1,721,088 research outputs found
Replication Data for: The Role of Career and Wage Incentives in Labor Productivity: Evidence from a Two-stage Field Experiment in Malawi
No full textKim, Hyuncheol Bryant, Kim, Seonghoon, and Kim, Thomas T., (2020) “The Role of Career and Wage Incentives in Labor Productivity: Evidence from a Two-Stage Field Experiment in Malawi.” Review of Economics and Statistics 102:5, 839–851
Replication Data for: The Role of Career and Wage Incentives in Labor Productivity: Evidence from a Two-stage Field Experiment in Malawi
No full textKim, Hyuncheol Bryant, Kim, Seonghoon, and Kim, Thomas T., (2020) “The Role of Career and Wage Incentives in Labor Productivity: Evidence from a Two-Stage Field Experiment in Malawi.” Review of Economics and Statistics 102:5, 839–851
Satellite User Grouping and Multi-Beam Patterning for Generalized Rate-Splitting Multiple Access
No full textWith an exponential increase of data traffic, satellite communication systems are being required to make an efficient use of limited frequency resources, and several multiple access schemes have been studied to achieve a higher sum-rate than orthogonal multiple access (OMA) on a broadcasting (BC) channel such as satellite downlink. Encompassing spatial division multiple access (SDMA) and non-orthogonal multiple access (NOMA) on the whole, generalized rate-splitting multiple access (RSMA) suffers from high complexity of optimizing the number of common streams corresponding to all user combinations and a brute-force procedure to find the best decoding order. To tackle this problem, in this paper, we preemptively optimize the location of the satellite beams and convert the precoding matrix design of generalized RSMA into a low complex power allocation problem. In addition, a heuristic decoding order is set instead of the exhaustive search by using the intensity of the pre-manipulated beams. We then propose a user grouping method that reduces the number of common streams by using a sequential search algorithm based on the position of users, and derive a solution of leakage-based beam patterning from non-convex programming regarding the location of each beam. Finally, simulation results show that the novel framework of generalized RSMA in the satellite BC channel has a multiplexing gain up to 48 percent compared to NOMA and 1-layer RSMA with fixed cells
A Location Update Scheme using Multi-hop Pointer Forwarding in Low-rate Wireless Mesh Networks
No full textRecently, a pointer forwarding scheme (PFS) was proposed to reduce location update overhead in wireless mesh networks. Using the PFS, location update is replaced with a simple forwarding pointer setup between two neighboring MRs until the forwarding chain K is less than or equal to the configurable parameter Kmax for each MC. However, in PFS, if the two MRs are not one hop neighbors, the PFS fails to set up a forwarding pointer, and a location update event must be triggered, increasing location update overhead. To improve PFS, we present a novel location update scheme called a multi-hop pointer forwarding scheme (MPFS). The MPFS allows forwarding pointers to be constructed over multi-hop at once even if MRs are not one hop neighbor with each other. The key to achieving this lies in the logical tree distance constructed during network formation. The tree distance is used to relay forwarding pointer packets over multi-hop links without additional control overhead and to estimate hop distance between two MRs. By doing so, the MPFS improves the probability of success in forwarding pointer setup while ensuring K ≤ Kmax, resulting in lowering the location update overhead. To evaluate our scheme we implement both the PFS and the MPFS in ns-2 and compare them. As a result, we show that the MPFS significantly reduces the number of location update events, resulting in reduction of location update delay and signaling overhead, and packet losses during location updates
Location-free Semi-directional Flooding for On-demand Routing in Low-Rate Wireless Mesh Networks
No full textIn this paper, we propose a novel on-demand routing protocol for IEEE 802.15.4-based low rate wireless mesh networks (LRWMNs). The novelty of our work is that the proposed routing algorithms enable route discovery packets (RREQs) to be semi-directionally flooded with respect to a source-destination pair in a distributed manner without either physical or virtual location systems. Instead, we use the logical tree distance derived from the hierarchical addressing structure. The idea behind this is that nodes with longer tree distance to the destination than that of the source-destination pair are not involved in flooding RREQs. To evaluate the algorithms, we apply our algorithms into AODVjr and carry out extensive simulations while comparing the algorithms with AODVjr using network-wide flooding (NWF). Results show that the proposed algorithms drastically reduce RREQ overhead while providing comparable or better performance than NWF in AODVjr
A Study on Inter-region Flow Control of Urban Traffic: A Modification of the Greedy Control Strategy
No full textBrowsing Architecture with Presentation metadata for the Internet of Things
No full textTo realize the Internet of Things (IoT), an important step would be to allow things and information about them to be accessible in an easy way and a platform-independent manner. As World Wide Web (WWW, Web) shows explosive growth over the last decade, the web is the most popular and familiar user interface to acquire knowledge about everyday life. In this respect, web browsing through standard protocols like HTTP over TCP could be a promising approach to access things and to collect things' information. In future, IP-based wireless sensor networks (IP-WSNs) are expected to be integrated into the IoT. However, due to the characteristics of IP-WSN such as resource limited and low data-rate, the challenges that we confronted are 1) how to make clients access IP-WSNs as if they use regular web browsers with rich presentation and acceptable response time and 2) how to embed the standard web in such resource-constrained sensor nodes. In this paper, to address these challenges, we introduce a new browsing architecture, which enables the exploration of the IP-WSNs through a conventional web browser and the navigation with rich user interfaces. We also design lightweight web protocols, lwHTTP and lwTCP, with header compression in order for HTTP and TCP to run on the resource-constrained IP-WSNs. To show the feasibility, we implement the proposed architecture in SNAIL (Sensor Networks for an All-IP world), our IP-WSN platform, and we evaluate the performance of proposed browsing architecture
DRL-Based Satellite Network Slice Planning and Handover in the Korean Peninsula Scenarios
Full text linkThis paper introduces a novel approach using deep reinforcement learning (DRL) to enhance network slicing planning and handovers in satellite networks. We propose a proactive handover trigger based on remaining service time and employ the deep deterministic policy gradient (DDPG) algorithm to maximize the utility of virtual networks (VNs). Focusing on the Korean Peninsula, we simulate a low earth orbit (LEO) satellite network based on Starlink satellite specifications and demonstrate the superiority of our intelligent network management technique compared to baseline methods, particularly in terms of latency performance and the number of handovers. © 2023 IEEE
SNAIL Gateway: Dual-mode Wireless Access Points for WiFi and IP-based Wireless Sensor Networks in the Internet of Things
No full textOne of the important challenges in the Internet of Things (IoT) is how to acquire the physical context of things. IP-based wireless sensor networks (IP-WSNs) could be a promising approach to collecting the physical context of things and to integrating WSNs to the Internet. However, realizing IP-WSNs in IoT exposes two major challenges. One is how to embed the Internet Protocol (IP) in resource-constrained sensor nodes. The other is how to achieve real-world deployment of WSNs and its integration with the Internet on the fly and on the cheap. In this paper, we present the SNAIL (Sensor Networks for All-IP World) project and introduce a new type of IP-WSN gateway, which supports dual wireless access points for WiFi and IP-WSN, enabling deployment of SNAIL nodes in an easy and rapid manner as for the solution. To show the proof-of-concept, we implement a new SNAIL platform from tiny sensor nodes to a gateway
- …
