• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.1
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• pp.100-106
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• 2020

In this paper smart shoes for dementia care using embedded boards and Low Power Wide Area technology and their application software are implemented. The communication board composed of Cortex-M3 board and LoRa module is embedded into groove made in outsole of smart shoes. Including the mold, the shoe outsole was manufactured by hand. By using application software and embedded board, caregiver can track the position of dementia patient using GPS and LoRa network. The location tracking and data transmission operations of smart shoes have been successfully verified in the outdoor environment. The smart shoes of this paper are applicable to a safety device to prevent the disappearance of demented patients through results of experiments and if bigdata is collected and analyzed by deep-learning, it may be helpful to analyze the predictive path of dementia patients or the pattern of dementia.

• Smart Structures and Systems
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• v.22 no.4
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• pp.469-479
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• 2018

The present research study utilizes a multi-objective optimization method for Pareto optimization of an eight-degree of freedom full vehicle vibration model, adopting a non-dominated sorting genetic algorithm II (NSGA-II). In this research, a full set of ride comfort as well as ride safety parameters are considered as objective functions. These objective functions are divided in to two groups (ride comfort group and ride safety group) where the ones in one group are in conflict with those in the other. Also, in this research, a special optimizing technique and combinational method consisting of weighted sum method and Pareto optimization are applied to transform Pareto double-objective optimization to Pareto full-objective optimization which can simultaneously minimize all objectives. Using this technique, the full set of ride parameters of three dimensional vehicle model are minimizing simultaneously. In derived Pareto front, unique trade-off design points can selected which are non-dominated solutions of optimizing the weighted sum comfort parameters versus weighted sum safety parameters. The comparison of the obtained results with those reported in the literature, demonstrates the distinction and comprehensiveness of the results arrived in the present study.

• Nuclear Engineering and Technology
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• v.41 no.1
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• pp.53-62
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• 2009

A set of experiments has been conducted on the performance sensitivity of the passive residual heat removal system (PRHRS) for an advanced integral type reactor, SMART, by using a high temperature and high pressure thermal-hydraulic test facility, the VISTA facility. In this paper the effects of the opening delay of the PRHRS bypass valves and the closing delay of the secondary system isolation valves, and the initial water level and the initial pressure of the compensating tank (CT) are investigated. During the reference test a stable flow occurs in a natural circulation loop that is composed of a steam generator secondary side, a secondary system, and a PRHRS; this is ascertained by a repetition test. When the PRHRS bypass valves are operated 10 seconds later than the secondary system isolation valves, the primary system is not properly cooled. When the secondary system isolation valves are operated 10 or 30 seconds later than the PRHRS bypass valves, the primary system is effectively cooled but the inventory of the PRHRS CT is drained earlier. As the initial water level of the CT is lowered to 16% of the full water level, the water is quickly drained and then nitrogen gas is introduced into the PRHRS, resulting in the deterioration of the PRHRS performance. When the initial pressure of the PRHRS is at 0.1MPa, the natural circulation is not performed properly. When the initial pressures of the PRHRS are 2.5 or 3.5 MPa, they show better performance than did the reference test.

• Smart Structures and Systems
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• v.25 no.5
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• pp.531-541
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• 2020

This paper demonstrates the possibility of evaluating the safety of a building right after an earthquake using consumer-grade surveillance cameras installed in the building. Two cameras are used in each story to extract the time history of interstory drift during the earthquake based on camera calibration, stereo triangulation, and image template matching techniques. The interstory drift of several markers on the rigid floor are used to estimate the motion of the geometric center using the least square approach, then the horizontal interstory drift of any location on the floor can be estimated. A shaking table collapse test of a steel building was conducted to verify the proposed approach. The results indicate that the accuracy of the interstory drift measured by the cameras is high enough to estimate the damage state of the building based on the fragility curve of the interstory drift ratio. On the other hand, the interstory drift measured by an accelerometer tends to underestimate the damage state when residual interstory drift occurs because the low frequency content of the displacement signal is eliminated when high-pass filtering is employed for baseline correction.

• Journal of Korea Ship Safrty Technology Authority
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• s.33
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• pp.32-52
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• 2012

선박의 경사시험에 사용되는 수동식 계측기기는 측정 자체가 사람의 관능에 의존하기 때문에 현장계측자 개인의 경험에 따라 측정 데이타의 신뢰도에 편차가 발생할 개연성이 높다. 그러나 경험치에 의존하지 않고 경사시험의 신뢰성을 담보할 측정방법의 개선이나 개발은 현재까지 없었다. 경사시험 시 정밀한 계측센서를 이용하여 경사각을 계측한다면, 선박의 복원성판정에 정확성을 기할 수 있을 것이다. 따라서 본 연구에서는 전자식 자이로 센서가 내장된 스마트폰(태블릿 PC)을 이용하여 선박의 경사각을 계측하고, 아울러 그에 따른 선박의 경하 상태의 배수량 및 중량중심을 자동으로 계산할 수 있는 앱을 개발하여 선박 복원성판정의 유효성을 검증하였다.

• Smart Structures and Systems
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• v.26 no.6
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• pp.703-720
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• 2020

This paper investigates the safety of the wind turbine blade against excessive deformation. For this purpose, the performance of the blade in the along-wind direction is improved by longitudinal stiffener made of shape memory alloy. The rationale behind the selection of this smart material is due to its ability to offer excellent thermo-mechanical behaviour at low strain. Here, Liang-Roger model is adopted for vibration control, and the super-elastic effects are utilised for blade stiffening. Turbulent wind fields are generated at the hub height using TurbSim and the corresponding loads are evaluated using blade element momentum theory. An efficient switching algorithm is developed along with performance curves that enable the designer to select an optimal mode of heating depending upon the operational scenario. Numerical results presented in this paper clearly demonstrate the performance envelope of the proposed stiffener and its influence on the reliability of the blade.

• Journal of Drive and Control
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• v.19 no.1
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• pp.1-7
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• 2022

Recently, a re-painting robot was developed to semi-automatically conduct blasting work in bridge spaces to improve work productivity and worker safety. In this study, a vision sensor-based monitoring module was developed to automatically move the re-painting robot along the path. The monitoring module provides direction information to the robot by analyzing the boundary between the painting surface and the metal surface. To stably measure images in unstable environments, various techniques for improving image visibility were applied in this study. Then, the driving performance was verified in a similar environment.

• Convergence Security Journal
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• v.22 no.1
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• pp.129-134
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• 2022

A smart platform is defined as an evolved platform that realizes physical and virtual space into a hyper-connected environment by combining the existing platform and advanced IT technology. The hyper-connection that is the connection between information and information, infrastructure and infrastructure, infrastructure and information, or space and service, enables the realization and provision of high-quality services that significantly change the quality of life and environment of users. In addition, it is providing everyone with the effect of significantly improving the social safety net and personal health management level by implementing smart government and smart healthcare. A lot of information produced and consumed in these processes can act as a factor threatening the basic rights of the public and individuals by the informations themselves or through big data analysis. In particular, as the smart platform as a core function that forms the ecosystem of a smart city is naturally and continuously expanded, it faces a huge security burden in data processing and network operation. In this paper, platform components as core functions of smart city and appropriate security threats and countermeasures are studied.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.115-128
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• 2016

Many research activities to reduce accidents on the road and to improve traffic efficiency have been performed and almost research projects are developing technologies and services based on C-ITS technology nowadays. The main concept of C-ITS is improving road safety and traffic efficiency by sharing and reproducing information between various elements. To accomplish this goal, V2X communication technology has been adopted. In Korea, we have studied V2X communication technology in support of SMART-Highway research project and are managing test-bed to verify the developed technology recently. In this paper, we introduce SMART-Highway test-bed and show the procedure and result of V2X communication performance analysis on the test-bed.

• Journal of KIBIM
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• v.10 no.3
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• pp.1-11
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• 2020

The introduction of BIM technology is expanding not only in the field of design and construction, but also in the maintenance and use stage. In particular, researchers are looking to build a smart facility management system that integrates advanced IT technology and BIM. This study proposes the parts to be used and added to the BIM information, focusing on information generated and exchanged in the application case that is an issue during the current facility maintenance work by introducing the smart facility management technology and its use cases. The effectiveness of this proposal is compared with the scenario in which BIM-based facility safety management is applied and the current business scenario. In conclusion, the requirements for smart facility management are analyzed, and linkable parts between facility management tasks and BIM data that should be reflected in the facility management system are presented. In the maintenance phase, through the use case scenario, the facility management phase is subdivided according to the characteristics and contents of the work. In addition, information about the facilities required for each task is specified. Furthermore, it is examined whether BIM data and IT information can be linked with existing facility management systems. It is a process and guideline that can be provided to practitioners who want to introduce BIM and smart technology to facility management. It can define the required data items and levels according to the required information step by step based on the maintenance case.