• Journal of Positioning, Navigation, and Timing
• /
• v.9 no.4
• /
• pp.367-378
• /
• 2020

This paper introduces the development of the iterative multiple signal classification (MUSIC)-based direction-of-arrival (DOA) estimation system using a rotator that can control the direction of antenna for the global navigation satellite system (GNSS) interference. The system calculates the spatial spectrum according to the noise eigenvector of all dimensions to measure the number of signals (NOS). Also, to detect the false peak, the system adjusts the array antenna's direction and checks the change's peak angles. The phase delay and gain correction values for system calibration are calculated in consideration of the chamber's structure and the characteristics of radio waves. The developed system estimated DOAs of interferences located about 1km away. The field test results show that the developed system can estimate the DOA without NOS information and detect the false peak even though the inter-element spacing is longer than the half-wavelength of the interference.

• Journal of the Economic Geographical Society of Korea
• /
• v.1 no.1
• /
• pp.137-149
• /
• 1998

It is likely that the spatial structure of the intraurban accessibility as well as the accessibility value of each of the nodes in the subway network is affected by the addition of new linkages. The changes in the accessibility at individual nodes also affect the accessibility in the surrounding areas at some distances away from the nodes. Graph-theoretic algorithms have been developed as a proper measurement scheme for the nodal accessibility in tracked transport networks such as subway networks. However, the graph-theoretic measurements have limitations to estimate the spatial diffusion effect on the surrounding areas. This study proposes a new model for the spatial diffusion effect estimation of nodal accessibility increment in the subway network toward the surrounding areas. Since the distance decay trend of subway station use reflect the spatial diffusion effect of the accessibility of subway station toward the surrounding area. The model is deduced from the subway station use density function which is formulated by the questionnaire survey data.

• Journal of Information Technology Services
• /
• v.15 no.3
• /
• pp.211-221
• /
• 2016

The human spatial mobility information is in high demand in various businesses; however, there are only few studies on human mobility because spatio-temporal data is insufficient and difficult to collect. Now with the spread of smartphones and the advent of social networking services, the spatio-temporal data began to occur on a large scale, and the data is available to the public. In this work, we compared the movement behavior of residents and tourists by using geo-tagged tweets which contain location information. We chose Seoul to be the target area for analysis. Various creative concepts and analytical methods are used: grid map concept, cells visited concept, reverse geocoding concept, average activity index, spatial mobility index, and determination of residents and visitors based on the number of days in residence. Conducting a series of analysis, we found significant differences of the movement behavior between local residents and tourists. We also discovered differences in visiting activity according to residential countries and used applications. We expect that findings of this research can provide useful information on tourist development and urban development.

• Journal of Korea Multimedia Society
• /
• v.25 no.10
• /
• pp.1535-1545
• /
• 2022

Sign language has completely different meaning depending on the direction of the hand or the change of facial expression even with the same gesture. In this respect, it is crucial to capture the spatial-temporal structure information of each movement. However, sign language translation studies based on Sign2Gloss2Text only convey comprehensive spatial-temporal information about the entire sign language movement. Consequently, detailed information (facial expression, gestures, and etc.) of each movement that is important for sign language translation is not emphasized. Accordingly, in this paper, we propose Spatial-temporal Keypoints Centered Sign2Gloss2Text Translation, named STKC-Sign2 Gloss2Text, to supplement the sequential and semantic information of keypoints which are the core of recognizing and translating sign language. STKC-Sign2Gloss2Text consists of two steps, Spatial Keypoints Embedding, which extracts 121 major keypoints from each image, and Temporal Keypoints Embedding, which emphasizes sequential information using Bi-GRU for extracted keypoints of sign language. The proposed model outperformed all Bilingual Evaluation Understudy(BLEU) scores in Development(DEV) and Testing(TEST) than Sign2Gloss2Text as the baseline, and in particular, it proved the effectiveness of the proposed methodology by achieving 23.19, an improvement of 1.87 based on TEST BLEU-4.

• Journal of Environmental Science International
• /
• v.6 no.3
• /
• pp.195-203
• /
• 1997

Pusan has experienced some different paths of urbanization and industrialization compared to other cities. and has faced the problem of over-saturation In enoronmental capacity. Pusan needs to fond out sustainable development strategies based on Agenda 21 by UNCED In 1992 to secure urban renewal. Therefore. Pusan's sustainable development strategies focus on the 1)research on envlronmental capacity and reasonable population accommodation 2)supp1y of basic enoronmental facilities for the human settlement 3)protection and efficient management of environmental pollution 4)saving and control of energy and other resources S)independent and stable euecution of plan based on biological relation 6)harmony between nature and urban spatial organization. In addition. these policies can be suggested along with the conclusions; First, ostablishment of green plan-muddle and long term environmental goals Included In the urban planning to reduce enoronmental deterioration and pollution. Second, computation of sustalnability Indeu the Index Is necessary to sustainable urban development, which is related with green GNP of the national level. Third, capacity estimation of nature and social environment-estimation of enoronmental capacity to the civilized area is required become an ecopolis, and is required to focus on the western area of Pusan which has high decree of potentiality.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.46 no.2
• /
• pp.29-37
• /
• 2004

An areal elderly migration model (AEMM) was developed to assess the demand of rural development projects targeted towards elderly people. The AEMM was developed with adaptation of the gravity model to represent spatial interaction regarding amenities. Areal characteristics were classified for estimating the amenities from the perspective of net migration. From 1990 to 2000, data were acquired from USCB, PASDA, PAHEALTH, PADCNR, PFBC, and NCDC in 67 Pennsylvania counties for analysis and application. The results revealed that elderly migration can be explained not only by areal characteristics but also by spatial interaction considering the population, distances, and amenities of surrounding areas.

• Journal of Korean Society for Geospatial Information Science
• /
• v.23 no.4
• /
• pp.11-16
• /
• 2015

Spatial and temporal information on near-surface air temperature is important for understanding global warming and climate change. In this study, the estimation algorithm of near-surface air temperature in Korea was developed by using spatial homogeneous surface information obtained from satellite remote sensing observations. Based on LST(Land Surface Temperature), NDWI(Normalized Difference Water Index) and NDVI(Normalized Difference Vegetation Index) as independent variables, the multiple regression model was proposed for the estimation of near-surface air temperature. The different regression constants and coefficients for warm and cold seasons were calculated for considering regional climate change in Korea. The near-surface air temperature values estimated from the multiple regression algorithm showed reasonable performance for both warm and cold seasons with respect to observed values (approximately $3^{\circ}C$ root mean-square error and nearly zero mean bias). Thus;the proposed algorithm using remotely sensed surface observations and the approach based on the classified warm and cold seasons may be useful for assessment of regional climate temperature in Korea.

• Journal of Korean Society of societal Security
• /
• v.1 no.2
• /
• pp.73-78
• /
• 2008

Recently, large scale natural disasters such as floods and typhoons due to climate change have been occurring all over the world causing severe damages. Among the various efforts to reduce and recover damages, recently, advanced information technology and remote sensing techniques are applied in disaster management. In this study, a real-time automated damage estimation system using information technology and spatial imagery was developed to accomplish prompt and accurate disaster damage estimation. This system is able to estimate the damage amounts of public facilities such as roads, rivers, bridges automatically through spatial imageries including ground based digital images, aerial photos, satellite images of disaster sites. Based on these spatial imageries, the damage amounts are analyzed in the Web-GIS based analysis system. Consequently, the digital damage reports such as digital disaster information sheets and damage maps can be made promptly and accurately. This system can be a useful tool to carry out prompt disaster damage estimation and efficient disaster recovery.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.2122-2136
• /
• 2010

Existing model formula in the 4 phase model is limited in the estimation of the demand for urban railway because the administrative region-based formula reflects no spatial characteristics of station surrounding area(SSA) that urban railway forms. The purpose of this study is both to analyse the behavior in selecting the method regarding spatial range of SSA and to do the basic research for the development of new model through the survey conducted in the stations of the metropolitan area. This study will review the domestic and foreign cases about designation of SSA, study the spatial range of SSA through case studies, analyze the selection of methods by the spatial range and estimate the demand of the station on the basis of social and economic indices regarding SSA. This study focuses on the verification of real results and model estimates, due to the time constraint and lack of resources for collecting and analysing the data. According to this study, 500m,1000m division of SSA shows the closest results of the model estimates to the real demand of the targeted stations.

• Journal of Korea Multimedia Society
• /
• v.24 no.5
• /
• pp.659-666
• /
• 2021

With the continuous development of deep learning, human behavior recognition algorithms have achieved good results. However, in a multi-person recognition environment, the complex behavior environment poses a great challenge to the efficiency of recognition. To this end, this paper proposes a multi-person pose estimation model. First of all, the human detectors in the top-down framework mostly use the two-stage target detection model, which runs slow down. The single-stage YOLOv3 target detection model is used to effectively improve the running speed and the generalization of the model. Depth separable convolution, which further improves the speed of target detection and improves the model's ability to extract target proposed regions; Secondly, based on the feature pyramid network combined with context semantic information in the pose estimation model, the OHEM algorithm is used to solve difficult key point detection problems, and the accuracy of multi-person pose estimation is improved; Finally, the Euclidean distance is used to calculate the spatial distance between key points, to determine the similarity of postures in the frame, and to eliminate redundant postures.