• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.908-910
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• 1998

Modern AC electric car has PWM(Pulse Width Modulation) -controlled converters, which give rise to higher harmonics. The current harmonics injected from AC electric car is propagated through power feeding circuit. As the feeding circuit is a distributed constant circuit composed of RLC, the capacitance of the feeding circuit and the inductance on the side of power system cause a parallel resonance and a magnification of current harmonics at a specific frequency. The magnified current harmonics usually brings about various problems. That is, the current harmonics makes interference in the adjacent lines of communications and the railway signalling system. Furthermore, in case it flows on the side of power system, not only overheating and vibration at the power capacitors but also wrong operation at the protective devices can occur. Therefore, the exact assessment of the harmonic current flow must be undertaken at design and planning stage for the electric traction systems. From these point of view, this study presents an approach to model and to analyse traction power feeding system focused on the amplification of harmonic current. The proposed algorithm is applied to a standard AT(Auto-transformer)-fed test system in which electric car with PWM-controlled converters is running.

• Review of Culture and Economy
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• v.20 no.2
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• pp.119-147
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• 2017

This study analyzes Big Data to understand the economic influence of K-Beauty which is expected as a fast-growing industry. Because the content of K-beauty is mainly transmitted over the Internet, Big Data about K-Beauty in the database of online services can show interest and engagement in K-Beauty. The export volume of the beauty industry and the number of foreign tourist in Korea were used as dependent variables. The volume of Google search and the volume of YouTube page view were independent variables. According to the result of a multi-regression analysis, the volume of Google search of K-Beauty had a positive influence on both dependent variables, even after controlling for GDP (Gross Domestic Product) and distances between nations. When it comes to the volume of YouTube page view of K-Beauty, it had a positive relationship with the export volume of the beauty industry, whereas there was no significant relationship between the volume of YouTube page view and the number of foreign tourists. The result indicates that the content of K-Beauty has a significant impact on the beauty industry. Moreover, this empirical study shows that web search and YouTube search have a positive relationship with the economical aspect. These results can be used to discuss public relations strategy to promote K-Beauty industry.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.343-362
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• 2020

English is a stress-timed language that has a phonetic system in which the speech is restructured by stress changes. On the other hand, Korean is a syllable-timed language in which each syllable is pronounced at almost the same length and intensity, and Korean and English have distinctly different metrical systems in general speech. However, as the language of the lyrics in K-Pop music is mixed in both languages, Korean and English, the Korean lyrics in K-Pop music have a metrical system by stress changes as in English. The writer's view is that the change in the metrical structure of Korean lyrics is inevitable in order to sustain the new Korean Wave. Therefore, in this study, dance music - a major genre of K-Pop music that focuses on rhythm expression - is classified into 1998, 2003, and 2009 according to the changes in the Korean Wave, and the metrical structure of each period is compared and analyzed. Based on this, the current K-Pop metrical structure features are derived and the K-Pop Korean writing method is proposed that deviates from the existing limited writing method which allocates one syllable per note. The author hopes this research will be used as a methodology for writing lyrics in Korean songs in K-Pop, as well as a way to encourage the use of Korean lyrics.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.557-564
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• 2023

In this study, 3D printing technology was used to compensate for the shortcomings of the use of lead, which has proven to have excellent shielding performance, and to control unnecessary human exposure. 3D printers can implement three-dimensional shapes and can immediately apply individual ideas, which has great advantages in maintaining technology supplementation while reducing the cost and duration of prototyping. Among the various special 3D printers, the FDM method was adopted, and the filament used for output was manufactured using a research extruder by mixing two materials, PLA (Poly-Lactic-Acid) and tungsten. The purpose was to verify the validity through dose evaluation and to provide basic information on the production of chapezones of various materials. The mixed filament was implemented as a morphological shield. Filaments made of a research extruder by mixing PLA and tungsten were divided into 10 %, 20 %, 30 %, 40 %, and 50 % according to the tungsten content ratio. Through the process of 3D Modeling, STL File storage, G-code generation, and output, 10 cm × 10 cm × 0.5 cm was manufactured, respectively, and dose and shielding ability were evaluated under the conditions of tube voltages of 60 kVp, 80 kVp, 100 kVp, 120 kVp, and tube currents of 20 mAs and 40 mAs.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.267-280
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• 2019

The hybrid phenomenon of pronunciation of K-Pop lyrics, which is the diction fusion phenomenon of lyrics, is not a strategic measure for an overseas expansion but a natural formation in the course of history of K-Pop. With the debut of Seo Tai-ji and Boys in 1992, the course of K-Pop changed and settled from ballad to dance music. After three years, the success of a hip hop dance music, 'Come Back Home', opened up a door to Korean Americans who ascertained the potential competitiveness of a hip hop music in K-Pop market. And the writer insists that such advance of Korean Americans into K-Pop market is the origin of the bilingual usage and diction fusion phenomenon of K-Pop lyrics. Therefore, this research will look into the pronunciation system of Korean and English in order to understand the bilingual pronunciation system shown in the lyrics sung by Korean American hip hop singers in the 1990s. Moreover, through Korean pronunciation system, this analysis will discover the main cause of continual acceptance and application of Korean American's broken Korean in the diction of lyrics. Last but not least, this exploration will show the correlation of English pronunciation method of Korean lyrics appeared in K-Pop and the diction of Korean lyrics used by Korean American hip hop singers in late 90s. This research will identify the primary cause of the diction fusion phenomenon in the course of history of K-Pop.

• Journal of Nutrition and Health
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• v.56 no.5
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• pp.510-522
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• 2023

Purpose: In this study, data from the 7th Korea National Health and Nutrition Examination Survey (2016-2018) were used to examine the relationship between the prevalence of anemia and dietary intake among adults according to household types. Methods: Using data from a total of 10,646 subjects (4,428 men and 6,218 women), the general information, body measurements, results of biochemical examination, food and nutrient intake, and meal quality evaluation were analyzed according to the type of household. Results: The prevalence of anemia was higher in men belonging to single-person households (SPH) than in those from multi-person households (MPH), while anemia prevalence was higher among the women in the MPH than in the SPH. The men in SPH had a lower total food intake of nuts, vegetables, fruits, fish, and seaweed than the men in MPH, and consumed higher quantities of milk, oil, and processed foods. The women from SPH had a lower intake of seaweed and a higher intake of milk than those belonging to the MPH. In addition, the men in SPH had a lower iron intake and iron intake per 1,000kcal than the men in MPH, lower iron intake through plant-based foods, and a lower iron intake ratio compared to the reference nutrient intake. The total Korean Healthy Eating Index (KHEI) score was lower in both men and women in SPH than in those from the MPH. When analyzing the relationship between household type and anemia risk after correcting for the confusion variable, the risk of anemia in men in SPH increased compared to those belonging to the MPH. However, women showed no such significant correlation. There was no relationship between the total KHEI score and the risk of anemia by gender and household type. Conclusion: In conclusion, since anemia in men belonging to SPH is a matter of concern, it is essential to develop guidelines for anemia-related nutrition education for men living alone.

• Food Engineering Progress
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• v.13 no.3
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• pp.195-202
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• 2009

This study was accomplished that analysis of seven polycyclic aromatic hydrocarbons (PAHs) in smoked or nonsmoked processing foods by high performance liquid chromatography (HPLC) with fluorescence detection. The calibration line was constructed with injected different levels of standard concentration. Limit of detection (LOD) and limit of quantification(LOQ) showed higher linearity ($r^{2}$=0.998) reasonably, and recovery exhibited 0.033-0.666 $\mu$g/kg, 0.108-2.217 $\mu$g/kg and 69.31-90.14%, respectively. As a result, the samples using smoked tuna as smoked materials contained seven PAHs with different range from 0.256 to 0.486 $\mu$g/kg. The benzo[a]pyrene, indicator of PAHs, was detected to below the LOQ in two samples. Concentrations of benzo[a]pyrene in three samples were below the 2 $\mu$g/kg which is the limit of regulation. Smoked tuna sauces were detected from 0.321 to 0.552 $\mu$g/kg and not detected in drying powders. PAHs of smoked meat products were ranged from 0.720 to 2.027 $\mu$g/kg and are higher than concentration of tuna smoked samples. PAHs were very low in non-smoked foods including mustard, herb, and roasted meats.

• Journal of the Korean Society of Tobacco Science
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• v.36 no.1
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• pp.20-25
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• 2014

As part of a balanced testing battery, subchronic inhalation studies on rats are performed to ensure that proposed cigarette modifications do not increase the toxicity of smoke and to demonstrate any instances where a modification may actually contribute to harm reduction. For subchronic inhalation studies with aerosols, the OECD suggests an exposure regimen of 6 hours/day (OECD Guideline 413, 1981), but alternative regimens have also been published: 1 hour/day and $2{\times}1$ hour/day. The aim of this study was to validate a rodent nose-only exposure system for the assessment of inhalation toxicity of cigarette smoke. In this study, cigarette smoke exposure system is consisted of cigarette smoke generator, smoke concentration adjusting system, and 20-port nose-only exposure system. Male SD rats were exposed for 35 days ($2{\times}1$ hour/day) to 3R4F Reference cigarette smoke and analysed major monitoring items of OECD Gudeline 413. WTPM, was measured in the test atmosphere, respiratory function (Buxco Biosystems) during exposure, postexposure urinary exposure biomarkers and alveolar neutrophiles in BAL fluid (Day 35) were evaluated. Validation demonstrated steady WTPM ($257{\pm}20ug/L$, $502{\pm}27ug/L$) and spatial uniformity (<10%). Nose port temperature ($22{\sim}26^{\circ}C$ and RH (45~75%) were acceptable over 35 days. Reductions in respiratory rate and minute volume and increase in the neutrophiles in BALF and the urinary exposure biomarkers were observed cigarette smoke dose dependently. This validation and 35-day inhalation study has shown that the rodent nose-only exposure system may be useful in the inhalation toxicity assessment of cigarette smoke.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.67-71
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• 2021

In this study, graphene layer was grown on metal microwire using chemical vapor deposition. The difference of carbon solubility between copper and nickel resulted in the formation of mono-layer and multi-layer graphene were formed on the surfaces of copper and nickel microwires, respectively. During the growth of graphene at high temperature, copper and nickel were recrytallized and the grain size increased. The ampacity of graphene/copper microwire was improved by approximately 27%, 1.91×105 A/㎠, compared to pristine copper microwire. Similar to this behavior, the ampacity of multilayer graphene/nickel microwire was 4.41×104 A/㎠ which is about about 36% improved compared to the pure nickel microwire. The excellent electrical properties of graphene/metal composites are beneficial for supplying the electrical energy to the high-power electronic devices and equipment.

• Journal of Technologic Dentistry
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• v.43 no.1
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• pp.29-33
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• 2021

Purpose: This study was conducted on dental technicians to examine the problems of the dental laboratory registration system and devise a plan to improve it. Methods: For data collection, an online survey was conducted on 14,015 dental technicians registered in the Korea Dental Technologist Association as of October 2020. Among the collected 405 questionnaires, 391 data were used for analysis. Results: We found that dental technicians felt that the dental laboratory opening registration system was unfair. There were problems including the problem of the verification method of job performance, not acknowledging the difference in the job field, and the lack of understanding of the structure of work cooperation between dentistry and dental laboratories. Furthermore, it was recognized that the system was improved by reflecting the change in job area according to the change of the times. Conclusion: There is an urgent need to reorganize the legal system so that the dental technicians can have their professionalism and autonomy recognized while remaining faithful to the public interest of protecting the national oral health by revising the related regulations, thereby ensuring smooth work activities.