반복하중의 응력비 및 주기가 무근 콘크리트의 피로거동에 미치는 영향

변근주,박병희,이호범 연세대학교 산업기술연구소 1985 논문집 Vol.17 No.1

The paper is concerned with the fatigue characteristics of plain concrete. The primary objective is to evaluate the effect of load variations on the fatigue life. To obtain necessary data, 15 ×30 plain concrete cylinders are subjected to loads of constant amplitude, until failure occur. Based on the results of fatigue strength, empirical expressions between the stress level(f), number of cycles(N), frequency of cyclic loading(?) and stress ratio(R) (f-N-?-R relationships) are derived. Then, the modified Goodman Diagram is derived and the effect of the size of coarse aggregates on fatigue strength is examined and discussed.

위장관 출혈을 일으킨 공장의 형활근종 1예

김병수,장성종,부귀범,조운택,박찬국,김만우,변주남,김정용,전호종 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.1

Small bowel leiomyoma is a rare tumor which may occur wherever smooth muscle is present. The small bowel is the most common site and it makes up 20~30% of all benign small intestinal neoplasms. A spectrum of symptoms are common ranging from nausea, vomiting, abdominal pain, to massive intestinal bleeding. Bleeding is the most common symptom and is usually gross and recurrent. Occasionally it may be life threatening. But, the most serious problem is both the absence of specific clinical symptoms, and the difficulties shown in radiological diagnostics of the small bowel. If conventional diagnostic methods fail to reveal any positive findings for gastrointestinal bleeding, the diagnosis of intestinal leiomyoma should be suspected and an SMA angiography shoud be performed. The angiographic criteria of small bowel leiomyoma is very characteristic. We present a case of leiomyoma with considerable and prolonged gastrointestinal bleeding, which was diagnosed by angiography. A 61-year old woman was admitted with a history of melena over the last 10 days. An SMA angiography showed a hypervascular mass with a diameter of 3×3cm. A segmental resection was performed under the impression of the gastrointestinal bleeding due to leiomyoma of the small bowel. Microscopic examination of the lesion shows interlacing or whorl bundles of spindle shaped ces and no mitosis.

자기정렬공정에 의한 GaAs/ AlGaAs 광위상변조기의 제작 및 특성 측정

김병성,정영철,변영태,박경현,김선호,임동건 광운대학교 신기술연구소 1996 신기술연구소논문집 Vol.25 No.-

MOCVD(metal-organic chemical vapour deposition) 방법으로 성장시킨 이중 이종접합구조GaAs / AlGaAs 웨이퍼를 이용하여 광위상변조기를 제작하였다. 제작과정에서 도파로와 절연층의 형성시 동일 포토레지스트 패턴을 이용하는 자기정렬공정을 개발하여 그 효용성을 입증하였다. Fabry-Perot 간섭법을 이용하여 변조기의 위상변조효율을 측정하였으며, 1.31㎛ 파장에서 TE 편광의 경우 22.5˚/Vmm의 위상변조특성을 얻었다. An optical phase modulator is fabricated in GaAs / AlGaAs double heterostructure wafer grown by MOCVD. A self-aligned process, in which the same photoresist pattern is used for both the waveguide etching and the insulation layer formation, is developed and is found to be very useful. Fabry-Perot interference technique is applied to the measurement and the phase modulation efficiency is measured to be 22.5˚/Vmm at 1.31㎛ for TE polarization.

울진원자력발전소 주변 소나무림의 종조성과 군락 특성

방제용,전영문,변두원,류병혁,이호준 建國大學校基礎科學硏究所 1995 理學論集 Vol.20 No.-

울진원자력발전소 주변 소나무림의 종조성과 군락특성을 1994년 3월부터 95년 2월까지 조사한 결과는 다음과 같다. 소나무군락은 상수리나무하위군락과 산철쭉하위군락으로 분류되었으며, 전조사방형구 내에서 출현한 종수는 총 116종으로 상수리나무하위군락과 산철쭉하위군락에서 방형구당 출현종수는 각각 28종, 23종으로 나타났다. 소나무군락의 계층별 평균 수고와 식피율은 상수리나무하위군락에서 교목층이 각각 13.5m와 78.8%, 아교목층이 6m와 37.5%, 관목층이 1.9m와 53.6%, 초본층이 0.4m와 64.4%, 산철쭉하위군락에서는 교목층이 13m와 83.8%, 아교목층이 5.5m와 52.5%, 관목층이 1.9m와 57.5%, 초본층이 0.6m와 69.4%로 나타났다. 피복지수에 의한 계층별 우점순위는 교목층과 아교목층에서 각각 소나무가 8437.5, 1111.3으로 나타났고 관목층에서 진달래(2638.5), 초본층에서 큰기름새(1048.2)가 가장 높게 나타났다. 소나무의 DBH별 분포를 보면 11-15cm급이 상수리나무하위군락과 산철쭉하위군락에서 각각 29.1%(4.2 individuals/a), 26.7%(4.5 individual/a)로 가장 높게 나타났다. 현존식생도에 따른 각 식생형의 분포면적은 소나무림이 133.1k㎡(80.5%), 경작지와 주거지 28.7k㎡(16.2%), 곰솔림 1.8k㎡(1.1%) 순으로 나타났다. 녹지자연도의 등급별 분포는 7등급(이차림)이 70.4%, 2등급(경작지와 주거지) 17.4%, 8등급(이차림) 11.6%, 4등급(벌목지) 0.2%, 6등급(인공조림지) 0.1% 순으로 나타났다. Montreal model에 의한 소나무림의 식물현존량은 3,077,327.8ton으로 산정되었다. The floristic composition and community characteristics of Pinus densiflora forest in vicinity of Ulchin Atomic Power Plant were surveyed from March, 1994 through February, 1995. The results obtained are summarized as follows: The Pinus densiflora community was classified into the subcommunity of Quercus acutissima and Rhododendron yedoence var. poukhanense. The total number of species appearing in the entire surveyed quadrats was 116 sepcies, then 28 and 23 species per quadrat in Quercus acutissima subcommunity and Rhododendron yedoence var. poukhanense subcommunity, respectively. Tree height and vegetation cover by the layer of the Pinus densiflora community were 5m and 78.8% in tree layer, in subtree layer(6m, 37.5%), in shrub layer(1.9m, 53.8%) and in herb layer(0.4m, 64.4%) in Quercus acutissima subcommunity, and in tree layer(13m, 83.8%), in subtree layer(5.5m, 52.5%), in shrub layer(1.9m, 57.5%) and in herb layer(0.6m, 69.4%) in Rhododendron yedoence var. poukhanense subcommunity. The dominance sequences on each stratum determined by the coverage index showed that Pinus densiflora was most dominant in tree layer with 8437.5 and in subtree layer with 1111.3, Rhododendron yedoence var. poukhanense in shrub layer with 2638.5, and Spodiopogon sibiricus in herb layer with 1048.2 value. The highest value of diameter breast height(DBH) distritued in the range of 11~15cm in Quercus acutissima subcommunity(29.1%, 4.2 individuals/a) and Rhododendron yedoence var. poukhanense subcommunity(26.7%, 4.5 individuals/a), respectively. The distribution area of each vegetation type in the actual vegetation map was 80.5% in Pinus densiflora forest, 16.2% in cultivated land and residential section, and 1.1% in Pinus thunbergii forest. The distribution of the degree of green naturality(DGN) was 70.4% in the 7th grade(second forest), 17.4% in the 2nd grade(cultivated land and residential section), 11.6% in the 7th grade(second forest), 0.2% in the 4th grade(cutted area), and 0.1% in the 6th grade(afforestation). It was estimated that phytomass of Pinus densiflora in the study sites, which was calculated by Montreal model, was 3,077,327.8ton.

Head-to-head comparison of ¹¹ C-PiB and ¹⁸ F-FC119S for Aβ imaging in healthy subjects, mild cognitive impairment patients, and Alzheimer's disease patients

Byun, Byung Hyun,Kim, Byung Il,Park, Su Yeon,Ko, In Ok,Lee, Kyo Chul,Kim, Kyeong Min,Kim, Yu Kyeong,Lee, Jun-Young,Bu, Seon Hee,Kim, Jung Hwa,Chi, Dae Yoon,Ha, Jeong Ho,Lim, Sang Moo Williams & Wilkins Co 2017 Medicine Vol.96 No.12

<P><B>Abstract</B></P><P>As a new beta amyloid (Aβ) positron emission tomography (PET) tracer, <SUP>18</SUP>F-FC119S has shown higher cortical uptake in patients with Alzheimer's disease (AD) than that in healthy control subjects without adverse effects in a previous preliminary study. The aim of this study was to compare <SUP>18</SUP>F-FC119S PET and <SUP>11</SUP>C-PiB PET in healthy control (HC) subjects, mild cognitive impairment (MCI) patients, and AD patients.</P><P>A total of 48 subjects, including 28 HC subjects, 10 MCI patients, and 10 AD patients, underwent static <SUP>18</SUP>F-FC119S PET (30 minutes after intravenous [i.v.] injection) and <SUP>11</SUP>C-PiB PET (40 minutes after i.v. injection) on the same day. Both PET images were visually and quantitatively assessed. Standardized uptake value ratios (SUVRs) were calculated for each brain region using the cerebellar cortex as a reference region.</P><P>None (0%) of the 28 HC subjects and 4 (40%) of 10 MCI patients had positive scans on both PET images. Of the 10 AD patients, 7 (70%) had positive scans on <SUP>11</SUP>C-PiB PET while 6 (60%) had positive scans on <SUP>18</SUP>F-FC119S PET. Overall, 47 (98%) of 48 participants showed identical results based on visual analysis. Cortical SUVR of <SUP>18</SUP>F-FC119S was higher in AD patients (1.38 ± 0.16), followed by that in MCI patients (1.24 ± 0.10) and in HC subjects (1.14 ± 0.05). Compared with <SUP>11</SUP>C-PiB PET, <SUP>18</SUP>F-FC119S PET yielded a higher effect size (<I>d</I> = 2.02 vs. 1.67) in AD patients and a slightly lower effect size (<I>d</I> = 1.26 vs. 1.38) in MCI patients. In HC subjects, the nonspecific binding of <SUP>18</SUP>F-FC119S to white matter (with the frontal cortex-to-white matter SUV ratio of 0.76) was slightly lower than that of <SUP>11</SUP>C-PiB (ratio of 0.73). There was a significant linear correlation (slope = 0.41, <I>r</I> = 0.78, <I>P</I> < 0.001) between <SUP>11</SUP>C-PiB and <SUP>18</SUP>F-FC119S cortical SUVR.</P><P>We could safely obtain images similar to <SUP>11</SUP>C-PiB PET imaging Aβ in the brain using <SUP>18</SUP>F-FC119S PET. Therefore, <SUP>18</SUP>F-FC119S might be suitable for imaging Aβ deposition.</P>

버즘나무방페벌레의 약제방제에 관한 연구

변병호,김철수,박일권,박지두,채정석 한국임학회 2000 한국산림과학회지 Vol.89 No.3

For the control of Corythucha ciliata, the insecticidal activity of five commercial pesticides (Monocrotophos 25%SL, Phosphamidon 50%SL, Imidacloprid 20%DC, Thiamethoxam 15%DC and Acetamiprid 20%SL) were examined with trunk injection method in Seoul, Sanbon and Chungju. The insecticidal activity of five commercial pesticides was $gt;88%. The insecticidal activity of Monocrotophos maintained 31 days later after trunk injection when treated leaves were supplied to this pest. This result indicates that one application of trunk injection is enough to control this pest, and this method can save the control cost compared with ground application which should be applied two or three times per year to control this pest. To make the model of treatment dosage at each D.B.H class (㎝), 1.0㎖/DBH, 1.5㎖/DBH and 2.0㎖/DBH pesticide dosage was used. At $lt;20㎝, the insecticidal activity of 1.0㎖ dosage was $gt;95%, and 1.5-2.5㎖ dosage was needed for the effective control at 30-50㎝. More than 2.5㎖ dosage was effective at $gt;50㎝. ray method was used in laboratory to select pesticides for ground application. Three commercial pesticides (Ethofenprox 20%EC, Ethofenprox 10%WP and Cyfluthrin 1%EC) were used, and all pesticides showed $gt;95% insecticidal activity.

뇌해면상혈관종

변양호,이선일,정용태,최병욱,김수천,심재홍 대한신경외과학회 1995 Journal of Korean neurosurgical society Vol.24 No.5

Intracranial cavernous hemangioma is one of vascular malformations composed of thin walled sinusoidal spaces lined with endothelium. The authors described 7 cases of cavermous hemangioma that were verified histologically and 5 lesions that were diagnosed onlywith symptoms. radiological and magnetic resonance imaging(MRI) findings. The clinical features are as follows : 7 patients had seizures. 3 focal neurological signs and 2 intracaranial hematomas. Computed tomography(CT) usually demonstrated nodular or irregular hyperdense lesions without significant mass effect MRI usually revealed central area of mixed signal intensiy and peripheral rim of low signal intensity. Angiography usually showed an avascular area or normal angiographic appearance. The combination of a clinical history with CT. angiography and MRI findings-would suggest cavernous hemangioma. Four epilepsy patients underwent surgical procedures. resulting in improved seizure control and/or lessened neurological deficit.

A NEW CURRENT CONTROL FOR 3-LEVEL INVERTER

Byung-Song Lee,Yun-Ok Cho,Hyun-June Park,Myung-yong Kim,Yeun-Sub Byun,Yun-Ho Kim,Jae-Hak Lee 전력전자학회 1998 ICPE(ISPE)논문집 Vol.- No.-

A new current controlled PWM technique for a 3-level inverter has been proposed and described in the paper. The proposed current control has the simple structure without needing to calculate the switching angles of the voltage vectors. The output in the proposed inverter contains less harmonic content than that of a conventional current controlled PWM controller, since the current control can be applied to the 3-level inverter. In addition, the proposed current controlled PWM technique has lower switching frequency than that of a conventional current controlled PWM technique at the same current limit. The control method and the performance for a proposed 3-level inverter has been discussed and investigated by the computer simulation.<br/>

Analysis of polyamines as carbamoyl derivatives in urine and serum by liquid chromatography–tandem mass spectrometry

Byun, Jeong Ah,Lee, Sang Hee,Jung, Byung Hwa,Choi, Man Ho,Moon, Myeong Hee,Chung, Bong Chul John Wiley Sons, Ltd. 2008 Biomedical chromatography Vol.22 No.1

<P>A quantitative analysis of polyamines in urine and serum by liquid chromatography–tandem mass spectrometry (LC-MS/MS) is described. The polyamines were carbamylated with isobutyl chloroformate, extracted with diethyl ether under pH 9.0, and analyzed by LC-MS/MS with single reaction monitoring mode. The limit of quantification was 1 ng/mL based on a signal-to-noise ratio >3, and the correlation coefficient (r<SUP>2</SUP>) for the calibration curves was >0.99 for both urine and serum samples. The present method was applied to urine and serum samples from 30 breast cancer patients and 30 normal female controls. There was no significant difference in the urinary polyamine levels between breast cancer patients and controls. However, 1,3-diaminopropane, putrescine, spermine and N-acetylspermidine levels in serum increased in breast cancer patients. These four serum polyamines may be a good index to study both production and metabolism of polyamines, and a useful tool in assessment of the polyamine status of breast cancer patients. Copyright © 2007 John Wiley & Sons, Ltd.</P>

The Efficacy of Bisphosphonates for Prevention of Osteoporotic Fracture: An Update Meta-analysis

Byun, Ji-Hye,Jang, Sunmee,Lee, Sumin,Park, Suyeon,Yoon, Hyun Koo,Yoon, Byung-Ho,Ha, Yong-Chan The Korean Society for Bone and Mineral Research 2017 대한골대사학회지 Vol.24 No.1

<P><B>Background</B></P><P>The efficacy of bisphosphonates for osteoporotic fracture has been consistently reported in recent randomized controlled trials (RCTs) enrolling hundreds of patients. The objective of this study was to update knowledge on the efficacy of available bisphosphonates in the prevention of vertebral and non-vertebral fractures.</P><P><B>Methods</B></P><P>An approach “using systematic reviews” on PubMed and Cochrane Library was taken. Twenty-four RCTs investigating the effects of bisphosphonates for the prevention of osteoporotic fracture were included in final analysis. A pairwise meta-analysis was conducted with a random effects model. Subgroup analysis was performed according to the type of bisphosphonate.</P><P><B>Results</B></P><P>The use of bisphosphonate decrease the risk of overall osteoporotic fracture (odds ratio [OR] 0.62; <I>P</I><0.001), vertebral fracture (OR 0.55; <I>P</I><0.001) and non-vertebral fracture (OR 0.73; <I>P</I><0.001). Subgroup analysis indicated that zoledronic acid showed the lowest risk reduction (OR 0.61; <I>P</I><0.001) for overall osteoporotic fractures but no significance was observed for etidronate (OR 0.34; <I>P</I>=0.127).</P><P><B>Conclusions</B></P><P>This update meta-analysis re-confirmed that bisphosphonate use can effectively reduce the risk of osteoporotic fracture. However, there is a lack of evidence regarding etidronate for the prevention of osteoporotic fracture.</P>