• Journal of information and communication convergence engineering
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• 제12권4호
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• pp.237-245
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• 2014

In this study, software-based countermeasures against a side-channel cryptanalysis of the Rabbit stream cipher were developed using Moteiv's Tmote Sky, a popular wireless sensor mote based on the Berkeley TelosB, as the target platform. The countermeasures build upon previous work by improving mask generation, masking and hiding other components of the algorithm, and introducing a key refreshment scheme. Our contribution brings improvements to previous countermeasures making the implementation resistant to higher-order attacks. Four functional metrics, namely resiliency, robustness, resistance, and scalability, were used for the assessment. Finally, performance costs were measured using memory usage and execution time. In this work, it was demonstrated that although attacks can be feasibly carried out on unprotected systems, the proposed countermeasures can also be feasibly developed and deployed on resource-constrained devices, such as wireless sensors.

• 한국소음진동공학회논문집
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• 제24권2호
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• pp.131-138
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• 2014

Vibration measurement of rotating shafts by installing sensors such as accelerometers or displacement sensors is costly and dangerous in some cases. As an alternative method, vibration measurement using camera images has been researched because sensor installation is not needed and displacement of a rotating shaft can be directly evaluated. This paper also suggests the enhanced technique applicable to the measurement of vibration of a large-scale rotating shaft. The concurrent methods based on camera images use marks, which are hardly applicable to rotating shafts. The proposed method measures vibration without any marks by evaluating shape errors. The working principle of the method is described and verified by a series of experiments.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1995년도 춘계학술대회논문집
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• pp.55-61
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• 1995

We spend about 40% of lifte time on a bed and seek how such amount of time is spent comfort. Bed comfort has been pursuited. The pressure distributions on a bed by body pressure has been considered as one of the most important factors of bed comfort. This study is to quantify the subjective assessment by the body pressure distribution and develop the objective evaluation method of bed comfort. A new measurement system for body pressure on a bed was developed in this study. The thin film pressure sensor (FSR: Force Sensing Resistor) of an elastomer-type was used to prevent the distortion of contact pressure. The pressure distribution is measured by FSR and displayed on the monitor by color-coded contour patterns. Some of the bed test results were described. And the relations between body pressure distribution and bed comfort were evaluated.

• 해양환경안전학회지
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• 제6권1호
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• pp.1-9
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• 2000

The paper describes system design of next-generation Ship Simulator using Virtual Reality (VRSS), well known as human-computer interaction. VRSS system is required to have special condition that comprises multiple user participants such as captain, officer, pilot, and quartermaster. To cope with that condition, core technologies were explored and proposed multi-networking system with broker server. The evaluation of the proposed system was done with PC-based immersion-type VR device, constituted with HMD (Head Mounted Display), Head Tracking Sensor, Puck, Headphone, and Microphone. Using the VR device, assessment test was carried out in a virtual bridge with 3D objects, which are created by VRML (Virtual Reality Model Language) program. As results of tests, it is shown that the cybernetic 3D objects were act as if real things in a real ship's bridge. Therefore, interesting interaction with participants can be obtained in the system, Thus, we found that the proposed system architecture can be applicable to VRSS system construction.

• International Journal of Concrete Structures and Materials
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• 제10권2호
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• pp.189-203
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• 2016

This paper investigates on the use of advanced optical measurement methods, i.e. 3D coordinate measurement machines (3D CMM) and stereo-vision digital image correlation (3D DIC), for the mechanical analysis of shear deficient prestressed concrete members. Firstly, the experimental program is elaborated. Secondly, the working principle, experimental setup and corresponding accuracy and precision of the considered optical measurement techniques are reported. A novel way to apply synthesised strain sensor patterns for DIC is introduced. Thirdly, the experimental results are reported and an analysis is made of the structural behaviour based on the gathered experimental data. Both techniques yielded useful and complete data in comparison to traditional mechanical measurement techniques and allowed for the assessment of the mechanical behaviour of the reported test specimens. The identified structural behaviour presented in this paper can be used to optimize design procedure for shear-critical structural concrete members.

• Journal of Advanced Marine Engineering and Technology
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• 제32권3호
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• pp.437-445
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• 2008

This paper deals with the experimental assessment of the vibration suppression of the smart structures. First. we have presented a new high-speed active control system using the DSP320C6713 microprocessor. A peripheral system developed is composed of a data acquisition system, N/D and D/A converters, piezoelectric (PZT) actuator/sensors, and drivers for fast data processing. Next, we have tested the processing time of the peripheral devices, and provided the corresponding test results. Since fast data processing is very important in the active vibration control of the structures, we have focused on achieving the fast loop times of the control system. Finally, numerous experiments were carried out on the aluminum plate to validate the superior performance of the vibration control system at different control loop times.

• Structural Engineering and Mechanics
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• 제62권5호
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• pp.519-535
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• 2017

In this article, static analysis of a magneto-electro-elastic (MEE) beam subjected to various thermal loading and boundary conditions has been investigated. Influence of pyroeffects (pyroelectric and pyromagnetic) on the direct quantities (displacements and the potentials) of the MEE beam under different boundary conditions is studied. The finite element (FE) formulation of the MEE beam is developed using the total potential energy principle and the constitutive equations of the MEE material taking into account the coupling between elastic, electric, magnetic and thermal properties. Using the Maxwell electrostatic and electromagnetic relations, variation of stresses, displacements, electric and magnetic potentials along the length of the MEE beam are investigated. Effect of volume fractions, aspect ratio and boundary conditions on the direct quantities in thermal environment has been determined. The present investigation may be useful in design and analysis of magnetoelectroelastic smart structures and sensor applications.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.780-783
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• 2006

The KOrea Multi-Purpose Satellite-2 (KOMPSAT-2) was launched in July 2006 and the main mission of the KOMPSAT-2 is a high resolution imaging for the cartography of Korea peninsula by utilizing Multi Spectral Camera (MSC) images. The camera resolutions are 1 m in panchromatic scene and 4 m in multi-spectral imaging. This paper provides an initial geometric accuracy assessment of the KOMPSAT-2 high resolution image without ground control points and briefly introduces the sensor model of KOMPSAT-2. Also investigated and evaluated the obtained 3-dimensional terrain information using the MSC pass image and scene images acquired from the KOMPSAT-2 satellite.

• 전기학회논문지
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• 제61권6호
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• pp.845-850
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• 2012

Currently power of the diesel engine is increasing continuously, where the wearing problems become more severe. The wearing happens irregularly inside the cylinder, which causes a high burden to the marine engine. In this paper, a novel scheme to measure the wearing and to represent the engine states has been proposed. To monitoring the states of the marine engine efficiently, a laser displacement sensor has been utilized to measure the wearing happening inside the marine engine. To eliminate the noise signals in the distance measurement, the wavelet transform has been adopted, which is robust against the noises caused by vibrations. An engine simulator is designed to develop the system for measuring the engine wears, where the superiority of the wavelet transform against the conventional filtering schemes has been demonstrated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.64-66
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• 2007

In this paper, a digital inclinometer to measure the angle and acceleration signals of subject laid on Roll was designed. The designed system consists of a tilt sensor, biaxial accelerometer, microcontroller and BlueTooth module. The designed digital inclinometer was easy to handle and easy to wear. To evaluate the performance of the system, we measured simultaneously the angle and acceleration signals from the 3 subjects on the Roll with two instruments which are ZEBRIS and our system. The measured signals were processed by statistical method and then the correlation coefficient of 0.93 was shown. From the results, the designed digital inclinometer is shown to be useful in assessment of body movement.