• Smart Structures and Systems
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• v.24 no.5
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• pp.617-630
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• 2019

Currently most of the vision-based structural identification research focus either on structural input (vehicle location) estimation or on structural output (structural displacement and strain responses) estimation. The structural condition assessment at global level just with the vision-based structural output cannot give a normalized response irrespective of the type and/or load configurations of the vehicles. Combining the vision-based structural input and the structural output from non-contact sensors overcomes the disadvantage given above, while reducing cost, time, labor force including cable wiring work. In conventional traffic monitoring, sometimes traffic closure is essential for bridge structures, which may cause other severe problems such as traffic jams and accidents. In this study, a completely non-contact structural identification system is proposed, and the system mainly targets the identification of bridge unit influence line (UIL) under operational traffic. Both the structural input (vehicle location information) and output (displacement responses) are obtained by only using cameras and computer vision techniques. Multiple cameras are synchronized by audio signal pattern recognition. The proposed system is verified with a laboratory experiment on a scaled bridge model under a small moving truck load and a field application on a footbridge on campus under a moving golf cart load. The UILs are successfully identified in both bridge cases. The pedestrian loads are also estimated with the extracted UIL and the predicted weights of pedestrians are observed to be in acceptable ranges.

• Structural Monitoring and Maintenance
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• v.9 no.3
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• pp.259-270
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• 2022

This study explores the use of the recently developed "strain-sensing smart skin" (S⁴) method for noncontact strain measurements on cement-based samples. S⁴ sensors are single-wall carbon nanotubes dilutely embedded in thin polymer films. Strains transmitted to the nanotubes cause systematic shifts in their near-infrared fluorescence spectra, which are analyzed to deduce local strain values. It is found that with cement-based materials, this method is hampered by spectral interference from structured near-infrared cement luminescence. However, application of an opaque blocking layer between the specimen surface and the nanotube sensing film enables interference-free strain measurements. Tests were performed on cement, mortar, and concrete specimens with such modified S⁴ coatings. When specimens were subjected to uniaxial compressive stress, the spectral peak separations varied linearly and predictably with induced strain. These results demonstrate that S⁴ is a promising emerging technology for measuring strains down to ca. 30 𝜇𝜀 in concrete structures.

• Structural Monitoring and Maintenance
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• v.9 no.2
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• pp.107-127
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• 2022

Structural health monitoring (SHM) has been related to damage identification with either operational loads or other environmental loading playing a significant complimentary role in terms of structural safety. In this study, a non-parametric method of time frequency analysis on the measurement is used to address the time-frequency representation for modal parameter estimation and system damage identification of structure. The method employs the wavelet decomposition of dynamic data by using the modified complex Morlet wavelet with variable central frequency (MCMW+VCF). Through detail discussion on the selection of model parameter in wavelet analysis, the method is applied to study the dynamic response of both steel structure and reinforced concrete frame under white noise excitation as well as earthquake excitation from shaking table test. Application of the method to building earthquake response measurement is also examined. It is shown that by using the spectrogram generated from MCMW+VCF method, with suitable selected model parameter, one can clearly identify the time-varying modal frequency of the reinforced concrete structure under earthquake excitation. Discussions on the advantages and disadvantages of the method through field experiments are also presented.

• Journal of the Korea Society of Computer and Information
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• v.17 no.7
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• pp.97-106
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• 2012

Management of biosignal data in mobile devices causes many problems in real-time transmission of large volume of multimedia data or storage devices. Therefore, this research paper intends to suggest an m-Health system, a clinical data processing system using mobile in order to provide quick medical service. This system deployed health system on IP network, compounded outputs from many bio sensing in remote sites and performed integrated data processing electronically on various bio sensors. The m-health system measures and monitors various biosignals and sends them to data servers of remote hospitals. It is an Android-based mobile application which patients and their family and medical staff can use anywhere anytime. Medical staff access patient data from hospital data servers and provide feedback on medical diagnosis and prescription to patients or users. Video stream for patient monitoring uses a scalable transcoding technique to decides data size appropriate for network traffic and sends video stream, remarkably reducing loads of mobile systems and networks.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.51-60
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• 2016

Consumers who use mobile applications for their skin care are increasing due to increasing interest in skin care and smart phone use. A survey was conducted to select popular skin care mobile applications to be installed in the smart phone targeting 1,000 men and women in South Korea who are interested in their skin care. Questioned items included skin care awareness and recognition, skin care type, and the intention of using skin health care mobile services. The respondents thought the best skin as 'Flawless skin (52.3%)'. Also, 'Skin trouble' and 'Skin aging' were their major concerns. 47.1% of the respondents used mobile skin care applications, and 56.6% intended to try new mobile skin care services. The results on interesting field of skin care showed significant difference depending on gender, marital status, and annual average household income. Moreover, the results on effort made for skin care showed significant difference depending on age, gender, and marital status. They wanted the functions such as 'Review on cosmetic products by brand (23.8%)', 'Self skincare method (16.8%)', 'Continuous monitoring service (16.2%)', 'Information on cosmetic products (13.4%)'. The result of this study would be reliable as basic material for skincare mobile service area. Further studies could be focused on developing application in accordance with needs and how it should be applied.

• Journal of Biomedical Engineering Research
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• v.44 no.5
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• pp.315-323
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• 2023

The objective of this study is to identify the selective application targets for reporting on details of supply of class 1 and 2 medical devices as part of the improvement of the reports on details of supply of medical device system, and to analyze its effectiveness. Therapeutic materials covered by health insurance and secondhand medical devices were chosen based on the transparency of health insurance coverage and the management of medical device distribution. As a result, approximately 85% of groups can be excluded from the reporting requirements compared to reporting all items under Class 1 and 2 medical devices. This is expected to enhance the efficiency of supply reporting tasks. Additionally, the information on supply details managed by the regulatory authority can be utilized for statistical analysis and periodic monitoring, serving as fundamental data for the development of medical device-related policies and research in the field of medical devices.

• Safety and Health at Work
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• v.11 no.3
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• pp.322-334
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• 2020

Background: Spontaneous combustion of coal is one of the factors which causes direct or indirect gas and dust explosion, mine fire, the release of toxic gases, loss of reserve, and loss of miners' life. To avoid these incidents, the prediction of spontaneous combustion is essential. The safety of miner's in the mining field can be assured if the prediction of a coal fire is carried out at an early stage. Method: Adularya Underground Coal Mine which is fully mechanized with longwall mining method was selected as a case study area. The data collected for 2017, by sensors from ten gas monitoring stations were used for the simulation and prediction of a coal fire. In this study, the fuzzy logic model is used because of the uncertainties, nonlinearity, and imprecise variables in the data. For coal fire prediction, CO, O₂, N₂, and temperature were used as input variables whereas fire intensity was considered as the output variable.The simulation of the model is carried out using the Mamdani inference system and run by the Fuzzy Logic Toolbox in MATLAB. Results: The results showed that the fuzzy logic system is more reliable in predicting fire intensity with respect to uncertainties and nonlinearities of the data. It also indicates that the 1409 and 610/2B gas station points have a greater chance of causing spontaneous combustion and therefore require a precautional measure. Conclusion: The fuzzy logic model shows higher probability in predicting fire intensity with the simultaneous application of many variables compared with Graham's index.

• Analytical Science and Technology
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• v.32 no.2
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• pp.35-47
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• 2019

In this study, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to detect 26 antidiabetic compounds in adulterated dietary supplements using a simple, selective method. The work presented herein may help prevent incidents related to food adulteration and restrict the illegal food market. The best separation was obtained on a Shiseido Capcell Pak(R) C18 MG-II ($2.0mm{\times}100mm$, $3{\mu}m$), which improved the peak shape and MS detection sensitivity of the target compounds. A gradient elution system composed of 0.1 % (v/v) formic acid in distilled water and methanol at a flow rate of 0.3 mL/min for 18 min was utilized. A triple quadrupole mass spectrometer with an electrospray ionization source operated in the positive or negative mode was employed as the detector. The developed method was validated as follows: specificity was confirmed in the multiple reaction monitoring mode using the precursor and product ion pairs. For solid samples, LOD ranged from 0.16 to 20.00 ng/mL and LOQ ranged from 0.50 to 60.00 ng/mL, and for liquid samples, LOD ranged from 0.16 to 20.00 ng/mL and LOQ ranged from 0.50 to 60.00 ng/mL. Satisfactory linearity was obtained from calibration curves, with $R^2$ > 0.99. Both intra and inter-day precision were less than 13.19 %. Accuracies ranged from 80.69 to 118.81 % (intra/inter-day), with a stability of less than 14.88 %. Mean recovery was found to be 80.6-119.0 % and less than 13.4 % RSD. Using the validated method, glibenclamide and pioglitazone were simultaneously determined in one capsule at concentrations of 1.52 and 0.53 mg (per capsule), respectively.

• Journal of the Korean Society for information Management
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• v.40 no.4
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• pp.1-31
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• 2023

This study conducted user experience evaluation by introducing various text mining techniques along with topic modeling techniques for mobile menstrual cycle measurement applications that are closely related to women's health and analyzed the results by combining them with a honeycomb model. To evaluate the user experience revealed in the menstrual cycle measurement application review, 47,117 Korean reviews of the menstrual cycle measurement application were collected. Topic modeling analysis was conducted to confirm the overall discourse on the user experience revealed in the review, and text network analysis was conducted to confirm the specific experience of each topic. In addition, sentimental analysis was conducted to understand the emotional experience of users. Based on this, the development strategy of the menstrual cycle measurement application was presented in terms of accuracy, design, monitoring, data management, and user management. As a result of the study, it was confirmed that the accuracy and monitoring function of the menstrual cycle measurement of the application should be improved, and it was observed that various design attempts were required. In addition, the necessity of supplementing personal information and the user's biometric data management method was also confirmed. By exploring the user experience (UX) of the menstrual cycle measurement application in-depth, this study revealed various factors experienced by users and suggested practical improvements to provide a better experience. It is also significant in that it presents a methodology by combines topic modeling and text network analysis techniques so that researchers can closely grasp vast amounts of review data in the process of evaluating user experiences.

• Korean Journal of Veterinary Service
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• v.36 no.3
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• pp.203-208
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• 2013

This survey was conducted to evaluate the microbial contamination level of butcher's shops in Seoul, Korea. For microbial inspections, a total of 584 samples (146 cotton work gloves, 146 utensils and equipments, 154 beef samples, 138 pork samples) were collected from butcher's shops. E. coli and pathogenic bacteria such as Staphylococcus aureus, Yersinia enterocolitica, Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were tested in the samples. As a result, the level of aerobic plate count (APC) ranged ${\leq}10^4\;CFU/cm^2$ from utensils and equipments, $10^1{\sim}10^9$ CFU/glove from cotton work gloves and ${\leq}10^6$ CFU/g from meat. The APC level of E. coli ranged ${\leq}10^1\;CFU/cm^2$ from utensils and equipments, ${\leq}10^5$ CFU/glove from cotton work gloves, and ${\leq}10^3$ CFU/g from meat, respectively. Staphylococcus aureus was detected in 2 beef samples, 1 pork sample, and 10 used cotton work gloves. Yersinia enterocolitica was detected in 3 beef samples, 1 pork sample, and 3 used cotton work gloves. Listeria monocytogenes was detected in 2 used cotton work gloves. In order to improve the sanitation status of butcher's shops, application of HACCP (Hazard Analysis Critical Control Point) or SSOP (Sanitation Standard Operating Procedure), regular hygiene education, and continuous monitoring for microorganisms will be required.