• 제목/요약/키워드: Threshold effect

검색결과 1,519건 처리시간 0.035초

시각 감지 기반의 저조도 영상 이미지 적응 보상 증진 알고리즘 (Adaptive Enhancement of Low-light Video Images Algorithm Based on Visual Perception)

  • 이원;민병원
    • 사물인터넷융복합논문지
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    • 제10권2호
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    • pp.51-60
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    • 2024
  • 저조도 환경에서 영상 이미지의 콘트라스트가 낮고 식별이 어려운 문제를 목표로 사람의 시각 감지 기반의 콘트라스트 적응 보상 증진 알고리즘을 제안한다. 첫째, 저조도 환경에서 평균 밝기, 평균 대역폭 요인의 영상 이미지 특징 요인을 추출하고, 원본 영상의 회색/색도 차이에 따라 사람의 시각적 콘트라스트 해상도 보상의 수학적 모델을 설정하며, 실제 컬러의 3원색에 대해 각각 비례 적분하여 보상한다. 다음으로 보상 정도가 명시각 차이를 적절하게 구별할 수 있는 것보다 낮을 때 보상 임계값 선형 보상이 명시각에서 전체 대역폭으로 설정된다. 마지막으로 주관적인 이미지 품질 평가와 이미지 특성 요인을 결합하여 비례 계수를 보상하는 자동 최적화 모델을 구축한다. 실험 테스트 결과는 영상 이미지 적응 증진 알고리즘이 우수한 증진 효과와 우수한 실시간 성능을 가지며 다크 비전 정보를 효과적으로 마이닝할 수 있으며 다양한 시나리오에서 널리 사용될 수 있음을 보여준다.

Effects of Pain Neuroscience Education on Pain, Body Function, Activity Disorders, and Depression in Patients with Chronic low back Pain: Randomized Controlled Trail

  • Kyoung-Gon Oh;Min-Ji Lee;Byoung-Hee Lee
    • 대한물리치료과학회지
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    • 제31권2호
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    • pp.1-14
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    • 2024
  • Background: Many patients with chronic low back pain have reduced movement due to pain. For that reason, muscle strength weakens, which leads to pain again. The pain caused by such a vicious circle is not only caused by structural problems, but also by physical function, activity disorder, or psychological depression due to biopsychosocial approaches and pain neuroscience education was applied as an intervention to find out its effect. Therefore, this study was experimented with to find out the effects of pain neuroscience education on pain, physical function, activity disorder, and depression in patients with chronic low back pain. Design: Randomized control trial Method: The study subjects were 39 patients with chronic low back pain, and the study subjects were randomized through computers to the experimental group applying pain neuroscience education and the control group applying only general physical therapy and myofascial release techniques, and the experiment was conducted for 4 weeks. Pressure Pain Threshold , Schober test, Korean Roland-Morris Disability Questionnaire, Korean Oswestry Disability Index, and Korean Depression Screening Assessment were measured. Results: As a result of the study, there was no significant difference in pain neuroscience education compared to the group that applied only general physical therapy and myofascial release techniques in both lumbar pressure pain thresholds, Schober test, Korean Roland-Morris disability questionnaire, and Korean Oswestry disability questionnaire. However, the Korean Depression Screening Assessment which is the result of measuring depression, showed significant results(p<0.05). Conclusion: Therefore, it is believed that it can be a way to mediate the psychological part through pain neuroscience education for patients with chronic low back pain in the future.

전자선 조사가 팽이버섯의 품질특성에 미치는 영향 (Effect of Quality Characteristics of Enoki Mushroom (Flammulina velutipes) by Electron-beam Irradiation)

  • 염서준;이건아;김상수;윤기남;송범석;박종흠;김영민;김재경
    • 방사선산업학회지
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    • 제17권1호
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    • pp.75-82
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    • 2023
  • This research was carried out to evaluate on microbiological (total aerobic bacteria, yeast and mold) and physicochemical (color, firmness, water content, water activity and weight loss) characteristics of 10MeV electron-beam irradiated(0, 0.5, 1, 2 and 3kGy) enoki mushroom during storage (0, 7, 14, 21 and 28 day) at 4℃ with 80% relative humidity. As compared to control, all irradiated samples exhibited dose-dependent decreases of microbial counts up to 28 days, and electron beam irradiation above 2 kGy kept below the microbiological safety threshold. Yellowness (b*) which is associated with discoloration of mushrooms was significantly reduced by electron beam irradiation (2 kGy). Firmness, water content, water activity and weight loss showed no significant difference in all group up to 28 days. Thus, the appropriate electron-beam irradiation dose was confirmed as 2 kGy to inhibit the microbial growth and browning reaction in enoki mushroom.

부식 저항성 평가에 따른 균열 콘크리트 보의 부식전위 연구 (A Study on Corrosion Potential of Cracked Concrete Beam According to Corrosion Resistance Assessment)

  • 송하원;이창홍;이근주
    • 한국구조물진단유지관리공학회 논문집
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    • 제13권1호통권53호
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    • pp.97-105
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    • 2009
  • 건설산업에서 혼합콘크리트의 개발 및 사용은 내구성 측면에서의 공극구조개선 및 투수성 감소등의 확장 연구를 통해 나날이 증가하고 있는 실정이다. 한편, 콘크리트내의 균열은 투수성, 염해 침투속도 및 압축강도등을 결정하는 중요한 인자이며, 이는 철근의 부식과도 밀접한 관련을 가지는 것으로 알려져 있다. 더욱이 콘크리트 구조물의 피복두께에 균열이 발생한 경우, 이를 통해 철근 부식이 가속화됨은 주지의 사실이다. 최근에 콘크리트내의 침투를 고려한 균열효과와 관련하여 다수의 연구가 수행되어져 온 것이 사실이며, 그에 따라 내구성을 고려한 균열 혼합콘크리트의 사용수명 평가에 관한 연구도 필요한 것이 사실이다. 본 연구에서는 0.3mm의 균열을 변수로 두고, OPC, 30% PFA, 60% GGBS 및 10% SF의 결합재를 혼입하여 사용한 혼합콘크리트보의 부식평가를 자연 및 인공 환경조건에 맞추어 반전지전위측정시험, 갈바닉전류측정시험, 무게감량법등으로 측정 및 비교분석하였다.

Effect of cement type, luting protocol, and ceramic abutment material on the shade of cemented titanium-based lithium disilicate crowns and surrounding peri-implant soft tissue: a spectrophotometric analysis

  • Peter Gehrke;Maria Julia Pietruska;Johannes Ladewig;Carsten Fischer;Robert Sader;Paul Weigl
    • The Journal of Advanced Prosthodontics
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    • 제16권4호
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    • pp.231-243
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    • 2024
  • PURPOSE. The objective of the study was to analyze the impact of cement, bonding pretreatment, and ceramic abutment material on the overall color results of CAD-CAM ceramic crowns bonded to titanium-based hybrid abutments. MATERIALS AND METHODS. For single implant restoration of a maxillary lateral incisor a total of 51 CAD-CAM-fabricated monolithic lithium disilicate crowns were fabricated and subsequently bonded onto 24 lithium disilicate Ti-base abutments, 24 zirconia Ti-base abutments and 3 resin abutment replicas as a control group. The 48 copings were cemented with three definitive and one provisional cement on both grit-blasted and non-blasted Ti-bases. The color of each restoration and surrounding artificial gingiva was measured spectrophotometrically at predefined measuring points and the CIELAB (ΔEab) color scale values were recorded. RESULTS. The color outcome of ceramic crowns bonded to hybrid abutments and soft tissues was affected differently by cements of different brands. Grit-blasting of Ti-bases prior to cementing CAD-CAM copings affected the color results of allceramic crowns. There was a significant difference (P = .038) for the median ΔE value between blasted and non-blasted reconstructions at the cervical aspect of the crown. Full-ceramic crowns on zirconia Ti-base abutments exhibited significantly lower ΔE values below the threshold of visibility (ΔE 1.8). In all subcategories tested, the use of a highly opaque temporary cement demonstrated the lowest median ΔE for both the crown and the artificial gingiva. CONCLUSION. Various cements, core ceramic materials and airborne particle abrasion prior to bonding can adversely affect the color of Ti-base supported ceramic crowns and peri-implant soft tissue. However, zirconia CAD-CAM copings and an opaque cement can effectively mask this darkening.

합곡-곡지 전침치료가 정상인의 뇌혈류에 미치는 영향 - Brain SPECT와 SPM을 이용하여 - (Effect of LI4-LI11 Electro-acupuncture on Regional Cerebral Blood Flow in Healthy Human - Evaluated by $^{99m}Tc-ECD$ Brain SPECT -)

  • 류종만;김영석;박성욱;정우상;고창남;조기호;배형섭;김덕윤;문상관
    • 대한한의학회지
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    • 제27권2호
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    • pp.36-43
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    • 2006
  • Objectives : Acupuncture has been widely applied to rehabilitation after stroke by Oriental medical doctors in Korea. It has been reported that acupuncture increased cerebral blood supply and stimulated the functional activity of brain nerve cells. In addition, a correlation between activation of specific areas of brain cortices and corresponding acupuncture stimulation at the therapeutic points had been well illustrated. rill now, however, there were few studies which evaluated a correlation between activation of specific areas of brain and frequently-used acupuncture therapy for stroke, such as LI4-LI11 electro-acupuncture (EA) for paresis after stroke. This study was undertaken to evaluate the effect of LI4-LI11 EA on regional cerebral blood flow (rCBF) in normal volunteers using Single Photon Emission Computed Tomography (SPECT). Methods : In the resting state, $^{99m}Tc-ECD$ brain SPECT scans were performed on 10 normal volunteers (8 males, 2 females, mean age $25.6{\pm}2.3$years; age range from 24 to 31 years). 7 days after the resting examination, 15 minutes of electro-acupuncture were applied at LI 4 and LI 11 on the right side of the subjects. Immediately after LI4-LI11 EA, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of regional cerebral blood flow after LI4-LI11 EA were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by Statistical parametric mapping with a threshold of p=0.001, uncorrected (extent threshold: k=100 voxels). Results : EA applied at right LI4-LI11 increased rCBF in right frontopolar area (Brodmann area 10) and left middle frontal area (Brodmann area 46). Interestingly, all the areas showing increased rCBF corresponded to the territories of both anterior cerebral arteries. However, LI4-11 EA decreased rCBF in the left occipital lobe (peristriate area, Brodmann area 19). Conclusions : The results demonstrated a correlation between LI4-11 EA and rCBF increase in the frontal lobes. It is also suggested that there may be a correlation between LI meridian and the territory of the anterior cerebral arterties.

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뇌 SPECT와 SPM을 이용한 합곡-곡지 TENS 치료의 뇌혈류에 대한 효과 (Effect of LI4-LI11 Transcutaneous Electrical Nerve Stimulation on Regional Cerebral Blood Flow in Healthy Human Using SPECT and Statistical Parametric Mapping)

  • 정동원;김영석;박성욱;정우상;박정미;고창남;조기호;배형섭;김덕윤;문상관
    • 대한한의학회지
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    • 제29권4호
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    • pp.205-212
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    • 2008
  • Background and purpose: So far it was reported that acupuncture increased cerebral blood supply and stimulated the functional activity of brain nerve cells. A previous study demonstrated a correlation between LI4-11 electro-acupuncture (EA) and rCBF increase in frontal lobe. However, there remained a need to study further using various controls in acupuncture research. Transcutaneous electrical nerve stimulation (TENS) has been used as a non-invasive control in acupuncture study. This study was to evaluate the effect of LI4-LI11 TENS on regional cerebral blood flow (rCBF) in normal volunteers using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Methods: In the resting state, $^{99m}Tc-ECD$ brain SPECT scans were performed on 10 normal volunteers (9 males, 1 female, mean age 26.6$\pm$0.5 years; age range from 26 to 27 years). On the other day, 7 days after the resting examination, 15 minute TENS were applied at LI 4 and LI 11 on the right side of the subjects. Immediately after LI4-LI11 TENS, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of regional cerebral blood flow after LI4-LI11 TENS were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by statistical parametric mapping with a threshold of p = 0.001, uncorrected (extent threshold: k=100 voxels). Results: TENS applied at right LI4-LI11 increased rCBF in the left somatosensory association cortex (Brodmann area 5, 7). However there was no area where LI4-11 TENS decreased rCBF. Conclusion and suggestions: These results demonstrate that right LI4-LI11 TENS increased rCBF only in corresponding somatosensory association cortex, which was different from the previous results using LI4-11 EA. It is suggested that there be a different mechanism between TENS and EA.

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성별에 따른 말초 opioid의 통증조절 (Sex Differences in the Pain Control by the Peripheral Opioid)

  • 배성제;김완수;강수경;어규식;홍정표;전양현
    • Journal of Oral Medicine and Pain
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    • 제38권4호
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    • pp.339-356
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    • 2013
  • 이 연구에서는 말초 opioid 수용체를 이용한 저작근 통증 조절 시 성별 효과의 차이를 확인하고자 RDC/TMD로 진단된 지원자 남성 20명, 여성 20명을 saline 주사군, lidocaine 주사군, morphine 1.5 mg 주사군, morphine 3 mg 주사군 각각 5명씩 배정하였다. 통증부위에 주사 전, 주사 후 1시간, 24시간, 48시간에 각각 주관적인 통증 평가인 시각유추척도평가, 맥길통증설문지 평가, 통증부위표시평가 그리고 객관적인 통증 평가인 압력통증역치평가와 압력통증한계평가를 실시하였다. 검사 후 평가된 자료를 통계 처리하여 다음과 같은 결과를 얻었다. 1. 시각유추척도평가에서는 남녀 모두가 morphine 3 mg군에서 통계학적으로 유의성 있는 효과가 있었다. (male: p<0.05, female: p<0.05) 2. 맥길통증설문지 평가에서는 남녀 모두가 morphine 1.5 mg군 보다 morphine 3 mg군에서 더 통계학적으로 유의성 있는 효과가 있었다. (male: p<0.001, female: p<0.01) 3. 통증부위표시평가와 압력통증역치평가에서는 남성이 morphine 3 mg군에서 통계학적으로 유의성 있는 효과가 있었다. (PD: p<0.001, PPT: p<0.05) 이상의 연구 결과로 저작근 통증을 조절하기 위해서 morphine 3 mg을 통증부위에 주사한 경우 객관적인 통증 평가에서 여성 환자보다 남성 환자에게 더 효과가 있다는 것을 알 수 있었으며, 앞으로 시간에 따른 그리고 용량에 따른 남녀 치료효과의 차이에 관한 연구가 더 필요 할 것으로 생각된다.

양릉천-현종 전침치료가 뇌경색환자 및 정상인의 뇌혈류에 미치는 영향 - SPECT와 SPM을 이용한 연구 - (Effect of GB 34-GB 39 Electro-acupuncture on Regional Cerebral Blood Flow in Stroke Patients and Normal Volunteers Evaluated by $^{99m}Tc-ECD$ SPECT)

  • 한진안;정동원;배형섭;박성욱;정우상;박정미;고창남;조기호;김영석;김덕윤;문상관
    • 대한한의학회지
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    • 제27권3호
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    • pp.187-200
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    • 2006
  • Objectives: Acupuncture has been applied in Asia for thousands of years, especially to rehabilitation after stroke. It has been reported that acupuncture increased cerebral blood supply and stimulated the functional activity of brain nerve cells shown by using brain imaging techniques. This study was to evaluate the effect of GB 34-GB 39 electro-acupuncture (EA) on regional cerebral blood flow (rCBF) in stroke patients and normal volunteers using single photon emission computed tomography (SPECT). Methods: The study procedure was divided into two parts: patients and volunteers studies. For the patients study, ten ischemic stroke patients (3 males, 7 females, mean age $68.5{\pm}8.9$ years old) were selected. Baseline brain SPECT was done with triple head gamma camera (MultiSPECT3, Siemens, USA) after intravenous administration of 1,110 MBq of $^{99m}Tc-ECD$. Fifteen-minute EA at GB 34 and GB 39 were applied on the affected limb. The same dose of $^{99m}Tc-ECD$ was injected during the EA, and the second set of SPECT images wasobtained. Using the computer software (ICON 7.1, Siemens, USA), 3 SPECT slices (upper, middle, lower) surrounding the brain lesion were selected and each slice was divided into 10-16 brain regions. Asymmetry indexes (AI) were analyzed in each brain region. We regarded over 10% changes of AI between before and after EA as significance. For the volunteers study, 10 healthy human volunteers (5 males, 5 females, mean age $28.1{\pm}6$ years old) were selected. In the resting state, $^{99m}Tc-ECD$ brain SPECT scans were performed. On the 7th day after the resting examination, 15 minute EA was applied at GB 34 and GB 39 on the right side of the subjects. Immediately after EA, the second SPECT images were obtained inthe same manner as the resting state. Significant increases and decreases of rCBF after EA were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by statistical parametric mapping with a threshold of p = 0.01, uncorrected (extent threshold: k=100 voxels). Results: In stroke patients, six of the eight (75%) had significantly increased perfusion in post-acupuncture scans compared to their baseline state. In normal volunteers, GB 34-GB GB EA increased rCBF in both hemispheres including right ventral posterior cingulate (Brodmann area (BA) 23), left superior temporal, anterior transverse temporal (BA 22, 41), left parastriate, peristriate (BA 18, 19), right occipitotemporal, angular (BA 37, 39), left rostral postcentral, caudal postcentral and preparietal (BA 2, 3, 5). However GB 34-GB 39 EA decreased rCBF in the right hemisphere including triangular and middle frontal lobes. Conclusions: The results demonstrated that OB 34-GB 39 EA increased cerebral perfusion in ischemic stroke patients and increased rCBF grossly in temporal lobes of normal volunteers. It is also suggested that there may be a correlation between the GB meridian and the territory of the middle cerebral artery.

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신장 핵의학 영상의 정량적 분석을 위한 관심영역 자동설정 기능 개발 및 사용자별 분석결과의 변화도 감소효과 분석 (Development of Automated Region of Interest for the Evaluation of Renal Scintigraphy : Study on the Inter-operator Variability)

  • 이형구;송주영;서태석;최보영;신경섭
    • 한국의학물리학회지:의학물리
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    • 제12권1호
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    • pp.41-50
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    • 2001
  • 신장 핵의학 영상의 정량적 분석시 설정하게 되는 관심영역은 그 설정 위치 및 모양과 크기에 따라 서로 다른 분석 결과를 도출하게 한다. 따라서, 관심영역을 사용자가 직접 육안으로 판별하여 수동으로 설정하는 경우, 사용자별 주관적 요소에 의해 위치 및 형태가 서로 상이한 관심영역을 설정하게 되어 동일한 자료를 분석하더라도 그 결과가 모두 상이한 값을 갖게 되는 문제점이 발생한다. 본 연구에서는 관심영역 수동설정시 사용자별 관심영역 설정의 변화도가 실제 신장기능 분석결과에 어느 정도의 영향을 주는지를 조사하였으며, 수동설정시보다 일관성 있는 결과를 얻기 위해 여러방법의 자동설정 기능을 개발하여 그 적용 결과를 분석하였다. 관심영역의 설정에 따른 결과분석을 위한 지표값으로 좌ㆍ우 신장의 상대적 섭취도, 사구체여과율 및 평균통과시간을 선정하였고, IDL5.2로 프로그래밍하여 분석용 도구로서 적합한 소프트웨어를 개발하였으며, $^{99m}$ Tc-DTPA를 주입하여 얻은 총 11명의 정상인 신장 핵의학 영상을 대상으로 9명의 사용자들이 수행한 신장기능 평가 결과를 분석하였다. 신장 관심영역의 자동설정을 위해 영상내 화소들의 gradient값을 이용한 역치(threshold)의 계산과 border tracing기법을 적용하였으며, 배후 관심영역과 대동맥의 관심영역은 좌ㆍ우 신장의 관심영역이 설정 완료된 후, 영상내 기하학적 정보와 화소값을 참조로 하여 자동으로 설정되도록 하였다. 신장 관심영역의 자동설정 기능으로 사용자 주관적 요소의 배제 정도에 따라 4가지 방법을 개발하였으며, 각각의 적용결과를 비교, 분석하였다. 이 4가지 관심영역 자동설정 기능들은 그 구현 방법에 따라 조금씩의 차이는 있었지만, 수동설정시보다 정량적 분석 결과값의 사용자별 편차를 확연히 감소시켜, 신장 핵의학 영상의 정량적 분석시 객관적 기준을 통한 일관성 있는 결과를 도출함에 있어 그 기능의 상대적 우수성을 입증하였다.

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