• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1802-1812
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• 2001

The purpose of this study is to analyze numerically the movement of particles included in turbulent fluid flow characteristics of metallic surfaces. To describe fluid flew, the incompressible Navier-Stokes equation discretized by the finite volume method were solved on the non-orthogonal coordinates with non-staggered variable arrangement, and the k-$\xi$ turbulence model was adapted. After fluid flow was calculated, particle movement was predicted from the Lagrangian approaches. Non-essential complexities were avoided by assuming that the particles had spherical shapes and the Stoke's drag formula only consisted of external farces acting upon them. In order to validate the numerical calculations, the results were compared with the experimental data reported in literature and agreed well with them. The drag force coefficient equation showed better agreement with the experimental data in the prediction of particle movement than the correction factor equation. Impact velocity and impact angle increased as inlet turbulence intensity decreased, relative jet height was lower. or the Reynolds number was larger.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1863-1870
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• 2000

When an impact stress is applied on the external boundary of double cantilever beam of orthotropic material which crack length is greater than specimen hight and anistropic ratio is very high, dyna mic energy release rate is derived, and the relationship between dynamic energy release rate and crack propagating velocity is studied. Dynamic energy release rate to static energy release rate is decreased with increasment of crack propagating velocity. The relationships between dynamic energy release rate and vertical strain have a similar pattern with those between static energy release rate and vertical strain. When normalized time(Cstla) is greater than or equal to 2, dynamic energy release rate approaches to a constant value.

• The Journal of Industrial Distribution & Business
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• v.9 no.4
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• pp.37-42
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• 2018

Purpose - The purpose of this study is to analyze the current status of various fusion research journals and the operational strategies of such journals and compare them with the operational strategies of IJIDB. Research design, data, and methodology - This study focused on the contents analysis of convergence journals after summarizing the development history from IJIDB's past and its external situation. In addition, we analyzed other strategies such as the number of publication journals, the number of publications, the academic scope, and the impact factor that other convergence journals operate on. Results - As a result of the analysis, the convergent journals showed to have several related journals, and some journals managed their impact factor well at 5.8. Also, some journals loaded 25 papers in one volume. Also, the managerial functions in IJIDB should be developed further to increase its stability. Finally, opportunities for articles by Candidates of Ph.D. and Masters degree students should be more open to in this field. Conclusions - If IJIDB finds its competitiveness in comparison with the operational strategies of other convergence journals, it will be the best journal in the Korea Citation Index to receive the most research papers and hospitality from scholars in the Korean journals.

• Journal of the Korean Society for information Management
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• v.25 no.3
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• pp.339-355
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• 2008

The purpose of this empirical case study is to explore what factors affect on the economic valuation of academic journals and to ascertain the degree of each impact. For this study, factors were categorized into three groups: internal factors external factors and demand theory factors. The on-line questionnaire was used to collect data and 383 responded from individual users of and the persons in charge of the DDS(Document Delivery Service). Collected data were analyzed using SPSS 12.0 for Windows/PC. The result showed that there exist a strong relationship between the internal factors of academic journals(i.e., Impact Factor, Cost, and Language) and economic valuation in terms of its use value.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.1 s.71
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• pp.105-111
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• 2006

Dolphin mooring system can be a good candidate for the VLFS fastening system in view point of strength and effectiveness. In the design process of the dolphin system, precise calculation of the wave forces and the subsequent selecting the proper number of the piles adopted are one of the main factors. In this paper, one of the design process of the dolphin system is investigated and a proper configuration of the system is derived based on the structural characteristics of the system that was obtained through the structural analysis of the basic pile element confronted to the external loadings including wave impact load. It was found that lot the better design of ihe mooring system for VLFS, mono pile mooring system is more recommendable in a specific condition than other multi piles mooring system.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.531-536
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• 2004

In-arm type hydropeumatic suspension unit(ISU) is an equipment of armed tracked vehicle to absorb impact load and vibration from the irregular ground. During the operation of ISU, main piston moves forward and backward and oil flowing through damper transmits the external impact load to floating piston. Heat is generated in ISU by the oil pressure drop through the damper orifice and the friction between cylinder wall and two pistons. On the other hand, internal heat dissipatis outside via heat convection. Occurrence of high temperature can deteriorate durability of major components and basic function of ISU. And, it can cause fatal problem in the ISU life time and the sealing performance of piston rings. As well, the spring constant change of nitrogen gas that is caused by the temperature rise exerts the negative effect to the vehicle stability. Therefore, in this paper, we analyze the heat transfer analysis of the entire ISU unit, by finite element method, with the outside flow velocities 8m/s and 10m/s.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.2
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• pp.173-181
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• 2019

The paper aims to evaluate the combination of strategies that influence the success of New Technology Based Firms (NTBFs) located in isolated areas with resource constraints. We utilize the Kauffman Firm Survey to construct a subset of 224 firms operating in primary metal manufacturing industries and who are located in non-thriving areas. We focus on the impact of technological strategy, in the form of Inward Technology Licensing (ITL), combined with financial strategy, in the form of increased financial slack. Using a negative binomial-specification technique to model these relations, we find that ITL positively impacts internal innovation in the firm and this relation is strengthened by the presence of greater financial slack. This positive impact of financial slack supports the behavioral theory of the firm rather than agency theory in that financial slack enables further innovation rather than stifling it. This research confirms the importance of resource acquisition, suggesting that entrepreneurs may utilize external sources of knowledge in an effort to build a favorable situation when facing the challenges of location. Finally, by presenting evidence showing the compatibility of a financial strategy with a knowledge strategy (ITL), this study emphasizes the importance to entrepreneurs of choosing the proper combination of varying strategies.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.412-412
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• 2019

Nature-based solutions (NBS) offer a wide variety of techniques that promote cost-efficient stormwater management practices. In particular, low impact development facilities utilize NBS principles to restore the ecosystem services in a highly-urbanized area. Despite the advancements in these technologies, several considerations should still be addressed to ensure optimum functionality and attainment of desired pollutant removal efficiency a LID facility. This study evaluated the mass flushing characteristics of pollutants in an urban catchment and the efficiency of a small constructed wetland (SCW) in treating urban stormwater runoff. 21 rainfall events from 2010 to 2018 were monitored to determine and quantify stormwater pollutants. The highest pollutant washoff was observed on rainfall depths ranging from 0.1mm to 10mm, whereas events with greater rainfall depths exhibited lower pollutant concentrations due to dilution effect. However, the SCW manifested lower pollutant-removal performance on rainfall depths exceeding 10mm due to the exceedance of the facility's design rainfall. This study is beneficial in assessing the dynamics of pollutant washoff and efficiency of LID facilities subjected under various external factors.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1561-1574
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• 2019

A standard form of six stylized human intrusion scenarios for a near-surface disposal facility (e.g. the planned Korean repository, Gyeongju Phase II) is proposed through re-categorization of totally thirty-one past cases reported in public literature. A reference assessment framework for inadvertent human intrusion is newly developed using GENII Version 2 conforming to the ICRP Publication 60 and thereafter. Calculated dose from the assessment framework is verified by comparing with hand calculation results for simplified model equations independently derived. Results from GENII Version 2 and 1.485 show inevitable differences, which is mainly attributed to the difference in the external dose assessment model. If intake dose coefficients in GENII Version 1.485 are modified, the difference can be reduced but still exist to an extent. Through deterministic and probabilistic sensitivity analysis, most affecting four parameters are derived and uncertainties of the parameters are quantified. It is expected that the reference assessment framework together with representative stylized scenarios can be used to do a human intrusion impact assessment for a specific repository using site-specific information. Especially, the past practice of human intrusion impact assessment using GENII Version 1.485 with or without modification may be replaced with the new assessment framework developed in this study.

• Journal of Information Technology Services
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• v.18 no.1
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• pp.187-200
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• 2019

Bankruptcy prediction model is an issue that has consistently interested in various fields. Recently, as technology for dealing with unstructured data has been developed, researches applied to business model prediction through text mining have been activated, and studies using this method are also increasing in bankruptcy prediction. Especially, it is actively trying to improve bankruptcy prediction by analyzing news data dealing with the external environment of the corporation. However, there has been a lack of study on which news is effective in bankruptcy prediction in real-time mass-produced news. The purpose of this study was to evaluate the high impact news on bankruptcy prediction. Therefore, we classify news according to type, collection period, and analyzed the impact on bankruptcy prediction based on sentiment analysis. As a result, artificial neural network was most effective among the algorithms used, and commentary news type was most effective in bankruptcy prediction. Column and straight type news were also significant, but photo type news was not significant. In the news by collection period, news for 4 months before the bankruptcy was most effective in bankruptcy prediction. In this study, we propose a news classification methods for sentiment analysis that is effective for bankruptcy prediction model.