• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.197-205
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• 2007

Radio frequency identification, or RFID, is a generic term for technologies that use radio wave to automatically identify people or objects. UHF RFID technology is used for everything from tracking goods within their supply chain, working in process and for other applications. If RFID is applied in wheel scanner that is a important equipment to measure a diameter, width, height of wheel, efficiency in maintenance will be improved because of checking data in real-time. In domestic technology, capacity of wheel scanner technology as well as RFID are less good than foreign goods there a up to current day a point of read range, anti-collision, a tolerance. Therefore, sturdy on the development of wheel scanner using RFID technology to measure wheel in maintenance of rolling stock was carried out in this paper.

• 한국정보과학회논문지:시스템및이론
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• 제28권3호
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• pp.155-160
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• 2001

본 논문은 영역별 근접 그래프 (geographic nearest neighbor graph)와 레인지 트리 (range tree)를 이용하여 평면 위의 n 개의 점에 대한 L$_{\infty}$ (L$_1$) 거리 (metric) 상의 디루니 삼각분할 (Delaunay triangulation)을 구축하는 방법을 소개한다. 이 방법은 L$_{\infty}$ (L$_1$) 거리 상에서 디루니 삼각분할에 있는 각 삼각형의 최소한 한 선분이 영역별 근접 그래프에 포함됨을 이용하여 레인지 트리 방법으로 디루니 삼각분할을 구축한다. 본 방법은 0(nlogn)의 순차계산 시간에 L$_{\infty}$ (L$_1$) 디루니 삼각분할을 구축하며, CREW-PRAM (Concurrent Read Exclusive Write Parallel Random Access Machine)에서 0(n)의 프로세서로 0(logn)의 병렬처리 시간에 L$_{\infty}$ (L$_1$) 디루니 삼각분할을 구축한다. 또한, 이 방법은 직선간의 교차점 계산 대신 거리비교를 하기 때문에 수치오차가 적고 구현이 용이하다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (1)
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• pp.545-547
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• 2000

본 논문은 영역별 근접 그래프(geographic nearest neighbor graph)와 레인지 트리(range tree)를 이용하여 평면 위의 n 개의 점에 대한 L$\infty$(L1) 거리(metric) 상의 디루니 삼각분할(Delaunay triangulation)을 구축하는 방법을 소개한다. 이 방법은 L$\infty$(L1) 거리상에서 디루니 삼각분할에 있는 각 삼각형의 최소한 한 선분이 영역별 근접 그래프에 포함됨을 이용하여 레인지 트리 방법으로 디루니 삼각분할을 구축한다. 본 방법은 O(nlogn)의 순차계산 시간에 L$\infty$(L1) 디루니 삼각분할을 구축하며, CREW-PRAM (Concurrent Read Exclusive Write Programmable Random Access Machine)에서 O(n)의 프로세서로 O(logn)의 병렬처리 시간에 L$\infty$(L1) 디루니 삼각분할을 구축한다. 또한, 이 방법은 직선간의 교차점 계산 대신 거리비교를 하기 때문에 수치오차가 적고 구현이 용이하다.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2007년도 제38차 춘계학술대회 초록집
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• pp.84-89
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• 2007

카메라의 정량 평가 결과로부터 신규 설치된 HVEM용 고전압 CCD 카메라 (SPUS1000 HV-IF)는 기존의 HV-MSC 카메라에 비해 read-out noise level과 shot noise 발생거동, average gain, dynamic range, uniformity, DQE 등이 향상된 결과를 보여 주었고 MTF는 전과 유사한 결과를 나타내었다. 그러나 linearity가 HV-MSC 카메라에 비해 그 범위가 좁으며 낮은 전자 조사 조건하에서는 전반적인 카메라 성능이 오히려 HV-MSC 카메라의 경우보다 낮은 결과를 나타내었다. 따라서 본 신규 카메라는 낮은 전자 조사 조건이 필요한 실험에서는 기록 성능의 개선을 나타내지 않지만 고속 영상 기록 기능을 활용한 재료의 역동적 분석과 함께 원자분해 영상 작업과 EELS 분석에 있어선 이전 보다 기록 성능의 뚜렷한 개선을 나타낼 것으로 기대할 수 있다.

• 수산해양기술연구
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• 제16권1호
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• pp.43-47
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• 1980

The author designed and tested the high sensitive three-phase power factor meter and relay circuit, and dealt with the circuit to detect the phase of the current and the voltage. An operational amplifier comparator circuit and two single-phase transformers are used to control and detect the phase angle between the current and the voltage. The results obtained are as follows: 1. Converting the sine wave input current into the constant amplitude rectangular wave form by using a transistor chopper circuit, the power factor can be measured precisely over the load current of 0.08 A. 2. Using the moving coil type current meter, the power factor meter can be read in uniform . scale all over the range. 3. Using the three-phase power factor meter, the power factor relay which works at any power factor can be made.

• 대한인간공학회지
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• 제6권2호
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• pp.9-18
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• 1987

The purpose of this study was to find the optimal stroke width-to-height ratio of the Korean character (Hangeul) which yields the greatest reading distance. In this study, black characters on a white background were used under 200 lux conditions in-doors, with the stroke width-to-height ratios ranging from a very thin 1:125 to heavier 1: 8.3. The criterion was the average reading distance at which three subjects (male university students) having normal visual acuity (1.2) could read the characters. Using the data obtained from the experi- ment, we analyzed the relationship between stroke width-to-height ratio and reading distance. In the case of the black characters on a white background, the greatest reading distances occurred with a range from 1:11.4 to 1:17.9.

• ETRI Journal
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• 제28권2호
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• pp.216-218
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• 2006

This letter presents the design for a low-profile planar inverted-F antenna (PIFA) that can be stuck to metallic objects to create a passive radio frequency identification (RFID) tag in the UHF band. The designed PIFA, which uses a dielectric substrate for the antenna, consists of a U-slot patch for size reduction, several shorting pins, and a coplanar waveguide feeding structure to easily integrate with an RFID chip. The impedance bandwidth and maximum gain of the tag antenna are about 0.3% at 914 MHz for a voltage standing wave ratio (VSWR) of less than 2 and 3.6 dBi, respectively. The maximum read range is about 4.5 m as long as the tag antenna is on a metallic object.

• 음성과학
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• 제14권3호
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• pp.7-19
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• 2007

The present study investigated some phonetic attributes which distinguish two Korean stop types $^-aspirated$ and $lax^-$ in a prosodic position which has previously received little attention, namely medial in an accentual phrase. The intonational pattern across syllables which are initial in an accentual phrase (Jun, 1993) is said to depend on the type of stop (aspirated or lax), while that of syllables which are medial in an accentual phrase are not. In Experiment 1, nine native Korean speakers read sentences with a controlled prosodic pattern in which aspirated or lax stops occurred in accentual phrase-medial position. Acoustic analysis revealed significant differences between aspirated and lax stops in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. The results indicate that a wider range of acoustic cues distinguish aspirated and lax Korean stops than previously demonstrated. Phonetic and phonological models of consonant-tone interactions for Korean will need to be revised to account for these results.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권4호
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• pp.176-181
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• 2001

As the data rate between chip-to-chip gets high, the skin effect and load of pins deteriorate noise margin. With these, noise disturbances on the bus channel make it difficult for receiver circuits to read the data signal. This paper has proposed a new pre-emphasis driver circuit which achieves wide noise margin by enlarging the signal voltage range during data transition. When data is transferred from a memory chip to a controller, the output boltage of the driver circuit reaches the final values through the intermediate voltage level. The proposed driver supplies more currents applicable to a packet-based memory system, because it needs no additional control signal and realizes very small area. The circuit has been designed in a 0.18 ${\mu}m$ CMOS process, and HSPICE simulation results have shown that the data rate of 1.32 Gbps be achieved. Due to its result, the proposed driver can achieved higher speed than conventional driver by 10%.

• ETRI Journal
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• 제30권4호
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• pp.597-599
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• 2008

This letter presents the design of a small and low-profile RFID tag antenna in the UHF band that can be mounted on metallic objects. The designed tag antenna, which uses a ceramic material as a substrate, consists of a radiating patch and a microstrip line with two shorting pins for a proximity-coupled feeding structure. Using this structure, impedance matching can be simply obtained between the antenna and tag chip without a matching network. The fractional impedance bandwidth for $S_{11}$ <3 dB and radiation efficiency are about 1.4% and 56% at 911 MHz, respectively. The read range is approximately from 5 m to 6 m when the tag antenna is mounted on a metallic surface.