• 한국동물위생학회지
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• 제29권4호
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• pp.507-511
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• 2006

Acanthomatous epulis is a malignant form of gingival tumor. This is a case of epulis affecting a four-year old, intact, female Maltese dog raised as indoor pet in Iksan city. Clinical examination showed an enlarged palpable mass along the rostral maxillary gingiva. Section of the excised mass showed epithelial overgrowth and expansion from the basal portions through the tissue stroma. Post-surgical radio-graph showed displacement of the first and second maxillary incisors. Histochemical staining showed strongly positive reaction to epithelial marker cytokeratin and moderately positive reaction to connective tissue marker vimentin. This case was diagnosed as a form of maxillary gingival acanthomatous epulis. Routine clinical oral examination is suggested.

• 전기학회논문지
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• 제58권2호
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• pp.415-421
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• 2009

TOA(time-of-arrival) and TDOA(time-difference-of-arrival) positioning techniques are commonly used in many radio-navigation systems. From the literature, it is known that the position estimate and error covariance matrix of TDOA obtained by GN(Gauss-Newton) method is exactly the same as that of TOA when the error source of the range measurement is only an IID white Gaussian noise. In case of geo-location and indoor positioning, however, multi-path or NLOS(non-line-of-sight) error is frequently appeared in range measurements. Though its occurrence is random, the multipath acts like a bias for a stationary user if it occurs. This paper presents the comparisons of error characteristics between TOA and TDOA positioning in presence of multi-path or NLOS error. It is analytically shown that the position estimate of TDOA is exactly the same as that of TOA even when bias errors are included in range measurements with different magnitudes. By computer simulation, position estimation error and error distribution are analyzed in presence of range bias errors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.331-332
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• 2007

In this paper we analyze whether recent Radio Frequence Identification technology can be used to improve the localization of mobile robot in their environment. This system make use of power control because Tag with Reader distance measurement. We are accurately the low at former time than the environment. A distance measurement is rather correct. This system used 900MHz Frequencies.

• 제어로봇시스템학회논문지
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• 제8권11호
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• pp.954-962
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• 2002

In a park or street, we can see many people jogging or walking with their dogs tracking their masters. In this study, an entertainment robot that imitates a dog's behavior is created. The robot's task is tracking a moving target that is recognized as the master. In order to design the robot, the ecological approach. in which the robot's goals and surroundings heavily influence its design, is used. A three-wheel type locomotion system is designed as the robot's physical structure which can follow a human jogging in outdoor space like a park. A sensor system which can detect the position of a master for the robot in the outdoor space, is developed. This sensor system consists of a signal transmitter which is at the hand of a master and some sensors which are mounted on the robot. The transmitter emits RF(radio frequency) and ultrasonic signals and the sensors detect the direction and distance from the robot to the transmitter by using the received signals. For the control architecture of the robot, a purely reactive behavior-based method is used in order to increase speed of response. The developed robot is evaluated through experiments conducted in indoor and outdoor environments.

• 한국정보통신학회논문지
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• 제2권3호
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• pp.309-315
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• 1998

본 논문에서는 직접대역확산방식을 이용한 DS-CDMA의 ISI나 ICI와 같은 문제점을 다수의 협대역 부반송파를 이용하여 해결할 수 있도록 제안된 변조방식인 MC-CDMA시스템의 성능을 분석하였다. 여기서 고려한 채널모델은 Rician 페이딩 분포를 가지며, 부반송파에서의 페이딩은 서로 독립적인 특성을 갖는 옥내이동통신 환경으로 하였다. 시스템의 성능분석을 위해 먼저 오류정정부호를 사용하지 않은 시스템의정방향과 역방향의 비트오율을 분석하였다. 그리고 (7,4) Hamming 부호, (15,7) BCH 부호, 구속장이 7인 1/2-길쌈부호와 같은 오류정정부호를 사용하였을 때 이용자수와 부반송파수 그리고 신호대 잡음비(SNR)에 따른 비트오율변화를 분석하므로써 부호화 MC-CDMA 시스템의 성능을 분석하였다.

• 대한전기학회논문지:전력기술부문A
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• 제51권1호
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• pp.23-28
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• 2002

In order to survey the radiation characteristics of pure line noise of unwanted noise from overhead high voltage AC transmission lines, a disk type gap noise generator was manufactured. Disk size which decides capacitance between the noise generator and earth was selected through preliminary indoor experiments and analysis by using surface charge method. The capacitance is one of principal parameters related to the injection of a proper noise current into lines. On the basis of the capacitance obtained from calculation, 5mm of space was given to the gap of the noise generator to be installed o test line and an aluminum disk of 60cm radius was made. The field experiments were performed with the noise generator hung on the Kochang 765 kV full scale test line. As the results, the useful data which can be used to analysis the radiation characteristics of noise from transmission lines were obtained. Those are the directivity of antenna toward the line, lateral profiles, frequency spectra, height pattern and so on.

• International Journal of Precision Engineering and Manufacturing
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• 제6권4호
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• pp.67-72
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• 2005

In a park or street, we can see many people jogging or walking with their dogs that are chasing their masters. In this study, a pet robot that imitates dog's behavior is developed. The task of robot is to chase a person who is recognized as the master. The physical structure and the sensor system are designed for the task and environment. A three-wheel type locomotion system is designed as the robot's physical structure which can follow a person who is jogging in outdoor environment like a park. A sensor system, which can detect relative position of the master to the robot in highly dynamic and hazardous worlds, is developed. This sensor system consists of a signal transmitter which is held by the master and ultrasonic sensor array which are mounted on the robot. The transmitter emits RF (radio frequency) and ultrasonic signals simultaneously. The ultrasonic sensor array detects the signals and calculates direction and distance between the robot and the transmitter. The developed RF-ultrasonic sensor is evaluated through experiments. A purely reactive behavior-based control architecture is used for the robot. The behavior control performance of the robot is assessed in outdoor and indoor tests.

• Healthcare Informatics Research
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• 제24권4호
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• pp.387-393
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• 2018

Objectives: This paper describes an experience of implementing seamless service trials online and offline by adopting Internet of Things (IoT) technology based on near-field communication (NFC) tags and Bluetooth low-energy (BLE) beacons. The services were provided for both patients and health professionals. Methods: The pilot services were implemented to enhance healthcare service quality, improve patient safety, and provide an effective business process to health professionals in a tertiary hospital in Seoul, Korea. The services to enhance healthcare service quality include healing tours, cancer information/education, psychological assessments, indoor navigation, and exercise volume checking. The services to improve patient safety are monitoring of high-risk inpatients and delivery of real-time health information in emergency situations. In addition, the services to provide an effective business process to health professionals include surveys and web services for patient management. Results: Considering the sustainability of the pilot services, we decided to pause navigation and patient monitoring services until the interference problem could be completely resolved because beacon signal interference significantly influences the quality of services. On the other hand, we had to continue to provide new wearable beacons to high-risk patients because of hygiene issues, so the cost increased over time and was much higher than expected. Conclusions: To make the smart connected hospital services sustainable, technical feasibility (e.g., beacon signal interference), economic feasibility (e.g., continuous provision of new necklace beacons), and organizational commitment and support (e.g., renewal of new alternative medical devices and infrastructure) are required.

• 해양환경안전학회지
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• 제18권5호
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• pp.488-495
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• 2012

전파를 이용한 실내 위치인식 기술은 현재 다양한 환경에서 연구되고 있다. 그 중 철골구조로 이루어진 선박은 전파의 반사에 의해 수신율은 높지만 레인징 오차가 크게 발생한다. 이러한 환경에서 발생하는 위치측정 오차를 줄이기 위하여 본 연구에서는 IEEE 802.15.4a의 CSS 기반으로 변형 이변측위와 초전센서를 이용한 선내 위치인식보정 알고리즘을 제안한다. 제안한 시스템은 선내 복도와 같은 좁은 통로에서 CSS의 특성분석을 통하여 이동노드와 고정노드 사이의 적합한 수신거리를 추정하여 고정노드의 수를 줄이고 또한 전파의 반사와 회절에 의한 레인징 오차가 크게 변동하는 코너영역에서 제안한 변형 이변측위기법과 초전센서를 이용하여 이동구간을 추적하여 위치를 인식하였다. 실험결과 제안한 알고리즘이 일반적인 방법 대비 86.2 %의 선내 위치인식 정확도와 효율이 향상됨을 확인하였다.

• 한국항해항만학회지
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• 제34권1호
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• pp.15-19
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• 2010

최근 빠르고 편리하게 데이터 송수신이 가능한 무선LAN은 가정, 사무실 등 다양한 장소에서 사용이 증가하고 있다. 그러나 실내에서 무선LAN을 사용할 경우 천장, 벽, 바닥, 책상 등에서의 반사파에 의한 다중반사가 발생하여 데이터 전송의 오류 및 성능 저하의 주된 원인이 된다. 이를 해결하기 위해 본 논문에서는 Graphite의 특성을 분석하고 최적의 조성비를 찾아내서 무선LAN 환경에 적합한 전파흡수체를 연구하였다. 먼저 Graphite와 지지재인 CPE(Chlorinated Polyethylene)를 이용하여 조성비별 전파흡수체 샘플을 제작하고, 각 샘플의 반사계수를 측정하였다. 측정된 데이터로부터 재료정수를 계산하고, 전파흡수체를 설계 및 제작하여 전파흡수능을 비교, 분석 하였다. 그 결과 조성비가 Graphite : CPE=50:50 wt%이고, 두께 1.7 mm 인 전파흡수체가 5.2 GHz에서 27 dB 이상의 전파흡수능을 가지는 우수한 전파흡수체를 개발하였다.