• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.77-83
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• 2006

Ultrasonic nonlinearity has been considered as a solution for the detection of microcracks or interfacial delamination in a layered structure. The distinguished phenomenon in nonlinear ultrasonics is the generation of higher-order harmonic waves during the propagation. Therefore, in order to quantify the nonlinearity, the conventional method measures a parameter defined as the amplitude ratio of a second-order harmonic component and a fundamental frequency component included in the propagated ultrasonic wave signal. However, its application In field inspection is not easy at the present stage because no standard methodology has yet been made to accurately estimate this parameter. Thus, the aim of this paper is to propose an advanced signal processing technique for the precise estimation of a nonlinear ultrasonic parameter, which is based on power spectral and bispectral analysis. The method of estimating power spectrum and bispectrum of the pulse-like ultrasonic wave signal used in the commercial SAM (scanning acoustic microscopy) equipment is especially considered in this study The usefulness of the proposed method Is confirmed by experiments for a Newton ring with a continuous air gap between two glasses and a real semiconductor sample with local delaminations. The results show that the nonlinear parameter obtained tv the proposed method had a good correlation with the delamination.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.320-331
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• 2013

The National Center for AgroMeteorology (NCAM) has designed a risk management solution for individual farms threatened by the climate change and variability. The new service produces weather risk indices tailored to the crop species and phenology by using site-specific weather forecasts and analysis derived from digital products of the Korea Meteorological Administration (KMA). If the risk is high enough to cause any damage to the crops, agrometeorological warnings or watches are delivered to the growers' cellular phones with relevant countermeasures to help protect their crops against the potential damage. Core techniques such as scaling down of weather data to individual farm level and the crop specific risk assessment for operational service were developed and integrated into a cloud based service system. The system was employed and implemented in a rural catchment of 50 $km^2$ with diverse agricultural activities and 230 volunteer farmers are participating in this project to get the user-specific weather information from and to feed their evaluations back to NCAM. The experience obtained through this project will be useful in planning and developing the nation-wide early warning service in agricultural sector exposed to the climate and weather extremes under climate change and climate variability.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.1
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• pp.150-168
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• 1991

A practical procedure for the ultimate compressive strength-based safety and reliability assessment of the double skin upper deck structure is described. The external compressive stress acting on the upper deck structure which is due to the still water and wave-induced sagging moment is approximately estimated by using the existing rule of classification society. The ultimate compressive stress of double skin structure under the action of sagging moment is analyzed by using idealized structural unit method. Here an idealized plate element subjected to uniaxial load is formulated by idealizing the nonlinear behaviour of the actual element taking account of the initial imperfections in the form of initial deflection and welding residual stress. The interaction effect between the local and global failure in the structure is also taken into consideration. The accuracy of the present method is verified comparing with the present solution and the existing numerical and experimental results for unit member and welded box columns. The safety of the structure is evaluated using the concept of conventional central safety factor and the reliability assessment is made by using Cornel's MVFOSM method. The present procedure is then applied to upper deck structure of double skin product oil carrier. The influence of the initial imperfections and the yield stress of the material on the safety and reliability of the structure is investigated.

• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.585-589
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• 1994

The complexation of cadmium(II) with a well characterized local soil fulvic acid was investigated at different solution pH and fulvic acid concentration using ion selective electrode. The stability constants were determined using a continuous distribution model based on Scatchard Plot; this model takes into consideration the diversitv of cation binding sites on a naturally occurring organic macromolecules even if the nature of the binding sites may not be known. The mean value of $logKi(\mu)$ was found to increase at higher pH(pH 4.0: ${\mu}=3.79{\pm}0.74$ l\;mol^{-1}; pH 6.0: ${\mu}=4.51{\pm}0.78$ l\;mol^{-1}$), and in more dilute fulvic acid concentration([FA] = 50 mgl$^{-1}: {\mu}=4.16{\pm}0.60$ l\;mol^{-1}; [FA]=151 mgl$^{-1}:{\mu}=3.75{\pm}0.5\;l\;mol^{-1}$). The intrinsic constant(logKint) for binding at the strongest site was measured to be around $4.72\;l\;mol^{-1}$ at both pH4.0 and 5.0, but was found to be increased to $6.03\;l\;mol^{-1}$ when pH was 6.0.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.5
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• pp.177-188
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• 2018

The scale of graph data has been increased rapidly because of the growth of mobile Internet applications and the proliferation of social network services. This brings upon the imminent necessity of efficient distributed and parallel graph processing approach since the size of these large-scale graphs are easily over a capacity of a single machine. Currently, there are two popular parallel graph processing approaches, vertex-centric graph processing and block centric processing. While a vertex-centric graph processing approach can easily be applied to the parallel processing system, a block-centric graph processing approach is proposed to compensate the drawbacks of the vertex-centric approach. In these systems, the initial quality of graph partition affects to the overall performance significantly. However, it is a very difficult problem to divide the graph into optimal states at the initial phase. Thus, several dynamic load balancing techniques have been studied that suggest the progressive partitioning during the graph processing time. In this paper, we present a load balancing algorithms for the block-centric graph processing approach where most of dynamic load balancing techniques are focused on vertex-centric systems. Our proposed algorithm focus on an improvement of the graph partition quality by dynamically reassigning blocks in runtime, and suggests block split strategy for escaping local optimum solution.

• Journal of Digital Contents Society
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• v.17 no.5
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• pp.307-316
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• 2016

A user usually gets the same suggesting results as everyone else in most of the multimedia social services, nowadays. To address the challenging problem of personalization in the social network, we propose a method which exploits user's activities, user's moods, and user's friend relationships from the social network to build a decision-making system. Depending on a current state of the user's mood, this system infers the most appropriated video for the user. In the system, the user evaluates a set of the given recommendation methods which extract from the user's database social network and assigns a vague value to each method by a weight. Then, we find the fuzzy collection solution for the system and classify the set of methods into subsets, and order the subsets based on its local dominance to choose the best appropriate method. Finally, we conduct an experiment using the YouTube API with a lot of video types. The experiment result shows that the channel recommendation system appropriately affords the user's character, it is more satisfying than the current YouTube based on an evaluation of several users.

• Journal of Veterinary Clinics
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• v.28 no.3
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• pp.273-279
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• 2011

Botulinum toxin type A (BoNT/A) has been proven to be a safe and effective treatment for wrinkles in human. As well as the anti-wrinkle effects, the anti-pruritic effect of BoNT/A has been revealed from several researches for new therapy. The aim of this study was to investigate the anti-pruritic effect of BoNT/A against histamine-induced pruritus on canine skin. Five clinically healthy beagles were included in the study. All dogs were received 0.05 ml (5 Unit) of BoNT/A on the right dorsal thoracic region as an experiment and the same volume of saline solution was injected on the left dorsal thoracic region as a control, respectively. Intradermal histamine injections were performed four times (before treatment and days 1, 3 and 7 after BoNT/A injection). The severity of pruritus, the diameter and thickness of wheal, the erythema index and cutaneous temperature were assessed. The severity of pruritus was reduced on BoNT/A treated sides, compared with saline treated sides (p < 0.05). BoNT/A decreased wheal size, in both diameter and thickness (p < 0.05). Although, erythema index of both sides were increased after first histamine injection, BoNT/A treated sides showed the low-value as compared with saline treated sides. Cutaneous temperature was decreased significantly on BoNT/A treated sides. These results indicates that BoNT/A reduce histamine-induced pruritus on canine skin and suggested a possibility of application of BoNT/A for local intractable dermatologic problem in dogs.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.186-191
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• 2012

The sodium hypochlorite is widely used in endodontic treatment. While it is effective solution for disinfection of root canal system, complications during canal irrigation are rarely reported, especially in primary teeth. This report demonstrates that sodium hypochlorite extruding through the root apex might cause severe complications. A 4-year-old female patient was referred from local dental clinic to the emergency room for the management of sudden facial swelling and pain during re-endodontic treatment of the maxillary primary central incisor using sodium hypochlorite. The patient was given systemic steroids, antihistamines, antibiotics and analgesics and the maxillary primary central incisor was extracted to prevent secondary infection. Swelling began to subside after 2 days. A negative result was obtained from skin patch test with sodium hypochlorite. Thorough care must be taken in primary teeth to prevent the inadvertent injection of sodium hypochlorite to periapical tissues during root canal irrigation. When adverse reaction occurs, proper management such as analgesia, cold compression and adequate medication should be done.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.121-130
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• 1990

Plain 0.5% bupivacaine and hyperbaric 0.5% tetracaine were compared for spinal anesthesia in 40 patients undergoing operation of lower extremities. Lumbar puncture was performed with a 22 gauge spinal needle with the patient in the lateral recumbent position. The third lumbar interspace was chosen for the puncture, when a free flow of clear CSF was obtained, the local anesthetic solution (2.5ml of 0.5% bupivacaine or 2.0ml of hyperbaric 0.5% tetracaine) was injected at a rate of 0.1ml/sec without barbotage. After injection of anesthetics, clinical features were observed and compared between the two groups. The results were as follows : 1. The two groups were well matched for age, sex, height and weight. 2. In both groups, sensory block to $T_{12}$ dermatome was obtained within 4 minutes, mean maximal level of analgesia was $T_{6-7}$, and the mean time for maximal level was around 20 minutes. 3. The onset times of motor block were similar in both groups and complete motor block was obtained in all cases within 20 minutes. 4. The duration of analgesia above the $T_{12}$ dermatome was 3 hours, postoperative analgesia was 7 hours. These values were significantly prolonged than those of the tetracaine group(p<0.05). 5. The changes in systolic pressure in the bupivacaine group were significantly less than those of the tetracaine group(p<0.05). 6. The complications after spinal anesthesia were headache, numbness, urinary retention and backpain, and were no significant difference in both groups. From the obtained results, we concluded that plain 0.5% bupivacaine was a relatively satisfactory agent for spinal anesthesia for operation of lower extremities. The time of onset, height of block and the complications of postoperative period were similar in both groups. The advantages of plain 0.5% bupivacaine were less hypotension and long duration of analgesia.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.295-305
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• 2004

Colloid and surface chemistry have been focused on surface area and surface energy. Local surface properties such as surface density, interaction, molecular orientation and reactivity have been one of interesting subjects. Systems of such surface energy being important would be listed as association colloid, emulsion, particle dispersion, foam, and 2-D surface and film. Such nanoparticle systems would be applied to drug delivery systems and functional cosmetics with biocompatible and degradable materials, while nanoparticles having its size of several nm to micron, and wide surface area, have been accepted as a possible drug carrier because their preparation, characteristics and drug loading have been inves-tigated. The biocompatible carriers were also used for the solubilization of insoluble drugs, the enhancement of skin absorption, the block out of UV radiation, the chemical stabilization and controlled release. Nano/micro emulstion system is classified into nano/microsphere, nano/microcapsule, nano/microemulsion, polymeric micelle, liposome according to its prep-aration method and size. Specially, the preparation method and industrial applications have been introduced for polymeric micelles self-assembled in aqueous solution, nano/microapsules controlling the concentration and activity of high concen-tration and activity materials, and monolayer or multilayer liposomes carrying bioactive ingredients.