• Title/Summary/Keyword: Key Change

Search Result 1,952, Processing Time 0.027 seconds

A Receiver-Driven Loss Recovery Mechanism for Video Dissemination over Information-Centric VANET

  • Han, Longzhe;Bao, Xuecai;Wang, Wenfeng;Feng, Xiangsheng;Liu, Zuhan;Tan, Wenqun
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.11 no.7
    • /
    • pp.3465-3479
    • /
    • 2017
  • Information-Centric Vehicular Ad Hoc Network (IC-VANET) is a promising network architecture for the future intelligent transport system. Video streaming applications over IC-VANET not only enrich infotainment services, but also provide the drivers and pedestrians real-time visual information to make proper decisions. However, due to the characteristics of wireless link and frequent change of the network topology, the packet loss seriously affects the quality of video streaming applications. In this paper, we propose a REceiver-Driven loss reCOvery Mechanism (REDCOM) to enhance video dissemination over IC-VANET. A Markov chain based estimation model is introduced to capture the real-time network condition. Based on the estimation result, the proposed REDCOM recovers the lost packets by requesting additional forward error correction packets. The REDCOM follows the receiver-driven model of IC-VANET and does not require the infrastructure support to efficiently overcome packet losses. Experimental results demonstrate that the proposed REDCOM improves video quality under various network conditions.

A Fiber Optic Sensor for Determination of 2,4-Dichlorophenol Based on Oxygen Oxidation Catalyzed by Iron(III) Tetrasulfophthalocyanine

  • Tong, Yilin;Li, Dapeng;Huang, Jun;Zhang, Cong;Li, Kun;Ding, Liyun
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.11
    • /
    • pp.3307-3311
    • /
    • 2013
  • A new fiber optical sensor was developed for the determination of 2,4-dichlorophenol (DCP). The sensor was based on DCP oxidation by oxygen with the catalysis of iron(III) tetrasulfophthalocyanine (Fe(III)PcTs). The optical oxygen sensing film with $Ru(bpy)_3Cl_2$ as the fluorescence indicator was used to determine the consumption of oxygen in solution. A lock-in amplifier was used for detecting the lifetime of the oxygen sensing film by measuring the phase delay change of the sensor head. The different variables affecting the sensor performance were evaluated and optimized. Under the optimal conditions (i.e. pH 6.0, $25^{\circ}C$, Fe(III)PcTs concentration of 0.62 mg/mL), the linear detection range and response time of the sensor are $1.0{\times}10^{-6}-9.0{\times}10^{-6}$ mol/L and 250 s, respectively. The sensor displays high selectivity, good repeatability and stability, and can be used as an effective tool in analyzing DCP concentration in practical samples.

Response of Saccharomyces cerevisiae to Ethanol Stress Involves Actions of Protein Asr1p

  • Ding, Junmei;Huang, Xiaowei;Zhao, Na;Gao, Feng;Lu, Qian;Zhang, Ke-Qin
    • Journal of Microbiology and Biotechnology
    • /
    • v.20 no.12
    • /
    • pp.1630-1636
    • /
    • 2010
  • During the fermentation process of Saccharomyces cerevisiae, yeast cells must rapidly respond to a wide variety of external stresses in order to survive the constantly changing environment, including ethanol stress. The accumulation of ethanol can severely inhibit cell growth activity and productivity. Thus, the response to changing ethanol concentrations is one of the most important stress reactions in S. cerevisiae and worthy of thorough investigation. Therefore, this study examined the relationship between ethanol tolerance in S. cerevisiae and a unique protein called alcohol sensitive RING/PHD finger 1 protein (Asr1p). A real-time PCR showed that upon exposure to 8% ethanol, the expression of Asr1 was continuously enhanced, reaching a peak 2 h after stimulation. This result was confirmed by monitoring the fluorescence levels using a strain with a green fluorescent protein tagged to the C-terminal of Asr1p. The fluorescent microscopy also revealed a change in the subcellular localization before and after stimulation. Furthermore, the disruption of the Asr1 gene resulted in hypersensitivity on the medium containing ethanol, when compared with the wild-type strain. Thus, when taken together, the present results suggest that Asr1 is involved in the response to ethanol stress in the yeast S. cerevisiae.

Video Conferencing Authentication : A Key Management Protocol Design for safety (화상상담 인증 : 안전한 키 관리 프로토콜 설계)

  • Deug, Jung-Young
    • Journal of the Korea Society of Computer and Information
    • /
    • v.15 no.12
    • /
    • pp.85-92
    • /
    • 2010
  • There is an authentication method for participants with an encrypted ID and password as a symmetric-key in multilateral video conferencing. It is hard to manage when the security-keys makes many while the transportation processing for the encryption and decryption get complicated when the video conferencing involves a number of participants and the third party as an attackers to gain unauthorized symmetric-key to access video conference which makes a problem less secrecy. This study suggests three ways to enhance security in video conference: first, we present PKI-based X.509 certificate for authenticating the participants of multilateral conferencing and we suggest to encode and decode the video conference media data using a secrecy key created by each of the conference participants; second, a more secured multilateral video conferencing can be expected in a group communication by using the participants secrecy key in creating and distributing group keys, where the group key will be renewed whenever there is change in the group member; and finally, we suggest to encode the RTP payload of the media data before transmission.

Transcriptome sequencing revealed the inhibitory mechanism of ketoconazole on clinical Microsporum canis

  • Wang, Mingyang;Zhao, Yan;Cao, Lingfang;Luo, Silong;Ni, Binyan;Zhang, Yi;Chen, Zeliang
    • Journal of Veterinary Science
    • /
    • v.22 no.1
    • /
    • pp.4.1-4.13
    • /
    • 2021
  • Background: Microsporum canis is a zoonotic disease that can cause dermatophytosis in animals and humans. Objectives: In clinical practice, ketoconazole (KTZ) and other imidazole drugs are commonly used to treat M. canis infection, but its molecular mechanism is not completely understood. The antifungal mechanism of KTZ needs to be studied in detail. Methods: In this study, one strain of fungi was isolated from a canine suffering with clinical dermatosis and confirmed as M. canis by morphological observation and sequencing analysis. The clinically isolated M. canis was treated with KTZ and transcriptome sequencing was performed to identify differentially expressed genes in M. canis exposed to KTZ compared with those unexposed thereto. Results: At half-inhibitory concentration (½MIC), compared with the control group, 453 genes were significantly up-regulated and 326 genes were significantly down-regulated (p < 0.05). Quantitative reverse transcription polymerase chain reaction analysis verified the transcriptome results of RNA sequencing. Gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the 3 pathways of RNA polymerase, steroid biosynthesis, and ribosome biogenesis in eukaryotes are closely related to the antifungal mechanism of KTZ. Conclusions: The results indicated that KTZ may change cell membrane permeability, destroy the cell wall, and inhibit mitosis and transcriptional regulation through CYP51, SQL, ERG6, ATM, ABCB1, SC, KER33, RPA1, and RNP genes in the 3 pathways. This study provides a new theoretical basis for the effective control of M. canis infection and the effect of KTZ on fungi.

Ginsenoside Rg1 alleviates vascular remodeling in hypoxia-induced pulmonary hypertension mice through the calpain-1/STAT3 signaling pathway

  • Chenyang Ran;Meili Lu;Fang Zhao;Yi Hao;Xinyu Guo;Yunhan Li;Yuhong Su;Hongxin Wang
    • Journal of Ginseng Research
    • /
    • v.48 no.4
    • /
    • pp.405-416
    • /
    • 2024
  • Background: Hypoxic pulmonary hypertension (HPH) is the main pathological change in vascular remodeling, a complex cardiopulmonary disease caused by hypoxia. Some research results have shown that ginsenoside Rg1 (Rg1) can improve vascular remodeling, but the effect and mechanism of Rg1 on hypoxia-induced pulmonary hypertension are not clear. The purpose of this study was to discuss the potential mechanism of action of Rg1 on HPH. Methods: C57BL/6 mice, calpain-1 knockout mice and Pulmonary artery smooth muscle cells (PASMCs) were exposed to a low oxygen environment with or without different treatments. The effect of Rg1 and calpain-1 silencing on inflammation, fibrosis, proliferation and the protein expression levels of calpain-1, STAT3 and p-STAT3 were determined at the animal and cellular levels. Results: At the mouse and cellular levels, hypoxia promotes inflammation, fibrosis, and cell proliferation, and the expression of calpain-1 and p-STAT3 is also increased. Ginsenoside Rg1 administration and calpain-1 knockdown, MDL-28170, and HY-13818 treatment showed protective effects on hypoxia-induced inflammation, fibrosis, and cell proliferation, which may be associated with the downregulation of calpain-1 and p-STAT3 expression in mice and cells. In addition, overexpression of calpain 1 increased p-STAT3 expression, accelerating the onset of inflammation, fibrosis and cell proliferation in hypoxic PASMCs. Conclusion: Ginsenoside Rg1 may ameliorate hypoxia-induced pulmonary vascular remodeling by suppressing the calpain-1/STAT3 signaling pathway.

Business Process Model for Progress Phase of Design-Build Project (설계시공일괄방식 사업의 진행단계별 업무프로세스 모델)

  • Song, Young-Woong;Son, Bo-Sik;Chun, Jae-Youl;Choi, Yoon-Ki
    • Korean Journal of Construction Engineering and Management
    • /
    • v.10 no.4
    • /
    • pp.38-49
    • /
    • 2009
  • In public project market, design-build projects have been increased because of market trend change which enables technical competition. In this condition, its importance is also getting important. Generally, life cycle of design-build project consists of planning, preliminary design, procurement, contract, detail design, start of construction, construction, end of construction, and evaluation. From contractor's viewpoint, it has problems such as difficulties in project management and information sharing because of frequent change of charged division. To solve these problems, it is desirable to change from function-based management system to process-based management system. The purpose of this study is to develop management process model for design-build project by progress phases. This study analyzed main conflicts and decision making factors of each stage in design-build projects, then systemized management subjects' responsibilities and management points' change. And also this study defined the key information that is the key point by project characteristics and progress phases. Based on this analysis, this study did business process modeling from planning stage to construction design check stage. At last, we proposed the way to manage business process by design-build project progress.

The Great Western Woodlands TERN SuperSite: ecosystem monitoring infrastructure and key science learnings

  • Suzanne M Prober;Georg Wiehl;Carl R Gosper;Leslie Schultz;Helen Langley;Craig Macfarlane
    • Journal of Ecology and Environment
    • /
    • v.47 no.4
    • /
    • pp.272-281
    • /
    • 2023
  • Ecosystem observatories are burgeoning globally in an endeavour to detect national and global scale trends in the state of biodiversity and ecosystems in an era of rapid environmental change. In this paper we highlight the additional importance of regional scale outcomes of such infrastructure, through an introduction to the Great Western Woodlands TERN (Terrestrial Ecosystem Research Network) SuperSite, and key findings from three gradient plot networks that are part of this infrastructure. The SuperSite was established in 2012 in the 160,000 km2 Great Western Woodlands region, in a collaboration involving 12 organisations. This region is globally significant for its largely intact, diverse landscapes, including the world's largest Mediterranean-climate woodlands and highly diverse sandplain shrublands. The dominant woodland eucalypts are fire-sensitive, requiring hundreds of years to regrow after fire. Old-growth woodlands are highly valued by Indigenous and non-Indigenous communities, and managing impacts of climate change and the increasing extent of intense fires are key regional management challenges. Like other TERN SuperSites, the Great Western Woodlands TERN SuperSite includes a core eddy-covariance flux tower measuring exchanges of carbon, water and energy between the vegetation and atmosphere, along with additional environmental and biodiversity monitoring around the tower. The broader SuperSite incorporates three gradient plot networks. Two of these represent aridity gradients, in sandplains and woodlands, informing regional climate adaptation and biodiversity management by characterising biodiversity turnover along spatial climate gradients and acting as sentinels for ecosystem change over time. For example, the sandplains transect has demonstrated extremely high spatial turnover rates in plant species, that challenge traditional approaches to biodiversity conservation. The third gradient plot network represents a 400-year fire-age gradient in Eucalyptus salubris woodlands. It has enabled characterisation of post-fire recovery of vegetation, birds and invertebrates over multi-century timeframes, and provided tools that are directly informing management to reduce stand-replacing fires in eucalypt woodlands. By building regional partnerships and applying globally or nationally consistent methodologies to regional scale questions, ecological observatories have the power not only to detect national and global scale trends in biodiversity and ecosystems, but to directly inform environmental decisions that are critical at regional scales.

Scoping for Environmental Impact and System Improvement of Marine Sand Mining in Korea (바다골재채취에 따른 환경영향 스코핑과 제도개선)

  • Lee, Dae-In;Eom, Ki-Hyuk;Jeon, Kyeong-Am;Kim, Gui-Young
    • Journal of Environmental Impact Assessment
    • /
    • v.19 no.3
    • /
    • pp.335-345
    • /
    • 2010
  • This paper assessed environmental impacts of marine sand mining on coastal areas and Exclusive Economic Zones (EEZs) of Korea, and diagnosed problems of the related assessment statements for suggesting key assessment items (scoping) and system improvement. To mitigate conflicts and environmental impacts caused by large-scale, concentrated sand mining, we suggest it is critical to promote sustainable and eco-friendly utilization of marine resources while listening opinions from various stakeholders and analyzing alternative plans. Especially, it should be mandatory as a scoping item to provide verifiable data on the amount of sand, potential and accumulative impacts by mining, and key assessment items (e.g. erosion and sedimentation by submarine topography, benthic change, spreading of suspended solids, water pollution, grain-size change, and impact on fisheries resources). We also suggest that postassessment and monitoring should be improved to enable tracking of environmental impacts caused by sand mining through seasonal monitoring together with intermittent short-term surveys. In addition, effective measures to mitigate the impacts is also essential. As repeated sand mining at large-scale can damage marine ecosystems by long-term accumulated impacts, we suggest that assessment systems and regulatory policies should be developed and established, especially for ensuring reliability of assessment and review on selected major sandmining projects.

Factors and Directions of the Change in Apparel Retail Structure in Korea (Part II) (우리나라 의류상품 소매유통구조의 변화요인과 방향 (제2보))

  • Ko, Sun-Young;Rhee, Eun-Young
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.34 no.7
    • /
    • pp.1087-1099
    • /
    • 2010
  • This study explores the retail environment factors of the changes mentioned in the "Factors and Directions of the Change of the Apparel Retail Structure in Korea" (Part I) to understand the changes in apparel retail institutions. This study was done through a literature research method and the results are as follows. First, changing consumer needs and trends require extensive new products, a method to manufacture diverse products according to the market demand, and the necessity to manufacture based on trends in demand. This limits the role of mass production, which brought about more flexible manufacturing modes, scaled down manufacturing factories, promoted more cooperative subcontract relationships, and increased global sourcing which uses other companies at the most appropriate global venue. How to organize and use cooperative networks that benefit companies is the key to global competitiveness in the new era and the information technology developed around retail shops plays a key role. Consequently, the management of consumers and their information becomes critical and retail distribution functions become a key corporate function. In addition, it is difficult for small shops to introduce effective new technologies that encourage the growth of large companies. Second, apparel companies that use to benefit from scale merits based on the previous mass production system are now becoming effective by using economies of scale through mass retailing while shops are enlarging their sizes as a way to survive. On the other hand, inexpensive clothes become even more inexpensive while expensive ones become even more expensive, promoting polarization and diverse price ranges that widen consumer options.