• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.245-253
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• 2006

A test of the 1/3 scale model was conducted to verify the tip-over analysis of a dry. concrete storage cask under a hypothetical accident condition. The tip-over analysis was executed using the velocity at each point as the initial conditions of the model just before the impact. The initial velocity was determined from the initial angular velocity, which would make the equivalent kinetic energy to the potential energy. To confirm the structural integrity of the canister, the visual testing and the non-detective testings such as Liquid Penetrant testing and Ultrasonic Testing were conducted. The lid of a storage cask was plastically deformed near the impact point. The structural integrity of storage cask was maintained. To verify the tip-over analysis the strains and the accelerations acquired by the tip-over test were compared with those by the analyses. The results of the analysis were larger than the test results about two times.

• Steel and Composite Structures
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• v.43 no.6
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• pp.773-784
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• 2022

This paper aims to investigate the axial compressive behavior of reinforced concrete (RC) columns strengthened with self-compacting and micro-expanding (SM) concrete-filled steel tubes (SM-CFSTs). Nine specimens were tested in total under the local axial compression. The test parameters included steel tube thickness, filling concrete strength, filling concrete type and initial axial preloading. The test results demonstrated that the initial stiffness, ultimate bearing capacity and ductility of original RC columns were improved after being strengthened by SM-CFSTs. The ultimate bearing capacity of the SM-CFST strengthened RC columns was significantly enhanced with the increase of steel tube thickness. The initial stiffness and ultimate bearing capacity of the SM-CFST strengthened RC columns were slightly enhanced with the increase of filling concrete strength. However, the effect of filling concrete type and initial axial preloading of the SM-CFST strengthened RC columns were negligible. Three equations for predicting the ultimate bearing capacity of the SM-CFST strengthened RC columns were compared, and the modified equation based on Chinese code (GB 50936-2014) was more precise.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.201-208
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• 2000

In this study, the behavior of saturated sandy soils under dynamic loads - pore water pressure and effective stress - was investigated using Disturbed State Concept(DSC) model. The model parameters are evaluated from laboratory test data. During the process of loading and reverse loading, DSC model is utilized to trace strain-hardening and cyclic softening behavior. The procedure of back prediction proposed in this study are verified by comparing with laboratory test results. From the back prediction of pore water pressure and effective mean pressure under cyclic loading, excess pore water pressure increases up to initial effective confining pressure and effective mean pressure decrease close to zero in good greement with laboratory test results. Those results represent the liquefaction of saturated sandy soils under dynamic loads. The number of cycles at initial liquefaction using the model prediction is in good agreement with laboratory test results. Therefore, the results of this study state that the liquefaction of saturated sandy soils can be explained by the effective tress analysis.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.101-110
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• 2013

PURPOSES : The purpose of this study is to evaluate the durability of ternary blended concrete mixtures adding ultra fine admixture. METHODS : From the literature review, crack was considered as the main distress failure criterion on concrete bridge deck pavement. To reduce the initial crack development due to drying shrinkage, CSA expansion agent and shrink reduction agent were used to ternary blended concrete mixtures as a admixture. Laboratory tests including chloride ion penetration test, surface scaling test, rapid freeze & thaw resistance test, non restrained drying shrinkage and restrained drying shrinkage test were conducted to verify the durability of ternary blended concrete mixtures. RESULTS : Based on the test results, proposed mixtures were verified as high qualified durable materials. Expecially initial drying shrinkage crack was not occurred in ternary blended concrete mixtures with CSA expansion agent. CONCLUSIONS : It is concluded that the durability of proposed ternary blend concrete mixture was acceptable to apply for the concrete bridge deck pavement.

• New & Renewable Energy
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• v.3 no.1 s.9
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• pp.60-67
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• 2007

Catalyst coated membrane [CCM] type and catalyst coated substrate [CCS] type of membrane electrode assembly [MEA] were manufactured and evaluated their performance. Degradation test were conducted to find the difference of long term stability in two types of MEA and the factor for performance degradation problem occurred. Performance degradation test of single cell in two different types of MEA were carried out when current density was $200mA/cm^{2}$. The degradation test had proceeded for 230 hours and performance degradation was checked by I-V curve and impedance measurement at regular intervals. Also, MEA before/after operation and changes of catalyst layer were characterized by SEM, TEM, and XRD. Maximum power density of CCM type was higher than that of CCS type. Meanwhile, an increase of particle size of catalyst and an increase of impedance resistance after long term operation were observed. In the case of using CCM type MEA, the performance was deteriorated 38% of initial performance. In the case of using CCS type MEA, the performance was deteriorated 43% of initial performance. In consideration of difference of initial performance, performance of CCM type is higher than that of CCS type but both types had similar problems during degradation test.

• Journal of Applied Reliability
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• v.16 no.3
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• pp.208-215
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• 2016

Purpose: ASRP for the domestic development guided missiles requires not only for the reliability evaluation of the products in storage but also for the life cycle management of the products including development prototypes and initial production items. Methods: For this purpose, it should be performed to build a performance database before and after the accelerated aging test with shelf life items including development prototypes and initial production items, based on which the lifetime prediction should also be carried out. In addition, HILS must be applied for the acceptance test with the initial and follow-up production items, and also for ASRP for the long-term storage products in order to secure systematic quality assurance. Results: The results for the life cycle reliability Improving of domestic development of guided missiles are DB building of prescription Item performance, active application of HILS, Management associated with guided missiles life cycle and to Secure technology data about the introduction of foreign guided missiles. Conclusion: Furthermore, it is demanded that DTaQ, the managing agency of ASRP, actively take part in the process to maintain reliability engagement consistency over the life cycle of guided missiles.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.91-99
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• 2010

This paper reports on an identification test where KFL learners identified the Korean three-way laryngeal contrast in the phrase-initial position, when the phrase-initial tone was systematically manipulated. It turns out that heritage learners have some sensitivity to phrase-initial tone and show a plain-aspirated alternation in their identification according to the phrase-initial tone, as native speakers do, whereas non-heritage students do not show such tone sensitivity. However, after a weekly prosody training, second-year non-heritage students have shown a significant improvement in their performance. This paper clearly shows that the phrase-initial tone plays a critical role in distinguishing laryngeal features of Korean obstruents, and also suggests that prosody including the tone-segment correlation should be incorporated in the KFL curriculum.

• Geotechnical Engineering
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• v.13 no.6
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• pp.95-106
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• 1997

A pressuremeter is an expandable tube which is placed in the soil, and then expanded under controlled condition against the soil. From this test a pressure expansion curve of the soil can be obtained. However soil disturbance during the test has significant influence on the results of tests. A general governing equation for pressuremeter test can be theoretically derived on the basis of the hyperbolic soil model and the cavity expansion theory. The curve fitting technique was used to establish the pressure-strain curve without disturbance of soil during testing. This interpretation makes use of both the loading and unloading portions of the test. An interpretation methodology is described and illustrated with pressuremeter test data carried out in the weathered granitic soil to estimate initial shear modulus. Standard penetration test is a very common site investigation technique in Korea. Therefore the blow counts of standard penetration test are discussed by comparing them with initial shear modulus.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3C
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• pp.115-125
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• 2009

The preconsolidation pressure has been commonly determined by oedometer test. However, it can also be determined by insitu test, such as piezocone test with theoretical and(or) empirical correlations. Recently, Neural Network (NN) theory was applied and some models were proposed to estimate the preconsolidation pressure or OCR. It was already found that NN model can come over the site dependency and prediction accuracy is greatly improved when compared with present theoretical and empirical models. However, since the optimization process of synaptic weights of NN model is dependent on the initial synaptic weights, NN models which are trained with different initial weights can't avoid the variability on prediction result for new database even though they have same structure and use same transfer function. In this study, Committee Neural Network (CNN) model is proposed to improve the initial weight dependency of multi-layered neural network model on the prediction of preconsolidation pressure of soft clay from piezocone test result. Prediction results of CNN model are compared with those of conventional empirical and theoretical models and multi-layered neural network model, which has the optimized structure. It was found that even though the NN model has the optimized structure for given training data set, it still has the initial weight dependency, while the proposed CNN model can improve the initial weight dependency of the NN model and provide a consistent and precise inference result than existing NN models.

• Journal of Acupuncture Research
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• v.25 no.3
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• pp.163-177
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• 2008

Objectives : This study was designed to evaluate clinical prognosis factors of Bell's palsy patients. Methods : The 100 subjects were chosen from 262 patients over 20years old who was diagnosised Bell's palsy through Acupuncture & Moxibustion and ENT medical specialist after visiting the hospital within 8days of onset of peripheral facial palsy and after Oriental-Western Medicine Treatment, recovered completely or had over three months cares because of incomplete recovery Oriental-Western Medicine Treatment included Acupuncture Treatment, Herb med treatment, medicines treatment, Physical therapy and Electrodiagnostic Test was operated after 7 to 10days after outbreaks of the disease. Clinical prognosis factors were analyzed using House-Brackmann grading system(HBGS) as a measurement of the degree of Facial Palsy. Collected data were analyzed as Chi-Square test, ANOVA test, Independent-Samples t-test regression analysis using SPSS 12.0 WIN Program. Results : 1. There was a significant difference in the results of treatment according to site of palsy, degree of initial palsy, time of initial recovery and existence of recovery after 3weeks from onset as clinical prognosis factors of Bell's Palsy, However, a statistically significant difference was not shown in the results of treatment according to gender, age, existence of Post Auricular Pain, Hypertension, Diabetes and existence of relapse. 2. As a result of overall treatment, 85% of patients were recovered almost entirely and 15% were not recovered completely. 3. There was a significant difference in the onset of Post Auricular Pain and duration of Post Auricular Pain according to the degree of Post Auricular Pain. 4. There was a significant difference in the degree of initial palsy and degree of palsy after 3weeks from onset according to the existence of Post Auricular Pain. However, a statistically significant difference was not shown in the period of time until initial treatment, The time of initial recovery, (H-B), The period from onset to recovey, ENoG value. Conclusions : Based on the above results, prognosis of Bell's palsy was affected by degree of initial palsy, time of initial recovery and existence of recovery after 3weeks from onset.