• 한국수자원학회논문집
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• 제46권6호
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• pp.629-642
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• 2013

본 연구에서는 낙동강 본류의 강정고령보에 설치된 인공하도식 어도의 효율성을 2차원 물리서식처 모형인 River2D를 이용하여 평가해 보았다. 강정고령보 상하류단의 실측 수위를 이용하여 모형을 보정 및 검정하였다. 모의조건은 2012년 풍수량, 평수량, 저수량을 기준으로 어도 입구 및 어도 내부의 흐름장을 분석하였다. 특히 본 연구의 목표종인 피라미가 산란기인 봄철에 주로 이동을 하므로, 저수기를 기준으로 어도가 기능을 잘 유지하는지 살펴보았다. 분석결과, 풍수 및 평수기에는 본류 수위가 높아 어도로의 피라미 유입 효율성이 떨어져 보였다. 반면 저수기에는 본류의 낮은 수위로 인해 어도 입구에 상대적으로 적절한 유속이 발생하여 유입효율과 이동효율이 높아질 것으로 평가되었다. 어도 내 흐름은 어류가 소상하기에 무리가 없는 유속장이 발생하는 것으로 파악되었다.

• 한국재난정보학회 논문집
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• 제20권2호
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• pp.257-269
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• 2024

Purpose: The purpose of this study is to explain the pivotal role of the travel forecasting process in urban transportation planning. This study emphasizes the use of travel forecasting models to anticipate future traffic. Method: This study examines the methodology used in urban travel demand modeling within transportation planning, specifically focusing on the Urban Transportation Modeling System (UTMS). UTMS is designed to predict various aspects of urban transportation, including quantities, temporal patterns, origin-destination pairs, modal preferences, and optimal routes in metropolitan areas. By analyzing UTMS and its operational framework, this research aims to enhance an understanding of contemporary urban travel demand modeling practices and their implications for transportation planning and urban mobility management. Result: The result of this study provides a nuanced understanding of travel dynamics, emphasizing the influence of variables such as average income, household size, and vehicle ownership on travel patterns. Furthermore, the attraction model highlights specific areas of significance, elucidating the role of retail locations, non-retail areas, and other locales in shaping the observed dynamics of transportation. Conclusion: The study methodically addressed urban travel dynamics in a four-ward area, employing a comprehensive modeling approach involving trip generation, attraction, distribution, modal split, and assignment. The findings, such as the prevalence of motorbikes as the primary mode of transportation and the impact of adjusted traffic patterns on reduced travel times, offer valuable insights for urban planners and policymakers in optimizing transportation networks. These insights can inform strategic decisions to enhance efficiency and sustainability in urban mobility planning.

• 상하수도학회지
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• 제12권1호
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• pp.81-87
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• 1998

The possibility of collision of two particles slowly settling one after another in water can be described using the collision efficiency factor in differential sedimentation (${\alpha}_{DS}$). ${\alpha}_{DS}$ was found to be a function of several parameters particle size, particle size ratio, Hamaker constant, density of liquid and particle, gravity acceleration. Previous researches were limited to the case when there is no electric repulsion assuming that the suspension is destabilized. In this paper, ${\alpha}_{DS}$ is calculated for the stabilized condition. The relative trajectory of two particles are calculated including hydrodynamics, attraction and repulsion forces. Ionic strength and surface potential significantly affect the collision possibility of two settling particles. Depending on the surface potential and ionic strength, ${\alpha}_{DS}$ value is divided into three regions; stable, unstable and transition zone. ${\alpha}_{DS}$ increases as the ionic strength increases, and as the surface charge decreases. This result can be used to model both destabilized and stabilized suspension incorporating the collision efficiency factors of the other coagulant mechanisms such as fluid shear and Browian motion.

• Journal of Korean Society for Atmospheric Environment
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• 제17권E2호
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• pp.53-59
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• 2001

A hybrid dust-collector combining electrostatic charging with fabric filtration method was developed, and its performance characteristics were evaluated in this study. Charged particles build porous dendritic structure on the surfaces of filter by electrostatic attraction, increasing the collection efficiency of dust particles and reducing the pressure drop through the deposited dust layer and filter media. The cleaning performance of the dust layer is improved because the dendritic structured dust layer can be removed more easily by pulse jet cleaning flow. The results of the experiment showed a reduction of fine particle emission of 37% and the energy saving of 13% by precharging dust particles before filtration.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.33-42
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• 2021

This study aims to investigate the relationship between foreign direct investment (FDI) and economic growth at the provincial level by using time-series data in Binh Dinh from 1997 to 2019. We applied the quantitative approaches Vector Autoregression (VAR) and Autoregressive Distributed Lags (ARDL) in the model, which includes economic growth, real foreign direct investment capital, ratio of trained workers, and infrastructure. The results show that all these variables are stationary at the first difference. In ARDL analysis, we found that the economic growth positively affects FDI attraction. However, there is no evidence of the effect of FDI on economic growth in the condition of low capital implemented. Moreover, findings also show that the impact of FDI on economic growth is influenced by two factors: infrastructure and human capital. The lack of human capital, which is trained personnel and infrastructure, is the main barrier hindering and inhibiting FDI's contribution to local economic growth. In order to improve the efficiency of FDI on economic growth in the future, it is suggested that the Binh Dinh government should have proper policies in terms of the infrastructure, the human capital investment. They would allow Binh Dinh to enhance the capital absorptive capacity and capital efficiency.

• 무역학회지
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• 제46권2호
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• pp.141-160
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• 2021

The scale of global FDI has been decreasing since 2016 due to the ongoing US-China trade dispute, the strengthening of FDI inflow screening regulations with concern over strategic technology leaks, and the spread of reshoring trends due to the reinforcement of national preferences. Eventually, the competition to attract FDI between countries is expected to become more intense. Therefore, in order to attract high-quality FDI for Korea that will contribute to the development of the national economy, it is pressing to evaluate and improve the domestic FDI attraction environment. This study aims to analyze which areas of Korea's economic and non-economic environments need improvement for gaining advantage amid the fierce competition to attract FDI between countries, by the relative comparison between Korea and the U.S., and based on the ranking indicated in key FDI attractiveness indices. As a result, improvement is needed in the following areas. First, according to IMD's "World Competitiveness Ranking 2020," Korea was inferior to the US in terms of business efficiency, productivity, finance and business legislation in terms of government efficiency. Second, according to INSEAD's "Global Talent Competitiveness Index 2020," Korea was inferior to the US in terms of internal openness, external openness, employability, lifelong learning, access to growth opportunity, and business and labor landscapes. Third, according to WEF's "Global Competitiveness Index 2019", Korea was inferior to the US in terms of product market, labor market, business dynamism and workforce skills.

• Tribology and Lubricants
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• 제11권2호
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• pp.8-14
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• 1995

The filtration of the magnetic fibrous polymeric filter with packing density profile made of a self-bonded, nonwoven structure comprising a thermoplastic polymer and a magnetic substance was investigated using an oil filter tester, a particle quantifier and an image analyzer system. The magnetic fibrous polymeric filter showed excellent filtration efficiency compared with conventional paper filter. From the experimental results, It is deduced that the filtration mechanism of conventional paper filter is only the function of physical porosity by surface filteration. On the other hand, the newly magnetic fibrous polymeric filter is designed with a new concept in filtration mechanism. That is, it has a dual function of depth and magnetic filters by physical porosity and magnetic attraction. The newly magnetic fibrous polymeric filter has been shown to be a highly effective oil filter for lubrication systems.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.816-821
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• 2002

It is getting more important that energy efficiency and manufacturing cost of the electric motor in appliance. The SRM has been alternative choice. But acoustic noise and harshness in this motor was widely known. So this paper had been studied on the noise reduction of a SRM in air conditioner. This works include some parameters regarding to blown noise sources like a reluctance torque ripple, air gap eccentricity, Especially, it was focused on dynamic characteristics of the system based on mechanical viewpoint. It came to successful results. Besides, this gave us a validity of phase excitation in experimental measurements.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.147-157
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• 1996

Natural gas is gaining more attraction as a future fuel in particular both for environmental protection and energy conservation. In order to bring about more widespread use of gaseous engines, the technology capable of achieving output and efficiency performance equivalent to that of diesel engines needs to be developed. In the present paper, the requirements of the pilot torch from pre-chamber for ensuring ignition and promoting combustion are discussed by means of taking high-speed flame photography and system can run with leaner mixture of various fuels comparing to the electric plug ignition system cause the ignition delay period ignited with the torch and the combustion period are very short in spite of changing A/F of gaseous fuels in the main chamber. However, the suitable piston-cavity design for the use of lower-hydrocarbon fuels such as propane and butane must be discussed increasingly in the mear future.

• 한국조리학회지
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• 제2권
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• pp.25-46
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• 1996

The clients of hotel desire to be recognized as special persons who have their own personality and self-consciousness. The other hand, The hotel concentrates upon marketing strategy which acts a part of expanding sales. Namely, They find out the need of client, satisfy the desired need, ensure and manage the existing regular customers and make new clients regular customers. So they gain an advantage over competitive hotels. They make strategics of Telemarketing technique which is one of the developed-marketing techniques, can provide distinctive and familiar service and have an hight effect at the low cost. The attractions of Telemarketing strategy can be explained as follows. 1. It is the medium that have cost efficiency. 2. It possesses attractions to do time management. 3. It has control cash flow. 4. It can improve cash flow. 5. Market expansion can be accomplished. 6. It is a medium fit for prospecting over long-term period. 7. It can improve customer relations. 8. It fits seasonality (seasonal sales) 9. It brings greater order volume. 10. It benefits from lower personnel costs. 11. High volume productivity is realized. 12. It has attraction of versatility. 13. It has ease of start-up.