• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.7
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• pp.3475-3496
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• 2018

Most of current watermarking algorithms for GIS vector data embed copyright information by means of modifying the coordinate values, which will do harm to its quality and accuracy. To preserve the fidelity of vector line data and protect its copyright at the same time, a lossless watermarking algorithm is proposed based on storage feature in this paper. Firstly, the superiority of embedding watermark based on storage feature is demonstrated theoretically and technically. Then, the basic concepts and operations on storage feature have been defined including length and angle of the polyline feature. In the process of embedding watermark, the watermark information is embedded into directions of polyline feature by the quantitative mechanism, while the positions of embedding watermark are determined by the feature length. Hence, the watermark can be extracted by the same geometric features without original data or watermark. Finally, experiments have been conducted to show that coordinate values remain unchanged after embedding watermark. Moreover, experimental results are presented to illustrate the effectiveness of the method.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.1
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• pp.134-140
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• 2017

CFRP has many industrial applications due to its low weight and high strength properties. CFRP is a composite material composed of carbon fibers embedded in a polymer matrix; it provides excellent resistance to fatigue wear, corrosion, and breakage due to fatigue. It is increasingly demanded in aircraft, automotive, and medical industries due to its superior properties to aluminum alloys, which were once considered the most suitable for specific applications. The basic machining methods of CFRP are drilling and route milling. However, in the case of drilling, the delamination of each layer, uncut fiber, resin burning, spalling, and exit burrs are barriers to successful application. This paper investigates the occurrence of exit burrs when drilling holes with ultrasonic vibration. Depending on design parameters such as the point angle, the characteristics of hole drilling were identified and appropriate machining conditions were considered.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.70-76
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• 2013

Recently, the performance and function of electrical and electronic system in automotive vehicles is developing at a rapid rate with the advancement of IT technologies. Combined together with micro-controller and sensor technologies, the Vehicle Smart System (VSS) being developed to improve driver's convenience and comfort has been employed to a variety of applications. In addition to the convenience system, the Auto-parking Assistance System (AAS) that is now attracting a new attention has been already applied to some vehicles, but it is currently limited to luxury car models only. In this paper, we present a fuzzy controller that enables autonomous parking assistance without the AAS. The controller can perform the assistance with information provided from moving status, current position and steering angle as one is able to park a car based on his/her experience and knowledge for driving and parking. We have evaluated its performance of the proposed controller by simulation and tested the excellence of the controller by building a model vehicle embedded with the micro-controllers.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.6
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• pp.539-546
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• 2014

This paper describes an ultra-precision electronic clinometer, which is based on the capacitive-based fluid type, for detection of small inclination angles. The main parts of the clinometer low-noise electronics are two capacitance measurement circuits for converting the capacitances of the capacitors of the clinometer into voltages, and a differential amplifier for obtaining the difference of the capacitances, which is proportional to the input inclination angle. A 16 bit analog to digital (AD) converter is also embedded into the same circuit board, whose output is sent to a PC via RS-232C, for achieving a small noise level down to tens of ${\mu}v$. A compensation method, which is referred to as the delay time method for shortening the stabilization time of the sensor was also discussed. Experimental results have shown the possibility of achieving a measurement resolution of $0.0001^{\circ}$ as well as the quick measurement with the delay time method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6190-6213
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• 2019

For small-scale vector data, restrictions on watermark scheme capacity and robustness limit the use of copyright protection. A watermarking scheme based on robust geometric features and capacity maximization strategy that simultaneously improves capacity and robustness is presented in this paper. The distance ratio and angle of adjacent vertices are chosen as the watermark domain due to their resistance to vertex and geometric attacks. Regarding watermark embedding and extraction, a capacity-improved strategy based on quantization index modulation, which divides more intervals to carry sufficient watermark bits, is proposed. By considering the error tolerance of the vector map and the numerical accuracy, the optimization of the capacity-improved strategy is studied to maximize the embedded watermark bits for each vertex. The experimental results demonstrated that the map distortion caused by watermarks is small and much lower than the map tolerance. Additionally, the proposed scheme can embed a copyright image of 1024 bits into vector data of 150 vertices, which reaches capacity at approximately 14 bits/vertex, and shows prominent robustness against vertex and geometric attacks for small-scale vector data.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.34.1-34.1
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• 2016

Galaxy clusters are the sites where the most massive galaxies are found, and so the most dramatic merger histories are embedded. Our deep (mu ~ 28 mag/arcsec^2) images of Abell 119 at z = 0.044 using the Blanco 4-m telescope at CTIO revealed post-merger signatures in ~35% of galaxies brighter than Mr < -19.5, suggesting that so many galaxies even in clusters have gone through galaxy mergers at recent epoch. We went further to understand the impact of mergers in cluster galaxies using stellar kinematics from the SAMI Integral Field Unit on the galaxies of Abell 119 in three aspects of kinematics : orientations, levels of rotation, and kinematic shapes. We found that 30% of the merger-featured galaxies show misalignment in the angle between the photometric major and the rotation axes, and most of them show complex kinematics. For comparison, only 5% of non-merger-featured galaxies show the misalignment. Moreover, our analysis using the Tully-Fisher relation shows that galaxy interactions can both enhance or reduce galaxy spin depending on the merger geometry. We present our preliminary result and discussion on the role of galaxy mergers in cluster environment from the perspective of kinematics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.763-764
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• 2017

The use of barcodes in mobile phones has become generalized, and barcodes are widely used in security-sensitive applications, including mobile payment and personal identification. Generally, images photographed by a mobile phone generate geometric distortion due to the shooting angle, resulting in low quality images. Embedding watermark for low quality images makes it difficult to satisfy transparency. To solve such problem, this paper focuses on the technique of embedding barcode images in the image taken by mobile phone and proposes barcode watermarking for protecting mobile-based ownership. The barcode watermark embedded in the image can be used to prove ownership since it is readable by a machine such as illegal copy.

• Geomechanics and Engineering
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• v.9 no.3
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• pp.313-328
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• 2015

In the present study, a CPT-based p-y analysis method was proposed for offshore mono-piles embedded in sands. Static and cyclic loading conditions were both taken into account for the proposed method. The continuous soil profiling capability of CPT was an important consideration for the proposed method, where detailed soil profile condition with depth can be readily incorporated into the analysis. The hyperbolic function was adopted to describe the non-linear p-y curves. For the proposed hyperbolic p-y relationship, the ultimate lateral soil resistance $p_u$ was given as a function of the cone resistance, which is directly introduced into the analysis as an input data. For cyclic loading condition, two different cyclic modification factors were considered and compared. Case examples were selected to check the validity of the proposed CPT-based method. Calculated lateral displacements and bending moments from the proposed method were in good agreement with measured results for lateral displacement and bending moment profiles. It was observed the accuracy of calculated results for the conventional approach was largely dependent on the selection of friction angle that is to be adopted into the analysis.

• The Journal of Engineering Research
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• v.7 no.1
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• pp.61-70
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• 2005

Conventional geological survey utilizes the manual compass for mass amount of measurements of the geologic structure. Portable multifunction digital compass system was required by more detailed geological survey, due to increasing construction for rock slopes and runnels. In this paper, the system was implemented by using Intel PXA 255 embedded board as a system controller, and was composed of tilting sensor, digital azimuth sensor, and Global Positioning System (GPS) module. After the measured location, strike, and the angle of dip with our implemented system were transmitted to Personal Digital Assistant (PDA) or notebook, these data could be used for geologic structure analysis. It is expected that the availability of cheap and improved digital compass will reduce the coast and time of geological survey extensively.

• Journal of Power Electronics
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• v.15 no.1
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• pp.131-145
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• 2015

The voltage-source inverters (VSI) supplying a motor drive are prone to open transistor faults. To address this issue in fault-tolerant drives applicable to electric vehicles, a new open transistor fault diagnosis (FD) method is presented in this paper. According to the proposed method, in order to define the FD index, the phase angle of the converter output current is estimated by a simple trigonometric function. The proposed FD method is adaptable, simple, capable of detecting multiple open switch faults and robust to load operational variations. Keeping the FD in mind as a mandatory part of the fault tolerant control algorithm, the FD block is applied to a five-phase converter supplying a multiphase fault-tolerant PM motor drive with non-sinusoidal unbalanced current waveforms. To investigate the performance of the FD technique, the fault-tolerant sliding mode control (SMC) of a five-phase brushless direct current (BLDC) motor is developed in this paper with the embedded FD block. Once the theory is explained, experimental waveforms are obtained from a five-phase BLDC motor to show the effectiveness of the proposed FD method. The FD algorithm is implemented on a field programmable gate array (FPGA).