Solutions of Conformal Turbulence on a Half Plane

Exact solutions of conformal turbulence restricted on a upper half plane are obtained. We show that the inertial range of homogeneous and isotropic turbulence with constant enstrophy flux develops in a distant region from the boundary. Thus in the presence of an anisotropic boundary, these exact solutions of turbulence generalize Kolmogorov's solution consistently and differ from the Polyakov's bulk case which requires a fine tunning of coefficients. The simplest solution in our case is given by the minimal model of $p=2, q=33$ and moreover we find a fixed point of solutions when $p,q$ become large.Comment: 10pages, KHTP-93-07, SNUCTP-93-3

FedFwd: Federated Learning without Backpropagation

In federated learning (FL), clients with limited resources can disrupt the training efficiency. A potential solution to this problem is to leverage a new learning procedure that does not rely on backpropagation (BP). We present a novel approach to FL called FedFwd that employs a recent BP-free method by Hinton (2022), namely the Forward Forward algorithm, in the local training process. FedFwd can reduce a significant amount of computations for updating parameters by performing layer-wise local updates, and therefore, there is no need to store all intermediate activation values during training. We conduct various experiments to evaluate FedFwd on standard datasets including MNIST and CIFAR-10, and show that it works competitively to other BP-dependent FL methods.Comment: ICML 2023 Workshop (Federated Learning and Analytics in Practice: Algorithms, Systems, Applications, and Opportunities

A STUDY ON THE OPTIMAL DEFENSE POSITION OF HANDBALL GOALKEEPER: FACING A FORWARD JUMP SHOT MADE FROM 9M

The purpose of the study was to derive an optimal defense position for goalkeepers through calculating ideal defense area and actual defense area when blocking forward jump shots from 9 m distance. A total of 9 men's handball matches were captured with 4 digital video cameras from the 94th Korea National Sports Festival with consent from the Korea Handball Federation. Video clips with 78 forward jump shots from 9 m distance which included the whole movements of goalkeeper were analyzed. The ball's speed in the forward jump shot, release point of the ball, goalkeeper's defensive stance, and defensive position were analyzed. The actual defense position of goalkeeper was 1.10*0.37 m and the optimal defense position calculated through the movements of goalkeeper was 1.45 m from the goal line

A COMPARISON OF ACCURACY AND STROKE CHARACTERISTICS BETWEEN TWO PUTTING GRIP TECHNIQUES

Nowadays PGA golfers are experimenting with various golf putting grips. The purpose of this study was to investigate the traits of using two putting grips; reverse overlapping grip and finger bone grip at three different putting distances. 20 subjects with no previous golf experience participated in this study. The kinematic data of the subject and the putter’s shaft and head was recorded by 8 Qualisys cameras at 100Hz. There was no significant difference between the success rate of getting the ball in the hole at all distances. The finger bone grip produced statistically smaller radial error values than the reverse overlapping grip at the distances for 7 and 11 metres. The finger bone grip provided straighter putter head trajectories and less change in the movement of the COG, which implies more stability of the player and that the ball will travel in the desired path. In conclusion, the finger bone putting technique gave radial errors less than the reverse overlapping grip technique which seems to be due to the added stability and straighter putter head trajectories

Conformal Turbulence with Boundary

Based upon the formalism of conformal field theory with a boundary, we give a description of the boundary effect on fully developed two dimensional turbulence. Exact one and two point velocity correlation functions and energy power spectrum confined in the upper half plane are obtained using the image method. This result enables us to address the infrared problem of the theory of conformal turbulence.Comment: 10pages, KHTP-93-01, SNUCTP-93-0

Accessible and informative sectioned images and surface models of the maxillofacial area for orthognathic surgery

Background: The aim of this study was to describe sectioned images and stereoscopic anatomic models of the maxillofacial area by using Visible Korean which are beneficial for medical education and clinical training in the field of orthognathic surgery. Materials and methods: Serially sectioned images of the maxillofacial area of a cadaver were created. Significant structures in the sectioned images were outlined and stacked to build surface models. Results: Browsing software (95.1 MB) and portable document format (PDF) file (142 MB) that were constructed are freely downloadable from our website (http://anatomy.co.kr). In the browsing software, the names of structures associated with malocclusion and orthognathic surgery could be viewed on the sectioned images. In the PDF file, surface models and stereoscopic maxillofacial structures were displayed in real-time. Conclusions: The state-of-the-art sectioned images, outlined images, and surface models that were arranged and systematised in this study, may help students and trainees investigate the anatomy of the maxillofacial area for orthognathic surgery