• Journal of Korea Multimedia Society
• /
• v.23 no.1
• /
• pp.8-14
• /
• 2020

For a reliable fingerprinting system, improving fingerprint matching accuracy is crucial. In this paper, we try to improve a binary image fingerprint matching performance by utilizing auxiliary information, power mask, which is obtained while constructing fingerprint DB. The power mask is an expected robustness of each fingerprint bit. A caveat of the power mask is the increased storage cost of the fingerprint DB. This paper mitigates the problem by reducing the size of the power mask utilizing spatial correlation of an image. Experiments on a publicly-available image dataset confirmed that the power mask is effective in improving fingerprint matching accuracy.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2008.10a
• /
• pp.504-509
• /
• 2008

다수고객을 서비스하기 위한 설비의 입지선정문제는 현 기업환경 하에 많은 분야에서 광범위하게 응용되고 있다. 본 논문은 경쟁사 설비가 기 입지해 있는 상황에서 시장점유율을 최대화하기 위해 정해진 수의 설비를 주어진 입지후보지에 설치하기 위한 입지선정문제를 다룬다. 고객은 도시공학 분야에서 잘 알려진 4개의 도시공간구조 이론에 근거하여 분포시키고, 고객의 수요를 최대로 충족시킬 수 있는 매장의 입지를 선정한다. 실험을 통해 각 도시 공간형태별로 상이한 고객의 분포형태와 계층별 거주지역의 밀집도가 매장의 위치에 미치는 영향을 확인한다. 또한 입지선정문제는 잘 알려진 NP-hard 문제임에 따라 합리적인 시간에 근사 최적해를 도출하기 위하여 유전자 알고리즘을 적용함으로써 기업의 입장에서 이윤을 극대화하는 최적의 설비위치를 결정할 수 있는 모델을 제시하였다.

• International Journal of Contents
• /
• v.11 no.1
• /
• pp.69-72
• /
• 2015

Generally, existing parallel main-memory spatial index structures to avoid the trade-off between query freshness and CPU cost uses light-weight locking techniques. However, still, the lock based methods have some limits such as thrashing which is a well-known problem in lock based methods. In this paper, we propose a distributed index structure for moving objects exploiting the parallelism in multiple machines. The proposed index is a lock free multi-version concurrency technique based on the D-Stream model of Spark Stream. The proposed method exploits the multiversion nature of D-Stream of Spark Streaming.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.05
• /
• pp.279-282
• /
• 1997

Bayesian reconstruction methods for emission computed tomography have been a topic of interest in recent years, partly because they allow for the introduction of prior information into the reconstruction problem. Early formulations incorporated priors that imposed simple spatial smoothness constraints on the underlying object using Gibbs priors in the form of four-nearest or eight-nearest neighbors. While these types of priors, known as "membrane" priors, are useful as stabilizers in otherwise unstable ML-EM reconstructions, more sophisticated prior models are needed to model underlying source distributions more accurately. In this work, we investigate whether the "thin plate" model has advantages over the simple Gibbs smoothing priors mentioned above. To test and compare quantitative performance of the reconstruction algorithms, we use Monte Carlo noise trials and calculate bias and variance images of reconstruction estimates. The conclusion is that the thin plate prior outperforms the membrane prior in terms of bias and variance.

• Proceedings of the KIEE Conference
• /
• 2005.05a
• /
• pp.33-35
• /
• 2005

We propose an eye gaze tracking system under natural head movements. The system consists of one CCD camera and two front-surface mirrors. The mirrors rotate to follow head movements in order to keep the eye within the view of the camera. However, the mirror controller cannot guarantee the fast head movements, because the frame rate is generally 30Hz. To overcome this problem, we applied Kalman predictor to estimate next eye position from the current eye image. In the results, our system allows the subjects head to move 50cm horizontally and 40cm vertically, with the speed about 10cm/sec and 6cm/sec, respectively. And spatial gaze resolutions are about 4.5 degree and 4.5 degree, respectively, and the gaze estimation accuracy is 92% under natural head movements.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.541-544
• /
• 2004

Recently, the heat island phenomenon in which the temperature of a city part rises from the circumference ground has developed into a big problem. In this study, we aimed at examining the impact of increasing vegetation in urban areas to reduce the heat island phenomenon by taking the Fukuoka City of Japan as a case. In order to discuss the relation between vegetation environment and the heat island phenomenon, we have calculated Normalized Difference Vegetation Index (NDVI) and mapped the spatial vegetation distribution. These are then compared with the heat island phenomenon investigations in Fukuoka City. The results of the study revealed that the areas showing comparatively lesser heat island phenomenon are those having increased vegetation.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.188-190
• /
• 2006

A multistage hierarchical clustering technique, which is an unsupervised technique, was suggested in this paper for classifying large remotely-sensed imagery. The multistage algorithm consists of two stages. The local segmentor of the first stage performs regiongrowing segmentation by employing the hierarchical clustering procedure of CN-chain with the restriction that pixels in a cluster must be spatially contiguous. This stage uses a sliding window strategy with boundary blocking to alleviate a computational problem in computer memory for an enormous data. The global segmentor of the second stage has not spatial constraints for merging to classify the segments resulting from the previous stage. The experimental results show that the new approach proposed in this study efficiently performs the segmentation for the images of very large size and an extensive number of bands

• ETRI Journal
• /
• v.34 no.1
• /
• pp.98-101
• /
• 2012

The directional medium access control (MAC) protocol improves the throughput of mobile ad hoc networks but has a deafness problem and requires location information for neighboring nodes. In the dual-channel directional MAC protocol [12], the use of omnidirectional packets does not require the exact location of destination node. In this letter, we propose a tone dual-channel MAC protocol with directional antennas to improve the throughput of mobile ad hoc networks. In the proposed MAC protocol, we use a directional CTS and an out-of-band directional DATA tone with a new blocking algorithm to improve the spatial reuse. We confirm the throughput performance of the proposed MAC protocol by computer simulations using the Qualnet simulator.

• Journal of the Korean housing association
• /
• v.26 no.1
• /
• pp.19-30
• /
• 2015

As the number of homeless is increasing, there have been worries for social burden and social insecurity, along with crisis in human dignity. The purpose of this research is to identify characteristics of a Supportive Housing (SH) project which is considered best practice in dealing with homeless problem. A field visit walk through observation and in-depth interview was utilized as the main research method. As results, overall management, spatial and service characteristics were delineated, and its meaning and uniqueness were discussed, as well as, comparison with Korean conditions. In conclusion, the characteristics of the Supportive Housing were more realistically revealed through a current field case to inspire to explore housing for Korea. Besides current concerns were linked and implication to Korean adaptation was suggested. This study is unique in that SH of USA is firstly introduced in such details.

• Proceeding of KASS Symposium
• /
• 2008.05a
• /
• pp.113-118
• /
• 2008

This paper presents a flexural-torsional analysis of thin-walled open-section composite beams. A general geometrically nonlinear model for thin-walled composite beams and general laminate stacking sequences is given by using systematic variational formulation based on the classical lamination theory. The nonlinear algebraic equations of present theory are linearized and solved by means of an incremental Newton-Raphson method. Based on the analytical model, a displacement-based one-dimensional finite element model is developed to formulate the problem. Numerical results are obtained for thin-walled composite beams under general loadings, addressing the effects of fiber angle, laminate stacking sequence and loading parameters.