• Title/Summary/Keyword: potential severity assessment

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Damage detection of railway bridges using operational vibration data: theory and experimental verifications

  • Azim, Md Riasat;Zhang, Haiyang;Gul, Mustafa
    • Structural Monitoring and Maintenance
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    • v.7 no.2
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    • pp.149-166
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    • 2020
  • This paper presents the results of an experimental investigation on a vibration-based damage identification framework for a steel girder type and a truss bridge based on acceleration responses to operational loading. The method relies on sensor clustering-based time-series analysis of the operational acceleration response of the bridge to the passage of a moving vehicle. The results are presented in terms of Damage Features from each sensor, which are obtained by comparing the actual acceleration response from the sensors to the predicted response from the time-series model. The damage in the bridge is detected by observing the change in damage features of the bridge as structural changes occur in the bridge. The relative severity of the damage can also be quantitatively assessed by observing the magnitude of the changes in the damage features. The experimental results show the potential usefulness of the proposed method for future applications on condition assessment of real-life bridge infrastructures.

Sensors, smart structures technology and steel structures

  • Liu, Shih-Chi
    • Smart Structures and Systems
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    • v.4 no.5
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    • pp.517-530
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    • 2008
  • This paper deals with civil infrastructures in general, sensor and smart structure technology, and smart steel structures in particular. Smart structures technology, an integrated engineering field comprising sensor technology, structural control, smart materials and structural health monitoring, could dramatically transform and revolutionize the design, construction and maintenance of civil engineering structures. The central core of this technology is sensor and sensor networks that provide the essential data input in real time for condition assessment and decision making. Sensors and robust monitoring algorithms that can reliably detect the occurrence, location, and severity of damages such as crack and corrosion in steel structures will lead to increased levels of safety for civil infrastructure, and may significantly cut maintenance or repair cost through early detection. The emphasis of this paper is on sensor technology with a potential use in steel structures.

The relationship between nerve conduction studies and neuropathic pain in sciatic nerve injury due to intramuscular injection

  • Fidanci, Halit;Ozturk, Ilker
    • The Korean Journal of Pain
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    • v.34 no.1
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    • pp.124-131
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    • 2021
  • Background: Sciatic nerve injury due to intramuscular injection (SNIII) is still a health problem. This study aimed to determine whether there is a correlation between neuropathic pain and electrodiagnostic findings in SNIII. Methods: Patients whose clinical and electrodiagnostic findings were compatible with SNIII participated in this retrospective cohort study. Compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes of the sural, superficial peroneal, peroneal, and tibial nerves were graded from 1 to 4. Leeds assessment of neuropathic symptoms and signs scale (LANSS) was applied to all patients. Results: Forty-eight patients were included in the study, 67% of whom had a LANSS score ≥ 12. Sural SNAP amplitude abnormalities were present in 8 (50%) out of 16 patients with a LANSS score < 12, and 28 (87.5%) out of 32 patients with a LANSS score ≥ 12, with significant differences between the groups (P = 0.011). There was a positive correlation between the LANSS score and the sural SNAP amplitude grading (P = 0.001, r = 0.476). A similar positive correlation was also found in the LANSS score and the tibial nerve CMAP amplitude grading (P = 0.004, r = 0.410). Conclusions: This study showed a positive correlation between the severity of tibial nerve CMAP/sural SNAP amplitude abnormality and LANSS score in SNIII. Neuropathic pain may be more common in SNIII patients with sural nerve SNAP amplitude abnormality.

Analysis on Topographic Normalization Methods for 2019 Gangneung-East Sea Wildfire Area Using PlanetScope Imagery (2019 강릉-동해 산불 피해 지역에 대한 PlanetScope 영상을 이용한 지형 정규화 기법 분석)

  • Chung, Minkyung;Kim, Yongil
    • Korean Journal of Remote Sensing
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    • v.36 no.2_1
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    • pp.179-197
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    • 2020
  • Topographic normalization reduces the terrain effects on reflectance by adjusting the brightness values of the image pixels to be equal if the pixels cover the same land-cover. Topographic effects are induced by the imaging conditions and tend to be large in high mountainousregions. Therefore, image analysis on mountainous terrain such as estimation of wildfire damage assessment requires appropriate topographic normalization techniques to yield accurate image processing results. However, most of the previous studies focused on the evaluation of topographic normalization on satellite images with moderate-low spatial resolution. Thus, the alleviation of topographic effects on multi-temporal high-resolution images was not dealt enough. In this study, the evaluation of terrain normalization was performed for each band to select the optimal technical combinations for rapid and accurate wildfire damage assessment using PlanetScope images. PlanetScope has considerable potential in the disaster management field as it satisfies the rapid image acquisition by providing the 3 m resolution daily image with global coverage. For comparison of topographic normalization techniques, seven widely used methods were employed on both pre-fire and post-fire images. The analysis on bi-temporal images suggests the optimal combination of techniques which can be applied on images with different land-cover composition. Then, the vegetation index was calculated from the images after the topographic normalization with the proposed method. The wildfire damage detection results were obtained by thresholding the index and showed improvementsin detection accuracy for both object-based and pixel-based image analysis. In addition, the burn severity map was constructed to verify the effects oftopographic correction on a continuous distribution of brightness values.

Pharmacodynamic Drug-Drug Interactions Considered to be Added in the List of Contraindications with Pharmacological Classification in Korea (약물군-약물군 조합으로 도출한 약력학적 기전의 추가 병용금기성분)

  • Je, Nam Kyung;Kim, Dong-Sook;Kim, Grace Juyun;Lee, Sukhyang
    • Korean Journal of Clinical Pharmacy
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    • v.25 no.2
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    • pp.120-129
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    • 2015
  • Objectives: Drug utilization review program in Korea has provided 'drug combinations to avoid (DCA)' alerts to physicians and pharmacists to prevent potential adverse drug events or inappropriate drug use. Seven hundred and six DCA pairs have been announced officially by the Ministry of Food and Drug Safety (MFDS) by March, 2015. Some DCA pairs could be grouped based on the drug interaction mechanism and its consequences. This study aimed to investigate the drug-drug interaction (DDI) pairs, which may be potential DCAs, generated by the drug class-drug class interaction method. Methods: Eleven additive/synergistic and one antagonistic drug class-drug class interaction groups were identified. By combining drugs of two interacting drug class groups, numerous DDI pairs were made. The status and severity of DDI pairs were examined using Lexicomp and Micromedex. Also, the DCA listing rate was calculated. Results: Among 258 DDI pairs generated by the drug class-drug class interaction method, only 142 pairs were identified as official DCA pairs by the MFDS. One hundred and four pairs were identified as potential DCA pairs to be listed. QT prolonging agents-QT prolonging agents, triptans-ergot alkaloids, tricyclic antidepressants-monoamine oxidase inhibitors, and dopamine agonists-dopamine antagonists were identified as drug class-drug class interaction groups which have less than 50 % DCA listing rate. Conclusion: To improve the clinicians' adaptability to DCA alerts, the list of DCA pairs needs to be continuously updated.

Analysis of Train Delay in Daejeon Metro (대전도시철도의 열차 지연운행 분석연구)

  • Kwon, Young-Seok;Lee, Jin-Sun
    • The Journal of the Korea Contents Association
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    • v.17 no.1
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    • pp.50-57
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    • 2017
  • This study investigated the causes and problems of train operation impediments through the statistics analysis of 8 years'internal data of Daejeon Metropolitan Express Transit. By evaluating the risks regarding the system, equipment, and parts of high risk group, this study measured the Risk Index Severity, and applied the $5{\times}5$ Risk Assessment Matrix which is a method of risk management to calculate the scale of risk to analyze the safety level and allowance range. As a result, the car sector, the most serious risk, followed by machinery and equipment sector showed that the inherent risk. In particular, the door broken and the door rail signaling and control devices due to defects of the vehicle is high, but also the severity, and frequency are showing very frequent additional potential accidents. PSD also had defects in the machinery sector appeared to be the most dangerous of the PSD poor safety gates, it was found that the glass also involve the risk of mishandling and breakage of the PSD. This study intended to contribute to the transportation benefits through the safety and stable operation of Metropolitan Express Transit.

Clinical efficacy of L. plantarum, L. reuteri, and Ped. acidilactici probiotic combination in canine atopic dermatitis (개 아토피 피부염에서 3종 프로바이오틱스 복합제의 임상 효능 평가)

  • Hye-Kang Jung;Jae-Hun Kim;Jeseong Park;Yeonhee Kim;Minn Sohn;Chul Park
    • Korean Journal of Veterinary Service
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    • v.47 no.1
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    • pp.19-26
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    • 2024
  • Canine atopic dermatitis (CAD) is an inflammatory and pruritic skin disease with a genetic predisposition, characterized by allergic sensitivity. It is known for its distinctive clinical features, including a high recurrence rate and chronic progression. To manage CAD, medications such as steroids and immunosuppressants are commonly used, but consideration should be given to the potential resistance and side effects associated with long-term use. In order to reduce these risks, various adjunctive factors are currently under consideration. One of these adjunctive agents, probiotics have shown effectiveness in regulating atopic dermatitis by modulating immune responses, as demonstrated in several recent studies. In this study, a substance combining three probiotics-L. plantarum, L. reuteri, and Ped. Acidilactici-was used in patients diagnosed with CAD, and its clinical effects and safety were evaluated. The trial involved four groups: a group receiving conventional treatment for atopic dermatitis (A), a group prescribed low-dose probiotics (B), a group prescribed high-dose probiotics (C), and a group prescribed topical probiotics (D). For assessment, the Canine Atopic Dermatitis Extent and Severity Index (CADESI), Trans-Epidermal Water Loss (TEWL) test, gut microbiome, and serum IgE test were conducted. As a result, the CAD severity index (CADESI-4) significantly decreased in the probiotics groups (B & C). In the serum total IgE test, the groups consuming probiotics showed a significant difference, while the group using topical probiotics (D) did not exhibit a significant change. Also, the TEWL test showed improved scores in the probiotics groups (B & C). Therefore, L. plantarum, L. reuteri, and Ped. Acidilactici probiotic combination could be considered as an effective adjunctive treatment, especially for atopic patients with moderate to severe skin lesions.

Computerized occlusal analysis: correlation with occlusal indexes to assess the outcome of orthodontic treatment or the severity of malocculusion

  • Lee, Sang-Min;Lee, Jin-Woo
    • The korean journal of orthodontics
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    • v.46 no.1
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    • pp.27-35
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    • 2016
  • Objective: The aims of our study were to verify the validity of the T-Scan III system (Tekscan) as an objective occlusal evaluation tool, and to assess the differences between two occlusal indexes - the peer assessment rating (PAR) index and the American Board of Orthodontics objective grading system (OGS) - by comparing the scores derived from the T-Scan III system with the two occlusal indexes and analyzing the correlations between them. Methods: The final study sample included 48 adult volunteers (39 men and 9 women, mean age $24.14{\pm}3.16years$), after excluding 29 volunteers whose occlusion could not be evaluated by the T-Scan III system due to severe skeletal or occlusal problems. PAR index and OGS scores were assessed using dental study models, and measurements of centric occlusion, protrusive movement, and lateral excursion movement were obtained via the T-Scan III system. The results were analyzed to determine correlations. Results: Occlusal analysis by the T-Scan III system was clinically reliable (p < 0.05), and the PAR index and OGS scores were significantly correlated with several measurements obtained with the T-Scan III system (p < 0.05). Conclusions: The T-Scan III system is a quantitative and reliable method for occlusal evaluation, and represents a potential substitute for occlusal indexes. Compared to the PAR index, the OGS scores of more variables were significantly correlated with the T-Scan measurements.

A Study on Risk Frequency Estimation of Runway End Safety Area (활주로종단안전구역의 위험빈도 추정 연구)

  • Kim, Do-Hyeon;Sheen, Dong-Jin
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.18 no.3
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    • pp.34-41
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    • 2010
  • 'Aviation Safety' is the state in which the risk of harm to persons or of property damage is reduced to, and maintained at or below, an acceptable level through a continuing process of hazard identification and risk management in the aviation field. 'Risk' is the assessed potential for adverse consequences resulting from a hazard and 'Risk assessment' involves consideration of both the frequency and the severity of any adverse consequence. This study focused on the risk frequency about a case airport which does not meet the 'Runway end safety area' requirement of ICAO SARPs and Korea standards and used 'RSA risk model' for estimating the risk frequency. As results of this study, risk frequency of the runway end safety areas in the case airport is higher than that of 'Runway end safety area' requirement of ICAO SARPs and Korea standards, which means that alternatives for risk frequency mitigation to a level as low as reasonably practicable is required in the case airport. The optimum solution analysed from this study is to impose restriction of aircraft operation when the runway condition is poor(icing condition) and also it snows in the case airport.

Vibration based bridge scour evaluation: A data-driven method using support vector machines

  • Zhang, Zhiming;Sun, Chao;Li, Changbin;Sun, Mingxuan
    • Structural Monitoring and Maintenance
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    • v.6 no.2
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    • pp.125-145
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    • 2019
  • Bridge scour is one of the predominant causes of bridge failure. Current climate deterioration leads to increase of flooding frequency and severity and thus poses a higher risk of bridge scour failure than before. Recent studies have explored extensively the vibration-based scour monitoring technique by analyzing the structural modal properties before and after damage. However, the state-of-art of this area lacks a systematic approach with sufficient robustness and credibility for practical decision making. This paper attempts to develop a data-driven methodology for bridge scour monitoring using support vector machines. This study extracts features from the bridge dynamic responses based on a generic sensitivity study on the bridge's modal properties and selects the features that are significantly contributive to bridge scour detection. Results indicate that the proposed data-driven method can quantify the bridge scour damage with satisfactory accuracy for most cases. This paper provides an alternative methodology for bridge scour evaluation using the machine learning method. It has the potential to be practically applied for bridge safety assessment in case that scour happens.