• Journal of Korean Society for Atmospheric Environment
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• v.31 no.3
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• pp.201-208
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• 2015

We investigated the pollution levels of $PM_{2.5}$ at Wangsimni station at which four subway lines (Line 2, Line 5, the Jungang line, and the Bundang Line) are simultaneously under the operation. The analysis of $PM_{2.5}$ was made for the period of 1~ 11 Nov. 2014. The results of our field campaign were analyzed to assess the effects of various factors and conditions on the $PM_{2.5}$ pollution (such as installation of the screen door, density of floating population, weekdays and weekend, and the depth of platforms). The mean concentrations of $PM_{2.5}$ in each subway line of the Wangsimni station was measured as: the line 2 ($22.5{\mu}g/m^3$) ; the line 5 ($18.3{\mu}g/m^3$) ; the Jungang line ($31.8{\mu}g/m^3$); and the Bundang line ($32.2{\mu}g/m^3$). Based on the detailed analysis of $PM_{2.5}$ pollution at four subway lines, we aimed to provide some perspectives on reducing the concentration of ultrafine particles in a highly populated urban area.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.422-425
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• 2003

The purpose of this study is using a TACT planning and scheduling for apartment houses construction that have many of same units. Because using a TACT planning and scheduling is concluded time reduction at same units as apartment plan. The main contents of this study are 1) window and door work through the field study, 2) adjust worker assignment to minimize work time variation, and 3) an effect of working time through a case study. As a result, the total working time can be improved $21.2\%$ by using the TACT planning and scheduling. The stu요 recommends that 1) establish an accurate data between work period and resource, and 2) preparation to measures minimization of waiting time before using a TACT planning and scheduling.

• The Journal of Korean Physical Therapy
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• v.20 no.4
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• pp.71-78
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• 2008

Purpose: This study standardizes the position and direction of devices based on general user expectations and stereotypes. Population stereotypes are cognitive structures that contain the perceiver's knowledge, beliefs, and expectations about human groups. In this paper, the stereotypes that people typically expect when manipulating 'cylindrical key-in-knob locks' and 'lever-type water faucet handles' were investigated and data regarding their expectations were collected. Methods: Two sets of 600 participants, between 13 and over 60 years old, were recruited for the experiment. Each group was evenly subdivided into six age groups. Each participant was presented with cylindrical door locks mounted on a miniature door and actual lever-type water faucet handles mounted on a mockup sink. Results: If the cylindrical lock was positioned 'vertically,' 59.2% of the participants expected the device to be locked, and if the lever type faucet handle was positioned 'up,' 63.0% of the participants expected the device to be turned on. Thus, daily-use devices should be designed consistent with user expectations of operation. There was a significant difference between genders for manipulating the faucet handle between up and down. Conclusion: A more general stereotype may be defined by repetitive measurements under the same test conditions with fixed time intervals, as well as accounting for people with cognitive problems.

• Fire Science and Engineering
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• v.24 no.5
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• pp.79-86
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• 2010

In this study, we confirmed the fact that air egress velocity of pressure differential system which is installed in vestibule of smokeproof stairway in domestic high-rise building becomes back-flow into the vestibule not into the livingroom when the doors open to escape in case of fire by actual measurement. It concerned that fire smoke inflow into the vestibule of smokeproof stairway. so, reflux symptoms were developing the condition does not occur by creating an area of $2m^2$ and a model. if it‘s area is less, airflow in upper area was severely reflux. in the case upward 45 gradient of supply damper’s angle of blade, The results that reflux symptoms include upper door but bottom has some reflux. also vestibule of smokeproof stairway‘s area of $4m^2$ in the living room door in the direction of the flow distributon was normal. if a vestibule of smokeproof stairway is smaller, it designed to be performance-based design should be.

• Journal of the Korean housing association
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• v.28 no.1
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• pp.37-44
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• 2017

This study focuses on the university dormitory remodeled toward energy efficiency. The study has its purpose on deriving the aspects to be concerned for later green remodeling and enhancing the effects of green remodeling, by analyzing the changes of physical environment, changes of energy consumption amount, and needs of the residents. For this purpose, the study went through the review of project report from government office for green remodeling, field investigation of remodeling elements, and the occupancy evaluation by Focus Group Interview. FGI means interviewing small group of the residents who lived in the subjected dormitories both before and after the remodeling. As results, the elements of green remodeling in targeted dormitories were inner wall insulation, top-floor ceiling insulation, replacement of windows, installment of automatic entrance door and making transfer space connected the entrance door. As the parts of equipment system, EHP high-efficiency cooler, highly efficient radiator, upgraded LED lightings with covers, and automatic control system (only one building) were installed. Energy consumption was declined, and the satisfaction of residents was increased after the green remodeling. However, the aspects which were not improved or unsatisfying also have been detected. Therefore, the study states the suggestions each for the administrators, designers and planners, and residents to concern for enhancing the effects of green remodeling or construction of new dormitories.

• Journal of the Korea Institute of Building Construction
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• v.10 no.3
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• pp.129-136
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• 2010

This study is an evaluation of the water-tightness properties of rain-block systems in the sliding-roof joint of large-span membrane structures. In this study, we suggested a method of evaluating the water-tightness performance of the joint part of a sliding door in the roof of a large-span membrane structure (for a pilot project), in an environment of rain and wind. The shape of the rainwater blocking systems of the joint part in a sliding door verifies the defects and the effects of water leakage prevention when there is precipitation with wind conditions. To secure the water-tightness of large span membrane structures, it is necessary to have a guideline on the evaluation of the design for rain-block system of the joint part, and the quality of the membrane material, both of a retractable roof and a closed roof.

• Fire Science and Engineering
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• v.32 no.5
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• pp.57-66
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• 2018

A sports center fire in Jecheon that caused 29 deaths and 40 injuries was analyzed based on initial response and management in order to investigate the causes of the casualties. The aspects of initial response included delay of reporting 119, not being guided to the exit for the body scrubber on the $2^{nd}$ floor for escape, opening the fire doors of the exits on the $1^{st}$ floor and $3^{rd}$ floor, not closing the fire door of the main stairs on the $3^{rd}$ floor, and not doing an emergency broadcast. The management aspects included closing the alarm valve of the sprinkler system on the $1^{st}$ floor, starting-stop of the fire pump controller, neglecting leakage of water and electricity between the false ceiling and ceiling in the parking lot, hiding the exit light in the ladies bathroom lounge on the $2^{nd}$ floor and piling up things in the exit, neglecting the button of an automatic door on the $2^{nd}$ floor, conventional fire safety management, insufficient inspection of fire equipment, and not working fire shutters and smoke exhaust windows.

• Journal of Radiation Protection and Research
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• v.12 no.1
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• pp.34-39
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• 1987

Radiation shielding analysis for a 6MeV X-ray facility was carried out. The primary and leakage radiation for the facility can be evaluated based on the methodology in NCRP No. 49 and 51. The present study deals with radiation scattering analysis for the outside and inside door of the facility based on the albedo concept. The calculated dose rates were compared with the results of MORSE-CG code calculation and the measured data, resulting in a good agreement, even though there existed some deviation for the inside door. These results can be utilized to the radiation shielding design of the medical and industrial X and gamma ray facilities, and to the safety evaluation of these facilities.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.27-31
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• 2012

Objective : Although hydroxyapatite (HA) spacer has been used for laminoplasty, there have been no reports on factors associated with fusion and on the effects of HA shape. Methods : During January 2004 and January 2010, 45 patients with compressive cervical myelopathy underwent midline-splitting open door laminoplasty with winged (33 cases) and wingless (12 cases) HAs by a single surgeon. Minimal and mean follow up times were 12 and 28.1 months, respectively. Japanese Orthopedic Association (JOA) score was used for clinical outcome measurement. Cervical X-rays were taken preoperatively, immediately post-operatively, and after 3, 6, and 12 months and computed tomography scans were performed preoperatively, immediately post-operatively and after 12 months. Cervical lordosis, canal dimension, fusion between lamina and HA, and affecting factors of fusion were analyzed. Results : All surgeries were performed on 142 levels, 99 in the winged and 43 in the wingless HA groups. JOA scores of the winged group changed from $10.4{\pm}2.94$ to $13.3{\pm}2.35$ and scores of the wingless group changed from $10.8{\pm}2.87$ to $13.8{\pm}3.05$. There was no significant difference on lordotic and canal dimensional change between two groups. Post-operative 12 month fusion rate between lamina and HA was significantly lower in the winged group (18.2 vs. 48.8% p=0.001). Multivariate analysis showed that ossification of the posterior longitudinal ligament, male gender, and wingless type HA were significantly associated with fusion. Conclusion : Clinical outcome was similar in patients receiving winged and wingless HA, but the wingless type was associated with a higher rate of fusion between HA and lamina at 12 months post-operatively.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.3
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• pp.343-350
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• 2019

Objectives: This study aims to identify whether ventilation conditions and their effectiveness can be significantly improved in an experimental chamber by increasing the mixing factor (K-Factor). Methods: In a chamber with a volume of $1m^3$, air velocity was measured at six different points with four roof fans in the upper part of the chamber being operated in order. The impact of the ventilation conditions was analyzed when the flow rates were increasing and the first inlet of the chamber was either open or closed. Smoke patterns were also observed at four corner points where ventilation was limited. Kruskal Wallis and Mann-Whitney tests were performed to compare air velocities measured in the chamber. Results: The air velocities measured at only the third point increased significantly from $0.03{\pm}0.03m/s$ (door open) and $0.05{\pm}0.06m/s$ (door closed) with two fans, $0.08{\pm}0.08m/s$ with three fans, and $0.09{\pm}0.09m/s$ with four fans operating (p<0.05). However, air velocities at the four corner points did not significantly increase. Smoke patters also showed that the open inlet of the chamber had no effect on improvement of ventilation conditions and effectiveness. Conclusions: In this study, the air velocities at six points in the chamber did not significantly increase despite the increase in the mixing factor and flow rates of ventilation in the controlled environment. Therefore, the inflow of outdoor air throughout an open inlet and installation of a forced ventilation system can potentially increase the indoor air velocity and improve ventilation condition without an increase in the mixing factor.