• Journal of the Institute of Convergence Signal Processing
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• v.23 no.2
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• pp.107-114
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• 2022

In order to classify 3D film images as right or wrong, it is necessary to detect the pattern in a 3D film image. However, if the contrast of the pixels in the 3D film image is low, it is not easy to classify as the right and wrong 3D film images because the pattern in the image might not be clear. In this paper, we propose a method of classifying 3D film images as right or wrong by comparing the width at a specific frequency of each histogram after obtaining the histogram. Since, it is classified using the width of the histogram, the analysis process is not complicated. From the experiment, the histograms of right and wrong 3D film images were distinctly different, and the proposed algorithm reflects these features, and showed that all 3D film images were accurately classified at a specific frequency of the histogram. The performance of the proposed algorithm was verified to be the best through the comparison test with the other methods such as image subtraction, otsu thresholding, canny edge detection, morphological geodesic active contour, and support vector machines, and it was shown that excellent classification accuracy could be obtained without detecting the patterns in 3D film images.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.127-143
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• 2023

Currently, the domestic traditional market has not escaped the swamp of stagnation that began in the early 2000s despite various projects promoted by many related players such as the central government and local governments. In order to overcome the crisis faced by the traditional market, various R&Ds have recently been conducted on how to build a smart traditional market that combines information and communication technologies such as big data analysis, artificial intelligence, and the Internet of Things. This study analyzes various previous studies, users of traditional markets, and application cases of ICT technology in foreign traditional markets since 2012 and proposes a model to build a smart traditional market using ICT technology based on the analysis. The model proposed in this study includes building a traditional market metaverse that can interact with visitors, certifying visits to traditional markets through digital signage with NFC technology, improving accuracy of fire detection functions using IoT and AI technology, developing smartphone apps for market launch information and event notification, and an e-commerce system. If a smart traditional market platform is implemented and operated based on the smart traditional market platform model presented in this study, it will not only draw interest in the traditional market to MZ generation and foreigners, but also contribute to revitalizing the traditional market in the future.

• Journal of the Korean Geotechnical Society
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• v.23 no.4
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• pp.15-24
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• 2007

Two kinds of temperature monitoring technology have been introduced in this study, which can measure coincidently temperatures at many points along a single length of cable. One is to use a thermal sensor cable comprizing of addressable thermal sensors. The other is to use an optic fiber sensor with Distributed Temperature Sensing (DTS) system. The differences between two technologies can be summarized as follows: A thermal sensor cable has a concept of "point sensing" that can measure temperature only at a predefined position. The accuracy and resolution of temperature measurement are up to the capability of the individual thermal sensor. On the other hand, an optic fiber sensor has a concept of "distributed sensing" because temperature is measured practically at all points along the fiber optic cable by analysing the intensity of Raman back-scattering when a laser pulse travels along the fiber. Thus, the temperature resolution depends on the measuring distance, measuring time and spatial resolution. The purpose of this study is to investigate the applicability of two different temperature monitoring techniques in technical and economical sense. To this end, diverse experiments with two techniques were performed and two techniques are applied under the same condition. Considering the results, the thermal sensor cable will be well applicable to the assessment of groundwater flow, geothermal distribution and grouting efficiency within about loom distance, and the optic fiber sensor will be suitable for long distance such as pipe line inspection, tunnel fire detection and power line monitoring etc.

• Journal of the Korean Society for information Management
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• v.39 no.1
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• pp.91-117
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• 2022

The number of depressed patients in Korea and around the world is rapidly increasing every year. However, most of the mentally ill patients are not aware that they are suffering from the disease, so adequate treatment is not being performed. If depressive symptoms are neglected, it can lead to suicide, anxiety, and other psychological problems. Therefore, early detection and treatment of depression are very important in improving mental health. To improve this problem, this study presented a deep learning-based depression tendency model using Korean social media text. After collecting data from Naver KonwledgeiN, Naver Blog, Hidoc, and Twitter, DSM-5 major depressive disorder diagnosis criteria were used to classify and annotate classes according to the number of depressive symptoms. Afterwards, TF-IDF analysis and simultaneous word analysis were performed to examine the characteristics of each class of the corpus constructed. In addition, word embedding, dictionary-based sentiment analysis, and LDA topic modeling were performed to generate a depression tendency classification model using various text features. Through this, the embedded text, sentiment score, and topic number for each document were calculated and used as text features. As a result, it was confirmed that the highest accuracy rate of 83.28% was achieved when the depression tendency was classified based on the KorBERT algorithm by combining both the emotional score and the topic of the document with the embedded text. This study establishes a classification model for Korean depression trends with improved performance using various text features, and detects potential depressive patients early among Korean online community users, enabling rapid treatment and prevention, thereby enabling the mental health of Korean society. It is significant in that it can help in promotion.

• Analytical Science and Technology
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• v.19 no.3
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• pp.239-243
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• 2006

This method is used for the determination of itraconazole in human plasma by liquid-liquid extraction and high performance liquid chromatography. Felodipine was used as an internal standard. After extraction of the plasma with diethyl ether, the centrifuged upper layer was then transferred. The supernantant was evaporated and then reconsituted with mobile phase. The mobile phase was composed of 10 mM ammonium acetate adjusted to pH 7 by phosphoric acid with a flow rate of 0.2 mL/min. A C18 reversed-phase column with a pre-column was used as the analytial column. Linear detection responses were obtained for itraconzole concentration range for 2~1,000 ng/mL. The correlation coefficient of linear regression($R^2$) was 0.9991, limit of quantification (LOQ) was 2 ng/mL, reproducibility was less than 10.8 %, and accuracy was 97.2~108.2%. This method has been successfully applied to the pharmacokinetic study of itraconazole in human plasma.

• Analytical Science and Technology
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• v.20 no.4
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• pp.347-354
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• 2007

A simple and rapid high-performance liquid chromatography assay for the determination of residual novobiocin levels in bovine, porcine, chicken, flatfish and japanese eel muscle has been developed and validated. The separation condition for HPLC/UV was optimized with phenyl hexyl ($4.6{\times}150mm$, $5{\mu}m$) column with 10 mM monobasic sodium phosphate buffer (pH 2.5)/acetonitrile (50/50, v/v) as the mobile phase at a flow rate of 1.0 mL/min and detection wavelength was set at 254 nm. Residues were extracted from tissue by blending with methanol and lipid materials were removed with n-hexane. Then, the methanol extract was evaporated to dryness under a nitrogen stream, reconstituted in the mobile phase. Aliquot of the organic extract was decanted and filtered through $0.45{\mu}m$ syringe filter. The $20{\mu}L$ of the resulting solution was injected into the HPLC system. The calibration ranges were $0.5{\sim}5{\mu}g/g$ and calibration curves were linear with coefficients of correlation better than 0.95. The limits of quantification were $0.5{\mu}g/g$ for all muscles. The recoveries of bovine, porcine, chicken, flatfish and japaneseel muscles were 99.8%, 102.4%, 91.0%, 104.0% and 93.0%, respectively. The procedures were validated according to the CODEX guideline, determining specificity, linearity, accuracy, precision, quantitation limit and recovery.

• Analytical Science and Technology
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• v.21 no.1
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• pp.41-47
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• 2008

Although liquid-liquid extraction (LLE) method has been used routinely for the analysis of amphetamine-like drugs (amphetamine; AP, methamphetamine; MA, 3,4-methylenedioxyamphetamine; MDA, 3,4-methylenedioxymethamphetamine; MDMA, 3,4-methylenedioxyethylamphetamine; MDEA), a solid-phase extraction (SPE) method, which can be automated, was applied for the simultaneous determination by GC/MS in human urine. Urine samples (3 mL) and 0.1 M phosphate buffer (1 mL, pH 7.0) were extracted by an automated SPE system. The eluent was evaporated, derivatized with trifluoroacetic anhydride (TFAA), and analyzed by GC/MS. The calibration curves was linear with correlation coefficient ($r^2$) above 0.994 in the ranges of 34.0 (AP), 28.0 (MDA)~1000.0 ng/mL for AP, MDA, and 50.0~2000.0 ng/mL for MA, MDMA, and MDEA. The limits of detection ranged from 4.0 to 10.0 ng/mL, and the limits of quantitation ranged from 12.0 to 34.0 ng/mL. The relative recoveries were 93.5~107.7 %. The precisions and accuracies were 1.9~14.8 % and -8.7~14.8 %, respectively. The present method was successfully applied to identify the MA or Ecstasy (MDMA) abusers in exact as well as rapid.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.125-134
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• 2023

Objectives: The aim of the study was to quantify and compare craniofacial asymmetry in subjects with and without symptoms of temporomandibular joint disorders (TMDs). Materials and Methods: A total of 126 adult subjects were categorized into two groups (63 with a TMDs and 63 without a TMDs), based on detection of symptoms using the Temporomandibular Joint Disorder-Diagnostic Index (TMD-DI) questionnaire. Posteroanterior cephalograms of each subject were traced manually and 17 linear and angular measurements were analyzed. Craniofacial asymmetry was quantified by calculating the asymmetry index (AI) of bilateral parameters for both groups. Results: Intra- and intergroup comparisons were analyzed using independent t-test and Mann-Whitney U test, respectively, with a P<0.05 considered statistically significant. An AI for each linear and angular bilateral parameter was calculated; higher asymmetry was found in TMD-positive patients compared with TMD-negative patients. An intergroup comparison of AIs found highly significant differences for the parameters of antegonial notch to horizontal plane distance, jugular point to horizontal plane distance, antegonial notch to menton distance, antegonial notch to vertical plane distance, condylion to vertical plane distance, and angle formed by vertical plane, O point and antegonial notch. Significant deviation of the menton distance from the facial midline was also evident. Conclusion: Greater facial asymmetry was seen in the TMD-positive group compared with the TMD-negative group. The mandibular region was characterized by asymmetries of greater magnitude compared with the maxilla. Patients with facial asymmetry often require management of temporomandibular joint (TMJ) pathology to achieve a stable, functional, and esthetic result. Ignoring the TMJ during treatment or failing to provide proper management of the TMJ and performing only orthognathic surgery may result in worsening of TMJ-associated symptoms (jaw dysfunction and pain) and re-occurrence of asymmetry and malocclusion. Assessments of facial asymmetry should take into account TMJ disorders to improve diagnostic accuracy and treatment outcomes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1A
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• pp.61-73
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• 2009

In this paper, hybrid health monitoring techniques using acceleration-impedance features are newly proposed to detect two damage-type in steel plate-girder bridges, which are girder's stiffness-loss and support perturbation. The hybrid techniques mainly consists of three sequential phases: 1) to alarm the occurrence of damage in global manner, 2) to classify the alarmed damage into subsystems of the structure, and 3) to estimate the classified damage in detail using methods suitable for the subsystems. In the first phase, the global occurrence of damage is alarmed by monitoring changes in acceleration features. In the second phase, the alarmed damage is classified into subsystems by recognizing patterns of impedance features. In the final phase, the location and the extent of damage are estimated by using modal strain energy-based damage index method and root mean square deviation (RMSD) method. The feasibility of the proposed hybrid technique is evaluated on a laboratory-scaled steel plate-girder bridge model for which hybrid acceleration-impedance signatures were measured for several damage scenarios. Also, the effect of temperature on the accuracy of the impedance-based damage monitoring results are experimentally examined from combined scenarios of support damage cases and temperature changes.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.339-347
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• 2023

Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ¹³C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L^-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ¹³C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ¹³C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.