As the interest in leisure sports is recently increasing domestically and internationally, the number of descending experience in the air facilities is increasing. Study on the cable and wire installed on a bridge has been actively preceded from the past to the present, but for descending experience in the air facilities for leisure sports, an accident occurs frequently and examination the structural safety of these facilities is still insufficient. Therefore, structural safety by dynamic impact is evaluated through 3-dimensional infinite element modeling and analysis of the steel cable for leisure sports previously installed. It is judged that more systematical safety than before could be secured based on this.

The purpose of this study is to provide the damage detection method on shear building structures by the damage index directly induced from dynamic equation. The provided damage index could be estimated from measured mode shape of undamaged structure and frequency difference between undamaged and damaged structure. The damage detection method is applied to numerical analysis model such as MATLAB and MIDAS GENw for the verification. The damage index at damaged story represents (-) sign and 15 times than other undamaged stories.

Constitutive modeling of constituent materials is very important for reinforced concrete (RC) frames. Cyclic constitutive behavior of unconfined concrete, confined concrete and reinforcing steel should be well defined in fiber-based discretization of RC sections. This study performs nonlinear dynamic analyses of RC frame structures to investigate the sensitivity of seismic behavior of such frames to different constitutive models of constituent materials. The study specifically attempts to examine confinement effects in concrete modeling and degrading effects in steel modeling, which substantially affects the monotonic, cyclic and seismic responses of RC members and frames. Based on the system level analysis, it is shown that the response of non-ductile frames is less sensitive to confined concrete models while the modeling of reinforcing steel is quite influential to the inelastic response of both non-ductile and ductile frames.

비보강 조적벽체를 이용한 저층 건축물은 국내에 가장 흔히 볼 수 있는 주거형태이지만, 비보강 조적벽체는 높은 횡강성에 비하여 연성능력 부족 등의 이유로 지진으로부터 구조적 피해를 피하기 힘든 횡력저항시스템으로 알려져 있다. 하지만, 국내 비보강 조적벽체 전단강도와 전단강성에 대한 실험적 연구는 부족한 편이며, 실제 지진이 발생했을 비보강 조적벽체를 횡력저항요소로 사용하는 건축물의 내진성능에 대한 연구는 상대적으로 부족한 실정이다. 이로 인하여 국내 비보강 조적벽체의 특성을 반영하고 있다고 볼 수 없는 FEMA 356에서 제시하고 있는 비보강 조적벽체의 전단강도와 강성을 준용하여 사용하고 있다. 본 연구에서는 우선 FEMA 356에서 제시하고 비보강 조적벽체의 전단강도와 강성을 실험결과와의 차이에 대해 기술하고, 이 차이가 현황조사와 실험데이터를 바탕으로 결정한 표본 비보강 조적조 건축물의 내진성능에 미치는 영향과 경과년수에 따른 영향을 증분동적해석을 이용하여 계산된 붕괴여유비와 구조성능의 불확실성을 표현하는 베타값을 이용하여 분석하였다. 해석결과를 통하여 FEMA 356에 의한 전단강도와 강성을 사용할 경우 조적조 건축물의 붕괴여유비와 베타값을 과소평가하는 것으로 나타났다. 하지만, 두 경우 모두 국내 내진설계기준에서 제시하는 성능기준을 만족하지 않는 것으로 나타났으며, 경과연수가 클수록 이런 현상은 뚜렷해지며, 30년 이상 경과된 조적조 건축물은 2400년 재현주기의 지진에 붕괴확률이 약 90%에 도달하는 것으로 나타났다.

The displacement Deep-V catamaran concept was developed in Newcastle University(UNEW) through development of the systematic Deep-V catamaran series. One of the most important Deep-V catamaran launched to date is Newcastle University's own multi-purpose research vessel, The Princess Royal. The vessel was launched in 2011 and enhanced the Deep-V catamaran concept further with the successful adoption of a novel anti-slamming bulbous bow and tunnel stern for improved efficiency. It was however identified that the vessel has substantial amount of dynamic trim that limited the visibility of the captain. The dynamic trim also increased the wave-making resistance thereby preventing the vessel from attaining its maximum speed in certain sea states. This paper therefore presents the application of devices such as Trim Tabs, Interceptors, Transom Wedges and Integrated Transom Wedges-Tabs to control the dynamic trim and improvement of fuel efficiency of the vessel. All of these energy saving devices were fitted into a model for tests in Newcastle University's Towing Tank. Model test verification confirmed that the optimum appendage was the interceptors, they produced a 5% power saving and 1.2 degree trim reduction at 15 knots, and investigations of full scale trials will be scheduled with and without application of device to compare the improvement of performance.

For the reliable design of an offshore platform, it is very important to reduce the effects of wave forces as well as to increase the safety of structure. In order to reduce the wave forces on structures, the partial porous cylinder, which is composed of a porous part located near free surface and a rigid part bounded top and bottom by impermeable end caps, is newly suggested. Using the Eigen-function expansion method the wave force on partial porous cylinders are calculated. Applying the wave forces and seismic forces, the dynamic response evaluations of the platform are carried out through the modal analysis and the substructure method based on the effect of soil-structure interaction. The displacement and bending stress are computed using the various input parameters, such as the shear-wave velocity of soil and the porosity rate.

Vibration measurements were conducted before and after the experiment of static loading test for soil-wall in wooden structures. As a result, natural period was changed depending on the damage of soil-wall. Accordingly, the damage assessment was carried out using each specimen strength degradation and the dynamic characteristics.

This study focuses on dynamic behaviors of simply supported beams, especially, vertical displacements. Based on moving load model, the displacement is estimated by response superposition. The displacements tend to increase as load velocity increases except under resonance velocity and show very large values under resonance velocity. Therefore, we should investigate the resonance between train and structure.

In this study, experiments to evaluate concrete breakout capacity of anchor under dynamic shear loading were performed. The cast-in-place anchors without reinforcement were prepared for dynamic and static loading tests. Three specimens were tested for dynamic tests and one specimen for static test. It was found from the tests that the concrete breakout capacity of anchors without reinforcement under dynamic loading was about 6% higher than static loading.

To evaluate the traffic safety of PSC box bridge for high running speed up to 450km/h of KTX, a dynamic analysis of rotation spectrum on the centre of vehicle is needed concurrently with existing design specifications. All directions of rotation spectrum are considered to analyze the dynamic structural behaviors of PSC bridges as well as harmonic running movements of KTX due to three mass; a cargo body, front/rear bogies and four wheel axises connected with two suspensions. KTX power train is modeled by 38 degree-of -freedom ; 6 degree-of-freedom for body and bogies, and 5 degree-of-freedom for wheel axises. The rotation spectrum of KTX resulted in the analysis will be focused on the design specification of KTX running on the bridge, for increasing its speed as a new evaluation standards of traffic safety

This study analyzes descriptive statistics and tests homogeneity hypothesis, and applies a posteriori comparison procedures among treatment levels for the response characteristics such as static response ratios, impact factors, natural frequencies of bridges according to structural types and service periods. This study is expected to help understand the difference among response characteristics of groups and provides the practical information for safety assessment and structural design.

건설환경의 지속적인 변화로 인하여 교량 건설비용의 최소화뿐만 아니라 공용기간중의 유지관리를 포함한 전체 비용의 최소화 및 최적화의 요구가 증가하고 있다. 이러한 이유로 교량의 상부구조에서 하부구조로 힘을 전달하기 위해 사용되는 교량받침 대신에 스터드나 연결철근 등과 같은 연결재를 사용하여 교량의 상부구조와 하부구조를 라멘식으로 일체화 시킨 교량형식이 제시되고 있다. 이 논문은 교량의 상부구조 형식을 연속 UD PSC 거더로 하여 철근콘크리트 교각과 일체화 시킨 교각일체형 연속 UD PSC 거더교를 대상으로 한다. 교각일체형 연속 UD PSC 거더교는 라멘교 형식과 거더교 형식을 결합한 교량으로 일반 받침형식의 교량과 상이한 거동특성을 나타낸다. 하지만 거동 특성에 대해 명확히 규명되어 있지 않다. 따라서 본 논문에서는 해석적 방법을 이용하여 교각일체형 연속 UD PSC 거더교의 동적거동 특성을 분석하고 2, 3경간 교각일체형 연속 UD PSC 거더교에 적용할 수 있는 충격계수 산정식을 제시하였다.

본 연구에서는 복렬사주의 모드를 객관적으로 판단할 수 있는 2중 퓨리에 해석을 수행하여 하폭의 변화에 따른 복렬사주의 발달 과정을 정량적으로 분석하였다. 초기에 직선하도에서 하안침식이 발생하고, 하폭 대 수심의 비가 증가하면서 복렬사주가 발달하였다. 사주가 하류로 이동하면서 성장하고, 사주의 주변에서 흐름이 분리되어 하안 침식을 가속시키면서, 지형이 지속적으로 변하여 유사의 유출특성에 영향을 주었다. 2중 Fourier 해석에 의한 하상파(wave)의 분포와 지배적인 성분의 변화를 분석한 결과, 초기에 1-1 모드(mode)인 교호사주가 지배적이지만, 시간이 지나면서 하폭이 증가하여 상대적으로 수심이 감소하면서 2-3 모드가 지배적인 것으로 나타났으며, 교호사주의 강한 비선형 특성이 상호작용하기 때문이다. 하안침식이 진행되면서 하폭 대 수심의 비가 증가하고, 무차원 소류력이 감소하였다. 하폭 대 수심의 비가 증가할수록 사주의 이동속도가 감소하고, 사주의 파장은 증가하였다. 무차원 소류력이 증가하면서, 사주의 이동속도는 증가하였다.

This article analyzes the interdependency between nonrenewable marine sand resources and renewable fishery resources by the developed dynamic bioeconomic model. The developed bioeconomic model is applied to a case study of efficient sustainable management for marine sand mining, which adversely affects a valuable blue crab fishery and its habitat in Korea. The socially-efficient extraction plan for marine sand and the time-variant environmental external costs to society in terms of diminished harvest rate of blue crab are determined. To take into account long-term effects from destroyed fishery habitat, a Beverton-Holt age structure model is integrated into the bioeconomic model. The illustrative results reveal that the efficient sand extraction plan is dynamically constrained by the stock size of the blue crab fishery over time. Thus, the dynamic environmental external cost is more realistic resource policy option than the classical fixed external cost for determining socially optimal extraction plans. Additionally, the economic value of bottom habitat, which supports the on- and off-site commercial blue crab fishery is estimated. The empirical results are interpreted with emphasis on guidelines for management policy for marine sand mining.

Recently, tug boats are widely used for towing a barge which transports building materials, a large block of a ship, offshore crane, and so on. In order to simulate the dynamics of the coupled towing system correctly, the dynamics of the towline should be well modeled. In this paper, the towline was modeled as the multiple finite elements, and each element was assumed as a rigid cylinder which moves in five degrees of freedom except roll. The external tension and its moment acting on each element of the towline were modeled depending on the position vector's direction. Tugboat's motion was simulated in six degrees of freedom where wave and current effects were included, and towed barge was assumed to move in the horizontal plane only. In order to confirm the mathematical models of the coupled towing systems, standard maneuvering trials such as course changing maneuver, turning circle test and zig-zag test were simulated. In addition, the same trials were simulated when the external disturbances like wave and current exist. As the result, it is supposed that the results might be qualitatively reasonable.

In this study, anaerobic co-digestion experiments for mixtures consisting of sewage sludge with food wastewater and livestock wastewater were conducted to assess the methane yields, the volatile solids (VS) removal rates and the dynamic kinetics. An augmented simplex centroid design (ASCD) was employed to design the mixing rate of organic wastes for the anaerobic co-digestion. Also, synergistic effects on the anaerobic co-digestion were studied using models obtained by the ASCD. As a result, synergistic effects were not observed in terms of methane yield and VS removal rate. It was just showed that there was a linear relationship between the cumulative methane yield and the mixing rate of food wastewater. The results might be attributable that the sewage sludge and the livestock wastewater had very lower C/N ratio compared with food wastewater that had a C/N ratio within a range required for a correctly operating anaerobic co-digestion. Therefore, increasing mixing rates of food wastewater increased the methane yield and VS removal rate, but there was not a synergistic effect by the anaerobic co-digestion.

In this study, it was investigated dynamic behaviors of track roadbed with various loading frequency with real train loading using a full scale testing as MTS system. The dynamic behaviors of track roadbed system was increased linear regression with increased loading frequency at less than 35Hz, but was decreased at wheel load, displacement, and acceleration over 35Hz. It was found that critical loading frequency was about 35Hz, and that velocity level of train speed was evaluated about 320km/h～340km/h.

The key findings of the paper are as follows: Numerical parameters study of the interface-element was carried out, the friction angle depends on rockfill zone material and normal and shear stiffness coefficient of the two materials (concrete and rockfill), the average values were found to be the most appropriate.

세기조절방사선치료(intensity modulated radiation therapy ; IMRT)는 주변 정상장기 선량을 최소화하면서 종양에 집중적으로 고선량을 조사할 수 있는 장점으로 인하여 최근 그 사용이 급격히 증가하고 있다. 기능강화 동적쐐기 (enhanced dynamic wedge; EDW) 사용 시 기하학적 변화에 따른 Mapcheck에서의 선량분포를 측정 평가하고자 한다. Clinac ix에서 IMRT를 이용하여 EDW angle(10˚, 15˚, 20˚, 25˚,30˚, 45˚, 60˚), field size(asymmetric field),depth 변화(1,5 cm, 5 cm)에 따른 선량분포를 검증하기 위해 Mapcheck위에 고체팬텀을 올려놓고 6 MV, 10MVX-ray로 100MU를 조사하였다. 6MV, 10MV의 에너지를 사용하여 기하학적변화에 따라 최대선량깊이(1.5 cm)와 5cm 깊이에서 심부 선량백분율(percentage depth dose; PDD)은 치료계획장치에서 계산한 값의 차이가 최대 0.6%로 1%미만의 값으로 나타났다. 심부선량백분율은 조사야 중앙에서 최대선량깊이의 선량을 100%로 보았을 경우, 2.4%에서 7.2%의 범위에 있다. 또한 심부선량백분율 차이의 최대값은 Y2-OUT 방향에서 4.1%로 나타났고 Y1-IN 방향으로 1.7%로 나타났다. 동적쐐기를 사용하여 환자를 치료할 경우, 조사야 주변부의 불필요한 피폭을 유발하여 산란되는선량을 줄이기 위하여 기능 강화 동적쐐기를 사용하는 것이 바람직할 것으로 사료된다. 특히 임상에서 환자를 치료할경우, 쐐기의 toe방향 선량이 heel방향 선량보다 높다는 것을 염두에 두고 치료를 수행해야 할 것으로 사료된다.