• 제목/요약/키워드: two-stage failure

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Clinicopathological Characteristics of Triple Negative Breast Cancer at a Tertiary Care Hospital in India

  • Dogra, Atika;Doval, Dinesh Chandra;Sardana, Manjula;Chedi, Subhash Kumar;Mehta, Anurag
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권24호
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    • pp.10577-10583
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    • 2015
  • Background: Triple-negative breast cancer (TNBC), characterized by the lack of expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2, is typically associated with a poor prognosis. The majority of TNBCs show the expression of basal markers on gene expression profiling and most authors accept TNBC as basal-like (BL) breast cancer. However, a smaller fraction lacks a BL phenotype despite being TNBC. The literature is silent on non-basal-like (NBL) type of TNBC. The present study was aimed at defining behavioral differences between BL and NBL phenotypes. Objectives: i) Identify the TNBCs and categorize them into BL and NBL breast cancer. ii) Examine the behavioral differences between two subtypes. iii) Observe the pattern of treatment failure among TNBCs. Materials and Methods: All TNBC cases during January 2009-December 2010 were retrieved. The subjects fitting the inclusion criteria of study were differentiated into BL and NBL phenotypes using surrogate immunohistochemistry with three basal markers $34{\beta}E12$, c-Kit and EGFR as per the algorithm defined by Nielsen et al. The detailed data of subjects were collated from clinical records. The comparison of clinicopathological features between two subgroups was done using statistical analyses. The pattern of treatment failure along with its association with prognostic factors was assessed. Results: TNBC constituted 18% of breast cancer cases considered in the study. The BL and NBL subtypes accounted for 81% and 19% respectively of the TNBC group. No statistically significant association was seen between prognostic parameters and two phenotypes. Among patients with treatment failure, 19% were with BL and 15% were with NBL phenotype. The mean disease free survival (DFS) in groups BL and NBL was 30.0 and 37.9 months respectively, while mean overall survival (OS) was 31.93 and 38.5 months respectively. Treatment failure was significantly associated with stage (p=.023) among prognostic factors. Conclusions: Disease stage at presentation is an important prognostic factor influencing the treatment failure and survival among TNBCs. Increasing tumor size is related to lymph node positivity. BL tumors have a more aggressive clinical course than that of NBL as shown by shorter DFS and OS, despite having no statistically significant difference between prognostic parameters. New therapeutic alternatives should be explored for patients with this subtype of breast cancer.

6개월 금연 성공의 영향 요인 연구 - 인천광역시 보건소 금연클리닉을 방문한 흡연자를 중심으로 - (Factors Associated with Success of Smoking Cessation during 6 Months)

  • 이군자;장춘자;김명순;이명희;조영희
    • 대한간호학회지
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    • 제36권5호
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    • pp.742-750
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    • 2006
  • Purpose: This study was to identify which factors are likely to influence the effectiveness of smoking cessation on adults who smoke in Metropolitan Incheon. Method: Data from 9,083 smokers, who visited a smoking cessation clinic of a public health center from Jan. to Oct. 2005, were provided by the Korean Health Research Society, Among 9,083 smokers, 1,495 people were selected for follow up care at 6 months in order to analyze the differences between two groups one is a successful group and the other is a failure group. Results: The successful group included 639 people and the failure group 856 people. In the demographic profiles such as sex, age and motive registration, there was a significant difference between the two groups. In the view of smoking pattern and factors such as the expiratory CO level, the age of starting to smoke, the duration of smoking, alcohol, and dependence on alcohol use and nicotine, there were significant differences between the two groups. The smoking cessation method, results of uni variate analysis, the total number of visits to the smoking cessation clinics, and the use of nicotine gum or a patch(stage 1, stage 2) were significantly different in the two groups. Conclusion: The results of multi variate analysis have shown that the factors associated with the success for smoking cessation is the total number of visits to the smoking cessation clinic, and the dependence on alcohol.

Denoising Based on the Adaptive Lifting

  • Lee, Chang-Soo;Yoo, Kyung-Yul
    • The Journal of the Acoustical Society of Korea
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    • 제18권1E호
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    • pp.13-19
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    • 1999
  • This paper introduces an adaptive wavelet transform based on the lifting scheme, which is applied to signal denoising. The wavelet representation using orthogonal wavelet bases has received widespread attention. Recently the lifting scheme has been developed for the construction of biorthogonal wavelets in the spatial domain. Wavelet transforms are performed through three stages: the first stage or Lazy wavelet splits the data into two subsets, even and odd, the second stage calculates the wavelet coefficients (highpass) as the failure to interpolate or predict the odd set using the even, and the third stage updates the even set using neighboring odd points (wavelet coefficients) to compute the scaling function coefficients (lowpass). In this paper, we adaptively find some of the prediction coefficients for better representation of signals and this customizes wavelet transforms to provide an efficient framework for denoising. Special care has been given to the boundaries, where we design a set of different prediction coefficients to reduce the prediction error.

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Maximum standardized uptake value at pre-treatment PET in estimating lung cancer progression after stereotactic body radiotherapy

  • Park, Jisun;Choi, Yunseon;Ahn, Ki Jung;Park, Sung Kwang;Cho, Heunglae;Lee, Ji Young
    • Radiation Oncology Journal
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    • 제37권1호
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    • pp.30-36
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    • 2019
  • Purpose: This study aimed to identify the feasibility of the maximum standardized uptake value (SUVmax) on baseline 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) as a predictive factor for prognosis in early stage primary lung cancer treated with stereotactic body radiotherapy (SBRT). Materials and Methods: Twenty-seven T1-3N0M0 primary lung cancer patients treated with curative SBRT between 2010 and 2018 were retrospectively evaluated. Four patients (14.8%) treated with SBRT to address residual tumor after wedge resection and one patient (3.7%) with local recurrence after resection were included. The SUVmax at baseline PET/CT was assessed to determine its relationship with prognosis after SBRT. Patients were divided into two groups based on maximum SUVmax on pre-treatment FDG PET/CT, estimated by receiver operating characteristic curve. Results: The median follow-up period was 17.7 months (range, 2.3 to 60.0 months). The actuarial 2-year local control, progression-free survival (PFS), and overall survival were 80.4%, 66.0%, and 78.2%, respectively. With regard to failure patterns, 5 patients exhibited local failure (in-field failure, 18.5%), 1 (3.7%) experienced regional nodal relapse, and other 2 (7.4%) developed distant failure. SUVmax was significantly correlated with progression (p = 0.08, optimal cut-off point SUVmax > 5.1). PFS was significantly influenced by pretreatment SUVmax (SUVmax > 5.1 vs. SUVmax ≤ 5.1; p = 0.012) and T stage (T1 vs. T2-3; p = 0.012). Conclusion: SUVmax at pre-treatment FDG PET/CT demonstrated a predictive value for PFS after SBRT for lung cancer.

스크래치 시험을 통한 DLC 박막 파손과 밀착 특성 평가 (Evaluation of Failure Modes and Adhesion of DLC Films by Scratch Test)

  • 김주희;박찬형;안효석
    • Tribology and Lubricants
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    • 제33권4호
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    • pp.127-133
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    • 2017
  • In order to characterize the adhesive properties and failure mechanisms of diamond-like carbon (DLC) films of two different thicknesses (130 nm and $1.2{\mu}m$), deposited by plasma-enhanced chemical vapor deposition on a Si substrate, scratch testing with a micro-indenter ($12.5{\mu}m$ tip radius) was performed under a linearly increasing load. These scratch tests were conducted under the same test conditions for both films. The critical load of each film was estimated from the scratch test results, based on a sharp increase in the coefficient of friction and a clear distinction of failure modes. The critical load was the basis for evaluating the adhesion strength of the films, and the $1.2{\mu}m-thick$ DLC film had superior adhesion strength. For better understanding of the failure modes, the following analyses were conducted: friction behavior and scratch tracks analysis using scanning electron microscopy, energy-dispersive spectroscopy, and 3-D profilometry. The scratch test results showed that failure modes were related to the thickness of the films. The 130 nm-thick DLC film underwent cohesive failure modes (cracks and chipping) before reaching to a gross failure stage. On the other hand, the thicker DLC film ($1.2{\mu}m-thick$) did not exhibit micro cracks before a sudden gross failure of the film together with the evidence of cracking and chipping of the Si substrate.

Failure characteristics and mechanical mechanism of study on red sandstone with combined defects

  • Chen, Bing;Xia, Zhiguo;Xu, Yadong;Liu, Shuai;Liu, Xingzong
    • Geomechanics and Engineering
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    • 제24권2호
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    • pp.179-191
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    • 2021
  • In this study, the strength and failure mechanism of red sandstones with combined defects were investigated by uniaxial compression tests on red sandstones with different crack angles using two-dimensional particle flow code numerical software, and their mechanical parameters and failure process were studied and analyzed. The results showed that the mechanical characteristics such as peak strength, peak strain, and elastic modulus of the samples with prefabricated combined defects were significantly inferior than those of the intact samples. With increasing crack angle from 15° to 60°, the weakening area of cracks increased, elastic modulus, peak strength, and peak strain gradually reduced, the total number of cracks increased, and more strain energy was released. In addition, the samples underwent initial brittle failure to plastic failure stage, and the failure form was more significant, leading to peeling phenomenon. However, with increasing crack angle from 75° to 90°, the crack-hole combination shared the stress concentration at the tip of the crack-crack combination, resulted in a gradual increase in elastic modulus, peak strain and peak strength, but a decrease in the number of total cracks, the release of strain energy reduced, the plastic failure state weakened, and the spalling phenomenon slowed down. On this basis, the samples with 30° and 45° crack-crack combination were selected for further experimental investigation. Through comparative analysis between the experimental and simulation results, the failure strength and final failure mode with cracks propagation of samples were found to be relatively similar.

Energy evolution characteristics of coal specimens with preformed holes under uniaxial compression

  • Wu, Na;Liang, Zhengzhao;Zhou, Jingren;Zhang, Lizhou
    • Geomechanics and Engineering
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    • 제20권1호
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    • pp.55-66
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    • 2020
  • The damage or failure of coal rock is accompanied by energy accumulation, dissipation and release. It is crucial to study the energy evolution characteristics of coal rock for rock mechanics and mining engineering applications. In this paper, coal specimens sourced from the Xinhe mine located in the Jining mining area of China were initially subjected to uniaxial compression, and the micro-parameters of the two-dimensional particle flow code (PFC2D) model were calibrated according to the experimental test results. Then, the PFC2D model was used to subject the specimens to substantial uniaxial compression, and the energy evolution laws of coal specimens with various schemes were presented. Finally, the elastic energy storage ratio m was investigated for coal rock, which described the energy conversion in coal specimens with various arrangements of preformed holes. The arrangement of the preformed holes significantly influenced the characteristics of the crack initiation stress and energy in the prepeak stage, whereas the characteristics of the cumulative crack number, failure pattern and elastic strain energy during the loading process were similar. Additionally, the arrangement of the preformed holes altered the proportion of elastic strain energy Ue in the total energy in the prepeak stage, and the probability of rock bursts can be qualitatively predicted.

Geotelrtile 보강사면의 안정도표개발에 관한 연구 (A Study on the Development of Stability Charts for Reinforced Embankments by Geotextile)

  • 서인식
    • 한국지반공학회지:지반
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    • 제13권4호
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    • pp.67-74
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    • 1997
  • 본 논문은 연약한 기초지반 위의 토목섬유 보강제방의 2차원 안정해석을 산정하는 결정론적 모델을 제시한다. 본 연구에서 가능파괴면은 대수나선으로 가정되었다. 반복계산을 수행하기 위하여 보강제방의 정하여진 안전율에 필요한 보강재의 인장력을 산정하는 프로그램이 개발되었으며, 이 프로그램은 여러개의 토층과 토질로 이루어진 상황에서도 사용될 수 있다. 도식화된 단면에 대하여 많은 계산결과들이 만들어 졌으며, 그 결과들로서 안정도표를 만들었으며, 이것은 가능파괴면을 원호로 가정한 결과들과 비교되어진다. 예비설계단계에서 이러한 도표들을 이용하여 보강사면에 대한 비교적 정확한 안전율을 근사적으로 구할 수 있으며, 실시설계단계에서는 개발된 프로그램에 의하여 정확한 결과를 산정할 수 있다.

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Prioritized Multipath Video Forwarding in WSN

  • Asad Zaidi, Syed Muhammad;Jung, Jieun;Song, Byunghun
    • Journal of Information Processing Systems
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    • 제10권2호
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    • pp.176-192
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    • 2014
  • The realization of Wireless Multimedia Sensor Networks (WMSNs) has been fostered by the availability of low cost and low power CMOS devices. However, the transmission of bulk video data requires adequate bandwidth, which cannot be promised by single path communication on an intrinsically low resourced sensor network. Moreover, the distortion or artifacts in the video data and the adherence to delay threshold adds to the challenge. In this paper, we propose a two stage Quality of Service (QoS) guaranteeing scheme called Prioritized Multipath WMSN (PMW) for transmitting H.264 encoded video. Multipath selection based on QoS metrics is done in the first stage, while the second stage further prioritizes the paths for sending H.264 encoded video frames on the best available path. PMW uses two composite metrics that are comprised of hop-count, path energy, BER, and end-to-end delay. A color-coded assisted network maintenance and failure recovery scheme has also been proposed using (a) smart greedy mode, (b) walking back mode, and (c) path switchover. Moreover, feedback controlled adaptive video encoding can smartly tune the encoding parameters based on the perceived video quality. Computer simulation using OPNET validates that the proposed scheme significantly outperforms the conventional approaches on human eye perception and delay.

Retrofitting of shear damaged RC beams using CFRP strips

  • Altin, Sinan;Anil, Ozgur;Toptas, Tolga;Kara, M. Emin
    • Steel and Composite Structures
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    • 제11권3호
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    • pp.207-223
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    • 2011
  • The results of an experimental investigation are presented in this paper for retrofitting of shear damaged reinforced concrete beams by using U shaped CFRP strips. The experimental program is consisted of seven shear deficient T cross sectioned 1/2 scale simply supported beam specimens. One beam was used as reference specimen, and the remaining six specimens were tested in two stages. At the first stage, specimens were shear damaged severely, and then were retrofitted by using CFRP strips with or without fan type anchorages. Finally, retrofitted beams were tested up to failure. Three different CFRP strip spacing were used such as 125 mm, 150 mm, and 200 mm. The effect of anchorages on shear strength and behavior of the retrofitted specimens is investigated. CFRP strips without anchorages improved the shear strength, but no flexural failure mode was observed. Specimens showed brittle shear failure due to peeling of CFRP strip from RC beam surface. Shear damaged specimens retrofitted with anchoraged CFRP strips showed improved shear strength and ductile flexural failure. Maximum strains at anchoraged strips were approximately 68% larger than that of strips without anchorages.