Lightweight Dynamic Redundancy Control with Adaptive Encoding for Server-based Storage

With the recent performance improvements in commodity hardware, low-cost commodity server-based storage has become a practical alternative to dedicated-storage appliances. Because of the high failure rate of commodity servers, data redundancy across multiple servers is required in a server-based storage system. However, the extra storage capacity for this redundancy significantly increases the system cost. Although erasure coding (EC) is a promising method to reduce the amount of redundant data, it requires distributing and encoding data among servers. There remains a need to reduce the performance impact of these processes involving much network traffic and processing overhead. Especially, the performance impact becomes significant for random-intensive applications. In this article, we propose a new lightweight redundancy control for server-based storage. Our proposed method uses a new local filesystem-based approach that avoids distributing data by adding data redundancy to locally stored user data. Our method switches the redundancy method of user data between replication and EC according to workloads to improve capacity efficiency while achieving higher performance. Our experiments show up to 230% better online-transaction-processing performance for our method compared with CephFS, a widely used alternative system. We also confirmed that our proposed method prevents unexpected performance degradation while achieving better capacity efficiency.

Comparative Evaluation of a Seed Planter, the Modified Version and Local (Hand) Seed Planting Method

This study evaluated the performance of a seed planter against the modified version, and hand planting method. A performance test was carried out on the two planters and hand method on a piece of land of known dimension over a period of time. Performance was evaluated using five (5) different parameters; sowing rate, area covered, throughput capacity, efficiency and level of uniformity. Sowing rate showed that hand method had the lowest sowing rate of 1 seed per sec, while the modified planter had the highest sowing rate of 5 seeds per sec. The modified planter had the highest for area covered at 91.5 m2, while the existing planter performed second best at 73.5 m2. Throughput capacity was highest for the modified planter at 292.8 kg/hr and lowest for hand planting method at 29.3 kg/hr. Efficiency result showed that hand method was better than the existing method at an efficiency value of 94 % against 89 % for existing planter; the modified planter performed best at 97 % efficiency value, while uniformity result showed that the modified planter was the best along the row and column arrangement at 97 % for both, while hand method had the lowest for both cases at 85 % and 88 % respectively. This study showed that the modified planter performed better than the two others in all the parameters assessed.

INFORMATION SUPPORTING SYSTEM ABOUT TAX CAPACITY OF A COMPANY AND ITS EFFICIENCY: PRINCIPLES OF FORMATION AND EVALUATION

The principles of forming the system of information about tax capacity are grouped and the directions of activity of the enterprise are identified, in view of which it is expedient to establish criteria for assessing its efficiency. The formation of information about tax capacity of an enterprise should occur not chaotically, but according to certain principles. The lists of basic principles (unity, objectivity, competence, probability and periodicity) and additional principles (dynamism, rationality, conformity, control) have been substantiated. The system of indicators and criteria of the formalized expression of efficiency is offered. The list of indicators made it possible to build the system (vector) of criteria requirements to ensure the effectiveness of information about the tax capacity of a business entity. It has been proved that in assessing the effectiveness of the information supporting system on tax capacity of the entity, the impact of time and cost criteria, as well as other non-measurable parameters should be taken into account. The proposed approach to assessing the effectiveness of the current information supporting system on the taxpayer's capacity will allow assessing alternative information systems in terms of the effectiveness of their implementation. Keywords: information supporting system; taxation; tax capacity; efficiency; principles; criteria; assessment; evaluation

INFORMATION SUPPORTING SYSTEM ABOUT TAX CAPACITY OF A COMPANY AND ITS EFFICIENCY: PRINCIPLES OF FORMATION AND EVALUATION

The principles of forming the system of information about tax capacity are grouped and the directions of activity of the enterprise are identified, in view of which it is expedient to establish criteria for assessing its efficiency. The formation of information about tax capacity of an enterprise should occur not chaotically, but according to certain principles. The lists of basic principles (unity, objectivity, competence, probability and periodicity) and additional principles (dynamism, rationality, conformity, control) have been substantiated. The system of indicators and criteria of the formalized expression of efficiency is offered. The list of indicators made it possible to build the system (vector) of criteria requirements to ensure the effectiveness of information about the tax capacity of a business entity. It has been proved that in assessing the effectiveness of the information supporting system on tax capacity of the entity, the impact of time and cost criteria, as well as other non-measurable parameters should be taken into account. The proposed approach to assessing the effectiveness of the current information supporting system on the taxpayer's capacity will allow assessing alternative information systems in terms of the effectiveness of their implementation. Keywords: information supporting system; taxation; tax capacity; efficiency; principles; criteria; assessment; evaluation

Analisa Produktivitas Mesin Pemarut dan Pemeras Ubi Kayu

The process of making tapioca flour traditionally consists of three stages performed separately. The three stages of tapioca flour production can also be done mechanically, ie with the help of equipment, both for the process of dissolving and the process of extortion and filtering. Existing mechanical means, using two separate tools in which one device is used for the dissolution process, while the other is used for extortion and filtering. 5 tests were performed with the scales specified in the test ie 2 kg, 4 kg, 6 kg, 8 kg, and 10 kg. The average engine capacity of 12 Kg / Hr and the capacity of cassava hardener is 11 Kg / hour. The average efficiency of flour testing was 20.54% and the average efficiency of cassava dregs was 37.8%.Key words: Productivity, Capacity, Efficiency

THE ISSUES OF TRAIN SCHEDULE FULFILLMENT STABILITY IMPROVEMENT

Objective: At present the majority of railway lines experiences serious difficulties in handling of the increased flow of freight trains with considerable amount of passenger traffic. In view of this there is a necessity to improve the level of train schedule stability by creating certain time slacks in it, which make it possible to eliminate errors. Methods: The methods of simulation, computational theory and construction of a train schedule graph were applied. Results: The method of train routing was developed on the basis of simulation of schedule configuration. The characteristics of schedule configuration and conditions of its creation were presented. The influence of trainhandling capacity efficiency coefficient on the choice of a configured train routing diagram was studied, as well as one of the vital factors, causing degradation of train schedule fulfillment stability – disagreement in train traffic. It was shown that in case of selecting a configuration it was necessary to increase the headway between consecutive trains after a bunch of trains, and if train overtaking is inevitable – to use the time of extra removal. In order to eliminate the consequences of disagreement in train traffic, it was proposed to increase intervals not between all trains, but to compensate the disagreement after passage of a number of trains, the latter should be specified on an individual basis. The assessment of compensating interval efficiency was fulfilled by means of removal coefficient calculation for different conditions on three options. It was concluded that the compensating interval not only reduces disagreement impact, but also improves train-handling capacity. The example of train schedule stability improvement was considered on the basis of applying configurations at “Malaya Vishera – Bologoye” section on down trains within the period of time from 11.30 pm to 7.30 am. Practical importance: Application of configurations makes it possible to achieve higher implementable levels of speed and train-handling capacity, leads to the detection of time slacks and time buffers, which considerably increase train schedule stability and, consequently, the stability of its fulfillment.