• Journal of Digital Convergence
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• v.11 no.12
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• pp.665-672
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• 2013

In radiology department, where patients with a variety of diseases receive their tests, there is a large possibility of cross contamination of nosocomial infection. Magnetic resonance imaging (MRI) tests take particularly more time than other tests do, which increases the possibility of being exposed to cross contamination. Therefore, this research examines the status of MRI equipment sterilization and investigates the bacterial distribution on head coils, which have the most frequent contact with patients, patient fixation blocks, and bores, which are confined spaces. The status of MRI equipment disinfection was examined by a survey targeting 150 employees, and the distribution of bacteria was measured in ten medical facilities. The result of bacterial distribution tests on MRI equipment showed various bacteria, including Staphylococcus, Acinetobacter, Sphingomona, Pantoea agglomeranss, Micrococcus, Bacillus, Saprophyticus, Brevundimona, and Myroidesspecies. The result of examining the stat us of MRI room disinfection showed that the disinfections of the head coil, block, and bore were implemented well, and the largest proportion was carried out once a day in the morning. The time and implementation of disinfection by the disinfection manager showed that they were implemented well when the manager was the MRI room examiner. The disinfection after examining a patient using an appropriate disinfectant is mandatory to prevent cross contamination.

• The Journal of Korean Society for Radiation Therapy
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• v.15 no.1
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• pp.41-52
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• 2003

I. Purpose The dose distribution in normal tissues and target lesions is very important in the treatment planning. To make the uniform dose distribution in target lesions, many methods has been used. Especially in the head and neck, the dose inhomogeneity at the skin surface should be corrected. Conventional methods have a limitation in delivering the enough doses to the planning target volume (PTV) with minimized dose to the parotid gland and spinal cord. In this study, we investigated the feasibility and the practical QA methods of the forward IMRT. II. Material and Methods The treatment plan of the forward IMRT with the partial block technique using the dynamic multi-leaf collimator (dMLC) for the patients with the nasopharyngeal cancer was verified using the dose volume histogram (DVH). The films and pinpoint chamber were used for the accurate dose verification. III. Results As a result of verifying the DVH for the 2-D treatment plan with the forward IMRT, the dose to the both parotid gland and spinal cord were reduced. So the forward IMRT could save the normal tissues and optimize the treatment. Forward IMRT can use the 3-D treatment planning system and easily assure the quality, so it is easily accessible comparing with inverse IMRT IV. Conclusion The forward IMRT could make the uniform dose in the PTV while maintaining under the tolerance dose in the normal tissues comparing with the 2-D treatment.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.4
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• pp.240-249
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• 2016

In this study, we investigated wave force distribution at points on a vertical structure of semi-infinite breakwater considering diffraction. Wave forces of monochromatic and random waves on a vertical structure are studied considering diffractions in front and lee side of the breakwater for non-breaking wave condition. We selected width of breakwater are 0 for reference condition. In monochromatic wave case, relative wave force becomes 0 on the head of the breakwater by acting incident wave force and diffracting wave force simultaneously and oscillating patterns of relative wave force occurs based on 1.0 as distance from the head increases. Relative wave force of monochromatic waves decreases as incident wave angle increases. Relative wave force of random waves is defined by using ratio of root mean square and wave force spectrum in this study. The case considering random phase of each wave components are compared to the case which don't consider random phase and both results are almost similar. Relative wave force of random waves is also 0 near the head of the breakwater likewise monochromatic wave. Oscillating pattern of relative wave force of random waves becomes relatively weaker for composition of each wave components as distance from the head increases.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.409-412
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• 2007

A motorcycle helmet is the best means to protect the head of bike's driver and it is directly connected to a driver's life. Prior to producing of the helmet, it has to be passed the process of impact test to evaluate of its safety. This test evaluates peak acceleration and H.I.C (Head Injury Criteria). This paper analyzes impact test with finite element method to find the behavior of helmet during the test. Also, the effect of impact sites on the helmet was evaluated to improve the thickness distribution of the helmet.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.523-536
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• 1991

This dissertation analyzes the running mechanism of flexible and thin tape above rotating head through the numerical simulation and the experiment. The scope of analysis is confined to the phenomena of two dimensional elasto hydrodynamic lubrication between the protruded bump on a rotating cylinder and the running tape. This model is based on the elastic deformation equation of plate and shell and Reynolds equation. Finite difference method is employed as a numerical technique to calculate (1) the distribution of pressure between the running tape and rotating bump and (2) the vertical deformation of elastic thin tape over he rotating bump under hydrodynamic pressure. In numerical analyses, the effects of bump size on flying characteristics of the tape were evaluated and examined considering the influence of tension and stiffness of tape.

• Journal of KSNVE
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• v.10 no.2
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• pp.269-279
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• 2000

This paper deals with the development of biomechanical model on a seat with backrest support in the vertical direction. Four kinds of biomechanical models are discussed to depict human motion. One DOF model mainly describes z-axis motion of hip, two and three DOF models describe z-axis of hip and head, and while nine DOF model suggested in this study represents more motion than the otehr model. Three kinds of experiments were executed to validate these models. The first one was to measure the acceleration of the floor and hip surface in z-axis, the back surface in x-axis, and the head in z-axis under exciter. From this measurement, the transmissiblities of each subject were obtained. The second one was the measurement of the joint position by the device having pointer and the measurement of contact position between the human body and the seat by body pressure distribution. The third one was the measurement of the seat and back cushion by dummy. The biomechanical model parameters were obtained by matching the simulated to the experimental transmissiblities at the hip, back, and head.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1151-1156
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• 2001

In this paper, the electric field distribution and directivity on human head caused by portable phone is analyzed. An analysis model is composed of a human head model and the antenna mounted on the same ground plane as portable telephone size. The QMSA to load a capacitor without limitation of the electric force is used In the computational model to apply to the antenna mounted on portable phone. This antenna is designed to operate in the near of frequency 2.0㎓, is observed the radiation characteristics of the antenna and their variations as a function of distance from the human head.

• Transactions of Materials Processing
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• v.16 no.5 s.95
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• pp.370-374
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• 2007

A motorcycle helmet is very essential to protect the head of driver and it is directly connected to driver's life. Prior to producing the helmet, it has to be passed the process of impact test to evaluate its safety. This test evaluates peak acceleration and head injury criteria (H.I.C.). This paper simulates the impact test with finite element method to find the behavior of helmet during the test. Also, the effect of impact sites on the helmet was evaluated to improve the thickness distribution of the helmet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.1038-1047
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• 1996

The effect of electromagnetic wave on the biobody is to make a possibility not increasing temperature but also inducing physiological and psychological damage which is head or backbone. Generally a vital function of hean can be estimated by the measureing of Electro Encephalogram(EEG), and achieved a response of a find stimulus which can not be defected a subjective sympton and out of reaction. In this paper, the head can be modeled according to its medium and dervated the equation of SAR distritution, and the head of rabbit is approximately modeled three layers practically and the result of each SAR distribution is illustrated. Measured EEG from the nervous system of rabbit on a plane wave irradiated an be used quantitative analysis for the electrophysiogical effect of the biobody.

• Applied Science and Convergence Technology
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• v.26 no.1
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• pp.1-5
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• 2017

The spurt vacuum pump is widely used to transfer sludge and slurry, and to control flow rate in a variety of processing fields, such as the oil, chemical, and fiber industries. The efficiency of the pump depends on the design parameters of the impeller, such as the number of blades, and the blade angle. In this study, the effect of the configuration of the impeller discharge angle of a spurt vacuum pump, which influences total head, shaft power, and efficiency, was numerically investigated using the commercial code, ANSYS CFX ver. 16.1. In addition, the performance of the pump was evaluated on the basis of the correlations between the total head, pump efficiency, and pressure distribution.