• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.140-147
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• 2018

The performance of a hydrate anti-agglomerant (AA) on cyclopentane (CyC5) hydrate anti-agglomeration at various concentrations (0-1 wt%, based on the oil phase) using MMF apparatus has been investigated. At low AA concentrations up to 0.01 wt%, the AA reduces the cohesion force (capillary force) by reducing the CyC5-water interfacial tension. At concentrations higher than 0.1 wt%, hydrate hydrophobicity alternation and AA's thermodynamic inhibition effects are the main part of AA's mechanism. Additionally, a "temporary agglomeration" phenomenon caused by surface melting of the hydrate particles is also observed, which may indicate the AA's weak ability to produce stable water-CyC5 interface.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.273-296
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• 2006

The purpose of this paper is to investigate the formation and characteristics of Gwangju photonics agglomeration as a new agglomeration with a new industry. Data used in this study are locally investigatedfirm related data and the result of questionnaire surveys. Major findings are as follows. First, in the viewpoint of policy, national government suggested the whole policy frameworks and financial support for the strategic industrial development. Regional government picked up and fostered the strategic industry. The initial support of the national government and role of regional government triggered the initial development of the agglomeration. Second, in the spatial perspective, Gwangju photonics agglomeration is based on the externalities of knowledge and technology as well as the input-output network within value chains of production. There is a possibility that Gwangju photonics agglomeration will be developed as an innovation cluster of knowledge-based economy in the future beyond a mere production base of photonics.

• The Journal of Industrial Distribution & Business
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• v.10 no.1
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• pp.9-17
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• 2019

Purpose - Urban agglomeration construction is one of national strategic plans to accelerate the development of industrialization and urbanization in China, which has threatened the eco-environmental quality at the same time. This paper selected the urban agglomeration in the middle reaches of the Yangtze River as the research area. Research design, data, and methodology - The the slack-based measurement (SBM) model considering undesirable outputs is applied to measure the eco-efficiency of this urban agglomerations during 2006-2015. Results - The empirical results show that average eco-efficiency of the urban agglomeration in the middle reaches of the Yangtze River is 0.595. Regional ecological development is unbalanced. The highest eco-efficiency is recorded at Wuhan Metropolitan Area, and the lowest one is at the Changsha-Zhuzhou-Xiangtan City Group. Energy consumption and waste dust emissions are the key factors led to ecological inefficiency. Based on this, potentials for energy saving and waste dust reducing are calculated. Conclusions - Finally, this study provides policy implications targeted to promote the coordinating development of economy and eco-environment under the construction of urban agglomeration.

• Journal of the Economic Geographical Society of Korea
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• v.8 no.1
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• pp.17-29
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• 2005

This study has attempted to analyze the spatial structure of industrial agglomerations with elaborated spatial econometric techniques. First of all, spatial patterns and structures of industrial agglomerations in Korea show a multi-polar spatial pattern of industrial agglomeration, Major industries from industrial agglomerations in the Seoul Metropolitan Area, part of the Chungcheong Area and Dongnam Area. Second, as some industrial agglomerations show an agglomerative pattern beyond a regionally based-administrative jurisdiction, the effects of agglomeration seem to be produced across regionally based-administrative jurisdictions. Finally, it can be considered that industrial agglomerations have generally been produced by spatial divisions of labor in which the functions of conception and execution are separated from each other. According to this results, in designing regional innovation systems, their spatial coverage should draw upon an extended region with a few adjacent provinces, and there is a need to form networked clusters in order to sufficiently capitalize upon the spatial spillovers of agglomerations.

• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.13-26
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• 2004

According to economic growth theory, location configuration of business enterprises engaged in specific industries has spatial affinity. In this research we defined industrial concentration index to measure industry agglomeration using the characteristics of dispersion parameter of negative binomial distribution, and used the industrial concentration index to examine aspect of spatial configuration change. We utilized Census on Basic Characteristics of Establishments of 1995 and 2000 to deduce industrral concentration indices of 7 knowledge-based industries and 9 strategy-based industries of Choongbuk Province and analyzed the aspect of spatial configuration change.

• Journal of the Economic Geographical Society of Korea
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• v.23 no.1
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• pp.18-34
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• 2020

This study aims to investigate Dongdaemun fashion industry once thrived in Seoul, now in a rapid decline. For this purpose, three research themes are put forward. That is, to fix the boundary of Dongdaemun fashion industry, to analyze the characteristics of its value chain, production network and industrial agglomeration, and to search for the cause of its decline and to suggest political solutions against it. The following is the findings of this study. Firstly, Dongdaemun fashion industry has spreaded out over the last six decades and now its boundary can be marked within a radius of 10 kilometers of Dongdaemun Market in northeastern Seoul. Secondly, Dongdaemun fashion industry has a buyer-driven chain and star production network, and therefore can be assumed that it is spatially segmented industrial agglomeration. Lastly, its rapid decline is directly from the shrink of market demand on Dondaemun fashion, and inherently in the topological structure of its star production network. Thus the feasible political solutions can be found in that direction. Consequently, these results have academic implications for clearing up some previous studies' misunderstandings and getting over one of the long-criticized research biases that pervades in industrial agglomeration theory, primarily focusing on the successful regions.

• Journal of Industrial Technology
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• v.7
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• pp.27-47
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• 1987

Fine anthracite is very difficult to upgrade by conventional processes such as gravity concentration or froth flotation, because large quantities of fine coals are generated at the mining and preparation stages and a significant portion of these fine coals are mixed with gangue minerals. This study, therefore, was carried out for the purpose of improving recovery of low ash clean coal, effective beneficiation of low-grade coking coal and removal of sulphur from high-sulphur coals by employing the method of selective agglomeration using oil or polystrene flocculants, for coals which are generally hydrophobic in nature will be extracted by using flocculants. Studies were performed by varying solid concentration, concetration of bridging liquid, mixing speed and mixing time, balling speed and balling time, dispersant dosage, flocculant dosage, pulp pH, and particle size. The results were : when the methods of the oil agglomeration and selective flocculation were employ(in the two process the sample was ground to the size of -74 micron), 1) ash content of the agglomerated coal was 9.85, 7.83%, 2) combustibel recovery of it was 98.5%, 93.5%, respectively. It was observed in selective flocculation that polystyrene is an effective flocculant for coal, De-entrapment of shale from the concentrate flocculated by mechanical agitation was necessary for substantional reductions in final ash content.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1581-1584
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• 2008

In dual-polycide-gate structure with butting contact, net doping concentration of polysilicon was decreased due to overlap between $n^+$ and $p^+$ and lateral dopant diffusion in silicide/polysilicon layers. The generation of parasitic Schottky diode in butting contact region is attributed both to the $CoSi_2$-loss due to $CoSi_2$ agglomeration and to the decrease in net doping concentration of polysilicon layer. Parasitic Schottky diode reduces noise margin of sense amplifier in DDI DRAM, which causes column fail. The column fail could be reduced by physical isolation of $n^+/p^+$ polysilicon junction or suppressing $CoSi_2$ agglomeration by using nitrogen implantation into $p^+$ polysilicon before $CoSi_2$ formation.

• Journal of the Korean Geographical Society
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• v.40 no.6 s.111
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• pp.653-670
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• 2005

The purpose of this study is to explore a spatial agglomeration characteristics and innovative milieu of the shoemaking industry in Seoul. In order to explain it, currently discussed dynamic agglomeration economies approach is applied and as an example, shoemaking industry in Seoul has been analyzed. The result of this research can be boardly summarized into two points. Frist, agglomeration economy is changing from urbanization economy to localization economy in this newly rising core of shoemaking industry which is Sung-Su dong area. Also, cooperative effects based on collective efficiency between companies and people are being generated within the area. This is largely affected by networking infrastructure between companies and people within the area, non-trade dependency and social capital acclamation. Secondly, the lack of institutional agglomeration formation in this area is considered to be the obstacle for the long-term development and innovation spin-off. This means recognition switch-over and institutional concern and support is needed in the future from the public sector.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.158-164
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• 2016

Spherical DADNE/AP (1,1-diamino-2,2-dinitroethylen/ammonium perchlorate) energetic composites were produced by drowning-out/agglomeration (D/A). The agglomeration of DADNE with AP particles was found to be affected by the amount of the bridging liquid, stirring velocity and residence time. The composites appeared to grow dramatically with the amount of bridging liquid which triggers agglomeration. As the stirring velocity and the residence time increased, the size of composites increased and then tended to decrease. Thermal gravimetric analysis showed that the addition of DADNE activates the low temperature decomposition (LTD) of AP. For the neat AP, the only about 30 wt% of AP was found to decompose at the LTD. On the other hand, it was found that 70 wt% of AP decomposed when DADNE was added by physical mixing and 90 wt% of AP decomposed when the DADNE/AP composites were prepared by the D/A method.