• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.391-391
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• 2000

Manufacturing process generally exhibits major or minor variations due to deviation of raw materials, equipment degradation, controller malfunction, and so on. Extensive research based on multivariate statistical process control has been done to monitor the unstable states and indicate a corrective action. A prototype of intelligent operation support system ("ISYS-MSPC") has been developed as a tool that supports the enhanced operation to guarantee the high productivity and a uniform high quality product. This system has been applied to the industrial batch and continuous processes and its performance has been validated .

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5252-5268
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• 2018

To support a large-scale Hadoop cluster, Hadoop heartbeat messages are designed to deliver the significant messages, including task scheduling and completion messages, via piggybacking to reduce the number of messages received by the NameNode. Although Hadoop is designed and optimized for high-throughput computing via batch processing, the real-time processing of large amounts of data in Hadoop is increasingly important. This paper evaluates Hadoop's performance and costs when the heartbeat period is controlled to support latency sensitive applications. Through an empirical study based on Hadoop 2.0 (YARN) architecture, we improve Hadoop's I/O performance as well as application performance by up to 13 percent compared to the default configuration. We offer a guideline that predicts the performance, costs and limitations of the total system by controlling the heartbeat period using simple equations. We show that Hive performance can be improved by tuning Hadoop's heartbeat periods through extensive experiments.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1227-1232
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• 2008

High-speed train of push-pull type called as G7 train has been developed and chosen as the model of KTX-II which will be operated on Honam Line nexr year. However, the EMU-type high-speed train appeared to be the recent trend that foreign markets have shown. Also, in the near future, a great number of new train sets are needed to accommodate the increased passengers in our country. Thus, development of the high-speed EMU was decided, planned, and started. In the development, included were almost all fundamental key technologies such as noise and vibration reduction in a passenger cabin, running characteristics, aerodynamic analysis, crashworthiness evaluation, EMI/EMC analysis, design of the cooling system for the propulsion control system, enhanced performance of transformer and switching converters, synchronous traction motor with permanent magnets, new design of front nose and ergonomic interiors, application of advanced information technology(IT) and smart sensors and the cost reduction of construction of railway bridges, etc. Each key technologies are carried out as sub-project independently but under the supervision of a project. The project will develop the high advanced level of technologies and provide necessary know-why's and support the team in charge of the development of the high-speed EMU, Hyundai Rotem Co. Ltd. The high-speed EMU will be successfully developed with the support of the project.

• ETRI Journal
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• 제29권3호
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• pp.336-352
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• 2007

Sequential pattern mining has become an essential task with broad applications. Most sequential pattern mining algorithms use a minimum support threshold to prune the combinatorial search space. This strategy provides basic pruning; however, it cannot mine correlated sequential patterns with similar support and/or weight levels. If the minimum support is low, many spurious patterns having items with different support levels are found; if the minimum support is high, meaningful sequential patterns with low support levels may be missed. We present a new algorithm, weighted interesting sequential (WIS) pattern mining based on a pattern growth method in which new measures, sequential s-confidence and w-confidence, are suggested. Using these measures, weighted interesting sequential patterns with similar levels of support and/or weight are mined. The WIS algorithm gives a balance between the measures of support and weight, and considers correlation between items within sequential patterns. A performance analysis shows that WIS is efficient and scalable in weighted sequential pattern mining.

• 벤처창업연구
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• 제14권1호
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• pp.73-83
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• 2019

창업의 중요성에 대한 인식이 높아지면서 인생의 진로를 창업으로 결정하는 예비 창업가들이 점진적으로 많아지고 있다. 하지만 창업 실패율은 여전히 높고, 창업성과가 미비하여 질적인 수준은 매우 낮다. 이에 본 연구에서는 창업가 역량특성, 창업지원제도에 대한 관심을 가지고, 창업성과에 어떠한 영향을 미치는지 실증 분석하였다. 이를 위해 2018년 8월 1일부터 8월30일까지 전라북도의 7년 미만 창업가를 대상으로 361개의 유효데이터를 수집하여 SPSS 21.O, AMOS 21을 통해 연구검증에 활용하였다. 연구결과 첫째, 창업가 역량특성(기업가적 역량, 관리적 역량)이 창업지원제도에 유의미한 정(+)의 영향을 미치고, 기술적 역량은 유의미한 효과가 없는 것으로 나타났다. 둘째, 창업가 역량(기업가 역량, 관리적 역량, 기술적 역량)이 창업성과에 유의미한 영향을 미치는 결과가 증명되었다. 단, 기업가적 역량은 창업성과에 음(-)의 유의미한 영향을 미치는 의미 있는 결과가 나왔다. 셋째, 창업지원제도는 창업성과에 정(+)의 유의미한 영향을 미치는 것으로 나타났다. 끝으로 창업지원제도는 기업가적 역량과 창업성과 사이에 매개 효과가 있음을 검증하였다. 본 연구의 시사점은 창업기업들의 창업성과를 높이기 위해서는 창업가 역량 함양이 중요한 요인이라는 것을 증명하였다. 또한 창업지원제도 활용은 직 간접적으로 창업 성과에 유의미한 영향을 미치는 중요한 요소임을 실증연구를 통해 증명하였으며, 적극적으로 창업 지원 및 활용하는 것이 창업성과를 높이기 위해서는 반드시 필요한 부분이라는 것을 증명하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.277-280
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• 1998

As user's demands for high-speed data traffic are recently increased, ABR services are considered as one of important service requirements in ATM networks. Unfortunately, a number of existing ATM switching systems have structural drawbacks as to support ABR services because these switching systems have been developed to support realtime(rt) services such as CBR and rt-VBR services. To support ABR services in the existing ATM switching systems, new traffic control mechanisms for ABR services are required. This paper proposes a method for supporting ABR services in ATM swithcing systems without back-pressure mechanisms and evaluates the performance of the proposed method using simulation.

• Communications for Statistical Applications and Methods
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• 제19권5호
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• pp.655-662
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• 2012

Classification is an important research field in pattern recognition with high-dimensional predictors. The support vector machine(SVM) is a penalized feature selector and classifier. It is based on the hinge loss function, the non-convex penalty function, and the smoothly clipped absolute deviation(SCAD) suggested by Fan and Li (2001). We developed the algorithm for the multiclass SVM with the SCAD penalty function using the local quadratic approximation. For multiclass problems we compared the performance of the SVM with the $L_1$, $L_2$ penalty functions and the developed method.

• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.285-291
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• 2016

In chemical-looping combustion, pure oxygen is transferred to fuel by solid particles called as oxygen carrier. Chemical-looping combustion process usually utilizes a circulating fluidized-bed process for fuel combustion and regeneration of the reduced oxygen carrier. The performance of an oxygen carrier varies with the active metal oxide and the raw support materials used. In this work, spraydried Mn-based oxygen carriers were prepared with different raw support materials and their physical properties and oxygen transfer performance were investigated to determine that the raw support materials used are suitable for spray-dried manganese oxide oxygen carrier. Oxygen carriers composed of 70 wt% $Mn_3O_4$ and 30 wt% support were produced using spray dryer. Two different types of $Al_2O_3$, ${\gamma}-Al_2O_3$ and ${\alpha}-Al_2O_3$, and $MgAl_2O_4$ were applied as starting raw support materials. The oxygen carrier prepared from ${\gamma}-Al_2O_3$ showed high mechanical strength stronger than commercial fluidization catalytic cracking catalyst at calcination temperatures below $1100^{\circ}C$, while the ones prepared from ${\alpha}-Al_2O_3$ and $MgAl_2O_4$ required higher calcination temperatures. Oxygen transfer capacity of the oxygen carrier prepared from ${\gamma}-Al_2O_3$ was less than 3 wt%. In comparison, oxygen carriers prepared from ${\alpha}-Al_2O_3$ and $MgAl_2O_4$ showed higher oxygen transfer capacity, around 3.4 and 4.4 wt%, respectively. Among the prepared Mn-based oxygen carriers, the one made from $MgAl_2O_4$ showed superior oxygen transfer performance in the chemical-looping combustion of $CH_4$, $H_2$, and CO. However, it required a high calcination temperature of $1400^{\circ}C$ to obtain strong mechnical strength. Therefore, further study to develop new support compositions is required to lower the calcination temperature without decline in the oxygen transfer performance.

• 한국컴퓨터정보학회논문지
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• 제23권10호
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• pp.1-9
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• 2018

Modern graphics processing units (GPUs) have become one of the most attractive platforms in exploiting high thread level parallelism with the support of new programming tools such as CUDA and OpenCL. Recent GPUs has applied cache hierarchy to support irregular memory access patterns; however, L1 data cache (L1D) exhibits poor efficiency in the GPU. This paper shows that the L1D does not always positively affect the applications in terms of performance and energy efficiency for the GPU. The performance of the GPU is even harmed by using the L1D for lots of applications. Our proposed technique exploits the characteristics of the currently-executed applications to predict the performance impact of the L1D on the GPU and then decides whether to continuously use the cache for the application or not. Our experimental results show that the proposed technique improves the GPU performance by 9.4% and saves up to 52.1% of the power consumption in the L1D.

• 융합경영연구
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• 제10권3호
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• pp.1-8
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• 2022

Purpose: This study aims to examine the effect of SMEs' R&D competence on management performance. Research design, data, and methodology: The empirical data of this study are derived from 2,375 SMEs that participated in the material, parts, and equipment research and development support project conducted from 2014 to 2018. Among them, 2,230 data were analyzed by classifying them into high-tech and low-tech fields. SPSS 24.0 was used for statistical analysis and correlation analysis and T-TEST were applied. Results: It was analyzed that the level of R&D organization, research personnel, and the number of patent registrations all affected operating profit and sales. In particular, it has been proven that research personnel have a greater impact on management performance among the level of R&D organization, research personnel, and the number of patent registrations. In addition, there was a difference between high-tech and low-tech industries in the impact on operating profit and sales, which are indicators of management performance. Conclusions: This study suggests that R&D competence are strengthened to advance the material, parts, and equipment industries and to promote future growth, while differentiated support is needed according to each company's R&D competence and technology level.