• The Journal of the Acoustical Society of Korea
• /
• v.19 no.7
• /
• pp.7-14
• /
• 2000

In this paper, we propose a near-field target localization algorithm using a bottom-mounted linear sensor amy in a multipath environment. In a multipath environment, the conic angles of a target signals through each path are different, and the position of the target can be estimated using these conic angles and the time difference of these signals. We derive equations on the relation of time-difference of signals and conic angles estimates under the far-field assumption, and estimate the position of target by simultaneously solving these equations. For a certain geometry of a target and the sensor array, there exist cases when the conic angles are very close. In such a case, we estimate the position of the target using an additional 1-D search.

• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.2
• /
• pp.49.3-50
• /
• 2016

Deep Ecliptic Patrol of the Southern Sky (DEEP-South) observations have been conducted officially during the off-season for exoplanet search since October 2015. Most of the allocated time for DEEP-South is devoted to targeted photometry, Opposition Census (OC), of Near Earth Asteroids (NEAs) to increase the number of such objects with known physical properties. It is efficiently achieved by multiband, time series photometry. This Opposition Census (OC) mode target objects near their opposition, with km-sized PHAs in the early stage and goes down to sub-km objects. Continuous monitoring of the sky with KMTNet is optimized for spin characterization of various kinds of asteroids, including binaries, satellites, slow/fast- and non-principal axis-rotators, and hence is expected to facilitate the debiasing of previously reported lightcurve observations. We present the preliminary lightcurves of NEAs from year one of the DEEP-South with our long term plan.

• Bulletin of the Korean Space Science Society
• /
• 2009.10a
• /
• pp.29.4-30
• /
• 2009

Extra-tidal feature of the globular clusters such as tidal tails and halos can be a crucial evidence of the merging scenario of the Galaxy formation in the dynamical point of view. To search for such an extra-tidal feature of globular clusters located in the Galactic bulge(RGC<3kpc), we obtained wide-field near-infrared JHKs images of 6 metal-poor ([Fe/H]<-1.0) clusters and 3 metal-rich ([Fe/H]>-1.0) clusters. Observations were carried out using IRSF 1.4m telescope and SIRIUS near-infrared camera, during 2006~2007. The obtained images have a total maximum field-of-view of ~ $21'\times 21'$. To select clusters' member stars and minimize the field star contaminations, we applied CMD masking algorithm. Smoothed surface density contour maps with selected stars for each cluster show overdensity features around the tidal radius and beyond. Also, radial surface density profiles within the tidal radius of the clusters show an overdensity feature as a change of slope of the radial profile. The results add further observational constraints of the formation of the Galactic bulge.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.18 no.3
• /
• pp.102-112
• /
• 2015

In this paper we propose an application that can help you to find a school near you easily using smart phone GPS capabilities and Google map mounted on Android system. We use a shortest path algorithm to search near destinations. You can take advantage of the developed application when finding public places or destinations. Schools have usually been used as places for disaster evacuation, entrance examination, and qualifying examination. Even though you are not the young who use the smart phone easily, anyone can find a destination school easily with the proposed application of this paper.

• ETRI Journal
• /
• v.15 no.3
• /
• pp.47-59
• /
• 1994

A capacity expansion planning problem with buy-or-lease decisions is considered. Demands for capacity are deterministic and are given period-dependently at each period. Capacity additions occur by buying or leasing a capacity, and leased capacity at any period is reconverted to original source after a fixed length of periods, say, lease period. All cost functions (buying, leasing and idle costs) are assumed to be concave. And shortages of capacity and disposals are not considered. The properties of an optimal solution are characterized. This is then used in a tree search algorithm for the optimal solution and other two algorithms for a near-optimal solution are added. And these algorithms are illustrated with numerical examples.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.102.5-102
• /
• 2002

In this paper auto-tuning scheme of PID controller based on the reference model has been studied by immune algorithm for a process. Up to this time, many sophisticated tuning algorithms have been tried in order to improve the PID controller performance under such difficult conditions. However, in the actual plant, they are manually tuned through a trial and error procedure, and the derivative action is switched off. Therefore, it is difficult to tune. Simulation results by immune based tuning reveal that tuning approaches suggested in this paper is an effective approach to search for optimal or near optimal process control.

• Speech Sciences
• /
• v.11 no.2
• /
• pp.211-216
• /
• 2004

In this paper, we present a fast encoding algorithm for vector quantization with an approximate Euclidean distance calculation. An approximation is performed by converting floating point to the near integer. An inequality between the approximate Euclidean distance and the nearest distance is developed to avoid unnecessary distance calculations. Since the proposed algorithm rejects those codewords that are impossible to be the nearest codeword, it produces the same output as conventional full search algorithm.

• 한국초전도학회:학술대회논문집
• /
• v.11
• /
• pp.20-20
• /
• 2001

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2002.05a
• /
• pp.645-651
• /
• 2002

we propose a k-nearest neighbors(k-NN) based pattern selection method. The method tries to select the patterns that are near the decision boundary and that are correctly labeled. The simulations over synthetic data sets showed promising results: (1) By converting a non-separable problem to a separable one, the search for an optimal error tolerance parameter became unnecessary. (2) SVM training time decreased by two orders of magnitude without any loss of accuracy. (3) The redundant SVM were substantially reduced.

• The Bulletin of The Korean Astronomical Society
• /
• v.33 no.2
• /
• pp.61.2-61.2
• /
• 2008