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Sustainable Urban Industrial Space Policy: Experiences and Implications from US Cities (지속가능한 도시산업공간 정책 -미국 주요 도시의 경험과 시사점-)

  • Kim, Jin-Oh;Park, Jeong-Il
    • Journal of the Korean Regional Science Association
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    • v.36 no.3
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    • pp.53-65
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    • 2020
  • This study attempted to seek policy directions for development of sustainable urban industrial space through reviewing recent policies and projects of US cities that experienced urban industrial land replacement and industrial suburbanization. The policies and regulations for the urban industrial space preservation include the New York City's Industrial Business Zone, Chicago's Planned Manufacturing District, the no-net-loss framework in San Jose, and the subdivided and the state of the art in zoning systems in Philadelphia and Seattle. These policies and zoning systems have been effective for preventing the conversion of urban industrial lands to other uses, promoting business activities, and creating jobs for urban residents. In addition, the updated and innovative zoning systems allow for a wide variety of urban industrial spaces to meet newly emerging industrial demands. On the other hand, we suggested several policy implications through reviewing the cases of urban regeneration projects in Portland's Willamette Industrial Urban Renewal Area, Atlanta's BeltLine, and Milwaukee's Menomone Valley as follows: 1) updating and reinforcing spatial planning and policies for preservation and revitalization of urban industrial land; 2) considering existing businesses and local workers first; 3) setting up a participatory planning for local workers and residents; 4) preparing policies for brownfield cleanups.

Effect of multiple-failure events on accident management strategy for CANDU-6 reactors

  • YU, Seon Oh;KIM, Manwoong
    • Nuclear Engineering and Technology
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    • v.53 no.10
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    • pp.3236-3246
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    • 2021
  • Lessons learned from the Fukushima Daiichi nuclear power plant accident directed that multiple failures should be considered more seriously rather than single failure in the licensing bases and safety cases because attempts to take accident management measures could be unsuccessful under the high radiation environment aggravated by multiple failures, such as complete loss of electric power, uncontrollable loss of coolant inventory, failure of essential safety function recovery. In the case of the complete loss of electric power called station blackout (SBO), if there is no mitigation action for recovering safety functions, the reactor core would be overheated, and severe fuel damage could be anticipated due to the failure of the active heat sink. In such a transient condition at CANDU-6 plants, the seal failure of the primary heat transport (PHT) pumps can facilitate a consequent increase in the fuel sheath temperature and eventually lead to degradation of the fuel integrity. Therefore, it is necessary to specify the regulatory guidelines for multiple failures on a licensing basis so that licensees should prepare the accident management measures to prevent or mitigate accident conditions. In order to explore the efficiency of implementing accident management strategies for CANDU-6 plants, this study proposed a realistic accident analysis approach on the SBO transient with multiple-failure sequences such as seal failure of PHT pumps without operator's recovery actions. In this regard, a comparative study for two PHT pump seal failure modes with and without coolant seal leakage was conducted using a best-estimate code to precisely investigate the behaviors of thermal-hydraulic parameters during transient conditions. Moreover, a sensitivity analysis for different PHT pump seal leakage rates was also carried out to examine the effect of leakage rate on the system responses. This study is expected to provide the technical bases to the accident management strategy for unmitigated transient conditions with multiple failures.

Seasonal Fluctuations in Abundance and Species Composition of Fishes in Cheonsu Bay Using Trap Net Catches (小型定置網資料에 의한 淺水灣 魚類의 水質에 따른 種組成 및 量的 變動)

  • Lee, Tae-Won;Seok, Kyu-Jin
    • 한국해양학회지
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    • v.19 no.2
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    • pp.217-227
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    • 1984
  • Fish samples were collected by a trap net during 1981∼82 at the mouth of Cheonsu Bay to determine seasonal fluctuations in abundance and species composition. Examination of a series of trap net catches indicated that trap net data could be used, at least, for a qualitative analyses of a fish community and for a quantitative study of some pelagic fishes of Cheonsu Bay. Of the 64 species collected, a few temporal components predominated in abundance because of great seasonal fluctuations of water temperature. The early spring catch showed a low abundance value, and two cold weather seasonals, juvenile Enedrias fangi and Ammodytes personatus predominated in number and in weight. The number of species, abundance value in number and in biomass showed a peak in late spring when fishes move into bay for spawning and feeding after over-winterinig in the sea. Three pelagic species or warm weather seasonals, Harengula zunasi , Ammodytes personatus and Konosirus punctatus, predominated in abundance values. In this period night catch was significantly larger than day catch in terms of number of species, abundance in number and in weight Summer data showed a marked reduction of the number of species and abundance due to the loss of spawners probably by mortality or wide dipersion after spawning. A slight increase in abundance was observed in autumn by recruitment of the young-of-the-years. This catch was predominated by three juvenile fishes, H. zunasi, E. japonica and K. punctatus, which were the same species as in spring. The autumn catch showed no significant difference between day and night compositions.

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Dynamics of Carbon Sequestered in Concentric Layers of Soil Macroaggregates

  • Park, Eun-Jin;Smucker, Alvin J.M.
    • The Korean Journal of Ecology
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    • v.28 no.4
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    • pp.181-188
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    • 2005
  • Methods used to study carbon sequestration by soil aggregates have often excluded the concentric spatial variability and other dynamic processes that contribute to resource accessibility and solute transport within aggregates. We investigated the spatial gradients of carbon (C) and nitrogen (N) from the exterior to interior layers within macroaggregates, $6.3\sim9.5$ mm, sampled from conventional tillage (CT) and no tillage (NT) sites of a Hoytville silt clay loam. Spatial gradients in C accumulation within macroaggregates were related to the differences in C dynamics by determining the sizes and the turnover rates of fast C and slow C pools in the concentric layers of aggregates. Aggregate exteriors contained more labile C and were characterized by greater C mineralization rates than their interiors in both management systems. In contrast, C in the interior layers of aggregates was more resistant in both systems. These results indicated the spatial differentiation of C dynamics within macroaggregates, i.e., exterior layers as a reactive site and interior layers as a protective site. Greater total C distribution in the exterior layers of NT aggregates indicated more influx of C from the macropores in interaggregate space than C. mineralization (net gain of C), whereas lower C distribution within the exterior layers of CT aggregates indicated net loss of C by greater C mineralization than C influx. We found total C increased approximately 1.6-fold by the conversion of CT soils to NT management systems for a period of 36 years. Differences in total accumulation and the spatial distribution of C within aggregates affected by management were attributed to the differences in aggregate stability and pore networks controlling the spatial heterogeneities of resource availability and microbial activity within aggregates.

Quality Characteristics of French Bread with Various Dietary Fibers (다양한 식이섬유를 첨가한 프렌치브레드의 품질 특성)

  • Shin, Mal-Shick;Lee, Hyun-Ju
    • Korean journal of food and cookery science
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    • v.22 no.4 s.94
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    • pp.477-487
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    • 2006
  • The quality characteristics of dough and French breads containing dietary fibers, which were resistant starches (RS3 and RS4 types) and commercial non-starch polysaccharides (cellulose, pectin and chitosan), were investigated. The pH of the dough containing all dietary fiber except pectin was greater than that of control and was increased with increasing addition level. There was no correlation between pH and the expansion ratio of dough. As the level of added dietary fibers became high, the bread baking loss decreased, and the order of specific bread volume was 5% cellulose < 5% pectin < control bread, with no significant difference in specific volume. When a high level of dietary fibers was added to wheat flour, a complex phase appeared due to the formation between the network structure of additives and wheat gluten, and starch granules were heavily masted by the increased development of gluten-network matrix after the first fermentation like a wide spread net. Comparing the colorimetric changes of breads with the same added ratio (10%) of dietary fibers, the cellulose and RS4 addition breads had lower levels and the pectin-added bread had the highest value in the redness, while the chitosan-added bread had the highest value in the yellowness. Breads with a high level of dietary fibers showed increased hardness, gumminess, and brittleness and decreased springiness and cohesiveness. By sensory data, breads with 5% NSP and 10% RS addition showed high overall acceptability, with higher sensory RS score, compared to NSP addition. In conclusion, it was suggested that bread with lower than 10% RS or 5% NSP addition based on the amount of wheat flour, was acceptable with no considerable change in preference/overall quality and processing in bread-making.

Wear assessment of the WC/Co cemented carbidetricone drillbits in an open pit mine

  • Saeidi, Omid;Elyasi, Ayub;Torabi, Seyed Rahman
    • Geomechanics and Engineering
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    • v.8 no.4
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    • pp.477-493
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    • 2015
  • In rock drilling, the most important characteristic to clarify is the wear of the drill bits. The reason that the rock drill bits fail with time is wear. In dry sliding contact adhesive wear deteriorates the materials in contact, quickly, and is the result of shear fracture in the momentary contact joins between the surfaces. This paper aims at presenting an overview of the assessment of WC/Co cemented carbide (CC) tricone bit in rotary drilling. To study wear of these bits, two approaches have been used in this research. Firstly, the new bits were weighted before they mounted on the drill rigs and also after completion their useful life to obtain bit weight loss percentage. The characteristics of the rock types drilled by using such this bit were measured, simultaneously. Alternatively, to measure contact wear, namely, matrix wear a micrometer has been used with a resolution of 0.02 mm at different direction on the tricone bits. Equivalent quartz content (EQC), net quartz content (QC), muscovite content (Mu), coarseness index (CI) of drill cuttings and compressive strength of rocks (UCS) were obtained along with thin sections to investigate mineralogical properties in detail. The correlation between effective parameters and bit wear were obtained as result of this study. It was observed that UCS shows no significant correlation with bit wear. By increasing CI and cutting size of rocks wear of bit increases.

High Efficiency and Low Device Stress Voltage and Current Clamping ZVS PWM Asymmetrical Half Bridge Converter

  • Han Sang Kyoo;Moon Gun-Woo;Youn Myung Joong
    • Proceedings of the KIPE Conference
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    • 2004.07a
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    • pp.341-345
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    • 2004
  • A high efficiency and low device stress voltage and current clamping BVS PWM asymmetrical half bridge converter is proposed in this paper. To achieve the ZVS of power switches along the wide load range, the transformer leakage inductor $L_{Ikg}$ is increased. Then, to solve the problem related to ringing in the secondary rectifier caused by the resonance between $L_{Ikg}$ and rectifier junction capacitors, the proposed converter employs a voltage and current clamping cell, which helps voltages and currents of rectifier diodes to be clamped at the output voltage and output current, respectively. Therefore, no RC-snubber for rectifier diodes is needed and a high efficiency as well as low noise output voltage can be realized. In addition, since all energy stored in $L_{Ikg}$ is transferred to the output side, the circulating energy problem can be effectively solved and duty loss does net exist. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385-170Vdc prototype are presented.

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A Risk-Return Analysis of Loan Portfolio Diversification in the Vietnamese Banking System

  • HUYNH, Japan;DANG, Van Dan
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.105-115
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    • 2020
  • The study empirically examines the effects of loan portfolio diversification on bank risk and return in the nascent banking market of Vietnam. Loan portfolio diversification is captured through the Hirschman-Herfindahl index and the Shannon Entropy with sectoral exposures. We access each bank's financial reports to collect the required data, especially the breakdown of sectoral loan portfolios, thus constituting a unique dataset. To compute bank return, we use the traditional accounting indicators, including return-on-assets, return-on-equity, and net-interest margin. For bank risk, we utilize the loan-loss provisions and non-performing loans relative to gross customer loans. Using a sample of 30 commercial banks over the period from 2008 to 2019 and the system generalized method of moments estimator for the dynamic panel, we indicate the downsides of portfolio diversification. Concretely, we observe that all diversification measures exhibit significantly negative signs in all regressions across different bank return proxies. At the same time, the estimates display the significant and positive impact of diversification on the non-performing loan ratio. Hence, sectoral loan portfolio diversification significantly hampers bank performance in both aspects of lower return and higher credit risk. The results are robust across a rich set of bank performance and portfolio diversification measures.

Main Trends for Reforming the Law of Insurance Contract in England - Focused on the Insured's Post-Contract Duty of Good Faith in relation to Claims - (영국 보험계약법의 주요 개혁동향 - 보험금청구와 관련한 피보험자의 계약체결 후 선의의무를 중심으로 -)

  • Shin, Gun-Hoon
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.53
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    • pp.207-229
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    • 2012
  • In IP 7 and LCCP 201, Law Commission considers the insured's duty of good faith after the formation of the contract. This article intends to review and analyse the legal implications of proposals in IP 7 and LCCP 201. The results of analysis are following. First, Law Commission propose to end the remedy of avoidance under MIA 1906 section 17, because avoidance of past claims is unprincipled, impractical and unnecessarily harsh. Secondly, LC proposes that an insured who makes a fraudulent claim should forfeit the whole claim which the fraud relates, but that the fraud should not invalidate previous and legitimate claims. Thirdly, LC proposes to introduce a statutory right for the insurer to claim damages for the reasonable, foreseeable costs of investigate a fraudulent claim in specific circumstances and that damages would be limited to those cases where the insurer can show an actual, net loss. Finally, LC provisionally propose that an express fraud clause should be upheld in business insurance, whereas in consumer insurance, any term which purports to give the insurer greater rights in relation to fraudulent claims that those set out in statute would be of no effect.

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MONITORING SEVERE ACCIDENTS USING AI TECHNIQUES

  • No, Young-Gyu;Kim, Ju-Hyun;Na, Man-Gyun;Lim, Dong-Hyuk;Ahn, Kwang-Il
    • Nuclear Engineering and Technology
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    • v.44 no.4
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    • pp.393-404
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    • 2012
  • After the Fukushima nuclear accident in 2011, there has been increasing concern regarding severe accidents in nuclear facilities. Severe accident scenarios are difficult for operators to monitor and identify. Therefore, accurate prediction of a severe accident is important in order to manage it appropriately in the unfavorable conditions. In this study, artificial intelligence (AI) techniques, such as support vector classification (SVC), probabilistic neural network (PNN), group method of data handling (GMDH), and fuzzy neural network (FNN), were used to monitor the major transient scenarios of a severe accident caused by three different initiating events, the hot-leg loss of coolant accident (LOCA), the cold-leg LOCA, and the steam generator tube rupture in pressurized water reactors (PWRs). The SVC and PNN models were used for the event classification. The GMDH and FNN models were employed to accurately predict the important timing representing severe accident scenarios. In addition, in order to verify the proposed algorithm, data from a number of numerical simulations were required in order to train the AI techniques due to the shortage of real LOCA data. The data was acquired by performing simulations using the MAAP4 code. The prediction accuracy of the three types of initiating events was sufficiently high to predict severe accident scenarios. Therefore, the AI techniques can be applied successfully in the identification and monitoring of severe accident scenarios in real PWRs.