Narrow Results

Since the ability to control the investor’s income or loss within a certain range, barrier option has been among the most popular path-dependent options where its payoff depends on whether or not the underlying asset’s price reaches a given “barrier”. First, assuming the underlying asset as an uncertain variable for the case that the Caputo fractional-order derivative is adopted instead of the ordinary derivative, the real financial market is better modeled by the uncertain fractional-order differential equation with Caputo type. Then, a first-hitting time model which can measure the exercise ability is innovatively presented. Second, based on the first-hitting time theorem of the uncertain fractional-order differential equation, the reliability index (including validity and survival index) for the proposed model is obtained, and four types of European barrier option (including up-and-in call, down-and-in put, up-and-out put, and down-and-out call options) pricing formulas are obtained accordingly. Lastly, applying the predictor–corrector method, numerical algorithms are provided for calculating European barrier and the reliability index, numerical experiments and corresponding sensitivity analysis are also illustrated concerning various conditions.

A theoretical framework and models are proposed for reliability analysis and setting reliability requirements based on the cost of failure. It is demonstrated that a high availability target does not necessarily limit the risk of failure or minimize the total losses. The proposed models include:

(i) models for determining the value from the reliability investment,

(ii) optimization models for minimizing the total losses,

(iii) models for limiting the risk of failure below a maximum acceptable level,

(iv) a model for guaranteeing an availability target and

(v) a model for guaranteeing a minimum failure-free operating interval before each random failure in a finite time interval.

The models related to the value from the reliability investment can be used to determine the effect from reducing early-life failures on the financial revenue.

On the basis of a counterexample it is demonstrated that altering the hazard rates of the components may lead to decreasing the probability of failure of the system and a simultaneous increase of the risk of failure, which shows that the cost-of-failure reliability analysis requires new reliability tools, different from the conventional tools.

A new closed-form relationship has been derived related to reliability associated with an overstress failure mechanism. On its basis, a method for setting reliability requirements has been proposed, which limits the risk of impact failure within a maximum acceptable level. On the basis of counterexamples, it has also been demonstrated that for a load and strength not following a normal distribution, the standard reliability measures "reliability index" and "loading roughness" can be misleading. A new reliability integral has been proposed, based on integration performed only within the region of the upper tail of the load distribution and the lower tail of the strength distribution.

A fast, reliable and optimized numerical procedure of the hydrodynamic response analysis of a slender-body structure is presented. With this method, the dynamic response and reliability of a six-leg jack-up-type wind turbine installation vessel under various environmental conditions is analyzed. The modified Morison equation is used to calculate the wave and wind-driven current excitation forces on the slender-body members. The Det Norske Veritas (DNV) rule-based formula is used to calculate the wind loads acting on the superstructure of the jack-up leg. From the modal analysis, the natural period and standardized displacement of the structure are determined. The Newmark-beta time-integration method is used to solve the equation of motion generating the time-varying dynamic responses of the structure. A parametric study is carried out for various current velocities and wind speeds. In addition, a reliability analysis is conducted to predict the effects of uncertainty of the wave period and wave height on the safety of structural design, using the reliability index to indicate the reliability of the dynamic response on the critical structural members.

In traditional structural reliability analysis, the uncertainties, such as loads and strengths, are considered as random variables with specific probability distributions. When the information is insufficient, it is difficult to obtain the distribution functions. Hence, experts are usually asked to estimate the belief degrees. Uncertainty theory is a branch of mathematics used to model the belief degrees of experts. In this paper, the factors influencing system structures are treated as independent uncertain variables. Based on that, the concepts of safety margin, structural reliability and failure belief degree are proposed, respectively. Then the general calculation methods of structural reliability and failure belief degree for monotonic safety margins are given, which are not restricted by the specific distributions of variables and the safety margin forms. Furthermore, the reliability index is given for the structure with linear safety margin and normal uncertain variables, and the relationship between structural reliability and reliability index is proposed. In addition, the geometric property of reliability index is investigated and used to define the reliability index in non-linear safety margin and normal uncertain variables case. Finally, several numerical examples are employed to demonstrate the effectiveness of the methods.

Knowledge of the secondary structure and solvent accessibility of a protein plays a vital role in the prediction of fold, and eventually the tertiary structure of the protein. A challenging issue of predicting protein secondary structure from sequence alone is addressed. Support vector machines (SVM) are employed for the classification and the SVM outputs are converted to posterior probabilities for multi-class classification. The effect of using Chou–Fasman parameters and physico-chemical parameters along with evolutionary information in the form of position specific scoring matrix (PSSM) is analyzed. These proposed methods are tested on the RS126 and CB513 datasets. A new dataset is curated (PSS504) using recent release of CATH. On the CB513 dataset, sevenfold cross-validation accuracy of 77.9% was obtained using the proposed encoding method. A new method of calculating the reliability index based on the number of votes and the Support Vector Machine decision value is also proposed. A blind test on the EVA dataset gives an average Q₃ accuracy of 74.5% and ranks in top five protein structure prediction methods. Supplementary material including datasets are available on .

The seismic response and reliability analysis of a double-hinged articulated offshore tower under the action of sea waves, currents, and earthquakes have been investigated. Major nonlinearities associated with the system such as large deformation, variable submergence, drag force, and added mass have been incorporated. The responses are obtained by spectral analyses using El Centro earthquake ground motion records. The equations of motion are formulated by Lagrangian approach and solved by Newmark β integration scheme. A limit-state function for seismic demands at the universal joint has been derived. Using the derived limit-state function and the responses obtained after the dynamic analysis, reliability assessment of the critical joint has been carried out with a probabilistic method. The results of the study show that the earthquake response investigations are quite crucial for target-based probabilistic design of the articulated system, as seismic sea environment imposes significant demands for the survival of the tower.

In the past decade, industrial wireless technology and sensor technology have seen great development, such that the advantages of wireless sensor networks (WSN) in industrial applications have become increasingly obvious. Currently, the issue of how to design and build a stable and reliable industrial wireless sensor network remains an important research area in this field. In this paper, the operational information of each industrial wireless sensor network communication node is collected as a reliability test, and the information source is analyzed and evaluated. A reliability evaluation model is constructed based on factors affecting the reliability of industrial WSNs and a reliability assessment which uses traditional data analysis and mining methods. By using effective reliability evaluation strategies and methods, the reliability assessment's accuracy is guaranteed. As for the performance indicators of an industrial WSN's reliability, the impact of the protocol layer on network reliability was investigated. Based on this framework, the reliability index model and reliability evaluation method were studied.