• Journal of Auto-vehicle Safety Association
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• v.15 no.3
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• pp.53-58
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• 2023

Defects in the vehicle itself were considered the biggest risk factor for traffic accidents as the electrical and electronic components of vehicles, which were not there before, increase. Therefore, the vehicles have been developed based on ISO 26262 (an international functional safety standard) which is focusing on functional defect safety evaluation of electrical and electronic component systems. However, in the future, as autonomous driving technology is applied, even vehicles without functional defects must be prepared for the dangerous traffic situation that may arise from exceptional or external factors. SOTIF (Safety Of The Intended Functionality) is a concept to prevent exceptional or external factors. The main objective of SOTIF is to decrease Unknown & Unsafe factors as much as possible by finding Known factors and Unsafe factors. In this study, Prescan provided SIEMENS, one of the autonomous driving simulators, is used to make scenarios of IGLAD traffic accident cases. From the simulation results, Unsafe & Safe cases were classified and analyzed to derive unsafe factors.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.2
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• pp.113-121
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• 2023

High-precision lasers and anti-aircraft radars are the main equipment to protect the Korean Peninsula, and require preemptive maintenance before signs of failure. Of the key components in the drive sector, bearings do not have a fault alarm function. Therefore, the technology for diagnosing defects in bearings before the performance degradation of equipment occurs is becoming more important. In this paper, for the experimental analysis, we measured the acceleration of the four sets of the same lot using acceleration sensors. Through periodic measurements, the factors that changed until the bearing stopped rotating were analyzed. To determine the replacement time, the main factors and threshold values of the bearing signal were analyzed. The error of the theoretical and experimental analysis results of the defect frequency was within 2.8 %, and the validity of the theoretical analysis results could be confirmed. Based on the results, it is possible to remotely transmit trouble alerts to users through the system check function.

• Journal of Chest Surgery
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• v.56 no.6
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• pp.452-455
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• 2023

Patients who have undergone mechanical valve replacement require anticoagulation therapy with warfarin to prevent thromboembolism. However, administering warfarin to pregnant patients increases their risk of warfarin embryopathy or central nervous system disorders. Consequently, safer alternatives, such as heparin or low-molecular-weight heparin injection, are substituted for warfarin. However, limited research has been conducted on this subject, with no large-scale studies and particularly few investigations involving multiparous patients. A patient who had previously undergone mechanical mitral valve replacement for atrial septal defect and mitral stenosis received anticoagulant therapy with enoxaparin during 2 pregnancies. Upon confirmation of pregnancy, warfarin was replaced with subcutaneously injected enoxaparin with a dosage of 1 mg/kg at 12-hour intervals. The enoxaparin dosage was controlled using an anti-factor Xa assay, with a target range of 0.3-0.7 IU/mL. Intravenous heparin injections were administered starting 3 days prior to the expected delivery date and were continued until delivery, after which warfarin was resumed. No complications were observed during the deliveries.

• Structural Engineering and Mechanics
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• v.90 no.6
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• pp.591-600
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• 2024

This study investigated the acceleration response and shape change characteristics of a gravity quay wall according to the magnitude of the applied acceleration. The quay wall was defined as a port facility damaged by the Kobe earthquake. Four experimental scenarios were established based on the inclination condition grades, considered to be a significant defect factor in the quay wall. Then, the shaking table test was conducted using scaled-down quay wall models constructed per each scenario. The ground acceleration was gradually increased from the peak ground acceleration (PGA) of 0.1 g to 0.7 g. After each ground acceleration test, acceleration installed on the wall and backfill ground and inclination on the top of the wall were measured to assess the amplification of peak response acceleration and maximum response amplitude and the change in the inclination of the quay wall. This study also analyzed the separation of the quay wall from the backfill and the crack pattern of the backfill ground according to PGA values and inclination condition grades. The result of this study shows that response acceleration could provide a reasonable prediction for the changes in the inclination of the quay wall and the crack generation and propagation on the backfill from a current inclination condition grade.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.707-717
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• 2022

As the variability of recent rainfall is increasing, it is becoming important to recognize the possibility of changes in the current reservoir state in advance and to inspect the stability based on accurate evaluation standards. However, the evaluation standards for the state change factors of reservoirs are still not suitable for agricultural reservoirs and thus much improvement is needed. Therefore, in this study, the evaluation criteria for state change factors specialized for small reservoirs were categorized and standards were prepared by considering factors that may cause state changes on the dam crest, upstream slope, and downstream slope of the embankment. The categorized results were configured based on the number of mentions of the precision safety inspection report on major defects in 102 reservoirs and the defect factors found in field investigations. The findings of the study indicated that the current state change standards require many revisions for excessive or unnecessary state change factors in the reservoir. Specifically, the deletion of measurement gauges not applicable to the reservoir, the addition of defects found in the reservoir, and the scope of use of the term were proposed. The results of this study can contribute to efficient system operation and management by improving the deficiencies in the system and introducing a new state change factor.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.418-423
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• 2001

To investigate the modulation of nerve growth factor (NGF) during corneal epithelial wound healing and the effect of topical NGF on corneal epithelial wound healing in dogs. An axial epithelial defect was created in the right eye using 6mm axial corneal mechanical debridement while the left served as an unwounded control. The tears were collected from both eyes during 1 week and the corneal epithelium was processed for the measurement of NGF at day 0 and 7. The NGF content of tears and corneal epithelium was determined by enzyme-linked immunosorbent assay. In another experiment, the animals were divided into 3 groups. The right eyes in each group were treated every six hours with 200 ug/ml of recombinant human (rh) NGF, murine NGF, or 600 ug/ml of anti-NGF blocking antibody. The left eye of each animal was treated with bovine serum albumin (BSA) to serve as controls. Wound healing was analyzed using NIH image software. Tear NGF was markedly increased in the wounded eyes, relative to tears from control eyes during the early healing period. The NGF content of the corneal epithelium was elevated in the wounded eye (p=0.024). Time to wound closure and rate of epithelial migration were not significantly different between the NGF treated or the NGF antibody treated, and the control BSA treated eyes. Corneal epithelial wounding increased NGF content only on the wounded side during the early healing period. Neither topical recombinant human or murine NGF affected corneal epithelial wound healing in the normal dog.

• Journal of Chest Surgery
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• v.30 no.1
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• pp.17-26
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• 1997

Objeitives. The surgical mortality of congenital heart defects has been reduced (or the very young age group. Especially, young age at repair is an important risk factor for mortality after repair of tetralogy of Falloff. Some risk factors were analyzed Methods. Three hundred and sixty six patients underwent surgical Intervention. Ages ranged from 5 days to 64 years, and 80 patients were adults(over 15 years of age). The defects consisted of 313(84.2%) acyanotic and 53(15.8%) cyanotic anomalies. The surgical mortalities were evaluated by univariate and multivariate analysis. Results. The overall surgical mortality was 10.4%. Mos deaths occurred in the infant group younger than 6 months(20/38 deaths) and in cyanotic group(21/38 deaths). Surgical infant mortality younger than 12 months was 24.8%(25/101). Risk factors of mortality in open heart surgery were age(p< 0.0001), body weight(p< 0.0001), pump time(p< 0.0001), aortic cross clamp time(p< 0.0001), use of total circulatory arrest(p<0.0001) and cyanotic disease(p<0.0001) by univariate analysis. But by multivariate analysis, the risk factor of mortality in open heart surgery was disease entity(p=0.002) only. A disease group with the highest risk was a cyanotic group(odds ratio was 15.3 relative to ventricular septal defect) excluding tetralogy of Falloff(odds ratio=0.27). Conclusions. Even though the most important risk factor was disease entity, we should conentrate our efforts on the technically improvable factors affecting surgical mortality indicated by univarlate analysis.

• Journal of the Korean Geosynthetics Society
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• v.22 no.4
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• pp.17-26
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• 2023

To consider the risk of damage and fracture of P.C strands, the existing post-maintenance system alone has the limitations, hence it is necessary to quantitatively evaluate and predict the deterioration, durability and safety of facilities and establish a reasonable maintenance system considering the asset value of facilities. Therefore, it is worth considering a preventive maintenance plan that allows proactive measures to be taken before a major defect occurs in the temporary anchor. This study devised a preventive over tension method, reviewed its effectiveness through design and field tests, by calculating the resistance factors by performing a reliability-based optimization design. At this time, the over tension anchor method was evaluated using the ratio of the residual tension force after the fracture of P.C strands to the effective tension force before the fracture of P.C strand, followed by the resistance factor calculated by the optimal solution for each random variables using Excel solver and applying it to the limit state equations. As a result of the study, if the over tension ratio is 125% to 130%, the remaining strands showed a high resistance effect even after the fracture of P.C strand. As a result of the optimization design, it was found that it is appropriate to apply the load factor (γ) of 1.25, and the resistance factors of Φ₁, Φ₂, Φ₃ as 0.7, 0.5, 0.6.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.1
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• pp.1-11
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• 2012

Purpose: The purpose of this study was to evaluate the bone regeneration capacity of silk fibroin (SF) when combined with beta tricalcium phosphate (${\beta}$-tricalcium phosphate [TCP]) and rh-bone morphogenetic protein (BMP) in vivo by micro-computed tomography (CT), soft x-ray, and histological analysis. Methods: A total of 56 critical size defects formed by a trephine bur made on 28 adult female Spague-Dawley rats were used for this study and the defect size was 5.0 mm in diameter. The defects were transplanted with (1) no graft material (raw defect), (2) autogenous bone, (3) SF ($10{\mu}g$), (4) SF-BMP ($10{\mu}g$, $0.8{\mu}g$ each), and (5) SF+${\beta}$-TCP ($10{\mu}g$). At 4 and 8 weeks after operation, the experimental animals were sacrificed. Samples were evaluated with soft x-ray, histological examinations and 3-dimensional micro-CT analysis. Results: In the 3-dimensional micro-CT evaluation, bone volume and bone surface data were higher in the SF-BMP ($12.8{\pm}1.5$, $138.6{\pm}45.0$ each) (P<0.05) and SF-TCP ($12.3{\pm}1.5$, $144.9{\pm}30.9$ each) group than in the SF group ($6.1{\pm}3.3$, $77.2{\pm}37.3$ each) (P<0.05), except for the autogenous group ($15.0{\pm}3.0$, $190.7{\pm}41.4$ each) at 4 weeks. At 8 weeks, SF-BMP ($16.8{\pm}3.5$, $173.9{\pm}34.2$ each) still revealed higher (P<0.05) bone volum and surface, but SF-TCP ($11.3{\pm}1.5$, $1132.9{\pm}52.1$ each) (P=0.5, P=0.2) revealed the same or lower amount compared with the SF group ($13.8{\pm}2.7$, $127.5{\pm}44.8$ each). The % of bone area determined by radiodensity was higher in the SF-TCP ($31.4{\pm}9.1%$) and SF-BMP ($36.2{\pm}16.2%$) groups than in the SF ($19.0{\pm}10.4$) group at the period of 4 weeks. Also, in the histological evaluation, the SF-BMP group revealed lower inflammation reaction, lower foreign body reaction and higher bone healing than the SF group at postoperative 4 weeks and 8 weeks. The SF-TCP group revealed lower inflammation at 4 weeks, but accordingly, as the TCP membrane was absorbed, inflammatory and foreign body reaction are increased at 8 weeks. Conclusion: The current study provides evidence that the silk fibrin can be used as an effective grafted material for tissue engineering bone generation through a combination of growth factor or surface treatment.

• Progress in Medical Physics
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• v.5 no.2
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• pp.13-20
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• 1994

The thermoluminescence(TL) glow curves and the optical absorption of $Al_2O_3$ irradiated with ${\gamma}$-ray, electron, and $Li^{+}$ ion followed by electron irradiation have been investigated to determine the relation of TL peak to its defect type. The TL glow curve of $Al_2O_3$ irradiated with ${\gamma}$-ray shows TL peaks at 380 K, 415 K, and 475 K. The UV photobleached TL glow curve of $Al_2O_3$ irradiated with ${\gamma}$-ray shows that the 380 K and 475 K TL peaks completely disappear while the 415 K TL peak still exists. The electron beam induced TL glow curve of $Al_2O_3$ after $Li^{+}$ ion implantation shows that the TL peak at 440 K is enhanced by a factor of 2 over the TL intensity of unimplanted $Al_2O_3$ while the TL peak at 380 K evidently disappears The implanted $Li^{+}$ ions are assumed to form singly charged interstitial cations and then recombine with electron trapped in F centers to produce F+ centers. The 380 K and 475 K TL peaks are proposed to be associated with F center, while the 415 K and 440 K TL peak are connected with F$^{+}$ center.