• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.514-517
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• 1995

A new stroke output control algorithm with a fuzzy logic for an electrohydraulic left ventricular assist device(EH-LVAD) was developed. The EH-LVAD pumps out blood from left atrium actively. Excessive suction of blood may cause fatal damage in left atrium. The LVAD has to provide a maximal stroke output without collapse of left atrium. In this study a new fuzzy algorithm for predicting and detecting suction and doing proper action on LVAD without using an extra pressure sensor but with bellows pressure signal and motor current signal is developed. The performance of the fuzzy control algorithm is demonstrated by the results from mock circulatory experiments.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.161-166
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• 2003

The purpose Performance degradation of concrete structures is generally caused by the deteriorations, such as surface collapse, pop-out, crack, and so on. It may result in serious defects of the concrete structures. Thus it is very important to detect and repair the defects of concrete structures within a proper time to assure the structural safety. However, the defects due to the deteriorations are usually difficult to find by visual inspection. A sensor is developed in this study, which may give early indications for degradation of concrete structures and show the locations of the demage. Cracks can be defected by the liquid in a small glass capsules which are embedded in the concrete structures. This paper discusses the applicability of that was developed smart concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.191-199
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• 2000

Since a few decade ago, there has been a demand on the safety monitoring of civil infrastructures, such as bridges, in order to prevent possibly occurrable disaster due to human negligence. The main cause for a failure or collapse of structures is absolutely a structural crack. For the reason, it is necessary to monitor the propagation of a structural crack. But a crack in bridges is gradually propagating with the traffic loads through the long term. There are lots of sensors to monitor structural cracks on bridges, but much information about them was not given so far. Therefore, in this study, the experimental comparison for long-term monitoring sensors, especially, strain measurement sensors, in terms of duration, temperature dependency, accuracy was made extensively.

• Korean Institute of Interior Design Journal
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• v.21 no.3
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• pp.87-94
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• 2012

This thesis has purpose of explaining that blur color is not only appreciated but also undecided spacial color in contemporary space design and examining effects of space experience through the light. In keeping such developments, blur color has been perceived as the object of another tool in contemporary space and has provided us with new views by providing various program, sensor and screen from digital media. With the expansion of blur color, light has changed a spacial color structural that is not simple meaning factor into the essential concept. So this research aims to understand the principle of blur color in Olafur Eliasson's work, which of the fine artist in diverse fields from installation art to media art. The principle of blur color such as deconstruction of vanishing point, dimensional transfer, color gradation, and fiction of visual perception makes it possible to extract the expressed element and method of blur color. Meanwhile, the features of blur color such as sense of depth from viewpoint changes, hybrid from collapse of order, media metamorphosis from reconstitution and interaction from uncanny can be inferred from case analysis.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.946-948
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• 2003

This paper describes the development of an INS (Inertial Navigation System) integrated positioning system, which can monitor and track the firefighter's position for assisting effective fire-fighting activity and rescue services. The INS consists of highly accurate three-axis gyro sensor and three-axis accelerometer. By integrating an INS to positioning system, it is also possible to obtain the information of firefighter's physical state (e.g. standing, collapse and crouch) of posture including velocity. Consequently, this research would obviously make a contribution to effective rescue activities and safety of firefighters. Besides, this paper presents results from field tests conducted at Tokyo University demonstrating its viability and utility. We also summarize the overall system requirements and architecture, and describe the hardware and software used in the prototype system in detail.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.905-908
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• 2007

Concrete placement work is executed using temporary structures such as formwork, support, etc. The temporary structures could collapse when they are not properly supported, and need to be monitored for structural safety. This paper introduces a USN (Ubiquitous Sensor Network)-based monitoring system that are being tested at the Pusan National University for increasing structural safety. The system takes advantage of ubiquitous technologies together with a variety of sensors, which allows for wireless transmission of construction monitoring data. The temporary structures are constantly monitored to find out whether the structures are being supported in a stable condition. A field test is being conducted to acquire data, and use them for evaluating the safety condition of the construction operation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.153-172
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• 2018

Overloading of Commercial vehicles have been an important area of transportation as one of the main causes of pavement damage, bridge collapse, severe traffic accident, etc. In this study, we analyzed the effects of overweight prevention by analyzing overweight driving patterns and using weight sensors. First, we analyzed relevant literatures of overweight and surveyed the commercial weight sensors. Then we chose the typical type of overweight vehicles based of overweight enforcement data analysis. MEMs inclinometer weight sensor were installed to 10 test vehicles and data was collected by weight sensors and gps in real time. As a result of gross vehicle weight and axle weight analysis, it was found weight sensor could decrease overweight rate. However, since the number of samples of test vehicles is insufficient to represent the whole commercial vehicle, further studies are deemed possible through the extension test.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.57-68
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• 2018

A system to prevent disasters by collecting and analyzing environmental information such as road surface sedimentation, sinkholes, collapse risk of bridges, temperature and humidity around tram station is continuously monitored by monitoring the condition of road surface when constructing tram which is one of the urban railways. In this paper, we propose a wireless network security management system for tram roads based on LPWA that can recognize risk factors of road surface, bridge and tram station of tram in advance and prevent risk. The proposed system consists of a sensor node that detects the state of the tram road surface, a gateway that collects sensor information, and a safety management system that monitors the safety and environmental conditions of the tram road surface, and applies the low power long distance communication technology. As a result of comparing the proposed system with the LTE system in the field test, it was confirmed that there is no significant difference between the sensor information value and the critical alarm level in the monitoring system.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.99-106
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• 2016

When radon is staying at alveoli and bronchial tubes, the collapse of radon creates progeny nuclides (alpha ray, beta ray, gamma ray, etc.). They emit radiation causing a mutation in the chromosome of the cell, resulting in lung cancer. In other words, the main cause of lung cancer is radiation emitting as the result of radon collapse rather than radon gas. The 82% of radiation exposed to people is the natural radiation. Most of the natural radiation is radon. If we properly control the concentration of radon indoors, the probability of occurrence of lung cancer could be decreases to be 70%. Until now, to measure the indoor radon concentration, imported radon sensors are needed. So, DB construction of indoor radon emission and popular radon measuring apparatus should be developed. In this paper, we propose the radon detecting method using PIN photodiode. Also, we confirmed the PIN photodiode could be used as radon sensor module through some experimental studies.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.44-50
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• 2019

The underwater structures of landing pier are not easy to access and it is difficult to check the damage. Lately, typhoons and earthquakes have occurred frequently, which may cause damage to underwater structures of landing pier. In this study, to prevent collapse of underwater structures and to maintain systematically, the application method of FBG sensors and safety evaluation methods were studied. In order to confirm the application of the FBG sensor to the circular steel pipe used as a pile on the landing pier, we conducted laboratory tests and confirmed that the FBG sensor should be applied by welding. As a result of structural analysis of the landing pier structure, the optimal position of FBG sensor confirmed. The stresses on the dead load were calculated by structural analysis, the stresses on the live load were calculated by using the data obtained from the FBG sensor, and then the stress acting on the pile was calculated by adding the two stresses. The calculated stress was compared with the allowable stress to evaluate the safety of the pile. This study was carried out as a basic study to find a way to evaluate the safety of the landing pier in real time.