• Title/Summary/Keyword: Short-Range

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A Study on Accuracy Improvement for Range and Velocity Estimates in a FM-CW Radar (FM-CW 레이다에서의 거리 및 속도 추정 정확도 향상에 관한 연구)

  • Lee, Jong-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.8
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    • pp.1752-1758
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    • 2010
  • A FM-CW radar is used for the various purposes as a remote sensing device since it has the advantages of the relatively simple implementation and the low probability of signal interception. A FM-CW radar uses the same frequency modulated continuous wave for both transmission and demodulation. Therefore, the received beat frequency represents the range and Doppler information of targets. However, using the conventional FFT method, the degree of accuracy and resolution in the spectrum estimation can be seriously degraded in the detection and tracking of fast moving targets because of the short dwell time. Therefore, in this paper, the model parameter estimation methods called as an autoregressive method is applied to overcome these problems and showed that the improved accuracy and resolution can be obtained for the target range and velocity estimation.

A Study on the Characteristics of Short Circuit through the Cross Section Analysis of Electric Wire (전선의 단면분석을 통한 단락특성에 관한 연구)

  • Shong, Kil-Mok;Choi, Chung-Seog;Kim, Yun-Hoi;Kim, Sang-Hyeon;Park, Nam-Kyu
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.51-56
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    • 2005
  • For a fire cause judgement this paper describes the short circuit characteristics of a electric wire through the cross section analysis under ac condition. The cower wires prepared for the experiment were 1.2mm, 1.6mm, and 2.0mm in diameter. Through the cross section analysis(CSA), it was confirmed that the dendrite structure grew at the angle of about $40^{\circ}\;or\;60^{\circ}$ when the fusing current was applied to the wires. The larger the fusing current is, the more decreased the growth angle of the dendrite structure is. It was confirmed that the dendrite structure was arranged like the columnar structure. In this paper, the characteristics analysis of short circuit was carried out in the range of transient duration and the correlation constant k was investigated by measuring the short circuit duration and the fusing current.

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One Case of Ankle Fracture Treated with SAAM(舍岩)-Acupuncture and GamigungguitangGaNokyong after Short Leg Casting (보조기 착용 후 사암어혈방(舍岩瘀血方)과 가미궁귀탕가록용(加味芎歸湯加鹿茸)을 병행한 족관절 외과 단독 골절 치험 1례)

  • Kim, Jae-Su;Lee, Yoon-Kyoung
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.207-213
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    • 2007
  • Objectives : This study was designed to investigate the effect of SAAM-Acupuncture and GamigungguitangGaNokyong(GMGGTN) on Ankle Fracture. Methods : SAAM-Acupuncture was administered once daily. The following points were selected: $SP_3$(太白), $LU_9$(太淵), $LI_{11}$(曲池). After short leg casting, GMGGTN was taken 3 times per a day from March 28th to April 30th. We evaluated the patient using the Visual Analogue Scale(VAS) and Ankle Range of Motion(ROM). Results : After about 3 weeks of treatment, the patient's short leg cast was removed a week earlier than expected and the patient could walk without crutches and physical therapy. Their VAS changed from 10 to 1. And after added treatment for 2 weeks, there was no pain and limitation of ROM. Conclusions : According to the results, SAAM-Acupuncture and GMGGTN may have rapid effects on ankle fractures. But further studies are required to confirm this effect.

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Development of Nuclear Energy Attitude Scale (핵에너지 태도 측정도구의 개발)

  • 장우정;우형택
    • Journal of Environmental Science International
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    • v.11 no.9
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    • pp.829-842
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    • 2002
  • The purpose of this study was to design a reliable and valid Likert-type scale to measure nuclear energy attitudes of various groups. 8 tests were applied to the construction of a 26-item long form, a 12-item middle form, and a 6-item short form of the scale. Three scales were field tested on 760 respondents representing a diverse range of subjects. The 26-item scale appeared to be reliable, content valid and construct valid. Scale reliability and homogeneity were evidenced by 0.95 coefficient alpha and positive interitem correlations ranging from 0.18 to 0.74. The results of factor analysis and known-groups comparison revealed that this scale had high validity. Reliability of the middle form and short form were evidenced by coefficient alpha of 0.92 and 0.90 respectively. The long and middle forms were strongly correlated, r-value of 0.98 and the long and short forms were also highly correlated, r-value of 0.93. Consequently, long form, middle form and short form scales were evidenced very reliable and valid in measuring nuclear energy attitudes of various groups in general. They can be used for a variety of purpose of measuring and testing nuclear energy attitude.

Short-term Preservation of Sperm in the Tiger Puffer, Takifugu rubripes (자주복(Takifugu rrbripes) 정자의 액상보존)

  • 장영진;장윤정;임한규
    • Journal of Aquaculture
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    • v.10 no.3
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    • pp.273-279
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    • 1997
  • Condition for fresh storage of tiger puffer in the liquid state were investigated in several experiments. When marine fish ringer solution and 1% NaCl were used as the diluent for the short-term preservation method, spermatozoa activity index (SAI) and survival rate showed the best result among the various diluents tested. The dilution rate for the shortterm preservation of spermatozoa was suitable between 3 and 5 times with the 1% NaCi diluent. The appropriate range of temperature for the short-term preservation showed between 0 and $5^{\circ}C$. In order to keep high SAI and survival rate of spermatozoa, antibiotic addition (800 ppm neomycin) could be suggested. These results indicated that the short-term preservation method could be employed in tiger puffer spermatozoa.

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Implementation of Spectrum Sensing Module using STFT Method (STFT 기법을 적용한 스펙트럼 센싱 모듈 구현)

  • Lee, Hyun-So;Kang, Min-Kyu;Moon, Ki-Tak;Kim, Kyung-Seok
    • The Journal of the Korea Contents Association
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    • v.10 no.1
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    • pp.78-86
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    • 2010
  • The Spectrum Sensing Technology is the core technology of the Cognitive Radio (CR) System that is one of the future wireless communication technologies. In this paper, we proposed the efficient Spectrum Sensing Method using the Short Time Fourier Transform (STFT) that is the algorithm for Time-Frequency analysis of the raw data. Applied window function to STFT algorithm is a Kaiser window, it is piled up its 50% range. For the simulation, the DVB-H signal with the 6MHz bandwidth is used as the Input Signal. And we confirm the Spectrum Sensing result using Modified Periodogram Method, Welch's Method for compared with Short Time Fourier Transform Algorithm. And also, Spectrum Sensing Module is implemented using embedded board.

Analysis of Cloudiness and Radiation Characteristics during Summer in the Greater Daegu Area (대구지역의 하절기 운량과 장·단파 복사 특성 분석)

  • Baek, Chang-Hyeon;Choi, Dong-Ho;Lee, Bu-Yong;Lee, In-Gyu
    • Journal of the Korean Solar Energy Society
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    • v.37 no.4
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    • pp.13-22
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    • 2017
  • In this study, long and short-wave radiations were observed in urban and suburban areas during the summer season, and frequency analysis was performed for each radiation intensity by a new analysis method. The following results were obtained. (1) Long-wave radiation values were found to be larger in the afternoon than in the morning, in both urban and suburban areas, unlike short-wave radiation values. (2) Short-wave radiation showed a right-skewed frequency distribution. In the high energy area greater than $900W/m^2$, the frequency was significantly higher in the suburbs than in the urban areas. (3) Long-wave radiation was in the range of $290{\sim}479W/m^2$, its frequency distribution resembled a normal distribution, and the frequency of 410, $420W/m^2$ was the highest.

Changes in the quality of pork loin after short-term (ten-day) storage in a supercooling refrigerator

  • Park, Chun Ho;Park, Hye Sook;Yoon, Kyungah;Choe, Jeehwan
    • Journal of Animal Science and Technology
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    • v.63 no.4
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    • pp.884-891
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    • 2021
  • The study aimed to evaluate pork loin quality after short-term (ten-day) storage in a supercooling refrigerator. Pork loin samples were stored for 10 days in a traditional refrigerator (control) and a commercially available supercooling refrigerator (SC). Pork quality measurements included meat pH, meat color, water holding capacity (drip loss and cooking loss), tenderness (hardness), and a sensory evaluation. Temperature changes of 0.45 ± 0.2℃ and 0.02 ± 0.25℃ occurred in the control and the SC, respectively, during 10 days of storage. The temperature in the SC chamber did not remain below freezing point, failing to meet expectations. Regarding the pork quality measurements, only the drip losses in the control and the SC were significantly different (4.45% vs. 2.59%, p < 0.01) after 10 days of storage. There were no significant differences between the two types of refrigerator in terms of the other measurements. Additionally, the overall acceptability of the pork loin did not vary significantly between the control and the SC when the sensory evaluation was performed. Therefore, a commercial SC could prove beneficial in terms of water holding capacity during the short-term storage of meat. Further research should be performed to evaluate quality changes that occur during long-term storage of meat in SC s and evaluate a wide range of meat, such as beef and chicken.

The dynamic response of adjacent structures with the shallow foundation of different height and distance on liquefiable saturated sand

  • Jilei Hu;Luoyan Wang;Wenxiang Shen;Fengjun Wei;Rendong Guo;Jing Wang
    • Earthquakes and Structures
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    • v.25 no.2
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    • pp.135-148
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    • 2023
  • The structure-soil-structure interaction (SSSI) effect in adjacent structures may affect the liquefaction-induced damage of shallow foundation structures. The existing studies only analysed the independent effects on the structural dynamic response but ignored the coupling effect of height difference and distance of adjacent structures (F) on liquefied foundations on the dynamic response. Therefore, this paper adopts finite element and finite difference coupled dynamic analysis method to discuss the effect of the F on the seismic response of shallow foundation structures. The results show that the effect of the short structure on the acceleration response of the tall structure can be neglected as F increases when the height difference reaches 2 times the height of the short structure. The beneficial effect of SSSI on short structures is weakened under strong seismic excitations, and the effect of the increase of F on the settlement ratio gradually decreases, which causes a larger rotation hazard. When the distance is smaller than the foundation width, the short structure will exceed the rotation critical value and cause structural damage. When the distance is larger than the foundation width, the rotation angle is within the safe range (0.02 rad).

A Study on Architecture Analysis of DSRC System (DSRC시스템의 구조분석에 관한 연구)

  • 최광주
    • Proceedings of the IEEK Conference
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    • 2000.06a
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    • pp.232-235
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    • 2000
  • 본 논문에서는 ITS(Intelligent Transport System) 서비스를 위한 기반시설로 설치 예상되는 DSRC(Dedicated Short Range Communication) 시스템에 대하여 시스템의 개요와 특징 및 DSRC 기지국시스템의 신호흐름에 대하여 살펴보았으며, 일체형과 분리형 DSRC 시스템의 RSU구조에 관해 비교 분석하였다.

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