A Dynamic Model for End Milling Using Single Point Cutting Theory

1996 ◽  
Vol 118 (2) ◽  
pp. 272-274 ◽  
Author(s):  
N. M. Kulkarni ◽  
A. Chandra ◽  
S. S. Jagdale
Keyword(s):  
Process Design ◽  
Dynamic Models ◽  
State Of The Art ◽  
End Milling ◽  
Single Point ◽  
Milling Process ◽  
Current State ◽  
Set Up ◽  
Force Characteristics ◽  
Hierarchy Of Models

The dynamics of a milling process can significantly influence the surface quality and integrity of the finished part. Accordingly, various researchers have investigated the dynamics of milling processes using a hierarchy of models. Tlusty and Smith (1991) provides a review of these models. In recent years, several other researchers (e.g., Armarego and Deshpande, 1989; Montgomery and Altintas, 1991; Nallakatla and Smith, 1992) have also continued to enhance various aspects of such dynamic models. While these dynamic models provide significant insights into the cutting characteristics of a milling process, their utilization in process design has proven to be elusive. The accuracy of these models, however, depends significantly on the prediction of cutting force characteristics. Under the current state-of-the-art, detailed experimentations using actual set-up are necessary to make such predictions accurately. Experimentally obtained constants can vary widely from one milling situation to another, which in turn, significantly restricts their usefulness as predictive tools for process design.

scholarly journals An Overview of Lidar Imaging Systems for Autonomous Vehicles

2019 ◽  
Vol 9 (19) ◽  
pp. 4093 ◽  
Author(s):  
Santiago Royo ◽  
Maria Ballesta-Garcia
Keyword(s):  
Autonomous Vehicles ◽  
State Of The Art ◽  
Autonomous Vehicle ◽  
Single Point ◽  
Imaging Systems ◽  
Light Sources ◽  
Final Solution ◽  
Large Uncertainty ◽  
Current State ◽  
The Subject

Lidar imaging systems are one of the hottest topics in the optronics industry. The need to sense the surroundings of every autonomous vehicle has pushed forward a race dedicated to deciding the final solution to be implemented. However, the diversity of state-of-the-art approaches to the solution brings a large uncertainty on the decision of the dominant final solution. Furthermore, the performance data of each approach often arise from different manufacturers and developers, which usually have some interest in the dispute. Within this paper, we intend to overcome the situation by providing an introductory, neutral overview of the technology linked to lidar imaging systems for autonomous vehicles, and its current state of development. We start with the main single-point measurement principles utilized, which then are combined with different imaging strategies, also described in the paper. An overview of the features of the light sources and photodetectors specific to lidar imaging systems most frequently used in practice is also presented. Finally, a brief section on pending issues for lidar development in autonomous vehicles has been included, in order to present some of the problems which still need to be solved before implementation may be considered as final. The reader is provided with a detailed bibliography containing both relevant books and state-of-the-art papers for further progress in the subject.

scholarly journals Continuous Backbone “Continuum” Robot Manipulators

ISRN Robotics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-19 ◽  
Author(s):  
Ian D. Walker
Keyword(s):  
Dynamic Models ◽  
State Of The Art ◽  
Robot Manipulators ◽  
Complex Environments ◽  
Continuum Robots ◽  
Ongoing Research ◽  
Rigid Link ◽  
Future Developments ◽  
Current State ◽  
Continuum Robot

This paper describes and discusses the history and state of the art of continuous backbone robot manipulators. Also known as continuum manipulators, these robots, which resemble biological trunks and tentacles, offer capabilities beyond the scope of traditional rigid-link manipulators. They are able to adapt their shape to navigate through complex environments and grasp a wide variety of payloads using their compliant backbones. In this paper, we review the current state of knowledge in the field, focusing particularly on kinematic and dynamic models for continuum robots. We discuss the relationships of these robots and their models to their counterparts in conventional rigid-link robots. Ongoing research and future developments in the field are discussed.

Video-Confocal Microscopy: An “Electronic-Pinhole” Method using Narrow-Field Illumination and Wide-Field Image Detection.

1999 ◽  
Vol 5 (S2) ◽  
pp. 470-471
Author(s):  
Pier A. Benedetti ◽  
Valter Evangelista ◽  
Dante Guidarini ◽  
Stefano Vestri
Keyword(s):  
Confocal Microscopy ◽  
Optical Microscopy ◽  
State Of The Art ◽  
Single Point ◽  
Three Dimensional ◽  
Axial Direction ◽  
Wide Field ◽  
Biological Investigation ◽  
Photo Damage ◽  
Set Up

State of the art in optical microscopyOptical microscopy is still and increasingly one of the most valuable tools in biological investigation. In particular, confocal microscopies are capable of achieving best performances in the study of three-dimensional fluorescent and reflecting specimens. Nevertheless, current techniques adopted in confocal microscopy present some drawbacks and limitations that stimulate to devise and set-up further techniques, suited to a wider range of applications.Advantages of confocal microscopes mainly correspond to an improved spatial resolution, especially in the axial direction. Depending on the narrow-field scanning approach used, there are two main forms of confocal microscopes: single-point (SP) and multi-point (MP) ones. Unfortunately, SP confocal microscopes require the use of lasers as illumination sources with consequent high costs and scarce spectral flexibility. Moreover, specimen photo-damage due to relatively high instantaneous irradiation doses involved, can often limit their investigative capabilities. On the other hand, proposed MP confocal microscopes still rely on the revolving-disk approach and exhibit a relatively low luminous efficiency, substantial constructional complexity, and limited contrast in the study of thick fluorescent objects.

A Global Approach of the Finite Element Simulation of Hot Stamping

2005 ◽  
Vol 6-8 ◽  
pp. 763-770 ◽  
Author(s):  
P. Hein
Keyword(s):  
State Of The Art ◽  
Hot Stamping ◽  
Boron Steel ◽  
Simulation Tools ◽  
Weight Saving ◽  
Current State ◽  
Forming Technology ◽  
Element Simulation ◽  
Set Up ◽  
Boron Steels

The use of quenched boron steel components is an economic way to achieve significant improvements in terms of weight saving and crash performance. The material and process knowledge on the hot stamping of boron steels (e.g. Arcelor’s USIBOR 1500 P®) by the stampers needs to be extended and accurate simulation tools must be developed to support the growth of this forming technology. This paper simultaneously addresses the specific requirements of the hot stamping simulation and the current state of the art in this field. A specific approach is presented for the detection of the process limits within the simulation tool. A software chain has been set up with the target to decrease the computation times.

scholarly journals Modelling and analysis of surface topography generated in end milling process

2021 ◽  
Author(s):  
ruihu zhou ◽  
Chen Qilin
Keyword(s):  
Surface Topography ◽  
End Milling ◽  
Complex Surface ◽  
Cutting Parameters ◽  
Milling Process ◽  
Surface Geometry ◽  
Experimental Conditions ◽  
Workpiece Surface ◽  
Proposed Model ◽  
Set Up

Abstract The surface topography of workpiece plays an important role in the performance and service life of workpiece. Complex surface parts are widely used in shipbuilding, aerospace and other industries. At present, the study of milling surface topography is mainly on 3-axis milling. A prediction model of milling surface topography is proposed, which can obtain the machined workpiece surface topography and roughness directly from cutting parameters, cutter location file and workpiece surface geometry. The effects of cutting parameters on surface roughness is discussed. Different milling experimental conditions are set up to validate the proposed model. This method can be used to analyze the surface topography of milling, and further to optimize the cutting parameters to improve the surface quality.

scholarly journals Continuous Mobile User Authentication Using Combined Biometric Traits

2021 ◽  
Vol 11 (24) ◽  
pp. 11756
Author(s):  
Dominik Reichinger ◽  
Erik Sonnleitner ◽  
Marc Kurz
Keyword(s):  
Mobile Devices ◽  
State Of The Art ◽  
User Authentication ◽  
Single Point ◽  
Mobile User ◽  
Accelerometer Data ◽  
Point Of Entry ◽  
Current State ◽  
Continuous User ◽  
Data Points

Current state of the art authentication systems for mobile devices primarily rely on single point of entry authentication which imposes several flaws. For example, an attacker obtaining an unlocked device can potentially use and exploit it until the screen gets locked again. With continuous mobile user authentication, a system is embedded into the mobile devices, which continuously monitors biometric features of the person using the device, to validate if those monitored inputs match and therefore were made by the previously authenticated user. We start by giving an introduction towards the state of the art of currently used authentication systems and address related problems. For our main contribution we then propose, implement and discuss a continuous user authentication system for the Android ecosystem, which continuously monitors and records touch, accelerometer and timestamp data, and run experiments to gather data from multiple subjects. After feature extraction and normalization, a Hidden Markov Model is employed using an unsupervised learning approach as classifier and integrated into the Android application for further system evaluation and experimentation. The final model achieves an Area Under Curve of up to 100% while maintaining an Equal Error Rate of 1.34%. This is done by combining position and accelerometer data using gestures with at least 50 data points and averaging the prediction result of 25 consecutive gestures.

Behavioral Genetics: Concepts for Research and Practice in Language Development and Disorders

1995 ◽  
Vol 38 (5) ◽  
pp. 1126-1142 ◽  
Author(s):  
Jeffrey W. Gilger
Keyword(s):  
Language Development ◽  
Behavioral Genetics ◽  
State Of The Art ◽  
Genetic Research ◽  
Great Promise ◽  
Behavioral Genetic ◽  
Fine Grained ◽  
Future Goals ◽  
Current State ◽  
Research Designs

This paper is an introduction to behavioral genetics for researchers and practioners in language development and disorders. The specific aims are to illustrate some essential concepts and to show how behavioral genetic research can be applied to the language sciences. Past genetic research on language-related traits has tended to focus on simple etiology (i.e., the heritability or familiality of language skills). The current state of the art, however, suggests that great promise lies in addressing more complex questions through behavioral genetic paradigms. In terms of future goals it is suggested that: (a) more behavioral genetic work of all types should be done—including replications and expansions of preliminary studies already in print; (b) work should focus on fine-grained, theory-based phenotypes with research designs that can address complex questions in language development; and (c) work in this area should utilize a variety of samples and methods (e.g., twin and family samples, heritability and segregation analyses, linkage and association tests, etc.).

Schizophrenia Research: Current State of the Art

1976 ◽  
Vol 21 (7) ◽  
pp. 497-498
Author(s):  
STANLEY GRAND
Keyword(s):  
State Of The Art ◽  
Current State

Operational Aspects of National Securities Depository Limited (NSDL) in Depository System

2018 ◽  
Vol 6 (8) ◽  
pp. 249
Author(s):  
Rajnikant Kumar
Keyword(s):  
Capital Markets ◽  
Service Providers ◽  
State Of The Art ◽  
Stock Exchanges ◽  
Saving Account ◽  
Business Partners ◽  
Paper Work ◽  
Set Up ◽  
Buy Back ◽  
Operational Aspects

NSDL was registered by the SEBI on June 7, 1996 as India’s first depository to facilitate trading and settlement of securities in the dematerialized form. NSDL has been set up to cater to the demanding needs of the Indian capital markets. NSDL commenced operations on November 08, 1996. NSDL has been promoted by a number of companies, the prominent of them being IDBI, UTI, NSE, SBI, HDFC Bank Ltd., etc. The initial paid up capital of NSDL was Rs. 105 crore which was reduced to Rs. 80 crore. During 2000-2001 through buy-back programme by buying back 2.5 crore shares @ 12 Rs./share. It was done to bring the size of its capital in better alignment with its financial operations and to provide same return to shareholders by gainfully deploying the excess cash available with NSDL. NSDL carries out its activities through service providers such as depository participants (DPs), issuing companies and their registrars and share transfer agents and clearing corporations/ clearing houses of stock exchanges. These entities are NSDL's business partners and are integrated in to the NSDL depository system to provide various services to investors and clearing members. The investor can get depository services through NSDL's depository participants. An investor needs to open a depository account with a depository participant to avail of depository facilities. Depository system essentially aims at eliminating the voluminous and cumbersome paper work involved in the scrip-based system and offers scope for ‘paperless’ trading through state-of-the-art technology. A depository can be compared to a bank. A depository holds securities of investors in the form of electronic accounts, in the same way as bank holds money in a saving account. Besides, holding securities, a depository also provides services related to transactions in securities.

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