• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.457-461
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• 2002

This paper describes a development of a robot working in hazard environment. The developed robot consists of robot controller with vision system and host PC program. The robot and camera can move with 2 degree of freedom by independent remote controlling a user friendly designed joystick. An environment is recognized by the vision system and ultra sonic sensors. The visual image and command data translated through 900MHz and 447MHz RF controller, respectively. To show the validity of the developed system, operations of the robot in the field area were illustrated.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.70-74
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• 1998

This paper describes a method for recognition of two-dimensional position of an object by use of aerial ultra-sonic sensor and signal processing technique, which would become a help for blind person or self-mobile robot. First, we have developed a method for measuring the time difference between the transmitted and the received burst wave by use of one ultrasonic transmitter and three receivers. Secondly, a new method is developed for measuring the distance to an object by use of M-sequence correlation method. Thirdly, a measurement method to obtain the position of an object is described by use of phase-arrayed ultrasonic sensor, which gives us a wide-range position determination in a short time.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.27-30
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• 2016

본 논문은 일체형 플랫폼 디바이스인 ATMEGA-128을 이용하여 추적하는 이동로봇에 대해 서술한다. 최근 하드웨어의 개발로 일체형 플랫폼 디바이스들이 많이 개발되고 있다. 또한 디바이스와 센서 등을 접목한 여러 가지 제품들이 만들어 지고 있다. 본 논문에서는 일체형 플랫폼 디바이스중 하나인 ATMEGA 및 초음파 장비를 활용한 이동로봇의 설계 및 구현에 대해 서술한다. 초음파 장비의 발신부는 마이크로폰을 이용하여 초음파를 발생시키고 이동로봇에 부착된 수신부에서는 마이크로폰으로부터 초음파 신호를 수신 대기 한다. 이후, 수신 감도의 정확성 향상을 위해 초음파 신호를 증폭시켜 값을 판단 한다. 해당 신호를 통해 이동로봇은 초음파 신호 발신부와 수신부 사이의 거리 값을 알아낸다. 이후 가장 가까운 거리 값을 나타내는 방향을 로봇의 전면부가 되게 회전하고 직진하여 최종적으로 로봇은 발신부 방향으로 이동하게 된다.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3080-3082
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• 1999

본 논문에서는 실내환경에서 얻어진 격자 지도(grid map)상의 장애물 정보의 표현을 간략화 시키는 방법에 대하여 논하였다. 여기서 기본이 되는 격자 지도의 장애물 정보는 초음파 센서를 이용하여 얻어졌다고 가정하였다. 그리고 생성된 장애물 정보를 직선 성분으로 간단히 표현하여 저장될 정보의 양을 줄이는 변환 방법들인 체인 코드(chain code)와 호프 변환(Hough transform)에 대하여 논하였다. 그리고, 논의된 방법의 유효성을 증명하기 위하여 컴퓨터 시뮬레이션에 의한 결과를 제시하였으며, 단점들에 대한 앞으로의 연구 방향을 제시 하였다.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.476-479
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• 2003

Recently, Bluetooth has been regarded as a new technology for short-range wireless connection. Although initial application of Bluetooth technology has been focused mainly on replacing cables between hand-held devices due to a limited packet size and short-range, general wireless telecommunication such as PAN and Ad hoc networks via Bluetooth-equipped devices is expected to be one of the most popular applications. Wireless equipments have been used to exchange data between host and mobile unit. The exchanging data may be several bytes of control command and the value of sensors with ultra-sonic, vision sensor, and encoder from mobile robot. However, most wireless equipments have some drawbacks such as lack of authentication, large size and high price. On the other hand, the benefits of Bluetooth are small size, low power, low price except short-range. Especially, there are some difficulties when wireless modules are used in indoor environments. In this paper, a method of using wire network in Bluetooth network is investigated as a solution to overcome the short-range problem of Bluetooth and difficulty in indoor environment.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.375-379
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• 2016

Recently derived energy dissipation equation by Chamani(2008) and the profile function of the free overfall by Marchi(1993) were verified with present experiment data. The experiment was conducted in hydraulic laboratory, Hanyang University where the flume is 7m long and 0.44m wide, and the height of the drop structure is 0.205m. Water depth and free overfall profile data were collected using an ultra sonic distance sensor and photographic images. The time-averaged water depth data and the free overfall profile were analyzed to examine the energy dissipation pattern over the drop structure

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.876-878
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• 2016

본 연구에서는 자동차 및 기계부품의 제조공정에서 핵심부품인 밸브바디의 주물공정 후 생성된 버(burr)를 제거하기위한 초음파 디버링 장치를 개발하고자하였다. 초음파 디버링장치는 진동부와 제어부로 구성되고 디버링효과의 극대화를 위해 디버링 수에 포함된 용존가스의 제거가 매우 중요함에 따라 용존가스 제어기법을 적용한 초음파 디버링 장치를 개발하고 평가실험을 수행하였다. 본 연구에서는 초음파 디버링에서의 용존가스에 따른 디버링 성능을 평가하고 실제 시스템에 적용하기위한 산업적용 가능성 평가를 수행하였다.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.970-977
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• 2005

The commercial $V_2O_5-WO_3/TiO_2$ catalysts which had been exposed to the off gas from incinerator for a long time were remanufactured by washing with distilled water and arid solution and reimpregnation with catalytic active components($V_2O_5-WO_3$). The catalytic properties and NOx conversion reactivity of those catalysts were examined by analysis equipment and NOx conversion experiment. Under the experimental condition used in this study, the remanufactured catalysts activated by distilled water ultra sonic cleaning, the catalytic activity was recovered in the range of $66{\sim}93%$ of that of the fresh and the maximum activity was showed when the ultra sonic cleaning time was more than 3 minutes. The remanufactured catalysts by acid solution ultra sonic cleaning, the catalytic activity was recovered in the range of $81{\sim}97%$ of that of the fresh catalyst and the maximum catalytic activity was shooed when the pH of the acid solution was 5. The remanufactured catalysts by reimpregnation with $V_2O_5$ and $WO_3$, the catalytic activity was recovered in the range of $87{\sim}100%$ of that of the fresh catalyst. Maximum catalytic activity was showed when the $V_2O_5$ was reimpregnated more than 1.0 wt %. In this case, the catalytic activity was recovered 97% of that of the fresh catalyst especially at the $150^{\circ}C$ of the experimental temperature.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.316-324
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• 2004

Purpose : In radiotherapy of tumors in liver, enough planning target volume (PTV) margins are necessary to compensate breathing-related movement of tumor volumes. To overcome the problems, this study aims to obtain patients' body movements by using a moving phantom and an ultrasonic sensor, and to develop respiration sating techniques that can adjust patients' beds by using reversed values of the data obtained. Materials and Methods : The phantom made to measure patients' body movements is composed of a microprocessor (BS II, 20 MHz, 8K Byte), a sensor (Ultra-Sonic, range $3\~3$ m), host computer (RS232C) and stepping motor (torque 2.3 Kg) etc., and the program to control and operate it was developed. The program allows the phantom to move within the maximum range of 2 cm, its movements and corrections to take place In order, and x, y and z to move successively. After the moving phantom was adjusted by entering random movement data (three dimensional data form with distance of 2 cm), and the phantom movements were acquired using the ultra sonic sensor, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using guinea pigs, the real-time respiration gating techniques were drawn by operating the phantom with the reversed values of the data. Results : The result of analyzing the acquisition-correction delay time the three types of data values and about each value separately shows that the data values coincided with one another within $1\%$ and that the acquisition-correction delay time was obtained real-time $(2.34{\times}10^{-4}sec)$. Conclusion : This study successfully confirms the clinic application possibility of respiration gating techniques by using a moving phantom and an ultrasonic sensor. With ongoing development of additional analysis system, which can be used in real-time set-up reproducibility analysis, it may be beneficially used in radiotherapy of moving tumors.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.871-876
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• 2016

Abnormal odor similar with burning smell often appears at the cockpit in the beginning of ultra-sonic aircraft without air filter due to the heating of production materials remained at the bleed air duct. Sources of the odor should be removed by burn-in test before test flight in order to prevent pilot confuses order with emergency such as fire of engine. However, the present method cannot prevent abnormal odor completely at the high altitude flight because maximum temperature of flight is higher than it of burn-in-test. This paper suggests burn-in test improved based on the analysis of thermal conditions of high altitude flight. It is verified that the existing burn-in test cannot cover thermal conditions of high altitude flight due to the discontinuous flow control, high change rate of temperature per unit time and difference between limit temperature of condenser and turbine. In order to overcome the limitations of current methods, the new burn-in test with continuous flow control are suggested. The continuous flow control are achieved by ram air inlet control. The effect of suggested method are verified by ground tests and flight tests. The results show the bleed air temperature can cover the temperature of high altitude flight and prevent abnormal odor at the flight test.