• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.4
• /
• pp.327-334
• /
• 2010

Recently developed aircrafts use Fly-By-Wire(FBW) or Fly-By-Light(FBL) system. These systems have some merits; they can perform very complicated missions, they can expand the flight region and improve the reliability of the aircrafts. With the development of flight control systems that use FBW technique, flight envelope protection concept is introduced to guarantee reliability of the aircraft and improve the efficiency of mission achievement. In this study, flight envelope protection system is designed using a dynamic trim algorithm, a peak response estimation, and a gain scheduling technique. The performance of these methods are compared by performing numerical simulation.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.773-776
• /
• 2008

The corrosion of steel in concrete is significant in marine environment. Marine bridges are readily deteriorated due to the exposure to marine environment. Salt damage is one of the most detrimental causes to concrete bridges and port structures. Especially, the splash and tidal zones around water line are comparatively important in terms of safety and life-time point of view. During the last several decades, cathodic protection (cp) has been commonly accepted as an effective technique for corrosion control in concrete structures. Zn-mesh sacrificial anode has been recently developed and started to apply to the bridge column cp in marine condition. The detailed parameters regarding Zn-mesh cp technique, however, have not well understood. This study is to investigate how much Zn-mesh cp influences along the concrete column at elevated temperature. About 100cm column specimens with eight of 10cm segment rebars have been used to measure the variation of cp potential with the distance from Zn-mesh anode at both 10$^{\circ}$C and 40$^{\circ}$C in natural seawater. The cp potential change and current diminishment along the column specimens have been discussed for the optimum design of cp by Zn-mesh sacrificial anode

• Journal of the Korea Institute of Building Construction
• /
• v.19 no.2
• /
• pp.167-174
• /
• 2019

Protective facilities are the last means of ensuring the survivability of personnel and assets, and there is a greater amount of matters to consider than those of general buildings. However, the Defense Military Facilities Criteria and the Ministry of the Interior and Safety, Ordinance No. 20, are only considering the expected enemy threats. In this study, we use objective and statistical methods to refine the consideration of the required capacity of protection based on the opinions of the experts. Specifically, the study adopts the Delphi technique associating the experts related to 30 defense military facilities criteria. The first-round questions were open-ended, and it compiled the points to consider related to the bulletproof and explosion - proof design. The second questionnaire was applied as closed questionnaire with 7 points scale methods. As a result of the factor analysis on the opinions of the experts, it was confirmed that the protection requirement level was due to METT + TC.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06a
• /
• pp.116-119
• /
• 2011

Mobile devices are increasingly used, and changed persons' social habits of creating new relationship. While existed systems can not satisfied the principles of user-centered, convenient and ensure privacy. This paper describes an intelligent name-card exchange technique in context-aware smart phone, which has no verbose user operation, ability of intelligent match based on context-aware information, and privacy protection.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.1
• /
• pp.26-31
• /
• 2002

In this paper, an MPEG-2 based technique for embedding digital watermarks into MPEG-2 video is proposed. The technique hides watermarking information into the DCT coefficients of each frame from MPEG-2 video. Several experiments have been conducted to show the performance in different conditions: the location of embedding watermarks, the change of Bitrates, and relocation of I-pictures in the MPEG video.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.05a
• /
• pp.244-245
• /
• 2009

Sol-gel coatings of $TiO_2$ have been prepared from $TiO_2$ sol and deposited by dip-coating technique on 316L stainless steel sheets in order to study the electrochemical behaviorin corrosive solutions. The influence of the coatings on the chemical corrosion of the substrate has been evaluated by potentiodynamic polarization curves in different aqueous NaCl solution at $25^{\circ}C$.

• ETRI Journal
• /
• v.25 no.1
• /
• pp.52-54
• /
• 2003

We propose an improved algorithm for detecting audio watermarks based on a spread spectrum in the spectral domain. Since the energy of a watermark is much smaller than that of the cover audio data, pre-processing to reduce the effect of the cover data is needed to reliably extract watermarks. We introduce a spectral envelope filter as a pre-process that enhances detecting performance by filtering out the intrinsic spectral character of cover data. The proposed watermarking structure can be easily included in the compression system and can extract watermarks from partially decompressed spectral data. Our experimental results demonstrate that with a bit error rate of around 10 dB against general attacks, the proposed detecting scheme works better than detectors without the spectral filter.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.731-734
• /
• 2005

In this study, the design of advanced LVDS(Low Voltage Differential Signaling) I/O interface circuit with new structural low triggering ESD (Electro-Static Discharge) protection circuit was investigated. Due to the differential transmission technique and low power consumption at the same time. Maximum transmission data ratio of designed LVDS transmitter was simulated to 5Gbps. And Zener Triggered SCR devices to protect the ESD phenomenon were designed. This structure reduces the trigger voltage by making the zener junction between the lateral PNP and base of lateral NPN in SCR structure. The triggering voltage was simulated to 5.8V. Finally, we performed the layout high speed I/O interface circuit with the low triggered ESD protection device in one-chip.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.805-808
• /
• 2005

In this study, the design of advanced LVDS(Low Voltage Differential Signaling) I/O interface circuit with new structural low triggering ESD(Electro-Static Discharge) protection circuit was investigated. Due to the differential transmission technique and low power consumption at same time. maximum transmission data ratio of designed LVDS transmitter was simulated to 5Gbps, Also, the LIGCSCR(Latch-up Immune Gate Coupled SCR)was designed. It consists of PLVTSCR (P-type Low Voltage Trigger SCR), control NMOS and RC network. The triggering voltage was simulated to 3.6V. And the latch-up characteristics were improved. Finally, we performed the layout high speed I/O interlace circuit with the low triggered ESD protection device in one-chip.

• Corrosion Science and Technology
• /
• v.9 no.3
• /
• pp.137-141
• /
• 2010

Sodium nitrite is widely used as one of the popular corrosion inhibitors for the protection of ferrous metal in closed cooling water system, such as a diesel engine and a chiller. The optimum treatment conditions are studied through laboratory tests using linear polarization resistance (LPR) technique. Corrosion rate of the carbon steel electrode could be maintained less than $2.5{\times}10^{-3}$ mmpy in the test condition of 500 ppm as ${NO_2}^-$, 200 ppm as $Cl^-$, $70^{\circ}C$ and pH 6.8. The pH control is confirmed not to be an important factor in the protection of carbon steel by sodium nitrite inhibitor. The addition of tolyltriazole was needed for the protection of the copper alloy in the sodium nitrite treatment system.