Source depth estimation using multi-station waveform data

1984 ◽  
Vol 74 (5) ◽  
pp. 1623-1643
Author(s):  
Falguni Roy
Keyword(s):  
Depth Estimation ◽  
The United States ◽  
Digital Data ◽  
United States Geological Survey ◽  
Travel Times ◽  
Source Depth ◽  
Time Data ◽  
Waveform Data ◽  
Level Ii ◽  
Level I

Abstract A depth estimation procedure has been described which essentially attempts to identify depth phases by analyzing multi-station waveform data (hereafter called level II data) in various ways including deconvolution, prediction error filtering, and spectral analysis of the signals. In the absence of such observable phases, other methods based on S-P, ScS-P, and SKS-P travel times are tried to get an estimate of the source depth. The procedure was applied to waveform data collected from 31 globally distributed stations for the period between 1 and 15 October 1980. The digital data were analyzed at the temporary data center facilities of the National Defense Research Institute, Stockholm, Sweden. During this period, a total number of 162 events in the magnitude range 3.5 to 6.2 were defined by analyzing first arrival time data (hereafter called level I data) alone. For 120 of these events, it was possible to estimate depths using the present procedure. The applicability of the procedure was found to be 100 per cent for the events with mb > 4.8 and 88 per cent for the events with mb > 4. A comparison of level I depths and level II depths (the depths as obtained from level I and level II data, respectively) with that of the United States Geological Survey estimates indicated that it will be necessary to have at least one local station (Δ < 10°) among the level I data to obtain reasonable depth estimates from such data alone. Further, it has been shown that S wave travel times could be successfully utilized for the estimation of source depth.

Initial Approach to the Management of Multisystem Trauma

2019 ◽  
pp. 397-401
Author(s):  
David S. Morris
Keyword(s):  
Trauma Center ◽  
Injury Severity ◽  
Hospital Admissions ◽  
The United States ◽  
Emergency Department Visits ◽  
Severely Injured ◽  
Level Ii ◽  
Level I ◽  
Nonfatal Injuries ◽  
Injured Patients

Nearly 200,000 people die of injury-related causes in the United States each year, and injury is the leading cause of death for all patients aged 1 to 44 years. Approximately 30 million people sustain nonfatal injuries each year, which results in about 29 million emergency department visits and 3 million hospital admissions. Management of severely injured patients, typically defined as having an Injury Severity Score greater than 15 is best managed in a level I or level II trauma center. Any physician who provides care for critically ill patients should have a basic familiarity with the fundamentals of trauma care.

scholarly journals Patterns of Cervical Lymph Node Metastases in Primary and Recurrent Papillary Thyroid Cancer

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Neda Ahmadi ◽  
Ameet Grewal ◽  
Bruce J. Davidson
Keyword(s):  
Thyroid Cancer ◽  
Papillary Thyroid Cancer ◽  
Recurrent Disease ◽  
The United States ◽  
Common Type ◽  
Lateral Neck ◽  
Papillary Thyroid ◽  
Level Ii ◽  
Node Metastases ◽  
Level I

The incidence of thyroid cancer is rising in the United States with papillary thyroid cancer (PTC) being the most common type. We performed a retrospective study of 49 patients with PTC who underwent 57 lateral neck dissections (NDs). The extent of NDs varied, but 29 of 57 (51%) consisted of levels II–V. Twelve of 57 (21%) NDs consisted of levels I–V. Twelve of 57 (21%) NDs consisted of levels II–IV. One of 57 (1.8%) necks involved only levels I–IV. One of 57(1.8%) necks involved only levels I–V. One of 57(1.8%) necks involved only levels III–V. Two (3.5%) double-level (III–IV) neck surgeries were also performed. Metastatic PTC adenopathy was confirmed pathologically in 2%-level-I, 45%-level-II, 57%-level-III, 60%-level-IV, and 22%-level-V necks. Level-V was positive in 21% of primary and 24% of recurrent groups (). Comparing primary and recurrent disease, there was no difference in nodal distribution or frequency for levels I, II, III, and V. Level-IV was more common in the recurrent cases (). Based on the pathologic distribution of nodes, dissection should routinely include levels II–IV and extend to level-V in primary and recurrent cases. Our data does not suggest routine dissection of level-I.

Level II Neonatal Units

PEDIATRICS ◽  
1980 ◽  
Vol 66 (5) ◽  
pp. 810-811
Author(s):  
Alfred W. Brann ◽  
Robert T. Hall ◽  
Rita G. Harper ◽  
M. Jeffrey Maisels ◽  
Ronald L. Poland ◽  
...  
Keyword(s):  
Perinatal Outcome ◽  
Training Programs ◽  
The United States ◽  
Factual Information ◽  
American Academy Of Pediatrics ◽  
Level Ii ◽  
Canadian Provinces ◽  
Level I ◽  
Definition Of ◽  
Universal Solutions

The concept of a regionalized system encompassing three broadly defined levels of neonatal care is now well recognized and increasingly practiced in the United States. The American Academy of Pediatrics has described, in some detail, a system of classifying nurseries as Levels I, II, or III, based on the type of care they are capable of providing for the newborn infant.1 There has been little question about the composition of care in Level I or Level III units, but the committee recognizes that there is considerable diversity of opinion about the definition of Level II units and the functions these units should perform. The concept of the Level II neonatal unit has, in general, been supported by most pediatricians and neonatologists; however, there is little factual information available about Level II units, how they function, and how they contribute to perinatal outcome. The committee sent 300 questionnaires to the directors of all neonatal training programs, to the Chairmen of all Academy Chapters, and to 70 other practicing pediatricians. Responses were received from 114 Level III centers, 46 Level II centers, and 7 Level I hospitals. The responses came from 45 states and five Canadian provinces. According to the responses and the thoughtful comments received, the functions of Level II units are of considerable interest and concern to many pediatricians; but, obviously, it is impossible to suggest universal solutions for all regions which will cover all possible occurrences. The committee has considered all the opinions expressed and the information available regarding the functioning of Level II units and makes the following recommendations:

Motor Carrier Safety: Crash Patterns of Inspected Commercial Vehicles

2001 ◽  
Vol 1779 (1) ◽  
pp. 150-156 ◽  
Author(s):  
Piyushimita Thakuriah ◽  
George Yanos ◽  
Jung-Taek Lee ◽  
Athreya Sreenivasan
Keyword(s):  
Detection Rate ◽  
The United States ◽  
Motor Vehicles ◽  
Commercial Vehicles ◽  
Expected Number ◽  
Level Ii ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Violation Detection ◽  
Level I

A linked database comprising state and federal roadside inspection, crash, and firm records of commercial motor vehicles is described. This combined database links information on vehicles inspected in the state of Illinois to the crashes that these vehicles may have been involved in anywhere within the United States. Two issues are addressed: determination of the components of an inspection-violation detection rate and the relationship between inspections and crashes. The first issue involves an attempt to quantify the components of a violation detection rate. For the second issue, four separate research questions are posed. The results of the second component indicate that there is no evidence that a significant difference exists in the expected number of crashes in which vehicles incurring zero violations were involved compared with the expected number in which vehicles incurring one or more violations were involved. About 2 percent of all inspected vehicles, which incurred zero violations, were subsequently involved in crashes. With every increase in the number of violations, the percent of vehicles involved in crashes increases by about 0.04. Further, a smaller percentage of vehicles that incur zero violations in Level I inspections are subsequently involved in crashes, compared with vehicles incurring zero violations under all Level II and Level V inspections. Moreover, the rate of increase in the percent involvement in crashes is greatest for vehicles incurring a positive number of violations in Level I inspections compared with vehicles subject to other types of inspection.

scholarly journals An Overview of Trauma Center Levels and Disparities in Rural Trauma Care

2020 ◽  
Vol 10 ◽  
Author(s):  
Udit Dave ◽  
Brandon Gosine ◽  
Ashwin Palaniappan
Keyword(s):  
United States ◽  
Trauma Care ◽  
Rural Areas ◽  
The United States ◽  
Trauma Centers ◽  
Traumatic Injuries ◽  
Level Ii ◽  
Level I ◽  
Injured Patients

Trauma centers in the United States focus on providing care to patients who have suffered injuries and may require critical care. These trauma centers are classified into five different levels: Level I to Level V. Level V trauma centers are the least comprehensive, providing minimal 24-hour care and resuscitation, and Level I trauma centers are the most comprehensive, accepting the most severely injured patients and always delivering care through the use of an attending surgeon. However, there is a major inequity in access to trauma centers across the United States, especially amongst rural residents. Level III to Level V trauma centers tend to be dominantly situated in rural and underserved areas. Furthermore, trauma centers tend to be widely dispersed with respect to rural areas. Therefore, these areas tend to have a greater mortality rate in relation to traumatic injuries. Improvements in access to high-tier traumatic care must occur in order to reduce mortality due to traumatic injuries in underserved rural areas. Possible improvements to rural trauma care include bolstering the quality of care in Level III trauma centers, increasing Level II center efficiency through the involvement of orthopedic traumatologists, placing medical helicopter bases in more strategic locations that enable transport teams to reach other trauma centers faster, building more Level I and Level II trauma centers, and converting Level III centers into either Level I or Level II centers. 

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