• 한방재활의학과학회지
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• 제18권1호
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• pp.141-151
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• 2008

Objectives : The purpose of this study was to investigate effects of long-term taxi driving posture on the balance of musculoskelectal system. Methods : The author practiced Moire topography by using IBS-2000 for 30 male taxi drivers and general people. Then we measured difference of contour lines, difference of shoulder joint height, interval between vertical baseline of pelvis and vertical baseline of neck, ratio of thoracic curve and lumbar curve, difference of width between right and left through Moire topography. After we statistically analyzed difference of Moire topography's data between long-term employed male taxi drivers and general people. Results : 1. Taxi drivers, difference of contour lines in scapular, lumbar, gluteal region was bigger than general people and significant difference(p<0.05) was observed between subject group. 2. Taxi drivers, diference of shoulder joint height was more large than general people and significant difference(p<0.01) was observed between subject group. 3. Taxi drivers, diference of interval between vertical baseline of pelvis and vertical baseline of neck was more large than general people and significant difference((p<0.05) was observed between subject group. 4. Taxi drivers, ratio of thoracic curve was more large than general people and ratio of lumbar curve was more less than general people and significant difference(p<0.05) was observed between subject group. Conclusions : According to above results long-term taxi driving posture might cause musculoskelectal system unbalance.

• Progress in Superconductivity
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• 제7권1호
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• pp.6-10
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• 2005

We have studied feasibility of single-layer second-order $high-T_c$ SQUID gradiometers in magnetocardiography. We have measured human cardiomagnetic signals using a short-baseline (5.8 mm) single-layer second-order YBCO gradiometer in partially shielded environments. The gradiometer has an overall size of $17.6\;mm{\times}6\;mm$ and contains three parallel-connected pickup coils which are directly coupled to a step-edge junction SQUID. The gradiometer showed an unshielded gradient noise of $0.84\;pT/cm^2/Hz^{1/2}$ at 1 Hz, which corresponds to an equivalent field noise of $280\;fT/Hz^{1/2}$. The balancing factor was $10^3$. Based on the same design rules as the short-baseline devices, we have studied fabrication of 30 mm-long baseline gradiometers. The devices had an overall size of $70.2\;mm{\times}10.6\;mm$ with each pickup coil of $10\;mm{\times}10\;mm$ in outer size. As Josephson elements we made two types of submicron bridges, which are variable thickness bridge (VTB) and constant thickness bridge (CTB), from $3\;{\mu}m-wide$ and 300 nm-thick YBCO lines with a thin layer of Au on top by using a focused ion beam (FIB) patterning method. VTB was 300 nm wide, 200 nm thick, 30 nm long with Au removed and CTB 100 nm wide and 30 nm long. In temperature-dependent critical currents, $I_c(T)$, VTB showed an nonmetallic barrier-type behavior and CTB an SNS behavior. We believe that those characteristics are ascribed to naturally formed grain boundaries crossing the bridges.

• 한국측량학회지
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• 제16권1호
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• pp.51-58
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• 1998

본 논문에서는 최저 관측각을 변화시켜가면서 일반력, 정밀력을 이용하여 장기선 해석을 실시하고 이를 이용하여 ’96년 실시된 GPS 전국망을 조정하여 그 성과를 실용성과와 비교분석 하였다. 또한, 정밀 측지 기준점의 성과 획득과 합리적인 GPS작업을 위한 작업규정의 개정 및 작업과정, 데이터 처리, 품질관리 등에 관한 표준화의 필요성을 제기하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.185-190
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• 2006

The correct estimation of the ionospheric delays is very important for the precise kinematic positioning especially in case of the long baseline. In case of triple frequency system, the ionospheric delays can be estimated from the measurements, but, in case of dual frequency system, the situation is not so simple. The precision of those supplied by the external information source such as IONEX is not sufficient. The high frequency component is neglected, and the precision of the low frequency component is not sufficient for the long baseline positioning. On the other hand, the high frequency component can be estimated from the phase range measurements. If the low frequency components are estimated by using the external information source or pseudo range measurements, a more reasonable estimation of the ionospheric delays may be possible. It has already been discussed by the author that the estimation of the low frequency components by using the external information source is not sufficient but fairly effective. The estimation using the pseudo range measurements is discussed in the present paper. The accuracy is not sufficient at present because of the errors in the pseudo range measurements. It is clarified that the bias errors in the pseudo range measurements are responsible for the poor accuracy of the ionospheric delays. However, if the accuracy of the pseudo range measurements is improved in future, the method would become very promising.

• 대한공간정보학회지
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• 제8권2호
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• pp.101-108
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• 2000

단시간으로 많은 3차원 지형정보를 획득할 수 있는 GPS 이동측량은 수 km 이하의 단기선에서 주로 활용되고 있으며, 장기선에 대한 위치결정은 비교적 오랜 시간이 요구되는 정지 측량에 의존하고 있어 단시간으로 장기선 위치결정을 할 수 있는 방법이 요구되고 있다. 본 연구는 GPS에 의한 장기선 이동측량의 효율적 이용 가능성을 검토하기 위하여 수 십 km 이상의 기선에 대한 기선 거리별, 궤도력별 그리고 관측시간대별로 기선해석 정확도를 정지측량 결과와 비교 분석하고자 한다. 연구결과, cycle slip이 발생한 경우 기선해석 정확도가 크게 저하됨을 알 수 있었다 정밀궤도력을 이용한 경우 70km 이내에서 수 분의 이동측량으로 1ppm 이하의 정확도를 얻을 수 있었다. 앞으로 좀더 심도 있는 연구가 수행된다면, 수 십 km 이내에서 GPS 이동측량을 이용하여 국토개발을 비롯한 각종 건설분야에 필요한 지형정보를 보다 효율적으로 획득할 수 있을 것으로 기대된다.

• Ocean and Polar Research
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• 제27권3호
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• pp.335-339
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• 2005

The underwater positioning system is important in interpreting data that are acquired from towing vehicles such as the deep-sea camera (DSC) system. Currently, several acoustic positioning systems such as long baseline (LBL), short baseline (SBL), and ultra short baseline (USBL), are used for underwater positioning. The accurate position of DSC, however, could not be determined in a R/V Onnuri unequipped with any of these underwater positioning systems. As an alternative, the DSC position was estimated based on the topography of towing track and cable length in the cruises before 1999. The great uncertainties, however, were found in the areas of flat bottom topography. In the 2003 and 2004 cruises these uncertainties were reduced by calculating the position of DSC with the cable length and seafloor depth below the vessel. The Japanese cruises for Mn-nodule used a similar estimation method for the DSC positioning system with a CTD sensor. Although the latter can provide better information for the position of DSC, the USBL underwater positioning system is strongly recommended for establishing better positioning of DSC and other towing devices.

• Journal of Electrochemical Science and Technology
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• 제15권3호
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• pp.405-413
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• 2024

Several techniques for determining the reverse peak current from a cyclic voltammogram (CV) for a reversible system are described in the literature: CV itself as a baseline with long switching potential (E_λ) that serves as a baseline for other CVs, Nicholson equation that uses CV parameters to calculation reverse peak current and linear extrapolation of the current obtained at the switching potential. All methods either present experimental difficulties or large errors in the peak current determination. The paper demonstrates, both theoretically and experimentally, that trapezoidal cyclic voltammetry (TCV) can be used as a baseline to determine anodic peak current (i_ap) with high accuracy and with a switching potential shorter than that used by CV, as long as E_λ is at least 130 mV away from the cathodic peak. Beyond this value of switching potential the electroactive specie is completely depleted from the electrode surface. Using TCV with E_λ = 0.34 V and a switching time (t_λ) of 240 s as a baseline, the determination of the reverse peak current presents a deviation from the expected value of less than 1% for most of the CVs studied (except cases when E_λ is close to the direct potential peak). This result presents better accuracy than the Nicholson equation and the linear extrapolation of the current measured at the switching potential, in addition to presenting a smaller error than that obtained in the acquisition of the experimental current. Furthermore, determining the reverse peak current by extrapolating the linear fit of i_ap vs. ${\sqrt[1/]{t_{\lambda}}}$ to infinite time gave a reasonable approximation to the expected value. Experiments with aqueous potassium hexacyanoferrate (II) and ferrocene in acetonitrile confirmed the theoretical predictions.

• Journal of Multimedia Information System
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• 제7권3호
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• pp.231-238
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• 2020

This work presents a fully analog baseline wander tracking and removal circuitry using high-pass filter (HPF) based R-peak detection and quadratic interpolation that does not require digital post processing, thus suitable for compact and low power long-term ECG monitoring devices. The proposed method can effectively track and remove baseline wander in ECG waveforms corrupted by various motion artifacts, whereas minimizing the loss of essential features including the QRS-Complex. The key component for tracking the baseline wander is down sampling the moving average of the corrupted ECG waveform followed by quadratic interpolation, where the R-peak samples that distort the baseline tracking are excluded from the moving average by using a HPF based approach. The proposed circuit is designed using CMOS 0.18-㎛ technology (1.8V supply) with power consumption of 19.1 ㎼ and estimated area of 15.5 ㎟ using a 4^th order HPF and quadratic interpolation. Results show SNR improvement of 10 dB after removing the baseline wander from the corrupted ECG waveform.

• 대한간호학회지
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• 제41권6호
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• pp.780-787
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• 2011

Purpose: This study was conducted to examine activities of daily living (ADL) of older adults admitted to Korean long-term care hospitals (LTCHs), and to explore the patient and organizational factors that have an impact on the ADL of this population. Methods: A secondary analysis of the Korean minimum data set (K-MDS) of patients (N=14,369) and of the profiles of LTCHs (N=358) from the Health Insurance Review and Assessment Service was done between January and July 2008. The outcome variable was ADL score 6 months after baseline assessment. Multi-level linear regression was employed to explore the patient and organizational factors that affected ADL scores. Results: Of the patients, 45.4% had a baseline ADL score of between 31 and 40, with a score of 40 indicating that the patient was entirely dependent for all items. None of the organizational characteristics were significantly associated with effects on the ADLs of older adults who had been in a LTHC for at least 6 months. However, patient characteristics, such as age, baseline ADL, frequency of physical therapy, urinary incontinence, fecal incontinence, pressure ulcers, and having a tube or catheter, were significantly associated with ADL 6 months after baseline. Conclusion: In order to maintain and improve the ADL of older adults in LTCHs, we should develop strategies to prevent urinary and fecal incontinence, pressure ulcers, unnecessary tubes or catheters, providing adequate physical therapy. Additional studies should include more detailed information regarding nursing staff, including RN hours for direct care, education level and turnover.

• Safety and Health at Work
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• 제5권4호
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• pp.186-190
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• 2014

Background: Physical exercise during leisure time is known to increase physical capacity; however, the long-term effects on work ability and work strain are inconclusive. The aim of this study was to investigate the effects of a 6-month physical exercise program on work ability and work strain after 6 months and 30 months, among women with menopausal symptoms at baseline. Methods: A questionnaire including questions on work ability and work strain was mailed in the beginning, at 6 months and after 30 months after the intervention to occupationally active women participating in a randomized controlled study on physical exercise and quality of life. The intervention included aerobic exercise training 4 times per week, 50 minutes per session. Work ability was measured with the Work Ability Index (WAI) and with questions about physical and mental work strain. Results: Women aged 47-62 years (N=89) who were occupationally active at baseline were included in the analyses. The increase in WAI from baseline to the end of the exercise intervention (6 months) was statistically significantly greater among the intervention group than among the control group (regression coefficient 2.08; 95% confidence interval 0.71-3.46). The difference between the groups persisted for 30 months. No significant short- or long-term effects on physical and mental work strain were found. Conclusion: A 6-month physical exercise intervention among symptomatic menopausal women had positive short-term as well as long-term effects on work ability.