• 제목/요약/키워드: bifurcation point

검색결과 116건 처리시간 0.02초

조선 침구(鍼灸)의 지향에 대한 소고(小考) (A Study on the Mind of Joseon's Acupuncture and Moxibustion Technology)

  • 전종욱
    • 대한한의학원전학회지
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    • 제32권3호
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    • pp.59-71
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    • 2019
  • Objectives : This paper looks at the history of East Asian acupuncture and moxibustion in the context of the general orientations of craft and art. It is understood that acupuncture and moxibustion was the ultimate integration of reason and craft in which text and experience mutually influenced each other throughout its development. In Joseon, the pursuit of integration between the body and the order of the Heaven and Earth was particularly prominent. Methods : As in the words of Zhunagzi(莊子), the state in which something that deeply touches the mind manifests in the hands has been understood as the ultimate state in modern and ancient art. Starting here, I examined the possibility that Korean acupuncture and art has evolved from such foundations step by step. Major acupuncture and moxibustion texts were examined historically, starting with "Shenyingjing(神應經)", leading to "Junggan-Shenyingjing (重刊神應經)", "Chimgu-Gyeongheombang(鍼灸經驗方)", "Chijongjinam(治腫指南)", "Chijongjinam-Joseonchambon治腫指南朝鮮?本", "Chimgutaegilpyeonjip(鍼灸擇日編集)", "Chimgu-Myeonggam(鍼灸明鑑)". Introductions and main contents of the texts were analyzed and presented appropriately. Results : East Asian acupuncture and moxibustion has developed based on the study of pathways that correspond to Shen, of the accordance and harmony between body and the order of Heaven and Earth together with theoretical refinement, technical development, and acceptance of new discoveries. In the perspective of craft, this was motivated by artistic passions such as '得於心 應於手' and '醫者意也'. In the case of refined acupuncture methods, due to their difficulty in education and transmission there has been some fluctuation. Conclusions : Korea, China, and Japan share a largely similar philosophical and cultural basis. Reason and craft, text and experience mutually influenced each other while the core of refined acupuncture was widely shared. However, a certain bifurcation point could be detected.

흉부 CT촬영에서 저선량 프로토콜의 선량과 화질: 표준선량 프로토콜과 비교 (Radiation Dose and Image Quality of Low-dose Protocol in Chest CT: Comparison of Standard-dose Protocol)

  • 이원정;안봉선;박영선
    • Journal of Radiation Protection and Research
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    • 제37권2호
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    • pp.84-89
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    • 2012
  • 임상에서 사용하고 있는 흉부 CT촬영의 저선량 프로토콜과 표준선량 프로토콜 간의 선량과 화질을 비교 분석하였다. 흉부 저선량 프로토콜(120 kVp, 30 mAs)과 표준선량 프로토콜(120 kVp, 180 mAs)로 촬영($Brilliance^{TM}$ CT 16slice, PHILIPS)한 61명의 조영제를 사용하지 않은 영상에서 기관 분기부 위치의 종격동 영상을 본 연구를 위해 사용하였다. 상행대동맥과 가시아래근에서 CT number와 잡음을 측정하였고, Back-ground 잡음을 측정하여 신호대잡음비(signal-to-noise ratio. SNR)와 대조도잡음비(contrast-to-noise ratio, CNR)를 구하였다. 두부 아크릴 팬텀을 이용하여 선량을 측정하였고, 워터 팬텀으로 얻은 영상에서 CT number와 잡음을 측정하였다. 모든 측정은 3회 실시하여 평균값을 SPSS 프로그램(version 14.0)으로 분석하였고, 그래프는 시그마 플롯 프로그램(version10.0)을 사용하였다. 결과: 상행대동맥과 가시아래근에서 저선량 프로토콜 영상이 표준선량 프로토콜 영상 보다 유의하게 높은 잡음을 보였고, SNR과 CNR은 유의하게 낮았다. 두 영상에서 비만지수에 대한 잡음은 양의 관련성을 보였지만, SNR과 CNR은 음의 관련성을 보였다. 팬텀 결과에서 저선량 프로토콜의 선량이 표준선량 프로토콜 보다 유의하게 낮았지만(0.35 mGy vs. 1.95 mGy, p=0.008), 잡음은 저선량 프로토콜에서 유의하게 높았다(p=0.029). 저선량 프로토콜이 표준선량 프로토콜 보다 유의하게 낮은 선량을 보였지만, 화질 평가도 유의하게 낮은 결과를 보임으로서 임상에서 사용하는 저선량 프로토콜의 노출 선량은 화질을 고려하여 상향 조정할 필요가 있다.

An Assessment of the Usefulness of Time of Flight in Magnetic Resonance Angiography Covering the Aortic Arch

  • Yoo, Yeong-Jun;Choi, Sung-Hyun;Dong, Kyung-Rae;Ji, Yun-Sang;Choi, Ji-Won;Ryu, Jae-Kwang
    • 방사선산업학회지
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    • 제12권4호
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    • pp.325-332
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    • 2018
  • Carotid angiography covering the aortic arch includes contrast-enhanced magnetic resonance angiography (CEA), which is applied to a large region and usually employs contrast media. However, the use of contrast media can be dangerous in infants, pregnant women, and patients with chronic renal failure (CRF). Follow-up patients informed of a lesion may also want to avoid constant exposure to contrast media. We aimed to apply time-of-flight (TOF) angiography to a large region and compare its usefulness with that of CEA. Ten patients (mean age, 58 years; range, 45~75 years) who visited our hospital for magnetic resonance angiography (MRA) participated in this study. A 3.0 Tesla Achieva magnetic resonance imaging (MRI) system (Philips, Netherland) and the SENSE NeuroVascular 16-channel coil were employed for both methods. Both methods were applied simultaneously to the same patient. Three TOF stacks were connected to cover the aortic arch through the circle of Willis, and CEA was applied in the same manner. For the quantitative assessment, the acquired images were used to set the regions of interest (ROIs) in the common carotid artery (CCA) bifurcation, internal carotid artery, external carotid artery, middle cerebral artery, and vertebral artery, and to obtain the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) for the soft tissues. Three radiologists and one radiological resident performed the qualitative assessment on a 5-point scale - 1 point, "very bad"; 2 points, "bad"; 3 points, "average"; 4 points, "good"; and 5 points, "very good" - with regard to 4 items: (1) sharpness, (2) distortion, (3) vein contamination, and (4) expression of peripheral vessels. For the quantitative assessment, we estimated the mean SNR and CNR in each of the 5 ROIs. In general, the mean SNR was higher in TOF angiography (166.1, 205.2, 154.39, 172.23, and 161.95) than in CEA(92.05, 95.43, 84.76, 73.69, and 88.3). Both methods had a similar mean CNR: 67.62, 106.71, 55.9, 73.74, and 63.46 for TOF angiography, and 67.82, 71.19, 60.52, 49.45, and 64.07 for CEA. In all ROIs, the mean SNR was statistically significant (p<0.05), whereas the mean CNR was insignificant (p>0.05). The mean values of TOF angiography and CEA for each item in the qualitative assessment were 4.2 and 4.28, respectively for item 1; 2.93 and 4.55, respectively, for item 2; 4.6 and 3.13, respectively, for item 3; and 2.88 and 4.65, respectively, for item 4. Therefore, TOF angiography had a higher mean for item 3, and CEA had a higher mean for items 2 and 4; there was no significant difference between the two methods for item 1. The results for item 1 were statistically insignificant (p>0.05), whereas the results for items 2~4 were statistically significant (p<0.05). Both methods have advantages and disadvantages and they complement each other. However, CEA is usually applied to a large region covering the aortic arch. Time-of-flight angiography may be useful for people such as infants, pregnant women, CRF patients, and followup patients for whom the use of contrast media can be dangerous or unnecessary, depending on the circumstance.

입자영상유속계를 이용한 분기관내 유동가시화 (Flow Visualization in the Branching Duct by Using Particle Imaging Velocimetry)

  • 노형운;서상호;유상신
    • 대한의용생체공학회:의공학회지
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    • 제20권1호
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    • pp.29-36
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    • 1999
  • 본 연구는 목적은 PIV 시스템을 이용하여 분기관내 유동현상을 가시화하여 분기부 영역의 유동특성을 분석하는데 있다. PIV 시스템으로 유동장을 가시화하기 위해서 분기관 모델은 투명 아크릴판으로 제작하였고 작동유체와 추적입자는 각각 물과 송화가루를 사용하였다. 유동장에서 획득된 영상으로부터 속도벡터를 얻기 위해서 입자추적방법의 1-프레임 법과 2-프레임 법, 상호상관 PIV법인 2-프레임법을 사용하였다. PIV 시스템으로 측정된 실험결과의 신뢰성을 확보하기 위해서 표면구동 캐비티 유동의 속도분포를 4-프레임법으로 얻어진 기준 실험 데이터와 비교하였다. 분기관에서 뉴턴유체의 유동현상을 효과적으로 가시화하는데 필요한 상호상관 PIV방법의 2-프레임법을 적용하는 알고리즘을 개발하였고, sub-pixel과 면적보간을 사용하여 오벡터를 제거후 최종속도벡터를 얻었다. PIV를 이용한 분기관내 유동가시와 실험결과를 신뢰할 수 있는 수치해석 결과를 이용하여 검증한 결과 PIV 실험으로 얻어진 속도벡터는 수치해석의 결과와 잘 일치하였다. PIV 실험과 수치해석 결과로부터 분기관모델의 분기점 원위부에 재순환영역이 형성됨이 확인되었고 두 다른 방법을 이용한 재순환영역의 길이와 높이는 거의 동일하였다.

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클라우드 컴퓨팅 서비스 활성화를 위한 기술적 측면 특성요인의 중요도 우선순위 분석 (Analysis of Priority of Technical Factors for Enabling Cloud Computing Services)

  • 강다연;황종호
    • 디지털융복합연구
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    • 제17권8호
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    • pp.123-130
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    • 2019
  • 본격적인 사물인터넷(IoT) 시대의 도래는 다양한 형태의 정보를 사물인터넷 기기를 통해 수집하게 되고, 수집된 방대한 정보는 분석과정에 의해 새로운 정보로 탄생한다. 이렇게 생성된 정보를 효과적으로 저장하기 위해서는 유연성과 확장성이 뛰어난 클라우드 컴퓨팅 시스템이 유리하다. 따라서 본 연구에서는 효과적인 클라이언트 시스템 수용을 위한 주요 결정요인을 동기요인(경제성, 효율성 등)과 저해요인(전환비용, 보안문제 등)으로 보고, 저해요인을 중심으로 새로운 시스템 수용결정을 함에 있어서 어떤 세부요인이 주요하게 작용하는지에 대한 순위 파악에 연구목적을 두고 있다. 주요우선순위 결정에 필요한 요인은 문헌고찰을 통해 확보된 기술 관점의 시스템 수용결정 요인으로 정하고, 도출된 요인을 중심으로 설문지를 작성한 후, 관련 전문가를 대상으로 설문을 실시하고자 한다. 그리고 AHP분석을 통해 의사결정단위 측정을 위한 요소들 간의 쌍대비교를 수행하여 최종 우선순위를 도출하고자 한다. 나아가 본 연구 결과는 기술 수용(활성화)에 따른 의사결정을 함에 있어서 중요한 판단 근거가 될 것이다.

Efficacy and Safety of Sirolimus-Eluting Stent With Biodegradable Polymer UltimasterTM in Unselected Korean Population: A Multicenter, Prospective, Observational Study From Korean Multicenter Ultimaster Registry

  • Soohyung Park;Seung-Woon Rha;Byoung Geol Choi;Jae-Bin Seo;Ik Jun Choi;Sung-Il Woo;Soo-Han Kim;Tae Hoon Ahn;Jae Sang Kim;Ae-Young Her;Ji-Hun Ahn;Han Cheol Lee;Jaewoong Choi;Jin Soo Byon;Markz RMP Sinurat;Se Yeon Choi;Jinah Cha;Su Jin Hyun;Cheol Ung Choi;Chang Gyu Park
    • Korean Circulation Journal
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    • 제54권6호
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    • pp.339-350
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    • 2024
  • Background and Objectives: UltimasterTM, a third-generation sirolimus-eluting stent using biodegradable polymer, has been introduced to overcome long term adverse vascular events, such as restenosis or stent thrombosis. In the present study, we aimed to evaluate the 12-month clinical outcomes of UltimasterTM stents in Korean patients with coronary artery disease. Methods: This study is a multicenter, prospective, observational registry across 12 hospitals. To reflect real-world clinical evidence, non-selective subtypes of patients and lesions were included in this study. The study end point was target lesion failure (TLF) (the composite of cardiac death, target vessel myocardial infarction [MI], and target lesion revascularization [TLR]) at 12-month clinical follow up. Results: A total of 576 patients were enrolled between November 2016 and May 2021. Most of the patients were male (76.5%), with a mean age of 66.0±11.2 years. Among the included patients, 40.1% had diabetes mellitus (DM) and 67.9% had acute coronary syndrome (ACS). At 12 months, the incidence of TLF was 4.1%. The incidence of cardiac death was 1.5%, MI was 1.0%, TLR was 2.7%, and stent thrombosis was 0.6%. In subgroup analysis based on the presence of ACS, DM, hypertension, dyslipidemia, or bifurcation, there were no major differences in the incidence of the primary endpoint. Conclusions: The present registry shows that UltimasterTM stent is safe and effective for routine real-world clinical practice in non-selective Korean patients, having a low rate of adverse events at least up to 12 months.