무선센서 기반 다차원 사용자 움직임 탐지 시스템

김정래,정인범,Kim, Jeong-Rae,Jeong, In-Bum 한국정보통신학회 2011 한국정보통신학회논문지 Vol.15 No.3

현대의 인간은 시간과 공간에 상관없이 정보기기를 이용하여 네트워크에 접근할 수 있는 환경에 노출되어 있다. 이러한 환경에서 사용자들은 다수의 온라인 정보 기기들을 통해 정보를 수신, 입력, 가공이 가능하다. 하지만, 현대에 널리 사용되는 마우스, 조이스틱, 트랙볼 등과 같은 포인팅 시스템은 휴대가 불편하고, 사용시 손이 자유롭지 않기에 유비쿼터스 환경에서 사용하기 어렵다. 본 논문에서는 휴대 및 설치가 간편하고, 사용시 사용자의 손이 자유로운 무선 센서기반의 다차원 사용자 움직임 탐지 시스템을 구현하였다. 본 시스템은 사용자 팔 움직임을 감지하여 수신기로 전달하는 입력기와 입력기로부터 받은 데이터를 응용프로그램으로 전달하는 수신기, 수신한 데이터를 처리하여 명령을 수행하는 응용프로그램으로 구성된다. 실험을 통하여 제안된 시스템이 사용자의 팔 움직임을 정확히 탐지하고, 해당된 입력 요구사항을 충분히 수행함을 보인다. Due to recently advanced electrical devices, human can access computer network regardless of working location or time restriction. However, currently widely used mouse, joystick, and trackball input system are not easy to carry and they bound user hands exclusively within working space. Those make user inconvenient in Ubiquitous environments.. In this paper, we propose multiple dimension human motion detection system based on wireless sensor networks. It is a portable input device and provides easy installation process and unbinds user hands during input processing stages. Our implemented system is comprised of three components. One is input unit that senses user motions and transmits collected data to receiver. Second is receiver that conveys the received data to application, which runs on server computer. Third is application that performs command operations according to received data. Experiments shows that proposed system accurately detect the characteristics of user arm motions and fully support corresponding input requests.

블레이드 앞전 3차원 형상 변형에 의한 터빈 캐스케이드 내의 이차유동 제어

김정래,문영준,정진택,Kim, Jeong-Rae,Moon, Young-June,Chung, Jin-Tack 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.11

The blade leading edge is modified to control the secondary flow generated in the turbine cascade with fence by intensifying the suction side branch of the horseshoe vortex. The incompressible Navier-Stokes equations are numerically solved with a high Reynolds number k-$\varepsilon$ turbulence closure model for investigating the vortical flows in the turbine cascade. The computational results of total pressure loss coefficients in the wake region are first compared with experiments for validation. The structure and strength of the passage vortex near the suction surface are examined by testing various geometrical parameters of the turbine blade leading edge.

'99년도 석유산업의 회고와 전망

김정래,Kim, Jeong-Rae 대한석유협회 1999 석유와 에너지 Vol.1999 No.11

GRACE 위성 간 거리측정기 비행성능 분석

김정래 ( Jeong Rae Kim ) 大韓遠隔探査學會 2006 大韓遠隔探査學會誌 Vol.22 No.4

2002년 3월에 발사 된 GRACE (Gravity Recovery and Climate Experiment)는 미국과 독일 합작으로 개발된 최초의 지구중력장 측정 전용 위성으로 동일한 궤도를 비행하는 두 개의 위성 사이 거리 변화를 측정하여 지구 중력장을 추정하는 사업이다. 위성 발사 후 이전 보다 수 십배 정확한 지구중력장 모델을 생성하였으며, 지구중력장 변화도 30일마다 추정하고 있다. GRACE 위성의 핵심 관측기인 위성간 거리 측정기의 원리에 대해 소개하고, 운용 결과 및 성능에 대해 소개 하였다. 발사 전 성능 분석 단계에서 고려되지 못했던 거리측정기 오차 요인에 대해 분석하고, 향후 연구 방향을 제시 하였다. GRACE (Gravity Recovery and Climate Experiment) is the first dedicated gravity mapping mission. Its primary measurements are the distance changes between two co-orbiting low earth satellites. GRACE is a joint development by NASA and German DLR and was launched in March 2002. GRACE improves the Earth gravity model accuracy by nearly two factor of magnitude over pre-launch models. After brief description of the GRACE primary instrument, inter-satellite ranging system, its flight status and preliminary performance evaluation is presented. Ranging system error models, which were not included in the pre-launch performance model and design specifications, are identified through analyzing the flight data. Base on this analysis, future research topics on the GRACE instrument performance analysis are discussed.

위성항법 신호 이중주파수간 편이 추정오차 분석

김정래 ( Jeong Rae Kim ),노정호 ( Jeong Ho Noh ),이형근 ( Hyung Keun Lee ) 한국항공운항학회 2012 한국항공운항학회지 Vol.20 No.3

Global navigation satellite systems (GNSS) use dual frequency signals to remove ionosphere delay effect. GNSS receivers have their own biases, called inter-frequency bias (IFB) between dual frequencies due to differential signal delays in receiving each frequency codes. The IFB degrades pseudo-range and ionosphere delay accuracies, and they must be accurately estimated. Simultaneous estimation of ionosphere map and IFB is applied in order to analyze the IFB estimation accuracy and variability. GPS network data in Korea is used to compute each receiver`s IFB. Accuracy changes due to ionosphere model changes is analyzed and the effect of external GNSS satellite IFB on the receiver IFB is analyzed.

생물교사와 예비 생물교사의 대진화 개념에 관련된 변인들 간의 관계 분석

김정래 ( Jeong Rae Kim ),차희영 ( Hee Young Cha ) 한국생물교육학회 2014 생물교육 Vol.42 No.4

The objective of this study was to know about the understanding of macroevolution among biology teachers regarded as contributing factor in education. Especially, the focus of this study was to speculate the status of the conception of macroevolution, and then the relationships with several factors such as natural selection, acceptance of the theory of evolution, the nature of science, understanding of time, religiosity, and the perception of the importance of evolution. To do this research, five kinds of instruments were chosen and developed. The subjects were 94 in-service and pre-service biology teachers. It was found that teachers didn``t have excellent understanding in macroevolution and they were difficult to understand the concept of deep time. Religiosity affected the acceptance of the theory of evolution negatively. The knowledge of natural selection associated with the one of macroevolution. It was also found that the nature of science correlates positively with the knowledge of macroevolution and natural selection, and the acceptance of the theory of evolution. It is suggested that the enforcement of the nature of science through biology teacher education programs to lessen the influence of the religiosity. Further studies for associations among factors affecting macroevolution of science teachers with various academic background basis are required because they are in charge of evolution education in classrooms regardless of their academic majors.

論文(논문) : 정밀좌표변환 및 중력가속도 계산 알고리듬 분석

김정래 ( Jeong Rae Kim ),노정호 ( Jeong Ho Noh ) 한국항공운항학회 2011 한국항공운항학회지 Vol.19 No.4

Inertial navigation systems requires gravity model to compute gravity acceleration and its trajectory accuracy depends on the gravity model accuracy especially for a long range flight. The gravity model accuracy is important for satellite orbit prediction as well. The precision gravity model requires a precision coordinate transformation between inertial and Earth fixed coordinates. Precision gravity acceleration algorithms with a coordinate transform are studied and a computer program is developed. The effects of individual model components on trajectory error are analyzed.

IRI 모델을 이용한 저궤도 전리층 지연값 배율 결정

김정래 ( Jeong Rae Kim ),김민규 ( Ming Yu Kim ) 대한원격탐사학회 2014 大韓遠隔探査學會誌 Vol.30 No.2

지상기반 전리층모델로 계산한 전리층 지연값을 저궤도에서의 전리층 지연값으로 변환하기 위해서는 전리층 변환 배율 적용해야 하는데, 이러한 배율을 IRI 전리층모델을 사용하여 결정하는 기법을 제안하였다. IGS 전리층모델에 전리층 배율을 적용하여 계산한 전리층 지연값을 NASA GRACE 위성의 관측값과 비교하였다. 약 480 km 고도에서 2004년 평균 배율은 0.25이며, 표준편차는 0.01이다. 전리층 배율은 주간에 비해 야간에 상대적으로 증가하며, 계절적으로는 봄, 가을에 높은 값을 가진다. IGS모델에 전리층배율을 결합해서 추정한 저궤도 전리층 지연값 추정 오차 평균은 3.50 TECU이다. Determination of an ionospheric delay scale factor, which converts ground-based ionospheric delay into low Earth orbit ionospheric delay, using the international reference ionosphere model is proposed. Ionospheric delay from international GNSS service model combined with IRI-derived scale factor is evaluated with NASA GRACE satellite data. At approximately 480km altitude, mean and standard deviation of the scale factor are 0.25 and 0.01 in 2004. The scale factor reaches high in night time and Spring and Fall seasons. Ionospheric delay error by the proposed method has a mean of 3.50 TECU in 2004.

이중단방향 반송파 거리측정기 비행성능 분석

김정래 ( Jeong Rae Kim ) 한국항공운항학회 2009 한국항공운항학회지 Vol.17 No.1

One of the error sources for microwave ranging is the instability of the oscillator that drives the microwave signals. Dual one-way ranging (DOWR) minimizes the oscillator effect by combining two one-way carrier phase signals from two transmitter/receiver instrument. The DOWR is first implemented in the GRACE (Gravity Recovery and Climate Experiment) satellites. Direct evaluation of the DOWR is not possible due to its extremely high accuracy. The flight performance of the GRACE DOWR is analyzed by applying several indirect methods. Comparison with the design noise level is discussed.

GNSS를 이용한 전리층 기울기 추정 방법 비교

김정래 ( Jeong Rae Kim ),정명숙 ( Myeong Sook Jeong ) 한국항공운항학회 2007 한국항공운항학회지 Vol.15 No.2

The high ionospheric spatial gradient during ionospheric storm is the most concern when applying GNSS(Global Navigation Satellite System) augmentation systems for aircraft precision approach. Since the ionospheric gradient level depends on geographical location as well as the storm, understanding the ionospheric gradient statistics over a specific regional area is necessary for operating the augmentation systems. This paper compares three ionosphere gradient computation methods, direct differentiation between two receivers` ionospheric delay signal for a common satellite, derivation from a grid ionosphere map, and derivation from a plate ionosphere map. The plate map method provides a good indication on the gradient variation behavior over a regional area with limited number of GNSS receivers. The residual analysis for the ionosphere storm detection is discussed as well.