• Smart Structures and Systems
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• 제10권3호
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• pp.299-312
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• 2012

The authors' research efforts recently led to the development of a customized wireless control unit which receives the real-time feedbacks from the sensors, and elaborates the consequent control signal to drive the actuator(s). The controller is wireless in performing the data transmission task, i.e., it receives the signals from the sensors without the need of installing any analogue cable connection between them, but it is powered by wire. The actuator also needs to be powered by wire. In this framework, the design of a power management unit is of interest only for the wireless sensor stations, and it should be adaptable to different kind of sensor requirements in terms of voltage and power consumption. In the present paper, the power management efficiency is optimized by taking into consideration three different kinds of accelerometers, a load cell, and a non-contact laser displacement sensor. The required voltages are assumed to be provided by a power harvesting solution where the energy is stored into a capacitor.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권3호
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• pp.578-597
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• 2014

Understanding of 'spatial' pressure distribution is required to determine design loads on local structures, such as plating and framing. However, obtaining a practical 'spatial' pressure distribution is a hard task due to the sensitivity of the data acquisition frequency and resolution. High-resolution Pessure-Idicating Flm (PIF) was applied to obtain pressure distribution and pressure magnitude using stepped crushing method. Different types of PIF were stacked at each test to creating a pressure distribution plot at specific time steps. Two different concepts of plotting 'spatial' pressure-area curve was introduced and evaluated. Diverse unit pixel size was chosen to investigate the effect of the resolution in data analysis. Activated area was not significantly affected by unit pixel size; however, total force was highly sensitive.

• 한국화재조사학회지
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• 제3권1호
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• pp.43-46
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• 2003

In this experimental report, We introduce an idea of thermal corrosion in sandwich panel. In brief, Because the structures of sandwich panel are easily collapsed by thermal damage caused by a fire, it is very difficult to investigate a point and origin of fire. Therefore, If the shapes of thermal corrosion are reconstructed according to change of temperature and lapse time by experiment in sandwich panel, it is very simple task that fire scene investigators search for a point and origin of fire. As a result, we present the difference of thermal corrosion between samples which are applied heat by many-sided variable, such as temperature, heating time, lapse time, humidity, and others.

• International Journal of Advanced Culture Technology
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• 제7권3호
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• pp.158-165
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• 2019

Knowledge based system includes tools for constructing, testing, validating and refining the system along with user interfaces. An important issue in the design of a complete knowledge based system is the ability to produce explanations. Explanations are not just a series of rules involved in reasoning track. More detailed and explicit form of explanations is required not only for reliable reasoning but also for maintainability of the knowledge based system. This requires the explanation mechanisms to extend from knowledge oriented analysis to task oriented explanations. The explicit modeling of problem solving structures is suggested for explanation generation as well as for efficient and effective reasoning. Unlike other explanation scheme such as feedback explanation, the detailed, smaller and explicit representation of problem solving constructs can provide the system with capability of quality explanation. As a key step to development for explanation scheme, the problem solving methods are broken down into a finer grained problem solving primitives. The system records all the steps with problem solving primitives and knowledge involved in the reasoning. These are used to validate the conclusion of the consultation through explanations. The system provides user interfaces and uses specific templates for generating explanation text.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제26권2호
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• pp.105-120
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• 2023

With the rapid advancement of educational technology, recent studies have connected teachers' professional noticing with the use of digital resources in mathematical instructions. In this study, I examined elementary mathematics preservice teachers' attending and interpreting a mathematical software, ST Math, in the exploring and implementing phases. The findings indicate that preservice teachers paid attention to visual representations and manipulation prior to interactions with children and further took into consideration on task structures and situated context after interactions. They interpreted the events based on connected mathematical knowledge of prior interactions and further reflected on the progression of problem-solving strategies and sequence of tasks. In addition, four distinctive profiles of transitioning of evaluation on ST Math activities were identified with illustrations. Implications for noticing and teacher education were discussed.

• Smart Structures and Systems
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• 제6권1호
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• pp.17-27
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• 2010

The approach to damage detection and localization adopted in this paper is based on a statistical comparison of models built from the response time histories collected at different stages during the structure lifetime. Some of these time histories are known to have been recorded when the structural system was undamaged. The consistency of the models associated to two different stages, both undamaged, is first recognized. By contrast, the method detects the discrepancies between the models from measurements collected for a damaged situation and for the undamaged reference situation. The damage detection and localization is pursued by a comparison of the SSE (sum of the squared errors) histograms. The validity of the proposed approach is tested by applying it to the analytical benchmark problem developed by the ASCE Task Group on Structural Health Monitoring (SHM). In the paper, the results of the benchmark studies are presented and the performance of the method is discussed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.434-440
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• 2003

The exchange of model design date among heterogeneous CAD systems is a difficult task because each system has different data structures suitable for its own functions. STEP has been able to represent product information as a common computer-interpretable form that is required to remain complete and consistent when the product informant is needed to be exchanged among different computer system. However, STEP has difficult architecture in is representing point, line, curve and vectors of element, more over it can't represent geometry data of feature based models. In this study, a structure of XML document that represents geometry data of feature based models as neutral format has been developed. To use the developed XML document, a Converter has also been developed to exchange modules so that it can exchange feature based data models among heterogeneous CAD systems. Aa for evaluation of the developed XML document and Converter, Solidworks and SolidEdge are selected.

• 대한안전경영과학회지
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• 제6권3호
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• pp.161-174
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• 2004

The existing PKI authentication structure uses the OCSP method. The primary task of OCSP is to verify the status of a transaction after verifying the validity of the certificate; but, because of continuing policy changes and updates within the PKI authentication method, the status of certificates and the structures are not consistent. Therefore, the SCVP method can be selected as the broadest method for completing authentication tasks accurately because the SCVP method includes validation of policy changes. An appropriate method for building an mobile environment within the capabilities of low-memory and reduced processing CPU needs to be assessed and developed. This thesis proposes a verification method that is independent of platform and applicable to any 05 in building and expanding the mobile environment.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.219-226
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• 2001

In general, engineers have to consider a variety of factors in design of a structure. For this reason, it was difficult to make a design program up to now. But the rapid development of hardware and software turns it into a possibile one with considering complex factors and designing simple structures. When we use the design program including structural analysis, we can save time and cost to make calculations; report and drawing. In addition, the design program was developed to reduce the man made errors. Therefore, in this study, we try to develope the design program of the superstructure of P.S.C girder bridge and abutment. This program will provide engineers with time that they can spend on a creative and efficiency task for development of design.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.186-188
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• 2003

Rail Route Alignment in hilly terrain is a difficult task to implement as several natural constraints poses threat to the safety and stability of the alignment. The conventional methods followed to find out the final location survey or the feasibility analysis for alignment is time taking consuming. Some times, due to inaccessibility of the terrain it becomes impossible to carry out such works. The construction works in hilly terrain, which are associated with the proposed alignment, are not same as carried out in plane areas due to a vast contrast between the two areas. Different geological structures such as faults, thrusts, synclines and anticlines are a big problem to carry out normal construction practices. Thus for a safe and stable railway route in the unstable hilly areas, it is required to carry out the feasibility analysis of the proposed alignment to assist the policy makers for a successful implementation of the alignment. In the present work Remote Sensing and GIS has been successfully used to carry out geological feasibility and slope stability analysis for rail route alignment work.