• Journal of Radiation Protection and Research
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• v.17 no.1
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• pp.21-30
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• 1992

The frequencies of KCCH cyclotron neutron (30 cGy/min) or $^{60}Co\;{\gamma}-rays$ (210 cGy/min)-induced asymmetrical interchanges (dicentrics and centric rings) and acentric fragments (deletion) at several doses were measured in the normal human peripheral blood lymphocytes Chromosome aberrations were scored at the first nitosis after stimulation with phytohemagglutinin. The neutron and y-ray data were analysed on linear, power-law, quadratic and linear-quadratic model . When the dicentrics and centric rings of ${\gamma}-rays$ datas were pooled and fitted to these model, good fits were obtained to power-law $[Y=(5.81{\pm}1.96){\times}10^6D^{1.93+0.06},\; P=0.931]$, quadratic $[Y=(3.91{\pm}0.09){\times}10^{-6}D^2,\;P=0.972]$ an linear-Quadrati model $[Y=(6.55{\pm}6.83){\times}10^{-5}D+(3.72{\pm}0.22){\times}10^{-6}D^2\; P=0.922]$, except for linear model (P=0.067) As in the case of neutron data, the best fit was obtained to the linear model $(Y=(6.12{\pm}0.17){\times}10^{-3}\;D-0.22,\;P=0.987]$ and good fits were obtained to power-law$[Y=(5.36{\pm}3.02) {\times}10^{-4}D^{1.42+0.11},\; P=0.601]$ and linear-quadratic model$[Y=(2.43{\pm}0.70){\times}10^{-3}D+(1.21{\pm}0.39){\times}10^{-7}D^2$, \;P=0.415], except for quadratic model (P<0.005). The relative biological effectiveness (RBE) of neutron compared with y-ray was estimated by best fitting model. In the asymmetrical interchanges range between 0.1 and 1.5 per cell, the RBE was found to be $2.714{\pm}0.408$.

• Journal of Radiation Protection and Research
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• v.18 no.2
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• pp.1-16
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• 1993

As guides to decision-making in the management of the victims in case of acute whole body or partial body radiation exposure, we studied the relationship between radiation dose and the frequency of chromosomal aberrations observed in peripheral lymphocytes that were irradiated in vitro with $^{60}Co\;{\gamma}-rays$ at doses ranging from 2Gy to 12Gy. The yields of cells with unstable chromosomal aberrations (dicentric chromosomes, ring chromosomes, and acentric fragment pairs) were 32% at 2Gy, 47% at 4Gy, 80% at 6Gy, 94% at 8Gy, and 100% at 10Gy and over. Ydr, which reflect average dose to the whole body in case of acute whole body exposure, were 1.373 at 2Gy, 0.669 at 4Gy, 1.734 at 6Gy, 2.773 at 8Gy, 3.746 at 10Gy and 5.454 at 12Gy. The relationship between radiation dose (D) and the frequency of dicentric plus ring chromosomes per cell(Ydr) could be expressed as $Ydr=9.322{\times}10^{-2}/Gy {\times}D+2.975{\times}10^{-2}/Gy^2{\times}D^2$. Qdr, which are used in estimating dose of partial body exposure and dose of past exposure, were 1.166 at 2Gy, 1.436 at 4Gy, 2.173 at 6Gy, 2.945 at 8Gy, 3.746 at 10Gy and 5.454 at 12Gy. To see how confidently this dosimetry system may be used, we obtained Qdr values from those who received one fraction of homogenous partial body irradiation of 1.BGy, 2.5Gy, and 7.OGy therapeutically; in vivo Qdr values were 1.109, 1.222 and 2.222 respectively. The estimated doses calculated from these in vivo Qdr values using the equation $Qdr=Ydr/(1- e^{-Ydr})$ were 1.52Gy, 2.48Gy, and 6.54Gy respectively, which were very close to the doses actually given.

• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.89-96
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• 2007

Radiation safety managements in medical institutions are needed to protect certain radiation damages as a part of National Coalition. This study investigates the characteristics of self-efficacy that become the major factor on the knowledge, attitude, and behavior on the radiation safety management of radiation workers as an approach of educational aspects and analyzes the relationship between such factors to provide basic materials for improving the activity level of radiation safety managements. In order to implement the goal or this study, a survey was performed for 1,200 workers who were engaged in radiation treatments in medical centers, such as general hospital, university hospital, private hospital, and public health center for 42 days from July 23,2006. Then, the results of the analysis can be summarized as follows: 1. Average scores on knowledge, attitude, and behavior in the radiation safety management were presented as $75.76{\pm}11.20$, $90.55{\pm}8.59$, $80.58{\pm}11.70$, respectively. Also, the average score of self-efficacy was recorded as $73.55{\pm}9.82$. 2. Knowledge levels in the radiation safety management showed significant differences according to the sex, age, marriage, education, and experience. Also, males of married, older, highly educated, and largely experienced represented high knowledge levels. Attitude levels in the radiation safety management showed certain significant differences according to the type of medical centers in which private hospitals showed a relatively low level compared to that of high levels in university hospitals. Behavior levels in the radiation safety management also represented significant differences according to the age, marriage, education, experience, and types of medical centers. Factors in married, general hospital, older, highly educated, and largely experienced showed high behavior levels. In addition, the self-efficacy showed certain differences according to the marriage and types of medical centers. Factors in married and general hospital demonstrated high self-efficacy levels. 3. Relationship between knowledge, attitude, behavior, and self-efficacy on the radiation safety management showed statistical differences according to the relationship between the knowledge and the attitude, the knowledge and the behavior, the attitude and the behavior, the attitude and the self-efficacy, and the behavior and the self-efficacy. The relationship between the behavior and the self-efficacy was represented as r = 0.482, which was the strongest relationship in such factors. Also, the knowledge and self-efficacy didn't show certain relationships.

• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.65-69
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• 2007

The effects of bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BLE) on the changes of ultraviolet (UV) light B radiation-induced apoptotic sunburn cell (SBC) and epidermal ATPase-positive dendritic cell (DC) in SKH1-hr or ICR mouse were investigated. The mice were treated with UVB ($200mJ/cm^2$) and were sacrificed 24 hours later. BLE (50 mg/kg of body weight) or vehicle (saline) was given i.p. at 36 and 12 hours before irradiation, and 30 minutes after irradiation. BLE cream (0.2%) or cream base (vehicle) was also topically treated at 24 hours and 15 minutes before irradiation, and immediately after irradiation. The skin of SKH1-hr mouse prepared from the back of untreated mice exhibited about 0.3 SBC/cm length of epidermis, and 24 hours after UV irradiation, the applied areas show an increased number of SBCs. But the frequency of UVB-induced SBC formation was significantly reduced by intraperitoneal injection (59.0%) and topical application (31.8%) of BLE extract. The numbers of DC in normal ICR mouse were $628.00{\pm}51.56\;or\;663.20{\pm}62.58\;per\;mm^2$ of ear epidermis. By 1 day after UVB treatment, the number of ATPase-positive $cells/mm^2$ were decreased by 39.0% or 27.1% in i.p. or topical application group with vehicle. The frequency of UVB ($200mJ/cm^2$)-induced DC decrease was reduced by treatment of BLE as 25.7% in i.p. group and 3.2% in topical application group compared with the irradiation control group. The results presented herein that BLE administration could reduce the extent of skin damages produced by UVB.

• Journal of Radiation Protection and Research
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• v.33 no.2
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• pp.61-65
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• 2008

Objective: To reduce urinary side effects in prostate cancer patients receiving radiation, patients were asked to drink certain amount of water to maintain bladder volume constant and the bladder volumes were measured weekly using ultrasound scanner. Materials and Methods: Twenty-six patients with prostate cancer who received radiation between December 2002 and August 2007 were enrolled in this study. Thirteen patients were enrolled in experimental group. These patients were asked to drink 450 cc of water, one hour prior to simulation, CT scan, and treatment. The other thirteen patients were given no information about bladder filing. Bladder, prostate, and rectum were contoured on CT and volumes were calculated. 3D conformal treatment planning was performed and effective volumes of bladder were calculated when a prescription dose of 70.2 Gy was delivered. For the patients in experimental group, bladder volumes were measured weekly using ultrasound scanner for 6-8 weeks and the bladder volume variations were analyzed. Results: Average bladder volumes and standard deviations obtained at CT scanning were $283.5{\pm}114.0\;cc$ (40%) and $181.2{\pm}120.1\;cc$ (66%) in experimental and control groups, respectively. Although it was not statistically significant, there was correlation between the bladder volumes measured from CT and ultrasound. The volumes measured using ultrasound scanner were 62% lower than the volumes using CT images on average. There was significant variations in volumes measured weekly for 6-8 weeks. It ranged between 33 - 75 %. Conclusion: Our results showed that it is possible to obtain larger bladder volume if they are asked to drink certain amount of water prior to CT scan. However, patients were unable to maintain constant bladder volumes over the 6-8 weeks of treatment period although they were asked to drink constant amount of water.

• Journal of Radiation Protection and Research
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• v.33 no.2
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• pp.77-86
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• 2008

This study attempted to provide reference materials for improving the behavior level in radiation safety managements by drawing a prediction model that affects the radiation safety management behavior because the radiation safety management of medical Cyclotrons, which can be used to produce radioisotopes, is an important factor that protects radiation caused diseases not only for radiological operators but average users. In addition, this study obtained follows results through the investigation applied from January 2 to January 30, 2008 for the radiation safety managers employed in 24 authorized organizations, which have already installed Cyclotrons, through applying a specific form of questionnaire in which the validity was guaranteed by reference study, site investigation, and focus discussion by related experts. The radiation safety management were configured as seven steps: Step 1 is a production preparation step, Step 2 is an RI production step, Step 3 is a synthesis step, Step 4 is a distribution step, Step 5 is a quality control step, Step 6 is a carriage container packing step, and Step 7 is a transportation step. it was recognized that the distribution step was the most exposed as 15 subjects (62.5%), the items of 'the sanction and permission related works' and 'the guarantee of installation facilities and production equipments' were the most difficult as 9 subjects (37.5%), and In the trouble steps in such exposure, the item of 'the synthesis and distribution' steps were 4 times, respectively (30.8%). In the score of the behavior level in radiation safety managements, the minimum and maximum scores were 2.42 and 4.00, respectively, and the average score was $3.46{\pm}0.47$ out of 4. Prosperity and well-being programs in the behavior and job in radiation safety managements (r=0.529) represented a significant correlation statistically. In the drawing of a prediction model based on the factors that affected the behavior in radiation safety managements, general characteristics, organization characteristics, and selfefficacy didn't show a significant path statistically in which the prosperity and well-being programs in job characteristics affected the behavior in radiation safety managements. Therefore, it is necessary to establish a strategy that improves the level of prosperity and well-being levels in job characteristics in order to increase the behavior in radiation safety managements. Thus, this study provides basic materials for the radiation safety management of Cyclotron through the full-scale investigation that is first applied in Korea.

• Journal of Radiation Protection and Research
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• v.33 no.2
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• pp.47-51
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• 2008

Objective: This study analyzed errors due to rotation or tilt of the magnetic resonance (MR) imaging indicator during image acquisition for a stereotactic radiosurgery. The error correction procedure of a commercially available stereotactic neurosurgery treatment planning program has been verified. Materials and Methods: Software virtual phantoms were built with stereotactic images generated by a commercial programming language, Interactive Data Language (version 5.5). The thickness of an image slice was 0.5 mm, pixel size was $0.5{\times}0.5mm$, field of view was 256 mm, and image resolution was $512{\times}512$. The images were generated under the DICOM 3.0 standard in order to be used with Leksell GammaPlan$^{(R)}$. For the verification of the rotation error correction function of Leksell GammaPlan$^{(R)}$, 45 measurement points were arranged in five axial planes. On each axial plane, there were nine measurement points along a square of length 100 mm. The center of the square was located on the z-axis and a measurement point was on the z-axis, too. Five axial planes were placed at z=-50.0, -30.0, 0.0, 30.0, 50.0 mm, respectively. The virtual phantom was rotated by $3^{\circ}$ around one of x, y, and z-axis. It was also rotated by $3^{\circ}$ around two axes of x, y, and z-axis, and rotated by $3^{\circ}$ along all three axes. The errors in the position of rotated measurement points were measured with Leksell GammaPlan$^{(R)}$ and the correction function was verified. Results: The image registration errors of the virtual phantom images was $0.1{\pm}0.1mm$ and it was within the requirement of stereotactic images. The maximum theoretical errors in position of measurement points were 2.6 mm for a rotation around one axis, 3.7 mm for a rotation around two axes, and 4.5 mm for a rotation around three axes. The measured errors in position was $0.1{\pm}0.1mm$ for a rotation around single axis, $0.2{\pm}0.2mm$ for double and triple axes. These small errors verified that the rotation error correction function of Leksell GammaPlan$^{(R)}$ is working fine. Conclusion: A virtual phantom was built to verify software functions of stereotactic neurosurgery treatment planning program. The error correction function of a commercial treatment planning program worked within nominal error range. The virtual phantom of this study can be applied in many other fields to verify various functions of treatment planning programs.

• The Journal of Small Business Innovation
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• v.20 no.1
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• pp.1-18
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• 2017

This study examined whether divided and spun-off companies design and execute spin-offs to minimize tax burdens by analyzing multiple spin-off transactions in the Dongbu Group, when the Korean tax law regarding corporate restructuring was amended in July 2010. Before the July 2010 tax amendment, taxes on the capital gains arising from the qualifying spin-off were deferred to the earlier of the shares in or assets acquired by the spun-off company are disposed. This tax treatment relieves the divided company's tax burden by deferring taxes on capital gains, compared with non-qualifying spin-offs. However, if shares in or assets acquired by the spun-off company are disposed after the July 2010 tax amendment, the capital gain incurred at the time of the qualifying spin-off would be taxed again at the spun-off company, in addition to a taxation on the divided company's capital gains. This creates double taxation implications for the parties involved in the spin-off. As a result, the double taxation may outweigh the benefit from the tax deferral on the qualifying spin-off, which may make a qualifying spin-off tax unfavorable. Among the four spin-off cases in the Dongbu Group addressed in this study, a spin-off occurred before the tax amendment, whereas three spin-offs occurred after the tax amendment. Initially, we expected that the spin-off before the tax amendment would be a qualifying spin-off, and the other three spin-offs would be non-qualifying spin-offs, considering the taxation rules before and after the July 2010 tax amendment. However, based on the review of summarized balance sheets disclosed in the spin-offs' corporate filings, no capital gains arose during the four spin-offs that occurred in the Dongbu Group. Therefore, we concluded that the Dongbu Group considered non-tax factors more than tax factors while designing and executing the spin-offs. The local media posited during this period that these spin-offs may intend to resolve financial issues in the Dongbu Group, and this analysis was supported by the fact that some shares in the new spun-off companies were sold by the Dongbu Group. Our case studies provide evidence that all costs, including both tax and non-tax costs, must be considered in the course of spin-offs, in addition to the tax burdens on all parties involved in the corporate restructuring, which parallels the work of Scholes et al. (2008). This study provides implications that various aspects should be considered and reviewed in advance when the management makes decisions for effective tax planning.

• The Journal of Small Business Innovation
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• v.20 no.1
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• pp.35-46
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• 2017

The purpose of this study is to obtain the implications for establishing a marketing strategy for retailers by analyzing whether the consumer's preference for products (food) is influenced by on-line, off-line, and omni-channel preferences. The research model consisted of the effects of consumers' food selection characteristics on business preference and omni channel preference. The results of analysis based on 477 questionnaires are summarized as follows. First, food purchasing characteristics that utilize the seven characteristics of (1) freshness of food, (2) taste, (3) quality and safety, (4) tasting, (5) food function and information, (6) country of origin, and (7) brand loyalty, has various effects on types of business preference, omni-channel preference. The adopted hypotheses were selected in order of brand loyalty (5 times), freshness (3 times), tasting (3 times), and origin (1 time). The selective attributes on foods are: (1) what kind of brand, (2) how good the freshness is, (3) tasting. (4) The country of origin is to be compressed. Actually consumers seem to utilize only the core selective factors that are appropriate to the characteristics of the distribution channel rather than all of them in the shopping of the food, and there is three characteristics on Convenience Store and only one or two factors in the other types of business. Second, in the analysis of the omni-channel preference analysis, food selection characteristics has been shown to have a limited effect, which is attributed to the fact that the consumer has not yet understood the concept of omni channel. Third, the results of this study suggest that there is a need to reflect the selection characteristics of foods that have diverse influences by business type in the marketing strategies. Because consumers make reasonable consumption to use both on-line and off-line simultaneously, consumers who use Omni Channel focus on quality and safety of food, identify products through tasting, pursue brands that can trust anywhere. Customers who pursue rationality will have a high preference for using Omni Channel. Product choice characteristic has significant effect on omni-channel preference. For a few years, omni-channel strategy of retailers meets with a difficulty. This study make a first attempt to study omni-channel preference changing retailing paradigm.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.2
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• pp.86-95
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• 2015

Purpose: The aim of the study was to evaluate the subjective symptoms and clinical signs through the TMD-questionnaire, clinical examination and radiography against the many instrumental performers and to investigate the association between playing instruments and TMDs. Materials and Methods: A total of 803 instrumental performers received TMD-related questionnaire and evaluations of prevalence and disease distribution were performed. Among those who reported at least one symptom of TMD, 70 volunteers visited in clinic then received clinical examination and radiography for diagnosis and evaluations of prevalence and disease distribution were performed. 70 subjects were divided into three groups as woodwind, brass wind, string. Comparative analysis of disease distribution was performed. Results: Among 803 instrumental performers, 610 people (75.97%) were reported to one or more symptoms of TMD. The most frequent symptom was click (29.68%).70 subjects underwent a clinical examination and radiography survey results, the most frequent symptom was a click (29.75%). Most commonly diagnosed disease was a myofacial pain (30.53%).Comparison of the three groups, a significant difference was not observed in the clinical sign. But among subject symptom, muscle pains howed significant differences in accordance with the Group (P = 0.024). During the 70 people who underwent clinical examination, 66 people (94.3%) showed moderate to severe attrition, mild to severe tongue ridging, mild to severe cheek ridging assigns of parafunction. Conclusion: Instrumental performers showed a high prevalence of TMD and the most of the musicians with temporomandibular disorder had bruxism or clenching habits.