• ETRI Journal
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• v.38 no.3
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• pp.469-478
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• 2016

In this paper, we investigate the effects of pre-reducing Sb-doped $SnO_2$ (ATO) electrodes in viologen-anchored $TiO_2$ (VTO) nanostructure-based electrochromic devices. We find that by pre-reducing an ATO electrode, the operating voltage of a VTO nanostructure-based electrochromic device can be lowered; consequently, such a device can be operated more stably with less hysteresis. Further, we find that a pre-reduction of the ATO electrode does not affect the coloration efficiency of such a device. The aforementioned effects of a pre-reduction are attributed to the fact that a pre-reduced ATO electrode is more compatible with a VTO nanostructure-based electrochromic device than a non-pre-reduced ATO electrode, because of the initial oxidized state of the other electrode of the device, that is, a VTO nanostructure-based electrode. The oxidation state of a pre-reduced ATO electrode plays a very important role in the operation of a VTO nanostructure-based electrochromic device because it strongly influences charge movement during electrochromic switching.

• Earthquakes and Structures
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• v.15 no.2
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• pp.133-144
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• 2018

To study the effectiveness of sliding isolation in a CRLSS (concrete rectangular liquid-storage structure) and develop a reasonable limiting-device method, dynamic responses of non-isolation, sliding isolation with spring limiting-devices and sliding isolation with steel bar limiting-devices are comparatively studied by shaking table test. The seismic response reduction advantage of sliding isolation for concrete liquid-storage structures is discussed, and the effect of the limiting-device type on system dynamic responses is analyzed. The results show that the dynamic responses of sliding isolation CRLSS with steel bar-limiting devices are significantly smaller than that of sliding isolation CRLSS with spring-limiting devices. The structure acceleration and liquid sloshing wave height are greatly influenced by spring-limiting devices. The acceleration of the structure in this case is close to or greater than that of a non-isolated structure. Liquid sloshing shows stronger nonlinear characteristics. On the other hand, sliding isolation with steel bar-limiting devices has a good control effect on the structural dynamic response and the liquid sloshing height simultaneously. Thus, a limiting device is an important factor affecting the seismic response reduction effect of sliding isolation. To take full advantage of sliding isolation in a concrete liquid-storage structure, a reasonable design of the limiting device is particularly important.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.297-308
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• 1995

This study was designed to measure the absorbed dose to organs of special interest from full mouth with intraoral film(l4 films) and to compare the five periapical techniques. Thermoluminescent crystals(TLD-100 chip) were located in brain, orbit, bone marrow of mandibular ramus, bone marrow of mandibular body, bone marrow of 4th cervical spine, parotid gland, submandibular gland and thyroid gland. X -ray machine was operated at 70kVp and round collimating film holding device(XCP) and rectangular collimating film holding device(Precision Instrument) were used. The distance from the X-ray focus to the open end of the collimator was 8 inch, 12 inch and 16 inch. The results were as follows : 1. The absorbed dose was the highest in bone marrow of mandibular body(5.656mGy) and the lowest in brain (0.050mGy). 2. Generally, the lowest absorbed dose was measured from 16 inch cylinder, rectangular collimating film holding device with paralleling technique. But, in bone marrow of mandibular body and the floor of mouth, the highest absorbed dose was measured from 12 inch cylinder, rectangular collimating film holding device with paralleling techniques. 3. Comparing of five intraoral radiographic techniques, it was appeared statistically significant reduction of the absorbed doses measured with rectangular collimating film holding device compared to XCP film holding device (P<0.05). 4. No statistically significant reduction in the absorbed dose was found as cylinder length was changed(P>0.05).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.376.1-376
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• 2002

Reduction of the propagation noise generated during pass-by of KTX by noise barrier was measured and analysed fur the two kinds of top-shaped noise reduction devices; one as a plywood board and the other as a PVC pipe were placed periodically. The height and length of reference noise barrier are 2.4 m and 50 m, respectively. The noise reduction with and without noise reduction devices was investigated. (omitted)

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.407-416
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• 2023

Demand for leisure facilities such as mooring facilities for berthing leisure vessels and floating pensions based on floating bodies is increasing owing to the rapid growth of the population and related industries for marine leisure activities. Owing to its relatively light weight as a fluid, inclination is easily generated by waves and surcharges flowing to the coast, resulting in frequent safety accidents because of the low stability. As a solution to this problem, a motion reduction device for floating bodies is proposed in this study. The device (motion reduction device based on the air pressure dif erence) was attached to a floating body and the effect was analyzed by comparing the results with those of a floating body without motion reduction. The effect analysis was further analyzed using a computer analysis test, and the method for increasing the stability of the floating body was studied, and its the effect was verified. Based on the analysis of the test results, the stability of the floating body increased with a motion damping device is higher than that of the floating body without a motion reducing device as the wave momentum reduces, owing to the air pressure difference. Therefore it was concluded that the use of such a device for reducing motion a floating body is useful not only for non-powered ships but also for powered and semi-submersible ships, and further research should be conducted by applying it to various fields.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1073-1077
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• 2006

Proton irradiation technology was used for improvement of switching characteristics of the PT-IGBT. Proton irradiation was carried out at 5.56 MeV energy with $1{\times}10^{12}/cm^2$ doze from the back side of the wafer. The I-V, breakdown voltage, and turn-off delay time of the device were analyzed and compared with those of un-irradiated device and e-beam irradiated device which was conventional method for minority carrier lifetime reduction. For proton irradiated device, the breakdown voltage and the on-state voltage were 733 V and 1.85 V which were originally 749 V and 1.25 V, respectively. The turn-off time has been reduced to 170 ns, which was originally $6{\mu}s$ for the un-irradiated device. The proton irradiated device was superior to e-beam irradiated device for the breakdown voltage and the on-state voltage which were 698 V and 1.95 V, respectively, nevertheless turn-off time of proton irradiated device was reduced to about 60 % compared to that of the e-beam irradiated device.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1103-1107
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• 2016

The automatic tensioning device of the catenary system constantly maintains the tension of the trolley wire by absorbing the variations due to the elasticity of the line caused by temperature variation. The tension plays an important role in affecting the electric motorcar operation directly. This paper suggests the methodology of the life cycle extension and the maintenance of the automatic tensioning device by means of performance diagnosis of the pulley type automatic tensioning device which has been commonly used for the electric railway system. Through conducting performance diagnosis and comparative test for the wornout pulley type automatic tensioning device by replacing the components such as the bearing and the bearing shaft without replacing all the assembly, the tensioning device is analyzed whether it is properly functioned. Provided that the maintenance regulation is reinforced so as to implement the bearing replacement through periodical precise inspection along with random check-up inspection which is now carried out by the operating organizations, it is ensured that the life cycle extension and the reduction of maintenance cost of the tensioning device could be achieved.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.1
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• pp.58-60
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• 2000

In order to improve the loading efficiency in bulk dryer for the flue-cured tobacco leaves, a new hanger device was developed. It consists of two layers frame, in which large volume of the harvested leaves could be simply loaded. As the results of experiments with new hanger device, labor hours for loading could be saved by 34 % as compared with those in conventional 3 layers hanger, and loading capacity increased by 36%. The weight of hanger could be also reduced by 0.6kg compared to conventional 3.4kg, showing possibility of cost reduction for the developed hanger device with saved number of punching the rolled steel panels.

• Structural Engineering and Mechanics
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• v.61 no.6
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• pp.795-806
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• 2017

According to the characteristics of continuous beam bridges, the relative displacement is too large to collision or even girder falling under earthquakes. A device named Cable-sliding Modular Expansion Joints(CMEJs) that can control the relative displacement and avoid collision under different ground motions is proposed. Working principle and mechanical model is described. This paper design the CMEJs, establish the restoring force model, verify the force model of this device by the pseudo-static tests, and describe and analyze results of the tests, and then based on a triple continuous beam bridge that has different heights of piers, a 3D model with or without CMEJs were established under Conventional System (CS) and Seismic Isolation System (SIS). The results show that this device can control the relative displacement and avoid collisions. The combination of isolation technology and CMEJs can be more effective to achieve both functions, but it need to take measures to prevent girder falling due to the displacement between pier and beam under large earthquakes.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1187-1192
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• 2013

In the case of 4 wheel drive (4-WD) type car, power switching occurs to 4-WD by operating lever or switch that operates power switching device attached in transfer case which can operate motor by electric signal. So if the RPM of motor is high, power switching will not exactly occur and can cause damage to gear in transfer case according to circumstances. So in this study, we applied 2 level of planet gear type motor spindle of motor drive part of a power train. And conducted decelerating to increase torque to switch power safe and accurately. Also, we researched efficiency of gear by designing reduction gear ratio and gear type and by calculating contact stress and bending strength. Based on researched content, we made drive head of power switching device and a reduction module which uses type that uses motor spindle as sun gear and ring gear as cover.