• Journal of Radiation Protection and Research
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• v.18 no.2
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• pp.27-35
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• 1993

A shielding analysis of the shipping cask for transporting the CANDU spent fuel bundles has been studied. Radiation source term has been calculated on spent fuel with burn-up of 7,800 MWD/MTU and 5 years cooling time by ORIGEN2 code. The shielding calculation for the cask capable of transporting 378 bundles of CANDU spent fuel has been made by use of 1-D ANISN and 2-D DOT 4.2 codes. As a result of analysis, the optimum shield thickness of cask was obtained. And it is proved that the safety in radiation shielding under normal transport and hypothetical accident conditions is confirmed to satisfy the allowable values specified in IAEA Safety Series No. 6 and the Korean Atomic Law.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.857-863
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• 2017

In this paper, the process of electro Ni and electro Cr plating is studied for the purpose of thermal barrier to protect the inner wall combustion chamber. The chamber is under the environment of very high temperature and high pressure when propellants burn in there. As one of the thermal barrier coatings, Zr-based thermal spray coating has been applied to the chamber. However, peeling of coating layer can occur under such a hard condition because of the difference of thermal expansion coefficients between the ceramic and the metallic wall. We study the characteristics of Ni-Cr coating and establish its process. It is found that the thickness of over $100{\mu}m$ of Ni and Cr coating layers with the uniformity of ${\pm}10%$ can be obtained with the used of as-developed plating bath.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.53-58
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• 2000

It was carried out consequence analysis(CA) of CNG (compressed natural gas) service station and we compared the results of CA of CNG service station with LPG service station which was installed by high Pressure gas law. The results of CA were that distance of CNG LFL was 1.5 times than the length of LPG LFL. Thermal radiation effect about CNG may not be showed damage of process facilities, but in the case of LPG, it was enough to have an large damage effect on a downtown. The thermal radiation of 37.5 $kw/m^2$ extended 12.6 m. Also, in the case of 12.5 $kw/m^2$ which was able to burn wood, the radiation effect of LPG is 3 times than CNG.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.1
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• pp.41-50
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• 2008

Recent progress in state-of-the-art geospatial information technologies such as digital mapping, LiDAR(Light Detection And Ranging), and high-resolution satellite imagery provides various data sources fer Digital Elevation Model(DEM). DEMs are major source to extract elements of the hydrological terrain property that are necessary for efficient watershed management. Especially, watersheds extracted from DEM are important geospatial database to identify physical boundaries that are utilized in water resource management plan including water environmental survey, pollutant investigation, polluted/wasteload/pollution load allocation estimation, and water quality modeling. Most of the previous studies related with watershed extraction using DEM are mainly focused on the hydrological elements analysis and preprocessing without considering grid size of the DEMs. This study aims to analyze accuracy of the watersheds extracted from DEMs with various grid sizes generated by LiDAR data and digital map, and appropriate preprocessing methods.

• Journal of the Korea Safety Management & Science
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• v.22 no.2
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• pp.57-71
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• 2020

The purpose of this study is to explore the effects of fire officers' experience of traumatic events and subsequent forest healing on their occupational burnout. The results are as follows: First, the experience of traumatic events, social and psychological healing, and relieving stress by strolling had a significant effect on burnout. The more fire officers are exposed to traumatic events, the more they lose self-control in social and psychological aspects, and the lower the level of stress relieved through strolling, the higher the level of burnout. Thi sresult suggests that the more fire office rsare called out for fire fighting, the more they see their colleagues with severein juries, and the higher the level of mental and physical an xiety, the more they areex hausted. Moreover, for es thealing help store duce the irmental and physi calfatig uecaused by traumatic events, thu spreven ting them from suffering from burn out. Second, the experience of traumatic events, social and psychological healing, and relieving stress by strolling had a significant impact on occupational stress. The more fire officers are exposed to traumatic events, the more they lose self-control in social and psychological aspects, and the lower the level of stress relieved through strolling, the higher the level of occupational stress. This result indicates that to relieve job stress caused by fire fighting, increased forest healing activities, including various programs such as psychotherapy, developing interpersonal relationships and self-control, and creating a positive mind-set, can reducejobstress and help fire officers recover from it. Lastly, job stress had a mediation effect on the effects of the experience of traumatic events and forest healing on burnout. This implies that burnout can be prevented when fire officers gain high emotional stability through social and psychological healing and stress-relief strolling over a traumatic experience, and stronger support from the organization and family can keep them from being emotionally drained, thus contributing to the prevention of burnout.

• Journal of Technologic Dentistry
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• v.40 no.4
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• pp.209-215
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• 2018

Purpose: The purpose of this study was to evaluate the clinical acceptability of the marginal and internal gap of Co-Cr metal copings fabricated with stereolithography (SLA). Methods: Titanium master dies were milled after scanning of the prepared tooth (n=30). For group I, Co-Cr metal copings were made from conventional lost-wax technique(LWT, n=10). For group II, the master dies were scanned and designed with CAD system. Then, metal copings were milled with Co-Cr(SUB, n=10). For group III(ADD, n=10), the scanning and design procedures were same as group II and burn-out resins were fabricated with SLA device. The marginal and internal discrepancies were measured under an optical microscope(100x) on ten reference points and were statistically analyzed with one-way ANOVA(${\alpha}=.05$). Results: The mean total discrepancies were $53.76{\pm}12.42{\mu}m$ in the LWT group and $69.82{\pm}15.48{\mu}m$ in the ADD group. The SUB group showed the largest total mean value $110.33{\pm}13.77{\mu}m$. There was statistically significant difference between the SUB and the other groups(P<0.05). Conclusion : Co-Cr metal copings fabricated with SLA technology showed clinically acceptable value on marginal and internal gap and there was no statistically significant difference between conventional lost-wax technique and SLA.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.123-130
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• 2022

During the past decades, detection of gear defects remains as a major problem, especially when the gears are subject to non-stationary phenomena. The idea of this paper is to mixture a multilevel wavelet transform with a fast EMD decomposition in order to early detect gear defects. The sensitivity of a kurtosis is used as an indicator of gears defect burn. When the gear is damaged, the appearance of a crack on the gear tooth disrupts the signal. This is due to the presence of periodic pulses. Nevertheless, the existence of background noise induced by the random excitation can have an impact on the values of these temporal indicators. The denoising of these signals by multilevel wavelet transform improves the sensitivity of these indicators and increases the reliability of the investigation. Finally, a defect diagnosis result can be obtained after the fast transformation of the EMD. The proposed approach consists in applying a multi-resolution wavelet analysis with variable decomposition levels related to the severity of gear faults, then a fast EMD is used to early detect faults. The proposed mixed methods are evaluated on vibratory signals from the test bench, CETIM. The obtained results have shown the occurrence of a teeth defect on gear on the 5th and 8th day. This result agrees with the report of the appraisal made on this gear system.

• Archives of Plastic Surgery
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• v.49 no.1
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• pp.108-114
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• 2022

Reconstruction of defects around the knee region requires thin and pliable skin. The superior lateral genicular artery (SLGA) flap provides an excellent alternative to muscle-based flaps. The anatomy and the surgical techniques of the SLGA flap were reviewed and the results of cases using the SLGA flap for coverage of knee and proximal leg defects were analyzed. SLGA flaps were performed in two cases and followed up for at least 6 months. Twelve articles on the use of the SLGA flap were also identified. A review of 39 cases showed that the mean diameter of the perforator supplying the skin of the flap was 1.04 mm, while the mean diameter of the SLGA at its origin was 1.78 mm. The mean length of the pedicle measured from the origin of the popliteal artery was 7.44 cm. The average dimensions of the flap were 14.8×6.6 cm with primary closure of the donor site in 61.5% of cases. Of these cases, 38.5% were due to trauma, 23.1% were post-burn complications, 12.8% were defects after resection of tumors, and 10.3% were for ulcers post-bursectomy. The most common complication was flap tip necrosis. All studies reported favorable outcomes with complete wound healing.

• Journal of Fashion Business
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• v.26 no.2
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• pp.15-27
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• 2022

The purpose of this study is to perform research of ecology concepts expressed in fashion and to propose a new ecology fashion design based on the results. As a specific research method, first, to determine the concept of ecology, the contents related to ecology were extracted and organized through literature research, and then a fashion collection research was conducted to acquire basic design data, such as silhouettes, materials, details, and colors. From WGSN, and a total of 57 images were selected and used as basic data for the design suggestions. As a result of collecting the collection images, it was found that cotton or denim fabrics were mainly used, and in particular, the frequency of use was high mainly for bright tones. The use of chambray, lace, and wrinkles, was also frequent, and the use of expression techniques using burn-out, bleach, and bleaching effects or parts, or entire dyeing was often noticeable. The colors showed neutral and pastel-toned characteristics, and the silhouette was mainly composed of long silhouettes centered on maxi, such as a top or calf based on the knee, rather than a mini. Fabrics for the final designs were linen and sappan wood, and they were used for the dye and red was used as the overall color. The silhouettes were simplified, and care was taken to prevent unnecessary waste, such as paper or materials, from being generated during the production stage. We tried to achieve the purpose of eco-logy by refraining from excessive trimming, except for essential subsidiary materials, such as zippers.

• Journal of Biomedical Engineering Research
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• v.44 no.1
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• pp.85-91
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• 2023

Stress urinary incontinence (SUI) occurs when abdominal pressure increases, such as sneezing, exercising, and laughing. Surgical and non-surgical treatments are the common methods of SUI treatment; however, the conventional treatments still require continuous and invasive treatment. Laser have been used to treat SUI, but excessive temperature increase often causes thermal burn on urethra tissue. Therefore, the optimal conditions must be considered to minimize the thermal damage for the laser treatment. The current study investigated the feasibility of the laser irradiation condition for SUI treatment using non-ablative 980 nm laser from a safety perspective through numerical simulations. COMSOL Multiphysics was used to analyze the numerical simulation model. The Pennes bioheat equation with the Beer's law was used to confirm spatio-temporal temperature distributions, and Arrhenius equation defined the thermal damage caused by the laser-induced heat. Ex vivo porcine urethral tissue was tested to validate the extent of both temperature distribution and thermal damage. The temperature distribution was symmetrical and uniformly observed in the urethra tissue. A muscle layer had a higher temperature (28.3 ℃) than mucosal (23.4 ℃) and submucosal layers (25.5 ℃). MT staining revealed no heat-induced collagen and muscle damage. Both control and treated groups showed the equivalent thickness and area of the urethral mucosal layer. Therefore, the proposed numerical simulation can predict the appropriate irradiation condition (20 W for 15 s) for the SUI treatment with minimal temperature-induced tissue.