• Korean Journal of Construction Engineering and Management
• /
• v.19 no.3
• /
• pp.33-42
• /
• 2018

In the aftermath of an earthquake, seismic-damaged infrastructure systems loss estimation is the first step for the disaster response. However, lifeline systems' ability to supply service can be volatile by external factors such as disturbances of nearby facilities, and not by own physical issue. Thus, this research develops the bayesian model for probabilistic inference on common-cause and cascading failure of seismic-damaged lifeline systems. In addition, the authors present network robustness estimation metrics in the context of failure propagation. In order to quantify the functional loss and observe the effect of the mitigation plan, power and water supply system in Daegu-Gyeongbuk in South Korea is selected as case network. The simulation results show that reduction of cascading failure probability allows withstanding the external disruptions from a perspective of the robustness improvement. This research enhances the comprehensive understanding of how a single failure propagates to whole lifeline system performance and affected region after an earthquake.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.3
• /
• pp.61-69
• /
• 2013

According to ISO 26262 (the international standard on functional safety for automotive industry), the functional safety should be considered during the whole automotive systems life cycle from the design phase throughout the production phase. In order to satisfy the standard, the automotive and related industry needs to take appropriate actions while carrying out a variety of development activities. This paper presents an approach to coping with the standard. Analyzing the standard indicates that the safety issues of the automotive systems should be handled with a system's view whereas the conventional approach to solving the issues has been practiced with focus on the component's level. The aforementioned system's view implies that the functional safety shall be incorporated in the system design from both the system's life-cycle view and the hierarchical view for the structure. In light of this, the systems engineering framework can be quite appropriate in the functional safety development and thus has been taken in this paper as a problem solving approach. Of various design issues, the analysis and verification of the safety requirements for functional safety is a key study subject of the paper. Note, in particular, that the conventional FMEA (failure mode effects analysis) and FTA (fault tree analysis) methods seem to be partly relying on the insufficient experience and knowledge of the engineers. To improve this, a systematic method is studied here and the result is applied in the design of an ABS braking system as a case study.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.16 no.6
• /
• pp.267-276
• /
• 2021

The automotive industry and academic research have been continuously conducting research on standardization such as AUTOSAR (AUTomotive Open System ARchitecture) and ISO26262 to solve problems such as safety and efficiency caused by the complexity of electric/electronic architecture of automotive. AUTOSAR is an automotive standard software platform that has a layered structure independent of MCU (Micro Controller Unit) hardware, and improves product reliability through software modularity and reusability. And, ISO26262, an international standard for automotive functional safety and suggests a method to minimize errors in automotive ECU (Electronic Control Unit)s by defining the development process and results for the entire life cycle of automotive electrical/electronic systems. These design methods are variously applied in representative automotive safety-critical systems. However, since the functional and safety requirements are different according to the characteristics of the safety-critical system, it is essential to research the AUTOSAR functional safety design method specialized for each application domain. In this paper, a software functional safety mechanism design method using AUTOSAR is proposed, and a new failure management framework is proposed to ensure the high reliability of the product. The AUTOSAR functional safety mechanism consists of memory partitioning protection, timing monitoring protection, and end-to-end protection. The fault management framework is composed of several safety SWCs to maintain the minimum function and performance even if a fault occurs during the operation of a safety-critical system. Finally, the proposed method is applied to the Shift-by-Wire system design to prove the validity of the proposed method.

• Molecules and Cells
• /
• v.44 no.7
• /
• pp.500-516
• /
• 2021

Cardiac hypertrophic signaling cascades resulting in heart failure diseases are mediated by protein phosphorylation. Recent developments in mass spectrometry-based phosphoproteomics have led to the identification of thousands of differentially phosphorylated proteins and their phosphorylation sites. However, functional studies of these differentially phosphorylated proteins have not been conducted in a large-scale or high-throughput manner due to a lack of methods capable of revealing the functional relevance of each phosphorylation site. In this study, an integrated approach combining quantitative phosphoproteomics and cell-based functional screening using phosphorylation competition peptides was developed. A pathological cardiac hypertrophy model, junctate-1 transgenic mice and control mice, were analyzed using label-free quantitative phosphoproteomics to identify differentially phosphorylated proteins and sites. A cell-based functional assay system measuring hypertrophic cell growth of neonatal rat ventricle cardiomyocytes (NRVMs) following phenylephrine treatment was applied, and changes in phosphorylation of individual differentially phosphorylated sites were induced by incorporation of phosphorylation competition peptides conjugated with cell-penetrating peptides. Cell-based functional screening against 18 selected phosphorylation sites identified three phosphorylation sites (Ser-98, Ser-179 of Ldb3, and Ser-1146 of palladin) displaying near-complete inhibition of cardiac hypertrophic growth of NRVMs. Changes in phosphorylation levels of Ser-98 and Ser-179 in Ldb3 were further confirmed in NRVMs and other pathological/physiological hypertrophy models, including transverse aortic constriction and swimming models, using site-specific phospho-antibodies. Our integrated approach can be used to identify functionally important phosphorylation sites among differentially phosphorylated sites, and unlike conventional approaches, it is easily applicable for large-scale and/or high-throughput analyses.

• Journal of Periodontal and Implant Science
• /
• v.37 no.2
• /
• pp.165-180
• /
• 2007

Dental Implants have been proved to be successful prosthetic modality in edentulous patients for 10 years. However, there are few reports on the survival of implant according to location in molar regions. The purpose of this study was to evaluate the $4{\sim}5$ years' cumulative survival rate and the cause of failure of dental implants in different locations for maxillary and mandibular molars. Among the implants placed in molar regions in Gwangju Mir Dental Hospital from Jan. 2001 to Jun. 2002, 473 implants from 166 patients(age range; $26{\sim}75$) were followed and evaluated retrospectively for the causes of failure. We included 417 implants in 126 periodontally compromised patients, 56 implants in 40 periodontal healthy patients, and 205 maxillary and 268 mandibular molar implants. Implant survival rates by various subject factors, surgical factors, fixture factors, and prosthetic factors at each location were compared using Chi-square test and Kaplan-Meier cumulative survival analysis was done for follow-up(FU) periods. The overall failure rate at 5 years was 1O.2%(subject level) and 5.5%(implant level). The overall survival rates of implants during the FU periods were 94.5% with 91.3% in maxillary first molar, 91.1% in maxillary second molar, 99.2% in mandibular first molar and 94,8% in mandibular second molar regions. The survival rates differed significantly between both jaws and among different implant locations(p<0.05), whereas the survival rates of functionally loaded implants were similar in different locations. The survival rates were not different according to gender, age, previous periodontal status, surgery stage, bone graft type, or the prosthetic type. The overall survival rate was low in dental implant of too wide diameter(${\geq}5.75$ mm) and the survival rate was significantly lower for wider implant diameter(p

• Mycobiology
• /
• v.42 no.3
• /
• pp.215-220
• /
• 2014

Mushrooms are a recognized component of the human diet, with versatile medicinal properties. Some mushrooms are popular worldwide for their nutritional and therapeutic properties. However, some species are dangerous because they cause toxicity. There are many reports explaining the medicinal and/or toxic effects of these fungal species. Cases of serious human poisoning generally caused by the improper identification of toxic mushroom species are reported every year. Different substances responsible for the fatal signs and symptoms of mushroom toxicity have been identified from various poisonous mushrooms. Toxicity studies of mushroom species have demonstrated that mushroom poisoning can cause adverse effects such as liver failure, bradycardia, chest pain, seizures, gastroenteritis, intestinal fibrosis, renal failure, erythromelalgia, and rhabdomyolysis. Correct categorization and better understanding are essential for the safe and healthy consumption of mushrooms as functional foods as well as for their medicinal use.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.87-91
• /
• 2004

This paper dealt with FMEA, Which is a method of the analysis to secure safety and confidence coming up to customer's expectation in consideration of the environment of the corporation, the industrial environment, and the functional improvement. And by using FMEA, We showed the example analyzed the confidence of the reduction gear. It was proved by the result of the analysis that the rate of the breakdown which is usually regarded as the first important point to reform can't satisfy the selecting basis to improve. Also the result said that it is not right to depend on only the rate of the failure in making the list of the reform. Through the analysis of the breakdown, FMEA can present the important factors of the reform to improve the confidence of the system. In this study would show the important factors of the improvement in order to product the goods guaranteed confidence through the method of FMEA.

• Journal of Chest Surgery
• /
• v.21 no.3
• /
• pp.588-593
• /
• 1988

We experienced a case of interrupted aortic arch[Type A] associated with PDA, VSD, mitral regurgitation and single coronary artery. The patient was 7 years old boy, who showed congestive heart failure[NYHA functional class III]. One stage total correction was performed under profound hypothermia with total circulatory arrest. Aortic continuity was established using PDA with anterior wall of main pulmonary artery flap. VSD was closed with Dacron patch and mitral regurgitation repaired by Reed`s annuloplasty method. The postoperative cardiac catheterization revealed no pressure gradient between ascending aorta and descending aorta, decreased pulmonary artery pressure and trivial residual shunt[Qp/Qs: 1.28]. The aortogram showed good continuity of the aorta without narrowing of the anastomotic site. During the period of 1 year follow up, heart failure symptoms were nearly subsided.

• IE interfaces
• /
• v.25 no.4
• /
• pp.405-415
• /
• 2012

The reliability performance measures for low and high or continuous demand modes of operation of safety instrumented systems(SISs) are examined and compared by analyzing the official definitions in IEC 61508 standard. This paper also presents a status of common cause factor(CCF) models used in IEC 61508 and problems relating CCF modelling are discussed and ideas to solve these ones are suggested. An example with mixed M-out-of-N architecture is carried out to illustrate the proposed methods.

• International Journal of Reliability and Applications
• /
• v.1 no.1
• /
• pp.49-64
• /
• 2000

We consider a system whose inherent life follows an Erlang distribution, which is subject to two heterogeneous random shocks. Minor shocks arrive according to a renewal process and each causes the system to fail independently with a certain probability. A major shock whose interarrival times follow an Erlang distribution causes the system to fail with probability one. The Laplace transform of the distribution of the time to system failure is derived in a functional form of the Laplace transform of the interarrival time distribution of minor shocks. An algorithm is given for the computation of the moments of the time to system failure.