• Title/Summary/Keyword: Defect Possibility

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Modified Design of Anterolateral Thigh Free Flap for Hypopharyngeal Reconstruction (하인두 재건을 위한 전외측 대퇴부 유리 피판의 변형된 도안)

  • Kim, Sung-Chan;Kim, Eun-Key
    • Archives of Reconstructive Microsurgery
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    • v.21 no.1
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    • pp.14-20
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    • 2012
  • Purpose: Defect after ablation of hypopharyngeal cancer often requires reconstruction by free tissue transfer. Since neo-hypopharynx is totally buried, various methods have been suggested for monitoring. We propose a modified design of anterolateral thigh (ALT) free flap for reconstruction of pharyngolaryngectomy defect, which has an exteriorized part for clinical monitoring and allows for primary closure. Materials and Methods: Three consecutive patients with hypopharyngeal cancer were reconstructed with ALT flap with modified design: 1) distal part of flap was elongated into fusiform shape and used as exteriorized monitoring segment with a deepithelized bridge and 2) proximal part was designed as curve so the maximum width of the flap was reduced to less than 10 cm. Results: Patient 1, 2 had uneventful postoperative course with healthy skin color and fresh pin prick bleeding. In patient 3, defect after cancer ablation was shorter than usual and deepithelized bridge was longer. When the general hemodynamic status of the patient was aggravated in postoperative course, the color of monitoring skin was changed. Viability of the whole flap was confirmed by endoscopy. However, leakage developed after 3 weeks and repair was necessary. In all patients the donor sites were closed primarily. Conclusion: By the modified design of ALT flap, clinical monitoring can be possible by examining exteriorized monitoring flap and also donor site can be closed primarily. However possibility of false positive exists and technical caution and patient selection is needed because of danger of leakage.

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A Study on TOFD Inspection Using Phased Array Ultrasonic Technique (위상배열 초음파 기법을 이용한 TOFD 검사에 관한 연구)

  • Yoon, Byung-Sik;Kim, Yong-Si;Lee, Hee-Jong;Lee, Young-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.4
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    • pp.304-310
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    • 2005
  • The techniques in order to measure the depth of defect in weldment and structure accurately have been developed. Many researches have made efforts to develop the methods for the accurate depth sizing of defect. TOFD is known as the most accurate method of various methods for measuring depth sizing. However, there is a possibility to miss defects because of the limitation of beam coverage for the ultrasound incident angle. In this study, the results for detectability and depth sizing using phased array ultrasonic technique for thick body were compared with those of conventional TOFD technique. It was experimentally confirmed that the phased array ultrasonic TOFD technique gives good detectability and accurate depth measurement for the various types of defects. The phased array ultrasonic TOFD technique developed in this study will contribute to increase the inspection reliability in thick component such as the pressure vessel of power generation industry.

Numerical Analysis of Magnetic Flux Leakage Inspection (누설자속탐상의 수치해석)

  • Lee, Hyang-Beom;Kim, Sean
    • Journal of the Korean Society for Nondestructive Testing
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    • v.21 no.5
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    • pp.485-492
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    • 2001
  • In this paper, electro-magnetic numerical analysis of MFL(magnetic flux leakage) method is presented. For the electromagnetic numerical analysis, 2-D FEM(finite element method) is used. The magnetic vector potential is used as a variable. The analysis of the magnetic field considering the magnetic nonlinearity is performed for the effect of the magnetic salutation. For the verification of the validity of the numerical simulation results, by using the lab-made experimental setup, non-destructive inspection is performed. The SM 45C carbon steel is used as a specimen and the artificial defects are made on the specimen. The non-destructive testing for the detection of the defect is performed. The results according to the variation oi the defect depth and the defect shape are obtained. The experimental results are compared to the numerical ones, and we conclude that the numerical results are similar to the experimental ones. So the possibility of simulation of the MFL by using the numerical analysis is shown in this paper.

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A Study on Embedded Crack at the Hatch Coaming FCA Butt Weldment in an Ultra Large Containership on the Basis of Fracture Mechanics (초대형 컨테이너선의 해치 코밍 용접부의 내부 균열에 대한 파괴역학적 연구)

  • Shin, Sang-Beom;Lee, Joo-Sung
    • Proceedings of the KWS Conference
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    • 2010.05a
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    • pp.61-61
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    • 2010
  • The purpose of this study is to prevent the unstable fracture at the FCA butt weldment of hatch coaming deck in the ultra large containership during service life. In order to do it, the behavior of the embedded crack at the weldment under design loading conditions was evaluated in accordance with BS7910. Here, the level of primary stress induced by ship motion was evaluated by the design code of classification society and FEA. The level of residual stress as secondary stress was calculated in consideration of the restraint degree of weldment and welding heat input by using the predictive equation proposed by authors in the previous study. The fatigue crack growth rate at the weldment was evaluated using CT specimen in accordance with ASTM E647. According to the results, although the allowable defect for embedded crack specified in the classification society exists at the weldment, the occurrence possibility of unstable fracture at the weldment could not be negligible, regardless of CTOD value given in this study. So, in this study, the effect of initial defect size, welding heat input, restraint degree and CTOD on the fracture mechanical characteristics of embedded crack at the weldment was evaluated by the comprehensive fracture assessment. Based on the results, the design criteria including allowable defect, residual stress level and CTOD value was established to prevent the unstable fracture at the FCA butt weldment of hatch coaming deck in an ultra large containership during service life of 20years.

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Low Speed Rolling Bearing Fault Detection Using AE Signal Analyzed By Envelop Analysis Added DWT (웨이블릿변환이 접목된 포락처리를 이용한 저속 회전하는 구름요소베어링 결함 진단)

  • Kim, Byeong-Su;Kim, Won-Cheol;Gu, Dong-Sik;Kim, Jae-Gu;Choi, Byeong-Keun
    • Journal of Advanced Marine Engineering and Technology
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    • v.33 no.5
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    • pp.672-678
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    • 2009
  • Acoustic Emission (AE) technique is a non-destructive testing method and widely used for the early detection of faults in rotating machines in these days, because the sensitivity of AE transducers is higher than normal accelerometers. So it can detect low energy vibration signals. The faults in the rotating machines are generally occurred at bearings and gearboxes which are the principal parts of the machines. It was studied to detect the bearing faults by envelop analysis in several decade years. And the researches showed that AE had a possibility of the application in condition monitoring system(CMS) using the envelope analysis for the rolling bearing. And peak ratio (PR) was developed for expression of the bearing condition in condition monitoring system using AE. Noise level is needed to reduce to take exact PR value because the PR is calculated from total root mean square (RMS) and the harmonics peak levels of the defect frequencies of the bearing. Therefore, in this paper, the discrete wavelet transform (DWT) was added in the envelope analysis to reduce the noise level in the AE signals. And then, the PR was calculated and compared with general envelope analysis result and the result of envelope analysis added the DWT. In the experiment result about inner fault of bearing, defect frequency was difficult to find about only envelop analysis. But it's easy to find defect frequency after wavelet transform. Therefore, Envelop analysis added wavelet transform was useful method for early detection of default in signal process.

Clinical use of Platelet Rich Fibrin(PRF) in Various Hard and Soft Tissue Defect : Case Report (혈소판 유래 섬유소(Platelet Rich Fibrin(PRF))를 이용한 골결손부의 치료 : 증례보고)

  • Chee, Young-Deok;Go, Seo-Wook
    • Journal of Dental Rehabilitation and Applied Science
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    • v.23 no.4
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    • pp.303-312
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    • 2007
  • Recently several studies have been developed not only to apply bone materials to bony defect, but also to use osteogenic and osteoinductive materials to form bone more effectively. In 1998 Mark et al applied gel formation of PRP(platelet-rich plasma) in bony transplantation for mandibular reconstruction as one of the method of stimulating bone formation in maxillofacial area, which is contain of varies growth factors. After he reported that PRP accelerate bone formation, which is used in varies bone transplantation and augmentation with a good result. Especially there are amount of growth factors in PRP, and PRP increase angiogenesis, cell division, and mesenchymal cell growth. Moreover it is capable of osteoconduction, hemostatitis, anti-infection, forming the shape at transplantation, ease of handling, and recipient site stability. So it is known that success rate is high in bone transplantation. However PRP need tissue adhesive to make plasma to solid form. Thrombin and calcium chloride, component of PRP, is extracted from autogenic donor. So it is expensive to extract and there is possibility of hepatitis, AIDS, and hematogenous metastasis. After all, tissue adhesive have the limitation and danger of use. So we are willing to introduce that we had get some idea after using PRF(platelet-rich fibrin) in the various hard and soft tissue bony defect, which is self extracted simply and contain growth factors.

A Study on Analysis of Defect Types and Measures for Reduction of Tile Construction for Apartment Houses (공동주택 타일공사의 하자 유형 분석 및 저감 대책에 관한 연구)

  • Park, Hyun Jung;Eom, Yong Been;Jeong, U Jin;Kim, Dae Young
    • Journal of the Korea Institute of Building Construction
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    • v.21 no.6
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    • pp.701-712
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    • 2021
  • As the domestic housing supply problem has been resolved, the apartment construction market has shifted to a consumer-oriented market that wants high quality, and in particular, expectations in the area of finishing quality have increased. Looking at the status of complaints regarding apartment housing defects supplied by Korea Land and Housing Corporation, tile-related complaints are the type occurring the most frequently. While the Ministry of Land, Infrastructure and Transport(MOLIT) is making an ongoing effort to reduce complaints related to defects, through approaches such as drafting amendments to 「Investigation of defects in apartment houses, calculation of repair costs, and standards for determining defects」, the provision of preventive measures has been insufficient. In addition, by reviewing studies, there has been insufficient research to construct a classification system after deriving the characteristics of each type using the qualitative knowledge of experts, various quantitative indicators, and suggesting measures for reduction according to the causes of each type. Therefore, this study will reflect qualitative indicators to use the AHP analysis that makes it easy to identify the relationship between defects by surveying construction experts. Then, by visualizing the weight of 'Possibility of recurrence after repair,' 'Degree of difficulty in repairing defects' and 'Fault frequency' using a radial graph, we will analyze the characteristics of each type of tile construction defect and establish measures for reduction according to the cause. This will improve the quality of the living environment and contribute to the establishment of a system for smooth defect management and reduction of defects in apartment tile construction.

Massive Rhabdomyolysis Following Cardiopulmonary Bypass

  • Kim, Young Sam;Yoon, Yong Han;Kim, Joung Taek;Baek, Wan Ki
    • Journal of Chest Surgery
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    • v.47 no.2
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    • pp.181-184
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    • 2014
  • Here, we report a case of massive rhabdomyolysis following an uncomplicated repair of a ventricular septal defect in a five-month-old baby. Postoperatively, the patient was hemodynamically stable but metabolic acidosis continued, accompanied by fever and delayed mental recovery. The next day, he became comatose and never regained consciousness thereafter. The computed tomography of the brain revealed a diffuse brain injury. The patient followed a downhill course and eventually died on postoperative day 33. An unusually high level of creatine phosphokinase was noticed, peaking (21,880 IU/L) on postoperative day 2, suggesting severe rhabdomyolysis. The relevant literature was reviewed, and the possibility of malignant hyperthermia obscured by cardiopulmonary bypass and hypothermia was addressed.

A New Approach to Product Risk Analysis for Safe Product Design (안전한 제품을 설계하기 위한 새로운 제품위험분석 방법)

  • An, Chan-Sik;Jo, Am
    • Journal of the Ergonomics Society of Korea
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    • v.23 no.3
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    • pp.53-72
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    • 2004
  • Today we are observing a lot of injuries, casualties, and property losses that are mainly caused by the defects of products. In order to derive safety designs, which minimize the possibility of such product liability-related accidents, we need to take into account the user-product interaction as an important part of the danger factor analysis. Existing risk analysis techniques, however, have some limitations in detecting comprehensive danger factors that are peculiarly involved in human errors and the functional defects of products. Researches on danger factor analysis regarding the user-product interaction have been carried out actively in ergonomics. In this paper, we suggest a novel product risk analysis technique, which is more objective and systematic compared to the previous ones, by combining a modified TAFEI (Task Analysis For Error Identification) technique with SASA (Systematic Approach to Accident Scenario Analysis) technique. By applying this technique to the product design practice in industry, corporations will be able to improve the product safety, consequently strengthening the competitiveness.

Approach to Method of Process Failure Mode and Effect Analysis for Construction Industry (건설업에서의 시공FMEA적용 방안 연구)

  • Kim Yoon-Sung
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.271-274
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    • 2002
  • The aim of FMEA method which is already generalized in the industry engineering is to grasp a possibility that defect forms will appear. And it is a means of prevention step to let person remove obstacles which have an influence on customers beforehand in order. The two parts of FMEA are Design FMEA which we prepare in an early stage and Process FMEA which we prepare in time previous to mass production. This Study apply Process FMEA to execution fields of the construction industry.

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