• 마이크로전자및패키징학회지
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• 제20권4호
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• pp.41-45
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• 2013

Modern electronic devices such as tablets and smartphones are getting more powerful and efficient. The demand in feature sets, functionality and usability increase exponentially and this has posed a great challenge to the design of a power distribution network (PDN). Power rails merging is a popular option used today in a PDN design as numerous power rails are no longer feasible due to form factor limitation and cost constraint. In this paper, the criteria and limitations for power rails merging are discussed. Despite having all the advantages such as pin count reduction, decoupling capacitors sharing, lower impedance and cost saving, power rails merging can however, introduce coupling noise to the system. In view of this, a PDN design with power rails merging that fulfills design recommendations and specifications such as noise target, power well placement, voltage supply values as well as power supply quadrant assignment is extremely important.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.177-184
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• 2001

For two kinds of the multi-stage centrifugal pump with diffuser vanes and return channel vanes the meanline performance prediction is applied to get information of hydraulic performance at each internal flow station, because only flange-to-flange test curves are available. As a first step of redesign fur higher efficiency, the impeller geometry is numerically investigated in the present study. Quasi-3D inviscid loading distributions are obtained, for the two impellers, using the state-of-the-art method of impeller 3D design, which provides a guide to optimal redesign. Full 3D turbulent flow fields are thereafter analyzed, using the specialized CFD code, to confirm the redesign results. The inherent limitation of the traditional graphic method of impeller design, which most of domestic pump manufacturers are now employing, is found.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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• pp.547-550
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• 2006

An analysis method is developed for the prediction of venting in multiple compartments which are connected in series or parallel through multiple ports. The existing method by the authors is modified to remove the limitation in number of ports and compartments, and the more general polytropic relation or solution of the additional energy equation replaces the previous isentropic relation allowing the prediction of pressure rise in addition to pressure drop. The accuracy of the method is verified by comparison with the results by NASA Flap code for the problem of pressure drop in a payload in the Space Shuttle cargo bay. It is expected that this method will be a useful tool in prediction of the pressure variation in a payload or payload capsule without mentioning the payload fairing itself.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.26.5-26
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• 2001

This paper proposes a new approach to identifying the unknown parameters of continuous LTI systems. For parameter identification in continuous-time systems, the Linear Integral Filter (LIF) method generally has been used in the beginning. Especially, one of the most efficient LIF methods in the literature is to use a weighting function satisfying specific three constraints. In high order systems, even though the weighting function satisfies the three constraints, it is impossible to identify the exact parameters of the systems because of information loss arising from a great amount of magnitude differences among the weighting function and its high-order derivatives. This paper, using an LMI technique, shows the limitation in designing the weighting function of the existing methods, and ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.103.3-103
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• 2001

Recently Electro active polymer has been discussed in various researches as new actuators replacing the human muscles. Since they have confronted a limitation of more advanced application with traditional actuator. IPMC (Ion exchange Polymer Metal Composite) is one of candidate materials for new actuators. In this paper, we propose a new approach and design principle for the IPMC polymer actuator to conquer the weaknesses of IPMC that is intrinsic weak structural stiffness and low trust forces. In the first we performs some experimental works about how the basic specific characteristics of IPMC vary and what the optimal operating conditions are. And we have applied IPMC as active cilium for realization of annelida motion like ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.181.3-181
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• 2001

Recently, the study on development of electrical and electronic device is done to get miniature, high degrees of integration and efficiency by using inorganic materials. the study of Langmuir-Boldgett(LB) method that uses organic materials because of the limitation for the ultrasmall size. In this paper, to do research for medical artificial organs as well as principal parts living body thin film application, electrical properties of L-$\alpha$-DLPC Langmuir(L) films were investigated a displacement current measuring technique with pressure stimulation. We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 20[mN/m]. LB layers of L-$\alpha$-DLPC deposited by LB method ...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.120.4-120
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• 2002

$\textbullet$ In order to operate EP actuator, high voltage is applied to that. $\textbullet$ Our previous control algorithm for an EP actuator was PI method with constant gain. $\textbullet$ But this Control method is limitation such as rising time, steady-state error, and settling time. $\textbullet$ A neural network algorithm is proposed for improvement of performance. $\textbullet$ To do this, neural network algorithm changes the gain of PI control. $\textbullet$ In order to efficient drive EP actuator, the gain is changed at some point. $\textbullet$ Neural network method improve the performance of operation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.50.6-50
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• 2002

In this paper, the relationship between a slave robot and the uncertain remote environment is modeled as the impedance to generate the virtual force to feed back to the operator. For the control of a teleoperated mobile robot equipped with camera, the teleoperated mobile robot take pictures of remote environment and sends the visual information back to the operator over the Internet. Because of the limitation of communication bandwidth and narrow view-angles of camera, it is not possible to watch the environment clearly, especially shadow and curved areas. To overcome this problem, the virtual force is generated according to both the distance between the obstacle and robot and the approachin...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.96.6-96
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• 2002

In this study an image processing system is designed and developed, which can detect and assort some defects on the surface of an object moving with high speed. For real time surface detection of high speed moving object, the fast processing should be managed and the image information including some surface features should be captured. It is difficult to acquire the noise free image due to various light sources and high speed moving materials under the environment of the general industrial site. In general, because pre-processing methods are employed for getting a noise free feature, the image processing speed has some limitation and the expensive image processing devices are required. This...

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.274-279
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• 1991

The development of a guided weapon system, such as a tactical missile, requires a performance analysis of a nonlinear system. Generally, the Monte Carlo analysis method is used for this purpose. The limitation of this method, a large number of simulations, for a nonlinear system performance analysis strongly motivated the development of a more efficient analytic technique. In this paper, the statisfical linearization methods is used for the performance analysis to the guided weapon system with the help of covariance analysis technique. Because the statistical linearization methods cannot be used to the look-up table nonlinear form such as aerodynamic coefficients, the second order polynomial representations is obtained from the table using the Lagrange interpolating polynomial and linearized statistically. Simple simulations about initial state conditions and random component in guidance command shows the results of this technique.