• 한국정보통신학회논문지
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• 제17권5호
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• pp.1070-1075
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• 2013

본 논문에서는 실내 보안지역내의 인간 출입을 통제하기위해 보안로봇을 이용한 출입통제 기능을 수행한 시스템 및 연구결과를 제시하고 있다. 제안된 로봇은 환경인식을 위한 레이저파인더를 탑재하고 보안지역을 상시 관찰을 수행하며 출입금지 구역에 인간을 출입이나 진행을 감지했을 때, 로봇이 인간의 속도벡터를 계산 및 주행할 경로를 계획하고 인간의 진행방향을 차단할 수 있도록 예측된 경로를 따라 주행을 하게 된다. 이때, 인간의 움직임은 포인터 물체로 간주하였으며 로봇의 기구학에 기반하여 인간의 위치를 추정한다. 실내에서 계속적인 환경변화에 대해 로봇은 감시기능 수행하게 된다. 통제구역에 대한 진입을 인식하게 되면 인간의 움직임의 반대방향으로 주행하여 진입차단 기법을 제시한다. 제안된 연구결과를 검정하기위해 로봇을 이용한 위치추정 및 추적 실험결과를 제시하였다.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2806-2820
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• 2024

Accurate reconstruction of radiation field and path planning are very important for the safety of operators in the process of dismantling nuclear facilities. Based on radial basis function (RBF) interpolation algorithm, this paper discussed the application of inverse multiquadric radial basis Function (IMRBF) interpolation method to the reconstruction of gamma radiation field, and proved the feasibility of reconstructing a radiation field with multiple γ sources. The average relative errors of IMRBF interpolation results were 4.28% and 8.76%, respectively, for the experimental scenarios with single and double gamma sources. After comparing the consistency between the simulated scene and the experimental scene, IMRBF method and Cubic Spline method were respectively used to reconstruct the gamma radiation field by Geant4 simulation data. The results showed that the interpolation accuracy of IMRBF method was superior to that of Cubic Spline method. Further, more RBF interpolation algorithms were used to reconstruct the multi-γ source radiation field, and then the Probabilistic Roadmap (PRM) algorithm was used to optimize the human walking path in the radiation field reconstructed by different interpolation methods. The optimal paths in radiation fields generated by multiple interpolation methods were compared. The results herein contribute to a comprehensive understanding of RBF interpolation methods in reconstructing γ radiation fields and their application in optimizing paths in radiation environments. The insights may provide valuable information for decision-making in radiation protection during the decommissioning of nuclear facilities.

• Spatial Information Research
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• 제20권3호
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• pp.83-93
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• 2012

최근 환경문제로 인해 보행, 자전거, 대중교통과 같은 친 환경 교통수단에 대한 관심이 높아지고 있다. 하지만 보행과 자전거는 경우에 따라 장거리 이동이 불가능하기 때문에 이용범위가 제한적이라는 단점이 있다. 반면에 대중교통은 교통체증이라는 사회적 문제점까지 해결할 수 있는 교통수단이다. 이러한 대중교통은 시간에 따라 운행여부가 달라진다는 특징을 갖고 있다. 하지만 현재 웹상에서 서비스중인 대중교통정보 안내 서비스는 이러한 특징을 반영하지 못하기 때문에 경우에 따라 사용자에게 잘못된 정보를 제공할 수 있다. 이러한 한계점을 해결하고 대중교통의 운행정보를 고려한 정보제공을 위해 본 연구에서는 STP(Space Time Point)데이터 모델을 제안하였다. STP데이터 모델은 객체의 최하위 개념을 포인트 단위로 인식하고 이들을 계층적으로 구성하여 객체를 표현할 수 있으며, 기존의 시공간 데이터 모델과는 달리 시간에 따라 객체정보가 변하는 다양한 동적 공간객체의 구현이 가능하다. 대전지역을 대상으로 대중교통 운행정보로 버스 및 지하철에 대한 STP모델을 설계 및 구축하고 이를 이용하여 동적 경로 안내 기능을 구현하였다. 구현한 경로안내 기능을 통해 대전국립현충원에서 한남대학교로 가는 경로를 시간대별로 탐색해 본 결과 대중교통의 운행에 제한이 발생하는 심야시간에는 운행이 제한되는 노선을 우회하는 경로를 안내함으로써 시간에 따라 서로 다른 경로를 나타내었다. 이는 기존 데이터 모델에서는 제공할 수 없는 결과로 실시간 운행정보를 고려한 경로안내가 가능함을 확인하였다. 이러한 기능은 실시간 교통정보나 통행이력정보등과 같은 다양한 데이터 모델의 적용을 통해 추가적인 기능 확장이 가능할 것으로 기대한다.

• 대한전자공학회논문지TC
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• 제44권10호
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• pp.76-82
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• 2007

노드들의 이동성을 보장하고, 별도의 인프라가 필요하지 않다는 점에서 최근에 MANET에 대한 관심이 커지고 연구가 활발히 진행되고 있다. 최근 들어 노드들이 이동한다는 개념이 단순이 걸어 다니는 것이 아니라 GPS를 기반으로 빠른 속도로 움직이는 자동차에 대한 Ad hoc 망의 이용에 많은 관심을 가지게 됨에 따라 MANET에서의 이동성이 과거에 비해 중요시되고 있다. 노드들이 빠르게 이동하는 경우 각 노드들이 목적지를 탐색하고 라우팅 하는 것은 많은 비용을 비롯하여 여러 문제가 발생한다. 이러한 문제를 해결하기 위하여 No path-Location Aided Routing (N-LAR) 란 새로운 라우팅 프로토콜을 제안한다. 제안하는 방법은 이동성이 큰 MANET에서 좀 더 짧은 응답속도와 높은 전송성공률을 갖는다.

• 전자공학회논문지SC
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• 제43권6호
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• pp.9-15
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• 2006

최근 로봇 개발의 현황을 살펴보면 인간과 로봇이 공존하면서 인간이 로봇으로부터 서비스를 받을 수 있는 로봇의 개발이 지속적으로 증가하는 추세다. 그 중에서도 특히 관심을 끌고 있는 것은 복지 로봇에 관한 연구이다. 현재 가장 일반화되어 있는 복지 로봇은 시각 장애인의 주행을 도와주는 안내 로봇이며 장애물을 인식하여 안전한 경로를 제공하는 것을 목적으로 한다. 본 논문에서는 장애물 충돌회피의 기능뿐만 다양한 센서를 장착하여 환경 정보를 파악하여 사용자에게 가장 안전한 이동방향과 이동 속도를 제시한다. 또한 지도 정보를 이용하여 사용자에게 가장 친숙하고 안전한 주행 경로를 선택하는 안내 로봇을 제시한다.

• The Journal of Korean Physical Therapy
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• 제25권3호
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• pp.136-142
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• 2013

Purpose: The application of transcutaneous electrical nerve stimulation (TENS) is beneficial for joint movements, inhibition of spasticity, and the improvement of walking ability in patients with chronic hemiplegia. This study aimed to identify the effect of the application of TENS to the knee extensor on the affected side with respect to postural-sway distance and velocity during the sit-to stand movement. Methods: We included 19 patients with post-stroke hemiplegia in this study. They underwent measurements during the sit-to stand movement on a force plate with 5 different stimulation dosages applied over 7 s:No TENS, high-frequency and high intensity TENS, high-frequency and low intensity TENS, low-frequency and high intensity TENS, and low-frequency and low intensity TENS The 5 different condition were administered in random order. Results: The group that received TENS application exhibited a significant decrease in path length and average velocity of center of pressure (COP) displacement compared with the group that did not receive TENS application. TENS dosage at low frequency (3Hz) and high intensity yielded a significant decrease in path length, average velocity, mediolateral distance and anteroposterior distance of COP displacement (p<0.05). Conclusion: Our results demonstrated the effectiveness of the application of low-frequency TENS on STS performance. These findings provide useful information on the application of TENS for the reduction of postural sway during the sit-to-stand movement after stroke.

• 한국실내디자인학회논문집
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• 제15권4호
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• pp.81-88
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• 2006

The form and function of modern museum present more a variety of aspects in need of transition of the mature civil society and culture than the past. Considering that an art museum is the space where a multitude of unspecified visitors inspect simultaneously, exhibitions and adequate construction make visitors lead to successively visual contact. Consequently a goal of this study is to analyze that there is correlation between exhibit space and exhibitions and to suggest an alternative plan at exhibition through relationship among exhibitions, exhibit space and spectators' behavior. Two Art galleries (one is a large-sized gallery and the other is a small-sized one) located in Pyung-Chang dong were selected to analyze the correlation and suggest the better display for the exhibition. The finding of the study is following. The exhibit space which spectators recognize is assumed diverse forms by an unique characteristics of exhibits and space and an arrangement of exhibitions and the path of flow of spectator who walking ahead have an huge effect on a spectators' behavior. In other words, spectators' watching patterns are affected by display of exhibitions and the path of flow. That is to say, the spectators' behavior and the concentration to watch exhibitions is decided by the exhibit form in the museum, and the quality of watching experience is depended on the spectators' relevant knowledge prior to exhibitions.

• 교육시설 논문지
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• 제25권6호
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• pp.21-28
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• 2018

To compare the physical quantity of students circulation along the moving path during recess of a variation type operation middle school, five points were actually observed. The flow coefficient for these points was calculated, and the change in flow coefficient was verified and tracked over time. During the operation of the classroom, the characteristics of crowdedness and congestion time depending on the physical conditions of the frequently moved paths were shown. Even in the same corridor, the difference between the flow coefficient and the congestion time of the corridor facing the open space and the blocked space was noticeably different. As a result, detailed factors such as free walking speed, the degree of freedom of passing and the possibility of collision were also identified. This means that detailed countermeasures for the student's path should be considered first when planning the moving space of a variation type school, and identifying the characteristics of these factors could be used as useful basic materials for developing various models of classroom space.

• 로봇학회논문지
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• 제17권4호
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• pp.407-416
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• 2022

Multiple AMRs have been proved to be effective in improving warehouse productivity by eliminating workers' wasteful walking time. Although Multi-agent Path Finding (MAPF)-based solution is an optimal approach for this task, its deployment in practice is challenging mainly due to its imperfect plan-execution capabilities and insufficient computing resources for high-density environments. In this paper, we present a MAPF-based fleet management system architecture that robustly manages multiple robots by re-computing their paths whenever it is necessary. To achieve this, we defined four events that trigger our MAPF solver framework to generate new paths. These paths are then delivered to each AMR through ROS2 message topic. We also optimized a graph structure that effectively captures spatial information of the warehouse. By using this graph structure we can reduce computational burden while keeping its rescheduling functionality. With proposed MAPF-based fleet management system, we can control AMRs without collision or deadlock. We applied our fleet management system to the real logistics warehouse with 10 AMRs and observed that it works without a problem. We also present the usage statistic of adopting AMRs with proposed fleet management system to the warehouse. We show that it is useful over 25% of daily working time.

• Physical Therapy Rehabilitation Science
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• 제11권4호
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• pp.591-597
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• 2022

Objective: The sitting and standing are motions that correspond to the previous stage of rehabilitation to go to walking for daily life. The purpose of this study was to measure task times, path length of the center of pressure (COP) and activity on the vastus femoris muscle using surface electromyography (EMG) when standing up and sitting down. Design: One group cross-sectional design Methods: Fifteen elderly subjects (8 male, 7 female) participated. All subjects were tested three times according to four assist levels (non-assist, lower, middle, and maximal assist) using adjusts the length of spring at sit-to-stand and stand to sit on a chair. The task duration, and COP path length were recorded for the balance function on the Nintendo Wii fit board. The activity of the rectus femoris muscle was recorded on both legs using surface EMG. Results: The results showed that the task duration of the sit-to-stand and stand-to-sit were significantly increased compared to without assist (p<.05). The activation of the rectus femoris muscle more significantly decreased compared to without assistance at standing or sitting (p<.05). Conclusions: The assistive chair showed less quadriceps muscle activation during sitting and standing compared to without assistance. We suggest that our assist-standing chair can help with activities of daily living such as standing up and sitting down movements adjusting the spring length for control assist level by safely.