A signomial programming approach for binary image restoration by penalized least squares

The authors present a novel optimization approach, using signomial programming (SP), to restore noise-corrupted binary and grayscale images. The approach requires the minimization of a penalized least squares functional over binary variables, which has led to the design of various approximation methods in the past. In this brief, we minimize the functional as a SP problem which is then converted into a reversed geometric programming (GP) problem and solved using standard GP solvers. Numerical experiments show that the proposed approach restores both degraded binary and grayscale images with good accuracy, and is over 20 times faster than the positive semidefinite programming approach. © 2007 IEEE.published_or_final_versio

Aberration-aware robust mask design with level-set-based inverse lithography

Optical proximity correction (OPC) is one of the most widely used Resolution Enhancement Techniques (RET) in mask designs. Conventional OPC is often designed for a set of nominal imaging parameters without giving sufficient attention to the process variations caused by aspherical wavefront leaving the exit pupil of the lithography system. As a result, the mask designed may deliver poor performance with process variations. In this paper, we first describe how a general point spread function (PSF) with wave aberration can degrade the output pattern quality, and then show how the wave aberration function can be incorporated into an inverse imaging framework for robust input mask pattern design against aberrations. A level-set-based time-dependent model can then be applied to solve it with appropriate finite difference schemes. The optimal mask gives more robust performance against either one specific type of aberration or a combination of different types of aberrations. © 2010 SPIE.published_or_final_versionThe Photomask and Next-Generation Lithography Mask Technology XVII, Yokohama, Japan, 13-14 April 2010. in Proceedings of SPIE, 2010, v. 7748, article no. 77481U, p. 1-

Robust level-set-based inverse lithography

Level-set based inverse lithography technology (ILT) treats photomask design for microlithography as an inverse mathematical problem, interpreted with a time-dependent model, and then solved as a partial differential equation with finite difference schemes. This paper focuses on developing level-set based ILT for partially coherent systems, and upon that an expectation-orient optimization framework weighting the cost function by random process condition variables. These include defocus and aberration to enhance robustness of layout patterns against process variations. Results demonstrating the benefits of defocus-aberration-aware level-set based ILT are presented. © 2011 Optical Society of America.published_or_final_versio

Measuring Coverage of Prolog Programs Using Mutation Testing

Testing is an important aspect in professional software development, both to avoid and identify bugs as well as to increase maintainability. However, increasing the number of tests beyond a reasonable amount hinders development progress. To decide on the completeness of a test suite, many approaches to assert test coverage have been suggested. Yet, frameworks for logic programs remain scarce. In this paper, we introduce a framework for Prolog programs measuring test coverage using mutations. We elaborate the main ideas of mutation testing and transfer them to logic programs. To do so, we discuss the usefulness of different mutations in the context of Prolog and empirically evaluate them in a new mutation testing framework on different examples.Comment: 16 pages, Accepted for presentation in WFLP 201

Cloud Ownership and Reliability – Issues and Developments

Cloud computing is a composite paradigm that provides crucial services to individuals and organisations over networked infrastructure at a cost. The Cloud provides custom built applications, made available by a CSP to customers. Several customers can access an instance of one application. The Cloud also affords an avenue for customers to build their own application in a language compatible with a CSP and subsequently deploy that application on the Cloud. In addition, massive scalable storage and computing devices are available on the Cloud. A customers expects optimum services whenever and wherever it is required. Hence, system failure on the part of a CSP must not affect the services being provided to the customer. This paper examines present trends in the area of Cloud ownership reliability and provides a guide for future research. The paper aims to answer the following question: what is the current trend and development in Cloud ownership reliability? In addition, analysis was done on existing work published in journals, conferences, white papers and those published in reputable magazines, to answer the question raised. The expected result is the identification of trends in Cloud ownership and reliability which will be of benefit to prospective Cloud users and service providers alike

Molecular markers associated with a new source of resistance to the cassava mosaic disease

The predominant source of resistance to the cassava mosaic disease (CMD) is known to be polygenic requiring evaluation in multiple environments to characterise resistant genotypes, which makes the detection of genes for resistance using segregation analysis inefficient. Recently, some landraces have been identified which exhibit high levels of resistance to CMD. In this study, molecular markers associated with resistance to CMD in a resistant landrace were identified, using F1 progenies derived from a cross between the CMD resistant landrace TME7 and the susceptible line TMS30555, as a first step in marker assisted breeding for CMD resistance. Bulk segregant analysis (BSA) on the parents, resistant and susceptible DNA pools, using simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers revealed that an SSR marker, SSRY28-180, donated by the resistant parent was linked with resistance to CMD. Marker-trait association detected by regression analysis showed that the marker, accounted for 57.41% of total phenotypic variation for resistance. The analysis furthershowed that another SSR marker, SSRY106-207 and an AFLP marker, E-ACC/M-CTC-225, accounted for 35.59% and 22.5% of the total phenotypic variation for resistance, respectively. The implication of the results in breeding for resistance to CMD is discussed

Projection optics design for tilted projection of fringe patterns

A challenge in the semiconductor industry is 3-D inspection of the miniaturized solder bumps grown on wafers for direct die-to-die bonding. An inspection mechanism proposed earlier requires the projection of a binary fringe grating to the inspected surface from an inclined angle. For high speed and accuracy of the mechanism, the projection optics has to meet these requirements: (1) it allows a tilt angle between the inspected surface and the projector's optical axis; (2) it has a high bandwidth to let high-spatial-frequency harmonics contained in the binary grating pass through the lens and be projected onto the inspected surface properly; (3) it has a high modulation transfer function; (4) it has a large field of view; and (5) it has an adequate depth of field that matches the depth range of the inspected surface. In this paper, we describe a projection optics design, consisting of a fringe grating and several pieces of spherical lens, that addresses the requirements. To reduce the lens aberrations, the grating is laid out with an angle chosen specifically to make the grating, the lens, and the average plane of the inspected surface intersect in the same line. Performance analysis and tolerance analysis are shown to demonstrate the feasibility of the design. © 2008 Society of Photo-Optical Instrumentation Engineers.published_or_final_versio

A study of time variability of surface currents at a point in Monterey Bay.

The geomagnetic electrokinetograph (GEK) was used to measure surface currents near the center of Monterey Bay during six separate 24-hour periods from May through July, 1972. An average of 244 current vectors were derived for each cruise. The mean currents from these cruises are all southerly and ranged from 4.1 cm/sec to 20.4 cm/sec. The average of these mean currents is 12.1 cm/sec toward 163 °T. These values were compared with individual currents derived from dynamic topographies from the same period. Diurnal and semi-diurnal variations of the current were studied after subjecting the data to a fourier analysis. It was concluded that there must be at least an indirect coupling of the ocean currents with the semi-diurnal tide at the data point. The diurnal component also is important; it may be tidal or inertial, or merely related to the passage of the sun.http://archive.org/details/studyoftimevaria00howtLieutenant, United States NavyApproved for public release; distribution is unlimited

Geological applications of machine learning on hyperspectral remote sensing data

The CRISM imaging spectrometer orbiting Mars has been producing a vast amount of data in the visible to infrared wavelengths in the form of hyperspectral data cubes. These data, compared with those obtained from previous remote sensing techniques, yield an unprecedented level of detailed spectral resolution in additional to an ever increasing level of spatial information. A major challenge brought about by the data is the burden of processing and interpreting these datasets and extract the relevant information from it. This research aims at approaching the challenge by exploring machine learning methods especially unsupervised learning to achieve cluster density estimation and classification, and ultimately devising an efficient means leading to identification of minerals. A set of software tools have been constructed by Python to access and experiment with CRISM hyperspectral cubes selected from two specific Mars locations. A machine learning pipeline is proposed and unsupervised learning methods were implemented onto pre-processed datasets. The resulting data clusters are compared with the published ASTER spectral library and browse data products from the Planetary Data System (PDS). The result demonstrated that this approach is capable of processing the huge amount of hyperspectral data and potentially providing guidance to scientists for more detailed studies