새로운 기술에 의한 고기능성 단결정 재료의 성장

윤대호,서창제,길택정인 (吉澤正人) ( Dae Ho Yoon,Chang Che Shur,Masahito Yoshizawa ) 대한금속재료학회 1996 대한금속재료학회 학술대회 개요집 Vol.1996 No.1

반도체 Wafer Back Grinding 공정에서 배출되는 Silicon Recycling 기술 개발

윤대호(Yoon, Dae-Ho) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.11

종합병원 외래환자의 진료서비스 만족 및 재이용에 관한 연구

윤대호(Dae-Ho Yoon) 한국보건복지학회 2012 보건과 복지 Vol.14 No.-

The purpose of this study was to analyze the major factors influencing satisfaction with ambulatory care in a general hospital. The study also aimed to provide basic data to help hospitals offer better medical service to patients, determine directionality to improve their management environments, and take competitive advantage over rival hospitals by presenting problems and improvement measures. The subjects of the study were outpatients using a general hospital in Jeonbuk Province. The research findings were summarized as follows: First, differences in satisfaction with ambulatory care were analyzed according to the general and hospital characteristics. As a result, there were statistically significant differences in satisfaction with ambulatory care according to such general characteristics as age, number of visits, and health state. There were no statistically significant differences in ambulatory care according to the hospital characteristics. Second, differences in reuse were analyzed according to the general and hospital characteristics. The analysis results show that there were statistically significant differences in reuse according to such general characteristics as number of visits and such hospital characteristics as hospital location, number of bed, and number of medical departments. Third, doctor"s care service, hospital environment, and others had statistically significant positive (+) impacts on satisfaction with ambulatory care, intention for reuse. It is required to provide doctors with an opportunity for ongoing education and training to improve outpatients" satisfaction with care, intention for recommendation, and reuse based on those research findings. It is also needed to monitor the state of internal cleanness constantly and deploy guidance helpers and signposts. Finally, there should be efforts to find ways to reduce waiting time by simplifying the reception procedure and install an institution device such as professional counselors to provide patients with clear explanations about the causes and results of examination.

Flow-3D 모형을 이용한 인공어초 설치 지반의 입경에 따른 세굴 특성 분석

윤대호(Yun, Dae-Ho),김정태(Kim, Jeong-Tae),윤한삼(Yoon, Han-Sam),나원배(Na, Won-Bae),김윤태(Kim, Yun-Tae) 한국방재학회 2022 한국방재학회논문집 Vol.22 No.1

해저 지반에 설치되는 인공어초는 유속 및 수심이 동일한 경우라도 지반 조건에 따라 세굴 패턴이 크게 차이나는 경우가 있다. 따라서 본 연구에서는 모래, 실트 및 점토 등과 같이 다양한 해저 지반에 설치하는 인공어초의 지반공학적 안정성을 평가하고자 Flow-3D를 이용하여 세굴 해석을 수행하였다. 수치해석 결과 지반 입경이 작을수록 인공어초 주변에서 발생하는 세굴량이 커지며, 평형상태에 도달하는 시간이 더 오래 걸리는 결과를 보였다. 반면 입경이 커질수록 세굴량이 작아지며, 세굴된 지반 입자가 인공어초 후면부에 퇴적되는 결과를 보였다. 또한 최대 세굴심도와 입경은 비선형적인 관계를 나타내었다. 특히 세립토에서 최대 세굴심도가 크게 증가하였다. Artificial reef-installed seabeds may have significantly different scouring patterns depending on the ground conditions, such as the soil particle size, even though the flow velocity and water depth are similar. In this study, the scour characteristics of the ground were determined using Flow-3D to evaluate the geotechnical stability of artificial reefs installed on various seabeds, such as sand, silt, and clay. The analysis results indicated that the smaller the particle size of the soil, the larger the amount of scour that occurs around the artificial reef and the longer it takes to reach an equilibrium state. However, eroded soil particles were deposited on the rear part of the artificial reef as the soil particle size increased. The maximum scour depth and average particle size showed a non-linear relationship. In particular, the maximum scour depth increased significantly in fine-grained soils.

전사 인쇄에 의한 3D와 다층의 Pt 전극의 CO가스 흡착

정윤서 ( Yoon-seo Jeong ),최유정 ( You-jeong Choi ),신정희 ( Jeong-hee Shin ),정영훈 ( Young-hun Jeong ),박종후 ( Jong-hoo Paik ),윤대호 ( Dae-ho Yoon ),조정호 ( Jeong-ho Cho ) 한국센서학회 2020 센서학회지 Vol.29 No.4

Three-dimensional (3D) multilayered Pt electrodes were fabricated to develop a porous electrode using a pattern-transfer printing process. The Pt thin films were deposited using a transferred sputtering pattern having a 250 nm line width on the substrate, and the uniform line patterns were efficiently transferred using our proposed method. Temperature-programmed desorption (TPD) analyses were used to evaluate the porosity of the electrodes. It was possible to distinguish between two resolved maxima at 168 and 227 ℃, which could be described in terms of desorption reactions on the Pt (111) planes. The results of the TPD analysis of the 3D and multilayered Pt electrodes prepared through transfer printing were compared to those of an electrode fabricated through screen printing using a commercial Pt-carbon paste commonly used as porous electrodes. It was confirmed that the 3D multilayered electrodes exhibited a desorption concentration approximately 100 times higher than that of the Pt-carbon composite electrode, and the desorption concentration increased by approximately 0.02 mg/mol per layer. The 3D multilayered electrode effectively functions as a porous electrode and a catalyst.

PECVD 법에 의해 제작된 저굴절률 차이 평판 SiON광도파로

김용탁,윤석규,윤대호,Kim, Yong-Tak,Yoon, Seok-Gyu,Yoon, Dae-Ho 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.3

Silicon oxynitride (SiON) 막은 플라즈마 화학기상증착법(PECVD)으로 $SiH_4,\;N_2O$와 $N_2$ 가스를 사용하여 $SiO_2/Si$ 위해 증착되었다. 증착 변수에 따라서 SiON 막의 굴절률은 prism coupler를 사용하여 1552nm 파장에서 $1.4480\~1.4958$까지 변화하였다. 평판 광도파로 코어로 사용되는 SiON 막의 두께는 $6{\mu}m$이고, buffer 막과의 굴절률 차이(An)는 $0.36\%$이다. 또한 식각 공정으로 $SiO_2$ 막 위에 증착된 SiON 막은 건식식각을 통해서 수행되었다. 광화이버에 $1.55{\mu}m$ 파장의 레이저론 입력단에 조사하였다. 결과적으로 저굴절률 차이 SiON 광도파로를 제작하였으며, 출력단에서 single-mode 형상을 확인하였다. Silicon oxynitride (SiON) layers deposited upon a $SiO_2/Si$ buffer layer placed upon silicon wafers have been obtained by using PECVD from $SiH_4,\;N_2O$, and $N_2$. It can be seen that the refractive index, measured by using a prism coupler, for the SiON films can be varied between 1.4480 and 1.4958 at a wavelength of 1552 nm by changing the process parameters. Optical planar waveguides with a thickness of $6{\mu}m$ and a refractive index contrast ($\Delta$n) of $0.36\% have been deposited. Also, etching experiments were performed using ICP dry etching equipment on thick SiON films grown onto Si substrates covered by a thick $SiO_2$ buffer layer. A polarization maintaining single-mode fiber was used for the input and a microscope objective for the output at $1.55{\mu}m$. As a result, a low index contrast SiON based waveguide is fabricated with easily adjustable refractive index of core layer. It illustrates that the output intensity mode is a waveguiding single-mode.

용매열합성법을 통한 단분산된 ZnGa₂O₄ 구형 입자의 제조 및 특성

우무현,강봉균,윤대호,Woo, Moo Hyun,Kang, Bong Kyun,Yoon, Dae Ho 한국결정성장학회 2016 한국결정성장학회지 Vol.26 No.3

용매열합성법과 하소 과정으로 이루어진 두 단계 공정을 통해 단분산된 마이크로 크기의 구형 $ZnGa_2O_4$ 입자를 합성하였다. 합성된 3차원 구조의 구형 $ZnGa_2O_4$ 입자는 핵 생성과정에서 발생된 $ZnGa_2O_4$ 핵들이 자기 조립에 의해 형성된다. 이렇게 3차원 구조의 입자를 형성하는 원리인 '핵 성성'과 '자기 조립' 과정은 계면활성제인 PEG(polyethylene glycol)의 영향을 받는다. 그 이유는 계면활성제인 PEG의 농도가 임계응집농도(critical aggregation concentration)를 결정짓기 때문이다. 그리고 $ZnGa_2O_4$ 단상 합성을 위해 원료인 zinc acetate의 양을 조절했으며, 최적의 하소 조건을 결정하고자 TG-DTA를 통해 열적 거동을 확인했다. 또한 열처리 전 모체와 $900^{\circ}C$에서 1시간의 열처리 과정을 거친 산화물을 구성하는 작용기의 변화를 규명하기 위해 FT-IR을 측정하였다. Monodispersed $ZnGa_2O_4$ microspheres were synthesized by a facile two-step process consisting of a solvothermal method and calcination process. The prepared monodispersed $ZnGa_2O_4$ microspheres were aggregated into 3D microstructures by self-assembly with a large number of small $ZnGa_2O_4$ particles generated in nucleation. This nucleation and self-assembly making hierarchical microstructures were depended on the concentration of PEG (polyethylene glycol) due to CAC (critical aggregation concentration) theory. And also we controlled the amount of zinc acetate to make pure $ZnGa_2O_4$ phase. Additionally, to fix the optimized calcination condition, sample was characterized by TG-DTA to prove the thermal property in the calcination process and by FT-IR to identify the changes of functional group bonding between each element of the $ZnGa_2O_4$ precursor and oxide calcined at $900^{\circ}C$ for 1 h.

비부식성 플럭스를 이용한 알루미늄 브레이징용 필러 소재의 저온 성형용 금속 복합 분말 개발

김대영,장하늘,윤대호,신윤호,김성호,최현주,Kim, Dae-Young,Jang, Ha-Neul,Yoon, Dae-Ho,Shin, Yun-Ho,Kim, Seong-Ho,Choi, Hyun-Joo 한국분말재료학회 (*구 분말야금학회) 2019 한국분말재료학회지 (KPMI) Vol.26 No.1

In aluminum brazing processes, corrosive flux, which is used in preventing oxidation, is currently raising environmental concerns because it generates many pollutants such as dioxin. The brazing process involving non-corrosive flux is known to encounter difficulties because the melting temperature of the flux is similar to that of the base material. In this study, a new brazing filler material is developed based on aluminum and non-corrosive flux composite powder. To minimize the interference of consolidation aluminum alloy powder by the flux, the flux is intentionally embedded in the aluminum alloy powder using a mechanical milling process. This study demonstrates that the morphology of the composite powder can be varied according to the mixing process, and this significantly affects the relative density and mechanical properties of the final filler samples.

RF-LPP법을 이용한 고순도 마이크로 Ag 입자 합성

임병석,송영현,이민지,맹성렬,윤대호,Lim, Byeong-Seok,Song, Young-Hyun,Lee, Min-Ji,Mang, Sung-Ryul,Yoon, Dae-Ho 한국결정성장학회 2015 韓國結晶成長學會誌 Vol.25 No.3

To synthesis of high purity micro silver particle, we extracted the silver from the waste by liquid-liquid extraction and used the rapid firing-liquid phase precursor (RF-LPP) method. The silver micro particle was synthesized at $500^{\circ}C$ for 3 hr in air atmosphere by RF-LPP method. As a result of the research, micro silver particle is measured X-ray diffraction (XRD), the main peak is nearly corresponded to the same as JCPDS card (No.87-0719). With using the RF-LPP method, the fine Ag micro particle indicated due to the control of nucleation site and the oxygen contents was decreased by reducing treatment. We expect this research contribute to advance in field of the recycling technology. 본 연구에서는 고순도 균질 마이크로 Ag 입자를 얻기 위하여 용매추출법과 RF-LPP법을 이용하여 Air 분위기에서 $500^{\circ}C$에서 3시간 동안 열처리하여 Ag 입자를 합성하였다. 합성된 마이크로 Ag 입자를 XRD에 의해 비교 분석한 결과 주요 peak들이 JCPDS card(No. 87-0719)와 일치하는 것을 확인하였다. RF-LPP법을 이용함으로써, 핵 생성 싸이트 제어를 통해 균질 마이크로 Ag 입자를 합성하였으며, 환원처리 후 산소의 함유가 줄어드는 것을 확인하였다. 본 연구를 통하여 재활용 기술에 큰 기여를 할 것이라 기대한다.

나노 텅스텐 카바이드 재료 내 입성장 억제제와 코발트의 영향

임형섭,허만규,김득중,윤대호,Lim, Hyung Sup,Hur, Man Gyu,Kim, Deug Joong,Yoon, Dae Ho 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.5

Influences of Co and inhibitors from nano-sized WC materials were observed in the sintering process. VC and $Cr_3C_2$ were used as inhibitors. The crystal structure and surface images of sintered nano-sized WC materials, as functions of Co and inhibitors, were evaluated by XRD and FE-SEM analyses. The relative densities of sintered nano-sized WC materials did not change even with increased quantity of Co and increased temperature. The density of sintered nano-sized WC materials with inhibitors was lower than that of sintered nano-sized WC materials without inhibitors. No difference in hardness due to change of inhibitors was found.