25,148 research outputs found
Seung-Min Mo
No full text학위논문(석사)--아주대학교 일반대학원 :산업공학과,2010. 2본 연구의 목적은 표면 근전도를 사용하여 동적인 반복 한손 작업에 대하여 주파수와 에너지의 추이를 분석하는 것이다. 실험에 참여한 피실험자는 20대 남성으로서 총 15명이었으며 전면삼각근, 후면삼각근, 상부승모근 총 3근육의 표면 근전도 신호를 측정하였다. 한손 작업에 영향을 미치는 인자로서 중량, 빈도, 거리의 인자들을 고려하였으며, 완전요인설계(33) 실험으로 주효과 및 교호 작용을 파악하였다. 본 연구에서 고려한 객관적 종속변수로서는 1) 순간평균주파수(IMNF; Instantaneous Mean Power Frequency), 2) 에너지(Energy), 3) 순간평균주파수 기울기, 4) 에너지 기울기이며 주관적 종속변수는 100mm의 VAS(Visual Analog Scale)를 사용한 주관적 피로도이다. 지속시간이 길며 주기적으로 발생하는 근전도 신호에 대하여 처음, 중간, 마지막 주기를 구분하여 신호를 분할하였으며, 각 구간에 대해 Continuous wavelet transform으로 신호처리 하여 Time-Frequency 분석을 하였다. 전반적으로 객관적인 종속변수에 대하여 인자별 분산분석 결과, 모든 근육에서 인자의 수준 증가에 따라 주파수는 감소하였으며, 에너지는 증가하였다. 또한 주파수 기울기도 감소하였으며, 에너지 기울기는 유의한 차이를 나타내지 않았다. 이러한 주파수와 에너지의 변화추이는 기존 선행연구들과 동일한 결과였으며, 지속시간이 길며 주기적으로 근력의 변화가 발생하는 동작에 대하여 근전도 신호를 처리하는 적절한 방법을 제안할 수 있었다. 나아가 한손 작업에 영향을 미치는 인자들과 작업부하의 관계를 세밀하게 규명하여 중량, 빈도, 거리 3가지 인자들이 피로에 미치는 관계를 정량적인 데이터와 함께 3차원 형태의 모델로서 제시할 수 있을 것이다.국문 요약 iv
목 차 v
표 목차 vi
그림 목차 vii
제 1 장 서론 1
제 2 장 문헌 조사 6
제 1 절 한손 수동물자취급 가이드라인 6
제 2 절 한손 취급 작업 10
제 3 절 반복적인 동적 근수축의 근전도 20
제 3 장 실험 방법 30
제 1 절 피실험자 30
제 2 절 실험계획 31
제 3 절 실험장비 34
제 4 절 데이터 검출 35
제 5 절 실험절차 36
제 6 절 신호처리 및 통계분석 39
제 4 장 결과 41
제 1 절 객관적인 종속변수 41
제 2 절 주관적인 종속변수 80
제 5 장 결론 및 검토 84
참고 문헌 92
Abstract 101Maste
Biofouling studies on reverse osmosis desalination of hypersaline waters
No full textBiological fouling of reverse osmosis (RO) membranes is affected by many factors, and it is not clearly understood, especially with respect to hypersaline waters. Biofouling minimisation requires understanding of the fundamentals of the biofilm development. It is also necessary to monitor biofilm development at various stages and its relation to concentration polarisation phenomena. The two main goals were to explore the biological diversity of a hypersaline lake called "Qabar-Onn"t located in the Sahara; and to better understand what biotic and abiotic factors govem biofouling of RO membranes treating hypersaline waters. Three halotolerant bacteria] strains (Euhalothece species, BAAOOl and BAA002, and Halomonas pantelleriensis species, BAA003) were isolated from the lake using conventional culturing methods, and were identified based on 16S rRNA sequencing. Two isolated species, Eukalothece species BAAOOI and Halomonas pantelleriensis species BAA003 were used as model microorganisms to evaluate the potential of biofilm development on RO membranes. Salinity and surface roughness, which affect biofilm initiation and growth, were investigated. A novel, in-situ monitoring device was used to detect initiation of biofilm formation, and its relation to solutes and concentrations near RO membrane surfaces. The results showed that Qabar-Onn Lake is inhabited by a wide range of microorganisms, which seem to have a strong potential to adapt to the rapid increase in the lake salinity. In addition to salinity, pH also is limiting factor on biodiversity and microorganisms' dominance. Biofouling was strongly controlled by membrane characteristics and feed salinity. Lower surface roughness and low salinity contributed to less biofilm formation. Furthermore, the absence of monovalent anions (i. e. chloride) in the feed enhanced flux at low salinities; however, its absence severely decreased flux at higher salinities. Similarly, microorganisms present in the feed extremely enhanced the permeate flux at low salinities, however, at high salinities the flux decreased in the presence of microorganisms
C-arm cone-beam CT virtual navigation-guided percutaneous mediastinal mass biopsy: Diagnostic accuracy and complications
No full textTo assess the usefulness of C-arm cone-beam computed tomography (CBCT) virtual navigation-guided percutaneous mediastinal mass biopsy in terms of diagnostic accuracy and complication rates. Seventy-eight CBCT virtual navigation-guided percutaneous mediastinal mass biopsies were performed in 75 patients (M:F, 38:37; mean age, 48.55 +/- 18.76 years). The procedural details, diagnostic sensitivity, specificity, accuracy and complication rate were investigated. Mean lesion size was 6.80 +/- 3.08 cm, skin-to-target distance was 3.67 +/- 1.80 cm, core needle biopsy rate was 96.2 % (75/78), needle indwelling time was 9.29 +/- 4.34 min, total procedure time was 13.26 +/- 5.29 min, number of biopsy specimens obtained was 3.13 +/- 1.02, number of CBCTs performed was 3.03 +/- 0.68, rate of lesion border discrimination from abutting mediastinal structures on CBCT was 26.9 % (21/78), technical success rate was 100 % (78/78), estimated effective dose was 5.33 +/- 4.99 mSv, and the dose area product was 12,723.68 +/- 10,665.74 mGya <...cm(2). Among the 78 biopsies, 69 were malignant, 7 were benign and 2 were indeterminate. Diagnostic sensitivity, specificity and accuracy for the diagnosis of malignancies were 97.1 % (67/69), 100 % (7/7) and 97.4 % (74/76), respectively, with a complication rate of 3.85 % (3/78), all of which were small pneumothoraces. CBCT virtual navigation-guided biopsy is a highly accurate and safe procedure for the evaluation of mediastinal lesions. aEuro cent CBCT virtual navigation-guided percutaneous mediastinal biopsy is highly accurate aEuro cent CBCT virtual navigation-guided percutaneous mediastinal biopsy is a safe procedure aEuro cent Mediastinal vascular injury can be avoided under CBCT virtual navigation guidance.N
Percutaneous transthoracic needle biopsy of small (a parts per thousand currency sign1 cm) lung nodules under C-arm cone-beam CT virtual navigation guidance
No full textTo describe our initial experience with percutaneous transthoracic needle biopsy (PCNB) of small (a parts per thousand currency sign1 cm) lung nodules using a cone-beam computed tomography (CBCT) virtual navigation guidance system in 105 consecutive patients. One hundred and five consecutive patients (55 male, 50 female; mean age, 62 years) with 107 small (a parts per thousand currency sign1 cm) lung nodules (mean size, 0.85 cm +/- 0.14) underwent PCNBs under CBCT virtual-navigation guidance system and constituted our study population. Procedural details-including radiation dose, sensitivity, specificity, diagnostic accuracy and complication rates of CBCT virtual navigation guided PCNBs-were described. The mean number of pleural passages with the coaxial needle, biopsies, CT acquisitions, total procedure time, coaxial introducer dwelling time, and estimated radiation exposure during PCNBs were 1.03 +/- 0.21, 3.1 +/- 0.7, 3.4 +/- 1.3, 10.5 min +/- 3.2 and 7.2 min +/- 2.5, and 5.72 mSv +/- 4.19, respectively. Sixty nodules (56.1 %) were diagnosed as malignant, 38 (35.5 %) as benign and nine (8.4 %) as indeterminate. The sensitivity, specificity, and diagnostic accuracy of CBCT virtual-navigation-guided PCNB for small (a parts per thousand currency sign1 cm) nodules were 96.7 % (58/60), 100 % (38/38) and 98.0 % (96/98), respectively. Complications occurred in 13 (12.1 %) cases; pneumothorax in seven (6.5 %) and haemoptysis in six (5.6 %). CBCT virtual-navigation-guided PCNB is a highly accurate and safe diagnostic method for small (a parts per thousand currency sign1 cm) nodules.N
DataSheet1_Effect of solution pH, precursor ratio, agitation and temperature on Ni-Mo and Ni-Mo-O electrodeposits from ammonium citrate baths.docx
No full textThe induced co-electrodeposition of Ni and Mo is a complex process, where metallic Ni-Mo alloys and Ni-Mo-O composites can originate from the complete and partial reduction of Mo respectively. By adjusting electrolyte compositions and electrodeposition parameters, various metallic, metal/oxide composite, and oxide thin films of Ni-Mo and Ni-Mo-O were electrodeposited from ammonium citrate baths. Ni-ammonia complexes, which play a critical role in promoting the deposition of metallic Ni-Mo alloys, were enhanced at alkaline pH (i.e., 8–10) and lower temperature (i.e., 25–45°C). Moreover, the electrochemical reduction of Ni is under mass transfer limitation, so the deposited Mo content decreased with increasing agitation. On the other hand, higher Mo content can be achieved by relatively higher citrate concentration and larger Mo-to-Ni precursor molar ratio. However, a critical molar ratio of metal precursor resulted in transition from alloy to composite due to Ni inducing the reduction of Mo.</p
Cone-beam CT virtual navigation-guided percutaneous needle biopsy of suspicious pleural metastasis: A pilot study
No full textObjective: To evaluate the diagnostic performance of cone-beam computed tomography (CBCT) virtual navigation-guided percutaneous pleural biopsy for suspected malignant pleural disease. Materials and Methods: This study enrolled 59 patients (31 males and 28 females; mean age, 63.4 years) with suspected malignant pleural disease diagnosed with CBCT from December 2010 to December 2016. Sixty-three CBCT-guided biopsies were performed using a coaxial system with 18- or 20-gauge cutting needles. Procedural details, diagnostic performance, radiation exposure, and complication rates were investigated. Results: The mean diameter perpendicular to the pleura of 51 focal and 12 diffuse pleural lesions was 1.53 +/- 0.76 cm. The mean distance from the skin to the target was 3.40 +/- 1.51 cm. Mean numbers of CT acquisitions and biopsies were 3.21 +/- 0.57 and 3.05 +/- 1.54. Total procedure time and coaxial introducer indwelling time were 11.87 +/- 5.59 min and 8.78 +/- 4.95 min, respectively. The mean dose area product was 12013.61 +/- 7969.59 mGym(2). There were 48 malignant, 10 benign, and 5 indeterminate lesions. Sensitivity, specificity, and diagnostic accuracy were 93.8% (45/48), 100% (10/10), and 94.8% (55/58), respectively. Positive and negative predictive values for malignancy were 100% (45/45) and 76.9% (10/13), respectively. Four patients (6.8%) with benign pathology during initial biopsy but still showing a high suspicion of malignancy underwent repeat biopsy and three of them were finally diagnosed with malignant pleural disease. There were three cases of minimal pneumothorax and no grave procedure-related complications. Conclusion: Cone-beam computed tomography-guided biopsy is an accurate and safe diagnostic technique for suspected malignant pleural lesion with reasonable radiation exposure and procedure time.Y
Evaluation of T categories for pure ground-glass nodules with semi-automatic volumetry: is mass a better predictor of invasive part size than other volumetric parameters?
No full textObjectivesThis study aimed to investigate the diagnostic advantage of nodule mass in differentiating invasive pulmonary adenocarcinomas (IPAs) among pure ground-glass nodules (pGGNs) over other volumetric measurements. Another aim of this study was to analyse the correlation between volumetric measurements on computed tomography (CT) scans and the pathological invasive component size.MethodsThis Institutional Review Board-approved retrospective study included 117 patients (men:women = 53:64; mean age, 57.3 years) with 117 pGGNs. Semi-automatic segmentation was performed for all nodules, and volumetric measurements, such as nodule volume, attenuation, mass, two-dimensional (2D) average diameter and three-dimensional (3D) longest diameter, were obtained. Receiver operating characteristic (ROC) curve analyses were performed to evaluate the diagnostic performances of the volumetric parameters in discriminating IPAs. Spearman correlation coefficients were calculated between the volumetric measurements and the invasive component size.ResultsArea under the ROC curve for mass was 0.792 (95% CI, 0.691-0.872) in non-enhanced CT and 0.730 (95% CI, 0.607-0.832) in contrast-enhanced CT. Nodule mass was not superior to 2D average diameter for the differentiation of IPAs in both non-enhanced (0.792 vs 0.780; p = 0.501) CT and contrast-enhanced CT scans (0.730 vs 0.700; p = 0.319). The correlation between the volumetric measurements (mass, 3D longest diameter and 2D average diameter) and the invasive component size was moderate (Spearman's rho, 0.401-0.422) in non-enhanced CT and weak (Spearman's rho, 0.276-0.310) in contrast-enhanced CT.ConclusionsNodule mass measurement had no strength over other volumetric parameters for the prediction of pathological invasiveness in the diagnosis of pGGNs.Key Points center dot Mass is not superior to other volumetric measurements for the diagnosis of pure ground-glass nodules.center dot Mass and two-dimensional average diameter exhibited comparable performance for the discrimination of invasive adenocarcinomas among pure ground-glass nodules.center dot The diagnostic performance of volumetric measurements was lower on contrast-enhanced CT scans.center dot The correlation between the volumetric measurements and the invasive component size was moderate on non-enhanced CT scans and weak on contrast-enhanced CT scans.N
Proceedings of the Colored People's Educational Convention held in Jefferson City, Missouri, January , 1870.
No full text1870 Missouri State Colored People's Educational Convention held in Jefferson Cityhttp://coloredconventions.org/items/show/30
Electronic structures of Mo pyrochlore: R2Mo2O7 (R=Nd, sm)
No full textThe electronic structures of Mo pyrochlore systems of R2Mo2O7 (R=Nd, Sm) have been investigated using photoemission spectroscopy (PES). The electronic states near E-F have mainly Mo 4d character. The R 4f states are located well below the Fermi level and the valence states of bulk Nd and Sm ions are very close to 3+. The local spin density approximation (LSDA) and LSDA+U+spin-orbit (SO) band calculations incorporating the effects of the on-site Coulomb correlation U and the SO interaction of Nd 4f electrons show the large hybridization between the Mo 4d and O 2p orbitals and the magnetic moment of similar to1.0mu(B) per Mo atom. The qualitative features of the measured valence-band PES spectra of Nd2Mo2O7 agree well with the LSDA+U+SO band structure calculation. The origin of the stable ferromagnetic phase in Nd2Mo2O7 has been discussed based on the nearly half-metallic electronic structure.open1116sciescopu
Percutaneous transthoracic localization of pulmonary nodules under C-arm cone-beam CT virtual navigation guidance
No full textPURPOSEWe aimed to describe our initial experience with percutaneous transthoracic localization (PTL) of pulmonary nodules using a C-arm cone-beam CT (CBCT) virtual navigation guidance system.METHODSFrom February 2013 to March 2014, 79 consecutive patients (mean age, 61±10 years) with 81 solid or ground-glass nodules (mean size, 12.36±7.21 mm; range, 4.8–25 mm) underwent PTLs prior to video-assisted thoracoscopic surgery (VATS) excision under CBCT virtual navigation guidance using lipiodol (mean volume, 0.18±0.04 mL). Their procedural details, radiation dose, and complication rates were described.RESULTSAll 81 target nodules were successfully localized within 10 mm (mean distance, 2.54±3.24 mm) from the lipiodol markings. Mean number of CT acquisitions was 3.2±0.7, total procedure time was 14.6±5.14 min, and estimated radiation exposure during the localization was 5.21±2.51 mSv. Postprocedural complications occurred in 14 cases (17.3%); complications were minimal pneumothorax (n=10, 12.3%), parenchymal hemorrhage (n=3, 3.7%), and a small amount of hemoptysis (n=1, 1.2%). All target nodules were completely resected; pathologic diagnosis included invasive adenocarcinoma (n=53), adenocarcinoma-in-situ (n=10), atypical adenomatous hyperplasia (n=4), metastasis (n=7), and benign lesions (n=7).CONCLUSIONPTL procedures can be performed safely and accurately under the guidance of a CBCT virtual navigation system
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