• Title/Summary/Keyword: hybrid protocol

Search Result 287, Processing Time 0.027 seconds

Prediction of Physicochemical Properties of Organic Molecules Using Semi-Empirical Methods

  • Kim, Chan Kyung;Cho, Soo Gyeong;Kim, Chang Kon;Kim, Mi-Ri;Lee, Hai Whang
    • Bulletin of the Korean Chemical Society
    • /
    • v.34 no.4
    • /
    • pp.1043-1046
    • /
    • 2013
  • Prediction of physicochemical properties of organic molecules is an important process in chemistry and chemical engineering. The MSEP approach developed in our lab calculates the molecular surface electrostatic potential (ESP) on van der Waals (vdW) surfaces of molecules. This approach includes geometry optimization and frequency calculation using hybrid density functional theory, B3LYP, at the 6-31G(d) basis set to find minima on the potential energy surface, and is known to give satisfactory QSPR results for various properties of organic molecules. However, this MSEP method is not applicable to screen large database because geometry optimization and frequency calculation require considerable computing time. To develop a fast but yet reliable approach, we have re-examined our previous work on organic molecules using two semi-empirical methods, AM1 and PM3. This new approach can be an efficient protocol in designing new molecules with improved properties.

Hierarchical network management based on MA+SNMP (MA+SNMP 기반의 계층적인 네트워크 관리구조)

  • Na, Ho-Jin;Cho, Kyung-San
    • Journal of the Korea Society of Computer and Information
    • /
    • v.15 no.5
    • /
    • pp.93-101
    • /
    • 2010
  • Although various network management architectures such as centralized, distributed, and hybrid have been presented, any one is not always efficient in all the environment. In this paper, we propose a hierarchical and split network management architecture based on MA+SNMP in order to manage a network of many small NEs distributed over the wide area. Our hierarchical architecture has MA-based proxy management nodes for the flexibility and overhead reduction in NMS as well as SNMP-based NEs considering NE's capacity. Through the analysis with real experiments, we show that our proposal improves some drawbacks and the processing delay of the existing architectures in the given environment.

A Hybrid Replication Protocol for Efficient and Secure Distributed System (효율적이고 안정한 분산시스템을 위한 하이브리드 복제 프로토콜)

  • Choi, Sung-Chune;Youn, Hee-Yong;Lee, Bo-Kyoung;Choi, Joong-Sup;Lee, Hyung-Su
    • Annual Conference of KIPS
    • /
    • 2002.11a
    • /
    • pp.197-200
    • /
    • 2002
  • 최근 분산 컴퓨팅 환경에서 데이터와 서비스의 복제는 통신 비용의 감소, 데이터 가용성 증가, 그리고 단일 서버의 병목현상을 피하기 위해 필수적이다. 기존의 대표적인 복제 프로토콜로 네트워크를 논리적으로 구성하는 Tree quorum 프로토콜과 Grid 프로토콜이 있다. Tree quorum 프로토콜은 최선의 경우 가장 우수한 읽기 성능을 보이는 반면 트리의 높이가 증가할수록 노드의 수가 기하급수적으로 증가한다는 단점을 가지고 있다. Grid 프로토콜은 읽기 동작에 있어 높은 가용성을 가지는 반면 고장이 없는 환경에서도 같은 읽기 및 쓰기 성능을 보이는 단점을 가지고 있다. 따라서 본 논문에서는 기존의 복제 프로토콜이 가지는 문제점을 해결하고, 복제 노드의 추가와 삭제가 보다 용이한 하이브리드 복제 프로토콜을 제안한다. 제안된 복제 프로토콜은 같은 수의 노드를 갖는 tree quorum 프로토콜에 비해 적은 읽기 비용을 가지며, 효율적인 노드의 구성을 통해 기존 복제 프로토콜보다 높은 데이터의 가용성을 가진다.

  • PDF

Blood pressure measurements and hypertension in infants, children, and adolescents: from the postmercury to mobile devices

  • Lim, Seon Hee;Kim, Seong Heon
    • Clinical and Experimental Pediatrics
    • /
    • v.65 no.2
    • /
    • pp.73-80
    • /
    • 2022
  • A mercury sphygmomanometer (MS) has been the gold standard for pediatric blood pressure (BP) measurements, and diagnosing hypertension is critical. However, because of environmental issues, other alternatives are needed. Noninvasive BP measurement devices are largely divided into auscultatory and oscillometric types. The aneroid sphygmomanometer, the currently used auscultatory method, is inferior to MS in terms of limitations such as validation and regular calibration and difficult to apply to infants, in whom Korotkoff sounds are not audible. The oscillometric method uses an automatic device that eliminates errors caused by human observers and has the advantage of being easy to use; however, owing to its measurement accuracy issues, the development of an international validation protocol for children is important. The hybrid method, which combines the auscultatory and electronic methods, solves some of these problems by eliminating the observer bias of terminal digit preference while maintaining measurement accuracy; however, the auscultatory method remains limited. As the age-related characteristics of the pediatric group are heterogeneous, it is necessary to reconsider the appropriate BP measurement method suitable for this indication. In addition, the mobile application-based BP measurement market is growing rapidly with the development of smartphone applications. Although more research is still needed on their accuracy, many experts expect that mobile application-based BP measurement will effectively reduce medical costs due to increased ease of access and early BP management.

Chromosomal Localization of Korean Cattle (Hanwoo) BAC Clones via BAC end Sequence Analysis

  • Chae, Sung-Hwa;Kim, Jae-Woo;Choi, Jae Min;Larkin, Denis M.;Everts-van der Wind, Annelie;Park, Hong-Seog;Yeo, Jung-Sou;Choi, Inho
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.3
    • /
    • pp.316-327
    • /
    • 2007
  • In this study, a Korean native cattle strain (Hanwoo) evidencing high performance in terms of both meat quality and quantity was employed in the generation of 150,000 BAC clones with an average insert size of 140 kb, and corresponding to about a 6X coverage of bovine chromosomal DNA. The BAC clones were pooled in a mini-scale via three rounds of a pooling protocol, and the efficiency of this pooling protocol was evaluated by testing the accuracy of accessibility to the positive clones, via a PCR-based screening method. Two sets of primers designed from each of two known genes were tested, and each yielded 2 or 3 positive clones for each gene, thereby indicating that the BAC library pooling system was appropriate with regard to the accession of the target BAC clones. Analyses of $3.3{\times}10^6$ base pairs obtained from the 7,090 BAC end sequence (BES) showed that 34.88% of the DNA sequence harbored the repetition sequence. Analysis of the 7,090 BES to the $1^{st}$ and $2^{nd}$ generation radiation hybrid map of the cattle genome, using the COMPASS program designed for the construction of a cattle-human comparative mapping, resulted in the localization of a total of 1,374 clones proximal to 339 $1^{st}$ generation markers, and 1,721 clones proximal to 664 $2^{nd}$ generation markers. Collectively, the BAC library and pooling system of the BAC clones from the Korean cattle, coupled with the chromosome-localized BAC clones, will provide us with novel tools for the excavation of desired clones for genome mapping and sequencing, and will also furnish us with additional information regarding breed differences in cattle.

An Analysis of Sectoral GHG Emission Intensity from Energy Use in Korea (기후변화 협약 대응을 위한 산업별 온실가스 배출 특성 분석)

  • Chung, Whan-Sam;Tohno, Susumu;Shim, Sang-Yul
    • Journal of Korea Technology Innovation Society
    • /
    • v.11 no.2
    • /
    • pp.264-286
    • /
    • 2008
  • In 2006, the share of energy in Korea amounted to 28% from the total import, 97% from overseas dependency, and 83% for the national Greenhouse Gas (GHG) emission in 2004. Thus, from the aspects of economical and environmental policies, an energy analysis is very important, for the industry to cope with the imminent pressure for climate change. However, the estimation of GHG gas emissions due to an energy use is still done in a primitive way, whereby each industry's usage is multiplied by coefficients recommended from international organizations in Korea. At this level, it is impossible to formulate the prevailing logic and policies in face of a new paradigm that seeks to force participation of developing countries through so called post-Kyoto Protocol. In this study, a hybrid energy input-output (E-IO) analysis is conducted on the basis of the input-output(IO) table of 2000 issued by the Bank of Korea in 2003. Furthermore, according to economic sectors, emission of the GHG relative to an energy use is characterized. The analysis is accomplished from four points of view as follows: 1) estimating the GHG emission intensity by 96 sectors, 2) measuring the contribution ratio to GHG emissions by 14 energy sources, 3) calculating the emission factor of 3 GHG compounds, and 4) estimating the total amount of national GHG emission. The total amount estimated in this study is compared with a national official statistical number. The approach could be an appropriate model for the recently spreading concept of a Life Cycle Analysis as it analyzes not only a direct GHG emission from a direct energy use but also an associated emission from an indirect use. We expect this model can provide a form for the basis of a future GHG reduction policy making.

  • PDF

A Transmission Scheme for Efficient Streaming in Large-delay Networks (높은 지연을 갖는 네트워크에서 효율적인 스트리밍 전송기법)

  • Lee, Sun-Hun;Chung, Kwang-Sue
    • Journal of KIISE:Information Networking
    • /
    • v.32 no.4
    • /
    • pp.483-494
    • /
    • 2005
  • The standard streaming delivery Is mostly based on UDP with no end-to-end congestion control. For this reason, wide usage of multimedia applications in Internet might lead to congested networks. To avoid such a situation, studies on the congestion controlled streaming delivery has been increasingly done after the 1990s. However, by considering only the stability aspect of network, these works ignore the characteristics of multimedia streaming applications. Moreover, most of previous works have no consideration on the network delay which produces an effect on streaming service. In this thesis, in order to overcome limitations of the previous transmission schemes for streaming, we propose a new transmission scheme called 'BEST(Buffer-driven Efficient STreaming)'. The BEST takes a hybrid approach that considers both user-level requirements and network-level requriements. Therefore, the BEST improves the stability of networks by adjusting the sending rate suitable for network status and it also provides the smoothed playback by preventing buffer underflow or overflow. The BEST is designed to consider high-delay networks. Through the simulation, we prove that the BEST satisfies both user-level and network-level requirements in a high-delay network environments.

A Study on clustering method for Banlancing Energy Consumption in Hierarchical Sensor Network (계층적 센서 네트워크에서 균등한 에너지 소비를 위한 클러스터링 기법에 관한 연구)

  • Kim, Yo-Sup;Hong, Yeong-Pyo;Cho, Young-Il;Kim, Jin-Su;Eun, Jong-Won;Lee, Jong-Yong;Lee, Sang-Hun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.9
    • /
    • pp.3472-3480
    • /
    • 2010
  • The Clustering technology of Energy efficiency wireless sensor network gets the energy efficiency by reducing the number of communication between sensor nodes and sink node. In this paper, First analyzed on the clustering technique of the distributed clustering protocol routing scheme LEACH (Low Energy Adaptive Clustering Hierarchy) and HEED (Hybrid, Energy-Efficient Distributed Clustering Approach), and based on this, new energy-efficient clustering technique is proposed for the cause the maximum delay of dead nodes and to increase the lifetime of the network. In the proposed method, the cluster head is elect the optimal efficiency node based on the residual energy information of each member node and located information between sink node and cluster node, and elected a node in the cluster head since the data transfer process from the data been sent to the sink node to form a network by sending the energy consumption of individual nodes evenly to increase the network's entire life is the purpose of this study. To verify the performance of the proposed method through simulation and compared with existing clustering techniques. As a result, compared to the existing method of the network life cycle is approximately 5-10% improvement could be confirmed.

Design of Software and Hardware Modules for a TCP/IP Offload Engine with Separated Transmission and Reception Paths (송수신 분리형 TCP/IP Offload Engine을 위한 소프트웨어 및 하드웨어 모듈의 설계)

  • Jang Hank-Kok;Chung Sang-Hwa;Choi Young-In
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.33 no.9
    • /
    • pp.691-698
    • /
    • 2006
  • TCP/IP Offload Engine (TOE) is a technology that processes TCP/IP on a network adapter instead of a host CPU to reduce protocol processing overhead from the host CPU. There have been some approaches to implementing TOE: software TOE based on an embedded processor; hardware TOE based on ASIC implementation; and hybrid TOE in which software and hardware functions are combined. In this paper, we designed software modules and hardware modules for a hybrid TOE on an FPGA that had two processor cores. Software modules are based on the embedded Linux. Hardware modules are for data transmission (TX) and reception (RX). One core controls the TX path and the other controls the RX path of the Linux. This TX/RX path separation mechanism can reduce task switching overheads between processes and overcome poor performance of single embedded processor. Hardware modules deal with creating headers for outgoing packets, processing headers of incoming packets, and fetching or storing data from or to the host memory by DMA. These can make it possible to improve the performance of data transmission and reception. We proved performance of the TOE with separated transmission and reception paths by performing experiments with a TOE network adapter that was equipped with the FPGA having processor cores.

A Study on Linkage Integration Control System Using Power Line Communication(PLC) and Wireless Sensor Network(WSN) (전력선 통신과 무선 센서 네트워크 기술을 이용한 연동 통합제어 시스템에 관한 연구)

  • Ji, Yun-il;Lim, Kang-il;Park, Kyung-sub
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2009.05a
    • /
    • pp.733-736
    • /
    • 2009
  • Power Line Communication(PLC) is need not additional communication line. So establishment expense is inexpensive and application is simple. Therefore, lower part network of various application field is possible. However, there are high subordinate interference and noise problem on limited transmission data and communication interference element. Wireless Sensor Network(WSN) is need not infrastructure, Self-regulating network architecture of sensor nodes is possible. So at short time, network construction is available. But, power consumption is increased by active sensing for QoS elevation and unnecessary information transmission, low electric power design and necessity of improve protocol are refered to life shortening problem and is studied. In this paper, supplement problem of power line communication and wireless sensor network mutually and because advantage becomes linkage integration control system using synergy effect of two technologies as more restriction be and tries to approach structurally control network that is improved for smooth network environment construction. Honeywell's hybrid sensor network does comparative analysis(benchmarking). Confirm performance elevation proposing teaming of power line communication and wireless sensor network. Through simulation, service delay decreases and confirms that performance elevation.

  • PDF