공동주택 화재 시 화재크기 및 실내 개구부 크기가 화재풍속에미치는 영향에 관한 수치해석적 연구

서찬원,신원규 한국화재소방학회 2014 한국화재소방학회논문지 Vol.28 No.5

In the case of interior fire in an apartment building, contamination of vestibule area by fire smoke before air fan operatingwhen fire doors are open makes the evacuation of people very difficult. In order to investigate the effect of heatrelease rate (HRR) and interior opening on fire flow velocity, numerical simulations using Fire Dynamics Simulator werecarried out. In simulations, actual dimensions and configuration of an apartment building were considered and interiorleakage and HRR were varied. From simulation results, it was found that fire flow velocity distribution is significantlyinfluenced by HRR and interior opening resulting in the change of the location of a neutral plane. Also, it is shown thatthere is a larger difference of the fire flow velocity between upper and lower part of the fire door when the neutral planebecomes closer to the ceiling. 재실자가 부속실로의 피난 시 부속실 송풍기가 작동하기 전단계에서는 실내화재로 인한 풍속이 발생하여 부속실 개방과 더불어 연소생성물이 부속실을 오염시켜 피난장애의 결과를 가져올 수 있다. 이로인한 화재크기 및 실내 개구부 크기가 화재풍속에 미치는 영향을 확인하기 수치해석 연구를 수행하였다. 수치해석에서는 화재크기 및 실내 개구부 크기를달리하였고, 실제의 공동주택 형상과 치수를 반영하였다. 수치해석 결과, 화재크기별 실내의 개구부 크기에 따라서 중성대 높이가 변화하여 부속실로 흐르는 화재풍속 특성이 다르게 나타남을 확인할 후 있었다. 또한, 실내 중성대가 높은 곳에 형성된 경우에는 방화문 상 · 하부에서 화재풍속의 차이가 나타남을 확인할 수 있었다.

연하(삼킴)곤란자용 점도증진 유체식품의 유변학적 특성

서찬원,유병승 한국식품영양과학회 2011 한국식품영양과학회 학술대회발표집 Vol.2011 No.10

추정된 타이어 힘을 이용한 능동 조향 제어

서찬원,김준영,홍대건,허건수,Seo, Chan-Won,Kim, Jun-Yeong,Hong, Dae-Geon,Heo, Geon-Su 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.9

Steering of the vehicles on a slippery highway is a difficult task for most passenger car drivers. The steering vehicles on slippery roads tend to slide outward with less lateral forces than on nor mal roads. When the drivers notice that their vehicles on a slippery highway start to depart from the cornering lane, most of them make a sudden steering and/or braking, which in turn may induce spin-out and instability on their vehicles. In this paper, an active steering control method is proposed such that the vehicles in slippery roads are steered as if they are driven on the normal roads. In the proposed method, the estimated lateral forces acting on the steering tires are compared with the reference values and the difference is compensated by the active steering method. A fuzzy logic controller is designed for this purpose and evaluated on a steering Hardware-In-the-Loop Simulation (HILS) system. Steering performance results on the slippery curved and sinus roads demonstrate the effectiveness of the proposed controller. This method can be realized with the steer-by-wire concept and is promising as an active safety technology.

Effect of galactomannan addition on rheological, physicochemical, and microbial properties of cultured sour cream

서찬원 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.5

Sour cream is a popular fermented dairy product and galactomannans are widely used in the food industry to improve texture and stability. In this study, it was investigated the effects of different galactomannans (guar gum (GG), locust bean gum (LBG), and GG/LBG) on the rheological, physicochemical, and microbial properties of sour creams. All the sour cream samples had similar pHs (4.55–4.57), acidity (0.83–0.86%), and lactic acid bacteria viable counts (8.08–8.15 log CFU/g) after fermentation. The rheological parameters (ηa,50, K, G′, G″, and tan δ) of the sour creams increased after the addition of galactomannans. The sour cream with GG showed higher ηa,50, K, G′, and G″ values than the sour cream with LBG. Furthermore, the combination of galactomannans (GG/LBG) did not have any synergistic effect on the sour cream. The water-holding capacity of sour creams was enhanced by the addition of galactomannans, resulting in reduced syneresis.

Rheological, Physicochemical, Microbiological, and Aroma Characteristics of Sour Creams Supplemented with Milk Protein Concentrate

서찬원,오남수 한국축산식품학회 2023 한국축산식품학회지 Vol.43 No.3

Milk protein concentrate (MPC) is widely used to enhance the stability and texture of fermented dairy products. However, most research has focused on yogurt products, and the effects of MPC on sour cream characteristics remain unknown. Therefore, we investigated the effects of different MPC levels (0%, 1%, 2%, and 3% w/w) on the rheological, physicochemical, microbiological, and aroma characteristics of sour creams in this study. We found that MPC supplementation stimulated the growth of lactic acid bacteria (LAB) in sour creams, resulting in higher acidity than that in the control sample due to the lactic acid produced by LAB. Three aroma compounds, acetaldehyde, diacetyl, and acetoin, were detected in all sour cream samples. All sour creams showed shear-thinning behavior (n=0.41–0.50), and the addition of MPC led to an increase in the rheological parameters (ηa,50, K, Gʹ, and Gʺ). In particular, sour cream with 3% MPC showed the best elastic property owing to the interaction between denatured whey protein and caseins. In addition, these protein interactions resulted in the formation of a gel network, which enhanced the water-holding capacity and improved the whey separation. These findings revealed that MPC can be used as a supplementary protein to improve the rheological and physicochemical characteristics of sour cream.

Effect of Milk Protein Isolate/κ-Carrageenan Conjugates on Rheological and Physical Properties of Whipping Cream: A Comparative Study of Maillard Conjugates and Electrostatic Complexes

서찬원,유병승 한국축산식품학회 2022 한국축산식품학회지 Vol.42 No.5

With increasing consumer demand for “clean label” products, the use of natural ingredients is required in the food industry. Protein/polysaccharide complexes are considered good alternatives to synthetic emulsifiers and stabilizers for formulating stable emulsion-based foods. Milk protein and carrageenan are widely used to improve the physical properties and stability of dairy food products. In a previous study, milk protein isolate (MPI) was conjugated with κ-carrageenan (κ-Car) in a wet-heating system through the Maillard reaction, and the Maillard conjugates (MC) derived from MPI and κ-Car effectively improved the stability of oil-in-water emulsions. Therefore, MPI/κ-Car conjugates were used in whipping cream as natural emulsifiers in this study, and the physical and rheological properties of whipping creams stabilized using MPI/κ-Car MC and MPI/κ-Car electrostatic complexes (EC) were investigated. The whipping creams stabilized with MPI/κ-Car MC have lower rheological parameters (ηa,50, K, G′, and G″) than those of whipping creams stabilized with MPI/κ-Car EC. Although the overrun value was slightly reduced owing to the addition of MPI/κ-Car MC, the stability of the whipped creams with MC was effectively improved due to enhanced water-holding ability by conjugation.

부속실 가압 시스템의 방연풍속에 관한 수치해석적 연구: 공동주택 부속실내에 다수 출입문의 존재시 기류특성

서찬원,신원규 한국화재소방학회 2014 한국화재소방학회논문지 Vol.28 No.5

The pressurized smoke control system in the vestibule is important for fire safety in buildings because it is concernedwith egress time of people and the safety of fire fighters. The vestibule pressurization system can prevent smoke fromentering the vestibule using differential pressure when fire doors are closed and using the egress velocity when fire doorsare open. Air supplying units in the vestibule need to be arranged by taking account of the location of doors and the volumeof the vestibule in order to assure the uniform air egress velocity through a fire door when it is open. In this study,computational fluid dynamics (CFD) simulations were conducted for the vestibule where multiple doors are installed andit was found that the reverse flow occurs when the damper position in vestibule is not appropriate. 건축물 내부에 화재가 발생 시 재실자 피난 및 소방관의 소화활동에 직접적인 영향을 미치는 급기가압 제연설비는 방화문 비개방 시에는 차압에 의하여, 방화문 개방 시에는 방연풍속에 의하여 연기의 침입을 방지하는 것을 핵심 개념으로하고 있다. 이를 위해서는 특히 재실자 피난 시 방화문이 개방되는 경우 균일한 방연풍속이 형성될 수 있도록 공기 공급 유니트를 배치할 필요가 있다. 본 연구에서는 대형건물에 설치되는 다수의 출입문을 갖는 부속실의 경우, 방연풍속이균일하게 형성될 수 있는지에 대하여 수치해석을 수행하였다. 부속실의 댐퍼위치가 한쪽으로 치우친 경우 방연풍속으로연기의 침입을 막는 것이 아니라, 역류현상이 발생하여 방연성능에 영향을 미칠 수 있음을 확인하였다.

HEVC의 계층적 부호화 블록 구조

서찬원,한종기 대한전자공학회 2011 전자공학회지 Vol.38 No.8

계층적 부호화 구조 및 변환 블록 구조에 따른 비디오 압축 성능

서찬원,한종기 한국방송공학회 2010 방송과 미디어 Vol.15 No.4

최근 차세대 비디오 코덱 표준화를 위해서 결성된 JCT-VC에서는 부호화 효율을 향상시키기 위하여 계층적 부호화 구조와 계층적 변환 블록 구조를 고려해왔다. 계층적 부호화 구조와 변환 블록 구조는 부호화 효율을 향상시킬 수 있는 장점이 있지만, 다양한 형태의 복수 계층 구조를 고려하기 때문에 부호화기의 복잡도를 증가시킨다. 따라서 복잡도 증가를 최소화하면서 부호화 효율을 최대화하기 위하여, 최대 부호화 블록 크기 및 최대 변환 블록크기를 최적의 값으로 제한할 필요가 있다. 본 문서에서는 다양한 실험결과들에 대한 분석을 통해서 부호화 효율과 복잡도를 동시에 고려한 최적의 최대 부호화 블록 크기와 계층적 변환 블록구조를 위한 최적의 깊이 제한에 대하여 설명한다.

공동주택 부속실내에 다수 출입문 존재 시 댐퍼위치별 방연풍속에 관한 수치해석적 연구

서찬원,김병준,신원규 한국화재소방학회 2016 한국화재소방학회 학술대회 논문집 Vol.2016 No.춘계