• Journal of Biosystems Engineering
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• 제38권1호
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• pp.64-71
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• 2013

Purpose: The purpose of this study was to select standing posture parameters that have a significant difference according to the severity of spinal deformity, and to develop a novel Cobb angle prediction model for adolescent girls with idiopathic scoliosis. Methods: Five normal adolescents girls with no history of musculoskeletal disorders, 13 mild scoliosis patients (Cobb angle: $10^{\circ}-25^{\circ}$), and 14 severe scoliosis patients (Cobb angle: $25^{\circ}-50^{\circ}$) participated in this study. Six infrared cameras (VICON) were used to acquire data and 35 standing parameters of scoliosis patients were extracted from previous studies. Using the ANOVA and post-hoc test, parameters that had significant differences were extracted. In addition, these standing posture parameters were utilized to develop a Cobb-angle prediction model through multiple regression analysis. Results: Twenty two of the parameters showed differences between at least two of the three groups and these parameters were used to develop the multi-linear regression model. This model showed a good agreement ($R^2$ = 0.92) between the predicted and the measured Cobb angle. Also, a blind study was performed using 5 random datasets that had not been used in the model and the errors were approximately $3.2{\pm}1.8$. Conclusions: In this study, we demonstrated the possibility of clinically predicting the Cobb angle using a non-invasive technique. Also, monitoring changes in patients with a progressive disease, such as scoliosis, will make possible to have determine the appropriate treatment and rehabilitation strategies without the need for radiation exposure.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.989-995
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• 2018

Argonne National Laboratory of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have cooperated on the development, design, and construction of a neutron source facility. The facility was constructed at Kharkov, Ukraine, and its commissioning process is underway. The facility will be used for researches, producing medical isotopes, and training young nuclear specialists. The neutron source facility is designed with a provision to include a cryogenically cooled moderator system-a cold neutron source (CNS). This CNS provides low-energy neutrons, which will be used in the scattering experiment and material structures analysis. Cold neutron guides, coated with reflective material for the low-energy neutrons, will be used to transport the cold neutrons to the experimental site. The cold neutron guides would keep the cold neutrons within certain energy and angular space concentrated inside, while most of the gamma rays and high-energy neutrons are not affected by the cold neutron guides. For the KIPT design, the cold neutron guides need to extend several meters outside the main shield of the facility, and curved guides will also be used to remove the gamma and high-energy neutron. The neutron guides should be installed inside a shield structure to ensure an acceptable biological dose in the facility hall. Heavy concrete is the selected shielding material because of its acceptable performance and cost. Shield design analysis was carried out for the CNS guide hall. MCNPX was used as the major computation tool for the design analysis, with neutron and gamma dose calculated separately. Weight windows variance reduction technique was also used in the shield design. The goal of the shield design is to keep the total radiation dose below the $5.0{\mu}Sv/hr$ guideline outside the shield boundary. After a series of iterative MCNPX calculations, the shield configuration and parameters of CNS guide hall were determined and presented in this article.

• 비파괴검사학회지
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• 제26권4호
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• pp.246-254
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• 2006

방사선 측정분야에서 사용되는 감마 서베이미터의 교정데이터 자동처리를 위한 전산 프로그램을 개발하였다. 전산 프로그램은 Visual Basic을 기반으로 개발되었으며, 교정과정에 따라 단계별로 윈도우를 제작하고 코드화하였다. 교정 데이터의 자동처리를 위해 Microsoft Excel 프로그램을 제어하여 미리 자동 연산된 엑셀 셀 내에 데이터가 입력되도록 하였다. 개발프로그램 성능평가의 일환으로 검증된 데이터와 프로그램에서 출력된 데이터를 비교한 결과, 교정인자 산출 및 불확도 평가에서 동일한 결과가 나왔다. 또한, 개발프로그램을 교정업무에 적용시킨 결과, 업무의 효율성 및 정확성은 증가하였다.

• 대한두경부종양학회지
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• 제13권1호
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• pp.24-29
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• 1997

Background: Supraglottic and hypopharyngeal regions drain into the upper deep cervical lymph nodes. And bilateral neck node metastasis is frequently occured especially, in the early stage. It influences on the prognosis of above diseases. The prognosis for patients wih supraglottic and hypopharyngeal cancers, although usually poor, has improved by modern imaging technique, better application of treatment modalities, increasing assortment of reconstructive procedures and improved application of radiation therapy. Objectives: This study was designed to obtain objective data about the patterns of neck node metastasis and to identify the necessity of elective bilateral neck dissection. Material and Methods: Twenty four patients with supraglottic cancer and twenty six patients with hypopharyngeal cancer were investigated from the chart review. Results: In supraglottic cancer, the most frequent sites of neck metastasis is level II (52.9%) and level III (52.9%) in ipsilateral side, level II (29.4%) in contralateral side, in hypopharyngeal cancer, level II (73.7%) and III (52.6%) in ipsilateral side, level II (10.5%) in contralateral side. In elective neck dissection, the occult metastasis is about 50% in supraglottic cancer, but there is no occult metastasis in hypopharyngeal cancer. Conclusion: In supraglottic cancer, elective bilateral neck dissection is necessary because of early contralateral neck metastasis, but in hypopharyngeal cancer, elective contralateral neck dissection may not be always necessary because of rare occult metastasis and contralateral neck metastasis.

• Journal of Korean Neurosurgical Society
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• 제60권1호
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• pp.15-20
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• 2017

Objective : Diagnosing tumor progression and pseudoprogression remains challenging for many clinicians. Accurate recognition of these findings remains paramount given necessity of prompt treatment. However, no consensus has been reached on the optimal technique to discriminate tumor progression. We sought to investigate the role of magnetic resonance perfusion (MRP) to evaluate tumor progression in glioma patients. Methods : An institutional retrospective review of glioma patients undergoing MRP with concurrent clinical follow up visit was performed. MRP was evaluated in its ability to predict tumor progression, defined clinically or radiographically, at concurrent clinical visit and at follow up visit. The data was then analyzed based on glioma grade and subtype. Resusts : A total of 337 scans and associated clinical visits were reviewed from 64 patients. Sensitivity, specificity, positive and negative predictive value were reported for each tumor subtype and grade. The sensitivity and specificity for high-grade glioma were 60.8% and 87.8% respectively, compared to low-grade glioma which were 85.7% and 89.0% respectively. The value of MRP to assess future tumor progression within 90 days was 46.9% (sensitivity) and 85.0% (specificity). Conclusion : Based on our retrospective review, we concluded that adjunct imaging modalities such as MRP are necessary to help diagnose clinical disease progression. However, there is no clear role for stand-alone surveillance MRP imaging in glioma patients especially to predict future tumor progression. It is best used as an adjunctive measure in patients in whom progression is suspected either clinically or radiographically.

• 전자공학회논문지
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• 제52권11호
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• pp.127-134
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• 2015

초음파를 이용한 조직 자극 기법은 지속적으로 연구, 개발되고 있으며, 최근 미용 및 비만 치료에 대한 관심이 높아짐에 따라 초음파 지방 제거술에 대한 다양한 연구가 진행되고 있다. 본 연구에서는 초음파 지방 제거술을 위한 초음파 변환기를 설계하고, 조사조건에 따른 집속영역의 형태와 열 변성 영역을 시뮬레이션 하였다. 이를 통하여 제원을 검증하였으며, 제작된 변환기의 초음파 방사 특성 및 가열 특성을 측정하여 유효성을 평가하였다. 또한 복합 구조의 매질을 대상으로 초음파 가열 특성을 예측하였으며 제작된 변환기의 집속점 형태 및 가열 특성이 지방층을 충분히 유화시킬 수 있을 것으로 판단하였다. 본 연구의 결과는 보다 효율적이고 안전한 초음파 지방 제거술의 기초 연구로 활용될 것으로 사료된다.

• Advances in materials Research
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• 제2권2호
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• pp.77-91
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• 2013

High quality nanoparticles of neodymium barium niobium ($NdBa_2NbO_6$) perovskites have been synthesized using an auto ignition combustion technique for the first time. The nanoparticles thus obtained have been characterized by powder X-ray diffraction, thermo gravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy, Raman spectroscopy and transmission electron microscopy. UV-Visible absorption and photoluminescence spectra of the samples are also recorded. The structural analysis shows that the nano powder is phase pure with the average particle size of 35 nm. The band gap determined for $NdBa_2NbO_6$ is 3.9 eV which corresponds to UV-radiation for optical inter band transition with a wavelength of 370nm. The nanopowder could be sintered to 96% of the theoretical density at $1325^{\circ}C$ for 2h. The ultrafine cuboidal nature of nanopowders with fewer degree of agglomeration improved the sinterability for compactness at relatively lower temperature and time. During the sintering process the wide band gap semiconducting behavior diminishes and the material turns to a high permittivity dielectric. The microstructure of the sintered surface was examined using scanning electron microscopy. The striking value of dielectric constant ${\varepsilon}_r=43$, loss factor tan ${\delta}=1.97{\times}10^{-4}$ and the observed band gap value make it suitable for many dielectric devices.

• 한국광학회지
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• 제1권1호
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• pp.46-51
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• 1990

Soft X-ray는 자연상태의 생물체를 높은 대비(high contrast)의 영상으로 관찰할 수 있는 광원이다. 1GW급의 광분해 옥소레이저 ($\lambda$=1.315$\mu\textrm{m}$, E=12.7J)를 몰리브덴(Mo) 표적에 집속시켜 플라즈마를 발생시켰으며 플라즈마에서 방출되는 넓은 파장 영역의 연속스펙트럼을 0.1$\mu\textrm{m}$ 두께의 알루미늄 필터를 거치게 하여 soft X-ray 영역에 중심세기를 갖는 광원을 얻었다. X-ray용 resist로 감도가 좋은 PBS를 사용하여 그물망(mesh), 거미줄, 적혈구의 replica를 얻었다. 본해능에 미치는 두 가지의 주된 영향인 광원의 크기에 의한 영향과 Fresnel 회절효과를 고찰하고 실험결과를 비교하였다. 본 실험에서는 0.1$\mu\textrm{m}$이하의 분해능을 얻었다.

• 한국육종학회지
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• 제42권4호
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• pp.365-373
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• 2010

TILLING (Targeting Induced Local Lesions IN Genomes) is broadly regarded as an excellent methodology for reverse genetics applications. Approximately 15,000 $M_3$ TILLING lines have been developed via the application of gamma-ray irradiation to rice seeds (cv. Donganbyeo), followed by subsequent selections. In an effort to evaluate the genetic diversity of the TILLING population, we have employed the AFLP multiple dominant marker technique. A total of 96 (0.64%) TILLING lines as well as Donganbyeo were selected randomly and their genetic diversity was assessed based on AFLP marker polymorphisms using 5 primer combinations. An average of 100.4 loci in a range of 97 to 106 was detected using these primer combinations, yielding a total of 158 (31.4%) polymorphic loci between Donganbyeo and each of the 96 lines. A broad range of similarity from 80% to 96% with an average of 89.4% between Donganbyeo and each of the 96 lines was also observed, reflecting the genetic diversity of the TILLING population. Approximately 28 polymorphic loci have been cloned and their sequences were BLAST-searched against rice whole genome sequences, resulting in 20 matches to each of the gene bodies including exon, intron, 1 kb upstream and 1 kb downstream regions. Six polymorphic loci evidenced changes in the coding regions of genes as compared to the rice pseudomolecules, 4 loci of which exhibited missense mutations and 2 loci of which exhibited silent mutations. Therefore, the results of our study show that the TILLING rice population should prove to be a useful genetic material pool for functional genomics as well as mutation breeding applications.

• 한국인터넷방송통신학회논문지
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• 제20권6호
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• pp.123-128
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• 2020

본 논문에서는 3차원 동영상을 구현하기 위하여 인체에 유해한 방사능 피폭량이 부챗살 형태의 Fan Beam 보다 상대적으로 적은 원추형 Cone Beam CT 시스템을 설계하였다. 설계된 시스템은 X-ray가 조사된 각도에서 획득한 데이터를 영상처리부로 전송하고 영상을 구성하는 계산 속도를 빠르게 하기 위하여 초월함수가 보다 적은 3단계 회전 행렬을 이용하여 3차원 영상을 구현하는 회전 기반법을 사용하였다. 본 연구에서는 3차원 영상을 구성하는 시간단축을 통해 초당 3~5장의 영상을 얻음으로써 3차원 동영상을 실시간으로 구현하였으며 기존의 데이터 적층 방법에 비해 본 논문에서 사용한 회전 기반법이 우수함을 증명하였으며 단점 및 해결방법 제시하였다.