http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Constitutive model coupled with damage for carbon manganese steel in low cycle fatigue
Zhiyong Huang,Qingyuan Wang,Danièle Wagner,Claude Bathias 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.2
Carbon-manganese steel A42 (French standards) is used in steam generator pipes of nuclear center and subject to low cycle fatigue (LCF) loads. In order to obtain the material LCF behavior, the tests are implemented in a hydraulic fatigue machine. The LCF plastic deformation and cyclic stress in macroscope have been influenced by the accumulated low cycle fatigue damage. The constitutive kinematic and isotropic hardening modeling is modified with coupling fatigue damage to describe the fatigue behavior. The improved model seems to be good agreement with the test results.
Zhiyong Zeng,Zhongxi Li,Stefan M. Goetz 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3
This paper aims at reducing the root mean square (RMS) values of the zero-sequence circulating current (ZSCC). The analysis reveals that the ZSCC is determined by the duty ratios of the medium voltage vector and zero vector. Whereas the reference voltage fxes the duty ratio of the medium vector, the duty ratio of the zero-voltage vector depends on the distribution of the small and larger vectors, which can be used to optimize the ZSCC. As such, we propose a generalized PWM architecture, where the distribution of the active vectors is parameterized by a coefcient k. Based on this, we derive regions for k that attain the same minimal ZSCC peak. Within these regions, we further optimize k to minimize the ZSCC RMS. Depending on the reference voltage, the method selects diferent coefcient k for the ZSCC RMS optimizations. The proposed modulation strategy is therefore a HBSVM due to its adaptive feature in the distribution of the active vectors. The proposed HBSVM uniformly applies to the entire vector plane and is computationally afordable for mainstream microcontrollers. Finally, the experimental results validate the merits of the proposed method.
ZhiYong Wu,Zhiheng Huang,Yucheng Ma,Hua Xiong,Paul P. Conway 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.1
Through-silicon vias (TSVs) have been investigated extensively in recent years. However, the physical mechanisms behind some of the common problems associated with TSVs, such as the protrusion of Cu vias, are still unknown. In addition, since the dimensions of TSVs have been shrunk to microscopic levels, the sizes of the microstructural features of TSVs are no longer small compared to the dimensions of the vias. Therefore, the role and importance of the microstructural features of TSVs need to be studied to enable more accurate reliability predictions. This study focused on the effects the microstructural features of TSVs, i.e., the Cu grains and their [111] texture, grain size distribution, and morphology, have on the thermally induced linear elastic behavior of the vias. The results of the study indicate that stress distribution in the model that takes into account the Cu grains, whose Young’s moduli and Poisson’s ratios are set according to their crystallographic orientations, is more heterogeneous than that in a reference model in which the bulk properties of Cu are used. Stresses as high as 250 MPa are observed in the via of the model that takes into consideration the Cu grains, while stresses in the via of the reference model are all lower than 150 MPa. In addition, smaller Cu grains in the vias result in higher stresses; however, the variation in stress owning to changes in the grain size is within 20 MPa. The frequency of the stresses ranging from 80 MPa to 100 MPa was the highest in the stress distribution of the vias, depending on boundary conditions. The stress level in the vias decreases with the decrease in the number of grains with the [111] texture. Finally, the stress level is lower in the model in which the grain structure is generated using a phase field model and is closer to that of the microstructures present in real materials.
An Improved Eclat Algorithm for Mining Association Rules Based on Increased Search Strategy
Zhiyong Ma,Juncheng Yang,Taixia Zhang,Fan Liu 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.5
Although Eclat algorithm is an efficient algorithm for mining association rules, there are some disadvantages which limit the efficient of Eclat. In this paper, we proposed an improved Eclat algorithm called Eclat_growth which is based on the increased search strategy. There are three main steps in the Eclat_growth algorithm. First, it scans the database and stores it into a table using vertical data format. Then, it builds an increased two-dimensional pattern tree and the TID_sets of itemsets in the vertical data format table are added into the pattern tree row by row. New frequent itemsets are generated by combining the new added item data with the existing frequent itemsets in the pattern tree. Finally, all frequent itemsets can be found by picking up all nodes of the pattern tree. In the process of generating new frequent itemsets, the prior knowledge is used to fully clip the candidate itemsets. In the process of generating an intersection of two itemsets and calculating the support degree, we proposed a new method called BSRI (Boolean array setting and retrieval by indexes of transactions) to reduce the run time. By comparing Eclat_growth with Eclat, Eclat-diffsets, Eclat-opt and hEclat, it is indicated that Eclat_growth has the highest performance in mining associating rules from various databases.
( Zhiyong Liu ),( Yinghua Wang ),( Lizhong Song ),( Yinyin Wang ),( Fusheng Dai ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.1
In this paper, we propose a joint adaptive combining and variable tap-length multiuser detector (MUD) for amplify-and-forward (AF) underwater acoustic cooperative interleave-division multiple access (IDMA) communication system. The proposed MUD jointly realizes tap-length adjustment, adaptive combining, and multiuser detection. In contrast to the existing methods, the proposed detector can adaptively combine the received signals from different nodes at destination, and does not need the assumption that full and perfect channel state information (CSI) of all the links at the receiver is known. Moreover, the proposed detector can adaptively adjust the tap coefficient vector and tap-length of each branch according to the specific channel profile of each branch. Simulation results validate the feasibility and show the advantages of the proposed detector against existing counterparts.
Zhiyong Ma,Jun Xie,Xian Zhen Shan,Jiabin Zhang,Qifan Wang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.2
45S5 Bioglass® has been widely used in bone tissue engineering scaffold due to its high bioactive properties. 3D printing method is a popular way to fabricate scaffolds. The extrusion printing method causes poor shape and dimensional accuracy of the scaffolds. The ordinary light-cured 3D printing method leads to low solid content of the scaffolds, which causes large shape shrinkages and low mechanical properties after sintering. In this study, we employed the stereolithographic ceramic manufacturing (SLCM) method to fabricate 45S5 Bioglass®-based scaffolds. Coating-then-stereolithographic layer by layer is the core process of SLCM method. Based on the optimization of the parameters of SLCM process and sintering process, the solid content of the 45S5 scaffold can be improved to a maximum of 70 %, and the linear shrinkage and compressive strength were effectively improved. The proposed method can be used not only for fabricating bone tissue engineering scaffold, but also for manufacturing other high solid content ceramic products.
Zhiyong Fu,Dandan Yu,Shuangshuang Zhang 한국HCI학회 2013 한국HCI학회 학술대회 Vol.2013 No.1
This paper presents how to improve the holistic user experience for the elderly with chronic disease by designing the new self-health management service based on multi-screen platform and tangible touch points. As the connected touch point, Med-Cube is designed to help the elderly feel in control when they handle with the complicated multi-screen devices, like TV, tablet PC and mobile phone. In order to create seamless connection between the elderly and the multi-screen service system, we designed the context aware interaction flow based on the elderly’s common experience and behavior of everyday self-health management, such as recording, reminding and navigating. This selfhealth service system helps the elderly to create integrated user experience between virtual online world and physical world as well. The self-health service system also links the elderly with family, friends and doctors by cross-media platform and social network. Our vision in this study is to give the elderly independent, healthy, self-controlled life by providing service from the tangible touch points and holistic cross-media interaction mode.