• Title/Summary/Keyword: Root mean square (RMS)

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Characteristics of wind-Induced Coupled Motion of Tapered and Setback Tall Buildings (비정형 초고층 건물의 바람에 의한 편심응답 특성)

  • Kim, Yong-Chul;Kanda, Jun;Tamura, Yukio
    • Journal of Korean Association for Spatial Structures
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    • v.13 no.1
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    • pp.79-86
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    • 2013
  • For most of recent tall buildings, one characteristic is that their building shapes vary with height such as taper and setback, and this implies that the distribution of their structural components may also vary with height. Because of these structural variations, although the sectional shapes of these buildings are symmetric, it is difficult to say whether or not they are structurally symmetric. The acceleration responses of structurally asymmetric tall buildings are larger than those of non-eccentric buildings, thus raising the possibility of problems during strong winds and typhoons. This paper describes wind tunnel tests carried out using building models with height variations and acceleration response analyses, and discusses the resulting response characteristics. For tapered and setback buildings, although the across-wind accelerations are larger than those of a square building, the total root-mean-square accelerations remain small because of smaller along-wind and torsional rms accelerations. And it was found that the effects of statistical couplings between along-wind force and other two forces are negligible.

Surface Treatment of ITO (Indium-Tin-Oxide) thin Films Prepared by Sol-Gel Process (졸-겔 공정에 의해 제조된 ITO (Indium-Tin-Oxide) 박막의 표면처리)

  • Jung, Seung-Yong;Yun, Young-Hoon;Yon, Seog-Joo
    • Journal of the Korean Ceramic Society
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    • v.44 no.6 s.301
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    • pp.313-318
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    • 2007
  • ITO (Indium-tin oxide) thin films have been prepared by a sol-gel spinning coating method and fired and annealed in the temperature range of $450-600^{\circ}C$. The XRD patterns of the films indicated the main peak of (222) plane and showed higher crystallinity with increasing an annealing temperature. The surface of the ITO thin films were treated with 0.1 N HCl 20% solution at room temperature. The effects of surface treatment on electrical properties and surface morphologies of the ITO films were investigated with the results of sheet resistance and FE-SEM, AFM images. The samples, subsequently treated with acidic solution for 40 sec showed the sheet resistance of $0.982\;k{\Omega}/square$. The surface treatment using acidic solution diminished the RMS (root mean square) value and the residual carbon content of the ITO films. It seemed that the acid-cleaning of the ITO thin films lead to the decrease of surface roughness and sheet resistance.

A Study on Enhancing the Performance of Detecting Lip Feature Points for Facial Expression Recognition Based on AAM (AAM 기반 얼굴 표정 인식을 위한 입술 특징점 검출 성능 향상 연구)

  • Han, Eun-Jung;Kang, Byung-Jun;Park, Kang-Ryoung
    • The KIPS Transactions:PartB
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    • v.16B no.4
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    • pp.299-308
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    • 2009
  • AAM(Active Appearance Model) is an algorithm to extract face feature points with statistical models of shape and texture information based on PCA(Principal Component Analysis). This method is widely used for face recognition, face modeling and expression recognition. However, the detection performance of AAM algorithm is sensitive to initial value and the AAM method has the problem that detection error is increased when an input image is quite different from training data. Especially, the algorithm shows high accuracy in case of closed lips but the detection error is increased in case of opened lips and deformed lips according to the facial expression of user. To solve these problems, we propose the improved AAM algorithm using lip feature points which is extracted based on a new lip detection algorithm. In this paper, we select a searching region based on the face feature points which are detected by AAM algorithm. And lip corner points are extracted by using Canny edge detection and histogram projection method in the selected searching region. Then, lip region is accurately detected by combining color and edge information of lip in the searching region which is adjusted based on the position of the detected lip corners. Based on that, the accuracy and processing speed of lip detection are improved. Experimental results showed that the RMS(Root Mean Square) error of the proposed method was reduced as much as 4.21 pixels compared to that only using AAM algorithm.

The Intertidal Area in Lake Sihwa After Operation of the Tidal Power Plant (조력발전소 가동 후 시화호 내 조간대의 면적 변화)

  • Kim, Minkyu;Koo, Bon Joo
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.18 no.4
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    • pp.310-316
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    • 2015
  • The intertidal area in Lake Sihwa formed after operation of Sihwa-Lake tidal power plant and the change of the area in Lake Sihwa by period were analyzed. For computation of the intertidal area, remote sensing techniques were applied and high resolution Digital Elevation Model (DEM) was generated with root mean square (rms) error 14.4 cm. The intertidal area was $165.1km^2$ in 1910s, $115.2km^2$ in 1991 before completion of Sihwa dyke, $5.6km^2$ in 2010 during the period on operation of sluice gate, and $20.3km^2$ in 2013 after operation of Sihwa tidal power plant. Intertidal in Lake Sihwa was nearly dissipated after completion of Sihwa dyke, but significantly increased with operation of Sihwa tidal power plant from April 2012 as developing a regular tide environment and increasing of sea water flux. The re-formation of tidal flat of Sihwa Lake is an uncommon case. This study that precisely analyzed on the area of artificially formed Sihwa tidal flat would be applicable for management and making conservation plan.

Marginal and internal discrepancy of 3-unit fixed dental prostheses fabricated by subtractive and additive manufacturing (절삭 및 적층 가공법으로 제작된 3본 고정성 국소의치의 변연 및 내면 적합도에 관한 연구)

  • Choi, Jae-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.58 no.1
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    • pp.7-13
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    • 2020
  • Purpose: This study was to evaluate marginal and internal discrepancy of 3-unit fixed dental prostheses (FDP) fabricated by subtractive manufacturing and additive manufacturing. Materials and methods: 3-unit bridge abutments without the maxillary left second premolar were prepared (reference model) and the reference model scan data was obtained using an intraoral scanner. 3-unit fixed dental prostheses were fabricated in the following three ways: Milled 3-unit FDP (MIL), digital light processing (DLP) 3D printed 3-unit FDP (D3P), stereolithography apparatus (SLA) 3D printed 3-unit FDP (S3P). To evaluate the marginal/internal discrepancy and precision of the prosthesis, scan data were superimposed by the triple-scan protocol and the combinations calculator, respectively. Quantitative and qualitative analysis was performed using root mean square (RMS) value and color difference map in 3D analysis program (Geomagic control X). Statistical analysis was performed using the Kruskal-Wallis test (α=.05), MannWhitney U test and Bonferroni correction (α=.05/3=.017). Results: The marginal discrepancy of S3P group was superior to MIL and D3P groups, and MIL and D3P groups were similar. The D3P and S3P groups showed better internal discrepancy than the MIL group, and there was no significant difference between the D3P and S3P groups. The precision was excellent in the order of MIL, S3P, and D3P groups. Conclusion: Within the limitation of this study, the 3-unit fixed dental prostheses fabricated by additive manufacturing showed better marginal and internal discrepancy than the those of fabricated by subtractive manufacturing, but the precision was poor.

Human-Computer Interface using sEMG according to the Number of Electrodes (전극 개수에 따른 근전도 기반 휴먼-컴퓨터 인터페이스의 정확도에 대한 연구)

  • Lee, Seulbi;Chee, Youngjoon
    • Journal of the HCI Society of Korea
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    • v.10 no.2
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    • pp.21-26
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    • 2015
  • NUI (Natural User Interface) system interprets the user's natural movement or the signals from human body to the machine. sEMG (surface electromyogram) can be observed when there is any effort in muscle even without actual movement, which is impossible with camera and accelerometer based NUI system. In sEMG based movement recognition system, the minimal number of electrodes is preferred to minimize the inconvenience. We analyzed the decrease in recognition accuracy as decreasing the number of electrodes. For the four kinds of movement intention without movement, extension (up), flexion (down), abduction (right), and adduction (left), the multilayer perceptron classifier was used with the features of RMS (Root Mean Square) from sEMG. The classification accuracy was 91.9% in four channels, 87.0% in three channels, and 78.9% in two channels. To increase the accuracy in two channels of sEMG, RMSs from previous time epoch (50-200 ms) were used in addition. With the RMSs from 150 ms, the accuracy was increased from 78.9% to 83.6%. The decrease in accuracy with minimal number of electrodes could be compensated partly by utilizing more features in previous RMSs.

Outlier Detection and Treatment for the Conversion of Chemical Oxygen Demand to Total Organic Carbon (화학적산소요구량의 총유기탄소 변환을 위한 이상자료의 탐지와 처리)

  • Cho, Beom Jun;Cho, Hong Yeon;Kim, Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.4
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    • pp.207-216
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    • 2014
  • Total organic carbon (TOC) is an important indicator used as an direct biological index in the research field of the marine carbon cycle. It is possible to produce the sufficient TOC estimation data by using the Chemical Oxygen Demand(COD) data because the available TOC data is relatively poor than the COD data. The outlier detection and treatment (removal) should be carried out reasonably and objectively because the equation for a COD-TOC conversion is directly affected the TOC estimation. In this study, it aims to suggest the optimal regression model using the available salinity, COD, and TOC data observed in the Korean coastal zone. The optimal regression model is selected by the comparison and analysis on the changes of data numbers before and after removal, variation coefficients and root mean square (RMS) error of the diverse detection methods of the outlier and influential observations. According to research result, it is shown that a diagnostic case combining SIQR (Semi - Inter-Quartile Range) boxplot and Cook's distance method is most suitable for the outlier detection. The optimal regression function is estimated as the TOC(mg/L) = $0.44{\cdot}COD(mg/L)+1.53$, then determination coefficient is showed a value of 0.47 and RMS error is 0.85 mg/L. The RMS error and the variation coefficients of the leverage values are greatly reduced to the 31% and 80% of the value before the outlier removal condition. The method suggested in this study can provide more appropriate regression curve because the excessive impacts of the outlier frequently included in the COD and TOC monitoring data is removed.

Influence of Functional Electrical Stimulation during Gait Training on Motor Unit Action Potential (기능적전기자극을 이용한 보행훈련이 편마비 환자의 하퇴근육의 근전위활동에 미치는 영향)

  • Kang, Yang-Hoon;Seo, Sam-Gi;Lee, Jeong-Woo;Yoon, Se-Won;Kim, Yong-Eok;Kim, Tae-Youl
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.5 no.1
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    • pp.33-43
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    • 2007
  • This study divided 35 hemiplegia patients into control group having standard physical therapy and gait training and functional electrical stimulation(FES) group using FES during gait training in order to examine the effects of applying FES to ankle joint dorsiflexor on motor unit action potential. Stimulation conditions of FES were pulse rate 35 pps, pulse width $250{\mu}s$, and on-time 0.3 second, treatment hour was 30 min. and treatment period was once a day for five days a week through six weeks. For functional evaluations before and after treatment, root mean square(RMS) were measured and the following conclusions were obtained. : In RMS analysis of motor unit action potential, gastrocnemius was significantly reduced in both weight bearing(p<.001) and bearing condition (p<.05). In conclusion, application of FES to hemiplegia patients in recovery stage during gait training decreased RMS and it was interpreted that it was caused by mitigation of muscular spasticity by reduction of motor unit.

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The heart rate variability(HRV) of the headache patients caused by Chiljungsang (칠정상(七情傷)으로 인한 두통 환자의 심박변이도(Heart Rate Variability)에 관한 고찰)

  • Park, Sun-Yong;Choi, Cheol-Hong;Chung, Dae-Kyoo;Ko, Kyung-Mo
    • Journal of Oriental Neuropsychiatry
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    • v.19 no.3
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    • pp.45-54
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    • 2008
  • Objective: To treat psychogenic headache patients, doctors have to amplify on the headache caused by emotional stress to patients, and assist the patients to cope with difficulties. So, we investigated HRV of the headache patients caused by Chiljungsang and would like to apply to the clinical treatment. Method: Our study measured time and frequency domain HRV indicies(5-min resting study) of 123 headache patients caused by emotional stress. Standardized tests of HRV allow a quantitative estimation of autonomic nervous system function. Results & Conclusions: 1. The study classed as aspects of the head pain showed the differences in RMS-SD(square root of mean squared difference of successive NN intervals) band, HF(high frequency) band significantly. 2. The male headache patients showed higher all the indicies except heart rate compared to the female patients, significantly in SDNN(standard deviation of NN interval), TP(total Power), HF band. 3. As the patients grow older, SDNN, RMS-SD band was lower and LF(low frequency) band, LF/HF ratio higher significantly. The beginning age lower, SDNN, RMS-SD band was higher significantly. The duration of the disease longer, LF band, LF/HF ratio was higher significantly.

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Comparative Analysis of Muscles Activation relate to Core Stability during 5 Therapeutic Exercise in Children with Spastic Diplegia (경직성 양하지 마비아의 5가지 치료적 운동시 핵심 안정성과 관련된 근활동 비교 분석)

  • Seo, Hye-Jung;Kim, Joong-Hwi;Shin, Hyun-Hee;Yoo, Sung-Hwan
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.4
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    • pp.583-592
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    • 2013
  • PURPOSE: This study aimed to investigate muscles activation relate to core stability during 5 therapeutic exercise in children with spastic diplegia. METHODS: The subjects of this study were 8 children with typical development and 12 children with spastic diplegia who have been treated in Bobath children's hospital, all of whom agreed to participate in the study. All subjects were measured to see their muscles activation of rectus abdominalis, external oblique abdominalis, elector spinae, gluteus maximus, rectus femoris, and semitendinosus with surface EMG. RESULTS: The results of this study were as follows : 1) There were statistically significant difference in the root mean square(RMS) of all muscles according to 5 therapeutic exercise in children with spastic diplegia. 2) There were statistically significant difference in the RMS of all muscles according to 5 therapeutic exercise in children with typical development. 3) Significant differences of the RMS between diplegic children and normal children were found in elector spinae and rectus femoris only curl-up exercise. CONCLUSION: As the above results, we suggest that 5 therapeutic exercises could be used for a core stability or core strengthening program. Depending on the individual needs of children with cerebral palsy, some of exercises may be more beneficial than others for achieving strength.