Coexistence Problem Research Articles

Abalone shells bioenhanced carboxymethyl chitosan/collagen/PLGA bionic hybrid scaffolds achieving biomineralization and osteogenesis for bone regeneration

Inspired by the formation of natural abalone shells (AS) similar to calcium salt deposition in human orthodontics, AS is used as an emulsifier in the scaffold to solve the problem of coexistence of natural and synthetic polymers and promote new bone formation. In this study, AS-stabilized and reinforced carboxymethyl chitosan/collagen/PLGA porous bionic composite scaffolds (AS/CMCS/Col/PLGA) were fabricated through the emulsion polymerization and bionic hybrid technology. As the addition of AS increased from 0.75 to 3.0 wt%, homogeneous distribution of flower-like particles could be observed on the inner surface of the scaffold, and its mechanical properties were improved. Particularly, 3.0 wt% AS-doped scaffolds (S3 and C + S3) exhibited excellent inorganic mineral deposition and osteoblast proliferation and differentiation abilities in vitro. In a SD rat calvarial defect model, they effectively promoted new bone formation in the defect and accelerated expression of osteogenic-angiogenic related proteins (COLI, OCN, VEGF). By virtue of its combined merits including good mechanical properties, inducing mineralization crystallization and facilitating osteogenesis, the 3.0 wt% AS-doped scaffold promises to be employed as a novel bone repair material for bone tissue regeneration.

Reinforcement Learning for FDA-MIMO Radar Power Allocation in Congested Spectral Environments

This paper studies the coexistence problem of frequency diverse array multiple-input multiple-output (FDA-MIMO) radar and communication systems. The communication system and radar share the same frequency band, and the overlap of the frequency spectrum will interfere with each other's performance, which constitutes a dynamic non-cooperative coexistence problem. We model the FDA-MIMO radar interference suppression process as a Markov decision process (MDP). The interference signals received by FDA-MIMO radar are generated by the communication system, including constant interference, frequency-hopping interference, and intermittent interference. FDA-MIMO radar realizes flexible transmission waveform spectrum control through transmission power allocation. Reinforcement learning (RL) is applied to obtain the optimal power allocation strategy of FDA-MIMO radar, and it is compared with the Sense and Avoid (SSA) algorithm. The simulation results show that the FDA-MIMO radar power allocation method based on reinforcement learning can effectively suppress the communication system's interference and improve the radar's signal-to-interference-and-noise ratio (SINR) and range resolution.

Joint beam power and pointing management in multi‐beam low earth orbit and low earth orbit co‐existing satellite system

SummaryRecently, the low earth orbit (LEO) satellite has attracted much attention due to its advantages of low latency and construction costs. However, the scarcity of frequency spectrum resources has resulted in these satellites sharing the same spectrum to provide services for ground users. So, challenges such as overlapping beam coverage and inter‐beam interference occur in the multi‐beam LEO satellite coexistence scenario. Therefore, this paper focuses on the issue of interference coexistence in LEO and LEO (LEO–LEO) co‐existing scenario, where the initially established system is the primary system, and the later established system is the secondary system. The interference coexistence problem is modeled as a multi‐objective optimization problem. The joint beam power and pointing management (JBPPM) based on particle swarm optimization (PSO) is proposed. The power control is applied to the LEO satellites in the secondary system to reduce the interference to the primary system user. Meanwhile, beam pointing optimization is adopted by the LEO users in the secondary system to avoid interference from the primary system and ensure the minimum communication ability. The simulation results verify that the proposed technique can adapt to various coexistence conditions and outperform the existing method.

Teachers' Perceptions and Position Regarding the Problem of Bullying and Its Socio-Educational Prevention.

The problems that arise with coexistence between schoolchildren are a challenge when it comes to carrying out the teaching-learning process. In recent years, the presence of bullying has increased in schools. The aim of this study is to identify the perceptions of teachers regarding the problems of coexistence among schoolchildren, more specifically concerning bullying, as well as to identify their position regarding the prevention of bullying. Research was carried out using a mixed approach. A total of 225 education professionals from different schools in Spain took part. From the results and our conclusions, it should be noted that teachers consider themselves to have a high level of knowledge of the essential characteristics of the dynamics of bullying, of the actors involved, and of some preventive measures that can be carried out to avoid this type of behaviour as much as possible. On the other hand, a large number of teachers downplay the importance of the problem of coexistence in their fields, and/or are not able to identify it, which makes it impossible to act. Some schools hardly carry out any prevention work, which makes it difficult to eradicate bullying.

Competition for time: Evidence for an overlooked, diversity-maintaining competitive mechanism.

Understanding how diversity is maintained in plant communities requires that we first understand the mechanisms of competition for limiting resources. In ecology, there is an underappreciated but fundamental distinction between systems in which the depletion of limiting resources reduces the growth rates of competitors and systems in which resource depletion reduces the time available for competitors to grow, a mechanism we call 'competition for time'. Importantly, modern community ecology and our framing of the coexistence problem are built on the implicit assumption that competition reduces the growth rate. However, recent theoretical work suggests competition for time may be the predominant competitive mechanism in a broad array of natural communities, a significant advance given that when species compete for time, diversity-maintaining trade-offs emerge organically. In this study, we first introduce competition for time conceptually using a simple model of interacting species. Then, we perform an experiment in a Mediterranean annual grassland to determine whether competition for time is an important competitive mechanism in a field system. Indeed, we find that species respond to increased competition through reductions in their lifespan rather than their rate of growth. In total, our study suggests competition for time may be overlooked as a mechanism of biodiversity maintenance.

Penerapan Data Mining Algoritma Apriori untuk Menemukan Pola Hubungan Status Gizi Balita

Malnutrition of toddlers can cause severely health problems, growth retardation, and decreased intelligence. Therefore, it is important to know the pattern of the relationship between the nutritional status of toddlers, especially against the condition of malnutrition to get information about the possible risk of nutritional coexistence problems. The purpose of this research is to apply data mining using the apriori algorithm in finding patterns of relationships betweennutritional status and to produce an accuracy level of association rules based on the value of support, confidence, and validation with the lift ratio. The results of this study are expected to generate information that can help prevent and treat malnutrition, as well as appropriate nutrition interventions. Analysis and implementation of data using the a priori algorithm method. Manual calculations are carried out using Microsoft Excell and accurate calculations with python programming. Data on the nutritional status of children under five, especially undernourished conditions will be processed to find patterns of association relationships. Determined the minimum support value of 0.1 or 10% and the minimum confidence of 0.5 or 50%. The research produces association rules in the form of association relationship patterns of nutritional status specifically malnutrition conditions (Underweight?Stunting ) with a support of 0.25 or 25% and confidence 0.57 or 57%. The rules have met the minimum support and minimum confidence values and have been validated by the lift ratio with a value > 1.

이주의 시대, 공동체와 타자

This paper examines the issues of community and others, focusing on Seo Seong-ran's 『Truong』, which is set in a multicultural society. As Korean society is rapidly becoming a multicultural society due to the increase in transnational migration, Korean society is in a situation where it must coexist with various immigrants. Seo Seong-ran's 『Truong』 shows the problem of coexistence with new members faced by this multicultural community against the backdrop of a closed mountain village. In 『Truong』, the Vietnamese married immigrant woman who entered the mountain village community is an eternal stranger because she is a foreigner, and the foreigner who moved from Korea to the mountain village community is also an object of caution like a stranger. 『Truong』 emphasizes the need for an ethics of the other that welcomes the other itself rather than hospitality based on the premise of sameness. Additionally, 『Truong』 shows that the conflict with heterogeneous strangers introduced into the community results in community violence, and in the meantime, solidarity among the vulnerable is achieved. Vulnerable beings, such as strangers in the community, understand each other's vulnerabilities, communicate, and form psychological solidarity, but as is not easy in reality, their solidarity does not last. As multicultural novels show, coexistence with strangers is an unavoidable situation. What is needed at such times is the ethics of a multicultural community. Immigrants who enter the community are strangers from the perspective of the community, but from the perspective of the strangers, the members of the community are also strangers. As Seo Seong-ran said, individuals are ultimately strangers to each other. Truong shows that what is needed for a new multicultural community is to seek peaceful coexistence with immigrants through tolerance that accepts each other's heterogeneity.

The competition between legal and illegal firms in the market: Theoretical models and empirical evidence

The main aim of this paper is to study the phenomenon of the coexistence of firms with illegal characteristics and firms showing legal behaviour in developed economies by using an evolutionary competition model known as the Lotka-Volterra equations. Enterprises in a ‘legal system’ obey the extant laws, particularly market rules, while enterprises in an ‘illegal system’ disregard them. Illegal enterprises have a competitive advantage over legal enterprises, yet they cannot survive if legal enterprises disappear completely. The numerical solution of the Lotka-Volterra equations are used to show how there can be a situation of coexistence between legal and illegal enterprises and how state intervention can help reduce illegality in an economic system. This paper outlines a new approach to address the problem of coexistence because it uses non-linear and evolutionary tools to define the competition between legal and illegal firms. The research gap presented in this paper is addressed using the predator-prey scheme to model the competition between legal and illegal firms, which is perceived as the competition between two populations with different fitness levels (survival probabilities). This competition gives rise to three different types of possible equilibrium outcomes: survival of only legal firms, survival of only illegal firms and coexistence of these two types of firms. An empirical analysis of an Italian case study confirms the results of this paper's theoretical model.

Fair and Efficiency Coexistence Between NR-U and WiGig Networks Enabled by a Matching-Based Framework With Forbidden Pairs

Deploying the 5 G new radio network on the unlicensed mmWave band (NR-U) is a promising solution to meet the constantly increasing traffic demand of the cellular network. However, the coexistence issue on the unlicensed mmWave spectrum between NR-U and Wireless Gigabit (WiGig) networks becomes a significant concern. The coexistence schemes between LTE and Wi-Fi networks cannot be readily applied to support the coexistence between NR-U and WiGig networks due to the directional beamforming and propagation characteristic of the mmWave band. The directional transmission complicates the coexistence problem but opens up possibilities for increased system capacity via concurrent multi-user MIMO (MU-MIMO) transmission at the expense of interference management. To this end, we consider an NR-U and WiGig coexisting scenario and aim to maximize the total NR-U throughput on the unlicensed spectrum via resource allocation and inter-beam interference mitigation. The optimization problem is formulated into an integer nonlinear programming (INLP) problem and is further transformed into a many-to-one matching game for tractability. We propose a matching-based concurrent algorithm (MBCA) to solve it and the inter-beam interference is mitigated via the forbidden pairs (FPs). In comparison to the exhaustive search-based algorithm (ESA), simulation results show that FP effectively mitigates inter-beam interference and achieves near-optimal performance. The proposed algorithm also outperforms the state-of-art algorithms in existing research.

Deformation patterns and coordination mechanisms of cross-size microchannels during thermocompression bonding process

High-quality bonding of microfluidic chips is essential for driving the rapid marketization of microfluidic devices. While thermocompression bonding is known for its simplicity, challenges such as high deformation and low bond strength persist. In this paper, we conducted micro-scale compression creep experiments to address the coexistence problem between low deformation and high bond strength during the thermocompression bonding process. Accurate creep models were constructed based on the experimental results, achieving an improved simulation accuracy of 95% for microchannel deformation in thermocompression bonding. Additionally, a finite element simulation model was developed to simulate microchannel deformation during the thermocompression process. To enhance bond strength and minimize microchannel deformation, we propose two methods: microchannel height compensation and cross-size microchannel coordination. Results demonstrate a remarkable 200% improvement in bond strength with reduced microchannel deformation under the same bonding conditions. The findings of this study offer valuable insights and serve as a process reference and design basis for enhancing the quality of microfluidic chip products.

Perceptions of teachers about the teaching of civic-citizen education in Colombia and the relationships with school coexistence

Civic and citizen education has been a relevant aspect in educational policy in Colombia. For this reason, the country has participated in studies by the International Association for the Evaluation of Educational Achievement (IEA) on Civic and Citizenship Education (ICCS). In 2016, the ICCS collected the perceptions of civic and citizenship education from 1,580 teachers. As the IEA databases are open access, the information was analyzed with the objective of describing the perceptions of teachers about the teaching of civic and citizenship education in Colombia, as well as the relationships with school coexistence in the educational institutions. It is concluded that the main coexistence problems reported by teachers in school institutions are: i) student absenteeism, ii) bullying, and iii) drug abuse. Likewise, it was established that students’ behavioral problems are related to poor care of school facilities and equipment, negative attitudes towards school, poor sense of belonging to school communities and conflicts during rest, entry and exit of the institution.

Can we all coexist? An empirical analysis of drivers' and pedestrians' behavior in four different shared space road environments

Shared space assumes that the elimination of physical segregation and traffic control measures forces road users to become more alert, move at lower speeds, and rely on the environmental context for negotiating movement. Still, pedestrians tend to feel reluctant about sharing the space with motorized traffic triggering a coexistence problem. By investigating trajectories, shared space is informally divided into three zones: circulation, safe, and activity zone. This study attempts to answer the following research questions: can all road users coexist in the same road space? If yes, under which circumstances, this can be achieved? Three German and one Greek case, presenting different design characteristics and traffic flow compositions, are empirically investigated. Relative variables, namely: pedestrian crossing rate, speed compliance rate and speed deviations, are considered. The findings indicate that vehicle speeds are reduced when the flow of both pedestrians and vehicles is above the mean. A high pedestrian crossing rate is related to higher speed deviations and consequently to heterogeneous driving behavior. By extending the activity or safe zones, the speed compliance rate is significantly reduced, while pedestrians cross more the circulation zone. By providing a wider circulation zone, average vehicle speeds exceed the speed limit.

Chronology of the Schism in the Estonian Orthodox Church in the Light of Relations between the Moscow and Constantinople Patriarchates

The question of property rights of Orthodox Estonians as well as the problem of coexistence of the two parallel Church jurisdictions on the Estonian territory remains unresolved to the present day, despite the regular meetings conducted and agreements reached. The relations between the Moscow and Constantinople Patriarchates on the Estonian issue have reached an impasse. The article presents and analyzes the chronology of the dissent in the Estonian Orthodox Church (EOC) from the perspective of the actions of the Moscow and Constantinople Patriarchates. This allows us to take a glance at the history of the dissent from a special angle in light of the relations between the two Patriarchates in order to identify the features of the strategy of the two Patriarchates, to note the main turning points in this relationship, to estimate the role of the Constantinople Patriarchate in the events related to the split of the EOC as a wholeas well as to propose ways out of the conflict, which is being exacerbated at this time. The novelty of the study lies in the fact that the problem of the dissent in the Estonian Orthodox Church is considered only against the background of the analysis of the actions of the Moscow and Constantinople Patriarchates. The connection is established between the events of 20-70s of the 20th century which preceded the dissent in the 1990s as well as the direct intervention of Constantinople Patriarchate in the EOC activity in the 1990s. For a research on the designated topic for the first time are used materials (as historical sources) from the archives of the Chancellery of the Estonian Orthodox Church of the Moscow Patriarchate. Based on the results of the study, the author comes to the conclusion that the dissent in the EOC was provoked by the Constantinople Patriarchate, whose campaign to seize some parts of the Estonian Orthodox Church was carried out with the tacit approval of the Estonian government circles. In this regard, the author sees a way out of the created crisis only in close cooperation between the Church and the state, namely at the level of the governments of Estonia and Russia.

Improved Spectrum Coexistence in 2.4 GHz ISM Band Using Optimized Chaotic Frequency Hopping for Wi-Fi and Bluetooth Signals.

Efficiently managing coexistence is crucial for achieving high-quality wireless communication in the Industrial, Scientific, and Medical (ISM) band where multiple wireless communication systems operate. Coexistence problems between Wi-Fi and Bluetooth Low Energy (BLE) signals are especially significant due to their shared frequency band, which often leads to interference and a reduced performance for both systems. Therefore, effective coexistence management strategies are essential for ensuring the optimal performance of Wi-Fi and Bluetooth signals in the ISM band. In this paper, the authors conducted a study to investigate coexistence management in the ISM band by evaluating four frequency hopping techniques: random, chaotic, adaptive, and an optimized chaotic technique proposed by the authors. The optimized chaotic technique aimed to minimize interference and ensure zero self-interference among hopping BLE nodes by optimizing the update coefficient. Simulations were conducted in an environment with existing Wi-Fi signal interference and interfering Bluetooth nodes. The authors compared several performance metrics, including the total interference rate, total successful connection rate, and trial execution time for channel selection processing time. The results indicated that the proposed optimized chaotic frequency hopping technique achieved a better balance between reducing interference with Wi-Fi signals, achieving a high success rate for connecting BLE nodes, and requiring minimal trial execution time. This makes it a suitable technique for managing interference in wireless communication systems. While the proposed technique had a higher interference than the adaptive technique for small numbers of BLE nodes, for larger numbers of nodes it had a much lower interference than the adaptive technique. The proposed optimized chaotic frequency hopping technique provides a promising solution for effectively managing coexistence in the ISM band, particularly between Wi-Fi and BLE signals. It has the potential to improve the performance and quality of wireless communication systems.

Ethical Aspects of Artificial Intelligence Functioning in the XXIst Century

"The article is devoted to the ethical aspects of artificial intelligence functioning. The problem of the safe coexistence of man and artificial intelligence is taking on increasing importance. The definition of artificial intelligence and the explanation of the difference between weak, strong artificial intelligence and super-intelligence are given. The first ethical problem of artificial intelligence functioning is the existential question of human redundancy due to the spread of artificial intelligence. The article emphasizes that artificial intelligence, on the one hand, frees a person from certain areas of activity, facilitating their existence, on the other hand, it makes them superfluous in production and in personal life. The second is the problem of responsibility for the actions of artificial intelligence. The article argues for the necessity of human responsibility for the actions of artificial intelligence because artificial intelligence does not have consciousness. The third problem is the intensification of the phenomenon of stupidity in society. Artificial intelligence creates the conditions for the increasing cleverness of some segments of the population and stupidity of others, which can result in even greater mental and property inequality. Keywords: intelligence, artificial intelligence, ethics, responsibility, legal responsibility, human existential state, problem of redundancy, stupidity. "

End-to-End Delay Bound Analysis for VR and Industrial IoE Traffic Flows under Different Scheduling Policies in a 6G Network

Next-generation networks are expected to handle a wide variety of internet of everything (IoE) services, notably including virtual reality (VR) for smart industrial-oriented applications. VR for industrial environments subtends strict quality of service constraints, requiring sixth-generation terahertz communications to be satisfied. In such an environment, an additional important issue is trying to get high utilization of network and computing resources. This implies identifying efficient access techniques and methodologies to increase bandwidth utilization and enable flows related to services, with different service requirements, to coexist on the same computation node. Towards this goal, this paper addresses the problem of coexistence of the traffic flows related to different services with given delay requirements, on the same computation node arranged to execute flow processing. In such a context, a theoretical comprehensive performance analysis, to the best of the authors’ knowledge, is still missing in the literature. As a consequence, this lack strongly limits the possibility of fully capturing the performance advantages of computation node sharing among different traffic flows, i.e., services. The proposed analysis aims to give a measure of the ability of the system in accomplishing services before the expiration of corresponding deadlines. The integration of martingale bounds within the stochastic network calculus tool is provided, assuming both the first-in–first-out and the earliest deadline first scheduling policies. Finally, the validity of the analysis proposed is confirmed by the tightness emerging from the comparison between analytical predictions and simulation results.

Adaptive Coexistence of Synchronization and Anti-Synchronization for a Class of Switched Chaotic Systems

This paper addresses the problem of coexistence of synchronization and anti-synchronization (CSAS) for a class of switched chaotic systems by adaptive control method, where the switched system is realized by unified chaotic systems under arbitrary switching signal. Firstly, necessary and sufficient conditions for the CSAS of the chaotic systems are proposed from two perspectives, one is by analyzing the parity of the system expression, and the other is by decomposing the system. Secondly, according to the obtained necessary and sufficient conditions, two algorithms are given to search the synchronization variables and anti-synchronization variables in the chaotic systems. Thirdly, the CSAS of the switched chaotic system can be achieved by a designed adaptive global controller with only one input channel under the arbitrary switching signal. Finally, the numerical simulation results verify the validity and effectiveness of the method we obtained.

Collaborative work as a didactic strategy to mitigate the inadequate coexistence between Venezuelan and Colombian students.

The objective of this research project is to mitigate school coexistence problems between Colombian and Venezuelan students through the implementation of collaborative work as a didactic strategy to achieve this goal. The project was based on the qualitative approach and action research. Tools such as focus group, semi-structured interview and direct observation were used. It was divided into 4 phases. The first phase consisted of carrying out a diagnostic analysis through the interview instrument in order to know through the testimonial source the level of difficulty with respect to the coexistence scenario. In the second phase, the didactic strategy based on collaborative work was applied, taking as a starting point the choice of certain topics that would generate impact and help the purpose of the work. In the third phase, the degree of assertiveness of the applied strategy was analyzed, as well as the opportunities for improvement of the group, with the participation of the teachers of the areas of Spanish, religion and ethics in this stage. Finally, the results were analyzed and showed signs of progress in the elimination of discriminatory and segregating scenarios of some students towards others. In the conclusions, the need to adapt the IEP, the curriculum, generate new spaces for interaction that enable collaborative work, respect and empathy, and train the teaching staff in the use of appropriate strategies to maintain a coexistence environment based on respect for differences is taken for granted.

Dynamic Interference Suppression for TV White Space: the Case of Thailand

In this work, we study the problem of co-existence between the LTE (Long Term Evolution) and the Digital Terrestrial Television Broadcasting (DTTB) channel. There are three scenarios: co-channel, upper and lower adjacent channels. We use the broadcasted signal from channel 3 called ThaiPBS, the actual case of Thailand for our study where the standard of digital terrestrial television broadcasting is DVB-T2 adopting 8 MHz bandwidth, while the 5 MHz bandwidth of LTE is considered as the interference. We propose a dynamic interference suppression method for increasing spectrum usage by optimizing TV white space utilization and minimizing interference. This method adopts the protection ratio concept to suppress the LTE interference on TV receiver. We implement our proposed algorithm as an adaptive interference controller using a Radio Frequency (RF) attenuator and a Raspberry Pi board for our testbed hardware. We illustrate the effectiveness of our proposed algorithm by doing experiment using our testbed and assessing the quality of the received TV signal by adopting the Quality of Experience (QoE) assessment. In our testbed hardware, a Log Periodic antenna is used for receiving the DTTB signal, while an RF digital transmitter is used for generating a 5MHz bandwidth of LTE signal, an ultra-high frequency (UHF) mixer is used to combine both signals, then a field strength meter is used to monitor video picture quality and to analyze the spectrum. According to the experiment, our proposed method can reduce the perceived video distortion by at least 62.5% for co-channel and 87.5% for adjacent channel, while the spectrum usage is increased by 100%.

Solar Maximum Power Point Tracking Algorithm Based on Wavelet Neural Network

With the development of human civilization, the shortage of resources and environmental pollution are increasing. Renewable energy is the only way to solve the problem of harmonious coexistence between human civilization and environment. More and more of them have come into our lives to reduce the burden of the earth and benefit mankind. Nowadays, due to the increasing gap of traditional power supply, solar energy has become a mainstream renewable energy, more and more applications, to provide us with green energy and improve our lives. The research on the application of solar energy system is of great academic value. This paper mainly studies the solar maximum power point tracking (MPPT) algorithm based on wavelet neural network (WNN). This paper analyzes several common maximum power tracking control methods, describes the structure design of WNN maximum power tracking control algorithm, and describes the structure and working principle of photovoltaic cells. In this paper, the output power of MPPT mode is analyzed and compared by simulating the use of solar photovoltaic system. In the meantime, the output voltage of solar charging panel in the charging process is studied. The experimental results show that the output power of the power supply in MPPT mode is kept at 0.2, and the output power of the solar panel is improved at every moment with the change of the external environment. At 9 o'clock, the output voltage of the solar panel is 3.6, and at 11 o'clock, the output voltage is 4.11.