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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.

Developing computational models of the human spine has been a hot topic in biornechanical research for a couple of decades in order to have an understanding of the behaviour of the whole spine and the individual spinal parts under various loading conditions. The objectives of this thesis are to develop a biofidefic multi-body model of the whole human spine especially for dynamic analysis of impact situations, such as frontal impact in a car crash, and to generate finite element (FE) models of the specific spinal parts to investigate causes of injury of the spinal components. As a proposed approach, the predictions of the multi-body model under dynamic impact loading conditions, such as reaction forces at lumbar motion segments, were utilised not only to have a better understanding of the gross kinetics and kinematics of the human spine, but also to constitute the boundary conditions for the finite element models of the selected spinal components. This novel approach provides a versatile, cost effective and powerful tool to analyse the behaviour of the spine under various loading conditions which in turn helps to develop a better understanding of injury mechanisms.

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