• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1506-1516
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• 2012

In a ship block logistics application, acquisition of locations is required in order to identify location of the ship blocks. A Smart device equipped with a GPS sensor can be used as a mobile client for a ship block logistics application. However the precision of GPS components on a commercial smart device is not high enough. Therefore, using the GPS for localization may produce significant positioning errors in a ship block logistics system. This paper proposes a method to reduce errors in measuring locations using a smart device. Based on the knowledge of how the location information is used in a ship block logistics application, and the predictability of the client's moving line based on geographical layout of a shipyard area, our proposed technique enables a better prediction of the ship blocks location. Performance evaluation shows that the proposed technique can significantly reduce the positional error.

• Journal of the Korean Wood Science and Technology
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• v.25 no.3
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• pp.96-104
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• 1997

The objective of this research project was to develop the wooden footpath block to reuse of wood waste. Some physical and mechanical properties of the wooden block such as water absorption, thickness swelling, modulus of rupture, internal bond, density profile and impact resistance were studied. Water absorption and thickness swelling of the wooden block were greatly reduced when the wooden block was pressed inside the forming device than by conventional hot pressing. Also, Modulus of rupture and internal bond of the wooden block were increased greatly when the pressing was completed inside the forming device. The density profile of the wooden block was improved up to 93.5%, minimum to average density ratio. The wooden block manufactured in this study have excellent physical and mechanical prperties in comparison with existing wood based materials. So, these wooden blocks are applicable to footpth block or other exterior members.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.6
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• pp.568-572
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• 2006

This paper presents the device of recognizing image of the studded paving blocks, transmitting, the information by vibration to a visually handicapped person. Usually the blind uses the walking stick to recognize the studded paving block. This research uses a PCA (Principal Component Analysis) based image processing approach for recognizing the paving blocks. We classify the studded paving blocks into 5 classes, that is, vertical line block, right-declined line block, left-declined line block, dotted block and flat block. The 8 images for each of 5 classes are captured for each block by 112*120 pixels, then the eigenvectors are obtained in magnitude order of eigenvectors by using principal component analysis. The principal components for images can be calculated using projection of transformation matrix composed of eigenvectors. The classification has been executed using Euclidean's distance, so the block having minimum distance with a image is chosen as matched one. The result of classification is transmitted to the blind by electric vibration signals with different magnitudes and frequencies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.304-305
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• 2018

Recently, Industrial-IoT (IIoT) solutions accounted for up to 55% in 2016 and technological innovation and various new business models are being developed. In this paper, apply IIoT device in various environments and implement an ontology system that can interwork with block type IIoT device to easily add / change / delete sensor. The proposed system consists of IIoT device, block-type module, and ontology server. When the block-type module is connected to the IIoT device, the appropriate driver is installed and the firmware is downloaded through the ontology server. Even if a block is added / changed / deleted, it can be updated automatically. Through experiments, we confirmed that the normal operation of the server and the updating and downloading of software are implemented normally.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.3
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• pp.249-255
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• 2007

Under the situation of a fire, it is difficult for a rescue robot to use sensors such as vision sensor, ultrasonic sensor or laser distance sensor because of diffusion, refraction or block of light and sound by dense smoke. But, braille blocks that are installed for the visaully impaired at public places such as subway stations can be used as a map for autonomous mobile robot's localization and navigation. In this paper, we developed a laser sensor stan device which can detect braille blcoks in spite of dense smoke and integrated the device to the robot developed to carry out rescue mission in various hazardous disaster areas at KIST. We implemented MCL algorithm for robot's attitude estimation according to the scanned data and transformed a braille block map to a topological map and designed a nonlinear path tracking controller for autonomous navigation. From various simulations and experiments, we could verify that the developed laser sensor device and the proposed localization method are effective to autonomous tracking of braille blocks and the autonomous navigation robot system can be used for rescue under fire.

• Imaging Science in Dentistry
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• v.45 no.2
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• pp.117-122
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• 2015

Purpose: Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues. Materials and Methods: A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device. Results: Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block. Conclusion: Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.367-375
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• 2018

The present paper considers the contact between energy-saving device of ice-class vessel and ice block. The main objective of this study is to clarify the tendency of the ice impact force and the structural response as well as interaction effects of them. The contact analysis is performed by using LS-DYNA finite element code. The main collision scenario is based on Finnish-Swedish ice class rules and a stern duct model is used as an energy-saving device. For the contact force, two modelling approaches are adopted. One is dynamic indentation model of ice block based on the pressure-area curve. The other is numerical material modelling by LS-DYNA. The authors investigated the sensitivity of the structural response against the ice contact pressure, the interaction effect between structure and ice block, and the influence of eccentric collision. The results of these simulations are presented and discussed with respect to structural safety.

• Journal of the Semiconductor & Display Technology
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• v.14 no.2
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• pp.67-72
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• 2015

For the development of UFS device test system, M-PHY specifications should be matched with MIPI-standard which is analog signal protocol. In this paper, the implementation methodology and hardware structure for the M-PHY AFE (Analog Front End) Block was suggested that it can be implemented using universal components without ASIC process. The testing procedure has a jitter problem so to solve the problems we using ASIC process, normally but the ASIC process needs a lot of developing cost making the UFS device test system. In is paper, the suggestion was verified by the output signal which was compared to the MIPI-standard on the Prototype-board using universal components. The board was reduced the jitter on the condition of HS-TX and 5.824 Gbps Mode in SerDes (Serialize-deserializer). Finally, the suggestion and developed AFE block have a useful better than ASIC process on developing costs of the industrial UFS device test system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3399-3406
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• 2015

NRD(Network RamDisk) is a scheme which allows a system to use the memory of the remote systems just as his own block device via networking. Basically, it consists of a client requesting an NRD access and server providing the NRD. In this paper, we describe the design, implementation and experiment of the block device driver for accessing the NRD in the Linux kernel(2.6) level. First of all, we have analyzed the flow of processing the requests for accessing the block devices in the traditional Linux kernel and figured out the additional functions required for supporting the NRD. Then we have designed and implemented the device diver of NRD client and NRD server for providing these functions. Finally, we have established a NRD server system, and reviewed its functional feasibility by experimenting the requests of NRD access through the NRD device driver implemented on a NRD client.

• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.65-71
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• 2019

IAs smart device penetration rate is more than 90%, mobile transaction ratio using smart device is increasing. Smart contracts are used in various areas of real life including smart trading. By applying smart contracts to the platform for smart transactions through block-chain technology, the threat of hacking or forgery can be reduced. However, various threats to devices in smart transactions can pose a threat to the use of block chain Etherium, an important element in privilege and personal information management. Smart contract used in block chain Ethereum includes important information or transaction details of users. Therefore, in case of an attack of privilege elevation, it is very likely to exploit transaction details or forge or tamper with personal information inquiry. In this paper, we propose a detection and countermeasure method for privilege escalation attack, which is especially important for block chain for secure smart transaction using block chain Ethereum. When comparing the results of this study with the results of similar applications and researches, we showed about 12~13% improvement in performance and suggested the future countermeasures through packet analysis.