• Communications for Statistical Applications and Methods
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• v.26 no.2
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• pp.91-102
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• 2019

In this paper, we propose a new estimation method based on a weighted linear regression framework to obtain some estimators for unknown parameters in a two-parameter Rayleigh distribution under a progressive Type-II censoring scheme. We also provide unbiased estimators of the location parameter and scale parameter which have a nuisance parameter, and an estimator based on a pivotal quantity which does not depend on the other parameter. The proposed weighted least square estimator (WLSE) of the location parameter is not dependent on the scale parameter. In addition, the WLSE of the scale parameter is not dependent on the location parameter. The results are compared with the maximum likelihood method and pivot-based estimation method. The assessments and comparisons are done using Monte Carlo simulations and real data analysis. The simulation results show that the estimators ${\hat{\mu}}_u({\hat{\theta}}_p)$ and ${\hat{\theta}}_p({\hat{\mu}}_u)$ are superior to the other estimators in terms of the mean squared error (MSE) and bias.

• Journal of Korean society of Dental Hygiene
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• v.15 no.1
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• pp.91-99
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• 2015

Objectives: The purpose of the study was to investigate the relationship between internet addiction and health in dental hygiene students. Methods: A self-reported questionnaire was completed by 216 dental hygiene students in Daegu from June 9 to 13, 2014. Data were analyzed by descriptive statistics, t-test, and ANOVA using SAS 9.2 program. The instruments included Korean internet addiction scale(K scale) and Korean version of the general health questionnaire. General characteristics consisted of grade, religion, residential types, economic condition, place of internet use, duration, purpose, and time of use. Physical characteristics consisted of subjective physical condition, smoking, alcohol drinking, exercise above twice per week, musculoskeletal disease, and location of physical symptoms. Psychiatric scale and 6 questions of physical characteristics were consulted by the statistician of preventive medicine department. Results: Internet users over 4 hours manifested the poor mental health, while those who uses internet under 2 hours showed good mental health(F = 1.41, p < 0.01). The students having good physical condition showed better mental health than those with poor physical condition(t = -2.81, p < 0.01). The students exercising at least twice a week showed better mental health than those who do not exercise(t = -3.10, p < 0.01). Those who having musculoskeletal symptoms showed higher index of internet addiction score than those who do not(t = 4.21, p < 0.01). Those who have no musculoskeletal symptoms tended to have better mental health than those who have musculoskeletal symptoms(t = 2.28, p < 0.05). The variables correlated to mental health were internet addiction, subjective physical condition, and exercise at least twice a week. The severity level of internet addiction leads to poor mental health(r = 0.26, p < 0.001). Conclusions: Internet addiction is closely related to mental health. So the students must know the danger of internet addiction. Proper health education is necessary for the prevention of addiction symptoms.

• Journal of Pharmacopuncture
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• v.24 no.2
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• pp.41-53
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• 2021

Objectives: Cesarean sections are one of the common surgical procedures around the world. Management of cesarean section side effects, including pain, hematoma, delayed wound healing, is of particular importance in maintaining maternal health and ability to care for the baby. The tendency to use complementary medicine strategies is on the rise because of the easy treatment with low side effects. The purpose of this study was to systematically review the efficacy and safety of clinical trials performed in Iran and worldwide on the effect of complementary medicine on pain relief and wound healing after cesarean section. Methods: PRISMA checklist was followed to prepare the report of this systematic review. The search process was carried out on databases on databases of Magiran, SID, Iran Medex, Scopus, Pub Med, Science direct, Medline and Cochrane library using keywords of cesarean, pain, wound healing, Herbal medicine, acupressure, massage, complementary medicine and their Persian equivalent and all possible combinations, from inception until February 2020. We used the Jadad scale to assess the quality of the searched articles. According to the Jadad scale, the articles with a score of at least 3 were included in the study. Results: Finally, 28 clinical trials (with a sample size of 3,245) scored at least 3 on the Jadad scale were included into the analysis. This article reviewed 13 articles on medicinal herbs, 4 articles on massage, 1 article on reflexology, 2 articles on acupressure. Conclusion: According to the present review, the use of medicinal herbs was the most common method of complementary medicine in pain relief and wound healing after cesarean section.

• Journal of Korean Neurosurgical Society
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• v.67 no.2
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• pp.217-226
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• 2024

Objective : The efficacy of sciatic nerve decompression via transgluteal approach for entrapment of the sciatic nerve at the greater sciatic notch, called piriformis syndrome, and factors affecting the surgical outcome were analyzed. Methods : The outcome of pain reduction was analyzed in 81 patients with sciatic nerve entrapment who underwent decompression through a transgluteal approach. The patients were followed up for at least 6 months. The degree of pain reduction was analyzed using a numerical rating scale-11 (NRS-11) score and percent pain relief before and after last follow-up following surgery. Success was defined by at least 50% reduction in pain measured via NRS-11. To assess the degree of subjective satisfaction, a 10-point Likert scale was used. In addition, demographic characteristics, anatomical variations, and variations in surgical technique involving sacrotuberous ligamentectomy were analyzed as factors that affect the surgical outcome. Results : At a follow-up of 17.5±12.5 months, sciatic nerve decompression was successful in 50 of 81 patients (61.7%), and the pain relief rate was 43.9±34.17. Subjective improvement based on a 10-point Likert scale was 4.90±3.43. Among the factors that affect the surgical outcome, only additional division of the sacrotuberous ligament during piriformis muscle resection played a significant role. The success rate was higher in the scarotuberous ligementectomy group (79.4%) than in the non-resection group (42.6%), resulting in statistically significant difference based on average NRS-11 score, percent pain relief, and subjective improvement (p<0.05, independent t-test). Conclusion : Sciatic nerve decompression is effective in pain relief in chronic sciatica due to sciatic nerve entrapment at the greater sciatic notch. Its effect was further enhanced by circumferential dissection of the sciatic nerve based on the compartment formed by the piriformis muscle and the sacrotuberous ligament in the greater sciatic notch.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.706-712
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• 2006

Recursive Partial Least Squares(RPLS) method has been used for processing the on-line available multivariate chemical process data and modeling adaptive prediction model for process changes. However, RPLS method is unstable in PLS model updating because RPLS method updates PLS model by merging past PLS model and new data. In this study, Adaptive Predictive Partial Least Squres(APPLS) method is suggested for more sensitive adaptation to process changes. By expanding APPLS method, block-wise Adaptive Predictive Partial Least Squares(block-wise APPLS) method is suggested for a lager scale data of chemical processes. APPLS method has been applied to predict the reactor properties and the product quality of a direct esterification reactor for polyethylene terephthalate(PTT), and block-wise APPLS method has been applied to predict the cetane number using NIR Diesel Spectra data. APPLS and block-wise APPLS methods show better prediction and updating performance than RPLS method.

• Journal of the Korea Concrete Institute
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• v.11 no.4
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• pp.43-54
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• 1999

Shear tests are performed on four full-scale 12.5 m proto-type models, "least depth double tee," which are resulted from the optimization process. Domestic superimposed live load regulation, domestic material properties which is available to product. Korean building code requirements, construction environments and economy are considered as the main factors to establish the process. All of the specimens tested fully comply with the shear strength requirements as specified by ACI 318-95. The research has shown following results. 1) The development length requirement of ACI 318-95 does not seem a good predictor for the estimation of bond failure in a beam with the strands below the supports. 2) The load required for the first initial coner cracking in the dap end and first web shear cracking does not seem to have any relation with the dimension and shear strength of the section in the test beams. 3) The strand slip has a direct relationship with the web shear cracking. However, the coner cracking in the dap end does not give any help for the slip in anchorage. 4) Use of whole area for bearing steel at the bottom of dap end is desired for safe bearing pressure design in the precast prestressed double tee beams. 5) The deflection of beam influences directly on the amount of strand slip at the anchorage after initiation of it, and relationship between them are very linear.

• Journal of the Korean Statistical Society
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• v.10
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• pp.105-121
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• 1981

The problem of selection of a subset containing the largest of several slope parameters of regression equations is considered. The proposed selection procedure is based on the weighted median estimators for regression parameters and the median of rescaled absolute residuals for scale parameters. Those estimators are compared with the classical least squares estimators by a simulation study. A Monte Carlo comparison is also made between the new procedure based on the weighted median estiamtors and the procedure based on the least squares estimators. The results show that the proposed procedure is quite robust with respect to the heaviness of distribution tails.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.186-191
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• 2017

An integrated pressure-sensor system was developed using the sensor-conditioning processes, which resulted in the optimum sensitivity of the pressure-sensor through the signal amplification, noise reduction, and level shift. Due to the specified characteristics among the components, such as operation range, the sensor output was generally limited compared to the full scale of the reading when coupled with other parts. Devices fabricated exhibited comparable characteristics with higher pressure sensitivity to that of the pressure sensor without sensor-conditioning process. In this work, the sensor resolution was at least enhanced at least by 25% using the sensor-conditioning processes.

• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.595-601
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• 2003

In this paper we propose an on line training method for classification based on least squares support vector machine. Proposed method enables the computation cost to be reduced and the training to be peformed incrementally, With the incremental formulation of an inverse matrix in optimization problem, current information and new input data can be used for building the new inverse matrix for the estimation of the optimal bias and Lagrange multipliers, so the large scale matrix inversion operation can be avoided. Numerical examples are included which indicate the performance of proposed algorithm.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.4
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• pp.44-50
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• 2011

This paper presents the algorithm for attitude determination of an aircraft using binary image. An image feature vector, which is invariant to translation, scale and rotation, is constructed to capture the functional relations between the feature vector and the corresponding aircraft attitude. An iterated least squares method is suggested for estimating the attitude of given aircraft using the constructed feature vector library. Simulation results show that the proposed algorithm yields good estimates of aircraft attitude in most viewing range, although a relatively large error occurs in some limited viewing direction.