• Title/Summary/Keyword: Phase-usage

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Design and Performance Analysis of Dynamic QoS Control for RTP-based Multimedia Data Transmission (RTP 기반 멀티미디어 데이터 전송을 위한 동적 QoS 제공방안의 설계 및 성능 분석)

  • Moon, Young-Jun;Ryoo, In-Tae;Park, Gwang-Hoon
    • The KIPS Transactions:PartC
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    • v.10C no.7
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    • pp.891-898
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    • 2003
  • This paper analyzes and proposes a scheme that improves the performance of the RTP that is developed to support the end-to-end transmission function and QoS monitor function for real-time multimedia data transmission. Although the existing RTP module supports real-time transmission, it has some problems in guaranteeing QoS parameters. To solve this problem, we propose a new Selective Repeat Adaptive Rate Control (SRARC). The SRARC can support QoS by referring to the data transmission status from the client and then classifying the network status into three levels. It selectively transmits multimedia data and dynamically controls transmission rates based on such information as bandwidth, packet loss rate, and latency that can be calculated in data transfer phase. To verify the SRARC, we implement it in real local area networks and compare the QoS parameters of the SRARC with those of the SR and RTP By the experimental results, the SRARC shows better performance in the aspects of bandwidth usage rate, packet loss rates, and transmission delays than the existing RTP schemes.

A Design Approach to $CrO_x/TiO_2$-based Catalysts for Gas-phase TCE Oxidation (기상 TCE 제거반응용 $CrO_x/TiO_2$계 복합 산화물 촉매 디자인)

  • Yang, Won-Ho;Kim, Moon-Hyeon
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.4
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    • pp.368-375
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    • 2006
  • Single and complex metal oxide catalysts supported onto a commercial DT51D $TiO_2$ have been investigated for gas-phase TCE oxidation in a continuous flow type fixed-bed reaction system to develop a better design approach to catalysts for this reaction. Among the $TiO_2$-supported single metal oxides used, i.e., $CrO_x,\;FeO_x,\;MnO_x,\;LaO_x,\;CoO_x,\;NiO_x,\;CeO_x\;and\;CuO_x$, with the respective metal contents of 5 wt.%, the $CrO_x/TiO_2$ catalyst was shown to be most active for the oxidative TCE decomposition, depending significantly on amounts of $CrO_x\;on\;TiO_2$. The use of high $CrO_x$ loadings greater than 10 wt.% caused lower activity in the catalytic TCE oxidation, which is probably due to production of $Cr_2O_3$ crystallites on the surface of $TiO_2$. $CrO_x/TiO_2$-supported $CrO_x$-based bimetallic oxide catalysts were of particular interest in removal efficiency for this TCE oxidation reaction at reaction temperatures above $200^{\circ}C$, compared to that obtained with $CrO_x$-free complex metal oxides and a 10 wt.% $CrO_x/TiO_2$ catalyst. Catalytic activity of 5 wt.% $CrO_x-5$ wt.% $LaO_x$ in the removal reaction was similar to or slightly higher than that acquired for the $CrO_x$-only catalyst. Similar observation was revealed for 5 wt.% $CrO_x$-based bimetallic oxides consisting of either 5 wt.% $MnO_x,\;CoO_x,\;NiO_x\;or\;FeO_x$. These results represent that such $CrO_x$-based bimetallic systems for the catalytic TCE oxidation on significantly minimize the usage of $CrO_x$ that is well known to be one of very toxic heavy metals, and offer a very useful technique to design new type catalysts for reducing chlorinated volatile organic substances.

Environmental Monitoring of Selected Veterinary Antibiotics in Soils, Sediments and Water Adjacent to a Poultry Manure Composting Facility in Gangwon Province, Korea (강원지역 계분 퇴비공장 인근 토양, 하천수 및 저질토의 항생물질 잔류특성 조사)

  • Lee, Hyeon-Yong;Lim, Jung-Eun;Kim, Sung-Chul;Kim, Kwon-Rae;Lee, Sang-Soo;Kwon, Oh-Kyung;Yang, Jae-E;Ok, Yong-Sik
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.3
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    • pp.278-286
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    • 2010
  • Veterinary antibiotics have been used to treat disease and to promote growth of livestock. However, the total amount of veterinary antibiotics in Korea was much greater than other developed countries, and there is a high potential to release residual of antibiotics to environment. Consequentially, released antibiotics into the environment produces antibiotic resistant bacteria and causes adverse effects on human health. The objective of this research was to monitor antibiotic concentration in the environment adjacent to facilities which compose chicken manure. Total of 10 antibiotics were selected based on the total amount of higher usage in Korea, and its residuals were measured from surface water, soil and sediment. The frequencies of detected antibiotics were ranged 31-92% from soil, 0-93% from water, and 33-93% from sediment. Generally, a higher frequency was observed in soil or sediment than water. Different ranges in concentration among 4 different antibiotic groups was found from not detected(N.D.) to 35.6 ${\mu}g/kg$ for soil, N.D. to 19.2 ${\mu}g/L$ for water and N.D. to 114.3 ${\mu}g/kg$ for sediment. Our findings suggest that solid phase such as soil and sediment is a critical component to be needed to conduct the environmental impact assessment of antibiotics.

A Comparative Case Study on the Adaptation Process of Advanced Information Technology: A Grounded Theory Approach for the Appropriation Process (신기술 사용 과정에 관한 비교 사례 연구: 기술 전유 과정의 근거이론적 접근)

  • Choi, Hee-Jae;Lee, Zoon-Ky
    • Asia pacific journal of information systems
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    • v.19 no.3
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    • pp.99-124
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    • 2009
  • Many firms in Korea have adopted and used advanced information technology in an effort to boost efficiency. The process of adapting to the new technology, at the same time, can vary from one firm to another. As such, this research focuses on several relevant factors, especially the roles of social interaction as a key variable that influences the technology adaptation process and the outcomes. Thus far, how a firm goes through the adaptation process to the new technology has not been yet fully explored. Previous studies on changes undergone by a firm or an organization due to information technology have been pursued from various theoretical points of views, evolved from technological and institutional views to an integrated social technology views. The technology adaptation process has been understood to be something that evolves over time and has been regarded as cycles between misalignments and alignments, gradually approaching the stable aligned state. The adaptation process of the new technology was defined as "appropriation" process according to Poole and DeSanctis (1994). They suggested that this process is not automatically determined by the technology design itself. Rather, people actively select how technology structures should be used; accordingly, adoption practices vary. But concepts of the appropriation process in these studies are not accurate while suggested propositions are not clear enough to apply in practice. Furthermore, these studies do not substantially suggest which factors are changed during the appropriation process and what should be done to bring about effective outcomes. Therefore, research objectives of this study lie in finding causes for the difference in ways in which advanced information technology has been used and adopted among organizations. The study also aims to explore how a firm's interaction with social as well as technological factors affects differently in resulting organizational changes. Detail objectives of this study are as follows. First, this paper primarily focuses on the appropriation process of advanced information technology in the long run, and we look into reasons for the diverse types of the usage. Second, this study is to categorize each phases in the appropriation process and make clear what changes occur and how they are evolved during each phase. Third, this study is to suggest the guidelines to determine which strategies are needed in an individual, group and organizational level. For this, a substantially grounded theory that can be applied to organizational practice has been developed from a longitudinal comparative case study. For these objectives, the technology appropriation process was explored based on Structuration Theory by Giddens (1984), Orlikoski and Robey (1991) and Adaptive Structuration Theory by Poole and DeSanctis (1994), which are examples of social technology views on organizational change by technology. Data have been obtained from interviews, observations of medical treatment task, and questionnaires administered to group members who use the technology. Data coding was executed in three steps following the grounded theory approach. First of all, concepts and categories were developed from interviews and observation data in open coding. Next, in axial coding, we related categories to subcategorize along the lines of their properties and dimensions through the paradigm model. Finally, the grounded theory about the appropriation process was developed through the conditional/consequential matrix in selective coding. In this study eight hypotheses about the adaptation process have been clearly articulated. Also, we found that the appropriation process involves through three phases, namely, "direct appropriation," "cooperate with related structures," and "interpret and make judgments." The higher phases of appropriation move, the more users represent various types of instrumental use and attitude. Moreover, the previous structures like "knowledge and experience," "belief that other members know and accept the use of technology," "horizontal communication," and "embodiment of opinion collection process" are evolved to higher degrees in their dimensions of property. Furthermore, users continuously create new spirits and structures, while removing some of the previous ones at the same time. Thus, from longitudinal view, faithful and unfaithful appropriation methods appear recursively, but gradually faithful appropriation takes over the other. In other words, the concept of spirits and structures has been changed in the adaptation process over time for the purpose of alignment between the task and other structures. These findings call for a revised or extended model of structural adaptation in IS (Information Systems) literature now that the vague adaptation process in previous studies has been clarified through the in-depth qualitative study, identifying each phrase with accuracy. In addition, based on these results some guidelines can be set up to help determine which strategies are needed in an individual, group, and organizational level for the purpose of effective technology appropriation. In practice, managers can focus on the changes of spirits and elevation of the structural dimension to achieve effective technology use.

A Study of Deconstruction in Clothing -Comparison of Clothing with Architecture- (복식에 나타난 해체주의 양식연구 -건축과 복식의 비교-)

  • 전혜정
    • Journal of the Korean Society of Costume
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    • v.32
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    • pp.293-312
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    • 1997
  • Deconstructionism is a philosophical stream in the latter half of 20'th century which goes against western metaphysics and tries to deconstruct the dualism e.g. eastern/west-ern man/woman. Its main concepts are 'indi-vidual' 'other' 'difference' 'restoration of the repressed' 'decentralization' 'Today it shows strong influences in literature art, and other social fields. This study investigated inner meanings and exterior forms represented in clothing on the base of Jacques Derrida's theory in order to re-search modes of deconstruction in is. And it compared clothing with architecture among other genres of art in order to discover similarities between through and modes of art in a certain period. For illuminating concept of deconstruction I referred to the literatures of preceding studies and for deconstruction's characteristics in both clothing and architec-ture I referred work's collection book $\ulcorner$collec-tions$\lrcorner$ and other related books dealing from 1960's to this point. As a rsult there are four modes of decons-truction in both clothing and architecture as follows; 1) Differenance which is a concept of the dif-ference in time and space as being trace. 2) In termeaning of meanings which is not present in reality but re-interpreted a new in the future. 3) Interxtuality in which a texte is not alone but with others 4) Dis.De phenomenon in which distortion and fragmentation forms occur as the result of the denial of perfection and reson. There are characteristics of modes of de-construction in clothing as follows; 1) Differance; R.Gigli, P. Rabanne. G.Bersace, V.Westwood are representatives of the cloth-ing which is combined with the past the pres-ent and the future or is re-viewed as the clothing of the past in the present point of view. J. Watanabe R. Dawakubo I miyake are representatives of the clothing which is out-date but re-viewed in the sense of recollec-tion and re-usage. 2) Intermeaning of meanings: R. kawakubo I, Miyake Y,Yamamoto are representatives of the clothing which is incomplete but re-interpreted in the future and appears to be new-fashioned according to ways of bnding wearing throwing on and tying J.C. Castel-bajac K.Hamnett S.Sprouse are representa-tives of the clothing which is made up of ab -stract forms scribbling or symbolic letters which appears to be different according to view-point of observers. 3) Intertextuality ;J.P.Gaultier K.Hamnett, Comme des Gar ons are representatives of intertextuality of gender which avoids the 여-ality of man/woman J.P Gaultier G,Versace J. galliano are representatives of the intertex-tuality of time place and occasion which mixes temporality extensity and purposiveness. J.P Gaultier G,Versace are representatives of the intertextuality of coordination which combines items different in image purpose and use. P.Rabanne A,Courr ges R,Gernreic I,Miyake are representatives of the intertextuality of mat-ter which uses heterogeneous matter different from cloth. 4) Dis.De-phenomenon: R, Kawakubo I.Mi-yake J.P.Gaultier are representatives of the de-composition which discloses distortion and exag-geration of form through destructing the estab-lished way of construction J.Galliano R.Kawa-kubo Devota Y Lomba arte representatives of the decentring which restores the repressed and the alienated on the one hane and shows front-centrality on the other. Comme des Gar ones is representative of the discontinuity because of which right and left up and down are not in har-mony with one another. J,Galliano J.P,Gaultier T,Mugler are representatives of the disruption by way of which one makes one's body exposed through intentional slashes or holes. As a consequence deconstructionism enabled us to investigate similarities between through of deconstruction and modes of art interms of diffrance Intermeaning of meanings intertextuality and Dis De-phenomenon. And we found that deconstruction was a phase of development in that it as a all-comprising and multiple concept tries to pursue the new through deconstruction.

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2015 (설비공학회 분야의 최근 연구 동향 : 2015년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.6
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    • pp.256-268
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    • 2016
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2015. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering were carried out in the areas of flow, heat and mass transfer, cooling and heating, and air-conditioning, the renewable energy system and the flow inside building rooms. Research issues dealing with air-conditioning machines and fire and exhausting smoke were reduced. CFD seems to be spreading to more research areas. (2) Research works on heat transfer area were carried out in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the economic analysis of GHG emission, micro channel heat exchanger, effect of rib angle on thermal performance, the airside performance of fin-and-tube heat exchangers, theoretical analysis of a rotary heat exchanger, heat exchanger in a cryogenic environment, the performance of a cross-flow-type, indirect evaporative cooler made of paper/plastic film. In the area of pool boiling and condensing, the bubble jet loop heat pipe was studied. In the area of industrial heat exchangers, researches were performed on fin-tube heat exchanger, KSTAR PFC and vacuum vessel at baking phase, the performance of small-sized dehumidification rotor, design of gas-injection port of an asymmetric scroll compressor, effect of slot discharge-angle change on exhaust efficiency of range hood system with air curtain. (3) In the field of refrigeration, various studies were carried in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, a cold-climate heat pump system, $CO_2$ cascade systems, ejector cycles and a PCM-based continuous heating system were investigated. In the alternative refrigeration/energy system category, a polymer adsorption heat pump, an alcohol absorption heat pump and a desiccant-based hybrid refrigeration system were investigated. In the system control category, turbo-refrigerator capacity controls and an absorption chiller fault diagnostics were investigated. (4) In building mechanical system research fields, eighteen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the user and location awareness technology applied dimming lighting control system, the lighting performance evaluation for light-shelves, the improvement evaluation of air quality through analysis of ventilation efficiency and the evaluation of airtightness of sliding and LS window systems. The subjects of building energy were worked on the energy saving estimation of existing buildings, the developing model to predict heating energy usage in domestic city area and the performance evaluation of cooling applied with economizer control. The studies were also performed related to the experimental measurement of weight variation and thermal conductivity in polyurethane foam, the development of flame spread prevention system for sandwich panels, the utilization of heat from waste-incineration facility in large-scale horticultural facilities.

A Study on the Characteristics of Seoul Olympic Organizing Committee's Official Documents (서울올림픽대회 조직위원회 공문서의 성격에 관한 연구)

  • Cheon, Ho-Jun
    • The Korean Journal of Archival Studies
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    • no.24
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    • pp.113-171
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    • 2010
  • The purpose of this study was to examine the characteristics of Seoul Olympic Organizing Committee's official documents. To conduct this work, the fundamental of producing archives were examined by analyzing structure and management of Seoul Olympic Organizing Committee and structure of official document production. After all, simultaneous and synthesis characteristics of Seoul Olympic Organizing Committee's official documents were presented through overall analysis of production fundamental and relationship between their management and remained archives. The result of this study are as follows. Firstly, The Organizing Committee had bicameral organizational structure and matrix organizational format consisting of functional department and project department. Indicating the institutions and development phase of decision making in the committee, most of institutions were in name only. Also, there were many problems occurred in the procedure of decision making since the president of committee exercised all of the authorities. Secondly, It was found that existing official documents of the committee were partial and caused fragment phenomenon and severe situations because of unsystematic archival management department and regulations. Moreover, as the result of investigating production procedure and management of official documents, procedure of production, distribution, preservation and abolition of them were specifically verified. Thirdly, It was verified that the official documents were abolished arbitrarily because of unsystematic archival management department and insufficient regulations. For the actual condition of management, filing or description activity which is essential measure for using and utilizing the official documents has not been conducted yet. Based on these facts, the characteristics of Seoul Olympic Organizing Committee's official documents can be referred as follows. The official archives of the committee have multiplicity of the origin and severe fragment phenomenon damaging the origin and the elementary substance of the archives. Also, the format of existing archives was unbalance. Besides, there was not enough related research since they were in adverse situation to utilize them as the archives which are not assessed or not arranged. Thus, it was hard to grasp the utility value at present and future, and was also limited for usage object.