• Journal of Multimedia Information System
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• v.6 no.4
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• pp.239-244
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• 2019

With the development of Cyber-Physical Systems(CPS), several technologies such as automation control, automotive and intelligent house systems have been developed. To enable communication among various components of such systems, several wired and wireless communication protocols are used. The Controller Area Network(CAN) is one of such wired communication protocols that is popularly used for communication in automobiles and other machinery in the industry. In this paper, we designed and implemented a response time analysis system for CAN communication. The reliable data transfer among various electronic components in a significant time is crucial for the smooth operation of an electric vehicle. Therefore, this system is designed to conveniently analyze the response time of various electronic components of a CAN enabled system. The priority for transmission of the messages in the CAN bus is determined by the message identifier. As the number of nodes increases the transmission of low priority messages is delayed due to the existence of higher priority messages on the bus. We used Raspberry Pi3 and PiCAN2 board to simulate the data transfer for studying the comparative delay in low priority nodes.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.357-364
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• 2010

This study was performed to get basic information about properties of high blaine slag cement(HSC) to use shotcrete(or sprayed concrete and mortar). Particle size distribution, setting time and compressive strength test, analysis like as SEM, DSC thermal analysis, XRD was carried out to investigate principle properties of HSC. Setting time of HSC was delayed slightly, but influence of accelerators was more bigger than ordinary portland cement(OPC). Compressive strength of HSC at 28 days was more higher than OPC regardless of using accelerators. Results of analysis showed early period hydration products of HSC is more small and located widely, because of the interface of between cement particle and water is increased as specific surface of cement increase. From the SEM observation and analysis of DSC and XRD results, aluminates accelerators bring on some hydration products like as calcium aluminium hydrates, alkali free accelerators increases ettringite and monosulfates. Aluminates accelerators has a advantage of setting time and early strength, alkali free accelerators increases strength after 7 days.

• Journal of Applied Reliability
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• v.15 no.4
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• pp.256-261
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• 2015

The aim of this paper is to present some issues to be discussed in relation to failure rate of a system that has identical parallel units. It is assumed that Time-to-Failure of each unit has the same exponential distribution and all units are repairable with a periodic maintenance of time interval T. Effective failure rate is widely recommended for nonrepairable systems as the reciprocal of MTTF but it should not be applied for repairable systems if delayed maintenance is used. And equivalent failure rate of an imaginary system is taken into consideration, the reliability value of which is the same as that of the redundant system when time interval T is given. With a numerical example, failure rate, effective failure rate, and equivalent failure rate of the redundant system are analyzed comparatively.

• Journal of Chest Surgery
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• v.28 no.11
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• pp.1001-1006
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• 1995

From January, 1990 to December, 1994, we have operated 10 patients with cardiac rupture. The patients are divided into two groups according to their clinical manifestation ; five patients in each hemorrhage and tamponade group. The patients in both groups could maintain their vital signs with closed thoracostomy and fluid resuscitation. The effect of pericardiocentesis was especially dramatic in three patients of tamponade group. The average time from injury to admission was 101 minutes and that of the patients who came our hospital via one or two other hospitals was 170 minutes comparing 31 minutes of those who came directly. The average time from admission to operation was 211 minutes. Considering 98 minutes for the diagnosis and preoperative management and another 30 minutes for the preparation for operation, operations were delayed by 83 minutes to get permission. We conclude that this delaying time for transport and operation of heart-ruptured patients should be shortened in order to manage them more effectively.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.4
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• pp.398-408
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• 2016

Based on non-completely hybrid flow line scheduling of panel block in shipbuilding, several uncertain factors influencing the problem were analyzed in a real environment, and a nonlinear integer programming model was built for each sub-scheduling problem. To narrow the difference between theory and application, rolling horizon and rescheduling methods are proposed. Moreover, with respect to the uncertainty of processing time, arriving time and due time, we take the minimizing of the early and delayed delivery costs as the objective, and establish an evaluation with a global penalty function. Finally, numerical experiments and a simulation analysis were undertaken to demonstrate the effectiveness of the model and algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1B
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• pp.109-116
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• 2004

Optical Burst Switching (OBS) technology has drawn much attention as a promising solution for IP/WDM networks. OBS has the features such as the offset time, the delayed reservation and the burst assembly. In particular, the burst assembly, which assembles IP packets into the data bursts, has a great impact on the performance of OBS network. In this paper, we compare the performance of three different burst assembly schemes and investigate their impact on the performance of OBS network.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.96-102
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• 2012

Recently, interests about frame error reduction method, using multiple PCM data which are received at several ground stations, are increasing. Simple data merge method is already applied to data processing system at Naro Space Center and have been used in the first and the second flight test analysis of KSLV-I. This paper is focused on error reduction with error correcting merge algorithm and time-delayed data correction algorithm. Result of applying the proposed algorithms to the flight test data shows 1.32% improvement in error rate, compared to simple-data-merge method. It is considered that presented algorithms could be very useful in generating various telemetry merge data.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.89-98
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• 2015

This paper provides a robust and non-fragile $H_{\infty}$ controller design algorithm for time-delayed systems with randomly occurring polytopic uncertainties and disturbances. First, we design time-delayed system considering randomly occurring uncertainties and disturbances. Next, The sufficient condition for the existence of robust and non-fragile $H_{\infty}$ controller is presented by LMI(linear matrix inequality) using Lyapunov stability analysis and $H_{\infty}$ performance measure. Since the obtained condition can be expressed as a PLMI(parameterized linear matrix inequality) by changes of variables and Schur complement, all solutions including controller gain, degrees of controller satisfying non-fragility, $H_{\infty}$ norm bound ${\gamma}$ can be calculated simultaneously. Finally, numerical examples are given to illustrate the performance and the effectiveness of the proposed robust and non-fragile $H_{\infty}$ controller compared with the deterministic uncertainty model even though there exists randomly occurring uncertainties, disturbances and time delays.

• Journal of Korean Society for Quality Management
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• v.44 no.2
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• pp.373-388
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• 2016

Purpose: This paper suggests a hierarchical time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). In place of the conventional RPN(risk priority number), a more reasonable and objective risk metric is proposed under hierarchical failure cause structure considering time delay between a failure mode and its causes. Methods: The structure of failure modes and their corresponding causes are analyzed together with the time gaps between occurrences of causes and failures. Assuming the severity of a failure depends on the length of the delayed time for corrective action, a severity model is developed. Using the expected severity, a risk priority metric is defined. Results: For linear and quadratic types of severity, nice forms of expected severity are derived and a meaningful metric for risk evaluation is defined. Conclusion: The suggested REM(risk evaluation metric) provides a more reasonable and objective risk measure than the conventional RPN for FMEA.

• The Korean Journal of Emergency Medical Services
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• v.24 no.2
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• pp.27-38
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• 2020

Purpose: Stroke is a time-sensitive disease that could have reduced complications and mortality with timely diagnosis and treatment. This study aimed to analyze the causes of delay in detecting the clinical signs and symptoms of stroke. Methods: This retrospective observational study analyzed the emergency medical services reports of suspected stroke patients with positive predictive values on the Cincinnati Prehospital Stroke Scale. The study was conducted in Daejeon, Republic of Korea from January 1, 2016 through December 31, 2017. Results: Prolonged prehospital time was associated with high blood pressure, history of cerebrovascular disease, and incidences during daily activities, and sleep. High blood pressure and complications from a previous stroke strongly associated with the prolonged stroke-detection phase (p<.05). Total prehospital time was shortened when patients had evident stroke symptoms, such as decreased level of consciousness, dysarthria, and hemiplegia (p<.05). There was no significant difference in gender or age as a factor that delayed the total prehospital time of the suspected stroke patients. Conclusion: Many patients did not recognize the early clinical symptoms and signs of a stroke. Furthermore, risk factors, such as high blood pressure and history of stroke, prolonged the total prehospital time. Therefore, we need targeted interventions that educate about warning symptoms of stroke, along with emphasis on the importance of emergency calls to substantially reduce the prehospital delays.