큰 개구부를 가진 단일구획 빌딩에서의 자연환기 모델의 개발

조석호 ( Seok-ho Cho ) 한국환경과학회 2018 한국환경과학회지 Vol.27 No.6

A model has been developed to predict natural ventilation in a single zone building with large openings. This study first presents pressure-based equations on natural ventilation, that include the combined effect of wind and thermal buoyancy. Moreover, the concept of neutral pressure level(NPL) is introduced to consider the two-way flow through a large opening. The total pressure differences across the opening and the NPL are calculated, and nonlinear equations are solved to find the zonal pressure to satisfy mass conservation. For this analysis, an iterative technique of successively approximating the zonal pressure is used. The results of applying this study model to several simple cases are as follows. When there is no wind and only the stack effect is caused, a one-way flow occurs in both the top and bottom openings in the case of two openings of equal-area, and a one-way flow occurs in the top opening; however, a two-way flow occurs in the bottom opening in the case of two openings of unequal-area. When there is a wind effect, regardless of whether the outside air temperature is lower or higher than the indoor air temperature, air flows into the room through the bottom opening and out of the room through the top opening. As the wind velocity increases, the wind effect appears to be more influential than the stack effect owing to the temperature difference.

사질토지반의 선단확장형말뚝의 인발거동 특성

조석호(Cho, Seok-Ho),김학문(Kim Hak-Moon) 한국산학기술학회 2010 한국산학기술학회논문지 Vol.11 No.9

연안개발과 해안매립을 사용하여 개발된 새로운 도시 건설의 수요가 증가하면서 해안구조물과 고층구조물의 시공이 증가하는 추세이다. 이러한 구조물에서 수평력과 인발력을 받는 구조물의 기초의 적용이 증가하고 있으며, 특 히 구조물에서 인발력에 효과적으로 저항하기 위한 기초형식으로 선단확장형말뚝의 사용이 증가하고 있는 실정이다. 압축력을 받는 기초에 관한 많은 연구들이 이루어지고 있으나, 선단확장형말뚝의 인발저항에 관한 연구는 미비한 상 태이다. 따라서 본 논문에서는 국외 4개 현장을 대상으로 선단확장형말뚝을 시공하고 정재하시험을 실시하여 말뚝의 지지력 및 하중-변위특성과 주면마찰력을 고려한 하중분담을 고찰하였다. 또한 3차원 유한요소해석 및 이론에 의해 산정된 극한인발력과 현장시험의 극한인발력을 비교‧평가하였다. Recently, the construction of coastal structures and high-rise structures against the horizontal and uplift forces increases with the developing the coastal developments. Especially the application of belled tension pile as foundation type to effectively resist uplift force is increasing in coastal structures. However, research on pullout resistance of belled tension pile has been limited and not yet been fully performed. Therefore, the pullout load tests of belled tension piles in four overseas sites were performed, then the bearing capacity, characteristics on load-displacement of piles and load distribution considering skin friction were investigated in this paper. In addition, the limit pullout bearing capacity calculated by the three-dimensional finite element analysis and theoretical methods were compared with values of in-situ test.

다구획 작업환경에서의 오염농도 예측을 위한 이론적 모델의 개발

조석호 ( Seok Ho Cho ) 한국산업위생학회 2011 한국산업보건학회지 Vol.21 No.4

To predict contaminant concentrations within a multi-zone work environment, an air quality model in the work environment was developed. To do this, airflow equations on the basis of orifice equation were solved by using the Conte and De Boor scheme, and then equations for the conservation of mass on contaminant were solved by using the fourth-order Runge-Kutta algorithm. To validate the accuracy of simulated results, this model was applied to the controlled environment chamber that had been tested in 1998 by Chung KC. The comparison of predicted concentrations by this study with measured concentrations by the Chung KC indicated that the average deviations were 2.66, 3.35, and 3.15% for zone 1, zone 2, and zone 3, respectively. Also, this model was applied to a working plant with four zones. Thus, the results of contaminant concentration versus time were predicted according to the schedule of the openings operation, and case studies were done for four cases of the openings operation to investigate the interaction of airflow and contaminant concentration. The results indicated that opening operation schedules had a significant effect on contaminant removal efficiency. Therefore, this model might be able to apply for the design of ventilation schedules to control contaminants optimally.

실내공기환경 예측을 위한 통합 다구획 모델의 개발

조석호 ( Seok Ho Cho ) 한국환경과학회 2008 한국환경과학회지 Vol.17 No.9

덤프트럭 재하 조건에 따른 지중 삼중관의 실험 및 수치해석적 진동 거동 분석

조석호(Seok Ho Cho),원종화(Jong Hwa Won),김정재(Jeong Jae Kim),김문겸(Moon Kyum Kim) 한국가스학회 2011 한국가스학회지 Vol.15 No.1

도심지 내 공사 현장 및 주변 지반에 매설된 지중 배관은 시공하중에 의한 진동에 노출이 되어있는 실정이다. 주기적으로 진동이 발생하는 매설된 배관의 지중 동적 거동 특성을 분석하기 위하여 기존 문헌 분석과 실증 실험의 결과를 토대로 수치해석을 수행하고 그 사용성을 검증하였다. 본 논문은 건설 장비중 하나인 덤프 트럭 하중의 매설 심도에 따른 배관의 거동을 분석하여 향후 지중 배관 관리기준 수립을 위한 기초 연구로서 수행되었다. 매설심도 0.6, 1.2, 1.8m 차량 이동 속도 10㎞m/h에 대하여 해석을 실시하였으며, 그 결과 매설 심도가 깊어질수록 진동속도 및 발생 응력이 작아지는 것을 확인할 수 있다. Pipes buried in around a construction site of urbanized area tend to be affected by the vibration caused by construction loads. The behaviors of buried pipes affected by periodic vibration were analyzed through numerical analyses based on existing study and experimental results. From the results of theses analyses, the serviceability of buried pipes subjected to vibration was verified. This study analyzed the pipe behaviors subjected to dump truck loads with respect to burial depths, and this research was performed as foundation study to establish standards for managing buried pipes. The analyses were performed with burial depth of 0.6, 1.2, 1.8m and vehicle velocity of 10㎞/h. From theses analyses, the vibration velocity and occurred stress tend to decrease as a burial depth increases.

외기상태의 변화에 따른 실내 환경인자의 민감도 분석

조석호 ( Seok Ho CHo ) 한국환경과학회 2010 한국환경과학회지 Vol.19 No.2

빌딩 내의 공기유동량 예측을 위한 누입 및 환기모델의 개발

조석호 ( Seok Ho Cho ) 한국환경과학회 2014 한국환경과학회지 Vol.23 No.2

A ventilation model was developed for predicting the air change per hour(ACH) in buildings and the airflow rates between zones of a multi-room building. In this model, the important parameters used in the calculation of airflow are wind velocity, wind direction, terrain effect, shielding effect by surrounding buildings, the effect of the window type and insect screening, etc. Also, the resulting set of mass balance equations required for the process of calculation of airflow rates are solved using a Conte-De Boor method. When this model was applied to the building which had been tested by Chandra et al.(1983), the comparison of predicted results by this study with measured results by Chandra et al. indicated that their variations were within -10%~+12%. Also, this model was applied to a building with five zones. As a result, when the wind velocity and direction did not change, terrain characteristics influenced the largest and window types influenced the least on building ventilation among terrain characteristics, local shieldings, and window types. Except for easterly and westerly winds, the ACH increased depending on wind velocity. The wind direction had influence on the airflow rates and directions through openings in building. Thus, this model can be available for predicting the airflow rates within buildings, and the results of this study can be useful for the quantification of airflow that is essential to the research of indoor air quality(temperature, humidity, or contaminant concentration) as well as to the design of building with high energy efficiency.

피로응력을 고려한 콘크리트 말뚝의 항타성

조석호(Cho Seok Ho),김주철(Kim Zu Cheol),정남훈(Jeong Nam Hoon),전성곤(Jeon Seong Kon) 대한토목학회 2003 대한토목학회 학술대회 Vol.2003 No.10

알칼리금속이온 열-전기 변환기술의 발전응용

최권우(Kwon-Woo CHOI),조석호(Seok-Ho CHO),김기주(Kee-Joo KIM),서민수(Min-Soo SUH) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.7

온도조절이 가능한 반려동물용 스마트 넥게이터 개발 연구

김수지(Suji Kim),조석호(Seok Ho Cho) 충북대학교 생활과학연구소 2023 생활과학연구논총 Vol.27 No.3

Background/Objectives: With the increasing number of households raismg compamon dogs in South Korea, pet tech products and services that use advanced technology to assist in pet care have been developed. However, there are few published studies on smart clothing with temperature control, which is necessary to maintain the health of pets. Therefore, in this study, we developed a temperature-adjustable smart neck gaiter for companion dogs. The main objective of this research is to fabricate smart clothing for dogs that can actively regulate body temperature using Peltier devices that can be cooled and heated. Methods: We designed and manufactured a temperature-adjustable smart textile in the form of a neck gaiter that wraps around the neck, considering the activity and comfort of pets. For the dog's hygiene, nonwashable components, such as Peltier devices and batteries, were also designed to be detachable for repeated washing. We tested the prototype of the temperature-controlled neck gaiter on an actual dog to confirm that it does not cause stress. Results: In this study, a smart neck gaiter that can actively adjust the temperature of dogs was implemented using Peltier devices. The smart neck gaiter is designed to allow dogs to perform various activities without any discomfort while wearing the smart neck gaiter. The results show that the cooling and heating functions of the smart neck gaiter help to regulate the dog's body temperature. Conclusion/Implications: Unlike the existing passive temperature control products, the proposed smart neck gaiter can actively regulate the dog's body temperature using a Peltier module. Additionally, this study presents a new paradigm of washable textile- based smart pet wearable products that is different from the existing accessory- type pet wearable products.