Design and optimization of index-guiding photonic crystal fiber gas sensor

Globalization is becoming an important issue for most businesses in the world. Since globalization changes business trends and shortens product life cycles, it requires companies to be more innovative in developing new ideas, products and processes. Clustering is one of ways to promote innovation by facilitating sharing information and ideas between firms, attracting buyers and suppliers, and providing opportunities for joint training. Many researches in developed countries found that the proximity between companies facilitated collaboration and provided a more conducive environment for R&D and knowledge sharing which can develop culture of entrepreneurship and innovation. Then, the success of clusters in developed countries has led many government and companies to establish new clusters.Since products from China have been dominated Indonesia's market share with lower price, it is very difficult for Indonesian Small and Medium Enterprises to compete with lower price also. Therefore, to face the competition, innovation is perhaps as an alternative strategy for Indonesian SMEs. In facts, more than 50% of small and medium enterprises in Indonesia are located in clusters and most of them are located in Java, Bali and Nusa Tenggara. Even though they located in cluster but their innovations still very low and judging from technology perspective, most of them have low level of technologies and still remain in the underdeveloped stage. Therefore, in this research, the author tries to find (1). To what extend do cluster Indonesia promote innovation, (2). To find the reasons why clusters in Indonesia has not been working well in promoting innovation and (3). To investigate what aspects can be improved by Indonesian SMEs to boost their innovation

Comparison of TOF, FMCW and Phase-Shift Laser Range-Finding Methods by Simulation and Measurement

Since 1970s the use of laser based range-finders has become a necessary part of many military and domestic systems. According to the needs and the circumstances, many different types of such systems have been developed and their technologies are adapted to the local needs. Distance or displacement measurement in the medium range is mainly divided to three groups; time of flight, frequency modulation continuous wave, and phase-shift laser range finder. In this paper we present the design, implementation and/or simulation of three such systems and compare their characteristics

Software-based teaching of optical demultiplexers by using photonic crystals with presenting the syllabus for MSc students in electronic engineering major

Background and Objective:Software-based education is one of the most important ways to transfer knowledge in the field of new technologies. Because the hardware implementation of some modern science phenomena is not possible due to its complexity or sometimes due to the lack of appropriate manufacturing technology. Therefore, appropriate software can be used to teach such phenomena. One of the sciences and technologies that has grown significantly in recent years is photonic crystal structures, which have also appeared in new editions of graduate courses syllabuses as photon crystals. In this paper, simulation-based (software-based) teaching of a 4-channel optical demultiplexer based on photonic crystal is presented by using the R-Soft software. Methods: The teaching of the demultiplexer structure is based on the use of a photonic crystal filter. In this analysis, with the variation of the radius of the cylindrical nano-ring resonator and the radius of the scattering rods, the critical length parameter of 1573.6 nm is improved in the design of the filter. The advantages of the 4-channel demultiplexer include the mean quality factor of 4525, mean channel power transfer factor of 95%, and maximum and minimum channel cross-talk of -19.6 and -40.4, respectively. Also, mean channel width is obtained as 0.375 nm. Moreover, the proposed 4-channel demultiplexer can be used in WDM systems. Findings: The simulation-based teaching of these structures is very important to develop and improve the multiplexers performance. Therefore, the related syllabus is suggested for master of science (MSc) students in Electronic Engineering major. This syllabus can be considered as a part of Photonic Crystal or Photonics courses. Conclusion: In this paper, a 4-channel optical demultiplexer based on photonic crystal was studied. In order to teach the theoretical principles and foundations which are mostly complex and its hardware implementation is difficult due to technological limitations, the use of appropriate software environments along with strengthening the basic knowledge required can Improve teaching-learning processes. For this purpose, in this article, we tried to express the appropriate concepts of designing a four-channel optical dimplexplexor system for effective training. Accordingly, the proposed principles and topics as well as the prerequisites in the design were described. In the training section of the four-channel dimplex structure, it was stated that a T-shaped input waveguide, square resonator rings and several output waveguides can be used   ===================================================================================== COPYRIGHTS  ©2019 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Low price foot pressure distribution screening technique: Optical podoscope with accurate foot print segmentation using hidden Markov random field model

Copyright © 2020 The Author(s). Background: Foot pressure assessment systems are widely used to diagnose foot pathologies. The human foot plays an important role in maintaining the biomechanical function of the lower extremities which includes the provision of balance and stabilization of the body during gait. Objective: There are different types of assessment tools with different capabilities which are discussed in detail in this paper. In this project, we introduce a new camera-based pressure distribution estimation system which can give a numerical estimation in addition to giving a visual illustration of pressure distribution of the sole. Material and Methods: In this analytical study we proposed an accurate Foot Print segmentation using hidden Markov Random Field model. In the first step, an image is captured from the traditional Podoscope device. Then, the HMRF-EM image segmentation scheme applies to extract the contacting part of the sole to the ground. Finally, based on a simple calibration method, per mm2, pressure estimates to give an accurate pressure distribution measure. Results: A significant and usable estimation of foot pressure has been introduced in this article. The main drawback of introduced systems is the low resolution of sensors which is solved using a high resolution camera as a sensor. Another problem is the patchy edge extracted by the systems which is automatically solved in the proposed device using an accurate image segmentation algorithm. Conclusion: We introduced a camera-based plantar pressure assessment tool which uses HMRF-EM-based method has been explained in more detail which gives a brilliant sole segmentation from the captured images.“Tosee Tadbir Tavan Teb” company under Grant No.IR-0120151-101. The compa- ny’s registration number in Iran is 40697

Development of Photonic Crystal Fiber Based Gas/ Chemical Sensors

The development of highly-sensitive and miniaturized sensors that capable of real-time analytes detection is highly desirable. Nowadays, toxic or colorless gas detection, air pollution monitoring, harmful chemical, pressure, strain, humidity, and temperature sensors based on photonic crystal fiber (PCF) are increasing rapidly due to its compact structure, fast response and efficient light controlling capabilities. The propagating light through the PCF can be controlled by varying the structural parameters and core-cladding materials, as a result, evanescent field can be enhanced significantly which is the main component of the PCF based gas/chemical sensors. The aim of this chapter is to (1) describe the principle operation of PCF based gas/ chemical sensors, (2) discuss the important PCF properties for optical sensors, (3) extensively discuss the different types of microstructured optical fiber based gas/ chemical sensors, (4) study the effects of different core-cladding shapes, and fiber background materials on sensing performance, and (5) highlight the main challenges of PCF based gas/ chemical sensors and possible solutions

Comparative evaluation of INNO-LiPA HBV assay, direct DNA sequencing and subtractive PCR-RFLP for genotyping of clinical HBV isolates

Genotypes (A to H) of hepatitis B virus (HBV) influence liver disease progression and response to antiviral therapy in HBV-infected patients. Several methods have been developed for rapid genotyping of HBV strains. However, some of these methods may not be suitable for developing countries. The performance of INNO-LiPA HBV Genotyping assay (LiPA), direct DNA sequencing and subtractive PCR-RFLP of genotype-specific HBV genome regions were evaluated for accurately determining the HBV genotypes by analyzing sera (n = 80) samples from chronic HBV patients. Both, LiPA and DNA sequencing identified 63, 4 and 13 HBV strains as belonging to genotype D, genotype A and mixed genotype A and D, respectively. On the contrary, the PCR-RFLP-based method correctly identified all 4 genotype A but only 56 of 63 genotype D strains. Seven genotype D strains yielded indeterminate results. DNA sequence comparisons showed that a single nucleotide change in the target region generated an additional restriction site for Nla IV that compromised the accuracy of this method. Furthermore, all the mixed genotype A and D strains were identified only as genotype A strains. The data show that the PCR-RFLP-based method incorrectly identified some genotype D strains and failed to identify mixed genotype infections while LiPA and DNA sequencing yielded accurate results

Suppression of HBV by Tenofovir in HBV/HIV coinfected patients : a systematic review and meta-analysis

Background: Hepatitis B coinfection is common in HIV-positive individuals and as antiretroviral therapy has made death due to AIDS less common, hepatitis has become increasingly important. Several drugs are available to treat hepatitis B. The most potent and the one with the lowest risk of resistance appears to be tenofovir (TDF). However there are several questions that remain unanswered regarding the use of TDF, including the proportion of patients that achieves suppression of HBV viral load and over what time, whether suppression is durable and whether prior treatment with other HBV-active drugs such as lamivudine, compromises the efficacy of TDF due to possible selection of resistant HBV strains. Methods: A systematic review and meta-analysis following PRISMA guidelines and using multilevel mixed effects logistic regression, stratified by prior and/or concomitant use of lamivudine and/or emtricitabine. Results: Data was available from 23 studies including 550 HBV/HIV coinfected patients treated with TDF. Follow up was for up to seven years but to ensure sufficient power the data analyses were limited to three years. The overall proportion achieving suppression of HBV replication was 57.4%, 79.0% and 85.6% at one, two and three years, respectively. No effect of prior or concomitant 3TC/FTC was shown. Virological rebound on TDF treatment was rare. Interpretation: TDF suppresses HBV to undetectable levels in the majority of HBV/HIV coinfected patients with the proportion fully suppressed continuing to increase during continuous treatment. Prior treatment with 3TC/FTC does not compromise efficacy of TDF treatment. The use of combination treatment with 3TC/FTC offers no significant benefit over TDF alone

Share of afghanistan populace in hepatitis B and hepatitis C infection's pool: is it worthwhile?

There is a notable dearth of data about Hepatitis B Virus (HBV) and Hepatitis C Virus(HCV) prevalence in Afghanistan. Awareness program and research capacity in the field of hepatitis are very limited in Afghanistan. Number of vulnerabilities and patterns of risk behaviors signal the need to take action now