scholarly journals A New Approach about the Determination of a Developable Spherical Orthotomic Ruled Surface in R(1,3)

2016 ◽  
Vol 9 (1) ◽  
pp. 62-69
Author(s):  
Ö. Gökmen YILDIZ ◽  
Sıddıka Ö. KARAKUŞ ◽  
H. Hilmi HACISALİHOĞLU
1986 ◽  
Vol 108 (4) ◽  
pp. 516-523 ◽  
Author(s):  
F. L. Litvin ◽  
P. Fanghella ◽  
Jie Tan ◽  
Yi Zhang

A new approach for the determination of singularities and displacement functions of spatial linkages is proposed. Singularities in motion occur at positions where an overconstrained group of links becomes movable while the driving link is fixed. Two alternative solutions for the conditions of the mobility of the link group are proposed: (i) The first one is based on the differentiation of matrices which describe the coordinate transformation; (ii) The second one is based on the presentation of the link motion as a screw motion. It is proven that singularities in motion occur in the cases where: (i) Some or all links of the overconstrained group of links are aligned; (ii) The links of the group are not aligned but they form a mobile configuration, (iii) A Certain number of axes of revolute or cylindrical pairs belong to a ruled surface. Cases (i) and (ii) cover the situations when the oscillating driving link reaches its extreme positions. The determination of displacement functions is based on the modeling of the linkage by two open kinematic chains formed: (i) by links of the overconstrained group of links and (ii) the driving link and the frame. The structure of equations for the link displacements is related with the structure of the velocity Jacobian for the overconstrained group and simplifies the computation procedure. The proposed methods are illustrated with examples of RCRCR and 7R linkages.


2014 ◽  
Vol 5 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Ö. Gökmen Yıldız ◽  
Sıddıka Ö. Karakuş ◽  
H Hilmi Hacısalihoğlu

2017 ◽  
Vol 30 (1) ◽  
pp. 273-289
Author(s):  
Anmari Meerkotter

The Constitutional Court (CC) judgment of Lee v Minister of Correction Services 2013 2SA 144 (CC) is a recent contribution to transformative constitutional jurisprudence in the field of the law of delict. This matter turned on the issue of factual causation in the context of wrongful and negligent systemic omissions by the state. In this case note, I explore the law relating to this element of delictual liability with specific regard to the traditional test for factual causation – the conditio sine qua non (‘but-for’) test. In particular, I note the problems occasioned by formalistic adherence to this test in the context of systemic state omissions as evidenced by the SCA judgment in the same matter. I also consider the manner in which English courts have addressed this problem. Thereafter, I analyse the CC’s broader approach to the determination of factual causation as one based on common sense and justice. I argue that this approach endorses a break from a formalistic application of the test and constitutes a step towards an approach which resonates with the foundational constitutional values of freedom, dignity and equality. Furthermore, it presents an appropriate solution to the problems associated with factual causation where systemic omissions are concerned. I then consider the transformative impact of the Lee judgment. In particular, I argue that the broader enquiry favoured by the CC facilitates the realisation of constitutionally guaranteed state accountability, and amounts to an extension of the existing norm of accountability jurisprudence. Hence, I contend that the judgment presents a further effort by the Constitutional Court to effect wholesale the constitutionalisation of the law of delict, as well as a vindicatory tool to be used by litigants who have been adversely affected by systemic state omissions.


Author(s):  
Romain Desplats ◽  
Timothee Dargnies ◽  
Jean-Christophe Courrege ◽  
Philippe Perdu ◽  
Jean-Louis Noullet

Abstract Focused Ion Beam (FIB) tools are widely used for Integrated Circuit (IC) debug and repair. With the increasing density of recent semiconductor devices, FIB operations are increasingly challenged, requiring access through 4 or more metal layers to reach a metal line of interest. In some cases, accessibility from the front side, through these metal layers, is so limited that backside FIB operations appear to be the most appropriate approach. The questions to be resolved before starting frontside or backside FIB operations on a device are: 1. Is it do-able, are the metal lines accessible? 2. What is the optimal positioning (e.g. accessing a metal 2 line is much faster and easier than digging down to a metal 6 line)? (for the backside) 3. What risk, time and cost are involved in FIB operations? In this paper, we will present a new approach, which allows the FIB user or designer to calculate the optimal FIB operation for debug and IC repair. It automatically selects the fastest and easiest milling and deposition FIB operations.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3070
Author(s):  
Sebastian Iwaszenko ◽  
Jakub Munk ◽  
Stefan Baron ◽  
Adam Smoliński

Modern dentistry commonly uses a variety of imaging methods to support diagnosis and treatment. Among them, cone beam computed tomography (CBCT) is particularly useful in presenting head structures, such as the temporomandibular joint (TMJ). The determination of the morphology of the joint is an important part of the diagnosis as well as the monitoring of the treatment results. It can be accomplished by measurement of the TMJ gap width at three selected places, taken at a specific cross-section. This study presents a new approach to these measurements. First, the CBCT images are denoised using curvilinear methods, and the volume of interest is determined. Then, the orientation of the vertical cross-section plane is computed based on segmented axial sections of the TMJ head. Finally, the cross-section plane is used to determine the standardized locations, at which the width of the gap between condyle and fossa is measured. The elaborated method was tested on selected TMJ CBCT scans with satisfactory results. The proposed solution lays the basis for the development of an autonomous method of TMJ index identification.


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