• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.92-97
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• 2021

In accordance with the revision of the Enforcement Regulations of the High-Pressure Gas Safety Management Act in February 2021, from August 27, 2021, the operation status of safety devices such as gas leak detection and alarm devices, emergency shut-off devices and flame detectors installed at hydrogen vehicle charging stations can be monitored in real time. It is transmitted and operated by the computer system managed by Korea Gas Safety Corporations. We intend to share the results of statistical analysis of abnormal signals that have occurred along with the results of the monitoring system construction so that they can be used for the safety management of hydrogen refueling stations, and to seek future safety management directions.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.13-21
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• 2022

Objective : Nontraumatic subdural hematoma (SDH) is a common disease, and spinal cerebrospinal fluid (CSF) leakage is a possible etiology of unknown significance, which is commonly investigated by several invasive studies. This study demonstrates that heavily T2-weighted magnetic resonance myelography (HT2W-MRM) is a safe and clinically effective imaging modality for detecting CSF leakage in patients with nontraumatic SDH. Methods : All patients who underwent HT2W-MRM for nontraumatic SDH workup at our institution were searched and enrolled in this study. Several parameters were measured and analyzed, including patient demographic data, initial modified Rankin Scale (mRS) score upon presentation, SDH bilaterality, hematoma thickness upon presentation, CSF leakage sites, treatment modalities, follow-up hematoma thickness, and follow-up mRS score. Results : Forty patients were identified, of which 22 (55.0%) had CSF leakage at various spinal locations. Five patients (12.5%) showed no change in mRS score, whereas the remaining (87.5%) showed decreases in follow-up mRS scores. In terms of the overall hematoma thickness, four patients (10.0%) showed increased thickness, two (5.0%) showed no change, 32 (80.0%) showed decreased thickness, and two (5.0%) did not undergo follow-up imaging for hematoma thickness measurement. Conclusion : HT2W-MRM is not only safe but also clinically effective as a primary diagnostic imaging modality to investigate CSF leakage in patients with nontraumatic SDH. Moreover, this study suggests that CSF leakage is a common etiology for nontraumatic SDH, which warrants changes in the diagnosis and treatment strategies.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.53-58
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• 2024

Due to the development of industry and improvement of living standards, the amount of natural gas used in the world is constantly increasing, and related industrial facilities such as power plants, storage facilities, and supply pipelines are constantly increasing. Natural gas is a convenient and clean fuel that does not pollute the environment, but in the event of an accident due to leakage, it can cause human casualties, large-scale property damage, and negative effects on the global warming effect. In addition to the severe penalties under the Severe Disaster Punishment Act, it is necessary to ensure safety. Therefore, by applying the principle of laser-based absorption spectroscopy, we developed a long-range portable methane leakage gas detection system that can detect the concentration of methane leaking from a distance of up to 30 meters and verified its effectiveness.

• Neonatal Medicine
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• v.17 no.1
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• pp.34-43
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• 2010

Purpose : The aim of this study was to examine whether hypercapnia during the first seven days of life was associated with severe intraventricular hemorrhage (IVH) in preterm infants requiring mechanical ventilation. Methods : A matched pair analysis was performed for 19 preterm infants with severe IVH(grade$\geq$3) and 38 infants with no severe IVH (normal or grade 1), who required mechanical ventilation for more than seven days. The univariate and multivariate analysis of severe IVH with maximal and minimal $PaCO_2$, averag $PaCO_2$, SD of $PaCO_2$, and difference in the $PaCO_2$ were assessed. The major perinatal factors and maximal ventilator index (VI) were also compared. Results : Infants with severe IVH had a higher maximal $PaCO_2$ (86.1$\pm$18.4 mmHg vs. 60.1$\pm$ 11.6 mmHg, P <0.001) and mean $PaCO_2$ (47.5$\pm$5.6 mmHg vs. 41.2$\pm$6.3 mmHg, P=0.004) and a larger SD or difference in $PaCO_2$ (14.0$\pm$4.4 mmHg vs. 9.0$\pm$2.4 mmHg; 60.3$\pm$20.9 mmHg vs. 35.5$\pm$11.8 mmHg, P <0.001). However the minimal $PaCO_2$ values did not differ between the groups. Disseminated intravascular coagulation, pulmonary hemorrhage, and the air leak syndrome were more frequent in the IVH group than in the controls. The maximal VI on each day was higher in the IVH group. The multivariate logistic regression analysis after controlling for bleeding tendency showed that the air leak syndrome, maximal VI, and maximal $PaCO_2$ were independently associated with severe IVH [OR, 1.324 (95% CI, 1.011-1.733; P=0.041)]. Conclusion : Extreme hypercapnia was significantly associated with severe IVH in preterm infants, after adjustment for major perinatal risk factors. Frequent monitoring of the $PaCO_2$ may be important for early detection of inadvertent hypercapnia and prompt correction of high PaCOS levels.

• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.95-103
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• 2017

A lot of hazardous materials have been used for product processing and utility plant. Many accidents including toxic release, fire and explosions occur in the ammonia related facility and plant. Various safety and environment management program including PSM, SMS, ORA etc. are being implemented for risk management and accident prevention in the production industry. Also much study and research have been carried about risk assessment of accident scenario in the academic and research area. In this paper, firstly risk level was assessed by using a typically used KORA program and LOPA PFD method for the selected ammonia unloading and storage facility. And then risk reduction measures for the risk assessed facility were studied in 3 aspects and some measures were proposed. Those Risk Reduction measures are including a leak detection and emergency isolation, water spray, dilution tank, dike and trench, scattering protection in hardware impovement aspect, and a applicable risk criteria, conditional modifier for existing LOPA PFD, alternative supporting modeling program in risk estimation methodology aspect, and last RBPS(Risk Based Process Safety) program, re-doing of process hazard analysis, management system compliance audit in managerial activity aspect.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.863-870
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• 2012

The market trends of automatic meter reading associated with smart water meters were investigated. Also, recent developments and field applications of key technology for automatic meter reading associated with smart water meters were analyzed. Smart water meters have been manufactured mostly in United States and Europe and have been expanded their business to Asia. Integrated water management system combining with the additional functions such as real-time consumption metering, cost notification, water conservation, leak detection, water quality monitoring, and flow control have been operated in automatic meter reading. Both water quality and quantity data measured from smart water meters and sensors were transferred to data concentration units through neighborhood area network, and then were transferred to integrated server through wide area network. The data transfer methods were determined by comprehensively considering urban scale, density of smart water meters, power supply and network topologies. Common data collection methods such as fixed network to data concentation units, vehicles drive by, people walk by, and drone fly by have been applied. The automatic meter reading associated with smart water meters are spread throughout the world, and both water and energy savings result in saving the money and reducing the greenhouse gases emission.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.132-137
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• 2018

Although the number of chemical accidents has been declining since the Chemical Control Act of 2015, there have been repeated occurrences of similar types of accidents at printed circuit board (PCB) manufacturing facilities. These accidents were caused by the overflow of hydrochloric acid and hydrogen peroxide, which are toxic chemicals used in the printed circuit board manufacturing process. An analysis of the $Cl^-$ content to identify the cause of the accident showed that in the mixed route of hydrochloric acid and hydrogen peroxide, which are accidental substances, the $Cl^-$ concentration was 66.85 ppm in the hydrogen peroxide sample. Through reaction experiments, it was confirmed that the deformation of a PVC storage tank and generation of chlorine gas, which is a toxic gas, occurred due to reaction heat occurring up to $50.5^{\circ}C$. This paper proposes a facility safety management plan, including overcharge, overflow prevention, leak detection device, and separation tank design for mixing prevention in printed circuit board manufacturing facility etch process. To prevent the recurrence of accidents of the same type, the necessity of a periodic facility safety inspection and strengthening of the safety education of workers was discussed.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.315-324
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• 2011

In Web environment, a flood of spam causes serious social problems such as personal information leak, monetary loss from fishing and distribution of harmful contents. Moreover, types and techniques of spam distribution which must be controlled are varying as days go by. The learning based spam classification method using Bag-of-Words model is the most widely used method until now. However, this method is vulnerable to anti-spam avoidance techniques, which recent spams commonly have, because it classifies spam documents utilizing only keyword occurrence information from classification model training process. In this paper, we propose a spam document detection method using a characteristic of repeating words occurring in spam documents as a solution of anti-spam avoidance techniques. Recently, most spam documents have a trend of repeating key phrases that are designed to spread, and this trend can be used as a measure in classifying spam documents. In this paper, we define six variables, which represent a characteristic of word repetition, and use those variables as a feature set for constructing a classification model. The effectiveness of proposed method is evaluated by an experiment with blog posts and E-mail data. The result of experiment shows that the proposed method outperforms other approaches.

• Korean Security Journal
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• no.62
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• pp.347-367
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• 2020

Rapid advancement of technology in today's society has allowed for easy access and use of data, promoting the process of informationization. Along with the merits of such development, unintended consequences of security risks involving wiretapping have been increasing as well. The security threats posed by wiretapping technology must be addressed by every organization and individual, as it could be used to leak confidential information about the nation's security, military and diplomatic strategies, industrial technologies, and personal information. Despite increasing threats stemming from the surrounding nations using advanced wiretapping technology, there is a lack of awareness at the government level, and the existing security measures for detecting and counteracting the wiretapping equipment are ineffective. In this research, the authors offered technical suggestions for improving the security strategies against the threats of wiretapping and information leakage by conducting a content analysis. The authors suggested the units of an agency be assigned a security grade based on its importance, and that adequate security equipment should be operated according to the grade. For instance, around-the-clock surveillance is recommended for grade-1 facilities, and portable wiretapping equipment detectors should be used to protect conference rooms and other key sites.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1479-1487
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• 2013

The river levee collapse and flood damages are dramatically increased due to the floods which caused by abnormal weather nowadays. The counterplan like TDR(Time Domain Reflectometry) river levee leaking exploration technique is needed to that levee failure causes of levee failure such as levee failure by penetration, piping, inadequate levee materials selection, poor compaction are almost 52% of the failure. This research practiced various comparing experiments of existing TDR(probe and tube types) and developing CAP type TDR to evaluate acrylic small CAP mould and low-cost TDR levee leaking monitoring system which was used probe type TDR. As the result, evaluated TDR system had 20cm critical exploration performance which was a leaking exploration performance, The functional ratio of TDR exploration sensitivity of dry density was sensitive more than 3 times than dry density, and weathered granite soil foundation water contents(w)-dielectric constant(${\epsilon}$) corelation formula was suggested to measure functional ratio on developing cap type TDR system.