• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.1
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• pp.10-18
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• 2013

Recently, a fixed complexity LR(fcLR) technique was proposed. Also QR-LRL signal detection method was proposed in which all constellation symbols are tried as the symbol corresponding to the least reliable layer (LRL), thereby achieving high error performance. In this paper, we combine these two efficient methods to propose a novel detection method. When the LRL is disregarded in the process of LR, the worst case complexity of LR is significantly reduced. Also, the proposed method is shown to be superior to the conventional fcLR-based detection method from the perspective of error performance. Simulations are performed to demonstrate the efficacy of the proposed method.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.46-56
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• 2017

Recently, the spread of IoT technology has been spreading, and it has been applied to all industrial fields such as home / home appliance / medical care. Due to the low specification, low power consumption characteristic and communication data characteristic of IoT, implementation of existing algorithm is difficult thing. From this reason, we have proposed for the first time that encryption and decryption can be proceeded by introducing a kind of variable length bit XOR operation method which changes a variable the bit length value by using carry up and carry down method. We confirmed the practicality of encrypting short message data frequently processed by IoT device / QR code / RFID / NFC without changing the size of data before and after encryption.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.5
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• pp.377-384
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• 2013

In order to improve the security strength in the password based user authentication, in which the security vulnerability is increased while the same password is repeatedly used, the OTP(One-Time Password) system has been introduced. In the OTP systems, however, the user account information and OTP value may be hacked if the user PC is infected by the malicious codes, because the user types the OTP value, which is generated by the mobile device synchronized with the server, directly onto the user PC. In this paper, we propose a new method, called DTOTP(Dual Transmission OTP), to solve this security problem. The DTOTP system is an improved two-factor authentication method by using the dual transmission, in which the user performs the server authentication by typing the user account and password information onto the PC, and then for the OTP authentication the mobile device scans the QR code displayed on the PC and the OTP value is sent to the server directly. The proposed system provides more improved security strength than that of the existing OTP system, and also can adopt the existing OTP algorithm without any modification. As a result, the proposed system can be safely applied to various security services such like banking, portal, and game services.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.948-954
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• 2005

In this study, we investigated antimicrobial and cytotoxicity effects to each fraction extracted from Solanum lyratum (SL), which were extracted methanol (SLM) and then the extract was fractionated into five different types : hexane (SLMH), ethyl ether (SLMEE), ethylacetate (SLMEA), butanol (SLMB) and aqueous (SLMA). The antimicrobial activity was analyzed by the paper disc method. Among the various solvent fractions, SLMEA showed the strongest antimicrobial activies. The cytotoxicity of SL fractions on HeLa, MCF-7, HT-29 and HepG2 cells was evaluated by MTT assay. Among various partition layers, SLMEE showed the strongest cytotoxic effects to all cancer cell lines. We also observed that quinone reductase (QR) was induced by all fraction layers of SL to HepG2 cells. Since the QR-induced effects of SLMEE on HepG2 cells at $160{\mu}g/ml$ concentration showed 2.1 when compared with a control value of 1.0, inducer of QR for cancer protection may be contained in this fraction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.519-521
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• 2022

As appearance of diverse electric power supplies and fuel cells have been emerging, UAVs have capacity to prolong their flight missions. Nowadays, the rotary based UAVs that are commonly distributed on the open market, adapt rechargeable batteries and have around 50 centimeters in width and generally within 30 minutes in hovering flight capacities. UAV's flight time highly depends on the capacity and the weight of its batteries. To cope with the flight time, recharging methods are also being researched. their researches are mainly divided into coupled and decoupled in manner. In this article, we propose the method to refine the position more effectivly and precisely adapting QR Code and 3-D position estimation so that UAVs enable to land on the recharging system successfully.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10C
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• pp.1010-1015
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• 2009

In this paper, we propose a novel detection ordering technique for MIMO signal detection methods based on QR decomposition and successive interference cancellation (SIC). Recently, new signal detection methods for spatially multiplexed (SM) MIMO systems were proposed, where all the constellation points are tried as the first layer symbol, and the remaining layer symbols are estimated via SIC, producing candidate vectors. Finally, the ML metric values are calculated for the candidate vectors, that are again used to select the best symbol vector. It was also shown that the ordering method in the conventional V-BLAST is not suitable to these signal detection methods. In this paper, we propose a novel ordering method, and we show via computer simulations that the proposed ordering method improves the error performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.31-37
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• 2015

The security of the image information is very important in many areas of the IoT(Internet of Things), and study a number of ways to display the security (copyright, etc.). In this paper, information of image that is used by the IoT is converted to a DCT(Discrete Cosine Transform) and QC(Quantization Coefficient). And watermark (message) is to create a new encoded message(WMQR) through a QR Code. QC and WMQR applies LSB steganography techniques, can get the security (copyright, etc.) of image information. LSB steganographic techniques may be inserted according to a message (Watermark) to determine the location (Secret Key). The encoded image is sent to the recipient via the Internet. The reverse process can be obtained image and a QR code, a watermark (Message). A method for extracting a watermark from the security of the image information is coded using only the image and Secret Key, through the DCT and quantization process, so obtained by separating the watermark (Message) for the image. In this paper, we were able to improve the security of the method of image information, the image quality of the image by the simulations (PSNR), in turn, benefits were also normalized correlation (NC) and security.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.1
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• pp.87-94
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• 2001

In multibody dynamics, differential and algebraic equations which can satisfy both equation of motion and kinematic constraint equation should be solved. To solve this equation, coordinate partitioning method and constraint stabilization method are commonly used. The coordinate partitioning method divides the coordinate into independent and dependent coordinates. The most typical coordinate partitioning method arc LU decomposition, QR decomposition, projection method and SVD(sigular value decomposition).The objective of this research is to find a efficient coordinate partitioning method in flexible multibody systems and a hybrid decomposition algorithm which employs both LU and projection methods is proposed. The accuracy of the solution algorithm is checked with a slider-crank mechanism.

• Journal of the Society of Disaster Information
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• v.16 no.2
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• pp.364-373
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• 2020

Purpose: Each local government has a variety of cultural spaces. However, users do not know exactly about cultural information or location. Therefore, information technology application methods are needed to effectively communicate the necessary information to local residents as well as to outsiders. In this paper, we studied the voluntary production of information for the sharing of local culture, and the methods for protecting the environment of the users themselves. Method: For this, information technology such as QR code, big data analysis, and interactive homepage based on SNS was used. Result: As a result, we derived a method of community creation by users, and the personal information protection from such activities. Conclusion: This research will contribute to the development of local culture by encouraging users to understand the local culture more and to participate in autonomous environmental improvement.

• Journal of Korea Game Society
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• v.11 no.4
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• pp.143-149
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• 2011

This paper presents a novel camera tracking method based on model with multiple planes. The proposed algorithm detects QR code that is one of the most popular types of two-dimensional barcodes. A 3D model is imported from the detected QR code for augmented reality application. Based on the geometric property of the model, the vertices are detected and tracked using optical flow. A clipping algorithm is applied to identify each plane from model surfaces. The proposed method estimates the homography from coplanar feature correspondences, which is used to obtain the initial camera motion parameters. After deriving a linear equation from many feature points on the model and their 3D information, we employ DLT(Direct Linear Transform) to compute camera information. In the final step, the error of camera poses in every frame are minimized with local Bundle Adjustment algorithm in real-time.