• Title/Summary/Keyword: 분석 및 평가

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Study on the calibration phantom and metal artifacts using virtual monochromatic images from dual energy CT (듀얼 에너지 CT의 가상 단색 영상을 이용한 영상 교정 팬텀과 금속 인공음영에 관한 연구)

  • Lee, Jun seong;Lee, Seung hoon;Park, Ju gyung;Lee, Sun young;Kim, Jin ki
    • The Journal of Korean Society for Radiation Therapy
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    • v.29 no.1
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    • pp.77-84
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    • 2017
  • Purpose: To evaluate the image quality improvement and dosimetric effects on virtual monochromatic images of a Dual Source-Dual Energy CT(DS-DECT) for radiotherapy planning. Materials and Methods: Dual energy(80/Sn 140 kVp) and single energy(120 kVp) scans were obtained with dual source CT scanner. Virtual monochromatic images were reconstructed at 40-140 keV for the catphan phantom study. The solid water-equivalent phantom for dosimetry performs an analytical calculation, which is implemented in TPS, of a 10 MV, $10{\times}10cm^2$ photon beam incident into the solid phantom with the existence of stainless steel. The dose profiles along the central axis at depths were discussed. The dosimetric consequences in computed treatment plans were evaluated based on polychromatic images at 120 kVp. Results: The magnitude of differences was large at lower monochromatic energy levels. The measurements at over 70 keV shows stable HU for polystyrene, acrylic. For CT to ED conversion curve, the shape of the curve at 120 kVp was close to that at 80 keV. 105 keV virtual monochromatic images were more successful than other energies at reducing streak artifacts, which some residual artifacts remained in the corrected image. The dose-calculation variations in radiotherapy treatment planning do not exceed ${\pm}0.7%$. Conclusion: Radiation doses with dual energy CT imaging can be lower than those with single energy CT imaging. The virtual monochromatic images were useful for the revision of CT number, which can be improved for target coverage and electron densities distribution.

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The Evolution of Cyber Singer Viewed from the Coevolution of Man and Machine (인간과 기계의 공진화적 관점에서 바라본 사이버가수의 진화과정)

  • Kim, Dae-Woo
    • Cartoon and Animation Studies
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    • s.39
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    • pp.261-295
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    • 2015
  • Cyber singer appeared in the late 1990s has disappeared briefly appeared. although a few attempts in the 2000s, it did not show significant successes. cyber singer was born thanks to the technical development of the IT industry and the emergence of an idol training system in the music industry. It was developed by Vocaloid 'Seeyou' starting from 'Adam'. cyber singer that differenatiated typical digital characters in a cartoon or game may be subject to idolize to the music as a medium. They also feature forming a plurality of fandom. therefore, such attempts and repeated failures, this could be considered a fashion, but it flew content creation and ongoing attempts to take advantage of the new media, such as Vocaloid can see that there are expectations for a true Cyber-born singer. Early-Cyber singer is made only resemble human appearance, but 'Sciart' and 'Seeyou' has been evolving to becoming more like the human capabilities. in this paper, stylized cyber singer had disappeared in the past in the process of developing the technology to evolve into own artificial life does not end in failure cases, gradually led to a change in public perceptions of the image look looking machine was an attempt in that sense. With the direction of the evolution of the mechanical function to obtain a human, fun and human exchanges and mutual feelings. And it is equipped with an artificial life form that evolved with it only in appearance and function. in order to support this logic, I refer to the study of the coevolution of man and machine at every Bruce Mazlish. And, I have analyzed the evolution of cyber singer Bruce research from the perspective of the development process since the late 1990s, the planning of the eight singers who have appeared and design of the cyber character and important voices to be evaluated as a singer (vocal). The machine has been evolving coevolution with humans. cyber singer ambivalent development targets are recognized, but strive to become the new artificial creatures of horror idea of human desire and death continues. therefore, the new Cyber-organisms are likely to be the same style as 'Seeyou'. because, cartoon forms and whirring voice may not be in the form of a signifier is the real human desires, but this is because the contemporary public's desire to be desired and the technical development of this type can be created at the point where the cross-signifier.

Evaluation on Organ Dose and Image Quality of Lumbar Spine Radiography Using Glass Dosimeter (유리선량계를 이용한 요추검사의 장기선량 및 영상의 평가)

  • Kim, Jae-Kyeom;Kim, Jeong-Koo
    • Journal of radiological science and technology
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    • v.39 no.1
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    • pp.1-11
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    • 2016
  • The purpose of this study was to provide resources for medical exposure reduction through evaluation of organ dose and image resolution for lumbar spine around according to the size of the collimator in DR system. The size of the collimator were varied from $8^{\prime\prime}{\times}17^{\prime\prime}$ to $14^{\prime\prime}{\times}17^{\prime\prime}$ by 1" in AP and lateral projection for the lumbar spine radiography with RANDO phantom. The organ dose measured for liver, stomach, pancreas, kidney and gonad by the glass dosimeter. The image resolution was analyzed using the Image J program. The organ dose of around lumbar spine were reduced as the size of the collimator is decreased in AP projection. There were no significant changes decreasing rate whenever the size of the collimator were reduced 1" in the gonad. The organ dose showed higher on liver and kidney near the surface in lateral projection. There were decreasing rate of less than 5% in liver and kidney, but decreasing rate was 24.34% in the gonad whenever the size of the collimator were reduced 1". Organ dose difference for internal and external of collimator measured $549.8{\mu}Gy$ in the liver and $264.6{\mu}Gy$ in the stomach. There were no significant changes organ dose difference that measured $1,135.1{\mu}Gy$ in the gonad. Image Quality made no difference because SNR and PSNR were over than 30 dB when the collimator size is less than $9^{\prime\prime}{\times}17^{\prime\prime}$ on AP projection and $10^{\prime\prime}{\times}17^{\prime\prime}$ on lateral projection. Therefore, we are considered that the recommendations criterion for control of collimator were suggested in order to reduce unnecessary X-ray exposure and to obtain good image quality because lumbar spine radiography contains a lot of peripheral organs rather than other area radiography.

Laterally Unbraced Length for Preventing Inelastic Lateral-Torsional Buckling of High-Strength Steel Beams (고강도 강재보의 비탄성 횡-비틀림좌굴 제어를 위한 횡지지 거리)

  • Park, Chang Hee;Lee, Cheol Ho;Han, Kyu Hong;Kim, Jin Ho;Lee, Seung Eun;Ha, Tae Hyu;Kim, Jin Won
    • Journal of Korean Society of Steel Construction
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    • v.25 no.2
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    • pp.115-130
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    • 2013
  • In this study, lateral-torsional buckling (LTB) strength of high-strength H-beams built up from 800MPa tensile-strength steel was experimentally and analytically evaluated according to current lateral stability provisions (KBC 2009, AISC-LRFD 2010). The motivation was to evaluate whether or not current LTB provisions, which were originally developed for ordinary steel with different stress-strain characteristics, are still applicable to high-strength steel. Two sets of compact-section specimens with relatively low (Set A) or high (Set B) warping stiffness were prepared and tested under uniform moment loading. Laterally unbraced lengths of the test specimens were controlled such that inelastic LTB could be induced. All specimens exhibited LTB strength exceeding the minimum limit required by current provisions by a sufficient margin. Moreover, some specimen in Set A reached a rotation capacity required for plastic design, although its laterally unbraced length belonged to the inelastic LTB range. All the test results indicated that extrapolation of current provisions to high-strength steel is conservative. In order to further analyze the test results, the relationship between inelastic moment and laterally unbraced length was also derived in explicit form for both ordinary- and high-strength steel based on the effective tangent modulus of inelastic section. The analytical relationship derived again showed that extrapolation of current laterally unbraced length limit leads to a conservative design in the case of high-strength steel and that the laterally unbraced length to control the inelastic LTB behavior of high-strength steel beam should be specified by including its unique post-yield strain-hardening characteristics.

Effectiveness of MDCT for the Followup of CABG Patients with LIMA to LAD and Saphenous Veins to Others (좌내흉동맥과 복재정맥편을 사용한 관상동맥우회로술 환자에서의 추적조사에서 MDCT의 유용성)

  • Kang Joon Kyu;Kim Hyung Tai;Park In Duk;Chung Young Mi;Lee Cheol Joo
    • Journal of Chest Surgery
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    • v.38 no.6 s.251
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    • pp.410-414
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    • 2005
  • There are several options for choosing a graft in CABG, we routinely chose LIMA for LAD and great saphenous vein for other target vessels. To evaluate the posoperative graft patency, we have studied the results using a 16 slices multi-detector computed tomography. Material and Method: From 1995 to 2003, 80 CABG patients who did not complain any event of MACE have been examined by 16-MDCT, mostly in an out patient clinic. Result: There were 61 men and 19 women. MDCT was used as early as 7 days to 9 years post-operatively with a median follow-up period of 6.5 years, and mean follow-up peiod of $31.5\pm25.4$ months. Mean age was $58.4\pm12.6$ years old in men and $61.5\pm17.2$ years old in women. 72180 patients received LIMA to LAD, and all other patients received vein grafts for bypass. The target vessel of vein grafts were 8 in LAD, 47 in RCA, 60 in diagonals, and 61 in obtuse marginals. Among them 42 sequential anastomoses were performed. The mean graft number was $3.1\pm1.8$ grafts. 5 year graft patency rate of each grafts was as followings; $93.1\%$ in LIMA to LAD, $94.9\%$ in vein to diagonals, $92.1\%$ in vein to obtuse marginals, and $79.2\%$ in vein to RCA. Sequential grafting showed better graft patency than the isolated grafting $(95.2\%\;vs\;78.7\~95.0\%)$. Conclusion: In this study, CABG with LIMA and saphenous veins showed satisfactory longterm results. 16-MDCT provided good images for follow-up study after CABG. Additionally, as radiologic tools (64-MDCT, MRI) improve more in the future, they can be used for diagnosing preoperative anatomical coronary disease as well as cardiac functions.

Effect of Modified Ultrafiltration on the Postoperative State after Pediatric Open Heart Surgery. (소아 개심술에 있어서 변형 초여과법(Modified Ultrafiltration)이 술후 상태에 미치는 영향)

  • 방종경;천종록;김규태
    • Journal of Chest Surgery
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    • v.31 no.5
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    • pp.456-465
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    • 1998
  • Cardiopulmonary bypass(CPB) in children is associated with the accumulation of body water after cardiac operation, as a consequence of an inflammatory capillary leak. Following work by Elliott in 1991, modified ultrafiltration(MUF) was introduced after bypass as a means of hemoconcentrating patients and a potential way of removing water from the tissues. We have carried out a prospective randomized study of 20 children undergoing open heart surgery, comparing MUF with nonfiltered controls. MUF was carried out for a mean of 18.9 minutes after completion of CPB to a hematocrit of 37.1%(mean). The mean water volulme removed by the ultrafiltration was 38.4 ml/kg and the mean blood volume retransfused from the oxygenator during the ultrafiltration was 32.1 ml/kg. Fluid balance, hemodynamics, hematocrit, osmolarity and dosage of drug treatment were recorded for 4∼12 hours postoperatively. The results were analyzed using Student t-test and ANOVA, comparing controls(n=10) to MUF(n=10). Blood loss(ml/kg/24hr) was 14.5(mean) in MUF versus 13.7 in controls; blood transfused(ml/kg/24hr) 6.6 in MUF versus 15.2 in controls; plasma transfused(ml/kg/24hr) 65.7 in MUF versus 59.6 in controls. There was rise in arterial blood pressure and hematocrit during MUF. Percent rise of systolic blood pressure was 28.8% in MUF versus 18.7% in controls(p=0.366); percent rise of diastolic blood pressure was 28.8% in MUF versus 8.5% in controls(p=0.135); and percent rise of mean blood pressure was 36.2% in MUF versus 8.2% in controls (p=0.086). Percent rise of hematocrit was 40.0% in MUF versus 23.5% in controls(p=0.002). There was no significant difference in the inotropic requirement and the postoperative serum osmolarity between two groups. The number of days on the ventilator, the duration of stay in the intensive care unit, and the postoperative hospital stay were not significantly different between the two groups.

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Efficiency of Staging Work-Ups in the Evaluation of Carcinoma of the Uterine Cervix (자궁경부암에 있어서 병기결정을 위한 검사의 효용성)

  • Kim, Jae-Sung;Ha, Sung-Whan
    • Radiation Oncology Journal
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    • v.9 no.2
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    • pp.271-276
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    • 1991
  • A series of 510 patients with carcinoma of the uterine cervix given the curative radiation therapy from March 1979 through December 1986 was evaluated to determine the value of intravenous pyelography (IVP), cystoscopy, sigmoidoscopy, and abdomino-pelvic CT as staging work-up prior to treatment. On IVP and cystoscopy, $10.7\%$(49/456) and $5.3\%$(24/452) showed abnormality, respectively, but only $0.7\%$(3/413) did on sigmoidoscopy. As a result of these work-ups prerequisite to FIGO staging, twenty six ($5.1\%$) out of 510 patients were upstaged from the stage determined by the findings of physical examination alone. The proportions of upstaging in each stage were as follows; none in stage IB (35), IIA (89) and IIIA (8), $7.9\%$(20/252) in stage IIB (14 patients to FIGO stage IIIB, 6 patients to FIGO stage IVA), and $4.8\%$(6/126) in stage IIIB (all to FIGO stage IVA). Positive findings of staging work-ups were found only in patients with advanced stages of stage IIB or over determined by physical examination alone but not in those with earlier stages. CT was performed in 337 patients. CT detected pelvic lymph node (LN) enlargement in $25.2\%$ (85/337) and paraaortic LN enlargement in $7.4\%$(25/337). Pelvic LN positivity was well correlated with increasing stage but paraaortic LN positivity was not. In the evaluation of parametrial involvement, CT findings were in accordance with those of physical examination only in $65.6\%$ (442/674). When compared with endoscopic studeies, CT had much lower positive predictive value than negative predicitive value in the evaluation of adjacent organ invasion. The staging work-ups should be individualized by the disease extent of each patient, and then the efficiency of work-uus may be increased without compromising the appropriate FIGO staging and treatment.

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The Assessment on Health Status of Workers by using HPLP and Sa-sang Constitutional Questionnaire (HPLP와 사상체질설문(四象體質說問)을 이용(利用)한 근로자(勤勞者)들의 건강상태(健康狀態) 평가(評價))

  • Choi Mun-Il;Lee Eun-Kyoung;Kwon So-Hee;Ko Kwang-Jae;Seo Byeong-Yun;Jeoung Jae-Yeal;Jahng Doo-Sub;Song Yung-Sun;Lee Ki-Nam
    • Journal of Society of Preventive Korean Medicine
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    • v.5 no.1
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    • pp.41-56
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    • 2001
  • Overview: The purpose of this study was to evaluate the determinants on the correlation between constitution and health promoting lifestyle profile on the workers. Also, the questionnaire on the HPLP (health promoting lifestyle profile) of Walker(1987) and Sa-sang constitution of Lee(l894) were utilized Methods: Data from a representative sample of 652 workers were analyzed Pearson's chi-square test analysis was utilized to test the explanatory causal model and to determine the direct and indirect effects of independent variables on quality of life. Results: Constitutional distribution among exposed group, were Tae-eum In(43.7%), So-eum In(33.6%), and So-yang In(22.7%). The degree of the subjects practicing health promoting lifestyle, on a scale of 1 to 4, is an average of 2.62, personal relations 2.94, self-realization 2.86, stress management 2.71, nutrition 2.68, responsibility for health 2.37, and exercise 2.21, with personal relations earning the highest points and exercise the lowest As for factors influencing health promoting lifestyle, there is significant difference between sex and age. That is female and higher age. On the difference between constitution and health promoting lifestyle, Tae-eum In is the highest all area except personal relations. So-eum In is the lowest all area except responsibility for health. Conclusions: Tae-eum In totally do health promoting lifestyle well but So-eum In relatively not. On the Study we used the HPLP(health promoting lifestyle profile) on the premise that each person's daily life, the attitude and the practice level to the health have an influence on the health. So in the constitution there is a little differences in the consideration and the practice level and health condition will be different. On this study we finish up by knowing about the health promoting lifestyle. But on next time we will have to go on studying about the sign and the comparison with the result of western and oriental medical health examination to the each constitution on carrying out continuously oriental medical health examination.

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Analysis of Palivizumab Prophylaxis in Patients with Acute Lower Respiratory Tract Infection Caused by Respiratory Syncytial Virus (Respiratory syncytial virus로 인한 급성 하기도 감염 입원 환자에서 Palivizumab 예방요법 유무에 따른 비교 분석)

  • Min, Sung Ju;Song, Jung Sook;Choi, Jang Hwan;Seon, Han Su;Kang, Eun Kyeong;Kim, Do Hyun;Kim, Hee Sup
    • Pediatric Infection and Vaccine
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    • v.18 no.2
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    • pp.154-162
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    • 2011
  • Purpose : The aim of this study was to identify the clinical characteristics of lower respiratory tract infection due to respiratory syncytial virus (RSV) in young children and to provide information for an effective guideline for palivizumab administration in Korea. Methods : We reviewed medical charts of 167 patients under 3 years of age who were hospitalized in Dongguk University Ilsan Hospital for lower respiratory tract infection between January 2007 and February 2011. Diagnosis of the virus was made based on the multiplex real time polymerase chain reaction. Results : There were 113 patients who were infected by respiratory syncytial virus. 90 patients were term infants and 23 patients were preterm infants. No difference was shown between term and preterm infants except the days of admission which was 9.0${\pm}$6.0 days and 12.6${\pm}$21.0 days respectively. In the preterm group their mean age at the time of admission was 5.21${\pm}$4.9 months and the mean gestational age was 33.1${\pm}$4.3 weeks, and the mean birth weight was 2,152${\pm}$950 g. Only 4 patients were born under 28 weeks gestational age and were candidates for palivizumab administration. Conclusion : Most of the patients with severe RSV lower respiratory tract infection were term or near term infants who were not candidates for palivizumab prophylaxis. A nationwide study is needed to make a new risk stratified guideline for RSV prophylaxis for our country.

Assessment of Hyperperfusion by Brain Perfusion SPECT in Transient Neurological Deterioration after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis Surgery (천측두동맥-중대뇌동맥 문합술 후 발생한 일과성 신경학적 악화에서 뇌관류 SPECT를 이용한 과관류 평가)

  • Lee, Jeong-Won;Kim, Yu-Kyeong;Lee, Sang-Mi;Eo, Jae-Sun;Oh, Chang-Wan;Lee, Won-Woo;Paeng, Jin-Chul;Kim, Sang-Eun
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.4
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    • pp.267-274
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    • 2008
  • Purpose: Transient neurological deterioration (TND) is one of the complications after extracranial-intracranial bypass surgery, and it has been assumed to be caused by postoperative transient hyperperfusion. This study was performed to evaluate the relationship between TND and preoperative and postoperative cerebral perfusion status on brain perfusion SPECT following superficial temporal artery - middle cerebral artery (STA-MCA) anastomosis surgery. Materials and Methods: A total of 60 STA-MCA anastomosis surgeries of 56 patients (mean age: $50{\pm}16$ yrs; M:F=29:27; atherosclerotic disease: 33, moyamoya disease: 27) which were done between September 2003 and July 2006 were enrolled. The resting cerebral perfusion and cerebral vascular reserve (CVR) after acetazolamide challenge were measured before and 10 days after surgery using 99mTc-ethylcysteinate dimer (ECD) SPECT. Moreover, the cerebral perfusion was measured on the third postoperative day. With the use of the statistical parametric mapping and probabilistic brain atlas, the counts for the middle cerebral artery (MCA) territory were calculated for each image, and statistical analyses were performed. Results: In 6 of 60 cases (10%), TND occurred after surgery. In all patients, the preoperative cerebral perfusion of affected MCA territory was significantly lower than that of contralateral side (p=0.002). The cerebral perfusion on the third and tenth day after surgery was significantly higher than preoperative cerebral perfusion (p=0.001, p=0.02). In TND patients, basal cerebral perfusion and CVR on preoperative SPECT were significantly lower than those of non-TND patients (p=0.01, p=0.05). Further, the increases in cerebral perfusion on the third day after surgery were significant higher than those in other patients (p=0.008). In patients with TND, the cerebral perfusion ratio of affected side to contralateral side on third postoperative day was significantly higher than that of other patients (p=0.002). However, there was no significant difference of the cerebral perfusion ratio on preoperative and tenth postoperative day between patients with TND and other patients. Conclusion: In patients with TND, relative and moderate hyperperfusion was observed in affected side after bypass surgery. These finding may help to understand the pathophysiology of TND.