• Journal of Korean Tunnelling and Underground Space Association
• /
• v.17 no.3
• /
• pp.215-226
• /
• 2015

In this study, with variables the cross section area ($97m^2$, $58m^2$, $38m^2$) and the wind velocity(0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 m/s), the time of getting off train dependent on the way of itself and the width of the evacuation route was analyzed, and also fire and evacuation characteristics is reviewed by cross section area of each wind velocity. As the result, if cross section become smaller, the density of harmful gases in the tunnel increased more than the ratio of decreasing cross section area. In the case of small cross sectional area, the surrounding environment from initial fire is indicated to exceed the limit criteria suggested in performance based design. In the analysis of effective evacuation time for evacuation characteristics, the effective evacuation time was the shortest in the case of evaluating effective evacuation time by the visibility. Also, there was significant difference between the effective evacuation time on the basis of performance based evaluation and the effective evacuation time obtained by analyzing FED (Fractional effective dose), one of the analysis method obtaining the point that deaths occur, against harmful gases.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.3
• /
• pp.333-344
• /
• 2017

This research analyzes Seoul station, a typical transfer station complex, focusing on the evaluation of its barrier free design suitable for vulnerable persons such as senior citizens. The analysis was conducted to assess its compliance with the "barrier-free" design standard for those with physical or other disabilities. This paper proposes a list of items to evaluate for transfer station complexes with a barrier-free design. The results showed that the overall connections and internal and sanitation facilities of (Seoul station/the design?)were excellent. However, because of the lack of transfer and guidance facilities, vulnerable persons felt uncomfortable when searching for information about transferring from one means of transport to another. Furthermore, there was an extremely high risk of accidents when they transferred to the bus station. Therefore, it is necessary to arrange the transfer information facilities, in order to improve their readability and visibility. Once this is done, vulnerable people will be able to use this station more safely and conveniently.

• Fire Science and Engineering
• /
• v.21 no.3
• /
• pp.15-23
• /
• 2007

In the events of a fire in the residential building, highly flammable polyurethane foam sofa produce toxic smokes. In this type of fire, the residents of the building can be gotten into the difficulties of evacuating from the fire places or may be to death due to a lot of hot toxic gases. In this study, CFD simulations were carried out to study the effects of the openings of stairwell on the fire characteristics of fire room and stairwell. Also, analysis of fire hazard based on the tenability limits of fire and FED(fractional effective dose) was performed to evaluate the life safety of the residents of the building. In the fire room, maximum temperature was about $290^{\circ}C$, maximum CO concentration was about 4,740 ppm, and the time to incapacitation of residents in fire room was about t=144 s. In the stairwell, temperature and CO concentration in the condition of openings to be open were even lower than those in it to be closed. Time to the tenability limit with respect to smoke visibility in the stairwell with openings, which was open, was shorter than that of it without openings to be open. It has been shown from this study that opening the stairwell openings is able to decrease the fire hazards to the life safety in the multi-story residential building fire.

• Journal of the Korean Society of Radiology
• /
• v.1 no.1
• /
• pp.11-16
• /
• 2007

In this study, we have performed contrast-detail analysis for an amorphous selenium(a-Se) based digital X-ray imaging system by using a contrast-detail phantom(CDRAD 2.0) to test its low contrast performance. The X-ray imaging system utilizes an 500-mm-thick a-Se semiconductor X-ray absorber coated over an amorphous silicon(a-Si) TFT(thin-film transistor) detector matrix with a $139mm{\times}139mm$ pixel size and a $46.7cm{\times}46.7cm$ active area. In the measurement of contrast-detail curves we first acquired X-ray images of the CDRAD 2.0 phantom at given test conditions(i.e., 40, 50, 60, 70, 80 kVp, and 16 mA.s), and then evaluated the contrast-detail characteristics of the imaging system from each phantom image by using an image quality factor called the image-quality-figure-inverse(IQFinv). The IQFinv values for the imaging system gradually improved with the photon fluence, indicating the improvement of image visibility: 24.4, 35.3, 39.2, 41.5, and 43.4 at photon fluences of $1.8{\times}105$, $5.9{\times}105$, $11.3{\times}105$, $19.4{\times}105$, and $29.4{\times}105$ photons/$mm^2$, respectively.

• Journal of Conservation Science
• /
• v.36 no.5
• /
• pp.333-338
• /
• 2020

Dye markers are used in the study of subterranean termites to determine colony territories and population sizes. Dyes not only allow the study of termite biology, but can also be used for control purposes. Although Reticulitermes speratus kyushuensis causes damage to wooden historical properties in Korea, the dye markers have not been applied. Therefore, we evaluated the applicability of Nile Blue A dye for R. s. kyushuensis. Filter papers dyed with concentrations of 0.05%, 0.10%, and 0.25% (w/w) were each fed to termite populations through a no-choice feeding test for 1, 3, or 7 days. After 4 weeks, the survival rate, dyeing rate, and maintenance of dyeing were recorded. The results showed high survival rates with lower dye concentrations and shorter feeding periods. Among the combinations of concentrations and days, high survival rates, dyeing rates, and dyeing maintenance periods were found at concentrations of 0.05% and 0.10% for 3 days of feeding. These maximized the survivorship and visibility. The results from the current study can be applied to investigate the ecology and control of R. s. kyushuensis in both the laboratory and field.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.14 no.6
• /
• pp.37-49
• /
• 2015

In Space Syntax, the greater the degree of integration between separate links, the greater the links' accessibility from the target network. As such, planning pedestrian walks so that links with high degrees of integration are connected, or else inducing high integration value land use are both valid options. The travel distribution model reflects how walking demand, or more specifically, the pedestrian, partakes in route choosing behavior that minimizes select criteria, notably level of discomfort, as measured using travel distance and time. The model thus demonstrates travel patterns associated with demand pertaining to minimization of discomfort experienced by the pedestrian. This research introduces a method that integrates Space Syntax and the pedestrian travel distribution model. The integrated model will determine whether regions with high degrees of integration are actually being used as pivots for pedestrian demand movement, as well as to explain whether the degree of integration is sustained at an appropriate level while considering actual movement demand. As a means to develop the integrated model, a method that combines display of the visibility of the space syntax network and road-divided links is proposed. The pedestrian travel distribution model also includes an alternative path finding mechanism between origin and destination, which allows for uniform allocation of demand.

• The Journal of Sustainable Design and Educational Environment Research
• /
• v.19 no.2
• /
• pp.1-10
• /
• 2020

Despite the legal and institutional measures that have been enacted for the safety management of school facilities, the number of school accidents has continued to rise, particularly in regards to the number of accidents related to schools. However, school facilities have had a difficult time creating safe school environments for the school administration and local governments. This is due to the fact that the Office of Education and the Ministry of Education, not the school or educational offices, have insufficient institutional devices such as standards and systems for the promotion of safe school environments. This study attempted to confirm the direction of the improvement of the safety of school facilities. To this end, four safety assessment topics (separation of pedestrians, pedestrian path management, pedestrian visibility, and surrounding risk factors) were derived based on the surveyed data for the safety of the external environment of domestic and international school facilities. 179 school facilities nationwide (kindergartens, elementary schools, middle schools, high schools, and special schools) were analyzed for current cases of accidents that occurred mainly on school roads. Roughly 50% of the analyzed evaluation scores showed that it is necessary to improve the external environment of school facilities.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.25 no.6
• /
• pp.111-120
• /
• 2021

When a fire occurs in a commercial building, the evacuation route is complicated and the direction of smoke and flame is similar to that of the egress route of occupants, resulting in many casualties. Performance-based evacuation design for buildings is essential to minimize human casualties. In order to apply the performance-based evacuation design to buildings, it requires a complex fire simulation for each building, demanding a large amount of time and manpower. In order to supplement this, it would be very useful to develop an Available Safe Egress Time (ASET) prediction model that can rationally derive the ASET without performing a fire simulation. In this study, the correlations between fire temperature with visibility and toxic gas concentration were investigated through a fire simulation on a commercial building, from which databases for the training of artificial neural networks (ANN) were created. Based on this, an ANN model that can predict the available safe egress time was developed. In order to examine whether the proposed ANN model can be applied to other commercial buildings, it was applied to another commercial building, and the proposed model was found to estimate the available safe egress time of the commercial building very accurately.

• Korean Journal of Clinical Laboratory Science
• /
• v.53 no.3
• /
• pp.233-240
• /
• 2021

Evaluation of the resected margins of the frozen section during breast-conserving surgery can determine the presence of cancer cells in a short time and have a significant impact on the scope of surgery and the prognosis of the patient. However, breast tissue is composed of adipose tissue, which affects the accuracy of the test. In this study, a new method was applied to the resected surface of the frozen section in which wiping the surface of the frozen section block with alcohol was expected to expose the parenchyma to the surface as the adipose tissue would melt momentarily. Indeed, of the total of 98 cases, 37 cases showed a better exposure ratio of the parenchyma in the improved frozen section test than in the previous frozen section test. Of the 37 cases with increased visibility of parenchymal sections obtained by this method, two cases of ductal carcinoma in situ (DCIS) were detected. Although there are limitations such as turnaround time (TAT), the diagnostic accuracy of histopathologic examination of the frozen section may improve through this method and may have a direct impact on patient safety, and should therefore be researched further.

• Journal of Digital Convergence
• /
• v.19 no.2
• /
• pp.93-103
• /
• 2021

S&OP(Sales and Operations Planning) is an ongoing process of periodic planning, reviewing, and evaluation through the involvement of all key stakeholders. Within this process, performance is regularly reviewed and early warning signals are generated, so that the company can react quickly to changing market and operational environment. This paper presents a framework for effective S&OP for fair alignment, accountability, teamwork, visibility, and risk management. This framework focuses on supply chain information governance, level of information sharing through S&OP, role of S&OP as coordination mechanism, APS effectivesness as a planning tool and SCM performance. In addition, a brief case study on the operating characteristics of S&OP at three Korean firms is presented. Implications of the study finding are also provided. It will also make companies that are considering the introduction of S&OP aware of the importance of S&OP, which will provide practical guidelines for the introduction of S&OP.