• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제25권2호
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• pp.132-142
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• 2023

Objective: Dual antiplatelet therapy (DAPT) is usually temporarily used after stent-assisted coil embolization (SACE), and is commonly converted to mono antiplatelet therapy (MAPT) for indefinitely. In this study, we aimed to find the possibility of discontinuing MAPT, and to determine the proper period of DAPT use. Methods: We used the Standard Sample Cohort DB dataset from the National Health Insurance Sharing Service. Among approximately 1 million people in the dataset, SACE was performed in 214 patients whose data this study analyzed. The relationship between discontinuation of antiplatelet therapy and intracranial hemorrhage or cerebral infarction was analyzed using multiple logistic regression, considering all confounding variables. The survival rate according to the continuation of antiplatelet therapy was obtained using Kaplan-Meier analysis, and the difference in survival rate according to the continuation of antiplatelet therapy was verified using the log-rank test. The hazard ratio according to continuation of antiplatelet therapy was obtained using the Cox proportional hazards model. The analysis was conducted by applying the same statistical method to the duration of DAPT use. Results: Among 214 patients who underwent SACE, 50, 159 and five patients continued, discontinued and did not use antiplatelet therapy (except at the time of procedure), respectively. In multiple logistic regression analysis, discontinuation of antiplatelet agents (including aspirin) and the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction, considering various confounding factors. In the survival analysis according to the continuation of antiplatelet agents, patients who continued to use antiplatelet agents had a higher survival rate than those in other groups (p=0.00). The survival rate was higher in the rest of the group than in the group that received DAPT for three months (p=0.00). Conclusions: Continuation of antiplatelet agents or the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction. Considering the survival rate, it would be better to maintain at least three months of antiplatelet therapy and it might be recommended to continue DAPT use for 12 months.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6553-6558
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• 2014

Background: This study was conducted to gauge how the demographic profile of smokeless tobacco (SLT) users from Gujarat and Andhra Pradesh, India, differs from that of smokers. It also addresses how factors associated with the initiation and continuation of smokeless tobacco vary by age, gender, and education. Materials and Methods: We analyzed 2011 cross-sectional survey data collected from 4,759 respondents (smokers/SLT users/non-users) in both states. Chi-square analysis was used to make comparisons between the demographic profiles of smokers and SLT users. Multivariable logistic regression analysis was used to obtain the odds ratios (ORs) for initiation and continuation factors regressed on socio-demographic variables (age, gender, education). Results: Initiation-women were less likely than men to report "peer pressure", "fashion statement", and "stress/coping" as relevant factors for SLT use (OR: 0.45 CI: 0.30-0.70; OR: 0.42 CI: 0.24-0.74; OR: 2.47, CI: 1.47-4.15). Older age groups had lower odds of choosing "peer pressure" than the 15-24 year olds. Respondents with 11 or more years of education were more likely to report "stress/coping" than those with no education (OR: 2.82, CI: 1.06-7.48). Continuation-women were less likely than men to choose "relaxation", and "distance from family" as important continuation factors (OR: 0.50, CI:0.32-0.80; OR: 0.20, CI: 0.06-0.65). All age groups were less likely to choose "stimulation" as a factor than the youngest group. Conclusions: Along with confirming and expanding upon previous literature, the findings of this study should encourage further SLT research in women and younger age groups (15-24 and 24-44). They also confirm the need for SLT prevention and cessation interventions in India in other community-based settings, besides schools.

• Tuberculosis and Respiratory Diseases
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• 제81권2호
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• pp.148-155
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• 2018

Background: Although targeted therapy and immuno-oncology have shifted the treatment paradigm for lung cancer, platinum-based combination is still the standard of care for advanced non-small cell lung cancer (NSCLC). Pemetrexed continuation maintenance therapy has been approved and increasingly used for patients with nonsquamous NSCLC. However, the efficacy of this strategy has not been proven in patients without driving mutations. The objective of this study was to compare the clinical benefit of pemetrexed continuation maintenance to conventional platinum-based doublet in epidermal growth factor receptor (EGFR)-negative lung adenocarcinoma. Methods: A total of 114 patients with EGFR-negative lung adenocarcinoma who were treated with platinum doublet were retrospectively enrolled. We compared the survival rates between patients received pemetrexed maintenance after four-cycled pemetrexed/cisplatin and those received at least four-cycled platinum doublet without maintenance chemotherapy as a first-line treatment. Results: Forty-one patients received pemetrexed maintenance and 73 received conventional platinum doublet. Median progression-free survival (PFS), which was defined as the time from the day of response evaluation after four cycles of chemotherapy to disease progression or death, was significantly higher in the pemetrexed maintenance group compared to conventional group (5.8 months vs. 2.2 months, p<0.001). Median overall survival showed an increasing trend in the pemetrexed maintenance group (22.3 months vs. 16.1 months, p=0.098). Multivariate analyses showed that pemetrexed maintenance chemotherapy was associated with better PFS (hazard ratio, 0.73; 95% confidence interval, 0.15-0.87). Conclusion: Compared to conventional platinum-based chemotherapy, premetrexed continuation maintenance treatment is associated with better clinical outcome for the patients with EGFR wild-type lung adenocarcinoma.

• 한국IT서비스학회지
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• 제12권3호
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• pp.331-343
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• 2013

In RFID systems, the anti-collision algorithm is being improved to recognize Tag's ID within recognition area of the reader quickly and efficiently. This paper focuses on Tag collision. Many studies have been carried out to resolve Tag collision. This paper proposes a new N-ary Query Tree Algorithm to resolve more than Tag collision simultaneously, according to the value of m(2 ~ 6). This algorithm can identify more tags than existing methods by treating a maximum 6 bit collision, regardless of the continuation/non-continuation Tag's ID patterns. So, it extracts maximumly different $2^6$ bit patterns per single prefix in recognition process. The performance of N-ary Query Tree Algorithm is evaluated by theoretical analysis and simulation program.

• Advances in nano research
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• 제9권4호
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• pp.277-294
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• 2020

In current paper, nonlocal (NLT), nonlocal strain gradient (NSGT) and Gurtin-Murdoch surface/interface (GMSIT) theories with classical theory (CT) are utilized to investigate vibration and stability analysis of Double Walled Piezoelectric Nanosensor (DWPENS) based on cylindrical nanoshell. DWPENS simultaneously subjected to direct electrostatic voltage DC and harmonic excitations, structural damping, two piezoelectric layers and also nonlinear van der Waals force. For this purpose, Hamilton's principle, Galerkin technique, complex averaging and with arc-length continuation methods are used to analyze nonlinear behavior of DWPENS. For this work, three nonclassical theories compared with classical theory CT to investigate Dimensionless Natural Frequency (DNF), pull-in voltage, nonlinear frequency response and stability analysis of the DWPENS considering the nonlocal, material length scale, surface/interface (S/I) effects, electrostatic and harmonic excitation.

• Journal of applied mathematics & informatics
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• 제10권1_2호
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• pp.41-50
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• 2002

We provide local and semilocal theorems for the convergence of Newton-like methods to a locally unique solution of an equation in a Banach space. The analytic property of the operator involved replaces the usual domain condition for Newton-like methods. In the case of the local results we show that the radius of convergence can be enlarged. A numerical example is given to justify our claim . This observation is important and finds applications in steplength selection in predictor-corrector continuation procedures.

• 생약학회지
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• 제12권1호
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• pp.15-18
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• 1981

In continuation of the previous papers, the presence of alkaloid, flavonoid, iridoid, terpenoid, steroid and saponin were screened with the usual test methods in another 53 species of Korean medicinal plants. The result is presented in the Table I.

• 한국전산구조공학회논문집
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• 제14권4호
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• pp.435-444
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• 2001

대변형 탄소성 프레임의 해석은 운동학적, 재질적, 수치해법상으로 매우 복잡하여 정확하고 효율적인 요소나 알고리즘이 부족하다. 본 논문에서는 3차원 보요소에 대하여 봉이론으로부터 유한요소를 만들고 소성을 적용하기 위하여 Cauchy응력과 공학적변형률을 구성방정식에 적용하는 방법으로 객관화된 증분해법에 의한 보요소를 제안하였다. 특히 항복조건의 만족을 위하여 정확하고도 효율적인 소성방정식의 적분법을 개발하고 적용하였으며 연속법과 일차원 탐색 등을 고려하여 광역수렴성과 2차 수렴속도를 갖는 수치해법을 개발하고 예제를 통하여 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.113-116
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• 2004

Many methods to examine the vulnerable areal for the contingencies in the power system. The most widely used index for the vulnerable area investigation has been the reactive power margin or sensitivity analysis. But we can get the results of these analyses if only the results of load flow are convergent in severe contingencies, otherwise these methods are not adoptable. We can present a good index for overcoming severe contingencies, if we can get the vulnerable areas by bus sensitivity in severe contingencies, though the power flow equation is unsolvable. This paper simulates unsolvable severe contingencies by using branch parameter continuation power flow. We can compute the vulnerable areas in unsolvable severe contingencies by normal vector at a nose point of a $\nu-V$ curve. Presented method is checked the input reactive power of the vulnerable areas in KEPCO system.

• 한국소음진동공학회논문집
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• 제26권7호
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• pp.795-805
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• 2016

Nonlinear normal modes(NNMs) is a branch of periodic solution of nonlinear dynamic systems. Determination of stable periodic solution is very important in many engineering applications since the stable periodic solution can be an attractor of such nonlinear systems. Periodic solutions of nonlinear system are usually calculated by perturbation methods and numerical methods. In this study, numerical method is used in order to calculate the NNMs. Iteration of the solution is presented by multiple shooting method and continuation of solution is presented by pseudo-arclength continuation method. The stability of the NNMs is analyzed using Floquet multipliers, and bifurcation points are calculated using indirect method. Proposed analyses are applied to two nonlinear numerical models. In the first numerical model nonlinear spring-mass system is analyzed. In the second numerical model Jeffcott rotor system which has unstable equilibria is analyzed. Numerical simulation results show that the multiple shooting method can be applied to self excited system as well as the typical nonlinear system with stable equilibria.