• Title/Summary/Keyword: Failed

Search Result 4,203, Processing Time 0.034 seconds

Determining the Priority of Investment for Remedial Works of Slopes (사면관리를 위한 재원의 투자 우선 순위 평가)

  • 김상규;류지협;구호본;정하익;윤수호
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 1999.03a
    • /
    • pp.269-276
    • /
    • 1999
  • The program ESRAS Ver 0.5 that can assess the risk of slopes by means of fuzzy inference is developed in this paper. The results of assessment involve the degree of stability of slopes, the possible travel distance of the soil mass being failed, and anticipated loss of life and properties. With this program, vulnerable slopes can be managed most effectively and the fuzzy inference is used to express quantitatively the judgement of an expert and the uncertainty of slope stability. The fuzzy rule base is composed of an evaluation list for slope stability together with the experience of an expert. This program has been examined for 88 slopes which have been failed or shown a possibility of failure. With this examination, the standards to assess the stability of slopes can be presented and it is proven that this is particularly useful in determining the priority of investment for remedial works of slopes.

  • PDF

Safety Assessment of the Evacuation at School Building by Escape Training and Simulation (학교건물에서 피난훈련과 시뮬레이션을 통한 피난안전성 평가)

  • Jeong, Mu-Heon;Lee, Beong-Gon
    • Fire Science and Engineering
    • /
    • v.22 no.3
    • /
    • pp.287-292
    • /
    • 2008
  • In this study, the evacuation training were performed in a high school building in Cheong-Ju and compared with the simulation program (Simulex). Also numerical analysis of room fire in school building was conducted by fire model (FDS, CFAST) and evaluated the available safe egress time for the safety assessment. As a result, the 8% of total egress persons were failed to escape at evacuation training and 40% of total egress persons were failed to escape at Simutex simulation. Simutex program was not reflected the real escape conditions, such as evacuation route, refuge place, etc.

Spinal Cord Stimulation in Pain Management: A Review

  • Jeon, Young-Hoon
    • The Korean Journal of Pain
    • /
    • v.25 no.3
    • /
    • pp.143-150
    • /
    • 2012
  • Spinal cord stimulation has become a widely used and efficient alternative for the management of refractory chronic pain that is unresponsive to conservative therapies. Technological improvements have been considerable and the current neuromodulation devices are both extremely sophisticated and reliable in obtaining good results for various clinical situations of chronic pain, such as failed back surgery syndrome, complex regional pain syndrome, ischemic and coronary artery disease. This technique is likely to possess a savings in costs compared with alternative therapy strategies despite its high initial cost. Spinal cord stimulation continues to be a valuable tool in the treatment of chronic disabling pain.

A New TLS-Based Sequential Algorithm to Identify Two Failed Satellites

  • Jeon, Chang-Wan;Lachapelle, Gerard
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.2627-2631
    • /
    • 2003
  • With the development of RAIM techniques for single failure, there has been increasing interest in the multiple failure problem. There have been many approaches to tackle the problem from various points of view. This paper approaches to two failure problem with total least squares (TLS) technique, which has rarely been addressed because TLS requires a great number of computations. In this paper, the special form of the observation matrix H, that is, one column is exactly known, is exploited so as to develop an algorithm in a sequential form, which reduces computational burden. The algorithm makes us enjoy the advantages of TLS without much computational burden. The proposed algorithm is verified through a numerical simulation.

  • PDF

The effects of consolidation time on the strength and failure behavior of freshwater ice rubble

  • Shayanfar, Hamid;Bailey, Eleanor;Pritchett, Robert;Taylor, Rocky
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.10 no.3
    • /
    • pp.403-412
    • /
    • 2018
  • Medium-scale tests were conducted to measure and observe the strength and failure behavior of freshwater ice rubble. A custom box measuring $3.05m{\times}0.94m{\times}0.94m$, with Plexiglas walls was built so that failure mechanisms could be observed. Ice rubble beams of nominal thickness 50 cm were produced by placing randomly sized ice pieces into the box filled with water at its freezing temperature. After the specified consolidation time, ranging between 0.2 and 70.5 h, the ice rubble beam was deformed by pushing a platen vertically downwards though the center of the beam until failure. For consolidation times less than 4 h, the ice beam failed progressively and tended to fail by shearing on macroscopic scale. At times greater than 4 h the beam failed by bending. The change in failure behaviour has been attributed to the degree of bonding between ice blocks.

The Effects of Failed Airline Services on the Complaint and Switching Behavior (항공서비스 실패가 불평행동과 전환행동에 미치는 영향)

  • Tran, Quang Thai;Kang, Hyunmo;Jeong, Eui Hyeon
    • Knowledge Management Research
    • /
    • v.18 no.2
    • /
    • pp.103-127
    • /
    • 2017
  • This study examines the effects of failed airline services on the consumers' psychological process and their behavioral responses. Having different classifications from the previous studies, this study focuses on dividing important factors of airline services into search attributes(e.g. sale and procedure services, services concerning flight attendant, in-flight services) and experience attributes(e.g. flight services, collateral services). Using structural equation modeling, this study shows that the failure of service factors of the experience attributes provokes the feeling of disappointment with mediation effect of external attribution while the failure of service factors of search attributes provokes the feeling of regret with mediation effect of internal attribution. Finally, disappointment leads to consumers' complaint behavior while regret leads to consumers' switching behavior. Unlike previous studies, we show that when a service failure occurs, depending on each attribute, consumers feel negative emotions of disappointment or regret through different attribution processes and finally show different behavioral responses with an empirical analysis.

LDPC Decoding by Failed Check Nodes for Serial Concatenated Code

  • Yu, Seog Kun;Joo, Eon Kyeong
    • ETRI Journal
    • /
    • v.37 no.1
    • /
    • pp.54-60
    • /
    • 2015
  • The use of serial concatenated codes is an effective technique for alleviating the error floor phenomenon of low-density parity-check (LDPC) codes. An enhanced sum-product algorithm (SPA) for LDPC codes, which is suitable for serial concatenated codes, is proposed in this paper. The proposed algorithm minimizes the number of errors by using the failed check nodes (FCNs) in LDPC decoding. Hence, the error-correcting capability of the serial concatenated code can be improved. The number of FCNs is simply obtained by the syndrome test, which is performed during the SPA. Hence, the decoding procedure of the proposed algorithm is similar to that of the conventional algorithm. The error performance of the proposed algorithm is analyzed and compared with that of the conventional algorithm. As a result, a gain of 1.4 dB can be obtained by the proposed algorithm at a bit error rate of $10^{-8}$. In addition, the error performance of the proposed algorithm with just 30 iterations is shown to be superior to that of the conventional algorithm with 100 iterations.

Analysis of Filament Wound Pressure Tank Considering Winding Angle Variation in Thickness Direction (두께 방향의 와인딩 각도 변화를 고려한 필라멘트 와인딩 된 압력탱크의 해석)

  • 김철웅;박재성;홍창선;김천곤
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2000.04a
    • /
    • pp.211-214
    • /
    • 2000
  • Filament wound pressure vessels have been studied for the efficient design tool to consider the variation of fiber angles through-the thickness direction. Filament winding patterns were simulated from semi-geodesic fiber path equation to calculate fiber path on arbitrary surface. Finite element analyses were performed considering fiber angle variation in longitudinal and thickness directions by ABAQUS. For the finite element modeling of the pressure tank, the 3-dimensional layered solid element was utilized. From the stress results of pressure tanks, maximum stress criterion in transverse direction was applied to modify material properties for failed region. In the end of each load increment, resultant layer stresses were compared with a failure criterion and properties were reduced to 1/10 for a failed layer. Results of progressive failure analysis were compared with two experimental data.

  • PDF

Influencing Factors on Toughness of Ring Type Fiber Concrete (원형강섬유 콘크리트의 인성 영향요인)

  • Choi, Oan-Chul;Lee, Cha-Don;Hur, Jun;Kim, Su-Hyen
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2001.05a
    • /
    • pp.55-60
    • /
    • 2001
  • Influencing factors on flexural toughness of ring-type fiber reinforced concrete(RSFRC) are investigated. An experiment proceeding ASTM C 78 is peformed to make a comparison between ring-type fibers and double-hook type fibers. Most specimen with ring type fibers have failed by the cone type failure, while discrete hook type fibers have failed by fiber pullout. For the hook-type fiber reinforced concrete(SFRC), the first crack load increases, as the fiber mixing volume increases. Aspect ratio(fiber length/fiber diameter) is critical for hook type fibers, so the flexural toughness increases significantly, as the length of fiber increases. However, for the ring type, the toughness indices Increase as the number of fibers in the specimen increases. Since there is no bond problem between the ring fiber and the concrete matrix, the aspect ratio does not affect the performance of the composite material with the newly developed steel fibers. Influencing factors with respect to flexural toughness RSFRC were observed to be ring diameter, diameter of steel fiber and fiber content.

  • PDF