Efficient Intersection Computation of the Bezier and Hermite Curves with Axis Aligned Bounding Box

Cubic parametric curves are used in many applications including the CAD/CAM systems. Especially the Hermite, Bezier and Coons formulations of a cubic parametric curve are used in E2 and E3 space. This paper presents efficient algorithm for the intersection computation of a cubic parametric curve with the Axis Aligned Bounding Box (AAB Box). Usual solution is to represent the cubic curve by a polyline, i.e. actually by sampled points of the given curve. However, this approach is dependent on the sampling frequency and can lead to problems especially in CAD/CAM systems and numerically controlled machines use.

Algorithms for Non-Relativistic Quantum Integral Equation

In low energy scattering in Non-Relativistic Quantum Mechanics, the Schödinger equation in integral form is used. In quantum scattering theory the wave self-function is divided into two parts, one for the free wave associated with the particle incident to a scattering center, and the emerging wave that comes out after the particle collides with the scattering center. Assuming that the scattering center contains a position-dependent potential, the usual solution of the integral equation for the scattered wave is obtained via the Born approximation. Assuming that the scattering center contains a position-dependent potential, the usual solution of the integral equation for the scattered wave is obtained via the Born approximation. The methods used here are arbitrary kernels and the Neumann-Born series. The result, with the help of computational codes, shows that both techniques are good compared to the traditional method. The advantage is that they are finite solutions, which does not require Podolsky-type regularization.

Local Platelet-rich plasma (PRP) injection for the treatment of Delayed Union after Internal Fixation in Fractures of Long Bones

Introduction: Long bone fractures are among the most common orthopaedic injuries encountered. A fracture that fails to progress to union despite appropriate fixation and absence of complications presents a treatment dilemma to the surgeon. The usual solution of re-fixation with or without bone graft constitutes repeat exposure to surgery and its risks, as well as added morbidity and cost. Recent advances in molecular biology suggest Platelet rich plasma (PRP) may have bone forming potential. This study was done to determine whether PRP has any beneficial role in patients with delayed healing of long bone fractures. Methods: A prospective interventional study was done on patients arriving at the department of orthopaedic surgery of Kathmandu Medical College with delayed union of long bone fractures after internal fixation between January 2014 and January 2017. Patients were treated with local injection of group-matched PRP directly into the fracture gap and were followed-up for six months to check for radiological signs of fracture union. Results: A total of 10 fractures were included in 10 patients that involved four humeri, three tibiae, and three femora. Eight out of the 10 fractures united at a median time of three months after the injection. Two had non-union that required revision surgery. Conclusion: Local Platelet rich plasma injection may constitute a ‘nothing to lose, everything to gain’ intermediate option before a decision for major reoperation on such patients is made.

Evaluation of Fresh Properties and Rheology of Mortar Using Carbon-Free Fly Ash and Normal Fly Ash

Usage of mineral admixture and chemical admixture in concrete or mortar is a usual solution to reach full compaction, particularly where reinforcement blockage and lack of skilled labor happen. In this paper effect of mineral admixtures (Carbon-free fly ash, hereafter CfFA, and normal fly ash) on fresh properties and rheology of mortar have been investigated. As a result, it was confirmed that CfFA increased significantly the fluidity and air content of mortar in comparison to normal fly ash, both in 15% and 30% replacement; however, the flow loss and air stability within one hour were almost equal. In addition, the initial setting time has also been affected by variation of materials. The two mixing of 30% and 15% of CfFA had a shorter setting time in comparison to the mortar with normal fly ash. Furthermore, CfFA based mortar had a great influence on rheology of mortar. Compared to normal fly ash, CfFA Considerably decreased the plastic Viscosity and increased the productivity of the mortar, both in non-vibrated and vibrated condition, particularly those with 30% replacement.

Decentralized Validation for Non-malicious Arbitrary Fault Tolerance in Paxos

Fault-tolerant distributed systems offer high reliability because even if faults in their components occur, they do not exhibit erroneous behavior. Depending on the fault model adopted, hardware and software errors that do not result in a process crashing are usually not tolerated. To tolerate these rather common failures the usual solution is to adopt a stronger fault model, such as the arbitrary or Byzantine fault model. Algorithms created for this fault model, however, are considerably more complex and require more system resources than the ones developed for less strict fault models. One approach to reach a middle ground is the non-malicious arbitrary fault model. In this paper we describe how we incremented an implementation of active replication in the non-malicious fault model with a basic type of distributed validation, where a deviation from the expected algorithm behavior will make a process crash. We experimentally evaluate this implementation using a fault injection framework showing that it is feasible to extend the concept of non-malicious failures beyond hardware failures.

Monitoring of a controlled space flexible multibody by means of embedded piezoelectric sensors and cameras synergy

Interaction between elastic dynamics and attitude control is a serious problem in space operations, which often involve satellites with highly flexible appendages. Monitoring and eventually control of the vibrations are a major concern to avoid a decrease in the expected performance. In particular, the classic case of a central bus with two lateral appendages (solar panels) is considered. The design of a system for structural vibration monitoring is proposed both from a numerical and an experimental point of view. Piezoelectric devices are a usual solution for measuring the deformation of the structures. In the proposed work, optical sensors are also implemented: the combined use of the two sets allows for the monitoring of the elastic displacement of the solar panels and for the reconstruction of the modal shapes of the entire flexible multibody system.

Conclusion

This concluding chapter talks about how the complexity of combining human and nonhuman elements presents an obvious challenge to one’s understanding and management of ecosystems. The usual solution for understanding such complexity is to concentrate observations on the co-variation between a limited set of variables within a limited time–space setting. Important as that approach is, the need to unify these findings and practices may be of even greater importance for meeting future challenges to human ecosystems. The chapter shares some of the lessons learned in trying to develop and apply a more unifying approach to the study of human ecosystems. It offers a template of concepts that helps in reducing information overload by not attending to all the possible and actual connections in a given system.

Magnetic characterization of the nickel layer protecting the copper wires in harsh applications

High Temperature (HT°) motor coils open new perspectives for extending the applications of electrical motors or generators to very harsh environments or for designing very high power density machines working with high internal temperature gradients. Over a temperature of 300°C, the classic enameled wire cannot work permanently, the turn-to-turn insulation must be inorganic and made with high temperature textiles or vitro-ceramic compounds. For both cases, a diffusion barrier must protect the copper wire against oxidation. The usual solution consists of adding a nickel layer that yields an excellent chemical protection. Unfortunately, the nickel has ferromagnetic properties that change a lot the skin effect in the HT wire at high frequencies. For many applications such as aeronautics, electrical machines are always associated with PWM inverters for their control. The windings must resist to high voltage short spikes caused by the fast fronted pulses imposed by the feeding inverter. The nickel protection layer of the HT° inorganic wire has a large influence on the high frequency behavior of coils and, consequently, on the magnitude of the voltage spikes. A good knowledge of the non-linear magnetic characteristics of this nickel layer is helpful for designing reliable HT inorganic coils. The paper presents a method able to characterize non-linear electromagnetic properties of this nickel layer up to 500°C.

The Klein-Gordon Equation

Two solutions to the Klein-Gordon equation are found. The existence of a maximum relativistic correction of 2 is thus indicated. The normal relativistic correction is given by the usual solution. A certain Hilbert Space is used to find the solutions using a group theory taught at LSU and the Texas Method of Math also taught at LSU. The usefulness of group theoretical manipulations in Hilbert Space is indicated. A lemma is proved using this group theory that predicts a charge of +/-1 is the only values of charge possible. The usefulness of the second solution to the Klein-Gordon equation of a maximum of 2 for the relativistic correction is basic to the mass predictions in [3]. The fact that the energy reaches mc^2 indicates a dipole spinning at velocity c. The dipole is spinning in a magnetic field created by other particles so it creates charge.