• Structural Engineering and Mechanics
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• v.72 no.4
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• pp.525-540
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• 2019

The purpose of the present work was to study the dynamic instability of a three-layered, symmetric sandwich beam subjected to a periodic axial load resting on nonlinear elastic foundation. A higher-order theory was used for analysis of sandwich beams with soft core on elastic foundations. In the higher-order theory, the Reddy's third-order theory was used for the face sheets and quadratic and cubic functions were assumed for transverse and in-plane displacements of the core, respectively. The elastic foundation was modeled as nonlinear's type. The dynamic instability regions and free vibration were investigated for simply supported conditions by Bolotin's method. The results showed that the responses of the dynamic instability of the system were influenced by the excitation frequency, the coefficients of foundation, the core thickness, the dynamic and static load factor. Comparison of the present results with the published results in the literature for the special case confirmed the accuracy of the proposed theory.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.259-264
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• 2014

Body insertion due to the recent development of sensor technology, the device is attached patients to receive medical services from anywhere, anytime environment is changing. Body insertion devices for the hospital, the patient's vital information attached personnel (doctors, nurses, pharmacists, etc.) to pass, however, when a problem occurs, a patient's information to a third party that can be exploited easily exposed. In this paper, we proposed signature authentication protocols mandate based on the patient's power of attorney from the center of the u-Healthcare services, hospital officials FormHelper third party disguised as a patient, the hospital patient information easily obtained from the officials to prevent. The proposed protocol, the patient's sensitive information to a third party, do not expose the patient's sensitive information to the random number generated by the u-Healthcare service centers and patients hash signature key to encrypt sensitive information of patients. From third parties to maintain synchronization between the patients and the hospital personnel in order to prevent patient information from being exploited illegally by the patient's vital information leakage can be prevented.

• Journal of Acupuncture Research
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• v.20 no.6
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• pp.63-79
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• 2003

Objective: It makes a through study on the popularization and usefulness paln of Moxa Combustion, therefore popularizing practical use of that. Methods: It was based on the established treatises and books, in order to studying about the literature of Moxa Combustion Results & Conclusions: It makes a through study on the whole of Moxa Combustion, the results as follows. 1. We explained(illustrated) the origin, history, classification and mechanism(effect) of Moxa Combustion 2. The study of standardization plan of Moxa Combustion for popularization - The thermal stimulation of Moxa Combustion was decided the characteristic pattern of combustion temperature by moxa burning and that makes a measure to grasp the effective action of Moxa Combustion upon human body. Thereupon it is necessary to continue further studies by analysing the characteristic pattern of combustion temperature by moxa burning and there clinical effects in practice. 3. The usefulness of Moxa Combustion - The therapeutic effect of Moxa Combustion are hematopoiesis(increase the blood), analgesic function, increase the immunity, antioxidant activity, diuretic action, control of hormone(endocrine gland), supression of carcinogenesis, increase the self involution(natural healing), decrease of GOT/GPT, Glucose, Cholesterol level.

• Journal of Society of Preventive Korean Medicine
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• v.9 no.2
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• pp.93-106
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• 2005

A survey was performed for 2 weeks in October 2004 in order to examine the effects and changes of far infrared and anion of office workers aged 40 and older before and after wearing the underwear. In the survey, questionnaires and photoplethysmography were used to measure the difference between the two tests conducted with one week interval. The findings could be summed up as follows: 1. There was no statistically significant difference in changes of vascular aging points and photoplethysmogram wave form before and after wearing the far infrared and anion underwear but the points showed the increasing tendency(p>0.05). 2. A statistically significant difference was confirmed since the total points of each item in the questionnaires increased after wearing the underwear(p<0.001). 3. In connection with the systemic symptoms, a significant difference was found with increased points in all items except for no. 6 after wearing the underwear(p<0.05). 4. With regard to the difference before and after wearing the underwear depending on the Kidney symptoms, there was a significant difference with increased points in all items except for item no. 1 after wearing the underwear(p<0.05). In conclusion, to put on the underwear with effect of far infrared and anion is believed to smooth metabolism and blood circulation, contributing by thus to promoting health and preventing disease. Further studies with wider sampling of subjects are requested to diversify and refine the findings from this sectional study.

• The Korean Journal of Air & Space Law and Policy
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• v.21 no.1
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• pp.65-95
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• 2006

It is essential that the liability for damage on the surface caused by aircraft be regulated at international level. However, the Rome Convention on Damage Caused by Foreign Aircraft to Third Parties on the Surface of 1952 and the Montreal Protocol of 1978 did not have significant worldwide repercussions since few countries have ratified them. So the Secretariat ofthe ICAO has produced the draft Convention for the modernization of the Rome Convention in 2002 and the Special group has considered the text of the draft Convention so far. The draft Convention contains main issues with regard to the liability system of the operator and the insurability of the risks for damage to third parties on the ground. In order to protect the air transport sector of a country as well as to facilitate speedy recoveries by victims, Work on modernizing the Rome Convention should be continued and the new Convention should be finalized in the near future.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.59-64
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• 2000

The real time monitoring system is developed to detect third party damage imposed on natural gas pipeline and to estimate a damage position in section of pipeline in need of monitoring the third party damage. The monitoring system uses wireless data communication in order to build up data communication network. The availability of monitoring system was evaluated through full scale field damage test at Masan's submarine gas pipeline. It was turned out that the estimation error was one percentage of the propagation speed of damage sound in the gas pipeline.

• Journal of Arbitration Studies
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• v.28 no.4
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• pp.153-172
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• 2018

In solving international commercial disputes, arbitration has a unique advantage. Therefore, when most parties sign a charter party, they contain arbitration clauses. Whether the arbitration clause in the charter party can be effectively incorporated into the bill of lading and bind to the third party-bill holder becomes an important issue. Based on the problem above, this paper compares the arbitration system between Korea and China, and discusses the composition of the Chinese Maritime Court and the Chinese court's adjudication of arbitration for foreign countries, which are recognized and enforced in China. What is most important in this study is observing the Chinese case from the beginning of 2000 to the present in order to rule whether the Chinese court can effectively incorporate the arbitration clause in the charter party into the bill of lading, as well as whether it constitutes an effective binding force for third parties and changes in standard of recognition. Finally, through comparative analysis, the study concludes that in China, the arbitration clause in the charter party can be effectively incorporated into the bill of lading, and that the conditions for the third parties can be effectively restrained. There must be several points to be noted when recording the bill of lading. This would then help reduce the legal risks and promote the sustainable development of international transactions.

• Journal of Korea Water Resources Association
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• v.41 no.2
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• pp.229-239
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• 2008

This study is to derive the fourth-order Geomorphologic Instantaneous Unit Hydrograph (GIUH), driven for only third-order basin, for the application of GIUH to various types of basin. The second, third, and fourth order GIUHs were compared for various topographical conditions. The results showed lower peak runoff and later peak time in GIUH with higher stream order. Initial state probability was estimated from a function of geomorphologic parameters such as area ratio and bifurcation ratio for the application of GIUH. However, initial state probabilities and early parts of the GIUHs have negative values for many basins due to the inherent errors in the parameters. Initial state probability was calculated by area ratio of direct drainage using ArcView GIS 3.2 model to solve the problem. GIUHs were estimated for three basins, Sanganmi, Byeongcheon, and Sangye, using the above suggested method, and the results showed that the method is free of the problem.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.9
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• pp.1227-1238
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• 2000

This study examines the effects of the discretization schemes on numerical solutions of viscoelastic fluid flows. For this purpose, a temporally evolving mixing layer, a two-dimensional vortex pair interacting with a wall, and a turbulent channel flow are selected as the test cases. We adopt a fourth-order compact scheme (COM4) for polymeric stress derivatives in the momentum equations. For convective derivatives in the constitutive equations, the first-order upwind difference scheme (UD) and artificial diffusion scheme (AD), which are commonly used in the literature, show most stable and smooth solutions even for highly extensional flows. However, the stress fields are smeared too much and the flow fields are quite different from those obtained by higher-order upwind difference schemes for the same flow parameters. Among higher-order upwind difference schemes, a third-order compact upwind difference scheme (CUD3) shows most stable and accurate solutions. Therefore, a combination of CUD3 for the convective derivatives in the constitutive equations and COM4 for the polymeric stress derivatives in the momentum equations is recommended to be used for numerical simulation of highly extensional flows.

• Structural Engineering and Mechanics
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• v.68 no.3
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• pp.325-334
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• 2018

The Nonlinear dynamic response of a sandwich plate subjected to the low velocity impact is theoretically and experimentally investigated. The Hertz law between the impactor and the plate is taken into account. Using the Extended High Order Sandwich Panel Theory (EHSAPT) and the Ritz energy method, the governing equations are derived. The skins follow the Third order shear deformation theory (TSDT) that has hitherto not reported in conventional EHSAPT. Besides, the three dimensional elasticity is used for the core. The nonlinear Von Karman relations for strains of skins and the core are adopted. Time domain solution of such equations is extracted by means of the well-known fourth-order Runge-Kutta method. The effects of core-to-skin thickness ratio, initial velocity of the impactor, the impactor mass and position of the impactor are studied in detail. It is found that these parameters play significant role in the impact force and dynamic response of the sandwich plate. Finally, some low velocity impact tests have been carried out by Drop Hammer Testing Machine. The results are compared with experimental data acquired by impact testing on sandwich plates as well as the results of finite element simulation.