• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.4
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• pp.76-83
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• 2001

In this study, the static and dynamic characteristics of turning process was modelled and the analytic realization of regen-erative chatter mechanism was discussed. In this regard, we have discussed on the comparative assessment of recursive times series modeling algorithms that can represent the machining process and detect the abnormal machining behaviors in precision turning operation. In this study, simulation and experimental work were performed to show the malfunction behaviors. For this purpose, new Recursive Extended Instrument Variable Method(REIVM) was adopted for the on-line system identification and monitoring of a machining process. Also, we can apply REIVE algorithms in real process for the detection of chatter frequency and dynamic property and analyze the stability lobe of the system by changing a parameter of cutting dynamics in regenerative chatter mechanics, if it is stable or unstable, Also, The stability lobe of chatter was analysed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.42-51
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• 1999

An experimental modeling of cutting and structural dynamics and the on-line detection of malfunction process is substantial not only for the investigation of the static and dynamic characteristics of cutting process but also for the analytic realization of diagnostic systems. In this regard, We have discussed on the comparative assessment of two recursive time series modeling algorithms that can represent the machining process and detect the abnormal machining behaviors in precision round shape machining such as turning, drilling and boring in mold and die making. In this study, simulation and experimental work were performed to show the malfunctioned behaviors. For this purpose, two new recursive approach (REIVM, RLSM) were adopted fur the on-line system identification and monitoring of a machining process, we can apply these new algorithm in real process for the detection of abnormal machining behaviors such as chipping, chatter, wear and round shape lobe waviness.

• Smart Structures and Systems
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• v.11 no.2
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• pp.135-161
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• 2013

This work presents a test platform for the assessment and benchmarking of modern actuators which have been specifically developed for the new field and service robotics applications. This versatile platform has been designed for the comparative analysis of actuators of dissimilar technology and operating conditions. It combines a modular design to adapt to linear and rotational actuators of different sizes, shapes and functions, as well as those with different load capacities, power and displacement. This test platform emulates the kinematics of robotic joints while an adaptive antagonist-load actuator allows reproducing the variable dynamic loads that actuators used in real robotics applications will be subjected to. A data acquisition system is used for monitoring and analyzing test actuator performance. The test platform combines hardware and software in the loop to allow actuator performance characterization. The use of the proposed test platform is demonstrated through the characterization and benchmarking of three controllable impedance actuators recently being incorporated into modern robotics.

• Ocean Systems Engineering
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• v.7 no.1
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• pp.53-74
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• 2017

Ship shaped FPSO (Floating Production, Storage and Offloading) units are the most commonly used floating production units to extract hydrocarbons from reservoirs under the seabed. These structures are usually much larger than general cargo ships and have their natural frequency outside the wave frequency range. This results in the response to first order wave forces acting on the hull to be negligible. However, second order difference frequency forces start to significantly impact the motions of the structure. When the difference frequency between wave components matches the roll natural frequency, the structure experiences a significant roll motion which is also termed as second order roll. This paper describes the theory and numerical implementation behind the calculation of second order forces and motions of any general floating structure subjected to waves. The numerical implementation is validated in zero speed case against the commercial code OrcaFlex. The paper also describes in detail the popular approximations used to simplify the computation of second order forces and provides a discussion on the limitations of each approximation.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.114-119
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• 2009

This study has been conducted to describe the establishment of national measures to reduce world energy consumption and $CO_2$ Emission. Particularly, Reductions in energy consumption from building operation is the most important part to achieve these national objectives. Element to evaluate the quantitative effects of these systems by having rationalized regulation and operation is essential, when planning for building energy reduction design. USGBC(US Green Building Council) have operated sustainable assessment method called LEED, which introduces baseline performance and evaluation direction for building simulation techniques. This research analyzed Quantitative assessments of the building energy consumption and analyzed baseline figures to provide comparative analysis with standard building settings.

• Nuclear Engineering and Technology
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• v.33 no.5
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• pp.498-513
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• 2001

Performed here is a comparative assessment study for the generation of the pressure- temperature (P/T) limit curve of the reactor vessel. Using the cooling or heating rate and vessel material properties, the stress distribution is obtained to calculate stress intensity factors, which are compared with the material fracture toughness to determine the relations between operating pressure and temperature during cool-down and heat-up. P/T limit curves are generated with respect to crack direction, clad thickness, toughness curve, cooling or heating rate and neutron fluence, and their results are compared.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1431-1432
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• 2015

A system was developed to continuously monitor the respiratory signal under critical care, followed by performance evaluation for clinical application. Very much accurate pressure measurement was made in the endo-tracheal tube with mean relative error of 0.13%. In the comparative experiment simulating inspiration and expiration, the tidal volume measurement was also accurate within mean relative error of 3%, validating reliable measurement of respiratory signals.

• Journal of the Korean Society of Safety
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• v.10 no.1
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• pp.56-63
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• 1995

Two methods of the numerical method of CPQRA(Chemical Process Quantitative Risk Analysis) and the manual method of IAEA(International Atomic Energy Agency) were used to estimate the individual risk and societal risk around the chemical plant. Where, the CPQRA is introduced to verify the theoritical background of the manual of international atomic energy agency. The Gaussian plume model which has a weather stability class D with velocity of 5m/s was applied to calculate dispersion of hazard material. Also, 8-point method was employed to the effects of accidents for wind distribution. Furthermore, historical record, FTA(Fault Tree Analysis) and ETA(Event Tree Analysis) were used to estimate the probability or frequency of accidents. Eventually, the individual risk shows isorisk contour and the societal risk shows F-N curve around hazard facility, especially in chemical plants. Caulculated results, which both individual and societal risk, by using IAEA manual show simillar results to those of calculation by numerical method of CPQRA.

• KIEAE Journal
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• v.13 no.1
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• pp.3-8
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• 2013

Environmental quality(EQ) is one of the most important components of the assessment of "Quality of Life(QOL)". Most EQ related research dealt with overall built environmental quality issues as represented by several clusters of factors related to occupants' satisfaction. This paper aims to identify and understand the theoretical background and the occupants' comparative standards of response to conditions of the built environment related to environmental quality(EQ). Therefore, this paper have reviewed the theoretical framework and empirical research for environmental quality in built environment. the concept of environmental quality if elaborated from diverse perspectives. Different ways of interpreting environmental quality have led to a variety of ways to conduct evaluations. A review of the theories and methods used for the analysis of perceived environmental quality provides a strong foundation for new research frameworks and environmental quality in built environment.

• Journal of Engineering Education Research
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• v.16 no.2
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• pp.37-49
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• 2013

In this paper, articles in full body of JEER in Korea and JEE in U.S. were classified into two categories- Research area and Key words-to endeavor a comparative study of the engineering education research(EER) topics and their temporal changes. In the recent 4 year term, 'Accreditation of Engineering Education' and 'Courses & Curriculum' were the most common key words appearing in JEER and 'Researches on EER' and 'Learner's Factor' in JEE. If we put curriculum/teaching materials/teaching as the input elements and learning/assessment as the output elements for education achievement, JEE demonstrates that many of the research topics have shifted from input to output in the recent years, while JEER research is in the transient stage.