• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.2
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• pp.78-83
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• 2009

In this paper, a novel method for data hiding into binary images is proposed. Binary image has two tones: black and white. For this reason, it is not easy to hide messages into binary images. PWLC (pair-wise logical computation) is a new method to hide message into binary images. However, it yields images of unacceptable quality and its decoding process is unclear. Therefore, in order to solve this problem, we adopt the run-length method to achieve advanced reversible data hiding. That is, we find a proper region to hide messages to reduce visual degradation. In this paper, we introduce an improved procedure to hide messages into binary images.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.4
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• pp.530-541
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• 2008

The early stage of 3D anthropometry data has been used to obtain qualitative rather than quantitative information. However recent 3D body scanners as a common research tool for anthropormatric measurments have made it possible to obtain body surface data of sufficient resolution and accuracy. The purpose of this study is finally to develop motorcycle jacket for enhanced comfort and fit, to test the accuracy and reliability of 3D measurments of motorcycle riding posture, and to analyze the change in 20's adult male's body surface measurements between the standard anthropometric position and motorcycle riding posture. The results of this study were as follows: There were no significant differences between the study and Size Korea measurments in total traditional measuring items and most of measuring items, such as length, circumference antropometric items and interscye items though not waist back length and upper arm circumference. A comparison of 3D body surface measurments in the two different measuring postures, the bodysurface measurments such as waist front length, biacromion length, front interscye, arm length, underarm length in the motorcycle riding posture decreased than that in basic posture, whereas waist back length, back interscye, C.T.W length increased. The body surface measurments such as chest, bust, upper circumference in the motorcycle riding posture decreased than that in basic posture, whereas neck, waist, hip, elbow circumference increased.

• Journal of the Korean Data and Information Science Society
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• v.27 no.6
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• pp.1487-1498
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• 2016

In monitoring a process, in-control process parameters must be estimated from the Phase I data. When we design the control chart based on the estimated process parameters, the control limits are usually chosen to satisfy a specific in-control average run length (ARL). However, as the run length distribution is skewed when the process is either in-control or out-of-control, the median run length (MRL) can be used as alternative measure instead of the ARL. In this paper, we evaluate the performance of Shewhart $\bar{X}$ chart with estimated parameters in terms of the average of median run length (AMRL) and the standard deviation of MRL (SDMRL) metrics. In simualtion study, the grand sample mean is used as a process mean estimator, and several competing process standard deviation estimators are used to evaluate the in-control performance for various amounts of Phase I data.

• Childhood Kidney Diseases
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• v.19 no.2
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• pp.131-135
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• 2015

Purpose: The aim of this study was to establish a simple formula to predict renal length in children using a Technesium-99m dimercaptosuccinic acid (DMSA) scan data, and to compare it with the formula derived from ultrasonography, which is widely accepted. Methods: Children who underwent a DMSA scan and ultrasonography were reviewed retrospectively, and those who had anatomical urinary tract abnormalities or urinary tract infections were excluded. Results: A total of 230 children (84 males and 146 females; age, 1 month to 16 years; mean age, $16.8{\pm}27.4$ months). Mean renal length measured by DMSA scan was longer than that by ultrasonography ($6.38{\pm}1.16$ vs. $6.02{\pm}1.14cm$; P < 0.001). Renal length was correlated with age, weight, height, and body surface area on the DMSA scan and ultrasonography, and showed the strongest positive correlation with height. The following formulae were established to predict renal length: mean renal length (cm) = 5.433 ${\times}$ height (m) + 2.330 (R2, 0.833) using the DMSA scan data, and mean renal length (cm) = 5.367 ${\times}$ height (m) + 2.027 (R2, 0.853) using ultrasonography data. Conclusion: We propose a simple height-based formula to predict renal length in children using a DMSA scan data, and validate it by comparing with ultrasonography formula.

• Journal of Fashion Business
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• v.13 no.6
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• pp.76-88
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• 2009

This study has the purposes to search the most visually effective and appropriate number of pleats and skirt length, when it's worn, with the changes in the number of pleats and skirt length that could be influential in analyzing the visual evaluation of pleats skirt and to analyze the changes when those factors are applied in real pattern. The stimuli were 18 samples: 6 variations of the number of pleats and 3 variations of the length of skirt. The data were obtained from 54 fashion design majors. The data were analyzed by Factor Analysis, Anova, Scheffe's Test and the MCA method. The results of the study were as follows: The visual image by the number of pleats and the length of skirt were composed of 4 factors : activity, attraction, neatness and commonness. In these factors, activity factor was estimated by the most important factor. The visual image according to the changes in the number of pleats and skirt length had significant differences, and the pleats skirts with 12 and 16 number of pleats and 38cm of skirt length were evaluated to be the most effective. The activity factor had interaction influence effect according to the number of pleats and the skirt length. The skirt length had more influence than the number of pleats in attraction and neatness factors, and the other way around for commonness factor.

• Physical Therapy Korea
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• v.3 no.2
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• pp.36-41
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• 1996

The purpose of this study was to determine whether the biomechanical variables of the walking patterns of the obese children compared with those of normal children would revealing significant differences. Normal(N=25) and obese(N=19) subjects were screened based on a health record which was examined to eliminate any subjects who had any pathological condition related to their gait. Data for a minimum of 5 repeated walking trials were collected using a stop watch and a tape measure. Basic kinematic analyses yielded data based on the following variables : stride length divided by leg length, and cadence divided by leg length. This measurement data was classified by the Obesity Index calculated from by height, weight data. Results showed no significant difference among normal, obese and subjects(p>.05). Difficulties in formulating the experimental condition and poor equipment quality are thought to be reason for the inconclusive results. Future studies might include medical complications such as tibia vara, genu valgum, other diseases caused by obesity.

• Korean Journal of Radiology
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• v.24 no.4
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• pp.284-293
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• 2023

Objective: To validate a simplified ordinal scoring method, referred to as modified length-based grading, for assessing coronary artery calcium (CAC) severity on non-electrocardiogram (ECG)-gated chest computed tomography (CT). Materials and Methods: This retrospective study enrolled 120 patients (mean age ± standard deviation [SD], 63.1 ± 14.5 years; male, 64) who underwent both non-ECG-gated chest CT and ECG-gated cardiac CT between January 2011 and December 2021. Six radiologists independently assessed CAC severity on chest CT using two scoring methods (visual assessment and modified length-based grading) and categorized the results as none, mild, moderate, or severe. The CAC category on cardiac CT assessed using the Agatston score was used as the reference standard. Agreement among the six observers for CAC category classification was assessed using Fleiss kappa statistics. Agreement between CAC categories on chest CT obtained using either method and the Agatston score categories on cardiac CT was assessed using Cohen's kappa. The time taken to evaluate CAC grading was compared between the observers and two grading methods. Results: For differentiation of the four CAC categories, interobserver agreement was moderate for visual assessment (Fleiss kappa, 0.553 [95% confidence interval {CI}: 0.496-0.610]) and good for modified length-based grading (Fleiss kappa, 0.695 [95% CI: 0.636-0.754]). The modified length-based grading demonstrated better agreement with the reference standard categorization with cardiac CT than visual assessment (Cohen's kappa, 0.565 [95% CI: 0.511-0.619 for visual assessment vs. 0.695 [95% CI: 0.638-0.752] for modified length-based grading). The overall time for evaluating CAC grading was slightly shorter in visual assessment (mean ± SD, 41.8 ± 38.9 s) than in modified length-based grading (43.5 ± 33.2 s) (P < 0.001). Conclusion: The modified length-based grading worked well for evaluating CAC on non-ECG-gated chest CT with better interobserver agreement and agreement with cardiac CT than visual assessment.

• Journal of Internet Computing and Services
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• v.25 no.4
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• pp.47-56
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• 2024

This paper proposes a method for fine-tuning BERT-based natural language processing models to perform sentiment analysis on Korean review data. By varying the input sequence length during this process and comparing the performance, we aim to explore the optimal performance according to the input sequence length. For this purpose, text review data collected from the clothing shopping platform M was utilized. Through web scraping, review data was collected. During the data preprocessing stage, positive and negative satisfaction scores were recalibrated to improve the accuracy of the analysis. Specifically, the GPT-4 API was used to reset the labels to reflect the actual sentiment of the review texts, and data imbalance issues were addressed by adjusting the data to 6:4 ratio. The reviews on the clothing shopping platform averaged about 12 tokens in length, and to provide the optimal model suitable for this, five BERT-based pre-trained models were used in the modeling stage, focusing on input sequence length and memory usage for performance comparison. The experimental results indicated that an input sequence length of 64 generally exhibited the most appropriate performance and memory usage. In particular, the KcELECTRA model showed optimal performance and memory usage at an input sequence length of 64, achieving higher than 92% accuracy and reliability in sentiment analysis of Korean review data. Furthermore, by utilizing BERTopic, we provide a Korean review sentiment analysis process that classifies new incoming review data by category and extracts sentiment scores for each category using the final constructed model.

• Health Policy and Management
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• v.28 no.2
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• pp.178-185
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• 2018

Background: We investigated association between introduction of the diagnosis-related groups (DRG) system for anal operation and length of stay. Also, we investigated how it is different among hospitals with longer length of stay and among hospitals with shorter length of stay before introduction of the DRG system. Methods: We used data from Health Insurance Review and Assessment which were national health insurance claim data. Total 13,111 cases of anal surgery cases were included which were claimed by hospitals since July 2012 to June 2014. Two-level multivariable regression was conducted to analysis the association between length of stay and characteristics of hospital and patient. Results: Before introducing DRGs, the average length of stay was 5.41 days. After introducing DRGs, average length of stay was decreased to 3.92 days. After introducing DRGs, length of stay has decreased (${\beta}=-1.0450$, p<0.0001) and it was statistically significant. Among hospitals which had short length of stay (shorter than mean of length of stay) before introducing DRGs, effect of introducing DRGs was smaller (${\beta}=-0.4282$, p<0.0001). On contrary, among hospitals which had long length of stay (longer than mean of length of stay) before introducing DRGs, effect of introducing DRGs was bigger (${\beta}=-1.8280$, p<0.0001). Conclusion: Introducing DRGs was more effective to hospitals which had long length of stay before introducing DRGs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.4
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• pp.265-275
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• 2005

A prerequisite for deriving the abundance estimates from acoustic surveys for commercially important fish species is the identification of target strength measurements for selected fish species. In relation to these needs, the goal of this study was to construct a data bank for converting the acoustic measurements of target strength to biological estimates of fish length and to simultaneously obtain the target strength-fish length relationship. Laboratory measurements of target strength on 15 commercially important fish species were carried out at five frequencies of 50, 70, 75, 120 and 200 kHz by single and split beam methods under the controlled conditions of the fresh and the sea water tanks with the 389 samples of dead and live fishes. The target strength pattern on individual fish of each species was measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down aspect) to $+45^{\circ}$ (head up aspect) in $0.2^{\circ}$ intervals, and the averaged target strength was estimated by assuming the tilt angle distribution as N $(-5.0^{\circ},\;15.0^{\circ})$. The TS to fish length relationship for each species was independently derived by a least-squares fitting procedure. Also, a linear regression analysis for all species was performed to reduce the data to a set of empirical equations showing the variation of target strength to a fish length, wavelength and fish species. For four of the frequencies (50, 75, 120 and 200 kHz), an empirical model for fish target strength (TS, dB) averaged over the dorsal sapect of 602 fishes of 10 species and which spans the fish length (L, m) to wavelength (\Lambda,\;m)$ ratio between 5 and 73 was derived: $TS=19.44\;Log(L)+0.56\;Log(\Lambda)-30.9,\;(r^2=0.53)$.