• Korean Journal of Computational Design and Engineering
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• v.14 no.3
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• pp.168-175
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• 2009

A recent advance in RFID technology is one of the major technological drives in reducing cost in logistics, distribution and even in the manufacturing sector. However, currently the technology is practically accepted only in the area of logistics and inventory control. The characteristic of these application areas is that the technology is used in the controllable environment. In this paper, we discuss a case study of using active and passive RFID technologies to automatically gather process information in the mold factory. Active RFID tags are attached on the main parts of molds and their positions in the floor are tracked with the routers. We also discuss on the idea of using mobile device with RFID reader to inquire information for molds on the spot in the factory floor. The inquirable information includes 3D design data and basic mold data. The paper shows implementation results with hardware configuration for the testbed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.12-13
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• 2019

Flexible Table Form is being used more frequently at the level of formwork in construction site. However, one of the most common structural frameworks, the RC column-beam structure, is having problems in these factors. To improve this problems, this study developed support devices and proposed installation specifications to enable application of the one-way void slab method to flexible table form. It is expected that the effects of reducing the self-weight of the slab in the floor slab construction using flexible table form.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.25-32
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• 2006

LonWorks over IP(LonWorks-IP) virtual device network(VDN) is an integrated form of LonWorks device network and IP data network. In especially real-time distributed servo applications on the factory floor, timely response is essential for predictive and preventive maintenance. The time delay in servo control on LonWorks-IP based VDN has highly stochastic nature. LonWorks-IP based VDN induced transmission delay deteriorates the performance and stability of the real-time distributed control system and can't give an effective preventive and predictive maintenance. In order to guarantee the stability and performance of the system, and give an effective preventive and predictive maintenance, LonWorks-IP based VDN induced time-varying uncertain time delay needs to be predicted and compensated. In this paper new Pill control scheme based on Smith predictor, disturbance observer and band pass filter is proposed and tested through computer simulation about position control of DC servo motor. It is shown that how can the proposed control scheme be designed to minimize the effects of uncertain varying time delay and model uncertainties. The validity of the proposed control scheme is compared and demonstrated with the comparison of internal model controllers(IMC) based on Smith predictor with and without disturbance observer.

• Journal of the Korean Society of Safety
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• v.37 no.3
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• pp.45-51
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• 2022

This paper focuses on a recently proposed asymmetric base-isolation coupling control system (ABiCS) for the vibration control of adjacent twin buildings. The ABiCS consists of inter-story diagonal dampers, a connecting damper between the two buildings, and a seismic isolation device at the base floor of one building. To investigate the control characteristics of ABiCS, a parametric study was performed by numerically simulating the 20-story twin buildings. In the parametric study, the control capacities of the inter-story diagonal dampers, connecting damper, and seismic isolation device were considered as varying parameters. The parametric study results indicate that the connecting damper between the two buildings reduces the responses of both buildings only at optimal or near-optimal capacity. In addition, adjusting the stiffness of the base isolation is found to be the most effective method for improving seismic performance and achieving cost-effectiveness. Accordingly, we presented a scenario-based performance improvement approach in which reducing the stiffness of the base isolation device could be an effective technique to improve the seismic performance of both buildings. However, note that checking the maximum allowable displacement of the base isolation device is essential.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.147-148
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• 2023

Steel doors, which are common in general buildings, do not seal the gap between the door and the floor, so drafts, noise, dust, and lights flow from the outside, and shielding devices are installed in various materials and methods, such as adding magnetic gate paper to the side of the door or installing a gasket under the door, but performance is limited. Accordingly, in order to fundamentally solve these problems, we researched and developed a double gap blocking device that can improve fire resistance and airtightness performance in steel doors. Unlike general products, the double gap blocking device has the advantage of maximizing airtight performance by forming an air layer in the center when the door is closed, as well as greatly improving the fire resistance performance, which is the basic performance of the fire door.

• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.78-86
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• 2008

The aim of this paper is to show the daylight environment of a light pipe system according to sun movement. A light pipe system has been mounted on the roof of the windowless full scale model: the solar spot has diameter of 0.65m and is 1.3m long, giving an aspect ratio of 1:2. The full scale model was installed on the rooftop of the SHINAN apartment in Yongin city that has no obstructions against sunlight. The test room is equipped with sensors for the measurements of the internal illuminance and has an area of 6m(W)$\times$6m(D)$\times$4m(H). The system has been monitored with a data-logger to evaluate the cumulative distribution of illuminance on a floor-plane from 16th, April to 29th, May, 2008 over one month and selected clear sky condition. For the daylight performance of floor area, the totally 49 measuring points has been used to determine the internal illuminance and an HP datalogger(HP34970A) records the measurements for one consecutive month. The horizontal external illuminance has been measured with two outdoor sensors. This paper presents the results of monitoring light pipe system with internal/external illuminance ratio and cumulative frequency distribution of floor-plane illuminance are discussed The results show that lightpipe is proficient device for introducing daylight into the building. However It provided different daylight indoor environment with wide or narrow Interquatile range of illuminance, internal/external illuminance ratio and cumulative frequency distribution according to solar positions under suuny sky condition. For more achieving the improvement of lightpipes also include energy savings, user visual comfort with various indicators; seasonal solar height, room and lightpipes geometries.

• Publications of The Korean Astronomical Society
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• v.39 no.1
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• pp.1-12
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• 2024

In this study, we investigated the time signal devices of Deungnu (circa 1270) and Gungnu (1354), the water clocks produced during the Yuan Dynasty (1271-1368). These clocks influenced Heumgyeonggaknu (1438) of the Joseon Dynasty (1392-1910), exemplifying the automatic water clocks of the Yuan Dynasty. Deungnu, Gungnu, and Heumgyeonggaknu can be considered as automatic mechanical clocks capable of performances. The Jega-Yeoksang-Jip (Collection of Calendrical and Astronomical Theories of Various Chinese Masters) contains records of Deungnu extracted from the History of the Yuan Dynasty. We interpreted these records and analyzed reproduction models and technical data previously produced in China. The time signal device of Deungnu featured a four-story structure, with the top floor displaying the four divine constellations, the third floor showcasing models of these divinities, the second floor holding 12-h jacks and a 100-Mark ring, and the first floor with four musicians and a 100-Mark Time-Signal Puppet providing a variety of visual attractions. We developed a 3D model of Deungnu, proposing two possible mechanical devices to ensure that the Time-Signal Puppet simultaneously pointed to the 100-Mark graduations in the east, west, south, and north windows: one model reduced the rotation ratio of the 100-Mark ring to 1/4, whereas the other model maintained the rotation ratio using four separate 100-Mark rings. The power system of Deungnu was influenced by Suunuisangdae (the water-driven astronomical clock tower) of the Northern Song Dynasty (960-1127); this method was also applied to Heumgyeonggaknu in the Joseon Dynasty. In conclusion, these automatic water clocks of East Asia from the 13th to 15th centuries symbolized creativity and excellence, representing scientific devices that were the epitome of clock-making technology in their times.

• Journal of Korean Physical Therapy Science
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• v.30 no.4
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• pp.9-16
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• 2023

Background: Bedridden patients and disabled persons need help from a guardian or caregiver even in performing simple activities of daily living. In particular, for body transfer of them, the use of a transfer lift has been recommended. However, the devices currently in use have limitations in terms of support according to the individual's characteristics. This study aimed to develop a transfer lift device utilizing the patients' body-fitting sling equipped with an air tube inside the sling. In addition, we have conducted usability tests to examine the safety, effectiveness, and satisfaction with this device. Design: This study conducted usability tests with 10 healthy adults. Methods: Customized sling lifts are generally floor-based devices that consisted of a sling that holds the patient's body and a lift that moves the sling to the desired position. One characteristic feature of the device is an air tube, which is used on the sling to allow the patient's body can be adjusted. A usability test was performed in terms of the operators, who operated the device to transfer the patients. Ten operators tried the device and tested its usability. Results: The mean of 10 question for Questions was 4.18. Conclusion: The device can be useful in the advance- ment and commercialization of customized sling lifts, to ensure the safe and efficient transfer of persons with disabilities.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2653-2660
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• 2011

Facilities for disabled person are currently required for rolling stock and its requirements are increased. Researching and development to meet these requirements must be necessary. One of them, ramp between platform and train for wheelchair user was developed and applied in real project, the case is described as per the result. The main contents of this paper is for double leaves type wheelchair ramp development operated by manual. This ramp is fixed at floor area of interior with locking device. So operating is allowed for authorized person only. Beside of this, brief comparison with other types will be mentioned.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.505-508
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• 2004

단열완충재 제품간의 경량충원 저감성능 평가를 객관적이고 신속하게 판별하기 위하여 실험실용 시험장치를 개발하였다. EVA계열 및 EPPㆍEPS계열의 단열완충재들에 대한 경량충격원 시험에서 제품간의 성능비교가 가능하였으며, 동탄성계수 및 손실계수 측정과 병행함으로써 제품들간의 우열성을 보다 정밀하게 평가할 수 있었다.