• 제목/요약/키워드: Defect types

검색결과 488건 처리시간 0.029초

필 댐의 특성을 고려한 농업용 저수지 정밀안전진단체계 개선 연구 (A Study on the Safety Inspection System Improvement of Agricultural Reservoir Considering Fill-Dam Characteristics)

  • 이창범;정남수;박승기;전상옥
    • 한국농공학회논문집
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    • 제58권4호
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    • pp.1-8
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    • 2016
  • In 2008, 17, 596 dams and reservoirs are scattered across South Korea, and 17, 505 of them (99.5 %) are used for agriculture and 99.3 % are fill dam types. This study aimed to review literature related to the precise safety diagnosis system for agricultural reservoirs established by Korea Rural Community Corporation (KRCC) and analyze problems of its evaluation method. And then, it proposed ways to improve the system including a modified diagnosis system, which was applied to pilot districts in order to verify the utility. For assessment model development of agricultural reservoir, we reviewed status of precision safety inspections systems of agricultural reservoir. There are many problems such as assess agricultural reservoir not by sheet which used in fill dam but by block which used in concrete dam construction and diversion tunnel which main element in reservoir levee is treated as water intake facility. For considering diversion tunnel in reservoir levee, previous precision safety inspection systems which summed in separated phenomenon, separated element, separated site, separated facility was change to new systems which summed in site, phenomenon, element, and facility. Compared results of previous inspection system calculated total assessment index (Ec) with new system calculated total assessment index (Ec) are not show statistical difference.

2대에 걸쳐 나타난 염색체 2번과 20번의 비균형적 전위 1례 (Unbalanced Translocations of Chromosome 2 and Chromosome 20 in a Two-Generation Family)

  • 민세아;임선웅;김영숙;이오경
    • Clinical and Experimental Pediatrics
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    • 제45권7호
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    • pp.917-922
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    • 2002
  • 저자들은 안구돌출, 각막혼탁, 혀 유착증, 짧은 목, 뇌실 확장, 심방중격결손증, 동맥관개존증 및 양측 다섯번째 중위지골이 짧은 증상을 갖은 선천성 이상 환아에서 세포 유전학 검사를 통해 2번과 7번의 비균형 전위로 인한 7번 염색체의 부분 삼체성, 2번과 20번의 비균형 전위가 모친에 의해 유전되어 나타났음을 경험하였기에 보고하는 바이다.

선전류에 의해 발생되는 자장의 해석을 위한 유한요소법과 해석해의 결합 기법 (Analysis of Magnetic Fields Induced by Line Currents using Coupling of FEM and Analytical Solution)

  • 김영선;조대훈;이기식
    • 전기학회논문지P
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    • 제55권3호
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    • pp.141-145
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    • 2006
  • The line current problem(2-dimensional space : point source) is not easy to analyze the magnetic field using the standard finite element method(FEM), such as overhead trolley line or transmission line. To supplement such a defect this paper is proposed the coupling scheme of analytical solution and FEM. In analysis of the magnetic field using the standard FEM. If the current region is a relatively small compared to the whole region. Therefore the current region must be finely divided using a large number of elements. And the large number of elements increase the number of unknown variables and the use of computer memories. In this paper, an analytical solution is suggested to supplement this weak points. When source is line current and the part of interest is far from line current, the analytical solution can be coupling with FEM at the boundary. Analytical solution can be described by the multiplication of two functions. One is power function of radius, the other is a trigonometric function of angle in the cylindrical coordinate system. There are integral constants of two types which can be established by fourier series expansion. Also fourier series is represented as the factor to apply the continuity of the magnetic vector potential and magnetic field intensity with tangential component at the boundary. To verify the proposed algorithm, we chose simplified model existing magnetic material in FE region. The results are compared with standard FE solution. And it is good agreed by increasing harmonic order.

초음파 비파괴검사의 신뢰도 평가 모델 (Models of Reliability Assessment of Ultrasonic Nondestructive Inspection)

  • 박익근;박은수;김현묵;박윤원;강석철;최영환;이진호
    • 비파괴검사학회지
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    • 제21권6호
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    • pp.607-611
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    • 2001
  • 초음파검사 시스템은 검사자, 검사장비, 검사절차서로 구성되어진다. 따라서 각각의 구성의 성능에 따라 초음파검사의 신뢰도가 좌우되며, 또한 검사환경이나 검사체의 재질, 결함의 유형에 따라서도 검사의 신뢰도는 영향을 받게된다. 이러한 다양한 인자들로 인해 비파괴검사의 신뢰도를 평가하는 것이 쉽지 않다. 본 연구에서는 로지스틱 모델과 몬테 카를로 시뮬레이션을 이용하여 초음파검사의 신뢰도를 척도할 수 있는 검출확률을 평가하고자 한다. 신뢰도 평가의 유용성을 검증하기 위해 원진배관에 대한 순회시험의 데이터에 신뢰도 평가 모델을 적용하였다.

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Distribution, side involvement, phenotype and associated anomalies of Korean patients with craniofacial clefts from single university hospital-based data obtained during 1998-2018

  • Chung, Jee Hyeok;Yim, Sunjin;Cho, Il-Sik;Lim, Seung-Weon;Yang, Il-Hyung;Ha, Jeong Hyun;Kim, Sukwha;Baek, Seung-Hak
    • 대한치과교정학회지
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    • 제50권6호
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    • pp.383-390
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    • 2020
  • Objective: To investigate the distribution, side involvement, phenotype, and associated anomalies of Korean patients with craniofacial clefts (CFC). Methods: The samples consisted of 38 CFC patients, who were treated at Seoul National University Dental Hospital during 1998-2018. The Tessier cleft type, sex, side involvement, phenotype, and associated anomalies were investigated using non-parametric statistical analysis. Results: The three most common types were #7 cleft, followed by #0 cleft and #14 cleft. There was no difference between the frequency of male and female. Patients with #0 cleft exhibited nasal deformity, bony defect, and missing teeth in the premaxilla, midline cleft lip, and eye problems. A patient with #3 cleft (unilateral type) exhibited bilateral cleft lip and alveolus. All patients with #4 cleft were the bilateral type, including a combination of #3 and #4 clefts, and had multiple missing teeth. A patient with #5 cleft (unilateral type) had a posterior openbite. In patients with #7 cleft, the unilateral type was more prevalent than the bilateral type (87.0% vs. 13.0%, p < 0.001). Sixteen patients showed hemifacial microsomia (HFM), Goldenhar syndrome, and unilateral cleft lip and palate (UCLP). There was a significant match in the side involvement of #7 cleft and HFM (87.5%, p < 0.01). Patients with #14 cleft had plagiocephaly, UCLP, or hyperterorbitism. A patient with #30 cleft exhibited tongue tie and missing tooth. Conclusions: Due to the diverse associated craniofacial anomalies in patients with CFC, a multidisciplinary approach involving a well-experienced cooperative team is mandatory for these patients.

전자기파의 생체 위해성에 관한 소고 (Biological Hazard of Electromagnetic Field Exposure: A Review)

  • 정경아;계명찬
    • 환경생물
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    • 제29권4호
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    • pp.241-250
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    • 2011
  • 현대인들은 가정생활과 직업환경 속에서 다양한 종류의 전자기파에 노출되며 전자기파 노출에 따른 생체위해성은 공중보건학적으로 중요한 이슈로 대두되었다. 현재까지 많은 체외 및 체내실험 결과에서 전자기파 노출이 세포대사, 내분비, 면역, 신경, 생식, 태아발달에 영향을 미치는 것으로 보고되었다. 세포나 개체 수준에서 시행된 실험연구에서는 전자기파 노출에 의해 세포내부 자유기의 증가, DNA 손상과 암발생, 발생기형, 생식기능 저하가 나타난다. 역학조사결과 전자기파 노출은 생명을 위협하는 질병인 백혈병, 뇌암, 근위축성 측삭경화증, 우울증, 자살, 알츠하이머와 상관성이 보고되었다. 이러한 생체기능 변화는 전자기파의 주파수, 노출기간, 강도 (에너지)에 따라 다르게 나타난다. 전자기파 노출은 곤충, 어류, 양서류, 파충류, 조류 등 야생동물에서도 동물행동, 번식, 생리기능의 변화를 초래한다. 본 소고에서는 인간보건학적 측면과 생태계에서 나타난 전자기파의 위해성을 전자기파의 종류, 노출시간에 따라 세포 및 개체 수준에서 보고된 위해성 자료를 정리하였다.

평판 구조물의 영상화를 위한 위상 배열 시스템 개발 및 응용 (Development and Application of Phased Array System for Defect Imaging in Plate-like Structures)

  • 이주경;권영의;이흥선;승홍민;김기연;이준규;김회웅;이호철;김윤영
    • 한국소음진동공학회논문집
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    • 제24권2호
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    • pp.123-130
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    • 2014
  • An ultrasonic magnetostrictive transducer-based phased-array system for imaging defects in plate structures is newly proposed. In that most ultrasonic phased array systems rely on piezoelectric transducers or electromagnetic acoustic transducers, this system has its own unique feature of employing magnetostrictive transducers. Interest in using a phased array system using magnetostrictive transducers has been recently reported for pipe inspection but no such system has been developed for plate inspection. In this investigation, we aim to propose a phased array system using OL-MPTs (Omnidirectional Lamb wave Magnetostrictive Patch Transducers) for plate inspection. The developed system consists of a multi-channel function generator, power amplifiers, preamplifiers and a data acquisition unit. In the process of its development, each of the units must be checked and in doing so, we suggest types of ultrasonic wave experiments that should be carried out. Finally, the phased system using a transducer array composed of eight OL-MPTs is newly configured and is applied for actual crack detection experiments.

Clinical, Biochemical, and Genetic Characterization of Glycogen Storage Type IX in a Child with Asymptomatic Hepatomegaly

  • Kim, Jung Ah;Kim, Ja Hye;Lee, Beom Hee;Kim, Gu-Hwan;Shin, Yoon S.;Yoo, Han-Wook;Kim, Kyung Mo
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제18권2호
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    • pp.138-143
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    • 2015
  • Glycogen storage disease type IX (GSD IX) is caused by a defect in phosphorylase b kinase (PhK) that results from mutations in the PHKA2, PHKB, and PHKG2 genes. Patients usually manifest recurrent ketotic hypoglycemia with growth delay, but some may present simple hepatomegaly. Although GSD IX is one of the most common causes of GSDs, its biochemical and genetic diagnosis has been problematic due to its rarity, phenotypic overlap with other types of GSDs, and genetic heterogeneities. In our report, a 22-month-old boy with GSD IX is described. No other manifestations were evident except for hepatomegaly. His growth and development also have been proceeding normally. Diagnosed was made by histologic examination, an enzyme assay, and genetic testing with known c.3210_3212del (p.Arg1070del) mutation in PHKA2 gene.

Point Defects and Photoluminescence of Green Phosphors Ca(1-1.5x)WO4:Tbx3+ and Ca(1-2x)WO4:Tbx3+, Nax+

  • Cho, Seon-Woog
    • 한국재료학회지
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    • 제23권9호
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    • pp.537-542
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    • 2013
  • Two types of Tb- and Na-substituted green phosphors $Ca_{(1-1.5x)}WO_4:Tb_x^{3+}$: and $Ca_{(1-2x)}WO_4:Tb_x^{3+},Na_x^+$ were synthesized with various x values, using a solid-state reaction. The former phosphors contained both substitutional and vacancy point defects, while the later had only substitutional defects. X-ray diffraction results showed that the main diffraction peak, (112), was centered at $2{\theta}=28.72^{\circ}$ and indicated that there was no basic structural deformation caused by substitutions or vacancies. The photoluminescence emission and photoluminescence excitation spectra revealed the optical properties of trivalent terbium ions, $Tb^{3+}$. Typical transitions, $^5D_3{\rightarrow}^7F_6,\;^7F_5,\;^7F_4$ and $^5D_4{\rightarrow}^7F_6,\;^7F_5,\;^7F_4,\;^7F_3$, and cross relaxations were observed. Subtle differences in the photoluminescence of green phosphors were observed as a result of the point defects. The FT-IR spectra indicated that some of the ungerade vibrational modes had shifted positions and changed shapes, spreading out over a wide range of frequencies. This change can be attributed to the different masses of $Tb^{3+}$ and $Na^+$ ions and $V_{Ca}$" vacancies compared to $Ca^{2+}$ ions. The gerade normal modes of the Raman spectra exhibited subtle differences resulting from point defects in $Ca_{(1-1.5x)}Tb_xWO_4$ and $Ca_{(1-2x)}Tb_xNa_xWO_4$.

특별히 고안된 감압술 장치를 이용한 하악의 치성 낭종의 치료: 증례보고 (DECOMPRESSION TREATMENT FOR ODONTOGENIC CYST IN MANDIBLE USING SPECIFIC DECOMPRESSION APPLIANCE : CASE REPORT)

  • 김경수;김진철;오해수;최빈;길용갑;홍용재
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제29권2호
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    • pp.182-186
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    • 2007
  • A cyst is a pathologic lesion characterized by a cavity filled with fluid, celluar products, air, or a combination of these. Dentigerous cysts were formed around the crown of unerupted teeth. The reduced enamel epithelium persists around the crown after it has formed. Proliferation of the epithelium in a fluid-filled sac may be induced by osmotic pressure. In the first decade the most frequent location is the premolar site. In each subsequent decade the largest number of cysts are in the mandibular third molar site, with the second most frequent site being the maxillary canine. The treatment of odontogenic cyst can be mostly classified into three types of cyst enucleation, marsupialization and decompression. We should consider age of patient, anatomic structure, location and size for choosing a treatment method. Advantage of cyst enucleation is fast healing, but a injury of a surrounding structure is highly. Marsupialization is conservative treatment that can reduce the damage of a adjacent structure, but it is only limited at superficial lesion. Decompression also is conservative treatment, but it has the difficulty of the oral hygiene and the troublesome of the lavage. We present the possibility that reduces the defect of decompression and cures the lesion efficiently. We report a male patient with the dentigerous cyst developed at left mandibular third molar in this study. We used the decompression for a treatment and created special appliance to treat the lesion efficiently. We report a case of the cyst treatment that is association with efficiency of decompression appliance.