Measurement of dynamic displacement of large structure is one of the most challenging issues in structural health monitoring. With a Kalman filter based technique, the proposed displacement measurement system which consists of GPS-RTK, accelerometer, DAQ, and computer shows the huge potential for precise measurement of dynamic displacement of large structure. The performance of the system has been verified by modal shaker test. This paper presents a new system for dynamic and pseudostatic displacement measurement for a large-scale civil infrastructure. Even though dynamic displacement measurement on a large-scale structure is one of the most challenging issues in structural health monitoring, traditional displacement sensors as well as cutting edge noncontact sensors suffers from the lack of accuracy and precision due to field conditions such as measurement distance and requirement for a fixed support. With a Kalman filter based technique, the proposed displacement measurement system, which consists of a GPS-RTK, accelerometer, DAQ and computer, efficiently estimates bias contained in the acceleration record by fusing the acceleration with intermittently recorded GPS-RTK data, and estimate high precision and high accuracy displacement by removing the bias from the acceleration record and conducting double integration. Through a series of lab-scale tests using a vibration exiciter, the performance of the system has been verified and shows the potential for accurate and precise measurement of dynamic displacement of a large-scale structure.

In the case of railway bridges through the downtown section is required for noise reduction performance is excellent bridge type. According to this request, the bridge of the noise barrier installation is not required and low vibration is under development. This railway bridge is corrugated steel plates composite lower route bridge. Because the bridge cross-section wraps a train, noise is reduced. In this study, Using a commercial finite element analysis program, the dynamic stability evaluation is performed.

In this paper, we fabricate arrayed-type flexible capacitive touch sensor using liquid metal (LM) droplets (4 mm spatial resolution). Poly-4-vinylphenol (PVP) layer is used as a dielectric layer on the electrode patterned Polyethylene naphthalate (PEN) film. Bonding tests between hydroxyl group (-OH) on the PVP film and polydimethylsiloxane (PDMS) are conducted in a various O2 plasma treatment conditions. Through the tests, we can confirm that non-O2 plasma treated PVP layer and O2 plasma treated PDMS can make a chemical bond. To measure dynamic range of the device, one-cell experiments are conducted and we confirmed that the fabricated device has a large dynamic range (~60 pF).

본 연구의 목적은 비선형 동적해석을 통한 국내 비보강 조적조의 내진성능을 평가하는데 있다. 보다 정밀한 내진성능 평가를 위해 조적벽체의 파괴모드를 고려한 비선형 이력모델을 이용하고자 하나, 선행연구의 비선형 이력모델은 정적반복가력해석에 대한 검증만이 수행 되었다. 이에 본 연구에서는 진동대실험과 동적해석 결과를 비교하여 제안한 비보강 조적조 비선형 해석모델의 신뢰성을 검증한 다음, 국내 비 보강 조적조 건축물의 비선형 동적해석을 수행하고 결과를 분석하여 내진성능을 평가하였다. 그 결과, 1층의 조적조 건축물의 경우 개구부율 에 관계없이 비교적 지진피해가 작은 반면, 2층 이상의 국내 비보강 조적조 건축물의 대부분이 국내에 발생가능한 지진에 취약하였다.

The maritime industry is expanding at an alarming rate hence there is a perpetual need to improve situation awareness in the maritime environment using new and emerging technology. Tracking is one of the numerous ways of enhancing situation awareness by providing information that may be useful to the operator. The tracking module designed herein comprises determining existing states of high dynamic target warship, state prediction and state compensation due to random noise. This is achieved by first analyzing the process of tracking followed by design of a tracking algorithm that uses α-β-γ tracking filter under a random noise. The algorithm involves initializing the state parameters which include position, velocity, acceleration and the course. This is then followed by state prediction at each time interval. A weighted difference of the observed and predicted state values at the nth observation is added to the predicted state to obtain the smoothed (filtered) state. This estimation is subsequently employed to determine the predicted state in the next radar scan. The filtering coefficients ,  and  are determined from a pre- determined value of the damping parameter, . The smoothed, predicted and the observed positions are used to compute the twice distance root mean square (2drms) error as a measure of the ability of the tracking module to manage the noise to acceptable levels.

The biological wastewater treatment plant, which uses microbial community to remove organic matter and nutrients in wastewater, is known as its nonlinear behavior and uncertainty to operate. Therefore, operation of the biological wastewater treatment process much depends on observation and knowledge of operators. The manual inspection of human operators is essential to manage the process properly, however, it is impossible to detect a fault promptly so that the process can be exposed to improper condition not securing safe effluent quality. Among various process faults, equipment malfunction is critical to maintain normal operational state. To detect equipment faults automatically, the dynamic time warping was tested using on-line oxidation-reduction potential (ORP) and dissolved oxygen (DO) profiles in a sequencing batch reactor (SBR), which is a type of wastewater treatment process. After one cycle profiles of ORP and DO were measured and stored, they were warped to the template profiles which were prepared already and the distance result, accumulated distance (D) values were calculated. If the D values were increased significantly, some kinds of faults could be detected and an alarm could be sent to the operator. By this way, it seems to be possible to make an early detecting of process faults.

Frequency-adaptive Lumped Mass Stick (LMS) method has been proposed recently to present the dynamic responses of a structure by a stick model which has identical frequencies to the original structure. The masses of the LMS model are obtained by an iterative method following a sequence of equations, where the masses always converge to certain values. Those values are solutions of a nonlinear equations system as will be shown in this study. This paper also investigates the significance of masses locations on the dynamic responses of the LMS models.

This study is a result of the dynamic characteristics of the tall building using real time structural health monitoring system. The monitoring system consist of an anemometer, accelerometers, GPS and internet-based data logging system. Through this realtime ambient measurement data, evaluate the serviceability of the building.

This study proposes a measurement method using angular sensors to measure deformation and displacement of bridges. The proposed measurement method consists of gyroscope sensors and data processor to transform angular to vertical displacement. This study contains experimental evaluation to verify the applicability of the proposed method. 3-points bending tests were conducted on a small-sized girder specimen. The displacements were measured with both conventional LVDT and gyroscope sensor to compare the accuracy of the proposed method. It is estimated that the method using gyroscope shows some noise in data, but the method using gyroscope has advantages to measure the vertical displacement. Therefore if the sampling rate and synchronizing problems can be approved, it can be a good alternative measuring method for the deformation of the bridges.

The purpose of this study is to evaluate propriety of impact factor in railway design code about truss bridge with dynamic loading test. This study also analyzes and compares impact factor and railway design code. A impact factor of all members of the truss is lowered by revising railway design code in 2013. The result of this study indicates that a reasonable standard for impact factor is required, because current impact factor which is specified in railway design code could not properly reflect dynamic response of specific type and member.

In this present study to investigate the seismic response of an offshore wind turbine, incorporating with bottom fixed Jacket support structure using semi-coupled analysis method. Fully coupled, aero-servo-hydro-elastic simulations and uncoupled seismic simulation have been done to carry out this investigation. The fully coupled simulation is accomplished and executed by FAST 8 (NREL, USA) to determine the global loads, which consists of six components of forces and moments at x-y-z directions of the tower base. In the uncoupled case, transient analysis has been done using the tower base loads as well as seismic loads by ANSYS. This paper presents a precise dynamic analysis, which can evaluate the dynamic response of three crucial points (tower top, tower base and mud line of substructure) under seismic load to make better decision in the case of structural design of wind turbine.

Purpose This study first explores – the possible dynamic relationship between ownership structure and firm performance using a panel of 4,900 Chinese-listed small- and medium-sized enterprises (SMEs) from 1999 to 2012. Research design, data, and methodology – We address this issue through a dynamic panel model using a method of moments (GMM) technique and dynamic simultaneous equations to alleviate the potential endogenous problem: unobserved heterogeneity, simultaneity, and dynamic endogeneity. Results – Under the framework of dynamic endogeneity, firm performance has a significantly positive influence on ownership, but not vice versa. Ownership and performance can be explained by their owned lagged values, respectively. Moreover, intertemporal endogeneity exists among ownership, investment, and performance through the application of system dynamic equations, which implies that the relationship among ownership structure, investment, and firm performance is dynamic by nature. Conclusions – This study also significantly contributes to a better understanding of dynamic corporate governance by providing further empirical evidence from the largest capital market in the Asian region.

In classical dynamics, the coefficient of restitution is one of variables to estimate the amount of impulse. In general, we have considered the coefficient of restitution as a constant value. However, coefficient of restitution (COR) is the function of contact material and colliding velocity. Furthermore, COR is also a function of contact area. Thus, without considering the variable characteristic of COR, the actual motion of an object just after impact is not the same as we expect. A general COR model is proposed in this work and its effectiveness is verified through a cart impact experiment and its result is applied to simulation of a ball impact problem. A three-degree-of-freedom manipulator is employed as a test-bed.

3D 게임에서 오브젝트의 위치를 파악하거나 사실감을 높이기 위하여 광원의 시점에서 정점 의 깊이 값을 계산하는 그림자 매핑 기법이 많이 사용된다. 그림자 맵의 깊이 값은 월드 좌표 를 통해 계산되기 때문에 월드 좌표가 변하지 않는 정적 오브젝트는 깊이 값을 갱신할 필요가 없다. 본 논문에서는, (1) 렌더링 속도를 향상시키기 위하여 한번만 저장하는 정적 오브젝트 깊 이 값과 매번 갱신하는 동적 오브젝트의 깊이 값을 다중 렌더 타겟을 이용하여 따로 관리한다. 또한 (2) 쿼터 뷰 기반 3D 게임에서 동적 오브젝트 그림자 품질을 높이기 위하여 광원의 위치 가 카메라를 따라다니며 동적 오브젝트에 가깝게 변동한다. 제안하는 방법의 효율성을 3D 게임 의 다양한 정적 및 동적 오브젝트 구성에 따른 실험을 통하여 검증하였다.

As the results of study, the difference of marshall stability is insignificant according to steel mesh reinforcement. But property of dynamic stability of steel mesh reinforced asphalt concrete is improved 2.6 times compared to the Plain.

Fracture behavior of concrete subjected to dynamic loading is affected by loading rate and strain rate. In this study, compressive strength properties according to strain rate of fiber reinforced concrete by rapid loading with 500ton rapid loading test machine was analyzed.

In this paper, we propose an image-based measurement method of structure dynamic characteristics to assess the damage of structure in a more cost-effective way than traditional structure health monitoring system.

In this paper, four damage detection techniques based on dynamic characteristics were utilized and compared to identify damage in a Steel Catenary Riser(SCR). Twelve damage scenarios were simulated by using a numerical model of SCR. The performance on damage detection for each technique was showed and the applicability was discussed.

철도교량의 경제성 확보를 전제로 PSC I형 거더의 장경간화 추세는 근간에 가장 활발히 진행되고 있는 연구이며, 이에 따른 교량의 강성확보를 위한 거더의 효율적인 기하형상 선정은 우선시 되어야할 과제이다. 본 연구에서는 회전반경과 휨효율을 기반으로 확장된 상부플랜지의 거더 단면을 선정하였으며, 본 거더가 적용된 경간장 25m, 30m, 35m, 40m PSC I형 거더교를 대상으로 수치해석을 수행하여 국내 및 국외의 동적성능 기준과의 부합여부를 검증하였다. 또한 경간장 40m PSC I형 거더의 동적성능을 상대적으로 비교하기 위해서 현재 호남고속철도에서 적용된 40m PSC Box 거더교를 대상으로 동적 해석을 수행하였고 KTX열차와 화물열차 주행 시의 동적안정성을 수치해석적으로 검토하여 국내 및 국외의 동적 안정성 기준과 부합여부를 검토하였다. 추가로 표준열차하중과 충격계수를 고려하여 정적해석을 수행하고 한계치와의 부합여부를 분석하였다. 그 결과, 검토대상 PSC I형 거더 철도교는 모든 항목에서 국내 철도교량 관련 정적, 동적안정성 기준치를 만족하는 것으로 분석되었다.

본 연구에서는 지진계 센서의 동적범위를 향상시키는 새로운 방법을 제안하였다. 먼저, 센서에 포함된 저주파수 대역 잡음을 ARMA(Auto Regresive Moving Average) 모델로 모델링하고 시스템 식별 방법으로 그 모델을 식별한다. 다음으로, 모델링된 잡음과 지진파 입력을 칼만필터 식에 포함하여 칼만필터에 의한 지진파입력을 추정한다. 제안한 방법을 새로이 개발된 MEMS 기반 3축 가속도 형태의 지진계에 적용하여 성능을 검증하였다. 시험 결과는 제안한 방법이 단순한 LPF(Low Pass Filter)를 사용한 경우에 비해 동적범위를 개선시킴을 보여준다.