• Title/Summary/Keyword: Data normality

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Correlations Between the Physical Properties and Compression Index of KwangYang Clay (광양점토의 물리적 특성과 압축지수의 상관성)

  • Bae, Wooseok;Kim, Jongwoo
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.7
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    • pp.7-14
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    • 2009
  • The correlation equation empirically proposed to obtain compression indexes has been proposed to conveniently obtain the value using the soil parameter that can be obtained through simple tests when the number of time of consolidation testing is low or the distribution is large but most of the analyzed regions are limited to certain regions abroad or in the country and multiple data were integrated for use in many cases, thus it is not very reasonable to apply it. Therefore, to establish a new design method considering the uncertainty of the ground, it was selected the Kwangyang port area of which the data have been collected recently thus are relatively more reliable as the subject region of the study in order to maximally reduce the uncertainty of test data. After performing the verification of the normality of the consolidation test data obtained from the selected region and the transformation of variables, a prediction formula was proposed through the regression model with the transformed variables and the proposed regression model with transformed variables was compared with existing empirical equations to verify the suitability of the proposed model formula. After analyzing, it was confirmed that the coefficient of determination was increased after the Box-Cox variable transformation, thus the explanatory power was being enhanced and through the root-mean-square-error method, it was confirmed that the proposed model formula showed the most closed value to the test value.

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Optimal design of a nonparametric Shewhart-Lepage control chart (비모수적 Shewhart-Lepage 관리도의 최적 설계)

  • Lee, Sungmin;Lee, Jaeheon
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.2
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    • pp.339-348
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    • 2017
  • One of the major issues of statistical process control for variables data is monitoring both the mean and the standard deviation. The traditional approach to monitor these parameters is to simultaneously use two seperate control charts. However there have been some works on developing a single chart using a single plotting statistic for joint monitoring, and it is claimed that they are simpler and may be more appealing than the traditonal one from a practical point of view. When using these control charts for variables data, estimating in-control parameters and checking the normality assumption are the very important step. Nonparametric Shewhart-Lepage chart, proposed by Mukherjee and Chakraborti (2012), is an attractive option, because this chart uses only a single control statistic, and does not require the in-control parameters and the underlying continuous distribution. In this paper, we introduce the Shewhart-Lepage chart, and propose the design procedure to find the optimal diagnosis limits when the location and the scale parameters change simultaneously. We also compare the efficiency of the proposed method with that of Mukherjee and Chakraborti (2012).

The Effect of Abdominal Massage on Sleep Colonoscopy Subjects (수면 대장내시경 검진자에게 시행한 복부마사지의 효과)

  • Lee, Yun-Jeong;Je, Nam-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.410-420
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    • 2019
  • The purpose of this study is to investigate the effect of abdominal massage, on abdominal bloating and the recovery of bowel movement after sleep colonoscopy. The study design is the time difference before and after the non-equality control. The subjects were 22 patients each in experimental group and control group who recieved sleep colonoscopy at the G hospital in C city, The data collection period was from June 1, 2018 to August 25, 2018, and the control group's data were first collected with time difference from the collection of experimental group's data to prevent the spread of the experiment. Data were analyzed using IBM SPSS 24.0 and tested by independent sample t-test, $x^2-test$ and Fisher's exact probability test to verify the homogeneity of general characteristics of the subjects. Shapiro-Wilk was used to verify the normality of the abdominal circumference changes in the experimental and control groups. Mann-Whitney U test was used to verify the pre-homogeneity of the abdominal circumference of the subjects. The experimental results were verified by Fisher's exact probability test, Friedman test and Mann-Whitney U test. These results suggest that the abdominal massage can be used as a nursing intervention after sleep colonoscopy by reducing the gas discharge time($x^2=19.75$, p<.001) and abdominal bloating($x^2=29.93$, p<.001).

Possibility of Estimating Daily Mean Temperature for Improving the Accuracy of Temperature in Forage Yield Prediction Model (풀사료 수량예측모델의 온도 정밀도 향상을 위한 일평균온도 추정 가능성 검토)

  • Kang, Shin Gon;Jo, Hyun Wook;Kim, Ji Yung;Kim, Kyeong Dae;Lee, Bae Hun;Kim, Byong Wan;Sung, Kyung Il
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.41 no.1
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    • pp.56-61
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    • 2021
  • This study was conducted to determine the possibility of estimating the daily mean temperature for a specific location based on the climatic data collected from the nearby Automated Synoptic Observing System (ASOS) and Automated Weather System(AWS) to improve the accuracy of the climate data in forage yield prediction model. To perform this study, the annual mean temperature and monthly mean temperature were checked for normality, correlation with location information (Longitude, Latitude, and Altitude) and multiple regression analysis, respectively. The altitude was found to have a continuous effect on the annual mean temperature and the monthly mean temperature, while the latitude was found to have an effect on the monthly mean temperature excluding June. Longitude affected monthly mean temperature in June, July, August, September, October, and November. Based on the above results and years of experience with climate-related research, the daily mean temperature estimation was determined to be possible using longitude, latitude, and altitude. In this study, it is possible to estimate the daily mean temperature using climate data from all over the country, but in order to improve the accuracy of daily mean temperature, climatic data needs to applied to each city and province.

The effect of resin cement type and cleaning method on the shear bond strength of resin cements for recementing restorations

  • Koodaryan, Roodabeh;Hafezeqoran, Ali;Maleki, Amin Khakpour
    • The Journal of Advanced Prosthodontics
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    • v.9 no.2
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    • pp.110-117
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    • 2017
  • PURPOSE. This laboratory study assessed the effect of different dentin cleaning procedures on shear bond strength of resin cements for recementing prosthesis. MATERIALS AND METHODS. A $4{\times}4$ flat surface was prepared on the labial surface of 52 maxillary central incisors. Metal frames ($4{\times}4{\times}1.5mm$) were cast with nickel-chromium alloy. All specimens were randomly divided into 2 groups to be cemented with either Panavia F2.0 (P) or RelyX Ultimate (U) cement. The initial shear bond strength was recorded by Universal Testing Machine at a crosshead speed of 0.5 mm/min. Debonded specimens were randomly allocated into 2 subgroups (n = 13) according to the dentin cleaning procedures for recementation. The residual cement on bonded dentin surfaces was eliminated with either pumice slurry (p) or tungsten carbide bur (c). The restorations were rebonded with the same cement and were subjected to shear test. Data failed the normality test (P < .05), thus were analyzed with Mann Whitney U-test, Wilcoxon signed rank test, and two-way ANOVA after logarithmic transformation (${\alpha}=.05$). RESULTS. The initial shear bond strength of group P was significantly higher than group U (P = .001). Pc and Uc groups presented higher bond strength after recementation compared to the initial bond strength. However, it was significant only in Pc group (P = .034). CONCLUSION. The specimens recemented with Panavia F2.0 provided higher bond strength than RelyX Ultimate cement. Moreover, a tungsten carbide bur was a more efficient method in removing the residual resin cement and increased the bond strength of Panavia F2.0 cement after recementation.

A Study of Reliability Analysis and Application on Naval Combat System Using Field Critical Failure Data (야전 치명고장자료를 이용한 함정전투체계 신뢰성 분석 및 활용 방안)

  • Kim, Young-Jin;Oh, Hyun-Seung;Choi, Bong-Wan
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.4
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    • pp.49-59
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    • 2016
  • Naval combat system developed in-country is progressing at an alarming rate since 2000. ROK navy will be achieved all vessels that have combat system in the near future. The importance of System Engineering and Integrated Logistics Support based on reliability analysis is increasing. However, reliability analysis that everyone trusted and recognized is not enough and applied practically for development of Defense Acquisition Program. In particular, Existing Reliability Analysis is focusing on reliability index (Mean Time Between Failure (MTBF) etc.) for policy decision of defense improvement project. Most of the weapon system acquisition process applying in the exponential distribution simply persist unreality due to memoryless property. Critical failures are more important than simple faults to ship's operator. There are no confirmed cases of reliability analysis involved with critical failure that naval ship scheduler and operator concerned sensitively. Therefore, this study is focusing on Mean Time To Critical Failure (MTTCF), reliability on specific time and Operational Readiness Float (ORF) requirements related to critical failure of Patrol Killer Guided missile (PKG) combat system that is beginning of naval combat system developed in-country. Methods of analysis is applied parametric and non-parametric statistical techniques. It is compared to the estimates and proposed applications. The result of study shows that parametric and non-parametric estimators should be applied differently depending on purpose of utilization based on test of normality. For the first time, this study is offering Reliability of ROK Naval combat system to stakeholders involved with defense improvement project. Decision makers of defense improvement project have to active support and effort in this area for improvement of System Engineering.

Analysis of relationship between K-CESA and creativity confluence competency and coaching skill of undergraduate students (대학생 핵심역량(K-CESA)이 창의융합역량에 미치는 영향과 코칭역량의 매개효과)

  • Park, Ji-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.206-215
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    • 2020
  • This study analyzes the relationship between K-CESA of undergraduate students, and their coaching skill and creativity confluence competences. Totally, 344 students attending private colleges in G province were evaluated for their competence. The data collected were analyzed by descriptive statistics, Pearson's correlation analysis, multiple regression analysis and Sobel test, using the SPSS/PC 22.0 computer program. Our results indicate that K-CESA, coaching skill, and creative convergence fulfill the assumption of normality. Moreover, significant positive relationships were determined between K-CESA and creativity confluence, as well as between coaching skill and creativity confluence. Furthermore, K-CESA was an important factor that predicts the creativity confluence competency, and coaching skill had mediating effects on the relationship between K-CESA and creativity confluence competency. In conclusion, our results indicate that K-CESA and coaching skills are important factors that will help strengthen creativity confluence competences.

Skeletal and dentoalveolar changes after miniscrew-assisted rapid palatal expansion in young adults: A cone-beam computed tomography study

  • Park, Jung Jin;Park, Young-Chel;Lee, Kee-Joon;Cha, Jung-Yul;Tahk, Ji Hyun;Choi, Yoon Jeong
    • The korean journal of orthodontics
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    • v.47 no.2
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    • pp.77-86
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    • 2017
  • Objective: The aim of this study was to evaluate the skeletal and dentoalveolar changes after miniscrew-assisted rapid palatal expansion (MARPE) in young adults by cone-beam computed tomography (CBCT). Methods: This retrospective study included 14 patients (mean age, 20.1 years; range, 16-26 years) with maxillary transverse deficiency treated with MARPE. Skeletal and dentoalveolar changes were evaluated using CBCT images acquired before and after expansion. Statistical analyses were performed using paired t-test or Wilcoxon signed-rank test according to normality of the data. Results: The midpalatal suture was separated, and the maxilla exhibited statistically significant lateral movement (p < 0.05) after MARPE. Some of the landmarks had shifted forwards or upwards by a clinically irrelevant distance of less than 1 mm. The amount of expansion decreased in the superior direction, with values of 5.5, 3.2, 2.0, and 0.8 mm at the crown, cementoenamel junction, maxillary basal bone, and zygomatic arch levels, respectively (p < 0.05). The buccal bone thickness and height of the alveolar crest had decreased by 0.6-1.1 mm and 1.7-2.2 mm, respectively, with the premolars and molars exhibiting buccal tipping of $1.1^{\circ}-2.9^{\circ}$. Conclusions: Our results indicate that MARPE is an effective method for the correction of maxillary transverse deficiency without surgery in young adults.

Effect of Treadmill Walking Training using the Metronome on Gait Pattern (메트로놈을 이용한 트레드밀 보행훈련이 보행패턴에 미치는 영향)

  • Yoon, Won-Chan;Park, Sun-Wook
    • Journal of the Korean Society of Physical Medicine
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    • v.15 no.2
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    • pp.101-108
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    • 2020
  • PURPOSE: The purpose of this study was to investigate the effect of treadmill walking training using the metronome on the gait pattern. METHODS: A total of 33 healthy persons were studied consisting of 17 female and 16 male in the 20-30 age group. A gait analysis program was installed on a treadmill with a built - in gait analysis sensor and laptop. After 9 minutes of treadmill walking, gait analysis was performed for 1 minute. The mean values of the differences in the step length, angle of COP, separation line standard deviation and step force of the lower legs affecting walking symmetry were calculated for treadmill walking and treadmill walking using the metronome. The Shapiro-Wilk test was used to test the normality of the collected data and a paired t-test was performed to analyze the difference in walking before and after using the metronome. RESULTS: As a result of the analysis, the mean of difference between the measured values of the bilateral lower extremity for step length, angle of COP, separation line standard deviation and step force were statistically significant before and after treadmill walking using the metronome. CONCLUSION: Therefore, the treadmill walking training using the metronome is effective in decreasing the difference in the foot width, gait angle, gait distribution, and foot pressure. Because of this, the treadmill walking training using the metronome has a significant effect on walking symmetry among the elements for correct walking, which is a means for enabling efficient and continuous walking.

Changes in the Spinal Motor Neuron Excitability Depending on Postural Changes in Post Stoke Hemiplegics (뇌졸중 후 편마비 환자의 체위변화에 따른 척수운동신경원 흥분성 변화)

  • Park, Young-Hyun;Kim, Yong-Nam;Kim, Su-Hyon;Oh, Seok;Choi, Ji-Ho;Kim, Tae-Youl
    • The Journal of Korean Physical Therapy
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    • v.22 no.4
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    • pp.15-20
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    • 2010
  • Purpose: The purpose of this study was to measure changes in the H-reflex and V wave under loading conditions (e.g. prone and standing position) and to investigate whether postural change would affect the H-reflex and V wave in post stroke hemiplegic patients. Methods: Thirty persons with hemiplegia resulting from stroke (20 males, 10 females) participated in this study. Electromyography (EMG) was used to electrically stimulate and record the soleus H-reflexes and V waves under various loading conditions. The normality of the distribution of each variable (H latency, $H_{max}/M_{max}$ ratio, $V_{max}/M_{max}$ ratio) was tested using the Kolmogorov-Smirnov test. The means of normally distributed continuous data were assessed by independent t-test (${\alpha}$=0.05). Results: There were statistically significant differences in $H_{max}/M_{max}$ ratio (p<0.01), $V_{max}/M_{max}$ ratio (p<0.01), H latency (p<0.01) among the prone and standing position. Conclusion: We found that the H-reflex and V wave in standing position was more active to weight bearing load than prone position.