• Journal of the Korea Safety Management & Science
• /
• v.26 no.1
• /
• pp.15-24
• /
• 2024

The purpose of this study is to improve the stack effect of the staircase and the failure to take into account the opening of the outside door of the staircase, which are the disadvantages of the existing smoke control only vestibule. As a result of the study, the new vestibule and the staircase simultaneous smoke control are equipped with an exhaust flap damper with an effective opening area of about 0.25 m² in the upper part of the staircase, and a ventilator-type air supply fan of about 5 m³/s in the lower part, and take measures to prevent overpressure in the staircase. If you use the new simultaneous smoke control method of the vestibule and staircase, you can achieve the following effects. First, it is possible to open the external entrance door. Second, it can reduce the stack effect. Third, the staircase door closes automatically without fail. And a new method of preventing overpressure was proposed for the vestibule.

• Progress in Superconductivity
• /
• v.9 no.1
• /
• pp.50-55
• /
• 2007

We have installed a 61-channel magnetocardiography (MCG) system inside a magnetically shielded room (MSR) with a size of $2.4\;m\;{\times}2.4\;m\;{\times}2.4\;m$. The MCG system consists of 1st-order axial gradiometers containing double relaxation oscillation SQUIDs (DROSs) with pick-up coils of a base line of 70 mm. The MSR holds a shielding factor of 50 at 0.1 Hz and 10000 at 100 Hz, when its door in the middle on a front wall is closed. On opening the MSR door, we have obtained the characteristics of the MCG system with a 2.9 Hz noise generated from an air conditioning unit at 13 m distance off the MSR. In an open-door MSR ($140^{\circ}$ opening), a noise at the center channel increases up to $700\;fT/Hz^{l/2}$ at 2.9 Hz and $1.7\;pT/Hz^{1/2}$ at 60 Hz. MCG signals for a healthy human do not show distortion until the door opens to $45^{\circ}$, but show the effect of noise when the door opens further at $90^{\circ}$ and $140^{\circ}$. With the door opens to $45^{\circ}$, MCG measurement can be performed with ease of door operation and without creating claustrophobia for the patient.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.559-571
• /
• 2008

Platform Screen Door(PSD) has been installed and operated at seoul subway line $1\sim4$ in the manual train operation mode(ATS/ATC) by SeoulMetro since 2005. SeoulMetro uses the wireless (RF) communication system and the train door detection system for the link between the train and PSD doors opening/closing motion in the manual train operation mode. For the convenience and safety of passengers, the train doors and the PSD doors opening/closing shall be synchronized as much as possible. In ATO(Automatic Train Operation) mode which provides the interface between train control system and PSD system, ATO signaling system makes the train doors and PSD doors open/close command signals systematically, so PSD doors can be opened/closed almost simultaneously with the train doors. But, in the manual train control(ATS/ATC) mode, PSD system needs to detect the train doors open/close operation and make PSD open/close command signals to actuate PSD doors. These PSD open/close commanding process cause time delay of PSD doors opening/closing motion in response to the train doors opening/closing motion. Sometimes the response delay time can be over 1 second, which is not proper to operate PSD, and need to be reduced This paper presents the reduction method of the PSD response delay time to improve the convenience and safety of passengers.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.157-158
• /
• 2023

Doors that are opened and closed when entering or exiting a general building are connected to the door frame and open and close. They are equipped with door locking devices of various structures, and are either locked to the door frame for the closing operation or released from the door frame for the opening and closing operation. Here, a single-stage door binding device having a door latch that is independently disposed at the center of one axis of the door is commonly used. On the other hand, if the size of the door is over a certain size or if the door is medium to large, the opening and closing operation may not be performed smoothly with only a single stage binder, or the closing state may not be achieved stably during the closing operation. In particular, in the case of the single-stage binding device provided in medium to large fire doors, the door is fixed to the door frame unstable, causing fatal errors in the fire prevention function of the fire door. Accordingly, in order to fundamentally solve these problems, we researched and developed a three-stage door binding machine that combines a top and bottom fastening structure with a single-stage fastening structure. This 3-stage door binder not only has the fire resistance performance of a fire door, but also has a T-shaped terminal in its fastening method, so if you eliminate the upper and lower fastening, it is a 1-stage binder like a regular product, but if you remove the door latch of the 1st-stage binder, it functions as an upper and lower 2-stage binder and forms a single mold. We researched and developed a three-stage door binder that can manufacture and produce three products at the same time, satisfying both product performance and price.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.6
• /
• pp.31-39
• /
• 2009

This paper proposes an ultrasonic sensor based intelligent automatic door system which improves the performance of conventional door systems by adding more intelligent functions such that it offers more convenience to passersby and reduces power loss. The conventional automatic door systems employed passive and active infrared sensors for detecting objects and human bodies. But, they have problems such as power loss in door closing, not sensing fast approaching objects, and safety. The proposed automatic door system with ultrasonic sensors prevents unnecessary door closings to save the power and senses fast approaching objects to open the door at proper time, and improves safety. Thus, the proposed system improves the performance of the conventional systems in terms of operation, economy, and safety.

• Journal of the Korea Convergence Society
• /
• v.10 no.9
• /
• pp.173-177
• /
• 2019

This study is door safety device for the structural analysis are described. Recently emerged as a key point of the door safety and increase the need of a door safety device. In order to improvement this inconvenience, the door safety device was design and structural analysis by using CATIA. CATIA utilizes door safety device element model for displacement, stress and strain energy were obtained. Consideration of door open angles were $95^{\circ}$, $100^{\circ}$, $105^{\circ}$, $110^{\circ}$, $115^{\circ}$, $120^{\circ}$. These results will be provided to develop new concepts of door safety device as initial data.

• Neurospine
• /
• v.15 no.4
• /
• pp.362-367
• /
• 2018

Objective: To assess the efficacy of cervical open-door laminoplasty by hydroxyapatite implant insertion between the lamina and the lateral mass without suturing. Methods: All patients who underwent cervical open-door laminoplasty with C2/C7 undermining and insertion of hydroxyapatite implants from C3 to C6 were retrospectively evaluated for surgical time and neurological outcomes according to the Japanese Orthopaedic Association (JOA) score. To assess the alignment of the cervical spine and postoperative cervical pain, the C2-7 angle and a visual analogue scale score were used, respectively. Results: The population consisted of 102 women and 222 men ranging in age from 32 to 90 years. The average surgical time was 86 minutes. Fourteen of 1,296 hydroxyapatite implants were kept in place with sutures due to a weak restoration force of the hinge during surgery. No hydroxyapatite implant dislocation was detected on cervical computed tomography at 1 year after surgery. The average JOA score was $10.2{\pm}2.5$ before surgery and $14.6{\pm}2.8$ at 1 year after surgery. The average recovery rate was 61.8%. The average C2-7 angle at the neutral position was $7.1^{\circ}{\pm}6.2^{\circ}$ before surgery and $6.5^{\circ}{\pm}6.3^{\circ}$ at 1 year after surgery. Conclusion: This method enabled us to achieve minimal exposure of the lateral mass, prevention of lateral mass injury and dural injury, and a shorter surgical time while maintaining acceptable surgical outcomes. The idea that firm suture fixation is needed to prevent spacer deviation during cervical open-door laminoplasty may need to be revisited.

• Journal of the Society of Disaster Information
• /
• v.16 no.4
• /
• pp.627-637
• /
• 2020

Purpose: This experimental study was conducted to find out whether a water-mist fire suppression system can be applied to C.E.P., a representative combustible material of a rack storage. Method: First, it was confirmed whether the water-mist fire-extinguishing system used in this experiment was capable of extinguishing oil fires. After that, the C.E.P. boxes were loaded in the same small space as used in the oil fire experiment, and then the experiment was conducted on three scenarios; door opening, door closing, and door closing and increasing the internal load. The scenario was set considering the opening and space size conditions, which are important factors for the water-mist fire suppression. Result: Oil fire suppression tests have shown that fires are well extinguished in both the door open and closed conditions. In case of a fire of C.E.P. boxes in the same space condition as an oil fire, the fire was not extinguished in the door open condition. Fires were extinguished in the case with the door closed condition, but the afterglow was confirmed. Conclusion: In the oil fire suppression test, a water-mist fire suppression system extinguished a fire in both the door open and closed conditions. However, for the C.E.P fire, it was possible to extinguish only under the door closed condition, and there was a possibility of re-ignition.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.9-11
• /
• 2018

Recently, door locks have become popular. However, it is often more difficult to recognize the vulnerability of the door lock than to recognize it as more convenient and secure than a mechanical key. Therefore, in this study, the function of the door lock was improved and the weak points were reinforced. Door lock is vulnerable to heat when a fire occurs, so that the door may not open. Therefore, the door is automatically opened when the internal temperature of the fire site exceeds a predetermined temperature by attaching a heat sensor. In the room, the door was automatically opened without having to press the password. Through the proposed function, it can be expected to prevent the casualties in case of fire.

• Proceedings of the SAREK Conference
• /
• 2008.11a
• /
• pp.469-474
• /
• 2008

The objective of this study is to propose basic design guidelines for more effective air ventilation system in apartments. It is well known that ventilation depends on whether the room doors are open or closed as well as people's living patterns. This study considers 84 ㎡-sized apartment which has extended living room without balcony. Ventilation of bathroom and kitchen is not considered. The height of the building, external air pressure and air infiltration through the windows are also neglected. The regulation on indoor air quality made it mandatory that the air change per hour be more than 0.7. Four models are suggested to study the effect of open and closed doors. Models 1 and 3 are open door types and models 2 and 4 are closed door types. The open types have 50 mm hole near the top of the door to substitute exhaust outlet. The ventilation effectiveness was evaluated by 3-dimensional numerical simulation using finite volume method by a commercial software. This work compares air flow, temperature of air, age of air and the efficiency of ventilation of apartments with wooden doors of bedroom 1 and 2, which are open or closed.