• Journal of Mechanical Science and Technology
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• 제17권2호
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• pp.197-206
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• 2003

It is intended to retrieve the time history of displacement from measured acceleration signal. In this study, the word retrieving means reconstructing the time history of original displacement signal from already measured acceleration signal not just extracting various information using relevant signal processing techniques. Unlike extracting required information from the signal, there are not many options to apply to retrieve the time history of displacement signal, once the acceleration signal is measured and recorded with given sampling rate. There are two methods, in general, to convert measured acceleration signal into displacement signal. One is directly integrating the acceleration signal in time domain. The other is dividing the Fourier transformed acceleration signal by the scale factor of - $\omega$$^2$and taking the inverse Fourier transform of it. It turned out both the methods produced a significant amount of errors depending on the sampling resolution in time and frequency domain when digitizing the acceleration signals. A simple and effective way to convert the time history of acceleration signal into the time history of displacement signal without significant errors is studied here with the analysis on the errors involved in the conversion process.

• 대한음성학회지:말소리
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• 제45호
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• pp.63-77
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• 2003

The purpose of voice color conversion is to change the speaker identity perceived from the speech signal. In this paper, we propose a new voice color conversion algorithm through the formant shifting and the spectrum-tilt modification in the frequency domain. The basic idea of this technique is to convert the positions of source formants into those of target speaker's formants through interpolation and decimation and to modify the spectrum-tilt by utilizing the information of both speakers' spectrum envelops. The LPC spectrum is adopted to evaluate the position of formant and the information of spectrum-tilt. Our algorithm enables us to convert the speaker identity rather successfully while maintaining good speech quality, since it modifies speech waveforms directly in the frequency domain.

• 센서학회지
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• 제26권5호
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• pp.348-352
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• 2017

In this paper, we propose a high resolution A/D converter for a sensor interface that processes low frequency AC signals. A 6b SAR ADC with low power consumption and a 11b incremental ADC with high resolution are combined together to perform 15b resolution. Conventional hybrid ADC has a disadvantage that it can convert t only DC signal, but in this paper, it is possible to convert data to AC signal by increasing input range of incremental ADC. The decimation filter is implemented on-chip. The designed Hybrid ADC operates at supply voltage of 1.8V and consumes the current of 6.98uA. The OSR (oversampling ratio) is 90. And SFDR, SNDR, ENOB and FoMs are 96.59dB, 88.47dB, 14.4-bit and 139.5dB, respectively.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.238-240
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• 2018

최근에는 다양한 생체신호 분석 툴을 활용하여 건강관리서비스가 개발 및 연구되고 있다. 대부분의 생체신호 분석 연구는 Matlab 및 R Programming을 활용한다. 그러나, Matlab과 R Programming으로 개발한 알고리즘을 시스템에 적용하기 위해서는 소스 코드의 변환 작업이 필요하다. 본 논문은 소스 코드의 변환 작업을 생략할 수 있는 스마트 인터페이스를 제공하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2140-2142
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• 2003

Recently, TCP/IP on Ethernet protocol is in use environment of LAN have developed a single chip by hardware. Therefore, the study about the single chip applies to the system control application like information electronic appliances, manufacturing automation machine has been made progress. This paper is the development of experimental Client node and Serve node that can transfer input-output data needed on Network Control System Client node is a sensor part of control system, that is, an analog signal is applicable to output data convert AD through LAN. Server node data sended in client convert DA, and then it is applicable to driver of Control System, so it achieves its part. In this study, is prove that using TCP/IP construct Network Control System.

• 한국정밀공학회지
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• 제17권8호
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• pp.94-99
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• 2000

In this study applied the general controller into th 16bit ordinary controller and recommand the simulator features the real system's propeties without DSP(Digital Signal Processing)-card. This simulator is designed to be synchronized in real time using A/D(Analog-Digital) convert and D/A(Digital-Analong) convert. In this study DSP card which is usually used for complex calculation is replaced with personal computer and designed to control, control-force using with the 16-bit micro processor.

• 한국광학회지
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• 제25권2호
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• pp.85-89
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• 2014

본 논문에서는 광 스캐닝 홀로그래피 기술을 이용하여 실제 반사형 물체의 복소 홀로그램을 스펙클 잡음 없이 촬영하고 데이터양을 줄이면서 동시에 일반적인 진폭 유일 공간 광 변조기를 이용해 광학적인 방법으로 복원할 수 있도록 탈축 수평 시차 홀로그램으로 변환하였다. 변환된 탈축 수평 시차 홀로그램이 공간상에 복원되어 디스플레이가 될 수 있음을 보이기 위하여 수치적인 방법을 이용하여 홀로그램을 복원하였다.

• International Journal of Computer Science & Network Security
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• 제21권6호
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• pp.207-212
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• 2021

Clustering Unlabeled Spatial-datasets to convert them to Labeled Spatial-datasets is a challenging task specially for geographical information systems. In this research study we investigated the NYC Taxi Limousine Commission dataset and discover that all of the spatial-temporal trajectory are unlabeled Spatial-datasets, which is in this case it is not suitable for any data mining tasks, such as classification and regression. Therefore, it is necessary to convert unlabeled Spatial-datasets into labeled Spatial-datasets. In this research study we are going to use the Clustering Technique to do this task for all the Trajectory datasets. A key difficulty for applying machine learning classification algorithms for many applications is that they require a lot of labeled datasets. Labeling a Big-data in many cases is a costly process. In this paper, we show the effectiveness of utilizing a Clustering Technique for labeling spatial data that leads to a high-accuracy classifier.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.205-208
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• 2024

Artificial Intelligence (AI) technology has evolved rapidly in recent years and is used in everything from banking to email management to surgery, but without the help of the visible, most of the fun features of the Internet include visual impairment. It benefits people with disabilities. The main purpose of this study is to find ways to help people with visual impairments using AI technology. A visually impaired request is made for the visually impaired. For example, when a message arrives that the program will notify you by voice (reads the sender's name, read the message, and replies to it if necessary), this is a special program installed on your mobile phone. This program uses a customized algorithm developed in Python to convert written text to voice, read text, and convert voice to written text on a message when a visually impaired person wants to respond. Then it sends the response in the form of a text message. Therefore, the research should lead to programs for people with visual impairments. This program makes mobile phones easier and more comfortable to use and makes the daily life easier for visual impairments.

• Smart Structures and Systems
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• 제9권3호
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• pp.231-251
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• 2012

The stochastic optimal control for a piezoelectric spherically symmetric shell subjected to stochastic boundary perturbations is constructed, analyzed and evaluated. The stochastic optimal control problem on the boundary stress output reduction of the piezoelectric shell subjected to stochastic boundary displacement perturbations is presented. The electric potential integral as a function of displacement is obtained to convert the differential equations for the piezoelectric shell with electrical and mechanical coupling into the equation only for displacement. The displacement transformation is constructed to convert the stochastic boundary conditions into homogeneous ones, and the transformed displacement is expanded in space to convert further the partial differential equation for displacement into ordinary differential equations by using the Galerkin method. Then the stochastic optimal control problem of the piezoelectric shell in partial differential equations is transformed into that of the multi-degree-of-freedom system. The optimal control law for electric potential is determined according to the stochastic dynamical programming principle. The frequency-response function matrix, power spectral density matrix and correlation function matrix of the controlled system response are derived based on the theory of random vibration. The expressions of mean-square stress, displacement and electric potential of the controlled piezoelectric shell are finally obtained to evaluate the control effectiveness. Numerical results are given to illustrate the high relative reduction in the root-mean-square boundary stress of the piezoelectric shell subjected to stochastic boundary displacement perturbations by the optimal electric potential control.