• The Journal of Korean Medicine
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• v.32 no.4
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• pp.149-158
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• 2011

Object: Any medication can have the risk of liver damage. To prevent this risk, liver function tests should be monitored carefully during every course of medication. This paper is a psoriasis case report on liver damage related to Scutellaria Radix medication. Shown by this case, herbal medicine has the possibility of liver damage, too. Therefore it should be carefully used under the direction of Oriental Medical Doctors who specialize in it. The purpose of this case report is to suggest this, and that more cases of liver damage related to herbal medicine should be reported. Methods: To monitor the medication's effect on the liver, liver function was evaluated during medications. Reflotron plus was used to evaluate AST and ALT by analyzing peripheral blood. Results: By this test, a case was identified as liver damage caused by a medication including Scutellaria Radix. Conclusion: This case suggests that Scutellaria Radix medication caused liver damage in a certain patient. Therefore, to prevent liver damage related to Scutellaria Radix, doctors should monitor patient's liver function regularly.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.1
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• pp.73-82
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• 2008

In this paper, a new regularization method by parameter subset selection method is proposed based on the residual force vector for damage localization. Although subset selection using the fundamental modal characteristics as a residual function has been successful in detecting a single damage location, this method seems to have limited capabilities in the detection of multiple damage locations and typically requires cumbersome weighting values. The method is presented herein and considers cases in which damage detection must be achieved using incomplete measurements of the structural responses. Model expansion is incorporated to deal with this challenge. The unique advantage of employing the new regularization method is that it can reliably identify multiple damage locations. Through an illustrative example, the proposed damage detection method is demonstrated to be a reliable tool for identifying multiple damage locations for a planar truss structure.

• Journal of Ocean Engineering and Technology
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• v.27 no.5
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• pp.63-69
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• 2013

The mooring lines of a floating type offshore plant are known to show wide banded and bimodal responses. These phenomena come from a combination of low and high frequency random load components, which are derived from the drift-restoring motion characteristic and wind- sea, respectively. In this study, fatigue models were applied to predict the fatigue damage of mooring lines under those loads, and the result were compared. For this purpose, seven different fatigue damage prediction models were reviewed, including mathematical formula. A FPSO (floating, production, storage, and offloading) with a $4{\times}4$ spread catenary mooring system was selected as a numerical model, which was already installed at an offshore area of West Africa. Four load cases with different combinations of wave and wind spectra were considered, and the fatigue damage to each mooring line was estimated. The rain flow fatigue damage for the time process of the mooring tension response was compared with the results estimated by all the fatigue damage prediction models. The results showed that both Benasciutti-Tovo and JB models could most accurately predict wide banded bimodal fatigue damage to a mooring system.

• Smart Structures and Systems
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• v.16 no.6
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• pp.1107-1132
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• 2015

A damage detection algorithm based on neuro fuzzy hybrid system is presented in this study for location and severity predictions of cracks in beam-like structures. A combination of eigenfrequencies and rotation deviation curves are utilized as input to the soft computing technique. Both single and multiple damage cases are considered. Theoretical expressions leading to modal properties of damaged beam elements are provided. The beam formulation is based on Euler-Bernoulli theory. The cracked section of beam is simulated employing discrete spring model whose compliance is computed from stress intensity factors of fracture mechanics. A hybrid neuro fuzzy technique is utilized to solve the inverse problem of crack identification. Two different neuro fuzzy systems including grid partitioning (GP) and subtractive clustering (SC) are investigated for the highlighted problem. Several error metrics are utilized for evaluating the accuracy of the hybrid algorithms. The study is the first in terms of 1) using the two models of neuro fuzzy systems in crack detection and 2) considering multiple damages in beam elements employing the fused neuro fuzzy procedures. At the end of the study, the developed hybrid models are tested by utilizing the noise-contaminated data. Considering the robustness of the models, they can be employed as damage identification algorithms in health monitoring of beam-like structures.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.4
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• pp.347-355
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• 2013

A damage estimation method for monopile support structure of offshore wind turbine using modal properties and committee of neural networks is presented for effective structural health monitoring. An analytical model for a monopile support structure is established, and the natural frequencies, mode shapes, and mode shape slopes for the support structure are calculated considering soil condition and added mass. The input to the neural networks consists of the modal properties and the output is composed of the stiffness indices of the support structure. Multiple neural networks are constructed and each individual network is trained independently with different initial synaptic weights. Then, the estimated stiffness indices from different neural networks are averaged. Ten damage cases are estimated using the proposed method, and the identified damage locations and severities agree reasonably well with the exact values. The accuracy of the estimation can be improved by applying the committee of neural networks which is a statistical approach averaging the damage indices in the functional space.

• Journal of Power System Engineering
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• v.19 no.2
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• pp.5-14
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• 2015

This investigation presents reviews of many research results on lightning damage to wind turbines and lightning protection strategies from IEC Standard, Europe, USA, Japan and Korea. There have been few studies on lightning protection of wind turbines in Korea, while various investigations have been performed in the other countries. It is necessary to apply some good lightning protection strategies of IEC Standard and the other countries to Korea. Those are as follows: The guideline for lightning protection of wind turbines should be established based on IEC Standards. It needs to be carried out both development of software and experimental studies for understanding the types of lightning damage to wind turbines and compiling the database. In order to minimize the lightning damage to wind turbines, it is a key factor for wind farm owners and researchers to provide the information about the damage cases and wind farm operation technique.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.1
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• pp.20-31
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• 2014

This paper deals with the development of a realistic shape optimization of damaged columns that are subjected to conservative and non-conservative forces, using the Genetic Algorithm (GA). The analysis is based on the design of the most optimized shape of the column under the constraint of constant weight, considering the Static, Vibrational, and Flutter characteristics. Under the action of conservative and non-conservative longitudinal forces, an elastic column loses its stability. A numerical analysis based on FEM has been performed on a uniform damaged column, to compute the fundamental buckling load, vibration frequency, and flutter load, under various end restraints. An optimization search based on the Genetic Algorithm is then executed, to find the optimal shape design of the column. The optimized column references the one having the highest buckling load, highest vibration frequency, and highest flutter load, among all the possible shapes of the column, for a given volume. A comparison is then made between the values obtained for the optimized damaged column, and those obtained for the optimized undamaged column. The comparison reveals that the incorporation of damage in the column alters its optimal shape to only a certain extent. Also, the critical load and frequency values for the optimized damaged column are comparatively low, compared with those obtained for the optimized undamaged column. However, these results hold true only for moderate-intensity damage cases. For high intensity damage, the optimal shape may not remain the same, and may vary, according to the severity of damage.

• Journal of Chest Surgery
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• v.16 no.1
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• pp.97-101
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• 1983

The steadily increasing number of operations performed on the heart has given rise to occasional complications involving the nervous system, and this has been interested to cardiac surgeons and neurologists. This survey has been carried out on all Gases submitted to open heart surgery at Seoul National University Hospital during 1982 to determine which operative features were associated with the occurrence of neurological damage. 514 subjects were studied and neurological damage was noted in twenty-five patients [4.9%]. Eight of these 25 patients died in the postoperative period, but neurological damage contributed to the fatal outcome in six cases. Remaining seventeen patients were discharged without problems except one Cortical blindness and one hemiplegic patients who were survived without other problems . A number of features were found to be related to the development of neurological damage, which were age, duration of perfusion, nature of operation, cardiac rhythm and presence of the thrombi or calcification and hypothermic arrest. But many unknown etiological factors are remained out of our sight. A significant increase in the incidence of neurological damage was shown in older age group [13.3% in over 40 year of age], and also the duration of the bypass was associated with subsequent neurological injury especially more than 120 minutes [11.6%]. The presence of atrial fibrillation with intracardiac thrombi or calcification was also a contributing factor to developing neurological complication [16.7%]. These factors were regarded to influence the postoperative neurological complications and more effective method for prevention of these neurologic complication should be studied.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.15
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• pp.119-136
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• 2001

The purpose of this paper is to consider how to decide the cause of loss or damage to the transport goods when maritime accident occurs. In marine insurance, the underwriter is liable for any loss or damage proximately caused by a risk insured(MIA Art.55). So it is very important to determine the proximate cause of loss or damage to ascertain whether it is to be recoverable under the policy. But there is no definite conception or rule what is the proximate cause. It was left to the tribunal as a question of fact. In this paper, I will suggest the general rules to determine the proximate cause of loss or damage of the transport goods in marine insurance. First, in MIA 1906, there is the rule of proximate causation and it has been established the effective causation by cases since 1918. Second, in Institute Cargo Clauses(B) & (C), there are rules of considerably relaxed standards to determine the causation of loss of or damage using the "attributable to" and "caused by" basis. Third, it is noted, under the complex causation situation, there are difference basises to decide the liability of underwriters between the case of successive occurrence of single risk and the case of concurrent occurrence of several risks. Forth, in practice, it couldn't be ascertained the underwrier's liability by a definite rule and it should be fully considered the circumstances and conditions of the loss.

• Wind and Structures
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• v.24 no.4
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• pp.385-403
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• 2017

In recent years, the wind energy has played an increasingly important role in national energy sector of many countries. To harvest more electric power, the wind turbine (WT) tower structure becomes physically larger, which may cause more risks during long-term operation. Associated with the great development of WT projects, the number of accidents related to large-scaled WT has also been increased. Therefore, a structural health monitoring (SHM) system for WT structures is needed to ensure their safety and serviceability during operational time. The objective of this study is to develop a hybrid damage detection method for WT tower structures by measuring vibration and impedance responses. To achieve the objective, the following approaches are implemented. Firstly, a hybrid damage detection scheme which combines vibration-based and impedance-based methods is proposed as a sequential process in three stages. Secondly, a series of vibration and impedance tests are conducted on a lab-scaled model of the WT structure in which a set of bolt-loosening cases is simulated for the segmental joints. Finally, the feasibility of the proposed hybrid damage detection method is experimentally evaluated via its performance during the damage detection process in the tested model.