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141.
针对乳腺癌数据存在的不平衡性问题,对标准的Adaboost算法进行改进,即首先引入BP神经网络,然后融合模拟退火遗传算法(SA-GA)较强的全局寻优能力和较快的收敛速度,最后通过权重的合理分配,提出BP-GamysBoost算法。同时为验证所提出的新算法BP-GamysBoost的合理性,从UCI机器学习知识库中获取WBCD数据库,比较BP-GamysBoost算法模型与BP模型、BP-GA模型、BP-Adaboost模型的稳定性、准确率、漏诊率、灵敏度等性能指标。最终结果表明,BP-GamysBoost模型在乳腺癌数据库中运行良好,并优于其他3种算法模型。 相似文献
142.
Hwichul Yang Hojae Lee Yonghyun Lim Young-Beom Kim 《Journal of the American Ceramic Society》2021,104(1):86-95
In this paper, we report successful fabrication of a gadolinia-doped ceria (GDC) thin film using atomic layer deposition (ALD) for improving the performance of solid oxide fuel cells (SOFCs). By varying the deposition conditions and adjusting the configuration of the ALD supercycle, the doping ratio of ALD GDC was controlled. The morphology, crystallinity, and chemical composition of ALD GDC thin films were analyzed. ALD GDC showed different surface chemistry, including oxidation states, at different doping ratios. The application of ALD GDC in a SOFC led to an output power density enhancement greater than 2.5 times. With an anodic aluminum oxide (AAO) porous support structure, an ALD GDC thin film SOFC (TF-SOFC) showed a high power density of 288.24 mW/cm2 at an operating temperature of 450°C. 相似文献
143.
Mario Bragaglia Tony McNally Francesca R. Lamastra Valeria Cherubini Francesca Nanni 《应用聚合物科学杂志》2021,138(20):50423
Immiscible blends of ethylene-propylene-diene-monomer (EPDM) and polyoxymethylene (POM), when EPDM is the major phase were compatibilized on the addition of an ionomer, poly(ethylene-co-methacrylic acid). The inclusion of the ionomer reduced the interfacial tension between the two phases, such that the diameter of the POM domains were significantly reduced to between 0.5 and 2 μm, typical of that required to toughen ductile polymers. The mechanical properties of the resultant compatibilized blends were significantly enhanced with increases in Young's modulus (↑54%), tensile strength (σ, ↑139%), elongation at break (ε, ↑97%), and tensile toughness (↑500%) with increasing ionomer content, relative to EPDM rubber alone. The ShoreA hardness of the compatibilized blend was 70.1 compared with 56.8 for the immiscible binary blend and, 50.2 for neat EPDM rubber. 相似文献
144.
Ahn Kyu-Hong Hwang Jong-Hyuk Song Kyung-Guen Jung Yong-Ho Cho Eul-Saeng Lim Byung-Ran Kim Kwang-Soo 《Metals and Materials International》2004,10(2):167-170
The performance of an attached growth wastewater treatment process was investigated in an effort to improve nitrogen removal
efficiency. Recycled Yakult (lactic acid fermentation drink) bottles made of polystyrene were used as a biofilm media. The
use of Yakult bottles as a biofilm media has been attempted by numerous researchers in Japan for the removal of solids and
organics. However, these studies focused only on the removal of solids and organics. This study extended their application
to the removal of nitrogen for domestic sewage treatment. Yakult media was placed in a reactor with 70% apparent reactor volume
in a conventional A/O process. The bottom of the Yakult media was removed, and randomly filled Yakult media were effectively
able to reduce the flow in tanks, resulting in an increase in the contact time between pollutants and microorganisms. With
higher HRT, the nitrogen removal efficiency was increased by up to 83% with 12 hr of HRT. Nitrification appeared to be the
limiting factor of nitrogen removal at an HRT that is less than 12 hr, indicating that the Yakult process requires more retention
time to achieve nitrification compared to other biofilm processes. The removal efficiencies of organics and solids were high
regardless of the change of operational parameters.
This article is based on a presentation in “The 7th Korea-China Workshop On Advanced Materials” organized by the Korea-China
Advanced Materials Cooperation Center and the China-Korea Advanced Materials Cooperation Center, held at Ramada Plaza Jeju
Hotel, Jeju Island, Korea on August 24–27, 2003. 相似文献
145.
The relationship between the yield ratio and the material constants,b andN, of the Swift equation for hotrolled low carbon steels has been established. The yield ratio calculated by using the Swift
equation agrees well with an experimentally obtained yield ratio. It was found that the yield ratio decreases with an increasing
value ofN or with a decreasing value ofb. It was also found, however, that high yield strength is associated with small values of bothb andN. Therefore, to obtain both high yield strength and low yield ratio, a detailed microstructural control is needed to determine
the optimum values ofb andN. 相似文献
146.
Feature-based design of progressive press tools 总被引:2,自引:0,他引:2
147.
Tony L. Schmitz Jeremiah Couey Eric Marsh Nathan Mauntler Duke Hughes 《International Journal of Machine Tools and Manufacture》2007,47(5):841-851
This paper investigates the effect of milling cutter teeth runout on surface topography, surface location error, and stability in end milling. Runout remains an important issue in machining because commercially-available cutter bodies often exhibit significant variation in the teeth/insert radial locations; therefore, the chip load on the individual cutting teeth varies periodically. This varying chip load influences the machining process and can lead to premature failure of the cutting edges. The effect of runout on cutting force and surface finish for proportional and non-proportional tooth spacing is isolated here by completing experiments on a precision milling machine with 0.1 μm positioning repeatability and 0.02 μm spindle error motion. Experimental tests are completed with different amounts of radial runout and the results are compared with a comprehensive time-domain simulation. After verification, the simulation is used to explore the relationships between runout, surface finish, stability, and surface location error. A new instability that occurs when harmonics of the runout frequency coincide with the dominant system natural frequency is identified. 相似文献
148.
Y.S Wong M Rahman H.S Lim H Han N Ravi 《Journal of Materials Processing Technology》2003,140(1-3):303-307
Similar to EDM, in micro-EDM, intense heat is generated between the workpiece and tool electrode by the discharge through a dielectric medium to result in the formation of a microcrater that is much smaller in size. In this study, a single-spark generator has been developed to study the erosion characteristics from the microcrater size. Using a simple heat transfer model, the efficiency at different discharge condition is also deduced. It is found that at lower-energy (<50 μJ) discharges, the energy required to remove the unit volume of material, defined as the specific energy, is found to be much less than that at higher-energy discharges. Additionally, the ratio of the standard deviation to the measured microcrater size is found to be lower at lower discharge energy, indicating greater consistency in shape and size when the discharge occurs at lower energy. The fundamental erosion mechanism of material is discussed by considering melting and evaporation phenomena using theoretical modeling. The average efficiency of erosion, when estimated to be due primarily to melting or evaporation alone, is found to be up to an order of magnitude higher at lower-energy discharges than that at higher-energy discharges. 相似文献
149.
150.
This paper studies the partial consensus problem for identical feedforward dynamic systems with input saturations. We construct two consensus protocols using the partial‐state information and full‐state information, respectively. Applying a change of coordinates, feedforward system is transformed into the block diagonal form. Then, by utilizing the bounded real lemma and small gain theorem, we solve the partial consensus problem, and the existence of each protocol is derived. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献