• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.215-221
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• 2006

This research presents results from laboratory and pilot-scale experiments to remove high-nitrate in pickling wastewater using the sequencing batch reactor (SBR) as a biological method. During the experimental periods, the influent concentrations of NOx-N and $Ca^{+2}$ were analyzed to be 350-1,600 and 700-800 mg/L, respectively. In order to provide carbon source for denitrification, methanol has been added in proportion to the influent nitrate loading. The mean concentrations of MLSS and MLVSS, the fraction of volatile solids in sludge and the sludge volume index were measured to be 27 g/L, 5 g/L, 18.5% and 7.5, respectively. The solid retention time was kept in the range of 18 to 22 days, specific denitrification rate ($U_{dn}$) was $0.301g{NO_3}^--N/gVSS/day$. The oxidized nitrogen concentration of effluent ranged 2-34 mg/L with an average of 5.2 mg/L, the overall reduction in total nitrogen was more than 99.2%. In order to treat the pickling wastewater including the high concentration of nitrate and $Ca^{+2}$, the continuous flow process is not suitable because the specific gravity of the sludge is considerably increased by $Ca^{+2}$, thus the SBR process is shown to be very effective to treat the pickling wastewater.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.92-95
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• 1999

The patients with prolonged air leak after lung resection surgery were generally treated by pleurodesis with sclerosing agents such as talc, tetracyclin, doxycyclin, bleomycin, vibramycin, and OK432. However, for the case like dead space resulted by incomplete reexpansion of the remaining lung, chemical pleurodesis has shown to be not as effective as expected. If the patients keep the chest tube for long period of time, the risk of thoracic empyema would increase. Most thoracic surgeons have experienced prolonged airleak which developed after lung resection. Pleurodesis with autoblood was reported as an effective method in treatment of patients with prolonged airleak. The mechanism of blood pleurodesis may be direct obliteration of BPF and reduction of dead space by clot. Therefore we successfully treated the two patients with prolonged airleak using the autoblood plus OK432 or vibramycin.

• Smart Structures and Systems
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• v.26 no.3
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• pp.345-360
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• 2020

Modern swarm intelligence heuristic search methods are widely applied in the field of structural health monitoring due to their advantages of excellent global search capacity, loose requirement of initial guess and ease of computational implementation etc. To this end, a hybrid strategy is proposed based on butterfly optimization algorithm (BOA) and differential evolution (DE) with purpose of effective combination of their merits. In the proposed identification strategy, two improvements including mutation and crossover operations of DE, and dynamic adaptive operators are introduced into original BOA to reduce the risk to be trapped in local optimum and increase global search capability. The performance of the proposed algorithm, hybrid butterfly optimization and differential evolution algorithm (HBODEA) is evaluated by two numerical examples of a simply supported beam and a 37-bar truss structure, as well as an experimental test of 8-story shear-type steel frame structure in the laboratory. Compared with BOA and DE, the numerical and experimental results show that the proposed HBODEA is more robust to detect the reduction of stiffness with limited sensors and contaminated measurements. In addition, the effect of search space, two dynamic operators, population size on identification accuracy and efficiency of the proposed identification strategy are further investigated.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.5
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• pp.1033-1047
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• 2017

Traditional explicit authentication, which requires awareness of the user's authentication process, is a burden on the user, which is one of main reasons why users tend not to employ authentication. In this paper, we try to reduce such cost by employing implicit authentication methods, such as biometrics and location based authentication methods. We define the 4-level security assurance model, where each level is mapped to an explicit authentication method. We implement our model as an Android application, where the implicit authentication methods are touch-stroke dynamics-based, face recognition based, and the location based authentication. From user experiment, we could show that the authentication cost is reduced by 14.9% compared to password authentication-only case and by 21.7% compared to the case where 6-digit PIN authentication is solely used.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.151-157
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• 2020

Harmful aquatic organisms introduced by ship movement cause marine ecosystem disturbances and are in the form of ballastwater and biofouling. Harmful marine life from ballastwater has been considerably reduced because mandatory treatment on all vessels is required to install onboard vessels. However, there remains risk of migration because biofouling is recommended to countries for management through the IMO guidelines. In particular, biofouling management has recently attracted attention for achieving IMO GHG reduction targets because it contributes to energy efficiency, as well as there are reasons for marine ecosystem protection. In recent years, increasing international consensus on the need for biofouling management is likely to lead to enforcement regulations. Thus, this study suggests the management method of hull attachment organisms in Korea, focusing on the cases of foreign countries that have regulated hull attachment organisms.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.4
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• pp.393-405
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• 2018

Objective: This study examines the types of hazardous factors in the working environment and the time-trend for their exposure levels over 10 years (2007 to 2016). Study Design and Method: The types of hazardous factors and exposure levels were drawn from the 19 measurement reports on the working environment over 10 years at a shock absorber manufacturing facility. Risk assessment of the types of factors and time-trend of exposure levels were evaluated using the factors and exposure levels. Results: A total of 34 hazardous factors were evaluated. The types were noise, 15 organic compounds, seven kinds of acid sand alkalis, eight kinds of heavy metals, and three other compounds. Special management materials used were nickel, hexavalent chrome, and sulfuric acid. Human carcinogens (1A) used were trichloroethylene, nickel, and sulfuric acid. There were six types of substances belonging to the IARC's 2B (body carcinogens) classification or higher, including, methyl isobutyl ketone, ethyl benzene, and trichloroethylene. No detection was found for 627 out of the 2065 total measurements in 19 exposure survey reports, representing 30.4%. Organic solvents, acid and alkali products, and heavy metals showed continuous low exposure concentrations. Noise, welding fumes, and the evaluation of mixed solvents show a gradual decrease in geometric mean and maximum over the time-trend of 10 years. Conclusions: In the case of a shock absorber manufacturing facility, the hazardous factors of noise and the evaluation of mixed solvents still indicate high concentrations exceeding the exposure limits and necessitate reduction studies. These two factors and welding fumes showed a continuous decrease in their ten-year tendency. Organic compounds, acids/alkalis, and heavy metals were managed smoothly in a work environment of continuous low concentrations.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.33 no.1
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• pp.2-15
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• 2022

Objectives: Children with attention-deficit/hyperactivity disorder (ADHD) tend to be noisy and violate rules with their disruptive behaviors, resulting in greater difficulties with off-task behaviors and being at risk for social refusal. The visual activity schedule (VAS) intervention program is a frequently used method to teach multiple skills involving on-task, use of schedules, transition behaviors, social initiation, independent play skills, classroom skills, and academic skills. The current systematic review aimed to examine the efficacy of using VAS intervention in reducing problem behaviors in children with ADHD between 5 and 12 years of age. Methods: Systematic searches were conducted using two electronic databases (PubMed and Scopus) to identify relevant studies published in English between 2010 and 2020. Four studies met the inclusion criteria: two studies examined the effect of schedule-based tasks and the use of an iPad on classroom skills, while the other two examined randomized clinical trials (RCTs) of psychosocial treatment for ADHD inattentive type and a cross-sectional study examined the impact of the group size on task behavior and work productivity in children with ADHD. Results: The findings indicate that the interventions used in all four studies could lead to increased satisfaction among participants and parents, as well as a reduction in problem behavior. In terms of the research indicators, the RCT had low quality, while the others were of high quality. Conclusion: A larger number of studies and the ADHD clinical population would help to increase the generalizability of future reviews of treatments in this context.

• Journal of Yeungnam Medical Science
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• v.40 no.1
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• pp.78-85
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• 2023

Background: Poor sleep quality is associated with psychoactive substance abuse/addiction/withdrawal. Auricular acupuncture (AA) is a nonpharmacological method used for the treatment of sleep disturbances. This study aimed to examine the quality of sleep before and after AA in participants with mental and behavioral disorders due to prior multiple drug use in the therapeutic community. Methods: This was a consecutive case series of 27 participants (25 male [92.6%]). The median age was 35.0 years (interquartile range [IQR], 29.0-37.2 years), methadone/buprenorphine were not used, and the participants were treated with AA (median number of treatments, 15.0 [IQR, 12.0-18.0]) during a median period of 51.0 days (IQR, 49.0-51.0 days) according to the National Acupuncture Detoxification Association (NADA)-Acudetox protocol. Sleep quality was determined using the Pittsburgh Sleep Quality Index (PSQI), a self-rated questionnaire that assesses sleep quality and disturbances over a 1-month interval. Results: The global PSQI score dropped (indicating better sleep quality) by a median of 3.0 points (IQR, 0.0-8.0 points) after treatment. In the multivariate logistic regression analysis, with an increase in global PSQI score during AA by 1 point, there was a 0.73-fold reduction in the risk of poor sleep quality post-AA (adjusted odds ratio, 0.73; 95% confidence interval, 0.52-1.01; p<0.055; Nagelkerke's R² =0.66). Conclusion: The results revealed a positive effect of AA (by the NADA-Acudetox protocol) on sleep quality (as measured by PSQI) among participants in a treatment center with mental and behavioral disorders due to multiple drug use.

• Korean Journal of Culture and Social Issue
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• v.12 no.1
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• pp.15-33
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• 2006

There are less studies on the adult suicide even though it's steep increase and negative effect on person itself, family and society. The purpose of the present study was to investigate factors that influence on the adult suicide and to categorize it. Using a case-study approach, a total of 61 cases were analyzed. Specifically, on the basis of the stress-vulnerability model, I scrutinized vulnerability factors(classified personal, family-environment, and social-environment factors) and precipitating events(classified personal, interpersonal events) influencing on the adult suicide. As the results of this study, adult suicide classified into 3 types, that is, 'risk type suicide', 'event-response type suicide', 'complex type'. And then I discussed the characteristics of the suicidal types and the method for reduction of adult suicide.

• Smart Media Journal
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• v.12 no.11
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• pp.36-47
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• 2023

Industrial Control System(ICS), which controls facilities at major industrial sites, is increasingly connected to other systems through networks. With this integration and the development of intelligent attacks that can lead to a single external intrusion as a whole system paralysis, the risk and impact of security on industrial control systems are increasing. As a result, research on how to protect and detect cyber attacks is actively underway, and deep learning models in the form of unsupervised learning have achieved a lot, and many abnormal detection technologies based on deep learning are being introduced. In this study, we emphasize the application of preprocessing methodologies to enhance the anomaly detection performance of deep learning models on time series data. The results demonstrate the effectiveness of a Wavelet Transform (WT)-based noise reduction methodology as a preprocessing technique for deep learning-based anomaly detection. Particularly, by incorporating sensor characteristics through clustering, the differential application of the Dual-Tree Complex Wavelet Transform proves to be the most effective approach in improving the detection performance of cyber attacks.