• 한국측량학회지
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• 제34권1호
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• pp.79-90
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• 2016

본 논문에서는 지진 등으로 인해 발생하는 절대 지각변위 추정에 GPS 상시관측망의 동적기선해석 기법의 적용 가능성을 실험을 통해 정확도와 정밀도 측면에서 분석하였다. 국내 관측소의 절대좌표 추정을 위해 국외 관측소가 데이터처리에 포함 할 필요가 있어 실험 네트워크는 관측점 사이 거리가 수 백 ∼ 약 1,000km에 달하는 중기선으로 구성하였다. 따라서 대상 관측점의 동적 거동특성을 매개변수 추정단계에 반영하는 일련의 절차를 적용하여 GPS 동적 중기선해석 실험을 수행하였다. 이를 통하여 GPS 동적 중기선해석을 통해 센티미터 수준의 정확도와 그 이상의 정밀도로 GPS 상시관측소의 절대좌표를 동적모드로 추정할 수 있음을 확인하였다. 또한 본 논문은 위성궤도력, 관측데이터양 그리고 동적좌표 추정의 초기좌표 구속범위와 같은 기선해석 조건들이 동적좌표 추정 정확도와 정밀도에 미치는 영향을 분석하고 그 결과를 요약하고 있다.

• Journal of Positioning, Navigation, and Timing
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• 제7권1호
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• pp.43-52
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• 2018

In recent years, the need of high accuracy navigation for vehicles has increased due to the development of autonomous driving vehicles and increase in land transportation convenience. This study is performed for vehicle users to achieve a performance of centimeter-level positioning accuracy by utilizing Compact Network Real-time Kinematic (RTK) that is applicable as a national-level infrastructure. To this end, medium-baseline RTK was implemented in real time to estimate accurate integer ambiguities between reference stations for reliable generation of Network RTK correction using the linear combination of carrier-phase observations and L1/L2 pseudo-range measurements. The residual tropospheric error was estimated in real time to improve the accuracy of double-differenced integer ambiguity resolution between network configuration reference stations that have at least 30 km or longer baseline distance. In addition, C++ based software was developed to enable real-time generation and broadcasting of Compact Network RTK correction information by utilizing an accurately estimated double-differenced integer ambiguity values. As a result, the horizontal and vertical 95% accuracy was 2.5cm and 5.2cm, respectively, without performance degradation due to user's position change within the network.

• Clinics in Shoulder and Elbow
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• 제22권4호
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• pp.195-202
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• 2019

Background: This study investigates the effects of neuromuscular electrical stimulation (NMES) in preventing deltoid atrophy during the first 12 weeks after arthroscopic rotator cuff repair. Methods: Eighteen patients undergoing arthroscopic repair of a medium-sized rotator cuff tear by a single surgeon, were randomized into two groups: NMES and transcutaneous electrical nerve stimulation (TENS). Each group used the respective device for 6 weeks after surgery. Pain was measured at baseline, 6, and 12 weeks postoperatively, using the visual analogue scale (VAS); range of motion (ROM), abduction strength and functional scores were measured at baseline and 12 weeks postoperatively. Deltoid thickness and cross-sectional areas were measured using magnetic resonance imaging at 12 weeks postoperatively. Results: At 12 weeks post-surgery, no statistically significant difference was observed between the NMES and TENS groups in the pain VAS, the Disabilities of the Arm, Shoulder and Hand score, ROM, and abduction strength. Postoperative decrease in the thickness of the anterior, middle, and posterior deltoid, at the level just below the coracoid, was -2.5%, -0.7%, and -6.8%, respectively, in the NMES group, and -14.0%, -2.6%, and -8.2%, respectively, in the TENS group (p=0.016, p=0.677, and p=0.791, respectively). At the level of the inferior glenoid tubercle, postoperative decrease in area of the deltoid was -5.4% in the NMES group and -14.0% in the TENS group, which was significantly different (p=0.045). Conclusions: NMES has the potential for reducing deltoid atrophy after arthroscopic rotator cuff repair, suggesting that NMES might help minimize postoperative atrophy after various shoulder surgeries.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.90-94
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• 2007

The conventional single-reference station positioning is affected by systematic errors such as ionospheric and tropospheric delay, so that the rover must be located within 10 km from the reference station in order to acquire centimeter-level accuracy. The medium-range real-time kinematic has been proven feasible and can be used for high precision applications. However, the longer of the baseline, the more of the time for resolving the integral ambiguity is required. This is due to the fact that systematic errors can not be eliminated effectively by double-differencing. Recently, network approaches have been proposed to overcome the limitation of the single-reference station positioning. The real-time systematic error modeling can be achieved with the use of GPS network. For expanding the effective range and decreasing the density of the reference stations, Land Survey Bureau, Ministry of the Interior in Taiwan set up a national GPS network. In order to obtain the high precision positioning and provide the multi-goals services, a GPS network including 66 stations already been constructed in Taiwan. The users can download the corrections from the data center via the wireless internet and obtain the centimeter-level accuracy positioning. The service is very useful for surveyors and the high precision coordinates can be obtained real time.

• Clinical and Experimental Reproductive Medicine
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• 제16권2호
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• pp.139-146
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• 1989

The purpose of this study was to examine the qualitative variation of human fetal-cord sera (HCS) and to accept the sera in human lVF-ET program. One hundred and sixteenth RCS were tested with 1772 2-cell embryos of F1 (C57BL x CBA) virgin mice, Ten to sixteenth embryos were cultured in m-KRB medium with a aliquot of each serum (10%, v/v) or with bovine serum albumin(O.4%, w/v) as a control medium. Embryonic development were recorded at every 24hr for 4 days by such events as cellular compaction, cavitation, and hatching. In the control groups of eight assays, 98.1%(106/ 108) of 2-ce1l embryos developed above expanded blastocyst and the embryonic development was unified through the tests. But the developmental pattern in medium with each serum was various. Namely, the sera that supported development of 100% 2-cell embryos to above morula, early blastocyst, expanded blastocyst and hatching blastocyst was 45,7%(53/116) , 35.3%(41/116), 15.5%08/116.) and 6.9-%(8/116), respectively. And the sera that supported development of above 80% 2-cell embryos to the each embryonic stage was 92.2% (107/116), 83.6%(97/116), 63.8%(74/116) and 36.2%(42/116), respectively. Meanwhile two kinds of toxic pattern to the embryonic development were observed in some sera. The first pattern is that some sera arrested development of most embryos in pre- or post-stage of morula or blastocyst. The second pattern is that some sera promoted or arrested a part of embryos in the same dish. The ability of serum was depended on the batch of serum. Finally we could accept 69%(80/116) of the tested sera for human IVF-ET program. The base line for acceptance was the ability that supported above 80% 2-ce1l embryos to blastocyst. But some deterious sera were contained in this range. We cut off about 10% of the sera (83.6% , 97/116) that passed the baseline. This final percent of sera was similar to that of grade N of this study.