• ETRI Journal
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• 제30권1호
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• pp.59-67
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• 2008

The necessity for the precise time synchronization of measurement data from multiple sensors is widely recognized in the field of global positioning system/inertial navigation system (GPS/INS) integration. Having precise time synchronization is critical for achieving high data fusion performance. The limitations and advantages of various time synchronization scenarios and existing solutions are investigated in this paper. A criterion for evaluating synchronization accuracy requirements is derived on the basis of a comparison of the Kalman filter innovation series and the platform dynamics. An innovative time synchronization solution using a counter and two latching registers is proposed. The proposed solution has been implemented with off-the-shelf components and tested. The resolution and accuracy analysis shows that the proposed solution can achieve a time synchronization accuracy of 0.1 ms if INS can provide a hard-wired timing signal. A synchronization accuracy of 2 ms was achieved when the test system was used to synchronize a low-grade micro-electromechanical inertial measurement unit (IMU), which has only an RS-232 data output interface.

• 한국융합학회논문지
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• 제6권1호
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• pp.17-22
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• 2015

정보통신 분야와 관련하여 현재의 우리 사회에서 보여지고 있는 큰 특징중의 하나는 급변하는 IT환경에 대처하기 위한 노력일 것이다. 다양하게 나타나고 있는 비즈니스 환경에 대처하기 위해 기업들은 스토리지 및 서버 등과 관련된 IT 관련 구입에 꾸준히 비용을 투자하고 있다. 이같은 상황들은 기업입장에서는 기업의 생존과도 밀접하게 연관되어 있기 때문일 것이다. 이에 대한 해결책으로 최근 클라우드 컴퓨팅 서비스에 대한 연구가 활발히 진행되고 있다. 클라우드 컴퓨팅 서비스가 시장에 등장함에 따라 IT 자산과 관련된 개념은 소유에서 서비스를 이용한다는 의미로 변화되고 있다. 이러한 추세를 반영하듯 많은 관련 기업들이 클라우드 서비스를 제공하고 있다. 본 논문에서는 클라우드 컴퓨팅 서비스에 대한 일본의 산업 전망 및 사례들에 대해 연구하였다.

• 한국융합학회논문지
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• 제6권3호
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• pp.73-78
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• 2015

현재 우리 사회는 다양한 기술요소들이 혼합되어 하나의 또 다른 산업 및 기술을 창출하는 융, 복합 사회라 할 수 있다. 이러한 융, 복합현상들은 이미 경제, 사회, 문화등 사회의 전 부문에서 가시화되고 있다. 본 연구에서는 컨버전스의 대표적 사례이면서도 차세대 모바일 대표 시장의 가능성이 매우 큰 웨어러블 컴퓨터와 관련된 내용을 기술하였다. 웨어러블 컴퓨터는 착용 가능한 컴퓨터로서 미국의 MIT가 최근 기술 동향을 통해 2013년 10대 기술로 스마트 워치를 선정할 만큼 스마트 폰을 대체할 대표적인 차세대 모바일 기술로 꼽히고 있다. 따라서 본 논문에서는 웨어러블 컴퓨터에 필요한 필수적인 기술들에 대해 기술하고 관련 시장 및 미래, 이슈 등에 대해 기술하였다.

• 전자공학회논문지
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• 제50권6호
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• pp.267-275
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• 2013

GPS가 가지는 특징과 비선형, 비가우시안의 시스템에서도 강인한 특성을 지닌 파티클 필터(PF, Particle Filter)를 이용하여 위치 추정 성능을 향상시키는 방법에 대해 제안한다. 그리고 제안한 알고리즘으로 보정한 GPS 데이터와 관성센서를 저가형 시스템에 적합한 약결합 방식을 이용하여 결합하였으며 정확도 향상을 위해 자세에 관한 칼만필터를 추가시켜 구현하였다. 구현된 시스템의 성능확인을 위해 NovAtel사의 고정밀 GPS와 비교 분석하였다.

• 디지털산업정보학회논문지
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• 제13권1호
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• pp.69-78
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• 2017

As the smartphone-based devices are diffused and developed rapidly, they provide the convenience to the users. The abovementioned sentence technologies are being used not only in the existing sensor and wireless network technology but also in the application services of the diverse fields application services such as smart appliance, smart car, smart health care, etc. and the new fusion paradigm from the industry is presented by undertaking the researches in diverse area by the enterprises and research institutions. However, the smart environment exposes its weaknesses in the mobile terminal area, existing wireless network and IT security area. In addition, due to new and variant ways of attack, not only the critical information are disclosed However also the financial damages occur. This paper proposed the protocol to perform the smartphone-based safe device monitoring and safe communication. The proposed protocol designed the management procedure of registration, identification, communication protocol and device update management protocol and the safety against the attack techniques such as the an-in-the-middle-attack, impersonation attack, credential threat, information leaks and privacy invasion was analyzed. It was observed that the proposed protocol showed the performance improved by approximately 52% in the communication process than the existing system.

• 제어로봇시스템학회논문지
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• 제7권5호
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• pp.445-453
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• 2001

The multiple targets tracking problem has been one of the main issues in the radar applications area in the last decade. Besides the standard Kalman filtering, various methods including the variable dimen-sion filter, input estimation filter, interacting multiple model(IMM) filter, dederated variable dimension filter with input estimation, etc., have proposed to address the tracking and sensor fusion issues. In this pa- per, two existing tracking algorithm, i.e, the IMM filter and the variable dimension filter with input estima-tion(VDIE), are combined for the purpose of improving the tracking performance for maneuvering targets. To evaluate the tracking performance of the proposed algorithm, three typical maneuvering patterns, i.e., waver, pop-up, and high-diver motions, are defined and are applied to the modified IMM filter as well as the standard IMM filter. The smaller RMS tracking errors, in position and velocity, of the modified IMM filter than the standard IMM filter are demonstrated though computer simulations.

• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.898-904
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• 2010

Unmanned autonomous forklifts have a great potential to enhance the productivity of material handling in various applications because these forklifts can pick up and deliver loads without an operator and any fixed guide. There are, however, many technical difficulties in developing such forklifts including localization, map building, sensor fusion, control and so on. Implementation, which is often neglected, is one of practical issues in developing such an autonomous device. This is because the system requires numerous sensors, actuators, and controllers that need to be connected with each other, and the number of connections grows very rapidly as the number of devices grows. Another requirement on the integration is that the system should allow changes in the system design so that modification and addition of system components can be accommodated without too much effort. This paper presents a network-based distributed approach where system components are connected to a shared CAN network, and control functions are divided into small tasks that are distributed over a number of microcontrollers with a limited computing capacity. This approach is successfully applied to develop an unmanned forklift.

• 한국정밀공학회지
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• 제21권12호
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• pp.100-108
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• 2004

In reverse engineering, data acquisition methodology can generally be categorized into contacting and non-contacting types. Recently, researches on hybrid or sensor fusion of the two types have been increasing. In addition, efficient construction of a geometric model from the measurement data is required, where considerable amount of user interaction to classify and localize regions of interest is inevitable. Our research focuses on the classification of each bounded region into a pre-defined feature shape fer a hybrid measuring scheme, where the overall procedures are described as fellows. Firstly, the physical model is digitized by a non-contacting laser scanner which rapidly provides cloud-of-points data. Secondly, the overall digitized data are approximated to a z-map model. Each bounding curve of a region of interest (featured area) can be 1.aced out based on our previous research. Then each confined area is systematically classified into one of the pre-defined feature types such as floor, wall, strip or volume, followed by a more accurate measuring step via a contacting probe. Assigned to each feature is a specific digitizing path topology which may reflect its own geometric character. The research can play an important role in minimizing user interaction at the stage of digitizing path planning.

• 한국가스학회지
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• 제10권2호
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• pp.61-67
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• 2006

폴리에틸렌(PE) 배관 전기융착부에 대하여 위상배열초음파기술을 이용하여 전기융착부에 대한 비파괴검사를 실시하였다. 사례 1은 직경 300 mm의 PE배관 전기융착부에 대하여 3.5 MHz 배열초음파 센서를 이용하여 건전성 평가를 실시하였으며 사례 2는 직경 350 mm 3개의 새들융착부에 대하여 건전성을 평가하였고 사례 3은 400 mm 전기융착부에 대하여 3.5 MHz 배열초음파 센서를 가지고 비파괴검사를 실시하였다. 그리고 검사한 결과를 절단시험 결과와 비교하였다. 사례 4는 도시가스의 공급압력이 300 kPa인 400 mm PE배관 전기융착부를 탐상하고 그 결과를 살펴보았다.

• 전기학회논문지P
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• 제66권4호
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• pp.252-257
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• 2017

In this paper for developing and implementing the HD level triple streaming hybrid security camera which output the three type of video outputs(HD-SDI, EX-SDI, Analog). We design the hardware and program the firmware supporting the main and sub functions. We use MN34229PL as image sensor, EN778, EN331 as image processor, KA909A as reset, iris, day&night function part, A3901SEJTR-T as zoom/focus control part. We request the performance test of developed security camera at the broadcasting and communication fusion testing department of TTA (Telecommunication Technology Association). We can get the three outputs (HD-SDI, EX-SDI, Analog) from the developed security camera, get the world best level at the jitter and eye pattern amplitude value and exceed the world best level at the signal/noise ratio, and minium illumination, power consumption part. The HD level triple streaming hybrid security camera in this paper will be widely used at the security camera because of the better performance and function.