• 한국콘텐츠학회논문지
• /
• 제21권1호
• /
• pp.119-128
• /
• 2021

교통정보를 생성하기 위한 가장 전형적인 방법은 차량검지기를 도로에 설치하여 각종 교통변수를 수집하는 방법으로 차량검지기의 수집 정확성에 따라 생성되는 교통정보의 신뢰성에 영향을 미친다. 가장 범용적인 차량검지기는 영상검지기이며, 본 연구에서는 지자기검지기를 영상검지기와 동일 지점에 설치하여 장기간, 다양한 환경에 대해 교통량, 속도 자료에 대한 정확성 평가를 수행하였다. 평가결과 영상검지기는 카메라에서 멀어질수록 오차가 많이 발생하며, 주간보다는 야간에 오차가 많이 발생하는 것으로 분석되었다. 또한 강우량은 교통량 수집에는 영향을 미치지 않으나 속도 수집에는 악영향을 미치는 것으로 나타났다. 따라서 현재 운영 중인 영상검지기의 성능을 높이기 위해서는 설치위치 및 높이에 따른 카메라 화각분석 및 이에 따른 화각의 최적화가 요구되며, 악천후 시에는 별도의 성능평가기준이 마련되어야 할 것으로 판단된다.

• 전자공학회논문지B
• /
• 제30B권12호
• /
• pp.31-39
• /
• 1993

In the playback signal processing of a digital magnetic recording system, the major signal processing processes consist of pulse equalization. pulse detection, clock recovery, and data recovery. Equalizer which compensates interference occurrde between pulses recorded in high density on a magnetic media is realized by pulse slimming method, and pulse detection by a integrating detector. Clock recovery from the detector output was accomplished by using PLL. and data recovery to reduce noise effects was carried out by utilizing the three sampling clocks recovered in clock recovery process. In this paper these processes are implemented in hardware and its performance is evaluated by experimenting with a commercial DAT. It was found that the playback signal processor proposed is suitable to the practical high density magnetic recording system.

• 전기학회논문지
• /
• 제58권3호
• /
• pp.598-604
• /
• 2009

This paper proposes a vehicle detector with an anisotropic magnetoresistive (AMR) sensor and addresses experimental results to show the detector's performance. The detector consists of an AMR sensor and mechanical and electronic apparatuses. The AMR sensor, composed of four magnetoresistors, senses disturbance of the earth's magnetic field caused by a vehicle moving over the sensor and then produces an output indicative of the moving vehicle. This paper verifies performance of the detector on the basis of experimental results obtained from the field tests carried under the two traffic conditions on local highways in Korea. First, I show the vehicle counting performance on a low speed congested highway by comparing the vehicle counts measured by the detector with the exact counts. Second, both vehicle counts and average speeds calculated from the measured point-occupancy on another continuously free running highway are compared with the reference values obtained from a loop detector which has two independent loop coils, where I have used several performance indices including mean absolute percentage error (MAPE) to show the performance consistency between the two types of detectors.

• 전기학회논문지
• /
• 제60권3호
• /
• pp.600-605
• /
• 2011

This paper shows field test and evaluation results for a wireless vehicle detector with anisotropic magneto-resistive (AMR) sensors. The detector consists of two AMR sensors and mechanical and electronic apparatuses. The AMR sensor senses disturbance of the earth magnetic field caused by a vehicle moving over the sensor and then produces an output indicative of the moving vehicle. In this paper, vehicle speeds are calculated by using two AMR sensors fixed on a board, with constant distance. To test and evaluate the accuracy of the detector in real traffic situations, the detector was installed on a local highway and vehicle speeds and volumes were measured both in a free running and a highly congested traffic. The measurements from the detector are compared with the reference measurements obtained from a traffic camera with the Mean Absolute Percentage Errors (MAPE), which has proved the usefulness of the detector in the field.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 B
• /
• pp.714-716
• /
• 1997

In order to prevent the belt from being damaged by metal pieces, we developed multicoil-type metal detection system. This detects the presence of belt clips and position of metal pieces in ores being transported on conveyor belt. In this research, our coil sensor of multicoil-type metal detection system is divided into two parts, exciting part (transmitter coil) and sensing part composed of two receiver coils. Each receiver coil has several coils in the direction of belt width. Multicoil-type metal detection system is operated by supplying a transmitter coil with electric power resources to generate magnetic field, and then the change of magnetic flux resulted from a metal piece on the conveyor be a is induced into sensing coils. We can prevent detector from failing to catch metal pieces due to high threshold level produced by steel belt clips and male the sensitivity of belt-width direction uniform by using multicoil-type metal detection system. Besides, this developed system can recognize precise position and size of metal piece. The experiments shows that our multicoil-type metal detection system has better performances than the conventional metal piece detector.

• 한국초전도저온공학회:학술대회논문집
• /
• 한국초전도저온공학회 2003년도 추계학술대회 논문집
• /
• pp.222-225
• /
• 2003

In this paper the performance of the high speed circuit breaker with fault current detector is described. The operating mechanism of circuit breaker in use is a magnetic actuator and a fault current detector is based on the DSP and A/D converter. The results show that 3-cycle is enough to interrupt the fault current and the more speed up performance is expected with on-going project.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 하계종합학술대회논문집
• /
• pp.106-109
• /
• 1998

Wireless communication systems, in particular, must operate in a crowded electro-magnetic environmnet where in-band undesired signals are treated as noise by the receiver. These interfering signals are often random but not Gaussian Due to nongaussian noise, the distribution of the observables cannot be specified by a finite set of parameters; instead r-dimensioal sample space (pure noise samples) is equiprobably partitioned into a finite number of disjointed regions using quantiles and a vector quantizer based on training samples. If we assume that the detected symbols are correct, then we can observe the pure noise samples during the training and transmitting mode. The algorithm proposed is based on a piecewise approximation to a regression function based on quantities and conditional partition moments which are estimated by a RMSA (Robbins-Monro Stochastic Approximation) algorithm. In this paper, we develop a diversity combiner with modified detector, called Non-Linear Detector, and the receiver has a differential phase detector in each diversity branch and at the combiner each detector output is proportional to the second power of the envelope of branches. Monte-Carlo simulations were used as means of generating the system performance.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 1991년도 추계학술발표회논문집
• /
• pp.45-47
• /
• 1991

In this research, we verify the relations between the mechanical hardness of a strip and the output of Residual Magnetic Flux Detector, which is installed in the end side of #2 CAL. First, we install the strip speed detector and get a hardness signal and a speed signal 2 seconds, and then do signal processing and send an output to a printer every 30 seconds. The system that performs above functions is Magnetic Hardness Data Acquisition & Processing System. We got the relation between output current and hardness for the strip of T3 BP through on-line tests. Seconds, we made a hardness Measurement Simulator and observed the speed characteristics of residual magnetic flux, with using it.

• 한국통신학회논문지
• /
• 제33권11C호
• /
• pp.868-873
• /
• 2008

본 논문에서는 수직 자기기록 채널에서 연집에러에 따른 LDPC(low density parity check) 부호의 성능을 분석한다. 수직 자기기록 채널에서 연집에러가 발생하면 수신부에서는 채널상태정보(channel state information)를 통하여 연집에러 부분을 알아낸 후 채널검출기의 연판정(Log Likelihood Ratio) 값을 0으로 초기화하는 방법을 사용한다. 패리티 검사 행렬은 부호율이 0.94인 (4336,4096)와 (8672,8192)를 사용한다. 그리고 채널 검출기는 연산량이 적은 SOVA(soft output Viterbi algorithm)를 사용한다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 B
• /
• pp.711-713
• /
• 1997

The mechanical properties of a hot rolled steel is mostly governed by a cooling control on the run out table. During the cooling control, the hot rotted steel performs a metallurgical transformation(austenite ${\to}$ ferrite) which can be measured with a magnetic flux detector. The magnetic flux detector consisting of exciting and detecting coil can estimates the metallurgical transformation by measuring the variation of permeability in steel. We developed the method of detecting the magnetic property of hot rolled steel and processing the measured signal, Which makes possible to measure on-line metallurgical transformation.