• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.210-217
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• 2015

Fluoride removal by acid and heat treated red mud were studied in batch and column system regarding contact time, initial concentration, pH, adsorbent dose, and filter depth. The results showed that acid treated with 0.8 M HCl, had highest adsorption capacity of fluoride and adsorption capacity decreased as heat treatment temperature increased. Sorption equilibrium reached in 30 min at a initial concentration of 50 mg-F/L but 1 h was required to reach the sorption equilibrium at the initial concentration of 500 mg-F/L by 0.8 M acid treated red mud (0.8 M-ATRM). Equilibrium adsorption data were fitted well to Langmuir isotherm model with maximum fluoride adsorption capacity of 23.162 mg/g. The fluoride adsorption decreased as pH increased due to the fluoride competition for favorable adsorption site with $OH^-$ at higher pH. Removal percentage was increased but the amount of adsorption per unit mass decreased by adding the amount of 0.8 M-ATRM. It was concluded that the 0.8 M-ATRM could be used as a potential adsorbent for the fluoride removal from aqueous solutions because of its high fluoride adsorption capacity and low cost.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.8
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• pp.755-760
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• 2010

In this study, we mainly focused on the PM (Particulate Matter) emission characteristics of a diesel engine. To analyze particle behavior in the tail-pipe, particle emission was measured on the engine-out (downstream of turbocharger), each upstream and downstream both of DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter). Moreover, particle emission contours on each sampling point were constructed. The reduction efficiency of particle number concentration and mass through the DOC and DPF was studied. Parameters such as EGR (Exhaust Gas Recirculation) and the main injection timing were varied in part load conditions and evaluated using the engine-out emissions. The DMS500 (Differential Mobility Spectrometer) was used as a particle measurement instrument that can measure particle concentrations from 5 nm to 1000 nm. Nano-particles of sizes less than 30 nm were reduced by oxidation or coagulated with solid particles in the tail-pipe and DOC. The DPF has a very high filtration efficiency over all operating conditions except during natural regeneration of DPF.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.377-381
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• 2016

The Baermann funnel method requires approximately four Kimwipe tissues for research a nematode count under a stereo microscope. To select more efficient and economical nematode extraction paper for nematode extraction, 15 different kinds of tissue papers were tested and compared with Kimwipe tissues. Nematode species used in the extraction efficiency tests include juvenile (J2) of Heterodera sp., J2 of Meloidogyne sp., Pratylenchus sp., Rhabditis sp., Acrobeloides sp., Panagrolaimus sp., Poikilolaimus sp. and Diplogasterida. The extraction efficiency varied between 42.0 to 88.8%. Considering costs, extraction efficacy, and clarity, the Pulling Kitchen Towel (Monalisa Co., Korea) is the best tissue, with clarity A, isolation efficiency of 69.4% (not significantly different compared to Kimwipe 1 ply 88.8%), and 1/2 costs per isolation of Kimwipe 2 ply.

• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.612-624
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• 2005

In this paper, we propose a surface-based registration using a gaussian weighted distance map for PET-CT brain image fusion. Our method is composed of three main steps: the extraction of feature points, the generation of gaussian weighted distance map, and the measure of similarities based on weight. First, we segment head using the inverse region growing and remove noise segmented with head using region growing-based labeling in PET and CT images, respectively. And then, we extract the feature points of the head using sharpening filter. Second, a gaussian weighted distance map is generated from the feature points in CT images. Thus it leads feature points to robustly converge on the optimal location in a large geometrical displacement. Third, weight-based cross-correlation searches for the optimal location using a gaussian weighted distance map of CT images corresponding to the feature points extracted from PET images. In our experiment, we generate software phantom dataset for evaluating accuracy and robustness of our method, and use clinical dataset for computation time and visual inspection. The accuracy test is performed by evaluating root-mean-square-error using arbitrary transformed software phantom dataset. The robustness test is evaluated whether weight-based cross-correlation achieves maximum at optimal location in software phantom dataset with a large geometrical displacement and noise. Experimental results showed that our method gives more accuracy and robust convergence than the conventional surface-based registration.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.801-806
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• 2022

In the modern era, the necessity of color capability in the digital era is the demand of the era, and research on improving color practice on the subdivided digital four areas that are not in the existing practice is needed. For digital majors who are difficult to solve in existing paint color practice, classes in digital color practice in four more specialized areas are needed, and the use of efficient artificial intelligence was studied for classes in digitized color and color sense. In this paper, we tried to show the expansion of the color practice area by suggesting digital color practice and color matching method based on Photoshop artificial intelligence and big data technology that existing color and color matching were practice that only CMYK could do. In addition, based on the color quantification data of individual users provided by the latest Adobe Sceney program artificial intelligence, the purpose of the practice was to improve learners' predictions of actual color combinations and random colors using filter effects. In conclusion, it is a study on the use of programs that eliminate ambiguity in the mixing process of existing paint practice, secure digital color details, and propose a practical method that can provide effective learning methods for beginners and intermediates to develop their senses through artificial intelligence support. The Adobe program practice method necessary for coloration and main color through theoretical consideration and improvement of teaching skills that are better than existing paint practice were presented.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.1-8
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• 2023

If there is a defect in the wheel bearing, which is a major part of the car, it can cause problems such as traffic accidents. In order to solve this problem, big data is collected and monitoring is conducted to provide early information on the presence or absence of wheel bearing failure and type of failure through predictive diagnosis and management technology. System development is needed. In this paper, to implement such an intelligent wheel hub bearing maintenance system, we develop an embedded system equipped with sensors for monitoring reliability and soundness and algorithms for predictive diagnosis. The algorithm used acquires vibration signals from acceleration sensors installed in wheel bearings and can predict and diagnose failures through big data technology through signal processing techniques, fault frequency analysis, and health characteristic parameter definition. The implemented algorithm applies a stable signal extraction algorithm that can minimize vibration frequency components and maximize vibration components occurring in wheel bearings. In noise removal using a filter, an artificial intelligence-based soundness extraction algorithm is applied, and FFT is applied. The fault frequency was analyzed and the fault was diagnosed by extracting fault characteristic factors. The performance target of this system was over 12,800 ODR, and the target was met through test results.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.1
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• pp.35-42
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• 2018

Objectives: The objectives of this study are to research the usage characteristics of asbestos-containing building materials and to conduct exposure risk assessment by applying no. 2016-230 "Methods of Risk Assessment of Asbestos-Containing Buildings" from the Ministry of Environment. Methods: One hundred buildings located in the Seoul and Gyeonggi-Incheon area were chosen, with 29 in Seoul, 20 in Incheon, and 51 in Gyeonggi-do Province. The year of construction was divided between three buildings in the 1970s, 11 buildings in the 1980s, 42 buildings in the 1990s, and 44 buildings in the 2000s. The bulk samples were analyzed by using a polarizing microscope after a pre-process using a stereomicroscope in a hood with an HEPA filter. This study defined ACMs(asbestos-containing materials) as asbestos when the content percentage was over 1% in the analysis result. Methods and standards of risk assessment of asbestos-containing building materials were conducted by refering to no. 2016-230 "Method of Risk Assessment of Asbestos-Containing Buildings" from the Ministry of Environment. The risk of exposure to ACMs was rated by a score based on three categories(high, middle, low risk of asbestos exposure). Results: In this study, 30 of the 100 buildings and 36 of the 416 bulk samples(8.6%) were found to have had asbestos. Asbestos was detected at a high rate, in 18 out of 42, in buildings constructed in the 1990s and at the lowest rate(7 out of 44) for buildings constructed in the 2000s. As a result of the evaluation according to no. 2016-230 "Method of Risk Assessment of Asbestos-Containing Buildings" of the Ministry of Environment, the risk assessment level of two asbestos-containing building materials was found to be "Medium", and 28 buildings materials were found to be at the "Low" level. Conclusion: As asbestos is regulated by the government, it is required to conduct active management and implemention by introducing methods of risk assessment of asbestos exposure that are supported by data from various situations. In the case of buildings owned by individuals, building owners should be aware of the risk of exposure to asbestos.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.63-76
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• 2018

The purpose of this study was to investigate the effect of contact type textile electrode structure on heart activity signal acquisition for smart healthcare. In this study, we devised six contact type textile electrodes whose electrode size and configuration were manipulated for measuring heart activity signals using computerized embroidery. We detected heart activity signals using a modified lead II and by attaching each textile electrode to the chest band in four healthy male subjects in a standing static posture. We measured the signals four times repeatedly for all types of electrodes. The heart activity signals were sampled at 1 kHz using a BIOPAC ECG100, and the detected original signals were filtered through a band-pass filter. To compare the performance of heart activity signal acquisition among the different structures of the textile electrodes, we conducted a qualitative analysis using signal waveform and size as parameters. In addition, we performed a quantitative analysis by calculating signal power ratio (SPR) of the heart activity signals obtained through each electrode. We analyzed differences in the performance of heart activity signal acquisition of the six electrodes by performing difference and post-hoc tests using nonparametric statistic methods on the calculated SPR. The results showed a significant difference both in terms of qualitative and quantitative aspects of heart activity signals among the tested contact type textile electrodes. Regarding the configurations of the contact type textile electrodes, the three-dimensionally inflated electrode (3DIE) was found to obtain better quality signals than the flat electrode. However, regarding the electrode size, no significant difference was found in performance of heart signal acquisition for the three electrode sizes. These results suggest that the configuration method (flat/3DIE), which is one of the two requirements of a contact type textile electrode structure for heart activity signal acquisition, has a critical effect on the performance of heart activity signal acquisition for wearable healthcare. Based on the results of this study, we plan to develop a smart clothing technology that can monitor high-quality heart activity without time and space constraints by implementing a clothing platform integrated with the textile electrode and developing a performance improvement plan.