• Journal of Industrial Technology
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• v.26 no.B
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• pp.29-34
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• 2006

A convective, radiating rectangular fin is analysed by using the one dimensional analytic method. Instead of constant fin base temperature, heat conduction from the inner wall to the fin base is considered as the fin base boundary condition. Radiation heat transfer is approximately linearized. For different fin tip length, temperature profile along the normalized fin position is shown. The fin tip length for 98% of the maximum heat loss with the variations of fin base length and radiation characteristic number is listed. The maximum heat loss is presented as a function of the fin base length, radiation characteristic number and Biot number.

• Journal of the Korea Society of Computer and Information
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• v.8 no.1
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• pp.90-96
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• 2003

In this paper, arranged the isotropic point source of N number with the structure which is identical with the receive area. And against the array structure which has the radiation pattern which is identical with the receive area it researched. The arranged the element space flees grating lobe and in order to set the characteristic of optimum with half-wave equally space it selects. After inducing the array factor of each array structure, it calculated a radiation pattern. As a result of, the radiation pattern of the each Planar array antenna with structure of the receive area was similar and the possibility of getting an beam characteristic it was.

• Toxicological Research
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• v.20 no.2
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• pp.117-122
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• 2004

The present study was carried out to establish a short-term teratogenicity study for detecting developmental toxic potential induced by gamma radiation in ICR mice. Pregnant mice were exposed at dose levels of 0, 0.5, 1, 2, or 4 Gy on gestational day 8.5. All dams were subjected to caesarean section on gestational day 10.5 and their embryos were examined for growth, differentiation, and morphological abnormalities. An increase in the number of resorption was found at 4 Gy in a dose-dependent manner. Dose-dependent decreases in the developmental score of yolk sac circulation and olfactory system at above 1 Gy, in the number of somite pairs and developmental score of allantois, optic system, and maxillary process at above 2 Gy, and in the all growth and developmental parameters examined at 4 Gy were found. Various types of morphological abnormalities were seen at dose levels of 0.5 Gy or greater. Characteristic malformations induced by gamma radiation were abnormal axial rotation, hematoma, craniofacial hypoplasia, open neuropore, shortened prosencephalon, kinked somites, irregular somites, swelling, hydropericardium, absent branchial bar, and absent limb bud. Morphological alterations such as hematoma, craniofacial hypoplasia, open neuropore, and kinked somites were noted even in the lowest dose (0.5 Gy). These results indicated that the short-term teratogenicity study established in this study can be a useful tool for not only detecting the developmental toxic potential induced by gamma radiation, but also screening radio-protective agents in ICR mice.

• Journal of Digital Contents Society
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• v.13 no.3
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• pp.421-429
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• 2012

Lately, the number of interventional radiology is increased by the extension of procedure in medical radiation, and radiation exposure may be appeared differently by interventional radiologists, it is caused increase of radiation dose for radiation worker, patient, and radiologists. This study has done a comparative analysis characteristic of radiation exposure for five radiologists who executed interventional cardiology for 303 patients in S university hospital of Gyeong-Buk from Nov. 1, 2011 to Jan. 31, 2011. The average exposure time of five radiologists was 697.95sec. The average of cumulative DAP(exp) for patients was $52,730mGycm^2$ and the average of total DAP for patients was $104,875.14mGycm^2$. The average of frames for image was 855.52 frames in acquired images, and the average of frames for images was 802.2 frames in exposure images. They were statistically significant differences (p<0.05). Exposure time, cumulative DAP(fluro), cumulative DAP(exp), total DAP, acquired image, and exposure image were high correlation except cumulative DAP(exp), and acquired runs in x-ray exposure characteristics of machine. Exposure time was a great influence on radiologist. It signified that the more exposure time lead to the more radiation dose for radiologist. Radiation dose is related to ability, experience, difficulty, and precision of procedures in interventional procedure. The number of angiography and exposure time is difficult to control by radiologists. Therefore, it is in need of reasonable system which was evaluated the real dose of medical teams in interventional proceedings. We think that self education and training are required to reduce radiation dose for radiologists and radiation workers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.71-77
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• 2000

An axisymmetric supersonic jet is simulated at a Mach number of 1.5 and a Reynolds number of $10^5$ to identify the mechanism of sound radiation from the jet. The present simulation is performed based on the high-order accuracy and high-resolution ENO(Essentially Non-Oscillatory) schemes to capture the time-dependent flow structure representing the sound source. In this simulation, optimum expansion jet is selected as a target, where the pressure at nozzle exit is equal to that of the ambient pressure, to see pure shear layer growth without effect of change in jet cross section due to expansion or shock wave generated at nozzle exit. Shock waves are generated near vortex rings, and discernible pressure waves called Mach wave are radiated in the downstream direction with an angle from the jet axis, which is characteristic of high speed jet noise. Furthermore, vortex roll-up phenomena are observed through the visualization of vorticity contours.

• Communications for Statistical Applications and Methods
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• v.29 no.3
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• pp.287-299
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• 2022

In radiation epidemiology, the excess relative risk (ERR) model is used to determine the dose-response relationship. In general, the dose-response relationship for the ERR model is assumed to be linear, linear-quadratic, linear-threshold, quadratic, and so on. However, since none of these functions dominate other functions for expressing the dose-response relationship, a Bayesian semiparametric method using splines has recently been proposed. Thus, we improve the Bayesian semiparametric method for the selection of the tuning parameters for splines as the number and location of knots using a Bayesian knot selection method. Equally spaced knots cannot capture the characteristic of radiation exposed dose distribution which is highly skewed in general. Therefore, we propose a nonparametric Bayesian knot selection method based on a Dirichlet process mixture model. Inference of the spline coefficients after obtaining the number and location of knots is performed in the Bayesian framework. We apply this approach to the life span study cohort data from the radiation effects research foundation in Japan, and the results illustrate that the proposed method provides competitive curve estimates for the dose-response curve and relatively stable credible intervals for the curve.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.764-769
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• 2007

This paper is studied the noise and vibration characteristics analysis of the three-phase induction AC motor of the electrical forklift. And we suggest the method which the reduction orders the noise and vibration to be the mechanical. In other to investigate these characteristics, we considered the mechanical characteristics, the electromagnetic effects, and these interactions. In mechanical, we studied the characteristic of the stator, the bearing supported condition of the rotor, and the sound radiation. In electronically, this paper is considered the harmonic effect which is related the magnetic motive force (mmf) with respect to the characteristic of the slot number of the rotor and the stator and the pole number of the motor. Finally we investigated the overall noise and vibration of the induction motor by relations between the electronically harmonic and the mechanical resonance of the stator. By the analysis of the generally three-phase induction motor, we suggest the design methodology to low noise and vibration.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.83-90
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• 1993

During the period from January, 1975, to June, 1989, one hundred patients with histopathologically proven polymorphic reticulosis in the upper respiratory tract were treated with radiation therapy and the analysis of treatmemt results was undertaken. One hundred patients (69 males, 31 females) with a mean age of 46 years (range 12-79 years) were presented. Nasal cavity was the most frequent site of involvement ($56{\%}$), and 44 cases had multifocal sites of involvement. The incidence of cervical lymph node metastasis at initial diagnosis was $24{\%}$. Staging was determined by Ann-Arbor classification, retrospectively. The number of patients of stage IE, IIE, IIIE and IVE were 35, 60, 1, and 4, respectively. The overall 5 year actuarial survival rates were $38.4{\%}$. The difference in 5 year survival rates between patients with stage IE and IIE, with solitary and multiple, with CR and PR after irradiation were significant statistically. For the analysis of failure patterns, failure sites include the following: local failure alone (30/55=$54.6{\%}$), systemic failure alone (9/55=$16.4{\%}$), both local and systemic failure (16/55=$29.0{\%}$). Retrograde slide review was available in 29 cases of PMR with respect to histopathologic bases, and immunohistochemical studies were performed using MT1 and DACO-UCHL-1 as T-cell markers, MB2 as a B-cell marker and alpha-1-antichymotrypsin as a histiocytic markers. All that 29 cases showed characteristic histologic features similar to those of peripheral T-cell lymphoma and showed positive reactio to the T-cell marker. These findings suggest strongly that quite a significant portion of PMR may be in fact T-cell lymphoma.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.577-582
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• 1998

In nuclear power plant, it has been the important object to reduce the occupational radiation exposure (ORE). Recently, the optimization concept of management science has been studied to reduce the ORE in nuclear power plant. In optimization of the worker allocation, the collective dose, working time, individual dose, an total number of worker must be considered and their priority orders must be thought because the main constraint is necessary for determining the constraints variable of the radiological worker allocation problem. The ultimate object of this study s to look into the change of the optimal allocation of the radiological worker as priority order changes. In this study, the priority order is the characteristic of goal programming that is a kind of multi-objective linear programming. From a result of study using goal programming, the total number of worker and collective dose of worker have changed as the priority order has changed and the collective dose limit have played an important role in reducing the ORE.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.203-210
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• 2011

To evaluate the ability of Bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BL) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and BL-treated mice exposed chronically to ultraviolet (UV) were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back, increased epidermal thickeness, numerous cell infiltration, and many enlarged keratinizing cysts. BL-treated mice showed a significantly decreased wrinkling score and lack of proliferation of cysts. By the 22nd week, 88.9% (i.p. with saline) or 60.0% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. BL delayed tumor onset significantly. BL (i.p.) was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 37.5% (i.p.) of the mice treated with BL were tumor-free. Tumor multiplicity was reduced by 81.2% (i.p.) in the BL treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and regular use of BL would prevent these photodamaging effects of UV.