• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.359-374
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• 2024

A high-fidelity numerical analysis methodology was proposed for evaluating the fuel rod cladding integrity of a Prototype Gen IV Sodium Fast Reactor (PGSFR) during normal operation and Design basis events (DBEs). The MARS-LMR code, system transient safety analysis code, was applied to analyze the DBEs. The results of the MARS-LMR code were used as boundary condition for a 3D computational fluid dynamics (CFD) analysis. The peak temperatures considering HCFs satisfied the cladding temperature limit. The temperature and pressure distributions were calculated by ANSYS CFX code, and applied to structural analysis. Structural analysis was performed using ANSYS Mechanical code. The seismic reactivity insertion SSE accident among DBEs had the highest peak cladding temperature and the maximum stress, as the value of 87 MPa. The fuel cladding had over 40 % safety margin, and the strain was below the strain limit. Deformation behavior was elucidated for providing relative coordinate data on each active fuel rod center. Bending deformation resulted in a flower shape, and bowing bundle did not interact with the duct of fuel assemblies. Fuel rod maximum expansion was generated with highest stress. Therefore, it was concluded that the fuel rod cladding of the PGSFR has sufficient structural safety margin during DBEs.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.1
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• pp.11-16
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• 2001

Background and Objectives : A burn injury to the glottis differs from a burn injury to the trachea, bronchi, and lung parenchyma, in that thermal injury does not occur to any significant degree below the level of the larynx, due to the effective cooling of air by the upper airway and to reflex closure of the vocal cords from a blast of hot air. Therefore, the laryngeal inhalation injury give rise to airway problem and voice change. The objectives of this study is to assess management of laryngeal inhalation injury and voice change after management. Materials and Methods : Voice choses and laryngeal injuries of eight laryngeal inhalation patients were analyzed through questionnaire, voice dynamic laboratory, and laryngeal stroboscopy. Operative management was performed to five patients for airway patiency and vocal cord movement on laryngeal pathology ind voice therapy was performed to all patients. One-year after, voice changes and laryngeal injuries were reanalyzed with same methods. Results : Vocal breathiness, decreased voice intensity, reduced voice range, and easy fatigability were major complaints of laryngeal inhalation patients. Glottic stenosis were developed to five of eight patients, and vocal cord atrophy, bowing were developed to others. Vocal cord mucosal waves were significantly decreased in all patients. Jitter(%), Shimmer(dB) were increased and Maximal phonation time(MPT) was decreased. One-year after, subjective voice changes and objective voice parameters were improved. And vocal cord mucosal waves were recovered in all patients. Conclusions : Subjective voice quality and objective voice parameters were improved after operative management for laryngeal pathology and voice therapy. And we observed recovery of vocal fold mucosal waves by laryngeal stroboscopy. We think that early preventable tracheotomy is necessary to reduce the laryngeal contact injury in laryngeal inhalation patients.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.61.1-61.1
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• 2015

Nanoscale semiconductor plasma processing has become one of the most challenging issues due to the limits of physicochemical fabrication routes with its inherent complexity. The mission of future and emerging plasma processing for development of next generation semiconductor processing is to achieve the ideal nanostructures without abnormal profiles and damages, such as 3D NAND cell array with ultra-high aspect ratio, cylinder capacitors, shallow trench isolation, and 3D logic devices. In spite of significant contributions of research frontiers, these processes are still unveiled due to their inherent complexity of physicochemical behaviors, and gaps in academic research prevent their predictable simulation. To overcome these issues, a Korean plasma consortium began in 2009 with the principal aim to develop a realistic and ultrafast 3D topography simulator of semiconductor plasma processing coupled with zero-D bulk plasma models. In this work, aspects of this computational tool are introduced. The simulator was composed of a multiple 3D level-set based moving algorithm, zero-D bulk plasma module including pulsed plasma processing, a 3D ballistic transport module, and a surface reaction module. The main rate coefficients in bulk and surface reaction models were extracted by molecular simulations or fitting experimental data from several diagnostic tools in an inductively coupled fluorocarbon plasma system. Furthermore, it is well known that realistic ballistic transport is a simulation bottleneck due to the brute-force computation required. In this work, effective parallel computing using graphics processing units was applied to improve the computational performance drastically, so that computer-aided design of these processes is possible due to drastically reduced computational time. Finally, it is demonstrated that 3D feature profile simulations coupled with bulk plasma models can lead to better understanding of abnormal behaviors, such as necking, bowing, etch stops and twisting during high aspect ratio contact hole etch.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.94-100
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• 1996

Ossifying fibroma is one of a group of fibro-osseous lesions which arises typically within the jaw bones and only rarely affects the long bones. Ossifying fibroma of the long bones almost involve exclusively the tibia but may also involve the fibula. Ossifying fibroma of the long bones is distinct from fibrous dysplasia, adamantinoma and nonossifying fibroma with regard to age of the patient, site, radiographic appearance, histological features, and clinical course. We are reporting the cases of seven patients with a tumor-like lesion that named osteofibrous dysplasia. It is most commonly found in the tibia and fibula of a child ten years of age or younger. Of the seven cases reported in this study, only one patient was younger than ten years. In all cases, the lesions were usually located in the tibial diaphysis. The average duration of clinical manifestation was 5.2 years. The clinical symptoms were anterior bowing of the tibia in 2 cases, buldging of the tibia in 2 cases, and mass overlying the tibia in 3 cases. On the roentgenography, it shows multiple radiolucent lesion with intervening sclerotic rim of the tibial diaphysis. In seven patients, 6 cases were confirmed with biopsy. We had done curettage and bone graft in three cases, VFG was done in one case. The other three cases underwent conservative management.

• Journal of Korean Neurosurgical Society
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• v.55 no.2
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• pp.78-82
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• 2014

Objective : To investigate a diagnostic value of ultrasonography in carpal tunnel syndrome (CTS) patients and to evaluate a correlation of sonographic measurements with the degree of electrodiagnostic abnormalities and clinical severity. Methods : Two-hundred-forty-six symptomatic hands in 135 patients and 30 asymptomatic hands in 19 healthy individuals as control group were included. In ultrasonographic study, we measured the cross-sectional area (CSA) and flattening ratio (FR) of the median nerve at the pisiform as well as palmar bowing (PB) of the flexor retinaculum. Sensitivity and specificity of ultrasonographic measurements were evaluated and ultrasonographic data from the symptomatic and control hands were compared to the grade of electrodiagnostic and clinical severity. Results : The mean CSA was $13.7{\pm}4.2mm^2$ in symptomatic hands and $7.9{\pm}1.3mm^2$ in asymptomatic hands. The mean FR was $4.2{\pm}1.0$ in symptomatic hands and $3.4{\pm}0.4$ in asymptomatic hands. The mean PB was $3.5{\pm}0.5$ mm in symptomatic hands and $2.6{\pm}0.3$ mm in asymptomatic hands. Statistical analysis showed differences of the mean CSA, FR and PB between groups were significant. A cut-off value of $10mm^2$ for the mean CSA was found to be the upper limit for normal value. Both the mean CSA and PB are correlated with the grade of electrophysiological abnormalities and clinical severity, respectively. Conclusion : Ultrasographic measurement of the CSA and PB is helpful to diagnose CTS as a non-invasive and an alternative modality for the evaluation of CTS. In addition, ultrasonography also provides a reliable correlation with the grade of electrodiagnostic abnormalities and clinical severity.

• Journal of the Korean Society of Costume
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• v.59 no.3
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• pp.96-108
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• 2009

This study is made on the royal lady's dress In late Joseon dynasty according to the King Heon-jong and Lady Kyung-bin's Wedding Diary in the year of Jung-mi(1847) and summarised as follows: Girls' full dress was a set of a red skirt, a violet undo. jacket, and a light yellow jacket and a green Gyeon-ma-gi(a kind of top jacket) with he. hair Saeng-meo-ri hanging Do-tu-rak-daeng-gi(a kind of hair ribbon). At the big ceremony, girls wore a green Dang-ui instead of Gyeon-ma-gi. A girl picked up as a royal concubine wore a green Won-sam, which was decorated with gilt letters meaning longevity, patched emblems of gilt letter meaning longevity on the breast and on the back, belted with Bong-dae(a red sash with gilt phoenexes), like a princess's full dress. At the Kyung-bin's installation of Crown Princess and her first greeting ceremony with royal elders, she wore a green Won-sam as a formal dress, which had an embroidered emblem of phoenix, the belt with crystal ornaments, Pae-ok(佩玉), Kyu(圭) of blue jade, Shou(綬) with an phoenix. At a Dong-wrae-yun(drinking ceremony after bride and bridegroom's bowing to each other), she wore the embroidered red Jang-sam as a formal dress. Kyung-bin wore a purple Won-sam with Bong-dae as a full dress for a royal feast. According to the occasions, the same dress was differentiated with ornaments and rotors. Ji-keum-bal was an attire for ordinary ceremony. The attire was equipped with a woven gold green Dang-ui with an emblem of phoenix, a blue gilt underskirt and a red gilt overskirt. No-ui was worn as outdoor clothes. Jang-sam was worn by various classes, so it was differentiated with materials and names according to her class.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.14-14
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• 2006

Homoepitaxial growth of GaN on n-type GaN substrates was carried out by hydride vapor phase epitaxy (HVPE) method. This enables us to reduce or to eliminate the bowing of the GaN substrate caused by thermal mismatch. As a result, the two opposite crystal surfaces have been found to possess low dislocation density. The surface polarity of the homoepitaxially grown GaN was confirmed by both etching of the surface and conversion beam electron diffraction(CBED). The surface morphology and the photoluminescencemeasurement indicated that the surface properties of N-polar face of the homoepitaxlally grown GaN are quite different from the initial N-polar face of the heteroepitaxially grown GaN substrate Also, both surfaces of the GaN substrate were characterized by room temperature Double crystal X-ray diffraction (DCXRD) and photoluminescence measurement.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.152-157
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• 2005

Hypophosphatemia rickets, also known as Vitamin D-resistant rickets(VDRR) and refractory rickets, is a form of rickets which is resistant to the usual doses of vitamin D. VDRR is characterized by decreased renal tubular reabsorption of inorganic phosphate and is easily diagnosed by a normal blood calcium, hypophosphatemia, and slightly elevated alkaline phosphatase. Clinical features of Hypophosphatemia rickets included lateral bowing deformities of the legs, short stature, scoliosis, and enlargement of wrist and ankles. Dental finding in patient with VDRR were spontaneous dental abscesses in caries free teeth and other dental findings included delayed eruption, delayed apical closure, thin and hypoplastic enamel, absent or poorly defined lamina dura, enlarged pulp chambers, and numerous accessory canals and pulp horns that extend up and into the dentinoenamel junction. we reported the clinical feature and treatment of VDRR child who was referred from the department of pediatrics for early loss of primary teeth and its treatment.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.14-24
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• 2000

In present research, the plywoods made of radiata pine or Japanese larch, the potential softwood species in mass supply, were discussed to examine their feasibility as the structural and concrete form panels through the basic properties test. First, plywood qualities and its nail performance were tested. The performance test for concrete form or structural panel by concentrated and uniformly distributed load were conducted to investigate the possibility as structural material for light frame and concrete constructions. Test results of basic quality such as specific gravity, cupping, bowing, and twisting appeared to satisfy the criteria for structural use. Also, nail performance test results, for roof and wall sheathing panels, nail lateral resistance, nail withdrawal resistance, and nail push head resistance proved to meet the required standard for structural use. The test results on performance as structural panel by concentrated and uniformly distributed load and as concrete form panel showed that these two species could be used for structural sheathing, subfloor, and concrete form panels.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.472-472
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• 2011

The capacitive coupled plasma (CCP) has been extensively used in the semiconductor industry because it has not only good uniformity, but also low electron temperature. But CCP source has some problems, such as difficulty in varying the ion bombardment energy separately, low plasma density, and high processing pressure, etc. In this reason, dual frequency CCP has been investigated with a separate substrate biasing to control the plasma parameters and to obtain high etch rate with high etch selectivity. Especially, in this study, we studied on the etching of $SiO_2$ by using the pulse-time modulation in the dual-frequency CCP source composed of 60 MHz/ 2 MHz rf power. By using the combination of high /low rf powers, the differences in the gas dissociation, plasma density, and etch characteristics were investigated. Also, as the size of the semiconductor device is decreased to nano-scale, the etching of contact hole which has nano-scale higher aspect ratio is required. For the nano-scale contact hole etching by using continuous plasma, several etch problems such as bowing, sidewall taper, twist, mask faceting, erosion, distortions etc. occurs. To resolve these problems, etching in low process pressure, more sidewall passivation by using fluorocarbon-based plasma with high carbon ratio, low temperature processing, charge effect breaking, power modulation are needed. Therefore, in this study, to resolve these problems, we used the pulse-time modulated dual-frequency CCP system. Pulse plasma is generated by periodical turning the RF power On and Off state. We measured the etch rate, etch selectivity and etch profile by using a step profilometer and SEM. Also the X-ray photoelectron spectroscopic analysis on the surfaces etched by different duty ratio conditions correlate with the results above.