http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Robust Key Agreement From Received Signal Strength in Stationary Wireless Networks
( Aiqing Zhang ),( Xinrong Ye ),( Jianxin Chen ),( Liang Zhou ),( Xiaodong Lin ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.5
Key agreement is paramount in secure wireless communications. A promising approach to address key agreement schemes is to extract secure keys from channel characteristics. However, because channels lack randomness, it is difficult for wireless networks with stationary communicating terminals to generate robust keys. In this paper, we propose a Robust Secure Key Agreement (RSKA) scheme from Received Signal Strength (RSS) in stationary wireless networks. In order to mitigate the asymmetry in RSS measurements for communicating parties, the sender and receiver normalize RSS measurements and quantize them into q-bit sequences. They then reshape bit sequences into new l-bit sequences. These bit sequences work as key sources. Rather than extracting the key from the key sources directly, the sender randomly generates a bit sequence as a key and hides it in a promise. This is created from a polynomial constructed on the sender`s key source and key. The receiver recovers the key by reconstructing a polynomial from its key source and the promise. Our analysis shows that the shared key generated by our proposed RSKA scheme has features of high randomness and a high bit rate compared to traditional RSS-based key agreement schemes.
Point In Triangle Testing Based Trilateration Localization Algorithm In Wireless Sensor Networks
( Aiqing Zhang ),( Xinrong Ye ),( Haifeng Hu ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.10
Localization of sensor nodes is a key technology in Wireless Sensor Networks(WSNs). Trilateration is an important position determination strategy. To further improve the localization accuracy, a novel Trilateration based on Point In Triangle testing Localization (TPITL)algorithm is proposed in the paper. Unlike the traditional trilateration localization algorithm which randomly selects three neighbor anchors, the proposed TPITL algorithm selects three special neighbor anchors of the unknown node for trilateration. The three anchors construct the smallest anchor triangle which encloses the unknown node. To choose the optimized anchors, we propose Point In Triangle testing based on Distance(PITD) method, which applies the estimated distances for trilateration to reduce the PIT testing errors. Simulation results show that the PIT testing errors of PITD are much lower than Approximation PIT(APIT) method and the proposed TPITL algorithm significantly improves the localization accuracy.
Zhang Aiqing,Liu Wenjuan,Niu Lingyun,Zhu Liping,Yang Liuqing,Li Xueliang 한국유전학회 2023 Genes & Genomics Vol.45 No.5
Background Gastroesophageal reflux disease (GERD) is a highly prevalent and troublesome disease. Several differentially expressed microRNAs (miRNAs) have been found in GERD. Objective This study was to analyze the correlation of miR-29a-3p expression and CYP2C19 genotypes in exfoliated cells from tongue coating of GERD patients and its prognostic value. Methods Tongue coating specimens were collected from 130 GERD patients and 70 healthy volunteers and their clinical baseline information was recorded. miR-29a-3p expression in exfoliated cells from tongue coating was determined via RT-qPCR, and its diagnostic efficiency on GERD was evaluated via receiver operating characteristic curve. CYP2C19 genotypes and their correlation with miR-29a-3p were analyzed via polymerase chain reaction restriction fragment length polymorphism technique. The adverse events of patients were documented via 12-month follow-up. The impact of miR-29a-3p expression on the healing rate of patients was analyzed via Kaplan-Meier method. Qualification of miR-29a-3p as an independent prognostic factor of GERD patients was analyzed via multivariate Cox regression analysis. Results miR-29a-3p was highly-expressed in exfoliated cells from tongue coating of GERD patients. miR-29a-3p expression had high specificity and sensitivity in diagnosing GERD. CYP2C19 genotypes in GERD patients comprised rapid metabolizers, intermedia metabolizers, and poor metabolizers. miR-29a-3p expression showed a correlation with CYP2C19 genotypes. Higher miR-29a-3p expression predicted higher cumulative incidences of adverse outcomes. Highly-expressed miR-29a-3p was an independent prognostic factor for adverse outcomes of GERD patients. Conclusion High expression of miR-29a-3p aided the diagnosis and predicted poor prognosis of GERD patients.
이명훈 ( Myong Hoon Lee ),나창운 ( Chang Woon Nah ),황기준 ( Kee Jun Hwang ),( Aiqing Zhang ),( Xaingdan Li ) 한국화상학회 2001 한국화상학회지 Vol.7 No.2
4,4 -(Hexafluoroisopropylidene)diphthalic anhydride(6FDA)와 4,4 -oxydianiline(ODA)를 이용하여 용해성 폴리이미드를 합성하고, 클로로메틸화를 통하여 폴리이미드의 측쇄에 클로로메틸기를 도입하는 새로운 폴리이미드의 개질 방법을 개발하였으며, 클로로메틸화에 의한 클로로메틸기의 치환성에 대하여 연구하였다. 새로 합성한 클로로메틸화 폴리이미드의 구조는 1H-NMR를 통하여 확인하였으며, 열적안정성은 TGA와 DSC를 통하여 조사하였다. 열분해는 273 ~ 357℃ 범위에서 일어나며, 유리전이온도는 236 ~ 286℃ 범위에서 나타난다. 합성된 클로로메틸화 폴리이미드 들은 아주 우수한 용해성을 가지며, DMSO등과 같은 극성용매뿐만 아니라 클로로포름이나 THF에도 용해하며, 아세톤에도 부분 용해한다. From 4,4-(hexafluoroisoproylidene)diphthalic anhydride(6FDA) and 4,4-oxydianiline(OBA) soluble aromatic polyimides were synthesized and chloromethylated with chloromethyl methyl ether to devote a new modification method of aromatic polyimides. Chemical structure of the resulting polymer was confirmed by ^1H-NMR and FT-IR spectroscopy. Substitution of chloromethyl side group was also investigated in terms of the reaction condition. Thermal properties were characterized by DCS and TGA, which showed two step thermal degradations at 273 ~ 357℃, and Tg s at 236 ~ 286℃. All polymers have good solubility in common organic solvents such as chloroform and THF as well as in aprptic polar solvents such as DMSO and DMAc.