• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.371-372
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• 2006

In this paper, we propose a method that measures quality of digital correlator. Quality of digital correlator in field of image composition of radio astronomy have as important position for acquisition of radio wave image with high precision. Digital correlator should have wide bandwidth and high precision to study on deep space. Digital correlator, therefore, should be designed to have high speed processing and high precision. But, real time measurement of quality of digital correlator using acquisition data is difficult to compare accuracy of result because digital correlator should process a large quantity of data with high speed. Measurement method of quality, also, has intricate implementation of experiment equipment. this paper present methods that compose experiment equipment without external installation easily and verify quality of digital correlator perfectly.

• 한국언론정보학보
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• 제36권
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• pp.78-108
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• 2006

이 연구는 디지털 미디어 시대의 주요 이슈인 디지털 격차(digital divide)를 수용자 복지정책의 관점에서 디지털 리터러시 문제와 함께 고찰하였다. 매체 폭발, 수용자 선택권 무한 확대로 특징지어지는 디지털 미디어 환경에서의 과연 수용자 복지가 제대로 이루어지고 있는가라는 문제제기를 기반으로, 수용자 복지의 대척점이라 할 수 있는 디지털 격차에 대한 논의들을 검토하고, 이것이 수용자의 미디어 활용 능력, 즉 디지털 리터러시와 어떠한 관련성을 갖는지에 대해 살펴봄으로써, 향후 디지털 격차 연구의 방향성 및 수용자 복지의 정책적 방향성을 점검해 보는 것이 이 연구의 목적이다. 지금까지 우리나라를 비롯한 각국의 디지털 격차 해소정책은 물리적 접근 확대와 기초 기술 교육에 머물러 있다는 비판을 받고 있다. 디지털 격차는 사회구조적 제반 요인과 개인의 심리적 속성, 디지털 미디어 평가태도 및 활용능력 요인들이 복합적으로 관련된 중층개념으로 분석되어야 한다. 특히 활용능력인 디지털 리터러시 개념은 디지털 격차의 학술적 연구 및 정책에서 제대로 주목받지 못했다. 이 연구에서는 2단계 과정의 디지털 격차 해소 방안을 제시한다. 1단계에서는 기기보급과 기초기술 교육을, 2단계에서는 정보 추구와 삶의 질 향상을 연계시킬 수 있는 능력 교육으로서의 리터러시 교육의 도입을 제안하였다.

• 대한디지털의료영상학회논문지
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• 제7권1호
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• pp.39-44
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• 2005

Purpose of this research is that if Radiographer has focused on Radiation exposure research until now, he should realize that always exposed by Electro Magnetic Wave at given working environment And also, another purpose is that to minimize damage with measuring Electro Magnetic Wave which is happened area and distance of Radiation Control System and High Voltage Equipment, check occurrence rate and minimize damage from it.

• 대한디지털의료영상학회논문지
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• 제11권2호
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• pp.115-119
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• 2009

I think this will be valuable reference for assuring consistency and homogeneity of clarity and managing dental radiation equipment by experimentation of dental radiation equipment permanent which based on KS C IEC 61223-3-4 standard and KS C IEC 61223-2-7. Put a dental radiation generator and experiment equipment as source and film(sensor) length within 30 em, place the step-wedge above the film(sensor). Tie up tube voltage 60 kVp, tube current 7 mA and then get an each image through CCD sensor and film by changing the exposure time as 0.12sec, 0.25sec, 0.4sec. Repeat the test 5times as a same method. Measure the concentration of each stage of film image, which gained by experiment, using photometer. And the image that gained by CCD sensor, analyze the pixel value's change by using image J, which is analyzing image program provided by NIH(National Institutes of Health). In case of film, while 0.12sec and 0.25sec show regular rising pattern of density gap as exposure time's increase, 0.4sec shows low rather than 0.12sec and 0.25sec. In case of CCD sensor density test, the result shows opposite pattern of film. This makes me think that pixels of CCD's sensor can have 0~255 value but it becomes saturation if the value is over 255. The way that getting clear reception during decreasing human's exposed radiation is one of maintaining an equipment as a best condition. So we should keeping a dental radiation equipment's condition steadily through cyclic permanent test after factor examination. Even digital equipment doesn't maintain a permanent, it can maintain a clarity by post processing of image so that hard to set it as standard of permanent test. Therefore it would be more increase the accuracy that compare a film as standard image. Thus I consider it will be an important measurement to care for dental radiation equipment and warrant homogeneity, consistency of dental image's clarity through comparing pattern which is the result from factor test against cyclic permanent test.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.183-184
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• 2008

From the beginning of a new millennium, the digital broadcasting services had been adopted to cable, satellite and radio broadcasting services as well as the terrestrial TV broadcasting services. The government established the installation standard of digital receiving equipment in 2007, which is needed for taking the new digital broadcasting services without additional facilities in an apartment house. In this paper, I will show the installation standard of digital receiving equipment in an apartment house and give a detailed explanation for the main criteria of it.

• 한국해양공학회지
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• 제23권1호
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• pp.152-157
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• 2009

In designing and manufacturing a submarine, an expensive real mock up is usually built as a reference because of the spatial constraints of a submarine. This paper presents an integrated and automated design process for a submarine that uses a digital mock up. Various equipment libraries are built for feature based design. Using the developed digital mock up, this paper shows various ways to verify the design, including a space analysis to check for any interference between pieces of equipment and the hull and an ergonomic analysis using lifelike dummies to examine the work space and operability. As a part of the integrated design system, a design automation system was also developed to generate surface point data for the outer hull, pressure hull, casing, and sail. The whole process was applied to the design of a submarine for verification.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2000년도 춘계학술대회 발표논문집
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• pp.231-238
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• 2000

The distributed digital control system has many shared common components, and a single fault in the system may have effects on not a single function. Not as in an analog system, the faults in a digital system usually make discrete and abrupt changes in its output, which are hard to be expected. To cope with these situations, the fault-tolerance is an inevitable property of a distributed control system. A distributed digital control system consists of many equipments, and each equipment can be implemented by many different technologies. The fault-tolerance has to be implemented depend-ing on the overall architecture and how each equipment is implemented. The paper analyzes and compares the strategies and tactics to add the fault-tolerances in a distributed digital control system, and studies how they can be combined appropriately.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.242-244
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• 2017

Excavation for construction is implemented in natural geographical terrain using a variety of construction equipment. Therefore, 3D excavation simulation requires integration of geographical and equipment modeling. This paper proposes a technique that integrates geographical and equipment modeling for 3D simulations of construction excavation. The geographical model uses a digital map to show ground surface changes during excavation and the equipment model shows equipment movement and placement. This combination produced a state of the art 3D simulation environment that can be used for machine guidance. An equipment operator can use the 3D excavation simulation to help construction equipment operators with decisions during excavation work and consequently improve productivity.

• Journal of Power Electronics
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• 제11권2호
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• pp.156-162
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• 2011

The control loop time delay caused by sampling, the zero-order-holder effect and calculations is inevitable in the digital control of dc-dc switching converters. The time delay will limit the bandwidth of the control loop and therefore degrade the transient performance of digital systems. In this paper, the quantization time delay effects with different time delay values based on a generic second-order system are analyzed. The conclusion that the bandwidth of digital control is reduced by about 20% with a one cycle delay and by 50% with two cycles of delay in comparison with no time delay is obtained. To compensate the time delay and to increase the control loop bandwidth, a duty ratio predictive control scheme based on linear extrapolation is proposed. The compensation effect and a comparison of the load variation transient response characteristics with analogy control, conventional digital control and duty ratio predictive control with different time delay values are performed on a point-of-load Buck converter by simulations and experiments. It is shown that, using the proposed technique, the control loop bandwidth can be increased by 50% for a one cycle delay and 48.2% for two cycles of delay when compared to conventional digital control. Simulations and experimental results prove the validity of the conclusion of the quantization effects of the time delay and the proposed control scheme.

• 한국컴퓨터정보학회논문지
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• 제22권5호
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• pp.21-28
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• 2017

As technology related to digital imaging equipment is developed and generalized, digital imaging system is used for various purposes in fields of society. The object tracking technology from digital image data in real time is one of the core technologies required in various fields such as security system and robot system. Among the existing object tracking technologies, cam shift technology is a technique of tracking an object using color information of an object. Recently, digital image data using infrared camera functions are widely used due to various demands of digital image equipment. However, the existing cam shift method can not track objects in image data without color information. Our proposed tracking algorithm tracks the object by analyzing the color if valid color information exists in the digital image data, otherwise it generates the lightness feature information and tracks the object through it. The brightness feature information is generated from the ratio information of the width and the height of the area divided by the brightness. Experimental results shows that our tracking algorithm can track objects in real time not only in general image data including color information but also in image data captured by an infrared camera.