Safety reviews of existing roads are becoming a popular practice of many agencies nationally and internationally. Knowing road safety information is of great importance to both policymakers in addressing safety concerns and travelers in managing their trips. There have been various efforts in developing methodologies to measure and assess road safety in an effective manner. However, the existing research and practices are still constrained by their subjective and reactive nature. The goal of this research is to develop a framework of Road Risk Indices (RRIs) to assess road risks of existing highway infrastructure for both road users and agencies based on road geometrics, traffic conditions, and historical crash data. The proposed RRIs are intended to give a comprehensive and objective view of road safety, so that safety problems can be identified at an early stage before they rise in the form of accidents. A methodological framework of formulating RRIs that integrates results from crash prediction models and historical crash data is proposed, and Linear Referencing tools in the ArcGIS software are used to develop digital maps to publish estimated RRIs. These maps provide basic Geographic Information System (GIS) functions, including viewing and querying RRIs, and performing spatial analysis tasks. A semi-parameter count model and quantile regression based estimation are proposed to capture the specific characteristics of crash data and provide more robust and accurate predictions on crash counts. Crash data collected on Interstate Highways in Washington State for the year 2002 was extracted from the Highway Safety Information System (HSIS) and used for the case study. The results from the case study show that the proposed framework is capable of capturing statistical correlations between traffic crashes and influencing factors, leading to the effective integration of safety information in composite indices. / text

Feedback control of Chest Acceleration or Chest Deflection is believed to be a good way of minimizing the risk of injury. In order to implement such a controller in a car, an observer estimating these responses is needed. The objective of the study was to develop a model of the dummy’s chest capable of estimating the Chest Acceleration and the Chest Deflection during frontal crashes in real time. The used sensor data come from car accelerometer and spindle rotation sensor of the belt, the data has been collected from dummies during crash tests. This study has accomplished the aims using a simple linear model of the chest using masses, springs and dampers. The parameters of the model have been estimated through system identification. Two types of black-box models have also been studied, one ARX model and one state-space model. The models have been tested and validated against data coming from different crash setups. The results show that all of the studied models can be used to estimate the dummy responses, the physical grey-box model and the black-box state-space model in particular. / Genom att använda återkoppling av storheterna bröstacceleration och bröstintryck antas man kunna minska risken för skador vid krockar i personbilar. För att kunna implementera detta behövs en observatör för dessa storheter. Målet med denna studie är att ta fram en modell för att kunna skatta accelerationen i bröstkorgen samt bröstintrycket i realtid i frontala krockar. Sensordata som använts kom från en accelerometer och en givare för att mäta rotationen i bältessnurran. Detta har gjorts genom att modellera bröstkorgen med linjära fjädrar och dämpare. Dess parametrar har skattats från data från krocktester från krockdockor. Två s.k. black-box-modeller har också tagits fram, en ARX-modell och en på tillståndsform. Modellerna har testats och validerats mha data från olika sorters krocktester. Resultaten visar att alla studerade modeller kan användas för att skatta de ovan nämnda storheterna, den fysikaliska modellen och black-box-modellen på tillståndsform fungerade bäst.

Objectives This thesis is based on 4 papers that were all written with the same intent, which was to describe and demonstrate how epidemiologic concepts and data can serve as a basis for improved validity of probabilistic conclusions in forensic medicine (FM). Conclusions based on probability are common in FM, and the validity of probabilistic conclusions is dependant on their foundation, which is often no more than personal experience. Forensic epidemiology (FE) describes the use and application of epidemiologic methods and data to questions encountered in the practice of FM, as a means of providing an evidence-based foundation, and thus increased validity, for certain types of opinions. The 4 papers comprising this thesis describe 4 unique applications of FE that have the common goal of assessing probabilities associated with evidence gathered during the course of the investigation of traumatic injury and death.   Materials and Methods Paper I used a case study of a fatal traffic crash in which the seat position of the surviving occupant was uncertain as an example for describing a probabilistic approach to the investigation of occupant position in a fatal crash. The methods involved the matching of the occupants’ injuries to the vehicular and crash evidence in order to assess the probability that the surviving occupant was either the driver or passenger of the vehicle at the time of the crash. In the second and third papers, epidemiologic data pertaining to traffic crash-related injuries from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) was used to assess the utility and strength of evidence, such as vehicle deformation and occupant injury of a particular severity and pattern, as a means of assessing the probability of an uncertain issue of interest. The issue of interest in Paper II was the seat position of the occupant at the time of a rollover crash (similar to Paper I), and the association that was investigated was the relationship between the degree of downward roof deformation and likelihood of a serious head and neck injury in the occupant. The analysis was directed at the circumstance in which a vehicle has sustained roof deformation on one side but not the other, and only one of the occupants has sustained a serious head or neck injury. In Paper III the issue of interest was whether an occupant was using a seat belt prior to being ejected from a passenger vehicle, when there was evidence that the seat belt could have unlatched during a crash, and thus it was uncertain whether the occupant was restrained and then ejected after the seat belt unlatched, or unrestrained. Of particular interest was the relative frequency of injury to the upper extremity closest to the side window (the outboard upper extremity [OUE]), as several prior authors have postulated that during ejection when the seat belt has become unlatched the retracting seat belt would invariably cinch around the OUE and cause serious injury. In Paper IV the focus of the analysis was the predictability of the distribution of skull and cervical spine fractures associated with fatal falls as a function of the fall circumstances. Swedish autopsy data were used as the source material for this study. Results In Paper I the indifferent pre-crash probability that the survivor was the driver (0.5) was modified by the evidence to arrive at a post-test odds of 19 to 1 that he was driving. In Paper II NASS-CDS data for 960 (unweighted) occupants of rollover crashes were included in the analysis. The association between downward roof deformation and head and neck injury severity (as represented by a composite numerical value [HNISS] ranging from 1 to 75) was as follows: for each unit increase of the HNISS there were increased odds of 4% that the occupant was exposed to >8 cm of roof crush versus <8 cm; 6% for >15 cm compared to <8 cm, and 11% for >30 cm of roof crush compared to <8 cm. In Paper III NASS-CDS data for 232,931 (weighted) ejected occupants were included in the analysis, with 497 coded as seat belt failures, and 232,434 coded as unbelted. Of the 7 injury types included in the analysis, only OUE and serious head injury were found to have a significant adjusted association with seat belt failure, (OR=3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The results were used to construct a table of post-test probabilities that combined the derived sensitivity and (1 - specificity) rates with a range of pre-crash seat belt use rates so that the results could be used in an investigation of a suspected case of belt latch failure. In Paper IV, the circumstances of 1,008 fatal falls were grouped in 3 categories of increasing fall height; falls occurring at ground level, falls from a height of <3 meters or down stairs, and falls from ≥3 meters. Logistic regression modeling revealed significantly increased odds of skull base and lower cervical fracture in the middle (<3 m) and upper (≥3 m) fall height groups, relative to ground level falls, as follows: (lower cervical <3 m falls, OR = 2.55 [1.32, 4.92]; lower cervical ≥3 m falls, OR = 2.23 [0.98, 5.08]; skull base <3 m falls, OR = 1.82 [1.32, 2.50]; skull base ≥3 m falls, OR = 2.30 [1.55, 3.40]). Additionally, C0-C1 dislocations were strongly related to fall height, with an OR of 8.3 for the injury in a ≥3 m fall versus ground level. Conclusions In this thesis 4 applications of FE methodology were described. In all of the applications epidemiologic data resulting from prior FM investigations were analyzed in order to draw probabilistic conclusions that could be reliably applied to the circumstances of a specific investigation. It is hoped that this thesis will serve to demonstrate the utility of FE in enhancing evidence-based practice in FM.

No description available.

Skrydžio saugos užtikrinimas – tai pagrindinis lėktuvo pilotų darbo uždavinys kiekvieno reiso metu. Tinkama daugianarės skrydžio įgulos sąveika yra bene svarbiausias veiksnys garantuojantis skrydžio saugumą ir efektyvumą. Pagrindinis magistro baigiamojo darbo tikslas – ištirti netinkamą daugianarės įgulos sąveiką, dėl kurios įvyksta įvairaus pobūdžio lėktuvų avarijos ar katastrofos, išanalizuoti pilotų sąveiką sąlygojančius veiksnius ir pateikti galimus siūlymus, panašioms situacijoms išvengti ateityje. Nustatant ir tiriant netinkamą sąveiką sąlygojančius veiksnius, įvertinama ir jų svarba bendrai skrydžio saugai. Pagrindiniai netinkamo bendro pilotų darbo veiksniai:  Netinkamas kapitono vadovavimo stilius;  Nuovargis:  Stresas;  Netinkamas bendravimas. Vėliau šie veiksniai yra praktiškai patvirtinami analizuojant jau įvykusias aviakatastrofas. Ieškomos objektyvios netinkamos pilotų sąveikos priežastys kiekvienos avarijos metu. Daugumoje ištirtų įvykių aptikti kritiniai momentai, kuomet pilotams galimai imantis atitinkamai siūlomų veiksmų, dar įmanomas įvykio evoliucijos laike pakeitimas ir aviakatastrofos išvengimas. / Flight safety assurance is the main task for aircraft pilots during their every flight. Appropriate multi-crew cooperation is probably the most important factor that guarantees effective and safe flight. The main object of this master’s thesis is to analize inadequate multi-crew cooperation which leads to various airplane crashes, to research factors, that affect cooperation of pilots and to suggest probabale solutions, in order to avoid similar situations in the future. After identifying and researching factors that cause inadequate cooperation, the importance of elements for flight safety is also evaluated. The main factors for inappropriate mutual work between the pilots are:  Inappropriate commanding style of captain;  Fatigue;  Stress;  Inappropriate communication. Later these factors are practically confirmed while analizing airplane crashes. During every accident, a search is made for the objective factors that caused an appearance of inadequate cooperation of pilots. Critical moments were found in the most of the crashes, when taking the suggested action there is still a possibility to change the further evoliution of the happening and aircraft crash avoidance.

Recent researchers have suggested that the combination of horizontal curves or “bendiness” of a length of road contributes to traffic crash occurrence. A previous study of New Zealand fatal crashes using an aggregated approach found no significant correlation between crash occurrence and road bendiness for rural roads but a minor correlation for urban roads. This thesis further explores the effect of road bendiness on traffic crash occurrence in New Zealand by developing a method more suited to traffic engineering. The method involves Geographical Information Systems (GIS) firstly to process data and secondly to calculate bendiness values. The following bendiness measures: bend density, detour ratio, cumulative angle, mean angle and standard deviation of angles; are applied to “influence areas” surrounding crash and comparison sites. The method then dictates that some form of statistical analysis should be performed to distinguish between the bendiness of crash and comparison sites, while accounting for other influencing factors. Binary logistic regression is recommended. The method was applied in a case study of New Zealand fatal crashes, with two main analysis techniques employed. Firstly, binary logistic regression models were developed. It was found that, for rural roads, sections with consistent and frequent curves were safer than completely straight sections or those with isolated curves. The urban model was less conclusive, which suggests that the method was not appropriate in the urban situation. The second analysis method involved comparing bendiness values of a site’s “immediate area” with those of its influence area. It was found that, although the spreads of the comparison sites’ distributions were smaller than those of the crash sites, the mean values were generally very similar and no appropriate bendiness ratios could be specified to reduce crash risk. Overall it appears that, if design consistency is maintained, bendiness is a protective quality for rural roads.

In view of the expected increase in the proportion of elderly in the population in most western countries, we studied injuries among the elderly (&gt;60 years) by investigating hospital-treated injuries in inpatients and outpatients, and fatal injuries. One-year Hospital Injury Data - Even though the elderly made up only 15% of the injured in one year, they accounted for 42% of the total cost of trauma medical care, showing that injuries among the elderly place a disproportional burden on the health care system. The mean medical care cost increased significantly from the age of 60 years. Serious injuries (MAIS&gt;3) in the elderly cost almost 2.5 times more than those in the younger group (&lt;60 years). Study of 1,313 injury events in 1,268 elderly showed annual injury, fracture, and mortality rates per 1,000 elderly population of 57, 31, and 0.6, respectively. Almost half were injured in the home environment, and 23% in the traffic environment. Most of the severe and critical injuries (MAIS&gt;4) occurred in the traffic environment. Injury rate, severity of injuries, fractures, and the duration of hospitalization increased with age. Almost half of the injuries were fractures; most common were wrist and hip fractures. Women had a higher injury rate, more severe injuries, and longer duration in hospitalization than men had. Study of 621 injury events in 600 elderly injured in the home environment, showed annual injury and fracture rates of 30 and 15 per 1,000 elderly home population, respectively. Injuries were grouped into fall injuries (76%) and non-fall injuries (24%). The fall injury incidence was higher in women than in men. Most falls occurred indoors. Environmental factors played a role in half of the fall injuries, and intrinsic factors in at least one fifth. Intrinsic factors in falls became increasingly important with advancing age. Non-fall injuries were mostly sustained in woodworking. Fall injuries were of a greater severity and accounted for 80% of the cost of medical care of elderly in the home environment. Study of 298 injury events in 297 elderly injured in the traffic environment, showed that pedestrian falls accounted for 52% of the injuries, and vehicle-related events for 44%. The main groups in the vehicle-related injury category were bicyclists (48%), car occupants (34%), and pedestrians (4%). Two thirds of the pedestrian falls involved slipping on ice/snow. Ice/snow-related injuries (all categories) accounted for 37% of the total cost of all injuries in the elderly in the traffic environment. Vehicle-related crashes resulted in the most severe and critical injuries and the most fatalities, and cost (total and mean) more than pedestrian falls. Fatal Injury Data from Northern Sweden - Study of 379 elderly injured in the traffic environment in a ten-year period, showed that the car occupants (43%) made up the largest category followed by pedestrians (28%), bicyclists (15%), and two-wheel-motor-vehicle riders (8%), but the risk of fatal injury per unit distance travelled was highest for pedestrians and bicyclists. Males had double the death rate as females. Most car occupants were killed in multivehicle crashes, mostly in the daylight, and at intersections. Ice/snow was the major (31%) precrash factor. One quarter of pedestrians were injured at pedestrian crossings, and half of them during darkness. One in six pedestrians was under the influence of alcohol. All pedestrians and bicyclists were injured in collisions with motor vehicles and most were injured at intersections. Pedestrians and bicyclists had more serious head injuries than chest injuries. Study of 514 car drivers (&gt;18 years) injured in a 13-year-period, showed that fatalities per unit distance, and per licensed driver were highest for the &gt;70-year-old and 18-19-year-old drivers. Elderly (&gt;60 year old) and &lt;25 year old drivers had similar fatality frequencies. The older drivers (&gt;60 years) initiated the crash more often than younger (&lt;60 years) ones. Fatal head injuries decreased whilst chest injuries increased with age. The older drivers were more likely to die from post-trauma complications than younger ones. In a study of role of disease in 480 fatally injured drivers (&gt;18 years) who died within three days of the crash, a grading system was developed to assess the probability of contribution of medical intrinsic factors (MIF) to the crash. Almost one quarter of the drivers were found to have MIF. Drivers with MIF were more often at fault than those without. Medical intrinsic factors were probably an underlying cause in 1 of 17 fatal crashes in all ages, and 1 of 5 fatal crashes in the elderly; in 4% of the elderly the probability was strong. A "passive automatic" approach which does not require any action on the part of the elderly, is to be recommended when improving safety in the home and in the traffic environments. The elderly drivers can be regarded as the "miner's canary" to indicate which passive safety improvements are needed in the traffic environment. In view of the expected population trends, it is important that authorities and public health workers accept the challenge to continue and intensify the injury preventive work for the elderly. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 7 uppsatser.</p> / digitalisering@umu

As algae-derived biofuel is a promising renewable energy source, it is well-established that micro-algae have the potential to make a significant contribution to transportation fuel demand. Although it has many advantages including high areal productivity, there are many negative factors. One of these factors is the predation of algae by amoebas, protozoans, ciliates and rotifers, particularly in open pond systems. For example, the rotifer Brachionus plicatilis, is able to eat as much as 12,000 algae cells per hour and can be responsible for an entire pond crash within days. Thus, these higher organisms need to be controlled in order to satisfy large-scale algae crop and biofuel production demand. One method of predation control involves the introduction of a toxic chemical to an algal culture that the predator has a higher sensitivity to with respect to algae. Ideally, predation could be minimized or eliminated without a substantial effect on the algal culture growth. Chlorella kessleri was used as the algal culture and Brachionus calyciflorus as the source of predation. Research was conducted in five stages. First, chlorine dissipation tests were carried out using spring water, distilled water, Bolds Basal Medium (BBM), and three different dry weights of algal suspension in order to analyze the dissipation rate of the residual chlorine. The results showed that chlorine in distilled water and spring water rarely dissipated while chlorine concentration in algal suspension rapidly decreased by a maximum of 90% within the second hour. Second, acute chlorine toxicity tests were conducted in order to find the 24-hr LC50 of B. calyciflorus. The 24-hr LC50 of the test animal was 0.198 mg Cl/L. Third, chlorine toxicity tests were conducted in order to find the LC50 of Chlorella kessleri. The 24-hr LC50 of C. kessleri was 0.321 mg Cl/L. Based on these results, the test animal was more sensitive to chlorine than the test algae; therefore chlorine may be used to avoid algae pond crashes by B. calyciflorus. Fourth, C. kessleri and B. calyciflorus were combined into one test to determine how long it would take to observe an algal culture crash. The result demonstrated that the higher the population of predators in algal suspension, the faster it crashed. Finally, chlorine, C. kessleri, and B. calyciflorus were combined into one test to determine what chlorine concentration and dosing interval was needed to significantly reduce predation without significantly reducing algae growth. The results of the fifth experiment showed that the effective intermittent chlorine concentration was between 0.45 and 0.60 mg Cl/L, and a short interval of chlorine dosing was effective in inhibiting rotifers in algal suspension. Even though the rotifers in algal suspension were inhibited by 0.45 to 0.60 mg Cl/L, algae growth was greatly inhibited by chlorine. In this respect, future work is needed to reduce the effect on algae by chlorine or alternative chemicals.

This thesis investigates the pricing relationship between the FTSE 100 Stock Index and the FTSE 100 Stock Index futures market. We develop and apply a framework in which it is possible to evaluate whether or not markets can be said to function effectively and efficiently. The framework is applied to both the daily and intra-daily pricing relationship between the aforementioned markets. In order to analyse the pricing relationship within days, we develop a new method to remove the effects of nonsynchronous trading from the FTSE 100 Index. We find that on a daily basis the markets generally function effectively, although this does not carryover to the intra-daily pricing relationship. This is especially true during the October 1987 stock market crash, where it is argued that a possible cause of the breakdown lies with the stock market. If this is the case, then any regulation should be aimed at the stock market, not the stock index futures market.

Injury to the human neck is a frequent consequence of automobile accidents and has been a significant public health problem for many years. The term `whiplash' has been used to describe these injuries in which the sudden differential movement between the head and torso leads to abnormal motions within the neck causing damage to its soft tissue components. Although many different theories have been proposed, no definitive answer on the cause of `whiplash' injury has yet been established and the exact mechanisms of injury remain unclear. Biomechanical research is ongoing in the field of impact analysis with many different experimental and computational methods being used to try and determine the mechanisms of injury. Experimental research and mathematically based computer modelling are continually used to study the behaviour of the head and neck, particularly its response to trauma during automobile impacts. The rationale behind the research described in this thesis is that a computational model of the human head and neck, capable of simulating the dynamic response to automobile impacts, could help explain neck injury mechanisms. The objective of the research has been to develop a model that_,, can accurately predict the resulting head-neck motion in response to acceleration impacts of various directions and severities. This thesis presents the development and validation of a three-dimensional computational model of the human head and cervical spine. The novelty of the work is in the detailed representation of the various components of the neck. The model comprises nine rigid bodies with detailed geometry representing the head, seven vertebrae of the neck and the first thoracic vertebra. The rigid bodies are interconnected by spring and damper constraints representing the soft-tissues of the neck. 19 muscle groups are included in the model with the ability to curve around the cervical vertebrae during neck bending. Muscle mechanics are handled by an external application providing both passive and active muscle behaviour. The major findings of the research are: From the analysis of frontal and lateral impacts it is shown that the inclusion of active muscle behaviour is essential in predicting the head-neck response to impact. With passive properties the response of the head-neck model is analogous to the response of cadaveric specimens where the influence of active musculature is absent. Analysis of the local loads in the soft-tissue components of the model during the frontal impact with active musculature revealed a clear peak in force in the majority of ligaments and in the intervertebral discs very early in the impact before any forward rotation of the head had occurred. For the case of rear-end impact simulations it has been shown for the first time that the inclusion of active musculature has little effect on the rotation of the head and neck but significantly alters the internal loading of the soft-tissue components of the neck.