• International Journal of Reliability and Applications
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• v.17 no.2
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• pp.137-147
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• 2016

The engine mount of a car subjected to a pre-load related to the weight of the engine, and acts to insulate the vibration coming from the engine by moving on large or small displacement depending on the driving condition of the car. The vibration insulation of the engine mount is an effect obtained by dissipating the mechanical energy into heat by the viscosity characteristic of the rubber and the microscopic behavior of the additive carbon black. Therefore, dynamic stiffness from the intrinsic properties of rubber filled with carbon black at the design stage is an important design consideration. In this paper, we introduced a hyper-elastic, visco-elastic and elasto-plastic model to predict the dynamic characteristics of rubber, and developed a fitting program to determine the material model parameters using MATLAB. The dynamic characteristics analysis of the rubber insulator of the ACTIVE MOUNT was carried out by using MSC.MARC nonlinear structural analysis software, which provides the dynamic characteristics material model. The analysis results were compared with the dynamic characteristics test results of the rubber insulator, which is one of the active mount components, and the analysis results were confirmed to be valid.

• Current Optics and Photonics
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• v.5 no.3
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• pp.298-305
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• 2021

Modern distance sensing methods employ various measurement principles, including triangulation, time-of-flight, confocal, interferometric and frequency comb. Among them, the triangulation method, with a laser light source and an image sensor, is widely used in low-cost applications. We developed an omnidirectional two-dimensional (2D) distance sensor based on the triangulation principle for indoor floor mapping applications. The sensor has a range of 150-1500 mm with a relative resolution better than 4% over the range and 1% at 1 meter distance. It rotationally scans a compact one-dimensional (1D) distance sensor, composed of a near infrared (NIR) laser diode, a folding mirror, an imaging lens, and an image detector. We designed the sensor layout and configuration to satisfy the required measurement range and resolution, selecting easily available components in a special effort to reduce cost. We built a prototype and tested it with seven representative indoor wall specimens (white wallpaper, gray wallpaper, black wallpaper, furniture wood, black leather, brown leather, and white plastic) in a typical indoor illuminated condition, 200 lux, on a floor under ceiling mounted fluorescent lamps. We confirmed the proposed sensor provided reliable distance reading of all the specimens over the required measurement range (150-1500 mm) with a measurement resolution of 4% overall and 1% at 1 meter, regardless of illumination conditions.

• Medical Lasers
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• v.10 no.2
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• pp.106-110
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• 2021

Background and Objectives As the popularity of tattooing has increased, the number of people regretting their tattoos, and therefore seeking tattoo removal services has also increased. This study aimed to highlight the reasons for tattoo regrets. We explore herein, the reasons for seeking tattoo removal at a specialized laser center in South America. Materials and Methods This is a retrospective study of over 757 surveys, including patients who sought tattoo removal services between August 2017 and February 2020. The surveys were conducted using questionnaires which were sent to the patients through email and WhatsApp messages. Results Sixty percent of the patients seeking tattoo erasing services were women (α=0.001), an average of 30 years, with a high educational level (46.6% of them were university or tertiary). Most of the tattoos (89%) had a professional origin, 60% were done with black color and 65% were in exposed areas. More than half of the patients (51%) gave dissatisfaction as the main reason for erasing their tattoos. More than half of patients (51.2%) regretted their tattoos between the same day of being tattooed and five years later. Conclusion In the present study, in South America, tattoo regrets were mostly common among educated (university or tertiary level) women in their 30s. The most preferred color for a tattoo was black. Exposed areas, especially the arms, were preferred more than the covered areas. Most of the participants regretted their tattoos within five years of being tattooed.

• Geomechanics and Engineering
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• v.28 no.2
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• pp.171-180
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• 2022

Time-dependent stress-strain behaviour significantly influences the compressibility characteristics of the clayey soil. In this paper, a series of oedometer tests were conducted in two loading patterns and investigated the time-dependent compressibility characteristics of Indian Montmorillonite Clay, also known as black cotton soil (BC) soil, during loading-unloading stages. The experimental data are analyzed using a new non-linear function of the Elasto-Visco-Plastic Model considering Swelling behaviour (EVPS model). From the experimental result, it is found that BC soil exhibits significant time-dependent behaviour during creep compared to the swelling stage. Pore water entrance restriction due to consolidated overburden pressure and decrease in cation hydrations are responsible factors. Apart from it, particle sliding is also evident during creep. The time-dependent parameters like strain limit, creep coefficient and C_αe/C_c are observed to be significant during the loading stage than the swelling stage. The relationship between creep coefficients and applied stresses is found to be nonlinear. The creep coefficient increases significantly up to 630 kPa-760 kPa (during reloading), and beyond it, the creep coefficient decreases continuously. Several parameters like loading duration, the magnitude of applied stress, loading history, and loading path have also influenced secondary compressibility characteristics. The time-dependent compressibility characteristics of BC soil are presented and discussed in detail.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.3
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• pp.158-163
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• 2012

The purpose of this study is to improve recycling rate of the coal reject ash by investigating bloating mechanism for artificial lightweight aggregate of reject ash. In this study, we use reject ash (R/A) and dredged soil (D/S) as raw materials. The artificial lightweight aggregates were formed by plastic forming (${\phi}$ = 10 mm) and sintered by temperature raising method at different temperatures (between 1200 and $1275^{\circ}C$). The physical properties of the aggregates such as bulk specific gravity, adsorption and microstructure of surface and cross-section are investigated with the sintering temperature and rate of R/A-D/S contents. As the result of the bulk specific gravity graphs, we can found out the inflection point at content of R/A 80 wt.%. From the microstructure images, we considered the artificial lightweight aggregates content of R/A over 80 wt.% are distributed numerous uniform micro-pores by vitrification without Black Core and the artificial lightweight aggregates of R/A below 80wt.% are distributed macro-pores with Black Core.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.48-61
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• 2008

This study aimed to examine emo fashion, a very recent music-related fashion trend spreading fast amongst youths, and understand emo ideas and methods of expression for a greater understanding of contemporary youth sub-cultures and fashion trends. Documentary research, positive research and in-depth interviews were used throughout the study. 4 Korean emo bands and 4 U.S. emo bands were selected based on music chart rankings, and a total of 37 photographs from the bands' Internet websites were selected, and their clothes shown in the photographs were examined. 5 Korean emo band musicians were subjects of in-depth interviews, and they were asked about their emo culture, music, fashion, ideas and styles, and photographs were taken of the subjects and evaluated, too. Lastly, Korean and U.S. emo kids were studied through photographs, and comparatively analyzed. Both Korean and U.S. emo musicians wore slim silhouettes, skinny jeans, t-shirts, sneakers, black, studded belts and plastic-framed glasses. Korean fashion expressed a less depressive atmosphere with color and other details compared to the United States, and did not prefer dark black eye make-up, which United States emo style appeared to express frequently. Korean musicians' emo fashion was closer to other youth fashions, whereas U.S. emo fashion included more formal styles such as ruffled shirts and pin-striped vests. Korean emo kids wore clothes not much different from most Korean youths, but U.S. emo kids wore a lot of eye make-up and black t-shirts with graphic or skull prints, and had more geometrical hair styles, as if cut at home. The reasons for such differences were found to be a longer emo music and culture history in the United States leading to more elaborate fashion expressions and a difference in the states of mind, such as Korea pursuing to express love, and the United States pursuing loneliness.

• Animal Bioscience
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• v.37 no.1
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• pp.123-130
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• 2024

Objective: Beef of Jeju black cattle (JBC) is considered as a healthy meat type due to its significantly higher unsaturated fatty acids (UFA). Lipid (e.g., UFA) is highly susceptible to oxidizing agents, which results in the quality deterioration and economic value loss of meat products. Therefore, development and application of novel preservative techniques is necessary to improve the shelf-life stability of high-UFA beef. The objective of this study was to assess the applicability of chitosan-based coatings in preservation of JBC beef. Methods: Different coating solutions: 2% chitosan alone, and 2% chitosan containing 0.1% or 0.3% gallic acid were prepared to investigate their applicability in preservation of fresh beef during storage. Jeju black cattle beef (2-cm thick steaks) were non-coated (control) or coated with the above coating solutions, placed on trays, over-wrapped with plastic film and stored at 4℃. The microbiological indices, color, total volatile basic nitrogen (TVBN) and lipid oxidation of the beef were investigated after 1, 10, and 21 days of storage. Results: Coating with 2% chitosan alone reduced the spoilage bacteria count, TVBN and thiobarbituric acid reactive substances levels in the beef compared with control during storage (p<0.05). Noticeably, coating with 2% chitosan containing 0.1% or 0.3% gallic acid was more effective on retardation of spoilage bacteria growth, lipid oxidation and discoloration in the beef compared to the chitosan coating alone over the storage period (21 days) (p<0.05). Conclusion: Taken together, the combined chitosan and gallic acid coating could be used as a bio-preservative technique in the meat industry.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.883-885
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• 2011

Purpose: Nevus sebaceus is a congenital hamartomatous lesion, typically involving head and neck. Various benign and malignant neoplasms can develop in association with nevus sebaceus. We report a case of simultaneous occurrence of squamous cell carcinoma and basal cell carcinoma in nevus sebaceus. Methods: A 73-year-old man presented with erythematous to black verrucous nodules on the right subauricular area. The upper part was accompanied with inflammation and ulceration, and no specific findings suspicious for malignant degeneration were found in the lower part preoperatively. The mass was totally excised and the defect was directly closed. Lymph nodes were not involved on concomitant neck dissection. Results: Histopathologic examination confirmed the presence of squamous cell carcinoma in the upper part and basal cell carcinoma in the lower part of a nevus sebaceus. Negative margins were achieved on resection. No clinical problems were found during the 3-month follow-up period. Conclusion: We experienced a rare case of simultaneous occurrence of squamous cell carcinoma and basal cell carcinoma within the same nevus sebaceus. Because patients with nevus sebaceus have risk of malignant changes, surgical excision and work-up for recurrence and metastasis should be considered in suspicious cases. And even in a totally asymptomatic case, the possibility of occult secondary cancer should be informed before surgery in aged patients.

• Journal of Korean Society of Forest Science
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• v.47 no.1
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• pp.44-51
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• 1980

In order to find out the suitable methods that can omit the earth healing and increase the survival through improving the seedling-healing and transportable methods. Several trials with plastic vinyl have been done and its results are as follows: 1. Though P. rigitaeda seedling have been stored in the black and white vinyl sack for 35 days in the storehouse. This seedling have survived with very high percentage as Table 1. This means that the earth healing work at the nursery or planting area can be omitted if seedling sould be stored in the storehouse by using the vinyl sack. The possibilities of long-period storage in the black and white vinyl sack seem to be come from the reasons that air humidity in the sack is nearly 100% and its air temperature is only around $15^{\circ}C$ with very little difference between day and night time. This sack also can be utilized in place of the planting sack, and though this sack with seedling have been laid under direct sunshine for 1 to 2 days. Any difference between the sack stored in the storehouse has not been observed on the survival specially Table 2. 2. When the bundled seedling have been covered with the black and white vinyl instead of earth healing, even if these seedling have been laid for 18 days under the vinyl. This seedling show us high survival as Table 3. High humidity with nearly 95%, very little difference of air temperature between day and night time under the vinyl and not so big difference between out-and inside temperature could be reasons of high survival to be considered. So through covering by the black and white vinyl. The labour power for earth healing works can be saved also. 3. In order to protect the healed seedling from the direct sunshine and the eva-transpiration. Black vinyl net and reed mat could be effective for this purpose. Because vinyl net could intercept around one to third, reed mat two to third of total solar energy and also suppress more than 50% of total water loss by the transpiration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.146-152
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• 2018

In this study, to improve the performance of asphalt mixtures for plastic deformation occurring mainly in Korea, complex modifiers were prepared by mixing powders and liquid type modifiers. The main constituents were powdery diatomaceous earth, mica and carbon black, and liquid type solid 70% SBR latex. The tensile strength ratios for the two asphalt mixtures used in the test were above 0.80 for the Ministry of Land Transportation (2017) asphalt mixture production and construction guidelines. The effects of increasing the tensile strength in the dry state was more than 14% when the composite modifier was added. The deformation rate per minute by the wheel tracking test load was an average of 0.07 to 0.147 for each mixture. The strain rate per minute was improved by the modifier, and the dynamic stability was improved by almost 100% from 295 to 590. In addition, the final settling was reduced from 11.38 mm to 9.57 mm. A plastic deformation test using the triaxial compression test showed that the amount of deformation entering the plastic deformation failure zone at the end of the second stage section and in the third stage plastic deformation section was 1.76 mm for the conventional mixture and 1.50 mm for the complex modifier mixture. The average slope of the complex modifier asphalt mixture mixed with the multi-functional modifier was 0.005 mm/sec. The plastic deformation rate is relatively small in the section where the road pavement exhibits stable common performance, i.e. the traffic load.