A Distributed Decision-Making Mechanism forWireless P2P Networks

Xu Wu,Jingsha He,Fei Xu,Xi Zhang 한국통신학회 2009 Journal of communications and networks Vol.11 No.4

Trust-based solutions provide some form of payment to peers to encourage good behavior. The problem with trustmanagement systems is that they require prior knowledge to work. In other words, peers are vulnerable to attack if they do not have knowledge or correct knowledge of other peers in a trust management system. Therefore, considering only trust is inadequate when a decision is made to identify the best set of peers to utilize. In order to solve the problem, we propose a distributed decision-making mechanism for wireless peer-to-peer (P2P) networks based on game theory and relevant trust mechanisms in which we incorporate the element of trust and risk into a single model. The main idea of our mechanism is to use utility function to express the relationship between benefits and costs of peers, and then make the decision based on expected utility as well as risk attitude in a fully distributed fashion. The unique feature of our mechanism is that it not only helps a peer to select its partners, but also mitigates vulnerabilities in trust-based mechanisms. Through analysis and experiments, we believe our approach is useful for peers to make the decision regarding who to interact with. In addition, it is also a good starting point for exploring tradeoffs among risk, trust and utility.

Mortality Characteristic and Prediction of Nasopharyngeal Carcinoma in China from 1991 to 2013

Xu, Zhen-Xi,Lin, Zhi-Xiong,Fang, Jia-Ying,Wu, Ku-Sheng,Du, Pei-Ling,Zeng, Yang,Tang, Wen-Rui,Xu, Xiao-Ling,Lin, Kun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: To analyze the mortality distribution of nasopharyngeal carcinoma in China from 1991 to 2013, to predict the mortality in the ensuing five years, and to provide evidence for prevention and treatment of nasopharyngeal carcinoma. Materials and Methods: Mortality data for Nasopharyngeal Carcinoma in China from 1991 to 2013 were used to describe its epidemiological characteristics, such as the change of the standardized mortality rate, sex and age differences, urban-rural differences. Trend-surface analysis was used to study the geographical distribution of the mortality. Curve estimation, time series, gray modeling, and joinpoint regression were used to predict the mortality for the ensuing five years in the future. Results: In China, the standardized mortality rate of Nasopharyngeal Carcinoma increased with time from 1996, reaching the peak values of $1.45/10^5$ at the year of 2002, and decreased gradually afterwards. With males being 1.51 times higher than females, and the city had a higher rate than the rural during the past two decades. The mortality rate increased from age 40. Geographical analysis showed the mortality rate increased from middle to southern China. Conclusions: The standardized mortality rate of Nasopharyngeal Carcinoma is falling. The regional disease control for Nasopharyngeal Carcinoma should be focused on Guangdong province of China, and the key targets for prevention and treatment are rural men, especially after the age of 40. The mortality of Nasopharyngeal Carcinoma will decrease in the next five years.

Semi-analytical solution of horizontally composite curved I-beam with partial slip

Xu-xi Qin,Han-bing Liu,Chunli Wu,Zheng-wei Gu 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.27 No.1

This paper presents a semi-analytical solution of simply supported horizontally composite curved I-beam by trigonometric series. The flexibility of the interlayer connectors between layers both in the tangential direction and in the radial direction is taken into account in the proposed formulation. The governing differential equations and the boundary conditions are established by applying the variational approach, which are solved by applying the Fourier series expansion method. The accuracy and efficiency of the proposed formulation are validated by comparing its results with both experimental results reported in the literature and FEM results.

중국의 교육공동체 연구 동향 분석

XU XI,박창언 부산대학교 지역혁신역량교육연구센터 2022 교육공동체연구와실천 Vol.4 No.2

연구목적: 본문은 중국의 교육공동체 연구에 포함된 키워드를 도출하여 언어 빈도분석과 언어 네트워크 분석을 하여 중국의 교육공동체 연구 현황을 분석함으로써 향후 한국 관련 연구에 시사점을 제시하고 한국 교육공동체 미래 연구의 방향을 모색하는 데 목적이 있다. 연구방법: 중국의 교육공동체 연구 동향을 분석하기 위하여 중국지망에서 2006년부터 2022년까지의 관련 주제 학술지 논문 652편을 선정하여 키워드 빈도분석을 하여 언어 네트워크 분석으로 중심성과 하위영역을 살펴보았다. 연구결과: 출현 빈도수 9회 이상을 보이는 키워드가 40개 나오고, 그중에 '교육공동체', '균형 발전', '교사', '지역사회', '협력', '대학교', '패러다임', '하교', '학생' 등 키워드의 빈도가 제일 높게 나타났다. 전체 키워드 네트워크의 밀도는 0.371이고, ‘공동체’, ‘교육공동체’, '균형발전’, ‘패러다임’ '협력' 등 키워드는 중심적인 위치를 차지하였다. CONCOR 분석의 결과는 총 8개의 하위영역이 나왔다. 논의 및 결론: 교육공동체의 주체이며 연구대상인 '교사'와 '학교'가 높은 빈도가 나타났고 중심적인 위치를 차지하여 중요성이 강조되고 있음을 확인할 수 있다. 중국에는 '일대일로' 교육공동체, '도농교육공동체' 등 중국의 상황과 맥락에 맞는 교육공동체 개념이 형성되었다.

A Distributed Decision-Making Mechanism for Wireless P2P Networks

Wu, Xu,He, Jingsha,Xu, Fei,Zhang, Xi The Korea Institute of Information and Commucation 2009 Journal of communications and networks Vol.11 No.4

Trust-based solutions provide some form of payment to peers to encourage good behavior. The problem with trust management systems is that they require prior knowledge to work. In other words, peers are vulnerable to attack if they do not have knowledge or correct knowledge of other peers in a trust management system. Therefore, considering only trust is inadequate when a decision is made to identify the best set of peers to utilize. In order to solve the problem, we propose a distributed decision-making mechanism for wireless peer-to-peer (P2P) networks based on game theory and relevant trust mechanisms in which we incorporate the element of trust and risk into a single model. The main idea of our mechanism is to use utility function to express the relationship between benefits and costs of peers, and then make the decision based on expected utility as well as risk attitude in a fully distributed fashion. The unique feature of our mechanism is that it not only helps a peer to select its partners, but also mitigates vulnerabilities in trust-based mechanisms. Through analysis and experiments, we believe our approach is useful for peers to make the decision regarding who to interact with. In addition, it is also a good starting point for exploring tradeoffs among risk, trust and utility.

Expression of Pituitary Tumor Transforming Gene 1 is an Independent Factor of Poor Prognosis in Localized or Locally Advanced Prostate Cancer Cases Receiving Hormone Therapy

Cao, Xi-Liang,Gao, Jiang-Ping,Wang, Wei,Xu, Yong,Shi, Huai-Yin,Zhang, Xu Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

We investigated the prognostic value of pituitary tumor transforming gene 1 (PTTG1) expression according to clinicopathological features among localized or locally advanced prostate cancer cases receiving hormone therapy. A retrospective study involved 64 patients receiving combined androgen blockade treatment was performed. PTTG1 expression was determined by immunohistochemical staining using initial needle biopsy specimens for diagnosis. Associations of PTTG1 with various clinicopathological features and disease-free survival were examined via uni- and multivariate analyses. No association between PTTG1 expression and clinical T stage, Gleason score, pretreatment PSA levels, risk groups was found (p =0.682, 0.184, 0.487, 0.571, respectively). Univariate analysis revealed that increased PTTG1 expression, T3 stage and high risk group were associated with increased risk of disease progression (p =0.000, 0.042, and 0.001), and high PSA level had a tendency to predict disease progression (p =0.056). Cox hazard ratio analysis showed that PTTG1 low expression (p =0.002), PTTG1 high expression (p =0.000) and high risk group (p =0.0147) were significantly related to decreased disease-free survival. In conclusion, PTTG1 expression determined by immunohistochemical staining in needle biopsy specimens for diagnosis is a negative prognostic factor for progression in localized or locally advanced prostate cancer receiving hormone therapy.

Effectively promote catalytic performance by adjusting W/Fe molar ratio of FeWx/Ce0.68Zr0.32O2 monolithic catalyst for NH3-SCR

Haidi Xu,Yuanshan Li,Baoqiang Xu,Yi Cao,Xi Feng,Mengmeng Sun,Maochu Gong,Yaoqiang Chen 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.36 No.-

FeWx/Ce0.68Zr0.32O2 (x = 0, 0.35, 0.7, 1.03, 1.38) catalysts with different molar ratios (x) of W/Fe wereprepared for NH3-SCR. The experimental results showed that catalytic performances of catalysts wereobviously improved by adjusting the molar ratio of W/Fe. FeW1.03/Ce0.68Zr0.32O2 catalyst with W/Fe of1.03 displayed the best catalytic performance, it could obtain higher than 95% NOx conversion and nearly100% N2 selectivity in the temperature range of 250–435 8C. The characterization results indicated thatmore active species of Fe3+, chemical adsorbed oxygen species and surface acid sites would togethercontribute to the excellent NH3-SCR performance of FeW1.03/Ce0.68Zr0.32O2 catalyst.

Long-circulating siRNA nanoparticles for validating Prohibitin1-targeted non-small cell lung cancer treatment

Zhu, Xi,Xu, Yingjie,Solis, Luisa M.,Tao, Wei,Wang, Liangzhe,Behrens, Carmen,Xu, Xiaoyang,Zhao, Lili,Liu, Danny,Wu, Jun,Zhang, Ning,Wistuba, Ignacio I.,Farokhzad, Omid C.,Zetter, Bruce R.,Shi, Jinjun National Academy of Sciences 2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.112 No.25

<P><B>Significance</B></P><P>This study developed a new generation lipid–polymer hybrid nanoparticle platform for effective systemic delivery of small interfering RNA (siRNA) to tumors, which represents a challenging hurdle for the widespread application of RNA interference (RNAi) in cancer research and therapy. With promising in vivo features such as long blood circulation, high tumor accumulation, and effective gene silencing, the hybrid siRNA nanoparticles were successfully used to reveal and validate a putative therapeutic target, Prohibitin1 (PHB1), in non-small cell lung cancer treatment. In vivo antitumor efficacy results and human tissue microarray analysis further suggested the feasibility of utilizing PHB1 siRNA nanoparticles as a novel therapeutic agent. This hybrid RNAi nanoparticle platform may serve as a valuable tool for validating potential cancer targets and developing new cancer therapies.</P><P>RNA interference (RNAi) represents a promising strategy for identification and validation of putative therapeutic targets and for treatment of a myriad of important human diseases including cancer. However, the effective systemic in vivo delivery of small interfering RNA (siRNA) to tumors remains a formidable challenge. Using a robust self-assembly strategy, we develop a unique nanoparticle (NP) platform composed of a solid polymer/cationic lipid hybrid core and a lipid-poly(ethylene glycol) (lipid-PEG) shell for systemic siRNA delivery. The new generation lipid–polymer hybrid NPs are small and uniform, and can efficiently encapsulate siRNA and control its sustained release. They exhibit long blood circulation (<I>t</I><SUB>1/2</SUB> ∼8 h), high tumor accumulation, effective gene silencing, and negligible in vivo side effects. With this RNAi NP, we delineate and validate the therapeutic role of Prohibitin1 (PHB1), a target protein that has not been systemically evaluated in vivo due to the lack of specific and effective inhibitors, in treating non-small cell lung cancer (NSCLC) as evidenced by the drastic inhibition of tumor growth upon PHB1 silencing. Human tissue microarray analysis also reveals that high PHB1 tumor expression is associated with poorer overall survival in patients with NSCLC, further suggesting PHB1 as a therapeutic target. We expect this long-circulating RNAi NP platform to be of high interest for validating potential cancer targets in vivo and for the development of new cancer therapies.</P>

Identification of a novel circularized transcript of the AML1 gene

Ai Ning Xu,Xiu Hua Chen,Yan Hong Tan,Xi Ling Qi,Zhi Fang Xu,Lin Lin Zhang,Fang Gang Ren,Si Cheng Bian,Yi Chen,Hong Wei Wang 생화학분자생물학회(구 한국생화학분자생물학회) 2013 BMB Reports Vol.46 No.3

중등 예비수학교사가 경험한 학교현장실습에서의 원격수업에 대한 내러티브 탐구

김현하(Hyunha Kim), 서희(Xi Xu), 박창언(Changun Park) 학습자중심교과교육학회 2023 학습자중심교과교육연구 Vol.23 No.9

목적 본 연구에서는 중등 예비수학교사가 경험한 학교현장실습에서의 원격수업과 그 의미를 탐구하고, 앞으로의 학교현장 내의 원격수업과 학교현장실습 체제에 대해 논의하였다. 방법 이를 위하여 한 지방대학에 재학 중인 수학교육과 4학년 학생 3인을 연구 참여자로 선정하여, 자료 수집 및 인터뷰를 진행하였다. 자료는 2021년 10월부터 2개월 동안 수집되었으며, 면담은 연구참여자와 직접 면담하거나 줌(Zoom)을 활용하여 진행되었다. 결과 그 결과, 중등 예비수학교사가 경험한 간접실습은 유의미하지 않았으며, 중등 예비수학교사는 학교현장에서의 원격수업에서 학생과의 쌍방향적인 의사소통 부족, 시간 안배와 판서 구현의 미숙, 관심도와 성적에 따라 커지는 수업참여도의 격차로 인한 어려움을 경험한 것으로 나타났다. 그리고 학교현장실습은 중등 예비수학교사가 본인이 겪은 어려움과 문제점을 개선하고자 다짐하는 계기가 되는 것으로 나타났다. 결론 이러한 연구결과를 바탕으로, 학교현장과 학교현장실습체제에서 원격수업의 장점을 극대화하고, 실습학교 간의 차이로 야기되는 학교현장실습의 격차를 최소화하며, 중등 예비수학교사의 공학적 도구 사용 능력을 향상해야 함을 논의하였다. Objectives This study explores te experience of distance learning in practicum of seoncdary pre-service mathmatics teachers. The future of distance learning and the system for the effective practicum within and without the school field were discussed. Methods Three of fourth-grade students of the mathematics education department attending a local university were selected as research participants, and data collection and interviews were conducted. Data were collected for two months from October 2021, and interviews were conducted either directly with the research participants or using Zoom. Results The distance learning experienced by the secondary pre-mathematics teacher was insignificant, and the secondary pre-service mathematics teachers experienced difficulties due to the lack of interactive communication with students in distance learning at school, unskilled time arrangement and document implementation, and the gap of class participation among students. In addition, it was found that the practicum serves as an opportunity for secondary school pre-service mathematics teachers to improve the difficulties and problems they experienced. Conclusions Based on these findings, it was discussed that the advantages of distance learning should be maximized in the school field and the up-coming system of practicum, the gap of the quality of experience in practicum caused by differences between practical schools should be minimized, and the ability of pre-service mathematics teachers using technology in class should be improved.