• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.32 no.3
• /
• pp.555-564
• /
• 2022

Recently, cyberattacks are using hacking techniques utilizing intelligent and advanced malicious codes for non-face-to-face environments such as telecommuting, telemedicine, and automatic industrial facilities, and the damage is increasing. Traditional information protection systems, such as anti-virus, are a method of detecting known malicious URLs based on signature patterns, so unknown malicious URLs cannot be detected. In addition, the conventional static analysis-based malicious URL detection method is vulnerable to dynamic loading and cryptographic attacks. This study proposes a technique for efficiently detecting malicious URLs by dynamically learning malicious URL data. In the proposed detection technique, malicious codes are classified using machine learning-based feature selection algorithms, and the accuracy is improved by removing obfuscation elements after preprocessing using Weighted Euclidean Distance(WED). According to the experimental results, the proposed machine learning-based malicious URL detection technique shows an accuracy of 89.17%, which is improved by 2.82% compared to the conventional method.

• Journal of the Korean Society of Radiology
• /
• v.82 no.5
• /
• pp.1274-1280
• /
• 2021

Acute necrotizing encephalopathy (ANE) is a rare but distinctive type of influenza-associated encephalopathy characterized by symmetric multiple lesions with an invariable thalamic involvement. Although the exact pathogenesis of ANE remains unclear, the most prevalent hypothesis is the "cytokine storm," which results in blood-brain-barrier breakdown. We present the case of a 10-year-old boy with fulminant ANE confirmed with serial MRI studies, including diffusion-weighted imaging and susceptibility-weighted imaging. A comparison of these serial images demonstrated detailed and longitudinal changes in MRI findings during the clinical course corresponding to pathophysiological changes. Our case clarifies the pathogenesis of ANE brain lesions using serial imaging studies and suggests that early immunomodulatory therapy reduces brain damage.

• Steel and Composite Structures
• /
• v.52 no.2
• /
• pp.165-182
• /
• 2024

Grouted sleeve splice (GSS) is an effective type of connection applied in the precast concrete structures as it has the advantages of rapidly assembly and reliable strength. To decrease the weight and cost of vertical rebar connection in precast shear walls, a light-weight sleeve is designed according to the thick-cylinder theory. Mechanical behaviour of the light-weighted GSS is investigated through experimental analysis. Two failure modes, such as rebar fracture failure and rebar pull-out failure, are found. The load-displacement curves exhibit four different stages: elastic stage, yield stage, strengthening stage, and necking stage. The bond strength between the rebar and the grout increases gradually from outer position to inner position of the sleeve, and it reaches the maximum value at the centre of the anchorage length. A finite element model predicting the mechanical properties of the light-weighted GSS is developed based on the Concrete Damage Plasticity (CDP) model and the Brittle Cracking (BC) model. The effect of the rebar anchorage length is significant, while the increase of the thickness of sleeve and the grout strength are not very effective. A model for estimating ultimate load, including factors of inner diameter of sleeves, anchorage length, and rebar diameter, is proposed. The proposed model shows good agreement with various test data.

• Journal of Environmental Impact Assessment
• /
• v.28 no.4
• /
• pp.387-399
• /
• 2019

This research aimed to prepare the classification of the damage types and the damage rating system of noise barriers for expressway noise barriers and to develop deterioration evaluation method of noise barriers by reflecting them. The noise barrier consists of soundproof panels, foundations and posts and the soundproof panels with 10 different types of materials are used in a single or mixed form.In this paper, damage of soundproof panel shows a single or composite damage, and thus a evaluation model of deterioration has been developed for noise barriers that can reflect the characteristic of noise barriers. Materials used mainly for soundproof walls were divided into material types for metal, plastic, timber, transparent and concrete. And damage types for noise barrier were classified into corrosion, discoloration, deformation, spalling and dislocation and damage types were subdivided according to the noise barrier's components and materials. Damage rating was divided into good, minor, normal and severe for each major part of noise barrier to assess damage rating of soundproof panel, foundation and post. The deterioration degree of noise barrier was evaluated comprehensively by using the deterioration evaluation method of whole noise barrier using weighted average. Deterioration evaluation method that can be systematically assessed has been developed for noise barrier using single or mixed soundproof panel and noise barrier with single or complex damage types. Through such an evaluation system, it is deemed that the deterioration status of noise barrier installed can be systematically understood and utilized for efficient maintenance planning and implementation for repair and improvement of noise barriers.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.1 no.2 s.2
• /
• pp.123-137
• /
• 2001

Based on basic characteristics of urban disasters and their data availabilities in Korea, this study provides risk assessment models which are derived from Cheongju examples. In specific, the application models are confined to fire, facility and escape risk survey results in the paper. For the assessment criteria, major independent variables for the categories of fire include both the frequency levels and the amount of damage. And the degree of facility risk assessment is heavily hinged on both the weighted values of key facilities and their weighted rank-sizes. In the same context, the degree of escape risk assessment is hinged on both the weighted values and the amount of the classification of land. From the empirical configuration, this paper presents that the potential figure of fire risk is relatively higher in the built-up areas within the existing Central Business District where accommodates a number of dilapidated housing units and community-supportive facilities. In contrast, the potential figure of facility and escape risk is higher in both old residential areas and the newly-built apartment complex. In short, the CBD and its neighboring residential areas record a high potential figure in terms of total risk, juxtaposing fire, facility and escape risk all together.

• Journal of Korean Society of Disaster and Security
• /
• v.9 no.2
• /
• pp.9-13
• /
• 2016

The recent earthquakes in the peninsula've called safe areas prone to earthquakes occurred the unprecedented human and material damage. It does not have the seismic design of buildings for less than three layers, with the exception of some experts and organizations, and it does not have to read about the seriousness and evacuation tips for earthquake damage is thought to have been weighted. As mentioned above, most people are unaware of the evacuation tips or saengjonbeop, emergency supplies, such as earthquakes compared to a situation without the various needs education. So we were prepared for an earthquake is now managing investigate the cause and correct entities for the earthquake is considered as the time to prepare and formulate a policy. In this study, we investigated the cause to frequent earthquakes with respect to the Korean Peninsula and to organize for our government and local governments, NGOs, the media and individuals on how to proceed.

• Journal of the Korean Institute of Gas
• /
• v.11 no.4
• /
• pp.23-28
• /
• 2007

Damage ranges of accidents of the chemical facilities were estimated by the KS-RBI(Ver.3.0) program supporting the quantitative cause analysis, and the consequences were compared with the results of K-CARM(Ver2.0) program which assesses the quantitative risk in an usual method. As a result we found that the consequences of the KS-RBI program were similar to those of the K-CARM program. Therefore, the KS-RBI program could be applied to the quantitative risk assessment. In addition, it can be safely said that through appling the damage ranges of accidents by weighted average, industrial sites can come up with the effective plans of mitigation and emergency.

• Journal of Korean Society of Transportation
• /
• v.28 no.5
• /
• pp.155-162
• /
• 2010

Elderly pedestrians account for more than 30% of all deaths in traffic accident and the number of elderly-related traffic accidents are increasing every year. Considering Korea's quickly aging society, drastic measures must henceforth be taken. Taking notice of the elderly living in and moving around the provinces, this research focused on analyzing the characteristics of elderly pedistrians' traffic accidents on provincial roads and developing an Equivalent Property Damage Only (EPDO) model. The authors collected 720 traffic accident data points from the police agency and developed the EPDO model, weighted differently by light injury, severe injury, and death using Multiple Regression Analysis. As a result, the speed of vehicles is the most influential variable in EPDO, and the shape of the road is significant as well. Therefore, various policies should be established like improving the environmental factors of provincial roads, like expanding speed-reduction treatments and signage, and setting up detours around areas of high elderly concentration.

• Investigative Magnetic Resonance Imaging
• /
• v.10 no.1
• /
• pp.8-15
• /
• 2006

Purpose : To describe MR imaging features of hypoxic brain damage in relation to time elapse and prognosis of patients. Materials and methods : We reviewed 19 MR studies of 18 patients with hypoxic brain damage. MR imaging studies were performed between 1 to 20 days after the hypoxic insults (mean 8.6 days). MR images were analyzed with regard to the locations of abnormal signal intensities, the presence of brain edema. And imaging findings were correlated with the time elapse after the insults and the prognosis of patients. Results : On 19 cases of MR studies, abnormal high intensities on T2-weighted images were found in the basal ganglia (15, 78.9%), cerebral cortex (13, 68.4%), white matter (9, 47.4%), thalamus (6, 31.6%), cerebellum (4, 21.1%) and brainstem (1, 5.3%), respectively. Cerebral cortical involvement was typically bilateral and diffuse, but sometimes limited to the parieto-occipital area. The brainstem and cerebellar involvement was rare and in all cases, cerebral cortical lesions accompanied. Most of the white matter lesions were accompanied with cortical and deep gray matter lesions and found in subacute period(>6 days). The cortical high signal intensity lesions on T1-weighted image were found mostly in subacute stage, but in some cases involvement was also found in acute stage ($\leq$ 6 days). The cortical edema is found on 11 cases in acute and subacute stages. In cases of recovered consciousness, cortical involvement and edema on MR were rare. Conclusion : MR findings of hypoxic brain damage were various, but diffuse bilateral involvement of cortex and/or deep gray matter was found in most of the cases. White matter involvement was rarely found in acute stage and usually found in subacute stage. In cases of good pronosis, cortical involvement and edema were rare.

• 한국방재학회:학술대회논문집
• /
• 2009.02b
• /
• pp.36-42
• /
• 2009

A series of heavy rainfall, typhoon and earthquake disasters caused a proportionately large number of deaths among the elderly in the year 2004 in Japan. In response to these tragedies, the national government set up committees to reduce damage within the disaster vulnerable population for the next three years. The discussions in the committee led to a new conceptualization that disaster vulnerability was caused by a lack of interaction between a person's special needs and the environment's capacity and resources to meet them. This person-in-environment model of hazard vulnerability was applied to those who resided in the Nankai-Tonankai tsunami hazard-prone area. 123 home care service users were interviewed in terms of their self-evacuation ability, degree of social isolation, and building weakness as well as tsunami exposure risks. Results were quantified and scores of person-in-environmentmodel hazard vulnerability were obtained. These scores were then used to visualize socially created vulnerability by means of weighted kernel density mapping of both persons with special needs (PSN's) and persons with special needs at times of disaster (PSND's).