• Journal of Korea Game Society
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• v.12 no.5
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• pp.79-88
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• 2012

In this paper, we present a real-time hand pose recognition method to provide an intuitive user interface through hand poses or movements without a keyboard and a mouse. For this, the areas of right and left hands are segmented from the depth camera image, and noise removal is performed. Then, the rotation angle and the centroid point of each hand area are calculated. Subsequently, a circle is expanded at regular intervals from a centroid point of the hand to detect joint points and end points of the finger by obtaining the midway points of the hand boundary crossing. Lastly, the matching between the hand information calculated previously and the hand model of previous frame is performed, and the hand model is recognized to update the hand model for the next frame. This method enables users to predict the hidden fingers through the hand model information of the previous frame using temporal coherence in consecutive frames. As a result of the experiment on various hand poses with the hidden fingers using both hands, the accuracy showed over 95% and the performance indicated over 32 fps. The proposed method can be used as a contactless input interface in presentation, advertisement, education, and game applications.

• Journal of the Korean Geographical Society
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• v.43 no.6
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• pp.961-980
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• 2008

It is usual to prioritize the blocks to rearrange residential environment by the responsible officer's intuition or a few specialist's experienced knowledge. The aim of this research was to evaluate rebuilding priority in the context of spatially weighted framework integrating resident's view. The spatial weighting for the variables related to evaluation of dwelling environment was derived from AHP (Analytic Hierarchy Process) approach through the analysis of resident's view. An empirical study for a case study site has been conducted to confirm the validity for the spatial weighting. The spatial weighting has frequently influenced in changing the rebuilding priority and was identified as the important predictor for the improvement sites of dwelling environment. The spatially weighted analysis made it possible to identify area-wide patterns of rebuilding priority area subject to many different type of thematic variables, which cannot be acquired by traditional field sampling. The spatially weighting derived by integrating various formats of spatial data into a comprehensive GIS database in particular, was ideally suited to displaying the objective distribution patterns for rebuilding priority. The result of this study would play a crucial role in dealing with public complaints for rebuilding priority since it could provide objective evidences in accordance with spatial weighting.

• Journal of Korea Multimedia Society
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• v.7 no.2
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• pp.223-230
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• 2004

A shooting game is all game genres that hit targets through shooting. It include a lot of genres from a flying shot of game room to a personal shooting action game. In this point, a shooting game was regarded it as the origin of all game and it was developed from the early days of game. At present we can meet it in an electronic game room or personal computer, and mobile phone etc.. The popularity of shooting game caused to take aim by simple system, interface, and speedy play. Also it was enticed everyone to enjoy it easily. A shooting games is worked from old like ways until recently and a process of playing game is intuitive than another game. Therefore it popular with a PC player as well as persons of all levels. Beginners can train this game easily through direction such as control way of object, advent way of enemy aircraft and scroll way of background. But as an usability of working and controlling game, beginners of game development can pass over a shooting sense that shout and hit basically. And after design, they will feel that cannot convey realistic effect and thrill etc.. At a result, hitting sense happens to graphic elements and sound. Therefore a measure of effect on these elements is started from analysis of good shooting game. This study was to focus on the advance effect of hitting sense in shooting game through analysis centered for 'the Beetlewing' and '1945 Plus'.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.2
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• pp.241-262
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• 2010

This study was carried out to identify the cognitive obstacles while using addition and subtraction with fractions, and to analyze the sources of cognitive obstacles. For this purpose, the following research questions were established : 1. What errors do elementary students make while performing the operations with fractions, and what cognitive obstacles do they have? 2. What sources cause the cognitive obstacles to occur? The results obtained in this study were as follows : First, the student's cognitive obstacles were classified as those operating with same denominators, different denominators, and both. Some common cognitive obstacles that occurred when operating with same denominators and with different denominators were: the students would use division instead of addition and subtraction to solve their problems, when adding fractions, the students would make a natural number as their answer, the students incorporated different solving methods when working with improper fractions, as well as, making errors when reducing fractions. Cognitive obstacles in operating with same denominators were: adding the natural number to the numerator, subtracting the small number from the big number without carrying over, and making errors when doing so. Cognitive obstacles while operating with different denominators were their understanding of how to work with the denominators and numerators, and they made errors when reducing fractions to common denominators. Second, the factors that affected these cognitive obstacles were classified as epistemological factors, psychological factors, and didactical factors. The epistemological factors that affected the cognitive obstacles when using addition and subtraction with fractions were focused on hasty generalizations, intuition, linguistic representation, portions. The psychological factors that affected the cognitive obstacles were focused on instrumental understanding, notion image, obsession with operation of natural numbers, and constraint satisfaction.

• Journal of KIISE
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• v.41 no.11
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• pp.943-957
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• 2014

Removing noise, called denoising, is an essential factor for the more intuitive and more accurate results in boundary image matching. This paper deals with a partial denoising problem that tries to allow a limited amount of partial noise embedded in boundary images. To solve this problem, we first define partial denoising time-series which can be generated from an original image time-series by removing a variety of partial noises and propose an efficient mechanism that quickly obtains those partial denoising time-series in the time-series domain rather than the image domain. We next present the partial denoising distance, which is the minimum distance from a query time-series to all possible partial denoising time-series generated from a data time-series, and we use this partial denoising distance as a similarity measure in boundary image matching. Using the partial denoising distance, however, incurs a severe computational overhead since there are a large number of partial denoising time-series to be considered. To solve this problem, we derive a tight lower bound for the partial denoising distance and formally prove its correctness. We also propose range and k-NN search algorithms exploiting the partial denoising distance in boundary image matching. Through extensive experiments, we finally show that our lower bound-based approach improves search performance by up to an order of magnitude in partial denoising-based boundary image matching.

• The KIPS Transactions:PartB
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• v.15B no.5
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• pp.421-434
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• 2008

As computer graphics, virtual reality and augmented reality technologies have been developed, in many application areas based on those techniques, interaction for 3D space is required such as selection and manipulation of an 3D object. In this paper, we propose a framework for a vision-based 3D interaction which enables to simulate functions of an expensive 3D mouse for a desktop environment. The proposed framework includes a specially manufactured interaction device using three-color LEDs. By recognizing position and color of the LED from video sequences, various events of the mouse and 6 DOF interactions are supported. Since the proposed device is more intuitive and easier than an existing 3D mouse which is expensive and requires skilled manipulation, it can be used without additional learning or training. In this paper, we explain methods for making a pointing device using three-color LEDs which is one of the components of the proposed framework, calculating 3D position and orientation of the pointer and analyzing color of the LED from video sequences. We verify accuracy and usefulness of the proposed device by showing a measurement result of an error of the 3D position and orientation.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.749-762
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• 2020

Precipitation is closely related to various hydrometeorological phenomena, such as runoff and evapotranspiration. In Korean Peninsula, observing rainfall intensity using weather radar and rain gauge network is dominating due to their accurate, intuitive and precise detecting power. However,since these methods are not suitable at ungauged regions, rainfall detection using satellite is required. Satellite-based rainfall data has coarse spatial resolution (10 km, 25 km), and has a limited range of usage due to its reliability of data. The aim of this study is to obtain finer scale precipitation. Especially, to make the applicability of satellite higher at ungauged regions, 10 km satellite-based rainfall data was downscaled to 1 km data using MODerate Resolution Imaging Spectroradiometer (MODIS) based cloud property. Downscaled precipitation was verified in urban region, which has complex topographical and environmental characteristics. Correlation coefficient was similar in summer (+0), decreased in spring (-0.08) and autumn (-0.01), and increased in winter (+0.04) season compared to Global Precipitation Measurement (GPM) based precipitation. Downscaling without calibration using in situ data could be useful in areas where rain gauge system is not sufficient or ground observations are rarely available.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.6
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• pp.477-483
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• 2015

Investigations into cavity flows have been conducted for noise and vibration problems that arise in cavity systems. Cavity systems have been applied in engineering devices and have undergone rapid development in the aerospace industry. Meanwhile, to the author's best knowledge, the cavity on a curved wall has been seldom studied. The present work is conducted to study the flow physics of a cavity mounted on a curved wall. Numerical analysis is performed to investigate the cavity flow. Two variables of sub- and supersonic cavity flows were considered: the radius of curvature of the curved wall (L/R) and the inlet Mach number. The results show that the uniform vortex generated by the cavity flow on the curved wall stabilize the pressure fluctuation as time passes. As the inlet Mach number increases, the pressure fluctuation amplitude increases. The results obtained from the curved wall are compared with those from a straight wall using Rossiter's formula. The Strouhal number of the curved wall is lower than that of the straight wall. Lower Strouhal numbers have been obtained in the present computational fluid dynamics (CFD) results than in the theoretical results using Rossiter's formula.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.421-436
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• 2016

Public-Private-Partnerships tend to be committed high project development cost and recover the cost through future revenue during the operation period. In general, long-term concession can bring on more revenue to private investors, but short-term concession less revenue due to the short recovering opportunities. The concession period is usually determined by government in advance or by the private sectors's proposal although it is a very crucial factor for the PPPs. Accurate traffic forecasting should be most important in planing and evaluating the operation period in that the forecasted traffic determines the project revenue with user fees in PPPs. In this regards, governments and the private investors are required to consider the traffic forecast risk when determining concession period. This study proposed a model for the optimal concession period in the PPPs transportation projects. Monte Carlo simulation was performed to find out the optimal concession period while traffic forecast uncertainty is considered as a project risk under the expected return of the private sector. The simulation results showed that the optimal concession periods are 17 years and 21 years at 5.5% and 7% discount level, respectively. This study result can be applied for the private investors and/or any other concerned decision makers for PPPs projects to set up a more resonable concession period.

• Journal of the Korean association of regional geographers
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• v.8 no.2
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• pp.216-228
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• 2002

This study analyzes the decision-making processes for university students to choose the location of their future houses in metropolitan area. Based on their intuitive judgment, the university students prefer the general criteria, transportation, facility, education and society, and economy in order. The Kendall coefficient of concordance W which determines the association among the rankings of the students' judgement on the importance of the general criteria is so low. It means that the students highly disagree their rankings of the importance of the general criteria. The rankings of the importance of the criteria like as transportation and education society are concentrated on a mean value, but those of the criteria like natural environment and economy are relatively dispersed. The students prefer the area between the center of Taegu-si center and its outskirts, the outskirts of Taegu-si, and the center of Taegu'si in order as an alternative location of their future house. From the specific criteria like the price of land and house, the student's preferences on the alternative locations of future house are varied as compared with those of the general criteria. According to a sensitivity analysis, the student's preference on the center of Taegu-si is increased, but that on the the outskirts of Taegu-si is decreased as the importance of facility and transportation factor is increased. On the contrary, the student's preference on the outskirts of Taegu-si is increased, but that on the center of Taegu-si is decreased as the importance of natural environments is increased.