• 제목/요약/키워드: focal loss

검색결과 116건 처리시간 0.025초

난시안에서 주경선 간 시력차이와 교정시력의 손실 (Loss of Corrected Visual Acuity According to Different Meridional Visual Acuity in Astigmatic Eyes)

  • 조나영;김상엽;문병연;조현국
    • 한국안광학회지
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    • 제21권1호
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    • pp.77-81
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    • 2016
  • 목적: 난시교정의 중요성을 강조하기 위해 주경선 간 시력차이 유무와 교정시력의 손실정도를 알아보고자 하였다. 방법: 평균 나이 $22.75{\pm}2.36$세의 난시성 굴절이상자 64명(122안)을 대상으로 하였다. 난시안을 완전교정 한 후 열공판 중앙의 가는 틈을 난시교정 축방향과 $90^{\circ}$ 반대방향으로 일치시킨 상태에서 시력을 각각 측정하였다. 결과: 경선 간 시력차이가 존재하지 않는 경우는 52안이었고, 경선 간 시력차이가 존재하는 경우는 70안이었다. 단안시력이 1.0 미만인 경우는 52안 중 14안, 70안 중 24안으로 나타났다. 난시도는 경선 간 시력차이가 존재하는 경우가 경선간 시력차이가 존재하지 않는 경우보다 높게 나타났으며, 단안시력이 1.0 미만의 경우가 더 높은 것으로 나타났다. 단안시력은 주경선 중 시력이 높게 나타나는 경선과 높은 상관성을 보였다. 좋은 시력을 유지하기 적합한 안경 교체주기는 6~12개월로 분석되었다. 결론: 난시의 지속적인 저교정은 경선 간 시력차이를 일으키는 원인이 되므로 임상에서 난시안의 최종처방은 완전교정을 목표로 하여야 한다.

Focal loss와 데이터 증강 기법을 이용한 콘크리트 박락 탐지 심층 신경망 알고리즘 (Deep learning algorithm of concrete spalling detection using focal loss and data augmentation)

  • 심승보;최상일;공석민;이성원
    • 한국터널지하공간학회 논문집
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    • 제23권4호
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    • pp.253-263
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    • 2021
  • 콘크리트 구조물은 노후화와 외부 환경에 의한 요인으로 훼손된다. 이 같은 훼손은 가장 먼저 균열로 나타나고 향후에는 박락으로도 진행된다. 이러한 콘크리트 손상은 구조물이 갖는 본래의 설계 지지력을 감소시키는 주된 원인으로 작용할 수 있어 구조물의 안정성에 부정적인 영향을 미친다. 이러한 종류의 손상이 지속되면 안전사고로도 이어질 가능성이 있어 적절한 보수와 보강이 필요하다. 이를 위해서는 구조물에 대한 정확하고 객관적인 상태 점검이 이루어져야 하며 손상 영역을 탐지할 수 있는 센서 기술 또한 필요하다. 따라서 본 논문에서는 박락을 탐지할 수 있는 딥러닝 기반의 영상처리 알고리즘을 제안했다. 연구 과정에서 298장의 박락 영상을 확보하였으며, 이 가운데 253장을 학습용으로 사용했고, 나머지 45장을 테스트용으로 사용하였다. 아울러 본 논문에서는 탐지 성능을 향상하기 위해 향상된 손실함수와 데이트 증강 기법을 적용하였다. 그 결과 콘크리트 박락의 탐지 성능이 80.19%의 평균 중첩 정확도로 나타났다. 본 논문에서는 딥러닝 기반의 영상 처리 기법을 통해 콘크리트 박락을 탐지하는 기술을 개발했고, 향상된 손실 함수와 데이터 증강 기법으로 성능을 향상시키는 방법을 제안했다. 이 같은 기술은 향후 구조물의 정확한 점검과 진단에 활용될 것으로 기대된다.

단기 기억상실을 주증(主症)으로 하는 6례(例)의 임상보고 -중기(中氣), 건망(健忘), 해리성 기억장애 중심으로 (6 Clinical Reports of Temporary Severe Amnesia Patients -focusing on amnesia, hysteric convulsion, dissociative disorder)

  • 오영진;김보경
    • 동의신경정신과학회지
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    • 제16권2호
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    • pp.287-299
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    • 2005
  • Dissociative disorder is a psychiatric disorder characterized by a sudden loss of memory, but which has no organic disease or explanation. It usually occurs after heavy psychosocial stress or traumatic experience. A transient cerebral ischemic attack (TIA) is an acute episode of temporary and focal loss of cerebral function of vascular origin. TIAs are rapid in onset; symptoms reach their maximal manifestation in fewer than 5 minutes. Manifestations are of variable duration and typically last 2-15 minutes(rarely as long as 24 h). Most TIA durations are less than 1 hour. Of concern is the careful detection of changes in behavior, speech, gait, memory, movement, and vision. TIAs are uncommon in persons younger than 60 years. I treat 6 cases of Sudden Temporary Amnesia Patients with oriental medicine and they are improved. All of them had amnesia for $6{\sim}10\;hours$. During that time, they show behavioral changes and they are not on the state of unconsciousness. After recovery, they also forget what happen at the time. they have some emotional reason too. In conclusion, 4 cases of them belong to dissociative disorder and 2 other cases, TIA.

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Gelatinous Transformation of Bone Marrow Mimicking Malignant Marrow-Replacing Lesion on Magnetic Resonance Imaging in a Patient without Underlying Devastating Disease

  • Lee, Joohee;Yoo, Yeon Hwa;Lee, Sarah;Kim, Hak Sun;Kim, Sungjun
    • Investigative Magnetic Resonance Imaging
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    • 제22권1호
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    • pp.50-55
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    • 2018
  • Gelatinous transformation of bone marrow is characterized by hypoplasia of fat cells with focal loss of hematopoietic cells and deposition of extracellular gelatinous substances. It is known to be associated with devastating underlying diseases that starve bone marrow. Here, we present a case of a patient whose magnetic resonance (MR) imaging findings of vertebral column were interpreted as metastasis or hematologic malignancy, however, the final diagnosis revealed a gelatinous transformation of bone marrow. This is the first report of gelatinous transformation of bone marrow without evidence of underlying devastating disease.

다초점성 운동신경병증 (Multifocal Motor Neuropathy)

  • 이동국
    • Annals of Clinical Neurophysiology
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    • 제4권2호
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    • pp.98-107
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    • 2002
  • Multifocal motor neuropathy (MMN) is a chronic immune-mediated peripheral myelinopathy. The major clinical features include slowly progressive, painless, and asymmetric weakness, usually of distal limb muscle. Early in the course of the disease, weakness is not necessarily associated with muscle atrophy, owing to the initial primary involvement of peripheral myelin. Chronic progressive weakness is often associated with some degree of concurrent axonal loss and subsequent muscle atrophy. Sensory symptoms are usually mild or absent, and involvement of cranial and respiratory muscles is rare. The findings of multifocal motor conduction block, abnormal temporal dispersion, and focal conduction slowing at segments not at risk for common entrapment or compression injury, associated with normal sensory conduction studies along the same segments, are the hallmark electrophysiologic features of MMN. The slow progression and absence of upper motor neuron signs are the major clinical points that separate MMN from amyotrophic lateral sclerosis. The role of GM1 antibodies, found in high titers in 22~84% of MMN patients, remains uncertain. The contention that MMN is an autoimmune disorder is largely based on the often dramatic improvement in symptoms following the administration of intravenuos immunoglobulin or cyclophosphamide.

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Wallenberg's Syndrome 환자(患者)의 1례(例)의 증례(症例) 보고(報告) (A Case of Wallenberg's Syndrome)

  • 전찬용;박종형;심문기
    • 대한한방내과학회지
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    • 제21권3호
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    • pp.521-524
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    • 2000
  • Wallenberg's syndrome is well known of dorsolateral medullary syndrome. A 56-year-old women was admitted because vertigo, vomitting, vertiginous ataxia, ipsilateral loss Rt. face and Lt. lower limb sense. The result of all performed laboratory tests were normal, but Sr-MRI scan was right lateral medullary infarction. And Br-MRA was focal stenosis of Lt. ICA. We present here one case of Wallenberg's syndrome, who was admitted at Kyungwon University Hospital From 25th Apr. to 21th May. 1998.

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개에서 컴퓨터 단층촬영상을 통한 중이염의 진단 (Radiographic and CT Diagnosis Of Otitis Media In a Dog)

  • 이기창;서은정;권정국;송경진;윤정희;최민철
    • 한국임상수의학회지
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    • 제21권2호
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    • pp.184-186
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    • 2004
  • A castrated male, 6 year-old Shih-Tzu, weighing 4.6 kg with a discharge from the external ear canal and a mal-odor was referred to Verterinary Medical Teaching Hospital, Seoul National University. Radiographic findings were narrowing and focal loss of an air density in the left ear canal and bilateral thickening of the osseous bullae. For more detail examination, computed tomography was used. In computed tomographic findings, bilateral thickening of the bulla wall and increased opacity of the bulla space were observed. Thus this dog was diagnosed as bilateral otitis media. Then surgical correction, total ear canal ablation, was performed successfully and the patient showed a good prognosis thereafter. It is considered that computed tomography might serve as an useful imaging tool for otitis media and that it supplies information not obtained with a conventional radiography.

Introduction to cerebral cavernous malformation: a brief review

  • Kim, Jaehong
    • BMB Reports
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    • 제49권5호
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    • pp.255-262
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    • 2016
  • The disease known as cerebral cavernous malformations mostly occurs in the central nervous system, and their typical histological presentations are multiple lumen formation and vascular leakage at the brain capillary level, resulting in disruption of the blood-brain barrier. These abnormalities result in severe neurological symptoms such as seizures, focal neurological deficits and hemorrhagic strokes. CCM research has identified 'loss of function' mutations of three ccm genes responsible for the disease and also complex regulation of multiple signaling pathways including the WNT/β-catenin pathway, TGF-β and Notch signaling by the ccm genes. Although CCM research is a relatively new and small scientific field, as CCM research has the potential to regulate systemic blood vessel permeability and angiogenesis including that of the blood-brain barrier, this field is growing rapidly. In this review, I will provide a brief overview of CCM pathogenesis and function of ccm genes based on recent progress in CCM research.

NAG Vibrio의 검사에 관한 소고 (Study on the Identification Methods of the Non-agglutinating Vibrio)

  • 이명원
    • 환경위생공학
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    • 제2권2호
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    • pp.61-67
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    • 1987
  • The genus Vibrio contains some of the most important intestinal pathogens of humans, including Vibrio cholerae, the cause of epidemic Asiatic cholera. A group of organisms which have been reffered to as the non-agglutinating vibrio (NAG) do not agglutinate in the Vibrio cholerae 0 group 1 antisera, but are indistinguishable from the 0-1 group both chemically and genetically. Non-O-l Vibrio cholerae can cause isolated as well as focal outbreaks of diarrhea, but the volume of fluid loss does not approach that of classic cholera, and the disease is usually self-limiting. These free-living organisms are found world-widely distributed in the environment including sewage, contaminated water, estuaries, seafood and animals. These strains involved in several cases were isolated from the environment and some patients of diarrhea, and a few epidemiologic reports indicated the wide distribution of the strains throughout the country, giving an attention to the role the organisms may play in an outbreak of diarrhea in Korea. More research on the epidemiology, serologic typing and virulence of the group of organisms, should be, therefore, done to obtain a complete understanding of their role in human disease.

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P (VDF-TrFE ) 초음파현미경용 트랜스듀서의 특성에 관한 연구 (( A Study on the Characteristics of the P ( VDF-TrFE ) Acoustic Microscope Transducer)

  • 하강열
    • 수산해양기술연구
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    • 제30권3호
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    • pp.227-236
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    • 1994
  • The characteristics of the P(VDF-TrFE) acoustic microscope transducer were evaluated theoretically and experimentally by comparison with those of the PVDF and the ZnO acoustic microscope transducers. It was found that its insertion loss was about 5dB lower than that of the PVDF and about 13$\textbf{dB}$ higher than that of the ZnO. And its relative bandwidth was 20% which could produce the effective acoustic pulse waves having about 4 periods duration into water. Another finding was that the effective horizontal focusing resolution and the focal depth were $120\mu m and $1.5mm$, respectively.

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