• 제목/요약/키워드: Impact shock

검색결과 436건 처리시간 0.031초

Mitigating the Shocks: Exploring the Role of Economic Structure in the Regional Employment Resilience

  • Kiseok Song;Ilwon Seo
    • Asian Journal of Innovation and Policy
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    • 제12권3호
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    • pp.323-344
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    • 2023
  • This study investigates the resilient structural characteristics of a region by assessing the impact of the financial crisis. Utilizing panel data at the prefecture level for metropolitan cities across pre-shock (2006-2008), shock (2009), and post-shock (2010-2019) periods, we calculated an employment resilience index by combining the resistance and recovery indices. The panel logit regression measures the influences of the region's industrial structure and external economic factors in response to the global financial crisis. The results revealed that the diversity index of industries contributed to the post-shock recovery bounce-back. Additionally, the presence of large firms and industrial clusters within the region positively contributed to economic resilience. The specialization and the proportion of manufacturing industries showed negative effects, suggesting that regions overly reliant on manufacturing-centered specialization might be vulnerable to external shocks. Furthermore, excessive capital outflows for market expansion were found to have a detrimental impact on regional economic recovery.

유통 중 진동충격에 의한 배 포장 완충재의 동적 변위 추정 (Estimation for Dynamic Deformation of the Cushioning Materials of Packaging for the Pears by Shock and Vibration During Transportation)

  • 정현모;박인식;김만수
    • 한국포장학회지
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    • 제11권1호
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    • pp.17-24
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    • 2005
  • During handling unitized products, they are subjected to a variety environmental hazards. Shock and vibration hazards are generally considered the most damaging of the environmental hazards on a product, and it may encounter while passing through the distribution environment. A major cause of shock damage to products is drops during manual handling. The increasing use of unitization on pallets has been resulted in a reduction in the manual handling of products and with it a reduction in the shock hazards. This has caused and increasing interest in research focused on vibration caused damage. the use of pallets as a base for unitizing loads, aids in the mechanical handling, transportation and storage of products. Besides aiding in the handling, transportation and storage of products, a pallet also acts on and interface between the packaged goods and the distribution environment. The determination of the impact deformation of the cushioning materials such as tray cup (polymeric foam) and corrugated fiberboard pad must be carried out to design the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. In this study, the theoretical analysis of impact deformation for cushioning materials by dynamic vibration. The impact deformations of SW and DW corrugated fiberboard pad in acceleration amplitudes of 0.25 G-rms and 0.5 G-rms that were usually generated in transport vehicles during distribution environments were very small compare with the thickness of corrugated fiberboard pad. The maximum of vibration acceleration level of tray cup by vibration impact was about 3.2 G-rms. The theoretical allowable acceleration (G-factor) of the pear was 0.7102 G-rms, and the maximum dynamic deformation estimated within G-factor was about 1 mm.

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An Analysis of Macro Aspects Caused by Protectionism in Korea

  • Kim, Yuri;Kim, Kyunghun
    • Journal of Korea Trade
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    • 제25권1호
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    • pp.1-17
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    • 2021
  • Purpose - The global trend of protectionism has expanded since the onset of US President Donald Trump's administration in 2017. This global phenomenon has led to a significant reduction in world trade volume and a negative impact on economic development in some countries where the external sector accounts for a large proportion of GDP. Although Korea is a country vulnerable to this deteriorating trade environment, few studies have examined the relationship between protectionism and its business cycles based on Korean data. Thus, this paper investigates the impact of protectionism on Korea's business cycle. Design/methodology - To identify future implications, we conduct a structural vector autoregression (VAR) analysis using monthly Korean data from 1994 to 2015. Macroeconomic variables in the model include the industrial production index, inflation rates, exports (or net exports), interest rates, and exchange rates. For the identification of the shock reflecting the expansion of protectionism, we use an antidumping investigation (ADI) data. Since ADIs are followed generally by the imposition of antidumping tariffs, they have no contemporaneous impact on tariffs and are also contemporaneously exogenous to other endogenous variables in the VAR model. We examine two kinds of ADI shocks i) shocks on Korean exports imposed by Korea's trading partners (ADI-imposed shocks) and ii) shocks on imports imposed by the Korean government (ADI-imposing shocks). Findings - We find that Korea's exports decline sharply due to ADI-imposed shocks; the lowest point at the third month after the initial shock; and do not recover until 24 months later. Simultaneously, the inflation rate decreases. Therefore, the ADI-imposed shock can be regarded as a negative shock on the demand curve where both production and price decrease. In contrast, the ADI-imposing shock generates a different response. The net exports decline, but the inflation rate increases. These can be seen as standard responses with respect to the negative shock on the supply curve. Originality/value - We shed light on the relationship between protectionism and Korea's economic fluctuations, which is rarely addressed in previous studies. We also consider the effects of both protective policy measures on imports to Korea imposed by the Korean government and on policy measures imposed by Korea's trading partner countries on its exports.

ADAMS를 이용한 항공기 착륙장치 지상 충격하중 및 동적거동 해석 (An analysis on the ground impact load and dynamic behavior of the landing gear system using ADAMS)

  • 최섭;이종훈;조기대;정창래
    • 한국항공우주학회지
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    • 제30권4호
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    • pp.114-122
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    • 2002
  • 착륙장치 시스템의 개발은 설계특성상 충격흡수 성능에 대한 설계 파라메터, 최소한의 작동공간, 복잡성 및 중량과 비용 등의 복합적인 관계를 가지고 있다. 특히 항공기 착륙에 따른 지상충격하중 및 동적거동은 착륙장치 자체 구성품 뿐만 아니라 장착구조물의 설계 하중으로 적용되는 중요한 설계분야이다. 본 연구에서는 T-50 착륙장치를 모델로 ADAMS를 이용하여 지상 충격하중 및 동적거동을 해석할 수 있는 프로그램을 개발하였다. 항공기 운용/환경조건을 고려한 충격흡수특성 해석은 다양한 설계경험을 토대로 수행하였다. 설계변수 설정, 완충기에 작용하는 내력정의, 운동방정식을 유도하여 착륙 수직속도, 착륙 자세, 착륙 수평속도, 완충효율, 장착위치 작용하중 등을 고려한 해석결과와 동적거동 특성을 분석하고 제시하였다. 이러한 해석 결과를 바탕으로 향후 새로운 착륙장치 개발시 범용적인 해석이 용이할 뿐만 아니라 지상/비행시험의 문제점 발생시 고장탐구 해결에 활용할 수 있다.

적정 포장설계를 위한 과실의 바이오 허용 충격지수 추정 (Estimation of the Allowable Bio-shock Fragility Index of Fruits for Optimum Packaging Design)

  • 김기석;정현모;김기복;김만수
    • Journal of Biosystems Engineering
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    • 제32권6호
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    • pp.416-421
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    • 2007
  • Physical damage to fruits and vegetables caused by shock degrades the value of product in the fresh market. In order to design a product/packaging system to protect the product, the G-factor to the product that causes shock damage needs to be determined. The shock fragility of organisms such as fruits with a concept correspondent to the G-factor of industrial products was calculated and we defined the allowable bio-shock fragility index as the value divided peak acceleration that was generated in safe drop height by standard acceleration of gravity. We did modeling for safe drop hight that would prevent fruits from damage by drop tests and tried to estimate the allowable bio-shock fragility index of pears and apples for optimum packaging design. The bio-shock fragility index of pears was in the range of $0.74{\sim}2.29\;G$, while apples had a slightly higher value than that of pears, of $0.51{\sim}2.98\;G$. This result shows accordance with the general fact that apples have a firmer structure and get less damage from the same impact. Based on this result, it is possible to create an optimum packaging design by providing a damage standard by impact.

충격장치의 반 능동 제어시스템 설계 (Semi-Actively Controlled Impact System Design)

  • 김동환;최문철;이교일
    • 한국정밀공학회지
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    • 제16권4호통권97호
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    • pp.46-56
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    • 1999
  • A semi-actively controlled impact system which adjusts an impulse exerted by the external impact is studies. The main control variables are internal pressure difference inside the cylinder and the shock absorber displacement while it travels. Compared to a conventional one so called a passive system with a variable orifice inside the cylinder, a semi-actively controlled system utilizes an external orifice controlled by a highly fast responding electrical proportional valve. This device overcomes the temperature and viscosity change due to continuous operating and keeps the desired pressure difference and displacement in every operation. In this article a new prototype impact system is designed and manufactured based on a semi-actively control system. Through computer simulations and experiments, we verify the possibility of controlling the shock absorber pressure and displacement. After investigating the control performance a modified semi-actively controlled system with better control performance is also proposed.

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대형 디지털TV Display 모듈의 내충격 설계를 위한 손상평가 연구 (A Shock Damage Evaluation Study of Large Digital TV Display Modules)

  • 문성인;최재붕;김영진;서형원;이정권;구자춘
    • 한국소음진동공학회논문집
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    • 제14권10호
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    • pp.945-954
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    • 2004
  • Recently, specifications of flat display module is going to be higher definition, brightness and more wide viewing angle. On the other hand, physical thickness of those modules is forced to be slimmer and lighter. The flat display modules such as plasma or TFT-LCD employ thin crystallized panels that are normally weak to high level transient mechanical energy inputs. As a result, anti-shock performance is one of the most important design specifications of TFT-LCD modules. TFT-LCD module manufacturers and their customers like PC or TV makers perform a series of strict impact/drop test for the modules. However most of the large display module designs are generated based on engineer's own trial-error experiences. Those designs may result in disqualification from the drop/impact test during final product evaluation. A rigorous study on the impact failure of the displays is of course necessitated in order to avoid the problems. In this article, a systematic design evaluation is presented with combinations of FEM modeling and testing to support the optimal shock proof display design procedure.

The Impact of Global Uncertainty Shocks on Macroeconomics: The Case of Vietnam

  • TRAN, Ha Hong;NGUYEN, Vinh Thi Hong;TRINH, Nam Hoang
    • The Journal of Asian Finance, Economics and Business
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    • 제9권9호
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    • pp.263-269
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    • 2022
  • The global financial crisis of 2008-2009 and the COVID-19 pandemic that started in 2019 along with the slow and unstable recovery of the global economy have raised concerns about the impact of global uncertainty on the macroeconomics of the countries. The paper used the Structural Vector Autoregression (SVAR) model to examine the impact of global uncertainty shocks on Vietnam's economy from the period 2008-2022. We found that Vietnam's output dropped following the shock of global uncertainty, the peak was in the third month, and lasted for one year. Inflation in Vietnam had a rapid downturn in the first month, peaked in the seventh month, and took a long time to cease. When the economy experienced the shock of increased global uncertainty, Vietnam's policy interest rate was adjusted downward. Additionally, we included a long-term interest rate to consider the overall impact of monetary policy into account. A decreasing trend was also found with this rate. The global uncertainty shock effects acted as the aggregate demand shocks, reducing output and inflation as the uncertainty increases and vice versa, thus monetary policy can be used to regulate Vietnam's economy to deal with negative shocks without the trade-offs between output and inflation as aggregate supply shocks.

자영업이 국가경제에 미치는 영향 (The Impact of Self-Employment on the National Economy)

  • 김우형
    • 기업가정신과 벤처연구
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    • 제20권1호
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    • pp.19-33
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    • 2017
  • 우리는 본 논문에서 자영업의 변화가 국민경제에 미치는 영향 분석을 통해 올바른 정책 방향을 제시하고자 한다. 즉, 자영업의 현황 및 자영업자 지원의 정책 방향을 제시하고자 한다. 우리는 변수들의 동태적 관계를 파악하기에 위해 VAR 모형을 사용하여 자영업 추이와 경시경제 변수 간의 상호 영향을 파악하였다. 분석 결과 자영업자 비중의 외생적 충격은 실질성장률에 대해 유의한 영향이 없으나, 고용 있는 자영업자와 고용 없는 자영업자로 구분하여 분석할 경우 고용 있는 자영업자의 비중의 증가는 실질성장에 긍정적 영향이 있는 것으로 나타났다. 향후 연구에서는 자영업자 비중 변화에 대한 거시경제 변수의 단기적 효과를 추정하기 위해 분기별 자료 등으로 추가 분석을 시도할 필요가 있다.

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탄성플랫폼 충격응답 스펙트럼 기준에 따른 다기능콘솔 충격해석 연구 (A Study on the Shock Analysis of the Multi-Function Console According to the Shock Response Spectrum Requirements of the Elastic Platform)

  • 박재훈;김원형;김현실;최영철
    • 한국정밀공학회지
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    • 제33권10호
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    • pp.805-811
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    • 2016
  • Prior to installation in a navy ship, shipboard equipment should be qualified by shock test requirements. The multi-function console mounted on the elastic platform of the ship should also withstand given shock loads. In this study, both real shock test methods, as well as numerical computer simulations using the finite element method were used to verify structural durability under shock load conditions. First, we used domestic test facilities to perform possible shock tests, including an impact hammer test, a drop table test and a shaker shock test. Full model tests satisfying the shock response spectrum level were performed. Thereafter, an analytical model of the complex console structure was built by the finite element method. Finally, numerical results were verified by modal test results of the real product and an FEA analysis was also performed with a full model transient response analysis.