• 대한안전경영과학회지
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• 제6권2호
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• pp.231-239
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• 2004

To keep an enterprise's competitiveness on the condition of the automatic manufacturing system such as FA, FMS and CIM, all the maintenance problems should be considered seriously in not only in production and maintenance but also in related industrial productivity. This paper presents the study of equipment reliability improvement for rotary-machine vibration analysis. Based on these analyses, the maintenance management information system, and the machinery condition diagnosis technique are studied by using of the real-time diagnostic. Therefore, it is expected to improve the efficiency of business processes in the production and safety when we use this system.

• 한국방사선학회논문지
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• 제10권1호
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• pp.59-64
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• 2016

본 연구의 목적은 자기공명영상을 이용하여 외국인 환자를 검사할 때 언어의 소통을 위하여 자동음성시스템을 개발하고자 하였다. 자동음성을 위해 사용된 문장은 병원에서 자주 사용하고 있는 12개의 문장과 5개의 외국어를 선택하였다. 이러한 번역된 문장은 Oddcast's website로 부터 무료로 재공 되며 Wav 파일로서 각 언어 특징에 소리로 기록하게 된다. 기록된 오디오 파일은 Mobile phone 환경에서 적용되는 PHP 프로그램을 사용하여 MS-파워포인트(extension; ppsx) 와 Web-enabled system 형태로 재생하게 된다. 음성 시스템 개발은 방사선사에게 언어 소통의 어려움에 관하여 스트레스를 해소될 것이며, 다양한 언어로 설계된 자동음성시스템은 외국인 환자를 검사 할 때 환자에게 진단적 정보를 증가시킬 것이다. 본 연구를 위해 개발된 음성 시스템은 한국의 방사선사와 외국인 환자 사이에서 검사의 이해를 증가시킬 수 있기 때문에 임상실무에서 더욱더 유용하게 이용될 것이라고 기대된다.

• International Journal of Contents
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• 제5권3호
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• pp.65-70
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• 2009

This paper describes ongoing work on the correction of adverb errors committed by Korean learners studying English as a foreign language (EFL), using an automated English writing assessment system. Adverb errors are commonly found in learners 'writings, but handling those errors rarely draws an attention in natural language processing due to complicated characteristics of adverb. To correctly detect the errors, adverbs are classified according to their grammatical functions, meanings and positions within a sentence. Adverb errors are collected from learners' sentences, and classified into five categories adopting a traditional error analysis. The error classification in conjunction with the adverb categorization is implemented into a set of mal-rules which automatically identifies the errors. When an error is detected, the system corrects the error and suggests error specific feedback. The feedback includes the types of errors, a corrected string of the error and a brief description of the error. This attempt suggests how to improve adverb error correction method as well as to provide richer diagnostic feedback to the learners.

• 한국정밀공학회지
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• 제25권11호
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• pp.37-44
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• 2008

• 한국지능시스템학회논문지
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• 제19권5호
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• pp.706-712
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• 2009

본 논문에서는 프레스공정라인에서 발생하는 고장을 감지하고 분류하기 위한 고장진단기법을 제안한다. 또한 윤활유 레벨을 자동감지 하기 위한 방법도 제안하다. 제안한 방법에서는 FFT 주파수해석과 여러 경계인수를 갖는 ART2 신경회로망을 사용하며, LabVIEW를 이용하여 고장진단 및 윤활유 레벨 자동감시를 위한 GUI(Graphical User Interface) 프로그램을 제작하여 고장진단을 수행하였다. 실험결과들로부터 제안한 유도전동기 고장진단 및 윤활유 레벨 자동감시시스템의 성능을 확인하였다.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.149-156
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• 2017

Various kinds of accessories(e.g., clock, radio, automatic door locks, alarm devices, etc.) or unit components (e.g., black box, navigation system, alarm, private audio, etc.) require dark current even when the vehicle power is turned off. However, accessories or unit components can be the causes of excessive dark current generation. It results in battery discharge and the vehicle's failure to start. Therefore, immediate detection of abnormal dark current and response are very important for a successful repair job. In this paper, we can increase the maintenance efficiency by presenting a standardized diagnostic process for the measurement of the dark current and the existing problem. As a result of the absence of a system to block the dark current in a vehicle, diagnosis and repair were performed immediately by using a standardized dark current diagnostic process.

• 환경영향평가
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• 제11권2호
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• pp.109-116
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• 2002

The diagnostic and prognostic methods for generating 3 dimensional wind field were comparatively analyzed and 4 dimensional data assimilation (FDDA) technique by incorporating Automatic Weather System (AWS) into the prognostic methods was discussed for the urban scale air quality model. The A WS covered the urban scale grid distance of 10.6 km and 4.3 km in South Korea and Kyong-in region, respectively. This is representing that AWS for FDDA could be fairly well accommodated in prognostic model with the meso${\gamma}$~ microa scale (~5 km), indicating that the 3 dimensional wind field by FDDA technique could be a useful interpretative tool in urban area for the atmospheric environmental impact assessment.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.3-9
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• 2008

Recently, the plant industries are being activated and plant control systems use various technologies. Because the optimized design for the plants is very important for the reducing of operation and maintenance costs, automatic control systems become more important. Plant control systems consist of the master controller, the plant networks, the programming environment for engineering, monitoring software and the field devices. The control systems should have reliability, availability and safety. Modular architecture of hardware and software makes flexible configuration of the control systems. Each component should have diagnostic functions. It follows industrial standards and makes open systems. Open systems increase accessibility against the data which is distributed in the plants. The controllers including processor and communication modules use the up-to-date technology. They have real time and fault tolerant function by duplicating processors or networks. It also enables to make the distributed control systems. The distributed architecture makes more scalable main control system. Automatic control systems can be operated with better performance. In this paper, we analyzed the requirements of the seawater desalination plants and made some consideration facts for developing the optimized controller. Also we described the design concept of the main controller, which consists of several modules. We should validate and complement the design for the reliability and better performance.

• 대한방사선기술학회지:방사선기술과학
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• 제14권1호
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• pp.23-28
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• 1991

Automatic exposure control systems are now readily available and widly used in radiography. A device that automatically determines the amount of radiation required to produce an acceptable level of film blackness is called a phototimer, or automatic exposure control. There are limitations in the use of phototimers ; however, equipment can be used much more effectively if one recognize these limitations, and the goal of obtaining a properly exposed, reproducible radiography can be achieved. We have some results in this experimental study. The variations of film density due to kVp are in propotion to below 80 kVp range. But indicate constant level above 80 kVp to 120 kVp. The characteristic density variation by phantom thickness shows the higher the thiner in exit type. AEC system have a density control that is designed to make adjustments increase or decreas the density 10% per step or 25% per step. The automatic exposure control circuits must meet the several regulations of the HEW. Some forms of technique chart is recomened for use of AEC.

• Restorative Dentistry and Endodontics
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• 제38권3호
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• pp.146-153
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• 2013

Objectives: Aluminum step wedge (ASW) equivalent radiodensity (eRD) has been used to quantify restorative material's radiodensity. The aim of this study was to evaluate the effects of image acquisition control (IAC) of a digital X-ray system on the radiodensity quantification under different exposure time settings. Materials and Methods: Three 1-mm thick restorative material samples with various opacities were prepared. Samples were radiographed alongside an ASW using one of three digital radiographic modes (linear mapping (L), nonlinear mapping (N), and nonlinear mapping and automatic exposure control activated (E)) under 3 exposure time settings (underexposure, normal-exposure, and overexposure). The ASW eRD of restorative materials, attenuation coefficients and contrasts of ASW, and the correlation coefficient of linear relationship between logarithms of gray-scale value and thicknesses of ASW were compared under 9 conditions. Results: The ASW eRD measurements of restorative materials by three digital radiographic modes were statistically different (p = 0.049) but clinically similar. The relationship between logarithms of background corrected grey scale value and thickness of ASW was highly linear but attenuation coefficients and contrasts varied significantly among 3 radiographic modes. Varying exposure times did not affect ASW eRD significantly. Conclusions: Even though different digital radiographic modes induced large variation on attenuation of coefficient and contrast of ASW, E mode improved diagnostic quality of the image significantly under the underexposure condition by improving contrasts, while maintaining ASW eRDs of restorative materials similar. Under the condition of this study, underexposure time may be acceptable clinically with digital X-ray system using automatic gain control that reduces radiation exposure for patient.