Basis For Operation Research Articles

Comparative Analysis of International Environmental Communication Practices of DPRK and ROK in the Perspective of Framing Theory

Since the disclosure of the plan in 2021, the incident of Japan's Fukushima nuclear wastewater discharge into the sea has been strongly concerned by the international community, especially by the neighboring Asia-Pacific countries, and it has been intensifying in recent years, and it has triggered the world's public opinion once again before the official discharge of the plan in the summer of 2023. The media industry's coverage of this issue needs to consider the cross-cutting fields of environmental, health, and international communication, making it a good case for academic research. Meanwhile, the Democratic People's Republic of Korea (DPRK) the and Republic of Korea (ROK), which are located on the Korean Peninsula and have been greatly affected by the incident, have similar linguistic, cultural, and historical backgrounds, but the existing literature has not provided satisfactory comparative studies on the media industries of the two countries, especially on the mainstream media. In this regard, under the guidance of the framework of high and low levels, this paper selects the relevant reports of the Korean Central News Agency (KCNA) and the Korea JoongAng Daily (KJD) from June to July 2023, conducts content analysis and text analysis, reveals the main points of characteristics, similarities and differences, and provides an operational basis for the establishment of a diversified international communication system.

Fresh, mechanical and microstructural behaviour of high-strength self-compacting concrete using supplementary cementitious materials

Sustainable practices in the construction sector have become a major issue due to the overuse of natural raw materials. Industrial by-products like fly ash (FA), silica fume (SF), and marble powder (MP) incorporation in concrete production will be assessed in this paper in terms of fresh, mechanical, and microstructural states. Consequently, this study proposes an in-depth investigation of SCMs applied with varied substitute cement amounts, looking at components like MP, SF, and FA. The impacts on fresh characteristics of HSSCC were assessed using slump flow, V-funnel time, T50 time, L-box ratio, and J-ring slump flow. Compressive, flexural, and splitting tensile strength tests were performed to analyze the mechanical properties. Energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscope (SEM) techniques were used for the microstructural examination of HSSCC. It has been found that SCMs, including MP, FA, and SF, may enhance the characteristics of concrete. The slump flow values, which indicate the flowability and filling ability of HSSCC, were improved by a maximum of 9.6 % for 20 % SF and 10 % for both FA and MP replacement. The most promising outcomes on the basis of mechanical operation were gained by using SF, MP, and FA in HSSCC at respective percentages of 20 %, 10 %, and 10 %. This mixture revealed an increase in compressive strength of a maximum of 15 % at 56 days compared to the control mixture, which contained 10 % MP. However, the excessive addition of MP negatively impacted the strength of the concrete. The EDS examination illustrated that the ‘Ca’ to ‘Si’ proportion in HSSCC significantly affects the emergence of strength. This study will enlighten users during the preparation of high-strength self-compacting concrete (HSSCC) by replacing ordinary Portland cement (OPC) with different available supplementary cementitious material (SCM) combinations.

Integrated advance assessment of power system transient voltage and transient angle stability based on two-stage ensemble spatio-temporal graph neural network

Transient angle stability (TAS) and transient voltage stability (TVS) are important bases for safe operation of power system. With the replacement of a high percentage of new energy, the voltage and power angle problems are closely coupled, so an integrated assessment method that takes into account the rapidity, accuracy and stability is urgently needed to deal with the system risks. In order to solve this problem, firstly, we propose a multi-task spatio-temporal graph neural network model based on two-stage ensemble learning (TSEL-MT-STGNN) for integrated assessment of TAS&TVS. In the first stage of this model, the topological spatial features of the system are extracted through multi-type graph neural networks, and the obtained knowledge is input to the gated recurrent unit (GRU) for further temporal feature extraction, so as to achieve spatio-temporal information fusion. In this stage, TAS and TVS were combined through the multi-task framework to achieve integrated assessment under the shared features. In the second stage, meta-learner multi-layer perceptron (MLP) is used to fuse the output results of multi-type spatio-temporal graph neural network. Secondly, an integrated assessment method is proposed based on the model, which enables end-to-end assessment, and gives the stability result and safety margin of the system in the current state without knowing the fault clearing time. Thirdly, in order to ensure the timeliness of the assessment method, a multi-graph parallel training scheme is proposed to accelerate the training process. By introducing time constrained loss function and dynamic weight training, the response time is greatly reduced on the basis of maintaining the existing accuracy, thus achieving advance assessment. Finally, the improved New England 39-bus system is taken as an example for verification and analysis. The results show that the proposed method can achieve high-precision advance assessment of TAS&TVS, and has strong robustness and anti-noise capability.© 2017 Elsevier Inc. All rights reserved.

An Efficient Confidence Interval-Based Dual-Key Fuzzy Vault Scheme for Operator Authentication of Autonomous Unmanned Aerial Vehicles

The fuzzy vault is an innovative way to share secret keys, combining traditional cryptography with biometrics and biometric template protection. This method forms the basis for the reliable operation of unmanned aerial vehicles (UAVs) through anonymizing drone operators and safely using their data and onboard information. However, due to the inherent instability of biometrics, traditional fuzzy vault schemes face challenges, such as reduced recognition rates with increased chaff points, impractical runtimes due to high-order polynomial reconstruction, and susceptibility to correlation attacks. This paper proposes an efficient fuzzy vault scheme to address these challenges. We generate two secret keys based on biometrics: the first key is produced from the operator’s unique features like the face and iris, using a confidence interval; the second key, used to construct a polynomial, is based on what the operator remembers. These dual-key fuzzy vaults enable the stable generation of genuine points during encoding, easy extraction during decoding, and effective operator authentication while maintaining anonymity. Our experimental results demonstrate improved security and secret acquisition accuracy using the AR face database. These results are achieved regardless of increased false vaults, enabling real-time polynomial reconstruction and resilience against correlation attacks. Importantly, our enhanced fuzzy vault scheme allows the application of this secure, real-time authentication process, safeguarding the anonymity of drone operators.

A Digital Twin System of Capacitive DC Bank Using Rogowski Coil to Monitor Individual Capacitors

The reliability of dc link capacitors is closely related to the operational safety of the whole power electronic system. To meet the application requirements, it is usually necessary to use a series or parallel structure of multiple capacitors to increase the capacity and withstand voltage, which also makes it difficult to monitor the individual capacitors in the capacitor bank. This article proposed a digital twin system for dc-link capacitor banks with PCB integrated Rogowski coils as sensors. The system uses highly integrated Rogowski coils to obtain the operating currents of individual capacitors in order to realize parameter correction of the digital twin system and ensure that the digital twin system can accurately reflect the electrothermal behavior of the dc-link capacitor bank. In addition, the effect of operating temperature on capacitor parameters is also considered, and the capacitor parameters and the operating temperature monitored by the digital twin system simultaneously are used to standardize the parameters. The standardized parameters are used as indicators to realize the health status assessment of each capacitor in the capacitor bank, which further provide an important basis for operation and maintenance.

Comparison of Different Standard Test Methods for Evaluating Greases for Rolling Bearings under Vibration Load or at Small Oscillation Angles

Rolling bearings operated at small oscillation angles or exposed to vibrations during standstill show typical damage after only a short period of operation. This can be false brinelling damage, so-called standstill marks or classic fretting damage (fretting corrosion, tribo-oxidation). It is important to differentiate here according to the amplitude-ratio x/2b, which indicates the ratio between the rolling element Motion (x) and the Hertzian contact half-axis (b). Depending on this ratio, suitable laboratory test methods must be used to test the lubricating grease practically for the particular application. For this purpose, the Fafnir wear test, according to the standard of the American Society for Testing and Materials ASTM D4170, is also listed in the current high-performance multi-use specification of the National Lubricating Grease Institute (NLGI) as a release test for lubricating greases. In Europe, the SNR-FEB2 test is frequently used, which is also required to release greases in the blade bearings of wind turbines, among other things. In the case of standstill marks due to very small oscillation angles or vibrations, the Mannheim Tribology Competence Center (KTM) has developed a special test now established in the industry. The oscillating angles vary in these three different standard tests in the range from ±6° in the Fafnir test to ±3° in the SNR-FEB2 test to ±0.5° in the KTM standstill marking test; the x-to-2b ratios range from 5.5 (Fafnir) to 3.4 (SNR) to 0.5 (KTM). This paper will explain the scientific basis for these special operating and test conditions and compare test results of specially prepared model greases in these three standard rolling bearing tests, two test variations and a classical fretting test under oscillating sliding friction (ASTM D7594). The paper’s main objective is to show that the suitability of grease for such an application depends strongly on the prevailing operating conditions. Different tests in this field are, therefore, not interchangeable. Good results in one test do not automatically mean good results in a similar test at first glance. Therefore, selecting the right test for the application is important.

Life Cycle Assessment of Craft Beer Brewing at Different Scales on a Unit Operation Basis

Beer brewing is a complex process that comprises many fundamental unit operations. Over the last few years, craft brewing has become very popular, and the number of small-scale commercial brewers has drastically increased. However, due to the use of traditional beer-making methods, energy utilization in craft breweries tends to be inefficient, resulting in poor sustainability. Therefore, there is a necessity for a holistic analysis on the energy profile of craft beer brewing to evaluate its environmental performance on a unit operation basis. In this study, a gate-to-gate life cycle assessment was conducted to analyze and compare the environmental profiles of craft beer brewing, including ale and lager, at commercial (microbrewery) and pilot scales. A process simulation model was developed to estimate the electricity and/or natural gas uses of each unit operation, including heating, mashing, boiling, whirlpool, cooling, fermentation, and maturation. The model accurately predicted the steam use for pilot-scale brewing and the electricity and gas bills of a microbrewery. The beers brewed at the microbrewery scale (21.5-barrel brewhouse) had 2–11-fold lower environmental impacts than those brewed at the pilot scale (1-barrel brewhouse), and lager beer generally produced 11–32% higher impacts than ale. The fermentation and maturation steps in brewing were the major contributors to global warming and terrestrial acidification, whereas the mashing step was predominantly responsible for marine eutrophication. This study provides craft brewers with a useful tool for identifying the hotspots of energy use in their processes and developing potential improvement strategies.

Development of the virtual battery concept in the paper industry: Applying a dynamic life cycle assessment approach

Energy-intensive industries face the challenge of reducing carbon emissions while remaining competitive. Key measures include fossil fuel substitution, energy efficiency, and integration of renewable energy sources, but their fluctuating production profile makes them difficult to integrate and require industries to adapt their current consumption and production patterns to become more flexible.In this study, the virtual battery concept (VBC), exemplarily demonstrated for a specific site in the paper industry, is introduced and evaluated from an environmental, energetic, and techno-economic perspective. A mathematical optimization model of the class mixed integer linear programming (MILP) was applied to express the industrial site as VBC and derive the operational data basis for the subsequent life cycle assessment (LCA). A dynamic LCA approach is presented to allow the consideration and assessment of the temporal behavior of energy load profiles and their associated environmental implications.The results showed that compared to a static LCA, the dynamic approach leads up to 42 % lower greenhouse gas (GHG) emissions for 1 MJ of public electricity. The global warming potential (GWP) of the total energy supply chain was reduced by 40 % for electricity and 8 % for heat, respectively. By means of a scenario analysis, the GWP to produce one ton of paper was reduced up to 33 % compared to the business-as-usual (BAU) case to 672 kgCO2eq.r in the best case. However, the total primary energy demand (PED) increased by 34 %, but the fossil PED was reduced by 32 % and the renewable PED increased by 157 %. The renewable PED share covered up to 67 % of the total PED. The techno-economic analysis revealed total annual cost savings of up to 44 % to 64.6 € per ton of paper. Environmental costs were estimated to range from 79.6 to 88.9 € per ton of paper.The VBC is considered a promising approach to utilize regional renewable excess electricity effectively, reduce fossil-based energy generation, increase grid stability, and to avoid costly grid infrastructure investments in future. In principle, the VBC is site-independent and replicable to other industries but needs to be evaluated site specifically according to certain process characteristics and requirements.

Disinfection of Digestate Effluents Using Photocatalytic Nanofiltration

The disinfection properties of photocatalysis on liquid digestate derived from biogas plants have been investigated for the first time. The study presents the physiological characteristics of liquid digestate retrieved from various biogas plants based in northern Greece, revealing the heterogeneity of this matrix. Preliminary photocatalysis experiments conducted on inoculated liquid digestate samples showed that disinfection was possible when a pre-treated digestate underwent a combination of centrifuge–flocculation–μfiltration after 5.5 h with 0.7 g/L suspended TiO2 under UVA illumination. To explore the feasibility of an industrial application based on this concept, a novel design photocatalytic nanofiltration reactor was implemented for disinfection experiments on pre-treated liquid digestate. The synergistic action of photocatalysis during nanofiltration alleviated the leakage phenomena, and both the retentate and permeate effluents had lower concentrations of pathogens by approximately 1–2 log10 cfu/mL. This work sets out the basis for the efficient operation and engineering application of collaborative technology, with photocatalysis as the final step for liquid digestate sanitation and reusable water recovery.

Reassigning Departure Slots with Preferences of the Airline and Passengers

The recovery of a departure flight is an important part of airline disruption management. The commonly used optimization objectives for assessing airport slot-scheduling efficiency are delay cost and delay time. However, the current literature does not consider the preferences of airlines and passengers in the recovery process simultaneously. The objective of this paper is to focus on the departure slot reassignment problem and develop a bi-objective optimization model. We introduce a metric for the price of fairness and formulate the airport slot scheduling problem as a bi-objective optimization model that considers the trade-off between the total airline delay cost and total passenger delay time. To quantify the trade-off between total airline delay costs and total passenger delay time, we apply the metric of the price of fairness in the bi-objective model, treating the total airline delay cost as an efficiency metric and the total passenger delay time as a fairness metric, calculating the price of fairness for each Pareto solution. An adaptive non-dominated sorting genetic algorithm-II based on dominant strengths (ANSGA2-DS) is developed to solve this problem. More precisely, three improved operations are presented: the improved fast dominant strength sorting method, new crowding distance improvement, and an adaptive elitist retention strategy. Three scenarios derived from a Chinese airline’s operation data are applied to the proposed bi-objective model and algorithm. The experimental findings demonstrate that the proposed model and method can effectively and efficiently address the problem. This may provide a basis for airline operation controllers to achieve a generally acceptable solution.

Partial inhibition of acrylonitrile–butadiene–styrene dust explosion by sodium bicarbonate

During acrylonitrile–butadiene–styrene (ABS) plastic processing, dust explosions could occur in production and transportation. In this paper, the explosion properties and pyrolysis mechanism of ABS dust were studied. The inhibition effects of sodium bicarbonate (NaHCO3) on ABS dust were investigated using the 20-L explosion chamber, Hartmann tube, and G-G furnace. The results demonstrated that NaHCO3 effectively decreased both the ignition sensitivity and the explosion severity of ABS dust explosion by increasing the mass fraction of the inhibitor. Adding 50 wt% NaHCO3 could reduce the explosion hazard to an acceptable level. Combined with an analysis of gas phase products and thermal decomposition behaviour, it was discovered that incorporating NaHCO3 enhanced the heat stability of ABS dust. The decomposition of added NaHCO3 produced a substantial quantity of CO2, consuming many free radicals especially OH• and H•, which further reduced the decomposition temperature of ABS. The inhibitor effectively interrupted the combustion chain reaction and inhibited the propagation of the explosion. The results establish a scientific and operational basis for the prevention and management of dust explosion hazards in the ABS processing field.

AUTHENTICATED KEY AGREEMENT SCHEME BASED ON BLOCKCHAIN FOR AMI COMMUNICATION SECURITY

Security is the basis for the normal operation of advanced measurement infrastructure (AMI). As an important part of key management scheme, key establishment is indispensable in meeting AMI communication security requirements. Most proposed key management schemes rely on a trusted third party (TTP). Once there is a problem with TTP, the security of these schemes will be greatly reduced. Furthermore, the data concentrators (DCs) in traditional AMI architectures all manage smart meters (SMs) in their respective regions, and the lack of interaction between the DCs exposes a serious single point of failure. To alleviate these problems, we propose a blockchain-based authenticated key agreement scheme to secure the communication of AMI. In this scheme, the blockchain comprises DCs as network nodes that interact with the SMs. The proposed key agreement and distributed consensus protocol ensure the authenticity and validity of the communication content without relying on TTP. We analyse the resistance of the proposed protocol to multiple known attacks and evaluate its performance. The proposed protocol has higher security or better performance than other schemes.

Molecular basis of assembly, operation and regulation of a novel anti-phage defense system-RADAR

Molecular basis of assembly, operation and regulation of a novel anti-phage defense system-RADAR

ГРАФОАНАЛІТИЧНЕ ПРОФІЛЮВАННЯ СПРЯЖЕНИХ КРИВОЛІНІЙНИХ ПОВЕРХОНЬ РІЖУЧОГО ІНСТРУМЕНТУ

In the research, graphic-analytical methods for profiling the cutting tool for processing the helical surface of the drill groove were developed. The basis of these studies was the definition of the characteristics of conjugated surfaces, as the locus of the bases of the normal, which are directed from the points of the surface of revolution to a given helical surface. The methods were based on the position of the differential geometry about the common normal at the points of tangent conjugacy of the surface. Graphic-analytical profiling is a fairly wide and developed branch of science, based on the one hand on the theoretical and practical achievements of applied geometry, which makes it possible to use it, and on the other hand, it is a powerful analytical tool. Formation is an approximate representation of any set of objects, phenomena of the external world through geometric diversity and relationships between them. Conjugation of curvilinear surfaces of the cutting tool for processing parts in weapons and military equipment is one of the most important topics. The article proposes to optimize the process by creating universal tools, which may include the creation of a kinematic method that will be used to design products with specified parameters. The use of graphic-analytical formation of curved surfaces as a design tool in the "manual" mode, in which all graphic formations of conjugate curved surfaces, their interconnection and interdependence will be laid. Of great importance in the design of mating curvilinear surfaces of a cutting tool is the exact reproduction of their shape as the basis for reliable and long-term operation of future real products in weapons and military equipment. This article aims to take a certain step in this direction regarding the creation of mating curved surfaces for the design of cutting tools, processing of products in weapons and military equipment. Keywords: Graph-analytical formation, kinematic method, surface conjugation, kinematic pairs, parameters, shaping, curved surfaces, drill groove.

Achieving Minimum Deterrence: A New Dyadic Dataset on Strategic Nuclear Weapons Delivery Capabilities

This paper argues that existing quantitative studies mistakenly assume that all nuclear states can impose nuclear destruction on opponents by simply distinguishing nuclear states from non-nuclear states. This practice, however, does not capture variation in 1) nuclear states’ possession of delivery capabilities, 2) the range of deployed nuclear delivery systems, and 3) the geographic distance between nuclear states and their dyadic counterparts. Instead of this monadic nuclear statehood approach, I propose the dyadic nuclear reach approach, which uses a new dyad-specific measure of states’ strategic nuclear delivery capabilities. It codes whether a nuclear state can launch a nuclear strike against a given opponent by using the information about the estimated range of each nuclear state’s strategic nuclear delivery platforms, nuclear operation bases, and states’ capital cities. An empirical application shows that using an appropriate measure of nuclear capabilities does significantly alter existing empirical knowledge of nuclear weapons and international conflict.

Development of a green simple molecularly imprinted nanoprobe for rapid determination of trace thiamphenicol residual in animal derived foods

An environmentally friendly nitrogen-sulfur-doped carbon quantum dots molecularly imprinted fluorescent probe (N,S-CDs@MIP) was prepared for the detection of thiamphenicol (TAP) in animal-derived foods. The N,S-CDs, the core fluorophores in optical sensors, were synthesized from food waste of crayfish shells and l-cysteine and assembled to molecularly imprinted layers by Si–O–Si bond. The fluorescence produced by the novel probe in response to TAP ranged from 10.00 to 300.0 μg/L, with a detection limit of 6.20 μg/L. The developed method was also successfully applied to real milk, fish and tap water with 92.08–108.4% recoveries, which agrees with the high-performance liquid chromatography (HPLC) analysis (89.15%–110.7%). The developed probe is cheap with a short detection time (30 min) and provides a theoretical and practical operation basis for monitoring TAP residue levels.

Peran Kepemimpinan TNI dalam Mencapai Tujuan Organisasi di Lanud Suryadarma

TNI AU Suryadarma Air Force Base is one of the operational bases under the command of Koopsau I. Its main task is to ensure the operational readiness of helicopter aircraft and provide guidance to its subordinate units. Logistic components, including facilities and installations, play a crucial role in the success of aviation operations. The vision of Lanud Suryadarma is to become a professional, militant, innovative, and respected unit, with a focus on producing skilled helicopter pilots. This research utilizes a qualitative descriptive approach with a case study as the research method. Data is collected through interviews, observation, and documentation. The practical work unit is conducted at TNI AU Lanud Suryadarma, involving various tasks such as filing, manuscript delivery, and document management. Lanud Suryadarma has functions in unit development, equipment maintenance, aerospace potential development, and coordination with relevant agencies. Leadership also plays an important role in the organization, including Lanud Suryadarma. This research provides an understanding of the factors that contribute to operational success and offers insights for future improvements.

The endeavour for political and professional freedom in Hungarian television during the 1956 October revolution

This study tracks the activities of Hungarian Television’s Executive Committee, elected during the October 1956 revolution, which played a key role in the establishment of said television. The work of the Executive Committee included the development of a new television programme policy and structure, as well as the first transmissions of sports events, operas and theatrical performances, the renewal of newscasts and the introduction of entertainment and scientific programmes. It had a long-lasting impact and provided a solid basis for the future operation of Hungarian television.

Deployment of the French Civil Protection Field Hospital (ESCRIM) in Gölbaşi, Turkey after the February 2023 Earthquake: Lessons Learned.

Following the two earthquakes that occurred in Turkey on February 6, 2023 with magnitudes of 7.8 and 7.5, causing over 50,000 deaths and 100,000 injuries, France proposed to deploy, via the European Union Civil Protection Mechanism (EUCPM), the French Civil Protection Field Hospital (ESCRIM [Élément de Sécurité Civile Rapide d'Intervention Médicale]): the French World Health Organization (WHO)-classified Emergency Medical Team (EMT) Level 2 (EMT2).After the acceptance from Turkey on February 8, a disaster assessment team (DAT) was sent on February 10, 2023. It was decided, with local health authorities (LHA), to set up the field hospital in Gölbaşi, Adiyaman Province where the State Hospital was closed due to a structural risk.Arriving in Gölbaşi on February 13 at 2:00am in -12°C (10°F) temperatures, the detachment had no choice but to begin setting up the base of operation (BoO). At dawn, the cold was so intense that one doctor suffered from frostbite. Once the BoO was installed, the team set up the hospital tents. From 11:00am, the sun melted the snow and the ground became very muddy. The objective being to open the hospital as soon as possible, installation of the hospital continued, and it opened on February 14 at 12:00pm/noon, less than 36 hours after on-site arrival.This article describes the mechanics of setting up an EMT-2 in a cold climate, the many problems encountered, and the solutions imagined and proposed.

An Integrated Framework for Sustainable Development in Agri-Food SMEs

The primary objective of this study is the development of an integrated framework for sustainable development in agri-food Small and Medium Enterprises (SMEs) with a variety of production types. Dealing with the significant research problem of defining a successful record-keeping system, as this is the foundation of an integrated information framework in agri-food SMEs, this research identifies and explicates the several conceptual, methodological, organizational, and technical concerns related to the data collection, processing, and recording, as well as information generation in agri-food SMEs. Two main fields of research are distinguished: the micro-level, which is related to the monitoring of agri-food SMEs, and the macro-level, which relates to the collection, processing, and collective interpretation of different types of data. The findings show how the creation of a database for all levels of analysis, primarily business analyses, followed by an analysis of the development of the agri-food sector, as a whole and by individual regions and branches, etc., constitutes the basis for the effective operation and ongoing improvement of an integrated framework for the sustainable development of agri-food SMEs. Methodologically, this study employs the system approach, system analysis, and synthesis sequence to produce business, economic, and social findings of theoretical and practicable worth to scholars, executives, and decision makers.