• The KIPS Transactions:PartD
• /
• v.10D no.1
• /
• pp.1-12
• /
• 2003

Recently, there have been many indexing schemes for multimedia data such as image, video data. But recent database applications, for example data mining and multimedia database, are required to support multi-user environment. In order for indexing schemes to be useful in multi-user environment, a concurrency control algorithm is required to handle it. So we propose a concurrency control algorithm that can be applied to CBF (cell-based filtering method), which uses the signature of the cell for alleviating the dimensional curse problem. In addition, we extend the SHORE storage system of Wisconsin university in order to handle high-dimensional data. This extended SHORE storage system provides conventional storage manager functions, guarantees the integrity of high-dimensional data and is flexible to the large scale of feature vectors for preventing the usage of large main memory. Finally, we implement the web-based image retrieval system by using the extended SHORE storage system. The key feature of this system is platform-independent access to the high-dimensional data as well as functionality of efficient content-based queries. Lastly. We evaluate an average response time of point query, range query and k-nearest query in terms of the number of threads.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.5A
• /
• pp.717-725
• /
• 2000

Within the last several years, there has been a large number of algorithms developed for face recognition. The majority of these algorithms have been view- and projection-based algorithms. Our definition of projection is not restricted to projecting the image onto an orthogonal basis the definition is expansive and includes a general class of linear transformation of the image pixel values. The class includes correlation, principal component analysis, clustering, gray scale projection, and matching pursuit filters. In this paper, we perform a detailed analysis of this class of algorithms by evaluating them on the FERET database of facial images. In our experiments, a projection-based algorithms consists of three steps. The first step is done off-line and determines the new basis for the images. The bases is either set by the algorithm designer or is learned from a training set. The last two steps are on-line and perform the recognition. The second step projects an image onto the new basis and the third step recognizes a face in an with a nearest neighbor classifier. The classification is performed in the projection space. Most evaluation methods report algorithm performance on a single gallery. This does not fully capture algorithm performance. In our study, we construct set of independent galleries. This allows us to see how individual algorithm performance varies over different galleries. In addition, we report on the relative performance of the algorithms over the different galleries.

• Journal of Surface Science and Engineering
• /
• v.42 no.1
• /
• pp.8-12
• /
• 2009

Electronic structures and chemical bonding of Li-intercalated $LiTiS_2$ and $LiTiO_2$ were investigated by using discrete variational $X{\alpha}$ method as a first-principles molecular-orbital method. ${\alpha}-NaFeO_2$ structure is the equilibrium structure for $LiCoO_2$, which is widely used as a commercial cathode material for lithium secondary battery. The study especially focused on the charge state of Li ions and the magnitude of covalency around Li ions. The average voltage of lithium intercalation was calculated using pseudopotential method and the average intercalation voltage of $LiTiO_2$ was higher than that of $LiTiS_2$. It can be explained by the differences in Mulliken charge of lithium and the bond overlap population between the intercalated Li ions and anions in $LiTiO_2$ as well as $LiTiS_2$. The Mulliken charge, which means the ionicity of Li atom, was approximately 0.12 in $LiTiS_2$ and the bond overlap population (BOP) indicating the covalency between Ti and S was about 0.339. One the other hands, the Mulliken charge of lithium was about 0.79, which means that Li is fully ionized. The BOP, the covalency between Ti and O, was 0.181 in $LiTiO_2$. Because of high ionicity of Li and the weak covalency between Ti and the nearest anion, $LiTiO_2$ has a higher intercalation voltage than that of $LiTiS_2$.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.5
• /
• pp.295-305
• /
• 2010

Although the rubble mound breakwaters in Korea have been damaged by typhoons almost every year, quantification of erosion of armor block have seldomly been made. In this paper, the damage of armor units is standardized by the relative damage. In the case where the number of damaged units is reported, it is divided by the total number of units to calculate the relative damage. In the case where the rehabilitation cost is reported, the relative damage is calculated by using its relationship with the present value of the past rehabilitation cost. The relative damage is shown to have strong correlations with the typhoon parameters such as nearest central air pressure and maximum wind speed at each site. On the other hand, the existing numerical methods for calculating the cumulative damage are compared with hydraulic model tests. The method of Melby and Kobayashi (1998) is shown to give a reasonable result, and it is used to calculate the relative damage, which is compared with the measured damage. A good agreement is shown for the East Breakwater of Yeosu Harbor, while poor agreement is shown for other breakwaters. The poor agreement may be because waves of larger height than the design height occurred due to strong typhoons associated with climate change so that the relative damage increased during the last several decades.

• Journal of Korean Society of Transportation
• /
• v.25 no.4
• /
• pp.79-87
• /
• 2007

The interchanges of urban freeways have many problems with traffic operation due to high off-ramp flows and frequent congestion at adjacent intersections. The flow exiting from off-ramps is affected by the operational status and traffic volume conditions of the nearest signalized intersection. As a result, off-ramp flow cannot exit and the queue backs up the freeway mainline when queues from the signalized intersection form up to the junction of the off-ramp and street. The spacing between an off-ramp and an adjacent intersection is likely to determine the traffic conditions at the adjacent intersection. However, the current design guidelines do not consider such a factor. This study is to develop a model calculating the spacing between off-ramps and adjacent intersections considering the signal, traffic, and road conditions. The variables affecting the model in this study are effective green time (g/C), volume-capacity ratio (v/c), the number of lanes, and off-ramp volume. Various scenarios are designed to represent the effects of the variables and the road networks are constructed using VISSIM, which is a common traffic micro-simulation software package. The queue length is derived from VISSIM and this length is considered as the recommended spacing between the off-ramp and the adjacent intersection. Through the simulation analysis, regression models are developed to calculate the queue length reflecting the various conditions such as signals, traffic, and road configurations. The developed model can be used to create road design guidelines to determine the location of off-ramps in the planning stage.

• Journal of the Korean Magnetics Society
• /
• v.15 no.1
• /
• pp.1-6
• /
• 2005

In this study we investigate the electronic structure and magnetism of transition metal (TM = Ti, Cr, Mn, Fe, Co, Ni, Ru, Pd, Ag ) deped ZnO($TM_{0.25}Zn_{0.75}O$), which are expected to have Curie temperature. Full-potential Linearized Augmented Plane Wave(FLAPW) metod is adopted with exchange-correlation potential expressed as general gradient approximation(GGA). The calculated magnetic moments of ($TM_{0.25}Zn_{0.75}O$) are 0.83, 3.03, 4.03, 3.48, 2.47, 1.56, 0.43, 0.75, 0.01 ${\mu}_B$ for TM = Ti, Cr, Mn, Fe, Co, Ni, Ru, Pd, Ag, respectively. The nearest neighbor O atom to the transition metal is calculated to have a significant magnetic moment of about 0.1${\mu}_B$, ?? 새 strong hybridization between O-p and TM-d bands. As the results, the systems may have larger magnetic moments in total, compared to the corresponding isolated atoms. The 3d TM doped systems exhibit the half-metallic character except Co, wheres the 4d TM doped systems behave like normal metals and low spin polarization at the Fermi levels.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.1
• /
• pp.73-80
• /
• 2018

In motorway traffic flow control, the conventional way based on real-time response has been changed into advanced way based on proactive response. Future traffic conditions over multiple time intervals are crucial input data for advanced motorway traffic flow control. It is necessary to overcome the uncertainty of the future state in order for forecasting multiple-period traffic volumes, as the number of uncertainty concurrently increase when the forecasting horizon expands. In this vein, multi-interval forecasting of traffic volumes requires a viable approach to conquer future uncertainties successfully. In this paper, a forecasting model is proposed which effectively addresses the uncertainties of future state based on the behaviors of temporal evolution of traffic volume states that intrinsically exits in the big past data. The model selects the past states from the big past data based on the state evolution of current traffic volumes, and then the selected past states are employed for estimating future states. The model was also designed to be suitable for data management systems in practice. Test results demonstrated that the model can effectively overcome the uncertainties over multiple time periods and can generate very reliable predictions in term of prediction accuracy. Hence, it is indicated that the model can be mounted and utilized on advanced data management systems.

• Annals of Clinical Neurophysiology
• /
• v.1 no.2
• /
• pp.112-117
• /
• 1999

Background : Posterior tibial nerve somatosensory evoked potentials (PTSEP) have cortical potentials on primary sensory area of foot around 40 msec. The direct cortical recordings of the cortical potentials shows high voltage positive wave on medial hemisphere, especially on paracentral lobule (PCL). However, it is so difficult to record the potential directly on PCL that the cortical potential of PTSEP is not well understood. We investigated the cortical potential of PTSEP on subdural electrodes. Methods : We recorded cortical potentials to posterior tibial nerve stimulation on subdural electrodes which were on medial hemisphere near PCL in 15 intractable neocortical epilepsy patients. The numbers of subdural electrodes were 8 in 10 subjects ($1{\times}8array$) and 16 in 5 subjects ($2{\times}8arrays$). Seven subjects had three-dimensional imaging fusion (3D-fusion) of MRI and the electrodes using Analyze program. We investigated the amplitude, latency, polarity, and phase of the waves regarding location. Results : The waves had maximal amplitude on PCL in 4 subjects, precuneus in 1, cingulate gyrus nearest to PCL in 2 among 7 subjects with 3D-fusion. Also the electrodes were located on posterior area of PCL (2 out of 2 subjects with more than two electrodes put on PCL in 3D-fusion) and superior area of it (5 out of 5 subjects with $2{\times}8arrays $). All the high (more than 20 uV) amplitude around 40msec had positive polarity in 7 subjects. The phase reversals were detected between the electrodes with the highest amplitude and the just posterior (2 subjects) or anterior (6 subjects) located electrodes. The just posterior located electrodes had sharper phase reversal than the anterior one. Conclusion : PTSEP might have maximal amplitude of cortical potentials on the more superior and posterior area of PCL. The highest amplitude potential has positivity. The wave with maximal amplitude could have phase reversal of cortical potentials with surrounding electrodes, especially shaper with posterior part than with anterior one.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.4
• /
• pp.259-267
• /
• 2013

GIS-based web map service is all the more accessible to the public. Among others, location query services are most frequently utilized, which are currently restricted to only one keyword search. Although there increases the demand for the service for querying multiple keywords corresponding to sequential activities(banking, having lunch, watching movie, and other activities) in various locations POI, such service is yet to be provided. The objective of the paper is to develop the k-IPS algorithm for quickly and accurately querying multiple POIs that internet users input and locating the search outcomes on a web map. The algorithm is developed by utilizing hierarchical tree structure of $R^*$-tree indexing technique to produce overlapped geometric regions. By using recursive $R^*$-tree index based spatial join process, the performance of the current spatial join operation was improved. The performance of the algorithm is tested by applying 2, 3, and 4 multiple POIs for spatial query selected from 159 keyword set. About 90% of the test outcomes are produced within 0.1 second. The algorithm proposed in this paper is expected to be utilized for providing a variety of location-based query services, of which demand increases to conveniently support for citizens' daily activities.

• Korean Journal of Ecology and Environment
• /
• v.45 no.2
• /
• pp.252-260
• /
• 2012

The wetlands have eco-sociological values because their functions have proven to be useful to human society. Many countries are working to conserve and protect the wetland ecosystems. However, many wetlands have disappeared or have been fragmented due to a natural and/or anthropogenic disturbance. These isolated wetlands appear to work best in the landscape, as a spatially distributed system. We have analyzed the spatial-social distribution patterns of wetlands in Gyeongsangnam-do Province (GNP). We examined the frequency distribution of wetland sizes, the distances to the nearest wetlands, the shapes of the wetlands, land-use patterns, land owners, and official land values were confirmed as social characteristics for each wetland. A total of 146 wetlands (3,598.85 ha), including 76 riverine wetlands (1,955.60 ha), 49 palustrine wetlands (1,282.28 ha) and 21 mountain wetlands (1,282.28 ha) were identified in GNP. Most wetlands left for use to drainage were small (<2 ha) and located in agricultural areas. However, small and isolated wetlands were clustered, according to the location, indicating that these wetlands can be connected to each other using the linear riverine wetlands and water channels in agricultural areas. This is extremely valuable in maintaining the biodiversity, such that any loss of small wetlands will cause a direct reduction in the connectedness among populations of the remaining species. Due to most wetlands belonging to the nation or businesses, being classified as reservoirs (water storage areas), and consequently, degradation of wetlands will progress due to grand-scale engineering works. Therefore, wetland policy and ecologically sensitive laws and policies should be developed in order to promote the wise-use for wetlands.