• Title/Summary/Keyword: Enviroment

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Uplink/downlink - combined Fair Queueing Scheduling for Wireless TDMA/TDD Systems (무선 TDMA/TDD 시스템에서의 상.하향 링크 통합 페어큐잉 스케쥴링)

  • 최효현;최명환
    • Proceedings of the IEEK Conference
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    • 2002.06a
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    • pp.93-96
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    • 2002
  • Fair Queueing has been studied only on wired network. When it is applied to wireless netowork, the collision phenomenon makes a problem.'rho information of queue of MT cannot be transferred to fair queueing algorithm In real time easily. We propose wireless fair queueing scheduler that protects short term farirness and long term fairness. We developed it in TDMA/TDD enviroment. Our scheme also supports uplink and downlink at the same time. And it can make subframe boundary based on fair scheduling algorithm.

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A Study on the present of the distribution industry and the course that the Government & enterprise should take for strengthening competive power. (국내 유통산업의 현황과 경쟁력 강화를 위한 정부와 기업이 나아가야 할 방향에 관한 연구)

  • 이성일
    • Culinary science and hospitality research
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    • v.6 no.1
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    • pp.253-274
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    • 2000
  • This report deals with what the distribution industry is and the actual condition and keynote of the domestic distribution industry. Now, it is difficult compare with the domestic distribution industryand other advanced nation. because of inferior enviroment and given circumstance such as. Open market pressure. We will study about realities and weakness of the domestic distribution industry, also check how to cope with, especially the Government and enterprise, these difficulties for the development of the domestic distribution industry.

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Modal Analysis In The Dynamic Behavior Identification of the fluid-structure coupled Vertical Pump (유체와 구조물이 조합된 대형 수직펌프의 동특성 개선)

  • 배춘희;조철환;김성휘;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.622-627
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    • 2001
  • The paper presents the possibilities of a wide practical application of the modal analysis methods in dynamic testing of vertical pump. A pneumatic impact of testing vertical pumps submerged under deep water was developed and successfully applied. The problem with the enviroment is the it causes significants changes in modal parameters, compared with those in the airenviroment.

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Shipboard sewage treatment by Sequence Batch Reactor utilizing Beneficial Microorganisms (유용미생물을 적용한 선박오수용 SBR공정에 관한 연구)

  • Kim, In-Soo;Lee, Eon-Sung;Ha, Shin-Young;Oh, Yeom-Jae;Ekpeghere, Kelvin I.;Koh, Sung-Cheol
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2010.10a
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    • pp.36-37
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    • 2010
  • Lab scale experiment was carried out to study applicability of BM (Beneficial Microorganisms) to the conventional SBR system for the shipboard sewage treatment. BM has been successfully applied to the wastewater treatment by the SBR process and hence this system maintained a stable effluent quality together with an increased treatment efficiency, meeting the requirements of IMO regulations. The SBR system facilitated by BM would be a suitable process for cruise ships in terms of the malodor control, treatment efficiency and operation conveniences.

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The Design and development of online learning modules for the broadcasting content-based e-PBL (방송콘텐츠 기반 e-PBL을 위한 온라인 학습모듈 설계 및 개발)

  • Jung, Joon-Hwan
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.1
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    • pp.105-115
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    • 2012
  • This study paid attention to the possibility of broadcasting contents as a learning resource, which promoted the knowledge composition and the process of creation from the software having enriched contents not a delivering tool for the information in one direction. and tried to implement it thru e-PBL, which is one of teaching-learning models in e-learning. In order to implement the possibility of broadcasting contents in the e-PBL enviroment as a learning resource, the study focused on the design and development of e-PBL based on the broadcasting contents and found out the educational possibility for the broadcasting contents as the learning resource in e-PBL enviroment. This study focused on the design of learning module and development process which integrated strategic plans to maximize the utilization of broadcasting contents including development of online learning community. Also, This is verified by applying the learning module was to prove a differentiation.

Proposal of USN Configuratation and Routing Scheme Inside a Ship (선박 내 센서 노드 구성 및 라우팅 제안)

  • Lee, Seong Ro;Jeong, Min-A;Kim, Yeongeun;Min, Sang-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.8
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    • pp.660-666
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    • 2014
  • In this paper, we consider a classification criteria of sensor nodes based on equipment function, and propose a routing search algorithm between node when an IP-USN is applied inside a ship. whereas a tree-type routing algorithm is applied to the limited mobile enviroment, such as engine room or machine room, a mesh-type routing alogrithm is to free mobile enviroment, such as passager corridor liviing quarters or restanrats areas. For mesh-type routing, it is necessary to maintain a seamless route path between a sink node and sensor nodes for which we consider a novel message exchange periodically. We proposed a new message, RDES message, which is issued periodically to update the topology of sensor node and check a connectivity between nodes.

Evaluation about Contaminant Migration Near Abandoned Mine in Central Region (중부지역에 위치한 폐광산 주변의 오염물질 이동성 평가)

  • Lee, Jong-Deuk;Kim, Tae-Dong;Jeon, Gee-Seok;Kim, Hee-Joung
    • Journal of Soil and Groundwater Environment
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    • v.15 no.6
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    • pp.29-36
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    • 2010
  • Several mines including Namil, Solim and Jungbong which are located in the Gyeonggi and Kangwon province have been abandoned and closed since 1980 due to "The promotion policy of mining industry". An enormous amount of mining wastes was disposed without proper treatment, which caused soil pollution in tailing dam and ore-dressing plant areas. However, any quantitative assessment was not performed about soil and water pollution by transporting mining wastes such as acid mine drainage, mine tailing, and rocky waste. In this research, heavy metals in mining wastes were analyzed according to leaching method which used 0.1 N HCl and total solution method which used Aqua-regia to recognize the ecological effect of distance from hot spot. We sampled tailings, rocky wastes and soils around the abandoned mine. Chemical and physical parameters such as pH, electrical conductivity (EC), total organic carbon (TOC), soil texture and heavy metal concentration were analyzed. The range of soil's pH is between 4.3 and 6.4 in the tailing dam and oredressing plant area due to mining activity. Total concentrations of As, Cu, and Pb in soil near ore dressing plant area are 250.9, 249.3 and 117.2 mg/kg respectively, which are higher than any other ones near tailing dam area. Arsenic concentration in tailing dams is 31.0 mg/kg, which is also considered as heavily polluted condition comparing with the remediation required level(RRL) in "Soil environment conservation Act".

Effects of Catalyst Coating Methods on NO Removal Characteristics of Functional Fabric Filters (촉매 코팅방법에 따른 기능성여과포의 NO 제거 반응 특성)

  • Kang, Min Pil;Song, Yun-Seob;Lee, Hyo Song;Kim, Sang Do;Park, Young Ok;Hwang, Taek-Sung;Rhee, Young-Woo
    • Korean Chemical Engineering Research
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    • v.40 no.6
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    • pp.725-728
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    • 2002
  • A series of fabric filters including P-84, Nomex and PTFE were coated with a commercial $V_2O_5/TiO_2$ catalyst as an effort to develop a functional fabric filter of simultaneous removal of dust and NOx. The coating methods employed are sol-gel coating method, spray coating method and dip coating method, and the effects of coating method on NOx removal performance of functional fabric filter were investigated. Experimental conditions are as follows: the temperatures of $100-250^{\circ}C$ which are the normal operating temperature range of fabric filters, the space velocity of $5,000hr^{-1}$, the oxygen concentration of 6%, and the $NH_3/NO$ ratio of 1.0. Results showed that the sol-gel coating method gave the best NOx removal performance mainly due to its ability in controlling the amount of catalyst and uniform coating.

Natural Enemies of Wood Borers and Seasonal Occurrence of Major Natural Enemies of Monochamus saltuarius on Pine Trees (소나무류 천공충의 천적종류 및 북방수염하늘소 주요천적의 발생소장)

  • Kim, Jong-Kuk;Won, Dae-Sung;Park, Yong-Chul;Koh, Sang-Hyun
    • Journal of Korean Society of Forest Science
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    • v.99 no.3
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    • pp.439-445
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    • 2010
  • Wood boring insects collected around bait logs of Pinus densiflora and Pinus koraiensis were 45 species from 4 families, which were composed of 21 species of Cerambycidae, 9 species of Curculionidae, 2 species of Rhynchophoridae, and 13 species of Scolytidae. Parasitic or predatory insects were 35 species from 15 families in 6 orders. Among the natural enemies, 2 parasitoids of Dolochomitus nakamurai and Echthus reluctator, and 2 predators of Trogossita japonica and Thanassimus lewisi, were observed frequently attacking a vector insect, Monochamus saltuarius, which has been known to transmit pine wood nematode. Bursaphelenchus xylophilus. Adults of D. nakamurai and E. reluctator emerged during early April and early May. Both parasitoids laid eggs on M. saltuarius prepupa and papa, which passed winter inside the pupal chamber. The general predators, T. japonica and T. lewisi, preyed actively during April and October, and attacted almost all of developmental stages of wood borers.

An Analysis of the Water Quality Improvement Measures and Evaluation of Wonju Stream (원주천 수질개선 방안 및 개선효과 평가)

  • Kum, Donghyuk;Shin, Minhwan;Yu, Nayeong;Lee, Seolo;Kim, Dongjin;Sung, Younsoo;Lee, Sang Soo
    • Journal of The Korean Society of Agricultural Engineers
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    • v.63 no.1
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    • pp.61-73
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    • 2021
  • Recently, the deterioration of water quality in Wonju stream has been reported due to the increase in diverse pollution sources along with community development and urbanization. Various types of attempts with a huge budget were made for better water quality so far, but its effectiveness is still doubted. In order to establish site-oriented measures for water quality improvement, the topographic and hydrologic factors were evaluated based on site inspection and survey. As the major streams merged into the Wonju stream, the Hwa and Heungyang streams were found to have higher pollution loads and contributions compared to other streams due to the scattered livestock farms and industries, and vulnerable land use. Notably, the discharge water from the Wonju Public Sewage Treatment Plant had the highest level of pollution load, impacting on the water quality of Wonju Stream. According to the SWAT model as water quality measures, the improvement effect of water quality in this treatment plant can be reached to the reductions in BOD 11.06%, T-N 23.56%, T-P 10.60% when the proper managements applied, whereas the improvement of water quality would be 3.89%, 1.23%, and 3.32% for BOD, T-N, T-P, respectively, for the industries. The reduction of the livestock industry was generally very high as a pollution source, but it was not much higher at the end of Wonju Stream than other measures. These results recommended that the water q uality improvement measures should be designated for each upper-middle-lower section in Wonju stream.