• 제목/요약/키워드: Isolation System

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저심도 터널과 인접한 방진벽의 지반진동 저감효과 (Vibration Isolation of Wave Barriers Constructed Near a Shallow Tunnel)

  • 양신추
    • 한국철도학회논문집
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    • 제18권6호
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    • pp.567-577
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    • 2015
  • 본 논문에서는 계측자료와 해석방법의 조합에 의하여 지반진동을 평가하는 방법을 제시하였다. 평가방법의 기본개념은 FRA(Federal Railway Administration)에서 발간한 진동상세평가 매뉴얼에서 제시한 방법과 유사하나 구체적 평가방법은 다양한 유형의 방진벽의 진동저감 효과를 용이하게 평가할 수 있도록 수정되었다. 터널바닥에 작용하는 하중밀도(force density)는 해당선로의 차량 및 궤도조건을 잘 고려할 수 있는 차량-궤도 상호작용해석에 의하여 산정하였다. 지반진동의 전파유동성(transfer mobility) 2차원 지반진동해석을 통하여 평가하였다. 지반진동의 2차원 해석은 각 모델간의 상대비교에 있어서는 좋은 결과를 얻을 수 있으나 절대치 평가는 어렵다. 따라서 여기서는 사전에 계측된 자료와 해석결과의 비교를 통하여 실제 지반진동 전파특성을 반영할 수 있도록 계산된 전파유동성을 보완하였다. 정립된 진동평가방법을 적용하여 실제 진동민원문제가 크게 발생하였던 도시철도 저심도 터널구간을 대상으로 9가지 유형의 방진벽의 진동저감 효과를 분석하였다.

1인가구의 세대별 삶의 만족도 영향요인 비교 연구 (Generation Comparison of the Factors Affecting Life Satisfaction of One-person Households)

  • 김미숙;김안나
    • 한국학교ㆍ지역보건교육학회지
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    • 제21권1호
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    • pp.15-31
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    • 2020
  • Background and objectives: One-person households are the fastest growing family type in Korea. They bring social concerns such as weakened social integration, increasing poverty and social isolation. They are not homogeneous but heterogeneous groups depending on their socio-demographic characteristics including generation. This study compared the life satisfaction level as well as factors affecting it among the three one-person household generations Methods: The 13th wave of the Korea Welfare Panel dataset with 1,187 respondents was utilized. For data analysis Chi-square test, analysis of variance and hierarchical regression analysis were employed. Generations are divided into three, namely young adult (20-39), the middle-aged (40-64) and the elderly (65 and over). Result: The life satisfaction level was highest among the young adult one-person household generation, followed by the middle-aged and the elderly generation. The common factors affecting life satisfaction of the three generations were physical as well as mental health, including self-esteem and depression. However, there were more factors different from generation to generation. As for the young adult, age, religion, and smoking were significant. As for the middle aged and the elderly, gender (male) and income were significant. Additionally, age, home-ownership and drinking were significant to the elderly generation. Conclusions: As there are differences as well as similarities among the three generations, policies for one-person households need to be devised considering these findings. For all generations, both physical and mental health policies are needed. For young adult strengthening social relations, providing decent jobs, and promoting anti-smoking policy are major agenda, and for the middle-aged and the elderly, assisting in social capital accumulation (for male), providing stable jobs and diverse leisure activities, and securing income. Additionally, for the elderly, expanding the social security system and housing support are needed.

공연분석: 오스터마이어의 <햄릿> (프랑스 2008, 한국 2010) (Performance Analysis of Ostermeier's Hamlet)

  • 이인순
    • 한국연극학
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    • 제52호
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    • pp.229-270
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    • 2014
  • Ostermeier's Hamlet has no particular contemporary reinterpretation. Alternately devoting to show retrospect in illusion and existence through revenging actions. However, Shakespeare's metaphorical and implicative language is dissipated and the style of the play is not an illusive space-time, but a tragic theatrical production that uses rough language to express the depth of the story. The Perfomance of Hamlet is a sensuous jumble up of a diverse range of mass media. The double roles that the actors carry out give an affect of isolation between the audience and the play itself showing both empathy and liberty. Ostermeier's Hamlet distinctively shows a post-modern performance through the prominent elements of dirt, the use of mixed genre, theatric emphasis, making an image and the fulfillment of acting. Nonetheless, Ostermeier's performance stays off the point on the breakup strategy of the post-modern drama without suspending the narrative of Shakespeare's Hamlet. Besides aiming to show a performance centered by the imagery of physical expression, his performance shows New Realism in the 1960's, showing everyday life. Ostermeier thinks, that theatre helps give contemporary people an accurate reality check in the constant unstable periods of time. Therefore, Hamlet shows post-modern physical expression and outspoken dramaturgy using the effects of mass media in New Realism without breaking up realistic narration. With being the aberration of the Castle Helsingor, the main character Hamlet, expresses lunacy and can be considered as metaphor for young adults whom are broken down and isolated from the economic system. He is a substitute for those who experience agony, anger, torment, etc. and other suppressed emotions in everyday life. With the method of direction in the portrayal of Hamlet show signs of succession in the abundant popularization of the classics by communicating with the audience by following the trend of modern mass media and audio-visual perception; emphasizing the point of the philosophical topic 'life and death,' 'life and theatre,' and 'illusion and reality.'

Seismic damage mitigation of bridges with self-adaptive SMA-cable-based bearings

  • Zheng, Yue;Dong, You;Chen, Bo;Anwar, Ghazanfar Ali
    • Smart Structures and Systems
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    • 제24권1호
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    • pp.127-139
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    • 2019
  • Residual drifts after an earthquake can incur huge repair costs and might need to replace the infrastructure because of its non-reparability. Proper functioning of bridges is also essential in the aftermath of an earthquake. In order to mitigate pounding and unseating damage of bridges subjected to earthquakes, a self-adaptive Ni-Ti shape memory alloy (SMA)-cable-based frictional sliding bearing (SMAFSB) is proposed considering self-adaptive centering, high energy dissipation, better fatigue, and corrosion resistance from SMA-cable component. The developed novel bearing is associated with the properties of modularity, replaceability, and earthquake isolation capacity, which could reduce the repair time and increase the resilience of highway bridges. To evaluate the super-elasticity of the SMA-cable, pseudo-static tests and numerical simulation on the SMA-cable specimens with a diameter of 7 mm are conducted and one dimensional (1D) constitutive hysteretic model of the SMAFSB is developed considering the effects of gap, self-centering, and high energy dissipation. Two types of the SMAFSB (i.e., movable and fixed SMAFSBs) are applied to a two-span continuous reinforced concrete (RC) bridge. The seismic vulnerabilities of the RC bridge, utilizing movable SMAFSB with the constant gap size of 60 mm and the fixed SMAFSBs with different gap sizes (e.g., 0, 30, and 60 mm), are assessed at component and system levels, respectively. It can be observed that the fixed SMAFSB with a gap of 30 mm gained the most retrofitting effect among the three cases.

스마트 팩토리 구축을 위한 임베디드 보드 개발 (Development of Embedded Board for Construction of Smart Factory)

  • 이용민;이원복;이승호
    • 전기전자학회논문지
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    • 제23권3호
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    • pp.1092-1095
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    • 2019
  • 본 논문에서는 스마트 팩토리 구축을 위한 임베디드 보드의 개발을 제안한다. 제안하는 스마트 팩토리 구축을 위한 임베디드 보드는 메인모듈, ADC 모듈, I/O 모듈로 구성된다. 메인모듈은 주 연산장치로써 임베디드 보드를 구동하는 운영체제가 포팅되어서 외부장치와 산업용 프로토콜을 이용하여 통신할 수 있는 통신부를 탑재하고 있다. ADC 모듈은 필드에 설치되어 있는 센서들의 전기적신호를 디지털로 변환하여 메인모듈로 전달하는 역할을 한다. I/O 모듈은 필드기기의 상태, 경보, 가동명령 등을 전달하기 위하여 외부의 노이즈로부터 차단하기 위한 절연회로를 탑재한 디지털 입출력 모듈이다. 제안된 스마트 팩토리 구축을 위한 임베디드 보드의 성능을 평가하기 위하여 공인시험기관에서 실험한 결과, 프로토콜의 연동개수는 5개, 하드웨어의 클록 동기화 속도는 10us, 배터리로 구동되는 보드의 동작시간은 8시간 이상으로서 세계최고 수준과 동일한 결과를 산출하였다.

Taxonomic hierarchy of the phylum Proteobacteria and Korean indigenous novel Proteobacteria species

  • Seong, Chi Nam;Kim, Mi Sun;Kang, Joo Won;Park, Hee-Moon
    • Journal of Species Research
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    • 제8권2호
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    • pp.197-214
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    • 2019
  • The taxonomic hierarchy of the phylum Proteobacteria was assessed, after which the isolation and classification state of Proteobacteria species with valid names for Korean indigenous isolates were studied. The hierarchical taxonomic system of the phylum Proteobacteria began in 1809 when the genus Polyangium was first reported and has been generally adopted from 2001 based on the road map of Bergey's Manual of Systematic Bacteriology. Until February 2018, the phylum Proteobacteria consisted of eight classes, 44 orders, 120 families, and more than 1,000 genera. Proteobacteria species isolated from various environments in Korea have been reported since 1999, and 644 species have been approved as of February 2018. In this study, all novel Proteobacteria species from Korean environments were affiliated with four classes, 25 orders, 65 families, and 261 genera. A total of 304 species belonged to the class Alphaproteobacteria, 257 species to the class Gammaproteobacteria, 82 species to the class Betaproteobacteria, and one species to the class Epsilonproteobacteria. The predominant orders were Rhodobacterales, Sphingomonadales, Burkholderiales, Lysobacterales and Alteromonadales. The most diverse and greatest number of novel Proteobacteria species were isolated from marine environments. Proteobacteria species were isolated from the whole territory of Korea, with especially large numbers from the regions of Chungnam/Daejeon, Gyeonggi/Seoul/Incheon, and Jeonnam/Gwangju. Most Halomonadaceae species isolated from Korean fermented foods and solar salterns were halophilic or halotolerant. Air-borne members of the genera Microvirga, Methylobacterium, and Massilia had common characteristics in terms of G+C content, major respiratory quinones, and major polar lipids.

Early adjusting damping force for sloped rolling-type seismic isolators based on earthquake early warning information

  • Hsu, Ting-Yu;Huang, Chih-Hua;Wang, Shiang-Jung
    • Earthquakes and Structures
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    • 제20권1호
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    • pp.39-53
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    • 2021
  • By means of installing sloped rolling-type seismic isolators (SRI), the horizontal acceleration transmitted to the to-be-protected object above can be effectively and significantly reduced under external disturbance. To prevent the maximum horizontal displacement response of SRI from reaching a threshold, designing large and conservative damping force for SRI might be required, which will also enlarge the transmitted acceleration response. In a word, when adopting seismic isolation, minimizing acceleration or displacement responses is always a trade-off. Therefore, this paper proposes that by exploiting the possible information provided by an earthquake early warning system, the damping force applied to SRI which can better control both acceleration and displacement responses might be determined in advance and accordingly adjusted in a semi-active control manner. By using a large number of ground motion records with peak ground acceleration not less than 80 gal, the numerical results present that the maximum horizontal displacement response of SRI is highly correlated with and proportional to some important parameters of input excitations, the velocity pulse energy rate and peak velocity in particular. A control law employing the basic form of hyperbolic tangent function and two objective functions are considered in this study for conceptually developing suitable control algorithms. Compared with the numerical results of simply designing a constant, large damping factor to prevent SRI from pounding, adopting the recommended control algorithms can have more than 60% reduction of acceleration responses in average under the excitations. More importantly, it is effective in reducing acceleration responses under approximately 98% of the excitations.

Isolation of Dibutyl Phthalate-Degrading Bacteria and Its Coculture with Citrobacter freundii CD-9 to Degrade Fenvalerate

  • Wu, Min;Tang, Jie;Zhou, Xuerui;Lei, Dan;Zeng, Chaoyi;Ye, Hong;Cai, Ting;Zhang, Qing
    • Journal of Microbiology and Biotechnology
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    • 제32권2호
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    • pp.176-186
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    • 2022
  • Continued fenvalerate use has caused serious environmental pollution and requires large-scale remediation. Dibutyl phthalate (DBP) was discovered in fenvalerate metabolites degraded by Citrobacter freundii CD-9. Coculturing is an effective method for bioremediation, but few studies have analyzed the degradation pathways and potential mechanisms of cocultures. Here, a DBP-degrading strain (BDBP 071) was isolated from soil contaminated with pyrethroid pesticides (PPs) and identified as Stenotrophomonas acidaminiphila. The optimum conditions for DBP degradation were determined by response surface methodology (RSM) analysis to be 30.9 mg/l DBP concentration, pH 7.5, at a culture temperature of 37.2℃. Under the optimized conditions, approximately 88% of DBP was degraded within 48 h and five metabolites were detected. Coculturing C. freundii CD-9 and S. acidaminiphila BDBP 071 promoted fenvalerate degradation. When CD-9 was cultured for 16 h before adding BDBP 071, the strain inoculation ratio was 5:5 (v/v), fenvalerate concentration was 75.0 mg/l, fenvalerate was degraded to 84.37 ± 1.25%, and DBP level was reduced by 5.21 mg/l. In addition, 12 fenvalerate metabolites were identified and a pathway for fenvalerate degradation by the cocultured strains was proposed. These results provide theoretical data for further exploration of the mechanisms used by this coculture system to degrade fenvalerate and DBP, and also offer a promising method for effective bioremediation of PPs and their related metabolites in polluted environments.

무인기용 이중화 비행조종컴퓨터의 고장관리 설계 (A Fault Management Design of Dual-Redundant Flight Control Computer for Unmanned Aerial Vehicle)

  • 오태근;윤형식
    • 한국항공우주학회지
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    • 제50권5호
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    • pp.349-357
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    • 2022
  • 무인항공기의 비행조종컴퓨터는 비행 안전에 필수적인 장비로써 개발 단계에서부터 신뢰성과 안전성의 확보가 필수적이며, 고장 발생 시에도 정상적으로 기능을 수행할 수 있는 다중화 기반의 고장관리 설계가 요구된다. 무인기의 경우에는 비용, 무게, 전력소모 등을 감소하기 위하여 비행조종시스템의 이중화 설계를 고려하지만, 고장관리를 위한 고장 검출 및 분리 설계에 많은 제약이 있다. 본 논문에서는 무인기용 이중화 비행조종컴퓨터의 신뢰성을 향상시키기 위한 고장 검출 및 고장 분리를 위한 고장관리 설계 방안을 제안한다. 그리고 고장관리 설계를 적용해 개발한 비행조종컴퓨터는 통합시험환경에서 기능 시험을 수행하고 HILS 환경에서 고장 영향성 확인 시험을 수행한 후 무인기에 탑재하여 비행시험을 통해 그 신뢰성을 검증하였다.

Antimicrobial resistance in fecal Escherichia coli from different pig production systems

  • Mitchaothai, Jamlong;Srikijkasemwat, Kanokrat
    • Animal Bioscience
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    • 제35권1호
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    • pp.138-146
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    • 2022
  • Objective: The objective of the current study was to investigate the influences of conventional (CO) and deep litter (DE) systems on antimicrobial resistance in fecal Escherichia coli (E. coli). Methods: A cross-sectional study was carried out to detect antimicrobial resistance to E. coli in swine fecal samples in CO and DE systems located in western and northeastern Thailand. Individual rectal swab samples were taken only from healthy pigs. A total of 215 individual and healthy pigs were randomly selected for isolation and antimicrobial susceptibility test of E. coli by the disc diffusion method. The test panel included amoxicillin (AMX), colistin, doxycycline (DOX), enrofloxacin, gentamicin (GEN), kanamycin, neomycin (NEO), and trimethoprim-sulfamethoxazole (SXT). Results: There were significant (p<0.05) lower resistance levels for GEN, NEO, and SXT in the DE farms compared to those in the CO farms. There was a lower number of antimicrobial resistance agents (p<0.001) in the DE farms compared to those in the CO farms. This result was consistent with those in western (p<0.01) and northeastern (p<0.01) Thailand. Overall, antibiograms of AMX-SXT and AMX-DOX-SXT were found in the CO (19.09% and 20.91%, respectively) and the DE (16.19% and 24.76%, respectively) farms. No antimicrobial resistance (5.71%) was found and AMX (13.33%) resistant pigs in the DE farms, whereas the pattern of AMX-GEN-SXT (6.36%) and AMX-DOX-GEN-SXT (11.82%) resistant pigs was found in the CO farms. Conclusion: The DE system for pig farming was superior to conventional pig farming by lowering the resistance level of fecal E. coli to GEN, NEO, and SXT, with decreasing the number of antimicrobial resistance agents and inducing a small proportion of pigs to be free from antimicrobial resistance.