• Journal of Korean Association for Spatial Structures
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• v.6 no.2 s.20
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• pp.61-68
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• 2006

In this thesis, a full-scale K shape damper test model was constructed in which a passive vibration control system. This passive vibration control system was incorporated with the use of a newly developed turbulent flow damper sealed by viscoelastic material. A series of tests and earthquake observation has been conducted in this test model. The purpose of the present thesis is to investigate the vibration response characteristics of the building and to verify the effectiveness of the vibration control system. By the static loading test, it was recognized that incorporation of the dampers had little influence on static horizontal stiffness of the building. Free vibration tests revealed that the dampers incorporated increased the damping ratio of the building up to 3 times compared with the undamped case. The effectiveness of the developed vibration control system was confirmed based on the excitation tests and earthquake response observation.

• Journal of Drive and Control
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• v.20 no.4
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• pp.17-26
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• 2023

A forklift is an industrial vehicle that lifts or transports heavy objects using a hydraulically operated fork, and is equipped with an automatic transmission for the convenience of repetitive transportation, loading, and unloading work. The Transmission Control Unit (TCU) is a key component in charge of the shift control function of an automatic transmission. It consists of an electric circuit with an input/output signal interface function and firmware running on a microcontroller. To develop TCU firmware, the development process of shifting algorithm design, firmware programming, verification test, and performance improvement must be repeated. A simulator is a device that simulates a mechanical system having dynamic characteristics in real time and simulates various sensor signals installed in the system. The embedded transmission simulator is a simulator that is embedded in the TCU firmware. information related to the mechanical system that is necessary for TCU normal operation. In this study, an embedded transmission simulator applied to the originally developed forklift TCU firmware was designed and used to verify various forklift shift control algorithms.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.220-225
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• 2013

In this study, active control system using sliding mode control method is presented to achieve the gust response alleviation of a three-dimensional flexible wing model. For this purpose, aeroservoelastic model which is composed of aeroelastic plant, control surface actuator model, and gust model depicting the atmospheric turbulence is formulated in the state space. The aerodynamic force generated by the motion of a trailing edge control surface of a flexible wing is made use of as control means. An active control system combining state feedback sliding mode controller and state estimator based on measured responses such as wing tip acceleration and wing root strain is designed for gust response alleviation of a flexible wing aeroservoelastic model. The performance of the controller designed is demonstrated via numerical simulation for the representative flexible wing model under gust loading conditions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.363-369
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• 1999

In these days, there are a lot of studies in the port automation, for example, unmanned container trasporter, unmanned gantry crain, and automatic terminal operation systems and so on. In terms of loading and unloading equipments. we can consider container transporter. This paper describes the automatic control for the UCT(unmanned container transporter), especially steering control systems. UCT is now operated on ECT port in Netherland and tested on PSA ports in Singapore. So we present a design on the controller using neural network PID(NNPID) controller to control the steering system and we use the neural network self-tuner to tune the PID parameters. The computer simulations show that our proposed controller has better performances than those of the other.

• Journal of Chest Surgery
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• v.44 no.3
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• pp.208-214
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• 2011

Background: Periprocedural treatment with high-dose statins is known to have cardioprotective and pleiotropic effects, such as anti-thrombotic and anti-inflammatory actions. We aimed to assess the efficacy of high-dose rosuvastatin loading in patients with stable angina undergoing off-pump coronary artery bypass grafting (OPCAB). Materials and Methods: A total of 142 patients with stable angina who were scheduled to undergo surgical myocardial revascularization were randomized to receive either pre-treatment with 60-mg rosuvastatin (rosuvastatin group, n=71) or no pre-treatment (control group, n=71) before OPCAB. The primary endpoint was the 30-day incidence of major adverse cardiac events (MACEs). The secondary endpoint was the change in the degree of myocardial ischemia as evaluated with creatine kinase-myocardial band (CK-MB) and troponin T (TnT). Results: There were no significant intergroup differences in preoperative risk factors or operative strategy. MACEs within 30 days after OPCAB occurred in one patient (1.4%) in the rosuvastatin group and four patients (5.6%) in the control group, respectively (p=0.37). Preoperative CK-MB and TnT were not different between the groups. After OPCAB, the mean maximum CK-MB was significantly higher in the control group (rosuvastatin group $10.7{\pm}9.75$ ng/mL, control group $14.6{\pm}12.9$ ng/mL, p=0.04). Furthermore, the mean levels of maximum TnT were significantly higher in the control group (rosuvastatin group $0.18{\pm}0.16$ ng/mL, control group $0.39{\pm}0.70$ ng/mL, p=0.02). Conclusion: Our findings suggest that high-dose rosuvastatin loading before OPCAB surgery did not result in a significant reduction of 30-day MACEs. However, high-dose rosuvastatin reduced myocardial ischemia after OPCAB.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.144-151
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• 2009

Objective: To compare two testing protocols for evaluating range of motion (ROM) changes in the preloaded cadaveric spines implanted with a mobile core type Charite$^{TM}$ lumbar artificial disc. Methods: Using five human cadaveric lumbosacral spines (L2-S2), baseline ROMs were measured with a bending moment of 8 Nm for all motion modes (flexion/extension, lateral bending, and axial rotation) in intact spine. The ROM was tracked using a video-based motion-capturing system. After the Charite$^{TM}$ disc was implanted at the L4-L5 level, the measurement was repeated using two different methods: 1) loading up to 8 Nm with the compressive follower preload as in testing the intact spine (Load control protocol), 2) loading in displacement control until the total ROM of L2-S2 matches that when the intact spine was loaded under load control (Hybrid protocol). The comparison between the data of each protocol was performed. Results: The ROMs of the L4-L5 arthroplasty level were increased in all test modalities (p < 0.05 in bending and rotation) under both load and hybrid protocols. At the adjacent segments, the ROMs were increased in all modes except flexion under load control protocol. Under hybrid protocol, the adjacent segments demonstrated decreased ROMs in all modalities except extension at the inferior segment. Statistical significance between load and hybrid protocols was observed during bending and rotation at the operative and adjacent levels (p< 0.05). Conclusion: In hybrid protocol, the Charite$^{TM}$ disc provided a relatively better restoration of ROM, than in the load control protocol, reproducing clinical observations in terms of motion following surgery.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.97-99
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• 2008

It is possible to suppress voltage drops, power loading fluctuations and regeneration power lapses for DC railway systems by applying an energy storage system. Recently the electric double layer capacitor (EDLC) of the rapid charge/discharge type has been developed and used in wide ranges. The on board energy storage system with supercapacitor for railway vehicles presented in this paper seems to be a reliable technical solution with an enormous energy saving potential. In this paper, an efficient charge and discharge control method of a bidirectional DC-DC converter using the supercapacitor is proposed.

• Journal of the Korean Society of Safety
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• v.24 no.4
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• pp.11-16
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• 2009

This research investigates contact angle of Linear Guide Way through a experimental result and theoretical analysis. Since last ten years, most of researchers who concerned with the precision machinery and semiconductor device production etc. so the researches about Linear Guide Way have been unnoticed. The precision machinery and semiconductor device production system has the principle which transfers the mechanical moving to accuracy position control. The Linear Guide Way system has the principle which transfers mechanical moving to accuracy position control is very important to improve performance of the precision machinery and semiconductor device production system. So, In this research, in order to improvement for producing Linear Guide Way, bearing loading analysis and contact angle change through Linear Guide Way theoretical analysis and bearing modeling. Through this study, we may expect that there will be more improvement for producing Linear Guide Way.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1017-1021
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• 2005

There is a need for effective tracking and control of material loading and delivery time especially during the finishing-work phases to eliminate the need for lay-down space on the site. Hence, it is essential to monitor the relevant information regarding material procurement in construction sites, and it is also the key factor for successful site control and the adoption of the Just-in-Time concept for high-rise building construction. The purpose of this study is to test RFID's readability in order to develop a finishing material monitoring system through the application of RFID technology.

• Journal of Korean Association for Spatial Structures
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• v.23 no.3
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• pp.79-86
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• 2023

Damage to gas and fire protection piping systems can lead to secondary disasters after an earthquake, so their seismic design is crucial. Accordingly, various types of seismic restraint installations are being devised, and a new suspended piping trapeze restraint installation has also recently been developed in Korea. In this study, a cyclic loading test was performed on the developed trapeze support system, and its performance was evaluated according to ASHRAE 171, the standard for seismic and wind restraint design established by the American Society of Refrigeration and Air Conditioning Engineers (ASHRAE). The three support system specimens did not break or fracture, causing only insignificant deformations until the end of the experiment. Based on the experimentally rated strength and displacement performance, this trapeze support system is expected to control the seismic movement of piping during an earthquake.