Improved Bounds and Singleton-Optimal Constructions of Locally Repairable Codes With Minimum Distance 5 and 6

2021 ◽  
Vol 67 (1) ◽  
pp. 217-231
Author(s):  
Bin Chen ◽  
Weijun Fang ◽  
Shu-Tao Xia ◽  
Jie Hao ◽  
Fang-Wei Fu
Keyword(s):  
Minimum Distance ◽  
Locally Repairable Codes

scholarly journals On the Single-Parity Locally Repairable Codes with Multiple Repairable Groups

Information ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 265
Author(s):  
Yanbo Lu ◽  
Xinji Liu ◽  
Shutao Xia
Keyword(s):  
Minimum Distance ◽  
Distributed Storage ◽  
Standard Form ◽  
Erasure Codes ◽  
New Family ◽  
Distributed Storage Systems ◽  
Locally Repairable Codes ◽  
Generator Matrices ◽  
Straightforward Proof

Locally repairable codes (LRCs) are a new family of erasure codes used in distributed storage systems which have attracted a great deal of interest in recent years. For an [ n , k , d ] linear code, if a code symbol can be repaired by t disjoint groups of other code symbols, where each group contains at most r code symbols, it is said to have availability- ( r , t ) . Single-parity LRCs are LRCs with a constraint that each repairable group contains exactly one parity symbol. For an [ n , k , d ] single-parity LRC with availability- ( r , t ) for the information symbols (single-parity LRCs), the minimum distance satisfies d ≤ n - k - ⌈ k t / r ⌉ + t + 1 . In this paper, we focus on the study of single-parity LRCs with availability- ( r , t ) for information symbols. Based on the standard form of generator matrices, we present a novel characterization of single-parity LRCs with availability t ≥ 1 . Then, a simple and straightforward proof for the Singleton-type bound is given based on the new characterization. Some necessary conditions for optimal single-parity LRCs with availability t ≥ 1 are obtained, which might provide some guidelines for optimal coding constructions.

scholarly journals Bounds on the maximal minimum distance of linear locally repairable codes

2016 ◽  
Author(s):  
Antti Pollanen ◽  
Thomas Westerback ◽  
Ragnar Freij-Hollanti ◽  
Camilla Hollanti
Keyword(s):  
Minimum Distance ◽  
Locally Repairable Codes

Determining The Minimum Distance Between Centers of Two Parallel Tunnels to Apply The Law of Super Position in Order to Calculate Subsidence by Using The Software FLAC 3D

2015 ◽  
Vol 1 (1) ◽  
pp. 13-20
Author(s):  
Hamid Reza Samadi ◽  
Mohammad Reza Samadi
Keyword(s):  
Minimum Distance ◽  
Surface Subsidence ◽  
Urban Traffic ◽  
Underground Structures ◽  
Rapid Population Growth ◽  
The North ◽  
Flac 3D ◽  
The Law ◽  
3D Software ◽  
Twin Tunnels

Due to the development of cities as well as rapid population growth, urban traffic is increasing nowadays. Hence, to improve traffic flow, underground structures such as metro, especially in metropolises, are inevitable. This paper is a research on the twin tunnels Of Isfahan's metro between Shariaty station and Azadi station from the North towards the South. In this study, simultaneous drilling of subway's twin tunnels is simulated by means of Finite Difference Method (FDM) and FLAC 3D software. Moreover, the lowest distance between two tunnels is determined in a way that the Law of Super Position could be utilized to manually calculate the amount of surface subsidence, resulted by drilling two tunnels, by employing the results of the analysis of single tunnels without using simultaneous examination and simulation. In this paper, this distance is called "effective distance". For this purpose, first, the optimum dimensions of the model is chosen and then, five models with optimum dimensions will be analyzed separately, each of which in three steps. The results of analyses shows that the proportions (L/D) greater than or equal 2.80, the Law of Super Position can be applied for prediction of surface subsidence, caused by twin tunnels' construction

ENSURING THE PEDESTRIAN’S SAFETY DESIGN OF URBAN STREET CROSSWALKS

2019 ◽  
pp. 103-110
Author(s):  
Dmitriy Nemchinov
Keyword(s):  
Traffic Flow ◽  
Minimum Distance ◽  
Travel Speed ◽  
Vehicle Speed ◽  
Urban Street ◽  
Safety Design ◽  
Positive Practices ◽  
Time Required ◽  
Pedestrian Crossing ◽  
The City

The article presents an analysis of positive practices for ensuring the safety of pedestrians at the inter-section of the city streets carriageway, as well as a description of some innovations of regulatory and tech-nical documents, including an increased number of cases when a safety island can be arranged at a pedestri-an crossing. requirements for providing visibility at a pedestrian crossing to determine the minimum distance of visibility at a pedestrian crossing based on the time required pedestrians for crossing the roadway, recommended options for using ground unregulated pedestrian crossings on trapezoidal artificial irregularities according to GOST R 52605; traffic flow) and Z-shaped (also in the direction of the traffic flow), the requirements for the size of the securi-ty island have been established to allow put bicycle inside of safety island, a recommended set of measures to reduce the vehicle speed and describes the types of activities and describes a method of their application, describes methods zones device with reduced travel speed - residential and school zones, set requirements for turboroundabouts and methods of their design.

scholarly journals PSVIII-35 Late-Breaking Abstract: Administration of an appeasing substance at castration improves performance of pre-conditioned beef crossbred steers

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-348
Author(s):  
Kelsey Schubach ◽  
Bruno I Cappellozza ◽  
Marcos Renato Burim ◽  
André Velasco ◽  
Fernando Sagrado ◽  
...  
Keyword(s):  
Feed Efficiency ◽  
Minimum Distance ◽  
Descriptive Analysis ◽  
Bos Indicus ◽  
Experimental Unit ◽  
Water Restriction ◽  
Improve Performance ◽  
Treatment Groups ◽  
Improved Performance ◽  
To Receive

Abstract Alternatives that alleviate stress-related responses and improve performance of the beef cattle herd are imperative and deserve further investigation. In previous trials, administration of the bovine appeasing substance (BAS) has improved performance of newly-weaned and feedlot received beef animals, as well as reduced the risk of dark, firm, and dry (DFD) cuts in carcass obtained from Bos indicus cattle. Therefore, this study was designed to evaluate the effects of BAS administration at castration on pre-conditioning performance of crossbred beef animals. On day 0, 390 crossbred Angus × Nellore animals were ranked by initial shrunk BW (255 ± 21.1 kg) and assigned to receive or not (CON) 5 mL/head of BAS (SecureCattle; Nutricorp, Araras, SP, Brazil) immediately before castration. From d 0 to 30, animals within treatments were maintained in 2 feedot pens with a minimum distance (300 m) to avoid contact between treatment groups and received a grass hay-based diet (70:30 roughage:concentrate ratio) ad libitum. On day 30, animals were individually weighed following 16 hours of feed and water restriction. Hence, a descriptive analysis was performed to evaluate pen dry matter intake (DMI) and feed efficiency (FE). Animal was considered the experimental unit and all data were analyzed using the PROC MIXED procedure of SAS (version 9.4; SAS Inst. Inc., Cary, NC). Bovine appeasing substance administration at castration improved ADG and BW change (P < 0.0001) compared with CON cohorts (0.983 vs. 1.155 kg/d and 29.5 vs. 34.6 kg for ADG and BW change, respectively). Total DMI was similar among treatments when reported as kg/d (6.70 vs. 6.75 kg) or % of BW (2.48 vs. 2.48%), whereas FE was dramatically improved in BAS-administered animals (146 vs. 172 g/kg for CON and BAS, respectively). In summary, BAS administration improved performance of crossbred beef animals for 30 days post-castration.

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