Background and purpose: When dealing with a road accident and reconstructing the scene, one of the main parameters is the speed of the vehicle at the time of the accident. In the past, the speed of vehicles at the time of Collision or before the Collision was determined based on the effect of the remaining brake line. In the last decade, cars have been equipped with anti-lock braking system (ABS). However, many of the mentioned methods are not able to solve the problem of speed determination, and the need to provide new methods of speed calculation seems necessary.Method: The load dynamics of the seat belt, which is used as a means to limit the movement of people inside the car during sudden deceleration, has been used to calculate the speed of the car according to the change in the shape of the belt and the corresponding movement of the person.Findings: The findings of the research indicate that the use of seat belts reduces the probability of death and other types of injuries compared to drivers and passengers who do not use seat belts. In addition, as the weight of the driver increases, the speed of the vehicle in which the seat belt breaks at the moment of impact with the fixed obstacle decreases.Conclusion: The proposed method for determining the speed of the vehicle allows the court, judges, research institutions and investigators to have a correct assessment of the actions of the people involved in the accident.

In this paper, a new mechanism is proposed to transform the structural modeling elements of the UML class diagram and object-Z specifications into each other. A set of bidirectional rules is defined to transform the mentioned elements into each other. Bidirectional transformation of the UML class diagram, as one of the most useful diagrams of UML, and object-Z specifications into each other prepares the ground for the use of the unique advantages of both formal and visual modeling methods. The feasibility of the proposed approach is evaluated using the multi-lift case study. The results of conducting the multi-lift case study show that the proposed mechanism is feasible.

Background and objective: fixed drug eruption (FDE) is one kind of drug rashes that is characterized by re-appearance of the lesions on the same sites after re-exposure to the causative drug. This study was performed to evaluate the epidemiologic characteristics of FDE. Materials and Methods: This descriptive study was done on a series of 100FDE cases, whom were admitted at the outpatient dermatology clinic of Hazrat-e-Rasoul Hospital over a six-year period. The primary diagnosis of FDE was suggested according to clinical findings including a remaining hyperpigmentation at the site of healed skin lesion(s). Oral challenge test with a single low dose administration of the suspected drug was used to confinn the diagnosis. Recurrence of the lesion(s) at the same body area(s) was considered as positive result. Results: Most commonly causative agents were co-trimoxazole and codein, which were found in 88% and 3% FDE cases; respectively. The most common site of involvement was penile glans in 57.7% of male patients and trunk in 48.3% of females. In one patient, reaction to multiple drugs including co-trimoxazole, codein and tetracycline was observed and after re-challenge with each drug, re-appearance of the skin lesion at the same site was evident. Several patients reported concomitant acetaminophen intake, but there was no reaction to that drug. Conclusion: Co-trimoxazole is the most common cause of FDE.      

During their operating life on site, jacket structures may be subjected to boat impacts. It is useful to know the boat impact intensity a structure can withstand without considerable damage or disruption of normal operations. Furthermore, it is advantageous to know the maximum impact intensity that could cause platform failure. This paper deals with ship impact analyses of SPD1, one of south pars field wellhead jackets located in Persian Gulf. The Collision velocities are considered to be 0.5(m/s), 1(m/s) and 2(m/s). Each case was analyzed for two load cases, i.e. one representing impact on the brace and the other reflecting impact on the leg. The striking structure and struck structure are considered as one structural system connected by contact element. In order to allow for local deformation of the impacted leg or brace, a non-linear spring was used at the point of impact on the appropriate part of impacted member. The supply vessel was modeled at one end of the spring; the ship and impacted member springs were separated by a contact element as to allow rebound to occur. To account for hydrodynamic effect added mass is used. Jacket and piles are modeled together while the pile can slip axially relative to the leg. Dynamical pile-soil interaction is accounted. During simulation of impact scenario the concentrated mass, representing the displacement of the ship was prescribed with the required initial velocity. It is shown that strain hardening and large displacement play an important role in the impact response; therefore a rational Collision analysis should take into account the effect of large displacement, plasticity and strain hardening. Impact velocity and impact location have significant effect on the structure response. When brace is impacted the 3-hinge mechanism becomes the predominant absorbent of plastic energy and shipside indentation remains elastic. As impact velocity increases, plastic zone is extended in impacted member section. In impact velocity recommended by API (0.5m/s) impacted leg remains elastic and plastic zone of brace section is bounded to outer fibers of section. It is recommended to use impact force derived in this study to consider the behavior of tubular members under impact loads.

Due to the high fatalities of head-on accidents, the design of intelligent systems to prevent such severe Collisions is essential. In this study, path planning for head-on Collision avoidance with a deviated vehicle from the opposite lane has been investigated. The main approach is based on a model predictive controller with 2 seconds of prediction horizon and a linearized prediction model with low errors near the operational conditions. A conservative method is used for lateral motion prediction of the deviated vehicle and based on that, the Collision avoidance constraints of the model predictive planner are simply modeled by a new approach. Moreover, a novel method to choose the proper swerve direction of evasive maneuver is proposed. This method is based on keeping the ego vehicle away from dangerous directions and has different criteria for far and close encounters. The final algorithm is capable to control the steering of the prediction model with a constrained lateral acceleration and calculates safe and maneuverable paths for the aforementioned scenario. Four simulations are conducted to validate the algorithm in far and close encountering, and critical conditions of choosing swerve direction. Results show the robustness of the path planner, even to sudden deviations at close distances and with high lateral accelerations.