• Food Science of Animal Resources
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• v.37 no.3
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• pp.464-468
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• 2017

The identification of pork in commercially processed meats is one of the most crucial issues in the food industry because of religious food ethics, medical purposes, and intentional adulteration to decrease production cost. This study therefore aimed to develop a method for the detection of pork adulteration in meat products using primers specific for pig mitochondrial DNA. Mitochondrial DNA sequences for pig, cattle, chicken, and sheep were obtained from GenBank and aligned. The 294-bp mitochondrial DNA D-loop region was selected as the pig target DNA sequence and appropriate primers were designed using the MUSCLE program. To evaluate primer sensitivity, pork-beef-chicken mixtures were prepared as follows: i) 0% pork-50% beef-50% chicken, ii) 1% pork-49.5% beef-49.5% chicken, iii) 2% pork-49% beef-49% chicken, iv) 5% pork-47.5% beef-47.5% chicken, v) 10% pork-45% beef-45% chicken, and vi) 100% pork-0% beef-0% chicken. In addition, a total of 35 commercially packaged products, including patties, nuggets, meatballs, and sausages containing processed chicken, beef, or a mixture of various meats, were purchased from commercial markets. The primers developed in our study were able to detect as little as 1% pork in the heat treated pork-beef-chicken mixtures. Of the 35 processed products, three samples were pork positive despite being labeled as beef or chicken only or as a beef-chicken mix. These results indicate that the developed primers could be used to detect pork adulteration in various processed meat products for application in safeguarding religious food ethics, detecting allergens, and preventing food adulteration.

• Journal of Welding and Joining
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• v.31 no.2
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• pp.16-20
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• 2013

Titanium and its alloys have been widely using in the various field of industry application due to high corrosion resistant properties and mechanical properties. Titanium is highly reactive in the high temperature state and the formation of titanium oxide and porosities in the nuggets of fusion welding will results in the degradation of the mechanical properties. For this reason the studies of friction stir welding for titanium have been investigated recently. The FSW zones of titanium were classified by the weld nugget (WN), the linear transition boundary (TB) and the heat affected zone (HAZ). The WN along with titanium parent was characterized by the presence of twins and dislocations. The average grain size and hardness of WN has been changed according to heat input. The grain refinement resulted from the FSW increased the hardness in the stir zone. Sound dissimilar joints between SUS 304 and CP-Ti were achieved using an advancing speed of 50 mm/min and rotation speeds in the range of 700-1100 rpm. Aluminum 1060 and titanium alloy Ti-6Al-4V plates were lap joined by friction stir welding, hence the ultimate tensile shear strength of joint reached 100% of Al 1060. Mg alloy and Ti were successfully butt joined by inserting a probe into the Mg alloy plate with slightly offsetting. But Ti-Al intermetallic compound layers formed at the interface of these joints.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.1-11
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• 2022

In this study, an electric resistance dual-spot welding process using a copper electrode inserted in a heating electrode is suggested for the spot welding of AZ31 magnesium sheets. This spot-welding process involves two heating methods for welding at the interfacial zone between the magnesium sheets, one of which is the heating method by thermal conduction from the heating electrode heated by the welding current induced to the steel electrode, and the other heating method uses the electric resistance between the contacted surfaces of the two sheets by the welding current induced to the copper electrode. This welding process includes the welding variables, such as the current induced in the heating electrode and the copper electrode, and the outer diameters of the heating electrode. This is because the heat conducted from the heating electrode can be maintained at a higher temperature in the welding zone, which has a slow cooling effect on the nugget of the melted metal after the welding step. The pressure exerted during the pressing of the magnesium sheets by the heating electrode can be increased around the nugget zone at the spot-welding zone. Thus, it not only reduces the warping effect of the elastoplastic deformation of sheets, but also the corona bond can make it less prone to cracking at the welded zone, thereby reducing the number of nuggets expelled out of the corona bond. In conclusion, it was known that an electric resistance dual spot welding process using the copper electrode inserted in the heating electrode can improve the welding properties in the electric resistance spot welding process of AZ31 magnesium sheets.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.30.2-31
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• 2017

Compact elliptical (cE) galaxies are in a rare class of stellar systems characterized by high stellar densities, small sizes, high velocity dispersion, and high metallicity corresponding to elliptical galaxies. cE galaxies have been observed around massive galaxies, so they could be formed under strong influences of tidal stripping and truncation. However, the recent discovery of isolated cE galaxies requires the need of new formation scenarios. We aim at finding cE galaxies in various environments using SDSS DR12, and studying stellar population of cEs as function of environments. Based on the typical properties of cE galaxies, we selected cE candidates by restricting that low-luminosity Mg > 19.5 mag, small sizes Re < 700 pc, and high velocity dispersions ${\sigma}$ > $60kms^{-1}$. Since effect radii of cE candidates are mostly smaller than the seeing size of SDSS photometry, we calculated the effective radius by fitting a Sersic profile. In addition, we assumed that host galaxies have brightness with Mr < -21 mag, and an environmental parameter is computed as distances between cE galaxies and host-galaxies. We found 112 cE galaxies at z < 0.05, which have high sersic indices (mean value is 5.2) similar to the typical massive elliptical galaxies. Mgb values of cE galaxies increase as the distances from the host galaxies decrease. Especially, for cEs close to the host galaxies (NcE; $D_{host}$ < 300 pc), the Mgb values are similar to those of massive elliptical galaxies, which is consistent with the previous studies. On the other hand, cE galaxies distant from the host galaxies (DcE; Dhost >300 pc) have lower Mgb values than the conventional cE. The Mgb values follow the ${\sigma}$-Mgb relation of elliptical galaxies, and are connected to its faint end. This can be explained as a result of different merger histories for differing environments. For example, NcE galaxies are formed by tidal stripping by massive galaxies as suggested by previous studies, but DcE galaxies could be linked with high-redshift spheroids (e.g. red nuggets) which have not evolved into present-day elliptical galaxies because of the environmental influences.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.25-33
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• 2020

In this paper, the purpose is to verify the impact of performance expectations, effort expectations, social impact, individual innovation and perceived value on the intent of use and the behavior of use. Used Unified Theory of Acceptance and Use of Technology (UTAUT) to verify the applicability of this model in China, and established the research model by adding two new variables to UTAUT according to the situation of the Chinese market. To achieve this goal, 345 questionnaires were collected for experienced music creators using artificial intelligence nuggets in China by means of Internet research. The collected data were analyzed through frequency analysis, factor analysis, reliability analysis, and structural equation analysis through SPSS V. 22.0 and AMOS V 22.0. The verification of the hypotheses presented in the research model identified the decisive influence factors on the use of artificial intelligence music acceptance by Chinese users. The study is innovative in that it attempts to verify the applicability of UTAUT in the Chinese context. In the construction of the user acceptance model of AI music, three influencing factors will have an effect on users' intentions, and according to the degree of effect, from largest to smallest, they are respectively Perceived Innovativeness, Performance Expectancy and Effort Expectancy. This paper will also provide some management advices, i.e. improving the utility and usability of AI music, encouraging users with individual innovativeness, developing competitive and attractive pricing policies, increasing publicity, and prioritizing word-of-mouth advertising.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.794-801
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• 2021

This study examined the mechanical strength and corrosion resistance of a dissimilar joint with an aluminum alloy and steel by resistance element spot welding. SPFC980 steels and Al5052 alloys were applied as the base materials. S20C steels were assembled on Al5052 for the riveting element before the electric resistance welding process. The SPFC980-S20C riveted Al5052 was welded at a 6.5 kA current and 250 kgf/㎠. As a result, the engraved S20C elements formed unstable nuggets after the spot welding processes. In contrast, in the embossed S20C elements, exceptional mechanical properties, such as robust corrosion resistance and fatigue resistance, were obtained by structurally sound joints. The correlation between the microstructure and mechanical properties were examined by microstructural investigations and FEM simulations. The corrosion reliability of element spot-welded SPFC980-Al5052 dissimilar joints was investigated systematically.