• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2395-2402
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• 2013

An active-RC channel selection filter (CSF) with the bandwidth of 40MHz and the improved linearity is proposed in this paper. The proposed CSF is the fifth butterworth filter which consists of a first order low pass filter, two second order low pass filters of a biquad architecture, and DC feedback circuit for cancellation of DC offset. To improve the linearity of the CSF, a body node of a MOSFET for a switch is connected to its source node. The bandwidth of the designed CSF is selected to be 10MHz, 20MHz and 40MHz and its voltage gain is controlled by 6 dB from 0 dB to 24 dB. The proposed CSF is designed by using 40nm 1-poly 8-metal CMOS process with a 1.2V. When the designed CSF operates at the bandwidth of 40 MHz and voltage gain of 0 dB, the simulation results of OIP3, in-band ripple, and IRN are 31.33dBm, 1.046dB, and 39.81nV/sqrt(Hz), respectively. The power consumption and layout area are $450{\times}210{\mu}m^2$ and 6.71mW.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.948-950
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• 2003

In this literature, the CMOS current mode fout quadrant differentiator circuit is proposed. The implementation is base on an appropriate input stage that converts the input current into a compressed voltage at the input capacitor ($C_{gs}$) of the CMOS driver circuit. This input voltage use as the control output current which flow to the output node by passing through a MOS active load and use it as the feedback voltage to the input node. Simulation results with level 49 CMOS model of MOSIS are given to demonstrate the correct operation of the proposed configuration. But the gain of the circuit is too low so the output differentiate current also low. The proposed differentiator is expected to find several applications in analog signal processing system.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.4
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• pp.719-728
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• 1997

In the AGV routing a vehicle can select the shortest route on which no conflicts are anticipated. The procedure includes time constraint and the node/arc occupation times of vehicles in order to locate the conflicting paths. The slight differences among AGV routing algorithms exist in identifying the conflict regions encountered while reaching out to the destination node. In this paper, a novel approach to the use of the re-routing scheme is presented. It will be used to minimize the travel distance of vehicles in a regular vehicle routing process rather than to cope with emergency situations. The proposed algorithm provides existing active vehicles with the ability of changing their current paths for a new vehicle whenever the equal-distance paths exist, in on attempt to optimize the AGV transportation system. This ability is possible because of the flexibility of on AGV system controlled by a computer system.

• Journal of applied mathematics & informatics
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• v.26 no.1_2
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• pp.235-249
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• 2008

On-demand routing protocol in ad hoc network is that establishes a route to a destination node only when it is required by a source node. But, it is necessary to reestablish a new route when an active route breaks down. The reconstruction process establishes another route by flooding messages from the source to the destination, cause not only heavy traffic but also long delays in route discovery. A good method for analyzing performance of protocols is important for deriving better systems. In this paper, we suggest the numerical formulas of a representative on-demand routing protocol AODV, ARMP, and RRAODV to estimate the performance of these routing protocols for analyzing the performance of these protocols. The proposed analytical models are very simple and straightforward. The results of analysis show good agreement with the results of computer simulations.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.3
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• pp.227-230
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• 2002

A new iris segmentation and recognition method is described. Combining a statistical classification and elastic boundary fitting, the iris is first segmented robustly and accurately. Once the iris is segmented, one-dimensional signals are computed in the iris and decomposed into multiple frequency bands. Each decomposed signal is approximated by a piecewise linear curve connecting a small set of node points. The node points represent features of each signal. The similarity measture between two iris images is the normalized cross-correlation coefficients between simplified signals.

• Natural Product Sciences
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• v.7 no.4
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• pp.107-109
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• 2001

To investigate anti-diabetic component from the node of lotus rhizome (Nelumbo nucifera; Nymphaeaceae), activity guided isolation was conducted. One amino acid was isolated from active fraction of the aqueous methanolic extract. The structure of this compound was identified as tryptophan (1) by the analysis of spectroscopic evidences and comparisons with the data of authentic samples. Tryptophan reduced the blood glucose level significantly in glucose-fed hyperglycemic mice compared with glucose-treated group and exhibited 44.3% of activity compared with tolbutamide,.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5B
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• pp.390-396
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• 2006

Policy-based Network Management(PBNM) in the Mobile Ad-hoc network(MANETs) requires additional, reliable and efficient mechanism over PBNM in wired network. Thus, it is important that the management system in MANETs should cluster the moving nodes and manage their movements in an effective manner. In this thesis, I propose a mechanism for the policy-based management in ad hoc networks in which I consider several methods to discover the Policy Decision Point(PDP), set the management area, and manage the movements of Policy Enforcement Point(PEP) nodes in the PBNM system. Moreover, COPS-PR is extended for the mechanism. Finally, I analyze and validate the results through simulations.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.1
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• pp.106-117
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• 2006

The active vibration control of composite shell structure has been performed with the optimized sensor/actuator system. For the design of sensor/actuator system, a method based on finite element technique is developed. The nine-node Mindlin shell element has been used for modeling the integrated system of laminated composite shell with PVDF sensor/actuator. The distributed selective modal sensor/actuator system is established to prevent the effect of spillover. Electrode patterns and lamination angles of sensor/actuator are optimized using genetic algorithm. Continuous electrode patterns are discretized according to finite element mesh, and orientation angle is encoded into discrete values using binary string. Sensor is designed to minimize the observation spillover, and actuator is designed to minimize the system energy of the control modes under a given initial condition. Modal sensor/actuator for the first and the second mode vibration control of singly curved cantilevered composite shell structure are designed with the method developed on the finite element method and optimization. For verification, the experimental test of the active vibration control is performed for the composite shell structure. Discrete LQG method is used as a control law.

• Journal of KIISE:Information Networking
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• v.36 no.1
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• pp.12-23
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• 2009

Sensor networks deployed in battlefields to support military operations or deployed in natural habitats to monitor the rare wildlifes must take account of protection of the location of valuable assets(i.e., soldiers or wildlifes) from an adversary or malicious tracing as well as the security of messages in transit. In this paper we propose a routing protocol GSLP(GPSR-based Source-Location Privacy) that is capable of enhancing the location privacy of an active source node(i.e., message-originating node) in the presence of multiple dormant sources(i.e., nodes lying nearby an asset whose location needs to be secured). Extended is a simple, yet scalable, routing scheme GPSR(greedy perimeter stateless routing) to select randomly a next-hop node with a certain probability for randomizing paths and to perform perimeter routing for detouring dormant sources so that the privacy strength of the active source, defined as safety period, keeps enhanced. The simulation results obtained by increasing the number of dormant sources up to 1.0% of the total number of nodes show that GSLP yields increased and nearly invariant safety periods, while those of PR-SP(Phantom Routing, Single Path), a notable existing protocol for source-location privacy, rapidly drop off as the number of dormant sources increases. It turns out that delivery latencies of GSLP are roughly less than two-fold of the shortest path length between the active source and the destination.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.113-125
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• 1985

Electrophysiological difference of the central and peripheral area of the sinoatrial node in the rabbit was studied by glass microelectrode technique. Effects of $K^+,\;Na^+,\;Cs^+,$ adrenaline and ouabain on the action potential of the two areas were investigated, and transient hyperpolarization ($K^+-induced$ hyperpolarization) which developed following readmission of potassium after having pre-treated with $K^+-free$ Tyrode solution for 10 minutes was analyzed. The results obtained were as follows ; 1) The frequency of the spontaneous action potential recorded in the periphery of the SA node was faster than the central area. Reduction by $Cs^+$ and increase by O mM $K^+$, $10^{-6}M$ adrenaline and $10^{-6}M$ ouabain in the frequency of action potential were noticed more prominently in the peripheral than the central area. On the contrary, the frequency in the central area was more decreased than the Peripheral area by 13 mH $K^+$ and 1 mM $Co^{2+}$. 2) The amplitude of the K+_induced hyperpolarization was very small in the central area but large in the peripheral area. Transient hyperpolarization was abolished by ouabain and low sodium, and decreased by cooling the tissue $(17^{\circ}C)$. 3) By changing the concentration of $Ca^{2+}$ in the perfusate, the amplitude and the rate of transient hyperpolarization were increased in the high $Ca^{2+}$ concentration. It could be concluded that the central area of the SA node is less susceptible to the inhibition of Na-Pump and more susceptible to Ca-blocker and high concentration of $K^+$. The Na-Pump activity of the central area measured by means of transient hyperpolarization is found to be much less active than that of the peripheral area.