• Journal of Korea Multimedia Society
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• v.14 no.9
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• pp.1175-1181
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• 2011

Practice education using virtual medical simulation has been recently introduced to maximize the learning efficiency in clinical environment. Specially, in minimally invasive surgery, the necessity of virtual surgery medical simulation has been substantially increased. Since cauterizing effect occurred frequently in minimally invasive surgery has been represented by simple bleeding, realistic cauterizing effect animation has not been proposed yet. In this paper, we propose realistic real-time cauterizing effect animation. Proposed method changes the individual element of each vertex color of the mesh and uses sigmoid function to impose weights for the smooth color change inside the valid mesh region so that the results of cauterizing effect animation was realistic. In addition, by proposing cauterizing color buffer, overlapped cauterizing effects can be realistically represented. Proposed method greatly improves the sense of the real and absorption in virtual surgery medical simulation so that the education efficiency of doctors and students using medical simulation can be maximized.

• Journal of the Korean association of regional geographers
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• v.2 no.2
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• pp.1-8
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• 1996

The purpose of this study is to analyse the regional variation of tenancy system in later Yi-Dynasty in Korea. Materials for the analysis are acquired through materials(韓國土地農産調査報告), published in 1905 and agricultural census published in 1912. For the identification of difference of tenancy system between agricultural region, regionalization are conducted through by crop combination. Crop combination structure, using rank of LQ index, was clustered into five generic lesions through cluster analysis. In these contexts, this study has come to following conclusions. There are three types of tenancy system in materials; (1) Doji(賭地) system of which landrent was 1/3 agricultural products. Tenant healed the land tax and seeds. (2) Byoengjak(竝作) system of which landrent was 1/2 agricultural products. Landlords healed the land tax and seeds (3) Jeongaek(定額法) system of which landrent was fixed without relation to annual products. But through the analysis of relationship between agricultural region and tenancy system, a new tenancy system could be identified : Byeongjak(竝作) II system. In this system, landrent was 1/2 of agricultural products, but landlord and tenant shared the landtax and seed in common. In the distribution of these systems, relationship between tenancy system and agricultural regions could be identified. Doji system was distributed in the regions where rice and double cropping was specialized. But Byoeongjak(竝作) system was distributed in the regions where upland crops are specialized and ratio of Paddy field is comparatively low. Especially new types were emenged where ratio of paddy field was very low. These show that increase of productivity of land didn't induce the development of the right of ownership in land. The development of ownership was emerged only on the rice paddy fields. Barley cultivated through double-cropping passed into tenant's possessions. So nominal landrent in paddy field seemed to be raised, but actual landrent was maintained about 1/3 of Products through double cropping. On the contrary, rights of cultivation is developed through double cropping. As double cropping is developed, competition on paddy field between tenants was intensified. Consequently nominal land rent of Paddy fields should be raised.

• Journal of radiological science and technology
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• v.38 no.2
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• pp.155-161
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• 2015

This study confirmed the correlation between the change of the cooling water in internal cooling system and the size of the ablation site of bovine liver in RF heat treatment equipment. The bovine liver was resection with $4{\times}4{\times}4cm^3$ in 2cm cool-tip and with $6{\times}6{\times}6cm^3$ in 3cm cool-tip for the experiments. Area and perimeter of the ablation site for bovine liver were measured by Freehand techniques of MRI. It showed area and perimeter decreased during cool-tip temperature rises 6 and 12 minutes ablation using a 2cm and 3cm cool-tip. The correlation of cool-tip temperature and area and perimeter was statistically significant the result are shown(p=.000). The measurements of area and perimeter were more accurate with MRI in actual measurements and MRI for ablation range. The statistical results using Paired sample T-test was also significant(p=.038). The ablation range of bovine liver decreased according as cooling water temperature increases in RF heat treatment equipment for reason of carbonization occurred due to does not accurately pass the RF energy. Therefore, it is considered the effect of RF heat treatment would be increased if the temperature of the cooling water consistently maintain the low temperature in order to reduce the generation of carbide at RF heat treatment and RF energy is delivered accurately.

• Korean Journal of Head & Neck Oncology
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• v.30 no.2
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• pp.100-103
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• 2014

경부 염증을 주 증상으로 하는 이상와 누공의 치료로써, 전통적으로 외과적 절제술이 주로 시행되었으나, 근래에 들어서는 수술 관련 위험성이 적은 삼염화아세트산 소작술이 선호되고 있다. 본원에서, 2004년 5월부터 2013년 3월까지 컷 다운 튜브를 이용한 삼염화아세트산 소작술을 통해 이상와 누공을 치료한 5명 환자의 증례를 보고한다. 이전까지의 삼염화아세트산 소작술에서, 여러 도구를 이용해 누공의 입구만을 막는 시도를 했던 것과는 달리, 본 증례에서는, 컷 다운 튜브를 이용해 20~50%의 삼염화아세트산을 누공로에 주입함으로써, 이상와 누공 전장을 폐쇄하고자 하였다. 3명의 환자에서는 추적 관찰 중 재발 소견 없었으며, 2명의 환자는 추적 관찰 기간 중 재발하여 삼염화아세트산 소작술을 재시행하였다. 모든 증례에서 부작용 및 합병증은 발생하지 않았다.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1237-1241
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• 1997

Tracheal stenosis is a difficult disease entity to manage. Laser ablation is one effective treatment for treacheal stenosis and can be utilized if tracheal reconstructive surgery is impossible. Potassium titanyl phosphate laser, transmitted via flexible quartz fiber, can be precisely manipulated through flexible bronchoscope under local anesthesia. We treated 7 patients with trach al and broncheal lesion under local anesthesia with KTP laser from January 1995 to July 1996. The patients included three males and four females. The age of patients ranged from 22 to 66 years with a mean of 43.7 years The etiology of tracheal stenosis in patients was stenosis after tracheostomy(3 cases), prolong inturbation in cases of sepsis(1 cases), and the recurrence of lung cancer within endobronchial lesion(2 cases). In the cases of tracheal stenosis treated with laser ablation, there were 2 cases of recurrence of stenosis at the anastomosis site after the operation, 3 cases of stenosis at tracheostomy site, and 2 cases of local recurrence of lung cancer. The site of the tracheal stenosis was the balloon site of the tracheostomy tube(3-4cm inferior to the tracheostomy site, 2-3cm superior to the carina) and the anastomosis site that were narrowed to less than 5mm(4 cases). For the stenosis lesion in the endobronchial area, there were 2 patients with a lesion at the anterior wa l, 1 patient with a lesion at the posterior wall, 2 patients with circumferential stenosis. Laser ablation time was 25.4 $\pm$5.9min and used energy was 1768 $\pm$365J. We have used KTP laser via (lexible bronchoscope without major complications. Adjuvant radiation therapy may prevent fibroblast proliferation which leads to restenosis. In three patients of restenosis after laser ablation, adjuvant irradiation started within 4 hours after laser ablation, and the radiation doses were 1500cGy given in five fraction. In patients with adjuvant radiation therapy, stenosis has not recurred

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.29 no.2
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• pp.94-97
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• 2018

Background and Objectives : Fourth branchial cleft cyst is a rare congenital anomaly which cause a recurrent cervical abscess. Complete excision of fourth branchial cleft cyst is difficult because of a complicated fistula tract. In addition to attempting chemocauterization with trichloroacetic acid (TCA) to avoid surgical complications, authors performed an electrocauterization to close internal opening of pyriform sinus. Materials and Methods : We reviewed ten patients of fourth branchial cleft cyst underwent TCA chemocauterization and electrocauterization simultaneously. Clinical characteristics including patient informations, medical records, treatment results were analyzed retrospectively. Results : Interval time until diagnosed with fourth branchial cleft cyst was variable from several days to decades. Five patients had a history of incision and drainage. Mean follow up period was 36.1 months and all patients were treated with no recurrence. Conclusion : TCA chemocauterization with electrocauterization can be a effective choice to reduce recurrence rate and ensure safety of patients of fourth branchial cleft cyst.

• Tuberculosis and Respiratory Diseases
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• v.52 no.1
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• pp.54-61
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• 2002

Background: Tracheal stenosis is an urgent but uncommon disease. Therefore, primary care clinicians have limited clinical experience. Animal models of a tracheal stenosis can be used conveniently for the learning, teaching, and developing new diagnostic and therapeutic modalities for tracheal stenosis. Recently, a canine model of a tracheal stenosis was developed using a Nd-YAG laser. To describe the methods and results of developed animal model, we performed this study. Methods : Six Mongrel dogs were generally anesthetized and the anterior 180 degree of tracheal cartilage of the animal was photo-coagulated using a Nd-YAG laser. The animals were bronchoscopically evaluated every week for 4 weeks and a pathologic evaluation was also made. Results : Two weeks after the laser coagulation, the trachea began to stenose and the stenosis progressed through 4 weeks. All animals suffered from shortness of breath, wheezing, and weight loss in the 3 weeks after the laser treatment, and two died of respiratory failure just before the fourth week. The gross pathologic findings showed the loss of cartilage and a dense fibrosis, which resulted in a fibrous stricture of the trachea. Microscopy also showed that the fibrous granulation tissue replaced destroyed cartilage. Conclusion : The canine model can assist in the understanding and development of new diagnostic and therapeutic modalities for tracheal stenosis.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.620-631
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• 2020

Purpose We aimed to assess local tumor progression (LTP) rate and associated prognostic factors in 92 patients who underwent radiofrequency ablation (RFA) using saline-perfused electrodes to treat hepatocellular carcinoma (HCC) (≤ 5 cm). Materials and Methods Total 92 patients with 148 HCCs were treated with RFA using saline-perfused electrodes, from 2009 to 2015. We retrospectively evaluated technical success, technique efficacy, and LTP rates. Potential prognostic factors for LTP were perivascular tumor, subphrenic tumor, artificial ascites, tumor size (≥ 2 cm), and previous treatment of transarterial chemoembolization. Analysis was performed by lesion, rather than by person. Results During follow-up period from 1 to 97.4 months, total cumulative LTP rates were 7.9%, 11.4%, and 14.6% at 1, 3, and 5 years, respectively. These values were significantly higher in the perivascular (35.1%; p = 0.009) and subphrenic group (38.9%; p = 0.002) at 5-year. We did not observe any significant difference in LTP according to other prognostic factors (p > 0.05). Conclusion RFA with saline-perfused electrode is a safe and effective treatment modality for HCC (≤ 5 cm), with lower LTP rates. Nevertheless, perivascular and subphrenic HCCs demonstrated higher LTP rate than other sites. It is imperative to note that perivascular and subphrenic location of HCC are associated with a high risk of local recurrence, despite the use of saline-perfused electrodes.

• Korean Journal of Bronchoesophagology
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• v.14 no.1
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• pp.14-22
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• 2008

• The Science & Technology
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• v.5 no.5 s.36
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• pp.32-34
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• 1972