• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1255-1255
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• 2022

Recently, research on digital twins to generate digital information and manage construction in real-time using advanced technology is being conducted actively. However, in the construction industry, it is difficult to optimize and apply digital technology in real-time due to the nature of the construction industry in which information is constantly fluctuating. In addition, inaccurate information on the topography of construction projects is a major challenge for earthmoving processes. In order to ultimately improve the cost-effectiveness of construction projects, both construction quality and productivity should be addressed through efficient construction information management in large-scale earthworks projects. Therefore, in this study, a 3D digital map-based AR site management work support system for higher efficiency and accuracy of site management was proposed by using unmanned aerial vehicles (UAV) in wide earthworks construction sites to generate point cloud data, building a 3D digital map through acquisition and analysis of on-site sensor-based information, and performing the visualization with AR at the site By utilizing the 3D digital map-based AR site management work support system proposed in this study, information is able to be provided quickly to field managers to enable an intuitive understanding of field conditions and immediate work processing, thereby reducing field management sluggishness and limitations of traditional information exchange systems. It is expected to contribute to the improvement of productivity by overcoming factors that decrease productivity in the construction industry and the improvement of work efficiency at construction sites.

• 한국음향학회지
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• 제22권8호
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• pp.680-686
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• 2003

디지털 도파관 모델은 악기의 물리적 모델링에 사용되는 일반적인 방법이다. 디지털 도파관 모델에서 파동의 움직임은 시간 또는 공간을 기준으로 해석 가능하다. 음의 샘플링이 시간을 기준으로 이루어지므로 악기 모델은 시간에 의한 파동의 움직임으로 묘사되는 것이 일반적이다. 본 논문에서는 현에 대한 공간 기준의 디지털 도파관 모델에 악기 몸체 모델을 추가해 악기 음을 합성하였다. 그렇게 함으로써 합성 음의 음질을 향상시키고 악기 모델의 음색 조절 변수들을 효과적으로 처리할 수 있었다. 공간 기준 샘플링에서 현 및 몸체에서 발생하는 미소 지연 오차에 대해 설명하고 FD (Fractional Delay) 필터를 이용해 미소 지연을 처리하는 방법을 보였다. 그리고 지연에 수에 따른 합성음의 변화를 설명하고 그 결과를 시간 기준 디지털 도파관 모델과 비교하였다.

• 전자공학회논문지B
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• 제30B권5호
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• pp.27-33
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• 1993

This paper describes the hardware implementation of 2-D FIR digital filter for a real-time image processing. Generally, the most time-consuming operation in signal processing is the multiplication operation. To avoid it in digital filter. Pelid and Liu proposed the distributed arithmetic method for the one-dimensional case. The implementation method proposed in this paper is to extend Pelid's method to two-dimensional FIR filter using simple ROM lookup table and to use the technique of pipe lining two main operations of memory access and arithmetic. As a result, the speed of our proposed hardware implementation is two times faster than that of conventional methods and can be close to the real time speed.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.148-153
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• 2023

A digital controller uses a microprocessor and is a controller implemented as a program. This method has the advantage of being more maintenance-friendly than existing analog controllers. However, it inevitably requires computation time to execute the internal program. Therefore, the digital controller uses a method of controlling the system at a certain cycle by considering this time, and this cycle is very closely related to the performance of the microprocessor used. In other words, in the case of very high performance, this control cycle can be shortened to near real time, but this may result in a disadvantage in terms of cost. In this paper, we propose a method to solve this problem by implementing two processors with slightly lower performance in a control system in a series-parallel structure. For this purpose, we will use a digital distributed control system and implement an experimental system to examine its effectiveness.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.73-82
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• 2005

This paper describes shock waveform synthesis methods for a shock response spectnlm over a short time interval with which intereference between parts within a test item is increased to perform a sufficient shock test for damage or malfunction which may be caused by the interference between parts, and a digital filter for obtaining a shock response history required for the shock waveform synthesis and a digital inverse filter for restoration by inversely using the digital filter. The time at which the maximax value occurs in the response history is detected in order to establish a delay time which is one of the parameters in the wavelet, on the condition that the natural frequency of SDOF system with a Q (quality factor) of 10 equals to the wavelet frequency of the zero delay wavelet input. A shock response spectrum over a short time interval and an abrupt change in the acceleration for an instant are illustrated as features of the synthesized waveform.

• 제어로봇시스템학회논문지
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• 제5권7호
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• pp.868-875
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• 1999

In this paper, digital motor control center using protection relay is developed in order to protect power systems by means of timely fault detection and diagnosis during operation for induction motor which have various load environments and capacities in power systems. Digital motor control center is employed by power supervisory control systems without separate remote terminal unit and transducers adding communicational ability. Also we develope a maximum demand controller to control the load effectively at peak status and a power factor controller to minimize real power losses and improve the power factor. Therefore, when using the developed controller, real time computation is possible by loading DSP in hardware and applying real-time kernel which can convert each algorithm to task module.

• 정보처리학회논문지C
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• 제10C권5호
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• pp.575-584
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• 2003

모바일 단말기의 하드웨어 한계, 단말기에 탑재된 시스템의 비호환성, 무선의 낮은 대역폭 등으로 인해 유선 환경의 전자 계약 시스템을 M-Commerce에 그대로 적용하기에는 무리가 있다. 본 논문은 이러한 문제점들을 해결하기 위해 XML 기반의 전자 계약서를 정의하고 이를 바탕으로 모바일 환경에 적합한 전자 계약 시스템 M-XContract를 설계 구현한 내용을 다룬다. M-Xcontract 시스템은 전자 계약 서버, PDA 상에서 고객과 계약하고 전자 서명된 계약서를 서버에 전송하는 M-ESign 모듈, 서명된 전자 계약서를 서버로부터 수신한 후 고객에게 보여주는 M-EDecoder 모듈, 그리고 전자 계약서 저작 도구 X-Auth로 구성된다 M-XContract 시스템의 성능을 분석하기 위해 PDA 상에서 전자 서명 생성 시간, 서버로 전송 시간을 측정하였다. 성능 분석 결과 M-XContract 시스템은 모바일 전자 계약 시스템을 위한 효과적인 모델이라는 결론을 얻었다.

• 치과방사선
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• 제25권1호
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• pp.51-70
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• 1995

The purpose of this investigation was to compare the direct digital radiographic system with film-based digital imaging system using Ektaspeed and Ektaspeed Plus film with respect to image characteristics and detectability and evaluate the sensor noise with the use of subtraction method. Direct digital radiographic system which used was Sens-A-Ray system(Regam Medical Systems, Sundsvall, Sweden) and film-based digital imaging system was composed of Macintosh II ci computer, high resolution Sony XC-77 CCD camera and intraoral x-ray film(Kodak Ektaspeed film, Kodak Ektaspeed Plus film). Images were taken by using CCD sensor of Sens-A-Ray system, Ektaspeed film and Ektaspeed Plus film with variable exposure time(0.06s, 0.1s, 0.16s, 0.2s, 0.3s, 0.4s, 0.5s, 0.6s, O.8s, LOs), 5 times at each exposure time. And then ektaspeed films and ektaspeed plus films were digitized using CCD camera. Image groups were divided into 3 groups; Sens-A-Ray group(direct digital radiographic system), Ektaspeed group and Ektaspeed Plus group (film-based digital imaging system) They were assessed by the following three aspects; image density, image contrast and detectability and sensor noise of Sens-A-Ray system was also evaluated. The results were as follow : 1. S group showed higher density than E , EP group except at the low exposure time(p<0.01). 2. S group showed higher contrast than E,EP group except at the high exposure time(p<0.01). 3. All groups showed good detectability at the each proper exposure time. Lowest exposure time which shows maximum detectability in S,EP group(0.5s) was lower than that in E group(0.6s). 4. Sensor noise of Sens-A-Ray system generally increased according to exposure time. On the basis of the above results, it was considered that Sens-A-Ray system could show higher speed, higher contrast than Ektaspeed, Ektaspeed Plus film except at too high and low exposure time and the same detectability as the conventional intraoral film.

• 디지털융복합연구
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• 제10권6호
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• pp.283-288
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• 2012

본 논문에서 구현된 클라우드 컴퓨팅 기반의 디지털 사이니즈 시스템은 기존의 디지털 사이니지 소프트웨어의 콘텐츠 생산의 불편함과 IPTV처럼 제작된 셋톱박스 관리의 불필요한 비용, 시간, 인력 등을 절감함으로서 실시간 정보를 제공하는 인터렉티브 콘텐츠를 제작할 수 있는 웹에디터와 같은 저작기능을 추가하여 차세대 디지털 사이니지(Signage, 광고 또는 홍보)의 새로운 방향을 제시하였다.

• 한국IT서비스학회지
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• 제21권5호
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• pp.1-13
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• 2022

With the rapid development of computer technology and communication networks in modern society, human economic activities in the almost every field of our society depend on various electronic devices. The huge amount of digital data generated in these circumstances is refined by technologies such as artificial intelligence and big data, and its value has become larger and larger. However, until now, it is the reality that the digital data has not been clearly defined as an economic asset, and the institutional criteria for expressing its value are unclear. Therefore, this study organizes the definition and characteristics of digital data, and examines the matters to be considered when considering digital data in terms of accounting assets. In addition, a method that can objectively measure the value of digital data was presented as a quantitative calculation model considering the time value of profits and costs.