• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.4
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• pp.703-719
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• 2011

In multi-user wireless communication systems, adaptive modulation and scheduling are promising techniques for increasing the system throughput. However, a mass of wireless recourse will be occupied and spectrum efficiency will be decreased to feedback channel quality indication (CQI) of all users in every subcarrier or chunk for adaptive orthogonal frequency division multiplexing (OFDM) systems. Thus numerous limited feedback schemes are proposed to reduce the system overhead. The recently proposed compressive sensing (CS) theory provides a new framework to jointly measure and compress signals that allows less sampling and storage resources than traditional approaches based on Nyquist sampling. In this paper, we proposed two novel CQI feedback schemes based on general CS and subspace CS, respectively, both of which could be used in a wireless OFDM system. The feedback rate with subspace CS is greatly decreased by exploiting the subspace information of the underlying signal. Simulation results show the effectiveness of the proposed methods, with the same feedback rate, the throughputs with subspace CS outperform the discrete cosine transform (DCT) based method which is usually employed, and the throughputs with general CS outperform DCT when the feedback rate is larger than 0.13 bits/subcarrier.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.79-89
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• 2008

An end-of-life strategy is concerned with how to disassemble a product and what to do with each of the resultingdisassembled parts. A sound understanding of the end-of-life strategy at the early design stage could improve theease of disassembly and recycling in an efficient and effective manner. Therefore, the end-of-life decisionmaking for environmental conscious design has become a great concern to product manufacturers.We introduce a novel concept ofeco-architecture which represents a scheme by which the physical componentsare allocated to end-of-life modules. An end-of-life module is a physical chunk of connected components or afeasible subassembly which can be simultaneously processed by the same end-of-life option without furtherdisassembly. In this paper, a method for analyzing the eco-architecture of a product at the configuration designstage is proposed. It produces an optimal eco-architecture under the given environmental regulations. To dealwith the case ofa complex product, the method is extended for analyzing hierarchical eco-architecture.

• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1083-1091
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• 2004

This paper presents a chunking system employed as a preprocessing module to the parser in a Chinese to Korean machine translation system. The parser can benefit from the dependency information provided by the chunking module. The chunking system was implemented using transformation-based learning technique and an effective interface that conveys the dependency information to the parser was also devised. The module was integrated into the machine translation system and experiments were performed with corpuses collected from Chinese websites. The experimental results show the introduction of chunking module provides noticeable improvements in the parser's performance.

• Ocean and Polar Research
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• v.28 no.1
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• pp.13-23
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• 2006

This study was conducted to investigate the community structure and distributional pattern of meiobenthos on the sediment of the mangrove forest and seagrass bed in the Chuuk lagoon. The samples were collected by an acryl corer at 14 stations. Nematodes were the most abundant meiobenthos, followed by ciliophorans and polychaetes; these taxa comprised more than 70% of the total abundance at all stations. The meiofuuna sampled in seagrass bed were more diverse than those of mangrove substrates. Total densities were higher in mangrove stations than other sites, averaging 1,671 to $2,967inds/10cm^2$. Densities in seagrass area ranged between 605 and $1,053inds/10cm^2$. Biomasses, however, were higher in seagrass bed $(975-2,167{\mu}g\;free\;dry\;weight/10cm^2)$ than in mangrove area $(1,064-1,180{\mu}g\;free\;dry\;weight/10cm^2)$. Ordination chart by MDS of major meiofaunal density in each station showed difference between mangrove area and seagrass area in terms of habitat of meiobenthos.

• Journal of the Korean Society for Advanced Composite Structures
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• v.1 no.2
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• pp.44-50
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• 2010

The behaviour of Modular GFRP(Glass Fiber Reinforced Polymers) decks for use in deteriorated bridge decks replacement are investigated experimentally in this study. As for the performance evaluation of bridge decks, experimental studies on the 3 test specimens with 1/5 scale of full size were carried out. Three specimens were sandwich plates with box tube cores. The constituents of bridge decks were glass fiber preforms and epoxy resin. The experimental results of all the specimens were summarized for maximum strength, stiffness and deformation capacity. A finite element analyses were compared to verify validity of experimental results.

• Journal of Institute of Convergence Technology
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• v.6 no.2
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• pp.41-46
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• 2016

Based on Regional Industry Development Plan in 2014, machinery part industry and medical instrument industry has been designated as core industries of Chung-buk area. Machinery part industry plays an important role in economic growth of chung-buk area and it has been faced with signigicant changes - such as SMART factory and IoT(Internet of things). Also, medical instrument industry with 3D printing technology grows rapidly in Chung-buk area. It is believed that medical instrument could be next cash-cow items for Chung-buk area. In this paper, we survey, analyze and summarize the current machinery part industry and medical instrument industry focused on Chunk-buk Area.

• English Language & Literature Teaching
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• v.15 no.3
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• pp.151-170
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• 2009

Recently speech texts have been increasingly used for English education because of their various advantages as language teaching and learning materials. The purpose of this paper is to analyze speech texts in a corpus-based lexical approach, and suggest some productive methods which utilize English speaking or writing as the main resource for the course, along with introducing the actual classroom adaptations. First, this study shows that a speech corpus has some unique features such as different selections of pronouns, nouns, and lexical chunks in comparison to a general corpus. Next, from a collocational perspective, the study demonstrates that the speech corpus consists of a wide variety of collocations and lexical chunks which a number of linguists describe (Lewis, 1997; McCarthy, 1990; Willis, 1990). In other words, the speech corpus suggests that speech texts not only have considerable lexical potential that could be exploited to facilitate chunk-learning, but also that learners are not very likely to unlock this potential autonomously. Based on this result, teachers can develop a learners' corpus and use it by chunking the speech text. This new approach of adapting speech samples as important materials for college students' speaking or writing ability should be implemented as shown in samplers. Finally, to foster learner's productive skills more communicatively, a few practical suggestions are made such as chunking and windowing chunks of speech and presentation, and the pedagogical implications are discussed.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.880-888
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• 2016

In this paper, we propose a new HDFS-AIO framework to enhance HDFS with Adaptive I/O System (ADIOS), which supports many different I/O methods and enables applications to select optimal I/O routines for a particular platform without source-code modification and re-compilation. First, we customize ADIOS into a chunk-based storage system so its API semantics can fit the requirement of HDFS easily; then, we utilize Java Native Interface (JNI) to bridge HDFS and the tailored ADIOS. We use different I/O patterns to compare HDFS-AIO and the original HDFS, and the experimental results show the design feasibility and benefits. We also examine the performance of HDFS-AIO using various I/O techniques. There have been many studies that use ADIOS, however our research is expected to help in expanding the function of HDFS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3182-3202
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• 2015

Flexibly expanding the storage capacity required to process a large amount of rapidly increasing unstructured log data is difficult in a conventional computing environment. In addition, implementing a log processing system providing features that categorize and analyze unstructured log data is extremely difficult. To overcome such limitations, we propose and design a MongoDB-based unstructured log processing system (MdbULPS) for collecting, categorizing, and analyzing log data generated from banks. The proposed system includes a Hadoop-based analysis module for reliable parallel-distributed processing of massive log data. Furthermore, because the Hadoop distributed file system (HDFS) stores data by generating replicas of collected log data in block units, the proposed system offers automatic system recovery against system failures and data loss. Finally, by establishing a distributed database using the NoSQL-based MongoDB, the proposed system provides methods of effectively processing unstructured log data. To evaluate the proposed system, we conducted three different performance tests on a local test bed including twelve nodes: comparing our system with a MySQL-based approach, comparing it with an Hbase-based approach, and changing the chunk size option. From the experiments, we found that our system showed better performance in processing unstructured log data.

• Journal of The Korean Association For Science Education
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• v.22 no.5
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• pp.1030-1043
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• 2002

The development of cognitive psychology provides us a theoretical base from which we can obtain information about human problem solving. One purpose of this study was to investigate the effects of cognitive psychological factors on the problem solving of the two kinds of tasks (content free, content specific). And the other purpose was to find out the existence of critical situation in problem solving process. Even the items of tasks with the same logical structure and content knowledge could have different sizes of mental demand. The results were as follows. The mental demand of the problem, and the problem solver's mental capacity, might be the main factors in problem solving. Critical situation of both a group and an individual existed in the tasks that need content free knowledge (FIT 752 task). But the critical situation of a group was completely different from that of the individual in the tasks that need content specific knowledge (electric circuit task). According to the analysis of achievement for each individual in the task that need content specific knowledge, the critical situation of an individual existed in problem solving, but the critical situation of a group was not existed by were summed up the individual results.