• Title/Summary/Keyword: hop

Search Result 1,600, Processing Time 0.03 seconds

Cross-layer Design of Joint Routing and Scheduling for Maximizing Network Capacity of IEEE 802.11s based Multi-Channel SmartGrid NAN Networks (IEEE 802.11s 를 사용한 스마트그리드 NAN 네트워크의 최대 전송 성능을 위한 다중 채널 스케쥴링과 라우팅의 결합 설계)

  • Min, Seok Hong;Kim, Bong Gyu;Lee, Jae Yong;Kim, Byung Chul
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.5
    • /
    • pp.25-36
    • /
    • 2016
  • The goal of the SmartGrid is to maximize energy efficiency by exchanging bi-directional real-time power information with the help of ICT(Information and Communication Technology). In this paper, we propose a "JRS-MS" (Joint Routing and Scheduling for Multi-channel SmartGrid) algorithm that uses numerical modeling methods in IEEE 802.11s based STDMA multi-channel SmartGrid NAN networks. The proposed algorithm controls the amount of data transmission adaptively at the link layer and finds a high data-rate path which has the least interference between traffic flows in multi-channel SmartGrid NAN networks. The proposed algorithm improve transmission performance by enhancing network utilization. By comparing the results of performance analysis between the proposed algorithm and the JRS-SG algorithm in the previous paper, we showed that the JRS-MS algorithm can improve transmission performance by maximally utilizing given network resources when the number of flows are increasing in the multi-hop NAN wireless mesh networks.

Consumption of Milk and Milk Products (우유(牛乳) 및 유제품(乳製品)의 소비행동(消費行動0에 관(關)한 연구(硏究))

  • Choe, Sun-Hae;Mo, Su-Mi
    • Journal of Nutrition and Health
    • /
    • v.9 no.1
    • /
    • pp.16-24
    • /
    • 1976
  • To determine patterns of preference for and consumption of milk and milk products in Seoul city, a study was conducted of 724 girls and 587 boys ranging in age from elementary school to collage level, from July to August, 1974. Findings are summarized as follows: In general, milk and milk products were liked by both children and adults. A contrasting low tendency to purchase such products was due to socioeconomics, habitual, and educational factors, as well as a lack of adequate nutritional information, especially with regard to milk. Knowledge of the value of milk as a source of calcium was lacking, especially among boys. The majority of homemakers understood that milk was nutritious, but not specifically as the best source of calcium for their families. Milk, especially in beverage form, was commonly regarded as food for the infant and small child. Grandparents would not drink it. Such a beliefe is similar to that found in under-developed or developing nations. The need for nutrition education must be emphasized. Milk and milk products are expensive foods, particularly for the low income family; but even in higher income levels, consumption was limited. Milk was consumed mostly by the younger family members, less by the older. Among the children, preference, knowledge, and concern with the nutritional value of milk increased with age of subjects. It is presumed that awareness improved with increasing length of school education. Greater frequency of milk intolerance was found with decreasing age of respondents: about 10 percent had some form of milk intolerance. This percentage will be found to be much higher in villages where milk is less familiar. This study indicated that respondents liked ice cream best of all the milk products. For beverage, they preferred cider and cola in summer, coffee and milk in winter. Smaller families consumed more milk than larger families. Household consumption of condensed milk was very low, mostly as coffeemate. Among households interviewed, as many had regular as irregular delivery of dairy milk. Average consumption ranged 0.5 to 1.5 Hop. Engel indices of these families ranged 20 to 60. Use of milk at home was very simple. Not many methods of preparation were found. The milk was used mostly as beverage. In order to improve the nutritional level of Korean children and adults who especially need additional calcium, milk and milk products are recommended as the best source of calcium. Nutrition education of children and their parents should receive greater emphasis.

  • PDF

Design and Implementation of DNS Name Autoconfiguration for Internet of Things Devices (사물인터넷 디바이스를 위한 DNS 네임 자동설정의 설계 및 구현)

  • Lee, Sejun;Jeong, Jaehoon
    • Journal of KIISE
    • /
    • v.42 no.11
    • /
    • pp.1441-1451
    • /
    • 2015
  • As one of the most spotlighted research areas, these days, the Internet of Things (IoT) aims to provide users with various services through many devices. Since there exist so many devices in IoT environments, it is inefficient to manually configure the domain name system (DNS) names of such devices. Thus, for IPv6-based IoT environments, this paper proposes a scheme called the DNS Name Autoconfiguration (DNSNA) that autoconfigures an IoT device's DNS name and manages it. In the procedure for generating and registering an IoT device's DNS name, the standard protocols of the Internet Engineering Task Force (IETF) are used. Since the proposed scheme resolves an IoT device's DNS name into an IPv6 address in unicast through a DNS server, it generates less traffic than multicast-based mDNS (Multicast DNS) which is a legacy DNS application for the DNS name service in the smart home. Thus, the proposed scheme is more appropriate in multi-hop IoT networks than mDNS. This paper explains the design of the proposed scheme and its service scenarios, such as smart home and smart road. It also explains the implementation and testing of the proposed scheme in the smart grid.

Cloning and Phylogenetic Characterization of Coat Protein Genes of Two Isolates of Apple mosaic virus from ¡?Fuji¡? Apple

  • Lee, Gung-Pyo;Ryu, Ki-Hyun;Kim, Hyun-Ran;Kim, Chung-Sun;Lee, Dong-Woo;Kim, Jeong-Soo;Park, Min-Hye;Noh, Young-Mi;Choi, Sun-Hee;Han, Dong-Hyun;Lee, Chang-Hoo
    • The Plant Pathology Journal
    • /
    • v.18 no.5
    • /
    • pp.259-265
    • /
    • 2002
  • Apple mosaic virus (ApMV), a member of the genus Ilarvirus, was detected and isolated from diseased 'Fuji' apple (Malus domestica) in Korea. The coat protein (CP) genes of two ApMV strains, denoted as ApMV-Kl and ApMV-K2, were amplified by using the reverse transcription and polymerase chain reaction (RT-PCR) and were analyzed thereafter. The objectives were to define the molecular variability of genomic information of ApMV found in Korea and to develop virus-derived resistant gene source for making virus-resistant trans-genic apple. RT-PCR amplicons for the APMVS were cloned and their nucleotide sequences were determined. The CPs of ApMV-Kl and ApMV-K2 consisted of 222 and 232 amino acid residues, respectively. The identities of the CPs of the two Korean APMVS were 93.1% and 85.6% at the nucleotide and amino acid sequences, respectively. The CP of ApMV-Kl showed 46.1-100% and 43.2-100% identities to eight different ApMV strains at the nucleotide and amino acid levels, respectively. When ApMV-PV32 strain was not included in the analysis, ApMV strains shared over 83.0% and 78.6% homologies at the nucleotide and amino acid levels, respectively. ApMV strains showed heterogeneity in CP size and sequence variability. Most of the amino acid residue differences were located at the N-termini of the strains of ApMV, whereas, the middle regions and C-termini were remarkably conserved. The APMVS were 17.(1-54.5% identical with three other species of the genus Ilarviyus. ApMV strains can be classified into three subgroups (subgroups I, II, and III) based on the phylogenetic analysis of CP gene in both nucleotide and amino acid levels. Interestingly, all the strains of subgroup I were isolated from apple plants, while the strains of subgroups II and III were originated from peach, hop, or pear, The results suggest that ApMV strains co-evolved with their host plants, which may have resulted in the CP heterogeneity.

A Multistage Authentication Strategy for Reliable N-to-N Communication in CGSR based Mobile Ad Hoc Networks (CGSR 기반의 이동 애드 흑 네트워크에서 신뢰성 있는 통신을 위한 노드간 인증 기법)

  • Lee Hyewon K.;Mun Youngsong
    • Journal of KIISE:Information Networking
    • /
    • v.32 no.6
    • /
    • pp.659-667
    • /
    • 2005
  • A Mobile Ad Hoc Network(MANET) is a multi hop wireless network with no prepared base stations or centralized administrations, where flocks of peer systems gather and compose a network. Each node operates as a normal end system in public networks. In addition to it, a MANET node is required to work as a router to forward traffic from a source or intermediate node to others. Each node operates as a normal end system in public networks, and further a MANET node work as a router to forward traffic from a source or intermediate node to the next node via routing path. Applications of MANET are extensively wide, such as battle field or any unwired place; however, these are exposed to critical problems related to network management, node's capability, and security because of frequent and dynamic changes in network topology, absence of centralized controls, restricted usage on network resources, and vulnerability oi mobile nodes which results from the special MANET's character, shared wireless media. These problems induce MANET to be weak from security attacks from eavesdropping to DoS. To guarantee secure authentication is the main part of security service In MANET because networks without secure authentication are exposed to exterior attacks. In this paper, a multistage authentication strategy based on CGSR is proposed to guarantee that only genuine and veritable nodes participate in communications. The proposed authentication model is composed of key manager, cluster head and common nodes. The cluster head is elected from secure nodes, and key manager is elected from cluster heads. The cluster head will verify other common nodes within its cluster range in MANET. Especially, ID of each node is used on communication, which allows digital signature and blocks non repudiation. For performance evaluation, attacks against node authentication are analyzed. Based on security parameters, strategies to resolve these attacks are drawn up.

Energy Saving Characteristics of OSPF Routing Based on Energy Profiles (Energy Profile에 기반한 OSPF 라우팅 방식의 에너지 절약 특성)

  • Seo, Yusik;Han, Chimoon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.40 no.7
    • /
    • pp.1296-1306
    • /
    • 2015
  • Nowadays the research of energy saving on the IP networks have been studied the various methods in many research institutes. This paper suggests the energy saving method in IP networks which have the various energy profiles, and analyzes its energy saving characteristics in detail. Especially this paper proposes the energy profile based OSPF routing method which have the selectable weighted value in OSPF metric and energy consumption in IP network. This paper analyzes the energy saving effects of the various situations to minimize the energy consumption using the various weighted value on the proposed scheme. The results show that the energy saving efficiency can get about 67% at in ingress input load ${\rho}=0.5$ by using random energy profiles in IP networks. Although the number of hops is a slight increased due to routing the paths for the minimum energy consumption in the algorithm of this method, the increment hop number is limited the mean 1.4 hops. This paper confirms that the energy profile of core router has the large effects of energy saving than the energy profile of edge router, and the proposed method has the excellent energy saving characteristics in IP networks.

Multi-hop Routing Protocol based on Neighbor Conditions in Multichannel Ad-hoc Cognitive Radio Networks (인지 무선 애드혹 네트워크에서의 주변 상황을 고려한 협력적 멀티홉 라우팅 방법)

  • Park, Goon-Woo;Choi, Jae-Kark;Yoo, Sang-Jo
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.36 no.4A
    • /
    • pp.369-379
    • /
    • 2011
  • During the routing process between nodes on the CR(Cognitive Radio) network conducting for efficient use of limited frequency resources, spectrum handover process due to the appearance of the PU occupies most of the routing latency, and also decreases the reliability of the path. In this paper, a cooperative routing protocol in a multi-channel environment is proposed. The source node broadcasts a message with available channel lists and probability of PU appearance during its route guidance. The intermediate nodes re-transmit the message, received from the source node, and update and maintain the information, status table of the path. The destination node determines the optimal path and sends a reply message to the selected path after it receives the messages from the intermediate nodes. The average probability of the PU appearance and the average time of the PU appearance are updated while transferring data. During data transmission the channel with the lowest probability of appearance of the PU is selected dynamically and if a PU appears on the current channel partial repairment is performed. It is examined that reliability of the selected path considerably is improved and the routing cost is reduced significantly compared to traditional routing methods.

An Adaptive Coverage Control Algorithm for Throughput Improvement in OFDMA-based Relay Systems (OFDMA 기반 Relay 시스템에서 Throughput 성능 향상을 위한 적응적 커버리지 조절 기법)

  • Hyun, Myung-Reun;Hong, Dae-Hyoung;Lim, Jae-Chan
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.34 no.9B
    • /
    • pp.876-882
    • /
    • 2009
  • In this paper, we propose a sub-cell coverage control algorithm for enhancement of the cell throughput in OFDMA based relay systems. Relay station (RS) is exploited for improved quality of the received signal in cellular communication systems, especially in shadow areas. However, since a RS requires additional radio resource consumption for the link between the base station (BS) and the RS, we have to carefully control the coverage areas if a mobile station (MS) is serviced via the BS or the RS considering the cell throughput. We consider radio resource reuse as well for the sub-cell coverage configuration by applying various reuse patterns between RSs. We also consider a time varying system by adaptively changing the threshold for coverage depending on the MSs' traffic in the cell. We initially determine the sub-cell coverage of the system depending on the ratio of received signal-interference-noise-ratio (SINR) of the MS from the BS and RSs, respectively. Then, the "sub-cell coverage threshold" varies based on the "effective transmitted bits per sub-channel" with time. Simulation result shows that the proposed "time varying coverage control algorithm" leads to throughput improvement compared to the fixed sub-cell coverage configuration.

Security Design for Efficient Detection of Misbehavior Node in MANET (MANET에서 비정상 노드를 효율적으로 탐지하기 위한 보안 설계)

  • Hwang, Yoon-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.3B
    • /
    • pp.408-420
    • /
    • 2010
  • On a Mobile Ad hoc NETwork(MANET), it is difficult to detect and prevent misbehaviors nodes existing between end nodes, as communication between remote nodes is made through multiple hop routes due to lack of a fixed networked structure. Therefore, to maintain MANET's performance and security, a technique to identify misbehaving middle nodes and nodes that are compromise by such nodes is required. However, previously proposed techniques assumed that nodes comprising MANET are in a friendly and cooperative relationship, and suggested only methods to identify misbehaving nodes. When these methods are applied to a larger-scale MANET, large overhead is induced. As such, this paper suggests a system model called Secure Cluster-based MANET(SecCBM) to provide secure communication between components aperANET and to ensure eed. As such, this pand managems suapemisbehavior nodes. SecCBM consists apetwo stages. The first is the preventis pstage, whereemisbehavior nodes are identified when rANET is comprised by using a cluster-based hierarchical control structure through dynamic authentication. The second is the post-preventis pstage, whereemisbehavior nodes created during the course apecommunication amongst nodes comprising the network are dh, thed by using FC and MN tables. Through this, MANET's communication safety and efficiency were improved and the proposed method was confirmed to be suitable for MANET through simulation performance evaluation.

The Kinematic Analysis of Handspring Salto Forward Piked (핸드스프링 몸접어 앞공중돌기동작의 운동학적 분석)

  • Kwon, Oh-Seok
    • Korean Journal of Applied Biomechanics
    • /
    • v.17 no.1
    • /
    • pp.145-153
    • /
    • 2007
  • The purpose of this study is to compare and analyze the phase-by-phase elapsed time, the COG, the body joint angle changes and the angular velocities of each phase of Handspring Salto Forward Piked performed by 4 college gymnasts through 3D movement analysis program. 1. The average elapsed time for each phase was .13sec for Phase 1, .18sec for Phase 2, .4sec for Phase 3, and .3sec for Phase 5. The elapsed time for Phase 1 to Phase 3 handspring was .35sec on average and the elapsed time for Phase 4 to Phase 5 handspring salto forward piked was .7sec on average. And so it showed that the whole elapsed time was 1.44sec. 2. The average horizontal changes of COG were 93.2 cm at E1, 138. 5 cm at E2, 215.7 cm at E3, 369.2 cm at E4, 450.7 cm at E5, and 553.1 cm at E6. The average vertical changes of COG were 83.1 cm at E1, 71.3 cm at E2, 78.9 cm at E3, 93.7 cm at E4, 150.8 cm at E5, and 97.2 cm at E6. 3. The average shoulder joint angles at each phase were 131.6 deg at E1, 153.5 deg at E2, 135.4 deg at E3, 113.4 deg at E4, 39.6 deg at E5, and 67.5 deg at E6. And the average hip joint angles at each phase were 82.2 deg at E1, 60 deg at E2, 101.9 deg at E3, 161.2 deg at E4, 97.7 deg at E5, and 167 deg at E6. 4. The average shoulder joint angular velocities at each phase were 130.9deg/s E1, 73.1 deg/s at E2, -133.9 deg/s at E3, -194.4 deg/s at E4, 29.4 deg/s at E5, and -50.1 deg/s at E6. And the average hip joint angular velocities at each phase were -154.7 deg/s E1, -96.5 deg/s at E2, 495.9 deg/s at E3, 281.5 deg/s at E4, 90.3 deg/s at E5, and 181.7 deg/s at E6. The results shows that, as for the performance of handspring salto forward piked, it is important to move in short time and horizontally from the hop step to the point to place the hands on the floor and jump, and to stretch the hip joints as much as possible after the displacement of the hands and to keep the hip joints stretched and high in the vertical position at the takeoff. And it is also important to bend the shoulder joints and the hip joints fast and spin as much as possible after the takeoff, and to decrease the speed of spinning by bending he shoulder joints and the hip joints quickly after the highest point of COG and make a stable landing.