• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.153-165
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• 2006

A damage in a structure changes its dynamic characteristics such as natural frequencies, damping ratios, and the mode shapes. In this paper the effort has been spent in obtaining the characteristics of the reduction ratio in natural frequencies and the damage detection is performed using the reduction ratios. Most of the emphasis has been on using the artificial neural network to determine the location and the extent of the damage as well as the existence of the damage. The data for learning and verifying neural network were obtained from the analytical analysis. The data have no errors. Considering the real measurements the data including errors which are difference this study between other studies also were used for neural network. The position and extent of the damage can be detected using the neural network trained by reduction ratios of natural frequencies.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.3
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• pp.49-57
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• 2010

Most previous research on the seismic response of structures with plan irregularities have focused on the relationship between the eccentricity and the amount of torsion. This approach cannot provide the direct relationship between the irregularity and the damage. Therefore, an investigation on the relationship between the eccentricities of buildings with plan irregularities and the damage index was performed. Inelastic dynamic time-history analyses were performed on one-story buildings with various eccentricities. For the damage assessment, a 3D damage index was adopted to reflect the effect of the bi-directional response and torsion. Based on the analysis results, buildings with eccentricities of 10%, 20% and 30% will suffer 3~5%, 13~18%, and 33~47% more damage than their regular counterparts, respectively.

• Journal of Digital Convergence
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• v.22 no.1
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• pp.23-32
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• 2024

This study selected in-depth discharge damage survey data and analyzed 92,364 patients whose main diagnosis was S00-T98 (damage, addiction, and specific other results due to external factors) based on the Korean Standard Classification of Diseases and Deaths (KCD-7th) among patients discharged from the hospital after inpatient treatment from January 2016 to December 2018. As a result of analyzing the general characteristics of injured and traumatic patients, the incidence rate of men was higher in gender, and the incidence rate of women increased as the year increased. As a result of analyzing the characteristics of injury and trauma patients other than injury, the injury intention had a high rate of unintentional damage, the damage place was the highest on the road/road, and it showed a decreasing trend as the year increased, and it showed an increasing trend in the residential area. It can be used as basic data for the establishment of a related system to prevent damage as a result of subsang.

• Journal of agricultural medicine and community health
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• v.33 no.1
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• pp.82-89
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• 2008

Objective:　We compared the prevalence of injury and poisoning in the agricultural and fishery population with that of the general population.Methods: The national health insurance data and agricultufor this study. The age-adjusted standardized morbidity ratio was used to compare the prevalence of all injuries and poisonings of the agricultural and fishery population with that of the general population for the year 2002, as well as the prevalence of certain injuries and poisonings common to the agricultural and fishery population. The age-adjusted standardized morbidity ratio and 95% confidence intervals were attained by using the general population as the standard population group.Results: The age-adjusted standardized morbidity ratio of total injuries and poisonings was significantly high in the agriculture and fishery population. The standardized morbidity ratio was 137.6 in the male agriculture and fishery population and 123.3 in the female agriculture and fishery population. In terms of injuries and poisonings common to the agriculture and fishery population, the age-adjusted standardized morbidity ratio was significantly high regarding the dislocations and strains of lumbar spine/pelvis, shoulder and neck, the fracture of rib/thoracic spine/sternum and pesticide poisoning.Conclusions: The overall prevalence of injury/poisoning was significantly higher in the agriculture and fishery population than in the general population. Various forms of research should be conducted on the injuries of the agriculture and fishery population in the future. In order to compare the differences in the prevalence rates of injuries according to time and region, standard definitions of injuries and occupation related injuries are required.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.3
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• pp.37-44
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• 2003

In rough seas, bow-flare regions of the sea-going ships are subject to high impact pressures due to the bow-flare slamming and panting. And many ships suffer structural damages in that region, even though they were built under the bow structure strengthening rules of the ship classes. So, a new design method for bow-flare structure is highly required. In this paper, bow-flare damage analysis is performed for 17 ships (total number of damage/non-damage data is 782). Based on this analysis, a new design standard and method for bow-flare structure (shell plate, frame and web frame) is proposed. 80.4% of the present damage/non-damage data were well-explained by this new design standard.

• Journal of Digital Convergence
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• v.10 no.5
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• pp.289-299
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• 2012

The study was carried out to provide basic data of improving the accessibility of medical service through identifying the factors that make hospital injury inpatient in non-residential area not in their residential area in Gyeongsangnam-do. This study analyzed not only 8,225 cases of discharged patients with damages from 2008, provided by the Korea Centers for Disease Control and Prevention, but also using a census and a research data on the actual condition from health care system. This study conducted a frequency test, a chi-square test and a logistic regression In result, first, the centralization of medical utilization of patients with damages is apparent centrally the city area. Second, medical utilization of injury patients in non-residential areas were significantly higher local area compared to City area. To improve this, a policy that can not only provide medical centers and sickbed, but also improve the quality of local medical treatments for the localization of medical treatments, for the accessibility of medical services, government is demanded policy for patients with damages in local area.

• Computational Structural Engineering
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• v.6 no.2
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• pp.71-78
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• 1993

A method to estimate damage of bridge structures is developed using system identification approach. Dynamic behavior of damaged structures is represented by a non-linear hysteretic moment model. Structural properties can be evaluated through system identification. To incorporate variability of the structural properties and uncertainties of structural response, damage is represented as random quantities. Numerical example is shown for the bridge structure under different ground excitation.

• Journal of agricultural medicine and community health
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• v.39 no.1
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• pp.1-13
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• 2014

Objective: The objectives were to estimate the rate of the injury in the elderly over the past year and to identify factors related to injury in the elderly in South Korea. Method: Using data from the 2008 Community Health Survey, 43,049 elderly persons, aged 65 years and older, were selected as study subjects. Their experience of injury during the past year and other variables, including socio-demographic factors, health-related factors, and diagnosed chronic diseases, were used. The chi-squared test and multiple logistic regression analysis with weighted analysis were conducted and statistical significance was set at p<0.05. Result: The rate of injury in the elderly during the past year was 5.1%. The most common types of the injury were falling/slipping down and traffic accidents. Factors related to injury in the elderly were living alone, current drinking, depression, poor self-rated health, stroke, and osteoporosis. Living alone (odds ratio 1.23, 95% CI: 1.05-1.45), current drinkers (OR 1.19, 95% CI: 1.05-1.35), poor self-rated health (OR 1.72, 95% CI: 1.43-2.08), depression (OR 1.23, 95% CI: 1.17-1.68), and history of stroke (OR 1.40, 95% CI: 1.17-1.68), and history of osteoporosis (OR 1.45, 95% CI: 1.26-1.66) were related to an increased risk of injury. Conclusions: Intervention programs that consider the risk factors related to injury should be developed and implemented to decrease and prevent injuries in the elderly.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.2 s.72
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• pp.125-138
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• 2006

The use of system identification approaches for damage detection has been expanded in recent years owing to the advancements in data acquisition system andinformation processing techniques. Soft computing techniques such as neural networks and genetic algorithm have been utilized increasingly for this end due to their excellent pattern recognition capability. In this study, damage detection of bridge structures using neural networks technique based on the modal properties is presented, which can effectively consider the modeling uncertainty in the analysis model from which the training patterns are to be generated. The differences or the ratios of the mode shape components between before and after damage are used as the input to the neural networks in this method, since they are found to be less sensitive to the modeling errors than the mode shapes themselves. Two numerical example analyses on a simple beam and a multi-girder bridge are presented to demonstrate the effectiveness and applicability of the proposed method.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.6 s.52
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• pp.79-91
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• 2006

A new methodology of guided wave based nondestructive testing (NDT) is developed to detect crack damage in civil infrastructures such as steel bridges without using prior baseline data. In conventional guided wave based techniques, damage is often identified by comparing the "current" data obtained from a potentially damaged condition of a structure with the "past" baseline data collected at the pristine condition of the structure. However, it has been reported that this type of pattern comparison with the baseline data can lead to increased false alarms due to its susceptibility to varying operational and environmental conditions of the structure. To develop a more robust damage diagnosis technique, a new concept of NDT is conceived so that cracks can be detected without direct comparison with previously obtained baseline data. The proposed NDT technique utilizes the polarization characteristics of the piezoelectric wafers attached on the both sides of the thin metal structure. Crack formation creates Lamb wave mode conversion due to a sudden change in the thickness of the structure. Then, the proposed technique instantly detects the appearance of the crack by extracting this mode conversion from the measured Lamb waves even at the presence of changing operational and environmental conditions. Numerical and experimental results are presented to demonstrate the applicability of the proposed technique to crack detection.