• Journal of the Korean housing association
• /
• v.27 no.6
• /
• pp.145-153
• /
• 2016

The purpose of this study is to grasp the effectiveness of evacuation safety design by verifying the appropriateness of the standard of occupant load factor for residential buildings. To this end, the definition and current standard of occupant load factor for residential buildings were analyzed, and the problems of the current standard were clarified by interviewing professionals. In addition, changes in occupant load factor were examined by year based on statistical research, and evaluation on the current standard $18.6m^2/pers.$ was performed. As for evaluation methods, the need of redesigning of evacuation capacity was investigated by using evacuation simulation. As a result of the analysis, the most serious problem was clarification of the applicable standard for residential officetel, where the average occupant load factor was $26.1m^2/pers.$, which was not appropriate. However, as a result of evaluation on evacuation capacity, although there was no difference between statistical research results and the current standard in terms of evacuation capacity, when the standard for business facilities was applied to officetel, evacuation time doubled. Thus, this study suggests that when the current standard is applied to residential officetel, it is necessary to separate between residential use and business use.

• Fire Science and Engineering
• /
• v.25 no.1
• /
• pp.1-6
• /
• 2011

An evacuation simulation was carried out to confirm evacuation efficiency for stair width and problems in calculation of occupant load for high-rise buildings. The evacuation time and number of evacuated persons from a 39 story condominium-mercantile building were calculated by using Simulex for stair widths of 1.2 m, 1.5 m, and 1.8 m. The total occupant load based on the Korean code was higher than the number of actual residents by 2.3 times, and that based on the NFPA 101 Life Safety Code by 2.6 times, respectively. For the occupant load based on the Korean code, smaller stair width resulted in lower evacuation efficiencies due to bottlenecks in egress. For the actual residents and NFPA code-based occupant load, a high evacuation efficiency and negligible effects of the stair width on evacuation efficiency were confirmed. It was shown that there was a bottleneck even at the stair width of 1.8 m for the Korean code-based occupants, while the stair width of 1.2 m provided safe egress to the actual residents or NFPA code-based occupants. This recommended further studies on possibility of lowering the level of the Korean code in calculation of the occupant load.

• Journal of Auto-vehicle Safety Association
• /
• v.3 no.2
• /
• pp.5-10
• /
• 2011

Under the full frontal crash event, seatbelt system is the most typical and primary restraint device that prevents the second impact between an occupant and vehicle interior parts by limiting the forward motion of an occupant in the vehicle occupant packaging space. Today's restraint systems typically include the three-point seat belt with the pretensioner and the load limiter. A pretensioner preemptively tightens the seat belts removing any slack between a passenger and belt webbing which leads to early restraint of a passenger. After that a load limiter controls level of belt load by releasing the belt webbing to reduce occupant injurys. In this study, load characteristics of load limiters are optimized by the computer simulation with a MADYMO model for a frontal impact against the rigid wall at 56kph and then we suggest performance requirements. We derived optimum load characteristic from the results using four vehicle simulation models represented by the vehicle. Based on the results, we suggest the performance from the results of the second optimization using the simulation considering the design and the standardization. Finally, the performance requirements is verified by the sled tests including the load limiter device for the full vehicle condition.

• Fire Science and Engineering
• /
• v.13 no.3
• /
• pp.35-42
• /
• 1999

A occupant load density of contemporary office buildings were surveyed by a building w walk through procedure in Korea. The survey results of ten office buildings are range from 1 2 2 2 213.14 m !person 041.4 ft !person) to 22.69 m /person (244.34 ft !person) with 95% confidence l level and the mean occupant load density is 17.92 m2/person 092.87 ft2/야rson). The impacts of occupant load on evacuation flow time was analyzed by applying time-based egress m model, SIMULEX with various occupant load densities from previous studies. I In order to demonstrate the validation of egress modeling method, fire evacuation exercise a and computer simulation were used to simulate the actual evacuation plan for a high-rise office building. An analysis and comparison of the results of these approaches was made to i illustrate the influence of model limitations on the result of prediction The result of the study shows that the introduction of occupant load concept in building c code of Korea is essential to achieving resonable building life safety design in future.

• International Journal of Automotive Technology
• /
• v.7 no.7
• /
• pp.769-776
• /
• 2006

A mathematical model is developed in this paper to define the interaction between the occupant and vehicle passenger compartment and to predict the occupant dynamic response during a sudden impulse load. Two different types of occupants are considered in this study, child and adult occupants. The occupants are considered as lumped masses connected to the child seat and vehicle's body masses by means of restraint systems. In addition, the occupant restraint characteristics of seat belt and airbag are represented by stiffness and damping elements. To obtain the dynamic response of the occupant, the equations of motion of the occupants during vehicle collisions are developed and analytically solved. The occupant's acceleration and relative displacement are used as injury criteria to interpret the results. It is demonstrated from the numerical simulations that the dynamic response and injury criteria are easily captured and analyzed. It is also shown that the mathematical models are flexible, useful in optimization studies and it can be used at initial design stage.

• Fire Science and Engineering
• /
• v.32 no.6
• /
• pp.134-140
• /
• 2018

This study examined the adequacy of a school classroom's occupant load density standard to cope with the issues associated with the decreasing number of students and regional variations. Therefore, this study analyzed the occupant load density standards of kindergarten, elementary school, middle school, high school, and universities using the data open to the public by the Ministry of Education. The results revealed a high variance in the occupant load density according to the school type. The median values were 1.49, 3.45, 2.64, 2.45, and $3.41m^2/person$ for kindergarten, elementary school, middle school, high school, and universities, respectively. Although the occupant load density was higher than the current standard ($1.9m^2/person$), except for kindergarten, the present standard did not need to be improved immediately, considering the purpose of calculating the maximum occupancy. On the other hand, if improvements are made in line with other enhancements of a national education policy, it will be possible to mitigate the measure to $2.5m^2/person$ based on the survey results.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.7 no.8
• /
• pp.208-215
• /
• 1999

Using the orthogonal arrays and the occupant analysis software based on the multi-body dynamics , two interactive design algorithms are proposed to improve the initial design of the occupant protection systems. Algorithm 1 sequentially moves the narrow design space within the upper and the lower design limit. Algorithm 2 sequentially reduces the relatively wide design space. Each design algorithm is composed of two levels . The first level is to improve the characteristics of the crash performance considering the noise factors. In order to obtain the robust design, the second level reduces the variations the noise factors. In order to obtain the robust design, the second level reduces the variations due to the tolerance of the design variable. To utilize the algorithm 1, HIC(Head Injury Criterion) , 3 msec criterion value of the chest acceleration and the femur load decreased by 27.4%, 10.4% and 55.8%, respectively. To utilizer the algorithm 2 , the results decreased by 38.0%, 10.5% and 3.0% , respectively.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2003.04a
• /
• pp.299-304
• /
• 2003

The design of an occupant protection equipment has been considered as the important process in developing a new car since the crash performance plays an important role on the market. The cost is increased when an unexpected real test is carried out in the proto-design stage. Thus, the exact prediction of a crash performance can reduce the number of full-car test. In this research, the robust design of an airbag system considering the frontal crash is suggested to predict the more reliable responses. On the contrary, most existing researches do not consider the uncertainties. The uncertainties treated in this research are the tolerances of the vent hole, the time to fire and the length of a strap in airbag and the tolerance of the load limiter load in seat belt. The Taguchi method is utilized to determine the robust optimum of each parameter

• Fire Science and Engineering
• /
• v.15 no.1
• /
• pp.93-99
• /
• 2001

This study aims to improve the Evacuation Performance o( the I)inc()unto-store in underground that is rapidly new shopping store in Korea. In this paper, The architectural properties of the floor plan and section was reviewed with egress focus, occupant load density of the Discount-store was surveyed and the procedure and method of performance based egress design for this occupancy was analysed with SIMULEX model and calculation method. As a result of modeling, more longer available safe egress time (ASET) is expected than required safe egress time (RSET)in underground discount-store. In order to improve the Evacuation Performance for this type occupancy, egress capacity including escape stair, aisle width, escape door is calculated with based on occupant load density and review of shopping cart's structure and size and maximum escape capacity of the cash counter.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 1998.11a
• /
• pp.77-81
• /
• 1998