• Title/Summary/Keyword: Visual system

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A study of Brachytherapy for Intraocular Tumor (안구내 악성종양에 대한 저준위 방사선요법에 관한 연구)

  • Ji, Gwang-Su;Yu, Dae-Heon;Lee, Seong-Gu;Kim, Jae-Hyu;Ji, Yeong-Hun
    • The Journal of Korean Society for Radiation Therapy
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    • v.8 no.1
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    • pp.19-27
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    • 1996
  • I. Project Title A Study of Brachytherapy for intraocular tumor II. Objective and Importance of the project The eye enucleation or external-beam radiation therapy that has been commonly used for the treatment of intraocular tumor have demerits of visual loss and in deficiency of effective tumor dose. Recently, brachytherapy using the plaques containing radioisotope-now treatment method that decrease the demerits of the above mentioned treatment methods and increase the treatment effect-is introduced and performed in the countries, Our purpose of this research is to design suitable shape of plaque for the ophthalmic brachytherapy, and to measure absorbed doses of Ir-192 ophthalmic plaque and thereby calculate the exact radiation dose of tumor and it's adjacent normal tissue. III. Scope and Contents of the project In order to brachytherapy for intraocular tumor, 1. to determine the eye model and selected suitable radioisotope 2. to design the suitable shape of plaque 3. to measure transmission factor and dose distribution for custom made plaques 4. to compare with the these data and results of computer dose calculation models IV. Results and Proposal for Applications The result were as followed. 1. Eye model was determined as a 25mm diameter sphere, Ir-192 was considered the most appropriate as radioisotope for brachytherapy, because of the size, half, energy and availability. 2. Considering the biological response with human tissue and protection of exposed dose, we made the plaques with gold, of which size were 15mm, 17mm and 20mm in diameter, and 1.5mm in thickness. 3. Transmission factor of plaques are all 0.71 with TLD and film dosimetry at the surface of plaques and 0.45, 0.49 at 1.5mm distance of surface, respectively. 4. As compared the measured data for the plaque with Ir-192 seeds to results of computer dose calculation model by Gary Luxton et al. and CAP-PLAN (Radiation Treatment Planning System), absorbed doses are within ${\pm}10\%$ and distance deviations are within 0.4mm Maximum error is $-11.3\%$ and 0.8mm, respectively. As a result of it, we can treat the intraocular tumor more effectively by using custom made gold plaque and Ir-192 seeds.

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Clinical characteristics and prognosis of acute disseminated encephalomyelitis based on the lesions on MRI (자기공명영상의 병변에 따른 급성 파종성 뇌척수염의 임상 양상과 예후)

  • Chung, Sunghoon;Park, Sungsin;Chung, Sajun
    • Clinical and Experimental Pediatrics
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    • v.50 no.9
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    • pp.891-895
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    • 2007
  • Purpose : Acute disseminated encephalomyelitis (ADEM) is a demyelinating disease of the central nervous system and mostly develops after viral illness or vaccinations. We investigated the clinical differences and neurologic outcomes according to the distribution of the lesions on brain MRI. Methods : The study group was composed of 21 patients from January 1995 to August 2003 in Kyunghee University hospital. We grouped the patients according to the MRI findings as follows. Group I (14 cases): Multi- or unifocal lesions only in the cerebral white matter. Group II (7 cases): lesions in the gray matter with or without white matter involvement. Results : 1. Preceding events were as follows: no defined prodrome (38.1%), upper respiratory tract infection (28.6%), nonspecific febrile illness (19.0%), gastointestinal disturbance and vaccination. 2. Presenting symptoms were as follows: seizures (76.2%), headache/vomiting (47.6%), altered consciousness (38.1%), hemiparesis, cerebellar ataxia, visual disturbance and facial nerve palsy. 3. Laboratory findings were as follows: CSF pleocytosis (76.2%), leucocytosis (38.1%) and elevated CSF protein (28.6%). 4. Fifteen patients were recovered completely without neurological sequelae. Three patients in group I and 1 patient in group II had intractable seizures. Two patients in group I and 2 patients in group II had motor disturbance. Conclusion : There were no statistically significant differences in preceding events, presenting symptoms, and neurological outcomes according to the distribution of the lesions on brain MRI. However, the ADEM have quite diverse clinical manifestations and neuroimage findings. MRI plays an important role in making diagnosis of the patients who are suspected of ADEM.

A Case Study of Artist-centered Art Fair for Popularizing Art Market (미술 대중화를 위한 작가중심형 아트페어 사례 연구)

  • Kim, Sun-Young;Yi, Eni-Shin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.279-292
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    • 2018
  • Unlike the global art market which experienced rapid recovery from the impacts of the Global Financial Crisis in 2008, the Korean art market has not yet fully recovered. The gallery-oriented distribution system, vulnerable primary art market functions, and the market structure centered on a small number of collectors make it difficult for young and medium artists to enter the market and, as a result, deepen the economic polarization of artists. In addition, the high price of art works limits market participation by restricting the general public. This study began with the idea that the interest of the public in the art market as well as their participation in the market are urgent. To this end, we noted that public awareness of art transactions can be a starting point for improving the constitution of the fragile art market, focusing on the 'Artist-centered Art Fair' rather than existing art fairs. To examine the contribution of such an art fair to the popularization of the art market, we analyzed the case of the 'Visual Artist Market (VAM)' project of the Korea Arts Management Service. Results found that the 'Artist-centered Art Fair' focuses on providing opportunities for market entry to young and medium artists rather than on the interests of distributors, and promotes the popularization of the art market by promoting low-priced works to the general public. Also, the 'Artist-centered Art Fair' seems to play a primary role in the public sector to foster solid groups of artists as well as to establish healty distribution networks of Korean Art market. However, in the long run, it is necessary to promote sustainable development of the 'Artist-centered Art Fair' through indirect support, such as the provision of a publicity platform or consumer finance support, rather than direct support.

A Study on the Relationship between Visual Preferences and Visitors' Satisfaction in Bukhansan Dulegil (북한산 둘레길 경관선호도와 이용만족도의 상관성에 관한 연구)

  • Cho, Woo-Hyun;Im, Seung-Bin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.1
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    • pp.1-11
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    • 2013
  • In nature, to change the consciousness of those who wish to pursue something new, the road is turning function-oriented 'Walking Path' into purpose-oriented 'Walking Trails'. Though 'Walking Trails' is a long linear journey that leads people to see, to feel and to experience while walking on the trail, but considering on the landscape of trails when selecting routes is lacking. Landscapes, which are felt and perceived while walking on the trail, provide a purpose, and can be an important factor to improve visitor satisfaction. However, the study is insufficient in terms of landscape of trails. Therefore, it is the purpose of this study to find ways to help improving visitors' satisfaction in selecting routes, by analyzing the images and preferences of trails landscapes that are visually perceived, by analyzing the correlation between visitors' satisfaction and them. For this study, landscape assessment was carried out after selecting representative landscape photos of BukhansanDulegil 13 sections and landscape images adjectives for landscape assessment. Through the assessment, analyze landscape images of each section, landscape images factors affecting a wish to walk and landscape preferences, relationship between visitors' satisfaction and them. 'Refreshing' image was higher on the path with many trees and less artificial elements; 'urban' image was higher on the path with artificial elements. 'A wish to walk' and 'landscape preference' was higher on the path showed 'refreshing' and 'pastoral' image with many natural elements. Factors affecting 'a wish to walk' were "refreshing-unpleasant", "impressive-ordinary", factors affecting 'landscape preference' were "refreshing-unpleasant", "comfortable-uncomfortable". In addition, landscape preference was found to have a high correlation with visitors' satisfaction.

A Study on the Improvement for Medical Service Using Video Promotion Materials for PET/CT Scans (PET/CT 검사에서 동영상 홍보물을 통한 의료서비스 향상에 관한 연구)

  • Kim, Woo Hyun;Kim, Jung Seon;Ko, Hyun Soo;Sung, Ji Hye;Lee, Jeoung Eun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.17 no.1
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    • pp.30-35
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    • 2013
  • Purpose: One of the current services, providing information to the patients and their guardians by using promotion materials induces positive responses and contributes to the improvement of the hospital reliability. Therefore, the objective of this study is to evaluate the effectiveness of audio visual materials, one of the means of promotion, as a way to give accurate medical information to resolve patient's curiosity about purpose and procedure of their examination and deplete complains about waiting which attributes negative effect to service quality assessment. Materials and Methods: 60 patients(mean age $53.97{\pm}12.24$, male : female = 26 : 34) who had $^{18}F-FDG PET/CT$ scan from July 2012 to August 2012 in Seoul Asan Medical Center were referred to the study. All of the patients having PET/CT scan were asked to watch an informative video material before the injection of radiopharmaceutical ($^{18}F-FDG$) and to fill in a questionnaire. Results: As a result of analyzing the contents of questionnaire, 52% of 60 patients had PET/CT scan for the first time and 72.4% of the patients read the PET/CT guidebook offered from their outpatient department or inpatient wards before their scan. After we searched the level of previous knowledge of the purpose and method of PET/CT scan, the patients answered 25.1% "know well", 34% "not sure", 40.9% "don't know" respectively. And 84.7% of the patients answered that watching the PET/CT guide video before the injection helps understanding what exam they were having and 15.3% of the patients did not. For the question asking ever the patients have experienced using our homepage or smart phone QR code to see the guide video before they visit out PET center, only 3.3% of them answered "yes". Lastly, the patients answered 60.1% "yes", 31.4% "so so" and 8.5% "no" respectively for the question asking whether watching the video makes the patients to fill the waiting time short. Conclusion: It is found that understanding of objective and method of the PET/CT scan and level of satisfaction was improved after the patients watched the guide video whether they had PET/CT scan before and read the PET/CT guidebook or not. Also, watching the video was effective for the reduction of perceptible waiting time. But while displaying the PET/CT guide video is useful for providing information about the scan and shortening the waiting time as one of the medical service, utilization of service was actually very poor because of the passive promotion and indifference of the patients about their examination. Therefore, from now on, it is necessary to construct the healthcare system which can be offered to more patients through the active promotion.

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A Study on the Consciousness of the Environment Pollution Problem in Pohang City (환경문제에 관한 시민의식 조사 - 통합후 포항시민을 대상으로 -)

  • Ha, Yeong-Gil;Park, Kyung-Min;Kwon, Young-Sook
    • Journal of agricultural medicine and community health
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    • v.21 no.1
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    • pp.61-73
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    • 1996
  • This study conducted to determine the attitude on environment pollution by Pohang city citizens. 1,059 Pohang city citizens in the age group 20 and over were chosen and surveyed by officials's interview at Up, Myun and Dong during the period 6 September to 20 September 1995. The issue problems to be solved in Pohang city were traffic control 47.3%, environment pollution 22.7%, cultural institutions 11.6%, water service 9.9%, education system 5.1% and community security 2.1%. The 55.1% of subjects responded that responsibility for environment pollution is every citizens duty. The trash from houses were 'garbage'(48.1%), 'waste of life'(21.8%), 'reuse trash'(15.6%) and 'one use thing'(14.5%) in order. The 66.9% of subjects responded that the trash's standard envelopes can be easily tear and its texture is not good. The respondents sometimes or often had experienced foreign bodies, sediment in the water service supply. The 45.9% of the respondents use natural water as drinking water, and the water service supply(26.7%), underground water(17.0%) and buying water(9.3%) were followed. Pertaining to the air pollution(by percent) was pollution of the steel industry complex 78.0%, combustive gas 16.6% and construction dust 1.7%. The respondents at southern district complained of respiratory tract by air pollution and the respondents at northern district complained of the visual disturbance and the offensive odor(P<0.05). Water pollution problem is factory's wastewater 56.2%, home wastewater 36.4% and livestock's wastewater 5.6% in order. The respondents at southern district complained of the noise pollution by airplanes and factories at the afternoon and the respondents at northern district complained of the noise pollution by vehicles(P<0.05).

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A Study of Textured Image Segmentation using Phase Information (페이즈 정보를 이용한 텍스처 영상 분할 연구)

  • Oh, Suk
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.2
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    • pp.249-256
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    • 2011
  • Finding a new set of features representing textured images is one of the most important studies in textured image analysis. This is because it is impossible to construct a perfect set of features representing every textured image, and it is inevitable to choose some relevant features which are efficient to on-going image processing jobs. This paper intends to find relevant features which are efficient to textured image segmentation. In this regards, this paper presents a different method for the segmentation of textured images based on the Gabor filter. Gabor filter is known to be a very efficient and effective tool which represents human visual system for texture analysis. Filtering a real-valued input image by the Gabor filter results in complex-valued output data defined in the spatial frequency domain. This complex value, as usual, gives the module and the phase. This paper focused its attention on the phase information, rather than the module information. In fact, the module information is considered very useful at region analysis in texture, while the phase information was considered almost of no use. But this paper shows that the phase information can also be fully useful and effective at region analysis in texture, once a good method introduced. We now propose "phase derivated method", which is an efficient and effective way to compute the useful phase information directly from the filtered value. This new method reduces effectively computing burden and widen applicable textured images.

CT Simulation Technique for Craniospinal Irradiation in Supine Position (전산화단층촬영모의치료장치를 이용한 배와위 두개척수 방사선치료 계획)

  • Lee, Suk;Kim, Yong-Bae;Kwon, Soo-Il;Chu, Sung-Sil;Suh, Chang-Ok
    • Radiation Oncology Journal
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    • v.20 no.2
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    • pp.165-171
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    • 2002
  • Purpose : In order to perform craniospinal irradiation (CSI) in the supine position on patients who are unable to lie in the prone position, a new simulation technique using a CT simulator was developed and its availability was evaluated. Materials and Method : A CT simulator and a 3-D conformal treatment planning system were used to develop CSI in the supine position. The head and neck were immobilized with a thermoplastic mask in the supine position and the entire body was immobilized with a Vac-Loc. A volumetrie image was then obtained using the CT simulator. In order to improve the reproducibility of the patients' setup, datum lines and points were marked on the head and the body. Virtual fluoroscopy was peformed with the removal of visual obstacles such as the treatment table or the immobilization devices. After the virtual simulation, the treatment isocenters of each field were marked on the body and the immobilization devices at the conventional simulation room. Each treatment field was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR)/digitally composite radiography (DCR) images from the virtual simulation. The port verification films from the first treatment were also compared with the DRR/DCR images for a geometrical verification. Results : CSI in the supine position was successfully peformed in 9 patients. It required less than 20 minutes to construct the immobilization device and to obtain the whole body volumetric images. This made it possible to not only reduce the patients' inconvenience, but also to eliminate the position change variables during the long conventional simulation process. In addition, by obtaining the CT volumetric image, critical organs, such as the eyeballs and spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. The differences between the DRRs and the portal films were less than 3 mm in the vertebral contour. Conclusion : CSI in the supine position is feasible in patients who cannot lie on prone position, such as pediatric patienta under the age of 4 years, patients with a poor general condition, or patients with a tracheostomy.

Comparison of Clinical Results of Excimer Laser Correction of Myopia and Compound Myopic Astigmatism Using VISX 20/20B $VisionKey^{TM}$ (VISX 20/20B $VisionKey^{TM}$ 엑시머레이저의 version 4.01 software를 이용한 근시교정술 및 근시성난시교정술의 임상성적 비교)

  • Lee, Sang-Bumm;Bae, Sang-Bok
    • Journal of Yeungnam Medical Science
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    • v.17 no.1
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    • pp.55-65
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    • 2000
  • Purpose: To compare the efficacy, predictability, stability and safety of excimer laser photorefracive keratectomy(PRK) for myopia and photoastigmatic refractive keratectomy(PARK) for compound myopic astigmatism. Methods: Two-hundred and three eyes(l18 eyes < -7D spherical equivalent, 85 eyes ${\geq}$ -7D spherical equivalent) received excimer laser correction for compound myopic astigmatism and 152 eyes(116 eyes < -7D, 36 eyes ${\geq}$ -7D) for simple myopia. A VISX 20/20B $VisionKey^{TM}$ excimer laser was used to perform either PARK or PRK. Visual acuity with and without correction, refraction, IOP, corneal haze, and topography were evaluated at 1, 3, 6, and 12 months postoperatively. All patients were followed up for more than 12 months. Results: Postoperative refraction were generally stable after 3 months without significant early overcorrection. At 12 months, 110(94.8%) eyes that underwent PRK and 104(88.1%) eyes that underwent PARK achieved UCVA of 20/30 or better in the group who had lower than -7D correction. For eyes treated with -7D or more, these figures were 31(86.1%) eyes after PRK and 57(67.1%) eyes after PARK. The incidences of within 1D of plano refraction at 1 year follow-up were 97.4% after PRK and 93.2% after PARK in the group who had lower than -7D correction. For eyes treated with -7D or more, these figures were 80.6% after PRK and 70.6% after PARK. Conclusions Myopia with or without astigmatism was successfully treated in most of the eyes using PRK or PARK with VISX 20/20B $VisionKey^{TM}$ excimer laser. The predictability and stability of the postoperative refraction during the first 12 months seem to be quite reliable. Further improvement of excimer laser system and software should increase the clinical outcomes and safety of refractive procedures.

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The Acceptance Testing of 5 Mega Pixels Primary Electronic Display Devices and the Study of Quality Control Guideline Suitable for Domestic Circumstance (5 Mega 화소 진단용 전자표시장치 인수검사 및 국내 실정에 적합한 정도관리 가이드라인 연구)

  • Jung, Hai-Jo;Kim, Hee-Joung;Kim, Sung-Kyu
    • Progress in Medical Physics
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    • v.18 no.2
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    • pp.98-106
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    • 2007
  • In June 2005, Yonsei University Medical Center, Severance Hospital upgraded a full-PACS system by adding twenty (5 mega pixels) Totoku ME511L flat panel LCD display devices for diagnostic interpretation purposes. Here we report upon the quantitative (or visual) acceptance testing of the twenty Totoku ME511L display devices for reflection, luminance response, luminance spatial dependency, resolution, noise, veiling glare, and display chromaticity based on AAPM TG 18 report. The tools used in the tests included a telescopic photometer, which was used as a colorimeter, illuminance meter, light sources for reflection assessment, light-blocking devices, and digital TG18 test patterns. For selected 8 flat panel displays, mean diffuse reflection coefficient ($R_d$) was $0.019{\pm}0.02sr^{-1}$. In the luminance response test, luminance ratio (LR), maximum luminance difference ($L_{max}$), and deviation of contrast response were $550{\pm}100,\;2.0{\pm}1.9%\;and\;5.8{\pm}1.8%$, respectively. In the luminance uniformity test, maximum luminance deviation was $14.3{\pm}5.5%$ for the 10% luminance of the TG18-UNL10 test pattern. In the resolution test with luminance measurement method, percent luminance (${\Dalta}L$) at the center was $0.94{\pm}0.64%$. In all cases of noise testing, rectangular target In every square in the three quadrants was visible and all 15 targets except the smallest one in the every corner pattern and the center pattern. The glare ratio (GR) was $12,346{\pm}1,995$. The color uniformity, (u',v'), was $0.0025{\pm}0.0008$. Also, the research results of qualify control guideline of primary disply devices suitable for domestic circumstance are presented All test results are in-line with the criteria recommended by AAPM TG18 report and are thus fully acceptable for diagnostic image interpretation. As a result, the acceptance testing schedule described provides not only an acceptance standard but also guidelines for quality control, optimized viewing conditions, and a means for determining the upgrading time of LCD display devices for diagnostic interpretation.

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