• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2011년도 춘계학술대회
• /
• pp.563-565
• /
• 2011

본 논문에서는 IEEE 802.15.4a 기반 무선 센서네트워크의 통신시스템 구현 고려사항에 관한 연구를 수행하였고 UWB 위치인식 시스템 설계에 대하여 분석하였다. 먼저, 위치인식을 위한 UWB 신호의 설계 및 다양한 신호 파라미터 선정에 대하여 연구하였다. 또한, 거리에 따른 UWB 신호의 품질을 결정하기 위하여 링크분석을 수행하였다.

• Journal of Positioning, Navigation, and Timing
• /
• 제5권3호
• /
• pp.137-144
• /
• 2016

In this paper, the performance of ranging measurement, which is generated using two receiver clock offsets in one receiver, was analyzed. A spoofer transmits a counterfeited spoofing signal which is similar to the GPS signal with hostile purposes, so the same tracking technique can be applied to the spoofing signal. The multi-correlator can generate two receiver clock offsets in one receiver. The difference between these two clock offsets consists of the path length from the spoofer to the receiver and the delay of spoofer system. Thus, in this paper, the ranging measurement was evaluated by the spoofer localization performance based on the time-of-arrival (TOA) technique. The results of simulation and real-world experiments show that the position and the system clock offset of the spoofer could be estimated successfully.

• Computers and Concrete
• /
• 제5권1호
• /
• pp.21-36
• /
• 2008

Steel fiber reinforced concrete is increasingly used day by day in various structural applications. An extensive experimentation was carried out with w/cm ratio ranging from 0.25 to 0.40, and fiber content ranging from zero to1.5 percent by volume with an aspect ratio of 80 and silica fume replacement at 5%, 10% and 15%. The influence of steel fiber content in terms of fiber reinforcing index on the compressive strength of high-performance fiber reinforced concrete (HPFRC) with strength ranging from 45 85 MPa is presented. Based on the test results, equations are proposed using statistical methods to predict 28-day strength of HPFRC effecting the fiber addition in terms of fiber reinforcing index. A strength model proposed by modifying the mix design procedure, can utilize the optimum water content and efficiency factor of pozzolan. To examine the validity of the proposed strength model, the experimental results were compared with the values predicted by the model and the absolute variation obtained was within 5 percent.

• 제어로봇시스템학회논문지
• /
• 제2권3호
• /
• pp.200-208
• /
• 1996

This paper describes the mechanism, guidance, sensor system, and navigation algorithm of METRO, a free ranging mobile robot. METRO is designed for use in structured surroundings or factory environments rather than unstructured natural environments. An overview of the physical configuration of the mobile robot is presented as well as a description of its sensor system, an omnidirectional laser range finder. Except for the global path planning algorithm, a guidance and a navigation algorithm with a local path planning algorithm are used to navigate the mobile robot. In METRO the computer support is divided into a supervisor with image processing and local path planning and a slave with motor control. The free ranging mobile robot is self-controlled and all processing being performed on board.

• International Journal of Control, Automation, and Systems
• /
• 제5권2호
• /
• pp.184-191
• /
• 2007

Autonomous navigation of mobile robot requires a ranging system for measurement of distance to environmental objects. It is obvious that the wider and the faster distance measurement gives a mobile robot more freedom in trajectory planning and control. The active omni-directional ranging system proposed in this paper is capable of obtaining the distance for all 3600 directions in real-time because of the omni-directional mirror and the structured light. Distance computation including the sensitivity analysis and the experiments on the omni-directional ranging are presented to verify the effectiveness of the proposed system.

• 제어로봇시스템학회논문지
• /
• 제14권5호
• /
• pp.483-488
• /
• 2008

An active omni-directional raging system using an omni-directional vision with structured light has many advantages compared to the conventional ranging systems: robustness against external illumination noise because of the laser structured light and computational efficiency because of one shot image containing $360^{\circ}$ environment information from the omni-directional vision. The omni-directional range data represents a local distance map at a certain position in the workspace. In this paper, we propose a matching algorithm for the local distance map with the given global map database, thereby to localize a mobile robot in the global workspace. Since the global map database consists of line segments representing edges of environment object in general, the matching algorithm is based on relative position and orientation of line segments in the local map and the global map. The effectiveness of the proposed omni-directional ranging system and the matching are verified through experiments.

• 한국식생활문화학회지
• /
• 제10권2호
• /
• pp.119-123
• /
• 1995

This study was carried out to obtain the information concerning nutritional status, including factors of food habits of 293 men working at industry in Ulsan area. The subjects of this study were composed of 152 clerical workers and 141 physical workers. The results of this study can be summarized as follows: Average age of this subjects was 34.7 years (ranging from 21 to 52), the mean height and weight were 171.5 cm and 66.9 kg, corresponding to the BMI of 22.7. The mean food habit score was 4.4 (ranging from 0 to 9.5) and the mean nutrition knowledge score was 4.9 (ranging from 0 to 10.0) which showed significant correlations with food habit score. Dietary intake data showed the average daily intake of energy, protein, calcium and iron were higher than Korean recommended dietary allowances (RDA), vitamin A, $B_1,\;B_2$, niacin, ascorbic acid were lower than RDA. Among the various influential factors, nutrition knowledge, drinking, smoking and prevalence symptoms of subjects correlated with food habits significantly.

• 제어로봇시스템학회논문지
• /
• 제7권12호
• /
• pp.967-972
• /
• 2001

In this paper, an adaptive robust nonlinear predictive controller is developed for the continuous time nonlinear systems whose control objective is composed of the system output and its desired value. The basic control law is derived from the continuous time prediction model and its feedback dynamcis shows another from if input and output linearization. In order to cope with the parameter uncertainty, robust control is incorporated into the basic control law and the asymptotic convergence of tracking error to a certain bounded region is guaranteed. For stability and performance improvement within the bounded region, an adaptive control is introduced. Simulation tests for the motion control of an underwater wall-ranging robot confirm the performance improvement and the robustness of this controller.

• 한국축산시설환경학회지
• /
• 제5권3호
• /
• pp.171-174
• /
• 1999

This study was conducted to investigate the quantity and characteristics of manure and urine produced by lactating sow fed commercial diet for 24 days. 3 way cross bred 10 lactating sows with litters were alloted at farrowing pen. Crude protein and digestible energy were 14% and 3,467 kcal in diet, respectively. Average body weight of sow was 237.5kg. Feces with urine was produced 6.98kg per day by lactating sow ranging from 5.72 to 7.93kg. Manure solid was produced 2.75 kg per day ranging from 2.17 to 3.87kg and urine 4.23kg per day ranging from 3.55 to 4.06kg, respectively. Dry matter of feces and urine were 29.91 and 1.54%, respectively. Nitrogen and phosphorus contents in fresh feces were 0.86 and 0.30%, respectively. Nitrogen content in urine was 0.86, and phosphorus in urine was 0.47%. pH in manure was 6.73 and in urine was 8.38 respectively. Biochemical oxygen demand and suspended solid in urine were 5,196 and 308mg/$\ell$, respectively.

• 수산해양기술연구
• /
• 제26권2호
• /
• pp.151-166
• /
• 1990

1989년 11월 4~12일의 동지나해에서 관측한 자료를 사용하여 해황을 조사하였다. 그 결과 표층의 해황은 쓰시마 난류수와 중국 대륙 연안수로 대별되고 그 사이에는 강한 전선이 형성되고 있다. 쓰시마 난류수는 수온 22~24$^{\circ}C$, 염분 33.5~34.5$\textperthousand$의 고온.고염수로 용존산소는 4.5ml/l 이하로 낮았다. 그리고 중국 대륙 연안수는 수온 18~2$0^{\circ}C$, 염분 32.0$\textperthousand$ 이하인 저온.저염수로 용존산소는 4.5~5.0ml/l로 높게 나타났다. 저층에도 역시 표층과 같이 쓰시마 난류수와 중국 대륙 연안수가 존재하였다. 이 외에도 북쪽에는 수온 1$0^{\circ}C$ 이하, 염분 33.0$\textperthousand$ 내외, 용존 산소는 4.5ml/l 이상의 고산소수인 황해 저층냉수가 분포하고, 동남쪽에는 수온 15~19$^{\circ}C$ 염분 34.5$\textperthousand$, 용존산소는 2.0~3.5ml/l의 저산소수인 동지나해 남부 저층수도 분포하였다. 그리고 중국 대륙 연안수와 쓰시마 난류수의 중간 특성을 나타내는 수온 20.5~22.$0^{\circ}C$, 염분 32.3~33.3$\textperthousand$의 물은 중국 대륙 연안수와 쓰시마 난류가 혼합된 결과라고 판단된다.