• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.729-734
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• 2004

The e-Logistics means the virtual business activity and service architecture among the logistics companies based on the Internet technology. The management of vehicles' location in most conventional vehicle tracking system has some critical defects when it deals with data which are continuously changed. It means the conventional vehicle tracking system based on the conventional database is unable eventually to cope with the environment that should manage the frequently changed location of vehicles. The important things in the evaluation of the vehicle tracking system is to determine the threshold of cost of database ,update period and communication period between vehicles and the system. In other words, the difference between the reallocation of vehicle and the data in database can evaluate the overall performance of vehicle tracking systems. Most of the previous works considers only the information that is valid at the current time, and is hard to manage efficiently the past and future information. To overcome this problem, the efforts on moving objects management system(MOMS) and uncertainty processing have been started from a few years ago. In this paper, we propose an uncertainty processing model and system implementation of moving object that tracks the location of the vehicles. We adopted both linear-interpolation method and trigonometric function to chase up the location of vehicles for the past time as well as future time, respectively. We also explain the comprehensive examples of MOMS and uncertainty processing in parcel application that is one of major application of e-Logistics domain.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.726-729
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• 2004

Spatiotemporal phenomena are ubiquitous aspects of real world. In the spatial and temporal databases, integrity constraints maintain the semantics of specific application domain and relationship between domains when proceed update in the database. Efficient maintenance of data integrity has become a critical problem, since testing the validity of a large number of constraints in a large database and after each transaction is an expensive task. Especially, in spatiotemporal domain, data is more complex than traditional domains and very active. Additionally, it is not considered that unified frameworks deal with both spatial and temporal properties to handle integrity constraints. Therefore, there need a model to maintain integrity constraints in the unified frameworks and enforcement and management techniques in order to preserve consistence.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.5782-5799
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• 2018

With the development of GPS and the popularity of mobile devices with positioning capability, collecting massive amounts of trajectory data is feasible and easy. The daily trajectories of moving objects convey a concise overview of their behaviors. Different social roles have different trajectory patterns. Therefore, we can identify users or groups based on similar trajectory patterns by mining implicit life patterns. However, most existing daily trajectories mining studies mainly focus on the spatial and temporal analysis of raw trajectory data but missing the essential semantic information or behaviors. In this paper, we propose a novel trajectory semantics calculation method to identify groups that have similar behaviors. In our model, we first propose a fast and efficient approach for stay regions extraction from daily trajectories, then generate semantic trajectories by enriching the stay regions with semantic labels. To measure the similarity between semantic trajectories, we design a semantic similarity measure model based on spatial and temporal similarity factor. Furthermore, a pruning strategy is proposed to lighten tedious calculations and comparisons. We have conducted extensive experiments on real trajectory dataset of Geolife project, and the experimental results show our proposed method is both effective and efficient.

• Journal of Computing Science and Engineering
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• 제5권3호
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• pp.210-222
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• 2011

In this work, we study the problem of privacy-preservation data publishing in moving objects databases. In particular, the trajectory of a mobile user in a plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface of fixed width $2A_{min}$, where $A_{min}$ defines the semi-diameter of the minimum spatial circular extent that must replace the real location of the mobile user on the XY-plane, in the anonymized (kNN) request. The desired anonymity is not achieved and the entire system becomes vulnerable to attackers, since a malicious attacker can observe that during the time, many of the neighbors' ids change, except for a small number of users. Thus, we reinforce the privacy model by clustering the mobile users according to their motion patterns in (u, ${\theta}$) plane, where u and ${\theta}$ define the velocity measure and the motion direction (angle) respectively. In this case, the anonymized (kNN) request looks up neighbors, who belong to the same cluster with the mobile requester in (u, ${\theta}$) space: Thus, we know that the trajectory of the k-anonymous mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatiotemporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatiotemporal range queries executed on the original database and on the anonymized one.

• 한국항행학회논문지
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• 제27권1호
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• pp.43-49
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• 2023

객체 위치추적은 칼만필터나 루엔버거 추적기와 같은 다양한기법을 통해 연구되고 있는데, 시스템 모델이 명확하게 규정되지 않는경우와 같이 기존의 신호처리 기법을 성공적으로 적용하기 어려운 상황에서도 객체의 위치를 추적해 낼 수 있는 인공신경망을 설계하는 것이 가능하다. 본 논문에서는, 불규칙하게 운동 상태가 변화하는 객체의 위치를 지속적으로 추적하기 위해, 다양한 길이의 최대우도기법 객체위치 추정깂들을 도출한 뒤 신경망을 통해 이들을 적응적으로 가중평균하는 방법을 사용하는 '최대우도 가중평균 신경망'을 제안한다. 해당 신경망은 객체의 위치를 직접 추정하지 않고 데이터 길이가 다른 다양한 최대우도기법 추적 결과들을 가중평균하여 위치 추정을 수행한다. 우리는 제안하는 시스템의 추적성능을 칼만필터 및 최대우도기법들과 비교하여, 제안하는 기법이 물체의 움직임 특성에 잘 대처하여 우수한 성능을 나타내 줌을 보인다.

• Architectural research
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• 제25권4호
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• pp.73-84
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• 2023

Indoor thermal conditions greatly affect the health and comfort of humans who occupy the space in it. The purpose of this research is to analyze the influence of water and vegetation elements as a microclimate modifier in buildings to obtain thermal comfort through the study of thermal environment models. This research covers two objects, namely public buildings and housing in Makassar City, South Sulawesi Prov-ince - Indonesia. Quantitative methods through field surveys and measurements based on thermal and personal variables. Data analysis based on ASHRAE 55 2020 standard. The data was processed with a parametric statistical approach and then simulated with the Computational Fluid Dynamics (CFD) simulation method to find a thermal prediction model. The model was made by increasing the ventilation area by 2.0 m2, adding 10% vegetation with shade plant characteristics, moving water features in the form of fountains and increasing the pool area by 15% to obtain PMV + 0.23, PPD + 8%, TSV-1 - +0, Ta_25.7℃, and relative humidity 63.5 - 66%. The evaluation shows that the operating temperature can analyze the visitor's comfort temperature range of >80% and comply with the ASHRAE 55-2020 standard. It is concluded that water elements and indoor vegetation can be microclimate modifiers in buildings to create desired comfort conditions and adaptive con-trols in buildings such as the arrangement of water elements and vegetation and ventilation systems to provide passive cooling effects in buildings.

• ETRI Journal
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• 제35권1호
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• pp.80-88
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• 2013

A passive infrared or pyroelectric infrared (PIR) sensor is mainly used to sense the existence of moving objects in an indoor environment. However, in an outdoor environment, there are often outbreaks of false alarms from environmental changes and other sources. Therefore, it is difficult to provide reliable detection outdoors. In this paper, two algorithms are proposed to reduce false alarms and provide trustworthy quality to surveillance systems. We gather PIR signals outdoors, analyze the collected data, and extract the target features defined as window energy and alarm duration. Using these features, we model target and false alarms, from which we propose two target decision algorithms: window energy detection and alarm duration detection. Simulation results using real PIR signals show the performance of the proposed algorithms.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제11권2호
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• pp.95-102
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• 2011

In this paper, a Mobile Continuous Query Processing System (MCQPS) is designed to solve problems related to database hoarding, maintenance of shared data consistency, and optimization of logging. These problems are caused by weak connectivity and disconnection of wireless networks inherent in mobile database systems under mobile client-server environments. We show the superiority of the proposed MCQPS by comparing its performance to the Client-Intercept-Server (C-I-S) model. In addition, several experimental results show the effectiveness of our proposed indexing structure and methodology for real-time continuous queries.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제7권4호
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• pp.159-168
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• 2018

최근 높은 관심을 모으고 있는 모바일 증강현실 게임은 몰입감을 높이기 위한 접근 방법으로 손꼽히고 있다. 모바일 디바이스의 카메라를 이용하여 대상 물체를 인식하고 게임 캐릭터가 등장하도록 하는 기존 증강현실 기반의 게임에서는 대부분이 터치 기반의 인터랙션만을 사용하고 있다. 본 논문에서는 게임의 몰입도를 높이기 위하여 증강현실 타겟 이미지를 움직임으로써 게임 속 변형 객체를 직관적으로 조작하는 기법을 제안한다. 제안 방법에서는 타겟 이미지들 사이의 거리와 방향을 계산하고, 이에 따라 변형객체에 주어지는 외부력(external force)의 크기를 조정함으로써, 직관적 방법으로 변형 객체의 움직임을 조작할 수 있도록 하였다. 본 논문에서는 게임 콘텐츠에서 자연스러운 객체 표현을 위하여 많이 사용되고 있는 변형 직물(cloth) 모델에 초점을 맞추었고, 바람(wind)과 강체(rigid object)로 표현되는 게임 객체들과 상호작용하는 자연스러운 직물의 움직임을 표현하였다. 실험에서는 유니티 에셋 스토어에서 판매하는 기존 유료 직물 모델의 적용 결과와의 비교를 통하여 제안 기법이 보다 현실감 있는 직물의 움직임을 표현하고 있는 것을 보였다.

• 대한공간정보학회지
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• 제17권1호
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• pp.157-166
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• 2009

최근 유비쿼터스 관련 연구가 활발히 이루어지고 있으며 이를 활용한 응용분야들이 확대되고 있다. 대표적인 응용분야로는 GPS를 이용한 실외측위기술을 기반으로 발전한 위치기반서비스(LBS)가 있으며, 현재 많은 서비스들이 상용화 되어 있다. 최근 들어서는 대규모 실내공간과 실내에서의 사고의 증가와 함께 실내 공간을 대상으로 하는 서비스에 대한 관심이 증가하고 있으며 관련된 연구들이 진행되고 있다. 실내 공간 응용기술의 핵심은 3차원 실내 공간데이터의 모델링 기법과 이와 연동 가능한 센서기술이다. 하지만 아직은 실내위치기반서비스를 위한 측위기술 및 공간데이터에 대한 표준과 활용방안이 미비한 상태이다. 본 연구에서는 실내 위치기반서비스에서 사용 가능한 간단한 3차원 실내 공간 데이터 모델의 구축방법과 이를 활용할 수 있는 방법론을 제시하고자 한다. 본 연구에서 제시하는 모델은 2차원 기반의 multi-layered 구조를 가지며, 2차원 및 3차원으로 가시화가 가능하도록 하였다. 또한 제시한 3차원 실내 공간 모델의 실내 기반 서비스로의 적용을 테스트하기 위하여 CA(cellular automata)기반의 대피 시뮬레이터와 대피 경로 안내 시스템 그리고 실내센서(카메라)와의 연동 등 몇 가지 응용분야에 대한 테스트를 수행하였다.