鎔接이음한 構造用鋼의 疲勞龜裂進展擧動

정영화,이형근,김익겸,정진석 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

In recently, according to increase the construction rate fo steel bridge, it is necessary to develop the high strength, high toughness steel. Thus, this study show to evaluate the fatigue characteristic of SWS 570 B first used within a country. With the weld-joined compact tension specimens compared with each other, that is, transverse and lengthwise about the crack propagation, high and low in the imput heat level, the fatigue test were performed. The log-log curves between the fatigue crack propagation rate da/dN and the transition range of the stress intensity factor △K ahead the crack tip were drawed, with these data. By using this curve, we obtained C and m which is material constant from Paris-Erdogan power law. The opbtained resutls from this study indicate that fatigue crack growth rate of SWS 570 B is not heat input weld is carried out. Softening effects, which affect fatigue properties, are shown that it is not affected to the fatigue growth rates significantly.

The Relevance of Serum Ghrelin Concentration to Severity of Acute Pancreatitis

( Se Hyung Lee ),( Young Don Kim ),( Yun Ho Kong ),( Koon Hee Han ),( Woo Jin Jeong ),( Sang Jin Lee ),( Gab Jin Cheon ) 대한소화기기능성질환·운동학회 2010 Gut and Liver Vol.4 No.2

Background/Aims: Ghrelin has recently been reported as exerting a protective effect in the damaged pancreas in rats. We investigated the correlation between severity of acute pancreatitis and serum ghrelin concentrations. Methods: Blood samples were collected three times (at admission, after 48 hours, and at discharge) from patients admitted with acute pancreatitis. We divided the patients into nonrisk and risk groups. The risk group was defined as the presence of at least one of following risk factors for severe acute pancreatitis: Ranson`s score ≥3, acute physiology and chronic health evaluation (APACHE) II score ≥8, C-reactive protein (CRP) ≥150 mg/L, and CT severity index (CTSI) ≥4. Serum ghrelin concentrations were measured with RIA kit and analyzed based on clinical and biochemical parameters. Results: A total of 53 patients was enrolled in this study: 28 in the nonrisk group and 25 in the risk group. At admission, the ghrelin concentration was significantly higher in the risk group (286.39±272.19 vs 175.96±138.87 pg/mL [mean±SD], p=0.049). However, the ghrelin concentration did not differ significantly between the two groups after 48 hours (p=0.450) and at discharge (p=0.678). The overall ghrelin concentration was significantly lower at admission than at discharge (240.65±247.96 vs 369.41±254.27 pg/mL, p=0.001). Conclusions: Patients with risk factors for severe acute pancreatitis have higher serum ghrelin concentrations. (Gut Liver 2010;4:234-240)

Isolation of Flavonoids from the Fruits of Cornus kousa Burg

Lee, Dae-Young,Lyu, Ha-Na,Kwak, Ho-Young,Jung, La-Koon,Lee, Youn-Hyung,Kim, Dae-Keun,Chung, In-Sik,Kim, Sung-Hoon,Baek, Nam-In The Korean Society for Applied Biological Chemistr 2007 Journal of Applied Biological Chemistry (J. Appl. Vol.50 No.3

Dried, unripe fruits of Cornus kousa Burg. were extracted with 80% aqueous MeOH and the concentrated extracts were partitioned between EtOAc and $H_2O$. From the EtOAc fraction, four flavonoids were isolated through repeated silica gel, ODS and Sephadex LH-20 column chromatographies followed by a preparative HPLC. Based on the spectroscopic data including NMR, MS and IR, the chemical structures of the compounds were determined as kaempferol (1), astragalin (2), hyperin (3) and isoquercitrin (4). These compounds were isolated for the first time from the fruits of this plant.

Carbon Monoxide가 토끼 음경해면체 평활근 이완에 미치는 효과

나군호,최영득,최형기,이무상 大韓泌尿器科學會 2001 Korean Journal of Urology Vol.42 No.1

소화기 ; 집단으로 발생한 박새( Veratrum patulum) 중독 23예

이세형 ( Se Hyung Lee ),김영돈 ( Young Don Kim ),하동천 ( Dong Cheon Ha ),한군희 ( Koon Hee Han ),정우진 ( Woo Jin Jeong ),강희동 ( Hui Dong Kang ),천갑진 ( Gab Jin Cheon ) 대한내과학회 2010 대한내과학회지 Vol.79 No.4

고산 지대에서 임의로 산나물을 채취하여 먹은 후 구역, 구토 등을 호소하며 저혈압 및 서맥을 보이는 경우 임상적으로 박새 중독을 의심하여야 하며, 진단 후에는 입원 상태에서 면밀한 생체 징후 감시와 적절한 보존적 치료를 시행한다면 빠른 시일 내에 회복될 수 있다. 저자들은 박새 잎을 섭취 후 집단으로 구토와 서맥, 저혈압 등의 중독 증상을 보인 23명의 환자들을 아트로핀 정맥 주사와 대증요법을 통해 치료한 예를 경험하였기에 보고하는 바이다. Veratrum patulum is a perennial plant with toxicity, which grows wild in the high mountain areas of Korea. Various types of steroidal alkaloids contained in Veratrum patulum are known to cause symptoms such as nausea, vomiting, bradycardia and hypotension. Twenty-three patients were admitted to our center with chief complaints of nausea and vomiting after ingesting leaves of Veratrum patulum. The mean age of the group was 44 years old and was comprised of 19 males and 4 females. Some patients showed hypotension and bradycardia with symptoms such as dizziness. Ten patients with severe bradycardia coupled with other symptoms received atropine administration. Nausea and vomiting were improved after the administration of anti-emetics. Blood pressure and the pulse rate were all normalized on the day after admission, and all of the patients were discharged without any symptoms. (Korean J Med 79:417-421, 2010)

Study on Electrical Properties of X-ray Sensor Based on CsI:Na-Selenium Film

Park Ji-Koon,Kang Sang-Sik,Lee Dong-Gil,Choi Jang-Yong,Kim Jae-Hyung,Nam Sang-Hee The Korean Institute of Electrical and Electronic 2003 Transactions on Electrical and Electronic Material Vol.4 No.3

In this paper, we have introduced the x-ray detector built with a CsI:Na scintillation layer deposited on amorphous selenium. To determine the thickness of the CsI:Na layer, we have estimated the transmission spectra and the absorption of continuous x-rays in diagnostic range by using computer simulation (MCNP 4C). A x-ray detector with 65 ${\mu}m$-CsI:Na/30 ${\mu}m$-Se layer has been fabricated by a thermal evaporation technique. SEM and PL measurements have been performed. The dark current and x-ray sensitivity of the fabricated detector has been compared with that of the conventional a-Se detector with 100 ${\mu}m$ thickness. Experimental results show that both detectors exhibit a similar dark current, which was of a low value below $400 pA/cm^2$ at 10 V/${\mu}m$. However, the CsI:Na-Se detector indicates high x-ray sensitivity, roughly 1.3 times that of a conventional a-Se detector. Furthermore, a CsI:Na-Se detector with an aluminium reflective layer shows a 1.8 times higher x-ray sensitivity than an a-Se detector. The hybrid type detector proposed in this work exhibits a low dark current and high x-ray sensitivity, and, in particular, excellent linearity to the x-ray exposure dose.

X-ray Sensitivity of Hybrid-type Sensor based on CaWO₄-Selenium for Digital X-ray Imager

Park, Ji-Koon,Park, Jang-Yong,Kang, Sang-Sik,Lee, Dong-Gil,Kim, Jae-Hyung,Nam, Sang-Hee The Korean Institute of Electrical and Electronic 2004 Transactions on Electrical and Electronic Material Vol.5 No.4

The development of digital x-ray detector has been extensively progressed for the application of various medical modalities. In this study, we introduce a new hybrid-type x-ray detector to improve problems of a conventional direct or indirect digital x-ray image technology, which composed of multi-layer structure using a CaWO$_4$ phosphor and amorphous selenium (a-Se) photoconductor. The leakage current of our detector was found to be ∼180 pA/cm$^2$ at 10 V/m, which was significantly reduced than that of a single a-Se detector. The x-ray sensitivity was measured as the value of 4230 pC/cm$^2$/mR at 10 V/m. We found that the parylene thin film between a CaWO$_4$ phosphor and an a-Se layer acts as an insulator to prevent charge injection from indium thin oxide (ITO) electrode into an a-Se layer under applied bias.

Binocular Visual Function in Patients with Normal Tension Glaucoma

Jung-Un Jang,Joo-Hyung Choi,Yoon-Jung Choy,Koon-Ja Lee 대한시과학회 2021 대한시과학회지 Vol.23 No.3

목적 : 본 연구는 정상 안압 녹내장(NTG) 환자에서 양안시 기능을 평가하고자 한다. 방법 : 대상자 총 64명 중 안과에 내원하여 전문의에게 정상 안압 녹내장 진단을 받은 환자 정상 안압 녹내장 41명과 정상안 26명을 대상으로 하였다. 시야검사, 안압검사, 망막신경섬유층 두께 측정을 시행하였으며, 양안 시 기능 평가를 위해 사위각, 폭주근점검사, 티티무스와 TNO 입체시 검사를 시행하였다. 검사결과는 SPSS 22.0을 이용하여 분석하였으며 양안시 스크리닝과 입체시 기능을 분석하기 위해 ROC 곡선을 이용하여 분석하였다. 결과 : 정상안압 녹내장군에서 망막신경섬유층 두께와 남아있는 시야가 감소하였다. 원근거리 폭주여력은 정상 안압 녹내장군에서 정상군보다 높게 나타났다. 티티무스 입체시는 정상안압 녹내장군에서 102.36±4.40"이며 정상군에서는 44.61±1.85"으로 나타났으며, TNO 입체시는 정상안압 녹내장군에서 231.97±30.96"이며 정상군에서는 89.42±12.02"으로 나타났다. ROC 곡선은 티티무스와 TNO 입체시 검사에서 각각 0.797과 0.807로 나타 났고, 민감도와 특이도는 티티무스 입체시 검사에서 각각 0.737, 0.731, TNO 입체시 검사에서는 각각 0.500, 0.115로 나타났다. 결론 : 티티무스 입체시검사는 정상 안압 녹내장 선별에 유용할 것으로 사료된다. Purpose : This study aims to describe the binocular visual function alterations in patients with normal tension glaucoma (NTG). Methods : Of the patients who went to the ophthalmologist and were diagnosed, a total of 67 subjects of which 41 were classified as NTG, 26 non-glaucoma patients (control group) were participated. Standard visual field test, intra ocular pressure (IOP) measurement and retinal nerve fiber layer (RNFL) obsevation were performed. Also examined with binocular tests consisting of the measurement of phoria angles, near point of convergence (NPC), stereo acuity according to Titmus and TNO stereo tests. All measurements among groups were statistically compared with the SPSS 22.0 and ROC curves were plotted to describe the screening ability of binocular and stereopsis values. Results : NTG subjects showed decreased RNFL and visual field index. In far and near vision, NTG subjects were worse compared to in the control group except for fusional reserve. In Titmus test, NTG subjects exhibited stereo acuity of 102.36±14.40" whereas control group exhibited 44.61±1.85". In TNO test showed 231.97±30.96" for the NTG and 89.42±12.02" for the control group. The area under ROC for Titmus and TNO stereo test were 0.797 and 0.807. The sensitivity, specificity of Titmus stereo test were 0.737 and 0.731, and those of TNO stereo test were 0.500 and 0.115. Conclusion : Titmus stereo acuity could be used as the gold standard for screening tools for NTG.

Image quality of adaptive iterative dose reduction 3D of coronary CT angiography of 640-slice CT: comparison with filtered back-projection.

Yoo, Roh-Eul,Park, Eun-Ah,Lee, Whal,Shim, Hackjoon,Kim, Yeo Koon,Chung, Jin Wook,Park, Jae Hyung Kluwer Academic Publishers 2013 The international journal of cardiovascular imagin Vol.29 No.3

<P>To assess the image quality of coronary CT angiography (CCTA) of 640-slice CT reconstructed by Adaptive Iterative Dose Reduction (AIDR) three-dimensional (3D) in comparison with the conventional filtered back-projection (FBP). CCTA images of 51 patients were scanned at the lowest tube voltage possible on condition that the built-in automatic exposure control system could suggest the optimal tube current. They were, then, reconstructed with FBP and AIDR 3D (standard). Objective measurements including CT density, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were performed. Subjective assessment was done by two radiologists, using a 5-point scale (0:nondiagnostic-4:excellent) based on the 15-coronary segment model which was grouped into three parts as the proximal, mid, and distal segmental classes. Radiation dose was also measured. AIDR images showed lower noise than FBP images (45.0 +/- A 9.4 vs. 73.4 +/- A 14.6 HU, p < 0.001) without any significant difference in CT density (665.5 +/- A 131.7 vs. 668 +/- A 136.3 HU, p = 0.8). Both SNR (15.0 +/- A 2.1 vs. 9.2 +/- A 1.7) and CNR (16.8 +/- A 2.3 vs. 10.4 +/- A 1.8) were significantly higher for AIDR than FBP (p < 0.001). Total subjective image quality score was also significantly improved in AIDR compared with FBP (3.1 +/- A 0.6 vs. 1.6 +/- A 0.4, p < 0.001), with better interpretability of the mid and distal segmental classes (100 vs. 95 % for the mid, p < 0.001; 100 vs. 90 % for the distal, p < 0.001). Mean effective radiation dose was 2.0 +/- A 1.0 mSv. The AIDR 3D reconstruction algorithm reduced image noise by 39 % compared with the FBP without affecting CT density, thus improving SNR and CNR for CCTA. Its advantages in interpretability were also confirmed by subjective evaluation by experts.</P>

Comparison Study of the Modulation Transfer Function of a Prototype a-Se based Flat Panel Detector with Conventional Speed Class 400 Film/screen System

Park, Jang-Yong,Park, Ji-Koon,Kang, Sang-Sik,Moon, Chi-Woong,Lee, Hyung-Won,Nam, Sang-Hee The Institute of Electronics and Information Engin 2003 電子工學會論文誌-SC (System and control) Vol.40 No.3

디지털 방사선 검출기의 성능을 측정하기 위해 변조전달할수(Modulation Transfer Function)을 측정하여 기존 방사선 영상 시스템인 필름/스크린과 비교하였다. 제작된 디지털 방사선 검출기는 TFT 패널위에 진공 증착법을 통해 비정질 셀레늄이 코팅되었다. 비교 측정물이 감도 400의 필름/스크린은 아날로그 방식의 방사선 검출기로서 현재 임상에서 이용되고 있는 필름이다. Square wave & slit 측정법을 통해 두 시스템의 변조전달함수를 측정하였다. 필름/스핀린의 반치폭(FWHM)은 357㎛(1.4 lp/mm at 50% spatial frequency)으로 측정되었으며, 디지털 방사선 검출 시스템은 200㎛(2.5 lp/mm at 50%)였다. 영상의 표현성능 평가의 결과 디지털 방사선 시스템은 필름 시스템보다 높은 것으로 나타났다. To evaluate the performance of the digital radiography(DR) system developed in our group, the modulation transfer function(MTF) was measured and compared with that of an analog X- ray detector, film/screen system. The DR system has an amorphous selenium(a-Se) layer vacuum-evaporated on a TFT flat panel detector. The speed class 400 film/screen (Fuji) system has been being used in the clinical field as analog X-ray detectors. Both the square wave and slit method were used to evaluate their MTF. The square method was applied to both film/screen and the DR system. The slit method, however, was applied to only DR system. The full-width half maximum resolution of film/screen was 357${\mu}{\textrm}{m}$(1.4 lp/mm at 50% spatial frequency), and the resolution of DR was limited to 200${\mu}{\textrm}{m}$(2.5 lp/mm at 30%). These results indicate the measured resolution limitations approximate to the pixel pitch, 139 ${\mu}{\textrm}{m}$ of TFT. The MTF of DR is higher than that of film/screen by the factor of 1.785. It is proved that our a-Se based DR system has potential usefulness in the clinical field.