• Journal of Information Technology Applications and Management
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• 제14권3호
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• pp.49-77
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• 2007

Role-based access control (RBAC) models are recently receiving considerable attention as a generalized approach to access control. In line with the increase in applications that deal with spatial data. an advanced RBAC model whose entities and constraints depend on the characteristics of spatial data is required. Even if some approaches have been proposed for geographic information systems. most studies focus on the location of users instead of the characteristics of spatial data. In this paper. we extend the traditional RBAC model in order to deal with the characteristics of spatial data and propose new spatial constraints. We use the object-oriented modeling based on open GIS consortium geometric model to formalize spatial objects and spatial relations such as hierarchy relation and topology relation. As a result of the formalization for spatial relations. we present spatial constraints classified according to the characteristics of each relation. We demonstrate our extended-RBAC model called OOGIS-RBAC and spatial constraints through case studies. Finally. we compare our OOGIS-RBAC model and the DAC model in the management of access control to prove the efficiency of our model.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.758-759
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• 1995

In large-scale industry such as shipbuilding, aircraft manufacturing, and construction industry etc., it is required to consider two or three-dimensional spatial availability as one of bottlenecked resource constraints. We call this kind of scheduling a spatial scheduling, which considers the dynamic spatial layouts of objects as well as the traditional resource constraints. Since 1991, we have researched on the spatial scheduling for shipbuilding plant (Lee & Lee, 1992; Lee et al., 1994, Lee et al., 1995). In this paper, we present the various issues of spatial scheduling for the researchers and developers attacking spatial scheduling problems.

• 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.

• Journal of Sport and Applied Science
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• 제7권2호
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• pp.39-51
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• 2023

Purpose: The purpose of this study was to investigate differences in the control process to satisfy spatial and temporal constraints imposed upon the anticipation timing response by analyzing the effect of spatio-temporal accuracy demands on eye movements, response accuracy, and the coupling of eye and hand movements. Research design, data, and methodology: 12 right-handed male subjects participated in the experiment and performed anticipation timing responses toward a stimulus moving at three velocities (0.53m/s, 0.66m/s, 0.88m/s) in two task constraint conditions (temporal constraint, spatial constraint). During the response, response accuracy and eye movement patterns were measured from which timing and radial errors, the latency of saccade, fixation duration of the point of gaze (POG), distance between the POG and stimulus, and spatio-temporal coupling of the POG and hand were calculated. Results: The timing and radial errors increased with increasing stimulus velocity, and the spatio-temporal constraints led to larger timing errors than the temporal constraints. The latency of saccade and the temporal coupling of eye and hand decreased with increasing stimulus velocity and were shorter and longer respectively in the spatio-temporal constraint condition than in the temporal constraint condition. The fixation duration of the POG also decreased with increasing stimulus velocity, but no difference was shown between task constraint conditions. The distance between the POG and stimulus increased with increasing stimulus velocity and was longer in the temporal constraint condition compared to the spatio-temporal constraint condition. The spatial coupling of eye and hand was larger with the velocity 0.88m/s than those in other velocity conditions. Conclusions: These results suggest that differences in eye movement patterns and spatio-temporal couplings of stimulus, eye and hand by task constraints are closely related with the accuracy of anticipation timing responses, and the spatial constraints imposed may decrease the temporal accuracy of response by increasing the complexity of perception-action coupling.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.398-403
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• 2000

The design of multi-stage gear drives is a time-consuming process that includes additional design problems, which are not considered in the design of single-stage gear drives. In the previous research works, the authors have proposed a new algorithm to design multi-stage gear drives at the preliminary design phase. The proposed design algorithm automates the design process by integrating the dimensional design and the configuration design process. In the configuration design process, the positions of gears and shafts are determined by minimizing the geometrical volume (size) of a gearbox. However, various types of spatial constraints should be satisfied in practical design situation. To locate input and output shaft in specified positions is the typical example of such problems. In this paper, the authors show the formulations of spatial constraints applied to the design of four-stage gear drives. The design solution shows considerably good results, and the design system is confirmed to be readily applicable to practical design situation.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 2006년도 하계학술대회
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• pp.382-389
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• 2006

상황 인식 서비스가 발전하고 있는 요즘, 공간 인식 접근 제어 시스템에 높은 보안을 요구하고 있다. 이에 공간 역할의 사용자 할당, 권한의 할당, 역할 스키마와 역할 인스턴스, 공간 역할 계층, 그리고 공간제약을 제공하는 GEO-RBAC은 공간 인식 서비스에 적합한 접근 제어 모델이다. 하지만 GEO-RBAC은 공간 인식 환경에 필요한 시간 제약을 고려하지 않는 단점이 있다. 따라서 본 논문에서는 시간 제약의 개념을 사용하여 효과적인 접근제어 모델을 제시한 GTRBAC의 시간과 기간 제약 개념을 고려하여 GEO-RBAC의 유연성을 높이고 다양한 경우에도 효과적인 접근제어를 할 수 있도록 시간 제약을 고려한 GEO-RBAC 모델을 제안한다.

• 인터넷정보학회논문지
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• 제8권2호
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• pp.1-13
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• 2007

GPS/GIS와 RFID는 유비쿼터스 시대로 가는 우리 사회의 패러다임을 변화시켰다. 특히, 이러한 환경에서 지리적으로 분산되어 있고 운송해야 할 대상이 있는 이동 에이전트들은 자동으로 인식하고 추적할 수 있어야 한다. 그렇게 하기 위해서, 지리적 공간에서 에이전트들의 공간적/시간적 행위들을 명세하고 검증하기 위한 기본적인 이론과 기술들이 필요하다. 본 논문은 이를 위해 CaRDMI라는 새로운 정형기법을 제안한다. 명세를 위해 CaRDMI는 지도와 운송대상을 가지는 이동 에이전트들을 정의한다. 에이전트의 이동은 지도상의 경로로 표현되고 이들은 공간적/시간적 제약이 있는 노드와 에지들의 리스트들로 구성된다. 에이전트들 사이에서의 운송 대상에 관한 상호작용은 동기화 모드들에 의해 표현된다. 이들이 CaRDMI의 두드러진 특징이다. 특히, 시간 속성을 가진 다대다 동기화는 주목할만하다. CaRDMI는 분석과 검증을 위해 공간적, 시간적 그리고 상호작용을 위한 추론 규칙과 공간적/시간적 동일성 관계들을 제안한다.

• International Journal of Control, Automation, and Systems
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• 제6권3호
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• pp.401-412
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• 2008

This paper discusses a design methodology of cooperative path planning for dynamical multi-agent systems with spatial and temporal constraints. The cooperative behavior of the multi-agent systems is specified in terms of the objective function in an optimization formulation. The path of achieving cooperative tasks is then generated by the optimization formulation constructed based on a differential flatness approach. Three scenarios of multi-agent tasking are proposed at the cooperative task planning framework. Given agent dynamics, both spatial and temporal constraints are considered in the path planning. The path planning algorithm first finds trajectory curves in a lower-dimensional space and then parameterizes the curves by a set of B-spline representations. The coefficients of the B-spline curves are further solved by a sequential quadratic programming solver to achieve the optimization objective and satisfy these constraints. Finally, several illustrative examples of cooperative path/task planning are presented.

• 한국공간구조학회논문집
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• 제2권1호
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• pp.75-84
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• 2002

In this study, the 'force density method' for shape finding of cable net structures is presented. This concept is based on the force-length ratios or force densities which are defined for each branch of the net structures. This method renders a simple linear 'analytical form finding' possible. If the free choice of the force densities is restricted by further condition, the linear method is extended to a nonlinear one. The nonlinear one can be applied to the detailed computation of networks. In this paper, the general inverse matrix is introduced to solve the nonlinear equilibrium equation including Jacobian matrix which is rectangular matrix. Several examples for linear and nonlinear analysis applied additional constraints are presented. It is shown that the force density method is suitable for form finding of cable net and the general inverse matrix can be applied to solve the nonlinear equation without Lagrangian factors.

• 한국산림과학회지
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• 제101권1호
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• pp.96-103
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• 2012

본 연구에서는 산림수확계획 수립에 있어 벌채지 선정에 효과적으로 활용될 수 있는 수확분배시뮬레이션 모델의 도입을 위한 사례연구를 수행하였다. 이를 위해 Gustafson과 Crow가 개발한 HARVEST를 산림수확 공간분배 모델로 선정하고 국립산림과학원의 광릉시험림을 대상으로 벌채구획의 면적제한, 벌채지 선정방법, 및 벌채지 연접제한과 같은 기본적인 산림수확 경영방침을 적용하여 모델의 적용성을 검토하였다. 연구결과 벌채 구획의 면적제한 조건의 경우 허용벌채면적이 커질수록 벌채구획의 수는 적어지고 벌채구획간의 거리는 멀어지는 것으로 나타났다. 또한 임의산개형, 군상형 군상택벌형 및 영급순 등 벌채임분의 선정방법을 달리하여 수확 시뮬레이션에 적용한 경우 군상택벌형을 제외하고 벌채구획의 크기와 개소 수는 비슷한 경향을 나타내었으나 벌채지간 거리에서 차이를 나타내었다. 벌채지의 연접제한은 이미 벌채된 임분 주변에서의 벌채를 제한하므로 벌채구획의 수를 증가시키는 효과를 나타냈다. 이상의 연구결과를 종합한 결과 HARVEST는 산림수확을 수행하는데 있어 다양한 경영목표에 따라 벌채구획의 수와 공간분포의 정도를 조절할 수 있는 효과적인 도구로 평가되었다.