• Title/Summary/Keyword: repeated measurements

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A Study on Comparison of Response Time using Open API of Daishin Securities Co. and eBestInvestment and Securities Co.

  • Ryu, Gui Yeol
    • International journal of advanced smart convergence
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    • v.11 no.1
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    • pp.11-18
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    • 2022
  • Securities and investment services have and use large data. Investors started to invest through their own analysis methods. There are 22 major securities and investment companies in Korea and only 6 companies support open API. Python is effective for requesting and receiving, analyzing text data from open API. Daishin Securities Co. is the only open API that officially supports Python, and eBest Investment & Securities Co. unofficially supports Python. There are two important differences between CYBOS plus of Daishin Securities Co. and xingAPI of eBest Investment & Securities Co. First, we must log in to CYBOS plus to access the server of Daishin Securities Co. And the python program does not require a logon. However, to receive data using xingAPI, users log on in an individual Python program. Second, CYBOS plus receives data in a Request/Reply method, and zingAPI receives data through events. It can be thought that these points will show a difference in response time. Response time is important to users who use open APIs. Data were measured from August 5, 2021, to February 3, 2022. For each measurement, 15 repeated measurements were taken to obtain 420 measurements. To increase the accuracy of the study, both APIs were measured alternately under same conditions. A paired t-test was performed to test the hypothesis that the null hypothesis is there was no difference in means. The p-value is 0.2961, we do not reject null hypothesis. Therefore, we can see that there is no significant difference between means. From the boxplot, we can see that the distribution of the response time of eBest is more spread out than that of Cybos, and the position of the center is slightly lower. CYBOS plus has no restrictions on Python programming, but xingAPI has some limits because it indirectly supports Python programming. For example, there is a limit to receiving more than one current price.

Stiffness of the Central Corpus Cavernosum on Shear-Wave Elastography Is Inversely Correlated with the Penile Rigidity Score in Patients with Erectile Dysfunction

  • Joo Yong Lee;Dae Chul Jung;Seungsoo Lee;Nam Gyu Kang;Young Taik Oh;Kyunghwa Han
    • The World Journal of Men's Health
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    • v.39 no.1
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    • pp.123-130
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    • 2021
  • Purpose: To perform real-time quantitative measurements of penile rigidity for patients with erectile dysfunction (ED) using shear-wave elastography (SWE). Materials and Methods: A total of 92 patients with clinically diagnosed ED filled out an abridged five-item version of the International Index of Erectile Function (IIEF-5) questionnaire and underwent SWE as well as penile color Doppler ultrasound (CDUS) after intracavernosal injection for penile erection. Elasticity measurements were repeated on two sites of the corpus cavernosum (central and peripheral elasticity of corpus cavernosum [ECC]) and the glans penis during the erection phase. Correlations between penile elasticity and rigidity scores or IIEF-5 were evaluated statistically. Penile elasticity was also compared with the ED types based on CDUS. Results: The mean age of all patients was 53.5±13.4 years, and the mean IIEF-5 score was 9.78±5.01. The rigidity score and central ECC value demonstrated a significant correlation (r=-0.272; 95% confidence interval: -0.464 to -0.056; p=0.015). The IIEF-5 score was not significantly correlated with penile elasticity. Vascular ED patients showed significantly higher central ECC values than nonvascular ED patients (p<0.001). At a cut-off value of 8.05 kPa, the central ECC had a specificity of 41.5%, a sensitivity of 84.6%, and an area under the ROC curve of 0.720 with a standard error of 0.059 (p=0.019) for predicting vascular ED. Conclusions: Quantitatively measuring Young's modulus of the corpus cavernosum using SWE could be an objective technique for assessing penile erectile rigidity and the vascular subtype in patients with ED.

A statistical analysis of the fat mass repeated measures data using mixed model (혼합모형을 이용한 체지방 반복측정자료에 대한 통계적 분석)

  • Jo, Jinnam;Chang, Un Jae
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.2
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    • pp.303-310
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    • 2013
  • Forty two female students whose fat mass ratio was over 30% were participated in the experiment of fat mass loss of two treatments for 8 weeks. They kept diary for foods they ate every day, took a picture of the foods, transmitted the picture to the experimenter by the camera phone. Among those, 28 students took the picture by regular camera phone (Treatment A), and the other students used smart phone (Treatment B). Fat mass weight and its related variables had been measured repeatedly four times at an interval of two weeks during 8 weeks. It was shown from mixed model analysis of repeated measurements data that AR(1) covariance matrix was selected as the optimal covariance matrix pattern. The correlation between two successive times is highly correlated as 0.838. Based upon the AR(1) covariance matrix structure, the students using smart phones were somewhat more effective in losing fat mass weight than the students using regular camera phones. The time effect was highly significant, but the treatment-time interaction effect was insignificant. The baseline effect and total cholesterol were found to be significant, but the calories with taking foods were somewhat significant, but the waist to hip ratio was found to be insignificant.

An Investigation into the Equivalence of Three Pictures for Creative Story Writing: 'Dog Owners', 'Lost Dog', and 'Overslept' (창의적 이야기 작문용 세 그림의 동형 조사: 'Dog Owners,' 'Lost Dog,' 'Overslept')

  • Suh, Heejung;Bae, Jungok
    • Journal of Gifted/Talented Education
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    • v.26 no.4
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    • pp.699-719
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    • 2016
  • Alternate pictures that are proven to be equivalent are in high demand to assess creative thinking and language skills. This study aimed to investigate the equivalence of three pictures ('Dog owners,' 'Lost Dog,' and 'Overslept') recently developed for use in a creative writing task. Middle school students (N=183) wrote a story in English based on one of the three prompts distributed randomly. Four writing features (fluency, syntactic complexity, lexical diversity, and temporality) were analyzed with Coh-Metrix and MANCOVA. The three prompts were largely equivalent in their capacity to detect differences among writers in all the features of writing. The difficulty levels of the three prompts, however, were not necessarily the same. Two prompts, Dog Owners and Lost Dog, were verified as equivalent prompts, and therefore, they are recommended as alternate forms to assess creative language skills in repeated measurements. The Overslept prompt had greater facility in eliciting diverse words and more temporal connectives in composing stories. The differential difficulty shown among the prompts suggests that the validity of using different picture versions in repeated assessment remains questionable unless those versions undergo equivalence verification.

Repeated irradiation by light-emitting diodes may impede the spontaneous progression of experimental periodontitis: a preclinical study

  • Hyemee Suh;Jungwon Lee;Sun-Hee Ahn;Woosub Song;Ling Li;Yong-Moo Lee;Yang-Jo Seol;Ki-Tae Koo
    • Journal of Periodontal and Implant Science
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    • v.53 no.2
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    • pp.120-134
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    • 2023
  • Purpose: We investigated whether repeated irradiation with light-emitting diodes (LEDs) at a combination of 470 nm and 525 nm could suppress the progression of experimental periodontitis. Methods: A experimental periodontitis model was established in the second, third, and fourth premolars of the mandible in beagle dogs for 2 months. The spontaneous progression of periodontitis was monitored under the specified treatment regimen for 3 months. During this period, the animals were subjected to treatments of either plaque control only (control) or plaque control with LED application (test) at 2-week intervals. The clinical parameters included the probing pocket depth (PPD), gingival recession (GR), and the clinical attachment level (CAL). Histomorphometric analysis was performed using measurements of the length of the junctional epithelium, connective tissue (CT) zone, and total soft tissue (ST). Results: There were significant differences in PPD between the control and test groups at baseline and 12 weeks. When the change in PPD was stratified based on time intervals, it was shown that greater differences occurred in the test group, with statistical significance for baseline to 12 weeks, 6 to 12 weeks, and baseline to 6 weeks. There was no significant difference in GR between the control and test groups at any time points. Likewise, no statistically significant differences were found in GR at any time intervals. CAL showed a statistically significant difference between the control and test groups at baseline only, although significant differences in CAL were observed between baseline and 12 weeks and between 6 and 12 weeks. The proportion of CT to ST was smaller for both buccal and lingual areas in the control group than in the test group. Conclusions: Repeated LED irradiation with a combination of 470-nm and 525-nm wavelengths may help suppress the progression of periodontal disease.

A Study on Measurement of Blood Pressure by Partial Least Square Method (부분최소자승법을 이용한 혈압 측정에 관한 연구)

  • Kim, Yong-Joo;Nam, Eun-Hye;Choi, Chang-Hyun;Kim, Jong-Deok
    • Journal of Biosystems Engineering
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    • v.33 no.6
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    • pp.438-445
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    • 2008
  • The purpose of this study was to develop a measurement model based on PLS (Partial least square) method for blood pressures. Measurement system for blood pressure signals consisted of pressure sensor, va interface and embedded module. A mercury sphygmomanometer was connected with the measurement system through 3-way stopcock and used as reference of blood pressures. The blood pressure signals of 20 subjects were measured and tests were repeated 5 times per each subject. Total of 100 data were divided into a calibration set and a prediction set. The PLS models were developed to determine the systolic and the diastolic blood pressures. The PLS models were evaluated by the standard methods of the British Hypertension Society (BHS) protocol and the American Association for the Advancement of Medical Instrumentation (AAMI). The results of the PLS models were compared with those of MAA (maximum amplitude algorithm). The measured blood pressures with PLS method were highly correlated to those with a mercury sphygmomanometer in the systolic ($R^2=0.85$) and the diastolic blood pressure ($R^2=0.84$). The results showed that the PLS models were the effective tools for blood pressure measurements with high accuracy, and satisfied the standards of the BHS protocol and the AAMI.

Lesson with Students Generated Questions: Based on a Department of Health Science (학습자 질문 중심 교수법의 효과: 보건학부를 중심으로)

  • Ahn, Youngmi;Hwang, Sujin
    • The Journal of Korean Academic Society of Nursing Education
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    • v.21 no.2
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    • pp.266-275
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    • 2015
  • Purpose: The aim of this study was to evaluate the effect of student question-centered lessons for bi-directional faculty-student communication. Methods: This study performed one-group pretest-posttest design; participants were university students majoring in health science (nursing 58, physical therapy 45) in city C. Data was collected and the program was conducted from March 3 to June 14, 2014. Measurements employed were the ARCS model of motivational design, self-assertiveness, learning satisfaction, and interpersonal relationship. Data was analyzed through frequency statistics, descriptive statistics, and repeated measurement of one-way analysis of variance with the SPSS 19.0 program. Results: In this student question-centered lesson participants exhibited significant enhanced satisfaction in terms of learning motivation, learning satisfaction, self-assertiveness, behavioral assertiveness, general assertiveness, and sensibility regarding interpersonal relationships. Conclusion: The results suggest that student question-centered lessons are applicable to a variety of subjects. Also, for comparative purposes, a faculty-centered lesson will be undertaken.

Uncertainty evaluation in electrochemical noise resistance measurement (전기화학적 노이즈 저항 측정에서의 불확도 평가)

  • Kim, Jong Jip;Kang, Su Yeon
    • Corrosion Science and Technology
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    • v.12 no.5
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    • pp.220-226
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    • 2013
  • The uncertainty in statistical noise resistance measurement was evaluated for a type 316 stainless steel in NaCl solutions at room temperature. Sensitivity coefficients were determined for measurands or variables such as NaCl concentration, pH, solution temperature, surface roughness, inert gas flow rate and bias potential amplitude. The coefficients were larger for the variables such as NaCl concentration, pH, inert gas flow rate and solution temperature, and they were the major factors increasing the combined standard uncertainty of noise resistance. However, the contribution to the uncertainty in noise resistance measurement from the above variables was remarkably low compared to that from repeated measurements of noise resistance, and thus, it is difficult to lower the uncertainty in noise resistance measurement significantly by lowering the uncertainties related with NaCl concentration, pH, inert gas flow rate and solution temperature. In addition, the uncertainty in noise resistance measurement was high amounting to 17.3 % of the mean, indicating that the reliability in measurement of noise resistance is low.

An Experimental Study on the Characteristics of Rectangular Supersonic Jet on a Flat Plate

  • Kwak, Ji-Young;Lee, Yeol
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.3
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    • pp.324-331
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    • 2016
  • The present study focuses on the characteristics of a supersonic jet flowing from a rectangular nozzle exit on a flat plate. Flow visualization techniques using schlieren and kerosene-lampblack tracing are utilized to investigate shock reflection structures and boundary-layer separations over a flat plate. Wall pressure measurements are also carried out to quantitatively analyze the flow structures. All observations are repeated for multiple jet flow boundary conditions by varying the flap length and nozzle pressure ratio. The experimental results show that the jet flow structures over the flat plate are highly three-dimensional with strong bleeding flows from the plate sides, and that they are sensitive to plate length and nozzle pressure ratio. A multi-component force measurement device is also utilized to observe the characteristics of the jet flow thrust vectoring over the plate. The maximum thrust deflection angle of the jet is about $8^{\circ}$, demonstrating the applicability of thrust vector control via a flat plate installed at the nozzle exit.

A Study on the Uncertainty Estimation of Flowmeter Calibrator with Two Master Flowmeters (2개의 기준유량계를 이용한 유량계 교정장치의 측정불확도 평가에 관한 연구)

  • Choi Jong Oh;Lee Woan Kyu;Lim Ki Won
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.10
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    • pp.1219-1230
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    • 2004
  • Comparing to the gravimetric and volumetric method, the flowmeter calibration based on the master meter method is relatively economical and convenient, especially for high flowrate. The uncertainty of flow quantity and flowrate using the master meter method was evaluated according to the GUM (Guide to the Expression of Uncertainty in Measurement). In order to apply for the wider flow range, two master meters (electromagnetic flow meter) were employed as reference flowmeters. The uncertainty of the master meter was obtained by combining the statistical variation of the repeated measurements and the variation of fluid density and pipe material due to temperature and pressure changes were scrutinized. for a practical application, the uncertainty of calibrator, whose measuring capacity of 1000 ㎥/h obtained by employing two 500 ㎥/h electromagnetic How meters, was evaluated. The uncertainty budget shows the quantitative contribution of each uncertainty component to the overall uncertainty of the calibrator. As a result, it was found that the dominant uncertainties were from the master meter, which was evaluated statistically, and from the process of least squares fitting. On the contrary, the uncertainties arising from the variation of the fluid density and the pipe volume due to the temperature and pressure were negligible.