Chaotic dynamics in Parkfield region, California and characteristics earthquakes

Based on about 75000 earthquakes in the California region detected through Parkfield network during the years 1969-1987, the occurrence of chaos was examined by two different approaches, namely, strange at tractor dimension and the Lyapunov exponent. The strange at tractor dimension was found as 6.3 in this region suggesting atleast 7 parameters for earthquake predictability. Small positive Lyapunov exponent of 0.045 provided further evidence for deterministic chaos in the region which showed strong dependence on the initial conditions. Implications of chaotic dynamics on characteristic Parkfield earthquakes has been discussed. The strange at tractor dimension in the region could be representative for the Transform type of plate boundary which is lower than that reported for continent collision type of plate boundary which is lower than that reported for continent collision type of plate boundary near Hindukush northwest Himalayan region.

Modelling the Safety Performance of Roadways for Specific Collision Types

Safety performance functions (SPFs) are rarely developed for specific accident types because this can be very lengthy especially when relevant data are unavailable. Because of this constraint, a factor is applied along with the SPF for all accident types to estimate the safety for specific accidents types. This factor is the proportion of the individual collision type in the entire population of all accidents. However, there is no reason to believe that this factor is a constant which is independent of Annual Average Daily Traffic (AADT). Accordingly, a constant factor and the proportion model are applied to the SPF for all accident types combined to estimate the SPF for specific accident types on both rural road segments and Two-Way Stop-Controlled (TWSC) intersections. The validity of these factors are tested using the state-of-the-art network screening approaches. Furthermore, a detailed investigation on Property Damaage Only (PDO) estimates is carried out on certain aspects of safety performance functions, using negative binomial regression. PDO estimates are then evaluated based on three different approaches.

Modelling the Safety Performance of Roadways for Specific Collision Types

Safety performance functions (SPFs) are rarely developed for specific accident types because this can be very lengthy especially when relevant data are unavailable. Because of this constraint, a factor is applied along with the SPF for all accident types to estimate the safety for specific accidents types. This factor is the proportion of the individual collision type in the entire population of all accidents. However, there is no reason to believe that this factor is a constant which is independent of Annual Average Daily Traffic (AADT). Accordingly, a constant factor and the proportion model are applied to the SPF for all accident types combined to estimate the SPF for specific accident types on both rural road segments and Two-Way Stop-Controlled (TWSC) intersections. The validity of these factors are tested using the state-of-the-art network screening approaches. Furthermore, a detailed investigation on Property Damaage Only (PDO) estimates is carried out on certain aspects of safety performance functions, using negative binomial regression. PDO estimates are then evaluated based on three different approaches.

Network screening for specific collision types at urban signalized intersections - conventional and spatial methods

Transportation authorities are always looking for ways to improve road safety since vehicle collisions cost Canada 25 billion dollars of capital loss and around 2800 deaths each year. An important step in improving road safety is to sieve out the problem sites through network screening processes. screening for specific accident types is discussed in this thesis, using signalized intersections in Toronto in an illustrative application. each such collision type is associated with corresponding countermeasures, which allows the engineer to rank the entities with specific remedies in mind. In this way, the effectiveness of road network screening can improved through targeted treatments. Three different screening methods are introduced and compared; procedures for selecting entities from screening results by different methods are also presented. A process for ranking jurisdictions by regions is proposed. This is a method which combines the conventional network screening techniques with geographic information system (GIS) tools. The GIS can integrate the spatial information of a selected area with the conventional accident and road characteristic data and facilitate network screening by region.

Network screening for specific collision types at urban signalized intersections - conventional and spatial methods

Transportation authorities are always looking for ways to improve road safety since vehicle collisions cost Canada 25 billion dollars of capital loss and around 2800 deaths each year. An important step in improving road safety is to sieve out the problem sites through network screening processes. screening for specific accident types is discussed in this thesis, using signalized intersections in Toronto in an illustrative application. each such collision type is associated with corresponding countermeasures, which allows the engineer to rank the entities with specific remedies in mind. In this way, the effectiveness of road network screening can improved through targeted treatments. Three different screening methods are introduced and compared; procedures for selecting entities from screening results by different methods are also presented. A process for ranking jurisdictions by regions is proposed. This is a method which combines the conventional network screening techniques with geographic information system (GIS) tools. The GIS can integrate the spatial information of a selected area with the conventional accident and road characteristic data and facilitate network screening by region.

A Study for Locations of Accident Prone on Some Provincial Roads in Province of Kalimantan Barat

Nowadays more than one million people become victim in an accident on the roads. Some efforts have already been done to reduce globally the number accident. This paper is to show the condition of some provincial roads as location study in province of Kalimantan Barat regarding with description, characteristic, and the causes of accident. The results indicate that the human error take part dominantly around of 65% accident number, meanwhile vehicle condition and road environment contribute less than 5 %. The provincial road is dominated by the two-lane two-way facility. The finding shows the frontal collision type around of 42 % on the accident number. Number of motor cycle dominate the type of vehicle on the road. It coincides with percentage of motor cycle significant involved at an accident around of 71%. The frontal collision at location of study is more than twice compared to national data. Ratio number of accidents to length of road is located on the road segment from Ketapang to Pesaguan around of 0.884 each kilometer

Terms of repair works and forecasting of terms of service of contacts of disassembly type in conditions of incomplete of output information

Collapsible contact joints are the most numerous elements of electrical installations. The efficiency of the contacts, their reliability to a large extent depends on the modes of electric current and temperature, contact pressure, etc. Modification of modes and operation time lead to an increase in the resistance of the contacts, the temperature of their heating and possible thermal destruction. Traditional means for controlling the pressure in the contacts when changing the temperature regime are steel plate springs. Previous investigations have established that these means only partially solve the problem of regulation of contact pressure. An alternative to traditional means is the innovative development of dynamic pressure control tools based on the use of functional alloys with the shape memory effect. The mathematical analysis of terms of carrying out repair works and service life of collision type contacts with the use of probability theory in the conditions of incompleteness of the initial information is carried out. The research substantiates that the use of dynamic method of control of the thermomechanical regime of collapsible contacts allows to stabilize pressure and extend the life of collapsible contacts by 3-4 times.

Analysis of Factors Affecting the Severity of Automated Vehicle Crashes Using XGBoost Model Combining POI Data

The research and development of autonomous vehicle (AV) technology have been gaining ground globally. However, a few studies have performed an in-depth exploration of the contributing factors of crashes involving AVs. This study aims to predict the severity of crashes involving AVs and analyze the effects of the different factors on crash severity. Crash data were obtained from the AV-related crash reports presented to the California Department of Motor Vehicles in 2019 and included 75 uninjured and 18 injured accident cases. The points-of-interest (POI) data were collected from Google Map Application Programming Interface (API). Descriptive statistics analysis was applied to examine the features of crashes involving AVs in terms of collision type, crash severity, vehicle movement preceding the collision, and degree of vehicle damage. To compare the classification performance of different classifiers, we use two different classification models: eXtreme Gradient Boosting (XGBoost) and Classification and Regression Tree (CART). The result shows that the XGBoost model performs better in identifying the injured crashes involving AVs. Compared with the original XGBoost model, the recall and G-mean of the XGBoost model combining POI data improved by 100% and 11.1%, respectively. The main features that contribute to the severity of crashes include weather, degree of vehicle damage, accident location, and collision type. The results indicate that crash severity significantly increases if the AVs collided at an intersection under extreme weather conditions (e.g., fog and snow). Moreover, an accident resulting in injuries also had a higher probability of occurring in areas where land-use patterns are highly diverse. The knowledge gained from this research could ultimately contribute to assessing and improving the safety performance of the current AVs.

Combined Primary Hepatic Neuroendocrine Carcinoma and Hepatocellular Carcinoma: Case Report and Literature Review

Background: Hepatocellular carcinoma (HCC) can grow in a mosaic pattern, often combined with various non-hepatocellular cells. However, HCC combined with a neuroendocrine carcinoma (NEC) component is very rarely reported, and its clinical features, origin, diagnosis and behavior have not been established. In the literature, mixed HCC–NEC tumors are categorized as either collision type or combined type, depending on their microscopic features. Here we report a patient with a combined-type HCC–NEC tumor.Case presentation: An asymptomatic 84-year-old woman was found to have a solid mass in the right lobe of her liver. Laboratory and radiologic examinations showed findings typical of HCC, including arterial-phase enhancement, and portal- and delay-phase washout. She was preoperatively diagnosed with HCC, and treated with partial laparoscopic hepatectomy of her S5 segment. The tumor was 5.0 × 6.0 cm in diameter, and was predominantly HCC, partly admixed with a NEC component. A transitional zone between the HCC and NEC tissues was also observed. The tumor was finally diagnosed as a combined-type primary mixed NEC–HCC tumor. After the diagnosis, the patient underwent somatostatin receptor scintigraphy to look for the primary NEC lesion, but no accumulations were found in any other part of her body. She has been free of recurrence for 6 months since the surgery.Conclusion: Mixed HCC–NEC tumors are very rare. Correct diagnosis requires multidisciplinary collaboration. Accumulating cases is needed to help understand their exact pathology, diagnosis and treatment.