마이크로파를 이용한 콘크리트 강도의 조기판정기법에 관한 실험적 연구 ( An Experimental Study on Early Evaluation Method of the Compressive Strength of Concrete by Microwave )

백민수,이종규,안형준,정상진 대한건축학회 2000 大韓建築學會論文集 : 構造系 Vol.16 No.10

플라이애시를 다량 사용한 콘크리트의 강도특성에 관한 연구

백민수,이영도,정상진,Paik, Min-Su,Lee, Young-Do,Jung, Sang-Jin 한국건축시공학회 2002 한국건축시공학회지 Vol.2 No.4

To study of binder and fine aggregate a lot of replacement fly-ash concrete, initial characteristics, standard environment of curing temperature $20^{\circ}C$, hot-weather environment, cold weather environment of curing temperature $5^{\circ}C$. Flash concrete tested slump, air contest, setting and Hardening concrete valuated setting period of form, day of age 3, 7, 28 compression strength in sealing curing. Underwater curing specimen compression strength of age 3. 7, 28day used strength change accordingly fly-ash concrete curing temperature. Purpose of study is consultation materials in field that variety of fly-ash replacement concrete mix proportion comparison and valuation. (1) Setting test result, fly-ash ratio of replacement higher delay totting time. Same volume of fly-ash ratio of replacement is lower fly-ash ratio of replacement fine aggregate delay setting time. Setting test in curing temperature $35^{\circ}C$ over twice fast setting in curing temperature $20^{\circ}C$ and all specimen setting delay in curing temperature $5^{\circ}C$. F40 specimen end of setting about 30 time. (2) Experiment result age 28day compression strength more fisher plan concrete then standard environment in curing temperature $20^{\circ}C$, cold weather environment in curing temperature $5^{\circ}C$, most strength F43 is hot-weather environment in curing temperature $35^{\circ}C$ replacement binder 25%, fine aggregate 15%. (3) Hot-weather environment replacement a mount of fly-ash is a same of plan concrete setting period of form. Age 28day compression strength replacement a mount of fly-ash more hot-weather concrete then plan concrete.

2유체 분사노즐을 이용한 분무 및 연소특성에 관한 실험적 연구

백민수,오상헌 대한기계학회 1995 대한기계학회논문집 Vol.19 No.2

An experimental investigation has been conducted to study the spray and combustion characteristics using the air-assisted twin fluid atomizer. Axial mean and fluctuating velocity components as well as drop-size distributions in non-reaction spray were measured with a nonintrusive phase doppler technique. Droplet number density distributions were also visualized using high speed CCD camera. Locations of spray and flame boundaries are obtained by direct photographic method. It is confirmed that at the fixed fuel flow rate, the increase of the atomizing air flow causes improvements on both spray and combustion characteristics under stable flame conditions. Internal group combustion modes where flame is located inside the spray boundary are observed to exist in the upstream region of higher droplet number density.

플라이애시를 대량 사용한 콘크리트의 수화열특성 및 강도특성에 관한 연구

백민수,이영도,정상진,Paik, Min-Su,Lee, Young-Do,Jung, Sang-Jin 한국건축시공학회 2003 한국건축시공학회지 Vol.3 No.3

This study is for the great quantity use of fly-ash. For the producing of high volume concrete from the use of fly-ash, the method of replacement between bonding agents and fine aggregate by fly-ash was used at the same time. It was used that the adiabatic temperature rise of concrete about the mass member which had been produced by the method that was mentioned before, and the hydration heat of the core test pieces in concrete was measured. Also the core test pieces which were replaced with fly-ash was studied by the compressive strength's comparison between standard care test pieces and core test pieces. In the case of mass test pieces, hydration heat and the time to reach the highest temperature were decreased by an increase in replaced fly-ash's amounts of concrete. In addition, among the test pieces having the same amounts of concrete, the test pieces having more replaced amounts of fly-ash's fine aggregate showed higher hydration heat and the increased time to reach the highest temperature. Compressive strength was also increased by hydration heat's decrease according to fly-ash replacement. Replacement of fly-ash was more effective in high temperature environment.

플라이애시를 다량 치환한 콘크리트의 초기특성에 관한 실험적 연구 ( The Experimental Study on the Early Properties of High Volume Fly-Ash Concrete )

백민수,정상진 대한건축학회 2002 大韓建築學會論文集 : 構造系 Vol.18 No.11

분문 연소장의 속도 분포 특성에 관한 실험적 연구

백민수,김동일,오상헌 대한기계학회 1993 대한기계학회 춘추학술대회 Vol.- No.-

한 눈의 비동맥염 앞허혈시신경병증으로 내원한 환자의 반대편 눈의 기능

백민수,서영승,경성은 대한안과학회 2019 대한안과학회지 Vol.60 No.9

Purpose: To investigate the function of the fellow eye in patients with unilateral nonarteritic anterior ischemic optic neuropathy (NAION). Methods: From 2009 to March 2018, 18 patients with NAION who underwent bilateral visual field examinations and follow-up visits at least two times were enrolled in this study. Initial visual acuity, final visual acuity, degree of visual field defects, the cup-disc (C/D) ratio of the fellow eye, and the presence or absence of cardiovascular disease was retrospectively analyzed using medical records. Results: The fellow eye mean best-corrected visual acuity was 0.03 ± 0.53 (logMAR) and the mean visual field defect was -4.68 ± 3.65 dB in 18 eyes of patients with unilateral NAION (p = 0.007 and p = 0.001, respectively). The C/D ratios were divided into two groups: > 0.3 and < 0.3. The visual field defect was improved significantly from -4.92 dB to -2.37 dB in the group with optic disc ratios < 0.3 (p = 0.013). When the changes in visual field defects were analyzed according to the presence or absence of cardiovascular disease, the visual field defects were improved from -5.65 dB to -4.49 dB in patients with cardiovascular disease, and improved from -3.69 dB to -1.46 dB in patients without cardiovascular disease (p = 0.025 and p = 0.021, respectively). Conclusions: In patients with unilateral NAION, reduced function in the fellow eye may appear temporarily, so a visual field examination should be performed in both eyes. The possibility of incipient NAION should be considered in patients with visual field abnormalities in the fellow eye. 목적: 한 눈의 비동맥염 앞허혈시신경병증으로 내원한 환자에서 반대편 눈의 기능을 알아보고자 하였다. 대상과 방법: 2009년부터 2018년 3월까지 본원에서 한 눈의 비동맥염 앞허혈시신경병증으로 내원한 환자 41명 중 두 눈의 시야검사가최소 2번 이상 추적 관찰된 환자 18명을 대상으로 심혈관계 기저질환 유무, 반대편 눈의 시력, 시야결손 정도 및 형태, 시신경유두함몰비 등을 의무기록을 통해 후향적으로 분석하였다. 결과: 한 눈 비동맥염 앞허혈시신경병증환자 18명의 반대편 눈의 평균 최대교정시력(logMAR)은 0.03 ± 0.53이었고, 시야결손은 평균-4.68 ± 3.65 dB이었으며, 통계적으로 유의하였다(p=0.007, p=0.001). 시신경유두비가 0.3 초과인 군과 0.3 이하인 군으로 분류하여마지막 추적 관찰 때까지의 시야결손 변화 양상을 분석하였을 때, 시신경유두비가 0.3 이하인 군에서 시야결손은 -4.92 dB에서-2.37 dB로 호전되었으며 이는 통계적으로 유의하였다(p=0.013). 심혈관계 기저질환의 유무에 따라 시야결손의 변화 양상을 분석하였을 때, 심혈관계 기저질환이 있는 군에서 시야결손은 -5.65 dB에서 -4.49 dB로, 심혈관계 기저질환이 없는 군에서도 시야결손은-3.69 dB에서 -1.46 dB로 통계적으로 유의하게 호전되었다(p=0.025, p=0.021). 결론: 한 눈의 비동맥염 허혈시신경병증으로 내원한 환자에서 반대편 눈에 기능 이상이 일시적으로 나타날 수 있다. 한 눈의 비동맥염허혈시신경병증으로 내원한 환자에서 두 눈의 시야검사가 필요하며 반대편 눈에 증상 없는 시야이상 소견을 보이는 경우 초기 비동맥염 허혈시신경병증의 가능성도 고려하여야 할 것으로 생각된다.

인공수정체공막고정술 이후 발생한 인공수정체 동공끼임환자에서 레이저홍채절개술의 치료 2예

백민수,박율리,조경진 대한안과학회 2019 대한안과학회지 Vol.60 No.4

Purpose: We report two cases of intraocular lens (IOL) pupillary optic capture following IOL scleral fixation treated with argon laser iridotomy. Case summary: (Case 1) A 69-year-old man presented with suddenly decreased visual acuity of the left eye. The best-corrected visual acuity was finger count (FC) 30 cm in the left eye. Slit lamp examination revealed subluxation of the left eye IOL. An IOL scleral fixation and anterior vitrectomy were performed and no specific findings were observed. During the follow-up period, pupillary optic capture was repeated without specific causes, such as trauma, or IOL decentration thus, argon laser iridotomy was performed. (Case 2) A 77-year-old man presented with a 3-day history of congestion of the left eye and decreased visual acuity. Best-corrected visual acuity was 0.4 logarithm of the minimum angle of resolution (logMAR) in the left eye. Slit lamp examination revealed subluxation of the left eye IOL. An IOL scleral fixation and anterior vitrectomy were performed, and no specific findings were observed. During the follow-up period, pupillary optic capture was found, and IOL repositioning and argon laser iridotomy were performed. Conclusions: Laser iridotomy can be used to prevent recurrence of pupillary optic capture in eyes with IOL scleral fixation without decentration or distortion. 목적: 인공수정체공막고정술 이후 발생한 인공수정체 동공끼임환자에서 아르곤레이저홍채절개술을 통해 치료한 증례 2예를 보고하고자 한다. 증례요약: (증례 1) 69세 남자 환자가 갑작스러운 좌안 시력저하로 내원하였다. 최대교정시력 좌안 안전수지 30 cm였고, 세극등현미경검사상 좌안 인공수정체 불완전 이탈이 확인되었다. 인공수정체공막고정술 및 앞유리체절제술을 시행하였으며 이후 경과 관찰 도중 외상 등 특별한 원인 없이 인공수정체 동공끼임이 2회 반복되었고, 인공수정체 재위치 및 레이저홍채절개술을 시행하였다. (증례 2) 77세 남자 환자가 3-4일 전부터 발생한 좌안 충혈을 주소로 내원하였다. 최대교정시력은 좌안 0.4 logMAR였고, 세극등현미경검사상 좌안 인공수정체 불완전 이탈이 확인되었다. 좌안 인공수정체공막고정술 및 앞유리체절제술을 시행하였으며, 이후 경과 관찰 도중 발생한 인공수정체 동공끼임이 발견되어 인공수정체 재위치 및 레이저홍채절개술을 시행하였다. 결론: 인공수정체공막고정술 이후 중심이탈 또는 뒤틀림 등의 소견이 없던 눈에서 동공끼임이 발생하였을 경우에 레이저홍채절개술시행이 재발을 억제할 수 있는 치료 방법으로 고려될 수 있겠다.

철근부식에 의한 콘크리트의 귀열 발생거동

백민수,김연경,이영도,임남기,최응규,정란,정상진 대한건축학회 1997 大韓建築學會論文集 Vol.13 No.10

플라이애쉬 혼입에 따른 콘크리트의 강도성상에 관한 기초적 연구

백민수,박일용,이영도,손종규,최수,정상진 대한건축학회 1998 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.18 No.2