• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.6
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• pp.1971-1982
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• 1996

The breakup of liquid jet is the result of competing, unstable hydrodynamic forces acting on the liquid jet as it exit the nozzle. The nozzle geometry and up-stream injection conditions affect the characteristics of flow inside the nozzle, such as turbulence and cavitation bubbles. A set of calculation of the internal flow in a single hole type nozzle were performed using a two dimensional flow simulation under different nozzle geometry and up-stream flow conditions. The calculation showed that the turbulent intensity and discharge coefficient are related to needle position. The diesel nozzle with sharp inlet under actual engine condition has possibility of cavitation, but round inlet nozzle has no possibility of cavitation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.4
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• pp.362-369
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• 2004

LGP(Light-Guide Panel) of LCD backlight is one of the major componets which affect on the product quality of LCD. The optical relation between brightness and pattern has been investigated for LGP with the uniform distribution of brightness. When given the brightness distribution as target, the solutions of pattern distribution is not unique. Each solution of pattern designs shows the different brightness intensity even though they have the same brightness distribution with target's one. The manufacturing condition of pattern has an influence on the possibly-maximum-brightness intensity among the solutions of pattern design. The present study has examined the effects of LGP thickness, pattern shape errors, and reflection film on the optical characteristics of LGP.

• International Journal of High-Rise Buildings
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• v.8 no.4
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• pp.313-324
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• 2019

This paper presents the analysis of wind speeds data measured on top of three neighboring high-rise buildings close to a beach in Xiamen city, China, during Typhoon "Usagi" 2013. Wind tunnel simulation was carried out to validate the field measurement results. Turbulence intensity, turbulence integral scale, power spectrum and cross correlation of recorded wind speed were studied in details. The low frequency trend component of the typhoon speed was also discussed. The field measurement results show turbulence intensity has strong dependence to the wind speed, upwind terrain and even the relative location to the Typhoon center. The low frequency fluctuation could severely affect the characteristics of wind. Cross correlation of the measured wind speeds on different buildings also showed some dependence on the upwind terrain roughness. After typhoon made landfall, the spatial correlation of wind speeds became weak with the coherence attenuating quickly in frequency domain.

• East Asian Economic Review
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• v.25 no.2
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• pp.151-174
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• 2021

This paper empirically examines whether and how inward foreign direct investment (FDI) affected industrial productivity in Korea during the 2000-2016 period, based on dynamic panel data of inflow FDI on an arrival basis from 427 manufacturing industries. The paper adds to the literature by analyzing whether both technology spillovers and industrial restructuring from inward FDI can differ according to industrial characteristics such as capital intensity, imported intermediate inputs, and tariffs. The empirical results show that the overall effects of inward FDI on total factor productivity (TFP) were statistically insignificant in general. However, the positive effects of inward FDI on productivity became statistically significant for industries with lower tariffs. Capital intensity were not involved in the relationship between inward FDI and productivity. Thus, the paper highlights that the results in previous studies with inward FDI on a notification basis were overestimated and inward FDI policies in Korea should focus on channels such as trade liberalization and the redistribution of production factors rather than capital accumulation.

• Asian Journal of Innovation and Policy
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• v.10 no.1
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• pp.90-107
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• 2021

This paper analyses how technological capabilities and entrepreneurship of technology-based start-ups affect their performance. In this paper, a multiple regression analysis was conducted on 248 technology-based start-ups. The effects of indicators of technological capacity like R&D intensity, R&D organization, technology competitiveness, patents, and certification were analyzed. Factors affecting sales were R&D intensity and technological competitiveness. Technology competitiveness and patents were the significant factors influencing product competitiveness. The factor that positively influenced organizational performance, customer performance, and achievement of start-up goals was technological competitiveness. The results of such an analysis should be designed to discover and foster long-term innovation potential, rather than relying on short-term financial performance.

• Journal of Wind Energy
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• v.4 no.1
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• pp.46-52
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• 2013

The wind generally includes turbulence characteristics in nature. So the yaw errors between wind turbine direction and wind direction occur due to turbulence fluctuation. The yaw errors affect the fatigue load of wind turbine system and power reduction. The components of turbulence intensity are different from those of each site where the wind turbines are installed. We studied that the fatigue load and power efficiency are improved by controlling yaw motions. In this study, we controlled the averaged yaw error time according to site conditions by turbulence intensity.

• Wind and Structures
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• v.20 no.3
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• pp.405-422
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• 2015

In previous model- and full-scale studies, high-amplitude vertical vibrations of mast-arm traffic signal structures have been shown to be due to vortex shedding, a phenomenon in which alternatingly shed, low-pressure vortices induce oscillating forces onto the mast-arm causing a cross-wind response. When the frequency of vortices being shed from the mast-arm corresponds to the natural frequency of the structure, a resonant condition is created causing long-lasting, high-amplitude vibrations which may lead to the fatigue failure of these structures. Turbulence in the approach flow is known to affect the cohesiveness of vortex shedding. Results from this full-scale investigation indicate that the surrounding terrain conditions, which affect the turbulence intensity of the wind, greatly influence the likelihood of occurrence of long-lasting, high-amplitude vibrations and also impact whether reduced service life due to fatigue is likely to be of concern.

• Journal of the Korean Home Economics Association
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• v.23 no.1
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• pp.71-85
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• 1985

The study attempts to explore factors which affect life satisfaction of the elderly, and thereby to identify the most efficient strategy to enhance their happiness and satisfaction with life by means of a family support system. Previous research suggests that the family is the main origin from which emotional and ecionomic satisfacton of the aged evolves, and satisfaction is facilitated by societal assistance for the family to financially support old persons. These theoretical antecedents are incorporated into a causal model for empirical verificatio. To this end, interviews were conducted in Seoul with 300 individuals who are 60 years old or over. The major findings of this study support the theoretical assertions of previous studies. They are summarized as follows : 1. Family solidarity is highly correlated with life satisfaction of the elderly. 2. Family solidarity is raised by the intensity of their social association, satisfaction with housing, and financial resources. 3. Eduation, income and marital status as exogenous variables do not directly affect life satisfaction and family solidarity, despite their strong overall correlation. Casual effects of each variable are linked to family solidarity and then to life satisfaction through a family support system for the elderly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5A
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• pp.341-349
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• 2011

The main purpose of this study is to investigate the affect of various turbulence properties on aerodynamic characteristics of twin box bridge section. To achieve this goal, active turbulence generator which successfully simulated various target turbulences was developed in the wind tunnel. From the wind tunnel tests, turbulence integral length scale did not affect on the aerodynamic forces and flutter derivatives except for the $A_1^*$ curve. Turbulence intensity gave slight effect on the unsteady aerodynamic force, but turbulence integral length scale did not affect the self-excited forces except vertical direction component.

• Journal of Construction Engineering and Project Management
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• v.4 no.1
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• pp.1-7
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• 2014

The Sudanese construction sector is characterized by many small and large projects and high labor intensity, and accounted for 3.2% of the Sudanese country's GDP. The basic problems facing the Sudanese construction projects are the factors that affect on construction project performance. The objectives include identifying the factors affecting the performance of Sudanese construction projects, and to determine the critical factors. The literature review has been done to gather the information about the causes and their factors that affect on the performance of construction projects from the previous researches. The research methodology was conducted to gather the data by questionnaire which was examined to be reliable and valid according to statistical tests. The (34) factors were identified as factors affect on construction projects and the (10) factors were the critical factors which may lead to poor performance of Sudanese construction projects. This study has some conclusions such as the instrument for measuring the critical factors on the performance is reliable and valid, so the project management stage performance is 64.2%.