• International Journal of Control, Automation, and Systems
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• v.5 no.5
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• pp.594-600
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• 2007

A sufficient condition for the robust D-stability of dynamic interval systems is proposed in this paper. This D-stability condition is based on a parameter-dependent Lyapunov function obtained from the feasibility of a set of matrix inequalities defined at a series of partial-vertex-based interval matrices other than the total vertex matrices as previous results. This condition is also extended to the robust D-stabilization problem of dynamic interval systems, which supplies an effective synthesis procedure for any LMI D-region. The proposed conditions can be simplified to a set of LMIs, which can be solved by efficient interior point methods in polynomial time.

• Journal of IKEEE
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• v.26 no.4
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• pp.590-595
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• 2022

When a train is delayed because of a disturbance, the time interval deviation between successive trains increases, and high frequency metro lines can become unstable. Thus, it is necessary to control the traffic regularity to prevent any such instability. In this paper, we propose a simple but effective traffic regulation algorithm that gurantees system stability. In the proposed method, the control algorithm for running time is designed using a discrete traffic model where control input is determined from a linear combination of departure time deviations and control input of the preceding train to ensure an optimal time interval between successive trains. The results of the computer simulation are also given to demonstrate the validity of the proposed algorithm.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.577-583
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• 2019

A dynamic system is called positive if any trajectory of the system starting from non-negative initial states remains forever non-negative for non-negative controls. In this paper, we consider the new stability condition for the positive time-varying linear discrete interval systems with time-varying delay and unstructured uncertainty. The delay time is considered as time-varying within certain interval having minimum and maximum values and the system is subjected to nonlinear unstructured uncertainty which only gives information on uncertainty magnitude. The proposed stability condition is an improvement of the previous results which can be applied only to time-invariant systems or had no consideration of uncertainty, and they can be expressed in the form of a very simple inequality. The stability conditions are derived using the Lyapunov stability theory and have many advantages over previous results using the upper solution bound of the Lyapunov equation. Through numerical example, the proposed stability conditions are proven to be effective and can include the existing results.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.659-663
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• 2000

The motality rate of acute subdural hematoma(ASDH) associated with closed head injury is high in spite of recent advances in neurosurgery. Many variables in regard to outcome of ASDH have been assessed. But among them, intracranial pressure(ICP) control and the time interval between injury and operative evacuation are the only things that can be affected by doctor. We introduced a simple method to the management of ASDH for reducing the time interval between injury and operation. When the immediate decompressive operation of ASDH was impossible by any causes, we made a burr hole at the center of hematoma, usually on 2-3cm above temporal squama and 1-2cm behind coronal suture under local anesthesia before main operation. Partial hematoma evacuation was achieved through the burr hole and it was effective in preventing further worsening of patients neurological status before main operation. Prompt hematoma evacuation through the burr hole seemed to be effective in delaying secondary ischemic brain damage and made easy to closing the dura opening and replacement of the bone flap at the end of main decompressive operation. This easy method may reduce the time interval between injury and operation. We represent surgical technique with two cases of ASDH managed with this simple method.

• Journal of the Korean Statistical Society
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• v.29 no.3
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• pp.319-336
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• 2000

A mixed model with a white noise process and an IMA(0,1,1) process is considered as a process model. It is assumed that the process is a white noise in the absence of a special cause and the process changes to an IMA(0,1,1) due to a special cause. One useful scheme in measuring the process level is to use the variable measurement interval (VMI) between measurement times according to the value of the previous chart statistic. The advantage of the VMI scheme is to measure the process level infrequently when in control to save the measurement cost and to measure frequently when out of control to save the off-target cost. This paper considers the VMI scheme in order to detect changes in the process model from a white noise to an IMA(0,1,1). The VMI scheme is shown to be effective compared to the standard fixed measurement interval (FMI) scheme in both statistical and economic contexts.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.469-473
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• 2007

This study was performed to investigate the effects of urinary acupoint (BL-23, BL-28) by acupuncture (AP) and electroacupuncture (EA) on urinary bladder in dogs. Four healthy male dogs aged within the range of 6~8 months were used in this experiment. For Electrodes implantation on the bladder, dogs were to undergo surgical operation. The purpose of investigating the effect on urinary bladder was to evaluate electromyogram (EMG) changes according to AP or EA at Shen Shu (BL-23), Pang Guang Shu (BL-28) and non-acupoint. AP and EA (2~4 V, 10 Hz) were applied for 20 min to each point. EMG was evaluated when acupuncture began stimulation and as soon as the stimulation by electroacupuncture was gone. By the experiment of investigating the effect of urinary time it was estimated to measure time up to urination from stimulation on effective acupoint, after saline was filled with 70% of whole volumes on urinary bladder. The wave of EMG on resting stage showed simple and regular, whereas that of EMG on urination showed irregularly strong peaks before urination. Acupuncture of BL-28 had an influence on changes of EMG which had irregular peaks on urination. But the changes of EMG after acupuncture of BL-28 and control were regular like resting stage. The changes of EMG after EA at BL-23 and BL-28 showed irregularly a variety of wave forms. The interval through urination from stimulation at BL-28 and control become short as measuring time by EA (p<0.01). According to the results, AP at BL-28 was effective to urinary bladder. EA at BL-23 and BL-28 was effective to urinary bladder. Especially, the interval on stimulating at BL-28 by EA was the shortest in measuring time to urination from stimulation.

• Membrane and Water Treatment
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• v.10 no.1
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• pp.99-104
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• 2019

In Korea, nonpoint pollutants have a significant effect on rivers' water quality, and they are discharged in very different ways depending on rainfall events. Therefore, preparing an optimal countermeasure against nonpoint pollutants requires much monitoring. The present study was conducted to help prepare a method for installing an automatic nonpoint pollutant measurement system for the cost-effective monitoring of the effect of nonpoint pollutants on rivers. In the present study, monitoring was performed at six sites of a river passing through an urban area with a basin area of $454.3km^2$. The results showed that monitoring could be performed for a relatively long time interval in the upstream and downstream regions, which are mainly comprised of forests, regardless of the rainfall amount. On the contrary, in the urban region, the monitoring had to be performed at a relatively short time interval each time when the rainfall intensity changed. This was because the flow rate was significantly dependent on the rainfall's intensity. The appropriate sites for installing an automatic measurement system were found to be a site before entering the urban region, a site after passing through the urban region, and the end of a river where the effects of nonpoint pollutant sources can be well-decided. The analysis also showed that the monitoring time should be longer for the rainfall events of a higher rainfall class and for the sites closer to the river end. This is because the rainfall runoff has a longer effect on the river. However, the effect of nonpoint pollutant sources was not significantly different between the upstream and the downstream in the cases of rainfall events over 100 mm.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.2
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• pp.1-13
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• 2014

In IEEE 802.11p/1609-based vehicular networks, vehicles are allowed to exchange safety and control messages only within time periods, called control channel (CCH) interval, which are scheduled periodically. Currently, the length of the CCH interval is set to the fixed value (i.e. 50ms). However, the fixed-length intervals cannot be effective for dynamically changing traffic load. Hence, some protocols have been recently proposed to support variable-length CCH intervals in order to improve channel utilization. In existing protocols, the CCH interval is subdivided into safety and non-safety intervals, and the length of each interval is dynamically adjusted to accommodate the estimated traffic load. However, they do not consider the presence of hidden nodes. Consequently, messages transmitted in each interval are likely to overlap with simultaneous transmissions (i.e. interference) from hidden nodes. Particularly, life-critical safety messages which are exchanged within the safety interval can be unreliably delivered due to such interference, which deteriorates QoS of safety applications such as cooperative collision warning. In this paper, we therefore propose a new interference-aware Dynamic Safety Interval (DSI) protocol. DSI calculates the number of vehicles sharing the channel with the consideration of hidden nodes. The safety interval is derived based on the measured number of vehicles. From simulation study using the ns-2, we verified that DSI outperforms the existing protocols in terms of various metrics such as broadcast delivery ration, collision probability and safety message delay.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.456-459
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• 2006

Effects of pork thickness (5 and 7 mm), heating temperature (190 and $220^{\circ}C$) and time (40-180 sec), and flipping interval (10 and 30 sec) during cooking against survival levels of general bacteria and pathogenic microorganisms in pork were investigated. Under same heating temperature and time, 10 sec interval of flipping was more effective in sterilizing bacteria than 30 sec interval. Bacteria was not detected in 5-mm thick pork cooked for 80 sec at $190^{\circ}C$ with 10 sec flipping interval, and 120 sec heating at $190^{\circ}C$ and 30 sec flipping interval. Bacteria were not detected in most 7-mm thick pork cooked for 100 sec at $190^{\circ}C$ with 10 sec flipping interval, and 180 sec heating at $190^{\circ}C$ and 30 sec interval. Bacteria were not detected in most 5- and 7-mm thick pork cooked for 80 sec at $220^{\circ}C$ with 10 sec flipping interval, and 120 sec heating with 30 sec interval.

• Journal of the Korean Statistical Society
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• v.26 no.2
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• pp.181-198
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• 1997

The variable sampling rates scheme is proposed by taking random sample size and sampling interval during the process. The performance of the scheme is measured in terms of the average time to signal adjusted by teh sampling cost when the process is out of control. This measurement evaluates the effectiveness of the scheme in terms of the cost incurred due to nonconformation as well as sampling. The variable sampling rates scheme is shown to be effective especially for small and moderate shifts of the mean when compared to the standard scheme.