• Title/Summary/Keyword: 환경 소음

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A Comparison Study on the Design of Dynamic Response appears on Bridge as operation of Light Railway Train (한국형 경량 전철 주행시 동적 응답 처리의 설계 기준 비교 연구)

  • Yeon, sang-ho;Kang, sung-won
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.792-795
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    • 2008
  • AGT system is a kind of light railway train. AGT system use of concrete track and rubber tire, so it can be reduce the noise and vibration, compare to the normal train system. And, the dynamic responses of normal bridge are influenced by the dynamic characteristics of bridge, the speed of vehicle and the surface roughness of railway. But the AGT system bridge is influenced not only the above facts but also the guiderail unevenness, because, AGT vehicle steered by guiderail. So, in this study, optimized service condition is suggested for the design and operation of AGT system, by the means of experimental study. The experiments are executed for PSC bridge with length of 30m, at the AGT test line in Kyongsan. The test results are compared and investigated according to the prominence. In the test result, the guiderail prominence influenced on the dynamic response of bridge. It shows a increase as compared with no guiderail prominence in the dynamic response value acceleration, displacement, stain.

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A Fuel Cell Generation Modeling and Interconnected Signal Analysis using PSCAD/EMTDC (연료전지 발전시스템의 PSCAD/EMTDC 모델링 및 계통연계에 따른 전력신호 분석에 관한 연구)

  • Choi, Sang-Yule;Park, Jee-Woong;Lee, Jong-Joo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.5
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    • pp.21-30
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    • 2008
  • The fuel cell generation convert fuel source, and gas directly to electricity in an electro-chemical process. Unlike traditional and conventional turbine engines, the process of fuel cell generation do not burn the fuel and run pistons or shafts, and it has not revolutionary machine, so have fewer efficiency losses, low emissions and no noisy moving parts. A high power density allows fuel cells to be relatively compact source of electric power, beneficial in application with space constraints. In this system, the fuel cell itself is nearly small-sized by other components of the system such as the fuel reformer and power inverter. So, the fuel cell energy's stationary fuel cells produce reliable electrical power for commercial and industrial companies as well as utilities. In this paper, a fuel cell system has been modeled using PSCAD/EMTDC to analyze its electric signals and characteristics. Also the power quality of the fuel cell system has been evaluated and the problems which can be occurred during its operation have been studied by modeling it more detailed. Particularly, we have placed great importance on its power quality and signal characteristics when it is connected with a power grid.

Development of Lightweight Composite Sub-frame in Automotive Chassis Parts Considering Structure & NVH Performance (구조 및 NVH 성능을 고려한 복합재료 서브프레임 개발)

  • Han, Doo-Heun;Ha, Sung
    • Composites Research
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    • v.32 no.1
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    • pp.21-28
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    • 2019
  • Recently, according to environmental regulations, the automobile industry has been conducting various research on the use of composite materials to increase fuel efficiency. However, there has not been much research on lightweight chassis components. Therefore, in this research, the purpose of this study is to apply composite materials to the sub-frame of chassis components to achieve equivalent levels of stiffness, strength, NVH performance and 50% lightweight compared to the steel sub-frame. First, the Natural frequency of steel and composite specimens was compared to the damping characteristics of composite materials. Then, in this study, the Lay-up Sequence was derived to maximize the stiffness and strength of the sub-frame by applying composite materials. And this lay-up Sequence is proposed to avoid heat shrinkage due to curing during manufacturing. This process was designed based on a FEM structural analysis, and a Natural frequency and frequency response function graph was confirmed based on a modal analysis. The prototype type composite sub-frame was manufactured based on the design and the F.E.M analysis was verified through a modal experiment. Furthermore, it was fitted to the actual vehicle to verify the natural frequency and the indoor noise vibration response, including idling and road noise. This result was confirmed to be equivalent to the steel sub-frame. Finally, the composite sub-frame weight was confirmed to be about 50% of the steel sub-frame.

Development of Synthetic Signal Generator and Simulator for Performance Evaluation in Multiple Sonobuoy System (다중 소노부이 체계의 신호합성기 및 성능검증용 시뮬레이터 개발)

  • Lee, Su Hyoung;Park, Sang Bae;Han, Sang-Gyu;Kown, Bum Soo
    • Journal of the Korea Society for Simulation
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    • v.30 no.2
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    • pp.11-22
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    • 2021
  • Sonobuoy is widely used as a very important sensor in combat management system using P-3 patrol aircraft due to its advantages of rapid searching into wide exploration range. It is necessary to verify the performance of developed sonobuoy system using various maritime test data in order to be successfully applied in combat management system. But it is difficult to acquire various real maritime data because it needs much time and effort. Therefore we have developed in this paper a synthetic signal generator and a simulator that they can verify the performance of sonobuoy system and evaluate its operational effectiveness without conducting maritime test. We have synthesized target signals based on the characteristics of underwater sound sources, and then developed the synthesized signal generator which consider to sound propagation etc. like as underwater environment. And in the simulator development we use a HMI technique to enhance the convenience of operator, and design to verify the performance of sonobuoy system. The developed signal generator and simulator can be used as useful tools to evaluate the operational effectiveness such as optimal deployment of sonobuoy in combat management system using P-3 patrol aircraft.

A Study on the Creation Process of Dance based on the Concept of Murray Schafer's Soundscape (Murray Schafer의 사운드스케이프 개념을 바탕으로 한 무용작품 의 창작과정 연구)

  • Ra, Se-Young;Choe, Sang-Cheul
    • The Journal of the Korea Contents Association
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    • v.21 no.6
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    • pp.425-434
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    • 2021
  • This study is subjected to two linked research. First is the creation process of dance work applying noise and non-musical sounds in our daily life based on understanding the classification, perception, and factor of the sound, through Murray Schafer's concept of 'soundscape'. Second is to find the value of new type of choreography and musical effect of creation process of the dance work . According to methodological research of practice-based research, three stages which is practice, theory and evaluation were accumulated as somatic data, And the analysis was provided a basis by presenting in a figuration, form of the movement and method of specialization with reference to the paper 『space design and forming practice』(2003). As a result, the creation process was able to discover the musical effect of the sound in daily life and new method of choreography, and also find the possibilities that sound could convey the theme of the dance work, the meaning of the movement and the overall atmosphere of the work to audience. In addition, It is expected that will have been made another new creation environment by potential that music has based on concept 'soundscape'.

Analytical Study on Vibrational Properties of High Damping Polymer Concrete (고 감쇠 폴리머 콘크리트의 진동 특성에 관한 해석적 연구)

  • Kim, Jeong-Jin;Kim, Jong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.5
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    • pp.119-125
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    • 2020
  • Research on high-attenuation concrete for the vibration reduction performance by mixing epoxy-based synthetic resins and aggregates is actively being conducted. The curing time of high-attenuation concrete is very short because water is not used, and the physical and dynamic properties are very excellent. therefore, it is expected to be widely used in building structures requiring reduction of interior-floor noise and vibration. Furthermore, A way to expand the applicability of the high-damping concrete mixed with polymer in the field of reinforcement material have been variously studied. In order to replace polymer concrete with ordirnary concrete and existing anti-vibration reinforcement material, it is necessary to review overall vibration reduction performance considering physical properties, dynamic properties, productivity and field applicability. In this study, the physical and dynamic properties of polymer concrete by epoxy mixing ratio compared with ordirnary concrete. As a result, the elastic modulus was similar. On the other hand, polymer concrete for the compressive, tensile, and flexural strengths was quite more excellent. In particular, the measured tensile strength of polymer concrete was 4-10 times higher than that of ordirnary concrete. it was a big difference, and the frequency response function and damping ratio was studied through modal test and finite element analysis model. The dynamic stiffness of polymer concrete was 20% greater than that of ordirnary concrete, and the damping ratio of polymer concrete was approximately 3 times more than that of ordirnary concrete.

A Study on the Basic Direction of Housign Product Development Considering the Characteristics of Urban Townhouse (도시형 타운하우스의 특성을 고려한 주택상품개발의 기본 방향에 관한 연구)

  • Seong, Ki-Seon
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.4
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    • pp.77-89
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    • 2020
  • Nowadays, urban townhouses are being developed in various forms according to the characteristics of different regions in consideration of the trends of the housing market. Misperceiving the needs of consumers or their characteristics as a house for living, however, they often end up becoming products that are not suitable for urban life or degraded on account of reckless regional development. It is so unfortunate that such trial and error keeps being repeated. Urban townhouses are advantageous because there is no such problem as either invasion of privacy or noise from neighbors, and it is possible to have one's own garden and enlarged parking space, obtain quality of grounding, and plan unique interior and exterior design. They are also equipped with the strengths of apartment houses as well, for example, the efficiency of joint control in crime and disaster prevention or security, architecture of diaphragm walls with the separation of gates, or the planning of common space like a central square or park. Therefore, there is a great chance that they can be developed as the types of urban housing. Accordingly, the purpose of this study is to establish the basic direction of developing housing products right as space for urban life and maximize the roles of urban townhouses. By understanding their spatial as well as functional elements as a house for living, this author aims to provide a guideline for housing product development to realize urban townhouses that can meet consumer needs.

Content Analysis of the 'Housing' Unit in the 2015 Revised Middle School Technology and Home Economics Textbook Using Text Mining (텍스트 마이닝을 이용한 2015 개정 중학교 기술·가정 교과서의 주생활 단원 내용분석)

  • Kim, Do-Yeon
    • Journal of Korean Home Economics Education Association
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    • v.34 no.2
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    • pp.1-19
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    • 2022
  • The purpose of this study is to analyze the keywords of the middle school textbooks based on the 2015 revision of the technology and home economics curriculum to understand the core concepts and contents composition of the 'housing' unit. Using TEXTOM and UCINET programs, the frequencies and centralities of the keywords were analyzed, and CONCOR analysis was performed. The results are as follows. First, the content system of the 'housing' unit is divided into 'life culture' and 'safety' in the 'family life and safety' area. Second, in the 'safety' section, the frequencies of occurrence of the words were high in the order of indoor, occurrence, use, noise, and safety accidents, in the order of frequency of occurrence. It was confirmed that words related to daily life, safety accidents, and prevention were closely connected to each other. In the 'life culture' section, the frequencies of occurrence were high in the order of space, housing, family, and residential space, and the correlations between these keywords were also high. Third, the most influential core keywords were, indoor and occurrence in the 'safety' section, and space, family, and housing, in the 'life culture' section. Fourth, the 'safety' section were divided into two subunits, 'safe living environment' and 'comfortable living environment', and the 'life culture' section were divided into four subunits, 'living space composition', 'space utilization', 'housing value and lifestyle', and 'housing culture'.

Experiment on the Perception of Fire Alarm Sound of Small Construction Site Workers (소규모 건설공사현장 작업자의 화재경보음 인지 실험)

  • Pil-Jae Moon;Seo-Young Kim;Ha-Sung Kong
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.153-160
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    • 2023
  • This research experiments on the workers' recognition of the fire alarm sound for sirens and portable loudspeakers in a small construction site. As a result of analyzing the siren alarm sound recognition from measuring on the 1st, 2nd, and 4th floors, the sound was more unrecognizable on the 4th floor than on the 1st, and 1 person on the 1st floor was unable to recognize all sounds. In the case of the 2nd floor, one person could not notice the alarm in the last 3rd trial, and another did not realize it all three times. For the 4th floor, 3 people demonstrated unrecognition in all 3 tests. As a result of analyzing the recognition of portable loudspeaker alarm sounds, 1 person could not recognize all sounds on the first floor. In the case of the 2nd floor, 2 people were confirmed to be unable to notice, and lastly, 4 people could not recognize all trials on the 4th floor. The subjects who didn't recognize the sound were unable to distinguish between portable loudspeaker alarm sound and work noise due to the workspace and obstacles.

Development of Selection Model of Interchange Influence Area in Seoul Belt Expressway Using Chi-square Automatic Interaction Detection (CHAID) (CHAID분석을 이용한 나들목 주변 지가의 공간분포 영향모형 개발 - 서울외곽순환고속도로를 중심으로 -)

  • Kim, Tae Ho;Park, Je Jin;Kim, Young Il;Rho, Jeong Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6D
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    • pp.711-717
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    • 2009
  • This study develops model for analysis of relationship between major node (Interchange in expressway) and land price formation of apartments along with Seoul Belt Expressway by using CHAID analysis. The results show that first, regions(outer side: Gyeongido, inner side: Seoul) on the line of Seoul Belt Expressway are different and a graph generally show llinear relationships between land price and traffic node but it does not; second, CHAID analysis shows two different spatial distribution at the point of 2.6km in the outer side, but three different spatial distribution at the point of 1.4km and 3.8km in the inner side. In other words, traffic access does not necessarily guarantee high housing price since the graphs shows land price related to composite spatial distribution. This implies that residential environments (highway noise and regional discontinuity) and traffic accessibility cause mutual interaction to generate this phenomenon. Therefore, the highway IC landprice model will be beneficial for calculation of land price in New Town which constantly is being built along the highway.