Optical sampling based on ultrafast optical nonlinearities is a useful technique to monitor the waveforms of ultrashort optical pulses. In this paper, we present a new implementation of optical waveform sampling systems by employing our newly constructed free-running mode-locked fibre laser with a tunable repetition rate and a low timing jitter, an all-optical waveform sampler with a highly nonlinear fibre (HNLF), and our developed computer algorithm for optical waveform display and measurement, respectively. Using a femtosecond fibre laser to generate the highly stable optical sampling pulses and exploiting the four-wave mixing effect in a 100 m-long HNLF, we successfully demonstrate the all-optical waveform sampling of a 10 GHz optical clock pulse sequence with a pulse width of 1.8 ps and a 80 Gbit/s optical data signal, respectively. The experimental results show that waveforms of the tested optical pulse signals are accurately reproduced with a pulse width of 2.0 ps. This corresponds to a temporal resolution of 0.87 ps for optical waveform measurement. Moreover, the optical eye diagram of a 10Gbit/s optical data signal with a 1.8 ps pulse width is also accurately measured by employing our developed optical sampling system.

The third eyelid rotation associated with the nictitans gland prolapse and third eyelid cartilage eversion is a rarely encountered ocular disorder. The present retrospective study includes the distribution of the relevant deformations in the cartilage and nictitans gland accompanying the third eyelid rotation in the cat according to breed, age, and gender-based differences, as well as the clinical manifestations, surgical therapeutic approach (partial resection of the scrolled car- tilage portion combined with the Morgan pocket technique), and the outcome of the procedure, concurrently monitoring whether or not the functions of the nictitating membrane were preserved after the procedure, the likelihood of relapse and the potential complications. A total of sixteen eyes surgically treated with the above-mentioned surgical method that belonged to thirteen cats diagnosed with the nictitans gland prolapse and cartilage eversion accompanying the third eyelid rotation were included in the study. The most common breeds were Persian (38.4%) and British shorthair (38.4%), with five cases from each. Three cats (20%) were bilaterally affected, while there was a unilateral involvement in ten of the cases (80%). Out of the ten cases with a unilateral lesion, the right eye was affected in 6 (60%) individuals, while the left eye was involved in four (40%). Nine cats were male, and four were female. The study was conducted in an attempt to surgically correct the third eyelid cartilage eversion and prolapsed nictitans gland responsible for the nictitating membrane rotation in cats by the partial removal of the everted cartilage com- bined with the Morgan pocket technique. Follow-ups were performed twice every other week in the postoperative period, followed by a one-time clinical inspection at the end of the first, third, and sixth months.

New equivalent conditions of the asymptotical stability and stabilization of positive linear dynamical systems are investigated in this paper. The asymptotical stability of the positive linear systems means that there is a solution for linear inequalities systems. New necessary and sufficient conditions for the existence of solutions of the linear inequalities systems as well as the asymptotical stability of the linear dynamical systems are obtained. New conditions for the stabilization of the resultant closed-loop systems to be asymptotically stable and positive are also presented. Both the stability and the stabilization conditions can be easily checked by the so-called I-rank of a matrix and by solving linear programming (LP). The proposed LP has compact form and is ready to be implemented, which can be considered as an improvement of existing LP methods. Numerical examples are provided in the end to show the effectiveness of the proposed method.

Positively invariant sets play an important role in the theory and applications of dynamical systems. The stability in the sense of Lyapunov of the equilibrium x = 0 is equivalent to the existence of the ellipsoidal positively invariant sets. The constraints on the state and control vectors of dynamical systems can be formulated as polyhedral positively invariant sets in practical engineering problems. Numerical checking method of positive invariance of polyhedral sets is addressed in this paper. The validation of the positively invariant sets can be done by solving LPs which can be easily done numerically. It is illustrated by examples that our checking method is effective. Compared with the now existing algebraic methods, numerical checking method is an attractive method in that it’s easy to be implemented.

In this study, an energy-based spectrum sensing method combined with copula theory is proposed for cognitive radio systems. In the proposed spectrum sensing model, cognitive radio users first make their own local spectrum decision with energy-based spectrum sensing. Then, they forward their decision to the fusion center. In the fusion center, this decision is compared with the threshold value determined by copula theory and global spectrum decision is made. The test statistic at the fusion center were obtained with the Neyman Pearson approach. Thus, the fusion rule was created for the fusion center and necessary simulation studies were performed. According to the results of the simulation studies, the proposed detection method showed better results than the traditional energy based detection method.

When a truck impacts on a reinforced concrete (RC) column such as a bridge pier at a high velocity, a large reaction force would generate which would damage the truck, hurt the passengers and destroy the column. Lightweight foams with excellent energy absorbing performance are often used as safeguard constructions to resist impact. The impact behavior can be divided into soft and hard impact. In the case of soft impact, the impacted structure deformation is predominant. In the paper, metallic foam safeguarded RC square columns impacted by a rigid block are simulated using the ABAQUS code software, and the influential characteristic of foam density on the peak impact force and ultimate energy absorption is focused on. The simulated results indicate that the foam safeguard constructions play remarkable role on impact resistance. It is exciting that there appears almost an identical critical foam density corresponding to the minimum peak force and the ultimate energy absorption, which is of great significance for engineering design of this type of safeguard constructions to resist impact.

Chloride ion erosion in offshore environment may damage the mechanical properties of beam bridges. In this study, the reinforced concrete specimen was designed, accelerated erosion experiments were carried out to simulate the coastal corrosion environment, and the corrosion rate, nominal strength and equivalent strength of steel bars, concrete cracks and reliability of beam bridges were calculated to understand the time-varying mechanical properties of beam bridges. The results showed that the nominal and equivalent strength of reinforcing bars decreased with the increase of corrosion rate of reinforcing bars. The change of yield strength was greater than that of equivalent strength. The change of crack width of concrete showed a slow-fast-slow trend, and the reliability of beam bridges decreased significantly in about 50 years. The experimental results show that chloride ion corrosion can significantly damage the mechanical properties of the beam bridge and affect the time-varying reliability of the beam bridge. Therefore, it is necessary to carry out timely maintenance and inspection and take effective methods to control steel corrosion to ensure the safety of the use of the beam bridge.

The aim of the presented work was to examine the reliability assessment model on the example of a selected power grid object. The analyzed object was tested based on assumptions about technological breaks that were caused by overvoltage, among others. The study was conducted to check the reliability of integral elements of the power grid object and to assess the change in reliability level as a function of the frequency of inspections. The test results are to determine the optimal frequency of inspections of individual power grid objects in order to increase its reliability. In addition, the possibility of correlating optimal inspection periods resulting from the findings of this paper with periodic inspections of power network facilities was assessed.

The present paper describes a new architecture of a high-voltage solid-state pulse generator. This generator combines the two types of energy storage systems: inductive and capacitive, and consequently operates two types of switches: opening and closing. For the opening switch, an isolated gate bipolar transistor (IGBT) was chosen due to its interesting characteristics in terms of controllability and robustness. For the closing switch, two solutions were tested: spark-gap (SG) for a powerful low-cost solution and avalanche mode bipolar junction transistor (BJT) for a fully semiconductor structure. The new architecture has several advantages: simple structure and driving system, high and stable controllable repetition rate that can reach 1 kHz, short rising time of a few nanoseconds, high gain and efficiency, and low cost. The paper starts with the mathematical analysis of the generator operation followed by numerical simulation of the device. Finally add a comma the results were confirmed by the experimental test with a prototype generator. Additionally, a comparative study was carried out for the classical SG versus the avalanche mode BJT working as a closing switch.

The purpose of this study is to investigate a structure’s response to blast loading when composite columns are used instead of conventional reinforced concrete (RC) cross sections and when a conventional structure is retrofitted with braces. The study includes conducting dynamic analyses on three different structures: a conventional reference RC structure, a modified structure utilizing composite columns, and a modified structure retrofitted with steel braces. The two modified structures were designed in order to investigate their performance when subjected to blast loading compared to the conventional design. During the dynamic analyses, the structures were exposed to simulated blast loads of multiple intensities using the finite-element modelling software, SeismoStruct. To evaluate their performance, the responses of the modified structures were analyzed and compared with the response of the conventional structure. It was concluded that both the structure with composite columns and the steel brace structure experienced less damage than the conventional model. The best performance was obtained through the steel brace structure.

The pharmacokinetics of a diclofenac sodium was investigated in swine. A single intravenous (i.v.) or intramuscular (i.m.) injection of 5% diclofenac sodium (concentration = 2.5 mg · kg-1) was administered to 8 healthy pigs according to a two-period crossover design. The pharmacokinetic parameters were calculated by non-compartmental analysis with DAS2.1.1 software. After a single i.v. administration, the main pharmacokinetic parameters of diclofenac sodium injection in swine were as follows: the elimination half-time (T1/2β) was 1.32±0.34 h; the area under the curve (AUC) was (55.50±5.50 μg · mL-1 h; the mean residence time (MRT) was 1.60±0.28 h; the apparent volume of distribution (Vd) was 0.50±0.05 L · kg-1; and the body clearance (CLB) was 0.26±0.04 L · (h · kg)-1. After the single i.m. administration, the pharmacokinetic parameters were as follows: peak time (Tmax) was 1.19±0.26 h; and peak concentration (Cmax) was 11.61±5.99 μg mL-1. The diclofenac sodium has the following pharmacokinetic characteristics in swine: rapid absorption and elimination; high peak concentration; and bioavailability.

Canine status epilepticus (CSE) is characterized by epileptic seizures that are longer than 5 min or more than one seizure with incomplete recovery. Currently, diazepam suppositories are generally prescribed for CSE. Levetiracetam (LEV) is one of the newest antiepileptic drugs currently available. This study compared the pharmacokinetics of intragastric and intrarectal administration in oral formula of LEV in four healthy beagles as a reference data when the owner administers levetiracetam to dogs by himself at home. Blood for measuring plasma LEV concen- trations was collected 0, 30, 60, 90, 120, 240, 360, and 540 min after LEV administration. The time to reach the maximum plasma concentration (Tmax) was markedly shorter with intra- rectal administration (45±26 min) than with intragastric administration (270±99 min). Intrarectal administration of LEV tablets could be an effective option for treating canine seizures although it might be a limit for treating CSE because the absorption rate is not fast enough.