With the establishment of a modem corporate system, the separation of ownership and management appears in the company. The rational allocation of corporate control between different behavioral agents has attracted mor...With the establishment of a modem corporate system, the separation of ownership and management appears in the company. The rational allocation of corporate control between different behavioral agents has attracted more and more attention. This paper points out that scholars have studied the allocation of corporate control from the angles of the agency cost theory, property rights theory, corporate finance theory, and the theory of corporate governance, which has great value. However, the existing theories also have some flaws on the allocation of corporate control. First, people still have different understandings and views over the meaning of corporate control. Secondly, the existing research theoretically only observes and studies an arrangement of sheer level control, the allocation between final control and real control. This paper argues to build the two-tier allocation of corporate control: The first tier relation is between ultimate control rights and actual control rights, the second tier relation is between indirect control rights and direct control rights which are in actual control rights. This study can explain the resource allocation effects of corporate control, promote the development and improvement of the theory of the firm.展开更多
This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided in...This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently.展开更多
Role mining and setup affect the usage of role-based access control(RBAC).Traditionally,user's role and permission assigning are manipulated by security administrator of system.However,the cost is expensive and th...Role mining and setup affect the usage of role-based access control(RBAC).Traditionally,user's role and permission assigning are manipulated by security administrator of system.However,the cost is expensive and the operating process is complex.A new role analyzing method was proposed by generating mappings and using them to provide recommendation for systems.The relation among sets of permissions,roles and users was explored by generating mappings,and the relation between sets of users and attributes was analyzed by means of the concept lattice model,generating a critical mapping between the attribute and permission sets,and making the meaning of the role natural and operational.Thus,a role is determined by permission set and user's attributes.The generated mappings were used to automatically assign permissions and roles to new users.Experimental results show that the proposed algorithm is effective and efficient.展开更多
Attribute-based encryption(ABE) supports the fine-grained sharing of encrypted data.In some common designs,attributes are managed by an attribute authority that is supposed to be fully trustworthy.This concept implies...Attribute-based encryption(ABE) supports the fine-grained sharing of encrypted data.In some common designs,attributes are managed by an attribute authority that is supposed to be fully trustworthy.This concept implies that the attribute authority can access all encrypted data,which is known as the key escrow problem.In addition,because all access privileges are defined over a single attribute universe and attributes are shared among multiple data users,the revocation of users is inefficient for the existing ABE scheme.In this paper,we propose a novel scheme that solves the key escrow problem and supports efficient user revocation.First,an access controller is introduced into the existing scheme,and then,secret keys are generated corporately by the attribute authority and access controller.Second,an efficient user revocation mechanism is achieved using a version key that supports forward and backward security.The analysis proves that our scheme is secure and efficient in user authorization and revocation.展开更多
The idea of this work arises from the analysis of the researches developed in the literature on topic of ownership and control that are mostly based on threshold of ownership stake to determine control equal for all c...The idea of this work arises from the analysis of the researches developed in the literature on topic of ownership and control that are mostly based on threshold of ownership stake to determine control equal for all companies and, in most cases, not supported by theoretical arguments and empirical evidences. In fact, the aim of this paper is to build a new method of determining the threshold of ownership stake that allows the shareholder to exercise control. In particular, this survey uses all Italian listed companies as reference, and the minutes of the Ordinary and Extraordinary General Meetings of shareholders, in 2009-2012, as database. The topic can be enriched with further and future researches aiming to adapt this new method in a cross-country investigation and so to identify the different threshold for the countries, on the basis of the different national laws regarding the ownership stakes that affect the control.展开更多
文摘With the establishment of a modem corporate system, the separation of ownership and management appears in the company. The rational allocation of corporate control between different behavioral agents has attracted more and more attention. This paper points out that scholars have studied the allocation of corporate control from the angles of the agency cost theory, property rights theory, corporate finance theory, and the theory of corporate governance, which has great value. However, the existing theories also have some flaws on the allocation of corporate control. First, people still have different understandings and views over the meaning of corporate control. Secondly, the existing research theoretically only observes and studies an arrangement of sheer level control, the allocation between final control and real control. This paper argues to build the two-tier allocation of corporate control: The first tier relation is between ultimate control rights and actual control rights, the second tier relation is between indirect control rights and direct control rights which are in actual control rights. This study can explain the resource allocation effects of corporate control, promote the development and improvement of the theory of the firm.
基金Supported by the Science Foundation of Shanghai Mu-nicipal Commission of Science and Technology under contract 045115012.
文摘This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently.
基金Project(61003140) supported by the National Natural Science Foundation of ChinaProject(013/2010/A) supported by Macao Science and Technology Development FundProject(10YJC630236) supported by Social Science Foundation for the Youth Scholars of Ministry of Education of China
文摘Role mining and setup affect the usage of role-based access control(RBAC).Traditionally,user's role and permission assigning are manipulated by security administrator of system.However,the cost is expensive and the operating process is complex.A new role analyzing method was proposed by generating mappings and using them to provide recommendation for systems.The relation among sets of permissions,roles and users was explored by generating mappings,and the relation between sets of users and attributes was analyzed by means of the concept lattice model,generating a critical mapping between the attribute and permission sets,and making the meaning of the role natural and operational.Thus,a role is determined by permission set and user's attributes.The generated mappings were used to automatically assign permissions and roles to new users.Experimental results show that the proposed algorithm is effective and efficient.
基金supported by the NSFC(61173141,U1536206,61232016, U1405254,61373133,61502242,61572258)BK20150925+3 种基金Fund of Jiangsu Engineering Center of Network Monitoring(KJR1402)Fund of MOE Internet Innovation Platform(KJRP1403)CICAEETthe PAPD fund
文摘Attribute-based encryption(ABE) supports the fine-grained sharing of encrypted data.In some common designs,attributes are managed by an attribute authority that is supposed to be fully trustworthy.This concept implies that the attribute authority can access all encrypted data,which is known as the key escrow problem.In addition,because all access privileges are defined over a single attribute universe and attributes are shared among multiple data users,the revocation of users is inefficient for the existing ABE scheme.In this paper,we propose a novel scheme that solves the key escrow problem and supports efficient user revocation.First,an access controller is introduced into the existing scheme,and then,secret keys are generated corporately by the attribute authority and access controller.Second,an efficient user revocation mechanism is achieved using a version key that supports forward and backward security.The analysis proves that our scheme is secure and efficient in user authorization and revocation.
文摘The idea of this work arises from the analysis of the researches developed in the literature on topic of ownership and control that are mostly based on threshold of ownership stake to determine control equal for all companies and, in most cases, not supported by theoretical arguments and empirical evidences. In fact, the aim of this paper is to build a new method of determining the threshold of ownership stake that allows the shareholder to exercise control. In particular, this survey uses all Italian listed companies as reference, and the minutes of the Ordinary and Extraordinary General Meetings of shareholders, in 2009-2012, as database. The topic can be enriched with further and future researches aiming to adapt this new method in a cross-country investigation and so to identify the different threshold for the countries, on the basis of the different national laws regarding the ownership stakes that affect the control.