• Title/Summary/Keyword: cross-validation test

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Psychometric Validation of the Malaysian Chinese Version of the EORTC QLQ-C30 in Colorectal Cancer Patients

  • Magaji, Bello Arkilla;Moy, Foong Ming;Roslani, April Camilla;Law, Chee Wei;Sagap, Ismail
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8107-8112
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    • 2016
  • Background and Aims: Colorectal cancer is the second most frequent cancer in Malaysia. We aimed to assess the validity and reliability of the Malaysian Chinese version of European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire core (QLQ-C30) in patients with colorectal cancer. Materials and Methods: Translated versions of the QLQ-C30 were obtained from the EORTC. A cross sectional study design was used to obtain data from patients receiving treatment at two teaching hospitals in Kuala Lumpur, Malaysia. The Malaysian Chinese version of QLQ-C30 was self-administered in 96 patients while the Karnofsky Performance Scales (KPS) was generated by attending surgeons. Statistical analysis included reliability, convergent, discriminate validity, and known-groups comparisons. Statistical significance was based on p value ${\leq}0.05$. Results: The internal consistencies of the Malaysian Chinese version were acceptable [Cronbach's alpha (${\alpha}{\geq}0.70$)] in the global health status/overall quality of life (GHS/QOL), functioning scales except cognitive scale (${\alpha}{\leq}0.32$) in all levels of analysis, and social/family functioning scale (${\alpha}=0.63$) in patients without a stoma. All questionnaire items fulfilled the criteria for convergent and discriminant validity except question number 5, with correlation with role (r = 0.62) and social/family (r = 0.41) functioning higher than with physical functioning scales (r = 0.34). The test-retest coefficients in the GHS/QOL, functioning scales and in most of the symptoms scales were moderate to high (r = 0.58 to 1.00). Patients with a stoma reported statistically significant lower physical functioning (p=0.015), social/family functioning (p=0.013), and higher constipation (p=0.010) and financial difficulty (p=0.037) compared to patients without stoma. There was no significant difference between patients with high and low KPS scores. Conclusions: Malaysian Chinese version of the QLQ-C30 is a valid and reliable measure of HRQOL in patients with colorectal cancer.

Pharmacokinetic and Bioequivalence Study of Zolpidem Tartate in Healthy Volunteers

  • Park, Jun-Sung;Myung, Ja-Hye;Wang, Hun-Sik;Koo, Ja-Seong;Cho, Won-Kyung;Cha, Kwang-Ho;Park, Hee-Jun;Kim, Min-So;Kim, Jeong-Soo;Hwang, Sung-Joo
    • Journal of Pharmaceutical Investigation
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    • v.41 no.3
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    • pp.191-196
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    • 2011
  • In this study simple and sensitive high performance liquid chromatographic method using a commercially available column, was developed and validated for the determination of zolpidem tartrate in human plasma. The developed method with suitable validation was applied to a bioequivalence study of two different kinds of zolpidem tartrate. Two different formulations containing 10 mg of zolpidem tartate (CAS : 99294-93-6) were compared in 24 healthy male volunteers in order to compare the bioavailability and prove the bioequivalence. The study was performed in an open, single dose randomized, 2-sequence, cross-over design in 24 healthy male volunteers with a one-week washout period. Blood samples for pharmacokinetic profiling were drawn at selected times during 12 h. The mean $AUC_{0-12h}$, $C_{max}$, $T_{max}$ and $T_{1/2}$ were $676.6{\pm}223.4$ $ng{\cdot}h{\cdot}mL^{-1}$, $177.4{\pm}34.2$ $ng{\cdot}mL^{-1}$, and $0.8{\pm}0.4$ and $3.5{\pm}2.1$, respectively, for the test formulations, and $640.7{\pm}186.6$ $ng{\cdot}h{\cdot}mL^{-1}$, $193.0{\pm}64.5$ $ng{\cdot}mL^{-1}$, and $0.9{\pm}0.4$ and $2.7{\pm}0.9$, respectively, for the reference formulation. Both primary target parameters $AUC_{0-12h}$ and $C_{max}$ were log-transformed and tested parametrically by analysis of variance (ANOVA). 90% confidence intervals of $AUC_{0-12h}$ and $C_{max}$ were in the range of acceptable limits of bioequivalence (80-125%). Based on these results, the two formulations of zolpidem tartate are considered to be bioequivalent.

Fully Automatic Segmentation of Acute Ischemic Lesions on Diffusion-Weighted Imaging Using Convolutional Neural Networks: Comparison with Conventional Algorithms

  • Ilsang Woo;Areum Lee;Seung Chai Jung;Hyunna Lee;Namkug Kim;Se Jin Cho;Donghyun Kim;Jungbin Lee;Leonard Sunwoo;Dong-Wha Kang
    • Korean Journal of Radiology
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    • v.20 no.8
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    • pp.1275-1284
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    • 2019
  • Objective: To develop algorithms using convolutional neural networks (CNNs) for automatic segmentation of acute ischemic lesions on diffusion-weighted imaging (DWI) and compare them with conventional algorithms, including a thresholding-based segmentation. Materials and Methods: Between September 2005 and August 2015, 429 patients presenting with acute cerebral ischemia (training:validation:test set = 246:89:94) were retrospectively enrolled in this study, which was performed under Institutional Review Board approval. Ground truth segmentations for acute ischemic lesions on DWI were manually drawn under the consensus of two expert radiologists. CNN algorithms were developed using two-dimensional U-Net with squeeze-and-excitation blocks (U-Net) and a DenseNet with squeeze-and-excitation blocks (DenseNet) with squeeze-and-excitation operations for automatic segmentation of acute ischemic lesions on DWI. The CNN algorithms were compared with conventional algorithms based on DWI and the apparent diffusion coefficient (ADC) signal intensity. The performances of the algorithms were assessed using the Dice index with 5-fold cross-validation. The Dice indices were analyzed according to infarct volumes (< 10 mL, ≥ 10 mL), number of infarcts (≤ 5, 6-10, ≥ 11), and b-value of 1000 (b1000) signal intensities (< 50, 50-100, > 100), time intervals to DWI, and DWI protocols. Results: The CNN algorithms were significantly superior to conventional algorithms (p < 0.001). Dice indices for the CNN algorithms were 0.85 for U-Net and DenseNet and 0.86 for an ensemble of U-Net and DenseNet, while the indices were 0.58 for ADC-b1000 and b1000-ADC and 0.52 for the commercial ADC algorithm. The Dice indices for small and large lesions, respectively, were 0.81 and 0.88 with U-Net, 0.80 and 0.88 with DenseNet, and 0.82 and 0.89 with the ensemble of U-Net and DenseNet. The CNN algorithms showed significant differences in Dice indices according to infarct volumes (p < 0.001). Conclusion: The CNN algorithm for automatic segmentation of acute ischemic lesions on DWI achieved Dice indices greater than or equal to 0.85 and showed superior performance to conventional algorithms.

Classification of Mental States Based on Spatiospectral Patterns of Brain Electrical Activity

  • Hwang, Han-Jeong;Lim, Jeong-Hwan;Im, Chang-Hwan
    • Journal of Biomedical Engineering Research
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    • v.33 no.1
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    • pp.15-24
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    • 2012
  • Classification of human thought is an emerging research field that may allow us to understand human brain functions and further develop advanced brain-computer interface (BCI) systems. In the present study, we introduce a new approach to classify various mental states from noninvasive electrophysiological recordings of human brain activity. We utilized the full spatial and spectral information contained in the electroencephalography (EEG) signals recorded while a subject is performing a specific mental task. For this, the EEG data were converted into a 2D spatiospectral pattern map, of which each element was filled with 1, 0, and -1 reflecting the degrees of event-related synchronization (ERS) and event-related desynchronization (ERD). We evaluated the similarity between a current (input) 2D pattern map and the template pattern maps (database), by taking the inner-product of pattern matrices. Then, the current 2D pattern map was assigned to a class that demonstrated the highest similarity value. For the verification of our approach, eight participants took part in the present study; their EEG data were recorded while they performed four different cognitive imagery tasks. Consistent ERS/ERD patterns were observed more frequently between trials in the same class than those in different classes, indicating that these spatiospectral pattern maps could be used to classify different mental states. The classification accuracy was evaluated for each participant from both the proposed approach and a conventional mental state classification method based on the inter-hemispheric spectral power asymmetry, using the leave-one-out cross-validation (LOOCV). An average accuracy of 68.13% (${\pm}9.64%$) was attained for the proposed method; whereas an average accuracy of 57% (${\pm}5.68%$) was attained for the conventional method (significance was assessed by the one-tail paired $t$-test, $p$ < 0.01), showing that the proposed simple classification approach might be one of the promising methods in discriminating various mental states.

Impacts of Sexual Knowledge and Sexual Self-Efficacy on Sexual Autonomy among Middle School Students in a Rural Area (일 지역 중학생의 성지식과 성자기효능감이 성자율성에 미치는 영향)

  • Ahn, Yang Heui;Lim, Young Mi;Kim, KiYon;Kim, Ki-Kyoung;Song, Hee Young
    • Journal of Korean Public Health Nursing
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    • v.29 no.1
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    • pp.90-101
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    • 2015
  • Purpose: The purpose of this study was to investigate impact of sexual knowledge and sexual self-efficacy on sexual autonomy in middle school students in a rural area. Methods: With a cross-sectional descriptive design, 236 second-grade students were recruited from 4 middle schools using convenience sampling. The instrument was a self-administered questionnaire on sexual knowledge, sexual self-efficacy, and sexual autonomy. Data were analyzed using 2-sample t-test, one-way ANOVA, Scheffe, Pearson correlation coefficient, and stepwise regression. Results: Results showed significant positive correlations among sexual knowledge, sexual self-efficacy, and sexual autonomy. Sexual self-efficacy and sexual knowledge explained 37% of the variance in sexual autonomy. Conclusion: Findings of this study suggest that it is relevant to address sexual self-efficacy as well as sexual knowledge in order to increase sexual autonomy in middle school students. Further studies are warranted to investigate these variables with a larger sample and for development and validation of interventions to enhance sexual self-efficacy and sexual autonomy in middle school students.

PowerShell-based Malware Detection Method Using Command Execution Monitoring and Deep Learning (명령 실행 모니터링과 딥 러닝을 이용한 파워셸 기반 악성코드 탐지 방법)

  • Lee, Seung-Hyeon;Moon, Jong-Sub
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.5
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    • pp.1197-1207
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    • 2018
  • PowerShell is command line shell and scripting language, built on the .NET framework, and it has several advantages as an attack tool, including built-in support for Windows, easy code concealment and persistence, and various pen-test frameworks. Accordingly, malwares using PowerShell are increasing rapidly, however, there is a limit to cope with the conventional malware detection technique. In this paper, we propose an improved monitoring method to observe commands executed in the PowerShell and a deep learning based malware classification model that extract features from commands using Convolutional Neural Network(CNN) and send them to Recurrent Neural Network(RNN) according to the order of execution. As a result of testing the proposed model with 5-fold cross validation using 1,916 PowerShell-based malwares collected at malware sharing site and 38,148 benign scripts disclosed by an obfuscation detection study, it shows that the model effectively detects malwares with about 97% True Positive Rate(TPR) and 1% False Positive Rate(FPR).

Application of Cokriging for the Estimation of Groundwater Level Distribution at the Nanjido Waste Landfill Area (난지도 매립지 일대의 지하수위 분포 추정을 위한 복합 크리깅의 응용)

  • 정상용;이강근
    • Journal of the Korean Society of Groundwater Environment
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    • v.2 no.2
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    • pp.58-63
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    • 1995
  • Cokriging was applied for the estimation of the water levels of the basal leachate and the surrounding groundwater at the Nanjido waste landfill area. When the groundwater level is estimated at the high relief area, it makes a good result to use the data of groundwater level and elevation simultaneously because groundwater level is correlated with topography. This study determined the best semivariogram model of 87 groundwater levels and 144 elevations through cross validation test, and produced the contour maps of groundwater levels using ordinary kriging and universal kiging. Two contour maps don't make big difference at the waste site because this area has a large number of groundwater level data. However, they show big difference at the upper left part of the study area because this area has high relief and a small number of sample data. Their difference is also found at the south area near the Han river. When the topography is considered for the both areas, the contour map of cokriging is thought to be closer to the real groundwater distribution than that of kriging.

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A Melon Fruit Grading Machine Using a Miniature VIS/NIR Spectrometer: 1. Calibration Models for the Prediction of Soluble Solids Content and Firmness

  • Suh, Sang-Ryong;Lee, Kyeong-Hwan;Yu, Seung-Hwa;Shin, Hwa-Sun;Choi, Young-Soo;Yoo, Soo-Nam
    • Journal of Biosystems Engineering
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    • v.37 no.3
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    • pp.166-176
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    • 2012
  • Purpose: This study was conducted to investigate the potential of interactance mode of NIR spectroscopy technology for the estimation of soluble solids content (SSC) and firmness of muskmelons. Methods: Melon samples were taken from local greenhouses in three different harvesting seasons (experiments 1, 2, and 3). The fruit attributes were measured at the 6 points on an equator of each sample where the spectral data were collected. The prediction models were developed using the original spectral data and the spectral data sets preprocessed by 20 methods. The performance of the models was compared. Results: In the prediction of SSC, the highest coefficient of determination ($R_{cv}{^2}$) values of the cross-validation was 0.755 (standard error of prediction, SEP=$0.89^{\circ}Brix$) with the preprocessing of normalization with range in experiment 1. The highest coefficient of determination in the robustness tests, $R_{rt}{^2}$=0.650 (SEP=$1.03^{\circ}Brix$), was found when the best model of experiment 3 was evaluated with the data set of experiment 2. The best $R_{cv}{^2}$ for the prediction of firmness was 0.715 (SEP=3.63 N) when no preprocessing was applied in experiment 1. The highest $R_{rt}{^2}$ was 0.404 (SEP=5.30 N) when the best model of experiment 3 was applied to the data set of experiment 1. Conclusions: From the test results, it can be concluded that the interactance mode of VIS/NIR spectroscopy technology has a great potential to measure SSC and firmness of thick-skinned muskmelons.

Bioequivalence of Favid Tablet to Tarivid Tablet (Ofloxacin 100 mg) (타리비드 정(오플록사신 100 mg)에 대한 파비드 정의 생물학적동등성)

  • Park, Wan-Su;Cho, Sung-Hee;Lee, Heon-Woo;Im, Ho-Taek;Hong, Seong-Je;Seo, Seong-Hoon;Rew, Jae-Hwan;Lee, Kyung-Tae
    • Journal of Pharmaceutical Investigation
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    • v.35 no.1
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    • pp.45-50
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    • 2005
  • The purpose of the present study was designed to evaluate the bioequivalence of two ofloxacin tablets, Tarivid (Jeil Pharm. Co., Ltd.) and Favid (ILHWA Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty-four normal male volunteers, $23.67{\pm}3.12$ year in age and $68.50{\pm}7.23$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After four tablets containing 100 mg of ofloxacin were orally administered, blood was taken at predetermined time intervals and concentrations of ofloxacin in plasma were determined using HPLC. Pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$ and untransformed $T_{max}$. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals for the log transformed data were acceptance range of log 0.8 to log 1.25 (e.g., $log0.94{\sim}log1.04\;and\;log0.90{\sim}log1.07\;for\;AUC_t\;and\;C_{max}$, respectively). The major parameters, $AUC_t$, and $C_{max}$, met the criteria of KDFA for bioequivalence indicating that Favid tablet is bioequivalent to Tarivid tablet.

A Study on the Prediction of Power Consumption in the Air-Conditioning System by Using the Gaussian Process (정규 확률과정을 사용한 공조 시스템의 전력 소모량 예측에 관한 연구)

  • Lee, Chang-Yong;Song, Gensoo;Kim, Jinho
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.1
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    • pp.64-72
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    • 2016
  • In this paper, we utilize a Gaussian process to predict the power consumption in the air-conditioning system. As the power consumption in the air-conditioning system takes a form of a time-series and the prediction of the power consumption becomes very important from the perspective of the efficient energy management, it is worth to investigate the time-series model for the prediction of the power consumption. To this end, we apply the Gaussian process to predict the power consumption, in which the Gaussian process provides a prior probability to every possible function and higher probabilities are given to functions that are more likely consistent with the empirical data. We also discuss how to estimate the hyper-parameters, which are parameters in the covariance function of the Gaussian process model. We estimated the hyper-parameters with two different methods (marginal likelihood and leave-one-out cross validation) and obtained a model that pertinently describes the data and the results are more or less independent of the estimation method of hyper-parameters. We validated the prediction results by the error analysis of the mean relative error and the mean absolute error. The mean relative error analysis showed that about 3.4% of the predicted value came from the error, and the mean absolute error analysis confirmed that the error in within the standard deviation of the predicted value. We also adopt the non-parametric Wilcoxon's sign-rank test to assess the fitness of the proposed model and found that the null hypothesis of uniformity was accepted under the significance level of 5%. These results can be applied to a more elaborate control of the power consumption in the air-conditioning system.