• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.9
• /
• pp.4375-4388
• /
• 2018

To solve the problem of transmission errors in stereoscopic images, this paper proposes a novel error concealment (EC) method using superpixel segmentation and adaptive disparity selection (SSADS). Our algorithm consists of two steps. The first step is disparity estimation for each pixel in a reference image. In this step, the numbers of superpixel segmentation labels of stereoscopic images are used as a new constraint for disparity matching to reduce the effect of mismatching. The second step is disparity selection for a lost block. In this step, a strategy based on boundary smoothness is proposed to adaptively select the optimal disparity which is used for error concealment. Experimental results demonstrate that compared with other methods, the proposed method has significant advantages in both objective and subjective quality assessment.

• Proceedings of the KOSOMBE Conference
• /
• v.1993 no.11
• /
• pp.175-179
• /
• 1993

A Study on the speech processing and coding strategy for cochlear implants have been developed to create a speech signal processing system which extracts stimulus parameter including formants, pitch, amplitude information. In this study we have presented the method which extracts characteristic information of speech signal and adapt patients with hearing handicap.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1995.10a
• /
• pp.147-152
• /
• 1995

During transients or major upsets, operators of a nuclear power plant are faced with a significant amount of information which oftentimes exceeds their capability of processing information in such a time-critical situation. To help resolve this problem of information overload, considerable work is underway worldwide to improve its man-machine interface systems (MMISs). The I&C research team of KAERI is developing a DYNamic Alarm processing System, called DYNAS, to suppress unnecessary or nuisance alarms, and at the same time, emphasize vital information. This paper describes our basic strategy to process alarms in DYNAS.

• Korean Journal of Remote Sensing
• /
• v.17 no.4
• /
• pp.319-334
• /
• 2001

Extracting primitives from imagery plays an important task in visual information processing since the primitives provide useful information about characteristics of the objects and patterns. The human visual system utilizes features without difficulty for image interpretation, scene analysis and object recognition. However, to extract and to analyze feature are difficult processing. The ultimate goal of digital image processing is to extract information and reconstruct objects automatically. The objective of this study is to develop robust method to achieve the goal of the image processing. In this study, an adaptive strategy was developed by implementing Gabor filters in order to extract feature information and to segment images. The Gabor filters are conceived as hypothetical structures of the retinal receptive fields in human vision system. Therefore, to develop a method which resembles the performance of human visual perception is possible using the Gabor filters. A method to compute appropriate parameters of the Gabor filters without human visual inspection is proposed. The entire framework is based on the theory of human visual perception. Digital images were used to evaluate the performance of the proposed strategy. The results show that the proposed adaptive approach improves performance of the Gabor filters for feature extraction and segmentation.

• The KIPS Transactions:PartA
• /
• v.10A no.3
• /
• pp.261-268
• /
• 2003

In this paper, we propose a new caching strategy for web servers. The proposed strategy collects only the statistics of the requested file, for example the popularity, when a request arrives. At a point of time, only files with higher forecasted popularity are cached all together. Forecasted popularity based lazy caching (FPLC) strategy uses exponential smoothing method for forecast popularity of web files. And, FPLC strategy shows that the cache hit ratio and the cache transfer ratio are better than those produced by other caching strategy. Furthermore, the experiment that is performed with real log files built from web servers shows our study on forecast method for popularity of web files improves cache efficiency.

• Food preservation and processing industry
• /
• v.14 no.2
• /
• pp.10-17
• /
• 2015

• Journal of Power Electronics
• /
• v.16 no.1
• /
• pp.227-237
• /
• 2016

A novel digital current control strategy for digitally controlled DC-DC switching converters, referred to as Adjacent Cycle Sampling (ACS), is proposed in this paper. For the ACS current control strategy, the available time interval from sampling the current to updating the duty ratio, is approximately one switching cycle. In addition, it is independent of the duty ratio. As a result, the contradiction between the processing speed of the hardware and the transient response speed can be effectively relaxed by using the ACS current control strategy. For digitally controlled buck DC-DC switching converters with trailing-edge modulation, digital current control algorithms with the ACS control strategy are derived for three different control objectives. These objectives are the valley, average, and peak inductor currents. In addition, the sub-harmonic oscillations of the above current control algorithms are analyzed and eliminated by using the digital slope compensation (DSC) method. Experimental results based on a FPGA are given, which verify the theoretical analysis results very well. It can be concluded that the ACS control has a faster transient response speed than the time delay control, and that its requirements for hardware processing speed can be reduced when compared with the deadbeat control. Therefore, it promises to be one of the key technologies for high-frequency DC-DC switching converters.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.7
• /
• pp.1694-1705
• /
• 1997

In the future mobile computing environment, it will be generalized that a mobile host with portable Laptop of Palmtop accesses to database through wireless communication channel. For solving the problems which are caused from low bandwidth of wireless communication, mobile hosts cache the datum used frequently on them. Thus the mobile hosts must always retain the cache consistency for the correctness of the cached datum. the cache consistency is mainly affected from the unrestricted host mobility and the disconnection of the communication between mobile hosts and mobile support station. In this situation, the strategy to retain efficiently cache consistency is required. In this paper, we propose a strategy using updatable message for retaining the cache consistency, in the mobile computing environment, with replicated database supporting 2 phase commit protocol. This strategy makes use of a updatable message to resolve the cache consistency problem, since mobile host crosses the boundary of cell. In using of this updatable, it find out and cache only the update data of missing invalidation message. As a result, the proposed strategy utilizes network bandwidth efficiently because it is not need to delete all the cached datum with any datum change.

• Journal of Astronomy and Space Sciences
• /
• v.24 no.4
• /
• pp.275-284
• /
• 2007

For the application to the numerical weather prediction (NWP) in active service, it is necessary to ensure that the GPS precipitable water vapor (PWV) data has less than one hour latency and three millimeter accuracy. The comparison and the verification between the daily products from GPS measurement by using the IGS final ephemeris and the conventional meteorological observation has been done in domestic researches. In case of using IGS final ephemeris, GPS measurements can be only post processed in daily basis in three weeks after the observation. Thus this method cannot be applied to any near real-time data processing. In this paper, a GPS data processing method to produce the PWV output with three mm accuracy and one hour latency for the data assimilation in NWP has been planned. For our new data processing strategy, IGS ultra-rapid ephemeris and the sliding window technique are applied. And the results from the new strategy has been verified. The GPS measurements during the first 10 days of January, April, July and October were processed. The results from the observations at Sokcho, where the GPS and radiosonde were collocated, were compared. As the results, a data processing strategy with 0.8 mm of mean bias and 1.7 mm of standard deviation in three minutes forty-three seconds has been established.

• Journal of the Korean Society of Systems Engineering
• /
• v.2 no.1
• /
• pp.18-23
• /
• 2006

The purpose of this study and report is to provide, to the MND, an independent cost analysis of modernizing software of F-16 fighter fleets to support the use of several weapon system options, including JDAM, AIM-9X and HARM Targeting System etc. The study analyzed each options with software sizing, software cost, enabling hardware cost, flight test cost, system engineering cost, and 3 strategies. And the study proposed and analyzed some alternative strategies: strategy1 is to modernize software only within existing electronic processing capability; strategy2 is a full upgrade of weapons avionics with plug compatible electronics; strategy3 is an approach defined to mirror the USAF Common Configuration Implementation Approach (CCIP). The recommended alternative is strategy2.