• Title/Summary/Keyword: Transformation methods

Search Result 1,391, Processing Time 0.029 seconds

Comparison of Recurrence Rates with Contour-Loop Excision of the Transformation Zone (C-LETZ) and Large Loop Excision of the Transformation Zone (LLETZ) for CIN

  • Boonlikit, Sathone;Srichongchai, Hemwadee
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.15
    • /
    • pp.6005-6008
    • /
    • 2014
  • Aim: To compare recurrence rates of large loop excision of the transformation zone (LLETZ) with those of contour-loop excision of the transformation zone (C-LETZ) in the management of cervical intraepithelial neoplasia (CIN). Materials and Methods: The medical records of 177 patients treated consecutively by LLETZ and C-LETZ for CIN at Rajavithi Hospital between 2006 and 2009 were retrospectively reviewed. Results: Of the 87 women in the C-LETZ group, 2 cases (2.30%) had recurrence compared with 13 cases (14.4%) of the 90 women in the LLETZ group, the higher recurrence rate in the latter being statistically significant (p<0.05). Median times of follow up in the C-LETZ and LLETZ groups were 12 months and 14 months respectively (p>0.05). The C-LETZ group showed less intraoperative bleeding compared to the LLETZ group, but the rate of achievement of single specimens and positive margins were similar in the two groups. Conclusions: The present study demonstrated the superiority of C-LETZ over LLETZ in terms of efficacy; C-LLETZ is associated with a lower recurrence rate and also carries a smaller risk of intraoperative bleeding than LLETZ. The rotating technique still has a potential role in treating precancerous lesions of the cervix.

Recent trends in tissue culture and genetic transformation of Phalaenopsis (팔레놉시스 조직배양 및 형질전환 최근 연구동향)

  • Roh, Hee-Sun;Lee, Sang-Il;Lee, Yi-Re;Baek, Sun-Young;Kim, Jong-Bo
    • Journal of Plant Biotechnology
    • /
    • v.39 no.4
    • /
    • pp.225-234
    • /
    • 2012
  • This report describes recent advances in tissue culture and genetic transformation of commercial Phalaenopsis. Recently, an importance of Phalaenopsis has been increased due to its popularity with beautiful flowers and is widely used for pot plants as well as cut-flower. Its use is rapidly enlarging in worldwide. Thus, demands for the release of new elite cultivars in Phalaenopsis have been increased. During the last several decades, some critical progresses have been made in tissue culture and genetic transformation in Phalaenopsis species. Cooperation with these biotechnological methods are supposed to promote the release of commercial Phalaenopsis cultivars in the near future. Until now, no technical review on tissue culture and genetic transformation in Phalaenopsis has been reported in Korea. Therefore, we inquired the brief history and techniques of tissue culture system in Korea.

Ageing assessment of zirconia implant prostheses by three different quantitative assessment techniques

  • Kyaw, Phyu Phyu;Pongprueksa, Pong;Anuchitolarn, Warangkana;Sirinukunwatta, Krongkarn;Suputtamongkol, Kallaya
    • The Journal of Advanced Prosthodontics
    • /
    • v.11 no.5
    • /
    • pp.253-261
    • /
    • 2019
  • PURPOSE. To evaluate the influence of cyclic loading on phase transformation of zirconia abutments and to compare the effectiveness of three different quantitative ageing assessment techniques. MATERIALS AND METHODS. Thirty two Y-TZP prostheses fabricated from two brands, InCoris ZI and Ceramill ZI, were cemented to titanium bases and equally divided into two subgroups (n=8): control group without any treatment and aged group with cyclic loading between 20 N and 98 N for 100,000 cycles at 4 Hz in distilled water at $37^{\circ}C$. The tetragonal-to-monoclinic phase transformation was assessed by (i) conventional x-ray diffraction (XRD), (ii) micro x-ray diffraction (${\mu}XRD$), and (iii) micro-Raman spectroscopy. The monoclinic-phase fractions (M%) were compared by two-way ANOVA. RESULTS. InCoris Zi presented significantly higher M% than Ceramill Zi in both control and aged groups (P<.001). Both materials exhibited significant phase transformation with monoclinicphase of 1 to 3% more in aged groups than controls for all three assessment techniques. The comparable M% was quantified by both ${\mu}XRD$ and XRD. The highest M% was assessed with micro-Raman. CONCLUSION. Cyclic loading produced significant phase transformation in tested Y-TZP prostheses. The micro-Raman spectroscopy could be used as an alternative to XRD and ${\mu}XRD$.

Effects of different finishing/polishing protocols and systems for monolithic zirconia on surface topography, phase transformation, and biofilm formation

  • Mai, Hang-Nga;Hong, Su-Hyung;Kim, Sung-Hun;Lee, Du-Hyeong
    • The Journal of Advanced Prosthodontics
    • /
    • v.11 no.2
    • /
    • pp.81-87
    • /
    • 2019
  • PURPOSE. The purpose of this study was to evaluate the effects of various protocols and systems for finishing and polishing monolithic zirconia on surface topography, phase transformation, and bacterial adhesion. MATERIALS AND METHODS. Three hundred monolithic zirconia specimens were fabricated and then treated with three finishing and polishing systems (Jota [JO], Meisinger [ME], and Edenta [ED]) using four surface treatment protocols: coarse finishing alone (C); coarse finishing and medium polishing (CM); coarse finishing and fine polishing (CF); and coarse finishing, medium polishing, and fine polishing (CMF). Surface roughness, crystal phase transformation, and bacterial adhesion were evaluated using atomic force microscopy, X-ray diffraction, and streptococcal biofilm formation assay, respectively. One-way and two-way analysis of variance with Tukey post hoc tests were used to analyze the results (${\alpha}=.05$). RESULTS. In this study, the surface treatment protocols and systems had significant effects on the resulting roughness. The CMF protocol produced the lowest roughness values, followed by CM and CF. Use of the JO system produced the lowest roughness values and the smallest biofilm mass, while the ME system produced the smallest partial transformation ratio. The ED group exhibited the highest roughness values, biofilm mass, and partial transformation ratio. CONCLUSION. Stepwise surface treatment of monolithic zirconia, combined with careful polishing system selection, is essential to obtaining optimal microstructural and biological surface results.

Crosswalk Detection using Feature Vectors in Road Images (특징 벡터를 이용한 도로영상의 횡단보도 검출)

  • Lee, Geun-mo;Park, Soon-Yong
    • The Journal of Korea Robotics Society
    • /
    • v.12 no.2
    • /
    • pp.217-227
    • /
    • 2017
  • Crosswalk detection is an important part of the Pedestrian Protection System in autonomous vehicles. Different methods of crosswalk detection have been introduced so far using crosswalk edge features, the distance between crosswalk blocks, laser scanning, Hough Transformation, and Fourier Transformation. However, most of these methods failed to detect crosswalks accurately, when they are damaged, faded away or partly occluded. Furthermore, these methods face difficulties when applying on real road environment where there are lot of vehicles. In this paper, we solve this problem by first using a region based binarization technique and x-axis histogram to detect the candidate crosswalk areas. Then, we apply Support Vector Machine (SVM) based classification method to decide whether the candidate areas contain a crosswalk or not. Experiment results prove that our method can detect crosswalks in different environment conditions with higher recognition rate even they are faded away or partly occluded.

Frequency-to-time Transformation by a Diffusion Expansion Method (분산 전개법에 의한 주파수-시간 영역 변환)

  • Cho, In-Ky;Kim, Rae-Yeong;Ko, Kwang-Beom;You, Young-June
    • Geophysics and Geophysical Exploration
    • /
    • v.17 no.3
    • /
    • pp.129-136
    • /
    • 2014
  • Electromagnetic (EM) methods are generally divided into frequency-domain EM (FDEM) and time-domain EM (TDEM) methods, depending on the source waveform. The FDEM and TDEM fields are mathematically related by the Fourier transformation, and the TDEM field can thus be obtained as the Fourier transformation of FDEM data. For modeling in time-domain, we can use fast frequency-domain modeling codes and then convert the results to the time domain with a suitable numerical method. Thus, frequency-to-time transformations are of interest to EM methods, which is generally attained through fast Fourier transform. However, faster frequency-to-time transformation is required for the 3D inversion of TDEM data or for the processing of vast air-borne TDEM data. The diffusion expansion method (DEM) is one of smart frequency-to-time transformation methods. In DEM, the EM field is expanded into a sequence of diffusion functions with a known frequency dependence, but with unknown diffusion-times that must be chosen based on the data to be transformed. Especially, accuracy of DEM is sensitive to the diffusion-time. In this study, we developed a method to determine the optimum range of diffusion-time values, minimizing the RMS error of the frequency-domain data approximated by the diffusion expansion. We confirmed that this method produces accurate results over a wider time range for a homogeneous half-space and two-layered model.

The effects of surface grinding and polishing on the phase transformation and flexural strength of zirconia

  • Lee, Ji-Young;Jang, Geun-Won;Park, In-Im;Heo, Yu-Ri;Son, Mee-Kyoung
    • The Journal of Advanced Prosthodontics
    • /
    • v.11 no.1
    • /
    • pp.1-6
    • /
    • 2019
  • PURPOSE. The purpose of this in vitro study was to evaluate the effect of surface grinding and polishing procedures using high speed zirconia diamond burs with different grit sizes on the phase transformation and flexural strength of zirconia. MATERIALS AND METHODS. Forty disc shape specimens ($15{\times}1.25mm$) with a cylindrical projection in the center of each disc ($1{\times}3mm$) were fabricated with 3Y-TZP (Prettau, Zirkonzahn, Italy). The specimens were divided into 4 groups (n=10) according to the grinding and polishing procedures: Control group - grinding (coarse-grit diamond bur), Group 1 - grinding (coarse-grit diamond bur) + polishing, Group 2 - grinding (fine-grit diamond bur) + polishing, and Group 3 - grinding (fine grit diamond bur). Each specimen was analyzed by 3D-OM, XRD analysis, and biaxial flexural strength test. RESULTS. Based on the surface morphology by 3D-OM images, polished specimens showed smoother surface and lower roughness value (Ra). In the result of XRD analysis, partial phase transformation from tetragonal to monoclinic zirconia occurred in all groups. Control group, ground with a coarse grit diamond bur, showed more $t{\rightarrow}m$ phase transformation and lower flexural strength than Groups 1 and 2 significantly. CONCLUSION. The flexural strength in all specimens after grinding and polishing showed over 500 MPa, and those were clinically acceptable. However, grinding with a coarse grit diamond bur without polishing induced the phase transformation and low strength. Therefore, surface polishing is required for the occlusal adjustment using a high speed zirconia diamond bur to reduce the phase transformation and to prevent the decrease of flexural strength of zirconia.

Image Compression by Linear and Nonlinear Transformation of Computed Tomography (전산화단층촬영의 선형과 비선형변환에 의한 영상압축)

  • Park, Jae-Hong;Yoo, Ju-Yeon
    • Journal of the Korean Society of Radiology
    • /
    • v.13 no.4
    • /
    • pp.509-516
    • /
    • 2019
  • In the linear transformation method, the original image is divided into a plurality of range blocks, and a partial transform system for finding an optimal domain block existing in the image for each range block is used to adjust the performance of the compression ratio and the picture quality, The nonlinear transformation method uses only the rotation transformation among eight shuffle transforms. Since the search is performed only in the limited domain block, the coding time is faster than the linear transformation method of searching the domain block for any block in the image, Since the optimal domain block for the range block can not be selected in the image, the performance may be lower than other methods. Therefore, the nonlinear transformation method improves the performance by increasing the approximation degree of the brightness coefficient conversion instead of selecting the optimal domain block, The smaller the size of the block, the higher the PSNR value, The higher the compression ratio is increased groups were quadtree block divided to encode the image at best.

An Enzymolysis-Assisted Agrobacterium tumefaciens-Mediated Transformation Method for the Yeast-Like Cells of Tremella fuciformis

  • Wang, Yuanyuan;Xu, Danyun;Sun, Xueyan;Zheng, Lisheng;Chen, Liguo;Ma, Aimin
    • Mycobiology
    • /
    • v.47 no.1
    • /
    • pp.59-65
    • /
    • 2019
  • Agrobacterium tumefaciens-mediated transformation (ATMT), as a simple and versatile method, achieves successful transformation in the yeast-like cells (YLCs) of Tremella fuciformis with lower efficiency. Establishment of a more efficient transformation system of YLCs is important for functional genomics research and biotechnological application. In this study, an enzymolysis-assisted ATMT method was developed. The degradation degree of YLCs depends on the concentration and digestion time of Lywallzyme. Lower concentration (${\leq}0.1%$) of Lywallzyme was capable of formation of limited wounds on the surface of YLCs and has less influence on their growth. In addition, there is no significant difference of YLCs growth among groups treated with 0.1% Lywallzyme for different time. The binary vector pGEH under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter was utilized to transform the enzymolytic wounded YLCs with different concentrations and digestion time. The results of PCR, Southern blot, quantitative real-time PCR (qRT-PCR) and fluorescence microscopy revealed that the T-DNA was integrated into the YLCs genome, suggesting an efficient enzymolysis-assisted ATMT method of YLCs was established. The highest transformation frequency reached 1200 transformants per $10^6$ YLCs by 0.05% (w/v) Lywallzyme digestion for 15 min, and the transformants were genetically stable. Compared with the mechanical wounding methods, enzymolytic wounding is thought to be a tender, safer and more effective method.

Robust Histogram Equalization Using Compensated Probability Distribution

  • Kim, Sung-Tak;Kim, Hoi-Rin
    • MALSORI
    • /
    • v.55
    • /
    • pp.131-142
    • /
    • 2005
  • A mismatch between the training and the test conditions often causes a drastic decrease in the performance of the speech recognition systems. In this paper, non-linear transformation techniques based on histogram equalization in the acoustic feature space are studied for reducing the mismatched condition. The purpose of histogram equalization(HEQ) is to convert the probability distribution of test speech into the probability distribution of training speech. While conventional histogram equalization methods consider only the probability distribution of a test speech, for noise-corrupted test speech, its probability distribution is also distorted. The transformation function obtained by this distorted probability distribution maybe bring about miss-transformation of feature vectors, and this causes the performance of histogram equalization to decrease. Therefore, this paper proposes a new method of calculating noise-removed probability distribution by using assumption that the CDF of noisy speech feature vectors consists of component of speech feature vectors and component of noise feature vectors, and this compensated probability distribution is used in HEQ process. In the AURORA-2 framework, the proposed method reduced the error rate by over $44\%$ in clean training condition compared to the baseline system. For multi training condition, the proposed methods are also better than the baseline system.

  • PDF