• 전산구조공학
• /
• 제35권1호
• /
• pp.25-34
• /
• 2022

• 설비공학논문집
• /
• 제29권6호
• /
• pp.306-315
• /
• 2017

This study introduces a software for real-time assessment of combustion stability for utility gas turbines. The software was written with LabView, and implemented the time-domain kurtosis as a parameter to proactively access the instantaneous combustion stability during operation of the industrial gas turbine. The simple time-domain assessment algorithm incorporated in the software is advantageous over conventional frequency-domain signal processing of dynamic pressure signal since it reduces the computational cost, thereby making the algorithm more appropriate for real-time monitoring of combustion stability. Benchmark data obtained from a model gas turbine combustor were used for the reproducibility test of the software. The assessment obtained from the software agreed well with previously published results, indicating that incorporation of the software could enhance the performance of systems monitoring the combustion stability for gas turbines during power generation.

• Journal of Electrical Engineering and Technology
• /
• 제8권2호
• /
• pp.197-205
• /
• 2013

Real time transient stability assessment mainly depends on real-time prediction. Unfortunately, conventional techniques based on offline analysis are too slow and unreliable in complex power systems. Hence, fast and reliable stability prediction methods and simple stability criterions must be developed for real time purposes. In this paper, two new methods for real time determining critical clearing time based on clustering identification are proposed. This article is covering three main sections: (i) clustering generators and recognizing critical group; (ii) replacing the multi-machine system by a two-machine dynamic equivalent and eventually, to a one-machine-infinite-bus system; (iii) presenting a new method to predict post-fault trajectory and two simple algorithms for calculating critical clearing time, respectively established upon two different transient stability criterions. The performance is expected to figure out critical clearing time within 100ms-150ms and with an acceptable accuracy.

• Structural Engineering and Mechanics
• /
• 제64권2호
• /
• pp.213-223
• /
• 2017

Bridges are lifeline and integral components of transportation system that are susceptible to seismic actions, their vulnerability assessment is essential for seismic risk assessment and mitigation. The vulnerability assessment of bridges common in Pakistan is very important as it is seismically very active region and the available code for the seismic design of bridges is obsolete. This research presents seismic vulnerability assessment of three real case simply supported multi-span reinforced concrete bridges commonly found in northern Pakistan, having one, two and three bents with circular piers. The vulnerability assessment is carried through the non-linear dynamic time history analyses for the derivation of fragility curves. Finite element based numerical models of the bridges were developed in MIDAS CIVIL (2015) and analyzed through with non-linear dynamic and incremental dynamic analyses, using a suite of bridge-specific natural spectrum compatible ground motion records. Seismic responses of shear key, bearing pad, expansion joint and pier components of each bridges were recorded during analysis and retrieved for performance based analysis. Fragility curves were developed for the bearing pads, shear key, expansion joint and pier of the bridges that first reach ultimate limit state. Dynamic analysis and the derived fragility curves show that ultimate limit state of bearing pads, shear keys and expansion joints of the bridges exceed first, followed by the piers ultimate limit state for all the three bridges. Mean collapse capacities computed for all the components indicated that bearing pads, expansion joints, and shear keys exceed the ultimate limit state at lowest seismic intensities.

• 전기학회논문지
• /
• 제59권3호
• /
• pp.485-491
• /
• 2010

Total Transfer Capability (TTC) should be pre-determined in order to estimate Available Transfer Capability (ATC). Typically, TTC is determined by considering three categories; voltage, stability and thermal limits. Among these, thermal limits are treated mainly in this paper on the evaluation of TTC due to the relatively short transmission line length of Korea Electric Power Corporation (KEPCO) system. This paper presents a new approach to evaluate the TTC using the Dynamic Line Rating (DLR) for the thermal limit. Since the approach includes not only traditional electrical constraints but also real-time environmental constraints, this paper obtains more cost-effective and exact results. A case study using KEPCO system confirms that the proposed method is useful for real-time operation and the planning of the electricity market.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.531-532
• /
• 2006

This paper presents the implementation of Real-time data acquisition system for dynamic characteristics of overhead contact wire in electric railway. The reconfigurable field-programmable gate array (FPGA) and LabVIEW graphical development tools have been used to Real-time monitoring system. The results from a field test show that the proposed technique and developed system can be practically applied to measure the assessment quantity or quantities on overhead contact lines for the online real-time process monitoring.

• International Journal of Advanced Culture Technology
• /
• 제12권2호
• /
• pp.72-89
• /
• 2024

Depression is a common disorder among the elderly, significantly affecting their quality of life. Traditional dance interventions, although beneficial, have limitations in convenience, personalization, and retention. With the advent of digital technology, digital dance interventions have emerged as a potential solution to these limitations. This paper involves an extensive review of literature on digital dance interventions. Research databases were searched for studies that focus on the use of digital dance in treating depression among older adults. The review also includes analyses of the advancements in digital dance technology, its application in therapeutic settings, and the evaluation of its efficacy. The paper identifies three main challenges in the current digital dance intervention research: real-time dynamic assessment, multimodal dance generation, and improving compliance. Despite these challenges, digital dance interventions show promise in addressing the limitations of traditional dance therapy. The research suggests that the integration of human-computer interaction and personalized approaches in digital dance interventions could significantly improve outcomes in elderly patients with depression. Digital dance interventions represent a novel and promising approach to treating depression in older adults. Future research should focus on overcoming the identified challenges and enhancing the effectiveness of these interventions.

• Steel and Composite Structures
• /
• 제35권2호
• /
• pp.199-213
• /
• 2020

This paper proposes a Global-Local Analysis Method (GLAM) to assess the progressive collapse of steel framed structures under fire-induced column failure. GLAM obtains the overall structural response by combining dynamic analysis of the heated column (local) with static analysis of the overall structure (global). Test results of two steel frames which explicitly consider the dynamic effect during fire-induced column failure were employed to validate the proposed GLAM. Results show that GLAM gives reasonable predictions to the test frames in terms of both whether to collapse and the displacement verse temperature curves. Besides, several case studies of a two-dimensional (2D) steel frame and a three-dimensional (3D) steel frame with concrete slabs were conducted by using GLAM. Results show that GLAM gives the same collapse predictions to the studied cases with nonlinear dynamic analysis of the whole structure model. Compared with nonlinear dynamic analysis of the whole structure model, GLAM saves approximately 70% and 99% CPU time for the cases of 2D and 3D steel frame, respectively. Results also show that the load level of a structure has notable effects on the restraint condition of a heated column in the structure.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2006년도 학술발표회 논문집
• /
• pp.261-268
• /
• 2006

This study represents results of fragility curve development for 3-span continuous bridge. To research the response of bridge under earthquake excitation, Monte Carlo simulation is performed to study nonlinear dynamic analysis. Because of limited number of real time histories from the Korean peninsula, a set of 150 synthetic time histories were generated. Fragility corves in this study are represented by lognormal distribution functions with two parameters and developed as a function of PGA. Five damage states were defined to express the condition of damage based on the actual experimental damage data of bridge column. As a result of this research, the value of damage probability corresponding to each damage state were determined. This approach may be used in constructing the fragility curves for all of bridge structure and, by extension, in constructing the seismic hazard map.

• 대한조선학회논문집
• /
• 제48권5호
• /
• pp.451-456
• /
• 2011

To ensure structural integrity of membrane type LNG tank, the rational assessment of the sloshing impact responses of tank structures should be preceded. The sloshing impact pressures acting on the insulation system of LNG tank are typical irregular loads and the resulting structural responses show very complex behaviors accompanied with fluid structure interaction. So it is not easy to estimate them accurately and immense time consuming calculation process would be necessary. In this research, a simplified method to analyse the dynamic structural responses of LNG tank insulation system under pressure time histories obtained by sloshing model test or numerical analysis was studied. The proposed technique based on the concept of linear combination of the triangular response functions which are the transient responses of structures under the unit triangular impact pressure acting on structures. The validity of suggested method was verified through the example calculations and applied to the dynamic structural response analysis of a real Mark III membrane type insulation system using the sloshing impact pressure time histories obtained by model test.