• 제목/요약/키워드: Positive operator

검색결과 210건 처리시간 0.034초

A GENERAL ITERATIVE ALGORITHM FOR A FINITE FAMILY OF NONEXPANSIVE MAPPINGS IN A HILBERT SPACE

  • Thianwan, Sornsak
    • Journal of applied mathematics & informatics
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    • 제28권1_2호
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    • pp.13-30
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    • 2010
  • Let C be a nonempty closed convex subset of a real Hilbert space H. Consider the following iterative algorithm given by $x_0\;{\in}\;C$ arbitrarily chosen, $x_{n+1}\;=\;{\alpha}_n{\gamma}f(W_nx_n)+{\beta}_nx_n+((1-{\beta}_n)I-{\alpha}_nA)W_nP_C(I-s_nB)x_n$, ${\forall}_n\;{\geq}\;0$, where $\gamma$ > 0, B : C $\rightarrow$ H is a $\beta$-inverse-strongly monotone mapping, f is a contraction of H into itself with a coefficient $\alpha$ (0 < $\alpha$ < 1), $P_C$ is a projection of H onto C, A is a strongly positive linear bounded operator on H and $W_n$ is the W-mapping generated by a finite family of nonexpansive mappings $T_1$, $T_2$, ${\ldots}$, $T_N$ and {$\lambda_{n,1}$}, {$\lambda_{n,2}$}, ${\ldots}$, {$\lambda_{n,N}$}. Nonexpansivity of each $T_i$ ensures the nonexpansivity of $W_n$. We prove that the sequence {$x_n$} generated by the above iterative algorithm converges strongly to a common fixed point $q\;{\in}\;F$ := $\bigcap^N_{i=1}F(T_i)\;\bigcap\;VI(C,\;B)$ which solves the variational inequality $\langle({\gamma}f\;-\;A)q,\;p\;-\;q{\rangle}\;{\leq}\;0$ for all $p\;{\in}\;F$. Using this result, we consider the problem of finding a common fixed point of a finite family of nonexpansive mappings and a strictly pseudocontractive mapping and the problem of finding a common element of the set of common fixed points of a finite family of nonexpansive mappings and the set of zeros of an inverse-strongly monotone mapping. The results obtained in this paper extend and improve the several recent results in this area.

Systematic Review on Epstein-Barr Virus (EBV) DNA in Diagnosis of Nasopharyngeal Carcinoma in Asian Populations

  • Han, Bao-Lin;Xu, Xiang-Ying;Zhang, Chun-Zhi;Wu, Jian-Juan;Han, Chun-Feng;Wang, Hui;Wang, Xuan;Wang, Guang-Shun;Yang, Shu-Juan;Xie, Yao
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2577-2581
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    • 2012
  • Objective: To conduct a meta-analysis to investigate the value of EBV DNA in diagnosis of nasopharyngeal cancer (NPC) in Asian populations, and provide important evidence for screening. Methods: Prospective or respective case-control or cohort studies regarding the detection role of EBV DNA for NPC were included in our study. We conducted a comprehensive literature search in PubMed, EMBASE, and the Chinese Biomedical Database (CBM database between January 1980 and March 2012. Results: A total of 18 studies with 1492 NPC cases and 2641 health controls were included. Almost of the included studies were conducted in China, and only one other conducted in Thailand. The overall results demonstrated that the pooled sensitivity, specificity, positive likelihood (+LR) and negative likelihood (-LR) were 0.73 (0.71-0.75), 0.89 (0.88-0.90), 8.84 (5.65-13.84) and 0.19(0.11-0.32), respectively. The overall EBV DNA detection showed the largest area of 0.932 under the summary receiver operator curve (SROC). The accuracy of detection by plasma for NPC (0.86) was higher than in serum (0.81), with largest areas under the SROC of 0.97 and 0.91, respectively. Conclusion: Our results demonstrated the EBV DNA detection in plasma or serum has high sensitivity and specificity in diagnosis of NPC, especially in Chinese populations with a high risk of cancer.

자율운항선박의 개발 및 운용을 위한 육상 운항사의 인적요인 이슈 고찰 (A Review of Human Element Issues of Remote Operators on Maritime Autonomous Surface Ships)

  • 김홍태;양영훈
    • 한국항해항만학회지
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    • 제43권6호
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    • pp.395-402
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    • 2019
  • 최근 보다 안전하고 효율적인 해상운송시스템을 위한 해결책으로 자율운항선박의 개발 및 운용에 대한 논의가 활발히 진행되고 있다. 자율운항기술은 해양사고 방지, 선박의 연비 증진, 비용 절감 등 긍정적인 측면과 함께 선원의 일자리 감소, 업무의 변화, 보안문제 등 부정적인 측면도 상존하고 있다. 향후 자율운항선박의 시대가 도래 하더라도 육상 센터에서의 제어가 이루어지게 되므로, 육상 운항사의 상황인식과 같이 새로운 인적요인 이슈가 존재할 것으로 예측된다. 본 논문에서는 자율운항선박의 개발 및 운용과정에 고려해야 할 주요 인적요인 이슈를 고찰하고, 육상 센터의 제어에 따라 예상되는 육상 운항사의 의사결정 및 업무수행에 영향을 미치는 요소에 대한 식별과 영향 요소의 평가를 위한 인적 신뢰성 분석 방안을 제시하였다.

Association of Serum and Salivary Tumor Necrosis Factor-α with Histological Grading in Oral Cancer and its Role in Differentiating Premalignant and Malignant Oral Disease

  • Krishnan, Rajkumar;Thayalan, Dinesh Kumar;Padmanaban, Rajashree;Ramadas, Ramya;Annasamy, Ramesh Kumar;Anandan, Nirmala
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권17호
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    • pp.7141-7148
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    • 2014
  • Background: Oral squamous cell carcinoma (OSCC) is an important malignancy throughout the world; early detection is an important criterion for achieving high cure rate. Out of the many reported markers for OSCC, this study validated the efficacy of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in differentially diagnosing premalignant oral lesions and OSCC. Also, the study aimed to correlate the levels of salivary and serum TNF-${\alpha}$ with clinicopathologic factors. Materials and Methods: A prospective experimental laboratory study was designed. Serum and salivary samples from 100 subjects in each group of healthy control, premalignant disease (PMD) and OSCC were collected for the study following appropriate exclusion and inclusion criteria. Serum and salivary level of TNF-${\alpha}$ was analysed by enzyme linked immunosorbent assay. The data obtained were subjected to appropriate statistical analysis. Results: Increased level of both serum and salivary TNF-${\alpha}$ was observed in OSCC subjects compared to healthy control and PMD group. Receiver operator characteristic curve analysis and area under curve values showed high specificity and sensitivity for salivary TNF-${\alpha}$ in differentiating OSCC from PMD and healthy controls. There was significant increase in TNF-${\alpha}$ level in moderately and poorly differentiated lesion compared to well differentiated lesion and in stage IV of clinical stage. A positive correlation was observed only with histological grading of OSCC and TNF-${\alpha}$. Conclusions: Salivary TNF-${\alpha}$ is proved to be superior for detecting OSCC. Increase in TNF-${\alpha}$ with histological grading and clinical staging suggests a role in prognosis.

Franz Diffusion Cell을 이용한 문신용 염료 내 유해물질의 피부 투과특성 연구 (Permeation Characteristics of Hazardous Substances in Tattoo Dye using Franz Diffusion Cells)

  • 박교현;정세훈;신호상;김배환
    • 한국환경보건학회지
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    • 제42권1호
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    • pp.61-70
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    • 2016
  • Objectives: The purpose of this study is to determine the exposure risk to tattoo components by analyzing skin absorption using the in vitro method. Tattoos are commonly used for cosmetic purposes, and the skin of not only the operator but of the people who are undergoing the cosmetic procedure is continuously exposed to hazardous chemicals. Methods: Skin permeation risk determination was conducted by the in vitro Franz diffusion cell method according to the ingredient types of tattoo dyes, such as volatile organic compounds (VOCs), non-volatile organic compounds and heavy metals, using hairless mouse full skin and human cadaver epidermis. Results: The major components with good skin penetration for each type of tattoo dye ingredient were clarified. Among the tatto dye ingredients, 1,2-Dichlorobenzene, Zn, Al, Pb and Ti showed good skin penetration. Most of the skin transmission rates were higher in hairless mouse full skin than in human cadaver epidermis. Conclusion: A possible exposure risk to hazardous substances in tattoo dyes was confirmed from this study. These results are expected to provide a positive contribution to the establishment of management regulations for tattoo dyes.

REGULARITY AND MULTIPLICITY OF SOLUTIONS FOR A NONLOCAL PROBLEM WITH CRITICAL SOBOLEV-HARDY NONLINEARITIES

  • Alotaibi, Sarah Rsheed Mohamed;Saoudi, Kamel
    • 대한수학회지
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    • 제57권3호
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    • pp.747-775
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    • 2020
  • In this work we investigate the nonlocal elliptic equation with critical Hardy-Sobolev exponents as follows, $$(P)\;\{(-{\Delta}_p)^su={\lambda}{\mid}u{\mid}^{q-2}u+{\frac{{\mid}u{\mid}^{p{^*_s}(t)-2}u}{{\mid}x{\mid}^t}}{\hspace{10}}in\;{\Omega},\\u=0{\hspace{217}}in\;{\mathbb{R}}^N{\backslash}{\Omega},$$ where Ω ⊂ ℝN is an open bounded domain with Lipschitz boundary, 0 < s < 1, λ > 0 is a parameter, 0 < t < sp < N, 1 < q < p < ps where $p^*_s={\frac{N_p}{N-sp}}$, $p^*_s(t)={\frac{p(N-t)}{N-sp}}$, are the fractional critical Sobolev and Hardy-Sobolev exponents respectively. The fractional p-laplacian (-∆p)su with s ∈ (0, 1) is the nonlinear nonlocal operator defined on smooth functions by $\displaystyle(-{\Delta}_p)^su(x)=2{\lim_{{\epsilon}{\searrow}0}}\int{_{{\mathbb{R}}^N{\backslash}{B_{\epsilon}}}}\;\frac{{\mid}u(x)-u(y){\mid}^{p-2}(u(x)-u(y))}{{\mid}x-y{\mid}^{N+ps}}dy$, x ∈ ℝN. The main goal of this work is to show how the usual variational methods and some analysis techniques can be extended to deal with nonlocal problems involving Sobolev and Hardy nonlinearities. We also prove that for some α ∈ (0, 1), the weak solution to the problem (P) is in C1,α(${\bar{\Omega}}$).

쿼드트리 기반의 다중 스케일 블록 영역 검출기를 통한 구간적 영상 잡음 제거 기법 (Piecewise Image Denoising with Multi-scale Block Region Detector based on Quadtree Structure)

  • 이지현;정제창
    • 방송공학회논문지
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    • 제20권4호
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    • pp.521-532
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    • 2015
  • 본 논문은 효과적인 열화영상의 복원을 위해 쿼드트리 구조를 갖는 다중-스케일 블록 지역적 이진 패턴 기반의 영역검출기를 제시하고, 이를 통한 구간적 잡음 제거 기법을 제안한다. 구간적 잡음 제거 기법은 영상 내 전체 화소를 일정한 블록 단위의 영역으로 나누어 화소의 변화량에 따라 검출을 수행하는 다중-스케일 블록 영역 검출기를 쿼드트리 형태로 제시하고 검출된 영역 특성에 맞게 영상분석을 진행한다. 처리되는 영역들은 강한 변화량을 갖는 영역, 약한 변화량을 갖는 영역, 평탄한 영역의 세 가지로 분류되며 차례로 주성분분석, 양방향 필터, 구조-텍스쳐 영상 분해의 기법들이 잡음제거를 위해 적용된다. 객관적 실험결과를 통하여 기존 알고리즘들 보다 제안하는 구간적 잡음 제거 기법이 최대 신호-대-잡음비 측면에서 이득을 가지며, 주관적 화질 비교를 통해 세부정보들이 최대한 보존되어 있음과 동시에 평탄한 영역에 대해서도 왜곡이 거의 없는 향상된 복원영상이 얻어지는 것을 확인할 수 있었다.

A clinical comparative study between conventional and camouflaged syringes to evaluate behavior and anxiety in 6-11-year-old children during local anesthesia administration-a novel approach

  • Melwani, Anjana M;Srinivasan, Ila;Setty, Jyothsna V;Murali, Krishna D.R.;Pamnani, Sunaina S;Lalitya, Dandamudi
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제18권1호
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    • pp.35-40
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    • 2018
  • Background: The sight of dental injection can bring about severe anxiety in children. Therefore, an alternative method that is convenient, effective, and keeps the needle hidden making it child friendly is necessary. The objective of the study was to compare the efficacy of a camouflaged syringe and conventional syringe on behavior and anxiety in 6-11-year-old children during local anesthesia administration. Methods: The study was a randomized, crossover clinical study including 30 children. Children were separated into two groups. Group 1 consisted of 15 children aged 6-8 years while group 2 consisted of 15 children aged 9-11 years. This study involved two sessions wherein all the children were injected using conventional and camouflaged syringes in separate sessions. Their behavior was assessed using the Faces, Legs, Activity, Cry, Consolability (FLACC) behavior pain scale and anxiety was assessed by measuring changes in pulse rate. Patient and operator preferences were compared. Results: The results showed a lower mean change in pulse rate and FLACC scores in the camouflaged group, suggesting a positive behavior and lesser anxiety with camouflaged syringes than with conventional syringes. Conclusions: The use of camouflaged syringes for anesthesia was demonstrated to be effective in improving the behavior of children and decreasing their anxiety, and is therefore recommended as an alternative to the use of conventional syringes for local anesthesia.

Le Fort II 골절단술을 이용한 비중안모 개선 효과에 대한 임상적 연구;경조직 이동에 따른 연조직 변화율에 대한 연구 (THE AMOUNT OF SOFT TISSUE CHANGE TO HARD TISSUE MOVEMENT FOLLOWING LE FORT II OSTEOTOMY)

  • 김명진;이안나
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제22권1호
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    • pp.63-69
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    • 2000
  • Le fort II osteotomy is much useful technique to correct the midfacial hypoplasia including nasomaxillary complex especilly in patient with dish face appearance. Not in simple orthognathic surgery but in Le Fort II osteotomy, the standardization of prognostic value is essential in treatment planning to achieve satisfactory postoperative results. According to pervious reports, the ratio of soft tissue change to hard tissue movements varies as to different surgical methods and different facial regions. But there are few report about the ratio of soft tissue change to hard tissue movement following Le Fort II osteotomy. So we tried to develop standarized soft tissue surgical treatment objective. We have followed up 16 patients, who had received Le Fort II osteotomy by one operator from 1990 to 1996, one year postoperatively. In cephalometrics, we used Frankfort line as horizontal reference line, and vertical reference line as one drawn from Sella to horizontal line perpendicularly. The landmarks are G to soft tissue G, N on reference line to soft tissue N, ANS to Pn and A to Sn. The results are as follows. 1. The value of soft tissue change to hard tissue movement showed positive correlation, having statistical significancy at G, N2, N3 point. 2. At G, N2, N3 point, the ratio of soft tissue change to hard tissue movement was 0.51, 0.98 and 0.80 respectively and showed statistical significancy, while at N1, ANS, A point, that was 0.72, 0.49 and 0.26 but didn't showed statistical significance. 3. This result shows much the same change of the soft tissue change to hard tissue movement on the upper nasomaxilla, and less the same change on the lower maxilla and so the Le Fort II osteotomy can be recommended as a reliable effective operation method for correction of nasomaxillary retrusion.

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광양항의 컨테이너터미널 운영사와 해운선사간의 상호리스크 관리방안 연구 (A Study on the Mutual Risk Management Between Container Terminal Operator and Shipping Company in Gwangyang Port)

  • 최용석;박성수
    • 한국항만경제학회지
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    • 제26권4호
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    • pp.168-187
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    • 2010
  • 항만에서 상호리스크관리는 항만서비스를 제공하는 터미널 운영사와 항만서비스를 사용하는 해운선사간의 기업경영의 운영측면에서 상호이익을 도모하기 위해 중요하다. 본 연구는 상호 윈-윈 전략이 될 수 있는 상호리스크 관리방안을 통하여 국적선사와 항만산업체의 경쟁력을 확보하는데 기여하고자 수행되었다. 광양항의 터미널 운영사별로 해운선사에 대한 리스크 요인 및 리스크관리 개선점을 도출하고, 광양항 입항 해운선사별로 터미널 운영사별 리스크 요인 및 리스크관리 개선점을 도출하여 터미널 운영사와 해운선사간의 리스크에 의한 손실을 감소시키면서 상호이익을 도모하는 리스크 사전인식모델과 리스크 예방모델 등 두가지 종류의 관리모델을 제시하였다. 제시된 관리모델은 광양항의 컨테이너터미널과 해운선사간의 상호리스크 요인에 의한 손실을 파악하고 사전인식을 통해 리스크를 관리하기 위한 리스크 사전인식모델과 리스크에 의한 손실을 예방하기 위한 리스크 예방모델로 구성되며, 사전인식을 통한 관리와 예방을 통한 관리를 동시에 수행하도록 수립하였다. 이를 통하여 광양항 컨테이너터미널 운영사와 해운선사 상호간의 리스크에 의한 손실을 최소화시키면서, 운영의 효율성을 높일 수 있는 논리적 근거를 마련하고자 하였다.