• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.69-77
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• 2021

This paper deals with the development of an application that converts the PDF music score entered by the user into a MIDI file of the chord the user wants. This application converts the PDF file into a PNG file for chord conversion when the user enters the PDF music score file and the chord which the user wants to change. After recognizing the melody of sheet music through image processing algorithm and recognizing the tempo of sheet music notes through deep learning, then the MIDI file of chord for existing sheet music is produced. The OpenCV algorithm and deep learning can recognize minim note, quarter note, eighth note, semi-quaver note, half rest, eighth rest, quarter rest, semi-quaver rest, successive notes and chord notes. The experiment shows that the note recognition rate of the music score was 100% and the tempo recognition rate was 90% or more.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.3
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• pp.31-39
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• 2016

As the computer technology is developed, score-writers that can edit music have more improved functions. A user not only can insert notes, chords, and musical symbols conveniently, but also can listen to music displayed in the score. Existing commercial score-writers make scores look good and play notes through VSTi(Virtual Studio Technology instrument). However chord accompaniment function is so vulnerable that it is hard to know whether or not displayed chords are suitable for music. If a score-writer has a proper function that plays chord sound good to hear, it will be a good reference to band music sheet writers. In this paper, to improve chord playback function in existing score-writers, we propose an algorithm that selects suitable chord tones for chord playback and implemented a program. If we apply this algorithm, the chord play function of a score-writer will be strengthened and resultantly a music sheet writer who makes a band music can make scores more conveniently.

• Journal of the Korean Mathematical Society
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• v.47 no.2
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• pp.277-288
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• 2010

The mixed chord-integrals are defined. The Fenchel-Aleksandrov inequality and a general isoperimetric inequality for the mixed chordintegrals are established. Furthermore, the dual general Bieberbach inequality is presented. As an application of the dual form, a Brunn-Minkowski type inequality for mixed intersection bodies is given.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.517-519
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• 2004

Chord(6)는 N개의 노드로 이루어진 P2P(Peer-to-Peer)네트워크에서 검색에 사용되는 메시지를 O(logN)으로 줄인 P2P 검색 알고리즘이다. 하지만 모바일 Ad-hoc 네트워크에 이를 적용할 경우 검색 성공률이 매우 떨어져 (1000개의 노드가 도보속도(2m/s)로 움직이는 경우： 검색 성공률 30%이하)P2P 검색이 거의 이루어지지 않는 문제점이 발생한다. 본 논문에서는 이 같은 문제점을 극복하기 위한 알고리즘인 Backtracking Chord을 제안한다. Backtracking Chord 방식은 O(logN)메시지를 사용하여 순차적으로 t번까지 검색을 요청함으로써(t： Timeout의 횟수(0 < t< logN)) t에 따라 최고 88%(t>4)까지 검색 성공률을 높일 수 있다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.18-28
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• 2001

Super computers has been utilized to carry out vehicle dynamics in real time. This research propose an implicit integra-tion method for vehicle state variables. Newton chord method is empolyed to solve the equations of motion and con-straints. The equations of motion and constraints are formulated such that the Jacobian matrix for Newton chord method is needed to be computed only once for a dynamic analysis. Numerical experiments showed that the Jacobian matrix generat-ed at the initial time could have been utilized for the Newton chord iterations throughout simulations under various driving conditions. Convergence analysis of Newton chord method with the proposed Jacobian updating method is carried out. The proposed algorithm yielded accurate solutions for a prototype vehicle multibody model in realtime on a 400 MHz PC compatible.

• Journal of Korea Multimedia Society
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• v.21 no.3
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• pp.391-399
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• 2018

In this paper, we construct and compare various guitar chord classification systems using perceptron neural network and convolutional neural network without pre-processing other than Fourier transform to identify the optimal chord classification system. Conventional guitar chord classification schemes use, for better feature extraction, computationally demanding pre-processing techniques such as stochastic analysis employing a hidden markov model or an acoustic data filtering and hence are burdensome for real-time chord classifications. For this reason, we construct various perceptron neural networks and convolutional neural networks that use only Fourier tranform for data pre-processing and compare them with dataset obtained by playing an electric guitar. According to our comparison, convolutional neural networks provide optimal performance considering both chord classification acurracy and fast processing time. In particular, convolutional neural networks exhibit robust performance even when only small fraction of low frequency components of the data are used.

• Journal of Korea Multimedia Society
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• v.18 no.11
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• pp.1358-1366
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• 2015

This paper proposes an automatic composition method using the training capability of artificial neural networks and chord progression rules that are widely used by human composers. After training a given song, the new melody is generated by the trained artificial neural networks through applying a different initial melody to the neural networks. The generated melody should be modified to fit the rhythm and chord progression rules for generating natural melody. In order to achieve this object, we devised a post-processing method such as chord candidate generation, chord progression, and melody correction. From some tests we could find that the melody after the post-processing was very improved from the melody generated by artificial neural networks. This enables our composition system to generate a melody which is similar to those generated by human composers.

• Journal of Navigation and Port Research
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• v.41 no.2
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• pp.33-38
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• 2017

A marine flapped rudder is designed to improve the effective lift generated by the rudder; this also improves the maneuverability of the ship. The flap is a high lift device installed at the trailing edge of the rudder to augment lift. In this paper, the characteristics of a thick flapped rudder are analyzed at a low Reynolds number with various ratios of flap chord length to total chord length and various aspect ratios, based on the computational fluid dynamics technique. The performance of the rudder with respect to lift, drag, and center of pressure are investigated, and the efficient ratio of flap chord length to total chord length and improved aspect ratio are determined. Ed: highlight - or 'superior'. As a case study, the flow on the flapped rudder of an NACA0021 section shape in free stream condition is simulated. The standard k-epsilon turbulence model is used to model the flow around the flapped rudder. The results indicate that the efficient ratio of the flap chord length to total chord length and aspect ratio are 0.3 and 1.4, respectively.

• The KSFM Journal of Fluid Machinery
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• v.19 no.5
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• pp.5-11
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• 2016

The purpose of this study is to design the transonic centrifugal compressor impeller with splitter blades and analyze the flow fields with respect to various splitter blades. Seven impellers with different splitter chord length or pitchwise location were tested by using CFD method. To investigate aerodynamic performance, Mach number distribution and entropy distribution were confirmed. As a result, it is found that the size of transonic region and shock wave location are related to the splitter chord length and pitchwise location. Also the impeller with long chord length of splitter shows higher total pressure ratio but lower efficiency than those of the impeller with short chord length of splitter. In terms of pitchwise location, the impeller with the splitter located in mid-pitch of main blades shows the best performance with respect to pressure ratio and efficiency.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1647-1652
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• 2008

Track geometry consists of tangent and curved lines, which caused undesirable changes in initial track geometry by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To be able to objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies use moving chord method, this method determine versine values via a chord. The versine is the vertical distance to curve measured in the middle of the chord. This type of method measures only versine of track irregularity curve by transfer function from specific property of measuring tool. In this report, review the characteristics of two types of measuring tools by comparing the measurements. The one is GRP-1000 system, optical surveying system with Total station and lazar prism trolly. This calculates track geometry by surveying absolute coordinates of two points each on both rail heads. The other is Trackmaster, measures versine with 2m of chord length.