• Journal of electromagnetic engineering and science
• /
• v.10 no.3
• /
• pp.121-126
• /
• 2010

A long range UHF RFID tag with a rectangular metallic cavity structure is proposed for various applications with metallic objects. The proposed tag consists of a rectangular metallic cavity structure and a folded dipole antenna which is located on top of the cavity. The tag is designed for Korean UHF RFID band(910~914 MHz) and the bandwidth, which satisfies the -10 dB input reflection coefficient requirement, is approximately 1.3 %(904~916 MHz). Measurement demonstrates that the proposed tag shows long reading range up to 15 m when it is placed on a metallic plate.

• Journal of Conservation Science
• /
• v.6 no.2 s.8
• /
• pp.141-148
• /
• 1997

When we have entered high economic growth since 1970s, many archaeological excavations were performed all over the country. Excavated objects composed of variable materials are inevitably subjected to deformations owing to surrounding environments and storage conditions. Although the importance of conservation treatment of the objects is greatly increased, a few conservation laboratories are there comparing with excavation groups. The metallic objects excavated are very unstable and deformable state. So it is important not to allow iron objects, especially cast iron, to dry out once excavated. Because the corrosion reactions on the surface proceed rapidly, the objects may be destroyed at the moment. The conservation procedures of the excavated metallic objects are as follows: (1)It is stable on-site storage method for objects to keep vinyl film with envelop or to immerse alkaline solution to prevent the environmental changes. (2)The objects must be treated at once under suitable methods in the conservation laboratory after excavation. (3)The continued existence of objects depends on environmental factors such as relative humidities, regular inspection, light etc.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.18 no.3
• /
• pp.109-116
• /
• 2023

This paper presents a network-based automation system for the detection of metallic objects in food and livestock. A metal detector is a core equipment used for the inspection required by HACCP. Since the existing metal detectors are manufactured as a single-body equipment, it is difficult to take into account various user requirements for the system. In order to overcome the drawback, this study presents a network-based automation system for metal detector utilizing an industrial fieldbus and modular components. The proposed system can effectively consider the various customer requirements and control schemes. The proposed system can also achieve the improvement in speed and success rate of detecting metallic objects. The effectiveness of the proposed system is demonstrated through a various experiments.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.2
• /
• pp.120-125
• /
• 2014

Conventional handheld metal detectors use a single induction coil to detect the metallic parts of explosive objects, and the detector generates an acoustic signal from its magnetic response to a metallic object so that an operator can confirm the existence of mines. Though metal detectors have very useful detection mechanisms to find mines, it is easy to cause a high false alarm ratio due to the detection of non-explosive metallic items such as cans, nails and other pieces of metal, etc. Also, because of the physical characteristic of a metal detector it is hard to detect non-metallic objects such as mines made of wood or plastic. Furthermore, the operator must move it to the left and right slowly and repeatedly to attain enough sensor signals to confirm the existence of mines using only a monotonous acoustic signal. To resolve the disadvantages of handheld detectors, many new approaches have been attempted, such as an arrayed detector and a visualization algorithm based on metal/non-metal sensor. In this paper, we introduce a visualization algorithm with a metal/non-metal complex sensor, an arrayed metal/non-metal sensor and the their testing and evaluation.

• Proceedings of the KIEE Conference
• /
• 1995.11a
• /
• pp.469-471
• /
• 1995

This paper describes the effect of floating metallic object on do flashover characteristics in all gap producing unipolar ion flow field. Needle-to-plane electrodes of 120mm in gap length were used as the main gap electrode and the tested metallic objects were spheres with the radius of 2,10 and 15mm or needles from 5 to 40mm long. The characteristics of flashover voltage vs. location of the floating object are different completely with the shape of the floating metal and polarity of the applied voltage.

• ETRI Journal
• /
• v.28 no.2
• /
• pp.216-218
• /
• 2006

This letter presents the design for a low-profile planar inverted-F antenna (PIFA) that can be stuck to metallic objects to create a passive radio frequency identification (RFID) tag in the UHF band. The designed PIFA, which uses a dielectric substrate for the antenna, consists of a U-slot patch for size reduction, several shorting pins, and a coplanar waveguide feeding structure to easily integrate with an RFID chip. The impedance bandwidth and maximum gain of the tag antenna are about 0.3% at 914 MHz for a voltage standing wave ratio (VSWR) of less than 2 and 3.6 dBi, respectively. The maximum read range is about 4.5 m as long as the tag antenna is on a metallic object.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2005.11a
• /
• pp.267-270
• /
• 2005

An RFID patch antenna for metallic object has been designed. The effects of variation of distance between the tag antenna and ground of the antenna have been studied. Various dielectric constants, thickness, permittivity, width of transmission line and length of transmission line have been used to design the better tag antenna for metallic object.

• Journal of the Korean institute of surface engineering
• /
• v.8 no.1
• /
• pp.1-9
• /
• 1975

The crorosion film of gilt bronz, silver and iron objects, which were excaved from Ancient Tomb of Silla Dynasty, was removed by the electrolytic reduction process. These metallic objects were mainly investigated for microstructure, designs and gilting film etc. Most iron objects might be made by hot forging process. The cold extrusion technique might be used for gold and silver objects, in addition to an amalgam method might be applied for the gilting Au film on Cu-alloy surface. For the gilting on glass surface, first, a Cu alloy was cladded on glass , next, Au-film was obtained on the Cu-ally by the amagum method.

• Journal of Sensor Science and Technology
• /
• v.24 no.3
• /
• pp.169-174
• /
• 2015

In this study, we developed a system to detect the various defects in the metallic objects using the phenomenon that the defects cause the changes of the natural resonant frequencies. Our system consists of a FFT Amp, an Auto Impact Hammer, a Hammer controller and a PC. Auto Impact Hammer creates vibrations in the metallic objects when tapped on the surface. These vibrational signals are converted to the voltage signals by an acceleration sensor attached to the metallic part surface. These analog voltage signals were fed into an ADC (analog-digital converter) and an FFT (fast fourier transform) conversion in the FFT Amp to obtain the digital data in the frequency domain. Labview graphical program was used to process the digital data from th FFT amp to display the spectrum. We compared those spectra with the standard spectrum to find the shifts in the resonant frequencies of the metal parts, and thus detecting the defects. We used PCB's acceleration sensor and TI's TMS320F28335 DSP (digital signal processor) to obtain the resolution of 2.93 Hz and to analyze the frequencies up to 44 kHz.

• 보존과학연구
• /
• s.7
• /
• pp.292-303
• /
• 1986

The purpose of this paper is to select the suitable resin as changed in environmental and ingredients, in the conservation of metallic objects. Disposal way of metallic objects were used to various resin and grease which will must be well selected in the nature of relics. The contents of this report are summed up as follows ; The resins of Incralac, Ruscoat, wash primer, Amerlock-400 wrer coated on the slice of ironware (5% saltspray test on the view of nature & Adherence). After the coating, add increasing speed to a corrosion rate, and then the adherence of resins were tested. In this study corrosion test, 0.10-0.25% Amerlock-400 jis proved to be a rare one of corrosion rate and 1.0-2.5% Wash primer is found to be a plenty one of corrosion area.