A combination of Broyden-Fletcher-Goldfarb-Shanno (BFGS) and n-th section method for solving small-scale unconstrained optimization

In this research, a new inexact line search method known as n-th section method is used to obtain the step size in BFGS method. The n-th section method is the modification of the original bisection method. As in bisection method, this simple n-th section method divides each interval section with an even number of interval which is greater than two. This new proposed algorithm is compared with the original bisection, newton and secant method in terms of number of iteration. Numerical results is obtained based on small scale functions .This research shows that the algorithm is more efficient than using the ordinary line search methods. Besides, this proposed algorithm also possessed global convergence properties.

Mooring System Calibration of the Damaged Condition, Accidental Limit State (ALS)

Structural reliability analysis (SRA) has been used to calculate the probability of two adjacent mooring line failures. The initial failure is caused by some exceptional causes which most likely is related to substandard strength, but could also be exceptionally high tension caused by mal operation. Empirical failure data are used to assess the probability of initial failure. The ALS in the context here should control the probability a second mooring line failure with ordinary strength, adjacent to the initial failure of a weak substandard line. This check is also called the ULS redundancy check in ISO 19901-7. A range of different units have been considered, comprising ship shaped units and semisubmersibles at different water depths from 100 m to 2200 m. Environmental conditions representative for the Norwegian continental shelf and the Gulf of Mexico are used in the analyses, and the characteristics of the results in the different environments are compared and discussed. Analyses for Brazilian environment are currently ongoing, but not included here. Considerations for when the initial failure occurs have been made, and three different time intervals are considered: i) Failure of the second line during the transient motion after first failure, ii) failure of both lines in the same storm and iii) failure of the second line during stationary conditions after the initial failure. Time interval ii) is identified as most critical, when there is practically no time to implement mitigating actions. Detailed SRA analyses have been carried out, and include the concept of having a weak line in the system that represents the first failure. It was found that weak lines, with strength distributions that are consistent with the empirical probability of line failure, are too weak to contribute significantly to reduce the probability of the 2nd line failure of an ordinary line. The probability of the combined event of 2 line failure can therefore be simplified and set equal to the product of the probability of the presence of a weak line and the probability of 2nd line failure of an ordinary line in a system with one line missing. Time domain analysis is applied to obtain the short-term, extreme value distribution of line tension in the most loaded line after one line is removed from the mooring system. A large number of different metocean conditions are considered. A response surface is used to interpolate on the distribution parameters to describe the tension response in varying conditions. Joint probabilistic models of the metocean environment corresponding to the different geographical locations have been applied, taking account of wind, wave and current and their respective heading angles. The mooring line component strength is based on strength data from break load tests. Conventional catenary chain-wire chain systems as well as polyester moorings are considered. The probability of failure, conditional on the initial failure, is calculated using SRA. Calibration of safety factors are provided for different reliability levels, and for different assumptions for the probability of the presence of a weak line. It is demonstrated how the ALS criterion can be relaxed if the frequency of initial line failures due to exceptional causes is reduced. The final recommendations on target reliability level and on the probability of having a weak line in the mooring system are given in a companion paper at OMAE 2017, which comprises both the ULS and the ALS. It is demonstrated that alternative design formats can provide a more consistent safety level across the cases. A different design philosophy is needed the Gulf of Mexico to achieve acceptable risk, and options are discussed. This paper is the second one in a series of three at OMAE 2017, where the first one deals with structural reliability analysis of the ULS and the third one provides summary and recommendations for safe mooring design in ULS and ALS.

Bagger–Witten line bundles on moduli spaces of elliptic curves

In this paper, we discuss Bagger–Witten line bundles over moduli spaces of SCFTs. We review how in general they are “fractional” line bundles, not honest line bundles, twisted on triple overlaps. We discuss the special case of moduli spaces of elliptic curves in detail. There, the Bagger–Witten line bundle does not exist as an ordinary line bundle, but rather is necessarily fractional. As a fractional line bundle, it is nontrivial (though torsion) over the uncompactified moduli stack, and its restriction to the interior, excising corners with enhanced stabilizers, is also fractional. It becomes an honest line bundle on a moduli stack defined by a quotient of the upper half plane by a metaplectic group, rather than [Formula: see text]. We review and compare to results of recent work arguing that well-definedness of the worldsheet metric implies that the Bagger–Witten line bundle admits a flat connection (which includes torsion bundles as special cases), and gives general arguments on the existence of universal structures on moduli spaces of SCFTs, in which superconformal deformation parameters are promoted to nondynamical fields ranging over the SCFT moduli space.

Lateral Shift Error due to Graduation Anomalies and Line-Detection Algorithm in Line Scale Measurement

The measurement error resulting from graduation anomalies and the signal processing algorithm used for determining the positions of graduations on line scales was investigated by simulation and experiment. Optical image-forming simulations were carried out on models of 6-µm-wide graduations with three sizes of defects (0.5, 1.0 and 1.5 µm) at one edge. A digital filter was used in signal processing to obtain the first differential to determine the positions of the graduations. The minimum values of the lateral shift of the determined graduation positions were observed for the three defect sizes when using a 9-µm-wide differential filter. An experiment was also carried out on an ordinary line scale with 6-µm-wide graduations using a high-precision laser-interferometric line scale calibration system by measuring seven positions on the scale in the direction perpendicular to the measurement axis. The root mean square of the standard deviations from the linear fitting lines constructed using the measured positions over a 300-mm-long line scale was 2.8 nmwhen the differential filter width was 9 µm. It was demonstrated that a differential filter was effective in reducing the lateral error due to graduation anomalies.

Developing a User Centered Model for Ubiquitous Healthcare System Implementation

In the advent of pervasive computing technologies, the ubiquitous healthcare information system, or u-health system, has emerged as an innovative avenue for many healthcare management issues. Drawing upon practices in healthcare industry and conceptual developments in information systems research, this article aims to explain the latent relationships amongst user-oriented factors that lead to individual’s adoption of the new technology. Specifically, this study focuses on the introduction of chronic disease u-health system. Using the ordinary line square (OLS) regression analysis, we are able to discover the insights concerning which constructs affect service subscriber’s behavioral intention of use. Based on the data collected from over 440 respondents, empirical evidences are presented to support that factors such as medical conditions, perceived need, consumer behavior, and effort expectancy significantly influence the formation of usage intention.

Towards a Conceptual Framework of Adopting Ubiquitous Technology in Chronic Health Care

In the advent of pervasive computing technologies, the ubiquitous healthcare information system, or U-health system, has emerged as an innovative avenue for many healthcare management issues. Drawing upon practices in healthcare industry and conceptual developments in information systems research, this paper aims to explain the latent relationships amongst user-oriented factors that lead to individual’s adoption of the new technology. Specifically, this study focuses on the introduction of chronic disease U-health system. Using the Ordinary Line Square (OLS) regression analysis, we are able to discover the insights concerning which constructs affect service subscriber’s behavioral intention of use. Based on the data collected from over 440 respondents, empirical evidences are presented to support that factors such as medical conditions, perceived need, consumer behavior, and effort expectancy significantly influence the formation of usage intention.

Key Issues in the Specification of High Strain Line Pipe Used in Strain-Based Designed Districts of the 2nd West to East Pipeline

The 2nd West-East Pipeline Project which are building now is the longest of X80 gas pipeline in China even in the world. The geological conditions along it are very complicate. Both stress-base and Strain-based design are all used in the pipeline design. Strain-based design are considered when the pipeline shall via seismic activities, fault crossing and other geological disaster area where ground moving may happen. The pipe which will be used in this kind of special area shall have some special properties besides the properties requirement of the ordinary line pipe. So Tubular Goods Research Center of China National Petroleum Corporation drafted “the Supplementary Technical Specification of High Strain LSAW Line Pipe for the 2nd West-East Pipeline Project”. In this specification, the strain capacity of current X80 line pipe and the testing methods for the mechanical properties are considered. In the mean time, the risk of aging when the pipes are coated is also be noted, and the coating temperature is specified in the specification. Certainly, besides the deformability of the pipe, strain-based design also needs more measures from pipeline construction, girth welding, etc. to ensure the pipeline can endure certain deformation. This paper introduced the general situation of the 2nd West-East Pipeline Project, and several key issues in the specification of high strain line pipe used in strain-based designed districts. At the end of the paper, the mechanical properties and the deformability of X80 pipe which are possible to be manufactured and used in this gas line are be presented.

Observed and computed spectral line profiles

For the diagnostics of stellar surface structure, studies of “ordinary” line profiles may prove inadequate. However, hydrodynamic models may be constrained by second-order quantities, such as line asymmetries and wavelength shifts (and especially the differential behavior between lines of different excitation potential, ionization stage, and height of formation, as well as by the time dependence).