• Title/Summary/Keyword: impact coefficient

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Analysis of the Economic Impact of Plan to Introduce Korea Nuclear Powered Submarines (한국형 원자력 잠수함 도입 방안별 경제적 파급효과 분석)

  • Jongwon Kang;Chanhyeon Park
    • Journal of The Korean Institute of Defense Technology
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    • v.5 no.4
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    • pp.1-8
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    • 2023
  • In this study the economic impact of each plan for introducing Korea unclear-powered submarines were analyzed. This study conducted a preliminary investigation into foreign countries cases of unclear-powered submarines and classified three introduction plans. In order to analyze the economic impact of each introduction plan, a multiple-level survey was conducted targeting experts with experience in developing and operating ship weapon systems, and quantitative results were calculated for subcategory items with industrial relevance for industrial correlation analysis. The value added inducement coefficient and production inducement coefficient and employment inducement coefficient were calculated for each introduction method, and a favorable introduction method was derived. It is hoped that the results of this study will serve as a reference for policy decision-making during prior research for the introduction of korea nuclear submarines.

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A study on abrasive wear characteristics of side plate of FRP ship (온도변화에 따른 유리섬유/폴리우레탄 복합재료의 충격파괴거동)

  • Kim, Byung-Tak;Koh, Sung-Wi
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.3
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    • pp.188-193
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    • 2009
  • The present study was undertaken to evaluate the effect of temperature on the results of Charpy impact test for glass fiber reinforced polyurethane(GF/PUR) composites. The Charpy impact test were conducted in the temperature range from -50$^{\circ}$ to 50$^{\circ}$. The impact fracture toughness of GF/PUR composites was considerably affected by temperature and it was shown that the maximum value was appeared at room temperature. It is believed that sensitivity of notch on impact fracture energy were increased with decrease in temperature of specimen. As the GF/PUR composites exposed in low temperature, impact fracture toughness of composites decreased gradually owing to the decrease of interface bonding strength caused by difference of thermal expansion coefficient between the glass fiber/polyurethane resin. And decrease of interface bonding strength of composites with decrease in specimen temperature was ascertained by SEM photographs of Charpy impact fracture surface.

Relationship between the Impact Value of Electronic Body Protector and the Impact Force of Force Platform in the Taekwondo (태권도의 전자호구 충격값과 포스플랫폼 충격력과의 관련성)

  • Bae, Young-Sang
    • Korean Journal of Applied Biomechanics
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    • v.23 no.2
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    • pp.125-130
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    • 2013
  • Although the electronic body protector has been officially adopted by the World Taekwondo Federation(WTF) in 2006, no scientific information is available about the reliability of its performance. The purpose of this study, therefore, was to investigate the relationship between the impact value of electronic body protector and the impact force of force platform. Male collegiate Taekwondo athletes([MCTA], n=21) and male collegiate Taekwondo students([MCTS], n=20) volunteered to participate in the study. Each subject performed the apchagi, dollyeochagi and dwichagi on the force platform and the electronic body protector. At the apchagi, it showed that MCTS(about 4,700 N) generated more maximum kick force than MCTA(about 3,900 N), but it expressed that MCTA(about 5,300 N) generated more maximum kicking force than MCTS(about 4,400 N) at the dwichagi. At the apchagi and the dwichagi, it indicated the high coefficient of correlation(over r=.8) which supports higher explanation force the relationship between the impact value of electronic body protector and the impact force of force platform, but there was no statistically significant difference at the dollyeochagi.

A modeling of dynamic cutting force and analysis of stability in chatter vibration (채터진동에서의 동적 절삭력의 모델링과 안정성 해석)

  • Kim, Jeong-Suk;Kang, Myeong-Chang
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.2
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    • pp.161-169
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    • 1993
  • The elimination of chatter vibration is necessary to improve the precision and the productivity of the cutting operation. A new mathematical model of chatter vibration is presented in order to predict the dynamic cutting force from the static cutting data. The dynamic cutting force is analytically expressed by the static cutting coefficient and the dynamic cutting coefficient which can be determined from the cutting mechanics. The stability analysis is carried out by a two degree of freedom system. The chatter experiments are conducted by exciting the cutting tool with an impact hammer during an orthogonal cutting. A good agreement is shown between the stability limits predicted by theory and the critical width of cut determined by experiments.

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Prediction of Long-Term Carbonation Depth by Measurement of the Air Permeability Coefficient of Coating on Concrete (콘크리트에 도포된 도막의 투기계수 측정을 통한 장기 중성화 깊이 예측)

  • Park, Dong-Cheon;Nam, Min-Seok;Kim, Yong-Ro;Ko, Hyo-Jin;Ryu, Dong-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.113-114
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    • 2023
  • This study measured the thickness and speculation coefficient of the coating for existing buildings and calculated the diffusion coefficient of the coating to predict the depth of carbonation through numerical analysis in order to evaluate the impact of the external finish and local environment. As a result, it was possible to predict the short-term and long-term carbonation depth of reinforced concrete buildings coated with coating film with considerable reliability.

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A study on the impact of ESG (Environmental, Social, and Governance) management activities of small and medium-sized enterprises on the organization's non-financial performance (중소기업 ESG 경영 활동이 조직의 비재무적 경영성과에 미치는 영향에 관한 연구)

  • Hyun-Gyu Kang;Sang-Ho Lim
    • Industry Promotion Research
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    • v.9 no.2
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    • pp.23-28
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    • 2024
  • The study investigated the impact of ESG management activities on the non-financial performance of organizations, focusing on small and medium-sized manufacturing companies. Using data from 78 survey responses, the following results were summarized. Firstly, ESG management activities positively influenced internal customer satisfaction. The correlation coefficient was .679, indicating a moderately strong correlation, and the coefficient of determination (R2) was .461, explaining 46.1% of the variance. Additionally, with a beta value of .679, a t-value of 8.058, and a p-value of .000, ESG management activities had a statistically significant impact on internal customer satisfaction. Secondly, ESG management activities also had a positive impact on corporate trust. The correlation coefficient was .695, indicating a moderately strong correlation, and the coefficient of determination (R2) was .483, explaining 48.3% of the variance. The beta value was .695, the t-value was 8.429, and the significance probability was .000, indicating a significant influence on corporate trust.The study aimed to shed light on the relationship between ESG management activities of small and medium-sized enterprises and their non-financial performance. These results suggest that companies can enhance internal customer satisfaction and corporate trust through fulfilling social responsibilities and practicing sustainable management.

Error Accumulation and Transfer Effects of the Retrieved Aerosol Backscattering Coefficient Caused by Lidar Ratios

  • Liu, Houtong;Wang, Zhenzhu;Zhao, Jianxin;Ma, Jianjun
    • Current Optics and Photonics
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    • v.2 no.2
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    • pp.119-124
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    • 2018
  • The errors in retrieved aerosol backscattering coefficients due to different lidar ratios are analyzed quantitatively in this paper. The actual calculation shows that the inversion error of the aerosol backscattering coefficients using the Fernald backward-integration method increases with increasing inversion distance. The greater the error in the lidar ratio, the faster the error in the aerosol backscattering coefficient increases. For the same error in lidar ratio, the smaller actual aerosol backscattering coefficient will get the larger relative error of the retrieved aerosol backscattering coefficient. The errors in the lidar ratios for dust or the cirrus layer have great impact on the retrievals of backscattering coefficients. The interval between the retrieved height and the reference range is one of the important factors for the derived error in the aerosol backscattering coefficient, which is revealed quantitatively for the first time in this paper. The conclusions of this article can provide a basis for error estimation in retrieved backscattering coefficients of background aerosols, dust and cirrus layer. The errors in the lidar ratio of an aerosol layer influence the retrievals of backscattering coefficients for the aerosol layer below it.

Impact and Wear Behavior of Side Plate of FRP Ship (FRP선박 외판재의 충격 및 마모 거동)

  • Kim, H.J.;Kim, J.D.;Koh, S.W.;Kim, Y.S.
    • Journal of Power System Engineering
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    • v.13 no.6
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    • pp.123-128
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    • 2009
  • The effects of temperature and initial crack length on the impact fracture behavior for the side plate material of FRP ship were investigated. And the effects of the counterpart roughness and sliding distance on the volumetric wear of same material were investigated as well. Impact fracture toughness of GF/PE composites displayed maximum value when the temperature of specimen is room temperature and $50^{\circ}C$, and with decreasing the temperature of specimen, impact fracture toughness decreased. Impact fracture energy of GF/EP composites decreased with increasing the initial crack length of specimen, and this value decreased rapidly when the temperature of specimen is lowest, $-25^{\circ}C$. It is believed that sensitivity of notch on impact fracture energy were increased with decreasing the temperature of specimen. With increasing the sliding distance, the transition sliding distance, which displayed different aspect on the friction coefficient and the volumetric wear loss, were found out. Counterpart roughness had a big influence on the wear rate at running in period, however the effect of counterpart roughness became smaller with sliding speed increase in. Volumetric wear loss were increased with increasing the applied load and the counterpart roughness.

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The Impact of Fiscal Policy Instruments on Economic Wellness: Evidence From Malaysian Per Capita Income

  • OTHMAN, Nor Salwati;TAI, Teh Lian
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.6
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    • pp.245-252
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    • 2022
  • This study examines the strength of the impact of fiscal policy tools on economic wellbeing as measured by per capita income in Malaysia from 1996 to 2020. The impact of fiscal policy instruments on economic wellness, represented by real income per capita, is measured using the autoregressive distributed lags model. The speed of adjustment from short-run disequilibrium to long-run equilibrium is also measured to assess the strength of the fiscal instruments' impact on per capita income. Empirical results exhibit the existence of co-integration relationships between per capita income, tax revenue, and government spending. The findings provide strong support for the presence of a long-run positive impact on government spending and a long-run negative impact of tax revenue on per capita income. The coefficient of ECTt-1 indicates that deviations from a short-run disequilibrium to a long-run equilibrium from the current to the future period are corrected with a speed of 76% (equivalent to a duration of 1.5-2 years to return to equilibrium). The practical and policy implication of the results is fiscal instruments play a significant role, mainly in alleviating the economic impact of the COVID-19 pandemic in the long run.