• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1433-1441
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• 2011

Design rules of optical transmission links with dispersion management (DM) and optical phase conjugation (OPC) for compensating optical signal distortion due to chromatic dispersion and self phase modulation (SPM) of single mode fiber (SMF) are investigated in this paper. Design rules consist of optimal net residual dispersion (NRD) and optimal range of launching power of wavelength division multiplexed (WDM) channels as a function of total transmission length and span length. In all considered total transmission length and span length, optimal NRD are obtained to +10 ps/nm and -10 ps/mn for transmission links, which is controlled by precompensation and postcompensation, respectively. It is confirmed that system performances are more improved and effective NRD for wide launching power have wider range as total transmission length and span length are more decreased.

• Journal of Fashion Business
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• v.7 no.5
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• pp.83-100
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• 2003

It has been known that the chitosan pre-treated fabrics can be dyed without the aid of mordanting process. It is due to the fact that chitosan treatment increases the dye uptake. However, the effect of chitosan on the dyeing mechanism has not been elucidated thus far. Following explanations have been presented regrading the action of the chitosan on the dyeing mechanisms: 1. Chitosan absorbs dyestuffs and facilitates dyeing since the chitosan itself has a good affinity toward dyestuffs. 2. Chitosan acts as a metallic mordant between the fiber molecule and dyestuff. 3. Fiber molecules and chitosan form a coordinate covalent bond. This study aims the quantitative investigation on the effect of the chitosan and the effect of sequence of the mordanting, pre-mordanting or post-mordanting, on the dyeing of the fabrics. Cotton fabrics and acylic fabrics were pre-treated with chitosan before dyeing with cochineal dyestuffs. Method 1: Fabrics were, firstly, mordanted with Al, Sn, Cu, and Fe; mordanted fabrics were, secondly, treated with chitosan; mordanted and chitosan-treated fabrics were, thirdly, dyed. Method 2: Fabrics were, firstly, treated with chitosan; chitosan-treated fabrics were, secondly, mordanted with Al, Sn, Cu, and Fe; these were dyed then. Method 2 gave distinguished specific color development with darker shade. Apart from this, chitosan-treated fabrics yielded darker shade compared to the pre-mordanted fabrics without chitosan-treatment.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.623-623
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• 2003

I. Objectives The aim of this was to evaluate the use possibility of light curing flowable composite resins as a luting agent for translucent fiber posts. II. Materials and Methods 20 single-rooted maxillary central incisors were selected and crown was sectioned below the cemento-enamel junction to obtain a 13 mm ling root. Root canals were filed, cleaned, and shaped to ＃40 with K-file. Prepared canals were filled with gutta percha and AH26 root canal sealer by lateral condensation method. Teeth were than divided into 4 groups of 5 specimens each. In group 1 and 2, the canal space of each root was enlarged with ＃3 DT Light post preparation drill (Bisco, USA) to a depth of 9mm from the cervical.(omitted)

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.431-436
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• 2021

In this study, a new shielding method was applied to an accessory device that produces electromagnetic waves in the magnetic resonance room to prevent the generation of artifact caused by electromagnetic waves. The research method applied a new shielding made of metal plating fiber to patient surveillance CCTVs without shielding technology, and obtained and evaluated noise map when the power was not cut off and when the new shielding technology was applied without shutting down the CCTV. As a result of the study, it was found that there was at least one group with significant differences. Type I and type III belonged to group 1 while type II belonged to group 2 in the Post-hoc analysis, which meant blocking power of the CCTV and the applying new shielding technology were in the same group. In conclusion, if electromagnetic waves are generated due to additional accessories in the scanning room, the shielding material proposed in this study should be applied which enables the electric state become similar to type I, not generating noise, thereby preventing the artifacts caused by electromagnetic waves.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.3
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• pp.60-67
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• 2021

Recently, research attention has been focused on vibration-free vehicles to transport small numbers of expensive electronic products. Vibration-free vehicles can be used to transport expensive test equipment or semiconductors, mainly produced in the domestic IT industry, and can serve as a readily available transportation system for short driving distances due to the increased efficiency on narrow national highways. This study was aimed at developing a Z-Spring to minimize the vibration by installing an air spring instead of the plate spring applied to conventional freight cars and to prevent the damage of the loaded cargo from the shock occurring during movement. The mechanical properties (elastic modulus, tensile strength, and shear strength) of carbon fiber (CF) and glass fiber (GF) prepreg were derived, and ANSYS ACP PrepPost analyses were performed. It was observed that in the case of hybrid composites, the total deformation and equivalent stress are higher than that of CFRP; however, in terms of the unit cost, the hybrid Z-Spring is more inexpensive and durable compared to the GF.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.1
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• pp.63-70
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• 2023

Purpose : Excessive alcohol causes damage to skeletal muscles, leading to the development of a specific disease entity called alcoholic myopathy. Chronic inflammation is related as an underlying mechanism for the loss of muscle mass induced by alcohol. Pro-inflammatory cytokines such as TNF-α (tumor necrosis factor-α) and IL-6 (interleukin-6) play a role in this process. The acupuncture point Feng Shi (GB 31) is located on the midline of the lateral aspect of the thigh, above the transverse popliteal crease. This acupoint is used for the treatment of weakness, atrophy, numbness, and post-stroke symptoms of lower limbs. The purpose of this study was to investigate the effect of Feng Shi stimulation on muscle atrophy caused by chronic alcohol administration. Method : Young male Sprague-Dawley rats were randomly divided into three groups of eight each: Normal, Control, and GB31. The rats in the Control and GB31 groups were orally given 25 % ethanol (5 ㎖/kg, body weight) daily for 4 weeks. The Normal group was similarly administered saline. The acupressure at Feng Shi was treated to rats in the GB31 group. After 4 weeks, the body weight, muscle weight and cross-sectional area of gastrocnemius were assessed and the histological changes in gastrocnemius muscle fiber were observed by hematoxylin and eosin staining. Moreover, TNF-α and IL-6 expressions were immunohistochemistrically evaluated. Results : Acupressure stimulation at Feng Shi had a protective effect on the weight reduction of the gastrocnemius muscle caused by alcohol intake, and had an effect of suppressing anatomical change in muscle fiber and decreasing the average cross-sectional area. Also, the immunoreactivities of TNF-α and IL-6 in the GB31 group were decreased. Conclusion : These results suggest that acupressure at Feng Shi has protective effects on chronic alcohol-induced muscle atrophy by inhibiting pre-inflammatory proteins such as TNF-α and IL-6.

• Clinical Nutrition Research
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• v.13 no.1
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• pp.8-21
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• 2024

In this study, the effects of a 12-month multidisciplinary education program on the health status, dietary quality, and eating habits of children and adolescents attending community childcare centers were investigated. A total of 88 participants aged 7 to 17 years from 7 community childcare centers in Gyeonggi-do were enrolled. The intervention consisted of 12 multidisciplinary education sessions covering topics such as nutrition, exercise, and psychological education. All participants received the same education, and the effectiveness of the program was evaluated by categorizing them into a high participation group (HPG) and a low participation group (LPG) based on their participation rates. After intervention, in physical activities, moderate-intensity exercise was significantly reduced in the LPG, and there was no significant difference in psychological parameters. However, notable differences were observed in nutritional data. After intervention, intakes of calorie, carbohydrate, protein, and fat were significantly increased in both groups, and in particular, the change was found to be greater in HPG. Additionally, dietary fiber intake compared to the 2015 Korean Dietary Reference Intakes was increased in both groups. Daily food intake also increased dietary fiber intake in HPG, and meat and fruit intake was increased in LPG. In the nutrition quotient, there was a significant difference in HPG's pre- and post-scores in the diversity category, and in nutrient adequacy ratio (NAR), the NAR of phosphorus was increased in both groups. The findings of this study suggest that multidisciplinary education implemented at community childcare centers primarily enhanced nutrition-related factors rather than physical activity or psychological aspects.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.6
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• pp.699-706
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• 2015

This paper presents results of one-year monitoring on prestressing force of a 7-wire steel post-tensioning strand which is installed in a UHPC(ultra high performance concrete) bridge with 11.0 m long, 5.0 m wide, and 0.6 m high by using a FBG-encapsulated 7-wire steel strand. The initial prestressing forces and the prestress changes during a vehicle load test were measured using the FBG-encapsulated strand. The results show that the FBG-encapsulated 7-wire strand is very effective for monitoring the prestress forces even the change in the tension force is very small. Additionally, it was indicated that selection of the thermal expansion coefficient which is used for the temperature correction shall be carefully carried out.

• Journal of radiological science and technology
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• v.41 no.5
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• pp.463-469
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• 2018

Morphological information such as shape and margin of micro lesion is important information for diagnosis of disease in clinical imaging. In this study, we investigated the morphological changes of the micro lesions by comparing the contrast and area in grid suppressed DR images according to grid frequency. In the profile analysis of the image, the mass showed an average intensity variation of 8.6 ~ 72.4 after suppression, The higher the grid frequency, the more the contrast was increased. However, in the images obtained using 103 lp / inch, which is a grid frequency less than the sampling frequency, the contrast of the mass in the vertical direction decreased after suppression. In the binary image, the area change of the mass was also large. As a result, the shape, size, and margin of the mass changed. In the case of very small calcification, the higher the grid frequency is the larger the change in contrast, so that a clear image can be obtained in the post-suppression image. However, we could confirm that the margin of the lesion was blurred and the lesion was lost in some of the images using the 103 lp / inch grid. The higher the frequency of the grid, The change of the contrast of fiber occurred largely and clear boundary was confirmed. The decrease of the number of pixels was small and morphological change was small. In conclusion, when using a grid frequency that is not suitable for the sample frequency, morphological changes or lesion loss of micro lesions in the post- suppression image may give the possibility of misdiagnosis in diagnosis and differentiation of the image.

• Journal of Fashion Business
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• v.11 no.1
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• pp.136-148
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• 2007

African marigold is a common plant easily available in many flower beds. It has been reported as a practical and prospective resource of dyes since the dyes can be extracted from their bodies as well as petals. In this research, cotton and ramie fabrics which are made from natural cellulose were dyed using the extract of the African Marigold which is a variety of marigold. Dyeing tests were carried out under different pH of the dye solution and mordants. Dyeability was evaluated by examining and measuring surface color, K/S value, and the changes in the maximum absorption wavelength. The probability of improving dyeability was investigated by pre-mordanting with pre-treated chitosan. For the dyeing with marigold extract, the color tone did not differ by pre-mordanting and non-mordanting. Reaction with post-mordanting was excellent, which was colored in various yellow series. The best dyeability was achieved in dye solution of pH 6.5-7.0 which is not conditioned. The largest K/S value and color difference were obtained in tin mordanting. The dye uptake was greatly increased in chitosan pre-treated mordanting compared with the post-mordanting without chitosan pre-treatment. Due to its high heat resistance, African Marigold extract is easy for dye extraction and dyeing, and its dyeability is excellent for natural cellulose fibers. Also, colorfastness was proved to be practically usable.