• Title/Summary/Keyword: Change points

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A Study on the Confidence Region of the Stationary Point in a second Order Response Surface

  • Jorn, Hong S.
    • Journal of the Korean Statistical Society
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    • v.7 no.2
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    • pp.109-119
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    • 1978
  • When a response surface by a seconde order polynomial regression model, the stationary point is obtained by solving simultaneous linear equations. But the point is a function of random variables. We can find a confidence region for this point as Box and Hunter provided. However, the confidence region is often too large to be useful for the experiments, and it is necessary to augment additional design points in order to obtain a satisfactory confidence region for the stationary point. In this note, the author suggests a method how to augment design points "eficiently", and shows the change of the confidence region of the estimated stationary point in a response surface.e surface.

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Neural Network Forecasting Using Data Mining Classifiers Based on Structural Change: Application to Stock Price Index

  • Oh, Kyong-Joo;Han, Ingoo
    • Communications for Statistical Applications and Methods
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    • v.8 no.2
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    • pp.543-556
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    • 2001
  • This study suggests integrated neural network modes for he stock price index forecasting using change-point detection. The basic concept of this proposed model is to obtain significant intervals occurred by change points, identify them as change-point groups, and reflect them in stock price index forecasting. The model is composed of three phases. The first phase is to detect successive structural changes in stock price index dataset. The second phase is to forecast change-point group with various data mining classifiers. The final phase is to forecast the stock price index with backpropagation neural networks. The proposed model is applied to the stock price index forecasting. This study then examines the predictability of integrated neural network models and compares the performance of data mining classifiers.

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Effect of Number of Measurement Points on Accuracy of Muscle T2 Calculations

  • Tawara, Noriyuki;Nishiyama, Atsushi
    • Investigative Magnetic Resonance Imaging
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    • v.20 no.4
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    • pp.207-214
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    • 2016
  • Purpose: The purpose of this study was to investigate the effect of the number of measurement points on the calculation of transverse relaxation time (T2) with a focus on muscle T2. Materials and Methods: This study assumed that muscle T2 was comprised of a single component. Two phantom types were measured, 1 each for long ("phantom") and short T2 ("polyvinyl alcohol gel"). Right calf muscle T2 measurements were conducted in 9 healthy male volunteers using multiple-spin-echo magnetic resonance imaging. For phantoms and muscle (medial gastrocnemius), 5 regions of interests were selected. All region of interest values were expressed as the mean ${\pm}$ standard deviation. The T2 effective signal-ratio characteristics were used as an index to evaluate the magnetic resonance image quality for the calculation of T2 from T2-weighted images. The T2 accuracy was evaluated to determine the T2 reproducibility and the goodness-of-fit from the probability Q. Results: For the phantom and polyvinyl alcohol gel, the standard deviation of the magnetic resonance image signal at each echo time was narrow and mono-exponential, which caused large variations in the muscle T2 decay curves. The T2 effective signal-ratio change varied with T2, with the greatest decreases apparent for a short T2. There were no significant differences in T2 reproducibility when > 3 measurement points were used. There were no significant differences in goodness-of-fit when > 6 measurement points were used. Although the measurement point evaluations were stable when > 3 measurement points were used, calculation of T2 using 4 measurement points had the highest accuracy according to the goodness-of-fit. Even if the number of measurement points was increased, there was little improvement in the probability Q. Conclusion: Four measurement points gave excellent reproducibility and goodness-of-fit when muscle T2 was considered mono-exponential.

A Study on the Yin-Yang Needling Method in the Shouyaogangrou chapter of the Lingshu (『영추(靈樞)·수요강유(壽夭剛柔)』의 음양(陰陽) 자법(刺法)에 대한 고찰(考察))

  • Kim, Do-Hoon
    • Journal of Korean Medical classics
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    • v.34 no.2
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    • pp.207-223
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    • 2021
  • Objectives : This paper studied the different disease sites according to Yin and Yang deviation and the principal to applying the Five Shu Points acupuncture method to these sites of the Yin-Yang needling method as explained in the Shouyaogangrou chapter of the Lingshu. Methods : Of the seasonal needling method in the Neijing, the principle to managing the Five Shu Points and indications of each point were examined. Next, clinical applications of the Five Shu Points were analyzed. Descriptions of clinical expression were collected and examined to understand the underlying pattern. Results : If we connect the disease sites of the Yin-Yang needling method to the Five Shu Points needling method according to the seasonal changes, the Yang of Yin connects to Spring, Yin of Yang to Summer, Yang of Yang to Autumn, and Yin of Yin to Winter. Of the needling site, the collateral vessel is the collateral vessel of Spring, 'Meridian of Yin' is the meridian of the Yin domain or the meridian points of the Yin meridian. 'He of Yang' is the He point of the Yang meridian, and the Yin Xing and Shu are the Xing and Shu points of the Yin meridian. Upon examining cases in the Neijing where the Five Shu Points were applied, it could be found that the Xing and Shu points of the Yin meridian were used together, while the He point of the Yang meridian was used to eliminate Yang pathogen or to stimulate Yang qi, which matches the Yin-Yang needling method of the Shouyaogangrou chapter of the Lingshu. Conclusions : The Yin and Yang of the needling sites from the Yin-Yang needling method in the Shouyaogangrou chapter of the Lingshu refers to the Yin and Yang meridians, or the Yin and Yang domains. In the context of disease site description, the former Yin and Yang describes a spatial aspect, while the latter Yin and Yang refers to the vicissitudes of qi according to temporal change.

Effects of sit-to-stand imagery group training on balance performance in individuals with chronic hemiparetic stroke: a randomized control trial

  • Lee, Jeongwon;Hwang, Sujin;Ahn, Sinae
    • Physical Therapy Rehabilitation Science
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    • v.5 no.2
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    • pp.63-69
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    • 2016
  • Objective: To evaluate the effects of sit-to-stand (STS) imagery group training (IGT) on STS movement and balance performance for chronic hemiparetic stroke. Design: Randomized controlled trial. Methods: A total of 30 people with chronic hemiparetic stroke (15 for STS-IGT group and 15 for control) were recruited in this study. The STS-IGT group participated in a videotape-based STS-IGT for 30 minutes a day, five days a week for six weeks, while the control group watched a documentary on television for the same period. The STS-IGT focused on a five-stage protocol. Specifically, external imagery was used during the four phases of the STS movement from the seat of the chair to standing up. All of the participants also participated in a regular rehabilitation program. STS movement and balance performance were assessed using three clinical measures. Results: After training, time to perform the 5-repetition STS test significantly increased in the STS-IGT group (change value, $4.0{\pm}2.0$ sec) compared with the control group (change value, $0.9{\pm}0.7$ sec) (p<0.05). There was a greater improvement in Berg balance scale scores in the STS-IGT group (change value, $0.2{\pm}4.1$ points) compared with the control group (change value, $0.3{\pm}0.9$ points) (p<0.05). There was a greater improvement in Timed Up and Go scores in the STS-IGT group (change value, $2.6{\pm}1.5$ sec) compared with the control group (change value, $0.9{\pm}1.0$ sec) (p<0.05). Conclusions: STS-IGT can be considered as a useful option for restoration of STS movement and balance performance for individuals with chronic hemiparetic stroke who are unable to fully participate in physical activities.

A study on the value orientation of nursing unit managers and nursing organization performances (간호단위 관리자의 가치지향성 리더쉽유형과 간호조직성과의 관계)

  • Han, Su-Jeong
    • Journal of Korean Academy of Nursing Administration
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    • v.9 no.2
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    • pp.159-170
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    • 2003
  • Purpose : This study is to confirm the relation of the value orientation of the nursing unit manager and the job satisfaction and organizational commitment of the nursing unit nurse. Method : We used the systematic questionnaires as a study tool. The contents were composed of 46 questions in total such as 4 questions of general feature, 23 value-oriented questions, 10 job satisfaction questions, and 9 organizational commitment questions. The period of data collection was from August to September 2000. Result : 1) The value of flexibility was 3.82 points (${\pm}.3788$), which is above average. The values of equalitarianism was 3.37 points (${\pm}.4422$), which is above average. 2) The leadership pattern according to the value orientation perceived by the head nurses in 6 clusters has been divided into 3 patterns of change-oriented leader, task-oriented and stability-oriented leader. 3) The nurses who worked with the change-oriented leader showed higher values of job satisfaction (F=5.941, p=O.003), and affective commitment (F=5.793, p=O.003) than those who worked with the stability-oriented leader. Conclusion : As revealed in this study, we think that we have to consider that the change-oriented leader can produce higher performance of an organization than the stability-oriented leader, and write the basic data for the educational courses of leadership development or workshops etc. in order for the nursing unit managers to play their roles for the effective ward-unit management.

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Detection of multiple change points using penalized least square methods: a comparative study between ℓ0 and ℓ1 penalty (벌점-최소제곱법을 이용한 다중 변화점 탐색)

  • Son, Won;Lim, Johan;Yu, Donghyeon
    • The Korean Journal of Applied Statistics
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    • v.29 no.6
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    • pp.1147-1154
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    • 2016
  • In this paper, we numerically compare two penalized least square methods, the ${\ell}_0$-penalized method and the fused lasso regression (FLR, ${\ell}_1$ penalization), in finding multiple change points of a signal. We find that the ${\ell}_0$-penalized method performs better than the FLR, which produces many false detections in some cases as the theory tells. In addition, the computation of ${\ell}_0$-penalized method relies on dynamic programming and is as efficient as the FLR.

Temperature variation of the outer skin above specific acupoints induced by controlling mind : Pilot Study (조심법(調心法)을 통한 혈위의 체표온도변화 관찰 : Pilot Study)

  • Lee, Hwa-Jin;Chae, Youn-Byoung;Park, Hi-Joon;Baik, You-Sang;Yi, Seung-Ho;Lee, Hye-Jung
    • Korean Journal of Acupuncture
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    • v.24 no.3
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    • pp.55-65
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    • 2007
  • Qi intention. Temperature variations on the outer skin above measured at acupuncture points, PC8, LI4, and ST7. Results : The change of temperature in PC8 of the Qigong trainees were significantly higher than that of non-trainees ($0.97{\pm}0.20$ vs. $0.45{\pm}0.10$ respectively, p< 0.05 ). The change of temperature of the other acupoints areas was not significantly different between the two groups. Conclusions : Qi intention resulted in temperature change at the outer skin on the specific acupoints.

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Minimal Clinically Important Difference of Berg Balance Scale scores in people with acute stroke

  • Song, Min-Jeong;Lee, Jae-Hyoung;Shin, Won-Seob
    • Physical Therapy Rehabilitation Science
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    • v.7 no.3
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    • pp.102-108
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    • 2018
  • Objective: To investigate whether the Minimal Clinically Important Difference (MCID) clinically defines improvement of Berg Balance Scale (BBS) scores in people with acute stroke in response to rehabilitation. Design: Retrospective study. Methods: Seventy-three participants with acute stroke participated in the study. Balance evaluation was performed using the BBS. All patients received rehabilitation with physical therapy for 4 weeks, 5 times a week, for 2 hours and 20 minutes a day. An anchor-based approach using the clinical global impression was used to determine the MCID of the BBS. The MCID was used to define the minimum change in the BBS total score (postintervention-preintervention) that was needed to perceive at least a 3-point improvement on the global rating of change. Receiver operating characteristic (ROC) curves was used to define the cut-off values of the optimal MCID of the BBS in order to discriminate between improvement and no improvement groups. Results: The optimal MCID cut-off point for the BBS change scores was 12.5 points for males with a sensitivity (Sn) of 0.62 and a specificity (Sp) of 0.89, and 12.5 points for females with a Sn of 0.69 and Sp of 0.85. The area under the curve of the ROC curve for all participants were 0.84 (95% confidence interval [CI], 0.72; 0.95, p<0.001), and 0.89 (95% CI, 0.77; 1.00, p<0.001), respectively. Conclusions: The MCID for improvement in balance as measured by the BBS was 13.5 points, indicating that the MCID does clinically detect changes in balance abilities in persons with stroke.

A Study on the Change of Non-Working Days of Incheon Metropolitan through BCP Analysis (BCP분석을 통한 인천지역 작업불능일 변화 연구)

  • Ko, Kyujin;Lee, Chansik
    • Korean Journal of Construction Engineering and Management
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    • v.16 no.4
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    • pp.80-88
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    • 2015
  • In the case of those types of work that are performed outdoor construction work, many non-working days occur due to climatic elements such as low temperature, rainfall, and high wind velocity. In particular, damage incurred construction delays hardly decreases because weather forecasting has become difficult due to global warming. In the present study, time points of drastic changes in annual average temperatures, annual average maximum temperatures, and annual average minimum temperatures were identified through BCP analysis and increasing/decreasing trends of non-working days in summer and winter were compared and analyzed on the basis of the change points. According to the results of the study, annual average temperatures drastically changed in 1988 and 1998. After the two time points, non-working days in summer and winter clearly showed increasing trends and decreasing trends respectively.