• Journal of Electrical Engineering and Technology
• /
• v.2 no.4
• /
• pp.428-433
• /
• 2007

This paper describes the new eigenvalue algorithm exploiting the Implicit Restarted Arnoldi Method (IRAM) and its application to power systems. IRAM is a technique for combining the implicitly shifted mechanism with a k-step Arnoldi factorization to obtain a truncated form of the implicitly shifted QR iteration. The numerical difficulties and storage problems normally associated with the Arnoldi process are avoided. Two power systems, one of which has 36 state variables and the other 150 state variables, have been tested using the ARPACK program, which uses IRAM, and the eigenvalue results are compared with the results obtained from the conventional QR method.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.11C
• /
• pp.1127-1133
• /
• 2007

This paper proposes one of normalized QR-typed LMS (Least Mean Square) algorithms with computational complexity of O(N). This proposed algorithm shows the normalized property in terms of theoretical characteristics. This proposed algorithm is one of algorithms which normalize variance of input signal in terms of mean because QR-typed LMS is proportional to variance of input signal. In this paper, convergence characteristic analysis of normalized algorithm was made. Computer simulation was made by the algorithms used for echo canceller. Proposed algorithm has similar performance to theoretical value. And, we can see that proposed method shows similar one to performance of NLMS.by comparison among different algorithms.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.11
• /
• pp.1371-1377
• /
• 2013

In this analysis, a method is presented to calculate the critical speed of a railway vehicle by using a multibody dynamic model. The contact conditions and contact forces between the wheel and the rail are formularized for the wheelset model. This is combined with the bogie model to obtain a multibody dynamic model of a railway vehicle with constraint conditions. First-order linear dynamic equations with independent coordinates are derived from the constraint equations and dynamic equations of railway vehicles using the QR decomposition method. Critical speeds are calculated for the wheelset and bogie dynamic models through an eigenvalue analysis. The influences of the design parameters on the critical speed are presented.

• Current Optics and Photonics
• /
• v.3 no.4
• /
• pp.320-328
• /
• 2019

A method for joint-transform correlator (JTC) multiple-image encryption based on a quick-response (QR) code key is proposed. The QR codes converted from different texts are used as key masks to encrypt and decrypt multiple images. Not only can Chinese text and English text be used as key text, but also symbols can be used. With this method, users have no need to transmit the whole key mask; they only need to transmit the text that is used to generate the key. The correlation coefficient is introduced to evaluate the decryption performance of our proposed cryptosystem, and we explore the sensitivity of the key mask and the capability for multiple-image encryption. Robustness analysis is also conducted in this paper. Computer simulations and experimental results verify the correctness of this method.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.12
• /
• pp.2906-2913
• /
• 2013

Only small numbers of medium-sized manufacturers have adopted a production management system. They have difficulty maintaining production cost and progress management, because they have used the ways that win a contract, not mass production system like a big company. Also a small company has to change standard features of products whenever customers want, by means of non-standardization and small quantity production method. As a result, it has been very difficult for a small company to establish a proper production management system. So, this paper tried to make a study about increasing production management system, using QR codes in a small-sized manufacturer with the ways that win a contract, based on real application case.

• International Journal of Contents
• /
• v.11 no.1
• /
• pp.1-6
• /
• 2015

The development of information and technology has brought plenty of changes to the educational environment. The prevalence of smart phones is particularly playing a huge role in shaping learning methods. Smart phones provide the opportunity to scan QR codes, which can greatly ease access to information. Due to a high recognition speed, recognition rate, and restoration rate, they can be useful tools for English teachers to use in their class. In this study, we suggest using QR codes for writing and picture descriptions. Based on this study, more research should invest in Technology Embedded English teaching models to create better English classes for students.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.7A
• /
• pp.535-544
• /
• 2012

Multi-Input Multi-Output (MIMO) transmission is now considered as one of essential techniques enabling high rate data transmissions in wireless communication systems. In addition, severe channel impairments in wireless systems should be compensated by using highly efficient forward error correction (FEC) codes. Turbo codes or low density parity check (LDPC) codes, using iterative decoding with soft decision detection information (SDDI), are the most common examples. The excellent performance of these codes should be conditioned on accurate estimation of SDDI from the MIMO detection process. In this paper, we propose a soft MIMO detection scheme using QR decomposition of channel matrices as an efficient means to provide accurate SDDI to the iterative decoder. The proposed method employed a two sequential soft MIMO detection process in order to reduce computational complexity. Compared to the soft ZF method calculating the direct inverse of the channel matrix, the complexity of the proposed method can be further reduced as the number of antennas is increased, without any performance degradation.

• Journal of Korea Game Society
• /
• v.11 no.5
• /
• pp.79-88
• /
• 2011

The purpose of this study is to confirm meaning for quest-based learning designed as one of learning methods with new media, which the contents were made of QR code based on smart-phone. For this purpose, this study conducted 8 times of class during one month with 32 elementary third graders. And analysis for the result of this study was carried out MANOVA focus on four sub-factor of motivation. The results showed positive effect for quest-based learning in attention and confidence factor on motivation. Quest-based learning of gaming version as a learning method using various media can use a learning method for facilitation of learner participation, supporting of learning by doing.

• Journal of Broadcast Engineering
• /
• v.17 no.2
• /
• pp.295-304
• /
• 2012

IPTV current service change from a TV IPTV service providing digital broadcast, one- way VOD service, terrestrial broadcast to a web IPTV service,which is using wireless networks which is also used by interactive digital broadcasting However, IPTV, is being currently serviced, causes a lot of interaction with viewers because of inconvenience of using and has problems that users do not have enough content type to access. Additionally, there is also a problem that adding contents cover a large part of screen. To solve these problems, the thing that adding QR code to IPTV screen being recognized by Smartphone. In this way, we can provide the idea how to access to interaction information and also provide to clients an easy way creating and accessing to the contents by developing an editor that can insert QR code to video.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.299-300
• /
• 2018

In public facilities, the hearing impaired people do not receive voice notifications, so they use dedicated applications for the facility as a means of obtaining information. However, there is the inconvenience of using dedicated applications for each facility. In this paper, we propose a subscription service for the hearing impaired people. The proposed method uses the MQTT protocol to design the notification service, and subscribes to the notification service by scanning the QR code through the application. The hearing-impaired people who subscribes to the notification service receives a message when the notification information is posted.