• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.397-416
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part II, based on the verified finite element (FE) models of aircrafts Airbus A320 and A380, as well as the NPP containment and auxiliary buildings in Part I of this paper, the whole collision process is reproduced numerically by adopting the coupled missile-target interaction approach with the finite element code LS-DYNA. The impact induced damage of NPP plant under four impact locations of containment (cylinder, air intake, conical roof and PCS water tank) and two impact locations of auxiliary buildings (exterior wall and roof of spent fuel pool room) are evaluated. Furthermore, by considering the inner structures in the containment and raft foundation of NPP, the structural vibration analyses are conducted under two impact locations (middle height of cylinder, main control room in the auxiliary buildings). It indicates that, within the discussed scenarios, NPP structures can withstand the impact of both two aircrafts, while the functionality of internal equipment on higher floors will be affected to some extent under impact induced vibrations, and A380 aircraft will cause more serious structural damage and vibrations than A320 aircraft. The present work can provide helpful references to assess the safety of the structures and inner equipment of NPP plant under commercial aircraft impact.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.3 s.116
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• pp.29-37
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• 2006

To use bamboo in the pulp industry, the anatomical characteristics of 60-day-old, 1-year-old, 2-year-old, and 3-year-old moso bamboo (Phyllostachys pubescens Mazel), and the characteristics of fiber and sheet of alkali pulp made of moso bamboo were investigated. Moso bamboo is composed of metaxylens and parenchyma cells in the inner part of the wall, and thick-walled small bundle sheathes near the outer walls. Moso bamboo showed the heterogeneity in anatomical structure. The longest fibers were shown in the middle part, and the widest width in the inner part. The lignin contents were 14.4% in 60-day-old bamboo, which was not lignified yet. The lignin contents in bamboo above 1 year were approximately 35%. The yields of alkali pulp of moso bamboo were in the range between 41 and 47%, and the yields tend to decrease with the increase of ages. The lignin contents of 60-day-old bamboo were 2.1% and those of bamboo above 1 year showed approximately 4% to 5% increment. The length, width, and curl index of fiber in alkali pulp appeared to be similar in all ages. However, coarseness increased slightly with the increase of bamboo ages. The distribution of long fiber was shown much in 60-year-old bamboo. The optical and mechanical properties of moso bamboo tended to decrease with the increase of bamboo age.

• Journal of architectural history
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• v.23 no.5
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• pp.47-60
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• 2014

Urban-Hanok emerged as a result of urbanization of Hanok in the modern period. In particular, Urban-Hanok has been mass-produced from the early 1920s, when the population is concentrated in cities, until the middle. Large-scale development by the professional developer has been developed in large-scale land rather than individual client because housing shortage was serious problem. 11 Gahoe-dong was made in 1935-36 is representative Urban-hanok area of Bukchon. It was formed through division of large-scale Land in 1930's. In the 1930's, the large-scale development projects of Urban-Hanok was triggered by the two events. One is Land Investigation Project performed by the Japanese government to capitalization of property, another is the pro-japanese bought the large scale-land in Gahoe-dong at bargain price from The Japanese government. Each lot has still a topographical characteristics such as land-dividing quality, the way of development, characteristic quality of urban-tissue. 11 Gahoe-dong, Urban-hanok area was developed two ways. First, development have been adapted to the topography. The lots have reflected topographical conditions such as land cutting area, a retaining wall, land-diving was maintaining the original topography almost. Second, it was street oriented development. The lots have developed sequentially along the street. So, the lots's shape and size is different each. For this reason, this area distribute various type of Hanok.

• Clinical and Experimental Pediatrics
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• v.60 no.6
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• pp.196-201
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• 2017

Purpose: Myocardial dysfunction and dysrhythmias are inevitable consequences of Duchenne muscular dystrophy. We aimed to evaluate specific trends of electrocardiographic changes that reflect the progress of cardiomyopathy in patients with Duchenne muscular dystrophy. Methods: Fifty electrocardiograms (ECGs) of 30 patients (ages 1 to 27 years) who had not been prescribed medications for heart failure treatment at the time of examination were retrospectively analyzed and compared with 116 ECGs of age-matched healthy 116 controls. Heart rate, leads with fragmented QRS (fQRS), corrected QT, Tpeak-to-Tend, and Tpeak-to-Tend/QT were analyzed. Results: The patients with Duchenne muscular dystrophy failed to show a normal age-related decline in heart rate but showed an increasing trend in the prevalence of fQRS, corrected QT, corrected Tpeakto-Tend, and Tpeak-to-Tend/QT over time. In the ${\leq}10-year-old$ patient group, a significant difference was found only in the prevalence of fQRS between the patients and the controls. The prevalence of fQRS, heart rate, Tpeak-to-Tend/QT, and corrected Tpeak-to-Tend demonstrated significant differences between the patients and the controls in the middle age group (11 to 15 years old). All the indexes were statistically significantly different in the ${\geq}16-year-old$ patient group. Conclusion: The prevalence of lead with fQRS representing regional wall motion abnormalities was higher in the young patients than in the young healthy controls, and this might be one of the first signs of myocardial change in the patients. Markers of depolarization and repolarization abnormalities were gradually prominent in the patients aged >10 years. Further studies are needed to confirm these findings.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.251-257
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• 1986

Optimum conditions for the protoplast formation and regeneration of Lactobacillus casei have been searched for. L. casei cells were converted to protoplast by treating with 10$\mu\textrm{g}$/$m{\ell}$ of mutanolysin in 20mM potassium phosphate buffer (pH6.8) containing 6mM CaCl$_2$, 6mM MgCl$_2$ and 1M sucrose. Maximum number of protoplasts was obtained when cells were taken from Tomochika's medium containing 0.5% glycine at the middle to late logarithmic growth phase. Regeneration was efficiently accomplished on the regeneration medium containing 6mM CaCl$_2$, 6mM MgCl$_2$, 0.8M sucrose and 10% of horse serum. The efficiently of the cell wall regeneration from protoplasts was 2-5% after 3-4 days of incubation at 3$0^{\circ}C$.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.3
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• pp.191-198
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• 2014

In this paper, structural integrity evaluation of reactor pressure vessel bottom head without penetration nozzles in core melting accident has been performed. Considering the analysis results of thermal load, weight of molten core debris and internal pressure, thermal load is the most significant factor in reactor vessel bottom head. The failure probability was evaluated according to the established failure criteria and the evaluation showed that the equivalent plastic strain results are lower than critical strain failure criteria. Thermal-structural coupled analyses show that the existence of elastic zone with a lower stress than yield strength is in the middle of bottom head thickness. As a result of analysis, the elastic zone became narrow and moved to the internal wall as the internal pressure increases, and it is evaluated that the structural integrity of reactor vessel is maintained under core melting accident.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.1
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• pp.53-57
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• 1999

The activities of myocardial antioxidant enzymes are known to increase in the hearts preconditioned with the brief episodes of ischemia. This study was undertaken to elucidate the possible involvement of adenosine in the stimulation of myocardial catalase induced by the brief regional ischemia in rabbit hearts. Coronary artery descending the middle anterior wall of left ventricle was occluded for 15 min, followed by 1 hr of reperfusion. Upon reperfusion after the brief ischemia, the activity of catalase increased significantly in both ischemic and non-ischemic parts of myocardium. Pretreatment of the heart with theophylline, a non-specific adenosine receptor blocker, completely abolished the increase of catalase activity in both the ischemic and non-ischemic regions of myocardium. On the other hand, the administration of exogenous adenosine instead of the ischemia failed to increase the catalase activity in in vivo hearts. Moreover, adenosine infusion did not affect the catalase activity in the isolated, perfused hearts either. These results suggest that the endogenous adenosine released from the ischemic myocardium is involved in the activation of catalase induced by brief ischemia, but that adenosine may not be a final direct activator of cellular catalase in the myocardium.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.4
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• pp.171-180
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• 2014

Since the execution of structural design by professional structural engineers is not mandatory for small-size buildings in Korea, structural design is conducted by architects or contractors resulting in concern about the seismic safety of the buildings. Therefore, the Korean Structural Engineers Association proposed dedicated structural design criteria in 2012. The criteria were developed based on a deterministic approach in which the structural members are designed only with information of story and span length of the buildings and without structural analyses. However, due to the short time devoted to their development, these criteria miss satisfactory basis and do not deal with structural walls popularly used in Korea. Accordingly, the Ministry of Land, Infrastructure and Transport launched a research on the 'development of structural performance enhancement technologies for small-size buildings against earthquakes and climate changes'.. As part of this research, this paper intends to establish direction for the preparation of deterministic structural design guidelines for seismic safety of domestic small-size reinforced concrete buildings. To that goal, a typical plan of these buildings is selected considering frames only and frames plus walls, and then design is conducted by changing the number of stories and span length. Next, the seismic performance is analyzed by nonlinear static pushover analysis. The results show that the structural design guidelines should be developed by classifying frames only and frames plus walls. The size and reinforcement of structural elements should be provided in the middle level of the current Korean Building Code and criteria for small buildings by considering story and span length for buildings with frames only, and determined by considering the shape and location of walls and the story and span length as well for buildings with frames plus walls. It is recommended that the design of walls should be conducted by reducing the amount of walls along with symmetrically located walls.

• Advances in pediatric surgery
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• v.13 no.2
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• pp.169-178
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• 2007

Teratomas arising from totipotential primitive germ cell are composed of 2 or 3 germ cell layers. We reviewed the records of 166 children who underwent the operation for teratoma from Jan, 1990 through April, 2007. There were 40 boys and 126 girls (average age $6.93{\pm}5.83$ years). Primary sites were ovary (n = 88), sacrococcygeum (n = 24), testis (n = 16), retroperitoneum (n = 16), mediastinum (n = 8), brain (n = 4), thymus (n = 3) and a single tumor involved the adrenal gland, neck, middle ear, oropharynx, stomach, pelvis, omentum, chest wall and scalp. Teratomas were mature in 141 patients, and immature in 25. Six patients who had ovarian immature teratomas grade 2 or 3 with peritoneal gliomatosis underwent adjuvant chemotherapy. During follow up period, 6 mature teratomas recurred at sacrococcygeal area (n = 1) and contralateral ovary (n = 5). Five patients of them underwent reoperation and diagnosed as a mature teratoma, but one who had underwent a left salpingooophrectomy with right ovary cystectomy at initial operation was observed carefully. Teratomas were dominant in female patients and developed at various organs. Complete excision was needed for good prognosis. In case of immature teratoma, complete excision and appropriate chemotherapy according to grading can contribute to favorable results.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.3
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• pp.399-407
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• 2002

A three-dimensional method of analysis is presented for determining the free vibration frequencies and mode shapes of hollow bodies of revolution (i.e., thick shells), not limited to straight line generators or constant thickness. The middle surface of the shell may have arbitrary curvatures, and the wall thickness may vary arbitrarily. Displacement components$U_\Phi, U_z, U_\theta$ in the meridional, normal and circumferential directions, respectively, are taken to be sinusoidal in time, periodic in$\theta$, and algebraic polynomials in the$\Phi$and z directions. Potential(strain) and kinetic energies of the entire body are formulated, and upper bound values of the frequencies are obtained by minimizing the frequencies. As the degrees of the polynomials are increased, frequencies converge to the exact values. Novel numerical results are presented for two types of thick conical shells and thick spherical shell segments having linear thickness variations. Convergence to four digit exactitude is demonstrated for the first five frequencies of both types of shells. The method is applicable to thin shells, as well as thick and very thick ones.