• 전기학회논문지
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• 제57권4호
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• pp.692-699
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• 2008

Semiconductor research and development(R&D) fabs are very different than production fabs in many ways such as the scales of production, job priority, production methods, and performance measures. Efficient operations of R&D fabs are very important to the development of new product, process stability, high yield, and ultimately company competitiveness. This paper proposes the fab-wide scheduling method for operational optimization of the R&D fabs. Most scheduling systems of semiconductor fabs have only focused on maximizing throughput of each separated areas without considering WIP(works in process) flows of entire fab. In this paper, we proposes the a fab-wide scheduling system which schedules all lots to entire fab equipment at once. We develop the MIP(mixed integer programing) model which allocates the lots to production equipment considering many constraints of all processes and the CP(constraint programming) model which determines the sequences of the lots in the production equipment. The proposed FAB-wide scheduling model is applied to the newly constructed R&D fab. As a result, we have accomplished the system based automated job reservation, decrease of the hot lot delay, increase of the queue time satisfaction, the high throughput by maximizing the batch sizes, decrease of the WIP TAT(Turn Around Time).

• 한국초등수학교육학회지
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• 제17권2호
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• pp.207-223
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• 2013

이 논문은 5+2=7과 같은 등호가 들어 있는 식의 읽기와 쓰기라는 두 행위 사이의 불일치 및 그 해소 과정에서 생길 수 있는 문제점에 관하여 논한 것이다. 기호 이해의 시간적 차원과 등호 개념의 이중성을 바탕으로, 초등 수학 교과서에 제시된 등식 읽기와 쓰기 방법을 분석하였다. 교사는 수업에서 기호 읽기와 기호 쓰기를 통해 무시간적인 차원의 기호를 시간 속에 펼쳐 놓는 시간화 작업을 수행한다. 이 때 읽기 순서와 쓰기 순서 사이에 불일치가 있을 수 있으며, 이를 교사가 어떻게 해소하는가는 학생들의 기호 이해에 영향을 줄 수 있다. 등식 읽기를 쓰기 관습에 종속시켜 이 불일치를 해소하면, 관계적 관점을 나타내고 있는 교과서의 등식 읽기를 조작적 관점의 읽기로 변환하는 현상이 일어나게 된다. 등호의 관계적 의미 이해를 중시하는 입장에서 보면, 쓰기를 교과서에 제시된 읽기 방식에 종속시키는 방향으로 불일치를 해소하는 것이 적절하다. 또한, 등호의 읽기 쓰기를 부등호의 읽기 쓰기와 통합적으로 다룰 필요가 있다.

• Journal of Microbiology
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• 제45권6호
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• pp.479-484
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• 2007

Bacterial communities at 10 cm, 100 cm, and 200 cm depths in a 100-year-old lead-zinc tailing heap were evaluated by constructing 16S rRNA gene libraries. In total, 98 operational taxonomic units (OTUs) were identified from 193 clones at a 3% sequence difference level. The OTU number and species richness decreased with the depth. Species composition was significantly different between the three libraries. Fifty-seven percent of the examined clones were Acidobacteria and 27% belonged to Proteobacteria. Other sequences included Chloroflexi, Firmicutes, Chlamydiae, Actinobacteria, Gemmatimonadetes, Nitrospira, and three unclassified OTUs. Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria were mainly distributed in the rhizosphere of naturally colonizing plants; however, Deltaproteobacteria, Acidobacteria, and Chloroflexi tended to inhabit the deeper tailings (below the 100 cm-depth).

• ETRI Journal
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• 제32권5호
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• pp.774-783
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• 2010

Many chaos-based encryption methods have been presented and discussed in the last two decades, but very few of them are suitable to secure transmission on noisy channels or respect the standard of the National Institute of Standards and Technology (NIST). This paper tackles the problem and presents a novel chaos-based cryptosystem for secure transmitted images. The proposed cryptosystem overcomes the drawbacks of existing chaotic algorithms such as the Socek, Xiang, Yang, and Wong methods. It takes advantage of the increasingly complex behavior of perturbed chaotic signals. The perturbing orbit technique improves the dynamic statistical properties of generated chaotic sequences, permits the proposed algorithm reaching higher performance, and avoids the problem of error propagation. Finally, many standard tools, such as NIST tests, are used to quantify the security level of the proposed cryptosystem, and experimental results prove that the suggested cryptosystem has a high security level, lower correlation coefficients, and improved entropy.

• 대한산업공학회지
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• 제24권1호
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• pp.23-35
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• 1998

This article presents a network flow analysis to form flexible machine cells with minimum intercellular part moves and a neural network model to form part families. The operational sequences and production quantity of the part, and the number of cells and the cell size are taken into considerations for a 0-1 quadratic programming formulation and a network flow based solution procedure is developed. After designing the machine cells, a neural network approach for the integration of part families and the automatic assignment of new parts to the existing cells is proposed. A multi-layer backpropagation network with one hidden layer is used. Experimental results with varying number of neurons in hidden layer to evaluate the role of hidden neurons in the network learning performance are also presented. The comprehensive methodology developed in this article is appropriate for solving large-scale industrial applications without building the knowledge-based expert rule for the cellular manufacturing environment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2691-2694
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• 1999

The multi-resonant converter(MRC) can reduce the switching losses exiting in a converter, so it is capable of operating at a high frequency. Such a few MHz high frequency application provides a high power density [$W/inch^{3}$]. But the high voltage stress across a switch of the resonant circuit is about 4$\sim$5 times the input voltage, it causes increasing of the conduction loss in MRC. In this paper, the mode analysis for the suggested AT Forward MRC with low voltage stress is discussed. The operational modes of the AT Forward MRC are divided to 8 equivalent modes according to the two switching sequences, Each mode is analyzed over all of the paper.

• Journal of Advanced Marine Engineering and Technology
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• 제22권5호
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• pp.617-625
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• 1998

A passive energy recovery snubber for high-power-factor boost rectifier, in which the main switch is implemented with a MOSFET, is described in terms of the equivalent circuits that are operational during turn-on and turn-off sequences. These equivalent circuits are analyzed so that the overshoot voltage across the main switch, the snubber current, and the turn-off transition time can be predicted analytically. From these results, the normalized overshoot voltage is reduced to 1 as $_W2T_on$ varies from zero to $\pi$/2, and then it is fIxed at 1 for $_W2T_on$> $\pi$/2. The peak snubber inductor current is directly proportional to the input current. The turn-offtransition time wltoffvaries from 0 to 2.57, depending on $_W2T_on$. The main switch combined with proposed snubber can be turned on with zero current and turned off at limited voltage stress. The high-power-factor boost rectifier with proposed snubber is implemented, and the experimental results are presented to confirm the validity of proposed snubber.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.668-676
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• 1998

A passive energy recovery snubber for high-power-factor boost rectifier, in which the main switch is described in terms of the equivalent circuits that are operational during turn-on and turn-off sequences. These equivalent circuits are analyzed so that the overshoot voltage across the main switch, the snubber current, and the turn-off transition time can be predicted analytically. The main switch combined with proposed snubber can be turned on with zero current and turned off at limited voltage stress. The high-power-factor boost rectifier with proposed snubber is implemented, and the experimental results are presented to confirm the validity of proposed snubber.

• Journal of Veterinary Science
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• 제22권3호
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• pp.37.1-37.14
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• 2021

Background: Ticks are one of the most common external parasites in dogs, and are associated with the transmission of a number of major zoonoses, which result in serious harm to human health and even death. Also, the increasing number of pet dogs and pet owners in China has caused concern regarding human tick-borne illnesses. Accordingly, studies are needed to gain a complete understanding of the bacterial composition and diversity of the ticks that parasitize dogs. Objectives: To date, there have been relatively few reports on the analysis of the bacterial community structure and diversity in ticks that parasitize dogs. The objective of this study was to investigate the microbial composition and diversity of parasitic ticks of dogs, and assessed the effect of tick sex and geographical region on the bacterial composition in two tick genera collected from dogs in China. Methods: A total of 178 whole ticks were subjected to a 16S ribosomal RNA (rRNA) next generation sequencing analysis. The Illumina MiSeq platform targeting the V3-V4 region of the 16S rRNA gene was used to characterize the bacterial communities of the collected ticks. Sequence analysis and taxonomic assignment were performed using QIIME 2 and the GreenGene database, respectively. After clustering the sequences into taxonomic units, the sequences were quality-filtered and rarefied. Results: After pooling 24 tick samples, we identified a total of 2,081 operational taxonomic units, which were assigned to 23 phyla and 328 genera, revealing a diverse bacterial community profile. The high, moderate and low prevalent taxa include 46, 101, and 182 genera, respectively. Among them, dominant taxa include environmental bacterial genera, such as Psychrobacter and Burkholderia. Additionally, some known tick-associated endosymbionts were also detected, including Coxiella, Rickettsia, and Ricketssiella. Also, the potentially pathogenic genera Staphylococcus and Pseudomonas were detected in the tick pools. Moreover, our preliminary study found that the differences in microbial communities are more dependent on the sampling location than tick sex in the tick specimens collected from dogs. Conclusions: The findings of this study support the need for future research on the microbial population present in ticks collected from dogs in China.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권3호
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• pp.1702-1721
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• 2019

A workflow process (or business process) management system helps to define, execute, monitor and manage workflow models deployed on a workflow-supported enterprise, and the system is compartmentalized into a modeling subsystem and an enacting subsystem, in general. The modeling subsystem's functionality is to discover and analyze workflow models via a theoretical modeling methodology like ICN, to graphically define them via a graphical representation notation like BPMN, and to systematically deploy those graphically defined models onto the enacting subsystem by transforming into their textual models represented by a standardized workflow process definition language like XPDL. Before deploying those defined workflow models, it is very important to inspect its syntactical correctness as well as its structural properness to minimize the loss of effectiveness and the depreciation of efficiency in managing the corresponding workflow models. In this paper, we are particularly interested in verifying very large-scale and massively parallel workflow models, and so we need a sophisticated analyzer to automatically analyze those specialized and complex styles of workflow models. One of the sophisticated analyzers devised in this paper is able to analyze not only the structural complexity but also the data-sequence complexity, especially. The structural complexity is based upon combinational usages of those control-structure constructs such as subprocesses, exclusive-OR, parallel-AND and iterative-LOOP primitives with preserving matched pairing and proper nesting properties, whereas the data-sequence complexity is based upon combinational usages of those relevant data repositories such as data definition sequences and data use sequences. Through the devised and implemented analyzer in this paper, we are able eventually to achieve the systematic verifications of the syntactical correctness as well as the effective validation of the structural properness on those complicate and large-scale styles of workflow models. As an experimental study, we apply the implemented analyzer to an exemplary large-scale and massively parallel workflow process model, the Large Bank Transaction Workflow Process Model, and show the structural complexity analysis results via a series of operational screens captured from the implemented analyzer.