• Title/Summary/Keyword: Defect Prevention

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Recurrent Traumatic Glenohumeral Instability Associated with Glenoid Bone Defect - 3 Case Report - (관절 와 골 결손이 동반된 재발성 견관절 외상성 불안정증 - 3례 보고 -)

  • Tae, Suk-Kee;Oh, Jong-Soo;Kim, Jin-Young
    • Clinics in Shoulder and Elbow
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    • v.12 no.1
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    • pp.76-79
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    • 2009
  • Purpose: Capsulolabral reconstruction in a traumatic anterior instability of the glenohumeral joint is successful not only for the prevention of recurrent instability but also for the restoration of function. Materials and Methods: However, a capsulolabral procedure alone cannot guarantee a successful result when there is severe bone loss of the glenoid. Results: We report the surgical technique and results of capsulolabral repair and extraarticular bone block with an autogenous iliac crest graft performed on three cases (all male, average age 28 years, minimum follow-up 12 months) with traumatic anterior instability associated with more than 30% glenoid bone loss.

Research on the Effects of MAAB Style Guidelines for Weapon System Embedded Software Reliability Improvement (무기체계 내장형 소프트웨어 신뢰성 향상을 위한 MAAB 스타일 가이드라인 영향성 연구)

  • Kim, Yeon-Gyun;Yoon, Hyung-Sik
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.2
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    • pp.213-222
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    • 2014
  • In this paper, we introduce that MAAB style guideline has effects on the codes generated from Simulink models for static and dynamic software testing, when weapon system embedded software design and implementation are performed using the model based method. As showing the effects, MAAB guideline is helpful for defect prevention related with coding rules and run time errors associated with the DAPA weapon system embedded software guide. Thus, we check related items between MAAB and DAPA software reliability testing including static and dynamic analysis. And then we propose the criterion to select proper items from MAAB for DAPA guideline and show how to verify the relationship and the effects on reliability of models in Simulink. In addition, we show the needs for clear logics in conditional block models or statements and simple complexity models for Simulink model based design.

Failure Evaluation Plan of a Reactor Internal Components of a Decommissioned Plant

  • Hwang, Seong Sik;Kim, Sung Woo;Choi, Min Jae;Cho, Sung Hwan;Kim, Dong Jin
    • Corrosion Science and Technology
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    • v.20 no.4
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    • pp.189-195
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    • 2021
  • A technology for designing and licensing a dedicated radiation shielding facility needs to be developed for safe and efficient operation an R&D center. Technology development is important for smooth operation of such facilities. Causes of damage to internal structures (such as baffle former bolt (BFB) of pressurized water reactor) of a nuclear power reactor should be analyzed along with prevention and countermeasures for similar cases of other plants. It is important to develop technologies that can comprehensively analyze various characteristics of internal structures of long term operated reactors. In high-temperature, high-pressure operating environment of nuclear power plants, cases of BFB cracks caused by irradiated assisted stress corrosion cracks (IASCC) have been reported overseas. The integrity of a reactor's internal structure has emerged as an important issue. Identifying the cause of the defect is requested by the Korean regulatory agency. It is also important to secure a foundation for testing technology to demonstrate the operating environment for medium-level irradiated testing materials. The demonstration testing facility can be used for research on material utilization of the plant, which might have highest fluence on the internal structure of a reactor globally.

Fatigue evaluation and CFRP strengthening of diaphragm cutouts in orthotropic steel decks

  • Ke, Lu;Li, Chuanxi;He, Jun;Lu, Yongjun;Jiao, Yang;Liu, Yongming
    • Steel and Composite Structures
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    • v.39 no.4
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    • pp.453-469
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    • 2021
  • The cracking at the transverse diaphragm cutout is one of the most severe fatigue failures threatening orthotropic steel decks (OSDs), whose mechanisms and crack treatment techniques have not been fully studied. In this paper, full-scale experiments were first performed to investigate the fatigue performance of polished cutouts involving the effect of an artificial geometrical defect. Following this, comparative experimental testing for defective cutouts strengthened with carbon fiber-reinforced polymer (CFRP) was carried out. Numerical finite element analysis was also performed to verify and explain the experimental observations. Results show that the combinative effect of the wheel load and thermal residual stress constitutes the external driving force for the fatigue cracking of the cutout. Initial geometrical defects are confirmed as a critical factor affecting the fatigue cracking. The principal stress 6 mm away from the free edge of the cutout can be adopted as the nominal stress of the cutout during fatigue evaluation, and the fatigue resistance of polished cutouts is higher than Grade A in AASHTO specification. The bonded CFRP system is highly effective in extending the fatigue life of the defective cutouts. The present study provides some new insights into the fatigue evaluation and repair of OSDs.

System Safety Application for the Weapon System (무기체계 시스템안전 적용방안)

  • Park, Suncheol;Kim, Jinsung;Jin, Jonghoon;Yoon, Donghwan
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.44 no.4
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    • pp.106-112
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    • 2021
  • In the early 1960s, US Air Force lost missile launch bases during ICBM development by a defect in the missile design and operation plan. U.S. DoD realized the limitation of the existing accident prevention method. Therefore, the weapon development required system safety activity, and procurement projects of U.S. DoD applied MIL-STD-882(System Safety). Development projects of U.S. DoD more emphasized the importance of system safety after the space shuttle Challenger exploded in 1986. Currently, Airworthiness certification for military aircraft uses system safety to minimize accidents. The domestic defense aviation R&D projects also use the system safety for the airworthiness certification. However, non-aviation weapon R&D projects rarely applied system safety. This paper presents a system safety application method for domestic weapon R&D projects by studying the U.S. military standards/organizations and domestic defense aviation projects.

Establishment of Condition Assessment Criteria in Agricultural Reservoirs by AHP (AHP 기법에 의한 농업용 저수지의 상태평가 기준 설정)

  • Shim, Jae-Woong;Lee, Young-Hak;Lee, Dal-Won
    • Journal of The Korean Society of Agricultural Engineers
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    • v.64 no.5
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    • pp.17-26
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    • 2022
  • In this study, in order to establish the criteria for evaluation of importance by the type of facility specialized for agricultural reservoirs, an expert group consisting of a total of 167 members who were in management, or specialized in the fields of design, research, and diagnosis were organized, and the importance for facilities was set with application of the AHP technique. The importance of dam body, spillway, and intake structure composing a reservoir were set at 59%, 24%, and 17%, and the importance of dam crest, upstream slope, and downstream slope constituting a dam body was set at 32%, 31%, and 37%, respectively. In addition, the importance of approach channel, regulated channel, chute channel, and stilling basin consisting a spillway was set at 15%, 44%, 26%, and 15%, and the importance of inclined conduit and outlet conduit consisting an intake structure was set at 35% and 65%, respectively. The safety grade of the reservoirs evaluated by applying the newly presented importance values in this study showed the rearrangement of the grades with a change of 11% compared to the previous grades. In this way, the newly established criteria are expected to be utilized as basic data with strategic importance in reservoir safety management and disaster prevention as well as the operation of systems in the future.

Prevention and treatment of microstomia

  • Sae Hwi Ki;Tae Jun Park
    • Archives of Craniofacial Surgery
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    • v.25 no.3
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    • pp.105-115
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    • 2024
  • The mouth, located in the lower third of the face, is a uniquely visible structure. It serves as a vital organ both aesthetically and functionally, playing a key role in speech, expression, and fundamental oral functions. Consequently, any alterations or defects in its shape, due to various causes, can lead to aesthetic and functional deficiencies. These issues may also result in challenges with social interactions and a decrease in confidence. In cases of microstomia, various surgical approaches are proposed based on the location, extent, shape, and cause of the defect, leading to numerous case reports. Plastic surgeons are proficient in oral reconstruction; however, cases of microstomia are relatively rare, which reduces their familiarity and interest in these cases. Additionally, preferences for oral size and shape vary according to factors such as geographical region and ethnicity, further complicating the functional definition of microstomia. Therefore, both subjective patient and physician judgments play crucial roles in the diagnosis and treatment of microstomia, as these may vary depending on individual and societal aspects. This review aims to classify the various causes and definitions of microstomia, as well as its non-surgical and surgical treatment options, with the goal of the treatment of this condition.

A study on transmission line configuration for structural health monitoring using electromagnetic waves

  • Dongsoo Lee;Dong-Ju Kim;Jinwook Kim;Jong-Sub Lee;Sang Yeob Kim
    • Smart Structures and Systems
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    • v.34 no.1
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    • pp.1-8
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    • 2024
  • Structural health monitoring (SHM) of concrete structures is necessary because structural safety is directly linked to life safety. This study proposes a transmission line configuration for SHM based on time domain reflectometry (TDR). For this purpose, six transmission lines consisting of electrical wires, rebars, and joints were prepared. The TDR waveforms were measured and analyzed in air and concrete using six transmission lines to select the most suitable configuration. A two-line wire with joints was selected as the optimal transmission line for SHM because it exhibited the highest sensitivity among the configurations. Experiments to apply SHM were performed on defective concrete blocks containing an optimal transmission line. The results showed that the defect locations in concrete were precisely investigated using TDR waveform analysis. The distances estimated from the TDR waveform were similar to the measured distances for the locations of the defects and joints in the concrete blocks. This study suggests that a transmission line consisting of two-line wires and joints may be an effective non-destructive evaluation tool for assessing the structural health of concrete.

Analysis and de lege ferenda of the Acts Related with Spread of MERS in Korea in the Year 2015 - Focused on the Controversial Clauses of Medical Service Act and Infectious Disease Control and Prevention Act - (중동호흡기증후군 2015년 사태와 관련된 의료법령의 분석과 입법론 - 「의료법」 및 「감염병의 예방 및 관리에 관한 법률」의 쟁점 조항을 중심으로 -)

  • Kim, Cheonsoo
    • The Korean Society of Law and Medicine
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    • v.16 no.2
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    • pp.197-225
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    • 2015
  • The presentation of this paper was triggered by the spread of MERS in Korea in the year 2015. The analysis of the present acts related with MERS is necessary in order to cope efficiently with any probable spread of such infectious diseases as MERS in future. The acts that should be analyzed in this paper include 'Medical Service Act' and 'Infectious Disease Control And Prevention Act' (hereafter, IDCAPA). At first the classification of the infectious diseases in IDCAPA should be referred to. The Act does not properly classify them because the scope of concept of each group of the infectious diseases overlaps each other. This overlap should be removed. The present system in IDCAPA is not proper for the efficient notification and reporting of the infectious disease patients. This is so in some viewpoints including the persons obligated to make the notification and reporting, the persons to whom they should notify and report such patients, and the process of notification and reporting. The efficient approach to the information related with the infectious disease is necessary for the rapid prevention of its spread. Cohort isolation and quarantine of the infectious patients and exposed contacts are the strongest and most efficient steps for the prevention of spread of the infectious diseases. One of the great problems related with such steps would be the conflict of powers or attributions, the likelihood of which is inevitable under the present system of IDCAPA. The IDCAPA distributed the power or attribution to take the steps to the three governments including the central government, the metropolitan government and the primary local government. The power should be concentrated in the central government, which could afford financially to compensate for the huge amount of damages caused likely by the steps. The power to take the steps would be actually just a useless thing for its holder without such financial capacity. The remedy for the victims by the fault of spreader should be approached to in the sense of national wealth. The general principle of tort law could not supply the victims with the sufficient remedy because the damages would be likely too huge for the wealth of such spreader to cope with. In future another parliamentary inspection could reveal another problems in the administration by the government of the MERS event in the year 2015. Any problem caused by defect in the legal system of the control and prevention of the infectious diseases should be taken into consideration when the legal system would be reformed in future.

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Incidence of Vesicoureteral Reflux and Renal Scar in Asymptomatic Siblings of Patients with Primary Vesicoureteral Reflux (선천성 방광요관역류 환아의 형제자매에서 방광요관역류와 신반흔의 유병률)

  • Yu Je-Yun;Suck Hyo-Chung;Song Jun-Young;Park Moon-Sung;Kim Young-Soo;Pai Ki-Soo
    • Childhood Kidney Diseases
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    • v.7 no.2
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    • pp.181-188
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    • 2003
  • Purpose : Vesicoureteral reflux(VUR) is known to be the main cause of childhood hypertension and renal failure. Knowing its familial occurrence, we determined the incidence of VUR and renal scar in asymptomatic siblings of Korean patients with primary VUR Methods : A total of 50 siblings from 37 index patients were included. Voiding cystourethro-graphy(VCUG) and renal scintigraphy using $^{99m}Tc-DMSA$ were peformed in these siblings from June, 1994 to May, 2001, Index patients were classified into two groups according to the presence of VUR in their siblings, and the clinical factors of the index patients such as age, sex, grade of reflux and renal cortical defect were compared between the groups. Results : Among the 50 siblings, VUR were found in 8(16%) and renal cortical defects were detected in 8(16%) siblings respectively. The incidence of renal cortical defects was 87.5%(7 out of 8) in the VUR(+) siblings. There was a case of VUR(-) cortical defect in one sibling, presumed as a scar from an old VUR. There was no relationship among age, sex, grade of reflux and renal cortical defect of the index patient to the presence of VUR in siblings. Conclusion : This study confirmed a significant incidence of VUR(16%) and renal cortical defects(16%) in the asymptomatic siblings of patients with primary VUR in Korea. It Is resonable to recommend screening studies to the siblings of patients with VUR for the early detection and prevention of probable reflux nephropathy. (J K orean Soc Pediatr Nephrol 2003;7:181-188)

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