Minimum Modification Research Articles

Gustav Mie's longitudinal electrical field lines and superluminal signals and longitudinal waves

In his textbook, Gustav Mie states, that the radiation field consists solely of transverse electrical field lines, which are closed. The longitudinal field lines goes without interruption from the positive to the negative charges; they cannot be expelled. This raises the question about the speed of propagation along them. For this, a mathematical description of Mie's field lines is developed the Helmholtz-transverse and longitudinal components of \vec{E} are non-local auxiliary quantities and thus not suitable for that. On the other hand, Mie also states, that the propagation of electromagnetic fields is governed by Maxwell's equations and Poynting's theorem. Here, however, there is a single wave equation for all vector components of the electrical field. In this contribution, a minimum modification of Maxwell's equations is proposed, which yields both, an instantaneous Coulomb field and longitudinal electrical radiation.

A Framework of Fingerprint Scaling

Fingerprint scaling refers to the adjustment of fingerprint images to solve the problem of sensor interoperability. In this paper, we present an innovative framework of fingerprint scaling with minimum modification to existing systems. For the purpose of facilitating system configuration, we have developed a series of scaling methods, including scaling factors, graph- and template-based scaling methods. In graph-based scaling methods, we have explored the application of various technologies in estimation of the average inter-ridge distance. In template-based scaling methods, we have developed an estimation method using Delaunay triangulation algorithm. The experiments show that the performance achieved by using this framework is better than that of original system. With a scaling module, the average EER in our experiments drops from 27.78% to 13.89%. DOI: http://dx.doi.org/10.11591/telkomnika.v11i3.2304

Temperature‐aware methodology for time synchronisation protocols in wireless sensor networks

To exploit distributed computation in wireless sensor networks (WSNs) time synchronisation protocols are required. These protocols support advanced distributed and synchronous tasks between several nodes. Temperature changes have a strong influence in oscillators and may vary the clock of the nodes. The flooding time synchronisation protocol (FTSP) is a common time-sync protocol in WSNs. It cannot deal with rapid temperature changes and needs several long periods to readjust the clock drift. Proposed is an innovative correction factor, implemented in a module called advanced adjustment temperature (A2T), that minimises the impact of temperature in the clock skew. This module may be placed on top of any clock-skew based time synchronisation protocol with minimum coding modifications. For this work, the module has been linked to the FTSP, producing A2T-FTSP. Experiments show that A2T-FTSP reduces noticeably the average synchronisation errors compared to FTSP for the same varying temperature conditions.

Fingerprint Scaling for Sensor Interoperability

The need for sensor interoperability has increased tremendously in many large-scale fingerprint applications such as e-commerce, welfare-disbursement and e-education. In this paper, we present fingerprint scaling, an innovative fingerprint system module, which resizes the fingerprint images to solve the problem of sensor interoperability with minimum modification to existing system. In template-based scaling methods, we have developed an estimation method using Delaunay triangulation algorithm. The efficacy of the scaling technique has been assessed by embedding a scaling module into a traditional fingerprint recognition system. Our experiments have shown very positive results. Experimental results indicated that the accuracy and robustness of fingerprint system can be improved effectively by embedding such a scaling module into the traditional framework of fingerprint systems under multi-sensor situation.

Semi-Random Backoff: Towards Resource Reservation for Channel Access in Wireless LANs

This paper proposes a semi-random backoff (SRB) method that enables resource reservation in contention-based wireless LANs. The proposed SRB is fundamentally different from traditional random backoff methods because it provides an easy migration path from random backoffs to deterministic slot assignments. The central idea of the SRB is for the wireless station to set its backoff counter to a deterministic value upon a successful packet transmission. This deterministic value will allow the station to reuse the time-slot in consecutive backoff cycles. When multiple stations with successful packet transmissions reuse their respective time-slots, the collision probability is reduced, and the channel achieves the equivalence of resource reservation. In case of a failed packet transmission, a station will revert to the standard random backoff method and probe for a new available time-slot. The proposed SRB method can be readily applied to both 802.11 DCF and 802.11e EDCA networks with minimum modification to the existing DCF/EDCA implementations. Theoretical analysis and simulation results validate the superior performance of the SRB for small-scale and heavily loaded wireless LANs. When combined with an adaptive mechanism and a persistent backoff process, SRB can also be effective for large-scale and lightly loaded wireless networks.

고품질의 3D 콘텐츠 제작을 위한 베이지안 접근방식의 사진측량기반 편위수정기법 개발

This paper proposes a photogrammetric rectification method based on Bayesian approach as a method that eliminates vertical parallax between stereo images to minimize visual fatigue of 3D contents. The image rectification consists of two phases; geometry estimation and epipolar transformation. For geometry estimation, coplanarity-based relative orientation algorithm was used in this paper. To ensure robustness for mismatch and localization error occurred by automation of tie point extraction, Bayesian approach was applied by introducing several prior constraints. As epipolar transformation perspective transformation was used based on condition of collinearity to minimize distortion of result images and modification for input images. Other algorithms were compared to evaluate performance. For geometry estimation, traditional relative orientation algorithm, 8-points algorithm and stereo calibration algorithm were employed. For epipolar transformation, Hartley algorithm and Bouguet algorithm were employed. The evaluation results showed that the proposed algorithm produced results with high accuracy, robustness about error sources and minimum image modification.

Effect of Pilot Fuel Quantity on the Performance and Emission Characteristics of a Pre-Mixed CNG - Diesel Dual Fuel Mode Engine

The serious environmental pollution and the energy crisis all over the world has caused for development of the lower pollution and lower energy consumption automobile to become major research goal. With huge back ground, Compressed Natural Gas (CNG) is projected as the best alternative fuel for the country like India. The properties of CNG make it an ideal fuel for direct use in spark ignition engines. Conversion of any existing spark ignition engine to operate on natural gas is relatively simple with available equipment. Many spark ignition engine vehicles are successfully operating in major cities of India with CNG fuel. However CNG cannot be used as a fuel in diesel engines with ease. Since the maximum engines at present run on diesel, it will be very much useful if a solution could be found to alter the existing diesel engine with minimum modifications to run on CNG. Several researchers could attempt to run diesel engines with CNG. In the process three methods were reported to be successful to use CNG as a fuel in diesel engines, they are (i) Spark ignited gas mode (ii) Direct injection of CNG in dual fuel mode and (iii) Premixed CNG dual fuel mode. In the present work a premixed dual fuel engine was developed which can perform well for the entire range of load and experiments are carried out by varying the pilot fuel amount and studied the effect of pilot fuel amount on engine performance and emissions characteristics and determined optimum fuel injection quantity for better performance and lower emissions.

Design and Implement a MapReduce Framework for Executing Standalone Software Packages in Hadoop-based Distributed Environments

The Hadoop MapReduce is the programming model of designing the auto scalable distributed computing applications. It provides developer an effective environment to attain automatic parallelization. However, most existing manufacturing systems are arduous and restrictive to migrate to MapReduce private cloud, due to the platform incompatible and tremendous complexity of system reconstruction. For increasing the efficiency of manufacturing systems with minimum modification of existing systems, we design a framework in this thesis, called MC-Framework: Multi-uses-based Cloudizing-Application Framework. It provides the simple interface to users for fairly executing requested tasks worked with traditional standalone software packages in MapReduce-based private cloud environments. Moreover, this thesis focuses on the multiuser workloads, but the default Hadoop scheduling scheme, i.e., FIFO, would increase delay under multiuser scenarios. Hence, we also propose a new scheduling mechanism, called Job-Sharing Scheduling, to explore and fairly share the jobs to machines in the MapReduce-based private cloud. Then, we prototype an experimental virtual-metrology module of a manufacturing system as a case study to verify and analysis the proposed MC-Framework. The results of our experiments indicate that our proposed framework enormously improved the time performance compared with the original package.

Research on Increasing Hob Tip Fillet Radius to Decrease Addendum Modification Coefficient

Reasonable design of hob tip fillet and calculation of modification coefficients were researched to avoid undercutting in this paper. The undercut gears were generated in the virtual environment based on Pro / E software. Meanwhile, parametric finite element models of undercut gear, ordinary modified gear generated by standard hob and modified gear generated by hob with tip fillet radius increased,were founded by APDL (ANSYS Parametric Design Language).The results show that the minimum modification coefficients chosen to avoid undercutting by traditional modification method may not meet the requirements of contact ratio or addendum thickness.While through reasonable design of hob tip fillet, modification coefficients calculated not only avoid undercutting to improve the tooth bending strength but also meet the requirements of contact ratio ε>1.2 and addendum thickness δ>0.25m (module) .

62. A method for filtering ultra-rapid cooling profiles using orthogonal wavelets

The temperature profile during the process of cooling is an important parameter in the design and description of any protocol for cryopreservation. Rapid and ultra-rapid cooling procedures, in which liquid nitrogen (LN 2 ) is used as cooling agent, require special equipment and methods in order to record and analyze the thermal history of the sample to be cryopreserved. Natural time series are a combination of stochastic behavior (noise) and determinist chaotic behavior. In cases where noise is only present on specific high frequency bands, non-linnear filtering process can be implemented in order to reduce noise without altering metric invariants. This is the case of temporal series obtained from cooling process which we are currently studying. Using a small diameter thermocouple embedded within the sample (20 μl of distilled water) mounted on a device which ensures a uniform velocity of immersion, temperature is recorded at high rate (1000 samples/s) during the cooling of the sample in LN 2 . (Juan de Paz et al., OBI 2011, O15, ISBN 978-987-27301-0-9; Kleinhans et al., Cryobiology 61 (2010) 61–63) With this configuration, system noise was ∼±2.9 °C at room temperature and ∼±6.9 °C at LN 2 temperature (−196 °C). This noise may, in some cases, cause difficulties with the analysis and interpretation of the signal. With the intention of eliminating high frequency noise, we applied a filter in such a way that in level “ j ” of the process, the residuals will be a softer version of the original signal having less high frequency signals in contrast with level “ j + 1” and half number of data. These are the main points by which, in the present work, we have used a signal isolation method based on orthogonal wavelets, in order to analyze the remaining signal with minimum modification of the associated dynamics. With this filtering method system noise was virtually eliminated allowing a more precise interpretation of the significance of cooling curves.

A review on advances of torrefaction technologies for biomass processing

Torrefaction is a thermochemical pretreatment process at 200–300 °C in an inert condition which transforms biomass into a relatively superior handling, milling, co-firing and clean renewable energy into solid biofuel. This increases the energy density, water resistance and grindability of biomass and makes it safe from biological degradation which ultimately makes easy and economical on transportation and storing of the torrefied products. Torrefied biomass is considered as improved version than the current wood pellet products and an environmentally friendly future alternative for coal. Torrefaction carries devolatilisation, depolymerization and carbonization of lignocellulose components and generates a brown to black solid biomass as a productive output with water, organics, lipids, alkalis, SiO2, CO2, CO and CH4. During this process, 70 % of the mass is retained as a solid product, and retains 90 % of the initial energy content. The torrefied product is then shaped into pellets or briquettes that pack much more energy density than regular wood pellets. These properties minimize on the difference in combustion characteristics between biomass and coal that bring a huge possibility of direct firing of biomass in an existing coal-fired plant. Researchers are trying to find a solution to fire/co-fire torrefied biomass instead of coal in an existing coal-fired based boiler with minimum modifications and expenditures. Currently available torrefied technologies are basically designed and tested for woody biomass so further research is required to address on utilization of the agricultural biomass with technically and economically viable. This review covers the torrefaction technologies, its’ applications, current status and future recommendations for further study.

OMERO.searcher: content-based image search for microscope images

OMERO.searcher: content-based image search for microscope images

Multi-objective flow-shop scheduling with parallel machines

In this paper, multi-objective flow-shop scheduling with parallel machines is considered, and an algorithm for production-scheduling optimisation is proposed. The objective is to design an algorithm to optimise production scheduling, taking into consideration customer changes to delivery dates and quantities, materials requisitioned from the supplier and inventory management. Manufacturing lead time for the production order is minimised, and, finally, resource use is considered as an auxiliary criterion. Numerical examples, modelled with data from a Mexican enterprise, and computational results are reported. The paper indicates that the mathematical model, as well as the program that solves it, provides flexibility with minimum modifications. Thus it can provide useful information for multiple decision processes.

Migration of a generic multi-physics framework to HPC environments

Creating a highly parallelizable code is a challenge specially for Distributed Memory Machines (DMMs). Moreover, algorithms and data structures suitable for these platforms can be very different from the ones used in serial code. For this reason, many programmers in the field prefer to start their own code from scratch. However, for an already existing framework supported by a long-time expertise the idea of transformation becomes attractive in order to reuse the effort done during years of development. In this presentation we explain how a relatively complex framework but with modular structure can be prepared for high performance computing with minimum modification. Kratos Multi-Physics [1] is an open source generic multi-disciplinary platform for solution of coupled problems consist of fluid, structure, thermal and electromagnetic fields. The parallelization of this framework is performed with objective of enforcing the less possible changes to its different solver modules and encapsulate the changes as much as possible in its common kernel. This objective is achieved thanks to the Kratos design and also innovative way of dealing with data transfers for a multi-disciplinary code. This work is completed by the migration of the framework from the 86× architecture to the Marenostrum Supercomputing platform. The migration has been verified by a set of benchmarks which show high scalability, from which we present the Telescope problem in this paper.

Attributes balance on the adoption of platform based solutions for satellites

This paper aims to propose the principles of a systems architecting method to assess and guide the conceptual design of platform based solutions for satellite space applications. The method helps the developers to assess the platform changeability to achieve future missions with a minimum impact in terms of modifications and to assess the platform comprehensiveness in terms of possible missions. Changeability attributes applicable to the platform aims to implement parameters like robustness, flexibility, agility, etc. showing the capacity of the platform to comply, fast and with minimum modifications, the future missions. Comprehensiveness aims to balance platform comprehensiveness attributes in terms of missions and the platform efficiency based on the additional mass necessary to cover space environment requirements like altitude (drag, radiation and torque), satellite pointing, etc. The more over dimensioned, the less efficient is the satellite. Conclusions are that the method promotes a great enhancement on the productivity of platform based solutions conception while increasing the quality of the conceptual phase results.

Finite element model updating with positive definiteness and no spill-over

Updating a finite element model to match measured spectral information has been a important task for engineers. In the process, it is desirable to match only the measured spectral information without tampering with the other unmeasured and unknown eigeninformation in the original model and to maintain positive definiteness (semidefiniteness) in the coefficient matrices. In this paper, we present a new direct method for the finite element model updating. By constructing a parametric symmetric low-rank correction form, the method can preserve both no spill-over and positive definiteness (semidefiniteness) of the mass and stiffness matrices. Using the parametric form, necessary and sufficient conditions under which this problem is solvable are obtained and a minimum modification is given explicitly. Numerical examples show that the method is efficient.

In-plane acoustic reflectors for reducing effective anchor loss in lateral–extensional MEMS resonators

In this paper, novel in-plane acoustic reflectors are proposed to enhance the quality factor (Q) in lateral-mode micromachined resonators. Finite element coupled-domain simulation is used to model anchor loss and to estimate the relative change in the resonator's performance without and with the inclusion of acoustic reflectors. Several 27 and 110 MHz AlN-on-silicon resonators are fabricated and measured to validate the theoretical and simulated data. An average Q enhancement of up to 560% is reported for specific designs with reflectors over the same resonators without reflectors. The measured results trend well with the simulated data and support that the acoustic reflectors can reduce the overall anchor loss with minimum modification in the resonator design.

Proposing Fiber Feedforward Coaxial Cascade HFC Networks

The long-historied feedforward technology was applied to an HFC network and, let's say, this FFCC(Fiber Feedforward Coaxial Cascade) HFC network acquired significant performance improvement of 3.4 dB in CNR, 4 dB in CSO and 10 dB in CTB respectively. The improvement of 3.4 dB in CNR permits more than doubling of the number of coaxial cascade i.e., 7 stages which result in the extension of coaxial path approximately 3 km in distance, with the existing same configuration. Thus, FFCC-HFC network would be very useful in upgrading or improving conventional HFC networks with minimum modification, either in the occasions of extending the network distance coverage, increasing the number of subscribers connected to the system, or expanding the frequency bandwidth for more transmission channels or emerging services.

1D–2D Coupled Numerical Model for Shallow-Water Flows

This paper presents a new method, the water stage prediction-correction (WSPC) method, based on the theory of characteristics to couple numerical models in the boundary-connected way for shallow-water flows. From the WSPC method, a one-dimensional (1D)–two-dimensional (2D) coupled numerical model is established, which incorporates the artificial porosity method and is thus capable of treating wetting and drying. Details of the 1D submodel and the 2D submodel are given, with special emphasis put on the coupling between the submodels. With the help of the WSPC method, the physically coupled submodels are executed separately and then coupled by means of prediction-correction of the water stages at the coupling units (i.e., where the submodels are linked) so that it is possible to make use of existing submodels with minimum modifications. The convergence of the WSPC method is proved, and the parameter identification is discussed, taking a flat-bottom channel with rectangular cross section as an example. The o...

A scalable network-based mobility management framework in heterogeneous IP-based networks

This paper proposes a mobility management scheme to provide a mobile node with high-quality handovers among heterogeneous wireless access networks. The proposed scheme employs a signaling architecture to support fast and reliable delivery of control messages by separating a control plane from a data transport plane in the core network. The proposed scheme is based on the network-based mobility management framework which requires the minimum modifications on terminal devices. With interaction between Layers 2 and 3, the proposed scheme accelerates the handover control procedures. It also enables a mobile subscriber to select a target network for a vertical handover with consideration of not only wireless signal strength but also user preference and quality-of-service status. The proposed scheme addresses the well-known problems of the Mobile IP-based approaches, triangular routing and bottleneck at the home agent, since it establishes a data tunnel for a mobile node along the shortest path between two different access networks. The simulation and experimental results indicate that our scheme provisions more efficient performance than the existing approaches in terms of handover latency, data packet loss, data delivery latency and load balancing.