Composite fermions close to the one-half filling of the lowest Landau level revisited

By strictly adhering to the microscopic theory of composite fermions for the Landau-level filling fractions nu_e = p/(2 p + 1), we reproduce, with remarkable accuracy, the surface-acoustic-wave (SAW)-based experimental results by Willett and co-workers concerning two-dimensional electron systems with nu_e close to 1/2. Our results imply that the electron band mass m_b, as distinct from the composite fermion mass m_*, must undergo a substantial increase under the conditions corresponding to nu_e approximately equal to 1/2. In view of the relatively low aerial electronic densities n_e to which the underlying SAW experiments correspond, our finding conforms with the experimental results by Shashkin et al. [Phys. Rev. B 66, 073303 (2002)], concerning two-dimensional electrons in silicon, that signal sharp increase in m_b for n_e decreasing below approximately 2 x 10^{11} cm^{-2}. We further establish that a finite mean-free path l_0 is essential for the observed linearity of the longitudinal conductivity sigma_{xx}(q) as deduced from the SAW velocity shifts.Comment: 5 pages, 2 postscript figure

Physically based multiscale-viscoplastic model for metals and steel alloys: theory and computation

The main requirement of large deformation problems such as high-speed machining, impact, and various primarily metal forming, is to develop constitutive relations which are widely applicable and capable of accounting for complex paths of deformation. Achieving such desirable goals for material like metals and steel alloys involves a comprehensive study of their microstructures and experimental observations under different loading conditions. In general, metal structures display a strong rate- and temperature-dependence when deformed non-uniformly into the inelastic range. This effect has important implications for an increasing number of applications in structural and engineering mechanics. The mechanical behavior of these applications cannot be characterized by classical (rate-independent) continuum theories because they incorporate no ‘material length scales’. It is therefore necessary to develop a rate-dependent (viscoplasticity) continuum theory bridging the gap between the classical continuum theories and the microstructure simulations. Physically based vicoplasticity models for different types of metals (body centered cubic, face centered cubic and hexagonal close-packed) and steel alloys are derived in this work for this purpose. We adopt a multi-scale, hierarchical thermodynamic consistent framework to construct the material constitutive relations for the rate-dependent behavior. The concept of thermal activation energy, dislocations interactions mechanisms and the role of dislocations dynamics in crystals are used in the derivation process taking into consideration the contribution of the plastic strain evolution of dislocation density to the flow stress of polycrystalline metals. Material length scales are implicitly introduced into the governing equations through material rate-dependency (viscosity). The proposed framework is implemented into the commercially well-known finite element software ABAQUS. The finite element simulations of material instability problems converge to meaningful results upon further refinement of the finite element mesh due to the successful incorporation of the material length scale in the model formulations. It is shown that the model predicted results compare very well with different experimental data over a wide range of temperatures (77K°-1000K°) and strain rates (10-3-104s-1). It is also concluded from this dissertation that the width of localization zone (shear band) exhibits tremendous changes with different initial temperatures (i.e., different initial viscosities and accordingly different length scales)

End‐to‐end continuous bioprocessing: impact on facility design, cost of goods and cost of development for monoclonal antibodies

This article presents a systematic approach to evaluate the business case for continuous processing that captures trade-offs between manufacturing and development costs for monoclonal antibodies (mAbs). A decisional tool was built that integrated cost of goods (COG) with cost of development models and new equipment sizing equations tailored to batch, hybrid and end-to-end continuous processes. The COG analysis predicted that single-use continuous facilities (sized using a dedicated DSP train per bioreactor) offer more significant commercial COG savings over stainless steel batch facilities at annual demands of 100-500 kg (~35%), compared to tonnage demands of 1-3 tons (~±10%) that required multiple parallel continuous trains. Single-use batch facilities were found to compete with continuous options on COG only at 100 kg/year. For the scenarios where batch and continuous facilities offered similar COG, the analysis identified the windows of operation required to reach different COG savings with thresholds for the perfusion rate, volumetric productivity and media cost. When considering the project lifecycle cost, the analysis indicated that while end-to-end continuous facilities may struggle to compete on development costs, they become more cost-effective than stainless steel batch facilities when considering the total out-of-pocket cost across both drug development and commercial activities. This article is protected by copyright. All rights reserved

Separating Reflections from Images Using Independent Components Analysis

The image of an object can vary dramatically depending on lighting, specularities/reflections and shadows. It is often advantageous to separate these incidental variations from the intrinsic aspects of an image. Along these lines this paper describes a method for photographing objects behind glass and digitally removing the reflections off the glass leaving the image of the objects behind the glass intact. We describe the details of this method which employs simple optical techniques and independent components analysis (ICA) and show its efficacy with several examples

Quantum back-action in measurements of zero-point mechanical oscillations

Measurement-induced back action, a direct consequence of the Heisenberg Uncertainty Principle, is the defining feature of quantum measurements. We use quantum measurement theory to analyze the recent experiment of Safavi-Naeini et al. [Phys. Rev. Lett. {\bf 108}, 033602 (2012)], and show that results of this experiment not only characterize the zero-point fluctuation of a near-ground-state nanomechanical oscillator, but also demonstrate the existence of quantum back-action noise --- through correlations that exist between sensing noise and back-action noise. These correlations arise from the quantum coherence between the mechanical oscillator and the measuring device, which build up during the measurement process, and are key to improving sensitivities beyond the Standard Quantum Limit.Comment: 11 pages and 4 figure

Guest editorial : In Journal of networks, v.7 n.3

Networking of computing devices has been going through rapid evolution and thus continuing to be an ever expanding area of importance in recent years. New technologies, protocols, services and usage patterns have contributed to the major research interests in this area of computer science. The current special issue is an effort to bring forward some of these interesting developments that are being pursued by researchers at present in different parts of the globe. Our objective is to provide the readership with some insight into the latest innovations in computer networking through this. This Special Issue presents selected papers from the thirteenth conference of the series (ICCIT 2010) held during December 23-25, 2010 at the Ahsanullah University of Science and Technology. The first ICCIT was held in Dhaka, Bangladesh, in 1998. Since then the conference has grown to be one of the largest computer and IT related research conferences in the South Asian region, with participation of academics and researchers from many countries around the world. Starting in 2008 the proceedings of ICCIT are included in IEEExplore. In 2010, a total of 410 full papers were submitted to the conference of which 136 were accepted after reviews conducted by an international program committee comprising 81 members from 16 countries. This was tantamount to an acceptance rate of 33%. From these 136 papers, 14 highly ranked manuscripts were invited for this Special Issue. The authors were advised to enhance their papers significantly and submit them to undergo review for suitability of inclusion into this publication. Of those, eight papers survived the review process and have been selected for inclusion in this Special Issue. The authors of these papers represent academic and/or research institutions from Australia, Bangladesh, Japan, Korea and USA. These papers address issues concerning different domains of networks namely, optical fiber communication, wireless and interconnection networks, issues related to networking hardware and software and network mobility. The paper titled “Virtualization in Wireless Sensor Network: Challenges and Opportunities” argues in favor of bringing in different heterogeneous sensors under a common virtual framework so that the issues like flexibility, diversity, management and security can be handled practically. The authors Md. Motaharul Islam and Eui-Num Huh propose an architecture for sensor virtualization. They also present the current status and the challenges and opportunities for further research on the topic. The manuscript “Effect of Polarization Mode Dispersion on the BER Performance of Optical CDMA” deals with impact of polarization mode dispersion on the bit error rate performance of direct sequence optical code division multiple access. The authors, Md. Jahedul Islam and Md. Rafiqul Islam present an analytical approach toward determining the impact of different performance parameters. The authors show that the bit error rate performance improves significantly by the third order polarization mode dispersion than its first or second order counterparts. The authors Md. Shohrab Hossain, Mohammed Atiquzzaman and William Ivancic of the paper “Cost and Efficiency Analysis of NEMO Protocol Entities” present an analytical model for estimating the cost incurred by major mobility entities of a NEMO. The authors define a new metric for cost calculation in the process. Both the newly developed metric and the analytical model are likely to be useful to network engineers in estimating the resource requirement at the key entities while designing such a network. The article titled “A Highly Flexible LDPC Decoder using Hierarchical Quasi-Cyclic Matrix with Layered Permutation” deals with Low Density Parity Check decoders. The authors, Vikram Arkalgud Chandrasetty and Syed Mahfuzul Aziz propose a novel multi-level structured hierarchical matrix approach for generating codes of different lengths flexibly depending upon the requirement of the application. The manuscript “Analysis of Performance Limitations in Fiber Bragg Grating Based Optical Add-Drop Multiplexer due to Crosstalk” has been contributed by M. Mahiuddin and M. S. Islam. The paper proposes a new method of handling crosstalk with a fiber Bragg grating based optical add drop multiplexer (OADM). The authors show with an analytical model that different parameters improve using their proposed OADM. The paper “High Performance Hierarchical Torus Network Under Adverse Traffic Patterns” addresses issues related to hierarchical torus network (HTN) under adverse traffic patterns. The authors, M.M. Hafizur Rahman, Yukinori Sato, and Yasushi Inoguchi observe that dynamic communication performance of an HTN under adverse traffic conditions has not yet been addressed. The authors evaluate the performance of HTN for comparison with some other relevant networks. It is interesting to see that HTN outperforms these counterparts in terms of throughput and data transfer under adverse traffic. The manuscript titled “Dynamic Communication Performance Enhancement in Hierarchical Torus Network by Selection Algorithm” has been contributed by M.M. Hafizur Rahman, Yukinori Sato, and Yasushi Inoguchi. The authors introduce three simple adapting routing algorithms for efficient use of physical links and virtual channels in hierarchical torus network. The authors show that their approaches yield better performance for such networks. The final title “An Optimization Technique for Improved VoIP Performance over Wireless LAN” has been contributed by five authors, namely, Tamal Chakraborty, Atri Mukhopadhyay, Suman Bhunia, Iti Saha Misra and Salil K. Sanyal. The authors propose an optimization technique for configuring the parameters of the access points. In addition, they come up with an optimization mechanism in order to tune the threshold of active queue management system appropriately. Put together, the mechanisms improve the VoIP performance significantly under congestion. Finally, the Guest Editors would like to express their sincere gratitude to the 15 reviewers besides the guest editors themselves (Khalid M. Awan, Mukaddim Pathan, Ben Townsend, Morshed Chowdhury, Iftekhar Ahmad, Gour Karmakar, Shivali Goel, Hairulnizam Mahdin, Abdullah A Yusuf, Kashif Sattar, A.K.M. Azad, F. Rahman, Bahman Javadi, Abdelrahman Desoky, Lenin Mehedy) from several countries (Australia, Bangladesh, Japan, Pakistan, UK and USA) who have given immensely to this process. They have responded to the Guest Editors in the shortest possible time and dedicated their valuable time to ensure that the Special Issue contains high-quality papers with significant novelty and contributions

Perancangan Ergonomi Kursi Kafe dengan Participatory Design

Studi ergonomi yang dilakukan adalah pengujian Kenyamanan produk kursi kafe. Desain kursi initerdiri dari enam komponen: bagian tempat duduk, sandaran bahu, dan empat buah kaki. Aplikasikursidigunakanbaikuntuk dirumahmaupunperhotelan mencakupkafetaria, terasdanrestoransederhana.Tujuan dari penelitian ini adalah untuk mengukur tingkat Kenyamanan dudukpada rancangan kursi tersebut.Oleh karena Kenyamanan merupakan sesuatu yang subyektif makaalam studi ini melibatkan pengguna dalam pengukurannya untuk memastikan bahwa produk yangdirancang sesuai dengan kebutuhan Kenyamanan pengguna.Untuk mengukur Kenyamanan ini makaukuran kursi harus sesuai dengan ukuran antropometri pengguna yang ditujukan untuk usia 20-30tahun dan diharapkan dapat menjangkau 90% populasi pengguna. Ukuran kursi yang dirancangdengan satu jenis ukuran atau all size. Karena sifatnya yang subyektif tersebut maka dalam studi inimenggunakan metode participatory design, dimana pengguna dilibatkan untuk memberikanpenilaian Kenyamanan desain kursi.7 partisipan terdiri dari 5 pria dan 2 wanita menguji prototipekursi dan memberikan penilaian terhadap dimensi: tinggi -, kedalaman -, lebar -, dan penilaiankenyamanan keseluruhan kursi. Pengujian dilakukan tiga kali menghasilkan ukuran optimal untuktinggi 470 mm, dalam 410 mm , dan lebar 435 mm

Dynamic Localizations in Structural Steel at High Strain Rates and Temperatures – COMPLAS XI

The proposed paper presents a numerical study on the formation of shear bands at localized regions in two ferrite steel alloys, HSLA-65 and DH-36, subjected to certain range of velocity impact. Constitutive relations developed by the author [1] for ferritic steels is utilized in simulating the thermal and athermal parts of the flow stress over a wide range of temperatures and strain rates. The proposed plasticity model is implemented into the commercially well-known finite element software ABAQUS through VUMAT user subroutine. This implementation enables studying the shear band formation over a wide range of initial temperatures and strain rates in a cylindrical hat-shaped specimen with certain dimensions where the location of shear localization preceding shear band formation is forced to be between the hat and the brim. Sensitivity analysis is performed on different mesh configurations in order to select the optimum mesh. Another sensitivity analysis is also performed on the constitutive plasticity model material parameters to study their effect on the shear bands formation. Several conclusions related to the width of the shear bands considering the velocity load and initial temperatures will be discussed throughout this work

GOOD VILLAGE GOVERNANCE: MENCEGAH FRAUD PENGELOLAAN KEUANGAN DANA DESA MELALUI APLIKASI SISKEUDES

Abstrac, This study aims to determine the application of the siskeudes application as an effort to overcome and prevent potential acts of corruption and fraud in village fund management activities in realizing good village governance. This research was conducted in Barangmamase Village, South Galesong District, Takalar Regency. This research is a qualitative research with a case study approach. The results of the study indicate that the Barangmamase Village government has managed village funds properly in accordance with applicable regulations. The siskeudes application applied in the village government system is able to prevent and overcome acts of fraud or fraud caused by pressure, opportunity, rationalization, competence and arrogance. And with the implementation of the siskeudes application in the Barangmamase Village government, it is able to support the realization of a good government system towards the concept of good village governance. Abstrak, Penelitian ini bertujuan untuk mengetahui penerapan aplikasi siskeudes sebagai upaya untuk mengatasi dan mencegah potensi perbuatan korupsi dan kecurangan terhadap kegiatan pengelolaan dana desa dalam mewujudkan good village governance. Penelitian ini dilakukan di Desa Barangmamase Kecamatan Galesong Selatan kabupaten Takalar. Penelitian ini merupakan penelitian kualitatif dengan pendekatan studi kasus. Hasil penelitian menunjukkan bahwa pemerintah Desa Barangmamase telah melakukan pengelolaan dana desa dengan baik sesuai dengan aturan yang berlaku. Aplikasi siskeudes yang diterapkan dalam sistem pemerintahan desa mampu mencegah dan mengatasi tindakan fraud atau kecurangan yang disebabkan oleh faktor tekanan (pressure), kesempatan (opportunity), rasionalisasi (rationalization), keahlian (competence) dan arogansi (arrogance). Serta dengan diterapkannya aplikasi siskeudes dalam pemerintahan Desa Barangmamase mampu mendukung terwujudnya sistem pemerintahan yang baik menuju konsep good village governance.Penelitian ini bertujuan untuk mengetahui penerapan aplikasi siskeudes sebagai upaya untuk mengatasi dan mencegah potensi perbuatan korupsi dan kecurangan terhadap kegiatan pengelolaan dana desa dalam mewujudkan good village governance. Penelitian ini dilakukan di Desa Barangmamase Kecamatan Galesong Selatan kabupaten Takalar. Penelitian ini merupakan penelitian kualitatif dengan pendekatan studi kasus. Hasil penelitian menunjukkan bahwa pemerintah Desa Barangmamase telah melakukan pengelolaan dana desa dengan baik sesuai dengan aturan yang berlaku. Aplikasi siskeudes yang diterapkan dalam sistem pemerintahan desa mampu mencegah dan mengatasi tindakan fraud atau kecurangan yang disebabkan oleh faktor tekanan (pressure), kesempatan (opportunity), rasionalisasi (rationalization), keahlian (competence) dan arogansi (arrogance). Serta dengan diterapkannya aplikasi siskeudes dalam pemerintahan Desa Barangmamase mampu mendukung terwujudnya sistem pemerintahan yang baik menuju konsep good village governance