• Title/Summary/Keyword: The safe factor

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Dynamic Behaviour of the LRB for Seismic Isolation Design (기초분리설계를 위한 탄성받침의 동적거동)

  • Im, Jung-Soon;Lee, Hee-Mok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.4 no.3
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    • pp.137-144
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    • 2000
  • Judging from the occasional occurrences of minor and major earthquakes in Korean peninsula, it is generally considered that Korean peninsula is not located in safe zone from earthquake any more. The worldwide damages from earthquake in public buildings such as bridges are also urging the necessity for an appropriate earthquake proof action. The elastomeric bearings have been used in seismic isolation design of bridges. and elastomeric bearings are quite ideal ones which allow movement and rotation in all directions without restraining superstruture. Within the limits of this study on dynamic behavior of the LBR for seismic isolation design, the reaearch results revealed that the Laminated Rubber Bearing(LRB) is useful in bridges for seismic isolation design. In addition, the relationship between the shape factor and compressive strength is linear. It was also found that the compressive strength gets higher as the shape factor increases.

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Analysis on Emergency Power Supplies in Buildings and a Model for Safe Operation of the Emergency Power System (건축물의 비상전원 적용실태 및 자가발전설비의 안전 운전 모델에 관한 연구)

  • Lee, Won-Kang;Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.27 no.3
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    • pp.49-56
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    • 2012
  • The purpose of this paper is to present a model for operating an emergency power system(EPS) that can secure a sufficient power supply used in case of a fire by analyzing the status of power supplies for emergency and firefighting operations. Investigations on the one of the causes of the operational failure of firefighting systems show evidence of EPS. Generally, when power to a building is interrupted, EPS supplies the emergency load(excepted firefighting load) first. When a power outage and a fire occur simultaneously, the EPS must be able to supply both the emergency load and the firefighting load, especially the firefighting load to the end. However, in order to save construction costs, emergency power generators in apartment, commercial, and business buildings can satisfy only one of the required loads. In cases like this, when a power outage and a fire occur simultaneously, there is a danger of firefighting equipment not operating due to insufficient power supply from the emergency generator. Therefore, an EPS must have a reserved firefighting power that can supply both the firefighting and the emergency load. Such EPS, when faced with a danger of an overload, will shut down the supply to all or part of the emergency load, thus securing a continuous power supply to the firefighting equipment. The generator power system with reserved firefighting power (RFP) will also have an indicator to show that the selective control is being used. General power generation systems for emergency load and firefighting load were found to have a demand factor of 50-60% with a lump. However, when installing an EPS, the builders must choose the higher demand factor suggested according to the official approval demand factor of the building.

A Prediction of Crack Propagation Rate under Random Loading (랜덤하중에서의 균열전파속도 추정법에 관한 연구)

  • 표동근;안태환
    • Journal of Ocean Engineering and Technology
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    • v.8 no.2
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    • pp.115-123
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    • 1994
  • Under variable amplitude loading conditions, retardation or accelerated condition of fatigue crack growth occurs with every cycle, Because fatigue crack growth behavior varied depend on load time history. The modeling of stress amplitude with storm loading acted to ships and offshore structures applied this paper. The crack closure behavior examine by recording the variation in load-strain relationship. By taking process mentioned above, fatigue crack growth rate, crack length, stress intensity factor, and crack closure stress intensity factor were obtained from the stress cycles of each type of storm ; A(6m), B(7m), C(8m), D(9m), E(11m) and F(15m) which was wave height. It showed that the good agreement with between the experiment results and simulation of storm loads. So this estimated method of crack propagtion rate gives a good criterion for the safe design of vessels and marine structure.

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Numerical Calculation of Energy Release Rates by Virtual Crack Closure Technique

  • Choi, Jae-Boong;Kim, Young-Jin;Yagawa, Genki
    • Journal of Mechanical Science and Technology
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    • v.18 no.11
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    • pp.1996-2008
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    • 2004
  • A seamless analysis of material behavior incorporating complex geometry and crack- tip modeling is one of greatly interesting topics in engineering and computational fracture mechanics fields. However, there are still large gaps between the industrial applications and fundamental academic studies due to a time consuming detailed modeling. In order to resolve this problem, a numerical method to calculate an energy release rate by virtual crack closure technique was proposed in this paper. Both free mesh method and finite element method have been utilized and, thereafter, robust local and global elements for various geometries and boundary conditions were generated. A validity of the proposed method has been demonstrated through a series of fracture mechanics analyses without tedious crack-tip meshing.

Estimation of the Allowable Bio-shock Fragility Index of Fruits for Optimum Packaging Design (적정 포장설계를 위한 과실의 바이오 허용 충격지수 추정)

  • Kim, Ghi-Seok;Jung, Hyun-Mo;Kim, Ki-Bok;Kim, Man-Soo
    • Journal of Biosystems Engineering
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    • v.32 no.6
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    • pp.416-421
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    • 2007
  • Physical damage to fruits and vegetables caused by shock degrades the value of product in the fresh market. In order to design a product/packaging system to protect the product, the G-factor to the product that causes shock damage needs to be determined. The shock fragility of organisms such as fruits with a concept correspondent to the G-factor of industrial products was calculated and we defined the allowable bio-shock fragility index as the value divided peak acceleration that was generated in safe drop height by standard acceleration of gravity. We did modeling for safe drop hight that would prevent fruits from damage by drop tests and tried to estimate the allowable bio-shock fragility index of pears and apples for optimum packaging design. The bio-shock fragility index of pears was in the range of $0.74{\sim}2.29\;G$, while apples had a slightly higher value than that of pears, of $0.51{\sim}2.98\;G$. This result shows accordance with the general fact that apples have a firmer structure and get less damage from the same impact. Based on this result, it is possible to create an optimum packaging design by providing a damage standard by impact.

Development of a Real-Time Driving Simulator for Vehicle System Development and Human Factor Study (차량 시스템 개발 및 운전자 인자 연구를 위한 실시간 차량 시뮬레이터의 개발)

  • 이승준
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.7
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    • pp.250-257
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    • 1999
  • Driving simulators are used effectively for human factor study, vehicle system development and other purposes by enabling to reproduce actural driving conditions in a safe and tightly controlled enviornment. Interactive simulation requries appropriate sensory and stimulus cuing to the driver . Sensory and stimulus feedback can include visual , auditory, motion, and proprioceptive cues. A fixed-base driving simulator has been developed in this study for vehicle system developmnet and human factor study . The simulator consists of improved and synergistic subsystems (a real-time vehicle simulation system, a visual/audio system and a control force loading system) based on the motion -base simulator, KMU DS-Ⅰ developed for design and evaluation of a full-scale driving simulator and for driver-vehicle interaction.

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A Study on the Local Strength Structural Analysis for Steel Yacht (강선요트의 국부강도 구조해석에 관한 연구)

  • Park Joo-Shin;Ko Jae-Yong;Lee Jun-Kyo;Bae Dong-Kyun
    • Proceedings of KOSOMES biannual meeting
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    • 2005.05a
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    • pp.155-159
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    • 2005
  • Analysis target ship is not introduced yet in domestic as steel yacht that is getting into the spotlight by leisure life in Australia or Japan. Sailing yacht or Yacht for leisure time made of FRP into controlling power fare mainly and the design and made of latest fishing boat and something of domestic is consisting mainly. To need investigated for concept is various kinds overall strength as that use mainly steel wire material structurally of steel yacht by small crafts about Longi strength, Transe strength portion even of design safety factor at subject to do Rule's allowable stress enough stable structure accomplish. But it is assessment of part intensity that become refer to most in small size ship.

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Burn Wound Successfully Treated with 830-nm Light Emitting Diode Phototherapy Combined with Epidermal Growth Factor Solution

  • Lee, Hae-Jin;Kim, Young Koo
    • Medical Lasers
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    • v.8 no.2
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    • pp.94-96
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    • 2019
  • Burns are one of the most extensive injuries of soft tissues as well as skin, occasionally resulting in extensive, deep wounds and death. Burn wounds can lead to severe physical and psychological distress because of excessive scarring and skin contractures. Treatment of burn wounds has always been a challenging problem and many different methods have been used to treat such injuries. We report here on treating a patient with a burn wound using 830-nm light emitting diode (LED) phototherapy combined with epidermal growth factor (EGF) solution. After five daily sessions of LED with EGF solution treatment, the patient demonstrated nearly complete improvement with no remarkable side effects. We suggest that LED phototherapy combined with EGF solution could be an effective and safe treatment option for treating burn wounds.

A Study on the Parameters Effecting on the Derailment Factor of Running Train on the Curved Track (곡선부에서 탈선계수에 영향을 미치는 매개변수들에 대한 연구)

  • Song, Bong-Hwan;Yang, Shin-Chu;Kang, Yun-Suk
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.348-356
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    • 2004
  • In this paper, Analysis of parameters effecting on the derailment factor was conducted in oder to deduce technical requisites have to be reflected in design of Track and rolling-stocks because it is important to grasp the risk of derailment quantitatively. And then go far toward becoming practical study with that select two section of sharp curved track of actual train in service, incheon Metro Line 1 and make field research in condition of vehicles and track and analysis As a result of parameter study, the following conclusions were obtained. The radius of curve and Cant is in inverse proportion to the derailment factor, but as train operation velocity, standard deviation of alignment irregularity and the ratio lateral force : wheel load of the inside track increase, the derailment factor rise. In the investigation for the derailment safety of incheon Metro Line 1, the derailment factor was below 0.43 in both section R=200 and R=300, so that it proved safe compare with allowance limits 0.8, but it appeared that risk of the derailment in second transition curve is the highest among the entire curve.

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A Case Study on CPTED Projects for Regeneration of Deteriorated Residential Area - Focused on Cases of 'Deokpo-dong', 'Chilsan-dong' and 'Sujeong-dong' in Busan City (노후주거지 재생을 위한 범죄예방 환경디자인 사업 사례연구 - 부산시 '덕포동', '칠산동', '수정동' 시행사례를 중심으로 -)

  • Choi, Kang-Rim
    • Korean Institute of Interior Design Journal
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    • v.25 no.5
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    • pp.16-30
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    • 2016
  • There is an increasing interest in and efforts for safe residential environment from crimes nationwide. Many cities are making efforts to create safe residential environment by enacting ordinances and guidances on safe design for preventing crimes and implementing demonstration projects. In line with the trends of the times toward 'improvement of living conditions' through urban regeneration, the importance of the Crime Prevention Through Environmental Design(CPTED) has recently emerged in the field of residential housing regeneration. Indeed, the CPTED is included as essential factor in the recent deteriorated residential area regeneration related projects. In this respect, the purpose of this study is to provide the basic data on the methodology of CPTED to be applied to the regeneration of deteriorated residential area in the future. To this end, this study selected three representative CPTED projects in Busan - 'Deokpo-dong Hope and Stepping Stone Village,' 'Chilsan-dong CPTED Happiness Village' and 'Sujeong-dong Crime Prevention and Safe Village' as objects of this study and then investigated and analyzed project contents, application of CPTED strategy, subjects who are implementing projects, and the time when they implement projects as the framework of my analysis. The findings from this study are as follows: First, the projects that were largely based on hardware should be improved by including software in the future. Second, the current Step 2 should expand into Step 3 Maintenance in applying CPTED strategy. Third, it is necessary to encourage exchange and cooperation between unit projects and subjects who are operating related projects.