• Structural Engineering and Mechanics
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• 제90권4호
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• pp.417-428
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• 2024

Nanocomposite-reinforced concrete systems have gained increasing attention in bridge construction due to their enhanced mechanical properties and durability. Understanding the transient dynamics of these advanced materials is crucial for ensuring the structural integrity and performance of bridge infrastructure under dynamic loading conditions. This paper presents a comprehensive study of the measurement techniques employed for assessing the transient dynamics of nanocompositereinforced concrete systems in bridge construction applications. A numerical method, including modal analysis are discussed in detail, highlighting their advantages, limitations, and applications. Additionally, recent advancements in sensor technologies, data acquisition systems, and signal processing techniques for capturing and analyzing transient responses are explored. The paper also addresses challenges and opportunities in the measurement of transient dynamics, such as the characterization of nanocomposite-reinforced concrete materials, the development of accurate numerical models, and the integration of advanced sensing technologies into bridge monitoring systems. Through a critical review of existing literature and case studies, this paper aims to provide insights into best practices and future directions for the measurement of transient dynamics in nanocompositereinforced concrete systems, ultimately contributing to the design, construction, and maintenance of resilient and sustainable bridge infrastructure.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1509-1514
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• 2009

CII BM&M(Benchmarking & Metrics) in USA and DTI(Department of Trade and Industry) in UK have built up systems that enable performance measuring and made the results of performance measurement comparable between projects to utilize them as benchmarking tools. By comparing the results of performance measurement, it is possible to grasp the success level of project management and to establish the direction of management. However, construction projects are much diversified and even those projects with the same work type have different attributes. Therefore, simply comparing the results of project performance measurement without considering the characteristics of projects is not justifiable and affects the reliability of the benchmarking results. Therefore, to solve this problem, this study presents a methodology that makes it possible to compare the individual construction projects considering various characteristics. The benefits and importance of project characteristics to overall project performance will be quantitatively expressed and they will be reflected on the results of performance management. By maximally converting multiple projects with different characteristics into the same projects through a new methodology to convert different projects into the same level utilizing such utility-bases and comparing the performances of those projects, project performance results can be utilized in project management as a tool for more accurate decision making and as a robust benchmarking tool.

• 제어로봇시스템학회논문지
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• 제18권3호
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• pp.285-294
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• 2012

Using bearing measurement only, target motion state is not directly obtained so that TMA (Target Motion Analysis) is needed for this situation. TMA is a nonlinear estimation technique used in passive SONAR systems. Also it is the one of important techniques for underwater combat management systems. TMA can be divided to two parts: batch estimation and sequential estimation. It is preferable to use sequential estimation for reducing computational load as well as adaptively to target maneuvers, batch estimation is still required to attain target initial state vector for convergence of sequential estimation. Selection of batch time interval which depends on observability is critical in TMA performance. Batch estimation in general utilizes predetermined batch time interval. In this paper, we propose a new method called the BTIS (Batch Time Interval and Initial State Estimation). The proposed BTIS estimates target initial status and determines the batch time interval sequentially by using a bank of GMM-TS (Gaussian Mixture Measurement-Track Splitting) filters. The performance of the proposal method is verified by a Monte Carlo simulation study.

• 센서학회지
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• 제28권1호
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• pp.30-35
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• 2019

Inertial measurement units (IMUs) are widely used for wearable motion-capturing systems in the fields of biomechanics and robotics. When the IMUs are combined with optical motion sensors (hereafter, OPTs) for their complementary capabilities, it is necessary to align the coordinate system orientations between the IMU and OPT. In this study, we compare the application of two coordinate transformation-based orientation alignment methods between two coordinate systems. The first method (M1) applies angular velocity coordinate transformation, while the other method (M2) applies gyroscopic angle coordinate transformation. In M1 and M2, the angular velocities and angles, respectively, are acquired during random movement for a least-square algorithm to determine the alignment matrix between the two coordinate systems. The performance of each method is evaluated under various conditions according to the type of motion during measurement, number of data points, amount of noise, and the alignment matrix. The results show that M1 is free from drift errors, while drift errors are present in most cases where M2 is applied. Thus, this study indicates that M1 has a far superior performance than M2 for the alignment of IMU and OPT coordinate systems for motion analysis.

• 한국산학기술학회논문지
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• 제14권9호
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• pp.4163-4170
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• 2013

최근의 무기체계 연구개발에서 실패의 주요인은 요구되는 핵심성능의 미충족과 기술성숙도 부족이다. 이러한 실패의 가능성에 대한 위험관리를 위해서 기술성능측정 관리와 기술성숙도 평가의 수행이 필요하다. 하지만 일반적인 기술성능측정 관리 기법의 적용은 컴포넌트 수준 이하에 대한 측정으로 시스템 통합의 효과를 반영하는 데는 제한이 있다. 한편으로 시스템 통합에 대한 효과를 반영하기 위한 시스템 성숙도 측정 방법이 제시되었지만 성능과 기술성숙도를 분명하게 연계시키지는 못했다. 따라서 본 연구에서는 컴포넌트 수준으로부터 상방향으로 확대하여 시스템 수준에서의 기술적 성능 달성도 평가방법과 함께 시스템 성숙도를 연계하는 시스템 성능 달성도 측정 기법을 제시하였다. 이를 통해 무기체계개발에서 위험관리에 활용할 수 있게 된다.

• 시스템엔지니어링학술지
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• 제19권2호
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• pp.117-125
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• 2023

Systematic performance evaluation of the Defense Acquisition Program is very important, since they are directly related to national security. In this paper, we reviewed various performance evaluation models from a methodological perspective for pragmatic performance evaluation, and the limitations of each model. In order to evaluate the performance of the Defense acquisition program efficiently, especially for the Naval ship Projects and considering their unique characteristics, both various stakeholders' participation, standard indicators for performance measurement, and tailoring them considering the projects' circumstances are necessary. We also propose indicators, contents, and detailed criteria example for the Requirements management. This approach enables a pragmatic and consistent evaluation of defense projects, and through this, meaningful insights could be acquired with accumulate data.

• 한국정보통신학회논문지
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• 제21권11호
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• pp.2191-2198
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• 2017

군 무기체계의 성능을 점검하기 위해 사용되는 정밀측정장비는 수명주기 동안 측정신뢰도 유지를 위해 주기적으로 교정된다. 기존의 교정주기 관련 연구들은 장비의 샘플 크기와 특성을 고려하여 측정신뢰도 모델을 결정할 것을 제안하고 있으나, 다양한 정밀측정장비의 정비 데이터에 동일한 특성 분포를 가정하고 단일 모델을 적용하는 것은 적합하지 않을 수 있다. 본 논문에서는 정밀측정장비의 수명주기 동안 욕조 곡선의 특성을 가정하여 측정신뢰도 모델들로부터 추정된 교정주기 가운데 F-검정과 성능지수 평가를 통해 정비 데이터에 가장 적합한 교정주기가 선택되도록 제안하였다. 제안한 방법을 다양한 장비에 적용한 결과 교정주기 동안 장비의 신뢰도가 유지됨을 확인하였다.

• 산업경영시스템학회지
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• 제41권2호
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• pp.65-73
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• 2018

The dynamic capabilities of sensing market signals, creating new opportunities and reconfiguring resources and capabilities to new opportunities in a rapidly changing economic environment determines the competitiveness of the enterprise to create added value and survival. This study conceptualized a two-stage performance measurement framework based on the casual model of resource (input)-process-performance (output). We have developed a 'Process capability index' that reflect the dynamic capabilities factors as a key intermediary product linking resource inputs and performance outputs in enterprise performance measurement. The process capability index consists of four elements : manpower (level of human resource), operation productivity, structure and risk management. The DEA (Data Envelopment Analysis) model was applied to the developed performance indicators to analyze the branch office performance of a telecom company. Process capability efficiency (stage 1) uses resource inputs to reach a certain level of process capabilities. In performance result efficiency (stage 2), the process capabilities are used to generate sales revenues and subscribers. The two-stage DEA model derives intermediate output values that optimize the individual stages simultaneously. Some branch offices in the telecom company have focused on process capability efficiency or some other branch offices focused on performance result efficiency. Positioning map using two-stage efficiency decomposition and benchmarking can help identify the sources of inefficiencies and visualize strategic directions for performance optimization. Applications of two-stage DEA in conjunction with the case study that are meaningfully used in performance measurement areas have been scarce. In particular, this paper has the contribution to present a new performance measurement model considering the organization theory, the dynamic capabilities.

• 품질경영학회지
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• 제27권4호
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• pp.20-41
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• 1999

This study addresses the development of a quality measurement of information systems integration(SI) service. Several dimensions which affect on quality of systems integration service have been identified and tested. Also, a measurement tool(questionnaire) of the factors has been developed. To achieve above purpose, extensive literature review and in-depth interview with several SI managers and customers were used. We suggested the analysis framework including performance variables such as quality, customer satisfaction, intention of renewal contract, and contribution to better customer's information system and the quality factors as well. To verify the research framework, collected data from the survey was analyzed statistically. The data from 73 respondents was used for analysis. Consequently, we identified eight factors and developed a 41-item instrument with Likert 5 points to measure the quality of SI service. It was proved that the 41-item instrument suggested in this study was very useful to measure the performance of SI service such as quality and customer satisfaction. Also it was shown that the instrument measured intention of renewal contract and contribution of customer's information system well.

• 한국군사과학기술학회지
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• 제11권1호
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• pp.75-84
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• 2008

A new automatic small target detection and tracking algorithm for the real-time IR surveillance system is presented. The automatic target detection and tracking algorithm of the real-time systems, requires low complexity and robust tracking performance in the cluttered environment. Linear-array and parallel-scan IR systems usually suffer from severe scan noise caused by the detector non-uniformity. After the spatial filtering and thresholding, this scan noise still remains as high amplitude clutter which degrades the target detection rate and tracking performance. In this paper, we propose a new feature which consists of area and validity information of a measurement. By adopting this feature to the measurements selection and track confirmation, we can increase the target detection rate and reduce both the track loss rate and false track rate. From the experimental results, we can validate the feasibility of the proposed method in the noisy IR images.