution of BMSB in the US. The original propagates are hypothesized to have come from northern Japan or western Korea. High climate suitable areas at risk of invasion include latitudes between 30°-50° including northern Europe, northeastern North America, southern Australia and the North Island of New Zealand. Angola in Africa and Uruguay in South America also showed high climate suitability. [ABSTRACT FROM AUTHOR]

Recent changes in pan-arctic land-surface hydrology may significantly affect ecosystems and the built environment. While spatial and temporal patterns in land-surface hydrology trends can be identified using in situ observations of river discharge, the existing studies of cold-season river discharge are often inconsistent and incomparable because they use different methodologies, time periods and geographic regions. By using a comprehensive dataset of river discharge and a trend analysis applying one algorithm over a range of temporal and spatial scales, a synthesis of pan-arctic cold-season low-flow was performed. Cold-season low-flow is increasing over most of the pan-arctic, with decreasing flow in eastern North America and unchanged flow in small basins in the late twentieth century in eastern Eurasia as the main exceptions. This study provides the first synthesis of spatially distributed cold-season low-flow trends in the pan-arctic and indicates that widespread changes in pan-arctic subsurface hydrology are occurring. [ABSTRACT FROM AUTHOR]

Because of a lack of regular, direct measurements, limited information is available about the frequency and the spatial and temporal distribution of icing conditions aloft, including supercooled large drops (SLD). Research aircraft provide in situ observations of these conditions, but the sample set is small and can be biased. Surface observations of freezing fog and freezing precipitation provide additional insight, but cannot be used alone to assess the presence of icing aloft. Climatologies based solely on such observations can underestimate their presence in areas where subfreezing temperatures are uncommon. Other techniques can be used in an effort to reduce some of these biases and limitations. Expanding upon results for North America reported in Part I, the frequencies of icing and SLD over Europe and Asia are inferred here using 1) surface weather observations in conjunction with vertical profiles of temperature and moisture and 2) model reanalyses of temperature and moisture. Icing maxima and minima are found to migrate seasonally, both geographically and in the vertical, and to vary in their intensity. They are linked to the location of common storm tracks and other forcing, such as that associated with sloped terrain. After establishing reasonable consistency between the methods over data rich regions, the model analyses are used to examine icing frequencies over the remainder of the globe. [ABSTRACT FROM AUTHOR]

An algorithm ( Weather Reader) was developed and used to analyze daily weather records from all existing Canadian and American weather stations of eastern North America (in excess of 2100 stations), from 1930 through 2000. Specifically, the Weather Reader was used to compile daily minimum, mean, and maximum air temperatures for weather stations with at least 30 years of data, and was used to calculate accumulated degree days for winter thaw–freeze events relevant to yellow birch ( Betula alleghaniensis Britt.) from beginning to end. A thaw–freeze event relevant to yellow birch was considered to take place when (i) the station daily maximum temperature reached or exceeded +4°C after being below freezing for at least 2 months of the winter, (ii) sufficient growing degree days accumulated (>50 growing degree days) to cause the affected yellow birch trees to prematurely deharden, and (iii) the daily minimum temperature dropped below −4°C causing roots and/or shoots of dehardened trees to experience freeze-induced injury and possibly dieback. The threshold temperature of +4°C represents the daily temperature above which biological activity occurs in yellow birch. The station growing degree day summaries were subsequently spatially interpolated with the Kriging function in GS+™ and mapped in ArcView™ GIS in order to display the geographic extent of the most severe thaw–freeze events. The ArcView™ maps were then compared with the extent of historically observed yellow birch decline. It was found that the years 1936, 1944, and 1945 were particularly uncharacteristic in terms of region-wide winter thaw–freeze extremes, and also in terms of observed birch decline events during 1930–1960. An overlay of suspected accumulated birch decline based on thaw–freeze mapping and observed decline maps prepared by , and for 1930–1960 demonstrated similar geographic patterns. The thaw–freeze projection for 1930–1960 was shown to coincide with 83% of the birch decline map appearing in and 55% of the geographic range of yellow birch in eastern North America. Thaw–freeze mapping was also applied to two significant events in 1981. Greatest impact was recorded to occur mostly in southern Quebec and Ontario, and several American Great Lake States, specifically in northern Michigan and New York, where the greatest growing degree day accumulation prior to refreeze in late February (February 28th) was projected to have occurred; and in southern Quebec, most of Atlantic Canada, and Maine, prior to a late spring frost in mid-April (April 17). [ABSTRACT FROM AUTHOR]

Spectrum sensing for the use of TV spectrum in North America is addressed in this paper. A unified signature-based spectrum sensing algorithm is designed for the primary licensed signals including NTSC analog TV and ATSC digital TV signals. In addition, an autocorrelation-based spectrum sensing algorithm is proposed for the secondary licensed signals such as wireless microphone signals. To our knowledge, the spectrum sensing algorithms presented in this paper are the first one which can reliably determine the availability of a TV channel for unlicensed radio transmissions in the presence of a strong adjacent channel interferer and the target signal strength is as low as -114 dBm. [ABSTRACT FROM AUTHOR]