• Title/Summary/Keyword: research impact

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Sound Metric for the Impact Sound of a Car (자동차 임팩트 소음에 대한 음질 요소 개발)

  • Park, Sang-Won;Kim, Ho-Wuk;Na, Eun-Woo;Lee, Sang-Kwon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.1
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    • pp.66-73
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    • 2010
  • Vehicles experience the impact due to harsh road conditions. Contact with a barrier on a road induces vehicles to vibrate, which brings about an impact sound. The attenuation of the impact sound is an important issue since passengers may complain about the impact noise. However, the perfect removal of impact noise is not possible as most of impact noise is caused by external conditions. It is thus necessary to make vehicles to possess more desirable sound quality characteristic of impact sound. More research is needed on objective attributes of impact sound; it is not a simple matter since impact noise is transient in nature and has a high level of sound at an instantaneous moment. A new objective attribute of impact noise is designed by using wavelet transform. Wavelet transform is appropriate for the analysis of transient signals such as impact noise. The usefulness of new objective attribute, which is a sound metric, is examined by comparison with the mean subjective rating for real impact noise of passenger cars. The new sound metric has better correlation with the mean subjective rating than already existing sound metrics

Impact resistant properties of Kagome truss reinforced composite panels

  • Choi, Jeong-Il;Park, Se-Eon;Lee, Sang-Kyu;Kim, Gyu-Yong;Hwang, Jae-Seung;Lee, Bang Yeon
    • Advances in concrete construction
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    • v.12 no.5
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    • pp.391-398
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    • 2021
  • This paper presents an experimental study exploring impact resistant properties of Kagome truss reinforced composite panels. Three types of panels with different materials and reinforcements, i.e., ultra-high-performance mortar, steel fiber, and Kagome truss, were designed and manufactured. High-velocity projectile impact tests were performed to investigate the impact response of panels with dimensions of 200 mm×200 mm×40 mm. The projectile used in the testing was a steel slug with a hemispherical front; the impact energy was 1 557 J. Test results showed that the Kagome truss reinforcement was effective at improving the impact resistance of panels in terms of failure patterns, damaged area, and mass loss. Synergy effects of a combination of Kagome truss and fiber reinforcements for the improvement of impact resistance capacity of ultra-high-performance mortar were also observed.

The Damage Behavior of Glass/Epoxy and Aramid/Epoxy in Leaf Spring of Ankle Foot Orthosis (A.F.O) due to the Various Impact Velocities (족부보장구(A.F.O.) 판스프링용 Glass/Epoxy와 Aramid/Epoxy의 충격속도 변화에 따른 손상 거동)

  • Song Sam-Hong;Oh Dong-Joon;Jung Hoon-Hee;Kim Cheol-Woong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.10
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    • pp.1526-1533
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    • 2004
  • The needs of walking assistant device such as the Ankle Foot Orthosis (A.F.O) are getting greater than before. However, most of the A.F.O are generally imported rather than domestic manufacturing. The major reason of high import reliability is the rack of impact properties of domestic commercial products. Therefore, this research is going to focus on the evaluation of impact properties of the A.F.O which has the high import reliability. Unfortunately, these kinds of researches are not performed sufficiently. This research is going to evaluate impact energy behavior in composite materials such as the glass/epoxy (S-glass, [0/90]sub 2S/) and the aramid/epoxy (Kevlar-29, woven type, 8 ply) of ankle foot orthosis. The approach methods were as follows. 1) The history of impact load and impact energy due to the various velocities. 2) Relationship between the deflection and damage shape according to the impact velocities. 3) The behavior of absorbed energy and residual strength rate due to the various impact velocities.

Impact on self-satisfaction of shopping tendencies and purchasing behaviors for luxury goods (명품쇼핑성향과 구매행동이 자기만족도에 미치는 영향)

  • Lee, Jeong-Min;Park, Sook-Hyun;Lee, Kyung-Lim
    • The Research Journal of the Costume Culture
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    • v.25 no.1
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    • pp.16-31
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    • 2017
  • This paper aims to identify the impact on self-satisfaction of shopping tendencies and purchase behaviors for luxury goods. The research was conducted by survey method using questionnaires. The subjects of this study were female consumers from 20 to years old with a high purchasing capability for luxury goods. Using the statistics program SPSS 21.0, factor analysis, reliability analysis, one-way ANOVA, and multiple-regression analysis were executed. The analysis results are summarized below. For shopping tendency depending on ages, pleasure pursuit tendency showed insignificant difference in 40~50s, but significant difference in 20~30s. For the self-satisfaction, the interpersonal satisfaction showed the difference by age group, which was much higher in the respondents in 30~50s than those in 20s. Individuality pursuit tendency and rational shopping tendency had impact on self-satisfaction and rational shopping tendency on interpersonal satisfaction in 20s. Pleasure pursuit tendency and rational shopping tendency had impact on self-satisfaction and interpersonal satisfaction and pleasure pursuit tendency on the economic satisfaction in 30s. Pleasure pursuit tendency had impact on self-satisfaction and economic satisfaction and rational satisfaction on interpersonal satisfaction in 40s. Pleasure pursuit tendency and rational shopping tendency had impact on self-satisfaction and interpersonal satisfaction in 50s. High quality had impact on self-satisfaction and economic satisfaction and practicality on interpersonal satisfaction in 20s. High quality had impact on self-satisfaction and interpersonal satisfaction in 30s. High quality had impact on interpersonal satisfaction in 40s. High quality had impact on all elements of self-satisfaction for the respondents in 50s, practicality had negative impact on interpersonal satisfaction.

Experiment Evaluation for the Heavy-weight Impact Sound of Dry Double-floor System - Effect of Rubber Hardness and Ceiling Structure - (건식이중바닥구조의 중량충격음에 대한 실험적 평가 - 지지구조 및 천장구조 구성에 따른 영향 -)

  • Yeon, Junoh;Kim, Kyoungwoo;Choi, Hyunjuong;Yang, Kwanseop;Kim, Kyungho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.1
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    • pp.34-40
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    • 2013
  • The 1st assessment(performance test) was applied to assure the floor impact sound performance for developing the dry double-floor with the change of rubber hardness of the upper panel's support and the ceiling structure of the sub-floor. Depends on the change of the rubber hardness in sub-structure, the heavy-weight sound impact value is improved up to 3 dB, and the light-weight sound impact value is moved up to 21 dB, comparing with the bare-slab. Also, the improved value for the floor impact sound conjugating with the sub-floor's ceiling was 5 dB. Based on this result, the 2nd assessment(performance test) was made the state that the rubber hardness of the sub-floor support was ranged between 50 and 70 for considering the stability of walking patients. In addition to this process, the assessment was carried out with a variety of ceiling structure applied to the dry double-floor structure with the air flow system on the sub-floor's ceiling. The result for the 2nd assessment proved that TYPEII-3 had the better sound reduction performance in the heavy-weight impact sound test than other types, and also for the light-weight impact sound TYPEII-3 had the 29 dB sound reduction performance overall. Henceforth, based on the result the research for the sound reduction performance from the floor impact sound shall be ongoing process as well as the development of a double-dry floor and a sound reduction ceiling to suitable on the field.

Research on Improving EIA Through Causality Analysis (환경영향평가 문제의 원인 및 연계성 분석을 통한 제도개선 연구)

  • Choi, Joon-Gyu;Seo, Seong-Cheol;Joo, Yong-Joon
    • Journal of Environmental Impact Assessment
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    • v.17 no.1
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    • pp.11-24
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    • 2008
  • The Korea Environmental Impact Assessment (EIA) system was introduced in 1977 through the Environmental Conservation Act. It has progressed through many laws and regulations promoting the balance between development and conservation, and functioning as a Preventitive environmental policy. Despite the efforts to minimize environmental damage from development and to uplift social awareness of environmental preservation, deficient impartiality and objectivity in completing and investigating environmental assessments, there have continously existed conflicts among related stakeholder, neglecting arrangements and ineffectiveness of public participation. This research present EIA obstacles and analyzes the overall status of the EIA through surveys from related experts. On the basis of this research, the actual complications regarding the developer, public participation, examiner and consultant are brought about. Also, remedies are proposed to ensure effective EIAs and restore confidence in them.

The Observing System Research and Predictability Experiment (THORPEX) and Potential Benefits for Korea and the East Asia

  • Park, Seon Ki
    • Atmosphere
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    • v.14 no.3
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    • pp.41-54
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    • 2004
  • In this study, a brief overview on a WMO/WWRP program - The Observing System Research and Predictability Experiment (THORPEX) and discussions on perspectives and potential benefits of Asian countries are provided. THORPEX is aimed at accelerating improvements in the accuracy of 1 to 14-day high-impact weather forecasts with research objectives of: 1) predictability and dynamical processes; 2) observing systems; 3) data assimilation and observing strategies; and 4) societal and economic applications. Direct benefits of Asian countries from THORPEX include improvement of: 1) forecast skills in global models, which exerts positive impact on mesoscale forecasts; 2) typhoon forecasts through dropwindsonde observations; and 3) forecast skills for high-impact weather systems via increased observations in neighboring countries. Various indirect benefits for scientific researches are also discussed. Extensive adaptive observation studies are recommended for all high-impact weather systems coming into the Korean peninsula, and enhancement of observations in the highly sensitive regions for the forecast error growth is required to improve forecast skills in the peninsula, possibly through international collaborations with neighboring countries.

Remote Sensing and Ecosystem Management in Korea (한국에서의 원격탐사와 생태계 관리)

  • Kim, Dae-Seon;Ryu, Cheol-Sang;Chun, Seung-Kyu
    • Journal of Environmental Impact Assessment
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    • v.3 no.1
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    • pp.77-82
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    • 1994
  • A Nationwide survey of ecosystem in the Republic of Korea was accomplished from 1986 to 1990 and in that survey, GIS and remote sensing were used partially. This was done by the Ministry of Environment(MOE), which introduced remote sensing and GIS for environment management in late 1980's. Especially the National Institute of Environmental Research (NIER) are under the research on systematization of environmental information with an ultimate goal of application of GIS and remote sensing to environmental impact assessment. Although the Korean peninsula is in a non-tropical zone, we introduce two case studies on remote sensing applications to ecosystem managements in the Republic of Korea. One is a study on change detection in urban vegetation of Seoul with Landsat data and the other is a study on detection of insect damaged pine tree area using Landsat TM data. The techniques involved and the conclusion from these studies were relevant to vegetation studies in tropical ecosystem.

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Investigation Research on the Residents Satisfaction Rating to the Floor Impact Sound in Apartment Buildings (공동주택 바닥충격음에 대한 거주자 만족도 조사 연구)

  • Kim, Kyoung-Woo;Choi, Hyun-Jung;Kim, Young-Su;Yang, Kwan-Seop
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.2
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    • pp.179-184
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    • 2010
  • In this study, the satisfaction rating to the floor impact sound was investigated for the residents in the apartment Building where the business scheme had been approved after 2005. The results are compared with existing research. The questionnaire survey was conducted to the 597 residents in 14 apartments complex which were applied with standard floor structure and approval floor structure. Most of respondents(71.1 %) answered that the performance of floor impact sound insulation, in case of standard floor structure, was improved compared to the apartments where they used to live. Comparing with the questionnaire survey result of existing research, the answered ratio of 'less annoyed' and 'less loud' is somewhat increased.

Impact of Destination Image and Satisfaction on Tourist Loyalty: Mountain Destinations in Thanh Hoa Province, Vietnam

  • LE, Hoang Ba Huyen;LE, Thi Binh
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.4
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    • pp.185-195
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    • 2020
  • The study aims to assess the impact of destination image, satisfaction and loyalty of tourists at mountain destinations in Thanh Hoa province, Vietnam. The study involves questionnaire surveys and multivariate data analysis methods (Cronbach Alpha test, EFA, CFA, SEM). Research results from 500 tourists in the mountain destinations of Thanh Hoa province demonstrate that all factors have imposed a positive impact on tourist satisfaction, specifically: The most influential factor is Natural features, followed by Human factors while the least influential factor is Infrastructure; On the other hand, research results also demonstrate that satisfaction has a substantial impact on tourist loyalty. Based on the research results, we also proposed some key solutions to enhance the destination image, thereby contributing to increased satisfaction and loyalty of tourists, including: (i) Promoting Natural Tourism Resources. (ii) Raising Awareness of Environmental Protection. (iii) Building Local Cultural Identity. (iv) Building Exclusive Tourist Products. (5) Strengthening the Support of Local Authorities for Tourism Activities. (vi) Developing a Price Policy.