• Title/Summary/Keyword: Connectivity efficiency

Search Result 175, Processing Time 0.032 seconds

A Study on Sustainable Earth Architecture Characteristic from Ecological Aesthetic Point of View - Focus on the thoughts of Lao-tzu - (생태미학적 관점에서의 지속가능한 흙건축 특성에 관한 연구 - 노자사상을 중심으로 -)

  • Kim, Seol-Hyi;Hur, Bum-Pall
    • Korean Institute of Interior Design Journal
    • /
    • v.20 no.4
    • /
    • pp.54-62
    • /
    • 2011
  • Fast industrialization caused from Descartes' dichotomy has enormously developed our world, but endangered the ecosystem. In this study, the ecosystem aesthetics is not only a critique against existing growth-ideology and technical civilization, but also the art pursuing the life as an artistic state and achieving the dream for qualitatively different new future. Lao-tzu's Natural Beauty assumes that the adaptation to natural laws can lead every purpose's achievement. Based on such theoretical alternative, the earth construction as a medium for coexisting mankind, nature and construction interacts with the other objects through the natural affinity, the energy efficiency, the material generation. The earth construction provides the images of naivety, naturalness, folk as well as emotional stability in cultural terms. This study's direction and method are as follows. First, it researches the ecosystem aesthetics from the Taoism viewpoint, the alternative for environmental healing based on theoretical reviews about the ecosystem aesthetics. Second, it researches the earth construction's ecosystem aesthetic features and construction features from the low-tech aspect in continual construction genealogy. Third, it analyzes some cases targeting domestic buildings by drawing out expression methods and features through the connectivity of earth construction and ecosystem aesthetics. The earth construction lies between the heaven and the earth, but coexists in natural cycle. The earth construction caused from ecosystem aesthetics will be a future alterative, and various studies about its features and methods should be continued.

GA-based Two Phase Method for a Highly Reliable Network Design (높은 신뢰도의 네트워크 설계를 위한 GA 기반 두 단계 방법)

  • Jo, Jung-Bok
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.9 no.5
    • /
    • pp.1149-1160
    • /
    • 2005
  • Generally, the network topology design problem, which is difficult to solve with the classical method because it has exponentially increasing complexity with the augmented network size, is characterized as a kind of NP-hard combinatorial optimization problem. The problem of this research is to design the highly reliable network topology considering the connection cost and all-terminal network reliability, which can be defined as the probability that every pair of nodes can communicate with each other. In order to solve the highly reliable network topology design problem minimizing the construction cost subject to network reliability, we proposes an efficient two phase approach to design reliable network topology, i.e., the first phase employs, a genetic algorithm (GA) which uses $Pr\ddot{u}fer$ number for encoding method and backtracking Algorithm for network reliability calculation, to find the spanning tree; the second phase is a greedy method which searches the optimal network topology based on the spanning ree obtained in the first phase, with considering 2-connectivity. finally, we show some experiments to demonstrate the effectiveness and efficiency of our two phase approach.

Brush-painted Ti-doped In2O3 Transparent Conducting Electrodes Using Nano-particle Solution for Printable Organic Solar Cells

  • Jeong, Jin-A;Kim, Han-Gi
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2014.02a
    • /
    • pp.458.2-458.2
    • /
    • 2014
  • We have demonstrated that simple brush-painted Ti-doped $In_2O_3$(TIO) films can be used as a cost effective transparent anodes for organic solar cells (OSCs). We examined the RTA effects on the electrical, optical, and structural properties of the brush painted TIO electrodes. By the direct brushing of TIO nanoparticle ink and rapid thermal annealing (RTA), we can simply obtain TIO electrodes with a low sheet resistance of 28.25 Ohm/square and a high optical transmittance of 85.48% under atmospheric ambient conditions. Furthermore, improvements in the connectivity of the TIO nano-particles in the top region during the RTA process play an important role in reducing the resistivity of the brush-painted TIO anode. In particular, the brush painted TIO films showed a much higher mobility ($33.4cm^2/V-s$) than that of previously reported solution-process transparent oxide films ($1{\sim}5cm^2/V-s$) due to the effects of the Ti dopant with higher Lewis acid strength (3.06) and the reduced contact resistance of TIO nanoparticles. The OSCs fabricated on the brush-painted TIO films exhibited cell-performance with an open circuit voltage (Voc) of 0.61 V, shot circuit current (Jsc) of $7.90mA/cm^2$, fill factor (FF) of 61%, and power conversion efficiency (PCE) of 2.94%. This indicates that brush-painted TIO film is a promising cost-effective transparent electrode for printing-based OSCs with its simple process and high performance.

  • PDF

An Architecture and Performance Evaluation of RDCDN (Re-Distribution based CDN) (콘텐츠 재분배 기능을 갖는 CDN(Content Delivering Network) 구조 및 특성)

  • Sung, Moo-Kyung;Han, Chi-Moon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.34 no.6B
    • /
    • pp.559-567
    • /
    • 2009
  • Distributed Content Delivering Network (DCDN) will make use of the existing resources of the common Internet users in terms of storage space, bandwidth and Internet connectivity to create it. However DCDN has some limitations that are inefficient using of storage space, reliability and having special load balancing (LB) algorithm. So, this paper proposes Re-distribution based CDN (RDCDN) that overcomes the limitations of DCDN. RDCDN has the content re-distribution algorithm and separates surrogates to main surrogate and sub surrogates. Main surrogate can help service reliability be improved by storing all contents as back-up system. And content re-distribution algorithm also can help storage space be saved because all contents are not stored in every surrogate. Especially, when RDCwDN uses content re-distribution algorithm, it can work active load balancing function without extra LB algorithm like as DCDN. Results of simulation show that the proposed architecture can improve reliability and efficiency of storage space, and it also can offer the same performance as that of commercial CDN and DCDN.

Optimization of Resource Allocation for Inter-Channel Load Balancing with Frequency Reuse in ASO-TDMA-Based VHF-Band Multi-Hop Data Communication System (ASO-TDMA기반 다중-홉 VHF 대역 데이터 통신 시스템의 주파수 재사용을 고려한 채널간 부하 균형을 위한 자원 할당 최적화)

  • Cho, Kumin;Lee, Junman;Yun, Changho;Lim, Yong-Kon;Kang, Chung G.
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.40 no.7
    • /
    • pp.1457-1467
    • /
    • 2015
  • Depending on the type of Tx-Rx pairs, VHF Data Exchange System (VDES) for maritime communication is expected to employ the different frequency channels. Load imbalance between the different channels turns out to be a critical problem for the multi-hop communication using Ad-hoc Self-Organizing TDMA (ASO-TDMA) MAC protocol, which has been proposed to provide the connectivity between land station and remote ship stations. In order to handle the inter-channel load imbalance problem, we consider a model of the stochastic geomety in this paper. After analyzing the spatial reuse efficiency in each hop region by the given model, we show that the resource utility can be maximized by balancing the inter-channel traffic load with optimal resource allocation in each hop region.

Multilayer QCA D-latch design using cell interaction (셀 간 상호작용을 이용한 다층구조 QCA D-래치 설계)

  • Jang, Woo-Yeong;Jeon, Jun-Cheol
    • The Journal of the Convergence on Culture Technology
    • /
    • v.6 no.2
    • /
    • pp.515-520
    • /
    • 2020
  • CMOS used in digital circuit design technology has reached the limit of integration due to quantum tunneling. Quantum-dot cellular automata (QCA), which can replace this, has many advantages such as low power consumption and fast switching speed, so many digital circuits of CMOS have been proposed based on QCA. Among them, the multiplexer is a basic circuit used in various circuits such as D-flip-flops and resistors, and has been studied a lot. However, the existing multiplexer has a disadvantage that space efficiency is not good. Therefore, in this paper, we propose a new multilayered multiplexer using cell interaction and D-latch using it. The multiplexer and D-latch proposed in this paper have improved area, cell count, and delay time, and have excellent connectivity and scalability when designing large circuits. All proposed structures are simulated using QCADesigner to verify operation.

A Scheme of Extracting Forward Vehicle Area Using the Acquired Lane and Road Area Information (차선과 도로영역 정보를 이용한 전방 차량 영역의 추출 기법)

  • Yu, Jae-Hyung;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.18 no.6
    • /
    • pp.797-807
    • /
    • 2008
  • This paper proposes a new algorithm of extracting forward vehicle areas using the acquired lanes and road area information on road images with complex background to improve the efficiency of the vehicle detection. In the first stage, lanes are detected by taking into account the connectivity among the edges which are determined from a method of chain code. Once the lanes proceeding to the same direction with the running vehicle are detected, neighborhood roadways are found from the width and vanishing point of the acquired roadway of the running vehicle. And finally, vehicle areas, where forward vehicles are located on the road area including the center and neighborhood roadways, are extracted. Therefore, the proposed scheme of extracting forward vehicle area improves the rate of vehicle detection on the road images with complex background, and is highly efficient because of detecting vehicles within the confines of the acquired vehicle area. The superiority of the proposed algorithm is verified from experiments of the vehicle detection on road images with complex background.

Protocol-Aware Radio Frequency Jamming inWi-Fi and Commercial Wireless Networks

  • Hussain, Abid;Saqib, Nazar Abbas;Qamar, Usman;Zia, Muhammad;Mahmood, Hassan
    • Journal of Communications and Networks
    • /
    • v.16 no.4
    • /
    • pp.397-406
    • /
    • 2014
  • Radio frequency (RF) jamming is a denial of service attack targeted at wireless networks. In resource-hungry scenarios with constant traffic demand, jamming can create connectivity problems and seriously affect communication. Therefore, the vulnerabilities of wireless networks must be studied. In this study, we investigate a particular type of RF jamming that exploits the semantics of physical (PHY) and medium access control (MAC) layer protocols. This can be extended to any wireless communication network whose protocol characteristics and operating frequencies are known to the attacker. We propose two efficient jamming techniques: A low-data-rate random jamming and a shot-noise based protocol-aware RF jamming. Both techniques use shot-noise pulses to disrupt ongoing transmission ensuring they are energy efficient, and they significantly reduce the detection probability of the jammer. Further, we derived the tight upper bound on the duration and the number of shot-noise pulses for Wi-Fi, GSM, and WiMax networks. The proposed model takes consider the channel access mechanism employed at the MAC layer, data transmission rate, PHY/MAC layer modulation and channel coding schemes. Moreover, we analyze the effect of different packet sizes on the proposed jamming methodologies. The proposed jamming attack models have been experimentally evaluated for 802.11b networks on an actual testbed environment by transmitting data packets of varying sizes. The achieved results clearly demonstrate a considerable increase in the overall jamming efficiency of the proposed protocol-aware jammer in terms of packet delivery ratio, energy expenditure and detection probabilities over contemporary jamming methods provided in the literature.

Development of Web GIS Based Road Sign Integrated System for Enhancing Management Efficiency (도로표지 관리 효율성 향상을 위한 Web GIS기반 통합시스템 개발)

  • Lee, Woo-Sik;Na, Joon-Yeop;Woo, Je-Yoon
    • Spatial Information Research
    • /
    • v.15 no.3
    • /
    • pp.335-346
    • /
    • 2007
  • Road sign is one of the road attached facilities to provide conveniences to motor drivers. The setup of location information according to the related regulation and the inclusion of various attributes such as place names, route numbers, symbols, bearings, distances to the place of interest distinguish the road sign from other facilities. These features give advantages to the informationization of road sign. Presently there established about 130,000 road signs on each class of roads, and about 280 road management offices have controlled these road signs independently, but there are plethora of ineffectiveness such as the lack of consistency, recognition, connectivity, and location suitability etc. These are the major factor of confusions rather than providing conveniences, and arisen a lot of public grievances. Accordingly, in this research the road signs throughout the nation were databased and the web-GIS based road sign management system was established to ameliorate the problems reveled. Since the road sign management system we developed reflected the demands of the persons in charge and users, the management effectiveness might be enhanced and the public inconveniences will be reduced.

  • PDF

Performance Enhancement of AODV Routing Protocol Using Interrupt Message in MANET (MANET에서 Interrupt message를 이용한 AODV 라우팅 프로토콜의 성능 개선)

  • Lee, Yun-Kyung;Kim, Ju-Gyun
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.38B no.10
    • /
    • pp.785-800
    • /
    • 2013
  • In MANET, AODV(Ad hoc On-demand Distance Vector) has its advantages as on-demand approach but it also has a disadvantage that the control packet overhead is high compared to other routing protocols. This paper improves the problem caused by Hello messages that are broadcasted periodically to detect the local connectivity and maintain neighbor list. Periodic hello messages reduce the Packet delivery ratio and the efficiency in the limited bandwidth. And its increased Control packet overhead leads to decrease the Residual battery capacity and the Network lifetime. Further, non-reactive nature of periodic hello messages in AODV has also been the source of numerous controversies. In order to solve these problems, this paper improves the performance by using the interrupt driven approach which removes periodic hello messages and decreases the Control packet overhead. Performance comparisons between the traditional AODV and proposed mod_AODV done with network simulator QualNet 5.0 show that the mod_AODV performs better in most performance metrics under scenarios with various values of simulation parameters.