• Smart Structures and Systems
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• v.33 no.3
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• pp.227-241
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• 2024

Safety and structural integrity of civil structures, like bridges and buildings, can be substantially enhanced by employing appropriate structural health monitoring (SHM) techniques for timely diagnosis of incipient damages. The information gathered from health monitoring of important infrastructure helps in making informed decisions on their maintenance. This ensures smooth, uninterrupted operation of the civil infrastructure and also cuts down the overall maintenance cost. With an early warning system, SHM can protect human life during major structural failures. A real-time online damage localization technique is proposed using only the vibration measurements in this paper. The concept of the 'Degree of Scatter' (DoS) of the vibration measurements is used to generate a spatial profile, and fractal dimension theory is used for damage detection and localization in the proposed two-phase algorithm. Further, it ensures robustness against environmental and operational variability (EoV). The proposed method works only with output-only responses and does not require correlated finite element models. Investigations are carried out to test the presented algorithm, using the synthetic data generated from a simply supported beam, a 25-storey shear building model, and also experimental data obtained from the lab-level experiments on a steel I-beam and a ten-storey framed structure. The investigations suggest that the proposed damage localization algorithm is capable of isolating the influence of the confounding factors associated with EoV while detecting and localizing damage even with noisy measurements.

• Journal of Yeungnam Medical Science
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• v.41 no.1
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• pp.45-47
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• 2024

Peripheral nerves may be affected or injured for several reasons. Peripheral nerve damage can result from trauma, surgery, anatomical abnormalities, entrapment, systemic diseases, or iatrogenic injuries. Trauma and iatrogenic injuries are the most common causes. The ulnar, median, and radial nerves are the most injured nerves in the upper extremities, while the sciatic and peroneal nerves are the most injured nerves in the lower extremities. The clinical symptoms of peripheral nerve damage include pain, weakness, numbness/ tingling, and paresthesia. Therefore, early diagnosis and appropriate treatment of peripheral nerve injuries are crucial. If a peripheral nerve injury is left untreated, it can lead to severe complications and significant morbidity. The sciatic nerve is one of the most affected nerves. This nerve is generally injured by trauma and iatrogenic causes. Children are more susceptible to trauma than adults. Therefore, sciatic nerve injuries are observed in pediatric patients. When the sciatic nerve is damaged, pain, weakness, sensory loss, and gait disturbances can occur. Therefore, the diagnosis and treatment of sciatic nerve injuries are important to avoid unexpected consequences. Ultrasound can play an important role in the diagnosis of peripheral nerve injury and the follow-up of patients. The aim of this case report is twofold. First, we aimed to emphasize the critical role of ultrasonographic evaluation in the diagnosis of peripheral nerve injuries and pathologies. Second, we aimed to present this case, which has distinguishing features, such as the existence of periostitis ossificans progressiva with sciatic neurotmesis due to a traumatic glass injury.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.338-343
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• 2009

Tomography is the imaging method of cross sectional area using multi beam signals and is mainly applied to the medical diagnosis to acquire the image of the inside human body. This method is pretty meaningful in nondestructive evaluation field since the imaging of the inspection region can enhance the comprehension of the inspector. Recently, much attention has been paid to the guided wave for the diagnosis of platelike structures. So, in this work, a study on the imaging of the damage location in a plate was carried out on the basis of computer aided analysis of guided waves and tomographic imaging. To this end, boundary element method was employed to analyze the effect of the damage in plate on the propagation of the guided waves and the analytic results were applied to the tomographic imaging method to identify the damage location. Consequently, it was shown that the number of sensors heavily affect the inspection performance of the damage location.

• Structural Engineering and Mechanics
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• v.72 no.6
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• pp.689-712
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• 2019

Time-series models like AR-ARX and ARMAX, provide a robust way to capture the dynamic properties of structures, and their residuals can be effectively used as features for damage detection. Even though several research papers discuss the implementation of AR-ARX and ARMAX models for damage diagnosis, they are basically been exploited so far for detecting the time instant of damage and also the spatial location of the damage. However, the inverse problem associated with damage quantification i.e. extent of damage using time series models is not been reported in the literature. In this paper, an approach to detect the extent of damage by combining the ARMAX model by formulating the inverse problem as a multi-constrained optimization problem and solving using a newly developed hybrid adaptive differential search with dynamic interaction is presented. The proposed variant of the differential search technique employs small multiple populations which perform the search independently and exchange the information with the dynamic neighborhood. The adaptive features and local search ability features are built into the algorithm in order to improve the convergence characteristics and also the overall performance of the technique. The multi-constrained optimization formulations of the inverse problem, associated with damage quantification using time series models, attempted here for the first time, can considerably improve the robustness of the search process. Numerical simulation studies have been carried out by considering three numerical examples to demonstrate the effectiveness of the proposed technique in robustly identifying the extent of the damage. Issues related to modeling errors and also measurement noise are also addressed in this paper.

• Research in Plant Disease
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• v.30 no.1
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• pp.99-102
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• 2024

Integrated pest management is essential for controlling plant diseases that reduce crop yields. Rapid diagnosis is crucial for effective management in the event of an outbreak to identify the cause and minimize damage. Diagnosis methods range from indirect visual observation, which can be subjective and inaccurate, to machine learning and deep learning predictions that may suffer from biased data. Direct molecular-based methods, while accurate, are complex and time-consuming. However, the development of large multimodal models, like GPT-4, combines image recognition with natural language processing for more accurate diagnostic information. This study introduces GPT-4-based system for diagnosing plant diseases utilizing a detailed knowledge base with 1,420 host plants, 2,462 pathogens, and 37,467 pesticide instances from the official plant disease and pesticide registries of Korea. The AI plant doctor offers interactive advice on diagnosis, control methods, and pesticide use for diseases in Korea and is accessible at https://pdoc.scnu.ac.kr/.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.19-32
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• 2024

An investigation into the detailed safety diagnosis report indicates that domestic highway bridges mainly suffer from defects, deterioration, and damage due to physical forces. In particular, deterioration is an inevitable damage that occurs due to various environmental and external factors over time. In particular, bridge deck is very vulnerable to cracks, which occur along with various types of damages such as rebar corrosion and surface delamination. Thus, this study evaluates a correlation between heterogeneous damage and deterioration environment and then identifies the main causes of such heterogeneous damage. After all, a bridge heterogeneous damage prediction model was developed using random forests to determine the top five factors contributing to the occurrence of the heterogeneous damage. The results of the study would serve as a basic data for estimating bridge maintenance and budget.

• Journal of Environmental Health Sciences
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• v.45 no.1
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• pp.71-81
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• 2019

Objectives: The lung injuries by exposure to the humidifier disinfectants (HDs) were reported in 2011, Korea. For the HD victims, environmental exposure level and clinical diagnosis were conducted to determine the levels of damage by HDs. Methods: The exposure assessment to the HDs from 1st to 4th questionnaire surveys were carried out for 5,245 victims. And the affecting factors of exposure levels were analyzed by characterizing exposure and demographic information. By using of exposure concentration and cumulative time, exposure levels were classified and compared by percentage of clinical diagnosis classes. The high exposure and low clinical diagnosis rating groups, and low exposure and high clinical diagnosis rating groups were analyzed to overcome the limitation of past exposure assessment such as recall bias. Results: Among the all applicants damaged by the humidifier disinfectants, survivors were 4,028 and the dead were 1,217. And male and female were 2,675, and 2,547, respectively. In case of occurrence age of lung disease, under 10 years was majority age group (1,536) and followed by thirties (917). Pregnant women and fetuses were 339 and 439, respectively. And the damages by exposure to the HDs were concentrated on these susceptible populations in groups with low exposure and high clinical diagnosis rating. On the other hand, the groups classified by high exposure and low clinical diagnosis rating were shown different characterization. Conclusions: The questionnaire survey on past exposure may be uncertain due to recall bias. However, the relationship between classified exposure levels and clinical diagnosis ratings might be shown positive correlation if the exposure assessment errors were analyzed and controlled.

• Journal of Mechanical Science and Technology
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• v.20 no.9
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• pp.1410-1417
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• 2006

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius-speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.2
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• pp.231-234
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• 2009

Recently, to the development of a highly information-oriented society to a large increase in dependence on power, Accordingly, it is need that active development and spread of preservation technology on accident prevention in operation electrical equipment. However, to lack of the use on maintenance technology of power equipment and to increase of power usage is growing deterioration of power equipment, this is a cause on casualties, property damage and the occurrence of disasters is a growing. GIS equipments which are operated from domestic except the equipment which manages from the big business are depend on a most visual inspection, and do inspection method or measuring instrument etc. a condition which is not supplied widely. Currently, many to measure instrument used in domestic is very expensive or foreign, it will be able to substitute this, the development necessity of the diagnosis technique and the measuring instrument is demanded.

• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1173-1179
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• 2007

The diagnosis of juvenile rheumatoid arthritis (JRA) is based on patient's age at disease onset, symptom duration, gender, and clinical manifestations. JRA is of unknown origin, begins under the age of 16, and persists for a minimum of 6 weeks. JRA is categorized into three principal types, systemic, oligoarticular and polyarticular. Infection, other connective tissue diseases, malignancy, trauma, and immunodeficiency are discussed as differential diagnoses for JRA. Because of joint damage, focusing on early diagnosis and intervention, a vigorous initial therapeutic approach must be taken in patients who have poor prognostic factors. A multidisciplinary team approach is also important for the care of patients with JRA.