• Journal of Technology Innovation
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• v.11 no.1
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• pp.147-176
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• 2003

This Paper Presents a new measurement technique to derive the level of BSRC (Basic Science and Research Capacity) index by use of the factor analysis which is extended with the assumption of the standard normal probability distribution of the selected explanatory variables. The new measurement method is used to forecast the gap of Korea's BSRC level compared with those of major OECD countries in terms of time lag and to make their international comparison during the time period of 1981∼1999, based on the assumption that the BSRC progress function of each country takes the form of the logistic curve. The US BSRC index is estimated to be 0.9878 in 1981, 0.9996 in 1990 and 0.99991 in 1999, taking the 1st place. The US BSRC level has been consistently the top among the 16 selected variables, followed by Japan, Germany, France and the United Kingdom, in order. Korea's BSRC is estimated to be 0.2293 in 1981, taking the lowest place among the 16 OECD countries. However, Korea's BSRC indices are estimated to have been increased to 0.3216 (in 1990) and 0.44652 (in 1999) respectively, taking 10th place. Meanwhile, Korea's BSRC level in 1999 (0.44652) is estimated to reach those of the US and Japan in 2233 and 2101, respectively. This means that Korea falls 234 years behind USA and 102 years behind Japan, respectively. Korea is also estimated to lag 34 years behind Germany, 16 years behind France and the UK, 15 years behind Sweden, 11 years behind Canada, 7 years behind Finland, and 5 years behind the Netherlands. For the period of 1981∼1999, the BSRC development speed of the US is estimated to be 0.29700. Its rank is the top among the selected OECD countries, followed by Japan (0.12800), Korea (0.04443), and Germany (0.04029). the US BSRC development speed (0.2970) is estimated to be 2.3 times higher than that of Japan (0.1280), and 6.7 times higher than that of Korea. German BSRC development speed (0.04029) is estimated to be fastest in Europe, but it is 7.4 times slower than that of the US. The estimated BSRC development speeds of Belgium, Finland, Italy, Denmark and the UK stand between 0.01 and 0.02, which are very slow. Particularly, the BSRC development speed of Spain is estimated to be minus 0.0065, staying at the almost same level of BSRC over time (1981 ∼ 1999). Since Korea shows BSRC development speed much slower than those of the US and Japan but relative]y faster than those of other countries, the gaps in BSRC level between Korea and the other countries may get considerably narrower or even Korea will surpass possibly several countries in BSRC level, as time goes by. Korea's BSRC level had taken 10th place till 1993. However, it is estimated to be 6th place in 2010 by catching up the UK, Sweden, Finland and Holland, and 4th place in 2020 by catching up France and Canada. The empirical results are consistent with OECD (2001a)'s computation that Korea had the highest R&D expenditures growth during 1991∼1999 among all OECD countries ; and the value-added of ICT industries in total business sectors value added is 12% in Korea, but only 8% in Japan. And OECD (2001b) observed that Korea, together with the US, Sweden, and Finland, are already the four most knowledge-based countries. Hence, the rank of the knowledge-based country was measured by investment in knowledge which is defined as public and private spending on higher education, expenditures on R&D and investment in software.

• The korean journal of orthodontics
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• v.32 no.6 s.95
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• pp.455-466
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• 2002

The objective of this study was to evaluate the changes that occurred over time in the distracted periodontal ligament space following the rapid retraction of a tooth by periodontal distraction after bone undermining surgery had been conducted in the dogs. The upper second premolars were extracted on the left and right side in 4 male beagle dogs. Immediately after extraction, the interseptal bone distal to the upper first premolar was thinned and undermined by grooving to decrease the bone resistance. Activating an individualized distraction appliance at the rate of 0.225mm twice a day, the upper first premolar was retracted rapidly toward the extraction socket. Periodontal distractions were performed for 5, 10, and 20 days, and 20-day-distraction cases were followed by maintenance periods of 0, 14, 28, and 56 days. After 20 days of rapid retraction, the average distal movement of the upper first premolar was 5.02mm, and the average mesial movement of the upper third premolars serving as an anchorage unit was 0.18 mm. On histological examination, the regeneration of bone occurred in a highly organized pattern. Distracted periodontal ligament space was filled with newly formed bone oriented in the direction of the distraction, and this was followed by extensive bone remodeling. This result was similar to those observed in other bones after distraction osteogenesis. In the periodontal ligament, the relationship between collagen fibers and cementum began to be restored 2 weeks after the distraction was completed, and showed almost normal features 8weeks after the completion of the periodontal distraction. However, on the alveolar side, the new bone formation was still in process and collagen fiber bundles and Sharpey's fibers were not present 8 weeks after the completion of the periodontal distraction. Reactions in the periodontal ligament of the anchorage tooth represented bone resorption on the compressed side and new bone deposition on the tension side as occurred in conventional orthodontic tooth movement. In conclusion, the results of this study showed that periodontal structures on the distracted side of the periodontal ligament were regenerated well histologically following rapid tooth movement.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.59-68
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• 1998

Digital hearing aids offer many advantages over conventional analog hearing aids. With the advent of high speed digital signal processing chips, new digital techniques have been introduced to digital hearing aids. In addition, the evaluation of new ideas in hearing aids is necessarily accompanied by intensive subject-based clinical tests which requires much time and cost. In this paper, we present an objective method to evaluate and predict the performance of hearing aid systems without the help of such subject-based tests. In the hearing impairment simulation(HIS) algorithm, a sensorineural hearing impairment medel is established from auditory test data of the impaired subject being simulated. Also, the nonlinear behavior of the loudness recruitment is defined using hearing loss functions generated from the measurements. To transform the natural input sound into the impaired one, a frequency sampling filter is designed. The filter is continuously refreshed with the level-dependent frequency response function provided by the impairment model. To assess the performance, the HIS algorithm was implemented in real-time using a floating-point DSP. Signals processed with the real-time system were presented to normal subjects and their auditory data modified by the system was measured. The sensorineural hearing impairment was simulated and tested. The threshold of hearing and the speech discrimination tests exhibited the efficiency of the system in its use for the hearing impairment simulation. Using the HIS system we evaluated three typical hearing aid algorithms.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.499-510
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• 2006

Malignant tumors of the human salivary glands may arise from major or minor salivary glands. Adenoid cystic carcinoma (ACC) is the second most common malignant neoplasm in the salivary glands. ACC is occasionally highly aggressive tumor that readily invades adjacent tissues and metastasize to distant organs at early stages of the disease. Although ACC tends to grow slowly, treatment outcome may be poor due to wide local infiltration, perineural or intraneural spread and a propensity for hematogenous metastasis. Therefore, knowledge of cellular and molecular characteristics that influence the growth, survival and metastasis of tumor cells, is important for new treatment strategies of salivary ACC. I determined expressions of epiderma growth factor (EGF)-signaling molecules using surgical specimens of human ACCs. Protein expressions of EGF, transforming growth $factor(TGF)-{\alpha}$, EGF receptor (EGFR), phosphorylated EGFR (pEGFR), and human EGF receptor (HER)-2 were assessed in 18 cases of salivary ACC by immunohistochemical staining. Adjacent normal salivary tissues and mucosal tissues, uninvolved by the malignant tumor, served as internal controls. Most of the tumors, especially ACC with a tubulocribriform pattern, were positive for EGF signaling molecules. The overall percentages of the 18 specimens expressing EGF, $TGF-{\alpha}$, EGFR, pEGFR, and HER2 were 50, 89, 61, 61 and 83% respectively. Moreover, tumor-associated endothelial cells and infiltrating immune-related cells in the stroma of ACC, also expressed these biomarkers. Taken together, EGF-signaling molecules are actively expressed in salivary ACC. Therefore, we suggest that these biomarkers can be molecular targets for new treatment strategies of salivary tumors.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.1
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• pp.13-21
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• 2004

Purpose: We analyzed the result of autologous bone marrow stromal cell transplantation with or without cancellous chip bone allograft for benign long bone lesions. Materials and methods: Since July 1996, eight benign bone lesions treated by curettage, cancellous chip bone allograft and bone marrow or marrow stromal cell transplantation were observed for resolution of clinical symptoms, new bone formation and consolidation. There were 6 males and 2 females. Average age was 24 (range 8 to 47) years old. Histologic diagnoses were 5 fibrous dysplasia, 2 simple bone cysts and one chondroblastoma and fibrous cortical defect each. Mean follow-up period was 16.3 (range 3 to 84) months. Results: In all four symptomatic patients, the pain was subsided in two weeks after surgery. New bone formation in the lesion was observed at 4 weeks, which incorporated into surrounding normal bone around 8 weeks. There were one pathologic fracture through the lesion at 3 weeks and one recurrence of simple bone cyst at 5 months postoperatively. Conclusion: Bone marrow or marrow stromal cell transplantation for bone defects from curettage of benign bone lesions, with or without cancellous chip bone allograft revealed rapid healing. Though it was the result of short-term follow up, it supports that bone marrow stromal cell transplantation will be very useful for the treatment of benign long bone cysts or other lesions. The complete curettage of inner cystic wall is important to prevent later recurrence, and the rigid internal fixation is also needed in selected high risk lesions of fracture.

• Journal of the Korean Society of Costume
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• v.35
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• pp.325-341
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• 1997

One of the noticeable trends of female wear in 1990s is the Outwearization of Underwear as it is called 'Lingerie look' This trend meaned 'Exposure Fashion' raised splendidly its head to the whole stage of fashion destrying the tradional concept having divided the fashion between outwear and underwear by Madonna an Americal populer singer showed up in front of the audience wearing the corset-dress as a stage custome. This corset-dress which can not be recognised whether it is underwear or outwear has been diffused into the mass as a fashionable trend re-gardless of any reason; therefore discrimi-nation of wear by space by far that is underwear should have the sstandard telling between private and public sector has been gradually tumbled. By the way what has propelled desigers to introduce the style continuously having the underwear motive such as outwear almost as same as underwear or underwear worn on out-wear etc. and has made it a fashion trends? How do we accept this "Ligerie look'fashion" The rearch on vogue of outwearization of underwear started by the questions above can be summarized as the followings The division between the sprit and the ma-terial-economic shrinkage by the collapse of the bubble economy in the late of 20 century and expectation for the next century doubt by changes of international politics dynamics for the next century and increasement of psycho-logical tention by the environmental destruc-tion etc, has been extended to break the sense of value down These frustration of the tra-ditional values and dissatisfaction on the pres-ent have reflected on the fashion pursuing some more sensational style to increase the ex-posure of the body. The revolution of wearing bouncing the con-servatismhas outwardly expressed underwear of the private sector. Therefore the spatial concept of wear which for the public sec-tor has been fallen into pieces and has broken the wall of the concept fixed by outwear on underwear. in addition the stage costome for the popular people like Madonna has not been limited by the specularity any more and has been assimilated with the normal wear on the street to take the distinction for away. The circumstances of the late of 20 century pursuing sensation and making sex commer-cialized have accordance with the outweari-zation of underwear. there it is on the basis of Minimalist's dogmatism has been expressed the maximization of expoure in the pubric space to popularize bra pants(knickers) as outwear. The reaction on the attribute of hiding and shanding has brought 'See-Through fashion' with the transparent materials, The contemporary doubt recalling the mem-ory of the past has sublimated corset which was an instument of toture for women into Romanticism to introduce it to fashion with the development of a new material not to be a tool of any oppression and maltretment any longer. The popularization of outwear like underwear what's more has brought high quality of underwear. There it has called for the variety of materials such as knit demin and velvet etc, and has urged the famous designers to enlarge their working boundaries to underwear designs, Besides outwearization of underwear has been popular even in the Orient which has the con-servative opinions on exposure ; so changes of the thoughts can be seen among the establish-ment generation on exposure of the body. As the more high tech information publi-cized and the more technology and media digitalized the more expression being analog the pursue for the new in fashion with vision never been seen and even though it is imprac-tical the experimental designers have drived the freedom beyond the traditional roles of the previous century. Consequently outwearization of underwear may be viewd as a trial as an expression responded the contemporary background. This trend in my opinion will have been lasted for a while by being proliperlated among lasted for a while by being proliperlated among the pub-lic who has the century-end anxiety and doubt and expectation for the next century.

• Journal of Chest Surgery
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• v.29 no.4
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• pp.373-380
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• 1996

Prevention of thromboembolism is the most important task in the development of bioconpatible small caliber artificial vascular graft. In normal vessels, vascular endothelial cells maintain homeosatsis by secreting numerous factors. The aim of this study is to develope a method which Improves biocompatibility of small caliver polyurethane graft using endothelial cell culture technique, and ev luate the efTectiveness of extracelluar matrix for endothelization which was produced by cultured fibroblast. Methods ; Multiporous polyurethane tube of 3 mm diameter, 0.3 mm thickness was manufactured for vascular graft. Three mongrel dogs were intubated and internal jugular veins removed. Extracelluar matrix produced by cultured flbrobast which was obtained from dog's internal jugular vein were coated to the polyurethane graft. Then, endothelial cells extracted from Jugular vein were cultured and fixed on the extracelluar matrix layer of vascular graft. Endothelial cell coated vascular grafts were implanted to the carotid arteries of experimental dogs as interposed autograft. Implanted grafts were removed after 3 and 6 weeks. As a control, PTFE graft was interposed on carotid artery. These experiments demonstrated that extracelluar matrix produced by fibroblast can afford a base for endothelial cell linings of polyurethane graft. Although thrombosis were developed on autografted en othelial cell coated graft, 33% opening was noticed, and showed less adhesion to adjacent tissue layer. These findings suggest that fiboblast produced extracelluar matrix which can be used for edothelial cell lining vascular graft, and by improving the cultured endothelial cell function, there will be a new modality for reducing thrombosis on small vascular graft.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.215-220
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• 2006

Background : A spirometric reference equation was recently developed for the general population in Korea. The applicability of the new Korean equation to clinical practice was examined by comparing it with the Morris equation, which is one of the most popular reference equations used for interpreting the spirometric patterns and for grading the disease severity in Korea. Methods : Spirometry was performed on 926 men and 694 women, aged 20 years or older, in November 2004 at the Asan Medical Center, Seoul, Korea. The subjects' age, gender, height, weight, and spirometric values ($FEV_1$ [forced expiratory volume in one second], FVC [forced vital capacity], and $FEV_1/FVC$) were obtained. The spirometric patterns and disease severity were evaluated using both equations, and the results of the Korean equation were compared with the Morris equation. The spirometric patterns were defined as normal, restrictive, obstructive, and undetermined according to the level of $FEV_1/FVC$ and FVC. The disease severity was defined according to the level of $FEV_1$ level for subjects with an airflow limitation, and according to the FVC level for those subjects without an airflow limitation. Results : Spirometric patterns were differently interpreted in 22.5% (208/926) of the men and 24.8% (172/694) of the women after the application of the Korean equation compared with the Morris equation. Of the subjects with airflow limitation, disease severity was differently graded in 30.2% (114/378) of the men and 39.4% (37/94) of the women after the application of the Korean equation. Of the subjects without airflow limitation, disease severity was differently graded in 27.9% (153/548) of the men and 30.2% (181/600) of the women after the application of the Korean equation. Conclusion : Achange in the reference equation for spirometry could have an effect on the interpretation of spirometric patterns and on the grading of disease severity.

• Journal of The Korean Association For Science Education
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• v.38 no.2
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• pp.293-304
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• 2018

In spite of a growing number of recent studies that indicate students are coming to view scientists with more varied images, the stereotypical image of scientists remains in many students' minds. In this study, the authors explore how college students change their perceptions of science and scientists through the use of a documentary that focuses on scientists' daily lives, including laboratory life, and their emotional ups-and-downs. We analyzed 109 college students' essays on perceptions about scientists after watching the documentary. As a result, 64.2% of the college students declared that there was a change in their perception of scientists. The students' new perceptions of science and scientists are as follows: 1) scientists undergo emotional ups-and-downs just like any normal person; 2) scientists experience numerous failures while researching; 3) science does not have a fixed answer and scientists undertake research with creativity; 4) scientists conduct research in collaboration, but also in highly competitive environments; 5) scientists are often frustrated with their socio-economic status. The students' previous perceptions on science and scientists were mainly stereotypical ones that have been reported in previous studies. In addition, of the other college students who did not change their perceptions, the majority declared that they have new perceptions such as 1) - 5). Only a small percentage of students (7.3%) had unchanged stereotypical perceptions. These results are interpreted as that college students relatively easily change their stereotypical images of scientists after watching the documentary but, alternatively, the results can be interpreted that the most stereotypical images of college students are not perceptions that form a deep impression, but rather they are simply depictions of representative images of scientists given from outside sources (e.g. the mass media and school).

• Progress in Medical Physics
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• v.16 no.1
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• pp.24-31
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• 2005

The stereotactic radiosurgery (SRS) describes a method of delivering a high dose of radiation to a small tar-get volume in the brain, generally in a single fraction, while the dose delivered to the surrounding normal tissue should be minimized. To perform automatic plan of the SRS, a new method of multi-isocenter/shot linear accelerator (linac) and gamma knife (GK) radiosurgery treatment plan was developed, based on a physical lattice structure in target. The optimal radiosurgical plan had been constructed by many beam parameters in a linear accelerator or gamma knife-based radiation therapy. In this work, an isocenter/shot was modeled as a sphere, which is equal to the circular collimator/helmet hole size because the dimension of the 50% isodose level in the dose profile is similar to its size. In a computer-aided system, it accomplished first an automatic arrangement of multi-isocenter/shot considering two parameters such as positions and collimator/helmet sizes for each isocenter/shot. Simultaneously, an irregularly shaped target was approximated by cubic structures through computation of voxel units. The treatment planning method by the technique was evaluated as a dose distribution by dose volume histograms, dose conformity, and dose homogeneity to targets. For irregularly shaped targets, the new method performed optimal multi-isocenter packing, and it only took a few seconds in a computer-aided system. The targets were included in a more than 50% isodose curve. The dose conformity was ordinarily acceptable levels and the dose homogeneity was always less than 2.0, satisfying for various targets referred to Radiation Therapy Oncology Group (RTOG) SRS criteria. In conclusion, this approach by physical lattice structure could be a useful radiosurgical plan without restrictions in the various tumor shapes and the different modality techniques such as linac and GK for SRS.