• Title/Summary/Keyword: In-group Failure

Search Result 1,689, Processing Time 0.034 seconds

Analysis of Risk Priority Number for Grid-connected Energy Storage System (계통연계형 에너지저장시스템의 위험우선순위 분석)

  • Kim, Doo-Hyun;Kim, Sung-Chul;Park, Jeon-Su;Kim, Eun-Jin;Kim, Eui-Sik
    • Journal of the Korean Society of Safety
    • /
    • v.31 no.2
    • /
    • pp.10-17
    • /
    • 2016
  • The purpose of this paper is to deduct components that are in the group of highest risk(top 10%). the group is conducted for classification into groups by values according to risk priority through risk priority number(RPN) of FMEA(Failure modes and effects analysis) sheet. Top 10% of failure mode among total potential failure modes(72 failure modes) of ESS included 5 BMS(battery included) failure modes, 1 invert failure mode, and 1 cable connectors failure mode in which BMS was highest. This is because ESS is connected to module, try, and lack in the battery part as an assembly of electronic information communication and is managed. BMS is mainly composed of the battery module and communication module. There is a junction box and numerous connectors that connect these two in which failure occurs most in the connector part and module itself. Finally, this paper proposes RPN by each step from the starting step of ESS design to installation and operation. Blackouts and electrical disasters can be prevented beforehand by managing and removing the deducted risk factors in prior.

Implant survival and risk factor analysis in regenerated bone: results from a 5-year retrospective study

  • Hong, Ji-Youn;Shin, Eun-Young;Herr, Yeek;Chung, Jong-Hyuk;Lim, Hyun-Chang;Shin, Seung-Il
    • Journal of Periodontal and Implant Science
    • /
    • v.50 no.6
    • /
    • pp.379-391
    • /
    • 2020
  • Purpose: The aims of this study were to evaluate the 5-year cumulative survival rate (CSR) of implants placed with guided bone regeneration (GBR) compared to implants placed in native bone, and to identify factors contributing to implant failure in regenerated bone. Methods: This retrospective cohort study included 240 patients who had implant placement either with a GBR procedure (regenerated bone group) or with pristine bone (native bone group). Data on demographic features (age, sex, smoking, and medical history), location of the implant, implant-specific features, and grafting procedures and materials were collected. The 5-year CSRs in both groups were estimated using Kaplan-Meier analysis. Risk factors for implant failure were analyzed with a Cox proportional hazards model. Results: In total, 264 implants in the native bone group and 133 implants in the regenerated bone group were analyzed. The 5-year CSRs were 96.4% in the regenerated bone group and 97.5% in the native bone group, which was not a significant difference. The multivariable analysis confirmed that bone status was not an independent risk factor for implant failure. However, smoking significantly increased the failure rate (hazard ratio, 10.7; P=0.002). Conclusions: The 5-year CSR of implants placed in regenerated bone using GBR was comparable to that of implants placed in native bone. Smoking significantly increased the risk of implant failure in both groups.

Evaluation of the Reliability of Distribution Power Systems Considering Composite Customer Interruption Cost

  • Choi Sang-Bong;Nam Kee-Young;Kim Dae-Kyeong;Jeong Seong-Hwan;Lee Jae-Duk;Ryoo Hee-Suk
    • KIEE International Transactions on Power Engineering
    • /
    • v.5A no.3
    • /
    • pp.286-292
    • /
    • 2005
  • As the power industry moves towards open competition, there has been a call for methodology to evaluate power system reliability by using composite interruption cost. This paper presents algorithms to evaluate the interruption cost of distribution power systems by taking into consideration the failure source and the composite customer interruption cost. From the consumer's standpoint, the composite customer interruption cost is considered as the most valuable index to estimate the reliability of a power distribution system. This paper presents new algorithms that consider the load by customer type and failure probability by distribution facilities while calculating the amount of unserved energy by customer type. Finally, evaluation results of unserved energy and system interruption cost based on composite customer interruption cost are shown in detail.

The effect of different cooling rates and coping thicknesses on the failure load of zirconia-ceramic crowns after fatigue loading

  • Tang, Yu Lung;Kim, Jee-Hwan;Shim, June-Sung;Kim, Sunjai
    • The Journal of Advanced Prosthodontics
    • /
    • v.9 no.3
    • /
    • pp.152-158
    • /
    • 2017
  • PURPOSE. The purpose of this study was to evaluate the influence of different coping thicknesses and veneer ceramic cooling rates on the failure load of zirconia-ceramic crowns. MATERIALS AND METHODS. Zirconia copings of two different thicknesses (0.5 mm or 1.5 mm; n=20 each) were fabricated from scanning 40 identical abutment models using a dental computer-aided design and computer-aided manufacturing system. Zirconia-ceramic crowns were completed by veneering feldspathic ceramics under different cooling rates (conventional or slow, n=20 each), resulting in 4 different groups (CONV05, SLOW05, CONV15, SLOW15; n=10 per group). Each crown was cemented on the abutment. 300,000 cycles of a 50-N load and thermocycling were applied on the crown, and then, a monotonic load was applied on each crown until failure. The mean failure loads were evaluated with two-way analysis of variance (P=.05). RESULTS. No cohesive or adhesive failure was observed after fatigue loading with thermocycling. Among the 4 groups, SLOW15 group (slow cooling and 1.5 mm chipping thickness) resulted in a significantly greater mean failure load than the other groups (P<.001). Coping fractures were only observed in SLOW15 group. CONCLUSION. The failure load of zirconia-ceramic crowns was significantly influenced by cooling rate as well as coping thickness. Under conventional cooling conditions, the mean failure load was not influenced by the coping thickness; however, under slow cooling conditions, the mean failure load was significantly influenced by the coping thickness.

Failure Management System for AREX's Signalling System (공항철도 신호시스템의 고장관리 체계)

  • Song, Mi-Ok;Lim, Sung-Soo;Lee, Chang-Hwan;Kim, In-Gyu
    • Proceedings of the KSR Conference
    • /
    • 2007.11a
    • /
    • pp.676-682
    • /
    • 2007
  • In this paper we introduce the Failure Management System for AREX's Signalling System which is applied by RAMS management. The corrective action report is classified into 3 group, scheduled maintenance, non-scheduled maintenance and the reported failure maintenance. The scheduled maintenance is for the failure detected by periodic inspection and it is concerned as the Preventive Maintenance. The reported failure maintenance is for the failure reported by non-maintenance staff and non-scheduled maintenance includes all corrective action except the works of the previous 2 group. RAMS analysis is based on the FRACAS data connected with the corrective action reports. AREX computerize the all process by the Facility Management System of Integrated Information System.

  • PDF

Effect of Electromagnetic Navigated Ventriculoperitoneal Shunt Placement on Failure Rates

  • Jung, Nayoung;Kim, Dongwon
    • Journal of Korean Neurosurgical Society
    • /
    • v.53 no.3
    • /
    • pp.150-154
    • /
    • 2013
  • Objective : To evaluate the effect of electromagnetic (EM) navigation system on ventriculoperitoneal (VP) shunt failure rate through comparing the result of standard shunt placement. Methods : All patients undergoing VP shunt from October 2007 to September 2010 were included in this retrospective study. The first group received shunt surgery using EM navigation. The second group had catheters inserted using manual method with anatomical landmark. The relationship between proximal catheter position and shunt revision rate was evaluated using postoperative computed tomography by a 3-point scale. 1) Grade I; optimal position free-floating in cerebrospinal fluid, 2) Grade II; touching choroid or ventricular wall, 3) Grade III; tip within parenchyma. Results : A total of 72 patients were participated, 27 with EM navigated shunts and 45 with standard shunts. Grade I was found in 25 patients from group 1 and 32 patients from group 2. Only 2 patients without use of navigation belonged to grade III. Proximal obstruction took place 7% in grade I, 15% in grade II and 100% in grade III. Shunt revision occurred in 11% of group 1 and 31% of group 2. Compared in terms of proximal catheter position, there was growing trend of revision rate according to increase of grade on each group. Although infection rate was similar between both groups, the result had no statistical meaning (p=0.905, chi-square test). Conclusion : The use of EM navigation in routine shunt surgery can eliminate poor shunt placement resulting in a dramatic reduction in failure rates.

Elective neck treatment in clinically node-negative paranasal sinus carcinomas: impact on treatment outcome

  • Lee, Won Hee;Choi, Seo Hee;Kim, Se-Heon;Choi, Eun Chang;Lee, Chang Geol;Keum, Ki Chang
    • Radiation Oncology Journal
    • /
    • v.36 no.4
    • /
    • pp.304-316
    • /
    • 2018
  • Purpose: The indication of elective neck treatment (ENT) for clinically N0 (cN0) paranasal sinus (PNS) carcinoma remains unclear. We aimed to investigate different treatment outcomes regarding ENT and propose optimal recommendations for ENT. Materials and Methods: We identified patients with cN0 PNS carcinoma who underwent curative-intent treatment between 1992 and 2015. Survival outcomes and pattern of failure were compared between patients who received ENT and those who did not. We sought to identify significant patient or pathologic factors regarding treatment outcomes. Results: Among 124 patients meeting the inclusion criteria, 40 (32%) received ENT ('ENT (+) group') and 84 (68%) did not ('ENT (-) group'). With a median follow-up of 54 months, the 5-year overall survival (OS) was 67%, and the 5-year progression-free survival (PFS) was 45%. There was no significant difference between the ENT (+) and ENT (-) groups regarding OS (p = 0.67) and PFS (p = 0.50). Neither group showed a significantly different pattern of failure, including regional failure (p = 0.91). There was no specific benefit, even in the subgroups analysis by tumor site, histologic type, and T stage. Nevertheless, patients who ever had regional and/or distant failure showed significantly worse prognosis. Conclusion: ENT did not significantly affect the survival outcome or pattern of failure in patients with cN0 PNS carcinomas, showing that ENT should not be generalized in this group. However, further discussion on the optimal strategy for ENT should continue because of the non-negligible regional failure rates and significantly worse prognosis after regional failure events.

Cystatin C for managing diuretic-induced kidney dysfunction in MMVD dogs

  • Donghyun Han;Jae Hyeon Cho;Chung Hui Kim
    • Korean Journal of Veterinary Service
    • /
    • v.46 no.3
    • /
    • pp.181-192
    • /
    • 2023
  • Cystatin C, a low-molecular-weight protein synthesized by cells, is being explored as a valuable biomarker for assessing renal function in veterinary medicine. Although the relationship between cystatin C and heart disease remains unclear, some studies suggest a possible association. This retrospective case-control study aimed to investigate the role of cystatin C as a biomarker for heart disease and its correlation with diuretic use in veterinary clinical practice. A total of 39 dogs were included in this study, comprising 9 control dogs without a predisposition to heart disease and 30 dogs in the study group diagnosed with heart disease. Among the 30 dogs with heart disease, 18 exhibited symptoms indicative of heart failure. Results showed significantly higher cystatin C levels in the heart disease group compared to the control group (P<0.05). However, no significant differences were observed among different stages of heart disease severity in the control group. Furthermore, cystatin-C showed statistically positive correlations with BUN (r=0.478, P<0.01), creatinine (r=0.506, P<0.01), and furosemide (r=0.338, P<0.05). Diuretics are essential for managing congestive heart failure, and the observed associations between cystatin C and furosemide suggest potential impacts of diuretic use on renal function in dogs with heart failure. Monitoring renal function markers, such as cystatin C, can aid in predicting and managing potential renal complications, ultimately improving the overall health and quality of life of dogs with heart disease.

A STUDY ON FAILURE STRENGTH OF THE IMPLANT PROSTHESIS LUTED WITH RESIN CEMENT BETWEEN GOLD CYLINDER AND SUPERSTRUCTURE (상부구조물과 금원주를 레진시멘트로 접착시킨 임프란트 보철물의 파절에 대한 연구)

  • Kim, Seung-Beom;Bae, Jeong-Sik
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.34 no.3
    • /
    • pp.438-447
    • /
    • 1996
  • This study was performed to determine the failure strength and pattern of implant prosthesis luted with resin cement between gold cylinder and superstructure, and to evaluate the bonding strength of resin cement. To evaluate failure strength and pattern, the groups were divided into 2. Group 1 : Casted gold cylinder Group 2 : Luted with resin cement between gold cylinder ans superstructure. To evaluate effects of the bonding strength of the implant prosthesis luted with resin cement according to storage condition, the groups were divided into 3 : Group A : Stored in waste at $37^{\circ}C$ for 24 hours. Group B : 1000 cycles thermocycled between $5^{\circ}C\;and\;55^{\circ}C$ in water. Group C : Stored in water at $37^{\circ}C$ for 30 days. The results were as follows. 1. Failure was found at gold screw in all specimens of group 1 & 2. 2. The bond strength in group 1 and 2 was 189.86 and 188.14kgf. There was no statistically significant difference between group 1 and 2(P>0.05). 3. The bond strength of group A, B and C was 53.28, 45,86 and 39.29Kgf. There result suggest the advantage of an improved fit of superstructure to the abutment and a simple procedure. But there was a measurable decrease of the bond strength according to storage condition. So, Further research is necessary to evaluate of the implant prosthesis luted with resin cement between gold cylinder and superstructure.

  • PDF

Effect of Acupuncture and Moxibustion at SP6(Sanyinjiao) and BL28(Pangguangshu) on Experimental Acute renal failure in rats (삼음교(三陰交)(SP6), 방광유(膀胱兪)(BL28)의 침자 및 애구자극이 흰쥐의 실험적 급성신부전에 미치는 영향)

  • Kim, Min-ho;Park, Chun-ha;Kim, Hyo-ean;Yun, Yeo-chung
    • Journal of Acupuncture Research
    • /
    • v.19 no.6
    • /
    • pp.49-60
    • /
    • 2002
  • Objective : The aim of this experiment is to investigate the effect of acupuncture and moxibustion at SP6(Sanyinjiao) and BL28(Pangguanshu) on uranyl acetate-induced acute renal failure in rats. Methods : To induce experimental acute renal failure, uranyl acetate was intraperitoneally injected to rats by 5mg/kg. 3 days later acupuncture and moxibustion treatment was done at SP6(Sanyinjiao) and BL28(Pangguanshu) bilaterally of the rats. And then 4 days later, we measured rats' body weight, kidney weight, serum BUN, creatinine and serum eletrolyte levels(Na, K and Cl). Results : In the moxibustion group, hypertrophy index of kidney and serum BUN level were decreased marginally significantly, and serum creatinine, K levels were decreased significantly. But in the acupuncture group, there was no significance at this experiment. Conclusions : SP6(Sanyinjiao) and BL28(Pangguanshu) moxibustion can decrease serum BUN, creatinine, and serum eletrolyte levels on uranyl acetate-induced acute renal failure in rats. And the study will be done continuously about non-effect in the acupuncture group at this experiment.

  • PDF