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171.
An efficient microfluidic sorter: implementation of double meandering micro striplines for magnetic particles switching 总被引:1,自引:1,他引:0
Tian Fook Kong Huan Shin E Hendrik Santoso Sugiarto Hwi Fen Liew Xinghua Wang Wen Siang Lew Nam-Trung Nguyen Yong Chen 《Microfluidics and nanofluidics》2011,10(5):1069-1078
The ability to trap, manipulate, and separate magnetic beads has become one of the key requirements in realizing an integrated
magnetic lab-on-chip biosensing system. In this article, we present the design and fabrication of an integrated magneto-fluidic
device for sorting magnetic particles with a sorting efficiency of up to 95%. The actuation and manipulation of magnetic beads
are realized using microfabricated square meandering current-carrying micro striplines. The current is alternated between
two neighboring micro striplines to switch the magnetic beads to either one of the two outlets. We performed a series of parametric
study to investigate the effect of applied current, flow rate, and switching frequency on the sorting efficiency. Experimental
results reveal that the sorting efficiency is proportional to the square of current applied to the stripline, and decreases
with increasing buffer flow rate and switching frequency. Such phenomena agree well with our theoretical analysis and simulation
result. The fastest switching rate, which is limited by the microchannel geometry and bead velocity, is 2 Hz. 相似文献
172.
173.
By modeling mass transfer phenomena, we simulate solids and liquids dissolving or changing to other substances. We also deal with the very small‐scale phenomena that occur when a fluid spreads out at the interface of another fluid. We model the pressure at the interfaces between fluids with Darcy's Law and represent the viscous fingering phenomenon in which a fluid interface spreads out with a fractal‐like shape. We use hybrid grid‐based simulation and smoothed particle hydrodynamics (SPH) to simulate intermolecular diffusion and attraction using particles at a computable scale. We have produced animations showing fluids mixing and objects dissolving. 相似文献
174.
Beomseok Nam Minho Shin Henrique Andrade Alan Sussman 《Journal of Parallel and Distributed Computing》2010
In distributed query processing systems, load balancing plays an important role in maximizing system throughput. When queries can leverage cached intermediate results, improving the cache hit ratio becomes as important as load balancing in query scheduling, especially when dealing with computationally expensive queries. The scheduling policies must be designed to take into consideration the dynamic contents of the distributed caching infrastructure. In this paper, we propose and discuss several distributed query scheduling policies that directly consider the available cache contents by employing distributed multidimensional indexing structures and an exponential moving average approach to predicting cache contents. These approaches are shown to produce better query plans and faster query response times than traditional scheduling policies that do not predict dynamic contents in distributed caches. We experimentally demonstrate the utility of the scheduling policies using MQO, which is a distributed, Grid-enabled, multiple query processing middleware system we developed to optimize query processing for data analysis and visualization applications. 相似文献
175.
176.
A telebiometric system mechanism model and biometric network protocol for the security of networked manufacturing 总被引:1,自引:1,他引:0
Networked manufacturing changes conventional enterprise activities. With a networked manufacturing system, enterprises are
able to perform a range of activities, such as product planning, design, production, and marketing, in collaboration with
international partners, regardless of geographical location. However, strict security measures are required, as the authentication
and information transfers for networked manufacturing are conducted over a network. With the development of biometric technology,
more and more enterprises are using the unique biometric data of individuals to verify the identity of users, in order to
restrict and provide access to technology research centers or factory facilities. This paper analyzes the vulnerabilities
of the biometric system used for access control and the authentication of access to confidential information in the networked
manufacturing system. In addition, the biometric systems that can be built in an open network environment are classified into
9 general models, and a biometric network protocol is suggested that is secure and compatible with international standards. 相似文献
177.
Examining influencing factors of post-adoption usage of mobile internet: Focus on the user perception of supplier-side attributes 总被引:1,自引:0,他引:1
Young Mee Shin Seung Chang Lee Bongsik Shin Ho Geun Lee 《Information Systems Frontiers》2010,12(5):595-606
Key supplier-side factors that affect the usage level of mobile Internet were identified and the procedural mechanism among
the independent and dependent variables was investigated. For this, a research model was introduced to describe associations
among four external variables (access quality, service variety, cost rationality, and ease of use), an intermediate variable
(usefulness) and a dependent variable (the usage level of mobile Internet). Through the on-line survey, data were gathered
from actual mobile Internet users. Confirmatory factor analysis and path analysis were applied to test the overall integrity
of the research model and of proposed hypotheses. All four external variables affected user perceptions on the usefulness
of mobile Internet. Among them, service variety and cost rationality had a relatively larger influence on perceived usefulness.
Perceived usefulness of the mobile Internet had a positive effect on its usage, confirming the important role of usefulness
as a significant mediator between the four external variables and the dependent variable. Meanwhile, the cost rationality
was the only external variable with direct influence on the MI usage. Theoretical and practical implications of the study
results are discussed. 相似文献
178.
The conventional approach to reducing control signal chattering in sliding mode control is to use the boundary layer design. However, when there is high‐level measurement noise, the boundary layer design becomes ineffective in chattering reduction. This paper, therefore, proposes a new design for chattering reduction by low‐pass filtering the control signal. The new design is non‐trivial since it requires estimation of the sliding variable via a disturbance estimator. The new sliding mode control has the same performance as the boundary layer design in noise‐free environments, and outperforms the boundary layer design in noisy environments. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society 相似文献
179.
Wonseok Lee Young-bong Bang Kyung-min Lee Bu-hyun Shin Jamie Kyujin Paik In-su Kim 《International Journal of Control, Automation and Systems》2010,8(5):1072-1081
Conventional robot motion teaching methods use a teaching pendant or a motion capture device and are not the most convenient
or intuitive ways to teach a robot sophisticated and fluid movements such as martial arts motions. Ideally, a robot could
be set up as if it were a clothing mannequin that has light limbs and flexible yet frictional joints which can be positioned
at desirable shape and hold all the positions. To do the same with a robot, an operator could pull or push the links with
minor forces until the desired robot posture is attained. For this, a robot should measure the applied external force by using
torque sensors at the robot joints. However, torque sensors are bulky and expensive to install in every DOF joints while keeping
a compact design, which is essential to humanoid robots. In this paper, we use only motor current readings to acquire joint
torques. The equations used to compensate for the effect of gravity on the joint torques and the self-calibration method to
earn link parameters are presented. Additionally, kinematic restrictions can be imposed on the robot’s arms to simplify the
motion teaching. Here, we teach the Kendo training robot with this method and the robot’s learnt martial art motions are demonstrated. 相似文献
180.
Sangmun Shin Nguyen Khoa Viet Truong Byung Rae Cho Sung Hoon Hong 《Computers & Industrial Engineering》2011
Robust design (RD) and tolerance design (TD) have received much attention from researchers and practitioners for more than two decades, and a number of methodologies for modeling and optimizing the RD and TD processes have been studied. However, there is ample room for improvement. Because most existing research considers RD and TD as separate research fields, the primary objective of this paper is to develop a sequential robust–tolerance design method to jointly determine the best factor settings and the closed-form solutions for the optimal specification limits. We then apply the proposed method to a destructive quality characteristic. Finally, a case study and sensitivity analyses are performed for verification purposes, and further studies are discussed. 相似文献