Age of Information in a Cooperative Slotted Aloha Network: Marginal and Joint Distributions

In this paper, we investigate a slotted Aloha cooperative network where a source node and a relay node send status updates of two underlying stochastic processes to a common destination. Additionally, the relay node cooperates with the source by accepting its packets for further retransmissions, where the cooperation policy comprises acceptance and relaying probabilistic policies. Exact marginal steady state distributions of the source and relay Age of Information (AoI) and Peak AoI (PAoI) sequences are obtained using Quasi-Birth-Death (QBD) Markov chain models. Extending this approach, we also obtain the joint distribution of the source and relay AoI sequences out of which one can obtain the steady state distribution of the Squared Difference of the two AoI sequences (SDAoI), which finds applications in network scenarios where not only the timeliness of status updates of each process is desired but also their simultaneity is of crucial importance. In this regard, we numerically obtain the optimal cooperation policy in order to minimize the expected value of SDAoI subject to a constraint on the average PAoI of the relay. Finally, our proposed analytical approach is verified by simulations and the performance of the optimal policy is discussed based on the numerical results.

Age of Information in a Cooperative Slotted Aloha Network: Marginal and Joint Distributions

In this paper, we investigate a slotted Aloha cooperative network where a source node and a relay node send status updates of two underlying stochastic processes to a common destination. Additionally, the relay node cooperates with the source by accepting its packets for further retransmissions, where the cooperation policy comprises acceptance and relaying probabilistic policies. Exact marginal steady state distributions of the source and relay Age of Information (AoI) and Peak AoI (PAoI) sequences are obtained using Quasi-Birth-Death (QBD) Markov chain models. Extending this approach, we also obtain the joint distribution of the source and relay AoI sequences out of which one can obtain the steady state distribution of the Squared Difference of the two AoI sequences (SDAoI), which finds applications in network scenarios where not only the timeliness of status updates of each process is desired but also their simultaneity is of crucial importance. In this regard, we numerically obtain the optimal cooperation policy in order to minimize the expected value of SDAoI subject to a constraint on the average PAoI of the relay. Finally, our proposed analytical approach is verified by simulations and the performance of the optimal policy is discussed based on the numerical results.

Japan’s Peacebuilding under the Abe Administration: Change and Continuity, 2012–2020

This article traces the developments in Japan’s peacebuilding policy in Abe Shinzo’s second term (2012–2020) and presents illustrative case studies to highlight the change and continuity that occurred during this period. Although Abe is internationally known for launching a new doctrine of “active pacifism”, his reforms in international peace cooperation policy incrementally built upon the existing discourses and practices. Abe’s vision of a more proactive peacebuilding policy has also been heavily circumscribed by Japan’s Constitution.

LAND REGISTRATION AND SPORADIC COOPERATION POLICY

This research aims tounderstand the complete systematic land registration policy and to understand the complete systematic land registration model at the Jepara Regency Land Office. The approach method used is sociological juridical and data collection is done using the interview method. The results of this study indicate that the complete systematic land registration policy has been implemented in a collaborative manner with sporadic registration, which is ultimately divided into 4 (four) clusters. This is because not all people agree with the Complete Systematic Land Registration program. Collaboration of the registration system is carried out in order to achievetarget group .