70 research outputs found
A Method For Iris Liveness Detection Using Passive Light Trigger
The present disclosure relates to a passive liveness detection method for a camera-based iris biometric system. The method comprising: detecting an initiation of transaction on one of a user device and a payment terminal in supervised/unsupervised payment environments, introducing a passive light trigger to record real-time involuntary biological response of user’s eye when the initiation of transaction is detected, comparing the recorded real-time involuntary biological response of the user’s eye to similar biological response of the user’s eye recorded at the time of enrollment and/or a previous successful transaction by the user stored in a database, and determining if the artifact being presented to the iris biometric system at the time of transaction is real or spoof based on the comparison. The present disclosure uses shutter speed and aperture of camera lens, and image sensor sensitivity settings coupled with a passive light trigger for liveness detection. This approach overcomes the need for specialized expensive hardware and the limitation of detecting a fixed set of fake artifacts (spoofs) for passive liveness detection
Extensiveness and homogeneity of diabetic/non-diabetic patients and their co-relation with CBNAAT confirmed tuberculosis patients in a tertiary care hospital of India
Background: Many studies reported association between TB susceptibility and diabetes mellitus (DM). Some studies were retrospective, did not assess other co morbidities related with tuberculosis. The effects of diabetes on tuberculosis severity (EDOTS) can be hypothesizing that burden of cases India is leading in TB and runner-up in diabetic. We report interim findings after enrolling 732 of a planned 212 subjects.Methods: This study conducted on patients with TB in west India with DM and normoglycemia defined by glucose tolerance test (GTT) and glucose fasting. Glycocylated hemoglobin (HbA1c), lipids profile and 25-hydroxyvitamin D were measured at the time of enrollment of patients. All patients were monitored monthly while they visited in TB and chest clinic for TB treatment.Results: Of 212 eligible patients, 117 (55.18%) were classified as diabetic, 49 (23.11%) with pre diabetic history (PDM), and 46 (21.70%) as normoglycemic (NG). DM patients were more likely to have a family history of diabetes in comparison to NG patients. Low density lipoprotein (LDH)) was higher in KDM as compared with NDM and NG patients. More patients (32) found diabetic through OGTT as compared with HbA1c (29).Conclusions: Early EDOTS, glycemic control and improve lifestyle can reduce the heterogeneity and implications for the TB-DM. Early diagnosis of TB and DM plays an important role in the management and treatment of TBDM.
Physical-mechanical characterization of biodegradable Mg-3Si-HA composites
Purpose Porous implant surface is shown to facilitate bone in-growth and cell attachment, improving overall osteointegration, while providing adequate mechanical integrity. Recently, biodegradable material possessing such superior properties has been the focus with an aim of revolutionizing implant's design, material and performance. This paper aims to present a comprehensive investigation into the design and development of low elastic modulus porous biodegradable Mg-3Si-5HA composite by mechanical alloying and spark plasma sintering (MA-SPS) technique. Design/methodology/approach This paper presents a comprehensive investigation into the design and development of low elastic modulus porous biodegradable Mg-3Si-5HA composite by MA-SPS technique. As the key alloying elements, HA powders with an appropriate proportion weight 5 and 10 are mixed with the base elemental magnesium (Mg) particles to form the composites of potentially variable porosity and mechanical property. The aim is to investigate the performance of the synthesized composites of Mg-3Si together with HA in terms of mechanical integrity hardness and Young's moduli corrosion resistance and in-vitro bioactivity. Findings Mechanical and surface characterization results indicate that alloying of Si leads to the formation of fine Mg2 Si eutectic dense structure, hence increasing hardness while reducing the ductility of the composite. On the other hand, the allying of HA in Mg-3Si matrix leads to the formation of structural porosity (5-13 per cent), thus resulting in low Young's moduli. It is hypothesized that biocompatible phases formed within the composite enhanced the corrosion performance and bio-mechanical integrity of the composite. The degradation rate of Mg-3Si composite was reduced from 2.05 mm/year to 1.19 mm/year by the alloying of HA elements. Moreover, the fabricated composites showed an excellent bioactivity and offered a channel/interface to MG-63 cells for attachment, proliferation and differentiation. Originality/value Overall, the findings suggest that the Mg-3Si-HA composite fabricated by MA and plasma sintering may be considered as a potential biodegradable material for orthopedic application
Revealing the benefits of Entropy weights method for multi-objective optimization in machining operations : a critical review
Machining operation optimization improves the quality of the product, reduces cost, enhances overall efficiency by reducing human error, and enables consistent and efficient operation. It is a vital decision-making process and achieves the best solution within constraints. It reduces reliance on machine-tool technicians and handbooks to identify cutting parameters, as a lack of awareness of the optimal combination of machining parameters leads to several machining inefficiencies. Subsequently, the optimization of the machining process is more useful for units of production, particularly machining units. In multi-objective optimization (MOO) problems, weights of importance are assigned, mostly identical. But, nowadays, the weights assignment techniques have received a lot of consideration from the professionals and researchers in MOO problems. Various techniques are developed to assign weights of significance to responses in MOO. The Entropy weights method (EWM) continues to work pleasingly across diverse machining operations to allocate objective weights. In this paper, a literature review is conducted to classify the articles on EWM applications in machining operations. The categorization proposal for the EWM reviews included 65 academic articles from different journals, books, and conferences since the year 2009. The EWM applications were separated into 18 categories of conventional and non-conventional machining operations. The implementation procedure of EWM is presented with an example along with method development. Scholarly articles in the EWM applications are further inferred based on (1) implementation of EWM in different machining operations, (2) MOO methods used with entropy weights in machining operations, (3) application of entropy weights by citation index and publication year, and (4) entropy weights applications in other fields. The review paper provided constructive insight into the EWM applications and ended with suggestions for further research in machining and different areas
Revealing the WEDM process parameters for the machining of pure and heat-treated titanium (Ti-6Al-4V) alloy
Ti-6Al-4V is an alloy that has a high strength-to-weight ratio. It is known as an alpha-beta titanium alloy with excellent corrosion resistance. This alloy has a wide range of applications, e.g., in the aerospace and biomedical industries. Examples of alpha stabilizers are aluminum, oxygen, nitrogen, and carbon, which are added to titanium. Examples of beta stabilizers are titanium-iron, titanium-chromium, and titanium-manganese. Despite the exceptional properties, the processing of this titanium alloy is challenging when using conventional methods as it is quite a hard and tough material. Nonconventional methods are required to create intricate and complex geometries, which are difficult with the traditional methods. The present study focused on machining Ti-6Al- 4V using wire electrical discharge machining (WEDM) and conducting numerous experiments to establish the machining parameters. The optimal setting of the machining parameters was predicted using a multiresponse optimization technique. Experiments were planned using the response surface methodology (RSM) technique and analysis of variance (ANOVA) was used to determine the significance and contribution of the input parameters to changes in the output characteristics (cutting speed and surface roughness). The cutting speed obtained during the processing of the annealed titanium alloy using WEDM was quite large as compared to the cutting speed obtained in the case of processing the pure, quenched, and hardened titanium alloys using WEDM. The maximum cutting speed obtained while processing the annealed titanium alloy was 1.75 mm/min
How Interactions Influence Users' Security Perception of Virtual Reality Authentication?
Users readily embrace the rapid advancements in virtual reality (VR)
technology within various everyday contexts, such as gaming, social
interactions, shopping, and commerce. In order to facilitate transactions and
payments, VR systems require access to sensitive user data and assets, which
consequently necessitates user authentication. However, there exists a limited
understanding regarding how users' unique experiences in VR contribute to their
perception of security. In our study, we adopt a research approach known as
``technology probe'' to investigate this question. Specifically, we have
designed probes that explore the authentication process in VR, aiming to elicit
responses from participants from multiple perspectives. These probes were
seamlessly integrated into the routine payment system of a VR game, thereby
establishing an organic study environment. Through qualitative analysis, we
uncover the interplay between participants' interaction experiences and their
security perception. Remarkably, despite encountering unique challenges in
usability during VR interactions, our participants found the intuitive
virtualized authentication process beneficial and thoroughly enjoyed the
immersive nature of VR. Furthermore, we observe how these interaction
experiences influence participants' ability to transfer their pre-existing
understanding of authentication into VR, resulting in a discrepancy in
perceived security. Moreover, we identify users' conflicting expectations,
encompassing their desire for an enjoyable VR experience alongside the
assurance of secure VR authentication. Building upon our findings, we propose
recommendations aimed at addressing these expectations and alleviating
potential conflicts
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Microwave sintering of porous Ti-Nb-HA composite with high strength and enhanced bioactivity for implant applications
In the present study, high order porous Ti-Nb(50-x)-HA(x) (x=0,10,20 wt. %) composites have been fabricated for orthopedic application by using powder metallurgical route consisting temporary space alloying and rapid microwave sintering process. Structural porosity, elastic modulus, compressive strength, corrosion resistance, and in-vitro bioactivity of as-sintered TiNb-HA composites were studied. Results showed that the reinforcement of the HA assists in the formation of structural porosity, which reduced the elastic modulus. Porous Ti-Nb (with HA 10- 20% content) composite possessed 40-60% structural porosity with a pore size of 150-260 μm and exhibited elastic modulus in the range of 12.5 – 29 GPa (near to human bone 8-20 GPa), which overcome the problem of stress shielding. The as-sintered composite not only possessed low elastic modulus but also exhibit high compressive strength (205-395 MPa). The alloying of HA improved the corrosion resistance and the protective efficiency of Ti-40Nb-10HA and Ti- 30Nb-20HA composites was measured 40% and 72%, respectively higher than the Ti-Nb composite. In-vitro biological evaluation tests confirmed that the developed composites are noncytotoxic and porous structure provides a vehicle for cell adhesion and growth. Moreover, various biocompatible phases such as Ca3(PO4)2 (known as TCP), Ti5P3 and CaO were developed, which helped in cell proliferation and differentiation. High biological activities were found on the Ti-30Nb-20HA composite have when compared with the Ti-Nb and Ti-40Nb-10HA composite and could be used as a potential biomaterial for the various possible orthopedic applications
Optimization of the cycle time of robotics resistance spot welding for automotive applications
In the automobile manufacturing industry, resistance spot welding (RSW) is widely used, especially to build the car's body. The RSW is a standard and wide‐ranging joining technique in several assembling ventures, showing a wide range of possibilities for a competent procedure. Robots are commonly used for spot welding in various industrial applications. After completing assembling design, interest increases to improve the designed processes, cost‐reduction, environmental impact, and increase time productivity when all is said to be done. In this paper, the robot movement between two welding points, a path followed while spotting, gripping and payload‐carrying activities, numbers of holds, moves, and a possibility to enhance interaction between four Robots were analyzed using an offline Robot simulation software 'DELMIA‐V5'. The body shop assembly line of the SML ISUZU plant has four robots that perform about 209 welding spots in 532 sec. The optimal model reduced the whole welding cycle time by 68 sec, and after modification and proper sequencing, a12.7% reduction in cycle time was achieved. The offline Robot simulation software 'DELMIA‐V5' has good potential to produce optimal algorithms while saving precious time. It enables an organization to promote higher quality and to encourage meaningful creativity by reducing design flaws
Vibration exposure and transmissibility on dentist's anatomy : a study of micro motors and air-turbines
The use of dental hand pieces endanger dentists to vibration exposure as they are subjected to very high amplitude and vibration frequency. This paper has envisaged a comparative analysis of vibration amplitudes and transmissibility during idling and drilling with micro motor (MM) and air-turbine (AT) hand pieces. The study aims to identify the mean difference in vibration amplitudes during idling, explore different grasp forces while drilling with irrigant injection by the dentist, and various vibration transmission of these hand pieces. The study utilized 22 separate frequency resonances on two new and eight used MMs and two new and eight used ATs of different brands by observing the investigator at 16 different dentist clinics. The study adopted a descriptive research design with non–probability sampling techniques for selecting dentists and hand pieces. Statistical methods like Levene Test of Homogeneity, Welch ANOVA, independent t-test, and Games–Howell test were utilized with SPSS version 22 and MS-Excel. The results reveal that vibration amplitudes and vibration transmissibility when measured at position 2 are higher than in another position 1. Vibrations during idling for used MMs are more than AT hand pieces, and the used MM (MUD) and used AT (AUA) hand pieces differ due to their obsolescence and over-usage. Vibration amplitudes increase every time with the tightening of grasping of the hand piece. Vibration amplitudes for each grasping style of MM hand piece differ from all other grasping styles of AT hand pieces. Routine exposure to consistent vibrations has ill physical, mental, and psychological effects on dentists. The used hand pieces more hazardous as compared to newer ones. The study suggests that these hand pieces must be replaced periodically, sufficient to break between two operations, especially after every hand piece usage. Hence, the present research work can be further extended by creating some control groups among dentists and then studying the vibration amplitude exposure of various dental hand pieces and subsequent transmissibility to their body parts
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