• Corrosion Science and Technology
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• v.20 no.6
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• pp.403-411
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• 2021

In this study, the reliability of a commercial ER-type corrosion sensor was evaluated under an accelerated corrosion environment to verify its suitability for application in monitoring of ship's seawater piping system. A closed-loop pump piping testbed was designed and constructed to compare the wall thickness reduction of the pipe and the response from the sensor. The sensor was attached inside the pipe near the outlet of the pump that was exposed to a 3.5% NaCl solution with or without copper accelerated acetic acid (CASS). The results demonstrated that the presence of CASS significantly increased the corrosivity of the solution as well as the thickness reduction of the pipe, as expected. On the other hand, the corrosion products formed by the solution with CASS were thicker compared with those without CASS. The sensor response to temperature variation was found to be a clear linear relationship for the solution without CASS but there was a non-linear relationship where CASS was present.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1167-1174
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• 2022

Cast austenitic stainless steels (CASSs) are widely used as structural materials in the nuclear industry. The main drawback of CASSs is the reduction in fracture toughness due to long-term exposure to operating environment. Even though ultrasonic non-destructive testing has been conducted in major nuclear components and pipes, the detection of cracks is difficult due to the scattering and attenuation of ultrasonic waves by the coarse grains and the inhomogeneity of CASS materials. In this study, the ultrasonic signals measured in thermally aged CASS were discriminated for the first time with the simple ultrasonic technique (UT) and machine learning (ML) models. Several different ML models, specifically the K-nearest neighbors (KNN), Support Vector Machine (SVM), and Multi-Layer Perceptron (MLP) models, were used to classify the ultrasonic signals as thermal aging condition of CASS specimens. We identified that the ML models can predict the category of ultrasonic signals effectively according to the aging condition.

• Asia Marketing Journal
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• v.15 no.4
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• pp.187-200
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• 2014

The case study of OB shows dramatic market dynamics between leader brand vs. follower brand similar to Kirin vs. Asahi in Japan for two decades. Almost 20yrs ago, the brand status of OB was dramatically fallen because of the environmental pollution of subsidiary company and harsh competition of rivalry brand. But OB made a ground change in its brand strategy. OB departed from the pride in its past to bet on the new. OB decided to vitalize Cass brand through brand portfolio strategy. They deployed 3 phase articulated marketing plans; Phase I, Acquisition of Cass brand through M&A and strategic segmentation/targeting (1993-2005), Phase 2 - Mega Brand Strategy through Line Extension(2006-2009), Phase 3 - Experiential Marketing focused on Young Culture (2010- present). Finally, OB restored not only brand reputation of Cass and other brands but dominant market position in beer market. Now Cass has been growing rapidly in the last 20 years achieving 50% M/S. The three phases shows the typical successful process of brand management and revitalization adopting brand concept management and S-T-P strategy of manufacturing company.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.621-625
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• 2020

Cast austenitic stainless steel (CASS) is used for fabricating different components of the primary reactor coolant system of pressurized water reactors. However, the thermal embrittlement of CASS resulting from long-term operation causes structural safety problems. Ultrasonic testing for flaw detection has been used to assess the thermal embrittlement of CASS; however, the high scattering and attenuation of the ultrasonic wave propagating through CASS make it difficult to accurately quantify the flaw size. In this paper, we present a different approach for evaluating the thermal embrittlement of CASS by assessing changes in the material properties of CASS using a nonlinear ultrasonic technique, which is a potential nondestructive method. For the evaluation, we prepared CF8M specimens that were thermally aged under four different heating conditions. Nonlinear ultrasonic measurements were performed using a contact piezoelectric method to obtain the relative ultrasonic nonlinearity parameter, and a mini-sized tensile test was performed to investigate the correlation of the parameter with material properties. Experimental results showed that the ultrasonic nonlinearity parameter had a correlation with tensile properties such as the tensile strength and elongation. Consequently, we could confirm the applicability of the nonlinear ultrasonic technique to the evaluation of the thermal embrittlement of CASS.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.2
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• pp.218-224
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• 2001

Although Attention Deficit Hyperactivity Disorder(ADHD) has been considered as the disorder occurring during childhood, the prevalence is increasing among adolescents and adults. The prevalence rate varies from 2.0 to 14.3% due to the difference of diagnostic criteria, different assessment methods, or subjects' age difference. Therefore, it needs to make age specific(i.e., for children, for adolescents, and for adults) assessment tools. Authors translated Conners-Wells Adolescents Self-Report Scales(short form)[CASS(S)] in to Korean to get validity and reliability as a way of development of assessment tool for adolescent with ADHD in Korea. CASS(S) was translated and corrtected by three psychiatrists and one clinical psychologist. To examine the concurrent validity and test-retest validity, CASS(S) was applied with K-YSR on one class of each grade in a middle school in Seoul with two week interval(total 115：male 58, female 57). To test validity, authors analysed and got Cronbach's as internal consistency. Construct validity was done by principal axis factor analysis on 4,354 students. As a result, Cronbach's alpha for internal consistency was .88, Pearson coefficient for test-retest reliability .83, and coefficient for concurrent validity .65. And in the factor analysis to examine construct validity, three factors were revealed as cognition, hyperactivity, and conduct. These results shows that CASS(S) may be useful tool for adolescents with ADHD, although there was a limit not to be done the comparison with clinical groups.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.6 no.1
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• pp.29-36
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• 2010

Ultrasonic inspection of heavy walled cast austenitic stainless steel(CASS)welds is very difficult due to complex and coarse grained structure of CASS material. The large size of anisotropic grain strongly affects the propagation of ultrasound by severe attenuation, change in velocity, and scattering of ultrasonic energy. therefore, the signal patterns originated from flaws can be difficult to distinguish from scattered signals. To improve detection and sizing capability of ID connected defect for heavy walled CASS piping welds, the low frequency segmented TRL Pulse Echo and Phased Array probe has been developed. The experimental studies have been performed using CASS pipe mock-up block containing artificial reflectors(ID connected EDM notch). The automatic pulse echo and phase array technique is applied the detection and the length sizing of the ID connected artificial reflectors and the results for detection and sizing has been compared respectively. The goal of this study is to assess a newly developed ultrasonic probe to improve the detection ability and the sizing of the crack in coarse-grained CASS components.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.94-95
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• 2014

The purpose of this study is to evaluate the corrosion protective property of Al-Mg high-freqeuncy arc metal spray method in comparison to Zn-Sn and Zn-Al alloys by electrochemical method and CASS test. As a result, it appeared that Al-Mg alloy had very higher corrosion protective property through the electrochemical characteristic and the CASS test comparing with the other alloys.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1357-1368
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• 2021

This paper presents thermal aging effect on fracture toughness properties of GTAW (gas tungsten arc welding) and SMAW (shielded metal arc welding) of 316L stainless steels, and investigates the applicability of the existing three thermal aging models for CASS (cast stainless steels). Thermal aging was carried out at 350 ℃ for up to 15,000h and at 400 ℃ up to 8,000h. After aging, tensile and fracture toughness tests using 0.5T C(T) specimens were carried out at room temperature and at 288 ℃. Comparing with the predictions using three (ANL, French and H3T) thermal aging models for CASS show that the predictions can be very non-conservative at operating temperature, and thus that the existing thermal aging models for CASS cannot be applied to the welded stainless steels.

• Journal of the Korean institute of surface engineering
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• v.36 no.4
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• pp.307-316
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• 2003

Salt spray, CASS(copper accelerated acetic salt spray) and EC(electrolytic corrosion) tests were performed in order to evaluate the corrosion resistance of plated Ni and Ni-Cr layers on Fe substrate. Compared with the conventional methods such as salt spray and CASS, the electrochemical method such as EC test may be beneficial in terms of test time span and quantitative accuracy. Furthermore, EC test can also become the alternative method to evaluate the resistance to corrosion of coatings by measuring the corrosion potentials of the coated layers in the electrolyte during the off-time of EC cycles. Compared with the corrosion potentials of pure iron, nickel, chromium, those potentials of coated layers can be used to anticipate the extent of corrosion. Results showed that in terms of the test time span, EC test gave 14 times and 21 times faster results than the salt spray test in cases of $5\mu\textrm{m}$ Ni and $20\mu\textrm{m}$ Ni plated layers, respectively. In addition, EC test also offered the shorter test time span than CASS test in cases of $5 \mu\textrm{m}$ Ni + $0.5\mu\textrm{m}$ Cr, and $20\mu\textrm{m}$ Ni + $0.5\mu\textrm{m}$ Cr on Fe substrate by 78 times and 182 times, respectively. Therefore, EC test can be regarded as the better method to evaluate the resistance to corrosion of coated layers than the conventional methods such as salt spray and CASS.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1153-1160
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• 2019

Objective: The objective of this study was to investigate the effect of bamboo grass (Tiliacora triandra, Diels) pellet (Bamboo-Cass) supplementation on feed intake, nutrient digestibility, rumen microbial population and methane production in Thai native beef cattle. Methods: Four Thai native beef cattle bulls ($190{\pm}2kg$) were randomly allotted to four respective dietary treatments in a $4{\times}4$ Latin square design. Treatments were the varying levels of Bamboo-Cass supplementation at 0, 50, 100, and 150 g/head/d, respectively. Rice straw was fed ad libitum and the concentrate offered at 0.5% of body weight. Results: Under this experiment, the findings revealed that acetate and butyrate production were decreased (p<0.05), propionate increased (p<0.05), whilst ruminal $NH_3-N$ concentration was decreased (p<0.05) by supplementation of Bamboo-Cass at 150 g/head/d. Moreover, rice straw intake, and microbial population were linearly increased (p<0.05), while methane production was decreased (p<0.05). Conclusion: The results from the present study indicate that supplementation of Bamboo-Cass at 150 g/head/d significantly enhanced feed intake, decreased protozoa and increased bacterial population, rumen fermentation efficiency while decreased methane production. Therefore, Bamboo-Cass as a supplement is promising as a rumen enhancer in beef cattle fed on rice straw.