• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2012년도 제45차 동계학술발표논문집 20권1호
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• pp.173-175
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• 2012

To spread the incredible experience of wandering around a building, we propose the architecture of indoor navigation system based on inter-floor. Firstly, we combine trilateration method with Fingerprint Positioning Algorithm for positioning and Dijkstra Algorithm for calculating paths. Then the system can get the user's current locations and provide relevant paths according to the user's choice. Moreover, it can also provide the navigation path which takes the inter-floor information into consideration. It breaks the traditional navigation based on planar graph and has abundant business value.

• International Journal of Internet, Broadcasting and Communication
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• 제10권2호
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• pp.13-18
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• 2018

Drones are controlled by the remote pilot from the ground stations using the radio control or autonomously following the pre-programmed flight plans. In this paper, we develop a method and an optimal path search system for providing 3D augmented reality flight (ARF) images for safe and efficient flight control of drones. The developed system consisted of the drone, the ground station and user terminals, and the optimal path search server. We use the Dijkstra algorithm to find the optimal path considering the drone information, flight information, environmental information, and flight mission. We generate a 3D augmented reality flight (ARF) image overlaid with the path information as well as the drone information and the flight information on the flight image received from the drone. The ARF image for adjusting the drone is generated by overlaying route information, drone information, flight information, and the like on the image captured by the drone.

• 대한교통학회지
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• 제17권5호
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• pp.111-122
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• 1999

소화물 일관 운송 과정에서 발생하는 직접비용을 최소화하는 수리 모형과 해법이 제안되었다. 고려되는 비용으로는 화물 운송을 위한 차량 운행에 필요한 제반 비용인 링크 비용과 터미널에서 일어나는 하차, 분류, 재적 재등 하역 작업에서 발생하는 노드 비용을 감안하였고 총비용을 줄이기 위한 화물의 운송 경로가 모형의 결정변수이다. 해법으로는 최종해의 품질은 다소 미흡하나 계산 시간이 짧은 Steepest Descent Method와 최종해의 품질이 우수하나 계산 시간이 많이 소요되는 Simulated Annealing Method를 활용한 두개의 알고리즘이 고안되었다. 최적해를 찾아가기 위한 탐색의 출발점이 되는 초기해는 Dijkstra의 최단경로 알고리즘을 수정하여 찾는다. 예제를 통하여 알고리즘의 계산 과정을 설명하였고 제시된 두 방법의 최종해는 초기해에 비하여 비용 측면에서 각각 12%. 15%의 절감 효과가 있음을, 적재율 측면에서 초기해의 62.6%에서 각각 774%. 87.4% 향상됨을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.2052-2067
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• 2011

Complementary trees are two spanning trees rooted at the sink node satisfying that any source node's two paths to the sink node on the two trees are node-disjoint. Complementary trees routing strategy is a special node-disjoint multi-path routing approach. Several complementary trees routing algorithms have been proposed, in which path discovery methods based on depth first search (DFS) or Dijkstra's algorithm are used to find a path for augmentation in each round of path augmentation step. In this paper, a novel path discovery method based on multi-tree-growing (MTG) is presented for the first time to our knowledge. Based on this path discovery method, a complementary trees routing algorithm is developed with objectives of low average path length on both spanning trees and low complexity. Measures are employed in our complementary trees routing algorithm to add a path with nodes near to the sink node in each round of path augmentation step. The simulation results demonstrate that our complementary trees routing algorithm can achieve low average path length on both spanning trees with low running time, suitable for wireless sensor networks in industrial scenarios.

• 한국IT서비스학회지
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• 제11권sup호
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• pp.61-74
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• 2012

As the retail industry has been challenged by stiff competition, the retailer becomes more interested in better understanding consumers' in-store behavior to gain and sustain competitive advantage. Consumers' shopping paths provide valuable clues to understanding customers' in-store behavior, which has been a long standing research issue in business. This study is to explore the shopping path patterns in a grocery using RFID technology and clustering method. To this end, we designed the RFID systems, affixing active RFID tags to the bottom of grocery carts. The tag emit signal that is received by receptors installed at various location throughout the store. The RFID systems provide the time and location of the cart while consumers shop around the store. The point of sale data are matched with the cart movement records to provide a complete picture of each shopping path. To find the distinctive patterns of consumers' shopping paths, we proposed the distance-index matrix using dijkstra method and normalization method to conduct the clustering in order to handle the problem in measuring the similarity among shopping paths, which is raised by the spatial nature of consumer movement in a grocery. After analyzing the RFID data obtained in one of the groceries in a major Korean retailer, we could successfully identify several distinctive patterns of shopping paths, which prove to provide the valuable implications for store management.

• Journal of Information Processing Systems
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• 제17권5호
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• pp.879-891
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• 2021

With improvements in living conditions, an increasing number of people are choosing to spend their time traveling. Comfortable tour routes are affected by the season, time, and other local factors. In this paper, the influencing factors and principles of scenic spots are analyzed, a model used to find the available routes is built, and a multi-route choice model based on a game theory utilizing a path recommendation weight is developed. A Monte Carlo analysis of a tourist route subjected to fixed access point conditions is applied to account for uncertainties such as the season, start time, end time, stay time, number of scenic spots, destination, and start point. We use the Dijkstra method to obtain multiple path plans and calculate the path evaluation score using the Monte Carlo method. Finally, according to the user preference in the input path, game theory generates path ordering for user choice. The proposed approach achieves a state-of-the-art performance at the pseudo-imperial palace. Compared with other methods, the proposed method can avoid congestion and reduce the time cost.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3151-3168
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• 2021

Internet of Things (IoT) connects several objects with embedded sensors and they are capable of exchanging information between devices to create a smart environment. IoT smart devices have limited resources, such as batteries, computing power, and bandwidth, but comprehensive sensing causes severe energy restrictions, lowering data quality. The main objective of the proposal is to build a hybrid protocol which provides high data quality and reduced energy consumption in IoT sensor network. The hybrid protocol gives a flexible and complete solution for sensor selection problem. It selects a subset of active sensor nodes in the network which will increase the data quality and optimize the energy consumption. Since the unused sensor nodes switch off during the sensing phase, the energy consumption is greatly reduced. The hybrid protocol uses Dijkstra's algorithm for determining the shortest path for sensing data and Ant colony inspired variable path selection algorithm for selecting active nodes in the network. The missing data due to inactive sensor nodes is reconstructed using enhanced belief propagation algorithm. The proposed hybrid method is evaluated using real sensor data and the demonstrated results show significant improvement in energy consumption, data utility and data reconstruction rate compared to other existing methods.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 춘계종합학술대회 A
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• pp.835-838
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• 2008

계층 경로 탐색 알고리즘의 탐색 기법에 대한 연구는 많은 논문에서 제시되어 왔다. 그러나 효과적인 영역의 분할에 대한 연구는 많지 않다. 본 논문에서는 계층 경로 탐색 알고리즘의 주 영역과 부 영역을 효과적으로 나눌 수 있는 다음과 같은 기법을 제안하고 평가한다: (1) 보로노이 알고리즘 이용하여 하나의 주 노드를 중심으로 영역을 분할하는 방법, (2)고정 그리드를 기반으로 주 영역과 부 영역을 설정하는 방법 제안한 기법의 성능평가를 위해 전통적인 Dijkstra 알고리즘을 주 노드에서 탐색하여 가장 인접한 주 노드 4개를 통해 주 영역을 지정하는 방법과 비교하였다. 실험 평가 항목은 탐색된 경로의 정확도와 연산시간이며, 실험 결과 연산 속도 측면에서는 보로노이 기반 기법이 좋은 성능을 보였으며, 그리드 기반 기법이 정확도 측면에서 가장 좋은 성능을 보였다.

• 대한원격탐사학회지
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• 제31권5호
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• pp.395-408
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• 2015

고해상도 위성영상 모자이크는 두 장 이상의 위성영상을 공간적으로 합성하여 보다 넓은 단일 영상을 만드는 영상 처리 과정으로 원격탐사 분야에서 그 중요성이 날로 커지고 있다. 본 연구에서는 영상 모자이크 작업 시 요구되는 접합선 자동 추출기법과 이를 기반으로 한 모자이크 영상 제작 방법을 제시하였다. 대용량인 고해상도 위성영상에서 보다 빠르고 효율적인 접합선 추출하기 위해서, NDVI의 특성을 활용하여 빠르게 경계선을 추출하는 NDVI 기반 접합선 추출 알고리즘을 개발하였다. NDVI는 식생의 분포량 및 활동성을 나타내는 정규화 식생지수로 이를 활용하여 인공지역과 자연지역을 분리하여 초기 접합선을 추출하였다. Canny 에지 연산자를 적용하여 비용범위이미지를 생성하고, 초기 접합선을 기준으로 버퍼링 기법을 사용하여 범위 비용 이미지를 생성하였다. 다익스트라 알고리즘을 사용하여 접합선을 추출하고, 획득시기가 다른 인접영상간의 방사 왜곡을 줄이기 위하여 히스토그램 매칭을 수행하였다. KOMPSAT-2/3 위성영상을 이용한 실험결과, 두 영상의 기하학적 차이로 인한 시각적 불연속 특징이 감소됨을 확인할 수 있었고, 접합선 추출시 소요되는 연산시간이 감소되는 것을 확인할 수 있었다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 가을 학술발표논문집 Vol.32 No.2 (1)
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• pp.976-978
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• 2005

We present a nearly optimal ($O(\nu\;min(\nu,\;n)n\;log\;n)$ time and O(n) srace) algorithm that constructs a shortest path map with n isothetic roads of speed $\nu$ under the $L_1$ metric. The algorithm uses the continuous Dijkstra method and its efficiency is based on a new geometric insight; the minimum in-degree of any nearest neighbor graph for points with roads of speed $\nu$ is $\Theta(\nu\;min(\nu,\;n))$, which is first shown in this paper. Also, this algorithm naturally extends to the multi-source case so that the Voronoi diagram for m sites can be computed in $O(\nu\;min(\nu,\;n)(n+m)log(n+m))$ time and O(n+m) space, which is also nearly optimal.