• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.996-999
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• 2001

This study is the election of optimum forming condition for RP system using ADS. Program using ADS reduces the required time for feedback between design and manufacturing of workpiece. When we produce rapid prototype using RP system, we investigate the relationship between Facetres in system variable number of AutoCAD and circularity of rapid prototype, and we will find optimum forming condition in RP system.

• 소음진동
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• 제9권6호
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• pp.1240-1246
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• 1999

A prior error estimator which is solving structural dynamic problems and which is based on the generalized-method, is developed. Since the proposed error estimator is computed with only previous information, the time step size can be adaptively selected without the feedback mechanism. This paper shows that the automatic time stepping algorithm using the error estimator performs an efficient time integration. To verify its efficiency, several examples are numerically investigated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.986-989
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• 1988

The new controller which conststs of IBM-PC/AT, SBC, servo module and motor driver has been developed for KIMMBOT II robot. The servo module which controls two axes at the same time also has beendeveloped. This module inputs relative number of pulse and feedrate via multbus, after then outputs analog command voltage with reference to feedback pulses from the encoder of a motor. This system has a great flexibility. The reduction of parts gives more reliability.

• 한국문헌정보학회지
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• 제35권4호
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• pp.141-160
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• 2001

본 연구에서는 자연어를 이용하여 자동으로 정보검색을 수행하는 시스템을 구축하였다. 구현 시스템은 Delphi 4.0(PASCAL)으로 프로그래밍 하였으며, 자동색인, 클러스터링 기법, 자연어 계층관계의 구축과 표현, 자동정보탐색이 가능하도록 구성했다. 이 시스템을 이용하여 질의어의 표현, 생성, 확장, 탐색식의 구성, 피드백 탐색 등 정보탐색의 전과정을 자동으로 수행할 수 있었다.

• ETRI Journal
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• 제46권1호
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• pp.48-58
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• 2024

This paper presents the development of language tutoring systems for nonnative speakers by leveraging advanced end-to-end automatic speech recognition (ASR) and proficiency evaluation. Given the frequent errors in non-native speech, high-performance spontaneous speech recognition must be applied. Our systems accurately evaluate pronunciation and speaking fluency and provide feedback on errors by relying on precise transcriptions. End-to-end ASR is implemented and enhanced by using diverse non-native speaker speech data for model training. For performance enhancement, we combine semisupervised and transfer learning techniques using labeled and unlabeled speech data. Automatic proficiency evaluation is performed by a model trained to maximize the statistical correlation between the fluency score manually determined by a human expert and a calculated fluency score. We developed an English tutoring system for Korean elementary students called EBS AI Peng-Talk and a Korean tutoring system for foreigners called KSI Korean AI Tutor. Both systems were deployed by South Korean government agencies.

• 디지털콘텐츠학회 논문지
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• 제18권6호
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• pp.1101-1107
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• 2017

본 논문은 스마트폰의 플랫폼에 내장되어 있는 자동음성인식 기술을 활용하여 영어 학습자의 발음에 대한 즉각적인 문자 피드백을 제공하는 모바일 기반 발음 교수법이 영어 학습자의 자음 발음 (V-B, R-L, G-Z) 인식과 출력에 미치는 영향에 대해 연구했다. 특히, 자동음성인식 기술을 이용한 모바일 기반 발음 교수법을 사용한 그룹, 전통적인 교사 중심의 발음 교수법 그룹, 그리고 이 둘을 합친 하이브리드 교수법 그룹으로 나누어 영어 학습자의 발음 평가 결과를 (인지, 출력) 비교, 분석했다. ANCOVA를 이용한 분석 결과, 영어 학습자의 발음 출력에 있어 하이브리드 교수법 그룹이 (M=82.71, SD =3.3) 전통적인 교수법 그룹 (M=62.6, SD=4.05) 보다 유의미하게 높은 결과를 나타냈다 (p<.05).

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1997년도 하계 학술대회 논문집
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• pp.89-98
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• 1997

This study was conducted to develop an automatic nutrient-solution control system for small-scale growers. The nutrient-solution control system consisted of a low-cost and precise metering device and a personal computer. The system controlled electric conductivity(EC) and pH of nutrient-solution based on the time-based feedback control method with the information about temperature, EC, and pH of the nutrient-soIution. The performance of the nutrient-solution control system was evaluated through the control of EC and pH while compared with those of commercial nutrient-solution control system. Also an experimental cultivation of tomato was conducted to verify and to improve the developed system. Results of this study were as follows. 1. An automatic nutrient-solution control system based on a low-cost and precise metering device was developed. 2. The developed system controlled EC and pH within $\pm$0.05 mS/cm and $\pm$0.2 pH full scale error respectively at $24^{/circ}C$. 3. When using the commercial system, the controlled values of EC and pH of the 500l of water were 1.29 mS/cm and 6.1 pH for the setting points of 1.4 mS/cm and 6.0 pH respectively at $22^{/circ}C$. 4. The developed nutrient-solution control system showed $\pm$0.05 mS/cm of deviation from the setting EC value over the experimental cultivation period. 5. The deviation from the average values of Ca and Mg mass content in the several nutrient-solution were 0.5% and 1.8% respectively.

• 한국정밀공학회지
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• 제30권10호
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• pp.1041-1049
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• 2013

One of the causes of malfunction of commercial vehicle is corrosion or wear. In order to prevent corrosion and wear, lubricants have to be supplied periodically. However, the period of lubrication usually depends on operator's judgment. If the period is too short, excess lubricant will cause pollution and unnecessary expenses, where as long periodic supply of lubricant might cause wear, damage and eventual breakdown. Therefore, an automatic lubrication system with predetermined interval will reduce the excessive supply of lubricating oil and prevent wear and damage. This thesis presents an automatic lubrication system which consists of a lubricant pump and an embedded controller. An automatic lubrication operating algorithm is used to operate the lubricant pump and feedback the pressure status of the system using pressure sensors. The developed system shows an efficient periodic supply of lubricant.

• 대한기계학회논문집A
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• 제21권11호
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• pp.1819-1826
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• 1997

Direct-drive robots are suitable to the position and force control with high accuracy, but it is difficult to design a controller because of the system's nonlinearity and link-interactions. This paper is concerned with the study of the force control of direct-drive robots. The proposed algorithm consists of feedback controllers and a neural network. After the completion of learning, the output of feedback controller is nearly equal to zero, and the neural network controller plays an important role in the control system. Therefore, the optimum retuning of parameters of feedback controllers is unnecessary. In other words, the proposed algorithm does not require any knowledge of the controlled system in advance. The effectiveness of the proposed algorithm is demonstrated by the experiment on the force control of the parallelogram link-type direct-drive robot.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.124.3-124
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• 2001

The nonlinearity of several chemical processes is usually approximated by a series of the nonlinear static element and the linear subsystem. In the case of the model that the nonlinear static element precedes the linear subsystem, it is called a Hammerstein model. It is a Wiener model when the order is reserved. Here we investigate a relay feedback identification method for Hammerstein type nonlinear processes. The proposed method separates the identification of the nonlinear static function from that of the linear subsystem by using a relay feedback method. From two times activation of nonlinear processes, we identify he whole range of the nonlinear static function as well as the ultimate information of the linear subsystem.