scholarly journals A Novel Mesh Quality Improvement Method for Boundary Elements

2012 ◽  
Vol 2012 ◽  
pp. 1-13
Author(s):  
Hou-lin Liu ◽  
Cui Dai ◽  
Liang Dong ◽  
Ming-gao Tan

In order to improve the boundary mesh quality while maintaining the essential characteristics of discrete surfaces, a new approach combining optimization-based smoothing and topology optimization is developed. The smoothing objective function is modified, in which two functions denoting boundary and interior quality, respectively, and a weight coefficient controlling boundary quality are taken into account. In addition, the existing smoothing algorithm can improve the mesh quality only by repositioning vertices of the interior mesh. Without destroying boundary conformity, bad elements with all their vertices on the boundary cannot be eliminated. Then, topology optimization is employed, and those elements are converted into other types of elements whose quality can be improved by smoothing. The practical application shows that the worst elements can be eliminated and, with the increase of weight coefficient, the average quality of boundary mesh can also be improved. Results obtained with the combined approach are compared with some common approach. It is clearly shown that it performs better than the existing approach.

2021 ◽  
Author(s):  
wei peng ◽  
Xinguang Wu ◽  
Yidong Bao ◽  
Chaoyang Zhang ◽  
Weixi Ji

Abstract Hexahedral mesh is of great value in the analysis of mechanical structure, and the mesh quality has an important impact on the efficiency and accuracy of the analysis. This paper presents a quality improvement method for hexahedral meshes, which consists of node classification, geometric constraints based single hexahedron regularization and local hexahedral mesh stitching. The nodes are divided into different types and the corresponding geometric constraints are established in single hexahedron regularization to keep the geometric shapes of original mesh. In contrast to the global optimization strategies, we perform the hexahedral mesh stitching operation within a few local regions surrounding elements with undesired quality, which can effectively improve the quality of the mesh with less consuming time. A number of mesh quality improvements for hexahedral meshes generated by a variety of methods are introduced to demonstrate the effectiveness of our method.


2020 ◽  
pp. 1-16
Author(s):  
Meriem Khelifa ◽  
Dalila Boughaci ◽  
Esma Aïmeur

The Traveling Tournament Problem (TTP) is concerned with finding a double round-robin tournament schedule that minimizes the total distances traveled by the teams. It has attracted significant interest recently since a favorable TTP schedule can result in significant savings for the league. This paper proposes an original evolutionary algorithm for TTP. We first propose a quick and effective constructive algorithm to construct a Double Round Robin Tournament (DRRT) schedule with low travel cost. We then describe an enhanced genetic algorithm with a new crossover operator to improve the travel cost of the generated schedules. A new heuristic for ordering efficiently the scheduled rounds is also proposed. The latter leads to significant enhancement in the quality of the schedules. The overall method is evaluated on publicly available standard benchmarks and compared with other techniques for TTP and UTTP (Unconstrained Traveling Tournament Problem). The computational experiment shows that the proposed approach could build very good solutions comparable to other state-of-the-art approaches or better than the current best solutions on UTTP. Further, our method provides new valuable solutions to some unsolved UTTP instances and outperforms prior methods for all US National League (NL) instances.


Author(s):  
Hendy Tannady Tan

One way to increase profitability internally in PT Mangul Jaya - Bekasi is decreasing any costs produced from poor product quality by producing shoes with good quality. This study uses the DMAIC (define, measure, analyze, improve, control) method as a measuring tool. DMAIC is a quality improvement method that directly solves any problems related to the quality of a product even the primary cause of it. From the results of the study it is concluded that at the phase “define” shoes type Cheetah is the most problematic. Furthermore, on phase “measurement” it is identified that the Cp value of the Cheetah is below 1 which means that the process capability is low. After passing through the three sequencing steps (analyze, improve and control), finally this research is able to reduce the defects that occur in the shoes type Cheetah.


2014 ◽  
Vol 1 (4) ◽  
pp. 34-50
Author(s):  
Roee Anuar ◽  
Yossi Bukchin ◽  
Oded Maimon ◽  
Lior Rokach

The task of a recommender system evaluation has often been addressed in the literature, however there exists no consensus regarding the best metrics to assess its performance. This research deals with collaborative filtering recommendation systems, and proposes a new approach for evaluating the quality of neighbor selection. It theorizes that good recommendations emerge from good selection of neighbors. Hence, measuring the quality of the neighborhood may be used to predict the recommendation success. Since user neighborhoods in recommender systems are often sparse and differ in their rating range, this paper designs a novel measure to asses a neighborhood quality. First it builds the realization based entropy (RBE), which presents the classical entropy measure from a different angle. Next it modifies the RBE and propose the realization based distance entropy (RBDE), which considers also continuous data. Using the RBDE, it finally develops the consent entropy, which takes into account the absence of rating data. The paper compares the proposed approach with common approaches from the literature, using several recommendation evaluation metrics. It presents offline experiments using the Netflix database. The experimental results confirm that consent entropy performs better than commonly used metrics, particularly with high sparsity neighborhoods. This research is supported by The Israel Science Foundation, Grant #1362/10. This research is supported by NHECD EC, Grant #218639.


Author(s):  
Sutrisno Harianto ◽  
Ellysa Nursanti

Traditional cast brass handicrafts Majapahit is one of the nation's cultural heritage which has a high historical value. The uniqueness and quality become the hallmark of this craft products. The results of handmade products such as sculptures, wall hangings, souvenirs, ornaments doors and so on. To increase the sales of traditional handicrafts of brass castings, required Majapahit applicative technical efforts in improving the quality of products which are ecofriendly. Quality improvement method such as Six sigma. Six sigma focuses on decreasing flawed rate, by reaching the standard 3, 4 flawed in a thousand possibility. Six sigma has 5 phases; define, measure, analyze, improvement, and control. In this research, six sigma is applied in producing cast brass handicraft starting from making the master mold, preparation of smelting raw materials, cooling process, releasing of the mold, and finishing. Purposefully to improve the quality by overcoming and decreasing the high of flawed possibility and also applying marketing mixture in improving the market segmentation of traditional cast brass of Majapahit market. The result is quality improvement is shown by decreasing happen in number of flawed product in total of mean for about 154, 8 decreased to 59,5. While the calculation of the six sigma, flawed product of cast brass handicraft is for about 1,7625 sigma value or being in level 2 and increased to 3,725 or being in level 4 with the flawed possibility in amount 235,000 for thousand times of production. The ability of production for the requirement which is wanted by the consumers and owning a good enough capability but still needed some correction to achieve world class home industry


Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 895 ◽  
Author(s):  
Junhyeok Choi ◽  
Harrim Kim ◽  
Shankar Prasad Sastry ◽  
Jibum Kim

We propose a novel deviation-based vertex reordering method for 2D mesh quality improvement. We reorder free vertices based on how likely this is to improve the quality of adjacent elements, based on the gradient of the element quality with respect to the vertex location. Specifically, we prioritize the free vertex with large differences between the best and the worst-quality element around the free vertex. Our method performs better than existing vertex reordering methods since it is based on the theory of non-smooth optimization. The downhill simplex method is employed to solve the mesh optimization problem for improving the worst element quality. Numerical results show that the proposed vertex reordering techniques improve both the worst and average element, compared to those with existing vertex reordering techniques.


2014 ◽  
Vol 543-547 ◽  
pp. 1227-1230
Author(s):  
Hong Na Guo ◽  
Jun Ming Zhu

DMAIC model is applied to improve the high welding defects in a welding line program of T company, and the quality data was analyzed by Minitab software. Firstly, define the project scope for improvement and the type of weld defects is measured; Secondly, analysis the cause of the main strength of welding defects with the help of brainstorming method. After that, the optimum process parameters are determined by orthogonal experimental design. Finally, all of these works makes defects reduced to 3500ppm,which improves the quality of products greatly and reduce the loss of production.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ankit Vidyarthi

AbstractThe quality of the medical image plays a major role in decision making by the radiologists. There exists a visual differentiation between the normal scene color images and medical images. Due to the low illumination and unavailability of the color parameter, medical images require more attention by radiologists for decision making. In this paper a new approach is proposed that enhances the quality of the Magnetic Resonance (MR) images. Proposed approach uses the spectral information present in form of Amplitude and Frequency within the MR image slices for an enhancement. The extracted enhanced spectral information gives better visualization as compared with original signal image generated from MR scanner. The quantitative analysis of the proposed approach suggests that the new method is far better than the traditional state-of-art image enhancement methods.


Liquidity ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 151-159
Author(s):  
Pitri Yandri

The purpose of this study is (1) to analyze public perception on urban services before and after the expansion of the region, (2) analyze the level of people's satisfaction with urban services, and (3) analyze the determinants of the variables that determine what level of people's satisfaction urban services. This study concluded that first, after the expansion, the quality of urban services in South Tangerang City is better than before. Secondly, however, public satisfaction with the services only reached 48.53% (poor scale). Third, by using a Cartesian Diagram, the second priority that must be addressed are: (1) clarity of service personnel, (2) the discipline of service personnel, (3) responsibility for care workers; (4) the speed of service, (5) the ability of officers services, (6) obtain justice services, and (7) the courtesy and hospitality workers.


2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.


Sign in / Sign up

Export Citation Format

Share Document