• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.281-288
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• 1999

Electrodeposited Zn-Ni alloy coatings are of particular interest for improving the corrosion resistance of steel in a number of enviornments. Of particular interest is the relationship between composition, structure and corrosion rate. This paper firstly reviews the literature regarding composition-structure relationships of Zn-Ni electrodeposits and compares them with the equilibrium phase diagram. Secondly, research was carried out on a wide range of coatings which were produced in the laboratory and their structure and corrosion rates determined. It was found that unambiguous identification of phases from XRD data can be difficult. Maximum corrosion resistance of deposits is obtained at 12-13% Ni, with a $\gamma$ phase structure and predomination of (600) and (411) reflections. Compatibility is important with regard to chromate conversion coatings.

• Elastomers and Composites
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• v.54 no.3
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• pp.188-200
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• 2019

Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

• Journal of Sensor Science and Technology
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• v.28 no.5
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• pp.318-322
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• 2019

In shooting training, an impact point identification system that uses the impact wave of the bullet to check the impact point in the target plate has been recently used. Acoustic sensors used in these systems must be able to detect shock waves of high sound pressure levels and be both waterproof and dustproof for rainy weather and dusty environments, respectively. In this study, membranes with excellent waterproof, dustproof, and sound transmitting characteristics were selected through a characteristics test; a protection cap was installed to install the selected materials. After coupling the produced protection cap to the acoustic sensor housing, the sensitivity and phase characteristics of the acoustic sensor were checked. Through the waterproof and dustproof test, the performances of its sensitivity and phase characteristics were confirmed. Finally, the normal shockwave of a 5.56 mm diameter bullet was measured using a shockwave detection signal collecting plate equipped with a prototype of the acoustic sensor at a 100 m firing range.

• Journal of the Korean Society of Visualization
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• v.17 no.2
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• pp.39-47
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• 2019

Impingement cooling utilizing synthetic jets is emerging as a popular cooling technique because of its high local cooling efficiency. The interaction between the vortex structure of the synthetic jet and the surface is crucial in understanding the mechanism of this technique. In this study, the impinging vortex structure and its advection are investigated by experiments with jet-to-surface spacing $2{\leq}H/D{\leq}7$, and synthetic jet Reynolds number $5120{\leq}Re{\leq}9050$. Using phase-locked particle image velocimetry, ensemble averaged (phase averaged) flow fields are obtained, and vortex identification and quantification techniques are applied. The shape, trajectory, and intensity change of the vortex are assessed. A sharp decline in the vortex intensity and the occurrence of a counter-rotating vortex at the impingement point are observed.

• Archives of design research
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• v.11 no.3
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• pp.177-185
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• 1998

Started from the Industrial Revolution in England, the design movement, the concept of plastic arts is spread and developed in many European countries. It meets new phase due to the much more developed industrial techniques and internationalized era since the World War II. The concept of identity in design appeared with industrial diversification, specialization, and inter- nationalization comes out through every visual identification standards. And the concept is used in public facilities and groups such as national institutions, schools, hospitals, or lots of religious bodies, as well as in industries to aim at the most profit from products' sale. Since the opening of Seoul National University of Technology in 1910, the university which has long history and tradition of about 90 years has used the unique visual identification in changing the University name to meet with the surrounding environment and the timely characteristics. However, the English name for the University was changed in 1998, so the new era to leap was open. Therefore, the University introduced formally the concept of U. I. (University Identification) with the new image. It is an inevitable outcome of modern time.

• Journal of KIISE
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• v.43 no.6
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• pp.662-667
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• 2016

As electric and electronic control systems have sharply increased in vehicles, safety accident has emerged as an important issue. Therefore, in order to ensure safety of the vehicle, engineers are required to identify the hazards utilizing PHA and HAZOP, etc. in the early phase of development and implement safety mechanisms to prevent them. HAZOP has been widely used in a systematic manner based on guidewords. However, HAZOP identifies malfunctions from the top-level functionality provided by the system, so it cannot sufficiently identify hazards during the system operation. This leads to restrictions in designing testcases, because the safety requirements are derived from only some of the hazards. This research aimed to provide a hazard identification method utilizing Use case description, which defines operation procedure of the system and HAZOP and a testcase design method based on safety requirements. We introduced a case study on Smart Key Control System in vehicles and compared with hazards identification results based on HAZOP, to demonstrate the effectiveness of this study. The result of this study could potentially reduce development cost and increase system quality by adequately identifying hazards and safety requirements and designing the related testcase.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.683-686
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• 2014

Objective: The purpose of the study was to evaluate clinical value of dual-phase $^{18}F$-FDG SPECT with serum procalcitonin (PCT) in identifying cancers in patients with fever of unknown origin (FUO). Methods: PCT test and dual-phase $^{18}F$-FDG SPECT were sequentially performed on 50 consecutive patients with FUO. Two radiologists evaluated all $^{18}F$-FDG SPECT data independently. A consensus was reached if any difference of opinions existed. Final diagnosis was based on a comprehensive analysis of results for the PCT test, dual-phase $^{18}F$-FDG SPECT and bacterial cultivation, regarded as a gold standard. Results: Among 50 patients, 34 demonstrated PCT ${\geq}0.5{\mu}g/L$. Coincidence imaging showed in 37 patients with inflammatory lesions, and 13 with malignancy. Finally, 36 bacterial, 1 fungal and 1 viral infections, as well as 12 cancerous fevers were confirmed by dual-phase $^{18}F$-FDG SPECT with PCT, combined with bacterial cultivation and clinical follow-up. Conclusion: Our study demonstrated that dual-phase $^{18}F$-FDG SPECT in association with PCT could be a valuable tool for diagnosis in tumor patients with FUO.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.147-152
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• 2023

Mostly in motor fault detection the instantaneous values 3 axis vibration and 3phase current in time domain are acquired and converted to frequency domain. Vibrations are more useful in diagnosing the mechanical faults and motor current has remained more useful in electrical fault diagnosis. With having some experience and knowledge on the behavior of acquired data the electrical and mechanical faults are diagnosed through signal processing techniques or combine machine learning and signal processing techniques. In this paper, a single-layer LSTM based condition monitoring system is proposed in which the instantaneous values of three phased motor current are firstly acquired in simulated motor in in health and supply imbalance conditions in each of three stator currents. The acquired three phase current in time domain is then used to train a LSTM network, which can identify the type of fault in electrical supply of motor and phase in which the fault has occurred. Experimental results shows that the proposed single layer LSTM algorithm can identify the electrical supply faults and phase of fault with an average accuracy of 88% based on the three phase stator current as raw data without any processing or feature extraction.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.169-173
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• 2007

During laser irradiation, mechanically deformed cartilage undergoes a temperature dependent phase transformation resulting in accelerated stress relaxation. Clinically, laser-assisted cartilage reshaping may be used to recreate the underlying cartilaginous framework in structures such as ear, larynx, trachea, and nose. Therefore, research and identification of the biophysical transformations in cartilage accompanying laser heating are valuable to identify critical laser dosimetry and phase transformation of cartilage for many clinical applications. quasi-elastic light scattering was investigated using Ho : YAG laser $(\lambda=2.12{\mu}m\;;\;t_p\sim450{\mu}s)$ and Nd:YAG Laser $(\lambda=1.32{\mu}m\;;\;t_p\sim700{\mu}s)$ for heating sources and He : Ne $(\lambda=632.8nm)$ laser, high-power diode pumped laser $(\lambda=532nm)$, and Ti : $Al_2O_3$ femtosecond laser $(\lambda=850nm)$ for light scattering sources. A spectrometer and infrared radiometric sensor were used to monitor the backscattered light spectrum and transient temperature changes from cartilage following laser irradiation. Analysis of the optical, thermal, and quasi-elastic light scattering properties may indicate internal dynamics of proteoglycan movement within the cartilage framework during laser irradiation.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2326-2333
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• 2015

Stator turn faults in permanent magnet synchronous motors (PMSMs) are more dangerous than those in induction motors (IMs) because of the presence of spinning rotor magnets that can be turned off at will. Condition monitoring and fault detection and diagnosis of the PMSM have been receiving a growing amount of attention among scientists and engineers in the past few years. The aim of this study is to propose a new detection technique of stator winding faults in a three-phase PMSM. This technique is based on the image analysis and recognition of the stator current Concordia patterns, and will allow the identification of turn faults in the stator winding as well as its correspondent fault index severity. A test bench of a vector controlled PMSM motor behaviors under short circuited turn in two phases stator windings has been built. Some experimental results of the phase to phase short circuits have been performed for diagnosis purpose.