• 보존과학연구
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• s.7
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• pp.278-291
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• 1986

In this report the practical case of Viking ship's conservation in Denmarke specially among the Eurpoean nations is introduced. The contents of it are summarized as follows :From 1957 to 1962 the Danish National Museum Salvaged five Viking ships from the bottom of Roskilde Fjord, Which were composed of the pieces of timber whose surface was soft because they had lain on the sea bed for about a thousand years. Excavation had been carried out in the same way as in the field by driving down a sheet piling around the wrecks and pumping the water out. These pieces of the wreck ships were packed in airtight plastic bags one by one to be transported for Brede and then immidiately had to go through the treatment for conservation. The conservation treatment process for the pieces includes three steps ; the preliminary process prior to the hardening treatment, the hardening and the assemble of the ships. In the first step ; the preliminary process, all remains of mud and shells from the fjord bed are washed off, and measuring followed ; every single piece of wreckage was drawn so that the form and size of the piece, nail holes, and breaks were registered before conservation. In the second ; the hardening treatment step, the pieces of the woreckage were filled with P.E.G. This Polyethylene Glycol method was the best to handle in the subsequent mounting of the ships in the museum. In the final, the Glycol-treated pieces were pieced together to spips with support of a system of reinforcements. They were to fit in place after corrections of the form were made several times.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.532-541
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• 2014

The ship-borne mobile down range telemetry antenna system having 4.6 m reflector antenna and 3-axis mounting structure at S-band requires the precise pointing accuracy at sea for the launch mission. Using the LEO satellites tracking, a method to determine and verify the antenna pointing and tracking performance, and to find the pointing bias which dominantly contributes to the pointing inaccuracy, is presented. Based upon the tests conducted on the Jeju sea and Pacific sea, the pointing bias is determined and its origin is also identified as the drift of the heading angle of the gyrocompass. The applied systematic correction taking into account the pointing bias, and the achieved improvement of the pointing accuracy are shown. Thanks to the correction, it is presented that this antenna tracked the launcher(KSLV-I) stably within the required pointing accuracy in the following KSLV-I third launch.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.3
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• pp.17-26
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• 2004

In this paper, power transmission systems converts the shaft power of a Turbo-shaft Engine with Free Power Turbine into the generator power and be composed of a method being supplied in the thrust motor driving a propellers. Being used this, Gas turbine engine works to flat rating about 110 kw (147 shp) that the thrust motor be extremely supplied from the engine of 317shp. In this test equipment, the engine is installed with the flywheel being able to the damping function when happen to the varying load between gas turbine engine output-shaft and generator. Then if the flywheel of inertial moment be not considered, the generator and motor not get the required power from the engine for raising the load. Also it is certified that the engine works the abnormal operation. Hence the flywheel of inertial moment is determined the required range to do the performance analysis with the dynamic transient from the given and tested engine data. This system is able to get the required power after a mounting test with the redesigned flywheel.

• Journal of the Semiconductor & Display Technology
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• v.6 no.4
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• pp.23-27
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• 2007

Rotary stages in semiconductor, display industry and many other fields require challenging accuracy to perform their functions properly. Especially, Axis of rotation error on rotary system is significant; such as the spindle error motion of the aligner, wire bonder and inspector machine which result in the poor quality products. To evaluate and improve the performance of such precision rotary stage, undesired movements on the other 5 degrees of freedom of the rotary stage must be measured and analyzed. In this paper, we have measured the three translations and two tilt motions of the worm gear type spindle with high precision capacitive sensors. To obtain the radial error motion, we have used Donaldson's reversal technique. And the axial components of the spindle tilt error motion can be obtained accurately from the axial direction outputs of sensors by Estler face motion reversal technique. Further more we have designed and developed the sensor mounting jig with standard cylinder for reversal method.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.2
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• pp.31-40
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• 1999

Characteristics of monopole antenna and planar conductor structure mounted on handheld telephone are anlayzed by using FDTD method. Feeding of monopole antenna is implemented with lumped elements and plastic case is coated on the surface of conductor box. Otherwise, resonant frequency of handheld telephone mounting monopole antenna with no plastic case is 877MHz, when plastic case (${\varepsilon}_r=2$) is coated, the resonant frequency is down to 82MHz and the bandwidth is broadened about 1.5 times. Planar structure of handheld telephone mounted on the body makes to change far-field gain radiation patterns. In this case, radiation patterns are somewhat asymmetrical. Handheld telephone using PIFA(Planar Inverted F Antenna), instead of monopole antenna, is resonated at frequency 1.52GHz that is available onPCS. In the radiation pattern of this structure, azimuth that electric field intensity is presented below 20dB is 14$^{\circ}$.

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.11-16
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• 1976

Casts are often transferred to the articulator by arbitrary means, because the method of locating the true hinge axis point thought to be a complicated and time consuming procedure, and because the importance and significance of the true hinge axis in the construction of dental prosthesis is not sufficiently understood. In this report, the author constructed the hinge axis locator and determined the variations in location of the true hinge axis points from the location of the hinge axis point determined by arbitrary means. For this report, the procedure was followed on 50 persons with normal occlusion and sound T.M.J. function, so 100 true hinge axis points were recorded and compared with the arbitrary hinge axis point. The results obtained were as follows. 1. The mean distance from the arbitrary hinge axis point to the true hinge axis point was as follows. Right; (O)5.17mm., (V)3.44mm., (H)3.55mm.. Left; (O)5.63mm., (V)3.95mm., (H)3.51mm.. 2. The percentage of true hinge axis points classified at intervals of 2mm was as follows. 0-2mm; 4%, 2-4mm; 21%, 4-6mm; 37%, 6-8mm; 26%, 8-10mm; 10%, Over 10mm; 2%. And only 50% of the 100 true hinge axis points were located within a 5mm. radius of the arbitrary hinge axis point. 3. Instead of transferring the casts to the articulator by arbitrary means, the careful location of the true hinge axis points is recommended to avoid potential sources of error in mounting casts.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.11
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• pp.795-800
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• 2013

Early detection of oestrus in Korean cows is one of the important issues in maximizing the economic benefit. Although various methods have been proposed, we still need to improve the performance of the oestrus detection system. In this paper, we propose a video surveillance system which can detect unusual behavior of multiple cows including the mounting activity. The unusual behavior detection is to detect the dangerous or abnormal situations of cows in video coming in real time from a surveillance camera promptly and correctly. The prototype system for unusual behavior detection gets an input video from a fixed location camera, and uses the motion vector to represent the motion information of cows in video, and finally selects a SVDD (one of the most well-known types of one-class SVM) as a detector by reinterpreting the unusual behavior into an one class decision problem from the practical points of view. The experimental results with the videos obtained from a farm located in Jinju illustrate the efficiency of the proposed method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.7-10
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• 2001

Recently, most jewelry design employ multiple prongs that grasp the front surface of the jewel to the metal frame To keep up with recent trends in fashion. jewelry manufacturers need to produce single-prong neckalces and earings constructed with non-precious metals. In responce to this demand, Ameth Development Division and The University of Seoul researched jointly and developed a technique for setting the jewel safely using a single prong with less weight. The setting process consists of making a small trench through the jewel at the mounting point and using a low melting point tin solder, to fill the trench and bonding with the prong. The application or this technology in the setting of a natural amethyst to a single 18K gold prong resulted in a 40% reduction in cost and weight and improvement of feeling for wearing.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1097-1102
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• 2007

This paper describes the development of 6-axis force/moment sensor for an intelligent robot's foot. In order to walk on uneven terrain safely, the foot should perceive the applied forces Fx, Fy, Fz and moments Mx, My, Mz to itself. The applied forces and moments should be measured from a 6-axis force/moment sensor attached to a humanoid robot's foot(ankle). They in the published paper already have some disadvantage in the size of the sensor, the rated output and so on. The rated output of each component sensor (6-axis force/moment sensor) is very important to design the 6-axis force/moment sensor for precision measurement. Therefore, each sensor should be designed to be gotten similar the rated output under each rated load. So, the sensing elements of the 6-axis force/moment sensor should get lots of design variables. Also, the size of 6- axis force/moment sensor is very important for mounting to robot's foot. In this paper, a 6-axis force/moment sensor for perceiving forces and moments in a humanoid robot's foot was developed using many PPBs (parallel plate-beams). The structure of the sensor was newly modeled, and the sensing elements (plate-beams) of the sensor were designed using FEM (Finite Element Method) analysis. Then, the 6-axis force/moment sensor was fabricated by attaching strain-gages on the sensing elements, and the characteristic test of the developed sensor was carried out. The rated outputs from FEM analysis agree well with that from the characteristic test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1212-1218
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• 2014

For OBC (On-Board Charger) and LDC (Low DC-DC Converter) used as essential power conversion systems of PHEV (Plug-in Hybrid Electric Vehicle), system performance is required as well as reliability, which is need to protect the vehicle and driver from various faults. While current development processor is sufficient for embodying functions and verifying performance in normal state during development of prototypes for OBC and LDC, there is no clear method of verification for various fault situations that occur in abnormal state and for securing stability of vehicle base, unless verification is performed by mounting on an actual vehicle. In this paper, a CCM (Charger Converter Module) was developed as an integrated structure of OBC and LDC. In addition, diverse fault situations that can occur in vehicles are simulated by a simulator to artificially inject into power conversion system and to test whether it operates properly. Also, HILS (Hardware-in-the-Loop Simulation) is carried out to verify whether LDC is operated properly under power environment of an actual vehicle.