A Bulk-Driven Quasi-Floating Gate Regulated Cascode Current Mirror and Its Application in Squarer Circuit

A regulated cascode current mirror (RGC) and its improved version with bulk driven quasi floating gate technique (BD-QFG) are presented in this paper. The proposed BD-QFG RGC current mirror (CM) is compared with the conventional (GD) RGC CM to show the performance improvement. The conventional and unconventional CM are implemented in Candace Virtuoso using 90 nm CMOS technology. For input current (Iin) varied from 0 to 200 μA and for 0.8 V supply voltage, the simulation results present that the proposed BD-QFG RGC CM has less variation in current transfer error (0.2%) as compared to the GD RGC CM (12%). The output voltage requirement for 200 µA input current is respectively 0.7 V and 0.17 V for the GD RGC CM and the BD-QFG RGC CM. The power consumption of the proposed circuit is 22.71 μW which is 0.15 μW higher than the GD RGC (22.56 μW). The total harmonic distortion (THD) of the proposed circuit is 0.4% which is 1.1% less than the conventional circuit (1.5%). All these improvements in the proposed BD-QFG RGC CM are attained at a cost of 0.05 GHz reduction in frequency (2.31 GHz). The minimum supply voltage of BD-QFG RGC CM and GD RGC CM is 0.4 V and

SS-Drop: A Novel Message Drop Policy to Enhance Buffer Management in Delay Tolerant Networks

A challenged network is one where traditional hypotheses such as reduced data transfer error rates, end-to-end connectivity, or short transmissions have not gained much significance. A wide range of application scenarios are associated with such networks. Delay tolerant networking (DTN) is an approach that pursues to report the problems which reduce communication in disrupted networks. DTN works on store-carry and forward mechanism in such a way that a message may be stored by a node for a comparatively large amount of time and carry it until a proper forwarding opportunity appears. To store a message for long delays, a proper buffer management scheme is required to select a message for dropping upon buffer overflow. Every time dropping messages lead towards the wastage of valuable resources which the message has already consumed. The proposed solution is a size-based policy which determines an inception size for the selection of message for deletion as buffer becomes overflow. The basic theme behind this scheme is that by determining the exact buffer space requirement, one can easily select a message of an appropriate size to be discarded. By doing so, it can overcome unnecessary message drop and ignores biasness just before selection of specific sized message. The proposed scheme Spontaneous Size Drop (SS-Drop) implies a simple but intelligent mechanism to determine the inception size to drop a message upon overflow of the buffer. After simulation in ONE (Opportunistic Network Environment) simulator, the SS-Drop outperforms the opponent drop policies in terms of high delivery ratio by giving 66.3% delivery probability value and minimizes the overhead ratio up to 41.25%. SS-Drop also showed a prominent reduction in dropping of messages and buffer time average.

A Discussion: Issue Improving the Accuracy of Turbine Blade Heat Transfer Simulation

To be able to set uniform inlet boundary conditions in simulation, there must be an inlet extension at the first guide vane. In the inlet extension, turbulence experiences strong numerical dissipation, which has not been paid attention to. In the current paper, the influence of the numerical dissipation of turbulence on accuracy in predicting heat transfer was discussed. Two cases, where the numerical dissipation of turbulence was neglected, were analysed. In the first case, wrong conclusion about effect of turbulence scale on heat transfer was drawn: blade heat transfer increases with inlet turbulence scale under the same inlet turbulence intensity. The mechanism for the wrong conclusion is that turbulence with larger scale numerically dissipates more slowly in the inlet extension so that turbulence intensity at blade leading edge is greater under turbulence with larger scale, it is the turbulence intensity not turbulence scale itself really affects heat transfer. In the second case, when the numerical dissipation of turbulence is neglected and turbulence parameters at measuring plane of inlet are directly as input for turbulence boundary condition, flow transition is postponed downstream and heat transfer error is greater, however, when the numerical dissipation of turbulence is considered and turbulence parameters at measuring plane are regard as benchmark and matched by adjusting parameters of inlet turbulence boundary condition, the result shows better agreement with experiment. Thus, the correct way to set turbulence boundary condition is to match turbulence parameters at measuring plane by adjusting parameters of inlet turbulence boundary.

The role of typology and formal similarity in third language acquisition (German and Spanish)

The focus of this study is the role of previously acquired languages in the acquisition of a third language (L3). It is focused on cross-linguistic influences (CLI) in German/Spanish third lan- guage acquisition (TLA) by learners with Croatian first language (L1) and English second language (L2). Participants in this study were third-year undergraduate students at Roch- ester Institute of Technology’s subsidiary in Croatia (RIT Croatia). All the participants had exclusively Croatian as L1, English as L2, and were learning German and Spanish as L3 at the time of the study. The present study investigates the relationship between language typology and formal similarity and transfer/error production, since many studies have demonstrated that typology plays a determining role in cross-linguistic transfer (Cenoz, Hufeisen & Jess- ner 2001; Hammarberg 2001; Rothman 2010). There are various areas of similarity and dis- similarity between Croatian, English, German, and Spanish. A significant portion of English vocabulary comes from Romance and Latinate sources. Due to these facts, we argue that the strongest L2 (English) influence will be found in the area of lexicon. On the other hand, Cro- atian, German, and Spanish are more similar in the area of morphology, due to the fact that these languages have a higher degree of inflection than English. Accordingly, we argue that the strongest L1 (Croatian) influence will be found in the area of morphology. The results of this research confirmed our initial hypothesis that the type of transfer episodes observed may be related to language typology and formal similarity between specific features of languages. Similarities at the level of lexis and grammar between L2 English and L3 German and Spanish can influence the acquisition process of German and Spanish.

A comparative assessment of transfer accuracy of two indirect bonding techniques in patients undergoing fixed mechanotherapy: A randomised clinical trial

Objectives To assess the transfer accuracy of three-dimensional (3D) printed transfer trays and compare them with transfer trays made up of polyvinyl siloxane (PVS) for use in indirect bonding. Design: This was a two-arm parallel prospective randomised controlled trial. Setting: The trial was undertaken at the outpatient department of a dental college. Participants: A total of 30 patients (18 men, 12 women) were randomly allocated to two groups. Methods: The inclusion criteria included patients with permanent and fully erupted dentition (age range = 17–24 years), Angles class I malocclusion with crowding <3 mm requiring non-extraction treatment, good oral hygiene and no previous history of orthodontic treatment. Blinding was applicable only for outcome assessment. Indirect bonding was performed by the primary investigator for both the groups. Digital images of the pre-transfer and post-transfer brackets were obtained by means of an intra-oral scanner and compared using software. Superimpositions of pre- and post-transfer images were done to determine the transfer error for linear and angular variables for all tooth types. Results: A total of 600 teeth were bonded, 300 each for both groups. Statistically significant differences were observed in all dimension between the two groups, with 3D-printed trays being more accurate than PVS trays except in the vertical dimension ( P < 0.05). The prevalence of clinically unacceptable transfer errors revealed that most of the transfer errors were in the vertical dimensions for 3D-printed trays. Conclusion: 3D-printed trays are more accurate than PVS trays except for transfers in vertical dimension.

Comparison of the transfer accuracy of two digital indirect bonding trays for labial bracket bonding

ABSTRACT Objectives To compare the transfer accuracy of two digital transfer trays, the three-dimensional printed (3D printed) tray and the vacuum-formed tray, in the indirect bonding of labial brackets. Materials and Methods Ten digital dental models were constructed by oral scans using an optical scanning system. 3D printed trays and vacuum-formed trays were obtained through the 3Shape indirect bonding system and rapid prototyping technology (10 in each group). Then labial brackets were transferred to 3D printed models, and the models with final bracket positioning were scanned. Linear (mesiodistal, vertical, buccolingual) and angular (angulation, torque, rotation) transfer errors were measured using GOM Inspect software. The mean transfer errors and prevalence of clinically acceptable errors (linear errors of ≤0.5 mm and angular errors of ≤2°) of two digital trays were compared using the Mann-Whitney U-test and the Chi-square test, respectively. Results The 3D printed tray had a lower mean mesiodistal transfer error (P &lt; .01) and a higher prevalence of rotation error within the limit of 2° (P = .03) than did the vacuum-formed tray. Linear errors within 0.5 mm were higher than 90% for both groups, while torque errors within 2° were lowest at 50.9% and 52.9% for the 3D printed tray and vacuum-formed tray, respectively. Both groups had a directional bias toward the occlusal, mesial, and buccal. Conclusions The 3D printed tray generally scored better in terms of transfer accuracy than did the vacuum-formed tray. Both types of trays had better linear control than angular control of brackets.

Investigation of the effect of the angle between drive shafts on vibration responses of main reducer

The drive shaft arrangement has a considerable influence on the vibration responses of the shaft-final drive system. In this research, a coupled vibration model is developed based on force analysis of hypoid gear and lumped mass method. The effect of time-varying mesh stiffness, gear backlash and transfer error are included to investigate the effect of the angle between drive shafts on vibration responses of main reducer. The vibration responses of main reducer are acquired using this model. The results show that the vibration amplitude of the gears of main reducer increase with the angle between drive shafts. This paper presents an analytical method to determine the value of the angle between drive shafts, so as to control the vibration of main reducer.