• 항공우주시스템공학회지
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• 제7권2호
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• pp.29-34
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• 2013

Safety requirements for aircraft and system functions include minimum performance constraints for both availability and integrity of the function. These safety requirements should be determined by conducting a safety assessment. The depths and contents of aircraft system safety assessment vary depending on factors such as the complexity of the system, how critical the system is to flight safety, what volume of experience is available on the type of system and the novelty and complexity of the technologies being used. Requirements that are defined to prevent failure conditions or to provide safety related functions should be uniquely identified and traceable through the levels of development. This will ensure visibility of the safety requirements at the software and electronic hardware design level. This paper has prepared to study on promoting the efficiency of establishing hierarchical safety requirements from aircraft level function to item level through system safety processes.

• 한국임상수의학회:학술대회논문집
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• 한국임상수의학회 2009년도 춘계학술대회
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• pp.127-133
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• 2009

Cardiomyopathies were previously defined as "an idiopathic myocardial disease that is not secondary to any other type of congenital/acquired heart disease or systemic diseases." With increasing understanding of etiology and pathogenesis in human medicine, the difference between cardiomyopathy and specific heart muscle disease has become indistinct. Cardiomyopathies are now classified by the dominant pathophysiology or, if possible, by etiological/pathogenetic factors. The American Heart Association recently advocated the following new definition of cardiomyopathy: Cardiomyopathies are a heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that usually (but not invariably) exhibit inappropriate ventricular hypertrophy or dilatation and are due to a variety of causes that frequently are genetic. Cardiomyopathies either are confined to the heart or are part of generalized systemic disorders, often leading to cardiovascular death or progressive heart failure-related disability. Because the understanding of etiology or pathogenesis of cardiomyopathy has been limited in veterinary medicine, the previous classification is generally used. It is considered a dilated, hypertrophic and restrictive group on the basis of the predominant morphological and functional abnormalities. In addition, arrhythmogenic right ventricular cardiomyopathy and unclassified cardiomyopathy were also recognized in dogs and/or cats.

• ETRI Journal
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• 제41권6호
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• pp.739-749
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• 2019

Security and accuracy are two issues in the localization of wireless sensor networks (WSNs) that are difficult to balance in hostile indoor environments. Massive numbers of malicious positioning requests may cause the functional failure of an entire WSN. To eliminate the misjudgments caused by malicious nodes, we propose a compressive-sensing-based multiregional secure localization (CSMR_SL) algorithm to reduce the impact of malicious users on secure positioning by considering the resource-constrained nature of WSNs. In CSMR_SL, a multiregion offline mechanism is introduced to identify malicious nodes and a preprocessing procedure is adopted to weight and balance the contributions of anchor nodes. Simulation results show that CSMR_SL may significantly improve robustness against attacks and reduce the influence of indoor environments while maintaining sufficient accuracy levels.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권1호
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• pp.71-78
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• 2013

In highly reliable and durable systems, failures due to aging might result in catastrophes. Aging monitoring techniques to prevent catastrophes by predicting such a failure are required. Aging can be monitored by performing a delay test at faster clocks than functional clock in field and checking the current delay state from the test clock frequencies at which the delay test is passed or failed. In this paper, we focus on test clock control scheme for a system-on-chip (SoC) with multiple clock domains. We describe limitations of existing at-speed test clock control methods and present an on-chip faster-than-at-speed test clock control scheme for intra/inter-clock domain test. Experimental results show our simulation results and area analysis. With a simple control scheme, with low area overhead, and without any modification of scan architecture, the proposed method enables faster-than-at-speed test of SoCs with multiple clock domains.

• Advanced Composite Materials
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• 제16권2호
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• pp.135-149
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• 2007

In the automobile industry, structural health monitoring of fiber reinforced polymer composite parts is a widespread need for maintenance before breakdown of the functional elements or a complete vehicle. High performance sensors are generally used in many of the structural health monitoring operations. Within this study, a carbon fiber sewing thread has been used as a low cost laminate failure sensing element. The experimentation plan was set up according to the electrical conductance and flexibility of carbon fiber threads, advantages of preforming operations, and sewing mechanisms. The influence of the single thread damages by changing the electrical resistance and monitoring the impact location by using carbon thread sensors has been performed. Innovative utilization of relatively cost-effective carbon threads for monitoring the delamination of metallic inserts from the basic composite laminate structure is a highlighting feature of this study.

• Journal of information and communication convergence engineering
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• 제11권4호
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• pp.235-240
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• 2013

Cloud systems are popular computing environment because they can provide easy access to computing resources for users as well as efficient use of resources for companies. The resources of cloud computing are heterogeneous and jobs have various characteristics. One such issue is effective job scheduling. Scheduling in the cloud system may be defined as a multiple criteria decision model. To address this issue, this paper proposes a priority-based two-step job scheduling algorithm. On the first level, jobs are classified based on preference. Resources are dedicated to a job if a deadline failure would cause severe results or critical business losses. In case of only minor discomfort or slight functional impairment, the job is scheduled using a best effort approach. On the second level, jobs are allocated to adequate resources through their priorities that are calculated by the analytic hierarchic process model. We then analyze the proposed algorithm and make a scheduling example to confirm its efficiency.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.177-183
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• 1999

This paper presents how to evaluate the transformer damage caused by reclosing scheme at the distribution substation. We describe a quantitative relationship between the reclosing scheme and the number of fault current flowing through transformer wsing the probability of a reclosing success/failure. The transformer damage from reclosing scheme is presented using a weight function and a damage function. A weight function is associated with the number of reclosing attempts and the reclosing deadtime to consider cumulative stress caused by reclosing scheme. A damage function is associated with a transformer impact ratio and a transformer functional life. In the case study, the transformer damage is simulated for the probability of a reclosing success. And the evaluation of transformer damage using KEPCO's operation data is performed.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.113-118
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• 2002

Wave overtopping is one of the most important hydraulic responses of breakwater because it significantly affects its functional efficiency, the safety of transit and mooring on the rear side, wave transmission in the sheltered area, rear side armor stones and to some extent, the structural safety itself. The hydrodynamic characteristics of low crest breakwater by the overtopping rate can be summarized as follows: 1. It is better to use maximum overtopping rate than to use mean overtopping rate for design of coastal structures. 2. Maximum overtopping rate was increase with wave steepness (between 0.01 and 0.02). 3. Overtopping rate is decreased when relation length of berm was over wave length.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.152-155
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• 1993

Protective Relay in power system play a prominent part in minimizing power delivery interruptions and help to get a fast and secure restoration when a failure occurs. In order to meet the higher functional requirements in power system, the performance tests on response characteristic of protective relay is essential to ensure reliability. The purpose of this study is as follows: In order to evaluate performance of protective relay, it is intended to develop performance of digital protective relay simulator which is composed of digital protective relay part, behaviour analysis part, waveform generation part and simulation program to simulate pour system in detail.

• Journal of Chest Surgery
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• 제27권2호
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• pp.161-165
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• 1994

We have experienced a case of ventricular septal defect due to blunt chest trauma. A 22 year old male patient was admitted due to chest pain after Motor cycle accident on July 1st,1993. On 5th hospital day, sudden onset of dyspnea was noted and auscultation represented newly developed systolic murmur. A cardiac catheterization and Left ventriculogram revealed ruptured septum at the apical portion. Because there was open wound on anterior chest wall and congestive heart failure was medically controlled, the patient was discharged for elective operation. He was readmitted on August 14th, 1993.At operation, ventricular septal defect was found in apico-posterior muscular septal area, about 2.0 x 1.5 cm in size. The defect was repaired by double velour patch with interrupted suture and ventriculotomy was closed with Teflon felt. The patient`s postoperative course was uneventful and discharged 10 days postoperatively without complication. The patient have been followed up~ for 2 months. He is on functional class I with small amount of residual shunt at the ventricular septum.