• Journal of Korean Institute of Industrial Engineers
• /
• v.17 no.2
• /
• pp.107-113
• /
• 1991

This article develops a control model for an open queueing network in terms of both the input and the output processes with stochastic intensities. The input and the output intensities are subject to some capacity limits and optimum control is characterized by a threshold type with a finite upper barrier. A discounted profit is used as a decision criteria, which is revenue minus operating and holding cost.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.38 no.10
• /
• pp.24-33
• /
• 2001

Delay, delay variation and packet loss rate are principal QoS(Quality of Service) elements of packet communication. This paper proposes a new buffer allocation mechanism to improve the packet loss performance in such a situation that multiple logical buffers share a single physical memory buffer. In the proposed buffer allocation mechanism, the movement of dynamic threshold follows a curved track instead of a straight line which is used in the DT(dynamic threshold) mechanism. In order evaluate the effectiveness of the proposed mechanism, it is compared with the existing previously proposed mechanisms in several aspects including NC(no control), ST(Static Threshold) and DT mechanisms.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.3
• /
• pp.277-283
• /
• 2006

A recently proposed method for stabilizing haptic interfaces and teleoperation systems was tested with a 'PHANToM' commercial haptic device. The 'Passivity Observer' (PO) and 'Passivity Control1er' (PC) stabilization method was applied to stabilize the system but also excited a high frequency mode in the device. To solve this problem, we propose a method to use a timevarying desired energy threshold instead of fixed zero energy threshold for the PO, and make the actual energy input follow the timevarying energy threshold. With the time-varying energy threshold, we make the PC control action smooth without sudden impulsive behavior by distributing the dissipation. The proposed new PO/PC approach is applied to PHANToM with high stiffness (K = 5000N/m), and stable and smooth contact is guaranteed. Resetting and active environment display problems also can be solved with the reference energy following idea.

• Journal of Electrical Engineering and information Science
• /
• v.2 no.3
• /
• pp.132-138
• /
• 1997

Electrical characteristics of split-gate flash EEPROM with triple polysilicon is investigated in terms of effects of floating gate and offset gate. In order to search for t the effects of offset gate on programming characteristics, threshold voltage and drain current are studied with variation of control gate voltage. The programming process is believed to depend on vertical and horizontal electric field as well as offset gate length. The erase and program threshold voltage are found to be almost constant with variation of control gate voltage above 12V, while endurance test indicates degradation of program threshold voltage. With increase of offset gate length, program threshold voltage becomes smaller and the drain source voltage just after program under constant control gate voltage becomes higher.

• The Journal of Korean Physical Therapy
• /
• v.32 no.2
• /
• pp.121-125
• /
• 2020

Purpose: The purpose of this study was to evaluate the forced vital capacity and sway area of respiratory muscles taping with threshold inspiratory muscles training for 1 week. Methods: Nineteen stroke patients were divided into two groups: experimental group (respiratory muscles taping with threshold inspiratory muscles training, n=10) and control group (threshold inspiratory muscles training, n=9). Forced vital capacity tests were performed using a spirometer. The instrument records the forced vital capacity (FVC). COP excursion test was performed using Zebris. The instrument records the sway area. All tests were measured before and after intervention. Results: The experimental group and control group showed significant increase in FVC (p<0.05). The sway area showed a significant decrease only in the experimental group (p<0.05). The FVC and sway area was no significant difference between the two groups (p>0.05). Conclusion: Threshold inspiratory muscles training is an effective intervention for improving FVC. Threshold inspiratory muscles training with respiratory taping is an effective intervention for improving FVC and sway area. Threshold inspiratory muscles training with respiratory taping can improve balance ability.

• Journal of Information Processing Systems
• /
• v.16 no.6
• /
• pp.1343-1358
• /
• 2020

In the stagewise arithmetic orthogonal matching pursuit algorithm, the weak threshold used in sparsity estimation is determined via maximum iterations. Different maximum iterations correspond to different thresholds and affect the performance of the algorithm. To solve this problem, we propose an improved variable weak threshold based on the stagewise arithmetic orthogonal matching pursuit algorithm. Our proposed algorithm uses the residual error value to control the weak threshold. When the residual value decreases, the threshold value continuously increases, so that the atoms contained in the atomic set are closer to the real sparsity value, making it possible to improve the reconstruction accuracy. In addition, we improved the generalized Jaccard coefficient in order to replace the inner product method that is used in the stagewise arithmetic orthogonal matching pursuit algorithm. Our proposed algorithm uses the covariance to replace the joint expectation for two variables based on the generalized Jaccard coefficient. The improved generalized Jaccard coefficient can be used to generate a more accurate calculation of the correlation between the measurement matrixes. In addition, the residual is more accurate, which can reduce the possibility of selecting the wrong atoms. We demonstrate using simulations that the proposed algorithm produces a better reconstruction result in the reconstruction of a one-dimensional signal and two-dimensional image signal.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1235-1238
• /
• 2004

Thresholding has been used to reduce the number of gray values in images. Typically, a single threshold value has been used, resulting in two gray level images. Image reduction of one single threshold value, however, may lose too much of the high-frequency edge information. Thus, dynamic thresholding that uses a different threshold for each pixel is preferred instead of using a single threshold value. Dynamic thresholding can preserve high frequency details as well as reduce the size of images. Since it takes long time to perform existing software dynamic thresholding in an embedded system, this paper proposes and implements a circuit by using a FPGA in order to perform a real-time dynamic thresholding,. The proposed circuit consists of two counters, and threshold look-up table, and control unit. The values of two counters determine each pixel position, the threshold look-up table converts each pixel value into other value, and the control unit generates necessary control signals. On arriving from a camera to the proposed circuit, each pixel is compared with its threshold value and is converted into other gray value. An image processing system by using the proposed circuit will be implemented and some experiments will be performed.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.7
• /
• pp.32-41
• /
• 1999

In this study, a new knocking control algorithm was developed using the knock threshold value auto-correction algorithm. This algorithm uses the Fast Fourier Transform9FFT) method by measuring cylinder block vibration signals of a 1498 cc four-cylinder spark ignition engine. The experimental results show the proposed knock control algorithm provides improved performance compared to existing methods. The results also show that the proposed FFT algorithm provides real-time adjustment of the knock threshold value.

• Journal of the Institute of Convergence Signal Processing
• /
• v.1 no.2
• /
• pp.97-104
• /
• 2000

Effective call admission control is desirable to control an ATM traffics. It should provide high fairness and utilization for different kinds of services during call admission. Complete bandwidth sharing method is efficient for utilization of bandwidth but not efficient for fairness of call admission. Complete bandwidth partitioning method is efficient for fairness but not efficient for utilization. We propose a new CST(Complete Sharing with Threshold) algorithm using threshold on a total link to improve fairness and utilization.

• International Journal of Control, Automation, and Systems
• /
• v.6 no.2
• /
• pp.214-222
• /
• 2008

Bode principle is applied to carry out traffic control for rate based ATM network, which guarantees the higher buffer utilization, buffer overflow-free, and well utilization of bandwidth. The principle confirms the relationship between the threshold of buffer queue and the network bandwidth, as well as the relationship between the threshold of buffer and source input rate. Theoretic warrant of the buffer threshold is proposed. The reference range of source input rate is provided in theory, which makes the source end respond to the change of network state rapidly and dynamically, and then the effect of time delay to the traffic control is avoided. Simulation results show that the better steady and dynamic performances of networks are obtained by Bode principle.