• Nuclear Medicine and Molecular Imaging
• /
• v.43 no.1
• /
• pp.48-54
• /
• 2009

Purpose: There are few studies evaluating the usefulness of dedicated high-resolution scintimammography and no studies using delayed washout with this dedicated high resolution scintimammography for the evaluation of breast lesions. We underwent this study to evaluate the clinical usefulness of Tc-99m MIBI in evaluating patients with palpable breast lesions using dedicated high-resolution scintimammography. Materials and Methods: This study included 19 patients with 23 palpable breast lesions who underwent mammography. Tc-99m MIBI was taken to further characterize these lesions. Scintimammography images were acquired with standard craniocaudal and mediolateral oblique views and delayed images were additionally taken. Final conclusions were based on histopathology, either by biopsy or mastectomy results. Results: Eighteen lesions were malignant and five were benign. Mammography was indeterminate for thirteen lesions, nine of those were malignant. Mammography also categorized one lesion as benign in a dense breast, but scintimammography and pathology results showed malignancy. Of the five benign lesions, two were visible on scintimammography, but delayed images showed washout. Conclusion: Based on our preliminary results, dedicated high resolution scintimammography seems to be very useful in characterizing palpable lesions that were indeterminate or negative on mammography.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.06a
• /
• pp.51-54
• /
• 2006

Cathode material, $(Ba_{0.5}Sr_{0.5})_{0.99}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$, for low temperature SOFC was prepared by the glycine-nitrate synthesis process (GNP). The characteristics of the synthesized powders were studied with controlling pH of a precursor. The synthesis BSCF powders with pH were agglomeration state and calcinations temperature has not influence on particles. Highly acidicprecursor solution increased a single phase forming the temperature. Also, synthesis BSCF powder was show result for thermal analysis and alteration of difference crystal with pH. It is considered that Ba and Sr cannot complex by carboxylic acid group of glycine, because under highly acidic condition the caboxylic group mainly combined with $H^+$ insead of alkali and alkaline earth cations. In case of using precursor solution with pH $2{\sim}3$, a single perovskite phase was obtained at $1000^{\circ}C$. Polarization resistance of $(Ba_{0.5}Sr_{0.5})_{0.99}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ was measured by AC impedance spectroscopy from the two electrode symmetric cell. Area specific resistance of the $(Ba_{0.5}Sr_{0.5})_{0.99}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ air electrode at $500^{\circ}C\;and\;600^{\circ}C$ were $0.96{\Omega}?cm^2$ and $0.16{\Omega}?cm^2$, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.10
• /
• pp.1855-1861
• /
• 2017

In this paper, the gain enhancement of an SDPA using a director and two parasitic patches is studied. The modified balun is used to increase the bandwidth, whereas the director and two parasitic patches are appended to the SDPA to enhance the gain in the middle and high frequency bands. The effects of the distance between the director and parasitic patches on the antenna performance are analyzed, and the SDPA with a gain over 7 dBi at 1.54-2.99 GHz band is designed. The proposed SDPA is fabricated on an FR4 substrate with a dimension of $90mm(L){\times}135mm(W)$ in order to validate its performance. The fabricated antenna shows a frequency band of 1.56-3.10 GHz for a VSWR < 2, and it is confirmed by measurement that gain maintains over 7 dBi in the frequency range of 1.54-3.00 GHz.

• The Korean Journal of Nuclear Medicine
• /
• v.26 no.2
• /
• pp.235-243
• /
• 1992

Patterns of abnormality in regional cerebral perfusion and its relation to clinical severity was evaluated with 32 head injury patients using $^{99m}Tc-HMPAO$ single photon emission tomography (SPECT). The findings were compared with computed tomography (CT) done within 48 hours of each SPECT study. The initial SPECT study was done within 7 days of injury in 16 cases, between 1 week and 2 months in 12, and after over 2 months in 4. Nineteen of the patients underwent followup SPECT and CT after a mean interval of 1 to 2 months. The initial SPECT showed abnormalities in 96% (31/32) of the patients while CT showed abnormal findings in only 81% (26/32). There were a total of 54 supratentorial SPECT lesions in all. Ninity percent (49/54) of these were of regional hypoperfusion, while 5 lesions showed focal hyperperfusion. The lesions were most often localized in the frontal and temporal lobes. Fifty five percent (30/54) were areas not detected as a lesion on CT. Cerebellar diaschisis was observed in 50% (16/32) of the patients. The degree of perfusion abnormality was quantified by the product of differential activity and a size factor. Correlation between the degree of perfusion abnormality and the clinical severity (Glasgow coma scale) failed to show statistical significance (p=0.053). The amount of change in the degree of perfusion abnormality on follow up SPECT was compared to the amount of change in clinical severity. Perfusion abnormality showed a tendancy to improve in most patients, and the degree of improvement showed significant correlation with the amount of clinical improvement (p < 0.01).

• Annual Conference on Human and Language Technology
• /
• 1995.10a
• /
• pp.188-194
• /
• 1995

한글 문서에서는 일부 조사와 일부 어미가 자주 출현하며 그 외의 조사/어미는 출현 빈도가 낮을 것으로 추측되고 있다. 본 연구에서는 실험에 통해서 이러한 사실을 확인하고 자주 출현하는 통합형 조사와 어미의 빈도를 구하기 위하여 한국어 말뭉치에서 통합형 조사와 통합형 어미의 상대적 출현 빈도를 조사하였다. 통합형 조사의 상대적 출현 빈도를 조사한 결과 말뭉치의 분야에 따라 약간의 차이가 있으나 평균 상위 9개의 통합형 조사가 전체 조사의 70%를 차지하고 있으며 상위 20개, 32개, 69개의 통합형 조사가 각각 90%, 95%, 99%를 차지하고 있음을 확인하였다. 통합형 어말어미의 경우에는 상위 10개의 통합형 어말어미가 전체 어말어미의 70%를 차지하고 상위 33개, 54개, 117개의 통합형 어미가 각각 90%, 95%, 99%를 차지하고 있다. 본 논문에서는 조사, 어미의 상대적 출현 빈도에 따라 계층적으로 조사/어미 사진을 구성함으로써 형태소 분석 효율을 높이고 형태소 분석기가 다양한 응용 분야에 쉽게 적응할 수 있도록 하는 방법을 제안한다. 또한 통합형 조사, 어미의 상대적 출현 빈도는 미등록어 추정을 용이하게 하거나 형태론적 모호성을 해결할 때에도 유용하게 활용될 수 있음을 보인다.

• Journal of radiological science and technology
• /
• v.18 no.1
• /
• pp.81-90
• /
• 1995

This study was conducted to find out the management status of radioisotopes and radioactive waste products in Korean medical institutions during the period of three years from 1991 to 1993. The results are summarized as follows : 1. The rate of medical institution to the institutions making use of radioisotopes was decreased every year, for example, 18.11 % in the year 1991, 17.86 % in the year 1992 and 15.87 % in the year 1993. 2. The use of domestic made radioisotopes in the medical institution was increased every year, for instance, 89.68 % in the year 1991, 94.21 % in the year 1992 and 99.79 % in the year 1993. 3. 91.01 % of the half life of isotopes used in the medical Institution were two month below. 4. The rate of radioactive waste products in the medical institution to all radioactive waste products was increased every year, for example, 54.44 % in the year 1991, 75.36 % in 1992 and 78.49 % in the year 1993. 5. The rate of inflammable waste products from medical institution was 76.47 % of all inflammable waste products, and 73.99 % of whole waste products was from the medical Institution.

• The Korean Journal of Nuclear Medicine
• /
• v.28 no.1
• /
• pp.141-144
• /
• 1994

As the laparoscopic cholecystectorny is performed more widely, complication associated with the procedure, although rare, are encountered occasionally. Injury to the bile duct occurs somewhat more frequently after the laparoscopic cholecystectorny than the open method. The bile leakage following a bile duct injury can be detected non-invasively either by ultrasonography or radionuclide hepatobiliary scan, but the former is not very specific. Hepatobiliary scan can show the bile leakge and the localization of the bile accumulation. We report two cases of the common bile duct injury following laparoscopic cholecystectorny, accurately detected by hepatobiliary scan using $^{99m}Tc$-diisoprophylimi-nodiacetic acid (DISIDA).

• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.04a
• /
• pp.978-980
• /
• 2014

본 연구에서는 스트레스 상태 측정을 위한 심전도 신호 QRS 검출 알고리즘을 제안한다. 심전도 신호의 QRS 검출 과정은 4단계로 wavelet, moving average, squaring, threshold method로 구성된다. wavelet은 기저선 변동과 노이즈를 제거하고 moving average는 전체 신호를 부드럽게 하고 잔여 노이즈를 제거하며 squaring은 신호를 강조하는 역할을 한다. 마지막으로 threshold 기법을 이용해 검출간격을 설정하여 QRS를 검출하였다. 그 결과 Sensitivity는 99.54%, Positive Predictivity는 99.69%, Detection Error는 0.76%를 보였다. 또한, 피험자를 대상으로 게임을 이용해 스트레스 상태 변화에 대한 실험을 하였고, HRV 시간-주파수 파라미터를 분석함으로써 스트레스 상태 변화를 관찰할 수 있었다.

• Journal of Korean Society on Water Environment
• /
• v.28 no.2
• /
• pp.277-284
• /
• 2012

This study developed a new ceramics in which natural zeolite was mixed and calcined with industrial by-product such as converter slag, red mud, and fly ash and evaluated the feasibility of the ceramics for removal of heavy metals in acid wastewater. The removal rate of heavy metal by ceramics increased in the order of ZS (zeolite and slag) > ZR (zeolite and red mud) > ZF (zeolite and fly ash) ceramics. The alkalinity increment and coherence of ceramics were increased in the order of ZS > ZR > ZF ceramics. The mixing ratio of natural zeolite to industrial by-product for maximum removal efficiency of heavy metal was 1:1 for ZS ceramics and 1:3 for ZR and ZF ceramics. The order of removal efficiency of heavy metal was observed to be ZS > ZR > ZF ceramics under the mixing ratio of 1:1 for ZS ceramics and 1:3 for ZR and ZF ceramics. The removal efficiency of heavy metal by ZS ceramics with 1:1 mixing ratio was Al 100%, Cd 54.6%, Cr 99.9%, Cu 98.7%, Fe 99.9%, Mn 42.2%, Ni 59.9%, Pb 99.8%, Zn 87.6%, respectively. In addition, the removal capacity of heavy metal by ZS ceramics was observed to be Al 2.01 mM/g, Cd 0.27 mM/g, Cr 1.02 mM/g, Cu 0.83 mM/g, Fe 0.95 mM/g, Mn 0.41 mM/g, Ni 0.55 mM/g, Pb 0.25 mM/g, Zn 0.70 mM/g, respectively. The comparative evaluation in the light of removal capacity, alkalinity increment, and coherence of ceramics showed the ZS ceramics had higher feasibility as a media than others for removal of heavy metals in acid wastewater.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.1A
• /
• pp.45-54
• /
• 2006

To obtain realistic stress-strain relation in concrete, it is necessary to improve the constitutive model for creep and shrinkage of concrete. This study is made up with predicting model of creep using rheological approach and mathematical development which is solution for phenomenon of concrete creep. Long-term deformation components are combined based on traditional 4-parameters model. Creep deformation is obtained adequately using 4-parameters determined by considering aging effect and microprestress among gels. And coefficient of effective viscosity is able to represent both basic creep and total creep included drying creep. This study attempt to establish mathematical model considering effects of aging, hydration, and variations of pore humidity. It can predict both basic creep and total creep. Values of result between prediction and experiment have greater than correlation factor 99%. Additionally experimental results report bad consentaneity with highway design specification adopting FIB MC 90. Rather than those are similar to FIB MC 90 rev.99.