Planning of the open-pit working edge positions by the periods of mining within the constraint programming paradigm

The work is aimed at solving the three-dimensional problem of finding the open-pit working edge positions by the periods of mining, taking into account the a priori specified productivity for the mineral and overburden. The proposed method uses a block model of a pit, where for each block its coordinates, the content of minerals in it, and the conditional initial value of the block are known. Also, a discounting function is set - a change in the total value of a block, depending on the period of its mining. The task is to find the distribution of blocks over mining periods that maximizes the total value of the blocks. Combinatorial search acceleration is achieved by representing a number of technological constraints in the form of global constraints.

Enhancing PV Hosting Capacity Using Voltage Control and Employing Dynamic Line Rating

Photovoltaic (PV) system installation has encouraged to be further expedited to minimize climate change and thus, rooftop solar PV systems have been sparkled in every corner of the world. However, due to technological constraints linked to voltage and currents, the PV hosting capacity has been substantially constrained. Therefore, this paper proposes a competent approach to maximize PV hosting capacity in a low voltage distribution network based on voltage control and dynamic line rating of the cables. Coordinated voltage control is applied with an on-load tap changing transformer, and reactive power compensation and active power curtailment of PV inverters. A case study with probabilistic and deterministic assessments is carried out on a real Sri Lankan network to show how the PV hosting capacity is constrained. The findings revealed the capability of integrated voltage control schemes and dynamic line rating in maximizing hosting capacity. The study is expanded by incorporating the PV rephasing approach in conjunction with the aforementioned control techniques, and the effectiveness of PV-rephasing is clearly demonstrated. When compared to voltage control and conductor static rating, the combined rephasing, voltage control, and DLR yielded a 60% increase in PV hosting capacity.

Biological inter-dependencies in 3D printing: Larvae scaffold excavation of high filigree clay structures

<p>Ceramic 3D printing has emerged in recent years as a new method for working with age-old material, a blend of the digital and analog that breeds a new type of artisan. Working with clay in an FDM extrusion system presents a number of challenges due to the nature of the material, restricting the forms that can be produced to rudimentary levels of ornament and shape. This research tackles the issue of resolution and thickness when creating and designing shell structures from ceramic materials, notably when 3D printing is used for complex geometry. This research aims to navigate these material and technological constraints by designing a novel approach to support scaffolds using a secondary material. This secondary material serves as an organic encasement for the ceramic object, and nature is treated as a co-collaborator in the excavation and controlled curing of a high filigree clay structure. By introducing edible bio matter and/or cellulose solutions, this encourages a new relationship with nature as a tool and co-author, becoming a stakeholder in the final result. This research examines the relationship between human, machine, and nature in the design and manufacturing of products.</p>

Biological inter-dependencies in 3D printing: Larvae scaffold excavation of high filigree clay structures

<p>Ceramic 3D printing has emerged in recent years as a new method for working with age-old material, a blend of the digital and analog that breeds a new type of artisan. Working with clay in an FDM extrusion system presents a number of challenges due to the nature of the material, restricting the forms that can be produced to rudimentary levels of ornament and shape. This research tackles the issue of resolution and thickness when creating and designing shell structures from ceramic materials, notably when 3D printing is used for complex geometry. This research aims to navigate these material and technological constraints by designing a novel approach to support scaffolds using a secondary material. This secondary material serves as an organic encasement for the ceramic object, and nature is treated as a co-collaborator in the excavation and controlled curing of a high filigree clay structure. By introducing edible bio matter and/or cellulose solutions, this encourages a new relationship with nature as a tool and co-author, becoming a stakeholder in the final result. This research examines the relationship between human, machine, and nature in the design and manufacturing of products.</p>

Operational Risk Analysis Based on Enterprise Risk Management Approach (ERM) in Export Document Service Company (Case Study at CV Tarukalpa Dewata)

Every company in carrying out its operational activities will definitely face a risk. The various possible risks that can be experienced by the company in carrying out its operational activities need to be managed and controlled by carried out risk management. The implementation of risk management is expected to assist companies in identified, analyzed, assessed, and controlled risks and the impact of risks. One approach that can be used to perform risk management is Enterprise Risk Management (ERM). This research aims to analyze operational risks that occurred at CV Tarukalpa Dewata based on an Enterprise Risk Management (ERM) approach by identified risks, risk assessments, efforts to respond the risks and carry out risk controls to find out what actions must be taken to minimize the possibility of risks and impact risk. This research used a qualitative descriptive research method by collecting data through interviews, observations and questionnaires. The results showed that in the operational activities of CV Tarukalpa Dewata there were seventeen possible risks consisting of four risks originating from human resources owned by the company, five risks that occurred in the process of making export documents, two risks that occurred due to technological constraints, and six external risks. The results of the risk assessment showed that there were three levels of risk that occurred in the operational activities of CV Tarukalpa Dewata namely moderate, low, and very low. Responses to existing risks are carried out by monitoring, controlling management, and paying special attention (urgent) in the company's operational activities.

Investigating Algerian EFL Students’ Online Learning Readiness

Readiness is a critical factor to implement effective educational change. Accordingly, the present study aims to examine Algerian university EFL students’ online learning readiness. To reach this aim, a survey is conducted with 150 first year EFL students from Ibn Khaldoun University of Tiaret using an online questionnaire. The findings of this study highlight the correlation between EFL students’ readiness and willingness to online learning. It is found that due to technological constraints, the majority of EFL students demonstrate low level of online learning readiness which, in turn, affects their willingness to engage actively in this process. They rate themselves lower in terms of prior experience of online learning, time management, self directed learning, self efficacy, online communication and motivation. Hence, this study ends up with some suggestions and further practical implications.

Synthesis of highly efficient multilayer dielectric diffraction gratings for spectral combining of laser beams

Статья посвящена синтезу многослойных диэлектрических отражательных дифракционных решеток, с высокой эффективностью обеспечивающих спектральное сложение пучков с различной длиной волны в заданном дифракционном порядке. Приводятся результаты решения задачи синтеза многослойных диэлектрических дифракционных решеток, обеспечивающих спектральное сложение в первом или минус первом порядке дифракции. Кроме того, решается задача синтеза для таких решеток с учетом возможных технологических ограничений на высоту профиля (глубину травления). Решение задачи синтеза проводится путем минимизации зависящего от параметров решетки целевого функционала методом Нелдера-Мида. Решение прямой задачи на каждом шаге минимизации осуществляется при помощи комбинации неполного метода Галеркина и метода матриц рассеяния. The paper is devoted to the synthesis of multilayer dielectric reflection diffraction gratings providing high-efficiency spectral combining of the beams with different wavelengths in a given diffraction order. The results are presented for solving the synthesis problems for multilayer dielectric diffraction gratings providing spectral combining in the first or minus first diffraction order. Besides, the synthesis problem for such gratings is solved with account taken of possible technological constraints imposed by the height of the grating profile (etch depth). The solution of the synthesis problem is obtained by means of Nelder-Mead minimization of the merit function depending on the grating parameters. At each minimization step the direct problem is solved using a combination of the incomplete Galerkin method and scattering matrix method.

Robot-Assisted Image-Guided Interventions

Image guidance is a common methodology of minimally invasive procedures. Depending on the type of intervention, various imaging modalities are available. Common imaging modalities are computed tomography, magnetic resonance tomography, and ultrasound. Robotic systems have been developed to enable and improve the procedures using these imaging techniques. Spatial and technological constraints limit the development of versatile robotic systems. This paper offers a brief overview of the developments of robotic systems for image-guided interventions since 2015 and includes samples of our current research in this field.

Fledgling cryptocurrency plans face obstacles in Cuba

Significance Cryptocurrency use could help counter US trade sanctions and offer Cuba a back door to international financial structures. Government plans nevertheless appear underdeveloped, and will face major technological constraints. Impacts Growing cryptocurrency use globally will increase the need for blockchain software to incorporate sanctions screening technology. International banks and companies will continue to avoid traditional banking transactions and correspondence involving Cuba. Private entrepreneurship in the crypto asset business will be heavily regulated by the Cuban authorities.