• International Journal of Control, Automation, and Systems
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• 제4권1호
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• pp.10-16
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• 2006

In this paper, moving a fragile object from an initial point to a specific location in the minimum time without damage is studied. In order to achieve this goal, initially, the maximum acceleration and velocity ranges are specified. These ranges can be dynamically generate on the planned path by the manipulator. The path can be altered by considering the geometrical constraints. Later, considering the impulsive force constraint on the object, the range of maximum acceleration and velocity are obtained to preserve object safety while the manipulator is carrying it along the curved path. Finally, a time-optimal trajectory is planned within the maximum allowable range of acceleration and velocity. This time-optimal trajectory planning can be applied to real applications and is suitable for both continuous and discrete paths.

• 한국멀티미디어학회논문지
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• 제9권12호
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• pp.1529-1541
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• 2006

Moving objects have been widely employed in traffic and logistic applications. Spatio-temporal aggregations mainly describe the moving object's behavior in the spatial data warehouse. The previous works usually express the object moving in some certain region, but ignore the object often moving along as the trajectory. Other researches focus on aggregation and comparison of trajectories. They divide the spatial region into units which records how many times the trajectories passed in the unit time. It not only makes the storage space quite ineffective, but also can not maintain spatial data property. In this paper, a spatio-temporal aggregation index structure for moving object trajectory in constrained network is proposed. An extended B-tree node contains the information of timestamp and the aggregation values of trajectories with two directions. The network is divided into segments and then the spatial index structure is constructed. There are the leaf node and the non leaf node. The leaf node contains the aggregation values of moving object's trajectory and the pointer to the extended B-tree. And the non leaf node contains the MBR(Minimum Bounding Rectangle), MSAV(Max Segment Aggregation Value) and its segment ID. The proposed technique overcomes previous problems efficiently and makes it practicable finding moving object trajectory in the time interval. It improves the shortcoming of R-tree, and makes some improvement to the spatio-temporal data in query processing and storage.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.467-470
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• 2003

When user wants to find objects which have the nearest position from him, we use the nearest neighbor (NN) query. The GIS applications, such as navigation system and traffic control system, require processing of NN query for moving objects (MOs). MOs have trajectory with changing their position over time. Therefore, we should be able to find NN object continuously changing over the whole query time when process NN query for MOs, as well as moving nearby on trajectory of query. However, none of previous works consider trajectory information between objects. Therefore, we propose a method of continuous NN query for trajectory of MOs. We call this CTNN (continuous trajectory NN) technique. It ran find constantly valid NN object on the whole query time by considering of trajectory information.

• 한국인터넷방송통신학회논문지
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• 제9권5호
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• pp.183-189
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• 2009

최근, PCS, PDA와 같은 이동기기 보급의 확산, GPS(Global Positioning System)의 활용, 유무선 네트워크의 급속한 발전 등으로 일반 사용자들조차 이미지, 오디오, 비디오 등과 같은 멀티미디어 데이타에 대한 활용이 증가하고 있다. 특히, 멀티미디어 데이타 중에서도 비디오 데이타는 텍스트나 이미지 데이타와는 달리 이동 객체에 대한 움직임 정보를 포함하고 있고 시간의 변화에 따라 공간의 변화를 가지는 시공간적 특성을 가진다. 객체의 공간적 위치가 시간의 흐름에 따라 계속 변하는 이동객체(Moving Object)들의 연속적인 움직임들의 모임을 궤적이라 하며, 데이타베이스에서 사용자로부터 주어진 질의 궤적과 유사한 궤적을 포함하는 데이타를 찾는 것을 유사 부분궤적 검색(Similar Sub-trajectory Retrieval)이라 한다. 그리고 이러한 유사 부분궤적 검색을 하기 위해선 사용자 질의 궤적과 주어진 유사정도(Tolerance) 내에서 유사한 데이타 궤적을 검색 할 수 있는 근사 매칭(Approximate Matching)이 가능해야 한다. 또한, 방대한 멀티미디어 데이타베이스에서 사용자가 원하는 데이타 만을 보다 빠른 시간 내에 찾을 수 있도록 기존 연구와는 다른 효과적인 검색방법이 요구된다. 이를 위해, 본 논문에서는 효과적인 검색을 위해 궤적을 그리드로 분할하여 이동 객체의 궤적에 대한 효율적인 유사 부분궤적 검색을 지원하는 새로운 그리드 기반 검색 기법을 제안한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.317-320
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• 1986

A co-operative position control is proposed for two robot manipulators with 5 degree of freedoms to transfer an object following a specified trajectory, where each manipulator is assumed to change the posture of its end effector without releasing the object.

• 대한전자공학회논문지
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• 제24권4호
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• pp.577-582
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• 1987

A co-operative position control is proposed for two robots manipulation with five degrees of freedom to transfer an object following a specified trajectory, where each manifulator is assumed to change the postrue of its end effector without releasing the object.

• 한국산업보건학회지
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• 제19권1호
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• pp.25-29
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• 2009

The purpose of this study was to investigate the effect of two different lifting posture on the plantar foot pressure, force and COP(center of pressure) trajectory path during object lifting. Fourteen healthy adults who had no musculoskeletal disorders were instructed to lift with two postures(stoop and squat) and two object weights(empty box and 10 kg box). Plantar foot pressures, forces and COP trajectory path were recorded by the F-mat system(Tekscan, Boston, USA) during object lifting with barefoot. Plantar foot surface was defined as seven regions for pressure measurement; two toe regions, three forefoot regions, one midfoot region and one heel region. Paired t-test was used to compare the outcomes of peak pressure and maximum force with different two lifting postures and two object weights. Plantar peak pressure and maximum force under hallux was significantly greater in squat posture than stoop posture during the two different boxes lifting(p<.05). During the empty box lifting, maximum force under lessor toes was significantly less and plantar peak pressure under second metatarsal region was significantly greater in squat than stoop(p<.05). Maximum force under heel was significantly less in squat than stoop posture during 10kg box lifting(p<.05). Finally, COP trajectory path was significantly greater in squat than stoop(p<.05). These findings confirm that there are significantly change in the structure and function of the foot during the object lifting with different posture. Future studies should focus on the contribution of both structural and functional change to the development of common foot problems in adults.

• 대한방사선기술학회지:방사선기술과학
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• 제42권1호
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• pp.39-46
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• 2019

This study conducted a comparative analysis of differences between cartesian trajectory in a linear rectangular coordinate system and MultiVane trajectory in a nonlinear rectangular coordinate system axial T1 and axial T2 images using an American College of Radiology(ACR) phantom. The phantom was placed at the center of the head coil and the top-to-bottom and left-to-right levels were adjusted by using a level. The experiment was performed according to the Phantom Test Guidance provided by the ACR, and sagittal localizer images were obtained. As shown in Figure 2, slices # 1 and # 11 were scanned after placing them at the center of a $45^{\circ}$ wedge shape, and a total of 11 slices were obtained. According to the evaluation results, the image intensity uniformity(IIU) was 93.34% for the cartesian trajectory, and 93.19% for the MultiVane trajectory, both of which fall under the normal range in the axial T1 image. The IIU for the cartesian trajectory was 0.15% higher than that for the MultiVane trajectory. In axial T2, the IIU was 96.44% for the cartesian trajectory, and 95.97% for the MultiVane trajectory, which fall under the normal range. The IIU for the cartesian trajectory was by 0.47% higher than that for the MultiVane trajectory. As a result, the cartesian technique was superior to the MultiVane technique in terms of the high-contrast spatial resolution, image intensity uniformity, and low-contrast object detectability.

• Spatial Information Research
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• 제19권2호
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• pp.57-64
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• 2011

이 논문은 PostgreSQL/PostGIS 기반의 궤적 정보 저장과 질의에 대하여 기술하고 있다. 최근 모바일 단말 기술의 발전과 함께 위치기반서비스와 이동 객체 궤적에 관련된 많은 연구들이 진행되고 있다. 궤적은 이동 객체가 시간에 따라 변하는 위치정보들의 모음이며, 위치기반서비스를 위한 가장 중요한 정보중 하나이다. 기존의 공간 데이터베이스 시스템은 이동 객체 데이터 타입을 지원하지 않는다. 이 논문에서는 공간 데이터베이스로 많이 활용되고 있는 PostgreSQL/PostGIS 상에서 궤적 데이터 타입을 구현하고, 궤적 연산을 위한 궤적 질의 함수들을 제안하고 있다.

• 한국융합학회논문지
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• 제10권4호
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• pp.33-38
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• 2019

최근 다양한 LBS(location-based service) 서비스를 지원하기 위해 실제 공간 네트워크를 고려한 연구가 활발하게 진행 중이다. 이를 위해, 도로 네트워크에서 데이터 처리를 위한 실험 데이터가 다수 존재한다. 그러나 이러한 이동 객체의 궤적을 처리하기 위한 데이터는 이용하기에 적합하지 않다. 따라서 본 논문에서는 도로 네트워크 환경에서 궤적 데이터를 처리할 수 있는 색인 구조와 궤적 데이터 생성 알고리즘을 제안한다. 또한, 제안하는 구조와 알고리즘의 우수성을 입증하기 위해, 샌프란시스코 맵으로부터 만들어진 데이터를 이용하여 제안하는 알고리즘을 통해 에지 기반의 궤적 데이터를 생성됨을 보인다.