• Progress in Medical Physics
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• v.21 no.3
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• pp.253-260
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• 2010

Most brachytherapy treatment planning systems employ a dosimetry formalism based on the AAPM TG-43 report which does not appropriately consider tissue heterogeneity. In this study we aimed to set up a simple Monte Carlo-based intracavitary high-dose-rate brachytherapy (IC-HDRB) plan verification platform, focusing particularly on the robustness of the direct Monte Carlo dose calculation using material and density information derived from CT images. CT images of slab phantoms and a uterine cervical cancer patient were used for brachytherapy plans based on the Plato (Nucletron, Netherlands) brachytherapy planning system. Monte Carlo simulations were implemented using the parameters from the Plato system and compared with the EBT film dosimetry and conventional dose computations. EGSnrc based DOSXYZnrc code was used for Monte Carlo simulations. Each $^{192}Ir$ source of the afterloader was approximately modeled as a parallel-piped shape inside the converted CT data set whose voxel size was $2{\times}2{\times}2\;mm^3$. Bracytherapy dose calculations based on the TG-43 showed good agreement with the Monte Carlo results in a homogeneous media whose density was close to water, but there were significant errors in high-density materials. For a patient case, A and B point dose differences were less than 3%, while the mean dose discrepancy was as much as 5%. Conventional dose computation methods might underdose the targets by not accounting for the effects of high-density materials. The proposed platform was shown to be feasible and to have good dose calculation accuracy. One should be careful when confirming the plan using a conventional brachytherapy dose computation method, and moreover, an independent dose verification system as developed in this study might be helpful.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.4
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• pp.308-314
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• 2010

Purpose: The purpose of this study is to analyze the change in re-osseointegration over time and bone reaction at the interface between implant fixture and the surface of the bone, after destroying re-osseointegration by distorting the bone-implant interface artificially. Materials and methods: Experimental implant fixtures (cp titanium, ${\phi}3.75\;mm{\times}4\;mm$) which didn't have surface treatment were produced. Two or three fixtures were implanted on both tibias of twelve female rabbits (New Zealand white, more than 3.5 kg). Then after six weeks, removal torque (RT) was measured and the results were recorded as the first measurement values. The fixtures were submerged again to get reosseointegration between the bone and fixture. To identify the change in re-osseointegration of submerged fixtures over time, six groups had the healing time for four days (group I), one week (group II), two weeks (group III), three weeks (group IV), four weeks (group V) and five weeks (group VI), and then the secondary removal torque was measured for each group. To identify the bone formation under fluorescent light, tetracycline (15 mg/kg, IM) were treated on the rabbits of each group. After the second measurement, the rabbits were sacrificed, and 16 slides were made, two or three for each group. The slides were observed under the fluorescent light with light microscope. To find out the change in the secondary removal torque over the primary removal torque in progress of time, the averages of the increase rate of the primary and secondary torque removal force were calculated. Then, to find out if there were any critical differences between the primary removal torque and the secondary removal torque in each group and among the groups, the results were analyzed statistically by paired t- test, one-way ANOVA, and Duncan's Multiple Range Test. Results: In group I and II, secondary removal torque decreased, especially in group I. In group III, IV, V, and VI, secondary removal torque increased critically. Comparing the differences among the groups, the critical difference was shown between group I, II and group III, IV, V, VI. Mineralization at the interface between the bone and implant fixture was identified from the first week, and bone formation was shown more clearly from the second week. Conclusion: If the implant fixture remains unforced for a certain period of time after the fixture has had iatrogenic mobility, re-osseointegration occurs at the surface of the fixture, and for tibias of rabbits, higher re-osseointegration was obtained within two weeks.

• Korea journal of population studies
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• v.10 no.2
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• pp.17-45
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• 1987

This study contributes to understanding women's labor market behavior by focusing on a particular set of labor force transitions - labor force withdrawal and entry during the period surrounding the first birth of a child. In particular, this study provides a dynamic analyses, using longitudinal data and event history analysis, to conceptualize labor force behaviors in a straightforward way. The main research question addresses which factors increase or decrease the hazard rates of leaving and entering the labor market. This study used piecewise Gompertz model, following the guide of the non-parametric analysis on the hazard rates, which allowed relatively detailed description on the distribution of timing of leave and entry to the labor market as parameters of interest. The results show that preferences and structural variables, as well as economic considerations, are very important factors to explain the labor market behavior of women in the period surrounding childbirth.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.920-926
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• 1997

Remarkable effect of pain relief and prevention of the postoperative Complications after thoracotomy has been achieved by continuous intravenous analgesia. This study was carried out with thirty patients who underwent posterolateral thoraco tony. The patients were divided into three groups: Group I(n= 10), the patients with intermittent intramuscular analgesia(piroxicam 20 mg), Group II(n=10), the patients with continuous epidural analgesia(0.5% bupivacaine 30m1 + normal saline 30 ml + morphine 10 mg), and Group III(n= 10) the patients with controlled intravenous infusion of analgesics(fentanyl 2500 mfg +normal saline 10 ml). The results w re as follows; 1) There were no significant changes of vital signs, between groups. 2) Tidal volume and FVC were significantly improved in the group II and III compared with the group I during the first postoperative day. 3) A significant reduction of immediate post-thoracotomy pain was achieved in the group II and III compared with the group I. 4) The limitation of motion in the operative side was less in the group II and III compared with the group I. 5) A signi(icant reduction of the postoperative analgegics consumption was noticed in group II and III. 6) Significant complications were not occured during follow-up period in all groups.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.899-907
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• 1997

Recently, primary lung cancer has increased markedly in incidence & prevalence in korea. Prom July 1979 to June 1996, 183 patients were diagnosed and operated for primary non-small cell lung cancer, and evaluated clinically. 1. There were 164 males and 19 females(M:P=8.6: 1), and the peak incidence of age was 50th and 60th decade of life(73.7%). 2. Most of symptoms were respiratory, whitch were cough(44.8%), chest pain(30.1%), dyspnea(20.8%), hemoptysis or blood tinged sputum(19.7%), sputum(15.3%), and asymptomatic cases were 12.0%. 3. Histopathologically, sguamous cell carcinoma was 68.9%, adenocarcinoma 19.7%, bronchioloalveol r cell carcinoma 2.2%, adenosguamous cell carcinoma 1.6%, and large cell carcinoma 7.7%. 4. In the operation, pneumonectomy was 41.0%, lobectomy 42.1%, bilobectomy 13.1%, stagmentectomy or wedge resection 1.6%, and explore tharacotomy 2.2%, and the overall resectability was 97.8%. 5. Postoperative complications were developed in 31.9%, and operative mortality was 1.6%. 6. In postoperative stagings, stage I was 38.3%, stage H 14.8%, stage llla 31.1%, and stage IIIb 15.8%. 7. The overall cumulative survival rates were 1 year 77.8%, 3 year 42.7%, and 5 year 39.5%. The 5 year survival rate according to stage were stage 153.0%, stage H 46.5%, stage I[la 28.2%, and stage IIIb 13.8%(p<0.05), according to operation method were lobectomy 45.0%, and pneumonectomy 30.3%(p<0.05), and according to mediastinal involvement were Nl 32.0%, and N2 11.1%(p<0.05). The 5 year survival rate according to histologic type were squamous cell carcinoma 43.1%, adenocarcinoma 23.3%, and large cell carcinoma 30.3 (p>0.05).

• Ocean and Polar Research
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• v.28 no.4
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• pp.407-413
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• 2006

The effect of water temperature and photoperiod on the oxygen consumption of the fasted juvenile parrot fish, Oplegnathus fasciatus was investigated to provide empirical data for the early-stage culture management and bioenergetic growth model of the species. The mean body weight of the juvenile used for the experiment was $21.5{\pm}1.9g$, and the oxygen consumption rate was measured under four water temperatures (10, 15, 20 and $25^{\circ}C$) and three photoperiods (24L:0D, 12L:12D and OL:24D) with an interval of 5 minutes for 24 hours using a continuous flow-through respirometer. In each treatment three replicates were set up and 15 juveniles were totally involved. The oxygen consumption rates increased with increasing water temperature under all photoperiod treatments (P<0.001). Mean oxygen consumption rates at 10, 15, 20 and $25^{\circ}C$ ranged $202.1{\sim}403.4,\;306.7{\sim}502.2,\;536.7{\sim}791.0\;and\;879.9{\sim}1,077.4mg\;O_2\;kg^{-1}h^{-1}$, respectively. $Q_{10}$ values ranged $1.58{\sim}2.30$ between 10 and $15^{\circ}C,\;2.44{\sim}3.06$ between 15 and $20^{\circ}C\;and\;1.86{\sim}2.6y9$ between 20 and $25^{\circ}C$, respectively. Mean oxygen consumption rates of O. fasciatus were the highest in continuous light (24L:0D) followed by 12L:12D and 0L:24D (P<0.001). The oxygen consumption of fish exposed to the 12L:12D photoperiod was significantly higher during the light phase than during the dark phase under all temperature treatments (P<0.001). In summary, oxygen consumption rates of the juvenile parrot fish increase with increasing water temperature and lengthening daylight period; and, thereby, changes in water quality resulted from the depletion of oxygen under high temperature and long daylight photoperiod conditions should be monitored.

• Journal of dental hygiene science
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• v.3 no.1
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• pp.5-10
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• 2003

The purpose of this study was to examine how medical personnels in the field of dentistry perceived the introduction of the yearly income system in an effort to determine some of the right directions for that and find out in which way that could be vitalized. For that purpose, literature concerned and relevant materials were reviewed, and a survey was conducted on 95 medical personnels, who were working at dental hospitals and clinics throughout the nation, for approximately five months from April through August 2002. After the collected data were analyzed, the following findings were acquired; (1) Regarding their awareness of the yearly income system by the type of institute, the workers from the dental hospitals found the yearly income system, more than the others from the dental clinics did, to enlarge their sense of involvement in management (p<.001), further work productivity(p<.01), awake their target-oriented sense of mission(p<.01) and make them feel uneasy about their future(p<.05). (2) As to differences between the dentists and dental hygienists, the former group had a higher opinion about that system(p<.01) and its effect on impartial performance appraisal(p<.01), encouraging medical personnels to deploy their abilities(p<.01), furthering work productivity(p<.001), intensifying a target-oriented sense of mission(p<.001). (3) Concerning their perception by career, those who had longer experience to work in that field considered it to strengthen work severity(p<.05) more than the others who had shorter experience did, and the former group thought that system was more likely to concentrate on a short-term achievement (p<.05). The workers who had been working for three to five years were more conscious of change in office hours (p<.01), and those who had been working for two or less years viewed that system most favorably(p<.05). (4) In order for that system to be successful, impartial performance appraisal was most widely called for(31.6%), followed by trust between labor and management(26.3%), worker's positive attitude toward that system(16.8%), CEO's firm belief in that(12.3%), and setting up a feasible target. The workers from the dental hospitals put more stress on medical personnel's favorable attitude toward that system(p<.05) than the others from the dental clinics did. And the dentists placed more stock in setting up a feasible target, which was a criteria of determining the amount of annual income, than the dental hygienists did.

• Journal of The Korean Association For Science Education
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• v.25 no.4
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• pp.514-525
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• 2005

The most important factor in providing education to gifted students as well as to students in general are the teachers themselves. However, at present in Korea, most of the teachers in charge of education for the gifted are educated by in-service training programs only for a short period of time. It is doubtful whether the teachers, who have taught ordinary students in general, can teach gifted students effectively only after completing such a short course. This research investigated the relationship between the teachers' beliefs about educating the gifted and the teachers' classroom practices in a Science Academy through case studies. The guiding questions for this study are as follows: First, what beliefs do the participating teachers have about education for the gifted? Second, how are the participants' beliefs reflected in their classroom practices? Of the five participants, two are physics teachers, two are biology teachers, and one is an earth science teacher. I observed and videotaped four classroom practices for each participant and conducted an in-depth interview with each participant. Further data were collected through e-mails with the participants. All data were carefully transcribed and analyzed. The results are as follows: Beliefs about education for the gifted do not exist independently, and form a belief system connecting with beliefs about teaching and learning, and subject matter. And the belief systems of participants can be divided into "student-centered," "teacher-centered," and "conflict chaos." In the classes of the participants who have "student-centered" belief system, students' questions or opinions played an important role and the participation structure in the classroom was determined by the students. On the contrary, participants who have "teacher-centered" belief system focused on teaching contents as much as possible in their classes. These teachers played a heavy role and formed a participation structure where students depended on their teacher's intellectual authority and therefore participated in their class passively. A participant who have "conflict chaos" belief did not form a firm belief system yet, and traditional beliefs about teaching and learning were reflected a lot in her classes. The research results imply teachers' beliefs play an important role in classroom practices and beliefs about teaching and learning and subject matter as well as beliefs about education for the gifted are important factors for teachers who guide gifted students. Additionally, I make some suggestions for the improvement of teacher education for the gifted.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.4
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• pp.377-382
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• 2007

This study was designed to investigate the effect of Plebeiae Herba (Salvia plebeia R. Br.) on the proliferation of AGS cell lines and the activation of splenocytes. In an anti-cancer test using AGS cells, water and ethanol extracts of Plebeiae Herba inhibited the growth of AGS cell lines and morphological changes were also observed in a dose-dependent manner. Water extract of Plebeiae Herba showed growth-inhibitory effect of 43.3% at $1,000{\mu}g/mL$ and 69.7% at $3,000{\mu}g/mL$. Ethanol extracts of Plebeiae Herba showed growth-inhibitory effect of approximately 37.3% for $1,000{\mu}g/mL$ and 75.8% for $3,000{\mu}g/mL$. The Plebeiae Herba induced the proliferation of spleen cells and increased interleukin (IL)-2, interleukin (IL)-6 and tumor necrosis factor $(TNF)-{\alpha}$. In conclusion, these results suggest that the Plebeiae Herba seems to have antiproliferationg effect against the AGS cell and acts as a potent immunomodulator.

• Information Systems Review
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• v.18 no.1
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• pp.157-175
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• 2016

Under the market economy of capitalism, several limitations reveal the inequity and redistribution problem of wealth, inefficiency of over-manufacturing and over-consumption, pollution of the natural environment, and the constraint of human liberty and dignity. The new challenge of symbiotic relationships that encourage individual corporations coincides with the need to practice social responsibility and share values to overcome these limitations. Social economy and the social enterprises that simultaneously pursue the making of corporate private profits and the realization of social values have been suggested and disseminated as alternative social value creators. Furthermore, the concept of a sharing economy, which refers to the sharing of things rather than owning them, is growing traction as a new paradigm of capitalism. However, these efforts of social enterprises have fallen short against the conflicts between private profit and social values. This study deals with the case of a start-up social corporation, "Purun Bike Sharing Inc.," which is based on a regional sharing economy business model about bike rental services that use Information and Communication Technology (ICT). This corporation pursues harmonic management to achieve a balance between private profit and social value. Its corporate mission is to achieve sharing, coexistence, and contribution for public welfare. This mission is a possible idea for use in the local community network as a core key for sustainable social enterprises. The model can also be an alternative approach to overcome the structural friction in the social corporation. This study considers the case of Purun Bike Sharing as a sustainable way to practice a sharing economy business model based on a regional cooperation network, which can be combined with social value, and to apply ICT to a sharing economy system. It also examines the definition and current state of social enterprises and the sharing economy, and the cases of the sharing economy business model for the review of prior research.