• Title/Summary/Keyword: Impact of event

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Analysis of vehicle progress before and after a collision using simulation (시뮬레이션을 이용한 충돌 전후 차량 진행궤적 분석)

  • Han, Chang-Pyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.402-408
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    • 2021
  • Vehicle engineering analysis in the event of an accident caused by a car built on mechanical design has not been investigated in-depth but relies on the subjective experience knowledge of the investigator. This study analyzed the correlation between the speed, progress, steering, and braking before impact, which is consistent with the final stop position, by drawing a site situation chart using the CAD (CAD) program and repeating 250 crashes using the PC-Crash program. The following situations were investigated: lower impact velocity; greater impact speed of the vehicle, which is not affected significantly by the departure angle; higher vehicle speed, such as the effective impact velocity, after the impact; higher vehicle speed; and lower vehicle speed. (Ed note: I am unsure what you are saying here. It appears contradictory and not a complete sentence. Please check the changes.)The simulation results of this study identified the process of returning to the magnetic progression lane after recognizing the opposite porter while Mighty was carried out on the uphill left-curve section in a position that crossed the center line, and the collision of the porter's front left side, pushing the porter in the right diagonal direction and making the front stop towards approximately 11 o'clock.

The Influence of the COVID-19 Pandemic on Stock Market Returns in Indonesia Stock Exchange

  • HERWANY, Aldrin;FEBRIAN, Erie;ANWAR, Mokhamad;GUNARDI, Ardi
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.39-47
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    • 2021
  • This research aims to confirm if the COVID-19 pandemic has had an impact on existing sectors, and how that affects the Indonesian Stock Exchange (IDX) market returns. The research method used is an event study employing market models in nine sectors of the Exchange with purposive sampling technique, and supported by Ordinary Least Square (OLS) regression. Based on the calculation of abnormal returns in the period of 30 days before up to 30 days after, the financial property, real estate, and construction sector results show a decreased abnormal return value. The infrastructure, utilities, and transportation sectors also show an abnormal return value that tends to be constant, while the abnormal return value increases in other sectors. Judging from the cumulative value of abnormal returns, the most affected sector is financials, followed by the trade, service, and investment sectors. The consumer goods and mining industry sectors are still optimistic, while other sectors show temporary negative sentiment. Overall, the stocks on the Indonesia Stock Exchange (IDX) were affected by the COVID-19 pandemic with a cumulative negative value of the average abnormal return sample. The results using OLS regression also strengthen the relationships between the COVID-19 pandemic, and negative and significant market returns.

Countermeasures for Management of Off-site Radioactive Wastes in the Event of a Major Accident at Nuclear Power Plants

  • Lee, Ji-Min;Hong, Dae Seok;Shin, Hyeong Ki;Kim, Hyun Ki
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.3
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    • pp.339-347
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    • 2022
  • Major accidents at nuclear power plants generate huge amounts of radioactive waste in a short period of time over a wide area outside the plant boundary. Therefore, extraordinary efforts are required for safe management of the waste. A well-established remediation plan including radioactive waste management that is prepared in advance will minimize the impact on the public and environment. In Korea, however, only limited plans exist to systematically manage this type of off-site radioactive waste generating event. In this study, we developed basic strategies for off-site radioactive waste management based on recommendations from the IAEA (International Atomic Energy Agency) and NCRP (National Council on Radiation Protection and Measurements), experiences from the Fukushima Daiichi accident in Japan, and a review of the national radioactive waste management system in Korea. These strategies included the assignment of roles and responsibilities, development of management methodologies, securement of storage capacities, preparation for the use of existing infrastructure, assurance of information transparency, and establishment of cooperative measures with international organizations.

A Structural Equation Model for Posttraumatic Growth among Cured Patients with COVID-19 (COVID-19 완치자의 외상 후 성장 예측모형)

  • An, Soo Young;Choi, Heejung
    • Journal of Korean Academy of Nursing
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    • v.53 no.3
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    • pp.309-323
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    • 2023
  • Purpose: This study aimed to develop and test a model for posttraumatic growth among cured patients with COVID-19. This model was based on Calhoun and Tedeschi's Posttraumatic Growth model and a literature review. Methods: The participants comprised 223 patients cured from COVID-19 who were ≥ 19 years of age. The data were collected through an online questionnaire from March 21 to 24, 2022. The assessment tools included the Impact of Event Scale: Revised Korean version, the Connor-Davidson Resilience Scale, the Distress Disclosure Index, the Multidimensional Scale of Perceived Social Support, the Korean version of the Event-related Rumination Inventory, and the Korean version of the Post-traumatic Growth Inventory. Data were analyzed using the IBM SPSS version 24.0 and IBM AMOS 26.0. Results: The modified model showed appropriate goodness of fit (χ2 = 369.90, χ2 /degree of freedom = 2.09, SRMR = .09, RMESA = .07, CFI = .94, TLI = .93). The post-traumatic growth of cured patients with COVID-19 was explained through distress perception, self-disclosure, and deliberate rumination, with the explanatory power being 70.0%. Conclusion: This study suggests preparing a disaster psychology program involving experts who can activate deliberate rumination is necessary. Further, this study may serve as basic data for developing a program to enhance the post-traumatic growth of patients cured from COVID-19.

Basic Analysis for Improvement of Mooring Stability Under Long Wave Impact

  • Ha, Chang-Sik;Moon, Seung-Hyo;Lee, Joong-Woo
    • Journal of Navigation and Port Research
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    • v.41 no.5
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    • pp.329-336
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    • 2017
  • This study suggests a general process of analyzing the mooring and cargo handling limit waves, which is an incident to the new energy port under long wave agitation. To reduce damages of ships and harbor structures due to strong wave responses, it is necessary to predict the change of wave field in the mooring berth to make the proper decision by dock master. The berthing area at a new LNG port in the east coast of Korea in this study is frequently affected by oscillations from waves of 8.5~13s periods in the wintertime. The long period waves give difficulties on port operation by lowering the annual berthing ratio. It needs to find the event waves from the real time offshore wave records, which cause over the mooring limits. For that purpose, the wave records from field measurement and offshore wave buoy were analyzed. From numerical simulation, the response characteristics of long period waves in the berthing area were deduced with or without breakwater expansion plan, analyzing the offshore field wave data collected for two years. Some event wave cases caused over the cargo handling and mooring limits as per the standard Korean port design guideline, and those were used for the decision of port operation by dock master, comparing with the real time offshore wave observations.

Impact of US-China Trade War on Stock Price of Korean Exporting Firms (미·중 무역분쟁이 한국 수출기업 주식가격에 미치는 영향)

  • Yoo-Kyung Won;Chae-Deug Yi
    • Korea Trade Review
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    • v.45 no.1
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    • pp.173-201
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    • 2020
  • As the US's trade deficit with China and China's manufacturing industry has risen rapidly, the US has begun to regulate trade items as part of China's checks. Four rounds of reprisal measures have greatly altered the trade structures of both countries. In particular, Korea, which is highly dependent on the US and China, has been directly affected by US-China trade disputes. The purpose of this study was to analyze the effects of US-China trade disputes on the stock price of Korean export firms by performing an event study. This study analyzed stock price fluctuations for 7 days before and after entry into forced [Please check] retaliatory tariffs on Korean exporters' export items subject to retaliatory tariffs. According to the analysis results, among companies that produce goods with major tariffs imposed on China by the US, such as electronic appliances, semiconductors, machinery, and automobiles, those producing electronics and semiconductor products were positively affected by the tariff incident. Secondly, among the companies producing steel, chemicals, and machinery, which the main tariffs imposed by the United States, companies producing steel and chemicals were negatively affected by the incident due to the stagnation of trade between China and the US. The results of this study suggest future trade policy directions for Korea and help to establish an export strategy for major industries.

Tree-dimensional FE Analysis of Acoustic Emission of Fiber Breakage using Explicit Time Integration Method (외연적 시간적분법을 이용한 복합재료 섬유 파단 시 음향방출의 3차원 유한요소 해석)

  • Paik, Seung-Hoon;Park, Si-Hyong;Kim, Seung-Jo
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.04a
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    • pp.172-175
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    • 2005
  • The numerical simulation is performed for the acoustic emission and the wave propagation due to fiber breakage in single fiber composite plates by the finite element transient analysis. The acoustic emission and the following wave motions from a fiber breakage under a static loading is simulated to investigate the applicability of the explicit finite element method and the equivalent volume force model as a simulation tool of wave propagation and a modeling technique of an acoustic emission. For such a simple case of the damage event under static loading, various parameters affecting the wave motion are investigated for reliable simulations of the impact damage event. The high velocity and the small wave length of the acoustic emission require a refined analysis with dense distribution of the finite element and a small time step. In order to fulfill the requirement for capturing the exact wave propagation and to cover the 3-D simulation, we utilize the parallel FE transient analysis code and the parallel computing technology.

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The Analysis and Experiments for the Design of Electro-mechanical Variable Valve Train System (VVT용 전자식 흡/배기 밸브 시스템 설계를 위한 해석 및 실험)

  • 박승현;오성진;이종화;박경석;김도중
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.3
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    • pp.60-67
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    • 2001
  • As a method of variable valve train(VVT), Electro-Mechanical Valve(EMV) has been studied. Compared with conventional VVT system, the EMV system has a relatively simple structure. The system has two electromagnets, springs and an armature. The system can be operated by reciprocal action between armature and two electromagnets. And, the operating event can be controlled by electrical signal from controller. Therefore, reduction of emission and fuel consumption can be achieved through valve event control at each engine operating condition. In this study, characteristics of EMV system were investigated by simulations and experiments. The results of simulation and experiment show that the core shape and material characteristics are dominant parameters on magnetic force and delay time. In order to apply the system to commercial engine, it has a compact size and high stiffness springs(50N/mm) to increase the valve speed. Because of high valve seating velocity, loud noise and high impact force generated, which can lead to reduction of actuator durability. Therefore, further research is required to reduce valve seating velocity.

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Does the Pandemic Declaration influence the Firm Value of the Untact Firms? (팬데믹 선언이 언택트 기업의 기업가치에 미치는 영향: 투자자 마니아 가설을 중심으로)

  • Park, Su-Kyu;Cho, Jin-Hyung
    • Asia-Pacific Journal of Business
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    • v.13 no.1
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    • pp.247-262
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    • 2022
  • Purpose - The purpose of this study is to examine the impact of the Pandamic Declaration on 'untact firms' listed in KOSPI and KOSDAQ market in order to verify Investor Mania Hypothesis. Design/methodology/approach - This study collected financial data for 44 untact firms in KOSPI and KOSDAQ market. Then, we employed ESM(Event Study Methodology), EGARCH model and DID(Difference-In-Difference) for analysis. Findings - First, in contrast with the benchmarking index, KOSPI 200 which shows a negative (-) abnormal return trend, the untact firms have positive abnormal return trend consistently. Second, after the Pandemic Declaration, the variability of abnormal return for the untact firms is found to be significantly positive. Third, we find that the cumulative abnormal return and volatility of the untact firms significantly increase after the Pandemic Declaration. Research implications or Originality - Based on the Investor Mania Hypothesis, we confirm that the market potential of untact firms after the Pandemic Declaration is observed when compared with the KOSPI 200.

Recovery of aquatic insect communities after a catastrophic flood in a Korean stream

  • Lee, Hwang-Goo;Bae, Yeon-Jae
    • Animal cells and systems
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    • v.15 no.2
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    • pp.169-177
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    • 2011
  • In August 2002, a heavy rainfall (445 mm in total for 5 consecutive days) resulted in a catastrophic flood, and it completely washed away the benthic fauna from the mainstream channel of the Gapyeong stream, a typical mid-sized stream in the central Korean peninsula. This study was to investigate the recovery patterns of aquatic insect communities that were damaged by the flood. Aquatic insects were sampled quantitatively using a Surber sampler ($50{\times}50$ cm, 1 riffle and 1 pool/run habitats per site) from three sites (4th-6th order) of the Gapyeong stream prior to 2000 and seasonally after the flood event from 2003 to 2006. Before the flood in the reference year (2000), a total of 77 species of aquatic insects were collected, whereas after the flood 47 species (2003), 51 species (2004), 64 species (2005) and 55 species (2006) were collected from the whole sampling sites. The aquatic insect density decreased to 26.85% (2003), 90.25% (2004), 52.53% (2005) and 54.95% (2006) of that recorded in the reference year. Although approximately 70% of the aquatic insect fauna has recovered since the flood event, the species composition in the most recent year differed substantially (similarity ca. 50%). On the other hand, the compositions of functional groups have not significantly changed. Aquatic insect communities at the riffle sites were affected more profoundly than those at the pool/run sites. The aquatic insect communities at the upstream site recovered more rapidly than those at the downstream sites.