• Title/Summary/Keyword: Class of Service

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Scalable Quasi-Dynamic-Provisioning-Based Admission Control Mechanism in Differentiated Service Networks

  • Rhee, Woo-Seop;Lee, Jun-Hwa;Yu, Jae-Hoon;Kim, Sang-Ha
    • ETRI Journal
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    • v.26 no.1
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    • pp.27-37
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    • 2004
  • The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per-class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable $qDPM^2$ mechanism based on a centralized bandwidth broker and distributed measurement-based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.

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Distribution Characteristics of Vascular Plants in the Mt. Hoemun (회문산 일대의 관속식물 분포 특성)

  • Oh, Hyun-Kyung;Beon, Mu-Sup
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.1
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    • pp.101-110
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    • 2009
  • The vascular plants in the Mt. Hoemun were listed 541 taxa composed of 113 families, 354 genera, 473 species, 1 subspecies, 64 varieties and 3 forms. Divided into 541 taxa; woody plants were 151 taxa (27.9%) and herbaceous plants were 390 taxa (72.1%). Based on the list of rare plants by the Korea Forest Service, 10 taxa were recorded in the studied areas; Lilium distichum (Preservation priority order: No. 159), Lilium callosum (No. 191), Tricyrtis dilatata (No. 97), Iris ensata var. sponianea (No. 197), Gastrodia elata (No.9), Aristolochia contorta (No. 151), Paeonia obovata (No. 30: Legal protection species), Prunus yedoensis (No. 110 : Planted species), Viola albida (No. 202), Schpolia japonica (No. 208). Based on the list of Korean endemic plants, 15 taxa were recorded; Cephalotaxus koreana, Lilium amabile, Salix purpurea var. japonica, Pseudostellaria multiflora, Aconitum pseudolaeve var. erectum, Filipendula glaberrima, Weigela subsessilis, etc. Based on the list of approved for delivering overseas of plants, 10 taxa were recorded; Carex okamotoi, Lilium distichum, Clematis trichotoma, Vaccinium oldhami, Paulownia coreana, Asperula lasiantha; etc. Specific plant species by floral region were total 4S taxa (8.3% of all 541 taxa of vascular plants); Gastrodia elata, Paeonia obovata in class V, Carex arenicola, Corydalis grandicalyx in class IV, 5 taxa (Spiraea salicifolia, Schpolia japonica, Asperula lasiantha, etc.) in class III, 7 taxa (Lilium distichum, Iris ensata var. spontanea, Caryopteris incana, etc.) in class II and 28 taxa (Camptosorus sibiricus, Orixa japonica, Lonicera praeflorens, etc.) in class I. The naturalized plants in the surveyed sites were 13 families, 38 genera, 43 species, 2 varieties, 45 taxa (Phleum pratense, Medicago sativa, Sonchus asper, etc.) and naturalization rate was 8.3% of all 541 taxa of vascular plants. Ambrosia artemisiifolia var. elatior an ecosystem disturbing wild plants have been increasing. Therefore, the counter plants for continuous control and conservation are needed on the ecosystem of Mt. Hoemun.

An Analytical Study on Space Configuration in After-School Care Class for Elementary School - Focused on Guidelines of Emementary School Care Classes - (초등돌봄교실 공간구성특징에 관한 분석연구 - 초등 돌봄교실 길라잡이를 중심으로 -)

  • Kim, Sora
    • Journal of the Korean Institute of Educational Facilities
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    • v.28 no.6
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    • pp.3-13
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    • 2021
  • Introduced in 2004 as an 'After-School Academy' policy, the 'After-School Care Class' has become a universal program for elementary schools over time. While the concept of public education service has expanded and changed in various ways including educational welfare, the physical environment of the care classroom has undergone fixed changes within the uniform classroom structure of a standardized school space. The purpose of this study is to identify spatial characteristics of care classroom through chasing and analysing changes in the care class space configuration from 2004 to the present. The findings are as follows. The plan of the early care classroom wasn't much different from the existing common classroom, and it was only in 2007 that the kitchen and floor heating appeared for the first time.From the 2015 standard plan, prominent differentiation of the space between learning activities and resting area was shown, but the spatial characteristics are nothing more than a division that utilizes ready-made furniture. A distinctive feature of the 2018 Seoul care classes are diversity. In the case of the care exclusive classrooms, the division between the support space and the main activity space became more clear using furniture integrated open walls and various floor levels. In the case of a shift classrooms that is used together with common classrooms, it is characterized by flexibility that allows dramatically different classroom configurations for each time period by using a convertible furnishing space.

Survey on the Current Science Education at Elementary School in Jeonnam Province (현행 초등 과학 교육에 대한 현장의 실태 조사 - 전라남도를 중심으로 -)

  • Lee, Gye-Choo
    • Journal of The Korean Association For Science Education
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    • v.1 no.1
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    • pp.73-88
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    • 1978
  • The survey is intended to improve science education by the analysis of problems produced in the following nine aspects (objectives, contents, materials, inquring methods, teaching methods, teachers, children, evalutions, admininative supports) during the past five years often the revision of new science curriculum. 1. View for science education. 1) The teacher's and children's view for science education can be seen renewed, being different from the old one. 2) Inquring method in learning and teaching began to take firm root and children came to know that it is the only way to study science. 3) Writers think that the new science education has stepped into the stage of being fixed to a considerable degree. 2. The aspect of administrative policy. 1) The amount of materials in possession is small and the present materials are lacking in solidity and precision. 2) Class room teacher's over load with miscellaneous things is a difficult problem to solve. 3) The shortage of the printed materials and books for children and teachers has an influence on the development of inquring method. 4) It causes cramming to examine all children at the same time by paper test. 5) It is more desirable to appoint qualified teacher only for science teaching. 3. Contents of science curriculum. 1) In current science textbooks. There can be found some contents which are difficult for teachers to understand and not in accordance with the reality of Korea. Therefore, it is imperative that contents of science textbooks should be reexamined. 2) As it is hard to teach concepts of reciprocal action and to prepare materials with teaching of the system of biological concepts, the teaching of contents is likely to be a cramming. 4. The aspect of in-service education. 1) It is obsolutely predominant reation that in-service education is making a great contribution to class room teaching. 2) As adiministrators' policy for science education has a great effect, in-service education for their enlightenment is needed.

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Physical characteristics and evaluation of deteriorations class of a trail in Deogyusan National Park

  • Ju-Ung Yun;Myeong-Jun Kim;Hong-Seok Bang;Jin-Won Kim;Won-Ok Jeong
    • Korean Journal of Agricultural Science
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    • v.49 no.2
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    • pp.367-377
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    • 2022
  • The purpose of this study was to analyze the deterioration of trail conditions and to obtain information for desirable maintenance and restoration of a trail in Deogyusan National Park. The physical characteristics of a trail were surveyed at a total of 412 sites over 79.8 km length. The average trail degree and width were found to be 14.31° and 1.60 m, respectively, while the average bare trail width was 1.40 m and the average maxim trail depth was 5.66 cm. Major deterioration types of trail were trail deepening (36.6%), rock exposure (33.9%), and root exposure (12.5%) in order of frequency. Deterioration classes of the trail were 0.626 km (0.8%), 3.110 km (3.9%) and 8.935 km (11.2%) for heavily, moderately, and lightly deteriorated, respectively, with a deterioration rate of 12.671 km (15.9%). Compared to other national parks, the ratio damaged trail to the total trail was 15.9%, which is slightly higher than other, including Jirisan National Park 9.6% (2019), Bukhansan National Park 13.6% (2019), Sokrisan National Park 11.7% (2019), Chiaksan National Park 12.3% (2015), and Woraksan National Park 10.5% (2015). The section of trail in Deokyusan National Park where the damage grade is analyzed as "Heavy" should therefore be restored in consideration of the field conditions. In particular, the damage status of the trail is expected to be greatly improved when the trail surface maintenance level is restored.

A Study on the Roles of Academic Library for Supporting Class and Learning Activities in Korea (대학도서관의 수업·학습 활동 지원 역할에 관한 연구)

  • Lee, Yong-Jae;Lee, Ji-Wook
    • Journal of Korean Library and Information Science Society
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    • v.50 no.4
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    • pp.359-379
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    • 2019
  • This study aims to suggest the ways to reinforce academic library's supports for users' class·learning activities. For this purpose, this study collected the development plans of academic libraries in Korea, and analysed the plans for supporting class·learning activities. As a result, it is shown that the most libraries emphasized 'expansion of learning material' and marked it on development plan. As subsequent plans, libraries provided the action plans of 'expansion of reading education and reading programs', 'expansion of electronic materials', 'expansion of characterized materials' one after another. This study suggests 'user-centered collection development and expansion of learning materials', 'activation of library services making use of big data', 'enlargement of engagement services for handicapped and foreign students' as ways to strengthen the services of academic libraries to support class·learning activities of users.

A New Implementable Scheduling Algorithm Supporting Various Traffics in ATM Networks (ATM 망에서 다양한 트래픽을 지원하기 위한 동적 셀 스케줄링 알고리즘)

  • 심재정;이원호;변재영;고성제
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.4B
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    • pp.675-682
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    • 2000
  • In this paper, we propose a new scheduling algorithm called the Adaptive Weighted Round Robin with Delay Tolerance (AWRR/DT). The proposed scheme is based on the per-class queueing mechanism in which a number of connections of similar characteristics are multiplexed into one class-queue. Traffic classes of the proposed method are classified into a single non-real-time traffic class and other real-time traffic classes. The proposed scheme determines the weights of classes according to the input traffic and delay characteristics of each class at the beginning of every cycle. Furthermore, this scheme incorporates a cell discarding method to reduce the QoS degradation that may be incurred by congestion of networks. We have evaluated the proposed scheme through discrete-event simulation. Simulation results indicate that the proposed scheme can reduce the average delay of non-real-time class while maintaining the QoS of real-timeclasses. The proposed algorithm can be effectively applied to high-speed networks such as ATM networks.

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Implementation of QoS-awared MAC Protocol for Home Networks (홈 네트워크를 위한 QOS 보장형 매체접속제어 프로토콜의 구현)

  • 황원주
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.2
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    • pp.228-238
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    • 2003
  • We believe that existing wire solutions such as HomePNA2.0 using phone lines and HomePlug using power line and wireless solution such as HomeRF are the most promising solutions, because of its cost-effectiveness. However, MAC protocols of these solutions provide only Class of Service(CoS) using priority mechanism like HomePNA and HomePlug or consider only voice among real-time traffics like HomeRF. For these reasons, we perceive the needs of the new MAC protocol which is no new wire solution and provides guaranteed Quality of Service (QoS) for not only voice but also video and audio. In light of this, we present the design and software implementation of a new MAC protocol for Home Networks. Our evaluation results of software implementation verify that proposed MAC protocol can provide low delay, low loss, and low jitter to real-time traffic by reserving bandwidth.

Classification Type of Vascular Plants in Ecological Forest Site on the Gujaebong (Mt.), Hadong (하동 구재봉 생태숲 조성부지의 관속식물상 유형별 분류)

  • Oh, Hyun-Kyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.4
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    • pp.18-29
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    • 2010
  • The vascular plants in ecological forest site on the Gujaebong (Mt.), Hadong were listed 338 taxa; 85 families, 219 genera, 290 species, 1 subspecies, 40 varieties and 7 forms. Divided into 338 taxa; woody plants were 121 taxa (35.8%) and herbaceous plants were 217 taxa (64.2%). Based on the legal protection species, endangered wild plants II were recorded; Aconitum austro-koreense, Corylopsis gotoana var. coreana and rare plants (IUCN) by the Korea Forest Service and Korea National Arboretum 5 taxa were recorded; Botrychium virginianum, Aconitum austro-koreense, Coreanomecon hylomecoides, Corylopsis gotoana var. coreana, Viola albida. Based on the list of Korean endemic plants, 13 taxa were recorded; Cephalotaxus koreana, Thalictrum actaefolium, Vicia nipponica, Indigofera koreana, Stewartia koreana, Weigela subsessilis, etc. Based on the list of approved for delivering overseas of plants, 5 taxa were recorded; Coreanomecon hylomecoides, Vaccinium oldhami, Paulownia coreana, Asperula lasiantha, Carex okamotoi. Specific plant species by floral region were total 21 taxa (6.2% of all 338 taxa of vascular plants); Aconitum austro-koreense, Corylopsis gotoana var. coreana in class V, Cimicifuga heracleifolia, Coreanomecon hylomecoides in class IV, 4 taxa (Stewartia koreana, Phacellanthus tubiflorus, Lonicera subhispida, etc.) in class III, Potentilla dickinsii, Viola orientalis in class II, 11 taxa (Aconitum jaluense, Angelica anomala, Erythronium japonicum, etc.) in class I. The naturalized plants in the surveyed sites were 8 families, 15 genera, 15 taxa (Phytolacca americana, Crassocephalum crepidioides, Lolium perenne, etc.) and naturalization rate was 4.4% of all 338 taxa of vascular plants.

Antimicrobial resistance and distribution of resistance gene in Enterobacteriaceae and Pseudomonas aeruginosa isolated from dogs and cats (개와 고양이에서 분리된 Enterobacteriaceae와 Pseudomonas aeruginosa의 항균제 내성 및 내성 유전자의 분포)

  • Cho, Jae-Keun;Kim, Jin-Hyun;Kim, Jeong-Mi;Park, Choi-Kyu;Kim, Ki-Seuk
    • Korean Journal of Veterinary Service
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    • v.36 no.3
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    • pp.171-180
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    • 2013
  • This study was carried out to investigate the antimicrobial resistance pattern and distribution of resistance gene in 44 Enterobacteriaceae and 21 Pseudomonas (P) aeruginosa isolated from hospitalized dogs and cats in animal hospital from 2010 to 2011 in Daegu. Among Enterobacteriaceae, Escherichia (E) coli was highly resistant to ampicillin (56.7%), followed by tetracycline (53.3%), cephalothin, streptomycine, sulfamethoxazole/trimethoprim, gentamicin and norfloxacin (40.0~43.3%). The remaining isolates of Enterobacteriaceae had high resistance to ampicillin (64.3%) and streptomycin (42.9%). Whereas, P. aeruginosa was low resistant to all antimicrobials tested (less than 15%). int I 1 gene was detected in 20 (57.1%) of 35 antimicrobial resistant Enterobacteriaceae and 2 (9.5%) of 21 P. aeruginosa., but int I 2 gene was not detected in all isolates. The eight resistance genes were found either alone or combination with other gene (s): $bla_{TEM}$, aadA, strA-strB, clmA, tetA, tetB, sul I and sul II. About 78% of integron-positive isolates were resistance to more than four antimicrobial agents. The findings suggest that class I integrons are widely distributed in E. coli among Enterobacteriaceae from dogs and cats and multi-drug resistance related to the presence of class I integrons. The prudent use of antimicrobials and continuous monitoring for companion animals are required.