• Title/Summary/Keyword: RPL

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Two Solutions for Unnecessary Path Update Problem in Multi-Sink Based IoT Networks (멀티 싱크 기반 IoT 네트워크에서 불필요한 경로 업데이트 문제와 두 가지 해결 기법)

  • Lee, Sungwon;Kang, Hyunwoo;Yoo, Hongsoek;Jeong, Yonghwan;Kim, Dongkyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.12
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    • pp.2450-2460
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    • 2015
  • Recently, as interest in IoT (Internet of Things) increase, research and standardization of a new protocol which reflects the characteristics of IoT has progressed. Among them, RPL(IPv6 for Low-Power Lossy Network) is a standardized routing protocol for IoT. RPL utilizes DIO (DODAG Information Object) messages which is flooded from the sink node to the whole network for path establish and maintenance. However, in large scale networks, not only a long time is required to propagate the DIO message to the whole networks but also a bottleneck effect around the sink node is occurred. Multi-sink based approaches which take advantage of reducing routing overhead and bottleneck effect are widely used to solve these problems. In this paper, we define 'unnecessary path update problems' that may arise when applying the RPL protocol to the multi sink based IoT networks and propose two methods namely Routing Metric based Path Update Decision method and Immediate Successor based Path Update Decision method for selective routing update.

eRPL : An Enhanced RPL Based Light-Weight Routing Protocol in a IoT Capable Infra-Less Wireless Networks (사물 인터넷 기반 기기 간 통신 무선 환경에서 향상된 RPL 기반 경량화 라우팅 프로토콜)

  • Oh, Hayoung
    • KIPS Transactions on Computer and Communication Systems
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    • v.3 no.10
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    • pp.357-364
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    • 2014
  • The first mission for the IoT based hyper-connectivity communication is developing a device-to-device communication technique in infra-less low-power and lossy networks. In a low-power and lossy wireless network, IoT devices and routers cannot keep the original path toward the destination since they have the limited memory. Different from the previous light-weight routing protocols focusing on the reduction of the control messages, the proposed scheme provides the light-weight IPv6 address auto-configuration, IPv6 neighbor discovery and routing protocol in a IoT capable infra-less wireless networks with the bloom filer and enhanced rank concepts. And for the first time we evaluate our proposed scheme based on the modeling of various probability distributions in the IoT environments with the lossy wireless link. Specifically, the proposed enhanced RPL based light-weight routing protocol improves the robustness with the multi-paths locally established based on the enhanced rank concepts even though lossy wireless links are existed. We showed the improvements of the proposed scheme up to 40% than the RPL based protocol.

Optimal Output Feedback Control Simulation for the Operation of Space Shuttle Main Engine (우주왕복선 액체로켓엔진 작동의 최적출력제어 시뮬레이션)

  • Cha, Jihyoung;Ko, Sangho
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.3
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    • pp.37-53
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    • 2016
  • This paper deals with an optimal output control for Space Shuttle Main Engine (SSME), a liquid propellant rocket engine using a staged-combustion cycle. For this purpose, we modeled simplified mathematical model of SSME using each SSME component divided into 7 major categories and found trim points called Rated Propulsion Level (RPL). For design the closed-loop system of SSME, we designed optimal output feedback Linear Quadratic Regulation (LQR) control system using SSME linearized model under RPL 104% and demonstrated the performance of the controller through numerical simulation.

PHOTOELASTIC STRESS ANALYSIS ON THE SUPPORTING TISSUE OF MANDIBULAR DISTAL EXTENSION REMOVABLE PARTIAL DENTURE WITH VARIOUS DESIGN OF DIRECT RETAINERS (직접유지장치 설계 변화에 따른 하악 후방연장 국소의치 지지조직의 광탄성 응력분석)

  • Lee Chang-Ho;Kim Kwang-Nam;Chang Ik-Tae
    • The Journal of Korean Academy of Prosthodontics
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    • v.30 no.2
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    • pp.203-224
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    • 1992
  • The purpose of this study was to evaluate the stress distribution developed in supporting structures by distal extension removable partial denture with 4-types of direct retainer. The direct retainers examined were Akers clasp, RPI clasp, RPA clasp and RPL clasp in bilateral & unilateral free end case. 3-dimensional photoelastic stress analysis was used to record the isochromatic fringe patterns and to calculate the compressive stress at measuring points. The results were as follows. 1. In bilateral free end case, RPI clasp exhibited the similar stress distribution on distal and mesial alveolar crest but Akers clasp exhibited higher stress concentration on distal alveolar crest than mesial alveolar crest. 2. In bilateral free end case, RPA clasp and RPL clasp exhibited the similar stress distribution on distal and mesial alveolar crest and RPL clasp exhibited higher stress concentration on buccal alveolar crest than lingual alveolar crest. 3. Akers clasp produced high stress concentration on residual alveolar ridge distally, but RPI clasp, RPA clasp and RPL clasp produced even stress distribution on residual alveolar ridge. 4. Removable partial denture in unilateral free end case exerted higher stress on abutment tooth root apex than bilateral distal extension removable partial denture.

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Antimutagenic Effects of Juices from the Peppers in Salmonella Assay System

  • Park, Kun-Young;Kweon, Young-Mi;Rhee, Sook-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.3
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    • pp.440-445
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    • 1995
  • The antimutagenic effects of juices from green pepper(GP), red pepper leaf(RPL), red pepper(RP) and sweet pepper(SP) were examined by the Ames method using Salmonella typhimurium TA100. The juice supernatants of GP, RPL and RP showed antimutagenic activities against afltoxin B1(AFB1) in Salmonella typhimurium TA 100. The juice supermatants of GP and RPL also exhibited the inhibitory effects(p<0.05) to the mutagenicities induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitro-quinoline-1-oxide(4-NQO). The juice of RP showed antimutagenic activities against indirect mutagen of AFB1, however, the activity was reduced at higher concentration(5.0%), furthermore, as the adding concentration of sample increased to 5.0%, it exhibited slight comutagenicith on direct mutagen of MNNG. Theantimutagenic activities of GP and RPL juices were reduced significantly after heating at 100℃ for 20min, supposing that the antimutagenic compound(s) in the juices were heat labile.

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Evaluation of Antioxidant and Antimicrobial Activities of Ethanol Extracts of Three Kinds of Strawberries

  • Seleshe, Semeneh;Lee, Jong Seok;Lee, Sarah;Lee, Hye Jin;Kim, Ga Ryun;Yeo, Joohong;Kim, Jong Yea;Kang, Suk Nam
    • Preventive Nutrition and Food Science
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    • v.22 no.3
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    • pp.203-210
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    • 2017
  • The antioxidant and antimicrobial activities of three kinds of strawberry ethanol extracts from Robus corchorifolius L. f. (RCL), Rubus parvifolius L. var. parvifolius (RPL), and Duchesnea chrysantha Miq. (DCM) were investigated. The RPL was highest (P<0.05) in phenolic, flavonoid, and anthocyanin contents. 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activities of RPL and DCM extracts were higher than that of RCL (P<0.05). Hydrogen peroxide scavenging activity of RPL was high compared to DCM and RCL (P<0.05). RCL exhibited a significant (P<0.05) potent antioxidant activity in nitric oxide radical inhibition. Inhibition diameter zone (nearest mm) of extracts against the test bacteria ranged from 11.5 in RCL to 12.5 in DCM against Staphylococcus aureus, from 10.5 in RCL to 13.5 in DCM against Streptococcus pneumoniae, from 8.5 in DCM to 10.5 in RCL against Escherichia coli, and the same inhibition of 10 mm in three of the extracts against Klebsiella pneumoniae. However, there was no inhibition against fungi Aspergillus niger and Candida albicans. Three of the extracts had the same minimum inhibitory concentration values of 12.50, 12.50, and $6.25{\mu}g/mL$ against S. aureus, K. pneumoniae, and S. pneumoniae, respectively. On the other hand, MIC values of 12.50, 12.50, and $6.50{\mu}g/mL$ were recorded for RPL, DCM, and RCL against E. coli, respectively. The result of present study revealed that extracts from three kinds of strawberries could be potential candidates as antioxidant and antimicrobial sources for functional food industries.

Inhibitory Effect of the Rodgersia podophylla Leave Extracts against Cell Proliferation through Activation of NF-κB in Human Colorectal Cancer Cells (도깨비부채 잎 추출물의 NF-κB 활성화를 통한 대장암 세포 HCT116에 대한 세포생육 억제활성)

  • Kim, Jeong Dong;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.33 no.5
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    • pp.460-466
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    • 2020
  • In this study, we evaluated the anti-cancer activity and potential molecular mechanism of 70% ethanol extracts of leaves from Rodgersia podophylla against human colorectal cancer cells, HCT116. RPL dose-dependently decreased the cell viability through RPL-induced apoptosis in HCT116 cells. RPL induced inactivation the nuclear factor κB(NF-κB) through blocking IκB-α degradtion and P65 nuclear accumulation. The inhibition of GSK3β by LiCl attenuated RP-L-mediated NF-κB signaling inactivation. In addition, RP-L induced GSK3β activation. Based on these findings, RPL may be a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer.

Molecular Phylogenetic Study of Korean Tilia L. (한국산 피나무속(Tilia L.) 식물의 분자 계통학적 연구)

  • Boo, Daun;Park, Seon Joo
    • Korean Journal of Plant Resources
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    • v.29 no.5
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    • pp.547-554
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    • 2016
  • The genus Tilia is characterized by linear form bracts of which the lower part is attached to the peduncle of a cyme. This character is distinguished from the others genus of Malvaceae. The purpose of this study is verifying the phylogenetic relationship of genus Tilia. Phylogenetic analyses were conducted to evaluate relationships of 10 taxa of Tilia in Korea and Japan including one outgroup (Gossypium hirsutum). The molecular phylogenetic analyses were conducted with sequences based on ITS, trnL-F and rpl32-trnL region. The combined data result of ITS, trnL-F and rpl32-trnL was formed by 6 clades. T. kiusiana situated as the most basal clade. T. amurensis, T. taquetii and T. rufa are composed a clade. T. koreana, T. insularis and T. japonica was formed independent clade. T. insularis has the closest relationship with T. japonica. T. miqueliana, T. mandshurica, and T. megaphylla are composed a clade and showed a sister relationship than other species.

A Study on Storing Node Addition and Instance Leveling Using DIS Message in RPL (RPL에서 DIS 메시지를 이용한 Storing 노드 추가 및 Instance 평준화 기법 연구)

  • Bae, Sung-Hyun;Yun, Jeong-Oh
    • Journal of IKEEE
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    • v.22 no.3
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    • pp.590-598
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    • 2018
  • Recently, interest in IoT(Internet of Things) technology, which provides Internet services to objects, is increasing. IoT offers a variety of services in home networks, healthcare, and disaster alerts. IoT with LLN(Low Power & Lossy Networks) feature frequently loses sensor node. RPL, the standard routing protocol of IoT, performs global repair when data loss occurs in a sensor node. However, frequent loss of sensor nodes due to lower sensor nodes causes network performance degradation due to frequent full path reset. In this paper, we propose an additional selection method of the storage mode sensor node to solve the network degradation problem due to the frequent path resetting problem even after selecting the storage mode sensor node, and propose a method of equalizing the total path resetting number of each instance.

Association of Three Polymorphisms in Porcine Ribosomal protein L27a (RPL27A) Gene with Meat-quality Traits

  • Cho, Eun-Seok;Jeon, Hyeon-Jeong;Lee, Si-Woo;Raveendar, Sebastian;Jang, Gul-Won;Kim, Tae-Hun;Lee, Kyung-Tai
    • Journal of Animal Science and Technology
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    • v.55 no.6
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    • pp.509-513
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    • 2013
  • We identified molecular markers associated with meat-quality traits in the porcine RPL27A (ribosomal protein L27a) gene. Three single nucleotide polymorphisms (SNPs) were discovered in the porcine RPL27A gene: g.920T>C, g.1013T>C, and g.1046T>C. The g.920 T>C SNP was significantly associated with pH24 (P < 0.05) and collagen (P < 0.05), while the g.1013T>C and g.1046T>C SNPs were significantly associated with moisture (P < 0.05). Either the TTT or CCC haplotype was significantly associated with moisture, pH24 and collagen (P < 0.05, respectively). The genotypes of RPL27A associated with meat-quality traits were all located in intron 2. The three SNPs of the RPL27A found in this study will provide useful information for genetic characterization or association studies of meat-quality traits in other populations. Additionally, these markers could potentially be applied in pig breeding programs to improve meat-quality traits after validation in other populations.