• Title/Summary/Keyword: Continuous bridge

Search Result 549, Processing Time 0.027 seconds

An Evaluation of Working Environment of the Ship Vibration by ISO Regulation (ISO규정에 의한 선박의 선내진동과 승선근무 환경평가)

  • Yu, Young-Hun
    • Proceedings of KOSOMES biannual meeting
    • /
    • 2007.11a
    • /
    • pp.139-144
    • /
    • 2007
  • The vibration generated on shipboard is very important because it is greatly affect on the comfortable mind of passenger and working conditions et crews. Shipboard vibration is closely concerned with the development of propulsion method tint is main engine to decide speed of ship. To make the propulsion power, the main engine of ship engine room have continuous explosion process, so the shipboard vibration is generated The physiological damage and psychological damage of human body have caused by the vibration et shipboard In the case of the human body is exposed to the shipboard vibration, the evaluation of human exposure to whole-body vibration is prescribed in ISO 6954: 2000(E). In this paper, to evaluate the shipboard working environment, the vibration levels of two kinds of ship onboard were measured and compared with engine rooms, engine control rooms and bridges by the regulation of ISO 6954: 2000(E)

  • PDF

Improved Damage Assessment Algorithm Using Limited Mode Shapes (제한된 모드형상을 이용한 개선된 손상평가 알고리즘)

  • 이종순;조효남;허정원;이성칠
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.15 no.1
    • /
    • pp.127-136
    • /
    • 2002
  • This papers presents a practical damage detection algorithm based on damage index method that accurately assesses both the location and severity of the localized detriment in a bridge structure using only limited mode shapes. In the algorithm, the ratio of the modal vector sensitivity of an undamaged structure to that of a damaged structure is used as an indicator of damage. However, a difficulty arises when the damaged element is located at a node of mode where the amplitude of medal vector is close to zero, leading the singularity of the ratio (i.e., division-by-zero). This singularity problem is overcome by introducing a parameter denoted a sensitivity filter, a function of mode shape of the structure, in modal vector sensitivity. Using this concept, an improvement can be considerably achieved in the estimation of both degree of severity and location of damage. To verify the proposed algorithm, its numerical implementations are conducted for a simply supported beam and a 2-span continuous beam.

The Burden in Women with Hysterectomy (자궁절제 여성의 부담감에 관한 연구)

  • Seong, Mi-Hye
    • Women's Health Nursing
    • /
    • v.3 no.2
    • /
    • pp.180-191
    • /
    • 1997
  • When women are removed with their matrix which is a emotionally significant organ of symbol in psychologically adapting themselves to mother and woman, that is threatened and injured with woman role decisively. The nursing for women with hysterectomy is limited to medical treatment and the nursing related to troubles in psychology, emotion they experience in general situation due to operations is hardly realized. New basis for nursing can be realized when we both have relation with lived human experience related th health and become to be a part of it. We need to catch their experience due to the loss of matrix to understand women with hysterectomy. The subjects of the study were nine patients who were admitted to a gynecological ward of a hospital in Seoul, suffering from vaginal bleeding, back pain, abdominal pain and so on and diagnosing as non-cancer. The data were collected from April to May 1997 by listening to the subjects' expression of their experience and by participant observation of the subjects' reactions. A tape-recorder was used under the permission of the subjects, to prevent the loss of spoken information. The result of the study was as follows : The data on burden content from the interview were categorized as psych-emotional, physical, personal interaction, financial burden and maternal role burden. The factors which have influence on the burden of the subjects are an offer of information, support system, age, occupation, economic situation, family history, character, season, the existence of ovary and religion. In conclusion, since we ascertained that the nursing in the process of recovery decide the quality of life, though women with hysterectomy undergo various burden experience and adapt to it in the end, it is necessary to give them enough information and educate husband, having on important effect on the burden experience, to be a good supporter. And technically skilled nurses of consultant are thought to be able to contrive better qualitative life of women with hysterectomy as an important bridge between the subjects and their required information, since the nurses have their well-formed position of relationship of confidence through continuous contact with patients and their family.

  • PDF

The Rise Ratio of the 3 Continuous Span Length Steel Arch Bridges Considering Dynamic Stability (동적안정성을 고려한 3경간 연속 중로식 강 Arch 교량의 Rise 비)

  • Kang, Sung-Hoo;Park, Sun-Joon;Choi, Myeong-Ki
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.8 no.4
    • /
    • pp.175-183
    • /
    • 2004
  • The most important element is a rise ratio when regarding beauty and economics of arch bridges. Only the effect of dead load has been considered to decide the rise ratio. In this study, when going over the rise ratio of arch bridges, examined the problems, that the determination of the rise ratio by the dead load has, by adding the factor of a determination of optimum rise ratio, which is not only the effect of the dead load that has been currently considered but also the problem with respect to dynamic stability that is now taken seriously. Synthetically, when deciding rise ratio that is investigated in basic step of design, it is necessary to consider the evaluation dynamic stability.

Stability Analysis for CWR on the Railway Bridges by Linearized Method (선형해석법을 이용한 교량상 장대레일의 안정성 해석 방법 연구)

  • Choi, Young-Gil;Oh, Ju-Won
    • Journal of the Korean Society for Railway
    • /
    • v.12 no.4
    • /
    • pp.472-480
    • /
    • 2009
  • The stability analysis for CWR is difficult in the theory itself because both geometric and material nonlinearity should be considered. Also the analysis results are varied according to the loading history. In contrast to the complexity in the theory, the analysis results for CWR on the railway bridges are quite simple and can be predicted because of a small buckling effect and its negligible nonlinearity. In this study, refined nonlinear analysis methods for the stability analysis of CWR on the railway bridges were developed which consider only material nonlinearity beeause the effects of geometric nonlinearity are nominal. In this study, the analysis results can be found within limited number of iterations with idealized linear force-displacement relationship. From the analysis result comparisons, it was found that the stability analysis for CWR on the railway bridges can be performed effectively by this method.

Conservative approach of a symptomatic carious immature permanent tooth using a tricalcium silicate cement (Biodentine): a case report

  • Villat, Cyril;Grosgogeat, Brigitte;Seux, Dominique;Farge, Pierre
    • Restorative Dentistry and Endodontics
    • /
    • v.38 no.4
    • /
    • pp.258-262
    • /
    • 2013
  • The restorative management of deep carious lesions and the preservation of pulp vitality of immature teeth present real challenges for dental practitioners. New tricalcium silicate cements are of interest in the treatment of such cases. This case describes the immediate management and the follow-up of an extensive carious lesion on an immature second right mandibular premolar. Following anesthesia and rubber dam isolation, the carious lesion was removed and a partial pulpotomy was performed. After obtaining hemostasis, the exposed pulp was covered with a tricalcium silicate cement (Biodentine, Septodont) and a glass ionomer cement (Fuji IX extra, GC Corp.) restoration was placed over the tricalcium silicate cement. A review appointment was arranged after seven days, where the tooth was asymptomatic with the patient reporting no pain during the intervening period. At both 3 and 6 mon follow up, it was noted that the tooth was vital, with normal responses to thermal tests. Radiographic examination of the tooth indicated dentin-bridge formation in the pulp chamber and the continuous root formation. This case report demonstrates a fast tissue response both at the pulpal and root dentin level. The use of tricalcium silicate cement should be considered as a conservative intervention in the treatment of symptomatic immature teeth.

Seismic performance evaluation of Pier-Shafts system with multi-layered soil (다양한 지반층을 갖는 Pier-Shafts 시스템의 내진성능평가)

  • Jang, Sung-Hwan;Nam, Sang-Hyeok;Song, Ha-Won;Kim, Byung-Chul
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2008.04a
    • /
    • pp.69-72
    • /
    • 2008
  • The so-called Pier-Shafts system which consists of the continuous column and shaft is often used to support the highway bridge structure because of advantages in easy construction and low cost. In the earthquake region, the Pier-Shafts system undergoes large displacements and represents a nonlinear behavior under the lateral seismic loading. The soil-pile interaction should be considered for more accurate analysis of the Pier-Shafts system. In this study, a transverse response of a reinforced concrete Pier-Shafts system inside multi-layered soil medium is predicted using a finite element program which adopts an elasto-plastic interface model for the interface behavior between the shaft and the soil. Then, seismic analysis is performed to evaluate the performance of Pier-Shafts system under strong ground motion and their results are verified with experimental data.

  • PDF

Experimental Study on the Dynamic Response of Box Girder Long-Span Bridges under Various Travelling Vehicles (다양한 차량주행에 의한 박스형 장대교량의 동적 응답에 관한 실험적 연구)

  • Lee, Rae-Chul;Lee, Sang-Youl;Yhim, Sung-Soon
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.8 no.1
    • /
    • pp.129-138
    • /
    • 2004
  • In this study we determine a dynamic analysis of the existing two-span prestressed concrete box girder bridge subjected to moving vehicle loads using the experimental measurements. The moving loads applied in this paper are classified as general travelling, suddenly brake, continuous travelling, reversely travelling and reversely travelling impact loads for increasing velocities. For each travelling load, we search dynamic behaviors and characteristic in various measuring point of box girder section. In addition, the three-dimensional numerical results analyzed by the developed finite element program using flat shell element with six degrees of freedom per a node are compared with the measured experimental data. Dynamic behaviors caused impact loads by suddenly braking, reversely travelling, are bigger than by general travelling in box girder. Three-dimensional numerical results are better than one-dimensional results.

A Study on the development of Explosion-proof type's the terminal box of the ventilator with the control of wind volume and operating time (풍량 및 운전시간 제어 방폭 배풍기 인버터 단자함 개발에 관한 연구)

  • Yoo, DongJoo
    • Journal of Convergence for Information Technology
    • /
    • v.8 no.6
    • /
    • pp.187-192
    • /
    • 2018
  • This thesis is about the study of inverter terminal boxes in a explosion proof type exhaust fan that can control wind volume and operating time. In Korea, there is no ventilator to adjust the amount of wind and operating time when working in poor conditions. The purpose of the project is to create a explosion terminal box that can control the operating time and wind speed of a suitable explosion ventilator in hazardous environments. The two explosion-proof switches allow the operation time to be driven 1 hour, 3 hours and continuous time, and the speed of the induction motor rotation was set in 3 stages at 2000 rpm, 2600 rpm and 3000 rpm to control the volume. The tested motor used a half-horsepower barrier three-phase induction motor and a full-bridge inverter to set the desired flow rate and operating time.

Case Study on the Development of STEAM Instruction Material for Mathematics Subject-Based Advanced Technology and ICT Teaching Tools (초등수학 교과 기반 첨단 기술 및 ICT 교구 활용형 융합교육 자료 개발에 대한 사례 연구)

  • Lee, Jong-hak
    • Journal of the Korean School Mathematics Society
    • /
    • v.25 no.4
    • /
    • pp.333-352
    • /
    • 2022
  • This study is aimed at developing the STEAM instruction materials for mathematics subject-based advanced technology and ICT teaching tools. In order to develop the STEAM materials, a PDI model in which the implementation and evaluation steps were simplified to Improvement was used. The developed STEAM materials were revised and supplemented by a group of experts. The subject of the STEAM class material developed in this study is 『Graph! The bridge that connects the past, present and future』 , 『You are the same but different!』 , 『Creating a virtual reality three-dimensional space together』 , 『And making interesting figures』 and 『Cover the roof of the turtle ship!』 . As a suggestion based on the results of this development study, various STEAM education materials should be developed and shared so that STEAM education can be performed in the elementary education field. And for the spread and settlement of STEAM education, the cultivation and expansion of STEAM education capabilities of on-site elementary school teachers or pre-service teachers will be an absolute prerequisite. And this suggests the need for a continuous and long-term approach to follow-up research on STEAM education.