• Fire Science and Engineering
• /
• v.18 no.2
• /
• pp.49-56
• /
• 2004

Today's popular ventilation systems include the combined jet fans and electrostatic precipitation systems or the combined jet fans and vertical shaft system. Tunnels with these two ventilation systems applied have been designed and opened, more and more interest has been put in maintenance of a tunnel after opening. Therefore. it is to become more important to come up with the optimal operation mode and the method for the evaluation of ventilation system. In this study, to evaluate a tunnel ventilation and its economy, a dynamic simulation program was developed which can simulate the unsteady-state tunnel air velocity and concentration of pollutants according to the traffic flow variations and operation condition of a ventilation system. We clarified the effectiveness usage on tunnel ventilation by using it and also we could found the most economical ventilation operation mode by application in real exit tunnel. We obtained that combination of fan system and electrostatic precipitation system was more economical than jet fan priority operation mode.

• Journal of Korean Society of societal Security
• /
• v.3 no.2
• /
• pp.57-64
• /
• 2010

In this study, the behavior and safety of an existing tunnel and its facilities are investigated when a new tunnel adjacent to the existing tunnel is blasted. The design of the new tunnel puts priority on stability of the tunnel itself over the safety of the facilities which are installed within the existing tunnel such as jet fans. And thus, a detailed consideration on securing the safety of the existing facilities has been insufficient. An analysis on the types of traffic accidents in the last ten years shows that most incidents were due to the driver's improper response in emergency situations and unexpected obstacles. In consideration of this analysis, the safety of the facilities in the existing tunnel was secured by minimizing the charging amount for each hangfire and changing the excavation method of evacuation communication shelters to the large center hole cut blasting method to reduce blasting vibration. For a more quantitative analysis, measurement devices were installed inside the existing tunnel, at houses adjacent to the new tunnel, near jet fans in the existing tunnel. This enabled real time measurement of displacements of the existing tunnel, adjacent houses, and jet fans without interrupting traffic flow. Therefore, the improvements of charging amount for each hangfire, the blasting method, and the measurement method are suggested in this paper to secure the safety of the facilities in the existing tunnel when a new tunnel, located on a large city and adjacent to an existing tunnel, is designed.

• Journal of Veterinary Clinics
• /
• v.29 no.5
• /
• pp.368-371
• /
• 2012

The present study evaluated the outcome of use of thoracostomy tube tunneling technique under the latissimus dorsi muscle for the evacuation of postoperative pneumothorax induced by thoracotomy in 11 dogs. A stab incision was made through the skin and the latissimus dorsi muscle over the rib in the fifth intercostal space caudal to a surgical window. The thoracostomy tube with a Kelly hemostat was advanced into the thoracic cavity in a cranioventral direction through the sublatissimal tunnel. After tube placement, a # 1 nylon horizontal mattress suture was placed around the skin incision. The thoracostomy tube was removed after creating a negative pressure in the thoracic cavity. Dogs were monitored after surgery for pneumothorax, subcutaneous emphysema, clinical signs including dyspnea, and tube kinking in a muscle tunnel using physical examination and postoperative radiography. There was no tube kinking in the sublatissimal tunnel in 11 dogs on introducing the tubes into the thoracic cavity. The mean (${\pm}SD$) follow-up period was $19{\pm}10$ months. On postoperative radiography, there was no evidence of pneumothorax in 11 dogs. Subcutaneous emphysema was identified around the stab incision in a dog postoperatively. The subcutaneous emphysema disappeared spontaneously within 3 days. On postoperative physical examination, there was no evidence of dyspnea in 11 dogs. Our results suggest that the sublatissimal tunneling technique for thoracostomy tube placement is effective to prevent air leakage around the thoracostomy tube while the tube remains in the thoracic cavity and along the thoracostomy tunnel after tube removal. Tunneling under the latissimus dorsi muscle should be considered the thoracostomy tube placement technique to prevent iatrogenic pneumothorax with first priority.

• Journal of Korea Water Resources Association
• /
• v.52 no.10
• /
• pp.729-742
• /
• 2019

Natural disasters such as floods has been increased in many parts of the world, also Korea is no exception. The biggest part of natural damage in South Korea was caused by the flooding during the rainy season in every summer. The existing flood vulnerability analysis cannot explain the reality because of the repeated changes in topography. Therefore, it is necessary to calculate a new flood vulnerability index in accordance with the changed terrain and socio-economic environment. The priority of the investment for the flood prevention and mitigation has to be determined using the new flood vulnerability index. Total 25 urban districts in Seoul were selected as the study area. Flood vulnerability factors were developed using Pressure-State-Response (PSR) structures. The Pressure Index (PI) includes nine factors such as population density and number of vehicles, and so on. Four factors such as damage of public facilities, etc. for the Status Index (SI) were selected. Finally, seven factors for Response Index (RI) were selected such as the number of evacuation facilities and financial independence, etc. The weights of factors were calculated using AHP method and Fuzzy AHP to implement the uncertainties in the decision making process. As a result, PI and RI were changed, but the ranks in PI and RI were not be changed significantly. However, SI were changed significanlty in terms of the weight method. Flood vulnerability index using Fuzzy AHP shows less vulnerability index in Southern part of Han river. This would be the reason that cost of flood mitigation, number of government workers and Financial self-reliance are high.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.5
• /
• pp.667-674
• /
• 2023

In the event of a disaster occurring within a building, the prompt and efficient evacuation and rescue of occupants within the building becomes the foremost priority to minimize casualties. For the purpose of such rescue operations, it is essential to ascertain the distribution of individuals within the building. Nevertheless, there is a primary dependence on accounts provided by pertinent individuals like building proprietors or security staff, alongside fundamental data encompassing floor dimensions and maximum capacity. Consequently, accurate determination of the number of occupants within the building holds paramount significance in reducing uncertainties at the site and facilitating effective rescue activities during the golden hour. This research introduces a methodology employing computer vision algorithms to count the number of occupants within distinct building locations based on images captured by installed multiple CCTV cameras. The counting methodology consists of three stages: (1) establishing virtual Lines of Interest (LOI) for each camera to construct a multi-camera network environment, (2) detecting and tracking people within the monitoring area using deep learning, and (3) aggregating counts across the multi-camera network. The proposed methodology was validated through experiments conducted in a five-story building with the average accurary of 89.9% and the average MAE of 0.178 and RMSE of 0.339, and the advantages of using multiple cameras for occupant counting were explained. This paper showed the potential of the proposed methodology for more effective and timely disaster management through common surveillance systems by providing prompt occupancy information.