• 전자공학회논문지B
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• 제33B권7호
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• pp.99-106
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• 1996

Estimation and removal procedures for baseline drift have been developed using linear, cubic spline, and bilineared transformed high pass filter. Linear and cubic spline interpolation with the PQ and TP segmens, which are considered to be isoelectric, as fiducial points ahve been estimated respectively. For a quantitative validation of the estimation procedure, 4 ECGs with arfificial baseline drift were constructed and analyzed by mean square error calculations and amplitude histograms. Also real ECGs were analyzed in a test set of the CSE data set 3 and set 4. Baseline drift detecton rule were designed and new method for the decision of fiducial point were constructed to avoid distorting as the case of premature ventricular or atrial contraction. From these comparison, proposed cubic spline method with PQ and TP segment (CS_PQ & TP) emerged as the most efficient method.

• 한국측량학회지
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• 제26권6호
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• pp.549-559
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• 2008

본 연구에서는 다양한 조건 하에서의 Bernese와 TGO와의 처리결과 비교를 통하여 상용 소프트웨어의 한계와 정밀측위에 대한 응용성을 검증하였다. 이를 위하여 전국규모의 세 가지의 관측데이터와 그 보다 작은 두 가지의 지역 데이터를 선정하여 망을 구성하고 Bernese와 TGO를 사용하여 기선해석 및 망조정을 통해 성과를 산출하여 소프트웨어별, 기선거리 및 망규모별, 관측시간별, 고정점 수별로 비교분석을 실시하였다. 소프트웨어 간 비교에서는 학술연구용 소프트웨어의 정확도가 우수하였다. 비록 GPS 관련 기술이 발달하면서 수신기의 정확도가 향상되었고 이에 병행하여 상용 소프트웨어도 발전을 거듭해왔으나 학술연구용 소프트웨어와의 평균성과차이를 볼 때 크지는 않지만 엄연한 차이가 존재했다. 따라서 가장 정밀한 위치정보가 요구될 때는, 특히 기선벡터가 큰 경우에는 필히 학술연구용 소프트웨어를 사용하여야 할 것이다.

• 지구물리와물리탐사
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• 제19권4호
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• pp.179-186
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• 2016

기준탐사를 이용하여 IAEA의 기준에 부합하는 방사능 함량도를 제작하는 일련의 절차 중에서 기존의 자료를 기준탐사 자료를 이용한 자료 맞추기(leveling)는 기존 자료들이 가지고 있는 정보들을 보존하면서도 자료들을 부드럽게 취합할 수 있도록 해야 한다. 기존의 논문에서 제시된 방법은 기존의 자료가 갖고 있던 소규모 이상대 정보가 많이 손상되는 등 원자료의 특성을 잃어버릴 염려가 있다. 이 논문에서는 기존 방사능 자료를 기준탐사 자료에 맞추는 방법에 대해 자세히 논술하고, 새로운 맞추기 방법을 제안한다. 새로운 방법은 기존의 자료를 모두 그대로 이용하는 것이 아니라 기준탐사의 측점과 일치하는 격자 자료만을 이용하여, 광역장(regional field)과 남은장(residual field)으로 나누어 광역장만으로 맞추기 계수를 결정하고 광역장과 남은장에 별도의 방법으로 적용하여 더해주는 것이다. 이 방법은 기존의 방법보다 자료를 보다 부드럽게 일치시키고, 자료 분포의 경향성을 더욱 잘 보여주며, 높은 진동수 정보를 잘 보존한다는 것을 보여준다.

• International Journal of Aeronautical and Space Sciences
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• 제16권1호
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• pp.89-101
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• 2015

To satisfy civil aviation requirements using the Global Navigation Satellite System (GNSS), it is important to guarantee system integrity. In this work, we propose a fault detection algorithm for GNSS ephemeris anomalies. The basic principle concerns baseline length estimation with GNSS measurements (pseudorange, broadcasted ephemerides). The estimated baseline length is subtracted from the true baseline length, computed using the exact surveyed ground antenna positions. If this subtracted value differs by more than a given threshold, this indicates that an ephemeris anomaly has been detected. This algorithm is suitable for detecting Type A ephemeris failure, and more advantageous for use with multiple stations with various long baseline vectors. The principles of the algorithm, sensitivity analysis, minimum detectable error (MDE), and protection level derivation are described and we verify the sensitivity analysis and algorithm availability based on real GPS data in Korea. Consequently, this algorithm is appropriate for GNSS regional implementation.

• KSTLE International Journal
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• 제6권1호
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• pp.21-27
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• 2005

A technique for a wear volume calculation is improved and verified in this research. The wear profile data measured by a surface roughness tester is used. The present technique uses a data flattening, the FFT and the windowing procedure, which is used for a general signal processing. The measured value of an average roughness of an unworn surfnce is used for the baseline of the integration for the volume calculation. The improvements from the previous technique are the procedures of the data flattening and the determination of a baseline. It is found that the flattening procedure efnciently manipulates the raw data when the levels of it are not horizontal, which enables us to calculate the volume reasonably well and readily. By comparing it with the weight loss method by using artificial dents, the present method reveals more volume by aroung 3~10%. It is attributed to the protruded region of the specimen and the inaccuracy and data averaging during the weght loss measurement. From a thorough investigation, it is concluded that the present technique can provide an accurate wear volume.

• 기본간호학회지
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• 제15권3호
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• pp.350-359
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• 2008

Purpose: The purpose of this study was to identify change in the exercise behavior and to identify factors influencing long-term adherence to aquatic exercise in patients with arthritis as a follow-up study after five years. Method: Baseline data had been collected using a structured interview 6 months after participants completed the aquatic exercise educational program. This second follow-up data collection included 133 participants from the original baseline study and was done 5 years after the original baseline study. Data was analyzed using SPSS 16 Win program. Results: The stage of change for the participants was as follows: Precontemplation (44.3%), Contemplation (24.1%), Preparation (3.0%), Action (0%) and Maintenance (adherence, 28.6%). The adherers (N=38) had significantly higher scores than non-adherers (N=91) in self-efficacy, outcome expectancy, group coherence and self-evaluation, and significantly lower scores in barriers to exercise. In logistic regression analysis, self-efficacy, group cohesion, barriers to exercise and self-evaluation were associated with exercise adherence (Chi Square=17.14, p=.002). Group cohesion (OR=2.5871, 95% CI=1.094-6.113, p= .030) was the most important factor. Conclusion: Self-efficacy, group cohesion, barriers to exercise and self-evaluation need to be considered in planning exercise programs to improve exercise adherence.

• 한국소음진동공학회논문집
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• 제11권5호
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• pp.108-122
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• 2001

As bridge design is advancing toward the performance-based design. it becomes increasingly important to monitor and re-evaluate the long-term structural performance of bridges. Such information is essential in developing performance criteria for design. In this research. sensor systems for long-term structural performance monitoring have been installed on two highway bridges. Pre1iminary vibration measurement and data analysis have been performed on these instrumented bridges. On one bridge, ambient vibration data have been collected. based on which natural frequencies and mode shapes have been extracted using various methods and compared with those obtained by the preliminary finite element analysis. On the other bridge, braking and bumping vibration tests have been carried out using a water truck In addition to ambient vibration tests. Natural frequencies and mode shapes have been derived and the results by the breaking and bumping vibration tests have been compared. For the development of a three dimensional baseline finite element model, the new methodology using a neural network is proposed. The proposed one have been verified and applied to develop the baseline model of the bridge.

• Journal of Astronomy and Space Sciences
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• 제27권2호
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• pp.173-180
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• 2010

As a preparatory study for Global Positioning System-Very Long Baseline Interferometry (GPS-VLBI) hybrid system, we examined if VLBI type observation of the GPS signal is realizable through a test experiment. The test experiment was performed between Kashima and Koganei, Japan, with 110 km baseline. The GPS L1 and L2 signals were received by commercial GPS antennas, down-converted to video-band signals by specially developed GPS down converters, and then sampled by VLBI samplers. The sampled GPS data were recorded as ordinary VLBI data by VLBI recorders. The sampling frequency was 64 MHz and the observation time was 1 minute. The recorded data were correlated by a VLBI correlator. From correlation results, we simultaneously obtained correlation fringes from all 8 satellites above a cut-off elevation which was set to 15 degree. 87.5% of L1 fringes and 12.5% of L2 fringes acquired the Signal to Noise Ratios which are sufficient to achieve the group delay precision of 0.1nsec that is typical in current geodetic VLBI. This result shows that VLBI type observation of GPS satellites will be readily realized in future GPS-VLBI hybrid system.

• 한국철도학회논문집
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• 제12권3호
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• pp.412-419
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• 2009

구조물 건전성 모니터 링에서 구조물에 발생한 손상을 어떠한 방법으로 가장 효율적이고 정확하게 탐지하느냐는 매우 중요한 연구과제이다. 기존의 대부분 SHM기술에서는 구조물에 손상이 발생하기 이전에 측정해 놓은 탄성파신호를 손상 검출을 위한 기준 데이터로서 활용하고 있다. 본 연구에서는 Lamb파를 이용하는 pitch-catch (PC)-기법을 기반으로 기준 데이터를 필요로 하지 않는 새로운 SHM기술을 제안하였다. 또한 손상 신호에 이미지화 기법을 적용하여 손상의 위치를 이미지화 함으로써 손쉽게 파악할 수 있도록 하였다. 제안된 SHM기술은 알루미늄 평판 시편에 대한 실험을 통해 응용 가능성을 고찰하였다.

• PNF and Movement
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• 제17권1호
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• pp.1-9
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• 2019

Purpose: This study investigates the effects of task-oriented training for a left trunk flexion pattern using real-time ultrasound imaging in a stroke patient with unilateral neglect symptoms. Methods: This study used the ABA experimental design, which is a single-subject research method among individual case research methods. For the ABA experimental design, changes in the degree of unilateral neglect, balance ability, and the thickness of the lateral abdominal muscle were visually analyzed during the baseline process, in the intervention period, and after the intervention. The experiments were performed 24 times in total for 8 times in each of the 3 periods. The unilateral neglect was measured using the Albert test, balance ability was measured using the Berg balance test, and the thickness of the lateral abdominal muscle was measured using ultrasound imaging. The subject was a 50-year-old male patient with unilateral neglect caused by right cerebral hemorrhage. He performed task-oriented training for a voluntary left trunk flexion pattern using real-time ultrasound imaging during the intervention period. Results: The result of comparing the data collected during the intervention period with the data point average of the baseline process showed that balance ability improved and the tendency line was above the baseline. The tendency line of unilateral neglect was below the baseline and showed a decreasing tendency. The thickness of the lateral abdominal muscle showed an increasing trend and the tendency line was above the baseline. Conclusion: The results of this study suggest that the task-oriented training for left trunk flexion pattern using real-time ultrasound imaging has a beneficial effect on balance ability, the degree of unilateral neglect, and the strength of the lateral abdominal muscle in unilateral neglect patients.