• Nuclear Engineering and Technology
• /
• v.48 no.4
• /
• pp.952-964
• /
• 2016

The prototype generation IV sodium-cooled fast reactor (PGSFR) has been developed by the Korea Atomic Energy Research Institute. This reactor uses sodium as a reactor coolant to transfer the core heat energy to the turbine. Sodium has chemical characteristics that allow it to violently react with materials such as a water or steam. When a sodium-water reaction (SWR) occurs due to leakage or breakage of steam generator tubes, high-pressure waves and corrosive reaction products are produced, which threaten the structural integrity of the components of the intermediate heat-transfer system (IHTS) and the safety of the primary heat-transfer system (PHTS). In the PGSFR, SWR events are included in the design-basis event. This event should be analyzed from the viewpoint of the integrities of the IHTS and fuel rods. To evaluate the integrity of the IHTS based on the consequences of the SWR, the behaviors of the generated high-pressure waves are analyzed at the major positions of a failed IHTS loop using a sodium-water advanced analysis method-II code. The integrity of the fuel rods must be consistently maintained below the safety acceptance criteria to avoid the consequences of the SWR. The integrity of the PHTS is evaluated using the multidimensional analysis of reactor safety-liquid metal reactor code to model the whole plant.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.2
• /
• pp.558-579
• /
• 2021

The cloud storage provides flexible data storage services for data owners to remotely outsource their data, and reduces data storage operations and management costs for data owners. These outsourced data bring data security concerns to the data owner due to malicious deletion or corruption by the cloud service provider. Data integrity verification is an important way to check outsourced data integrity. However, the existing data verification schemes only consider the case that a verifier launches multiple data verification challenges, and neglect the verification overhead of multiple data verification challenges launched by multiple verifiers at a similar time. In this case, the duplicate data in multiple challenges are verified repeatedly so that verification resources are consumed in vain. We propose a duplicate data verification algorithm based on multiple verifiers and multiple challenges to reduce the verification overhead. The algorithm dynamically schedules the multiple verifiers' challenges based on verification time and the frequent itemsets of duplicate verification data in challenge sets by applying FP-Growth algorithm, and computes the batch proofs of frequent itemsets. Then the challenges are split into two parts, i.e., duplicate data and unique data according to the results of data extraction. Finally, the proofs of duplicate data and unique data are computed and combined to generate a complete proof of every original challenge. Theoretical analysis and experiment evaluation show that the algorithm reduces the verification cost and ensures the correctness of the data integrity verification by flexible batch data verification.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.5 no.2
• /
• pp.40-44
• /
• 2009

In this study, Event Corrective Action Supporting System (ECAS) is developed for the accident evaluation in nuclear power plant. The ECAS system can be used in supporting regulator and/or operator under event situation in nuclear power plants. The ECAS system consists of 5 modules including failure location module, failure analysis module, failure integrity evaluation module, system vulnerability evaluation module, and reporting and operating experience feedback module. The ECAS system will be used as sub module of Knowledge-Based Event Evaluation Network (K-EvENT) which is developing for the against the accident in nuclear power plants.

• Journal of the military operations research society of Korea
• /
• v.24 no.2
• /
• pp.57-74
• /
• 1998

This paper is aimed to propose an testing and evaluation strategy and plan in Military Information Systems, especially focusing on development an“New-generation Wargame Model”. Through this research, we concluded that the effective and efficient testing/evaluation strategy/plan can aid the productivity, maintainability, availability, etc., of the Militray Information Systems. Highlights of the proposed testing and evaluation strategy and plan for Military Information Systems are as follows. First, in the unit and module integration testing phase, hybrid of black-box and white-box testing techniques are available for Military Information Systems and progressive approach for module integration phase should be considered because of the complexity. Second, in the system testing phase, integrated module should be tested with respect to the function and performance that should be satisfied with the user requirements, specifications, risk analysis, etc., Third, in the acceptance testing phase, reliability, interoperability, maintainability, availability, integrity, etc., must be considered in the actual or mini-operational environments for testing efficiently and effectively.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.627-631
• /
• 2003

In a various regulations and standards related to the spent fuel storage, the storage casks should be designed to sustain the structural integrity under the accident conditions of predicted operation and design criteria. These conditions for the structural evaluation requires the drop, tip-over, wind like tornado and typhoon, flood and earthquake. This paper describes the load cases and conceptual evaluation method for the structural evaluation. Preliminary safety analysis of the concrete storage system were peformed.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.11a
• /
• pp.210-211
• /
• 2021

This study introduces and demonstrates the application of an experimental regime for anti-seismic performance evaluation of waterproofing materials to used for concrete pile walls. Concrete pile walls are subject to high degree of seismic load, and the occurring stress can affect the waterproofing integrity of the structure, but there is currently no existing methodology or standard for evaluating this property of waterproofing materials. To propose and conduct this evaluation, a new testing apparatus was designed and manufactured intended to be able to test an installed waterproofing material's seismic resistance performance.

• Journal of Animal Science and Technology
• /
• v.49 no.6
• /
• pp.729-736
• /
• 2007

The objective of this study was to investigate the anti-oxidative effects of pyruvate, taurine and melatonin on sperm characteristics(motility, membrane integrity) and lipid peroxidation(LPO) for in vitro storage of boar semen. Semen was treated with various antioxidants such as pyruvate(1mM), taurine(50mM) and melatonin(100nM) with or without 100uM H2O2. Antioxidant treatments were significantly increased the sperm motility when compare to control group in all incubation periods(P≤0.05). Hypoosmotic swelling test(HOST), membrane integrity was similar to the result of motility. In lipid peroxidation measurement by TBA reactions of spermatozoal plasma membrane, malondialdehyde(MDA) level in control and antioxidant treatments were lower than those of antioxidant plus H2O2 or H2O2 treatment for 3 to 6 h incubation period. Relationships of evaluation methods for sperm viability were investigated by motility, membrane integrity and lipid peroxidation. Among evaluation methods, LPO vs motility and membrane integrity vs LPO were negatively correlated(－0.23~－0.92 and －0.68~－0.85), but membrane integrity vs motility was positively correlated (0.53~0.94) in all treatments. These experiments indicate that supplementation of antioxidant to the semen extender can increase the sperm motility and membrane integrity and decrease the lipid peroxidation of spermatozoal plasma membrane. The HOST might be utilized to evaluate the sperm quality instead of lipid peroxidation or motility.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.8
• /
• pp.1035-1041
• /
• 2013

To evaluate the structural integrity and dynamic characteristic of the knuckle part of a KTX anti-roll bar, an experimental and a numerical approach were used in this study. In the experimental approach, the acceleration and strain data for the knuckle parts of the KTX and KTX-SANCHUN anti-roll bar were respectively measured to evaluate and compare its structural dynamic characteristics under the operating environments of the Honam line. In the numerical approach, the evaluation of its structural integrity was conducted using LS-DYNA 3D, and then, the reliability of the finite element model used was ensured by a comparative evaluation with the experiment. The numerical results showed that the stress and velocity field of the knuckle part composed of a layered structure of a thin steel plate and rubber were more moderate than those of the knuckle part made of only a thick steel block owing to the reduction of relative contact between the knuckle and the connecting rod. It was found that the knuckle part made of a thin steel plate and rubber was recommended as the best solution to improve its structural integrity resulting from the elastic behavior of the KTX anti-roll bar being enabled under a repeating external force.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.9 no.4
• /
• pp.403-413
• /
• 2007

As rock bolts become one of the main support systems in tunnels and underground structures, the integrity of the rock bolts affects the safety of these types of structures. The purpose of this study is the evaluation of rock bolt integrity using Fourier and wavelet transforms of the guided ultrasonic waves. After five rock bolt specimens with various defect ratios are embedded into a large scale concrete block, guided waves are generated by a PZT (lead zirconate titanate) element and measured by an acoustic emission (AE) sensor. The captured signals are analyzed in the frequency domain using the Fourier transform, and in the time-frequency domain using the wavelet transform based on a Gabor wavelet. The spectrum obtained from the Fourier transform shows that a portion of high frequency contents increases with increase in the defect ratio. Peak values in the time-frequency domain represent the interval of travel time of each echo. The energy velocities of the guided waves increase with the defect ratio. This study shows that the spectrum ratio and the energy velocity may be indicators fur the evaluation of rock bolt integrity.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.31 no.2
• /
• pp.144-149
• /
• 2011

The lock-in thermography was employed to evaluate the integrity of railway bogies. Prior to the actual application on railway bogies, in order to assess the detectability of known flaws, the calibration reference panel was prepared with various dimensions of artificial flaws. The panel was composed of structural steel, which was the same material with actual bogies. Through lock-in thermography evaluation, the optimal frequency of heat source was determined for the best flaw detection. Based on the defects information, the actual defect assessments on railway bogie were conducted with different types of railway bogies, which were used for the current operation. In summary, the defect assessment results with thermography method showed a good agreement as compared with the conventional inspection techniques. Moreover, it was found that the novel infrared thermography technique could be an effective way for the inspection and the detection of surface defects on bogies since the infrared thermography method provided rapid and non-contact mode for the investigation of railway bogies.