Masking Strategies for Image Manifolds

We consider the problem of selecting an optimal mask for an image manifold, i.e., choosing a subset of the pixels of the image that preserves the manifold's geometric structure present in the original data. Such masking implements a form of compressive sensing through emerging imaging sensor platforms for which the power expense grows with the number of pixels acquired. Our goal is for the manifold learned from masked images to resemble its full image counterpart as closely as possible. More precisely, we show that one can indeed accurately learn an image manifold without having to consider a large majority of the image pixels. In doing so, we consider two masking methods that preserve the local and global geometric structure of the manifold, respectively. In each case, the process of finding the optimal masking pattern can be cast as a binary integer program, which is computationally expensive but can be approximated by a fast greedy algorithm. Numerical experiments show that the relevant manifold structure is preserved through the data-dependent masking process, even for modest mask sizes

A study of sexual violence in the digital age: Working with technology-facilitated sexual violence against women within sexual violence support services

The progressively interactive capabilities of new technologies are combining to change the landscape of personal, social and professional lives. Research is growing on the use of technologies to sexually exploit, harass and abuse individuals, with the majority of studies focusing on the experiences of young people. Less is known about the experiences of adult women and the subsequent impact of these events. Addressing this gap in the research is therefore important in responding to and supporting women’s experiences of sexual violence facilitated by the use of technology. The study is from a social constructionist perspective and utilised a qualitative methodological approach in the form of narrative inquiry and thematic analysis to analyse the data and is based upon interviews with five participants who work within sexual violence support services. It explored how participants construct meaning in relation to technology-facilitated sexual violence against women, how they respond to it and how it subsequently impacts victims. The data was then examined using thematic analysis, which identified four primary themes. The findings demonstrate that understanding technology-facilitated sexual violence is a complex process encompassing the context, frequency and type of sexual violence experienced; it involves the sexualisation of women online and understanding online predatory behaviour. Participants report a negative personal and professional impact on victims, ranging from feelings of shame and fear of exposure to being prevented from pursuing professional goals. Service provision is viewed as inconsistent and problematic. This study considers the findings in the context of theories of shame, the embodiment of harm online and the construction of identity in relation to technology. It also considers the changing landscape of sexual violence against women in relation to technology within the wider context of violence against women

Zero-one IP problems: Polyhedral descriptions & cutting plane procedures

A systematic way for tightening an IP formulation is by employing classes of linear inequalities that define facets of the convex hull of the feasible integer points of the respective problems. Describing as well as identifying these inequalities will help in the efficiency of the LP-based cutting plane methods. In this report, we review classes of inequalities that partially described zero-one poly topes such as the 0-1 knapsack polytope, the set packing polytope and the travelling salesman polytope. Facets or valid inequalities derived from the 0-1 knapsack and the set packing polytopes are algorithmically identifie

On the Order of the Schur Multiplier of a Pair of Finite p-Groups

In 1998, G. Ellis defined the Schur multiplier of a pair $(G,N)$ of groups and mentioned that this notion is a useful tool for studying pairs of groups. In this paper, we characterize the structure of a pair of finite $p$-groups $(G,N)$ in terms of the order of the Schur multiplier of $(G,N)$ under some conditions.Comment: 11 pages, to appear in Journal of Advanced Research in Pure Mathematic

Switchable filtering in vivaldi antenna

Presented is a new frequency switchable Vivaldi antenna that has a capability to operate in a wideband mode (1-3 GHz) and reconfigure to six different subbands of operations. The reconfiguration is realised by coupling and changing the effective electrical length of ring slots inserted in the structure by means of pin diode switches. To examine antenna performances, simulated and measured results are presented. Good impedance matches and radiation patterns have been achieved. The proposed antenna is suitable for wideband and multimode radio applications

A review on non-stereospecific haloalkanoic acid dehalogenases

Haloalkanoic acid dehalogenases remove halides from organic haloacids and have potential as bioremediation agents. DehE from Rhizobium sp. RC1, DehI from Pseudomonas putida PP3 and D,LDEX 113 from Pseudomonas sp. 113 are non-stereospecific dehalogenases that invert the configurations of D- and L- carbons bound to a halogen. The kinetics of DehE has been partially characterized and brominated compounds have greater specificity constant values than do the corresponding chlorinated compounds. The sequence of DehE is similar to that of DehI; therefore, the two enzymes may have similar structures and functions. The three-dimensional structure of DehI is known and its reaction mechanism was inferred from its structure and a mutagenesis study of D,L-DEX 113. Aspartate residues at positions 189 and 194 in DehI and D,L-DEX 113 were predicted to be involved in catalysis. These residues activate a water molecule that directly attacks the chiral carbon. Because DehE and DehI are sequentially related, delineating the structure of DehE is important to ascertain if the catalytic residues and reaction mechanism are the same for both enzymes. A structural prediction, sequence-homology modeling and a site-directed mutagenesis study of DehE might help achieve this goal.Key words: Haloalkanoic acids, non-stereospecific dehalogenase, DehE, Rhizobium sp. RC1, enzyme kinetics, protein structure prediction, site-directed mutagenesis

Motif Pemilihan Metode Penelitian dalam Penyusunan Skripsi (Studi pada Mahasiswa Fakultas Ilmu Komunikasi Universitas Mercu Buana Jakarta)

Adanya kewajiban membuat skripsi menuntut mahasiswa untuk mengelaborasi pemikirannya dengan merujuk pada teori dan pemilihan metode penelitian yang tepat. Tujuan penelitian ini adalah untuk mengetahui motif pemilihan metode penelitian dalam penyusunan skripsi bagi mahasiswa Fakultas Ilmu Komunikasi Universitas Mercu buana Jakarta. Aspek teoretis dalam penelitian ini mengkaji tentang perspektif dan paradigma dalam ilmu komunikasi, dan juga membahas aspek metodologis dan motif. Penelitian ini menggunakan pendekatan kualitatif melalui metode deskriptif kualitatif Subjek penelitian adalah mahasiswa Fakultas Ilmu komunikasi yang sedang dalam proses penyusunan skripsi. Teknik pengumpulan data menggunakan wawancara, observasi didukung studi literatur. Teknik analisis data merujuk pada analisis data deskriptif kualitatif. Hasil Penelitian menunjukkan bahwa motif mahasiswa menggunakan metode penelitian didasarkan pada kemudahan metode yang digunakan, dan juga faktor kesesuaian dengan fenomena yang diteliti. Faktor-faktor lain berkaitan dengan dosen pengampu matakuliah metode penelitian, minat dan kemampuan mahasiswa, buku rujukan atau referensi yang memadai dan faktor teman. Pemahaman mahasiswa akan metode penelitian relatif masih kurang. Adapun faktor pendukung dalam penyelesaian skripsi adalah: niat/kemauan atau mood, pembimbing yang mudah ditemui dan sering memberikan motivasi juga sarana seperti ketersediaan referensi dan lain-lain. Hambatan dalam penyusunan skripsi antara lain: faktor pembimbing, faktor mahasiswa sendiri, kendala di lapangan seperti objek maupun responden/informan yang sulit ditemu

The Rise of Islamic Religious-political Movements in Indonesia: the Background, Present Situation and Future

This paper traces the roots of the emergence of Islamic religious and political movements in Indonesia especially during and after their depoliticization during the New Order regime. There were two important impacts of the depoliticization, first, the emergence of various study groups and student organizations in university campuses. Second, the emergence of Islamic political parties after the fall of Suharto. In addition, political freedom after long oppression also helped create religious groups both radical on the one hand and liberal on the other. These radical and liberal groups were not only intellectual movements but also social and political in nature. Although the present confrontation between liberal and moderate Muslims could lead to serious conflict in the future, and would put the democratic atmosphere at risk, the role of the majority of the moderates remains decisive in determining the course of Islam and politics in Indonesia