• 조명전기설비학회논문지
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• 제20권9호
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• pp.78-83
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• 2006

A new measure, the distributed generation impact factor (DGIF), is used for evaluating the impact of newly introduced distributed generators on a networked distribution or a transmission system. Distribution systems are normally operated in a radial structure. But the introduction of distributed generation needs load flow calculation to analyze the networked system. In the developed framework, the potential share of every generation bus in each line flow of a networked system can be directly evaluated. The developed index does not require the solution of power flow equations to evaluate the effect of the distributed generation. The main advantage of the developed method lies in its capability of considering simultaneous outputs of multiple generation sites.

• Computers and Concrete
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• 제18권1호
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• pp.113-137
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• 2016

Extensive experimental studies on remarkable mechanical properties Polypropylene Fibre Reinforced Self-compacting Concrete (PFRSCC) have been executed, including different fibre volume fractions of Polypropylene fibers (0.25%, 0.5%, 0.75%, and 1%) and different water to cement ratios (0.21, 0.34, 0.38, and 0.41). The experimental program was carried out by using two hundred and sixteen specimens to obtain the impact resistance and mechanical properties of PFRSCC materials, considering compressive strength, splitting tensile strength, and flexural strength. Statistical and analytical studies have been mainly focused on experimental data to correlate of mechanical properties of PFRSCC materials. Statistical results revealed that compressive, splitting tensile, and flexural strengths as well as impact resistance follow the normal distribution. Moreover, to correlate mechanical properties based on acquired test results, linear and nonlinear equations were developed among mechanical properties and impact resistance of PFRSCC materials.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.460-465
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• 2002

The nonlinear vibration of the CRT shadow mask is analyzed in consideration of the V-shaped tension distribution and the effect of wire impact damping. The reduced order FEM model of the shadow mask is obtained from dynamic condensation for the mass and stiffness matrices. Damping wire is modeled using the lumped parameter method to effectively describe its contact interactions with the shadow mask. The nonlinear contact-impact model is composed of spring and damper elements, of which parameters are determined from the Hertzian contact theory and the restitution coefficient, respectively. The analysis model of the shadow mask with damping wires is experimentally verified through impact tests of shadow masks performed in a vacuum chamber. Using the validated analysis model of the shadow mask with damping wires, the‘design of experiments’technique is applied to search fur the optimal damping wire configuration so that the vibration attenuation of the shadow mask is maximized.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1759-1761
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• 2005

The exploitation of the resource wind energy is a rapidly growing area world-wide. The number of installed units is continuously increasing, and therefore, it is important to respect and to deal with the impact of wind power generation system. From the view of an electric grid utility, there is a major problem with the impact of the wind system on the voltage of the electric grid, to which a turbine in connected. The problem is rather common in the connection of a wind power system to an already existing grid, since the grid is very seldom designed for the transmission of additional power. In this paper, it is investigated the voltage impact of distribution line, to which wind power generation system is connected.

• International journal of advanced smart convergence
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• 제8권1호
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• pp.196-203
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• 2019

We have reviewed the potential impact of blockchain technology on the music industry by analyzing the views of academia and the industry experts. The music industry had rapid changes from the physical market to the digital market in the past decades. The consumers download and stream music online and mobile during the digital dominant market. While streaming music has been recently growing at a fast rate, fair distribution of revenue to the artists continues to be an issue. Some industry experts believe that the issue of fair distribution of revenue to the artist may be resolved using blockchain technology, while some are skeptical about the application or the duration of impact. The blockchain may enhance speedier payment using smart contracts, provide additional revenue and promote the music if excellent fan support is achieved. The positive impact on the music industry may only be possible if there are detailed consideration of the industry and careful understanding of the customers.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.191-194
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• 2005

Impact properties of glass/Kevlar hybrid composites which have 3-D braided structures were studied. Results were compared to those of composites made of only glass fibers where the same epoxy resin were used as matrix. Absorbed impact energies evaluated through the combination of the data from the impact tester and high speed camera were compared to each other. In order to see the difference between the damaged area distribution CCD camera captures were performed.

• 유통과학연구
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• 제18권6호
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• pp.83-91
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• 2020

Purpose: Research on the behavior of using digital banking services plays an important role for banks in the context of increasingly competitive banks, not only for domestic banks but also for foreign banks. Along with the development of science and technology brings new approaches to banking industry, digital banking increases the effectiveness of banking activities. Besides, information safety brings different feeling about digital banking system. Therefore, this research evaluates the relationship between Information safety and Intention to use banking services in Vietnam. Research design, data and methodology: With 329 Vietnamese customers using digital banking, reliability test, and structural equation model (SEM) analysis method. Results: the research shows that information safety has directly effects on perceived ease of use (PU), perceived risk (RIS) of customers to digital banking services. Perceived trust (TRU) has a negative impact on RIS. Perceived of usefulness (PEU) has a positive impact on attitude towards service (ATT), and RIS has a negative impact on ATT. RIS, PEU, ATT, convenience and enterprise image have positive effects on intention to use digital banking service. Conclusions: From the research results, the authors also propose some recommendations to enhance the intention to use digital banking services in Vietnam.

• 유통과학연구
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• 제21권2호
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• pp.111-118
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• 2023

After the outbreak of the COVID-19 in the early 2020, Korea has attempted to reinforce the existing rent controls to help the low-income households. From July 2000, the tenants' right of lease renewal came into effect, as a policy tool to enforce the upper bound percentage of rent increases within Korea. Purpose: This study aims to examine the impact of rent control on the uncontrolled rents in Seoul Metropolitan Area (SMA). Research design, data and methodology: The study regresses the monthly panel data from 58 municipalities in SMA from January 2020 to March 2022, during the COVID-19 pandemic. Results: The data indicates that the policy had the effect of lowering rents for a period of two months, and subsequently monetary policy including quantitative easing and low interest rates, coupled with asset market bubbles lead to rent increases. During the sample data period, the quantity of money supply increased by 12.6% and CPI rose by 3.0%, these phenomena collectively increased the rents by up to 14.7%. Conclusions: The results of the present study support the findings of earlier studies in part: namely, that rent control without the government's steps to stabilize the property price may have an undesirable effect on rental tenants.

• 유통과학연구
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• 제22권3호
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• pp.113-124
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• 2024

Purpose: This study is a quantitative study and analyzes the effect of evaluating the extreme and usefulness of product reviews on sales performance by using text mining techniques based on product review big data. We investigate whether the perceived helpfulness of product reviews serves as a mediating factor in the impact of product review extremity on sales performance. Research design, data and methodology: The analysis emphasizes customer interaction factors associated with both product review helpfulness and sales performance. Out of the 8.26 million Amazon product reviews in the book category collected by He & McAuley (2016), text mining using natural language processing methodology was performed on 300,000 product reviews, and the hypothesis was verified through hierarchical regression analysis. Results: The extremity of product reviews exhibited a negative impact on the evaluation of helpfulness. And the helpfulness played a mediating role between the extremity of product reviews and sales performance. Conclusion: Increased inclusion of extreme content in the product review's text correlates with a diminished evaluation of helpfulness. The evaluation of helpfulness exerts a negative mediating effect on sales performance. This study offers empirical insights for digital market distributors and sellers, contributing to the research field related to product reviews based on review ratings.

• 환경영향평가
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• 제4권2호
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• pp.71-91
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• 1995

In order to develop an appropriate set of criteria applicable for environmental impact assessment (EIA) of natural forest 8 items are proposed. The criteria are vegetation distribution area (DA), distribution pattern (DP), size (S), diameter of breast height of tree (DBH), humus (H), sustainment (ST), successional stage (SS) and impact of adjacent ecosystem (IAE), Each criterion has an interval which minimum 1 score to maximum 5 score Forest Evaluation Index (FEI) was obtained as the sum of 8 criteria value. Above 70% is considered to be absolutely conservative and from 50% to 70% range of total score is to be considered conservative. In the case of the Sancho˘ng Pumping-up Power Plant of Mt. Chiri, 8 criteria were applied base on actual vegetation map. Pinus densiflora community got 73%(29 scores) and Quercus variabilis - Q. serrata community got 60%(24 scores). This may be said that this local vegetation has high ecological potentiality. These criteria cannot always be absolutely evaluation tool. So it is expected to take the more time to be developed further, and holistically added by the other field such as fauna, geological feature etc.