• Applied Microscopy
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• v.24 no.1
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• pp.77-85
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• 1994

In order to investigating the pulmonary toxicity of the O-chlorobenzyledene malononitrile (CS), lacrimating agent, $2.6g/m^3$ of CS was inhalated to Sprague-Dawley rats in the plastic chamber for 20 minutes. The ultrastructural changes of type II pneumocytes in the lung were observed with Hitachi 600 transmission electron microscope. The results obtained were as follows: 1. 3 hours after exposure to CS the fusion of surface microvilli, dilatation of cristernae of the rough endoplasmic reticulum, atrophy of Golgi complex and condensation, deletion of lamellated membranes in lamellar bodies were observed in type II pneumocytes. 2. One and 2 days after CS-exposure, disorganization of mitochondrial double membranes, fragmentations of rough endoplasmic reticulum were found in the great alveolar cells. In addition, decrease in amount of polyribosome granules and deletion or condensation of lamellated membranes in lamellar bodies were also observed. 3. 4 days after exposure to CS, the type II pneumocyte revealed new whorled lamellar membranes in lamellar bodies, a few intact rough endoplasmic reticulum and restoration of polyribosome granules. It is consequently suggested that CS induces degenerative changes of cytoplasmic organelles in the type II pneumocytes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4B
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• pp.419-427
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• 2009

This paper propose DA-UDC(Double Authentication User, Device, Cross) Module which solves the cost problem and the appropriation of Certificate using User Authentication, Device Authentication and Cross Authentication with OTA(One Time Authentication) Key, and which is designed not to subscribe to the service of Home network business. Home Server transmits its public key which is needed to create OTA to the user which passed the first step of authentication which verifies User ID, Device ID and Session Key. And it performs the second step of authentication process which verifies the OTA key created by a user. Whenever the OTA key of DA-UDC module is generated, the key is designed to be changed. Therefore, DA-UDC Module prevents the exposure of User and Device ID by performing the two steps of authentication and enhances the authentication security of Home Network from malicious user with OTA key. Also, DA-UDC Module is faster than the existing authentication system in processing speed because it performs authentication calculation only once. Though DA-UDC Module increases data traffic slightly because of the extra authentication key, it enhances the security more than the existing technique.

• Archives of Craniofacial Surgery
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• v.15 no.2
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• pp.53-58
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• 2014

Background: Maxillomandibular fixation (MMF) is usually used to treat double mandibular fractures. However, advancements in reduction and fixation techniques may allow recovery of the premorbid dental arch and occlusion without the use of MMF. We investigated whether anatomical reduction and microplate fixation without MMF could provide secure immobilization and correct occlusion in double mandibular fractures. Methods: Thirty-four patients with double mandibular fractures were treated with open reduction and internal fixation without MMF. Both fracture sites were surgically treated. For bony fixations, we used microplates with or without wire. After reduction, each fracture site was fixed at two or three points to maintain anatomical alignment of the mandible. Interdental wiring was used to reduce the fracture at the superior border and to enhance stability for 6 weeks. Mouth opening was permitted immediately. Results: No major complications were observed, including infection, plate exposure, non-union, or significant malocclusion. Five patients experienced minor complications, among whom the only one patient experienced a persistant but mild malocclusion with no need for additional management. Conclusion: This study showed that double mandibular fractures correction with two-or three-point fixation without MMF simplified the surgical procedure, increased patient comfort, and reduced complications, due to good stability and excellent adaptation.

• International Journal of Safety
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• v.11 no.1
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• pp.33-36
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• 2012

Examples and experiences of risk management on radiation under prolonged exposure situation are shown. The accident of the Fukushima dai-ichi nuclear power plant after the great east Japan earthquake (11 March, 2011) elevates background level of environmental radiation around the east Japan. For example, ambient dose equivalent rate around Tohkatsu area next to Tokyo located about 200 km-south from the plant, is about 0.1-0.6 micro-Sv $h^{-1}$ mainly due to $^{134}Cs$ and $^{137}Cs$ falling on the ground soil. This level is about double or up to ten times higher than the genuine natural level around the area. International Commission on Radiological Protection (ICRP) recommends how to face the existing exposure situation; that is the prolonged exposure situation. Referring to ICRP's reports and/or related international/domestic documents, we have been discussing and acting to gain public's safety and relief, who have a possibility to be exposed to prolonged lower-dose radiation. Here, we introduce our several experiences on risk management, especially focusing on risk communication, radiation education to public, and stakeholder involvements into making decision in local governments on radiation protection, relating to the accident.

• International Journal of Safety
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• v.10 no.2
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• pp.6-9
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• 2011

Examples and experiences of risk management on radiation under prolonged exposure situation are shown. The accident of the Fukushima dai-ichi nuclear power plant after the great east Japan earthquake (11 March, 2011) elevates background level of environmental radiation around the east Japan. For example, ambient dose equivalent rate around Tohkatsu area next to Tokyo located about 200 km-south from the plant, is about 0.1-0.6 micro-Sv $h^{-1}$ mainly due to $^{134}Cs$ and $^{137}Cs$ falling on the ground soil. This level is about double or up to ten times higher than the genuine natural level around the area. International Commission on Radiological Protection (ICRP) recommends how to face the existing exposure situation; that is the prolonged exposure situation. Referring to ICRP's reports and/or related international/domestic documents, we have been discussing how to manage this situation and acting to gain safety and relief of public, who have a possibility to be exposed to prolonged lower-dose radiation. Here, we introduce our several experiences on risk management, especially focusing on risk communication, radiation education to public, and stakeholder involvements into decision making in local governments on radiation protection, relating to the accident.

• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1599-1604
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• 2001

Axisymmetric compressible flow field induced by shock diffraction from a finite cone is investigated with experimental and computational methods. Double-exposure holographic interferograms show ima ges of the density field integrated along the light path. Using the sight-integrated density based on the Able transformation, the axisymmetric computational results are compared qualitatively with the experiment. In the present paper, we observed some distinguishing flow physics: the fault structure of vortex ring, the shock-vortex interaction, and the morphological transformation of shock waves.

• Journal of radiological science and technology
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• v.38 no.1
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• pp.1-6
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• 2015

Whole spine scanography (WSS) is a radiological examination that exposes the whole body of the individual being examined to x-ray radiation. WSS is often repeated during the treatment period, which results in a much greater radiation exposure than that in routine x-ray examinations. The aims of the current study were to evaluate the patient dose of WSS using computer simulation, image magnification and angulation of phantom image using different patient position. We evaluated the effective dose(ED) of 23 consecutive patients (M : F = 13:10) who underwent WSS, based on the automatic image pasting method for multiple exposure digital radiography. The Anterior-Posterior position(AP) and Posterior-Anterior position( PA) projection EDs were evaluated based on the PC based Monte Carlo simulation. We measured spine transverse process distance and angulation using DICOM measurement. For all patient, the average ED was 0.069 mSv for AP position and 0.0361 mSv for PA position. AP position calculated double exposure then PA position. For male patient, the average ED was 0.089 mSv(AP) and 0.050 mSv(PA). For female patient, the average ED was 0.0431 mSv(AP) and 0.026 mSv(PA). The transverse process of PA spine image measured 5% higher than AP but angulation of transverse process was no significant differences. In clinical practice, just by change the patient position was conformed to reduce the ED of patient. Therefor we need to redefine of protocol for digital radiography such as WSS. whole spine scanography, effective dose, patient exposure dose, exposure direction. protocol optimization.

• Journal of Korea Multimedia Society
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• v.13 no.4
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• pp.526-534
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• 2010

This paper describes an algorithm which merges two HDR pictures taken under different exposure time to display on the LDR devices such as LCD or CRT. The proposed method does not generate the radiance map, but directly merges using the weights computed from the input images. The weights are firstly produced on the pixel basis, and then blended with a Gaussian function. This process prevents some possible sparkle noises caused by radical change of the weights and contributes to smooth connection between 2 image informations. The chrominance informations of the images are merged on the weighted averaging scheme using the deviations of RGB average and their differences. The algorithm is characterized by the feature that it represents well the unsaturated area of 2 original images and the connection of the image information is smooth. The proposed method uses only 2 input images and automatically tunes the whole internal process according to them, thus autonomous operation is possible when it is included in HDR cameras which use double shuttering scheme or double sensor cells.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.94-109
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• 1998

The purpose of this study was to evaluate the effect of materials and sizes of files on canal transportation in a curved canal. The stress and the strain energy of files of two kinds of materials (stainless steel and NiTi) and five sizes (No. 20, 25, 30, 35 and 40) in a curved canal were analyzed by a finite element program, NASTRAN. Curved canals in transparent resin blocks were instrumented with the 10 kinds of files, and the degree of canal transportation obtained by double exposure technique of photography was compared with the analysis by the finite element method. The results were as follows : 1. The stress of a file in a curved canal increased from the file body to the file tip. 2. The stress of a stainless steel file was about 2.5 times greater than that of a same-sized NiTi file. 3. The stress distributions of files of an identical material were the same, and the strain energies of files of an identical material increased as the size of files increased. 4. The strain energy of a No. 35 NiTi file was about the same as that of a No. 20 stainless steel file. 5. The degree of canal transportation by a stainless steel file was greater than that by a same-sized NiTi file. The degree of canal transportation generally increased as the size of a file increased. 6. The degree of canal transportation of a No. 35 NiTi file was about the same as that of a No. 20 stainless steel file.

• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.279-284
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• 2008

This paper aims to provide basic data for work environment control, prevention of worker exposure to asbestos and improvement of air quality to protect workers ‘health after measuring the level of airborne asbestos and workers' exposure in a shipbuilding repair businesses. For this study, a total of 27 samples were collected from 27 workers who had been exposed to asbestos during engine, piping, boiler and other manufacturing processes in 'A' Shipbuilding Repair Company in Gyeongnam. This research was conducted from Oct. 1 to 30, 2007 and had the following results: The target group (27 workers) consisted of all men with an average age of 35.9 years and 6.6 years of work on average. Among them, fifteen 15 (55.6%) were smokers. In terms of their duties at work, there were 12 plumbing repair engineers (44.4%), 8 boiler repair engineers (29.6%) and 7 engine engineers (25.9%). The geometric mean concentration of airborne asbestos was 0.004 f/cc. A total of 4 samples exceeded the exposure limit. In particular, three exceeded the legal limit by more than double, which means that some workers have been highly exposed to asbestos. In terms of the concentration of asbestos fibres by work process, plumbing repair was the highest (0.0071 f/cc($0.001{\sim}0.57\;f/cc$)) while boiler was the lowest (0.0015 f/cc($0.001{\sim}0.007\;f/cc$)). Based on this study, proper action needs to be taken as soon as possible to protect workers from the threat of asbestos.