• Journal of Nutrition and Health
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• v.40 no.2
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• pp.154-161
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• 2007

This study investigated the effects of xylooligosaccharide on feces bifidobacteria proliferation, lactic acid concentration and lipid metabolism in healthy woman. Fourteen volunteers were randomly assigned to 2 groups : 1.4 g/day xylooligosaccharide intake group, 2.8 g/day xylooligosaccharide intake group. The duration of the study was 28 days. The amount of feces and excretion time were not affected by xylooligosaccharide intake. The color of feces changed to yellow brown, and hardness of stool and effort to evacuation were reduced by xylooligosaccharide intake. Xylooligosaccharide intake reduced the fecal pH significantly after 14 days in 2.8 g/day intake group (p < 0.05). The number of fecal bifidobacteria were significantly increased after 28 days in 1.4 g/day intake group (p < 0.05), and in 2.8 g/day intake group, the number of fecal bifidobacteria significantly increased after 14 days (p < 0.05). Water contents of feces were not affected by xyloolgosacchride intake. The fecal triglyceride and cholesterol concentrations were increased in 2.8 g/day intake group (p < 0.05), and in 1.4 g/day intake group, fecal cholesterol concentration only was increased (p < 0.05). The fecal lactic acid concentration was significantly increased in 2.8 g/day intake group (p < 0.05). Serum trigly-ceride, cholesterol and glucose concentration were significantly decreased in 2.8 g/day intake group (p < 0.05). In conclusion, xylooligosaccharide dietary supplementation may be beneficial to gastrointestinal health and lipid metabolism, and 2.8 g/day intake was more effective than 1.4 g/day intake.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.6
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• pp.451-462
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• 2011

The smoke control system plays the most important role in securing evacuation environment when a fire occurs in road tunnels. Smoke control methods in road tunnels are classified into two categories which are longitudinal ventilation system and transverse ventilation system. In this study it is intended to review the characteristics of smoke behavior by performing numerical analysis for calculating the optimal smoke exhaust air volume with scaled-model and simulation when a fire occurs in tunnels in which transverse ventilation is applied, and for obtaining the basic data required for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions for various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173m^3/s$, $236m^3/s$ for the distance of the smoke moving which can limit the distance to 250 m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.

• Fire Science and Engineering
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• v.23 no.3
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• pp.79-84
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• 2009

The smoke control system plays the most important role in securing evacuation environment when a fire occurs in road tunnels. Smoke control methods in road tunnels are classified into two categories which are longitudinal ventilation system and transverse ventilation system. In this study it is intended to review the characteristics of smoke behavior by performing numerical analysis for calculating the optimal smoke exhaust air volume when a fire occurs in tunnels in which transverse ventilation is applied, and for obtaining the basic data required for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions for various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75m/s and 2.5m/s, the optimal smoke exhaust air volume has to be more than $173m^3/s$, $236m^3/s$ for the distance of the smoke moving which can limit the distance to 250m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.37 no.1
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• pp.49-56
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• 2024

An automated dynamic structural analysis module stands as a crucial element within a structural integrated mitigation system. This module must deliver prompt real-time responses to enable timely actions, such as evacuation or warnings, in response to the severity posed by the structural system. The finite element method, a widely adopted approximate structural analysis approach globally, owes its popularity in part to its user-friendly nature. However, the computational efficiency and accuracy of results depend on the user-provided finite element mesh, with the number of elements and their quality playing pivotal roles. This paper introduces a computationally efficient adaptive mesh generation scheme that optimally combines the h-method of node movement and the r-method of element division for mesh refinement. Adaptive mesh generation schemes automatically create finite element meshes, and in this case, representative strain values for a given mesh are employed for error estimates. When applied to dynamic problems analyzed in the time domain, meshes need to be modified at each time step, considering a few hundred or thousand steps. The algorithm's specifics are demonstrated through a standard cantilever beam example subjected to a concentrated load at the free end. Additionally, a portal frame example showcases the generation of various robust meshes. These examples illustrate the adaptive algorithm's capability to produce robust meshes, ensuring reasonable accuracy and efficient computing time. Moreover, the study highlights the potential for the scheme's effective application in complex structural dynamic problems, such as those subjected to seismic or erratic wind loads. It also emphasizes its suitability for general nonlinear analysis problems, establishing the versatility and reliability of the proposed adaptive mesh generation scheme.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.1-12
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• 2006

In this study, CFD computer simulations by FDS are carried out in order to confirm the performance of the combined operation of both sprinkler system and smoke curtain of 0.54 m depth installed for cooling and blocking the smoke which propagates beneath the sloped ceiling of a stairway corridor of which dimensions are 17.92 m long, 4.00 m wide, and 6.12 m high. It is shown that the response time of sprinklers decreases with fire size and it increases more about 1.1 second in case without smoke curtain than in case with smoke curtain, that the time of smoke transport from the fire source to the stairway outlet decreases considerably with fire size, and that the delay effect of smoke transport is not related to the sprinkler system, whether it is operated or not. This study shows that the combined operation of both sprinkler system and smoke curtain is very effective in smoke cooling, but it is a little for effect on smoke blockage. Although the hazard of skin burn due to radiative heat flux from hot smoke layer is decreased by spray cooling effect, the hazard of smoke suffocation and the weakening of visibility is increased by smoke downdrag and the turbulence of smoke-air mixing due to water spray. These conditions may result in preventing occupants from going out of the stairway during evacuation.

• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.394-398
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• 2006

Background: Goal of the initial treatment of primary spontaneous pneumothorax is re-expansion of the lung by evacuation of air from pleural space. Authors thought small caliber catheter could reach to this goal instead of conventional large bore chest tube. This retrospective study was undertaken to assess the effectiveness of 7-French (Fr) catheter for the initial treatment of primary spontaneous pneumothorax. Material and Method: Between May 2003 and April 2005, 111 patients with primary spontaneous pneumothorax were managed with tube drainage; 7 Fr catheter for 86 patients and 24-French chest tube for 25 patients. We analyzed catheter indwelling time, use of analgesics, re-expansion of the lung, and catheter related problems by medical records. Result: Mean catheter indwelling time was $2.4{\pm}1.1$ days in 7 Fr group and $2.3{\pm}1.3$ days in chest tube group (p>0.05). All patients with 24 Fr catheter needed analgesics injection but never in 7Fr group. Complete re-expansion of the lung based on plane chest radiograph was obtained in 77% of 7 Fr group. The problem related with 7 Fr catheter was kinking, which showed in 5.6%. Conclusion: Application of the 7 Fr catheter for initial management of primary spontaneous pneumothorax was as effective as 24 Fr catheter.

• Journal of Chest Surgery
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• v.37 no.12
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• pp.987-991
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• 2004

Background: Inadequate drainage of traumatic hemothoraces may result in prolonged hospitalization and complication such as empyema, fibrothorax and pleural calcification. This needs to be the placement of a tube thorascostomy which is efficacious in more than 80% of cases. Other cases require surgical treatment. Material and Method: From March 2002 to February 2003, there were 123 patients who was done closed thorascostomy in traumatic hemothorax. 10 patients (group I) were undergone early retained clot evacuation with video assisted thoracoscopic surgery, but 5 patients (group II) who developed a localized hematoma or empyema were operated. Male were more than female and mean average was similar in both group. The most common cause of injury was traffic accidents and frequently combined lesions were a abdomen. Result: Interval from injury and operation, mean operation time, duration of tube drainage and hospital stay in group I were shorter than group II (p<0.05). Operation-related complication and recurrence of fluid collection within follow up period (17.8$\pm$3.8 months) in group I were none, but in group II (21.5$\pm$5.3 months) were 2 cases. Conclusion: Video assisted thoracoscopic surgery can be utilized as an effective and safe method for the removal of retained clotted hemothorax within 7 days.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.392-401
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• 2020

Purpose: This study analyzes the operating characteristics of a lithium ion capacitor that can be used as a standby power supply in an emergency, and determines whether the standby power supply is abnormal even by measuring the voltage using a linear proportionality characteristic during charging and discharging. The aim is to provide an experimental basis that can be done. Method: As a method for this study, first, analyze the operation principle and characteristics of the existing backup power supply and lithium ion capacitor, and then measure the voltage of the lithium ion capacitor according to the configuration and system block diagram of the induction lamp used in the experiment. We proceed with the test of the measured value of discharge power for each voltage band to check the amount of power held by the battery and the operation test experiment using induction lamps. Results: Just by checking the charging voltage using the linear proportional characteristics of lithium ion capacitors, it provides a basis for accurately inferring the effective operating time of induction lamp lamps. Conclusion: In the event of a disaster, the lithium ion capacitor is used as a spare power supply for emergency induction lamps to prevent complete discharge of emergency induction lamps, to prevent the problem of performing normal operation of the standby power supply, and to use only a simple voltage measurement to reserve power. It was intended to suggest many uses for evacuation equipment application in the future by making it possible to check whether the device is abnormal.

• Journal of Korean Society of Disaster and Security
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• v.12 no.3
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• pp.25-34
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• 2019

Modern disasters prevent accidents in advance and recover after accidents are very important. Our government's current response to these accidents is not appropriate. As for disaster management so far, it has been the center of disaster response and recovery efforts, and has been led by the government against it. The reality is that most private organizations and agencies have only subsidized government disaster management agencies. Korea is no longer a safe zone for earthquakes. Now for the establishment of effective disaster management system for earthquakes in the diagnosis is very urgent and the problems of the operational disaster management, which the problems of the nation.Policies to improve academic efforts to seek alternative proposal is also at a time when volume can be said to be very big need to mine. This study from 2016 to 2019, about the earthquake that took place between National Statistical Office, based on analysis of data to. First of all, research 1: What was the government's plan on Pohang earthquake? The results showed that the residents' evacuation of Pohang was important in the Pohang earthquake, but for the sake of students' safety, they were directly assigned to the test site to cope with the emergency situation. Therefore, the research and analysis shows that the nation should continue to think about the causes and responses of the damage at the disaster site and strive to develop technologies and methods to minimize the damage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.602-609
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• 2020

In the event of a large-scale disaster such as an earthquake, typhoon, landslide, and building collapse, the disaster situation awareness and timely disaster information sharing play a key role in the disaster response and decision-making stages for disaster management, such as disaster site control and evacuation of residents. In this paper, an exited field investigation system of NDMI (National Disaster Management Research Institute) was enhanced with an LTE-VPN- based wireless communication system to provide an effective on-site response in an urgent disaster situation and share observation data or analysis information acquired at the disaster fields in real-time. The required performance of wireless communication for the disaster field investigation system was then analyzed and evaluated. The experimental result for field data transmission performance of an advanced wireless communication investigation system showed that the UDP transmission performance of at least 4.1Mbps is required to ensure a seamless video conference system between disaster sites. In addition, a wireless communication bandwidth of approximately 10 Mbps should be guaranteed to smoothly share the communication and field data between the survey equipment currently mounted on the survey vehicle.