• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.586-591
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• 2002

Bruxism can be generally regarded as a diurnal clenching or nocturnal teeth grinding or a combination of both. Clenching of the teeth is forceful closure of the opposing dentition in a static relationship of the mandible to the maxilla, whereas grinding of the dentition is forceful closure of the opposing dentition in a dynamic maxillo-mandibular relationship as the mandibular arch moves through various excursive positions. The causes of bruxism are not yet discovered clearly, but most consistently mentioned cause is psychological stress. Bruxism can be also associated with sleep disorders, medication, and disturbances of the central nervous system. There is no permanent treatment method of bruxism, so the objectives for management of bruxism are reduction of psychological stress and treatment of signs and symptoms of bruxism by occlusal adjustment, occlusal splint, systemic medication and physical therapy. These cases report present three cases of children with bruxism. The bruxism was reduced in these patients wearing occlusal splint.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.580-585
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• 2009

Pediatric dentists often meet children with abnormal in number of tooth. Presence of supernumerary teeth is frequent cause of malocclusion. Etiology for supernumerary teeth is not yet clearly defined, but it is thought to be caused by excessive proliferation of dental lamina by hereditary and environmental factors. Supernumerary teeth occur in the maxilla nine times more frequently than in the mandible. Most common supernumerary tooth is the mesiodens in the maxilla, and some are observed in the maxillary molar and mandibular premolar. It occurs rarely in the mandibular incisor region with the incidence of 1-2% among all supernumerary teeth. A six-year old boy visited the department of the pediatric dentistry, Yonsei University Dental Hospital, with the chief complaint of crowded supernumerary teeth on the mandibular incisor region. Clinical and radiographic examinations revealed six permanent mandibular incisors similar in size, shape, and length. Further investigation using computed tomography(CT) was proceeded on the mandible to measure and compare morphologic features and positions of the six incisors. Then, we decided to remove two incisors which were already erupted. Periodic check-up was followed to monitor the dental development and spontaneous positional enhancement of the remaining four incisors in the mandible.

• Journal of Radiation Protection and Research
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• v.24 no.4
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• pp.215-223
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• 1999

Characteristics of radiation field in the steam generator(S/G) water chamber of a PWR were investigated and the anticipated effective dose rates to the worker in the S/G chamber were evaluated by Monte Carlo simulation. The results of crud analysis in the S/G of the Kori nuclear power plant unit 1 were adopted for the source term. The MCNP4A code was used with the MIRD type anthropomorphic sex-specific mathematical phantoms for the calculation of effective doses. The radiation field intensity is dominated by downward rays, from the U-tube region, having approximate cosine distribution with respect to the polar angle. The effective dose rates to adults of nominal body size and of small body size(The phantom for a 15 year-old person was applied for this purpose) appeared to be 36.22 and 37.06 $mSvh^{-1}$) respectively, which implies that the body size effect is negligible. Meanwhile, the equivalent dose rates at three representative positions corresponding to head, chest and lower abdomen of the phantom, calculated using the estimated exposure rates, the energy spectrum and the conversion coefficients given in ICRU47, were 118, 71 and 57 $mSvh^{-1}$, respectively. This implies that the deep dose equivalent or the effective dose obtained from the personal dosimeter reading would be the over-estimate the effective dose by about two times. This justifies, with possible under- or over- response of the dosimeters to radiation of slant incidence, necessity of very careful planning and interpretation for the dosimetry of workers exposed to a non-regular radiation field of high intensity.

• Journal of Radiation Protection and Research
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• v.36 no.1
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• pp.28-34
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• 2011

The measurement-based verification for intensity modulated radiation therapy (IMRT) is a time-and labor-consuming procedure. Instead, this study aims to develop a MU fluence reconstruction method for IMRT QA. Total actual fluences from treatment planning system (TPS, Eclipse 8.6, Varian) were selected as a reference. Delivered leaf positions according to MU were extracted by the dynalog file generated after IMRT delivery. An in-house software was develop to reconstruct MU fluence from the acquired delivered leaf position data using MATLAB. We investigated five patient's plans delivered by both step-and-shoot IMRT and sliding window technologies. The total actual fluence was compared with the MU fluence reconstructed by using commercial software (Verisoft 3.1, PTW) and gamma analysis method (criteria: 3%/3 mm and 2%/1 mm). Gamma pass rates were $97.8{\pm}1.33$% and the reconstructed fluence was shown good agreement with RTP-based actual fluence. The fluence from step and shoot IMRT was shown slightly higher agreement with the actual fluence than that from sliding window IMRT. If moving from IMRT QA measurements toward independent computer calculations, the developed method can be used for IMRT QA. A point dose calculation method from reconstructed fluences is under development for the routine IMRT QA purpose.

• Journal of Radiation Protection and Research
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• v.38 no.3
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• pp.143-148
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• 2013

Operational nuclear facilities such as nuclear power plants and particle accelerators show various neutron spectra according to the type of facilities and specific position. Necessities of neutron dose management and neutron monitoring for radiation protection of radiation workers in such a kind of facilities have continuously increased in recent years. Bonner sphere spectrometers are widely used for measurement of neutron spectra. Data on response function of neutron detector, default neutron spectra and count rates of Bonner sphere spectrometer are required to obtain unfolded neutron spectra in specific workplaces. In this study, we carried out measurement of neutron spectra produced in MC50 cyclotron using Bonner sphere spectrometer with LiI scintillation detector. Additionally, we estimated quantitative data on neutron flux, mean neutron energy and ambient dose equivalent rate according to the incident proton energies and positions in MC50 cyclotron.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.487-496
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• 2020

For the purpose of next generation technology for robot perfomances, a RAoRA (Robot Actor on Robot Arm) structure was proposed using a robot arm joined with a humanoid robot actor. Mechanical analysis, machine design and fabrication were performed for motions combined with the robot arm and the humanoid robot actor. Kinematical analysis for 3D model, spline interpolation of positions, motion control algorithm and control devices were developed for movements of the robot actor. Preliminary visualization, simulation tools and integrated operation of consoles were constructed for the non-professionals to produce intuitive and safe contents. Air walk was applied to test the developed platform. The air walk is a natural walk close to a floor or slow ascension to the air. The RAoRA also executed a performance with 5 minute-running time. Finally, the proposed platform of robot performance presented intensive and live motions which was impossible in conventional robot performances.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.86-93
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• 2015

Recently, the development of Maritime Service Portfolios (MSPs) for the safe navigation of ship has been discussed internationally. For the successful service of the MSPs, first of all, studies for the standardization about the structure and data structure of MSPs should be preceded. Also, it is necessary to evaluate and assess whether the services are effective for safe navigation, and provided data and portrayal methods are proper. However, because great dangers will be accompanied when untested MSPs about their effectiveness and safety are applied in real ship navigation, it is necessary that effectiveness and safety of the MSPs should be proven under various navigational conditions and environments by simulation. In this paper, we propose a 3D navigation simulation system using desktop PC environment, which is proper for evaluating the effectiveness of MSPs. The system consists of three modules which are simulation scenario editor, 3D visualization of navigational environment and 2D navigational equipment. The scenario editor module provides an environment setting for simulation, such as properties, routes and positions of vessels and aids to navigations. It also provides functions to create a scenario for the simulation to operate. Additionally, the 3D visualization module provides 3D navigational environment which shows interplay between geographical and navigational environment based on the created scenario. The 2D navigational equipment module provides visualization functions of various navigational equipment, shows the interaction between ship's navigational equipment and ship's environment. The simulation scenario, in which various kinds of ships are routing in the port, is created by the developed simulation system, and experimented whether this developed system is appropriate to evaluate and assess the MSPs developed by the International Maritime Organization.

• Journal of Mushroom
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• v.3 no.2
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• pp.52-59
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• 2005

The Aphyllophorales is a large order containing about 2,000 known species. Many of these are the bracket and coral fungi. The vast majority of these fungi are saprophytic on the plant debris. Many species are significant in decomposing plant remains, as they are able to digest cellulose or lignin that occurs in plant cell walls. Many of these fungi have been involved in everyday human affairs. A few were used medicinally by the Greeks and Romans as a remedy for many complaints, including colic, fractured limbs and bruises. Other bracket fungi have been used as curry combs for horses, as snuff, as razor strops and as a source of dye for clothing. The texture of the basidiocarp may be similar to that of cork, wood, leather, paper, or cartilage. Unlike the basidiocarps of the Order Agaricales, the basidiocarps of the Aphyllophorales are not fleshly and moist. Division of the members of the Aphyllophorales into genera was originally made on the basis of gross morphology of the basidiocarp and hymenium and Donk(1964) recognizes 22 families in this order. The species and genus whose typical in Aphylloporales were listed in Table. with related information. The ITS region sequence of some genus were found by BLAST search. Sequences retrieved from GenBank were visually aligned by the program CLUSTAL G. As a result, the medicinal mushroom was separated in four groups. In this multiple alignment, the sequence analysis among Fomes group, Inonotus group and Phellinus group showed high genetic similarity except Hericium group and Sparassis group.

• Smart Structures and Systems
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• v.21 no.5
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• pp.623-635
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• 2018

In order to study the mechanical behavior of shield tunnel segments during assembly stage, the in-situ tests and FDM numerical simulation were conducted based on the Foguan Shiziyang Tunnel with large cross-section. Analysis for the load state of the assembling segments in different assembly steps as well as the investigation for the changing of inner forces and longitudinal stress of segments with assembling steps were carried out in this paper. By comparing the tested results with the simulated results, the conclusions and suggestions could be drawn as follows: (1) It is the most significant for the effects on axial force and bending moment caused by the assembly of adjacent segment, followed by the insertion of key segment while the effects in the other assembly steps are relative smaller. With the increasing value of axial force, the negative bending moment turns into positive and remains increasing in most monitored sections, while the bending moment of segment B1and B6 are negative and keeping increasing; (2) The closer the monitored section to the adjacent segments or the key segment, the more significant the internal forces response, and the monitored effects of key segment insertion are more obvious than that of calculation; (3) The axial forces are all in compression during assembling and the monitored values are about 1.5~1.75 times larger than the calculated values, and the monitored values of bending moment are about 2 times the numerical calculation. The bending moment is more sensitive to the segments assembly process compared with axial force, and it will result in the large bending moment of segments during assembling when the construction parameters are not suitable or the assembly error is too large. However, the internal forces in assembly stage are less than those in normal service stage; (4) The distribution of longitudinal stress has strong influence on the changing of the internal forces. The segment side surface and intrados in the middle of two adjacent jacks are the crack-sensitive positions in the early assembly stage, and subsequently segment corners far away from the jacks become the crack-sensitive parts either.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.174-183
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• 2001

During the rapid phase of gonadal development of the freshwater teleost, the catfish (Silurus asotus), the influence of hCG upon the inducement of final oocyte maturation and spawning was investigated electrophoretically and ultrastructurally. The electrophoretic patterns obtained were different in the presence and absence of some of the major or minor zones, because of the hormone level in catfish. The vitellogenin of hormone-treated fish was stained more intensively than that of sham-treated fish. These proteins showed some minor or main bands of egg extracts which migrated at positions corresponding to molecular weights of approximately 90,000. However, the thickness of electrophoretic band in molecular weight for hCG-treated fish was slightly lower than that for saline control. It seemed the plasma protein with molecular weight of approximately 45,000 in hCG-treated fish disappeared. In contrast to the control fish, the ovaries in the catfish treated with hCG shows a marked ultrastructural change under the electron microscope. No dilated profiles were seen in the granulosa cells of the mature oocyte before ovulation. After germinal vesicle breakdown (GVBD), the zona radiata interna (ZRI) becomes more compact, and there is a loss of all the processes from the pore canals. There is a wide space between the vitelline membrane and zona radiata. Also, during final maturation, the microvillar processes from the oocyte are seen no longer to penetrate deeply into the extracellular spaces of the overlying granulosa cells, and the reticulate patterns of the zona radiata interna becomes occluded, giving the zona radiata a more solid appearance. It has been possible to initiate 100% oocyte maturation in yolk granules and follicles in vivo by treatment with hCG and a high water temperature ($27^{\circ}C$). In hCG-treated fish, the percentages of successful artificial fertilization and hatching were maximal at 15 h after a single injection. It seems clear that a long acting preparation containing hCG can be successfully used in prespawning fish to advance the final events of gonadal maturation and initiate spawning. Further studies are necessary to evaluate the potential of hCG to either stimulate or inhibit the reproductive development of fish at other stages of the seasonal reproductive cycle.