• Title/Summary/Keyword: Section analysis method

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An analytical study on the structural behavior of H shape column base plates under axial loads and moments (축력과 모멘트를 받는 H형강 주각부의 거동에 관한 해석적 연구)

  • Kim, Jeong Hyun;Lee, Seung Joon
    • Journal of Korean Society of Steel Construction
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    • v.17 no.2 s.75
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    • pp.217-225
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    • 2005
  • The purpose of this study is to investigate the behavior of H-shape column base plates subjected to axial loads and moments. In this study, the behavior of H-shape column base plates is investigated using finite element analysis method and an analytical modelingof the base plates is obtained. The variations of six test specimens include ratiosof axial load, sizes of anchor bolts, and thicknesses of base plates. The experimental results are compared with the results from the finite element analyses and those of the analytical modeling. Bearing pressures of base plates from the finite element analyses are compared with those that are assumed in the design of the base plates. From the results of the research, it is observed that the initial stiffness and yield strengths in the analytical study are very similar to the experimental results. And bearing pressures are concentrated under column section with thin base plates.

A Study on the Development of Force Limiting Devices(FLD) which Induce Yielding before Elastic Buckling (좌굴전 항복유도 장치(FLD) 개발에 관한 연구)

  • Kim, Cheol Hwan;Chae, Won Tak;Oh, Young Suk;Kim, Chae Yeong
    • Journal of Korean Society of Steel Construction
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    • v.25 no.3
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    • pp.279-287
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    • 2013
  • The steel members are applied to high rise building since they have high strength compare to the concrete member. On the other hand, the elastic buckling is likely to occur in steel member because of their small section. When the elastic buckling occur, the steel structure lose a load carrying capacity. The steel frame would be unstable due to a rapid decline in strength by buckling. The purpose of this study is the development of FLD(Force Limiting Device) to prevent a elastic buckling for a slender member. Further, the behavior of steel structures with FLD would be stable by high energy absorption capacity. The proposed type of FLD is the type of out-of-plane resistance. In this study, member test and FEM analysis for proposed type were performed. The test parameters are thickness and gradient angle of out-of-plane plate. The proposed type may be effective method for FLD.

A Path-Volume Simulation Method to Select Arterial Section of Road Network (경로 교통량 시뮬레이션 기법을 이용한 간선구간 설정 방법론 연구)

  • 황준문;조중래;손영태
    • Journal of Korean Society of Transportation
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    • v.19 no.5
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    • pp.85-97
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    • 2001
  • In this study, the purpose behind this research is to propose index to be used for classification of functional the urban streets and to select the feasible length of special management link by the index. This special management link help decision makers found a transportation policy. In order to perform functional classification, index such as average traveled distance, link VKT and VKT per length-lane are use at the study. Average traveled distance index is average traveled distance divided by length of Path k and VKT per length-lane is trip volume characteristic considering lanes and length of Path k. Special management links on which major part of the vehicle are selected with using Path-VKT which represents how many long-distance touring vehicles are on the arterial road. The selection of special management links are performed with network composed of 14 paths (arterial roads) in seoul The total distance of special management links resulted from the above analysis is 141km(35.0% of the whole paths length) and total VKT of the special management links is 4,152,475 VKT(45.2% of the whole paths VKT)

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Target Localization for DIFAR Sonobuoy compensated Bearing Estimation and Sonobuoy Position Error (방위각 추정 및 소노부이 위치 오차를 보상한 DIFAR 소노부이의 표적 위치 추정 성능 향상 기법)

  • Gwak, Sang-Yell
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.221-228
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    • 2020
  • A sonobuoy is dropped onto the surface of water to estimate the bearing of an underwater target. A Directional Frequency Analysis and Recording (DIFAR) sonobuoy has an error in the specific angular section due to the method of estimating bearing and noise, which causes an error in target localization using multiple sonobuoys. In addition, the position of the sonobuoy continues to move, but since a sonobuoy with a GPS is intermittently arranged, it is difficult to estimate the exact position of the sonobuoy. This also causes target localization performance degradation. In this paper, we propose a technique to improve the target localization performance by compensating for bearing errors using characteristics of the DIFAR sonobuoy and multiple-sonobuoy position errors based on the intermittently arranged active sonobuoy with a GPS.

Physicochemical Properties and the Origin of Summer Bottom Cold Waters in the Korea Strait (하계 대한해협 저층냉수의 물리.화학적인 특성 및 기원)

  • Kim, Il-Nam;Lee, Tong-Sup
    • Ocean and Polar Research
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    • v.26 no.4
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    • pp.595-606
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    • 2004
  • Hydrographic survey in the Korea Strait has long history that has begun in August 1917 at the Busan - Tsushima cross section, still continues to date. However, chemical properties of bottom cold water found exclusively in the western channel of the Korea Strait during summer did not receive much scientific attention. The aim of the study is to decipher the enigmatic origin of the Korea Strait Bottom Cold Water (KSBCW) in terms of chemical properties. The physicochemical properties of the KSBCW are extracted from the CREAHS II hydrographic data. OMP method was applied to analyze origin of the KSBCW quantitatively. The KSBCW is well defined by low temperature below $10^{\circ}C$. The cold waters exhibited the local presence near the coast at about 120m depth with a thickness of 20m to 30m. The cold water was characterized by relatively cold, saline and higher chemical concentrations than adjacent waters. The KSBCW seems to have different origin kom that of the coastal upwelled waters at the Ulgi-Gampo because it is saline, denser and contains considerably less dissolved oxygen than upwelled waters. The physicochemical properties are reported to have noticeable annual variations which suggest the complex origin of the KSBCW. OMP analysis show that the KSBCW is a mixture of three water types; TMW (24%), ESIW (36%) and ESPW (40%). Relationship between the KSBCW and the east Sea circulation is traced by mapping the water masses that have similar T, S and DO of KSBCW. The result showed that the KSBCW is most possibly an extension of southward flowing coastal intermediate waters. Front these results, we expect that the monitoring KSBCW will provide us valuable information about the East Sea circulation.

Study of the correlation between postpartum joint symptoms and maternity season within 15 days after giving birth (출산 후 15일 이내에 나타난 관절증상과 출산계절의 상관성 연구)

  • Koo, Jin Suk;Kim, Yun Young;Seo, Bu Il
    • The Journal of Korean Medicine
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    • v.38 no.1
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    • pp.125-133
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    • 2017
  • Objectives: The purpose of this study is to investigate the correlation between postpartium joint diseases and maternal season. So it can prevent postpartum joint diseases and provide fundamental data about postpartum health care. Methods: The subject of the present study was 219 women (142 women who completed vaginal delivery and 77 women who delivered by cesarean section) who completed labor between November 1, 2013 and November 31, 2016, at the clinic of OB&GYN. They have been taking good care of their health at postpartum clinic in Andong Woori Women Hospital. We investigated the various symptoms and situation which occurred from the moment of hospital to postnatal admission health care period and oriental doctor examined the patients. We classified the symptoms by the age of patients, the method of delivery, the term of pregnancy, the body weight of infant, the weight change of mother and the way of feeding. Through data analysis, we investigated the correlation between maternal season and postpartum joint diseases. Results: Postpartum joint diseases were the most common among all symptoms after childbirth. Postpartum joint diseases were classified into shoulder area pain and low back pain. In low back pain, there was no significant difference between maternal season and postpartum joint diseases. In shoulder, wrist and finger pain, pain was the most severe at winter delivery. It was the most painful in winter, followed by autumn, spring and summer. Conclusion: There was a close correlation between postpartum joint disease manifestations and maternal season.

Effect on Supervisor's Leadership in the Hotel Organization on Employee's Cohesiveness and Trust (호텔기업에서의 상사의 리더십이 종사원의 신뢰 및 집단응집력에 미치는 영향)

  • Park, Jae-Youn;Kim, Jang-Eik
    • The Journal of the Korea Contents Association
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    • v.9 no.2
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    • pp.381-390
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    • 2009
  • The study is intended to investigates any effective hotel employee's leadership on cohesiveness and trust. The results were as follows; First, hotel employee's leadership has correlation in trust and cohesiveness according to statistics. It should be interested in the leadership to display their potential ability and an initiative spirit in the organization. Second, trust has positive influence on the cohesiveness. The cohesiveness will has positive influence every organization so hotel employees should be interested in the result. Therefore, hotel employee should grasps a training system and recognition to apply their organization. According to the effective analysis, this study provides basic data about human resource management of the hotel but there is the limit in the study and it needs to study later. Because the subject is the hotel, it couldn't compare with other company so there is the limit to make generalization. Methodology in hypothesis only relies on the survey, using of a overseas scale and cross-section data should be studied to make generalization by a vertical study. Hereafter hotel employee's leadership is effected what factor is and the study should be achieved about specifical process and method to get the reliability to employees.

Problem Analysis and Recommendations for Using Manual Wheelchair for One-hand Users

  • Park, Gemus;Hwang, Jung Bo;Jung, Hwa Shik
    • Journal of the Ergonomics Society of Korea
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    • v.33 no.2
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    • pp.109-124
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    • 2014
  • Objective: This study was conducted for one-hand users including hemiplegic clients currently using general folding manual wheelchairs, so as to analyze their specific problems and recommend solutions regarding usage. Background: Traditional manual wheelchairs require considerable use and control of both hands for operation, thus adaptations become necessary for individuals with asymmetrical use of hands. Method: Thirty hemiplegic clients who were admitted to rehabilitation and convalescent hospitals participated as subjects. The research tools were general folding manual wheelchairs commonly used by people with impaired gait, and the Wheelchair Skills Tests (WST) WST-M/WCU 4.1 version was adopted as the assessment tool. All participants were asked to fill out questionnaires on demographics and wheelchair usage characteristics. Assessment procedures were performed with currently used manual wheelchairs and with/without the use of foot to control the wheelchair. Results: When the participants drove folding manual wheelchairs without the use of foot, even the lowest failure rate among the WST items tested recorded 96.7%. On the contrary, with the use of foot in maneuvering the wheelchairs, failure rates dropped noticeably and success rate among the WST items tested was as high as 86.7%. Conclusion: These findings imply that the use of one-arm (hand) propellable (drivable) wheelchair can be an active and effective solution in resolving problems for hemiplegic clients using existing manual wheelchairs. As such, the government should provide institutional support to further develop and distribute this device or technology, and promote relative research in tandem. For now, the supply of commercially available device to hemiplegic clients is deemed urgent and also a mechanism to provide the devices and relevant services. Application: This study offers viable solutions for hemiplegic clients who rely on existing manual wheelchairs to increase their mobility and occupational performance.

Collision Analysis of Submerged Floating Tunnel by Underwater Navigating Vessel (수중운항체에 대한 해중터널의 충돌해석)

  • Hong, Kwan-Young;Lee, Gye-Hee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.5
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    • pp.369-377
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    • 2014
  • In this paper, to recognize the collision behavior between a submerged floating tunnel(SFT) and underwater navigation vessel(UNV), both structures are modeled and analyzed. The SFT of collision point is modeled tubular section using concrete with steel lining. The other part of SFT is modeled elastic beam elements. Mooring lines are modeled as cable elements with tension. The under water navigation vessel is assumed 1800DT submarine and its total mass at collision is obtained with hydrodynamic added mass. The buoyancy force on SFT is included in initial condition using dynamic relaxation method. The buoyancy ratio (B/W) and the collision speed are considered as the collision conditions. As results, energy dissipation is concentrated on the SFT and that of the UNV is minor. Additionally, the collision behaviors are greatly affected by B/W and the tension of mooring lines. Especially, the collision forces are shown different tendency compare to vessel collision force of current design code.

Case Study of Characteristic of Ground Deformation and Strut Axial Force Change in Long Span Deep Excavation(II) (장지간 깊은 굴착에서 지반변형 및 버팀보 축력변화 특성 사례연구(II))

  • Kim, Sung-Wook;Han, Byung-Won
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.248-259
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    • 2010
  • In the case of relatively good ground and construction condition in the deep excavation for the construction of subway, railway, building etc., flexible earth retaining systems are often used in an economical point of view. It is generally known that the mechanism of behavior in the flexible earth retaining system is relatively more complicated than the rigid earth retaining system. Moreover in the case of long span strut supporting system the analysis of strut axial force change becomes more difficult when the differences of ground condition and excavation work progress on both sides of excavation section are added. When deeper excavation than the specification or installation delay of supporting system is done or change of ground condition is faced due to the construction conditions during construction process, lots of axial force can be induced in some struts and that can threaten the safety of construction. This paper introduces one example of long span deep excavation where struts and rock bolts were used as a supporting system with flexible wall structure. The characteristics of ground deformation and strut axial force change, the measured data obtained during construction process, were analysed, the effects of relatively deeper excavation than the specification on one excavation side and rapid drawdown of ground water level on the other excavation side were deeply investigated from the viewpoint of mutual influences between ground deformations of both excavation sides and strut axial force changes. The effort of this article aims to improve and develop the technique of design and construction in the coming projects having similar ground condition and supporting method.

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