• Title/Summary/Keyword: statistical correction

Search Result 310, Processing Time 0.018 seconds

Quality Control on Water-level Data in Agricultural Reservoirs Considering Filtering Methods (필터링 기법을 이용한 농업용저수지 수위자료의 품질관리 방안)

  • Kim, Kyung-hwan;Choi, Gyu-hoon;Jung, Hyoung-mo;Joo, Donghyuk;Na, Ra;Choi, Eun-hyuk;Kwon, Jae-Hwan;Yoo, Seung-Hwan
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.63 no.5
    • /
    • pp.83-93
    • /
    • 2021
  • Agricultural reservoirs are important facilities for storing or managing water for the purpose of securing agricultural water, creating and expanding agricultural production bases, and using them to increase agricultural production. In particular, the Korea Rural Community Corporation (KRC) manages agricultural reservoirs scattered across the country, and officially recognizes and distributes hydrological data to increase their public utilization and aims to improve the value of water resources. Data on the water level of agricultural reservoirs are important. However, errors such as missing values and outliners limit utilization of the data in various fields of research and industry. Therefore, water quality data measures should be devised to increase reliability. this study categorized different error types and looked at automatic correction methods to enhance the reliability of the vast hydrological data. In addition, the water level data corrected from errors were compared to the reference hydrologic data through expert judgment in accordance with the quality control procedure, and the most appropriate measures were verified. As KRC manages more agricultural reservoirs than any other institution, the proposed method of efficient and automatic water level data correction in this study is expected to increase the availability and reliability of the hydrological data.

Comparison of Muscle Activities Serratus Anterior and Upper Trapezius Muscle During Scapular Protraction in Quadruped Position at Legs Difference (네발기기 자세에서 어깨뼈 내밈 운동시 다리들기에 따른 앞톱니근과 위등세모근의 근활성도 비교)

  • Kim, Hee-gon;Hwang, Byeong-jun;Kim, Jong-woo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
    • /
    • v.25 no.1
    • /
    • pp.29-36
    • /
    • 2019
  • Background: This study was conducted to investigate the effect of leg lift difference on the serratus anterior muscle and the upper trapezius muscle when a subject with winged scapula performs a scapula protraction exercise in a four-leg crawling posture. Method: Twenty normal adults and 20 subjects with winged scapula participated in the experiment. Surface EMG recordings were collected from serratus anterior muscle and back trapezius muscle during scapula protraction exercises. Scapular winging is measured with the lifting distance of scapula retraction to the back using an electronic digital caliper. In two groups of four-leg crawling posture, the two legs support, the dominant leg lifting, and the non-dominant leg lifting, including the scapula protraction, were performed. To examine the difference between groups in the variance analysis, the Bonferroni correction was used (significance level ${\alpha}=.017$). Statistical significance level ${\alpha}$ was .05. Results: There was a significant difference in serratus anterior muscle and upper trapezius muscle during push-up plus exercise in leg lifting in four-leg crawling posture, but there were no significant differences in muscle activity between serratus anterior muscle and upper trapezius muscle, and there was no significant difference according to the presence or absence of scapular winging. Conclusion: For the shoulder stability of the ipsilateral side with the serratus anterior muscle, the leg-lifting posture is effective in the four-leg crawling, and also when a subject with winged scapula chooses an exercise, lifting the ipsilateral side of leg with scapula protraction exercises at the same time may have a positive effect on scapula dysfunction.

A Wide Dynamic Range NUC Algorithm for IRCS Systems

  • Cai, Li-Hua;He, Feng-Yun;Chang, Song-Tao;Li, Zhou
    • Journal of the Korean Physical Society
    • /
    • v.73 no.12
    • /
    • pp.1821-1826
    • /
    • 2018
  • Uniformity is a key feature of state-of-the-art infrared focal planed array (IRFPA) and infrared imaging system. Unlike traditional infrared telescope facility, a ground-based infrared radiant characteristics measurement system with an IRFPA not only provides a series of high signal-to-noise ratio (SNR) infrared image but also ensures the validity of radiant measurement data. Normally, a long integration time tends to produce a high SNR infrared image for infrared radiant characteristics radiometry system. In view of the variability of and uncertainty in the measured target's energy, the operation of switching the integration time and attenuators usually guarantees the guality of the infrared radiation measurement data obtainted during the infrared radiant characteristics radiometry process. Non-uniformity correction (NUC) coefficients in a given integration time are often applied to a specified integration time. If the integration time is switched, the SNR for the infrared imaging will degenerate rapidly. Considering the effect of the SNR for the infrared image and the infrared radiant characteristics radiometry above, we propose a-wide-dynamic-range NUC algorithm. In addition, this essasy derives and establishes the mathematical modal of the algorithm in detail. Then, we conduct verification experiments by using a ground-based MWIR(Mid-wave Infared) radiant characteristics radiometry system with an Ø400 mm aperture. The experimental results obtained using the proposed algorithm and the traditional algorithm for different integration time are compared. The statistical data shows that the average non-uniformity for the proposed algorithm decreased from 0.77% to 0.21% at 2.5 ms and from 1.33% to 0.26% at 5.5 ms. The testing results demonstrate that the usage of suggested algorithm can improve infrared imaging quality and radiation measurement accuracy.

Effects of Neck and Pelvic Exercise Using Swiss Ball on Spinal Curve in Adults with Forward Head Posture (전방머리자세 대상자에 대한 목운동과 골반운동이 척추 굽이에 미치는 효과)

  • Bae, Won-Sik;Jang, Chel
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.9 no.3
    • /
    • pp.193-201
    • /
    • 2021
  • Purpose : The purpose of this study was to compare the effect of pelvic exercise on the CVA and spinal curve in adults with forward head posture compared to the group using only neck exercise when pelvic exercise was performed in parallel with conventional neck exercise. Methods : GPS 400 and Formetric were used to identify craniovertebral angle (CVA), thoracic kyphosis, lumbar lordosis, and pelvic torsion and were measured by an experienced research manager. Forward head posture (FHP) was selected for people whose angle between the line connecting the ear ball and the seventh cervical spine and the horizontal line is 50 degrees or less. The 30 selected students were randomly divided into 15 experimental groups and 15 control groups. Mackenzie exercise and sling exercise were performed for neck exercise in both the experimental group and the control group, and pelvic exercise using a Swiss ball was additionally performed in the experimental group. All data collected in this study were analyzed using SPSS statistics 21.0. Cervical vetebral angle (CVA), thoracic kyphosis, lumbar lordosis, and pelvic torsion were compared at 0 weeks, 3 weeks, and 6 weeks for each measurement factor using ANOVA with repeated measures. For the statistical significance test, the significance level of α was set to .05. Results : The changes of pelvic torsion, thoracic kyphosis and CVA due to pelvic exercise using Swiss Ball and neck exercise were changed over time, but lumbar lordosis were not changed. And there were no significant differences among the groups. Conclusion : In conclusion, the pelvic correction exercise is considered to be an effective exercise for correcting the FHP and requires regular pelvic correction exercises. We expect the results to be used in clinical trials.

Effects of Single Leg Ankle Balance Exercise and Neck Stabilization Exercise on Neck Alignment, Muscle and Vascular Thickness in Adults with Forward Head Posture (한발 서기 발목 균형 운동과 목 안정화 운동이 전방 머리 자세를 가진 성인의 목 부위 정렬, 근육 및 혈관두께에 미치는 영향)

  • Sam-Won Yoon;Yun-Hwan Kim;Young-Joo Cha
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.12 no.3
    • /
    • pp.71-81
    • /
    • 2024
  • Purpose : In this study, we compared the effects of ankle, McKenzie, and cervical stabilization exercises in individuals with a forward head posture. Outcome measures investigated included the neck disability index, craniovertebral angle (CVA), cranial rotation angle (CRA), and thickness of the longus colli muscle (LC) and carotid artery (CA) post-intervention. Methods : The study included 20 individuals with a forward head posture, who were assigned to an experimental group (EG, individuals performed ankle exercises) or control group (CG, individuals performed McKenzie and cervical stabilization exercises). The EG intervention was specifically designed to enhance proprioception in the ankle joint and strengthen the ankle muscles to improve overall stability and function. In contrast, CG interventions aimed to improve neck muscle balance and cervical spine alignment. Paired t-tests were used to analyze intragroup changes and independent t-tests to determine intergroup differences pre-and post-intervention. The significance level for all statistical tests was set at α=.05. Results : We observed significant post-intervention improvements in both groups, specifically, in the CVA, CRA, and LC and CA thickness (p<.05). These results indicate that ankle, McKenzie, and cervical stabilization exercises were useful for neck posture correction, improved muscle balance, and enhanced blood flow to the neck. Conclusion : This study underscores the positive effects of ankle, McKenzie, and cervical stabilization exercises in individuals with a forward head posture. Our study highlights the benefits of these exercises for posture correction and overall neck health and the clinical effectiveness and usefulness of ankle exercises as an important intervention to improve forward head posture.

The Change in Corneal Eccentricity on the Correction of Refractive Error using Reverse Geometry Lens (역기하렌즈(Reverse Geometry Lens)의 굴절교정시 각막 편심률(Eccentricity)의 변화)

  • Lee, Seok-Ju;Park, Seong-Jong;Chun, Young-Yun
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.15 no.2
    • /
    • pp.145-150
    • /
    • 2010
  • Purpose: In this study we investigated the correlation between the effect of myopia correction and the change of corneal eccentricity using reverse geometry lens. Methods: The 23 students (46 eyes) continuously wearing reverse geometry lens during 3 months were divided into Group I and Group II by different parameter fitting methods of wearing Reverse Geometry Lens. We measured a corneal eccentricity for Group I and Group II at $10^{\circ}$, $20^{\circ}$, and $30^{\circ}$ positions from corneal apex before wearing reverse geometry lens, 1 week, 1 month, and 3 months after wearing reverse geometry lens. We also measured an uncorrected visual acuity, a spherical equivalent, and a corneal radius and analyzed the correlation between them and the change of corneal eccentricity using statistical significance test. Results: There were the statistical significances of a change of corneal eccentricity (p=0.03, t=-2.29) for Group I and Group II at 10 position from corneal apex in a week after wearing reverse geometry lens, but were not those (p>0.05) in 1 month, and 3 months after wearing reverse geometry lens. There were the statistical significances of correlation between the change of corneal eccentricity and a corrected visual acuity, and a corneal radius, respectively. Particularly, the high correlation between the change of corneal eccentricity and a corrected visual acuity (r=-0.36, p=0.00, t=6.5), and a spherical equivalent (r=-0.72, p=0.00, t=-70.5) for Group II in a week after wearing reverse geometry lens showed. Conclusions: We knew from these results that the high correlation between the effect of myopia correction and the change of corneal eccentricity in a week after wearing reverse geometry lens represented.

A Simulation of Agro-Climate Index over the Korean Peninsula Using Dynamical Downscaling with a Numerical Weather Prediction Model (수치예보모형을 이용한 역학적 규모축소 기법을 통한 농업기후지수 모사)

  • Ahn, Joong-Bae;Hur, Ji-Na;Shim, Kyo-Moon
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.12 no.1
    • /
    • pp.1-10
    • /
    • 2010
  • A regional climate model (RCM) can be a powerful tool to enhance spatial resolution of climate and weather information (IPCC, 2001). In this study we conducted dynamical downscaling using Weather Research and Forecasting Model (WRF) as a RCM in order to obtain high resolution regional agroclimate indices over the Korean Peninsula. For the purpose of obtaining detailed high resolution agroclimate indices, we first reproduced regional weather for the period of March to June, 2002-2008 with dynamic downscaling method under given lateral boundary conditions from NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis data. Normally, numerical model results have shown biases against observational results due to the uncertainties in the modelis initial conditions, physical parameterizations and our physical understanding on nature. Hence in this study, by employing a statistical method, the systematic bias in the modelis results was estimated and corrected for better reproduction of climate on high resolution. As a result of the correction, the systematic bias of the model was properly corrected and the overall spatial patterns in the simulation were well reproduced, resulting in more fine-resolution climatic structures. Based on these results, the fine-resolution agro-climate indices were estimated and presented. Compared with the indices derived from observation, the simulated indices reproduced the major and detailed spatial distributions. Our research shows a possibility to simulate regional climate on high resolution and agro-climate indices by using a proper downscaling method with a dynamical weather forecast model and a statistical correction method to minimize the model bias.

Reducing Dose in SPECT/CT Using Adaptive Statistical Iterative Reconstruction Technique (Adaptive Statistical Iterative Reconstruction 기법을 이용한 Bone SPECT/CT 검사에서 피폭량 감소 방안)

  • Choi, Jin-Wook;Choi, Hyeon-Jun;Park, Chan-Rok;Cho, Sung-Wook;Kim, Jin-Eui;Lee, Jae-Sung;Lee, Dong-Soo
    • The Korean Journal of Nuclear Medicine Technology
    • /
    • v.18 no.1
    • /
    • pp.134-139
    • /
    • 2014
  • Purpose: Adaptive statistical iterative reconstruction (ASIR) technique is a reconstruction method of CT image using statistical noise modeling which is known to reduce image noise and to preserve image quality despite reducing radiation dose. The aim of this study is to evaluate images using ASIR on bone SPECT/CT which is primarily performed in our hospital. Materials and Methods: We compared the images of applied ASIR (ASIR level: 20-80%) and none ASIR by changing the mA based on 120 kVp, 100 mA using Discovery NM/CT 670 (GE, U.S.A). First, we evaluated attenuation correction in SPECT image by changing the ASIR level using Anthropomorphic phantom. Second, we compared the contrast to noise ratio (CNR), image noise and spatial resolution in CT image using ACR phantom. Third, after selecting the ASIR level applicable patient using lower torso phantom, we examined 2 patients who followed up bone SPECT/CT and we performed blind test. Results: The degree of attenuation correction in SPECT image showed no significant difference between applied ASIR and none ASIR (P>0.05). When applied ASIR, the noise of CT image were reduced at least 17 up to 52% by changing the mA. The CNR of image with ASIR was maintained more than 0.8 at 40 mA (ASIR 60%) while those without ASIR showed 0.42 at standard 40 mA. In comparison of the high contrast object, we distinguished 12 line pairs/cm at 40 mA regardless of appling ASIR. Comparison of the patients image applied ASIR level 60% (40 mA) which found out by spine image of lower torso phantom showed no signigicant difference between applied ASIR and none ASIR in blind test. The CTDIvol and DLP for applied ASIR 60% showed decreased by 60%, 60% on average than using standard mA. Conclusion: The study show that the radiation dose in SPECT/CT using ASIR can be reduced despite degradation of SPECT and CT images. In addition, higher ASIR level could be possibly applied characteristics of SPECT/CT that region of interest is limited to bone.

  • PDF

Investigation on Granger Causality between Economic Growth and Demand for Electricity in Korea: Using Quarterly Data (한국의 경제성장과 전력수요간의 인과성에 관한 연구: 분기별 자료를 이용하여)

  • Baek, Moon-Young;Kim, Woo-Hwan
    • The Korean Journal of Applied Statistics
    • /
    • v.25 no.1
    • /
    • pp.89-99
    • /
    • 2012
  • This study investigates the Granger-causality between economic growth and demand for electricity in Korea, using two quarterly time-series data (real GDP and electricity consumption) for 1970:Q1 through 2009:Q4. We apply Hsiao's sequential procedure to identify a vector autoregressive model to a decision of the optimal lags in the vector error-correction model because the two time-series data contain unit roots respectively and they are cointegrated. According to the empirical results in this study, we find that Hsiao's approach to the Granger-causality indicates a bidirectional causal relation between economic growth and demand for electricity in Korea. Following the Granger and Engle's approach, we also find the statistical evidence on (1) short-run bidirectional causality between real GDP and electricity consumption, (2) bidirectional strong causality between them, and (3) long-run unidirectional causality running from demand for electricity to economic growth. Our results show an inconsistency with the existing studies on Korea's case; however, the results appear to provide more meaningful policy implications for the Korean economy and its strategy of sustainable growth.

Digital Processing and Acoustic Backscattering Characteristics on the Seafloor Image by Side Scan Sonar (Side Scan Sonar 탐사자료의 영상처리와 해저면 Backscattering 음향특성)

  • 김성렬;유홍룡
    • 한국해양학회지
    • /
    • v.22 no.3
    • /
    • pp.143-152
    • /
    • 1987
  • The digital data were obtained using Kennedy 9000 magnetic tape deck which was connected to the SMS960 side scan sonar during the field operations. The data of three consecutive survey tracks near Seongsan-po, Cheju were used for the development of this study. The softwares were mainly written in Fortran-77 using VAX 11/780 MINI-COMPUTER (CPU Memory; 4MB). The established mapping system consists of the pretreatment and the digital processing of seafloor image data. The pretreatment was necessary because the raw digital data format of the field magnetic tapes was not compatible to the VAX system. Therefore the raw data were read by the personal computer using the Assembler language and the data format was converted to IBM compatible, and next data were communicated to the VAX system. The digital processing includes geometrical correction for slant range, statistical analysis and cartography of the seafloor image. The sound speed in the water column was assumed 1,500 m/sec for the slant range correction and the moving average method was used for the signal trace smoothing. Histograms and cumulative curves were established for the statistical analysis, that was purposed to classify the backscattering strength from the sea-bottom. The seafloor image was displayed on the color screen of the TEKTRONIX 4113B terminal. According to the brief interpretation of the result image map, rocky and sedimentary bottoms were very well discriminated. Also it was shown that the backscattered acoustic pressurecorrelateswith the grain size and sorting of surface sediments.

  • PDF