• Journal of Power System Engineering
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• v.10 no.1
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• pp.77-82
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• 2006

In this study, dissimilar friction welding were produced using 15mm diameter solid bar in chrome molybedenum steel(SCM440) to carbon steel(S45C) to investigate their mechanical properties and the relationship between the weld parameters and the nondestructive coefficients, such as AE counts and ultrasonic attenuation coefficient. The main friction welding parameters were selected to endure good quality welds on the basis of visual examination, tensile tests, Vickers hardness surveys of the bond of area and heat affected zone. The specimens were tested as-welded and post weld heat treated(PWHT). The tensile strength of the friction welded steel bars was increased up to 100％ of the S45C base metal under the condition of all heating time. The ductility of PWHT specimens is higher than as-welded.

• Journal of Ocean Engineering and Technology
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• v.10 no.4
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• pp.67-74
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• 1996

The paper focuse on the effect of a crack subjects to collaspe behabiors of statically indeterminate beams under concentrated load. Through the experiment and calculation, it was revealed that the collaspe load of statically indeterminate beams is much higher than that of statically determinate beams. The cumulative AE event counts of statically determinate beams was less than that of statically indeterminate beams, and the center notch beams sas revealed less than that of the side notch beams.

• Korean Journal of Clinical Pharmacy
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• v.23 no.3
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• pp.223-231
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• 2013

Objective: This study aimed to identify the status and risk factors of rituximab infusion-related adverse events (ADE) in rituximab-na$\ddot{i}$ve patients with cancer diseases. Method: A retrospective analysis using electronic medical records review was conducted. Inclusions were patients with a diagnosis of cancer disease with the initiation of rituximab-included treatment who were na$\ddot{i}$ve to rituximab during January 2011 to March 2013 at National Cancer Center (NCC) in Korea. Result: Total 110 patients, 582 cases of rituximab administrations, were reported in the study. About 57.2% of patients were 51-70 years old and evenly distributed between two genders and 72.7% were BMI less than $25kg/m^2$. All of study patients were diagnosed with non-Hodgkin lymphoma. Fifty patients (45.4%) and 54 cases (9.3%) were experienced rituximab infusion-related AEs even with conservative administration protocol at NCC. The most frequently occurring AEs were shivering followed by rash and itching. In single variant analysis, we found that the early stage of NHL, low exposure to rituximab administrations, high white blood cell counts, high lymphocyte counts, high absolute neutrophil count and low lactate dehydrogenase were associated with infusion-related AEs (p<0.05). The early stage of disease, high lymphocyte counts, low exposure to rituximab administrations were also related significantly with AEs in multiple variants analysis (p<0.05). Conclusion: Rituximab infusion-related AEs for patients who were na$\ddot{i}$ve to rituximab were still a concern with conservative administration protocol. The adverse drug reactions were significantly associated with early stage of NHL, higher lymphocyte counts and low exposure to rituximab administrations. The factors need to be considered with close monitoring to prevent rituximab infusion-related AE.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.1
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• pp.62-67
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• 2011

Nanoparticles-coated and impact-damaged carbon-fiber reinforced plastics(CFRP) laminates were tested under compression-after-impact(CAI) mode and the propagation of damage due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. CFRP laminates were made of carbon prepregs prepared by coating of conductive nano-particles directly on the fibers and the coupons were subjected to simulated lightning strikes with a high voltage/current impulse of 10~40 kA within a few microseconds. The effects of nano-particles coating and the degree of damage induced by the simulated lightning strikes on the AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terms of damage area by using ultrasonic C-scan images. From the results assessed during the CAI tests of damaged CFRP showed that AE monitoring appeared to be very useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes.

• Geomechanics and Engineering
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• v.12 no.6
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• pp.919-933
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• 2017

A series of Brazilian tests under diameter compression for disc specimens was carried out to investigate the strength and failure behavior by using acoustic emission (AE) and photography monitoring technique. On the basis of experimental results, load-displacement curves, AE counts, real-time crack evolution process, failure modes and strength property of granite specimens containing two pre-existing holes were analyzed in detail. Two typical types of load-displacement curves are identified, i.e., sudden instability (type I) and progressive failure (type II). In accordance with the two types of load-displacement curves, the AE events also have different responses. The present experiments on disc specimens containing two pre-existing holes under Brazilian test reveal four distinct failure modes, including diametrical splitting failure mode (mode I), one crack coalescence failure mode (mode II), two crack coalescences failure mode (mode III) and no crack coalescence failure mode (mode IV). Compared with intact granite specimen, the disc specimen containing two holes fails with lower strength, which is closely related to the bridge angle. The failure strength of pre-holed specimen first decreases and then increases with the bridge angle. Finally, a preliminary interpretation was proposed to explain the strength evolution law of granite specimen containing two holes based on the microscopic observation of fracture plane.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1081-1089
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• 2018

The deformation and strength of brittle rocks are significantly influenced by the crack closure behavior. The relationship between the strength and deformation of rocks under uniaxial loading is the foundation for design and assessment of such scenarios. The concept of relative crack closure strain was proposed to describe the influence of the crack closure behavior on the deformation and strength of rocks. Considering the crack compaction effect, a new damage constitutive model was developed based on accumulated AE counts. First, a damage variable based on the accumulated AE counts was introduced, and the damage evolution equations for the four types of brittle rocks were then derived. Second, a compaction coefficient was proposed to describe the compaction degree and a correction factor was proposed to correct the error in the effective elastic modulus instead of the elastic modulus of the rock without new damage. Finally, the compaction coefficient and correction factor were used to modify the damage constitutive model obtained using the Lemaitre strain equivalence hypothesis. The fitted results of the models were then compared with the experimental data. The results showed that the uniaxial compressive strength and effective elastic modulus decrease with an increase in the relative crack closure strain. The values of the damage variables increase exponentially with strains. The modified damage constitutive equation can be used to more accurately describe the compressive deformation (particularly the compaction stage) of the four types of brittle rocks, with a coefficient of determination greater than 0.9.

• Geomechanics and Engineering
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• v.22 no.5
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• pp.385-396
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• 2020

A uniaxial compression test was performed to analyse the mechanical properties and macroscale and mesoscale failure mechanisms of sandstone with pyrite concretions. The effect of the pyrite concretions on the evolution of macroscale cracks in the sandstone was further investigated through numerical simulations with Particle Flow Code in 2D (PFC2D). The results revealed that pyrite concretions substantially influence the mechanical properties and macroscale and mesoscale failure characteristics of sandstone. During the initial loading stage, significant stress concentrations occurred around the edges of the pyrite concretion accompanied by the preferential generation of cracks. Meanwhile, the events and cumulative energy counts of the acoustic emission (AE) signal increased rapidly because of friction sliding between the concretion and sandstone matrix. As the axial stress increased, the degree of the stress concentration remained relatively unchanged around the edges of the concretions. The cracks continued growing rapidly around the edges of the concretions and gradually expanded toward the centre of the sample. During this stage, the AE events and cumulative energy counts increased quite slowly. As the axial stress approached the peak strength of the sandstone, the cracks that developed around the edges of the concretion started to merge with cracks that propagated at the top-left and bottom-right corners of the sample. This crack evolution ultimately resulted in the shear failure of the sandstone sample around the edges of the pyrite concretions.

• Journal of the Korean Society of Food Culture
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• v.18 no.5
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• pp.428-436
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• 2003

The effect of addition with maesil(Prunus mume) juice for extending the shelf-life of wet noodle was investigated by measuring quality changes such as total microbial count and pH. The Prunus mume juice showed antimicrobial activities against Salmonella enteritidis, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Escherichia coli. When the wet noodles containing Prunus mume juice were kept at $4^{\circ}C$ for 20 days, it was showed that the drop of pH was not significantly occurred during the storage. Total microbial counts for control exceeded the initial putrefactive criterion level of $1.0{\times}10^6\;cfu/g$ at 16 days of storage at $4^{\circ}C$. However, total microbial count of wet noodles with the addition of 10%, 20% and 30% Prunus mume juice were $3.0{\times}10^2\;cfu/g,\;3.0{\times}10^2\;cfu/g,\;and\;1.5{\times}10^2\;cfu/g$, respectively, and these bacterial counts were still less than the criterion level ever at 20 days of storage. The addition of Prunus mume juice extended the shelf-life of wet noodle appreciably.

• Korean Journal of Plant Taxonomy
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• v.41 no.3
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• pp.215-222
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• 2011

Various aneuploidy and polyploidy have been reported in the genus Aconitum L. (ca. 300 species worldwide, Ranunculaceae), and there is a demonstrated association between major lineage diversification and polyploidy. This study reports chromosome counts of eight Aconitum from Korea, including the first counts for A. japonicum Thunb. subsp. napiforme ($H. L{\acute{e}}v.$ & Vaniot) Kadota (2n = 32) and A. longecassidatum Nakai (2n = 16). The study also includes chromosome numbers for two taxa on the Critically Endangered species list in Korea. Among Korean native species, chromosome numbers in Aconitum subgenus Aconitum range from 2n = 16 to 2n = 64 with diverse levels of polyploidy (2x, 4x, and 8x), whereas Aconitum subg. Lycoctonum exhibits only diploids (2n = 16). Greater chromosome number diversity in subg. Aconitum than subg. Lycoctonum might explain higher species diversity within the former subgenus (more than 250 species worldwide). Investigating chromosome number diversity of Aconitum in a phylogenetic framework will be a critical step to understand species richness of the genus.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6A
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• pp.39-49
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• 2008

AEA and ARIA are next generation standard block cipher of US and Korea, respectively, and these algorithms are used in various fields including smart cards, electronic passport, and etc. This paper addresses the first efficient unified hardware architecture of AES and ARIA, and shows the implementation results with 0.25um CMOS library. We designed shared S-boxes based on composite filed arithmetic for both algorithms, and also extracted common terms of the permutation matrices of both algorithms. With the $0.25-{\mu}m$ CMOS technology, our processor occupies 19,056 gate counts which is 32% decreased size from discrete implementations, and it uses 11 clock cycles and 16 cycles for AES and ARIA encryption, which shows 720 and 1,047 Mbps, respectively.