• Journal of KIISE:Computer Systems and Theory
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• v.34 no.7
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• pp.304-318
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• 2007

Grid computing is a service that share geographically distributed computing resources through high speed network. In this paper, we propose hybrid scheduling scheme which considers not only meta-scheduling scheme to distribute the job between the nodes of grid computing system but also the job scheduling to distribute the job within the local nodes. According to the number of processors needed and expected execution time, the job with high priority is allocated to job queue while the one with low priority and remote job are allocated to backfill queue. We evaluate the proposing scheme through the various experiments and the results show that the utilization of grid computing system increases and the job slowdown decreases.

• Elastomers and Composites
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• v.44 no.4
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• pp.423-428
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• 2009

The non-Newtonian flow curves of polyurethane melts were obtained by using a Physica cone-plate rheometer at various temperatures. The rheological parameters were obtained by applying non-Newtonian flow equation to the flow curves for polyurethane samples. When the polyurethane samples are under increasing-decreasing shear rate modes, the hysteresis loop and thixotropic behavior were shown. Polyurethane melts behave as strong gels when they are subjected to shear flow, but when the applied stress surpasses the yield stress, they exhibit non-linear viscoelasticity. Upon decreasing shear rate, its shear stress remains smaller than the values measured in the increasing shear rate mode, because of broken of its structure.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.95-102
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• 2005

This paper is purpose for improvement performance wireless lan of IEEE802.11a/b/g. Access point utilized a single server, multi-queuing system, FIFS system model to adapted priority multi-bufferto be alteration packet type. The main purpose of the paper improve the transmission rate and the performance of access point to settle transmission delay for load in MAC, has priority multi-buffer. We use experimentation to obtain our model of the access point and buffer-related parameters. Using our test design, we are able to extract the parameters of an analytic equation giving the average service time of a packet as a function of packer IP payload.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.1-13
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• 2022

The Paper Using the meta-analysis research method, first through literature retrieval to obtain 23 relevant empirical studies in China, and then using Review Manager for quantitative analysis, it is found that VR technology has a positive impact on students' overall learning effect and VR technology has a significant positive impact on all dimensions of learning effect (theoretical performance, operational performance, learning motivation, learning interest, learning attitude). There is no significant difference between the dimensions. Significant differences were found for moderating variables such as Discipline types, Teaching Length, and Teaching Method. No significant differences were found for the Academic segments and VR technology types.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.355-356
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• 2022

본 연구는 IT 비전공 대학생을 위한 코딩교과목 개발을 목표로 한다. 이를 위해 선행연구 및 이론탐색을 통해 대학교양 교과목으로서 코딩교육을 탐색하고, 적용 가능한 수업모형 및 교육내용을 선정하여 기초내용을 구성한 후 3인의 교육공학 전문가와 3인의 코딩교과목 개발 유경험 대학교수를 대상으로 FGI 인터뷰 방법을 통하여 연구결과를 도출한다. 대학교양 교과목으로서 코딩교육의 필요성이 대두되고 있음에도 불구하고 현재 운영 중인 코딩교과목은 프로그래밍이 중심으로 구성되어 비전공 대학생들에게는 환영받지 못하고 있다. 이에 본 연구에서는 코딩교과목의 방향을 컴퓨팅사고 및 SW 기초교육을 목표로 메타버스 등의 플랫폼을 활용한 체험중심 수업설계를 통해, 실행 가능한 수업모형을 개발하고 대상자 인터뷰와 분석을 통해 이를 위한 교수학습방법을 설정할 것이다. 본 연구를 통해 제시될 메타버스 플랫폼을 활용한 체험중심 코딩교육은 이후 고등교육기관의 교딩교육 교과목 개발을 위한 기초자료로 활용될 것이다

• Journal of English Language & Literature
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• v.55 no.4
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• pp.619-639
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• 2009

In his 1993 stage play, Arcadia, Tom Stoppard appropriates scientific theories to dramatize the difficulty in predicting the future and in describing the past. Arcadia tracks the archaeological efforts of two present-day literary critics, Hannah Jarvis and Bernard Nightingale, as they attempt to piece together the events that occurred at a large country house called Sidley Park, from 1809 to 1812. While employing a variety of historical and cultural references to the changes taking place in British landscape gardening around the early nineteenth century, the play also turns around the intuitive-romantic versus rational-classical dichotomy represented by Hannah, and present in its discussion of science and the recoverable/irrecoverable past. Stoppard's use of chaos theory as a metaphor for the difficulties faced by those involved in biographical/bibliographical literary research suggests that unsubstantiated assumption can result in the construction of its subject, rather than in its recovery. This paper explores the way in which Stoppard uses scientific concepts, particularly the chaos theory, as a metaphor for human life and behaviour, and how he successfully describes the dilemmas and contradictions of life in so doing. Influences from his famous British predecessors, George Bernard Shaw and Oscar Wilde, are evident, but Stoppard transcends both playwrights and crafts a dramatic style distinctively his own. The combination of wit, comedy, intellectual depth, intriguing ideas, literary allusions, scientific concepts, metaphors, and cultural references, all combine to make Arcadia a dramatic edifice that will stand the test of time.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.341-347
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• 2008

Recently, it has been widely recognized that water-front and coastal vegetations may have great value in supporting fisheries, protecting from wave attack, stabilizing the sea bed and maintaining good scenery. Hydrodynamic factors playa major role in the functions of water quality and ecosystems. However, the studies on numerical and analytical process of wave propagation are few and far behind compared to those on the hydrodynamic roles of water-front vegetations. In this study, in order to express wave attenuation into water-front vegetation, a numerical model based on the unsteady mild slope equation is developed. This result is compared with an analytical model for describing the wave attenuation by assumed simple long wave condition. Based on both the analytical and numerical results, the physical properties of the wave attenuation are examined under various wave, geometric and vegetation conditions. Through comparisons between the analytical and numerical results, the effects of the vegetation properties, wave properties and model parameters such as the momentum exchange coefficient have been clarified.

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.441-446
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• 2001

On global interconnectivity, the activation of real-time and worldwide contents will permeate and impact all aspects of day-to-day life well throughout this century. In managing contents and models, we too will see the impact of this rapidly changing environment. The real time availability of contents pertaining to a companys supply chain through means of the Internet and mobile networks(e.g., the IMT-2000) will necessitate a change in decision-making processes for effective management of contents and models. To increase the availability of many contents and models, a management system should have adaptive function in proving adequate content and model for companies. In the respect of management of contents and models, this paper discusses a production mechanism of meta-knowledge for effectively managing contents and models. Through two experimental analyses with the production mechanism, it is proven that the system enabling adaptive contents and models provision goes beyond existing ones in view of efficiency of management of contents and models in the wire and wireless networks.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.587-597
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• 2005

Flash memory based embedded computing systems are becoming increasingly prevalent.These systems typically have to provide an instant start-up time. However, we observe that mounting a file system toy flash memory takes 1 to 25 seconds mainly depending on the flash capacity. Since the flash chip capacity is doubled in every year, this mounting time will soon become the most dominant reason of the delay of system start-up time Therefore, in this paper, we present instant mounting techniques for flash file systems by storing the In-memory file system metadata to flash memory when unmounting the file system and reloading the stored metadata quickly when mounting the file system. These metadata snapshot techniques are specifically developed for NOR- and NAND-type flash memories, while at the same time, overcoming their physical constraints. The proposed techniques check the validity of the stored snapshot and use the proposed fast trash recovery techniques when the snapshot is Invalid. Based on the experimental results, the proposed techniques can reduce the flash mounting time by about two orders of magnitude over the existing de facto standard flash file system, JFFS2.

• Journal of the Korean Magnetics Society
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• v.27 no.2
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• pp.49-53
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• 2017

Metamaterials composed of split cut wire (SCW) on grounded polyimide film substrate have been investigated for the aim of electromagnetic wave absorbers operated in THz frequency band. Reflection loss and current density distributions are numerically simulated with variations of the SCW geometries using the commercial software. The minimum reflection loss lower than -20 dB has been identified at 5.5~6.5 THz. The simulated resonance frequency and reflection loss can be explained on the basis of the circuit theory of an inductance-capacitance (L-C) resonator. Dual-band absorption can be obtained by arrangement of two SCWs of different length on the top layer of the grounded substrate, which is due to multiple magnetic resonances by scaling of SCWs. With increasing the side spacing between SCWs, a more enhanced absorption peak is observed at the first resonance frequency that is shifted to a lower frequency.