수중펌프의 Leakage-free 자동탈착장치 개발

최영석,이경용,이창한,이종훈,Choi, Young-Seok,Lee, Kyoung-Yong,Lee, Chang-Han,Lee, Jong-Hun 한국유체기계학회 2003 한국유체기계학회 논문집 Vol.6 No.2

ADC (Automatic Discharge Connector) is commonly used for the easy maintenance of the submersible pumps. However, the small gap between the flange of the base plate and that of the pipe due to the head rise, the flow momentum change and the mis-installation make a leakage flow that may be a great loss to the pumping system. In this study, the performance degradation was predicted with the simple leakage flow model through the gap. The newly developed ADC was tested, and the leakage performance was compared with the old one and also no-leakage piping system. The newly developed ADC reduced the leakage flow in a satisfactory way in comparison with the old model.

유동안정화 장치가 홴 테스터의 성능에 미치는 영향

최영석,김덕수,윤준용,Choi Young-Seok,Kim Deok-Su,Yoon Joon-Yong 한국유체기계학회 2006 한국유체기계학회 논문집 Vol.9 No.4

In this study, the effect of flow settling means on the performance of fan tester were numerically investigated by using a computational fluid dynamics(CFD). The airflow rate was calculated from the pressure differential across a flow nozzle in the measuring plane and the flow settling means were generally installed in the chamber of the fan tester to provide proper airflow patterns ahead of the measuring plane. The predicted nozzle differential pressures with uniform inlet velocities were compared with the values of the ANSI/AMCA 210-99 to verify the performance of the commercial CFD code CFX 5.6. The influence of flow settling means on the measurement of airflow rate in a fan tester were discussed with various porosities and inlet jet velocities. The results obtained show that the proper band of porosities exist to meet the AMCA standard in a specified inlet jet velocity.

상용 CFD코드를 이용한 원심펌프 임펠러의 성능해석

최영석,이용갑,홍순삼,강신형,Choi, Young-Seok,Lee, Yong-Kab,Hong, Soon-Sam,Kang, Shin-Hyung 한국유체기계학회 2001 한국유체기계학회 논문집 Vol.4 No.1

A commercial CFD code is used to compute the 3-D viscous flow field within the impeller of a centrifugal pump. Several preliminary numerical calculations are carried out to determine the influence of the parameters such as the grid systems, the numerical schemes, the turbulence models and the shape of the vaneless diffusers at the design flow rate. The results of the preliminary study are used for the calculation of the off-design flow conditions. The circumferentially averaged results such as the radial and tangential velocities, the exit flow angle, the slip factor, the static pressure and the total pressure are compared with the experimental data at the impeller exit to discuss the influence of the prescribed parameters.

두영역모델을 사용한 원심펌프의 성능예측

최영석,심재혁,강신형,Choi, Young-Seok,Shim, Jae-Hyeok,Kang, Shin-Hyoung 한국유체기계학회 1999 한국유체기계학회 논문집 Vol.2 No.1

In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, a two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of a two zone model considers the primary zone that is an isentropic core flow and the secondary zone that has a non-isentropic region at the impeller exit. The flow goes through two different zones and is mixed out at the impeller exit and the mixing process occurs with an increase in entropy, a decrease in total pressure. The level of the core flow diffusion in an impeller was calculated using TEIS(two elements in series) model. The effects of various parameters which are used in this program on the prediction of head and efficiency are discussed. The correlation curves used to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.

사이드채널형 연료펌프의 성능예측

최영석,이경용,강신형,Choi, Young-Seok,Lee, Kyoung-Yong,Kang, Shin-Hyoung 한국유체기계학회 2003 한국유체기계학회 논문집 Vol.6 No.2

The periphery pump (or regenerative pump) has been generally applied in the automotive fuel pump due to their low specific speed (high heads and small flow rate) with stable performance curves. In this study, the performance prediction of side channel type periphery pumps has been developed. The prediction of the circulatory flow rate is based on the consideration of the centrifugal force field in the side-channel and in the impeller vane grooves. For the determination of performance curve (head-flow rate), momentum exchange theory is used. The effects of various geometric parameters and loss coefficients used in the performance prediction method on the head and efficiency are discussed, and the results were compared with experimental data.

소아 환자의 진정을 위한 chloral hydrate의 효과

최영석(Young Seok Choi),손영준(Young Joon Son),송은송(Eun Song Song),조영국(Eun Song Song),김영옥(Young Ok Kim),김찬종(Young Ok Kim, M),우영종(Young Jong Woo) 대한소아신경학회 2008 대한소아신경학회지 Vol.16 No.1

목 적 : 소아에게 검사나 시술을 하기 위해서는 진정이 필요하다. Chloral hydrate는 소아의 진정에 가장 많이 사용되는 약제이나 때로 그 진정효과가 나타나지 않는 경우를 볼 수 있다. Chloral hydrate의 진정 효과에 대한 보고는 많지 않아 이 에 chloral hydrate의 효과에 대하여 조사해 보고 소아에게 사용할 수 있는 효과적인 진정 방법을 찾아보고자 본 연구를 시행하였다. 방 법 : 2005년 1월부터 12월까지 전남대학교병원 소아과 입원 환아 중 chloral hydrate를 사용하였던 324명을 대상으로 하였다. 환아들의 나이, 성별, 체중, 진단명, 신경계 질환의 유무, 경련의 유무, 발달 지연의 유무, 시행한 검사, chloral hydrate의 용량, 초기 반응, 지연 반응 등을 조사하였다. 진정 효과는 투여 30분 후 Skeie scale 상 3점 미만인 경우 진정 실패로 간주하였다. 진정 효과가 없는 경우에는 midazolam, diazepam, ketamine 혹은 phenobarbital등을 단독 혹은 병용하여 추가로 사용하였고 이에 대한 반응을 조사하였다. 결 과 : 대상 환아의 연령은 평균 27개월(16일-14세 1개월) 이었다. 324명중 chloral hydrate에 의한 진정이 실패한 환아는 107명(33.0%) 이었다. 신경계 질환을 가지고 있는 환아 161명중 77명이 실패하여 47.8%에 해당되었다. 발달 지연, 경련, 발달 지연과 경련이 동시에 있는 경우의 진정 실패는 56.8%(25/44), 50.0%(58/116), 64.7%(22/34)이었다. Chloral hydrate에 반응하지 않아 midazolam 등의 추가 진정약물을 병용한 환아는 101명이었으며 그 중에서 14명(13.9%)이 진정에 실패하였다. 결 론 : 발달 지연, 경련 발작 등의 신경계 질환이 있는 환아에서는 chloral hydrate에 의한 진정이 힘들고 과도한 용량으로 인한 부작용을 보이기 쉬워 chloral hydrate 에 진정 작용을 보이지 않는 환아들에 있어서, 반복하여 동일 제제를 사용하기보다는 midazolam 등의 약제를 고려해 보아야 하며, 이들 약제에도 진정되지 않는 경우에는 다른 효과적인 방법이 연구되어야 할 것으로 사료된다. Propose : Sedation is often needed to perform an imaging study or procedure on a child. Although chloral hydrate is the most commonly used drug for pediatric sedation, little data are available for its efficacy or adverse effects. This study was undertaken to evaluate the efficacy of chloral hydrate for sedation and define any problems for using this agent in children. Methods : The medical records of 324 infants and children, who were admitted at Chonnam National University Hospital from January 2005 to December 2005 were retrospectively reviewed. Age, sex, body weight, underlying diagnosis, performed procedure, dose of chloral hydrate, initial response, delayed response and other additional agents for sedation were reviewed. If the desired level(3 on the Skeie scale) was not reached within 30 min after the administration of drugs, sedation was considered as potentially failed. Results : The average age of the study group was 27 months. Among 324 patients, 107 (33.0%) failed for chloral hydrate sedation. 77(47.8%) of the neurologically impaired 161 patients and 30(18.4%) of the unimpaired 163 patients failed on sedation with chloral hydrate. Among neurologically impaired cases, who had either developmental delay or seizures or both of them, 56.8%(25/44), 50.0%(58/116) and 64.7%(22/34) in each category respectively failed on sedation with chloral hydrate. Conculsion : In neurologically impaired patients, sedation by chloral hydrate was so difficult and prone to have adverse effects that it is recommended to supplement another drug than to administer the same drug again. However, further studies on effective methods of sedation are needed.

패턴언어를 활용한 특화거리의 물리적 환경 분석: 고양시 ‘라페스타 문화의 거리’를 대상으로

최영석(Young-Seok Choi),성보현(Bo Hyun Seong) 한국조리학회 2020 한국조리학회지 Vol.26 No.12

공간구문론을 활용한 월미관광특구의 관광호텔 배치특성 분석 -월미도권 관광호텔의 위상학적 접근성을 중심으로-

최영석 ( Choi Young-seok ),성보현 ( Seong Bo-hyun ) 한국사진지리학회 2018 한국사진지리학회지 Vol.28 No.1

본 연구는 공간구문론을 활용하여 월미관광특구의 관광호텔 배치특성을 분석하는데 목적을 두고 수행되었다. 연구목적 달성을 위해 공간구문론, 관광특구에 대한 문헌연구와 월미도권의 관광호텔에 대한 기본분석 및 위상학적 접근성 분석을 실시하였다. 기본분석 결과, 월미도권의 관광호텔은 바다와 근접한 월미문화거리 후면의 도로를 중심으로 분포되어 있었다. 또한, 공간구문분석을 통한 관광호텔의 전체통합도는 1.0이상으로 접근성이 양호한 것으로 분석되었으며, 위상학적 접근성이 가장 높은 도로축 주변으로 배치되어 있었다. 한편, 본 연구에서는 도심지·휴양지와 같은 관광공간의 성격에 따라 관광호텔의 전략적 배치가 필요하며, 월미도권 내 위상학적 중심성과 교차점 등을 고려한 관광안내시설의 재정비 필요성을 제시하였다. The purpose of this study is to analyze the layout characteristics of Wolmido area tourist hotels using space syntax. In order to accomplish the purpose of research, we conducted literature research on space syntax and tourism special zone. Next, we analyzed the basic analysis and topological accessibility of Wolmido area tourist hotels. As a result of the basic analysis, the tourist hotels of Wolmido area was arranged around the road on the back of Wolmi cultural street near the sea. Also, the global integration of tourist hotels through space syntax analysis is above 1.0, which means that accessibility is good. In addition, it is analyzed that the tourist hotels are arranged around the road with the highest topological accessibility. On the other hand, this study suggests the strategic arrangement of tourism hotels according to the characteristics of tourist area like downtown and resort area. Also, the necessity of rearrangement of tourist information facilities considering the topological center point and crossing point in Wolmido area was suggested.

제주 올레길 이용밀집에 대한 방문자 인식 분석

최영석 ( Choi Young-seok ),성보현 ( Seong Bo-hyun ),유기준 ( Ki Joon Yoo ) 한국사진지리학회 2017 한국사진지리학회지 Vol.27 No.3

본 연구는 제주 올레길의 환경적 특성이 다른 구간별 방문자들의 이용 밀집수준에 대한 인식의 파악을 목적으로 수행되었다. 이를 위해 제주 올레길의 생태적·물리적·사회적인 환경 특성을 고려하여 3가지 유형을 구분하여 각 구간별로 방문자 대상의 설문조사를 실시하였다. 분석결과, 자연성이 높은 구간인 지미오름에서 시야·소음·접촉·행동 등 밀집에 대한 인식요소에 대해 방문전보다 방문후에 보다 더 긍정적인 것으로 나타났다. 조사대상 구간 모두 현재 이용객 수에 대에서는 전반적으로 현재 이용밀도가 적정하다고 평가하였다. 또한, 방문자의 밀집에 관련하여 소음 항목이 만족도에 유의한 영향을 미치고 있는 것으로 나타났다. 이러한 결과는 외돌개 구간의 특정 혼잡구역에 대한 이용 밀도 조절 및 안전관리, 일반 관광객과의 이동동선 분리 등의 필요성을 시사하며, 이와 더불어 방문자 만족도 제고를 위해서는 특히, 방문자들에 의한 소음관리가 필요할 것으로 판단된다. The purpose of this study is to analyze the visitors’ perception of the crowding level in Jeju Olle trails. For this purpose, Olle trail routes were classified into three types based on it’s ecological, physical and social environment characteristics and a questionnaire was conducted for each type of trails. As a result, visitor perception level for visual, noise, contactual, and behavioral perceiving elements on site was more positive than expected level in Jimioleum route. In addition, it is assessed that the current crowding level is adequate in terms of number of visitors. A noise item in the visitor crowding have been shown to have a significant impact on the satisfaction level. These findings include the need to control visitor numbers, to separate genera travel routes, and to manage visitors’ safety in the congestion zones of the oedolgae section. And, there is necessary to manage noise by visitors, especially in order to improve visitor satisfaction.

Motor Imagery based Brain-Computer Interface for Cerebellar Ataxia

Young-Seok Choi(최영석),Hyun-Chool Shin(신현출),Sarah H. Ying,Geoffrey I. Newman,Nitish Thakor 한국지능시스템학회 2014 한국지능시스템학회 학술발표 논문집 Vol.24 No.2