critical path
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2022 ◽  
Vol 27 (3) ◽  
pp. 1-31
Yukui Luo ◽  
Shijin Duan ◽  
Xiaolin Xu

With the emerging cloud-computing development, FPGAs are being integrated with cloud servers for higher performance. Recently, it has been explored to enable multiple users to share the hardware resources of a remote FPGA, i.e., to execute their own applications simultaneously. Although being a promising technique, multi-tenant FPGA unfortunately brings its unique security concerns. It has been demonstrated that the capacitive crosstalk between FPGA long-wires can be a side-channel to extract secret information, giving adversaries the opportunity to implement crosstalk-based side-channel attacks. Moreover, recent work reveals that medium-wires and multiplexers in configurable logic block (CLB) are also vulnerable to crosstalk-based information leakage. In this work, we propose FPGAPRO: a defense framework leveraging P lacement, R outing, and O bfuscation to mitigate the secret leakage on FPGA components, including long-wires, medium-wires, and logic elements in CLB. As a user-friendly defense strategy, FPGAPRO focuses on protecting the security-sensitive instances meanwhile considering critical path delay for performance maintenance. As the proof-of-concept, the experimental result demonstrates that FPGAPRO can effectively reduce the crosstalk-caused side-channel leakage by 138 times. Besides, the performance analysis shows that this strategy prevents the maximum frequency from timing violation.

2022 ◽  
Vol 48 (1) ◽  
pp. 1-36
Mirko Myllykoski

The QR algorithm is one of the three phases in the process of computing the eigenvalues and the eigenvectors of a dense nonsymmetric matrix. This paper describes a task-based QR algorithm for reducing an upper Hessenberg matrix to real Schur form. The task-based algorithm also supports generalized eigenvalue problems (QZ algorithm) but this paper concentrates on the standard case. The task-based algorithm adopts previous algorithmic improvements, such as tightly-coupled multi-shifts and Aggressive Early Deflation (AED) , and also incorporates several new ideas that significantly improve the performance. This includes, but is not limited to, the elimination of several synchronization points, the dynamic merging of previously separate computational steps, the shortening and the prioritization of the critical path, and experimental GPU support. The task-based implementation is demonstrated to be multiple times faster than multi-threaded LAPACK and ScaLAPACK in both single-node and multi-node configurations on two different machines based on Intel and AMD CPUs. The implementation is built on top of the StarPU runtime system and is part of the open-source StarNEig library.

N.D. Iliinov ◽  
A.M. Mazhitov ◽  
A.B. Allaberdin ◽  
K.V. Vazhdaev

Currently, many underground mines are revising their design solutions to increase their production capacity. This tendency is explained by the decreasing ore grades, as well as by the extensive introduction of mechanization in underground mining operations that has improved the output of mobile equipment by increasing the box capacity and engine power. Dieselpowered mobile vehicles are the most common in underground mining practice. The advantages of such engines are obvious as they generate more power than other types of engines. However, the high air demand for mine ventilation limits their application. This is associated with the need to increase the cross-sections of permanent mine workings in order to comply with the standard air flow rate with account of the increased ventilation capacity along with an increase in the inventory of mobile equipment in order to ensure the specified output of the mine. The specific features of mining operations are defined by the stage-wise character of commissioning various blocks of the deposit. Managing of production and development works provides an opportunity to ventilate the mine sections due to their consecutive commissioning, locally, with an isolated stream of air by means of mine workings that do not have the intersection of air streams. This provides a reduction of critical path of air travel up to 30% and reduction of the general mine ventilating pressure drop by at least 20% at constant air flow rate. The results of the work can be used in designing the ventilation system of underground mines both under construction and in operation.

2022 ◽  
Vol 14 (4) ◽  
pp. 75-81
Tatyana Novikova ◽  
Svetlana Evdokimova ◽  
A. Novikov

The guiding principles of project implementation are planning. The discrepancy in time, cost, and quality between the plan and the actual implementation of the project requires management decisions supported by an analysis of the optimization of the duration of the project and the search for reserves to reduce the implementation time. For this purpose, a basic PERT model for a specific project was developed, early and late deadlines for work, time reserves, and a critical path were calculated. This work is aimed at applying methods of evaluation and analysis of projects to find optimal solutions and control the efficiency of time and costs in project planning, by varying the work on the project and the executors of the work. The results of this study showed that there are quite large time reserves for works 5-7, 7-9, 6-9, etc., which makes it possible to redistribute work between performers and allows you to vary performers during the implementation of several projects simultaneously.

2022 ◽  
Vol 3 (2) ◽  
pp. 55-62
Nihayatus Sa'adah ◽  
Evany Iqrammah ◽  
Tri Rijanto

Abstrak Kegiatan pembangunan proyek konstruksi sering terjadi keterlambatan. Pelaksanaan proyek konstruksi dibatasi oleh waktu dengan rencana biaya yang sudah ditentukan dalam perencanaan.  Pengendalian yang tepat dapat mengurangi risiko terjadinya keterlambatan serta pembengkakan biaya. Salah satu proyek yang mengalami keterlambatan adalah pembangunan Gedung Stroke Center (Paviliun Flamboyan) RSUD Jombang. Faktor yang menjadi penyebab yaitu: (1) kurangnya kesiapan alat yang digunakan untuk mengakses ke tempat pembangunan, (2) posisi struktur tidak sesuai dengan perencanaan sehingga terjadi pembongkaran dan pengecoran ulang, (3) jalur mobilitas traffic alat berat yang sulit untuk mengakses ke tempat pembangunan sehingga berdampak terhadap pelaksanaan. Tujuan penelitian ini adalah (1) memperoleh informasi waktu pekerjaan pelaksanaan (2) mengetahui perbandingan biaya dan waktu adanya percepatan waktu pelaksanaan proyek. Metode yang dipakai adalah metode CPM (Critical Path Method) yang digunakan untuk menganalisis lintasan kritis yang fokus pada pekerjaan struktur beton dan menggunakan metode Crashing untuk mengetahui perbandingan biaya dan waktu akibat adanya percepatan (crashing). Hasil analisa pada penelitian ini diperoleh durasi pelaksanaan pekerjaan bangunan proyek secara normal. Dari analisa dengan alternatif penambahan tenaga kerja dan jam kerja (lembur) yaitu lebih hemat menggunakan alternatif jam kerja lembur dengan perbandingan sebesar 0.010%. Kata Kunci: Critical Path Method (CPM), Crashing, Waktu, Biaya.

2022 ◽  
Vol 12 (1) ◽  
pp. 457
Rudolf Vávra ◽  
Vít Janoš

This article is focused on the reliability of transfer connections in regional railway transport. The reliability of the transportation chain in public transport is an essential element for functional, attractive, and long-term sustainable public transport. This article discusses the causes and consequences of railway traffic disruption and related impacts on passenger transfer connections. To reduce the negative impacts of common operational disruptions, the authors present an original approach for determining transfer waiting times between delayed trains based on a modified critical path method (CPM). In addition, an example of the implementation of this method in regional railway transport in the Vysočina Region of the Czech Republic is provided.

2022 ◽  
Vol 159 ◽  
pp. 104096
Barnabas Adeyemi ◽  
Behzad Ghanbarian ◽  
C.L. Winter ◽  
Peter R. King

2021 ◽  
Vol 6 (4) ◽  
pp. 34-41
Sergey Bolotin ◽  
Haitham Bohan ◽  
Aldyn-kys Dadar ◽  
Khenzig Biche-ool ◽  

Introduction: Planning integrated development of a residential area involves determining the composition of the objects to be built and creating an appropriate integration mechanism, backed up by a generalized work schedule. The existing methods of forming integrated work schedules do not use a systemic approach, based on a universal mathematical model, to describe the organizational and technological aspects of construction. Methods: The present study uses the method of uncertain resource coefficients to demonstrate a mechanism for systemically describing organizational and technological construction processes. We present a way of adapting this method to forming a generalized construction schedule during integrated development. The proposed adaptation mechanism is based on managing schedule calculations by rationally influencing the elements of the linear equation system that describes the organizational and technological processes. Results and Discussion: The solutions presented in the paper are fully consistent with the calculations obtained by different flow methods of organizing construction, as well as with the critical path method used in project management programs. The method described in the paper has been implemented in well-known project management software, Microsoft Project, as a macro program in the Visual Basic for Applications programming language, making it possible to form, calculate, and optimize a schedule for integrated territory development using the unified software toolkit.

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 27
Raouf Senhadji-Navarro ◽  
Ignacio Garcia-Vargas

Current Field Programmable Gate Arrays (FPGAs) provide fast routing links and special logic to perform carry operations; however, these resources can also be used to implement non-arithmetic circuits. In this paper, a new approach for mapping logic functions onto carry chains is presented. Unlike other approaches, the proposed technique can be applied to any logic function. The presented technique includes: (1) an architecture that is composed of blocks that implement AND and OR functions (called CANDs and CORs, respectively) by means of Look-Up-Tables (LUTs) and carry-chain resources; and (2) a mapping algorithm to reduce both the delay of the critical path and the number of used FPGA resources. The algorithm uses a heuristic to interconnect CORs and CANDs in order to reduce the delay. The problem of mapping the maxterms (or minterms) of a function to LUTs has been modelled as a Set Bin Packing (SBP) problem. Since SBP is NP-Hard, a greedy algorithm has been proposed, which is based on the First Fit Decreasing (FFD) heuristic. The results obtained have been compared with the conventional technique using both speed and area optimization. For this purpose, a large synthetic set of test cases has been generated. The proposed technique improves both the speed and area results for the vast majority of functions whose conventional implementation requires more than four logic levels. It is important to highlight that the improvement of one parameter (speed or area) is not achieved at the expense of the other.

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