• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.3889-3903
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• 2017

Fast and accurate localization of randomly deployed nodes is required by many applications in wireless sensor networks (WSNs). However, mobile nodes localization in WSNs is more difficult than static nodes localization since the nodes mobility brings more data. In this paper, we propose a Range-based Monte Carlo Box (RMCB) algorithm, which builds upon the Monte Carlo Localization Boxed (MCB) algorithm to improve the localization accuracy. This algorithm utilizes Received Signal Strength Indication (RSSI) ranging technique to build a sample box and adds a preset error coefficient in sampling and filtering phase to increase the success rate of sampling and accuracy of valid samples. Moreover, simplified Particle Swarm Optimization (sPSO) algorithm is introduced to generate new samples and avoid constantly repeated sampling and filtering process. Simulation results denote that our proposed RMCB algorithm can reduce the location error by 24%, 14% and 14% on average compared to MCB, Range-based Monte Carlo Localization (RMCL) and RSSI Motion Prediction MCB (RMMCB) algorithm respectively and are suitable for high precision required positioning scenes.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제34권4호
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• pp.236-241
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• 2023

Objectives: According to the 10th revision of the International Classification of Diseases, the main categories of tic disorders (F95.0, F95.1, and F95.2) follow a diagnostic hierarchy based on the duration and diversity of tic symptoms. The present study investigated the use of this diagnostic hierarchy in real-world clinical practice. Methods: Based on the National Health Insurance Service-National Health Information Database, the diagnosis of transient tic disorder (F95.0) made after a diagnosis of chronic motor or vocal tic disorder (F95.1) or Tourette's syndrome (F95.2) and diagnosis of chronic motor or vocal tic disorder (F95.1) made after a diagnosis of Tourette's syndrome (F95.2) were referred to as type A errors. The diagnosis of transient tic disorder (F95.0) repeated after a period of >12 months was referred to as type B error. Demographic and clinical differences according to the diagnostic error types were analyzed using analysis of variance, Student's t-tests, and chi-squared tests. Results: Most participants (96.5%) were without errors in the diagnosis of tic disorders. Higher proportions of males (p=0.005) and antipsychotic prescriptions (p<0.001) were observed in patients with type A or B diagnostic errors. A higher proportion of health insurance holders was observed among those with type A errors (p=0.027). Conclusion: Errors were absent in majority of the tic diagnoses in real-world clinical practice in terms of the diagnostic hierarchy.

• Radiation Oncology Journal
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• 제14권4호
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• pp.333-338
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• 1996

목적 : 반복되는 환자 치료에서 환자의 Setup 오차가 Multi-leaf Collimator의 scallop penumbra에 미치는 효과와 이의 임상적 의미를 살펴보고자 하였다. 대상 및 방법 : MLC의 leaf 방향에 대해 $0^{circ},{\;}15^{circ},{\;}30^{circ},{\;}45^{circ},{\;}60^{circ},{\;}75^{circ}$ block 모양을 MLC와 통상적인 block으로 만들었다. 팬톰내에서 필름 측정법으로 통상적인 블록과 MLC가 만든 치료면의 penumbra 차이를 비교하였다. 방사선 치료는 30회 반복할 때의 setup 오차가 고려된 선량분포를 중첩방식으로 구하였다. 위치 변화값은 연구보고 수치를 근거하여 구하였다. 결과 : 평균 4mm setup error를 갖는 모델에서 1cm 폭분해능을 갖는 MLC가 만든 penumbra은 기존 차폐 블록에서 생긴 penumbra 보다 차폐 모양에 따라 $0\~3mm$ 증가하는 효과를 볼 수 있었다. 결론 : 치료 조사면을 결정할 때 MLC를 사용하더라도 ICRU 50에 따라 환자의 움직임을 고려하여 치료조사면을 결정하였다면, 기존의 방식과 동일하게 치료면을 정할 수 있으며, 필요에 따라 3mm의 여유를 두면 MLC 치료 조사면 내에 치료 부위가 충분히 포함된다.

• 한국전문물리치료학회지
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• 제20권2호
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• pp.20-27
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• 2013

The purpose of this study was to compare the slouched and upright sitting positions on lumbar joint reposition error (LJRE). Twenty subjects without low back pain were recruited for this study and, using a random number table, were randomly assigned to two groups; the upright sitting position group (UP group) and the slouched sitting position group (SP group). UP group was first asked to sit in an upright position and the SP group to sit in a slouched position as an intervention, and then the LJRE of both groups was measured at the neutral sitting position (lumbar flexion $0^{\circ}$). The measurement of the LJRE was repeated after one day. The sitting positions were performed for five minutes each and the LJRE was measured using an electronic goniometer. An independent t-test was used to compare the LJRE of both groups after each sitting position and after one day. The results of this study showed that the LJRE after an intervention in the UP group was lower than in the SP group (p<.05) and the LJRE after one day in the UP group was lower than in the SP group (p<.05). The findings of this study indicate that the upright sitting position can be applied to decrease LJRE, compared with the slouched sitting position. These findings also support that the upright sitting position reduces the potential for proprioceptive loss.

• 대한기계학회논문집
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• 제14권1호
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• pp.259-266
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• 1990

본 연구에서는 지금까지 개발된 각종 소형 푸루버의 작동원리 및 장단점을 분 석 비교한 결과에 따라 이중 실린더형의 소형 푸루버를 직접 설계 제작하고, 개발된 소형 푸루버를 사용하여 펄스 주기 변동특성이 각각 다른 유량계를 대상으로 펄스보간 오차 시험을 실시하였다. 실험결과는 통계적 방법을 도입하여 분석함으로써 유량계 각각에 대하여 기대 검증 정확도 수준을 선정하였다. 또 기대검증 정확도가 좋지 않 게 예상되는 유량계에 대해서는 검증 정확도 향상 방안을 제시하였다.

• 대한수학회보
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• 제29권1호
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• pp.125-135
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• 1992

In various viscus flow problems it has been the custom to replace the convective derivative by the ordinary partial derivative in problems for which the data are small. In this paper we consider the Benard Convection problem with small data and compare the solution of this problem (assumed to exist) with that of the linearized system resulting from dropping the nonlinear terms in the expression for the convective derivative. The objective of the present work is to derive an estimate for the error introduced in neglecting the convective inertia terms. In fact, we derive an explicit bound for the L$_{2}$ error. Indeed, if the initial data are O(.epsilon.) where .epsilon. << 1, and the Rayleigh number is sufficiently small, we show that this error is bounded by the product of a term of O(.epsilon.$^{2}$) times a decaying exponential in time. The results of the present paper then give a justification for linearizing the Benard Convection problem. We remark that although our results are derived for classical solutions, extensions to appropriately defined weak solutions are obvious. Throughout this paper we will make use of a comma to denote partial differentiation and adopt the summation convention of summing over repeated indices (in a term of an expression) from one to three. As reference to work of continuous dependence on modelling and initial data, we mention the papers of Payne and Sather [8], Ames [2] Adelson [1], Bennett [3], Payne et al. [9], and Song [11,12,13,14]. Also, a similar analysis of a micropolar fluid problem backward in time (an ill-posed problem) was given by Payne and Straughan [10] and Payne [7].

• 구강회복응용과학지
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• 제28권1호
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• pp.27-36
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• 2012

임플란트를 이용한 치료가 대중화됨에 따라 다양한 문제가 보고되고 있는데, 이 중에서도 나사풀림현상과 관련된 토크 조절기의 사용에 있어 제조회사에서 권장하는 적절한 토크값과 실제 적용되는 조임력에는 차이가 있음이 여러 연구결과를 통해 보고되고 있다. 본 연구에서는 제품마다 사용기간이 다른 토크 조절기를 이용하여 각각에 따른 정확도를 비교, 분석하고자 하였다. 오차율은 제조회사별로 차이가 있었지만 모든 제품에서 사용기간이 증가할수록 기준값에 대한 오차율은 증가하였다. 그리고 반복 조임 횟수 증가에 따른 측정값의 변화를 살펴보면 반복 조임 초기에는 기준값에 근접한 값을 나타내었지만 기준값에 대한 변화의 폭은 크게 나타났고, 반복 조임 횟수가 증가할수록 기준값에 대한 오차율은 증가하였지만 변화의 폭은 줄어드는 것으로 관찰되었다.

• 대한전자공학회논문지
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• 제27권11호
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• pp.9-19
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• 1990

원통형 및 환형 유전체공진기의 복소유전율과 투자율을 측정하기 위한 이론적인 해석과 측정방법을 제시하였다. 두 개의 평면도체 사이에 유전체공진기를 놓고 공진주파수와 무부하 Q, 그리고 치수를 측정하면 복소유전율과 투자율을 구할 수 있으며 이 방법을 고차모우드에 대하여 반복적으로 행하면 더 넓은 주파수 범위에서 측정이 가능하다. 이 때 각각의 공진모우드는 유전체공진기의 방위각과 축방향에 대한 전계 세기의 변화를 측정함으로써 결정할 수 있다. 그리고 여러가지 오차의 요인들을 고려한 측정오차의 해석으로부터 $TE_{0np}$ 또는 quasi-TE 모우드를 측정에 이용할 경우 복소유전율의 실수부분은 $0.5{\%}$, 허수부분은 $4{\%}$ 이내의 측정오차를 가짐이 밝혀졌다.

• 한국전문물리치료학회지
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• 제28권4호
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• pp.256-265
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• 2021

Background: Individuals with scapular winging may have proprioceptive dysfunction which is important for motor control and causes shoulder instability. Reduced serratus anterior (SA) and lower trapezius (LT) muscle activity accompanied by over-active upper trapezius (UT), and pectoralis major (PM) may be contributing factors. Flexi-bar (FB) exercise may be used to increase joint position sense (JPS) and alter the target muscle activities. Objects: This study aimed to investigate the immediate effects of flexi-bar exercise prior to knee push-up plus (FPK) versus knee push-up plus (KPP) on JPS and muscle activity of SA, LT, UT, and PM in subjects with scapular winging. Methods: Eighteen subjects with scapular winging were recruited. JPS was investigated at baseline, after KPP and after FPK. Passive and active JPS errors were calculated by isokinetic equipment. Surface electromyography was used to record muscle activities during KPP and FPK. One-way repeated-measures analysis of variance and post hoc analyses were used to analyze the JPS error measured at baseline, after KPP and after FPK. Paired t-tests were used to compare muscle activities between KPP and FPK. Results: Passive JPS error was significantly decreased after KPP (p = 0.005) and after FPK (p = 0.003) compared to the baseline. Active JPS error was also significantly decreased after KPP (p = 0.016) and after FPK (p = 0.012) compared to the baseline. There was no significant difference in the passive and active JPS errors between KPP and FPK. SA activity during FPK was significantly increased (p = 0.024), and LT activity during FPK was significantly increased (p = 0.006). There were no significant differences in the UT and PM activity. Conclusion: FB might be recommended to immediately improve passive and active JPS and to selectively increase SA and LT muscle activities during KPP in individuals with scapular winging.

• 대한물리치료과학회지
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• 제30권3호
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• pp.49-58
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• 2023

Background: This study aims to examine the useful- ness of the portable spirometer "The Spirokit" as a clinical diagnostic device through technology introduction, precision test, and correction. Design: Technical note Methods: "The Spirokit" was developed using a propeller-type flow rate and flow rate measurement method using infrared and light detection sensors. The level of agreement between the Pulmonary Waveform Generator and the measured values was checked to determine the precision of "The Spirokit", and the correction equation was included using the Pulmonary Waveform Generator software to correct the error range. The analysis was requested using the ATS 24/26 waveform recognized by the Ministry of Food and Drug Safety and the American Thoracic Society for the values of Forced Voluntary Capacity (FVC), Forced Expiratory Volume in 1second (FEV1), and Peak Expiratory Flow (PEF), which are used as major indicators for pulmonary function tests. All tests were repeated five times to derive an average value, and FVC and FEV1 presented accuracy and PEF presented accuracy as the result values. Results: FVC and FEV1 of 'The Spirokit' developed in this study showed accuracy within ± 3% of the error level in the ATS 24 waveform. The PEF value of 'The Spirokit' showed accuracy within the error level ± 12% of the ATS 26 waveform. Conclusion: Through the results of this study, the precision of 'The Spirokit' as a clinical diagnosis device was identified, and it was confirmed that it can be used as a portable pulmonary function test that can replace a spirometer.