• Electronics and Telecommunications Trends
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• v.32 no.3
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• pp.98-106
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• 2017

GPS 등과 같은 위성항법 시스템은 정밀한 시각동기가 요구되는 동기식 이동통신망, 전력망, 금융망과 같은 분야와 사용자의 정밀한 위치를 요구하는 차량 내비게이션, 항공기 및 자동차, 측지 측량분야는 물론 향후 드론 및 자율주행 차량 등과 같은 다양한 응용분야에서 그 활용도가 증가될 것이다. 또한, 스마트폰에서는 기본적으로 위성항법 칩셋이 내장되어 사용자 위치를 제공하고 있다. 이렇듯 다양한 분야에서 활용되는 위성항법 수신 칩셋 또는 수신 시스템의 기능 및 성능을 다양한 환경에서 검증할 필요성이 대두되고 있다. 본고에서는 다양한 검증 환경을 제공할 수 있는 위성항법 신호생성기의 국외기술 동향을 살펴보고, 미래부 출연사업인 GNSS 전파교란 검증플랫폼 과제를 통해 개발된 GNSS 전파혼신 신호발생장치에서 확보한 실제 GPS 신호와 동기를 유지한 신호생성기술 개발 현황을 소개한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.84-89
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• 2006

GPS(Global Positioning System)는 이미 전 세계적으로 다양한 응용분야를 가지고 널리 사용되고 있다. 그러나 현재 지구 주위를 운항하고 있는 24개의 GPS 위성으로 지상 어느 곳에서나 24시간 동안 위성신호를 수신할 수 있게 되었지만 고층 빌딩과 같은 도심 계곡, 복잡한 한국지형, 산악지역 등에서의 위성 장애물에 의한 신호의 차단으로 한계가 발생하고 있다. NAVSYNC의 CW25 GPS 수신기는 -156dBm이하의 신호강도에서도 확실한 위치 fix가 가능하고, 이러한 능력은 도심지나, 울창한 숲과 심지어는 건물 안과 같이 신호가 미약한 지역에서도 사용될 수 있다. 이에 본 연구에서는 Indoor GPS 수신기를 이용하여 측지분야에서 검증된 GPS측량방법을 통해 수신 데이터를 비교 분석하고 수신기의 정밀도에 관한 연구를 하고자 한다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.11a
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• pp.49-52
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• 2004

• The Korean Journal of Pain
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• v.19 no.2
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• pp.257-260
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• 2006

Radiofrequency neurotomy of the lumbar medial branch, via a caudal approach, is a representative interventional procedure for lumbar zygapophysial joint pain, which can be performed more accurately and easily using a guide needle technique. We experienced a case of burn wound formation along the guide needle trajectory, where heat conduction through the guide needle was suggested to have resulted in the burn wound.

• Journal of Korean Foot and Ankle Society
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• v.22 no.4
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• pp.166-169
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• 2018

A schwannoma is a benign tumor that originates from the peripheral nerve sheath. Schwannomas occur most commonly in the head and neck region involving the brachial plexus and the spinal nerves. The lower limbs are less commonly affected. This paper presents a case of a patient with a schwannoma showing atypical localization at the digital nerve of the foot causing neurological symptoms.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.4
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• pp.319-326
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• 2006

To get the highly-accurate and precise position of a GPS receiver, they should consider the state-of-the-art GPS force and measurement models. Especially, the phase center variations (PCV) of a GPS antenna can cause several centimeters of positioning errors in the vertical direction. In this study, we implemented four different models of PCV and evaluated their impact on the computed coordinates. The test data were taken from the 14 National Geography Information Institute permanent GPS stations and 30 Minisry of Government Administration and Home Affairs sites. For different combinations of calibration methods, an average of 1.3-2.6cm of height difference was observed. Also, we found a maximum error of ${\sim}4mm$ in the estimates of the precipitable water vapors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2390-2395
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• 2012

Monitoring of crustal movement by earthquake is an important line of study in geophysics and geodesy. In this Study, before and after the earthquake data about nine IGS permanent stations were processed by Precise Positioning System to analysis the influence area about Japanese earthquake in March 11 at 2:46pm. As the result of crustal deformation monitoring, the quantitative earthquake displacement and change of crustal movement was presented. Crustal movement monitoring using continuous GPS data processing is necessary for crustal research and predicting earthquake because crustal movement assumed a new aspect before and after the earthquake in Japan.

• Journal of Navigation and Port Research
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• v.41 no.4
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• pp.189-194
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• 2017

The Moving Search Radar System (MSRS) monitors sea areas by moving along the coast. Since the radar is initially aligned to the front of the vehicle, it is important to know the changes in the heading azimuth of the vehicle to quickly acquire the target azimuth from the radar after the MSRS has moved. The heading azimuth can be obtained using the gyro compass, the GPS compass or the electronic compass. The electronic compass is suitable for MSRS requiring fast maneuverability due to its small volume, short stabilization time and low price. However, using a geomagnetic sensor may result in an error due to the surrounding magnetic field. Errors can make early automatic tracking of the satellites difficult and can reduce the radar detection accuracy. Therefore, this paper proposes a method to automatically compensate for the error reflecting the correction value on the radar obtained by comparing the reference azimuth calculated by solving the geodesic inverse problem using two coordinates between the radar and the geostationary satellite with the actually-directed azimuth angle of the satellite antenna. The feasibility and convenience of the proposed method were verified by applying it to the MSRS in the field.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.155-165
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• 2015

Well-feathered (over 10 feathers) 'Fuji'/M.9 apple trees were planted at $3.0{\times}1.0m$ and trained to slender spindle with 2.5 m height or to tall spindle with 3.5 m height, and the vegetative growth, productivity, and fruit quality of two training systems were compared for 8 years. The canopy volume of the tall spindle trees surpassed that of the slender spindle trees 4 years after planting and was 25% larger than that of the slender spindle trees 5 years after planting. The accumulated yield over 8 years for the tall spindle system was 14% higher than that of the slender spindle system. Alternate bearing and incidence of marssonina blotch were observed in both treatments after 5 years of planting. There was often vegetative imbalance in the trees however, the degree of yield loss and vegetative imbalance of the tall spindle trees was lower than those of the slender spindle trees. Soluble solid content and fruit red color of the tall spindle trees were higher than that of the slender spindle trees in 5 year after planting, resulting from increased light penetration in the canopy due to even distribution of lateral branches and from fruit bearing in different height locations of the trees. In conclusion, increasing the tree height to about 3.5 m using slender spindle 'Fuji'/M.9 apple trees planted with over 333 trees per 10a led to better light penetration, yield and fruit quality compared to a conventional wide training system with the slender spindle.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.108-112
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• 1998

This studies were conducted to investigate the effects of hexaconazole on growth of watermelon(Citrullus lanatus Schrad) and ethylene evolution from gourd(Lagenaria siceraria Standl). While foliar application of hexaconazole exhibited inhibition effect, little or no inhibition was found in the plants treated with soil drench application. The plant height and number of internode in watermelon were significantly inhibited at 7 days after treatment(DAT), but no significant difference was found at 42 DAT. No significant difference was found in site of female flower setting when treated with hexaconazole. The length of branch was significantly inhibited at the 2nd or the 3rd internode. It was suggested that the inhibition of stem elongation was related with application timing of the chemical. Hexaconazole increased ethylene evolution more effectively at earlier stage of gourd, but after 5 DAT ethylene evolution was decreased.