• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.3
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• pp.310-317
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• 1993

This paper presents a mechanism for improving performance of the IEEE 802.6 MAN(Metropolitan Area Network), a dual-bus structured high-speed communication network, by a more efficient use of bandwidth. The MAN protocol is able to handle various traffic and offers better transmission speed than the conventional LAN, but the unidirectional bus structure and propagation delay of request bits results in unfairness since higher nodes use more bandwidth. As the number of stations and the distances between them are increased, the problem becomes mere serious. As a solution, this paper presents a method that every station enables to identify the used slots, and that a specified class denoted 'erasure station' has with the functions of destination release, slot reuse. As a result, it is export to improve network bandwidth values of each station and the throughput and delay time was analytically analyzed, and it is shown that according to computer simulation results, this mechanism improves the network performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11A
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• pp.1106-1112
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• 2007

As a demand for high speed uplink packet services increases, the WCDMA enhanced uplink, also known as high speed uplink packet access (HSUPA), has been specified in release 6 by 3GPP. This HSUPA will provide various types of multimedia services, such as real-time video streaming, gaming, VoIP, and FTP. Generally, the performance of HSUPA is dominated by scheduling policy. Therefore, it is required to design a scheduling algorithm considering the traffic characteristics to provide QoS guaranteed services in various traffic environments. In this paper, we propose a scheduling algorithm considering the traffic characteristics to guarantee QoS in a mixed traffic environment. Finally, the performance of the proposed scheduling algorithm is evaluated in terms of average packet delay, packet delay jitter, and system throughput using a system level simulator.

• Spatial Information Research
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• v.23 no.3
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• pp.123-132
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• 2015

Recently both the importance and the interests of field-experience learning have kept increasing since the Education of Ministry encourages students to take a field-experience learning with the self-driven and creative education as the main issue in the 7th revised education curriculum in 2009. As the importance of field-experience learning goes up continuously, not only the release of its related mobile applications is increasing, but also a variety of researches for supporting the field-experience learning are ongoing. In this research we perform two things. First, we define the basic concept of authoring tool for which support the field-experience learning based on its characteristics and user requirements analysis. We confirmed that the authoring tool for the field-experience learning has to 1) support all activities that happen in pre-field, field-experience and post-field phases, 2) be possible to write the location-based field work, 3) have the authoring function which reflects the characteristics of curriculum such as history, science and geography, etc. that the field learning can be realized, 4) be designed as the structure that the results of inquiring activity after the field experience activity can be reused. Second, we create a conceptual design after confirming the authoring tool.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.221-230
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• 2016

The public mostly get the information regarding real estate policy not from the press release of the government but from news articles. This type of information, though, might be delivered in a different frame depending on inclination of media or press. The media runs the articles within its own frame, so that it often conveys either expectation or concern depending on its inclination. This study analyzed the articles regarding 'Agreement to revise three major real estate regulations to perk up property market' and examined how the real estate policy imprinted in them depending on the disposition of the press. The results showed that the conservative press ran articles within a positive frame expressing favorable expectation. On the other hand, progressive press mostly kept neutral or unfavorable tone on the same regulations within the negative frame. Therefore, it was confirmed that there exist different frames within articles depending on their disposition.

• Journal of Korean Library and Information Science Society
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• v.39 no.1
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• pp.377-407
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• 2008

This research allows purpose to investigate aspect of reading movement and reading education in the early period of the 1990's. This is succession research that is the Japanese Occupation Period, after release, the 1950's, the 1960's, the 1970's, the 1980's reading popularization movement research as current trend of opinion to examine modern reading popularization movement. Such series research that reading phenomenon analyzing comparison, is to find present address of reading movement and reading education. accordingly all sorts correct judgment about reading phenomenon, hereafter that will be foundation that unfold reading education more effectively. In main discourse first, investigated, reading movement, and second, observed classifying distinguish reading of student from reading of ordinary people by readers' interest etc.

• Journal of Korea Water Resources Association
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• v.42 no.9
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• pp.703-713
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• 2009

Dam has very important roles in both water use and flood control. Dam release and runoff from rainfall affect directly to the flood control at the downstream of dam during heavy storm especially. This study evaluates the applicability of a distributed model by applying the GRM (Grid based Rainfall-runoff Model) based on HyGIS (Hydro Geographic Information System) environment to runoff modeling at the downstream of dam where the discharge from dam and rainfall affect simultaneously. In order to do this, Yeoju watershed in Han River basin is selected. Rainfall data and discharge from Chungju regulation dam and Hoengseong dam are applied to runoff simulation. The modeling results are verified with Yeoju water level station, and they show good agreement with observed hydrographs. And this study shows that GRM is able to simulate appropriately the effect of dam discharge and rainfall on watershed runoff.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.1
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• pp.71-82
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• 2018

The purpose of this study is to minimize damage of chemical accidents through the appropriation analysis of evacuation facility position focused on Ulsan metropolitan city. For analysis, informations such as pollutant release and transfer registers(PRTR), population census, and evacuation facilities were used. After then, damage assessment of chemical accidents, accessibility and appropriation of evacuation facilities were analyzed. Damage of chemical accidents is high in around 5km of industrial complex there is dense of chemical facility and population. Evacuation facilities were mainly situated in hazard area of chemical accidents, but accessibility of evacuation facilities was vulnerable in chemical plant neighborhood. Therefore, safety check of deteriorated plants is important for prevention of chemical accidents. Also, effective evacuation plan considering capacity and scale of evacuation facilities will be established.

• 한국연소학회:학술대회논문집
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• 2003.12a
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• pp.103-108
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• 2003

The effect of equivalence ratio and fuel/air mixing quality on the phase-resolved gas temperatures at different phases of the oscillating pressure cycle was experimentally investigated. An atmospheric pressure, optically accessible and laboratory-scale dump combustor operating on methane with heat release rate of 1.59kW was used. Temperature measurements were made using coherent anti-Stokes Raman spectroscopy (CARS) at several spatial locations for typical unstable combustion conditions. Analysis was conducted using parameters such as phase-resolved averaged temperature, normalized standard deviation and temperature probability distribution functions (PDFs). Also the probability on the occurrence of high temperature (over 1900K) was investigated to get the information on the perturbation of equivalence ratio and NOx emission characteristics. It was shown that most of temperature histograms exhibit Gaussian profile which has short breadth of temperature fluctuation at equivalence ratio of 0.6, while beta profile was predominant for the cases of other equivalence ratios (${\Phi}$=0.55, 0.50). The characteristics on the occurrence of high temperature also displayed periodic wave form which is very similar to the pressure signal. And the amplitude of this profile goes larger as the fuel/air mixing quality become poorer. These also provided additional information on the perturbation of equivalence ratio at flame as well as NOx emission characteristics.

• Journal of the Korean Society for information Management
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• v.20 no.1
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• pp.251-270
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• 2003

Due to rapid internet supply and the increase of electronic resources including network resources, there has been a sudden change in cataloguing fields. To deal with rapid changes, IFLA revised cataloguing rules for electronic and continuing resources; ISBD(ER) and ISBD(CR), JSC(Joint Steering Committee for Revision of AACR) has published the 2002 revision of Anglo-American Cataloguing Rules, Second Edition. Major changes in both content and format make the release of the 2002 revision momentous. This study is to analyze activities of JSC and rule revisions of AACR2R 2002 edition, expecially in regards with concepts of change to rule 0.24, new categories of bibliographic materials, changes to chapter 3(cartographic materials), chapter 9(electronic materials), chapter 12(continuing materials), definition of a new terminologies, changes in MARC 21 coding, and issues concerned with revision of KORMARC.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.1
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• pp.1-12
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• 2009

The purpose of this study is to discovered assessment items for improving athletic efficiency and management of golf courses. Through this, the study intended to provide basic data for creating competitive golf courses and management. Important assessment items were selected by inducing preliminary assessment items and conducting a preliminary survey and a main survey for specialists through a theoretical study. For the survey results studied, reliability and average value for importance were calculated using SPSS/PC Window Release 12.0. As assessment of importance by assessment area, in athletic efficiency assessment, course management level was the highest, followed by fairness of games and operation of games. In management assessment, importance of service level, information management, facility management, management of game assistants, etc. were high. As assessment of importance by assessment item, it was found that 'variety of golf shot' and 'the length of a course' were important in course layout. Also 'start interval among teams' and 'disturbance of play' were assessed as important items in game operation, while 'fair reservation' and 'rounding rotation time' were important in fairness of games. In addition, in information management, 'kind service of golf course staffs' and 'prompt reservation and notification' were found to be important assessment items. In facility management, all assessment indexes were over 4.0, which means all of them are important for quality of golf course and competitiveness. In membership service, 'appropriate price of goods for sale' and 'service for members' were relatively important assessment items. Further, in management of game assistants, 'qualifications and skillfulness of game assistants' was assessed as a very important index. Although the current study only selected important items to assess excellent golf courses, it is necessary to apply the study results to the actual sites and verify them for golf course both at domestic and abroad.