• Journal of the Society of Naval Architects of Korea
• /
• v.29 no.4
• /
• pp.234-243
• /
• 1992

Fatigue crack initiation life has a wide scatter and this makes the fatigue design of structural members difficult. In order to make the fatigue life distribution clear, it is required to prepare a large number of specimens and repeat the fatigue tests under the same loading condition. Such fatigue tests usually take much time and cost. In this study, a fatigue testing method using a multi-notched test specimen for the purpose of estimating the distribution function of fatigue crack initiation life by small number of fatigue tests is used. The purpose of this study is to verify the above fatigue testing method of a multi-notched specimen by using Bayesian reliability analysis, Least square method and Skewness method for the determination of unknown Weibull parameters. The multi-notched specimen is a specimen in which several tens of statistically identical notches are prepared.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.14 no.1
• /
• pp.64-80
• /
• 2003

Although obsessive-compulsive disorder(OCD) affects children, adolescents, and adults whether its juvenile(dhild and adolescent) and adult forms are different subtype of a disorder remains unknown. But there are increasing findings that suggest that juvenile OCD may be unique subtype of the disorder. One proposed subtype is the childhood OCD associated with high comorbidity of tic disorder and increased familial loading for OCD or tic disorder. The other proposed subtype is the childhood OCD and/or tic disorder occuring in association with streptococcal infection(PANDAS). These two subtypes of OCD are unlikely to respond to SSRI due to possible different pathphysiological mechanism. So this paper reviews the characteristics of OCD and therapeutic approaches for treatment resistant OCD in childhood and adolescence. Considering the likely heterogeneity of OCD, the possibility that juvenild OCD may be a variant of the disorder can have important clinical and scientific implications because it may further our understanding of this disorder, its etiology, and perhaps its treatment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.17 no.3
• /
• pp.313-319
• /
• 2019

The A-KRS (Advanced Korean Reference Disposal System) is the disposal concept for pyroprocessed waste, which has been developed by the Korea Atomic Energy Research Institute. In this disposal concept, the amount of high-level radioactive waste is minimized using pyrochemical process, called pyroprocessing. The produced pyroprocessed waste is then solidified in the form of monazite ceramic. The final product of ceramic wastes will be disposed of in a deep geological repository. By the way, the decay heat is generated due to the radioactive decay of fission products and raises the temperature of buffer materials in the near field of radioactive waste repository. However, the buffer temperature must be kept below $100^{\circ}C$ according to the safety regulation. Usually, the temperature can be controlled by variation of the canister interdistance. However, KAERI has modelled thermal analysis under the boundary condition, where the waste canisters are in direct contact with each other. Therefore, a reliable temperature analysis in the disposal system may fail because of unknown thermal resistence values caused by the spatial gap between waste canisters. In the present work, we have performed thermal analyses considering the gap between heating elements and canisters at the beginning of canister loading into the radioactive waste repository. All thermal analyses were performed using the COMSOL software package.