Browsing by Author "Chang, HKC"

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A novel access control method using Morton number and prime factorization
(2000-12-01)
Chang, HKC
;
Hwang, JJ
;
Liu, HH
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
A novel scheme used for controlling access requests in security information system is proposed. In the proposed method, the system administrator chooses distinct prime numbers representing each atomic access right as well as four large prime numbers for encryption. By setting these representative prime numbers as input parameters, the proposed method applies a one-way function combining the Morton number theory transferring into a single value to derive the encrypted compound privilege (ECP). With ECP, verification of right of access can be achieved easily and secretly. Meanwhile, the proposed scheme provides the following advantages: (I) the verification of right of access can be effectively implemented using the Morton sequence with coordinate transformation; (2) the problem of dynamic access control also can be effectively implemented; (3) integrity and confidentiality while controlling system resources can be ensured; (4) the proposed method can decrease the redundancy of the access matrix in some specific circumstances. (C) 2000 Elsevier Science Inc. All rights reserved.
Discrete-event based simulation of airbase logistic provision model
(1999-01-01)
Tung, CY
;
Chang, HKC
;
Hsu, PY
;
科技管理研究所
;
Institute of Management of Technology
By means of a simulation technique, we developed and implemented a model of the provision of logistics at an air base; the results of the simulation are analysed. This model is constructed to evaluate all factors affecting the sorties of military aircraft from an airbase. All factors include logistic provision, takeoff, landing, maintenance and repair. Under the constraints of limited resources and inevitable consumption, the objective of the model is to setup an environment with which methods for increasing the average number of sorties of aircraft from an airbase can be analysed. The constraints of limited resources refer to logistic support personnel, repair engineers or required equipment; the inevitable consumption includes damage in combat, operational mistakes or depletion of fuel and ammunition. The simulation of the model is designed on the basis of discrete-event orientation. Given a specific interval with various constraints, the average sorties of aircraft from the airbase are simulated. The simulation, implemented with the SIMSCRIPT II.5 language, is tested with various input data. The outputs of the simulations are analysed and compared. With such simulations, the problem of resources allocation and distribution in an airbase can be effectively controlled and programmed. The proposed model and the simulations can be beneficial to the management of the logistic support system at an airbase.
Discrete-event based simulation of airbase logistic provision model
(1999-01-01)
Tung, CY
;
Chang, HKC
;
Hsu, PY
;
科技管理研究所
;
Institute of Management of Technology
By means of a simulation technique, we developed and implemented a model of the provision of logistics at an air base; the results of the simulation are analysed. This model is constructed to evaluate all factors affecting the sorties of military aircraft from an airbase. All factors include logistic provision, takeoff, landing, maintenance and repair. Under the constraints of limited resources and inevitable consumption, the objective of the model is to setup an environment with which methods for increasing the average number of sorties of aircraft from an airbase can be analysed. The constraints of limited resources refer to logistic support personnel, repair engineers or required equipment; the inevitable consumption includes damage in combat, operational mistakes or depletion of fuel and ammunition. The simulation of the model is designed on the basis of discrete-event orientation. Given a specific interval with various constraints, the average sorties of aircraft from the airbase are simulated. The simulation, implemented with the SIMSCRIPT II.5 language, is tested with various input data. The outputs of the simulations are analysed and compared. With such simulations, the problem of resources allocation and distribution in an airbase can be effectively controlled and programmed. The proposed model and the simulations can be beneficial to the management of the logistic support system at an airbase.