Understanding the Performance Guarantee of Physical Topology Design for Optical Circuit Switched Data Centers

As a first step of designing O ptical-circuit-switched D ata C enters (ODC), physical topology design is critical as it determines the scalability and the performance limit of the entire ODC. However, prior works on ODC have not yet paid much attention to physical topology design, and the adopted physical topologies either scale poorly, or lack performance guarantee. We offer a mathematical foundation for the design and performance analysis of ODC physical topologies in this paper. We introduce a new performance metric β(G ) to evaluate the gap between a physical topology G and the ideal physical topology. We develop a coupling technique that bypasses a significant amount of computational complexity of calculating β(G). Using β(G ) and the coupling technique, we study four physical topologies that are representative of those in literature, analyze their scalabilities and prove their performance guarantees. Our analysis may provide new guidance for network operators to design better physical topologies for their ODCs.

Design and analysis of a novel large-range 3-DOF compliant parallel micromanipulator

Compared with the traditional rigid mechanism, the flexible mechanism has more advantages, which play an important role in critical situations such as microsurgery, IC (integrated circuit) fabrication/detection, and some precision operating environment. Especially, there is an increasing need for 3-DOF (degrees-of-freedom) compliant translational micro-platform (CTMP) providing good performance characteristics with large motion range, low cross coupling, and high spatial density. Decoupled topology design of the CTMP can easily realize these merits without increasing the difficulty of controlling. This paper proposes a new three DOF compliant hybrid micromanipulator which have large range of motion up to 100 μm × 100 μm × 100 μm in the direction in the dimension of 90 mm × 90 mm × 50 mm, smaller cross-axis coupling (the max coupling only 2.5%) than the initial XY compliant platform in XY axial.

Sürdürülebilir Betonlu Betonarme Yüksek Kirişlerin Yapısal Optimizasyonu

Üretiminde, doğal betona göre daha düşük enerji tüketen ve daha az karbon gazı salınımı sağlayan beton yeşil, çevreci veya sürdürülebilir beton olarak isimlendirmektedir. Sürdürülebilir beton üretimin-de dönüştürülerek ekonomiye kazandırılmış atık beton malzemeleri kullanılmaktadır. Atık betonla-rın dönüştürülmesiyle elde edilen malzemelerden birisi de geri dönüşümlü agregadır. Yapılan kapsamlı deneysel ve analitik çalışmalarda bu agreganın belirli koşullar altında doğal agregaya alternatif bir ürün olabileceği belirtilmiştir. Bu çalışmada, dört farklı oranda geri dönüşümlü agrega içerdiği kabul edilen yüksek kirişlerin tasarımı “isoline topology design” eşdeğer-çizgi topoloji tasarım metoduna göre yapılmıştır. Elde edilen sonuçlar doğal agregalı yüksek kirişlerin tasarım sonuçları ile karşılaştı-rılmıştır. Bu sonuçlara göre; %25 ve %50 oranında geri dönüşümlü agrega içeren yüksek kirişlerin ta-sarım sonuçların doğal agregalı kirişlerin tasarım sonuçlarına benzediği görülmüştür. Yüksek kirişler-deki geri dönüşümlü agrega oranı arttıkça (%50 üstü) bu kirişlerin tasarım sonuçlarının doğal agregalı kirişlerin tasarım sonuçlarından hızla uzaklaştığı belirlenmiştir.

Multi-objective biomimetic optimization design of stiffeners for automotive door based on vein unit of dragonfly wing

In this paper, a biomimetic optimizing design of the stiffeners layout of the automotive inner door panels is proposed based on vein unit of dragonfly wing. The distributions features of the dragonfly veins and similarity as stiffeners are analyzed, and then the excellent structural features of mechanical properties of the dragonfly veins are extracted to work as a biomimetic design. In order to research the distribution of the reinforced areas in the interior door panels under various operating conditions, the finite element model is established firstly. Secondly, gray relation theory combined with analytic hierarchy analysis are imposed to determine the weight value of each condition in multi-objective topology optimization to fully consider both objective and subjective factors, and topological optimization results indicate that the stiffeners of the inner door panel are biconically designed. Finally, the original finite element results of the inner door panels are compared with that after optimized with biomimetic stiffeners under the same operating conditions, and the result of the comparison verify the effectiveness of the biomimetic topology design. Specifically, for the dent-resistant and sinking condition, the strength of new door increases by 20.2% and 14.3%, respectively. Therefore, doors with biomimetic stiffeners have an increased resistance to deformation and vibration, while the mass is reduced by 2.7%. The results can provide valuable new ideas for the optimal biomimetic design of automotive door inner panel stiffeners.