Earticle

Interoperability has been the problem of CAD/CAM systems. Starting from 1980's, national and international organizations have addressed the issue through development and release of standards for the exchange of geometric and nongeometric design data. To CAD/CAM vendors, the task of interpreting and implementing these standards falls into their products. This task is a balancing action between users' needs, available development resources, and the technical specifications of standards. This paper explores an area of CAD/CAM systems development, particularly the implementation of the effective exchange files translators'. A new approach is introduced, which proposes to enclose all the translation operations concerning each exchange format to a separate DLL, thus making a 'plug-in.' Then, this plug-in could be used together with the CAD/CAM system or with specialized translation software. This approach allows to create new translators rapidly and to gain the reliable, high-efficiency, and reusable program code. The second part of the paper concerns the possible problems of translators' development. These difficulties often come from the exchange standards' misunderstanding or ambiguity in standards. All examples come from the authors' practice experiences of dealing with CAD/CAM systems.

Orthogonal frequency division multiplexing (OFDM) is a multicarrier modulation technique for high-speed data transmission in wireless communications. In an OFDM system, a large number of subcarriers are used to transmit the modulated symbols and consequently, the OFDM signals have a high peak-to-average power ratio (PAPR). To reduce the high PAPR, we propose a partial transmit sequence (PTS) method based on the adaptive particle swarm optimization. Also, the proposed method efficiently search the optimal combination of phase rotation factors to decrease the computational complexity. Experimental results show that the proposed method significantly has reduced the PAPR and computational complexity.

Orthogonal frequency division multiplexing (OFDM) has been proposed to achieve high data rate transmission in wireless communications. The OFDM system usually suffers from the high envelope fluctuations called peak-to-average power ratio (PAPR). The high PAPR causes a signal clipping distortion, and consequently, the performance is degraded. To mitigate the PAPR, we introduce a new PAPR reduction approach using a compressive sensing approach at the transmitter side and an orthogonal matching pursuit (OMP) reconstruction algorithm at the receiver end. Numerical results show the significant reduction of the PAPR compared with the traditional OFDM system without degrading the bit error rate performance.

Reconfigurable intelligent Surface (RIS) can effectively improve the communication quality and extend the signal coverage range by reconfiguring the wireless communication transmission environment, which is very suitable for millimeter wave (mmWave) multiple-input multiple-output (MIMO) systems. In this paper, a product manifold optimization-based beamforming design (PMO-BD) algorithm for a RIS-assisted multi-user MIMO system is proposed to enhance fairness among users. We establish a lower bound for the minimum signal-to-interference-plus-noise ratio (SINR) among users as the optimization objective, which is subjected to multiple constraints. By maximizing the lower bound to ensure the quality of service (QoS) for each user, fairness among users get improved. The PMO-BD algorithm exploits the internal structure of the product manifold to deal with the high dimension and nonlinear characteristics of the problem effectively, thereby reducing algorithm complexity and enhancing convergence rates. Simulation results verify the advantages of the proposed PMO-BD algorithm in comparison to other algorithms.

With anchor positions and measurements of distances between an object and anchors, positioning algorithms calculate the position of an object, e.g. via lateration. Positioning systems require calibration and configuration prior to operation. In the past, approaches employed reference nodes with GPS or other reference location systems to determine anchor positions. In this article, we propose an approach to determine anchor positions without prior knowledge. We evaluate our approach with simulations and real data based on the Decawave DW1000 radio and show that the error is proportional to the mean error of the distance estimation.

Fractional derivative models, which are used to describe the viscoelastic behavior of material, have received considerable attention. Thus it is necessary to put forward the analysis solutions of dynamic systems containing a fractional derivative. Although previously reported such kind of fractional calculus-based constitutive models, it only handles the particularity of rational number in part, has great limitation by reason of only handling with particular rational number field. Simultaneously, the former study has great unreliability by reason of using the complementary error function which can't ensure uniform real number. In this paper, a new approach is proposed for an analytical scheme for dynamic system of a spring-mass-damper system of single-degree of freedom under general forcing conditions, whose damping is described by a fractional derivative of the order $0<{\alpha}<1$ which can be both irrational number and rational number. The new approach combines the fractional Green's function and Laplace transform of fractional derivative. Analytical examples of dynamic system under general forcing conditions obtained by means of this approach verify the feasibility very well with much higher reliability and universality.

Malfunctions or critical fatigue problems often occur in mistuned periodic structural systems since their vibration responses may become much larger than those of perfectly tuned periodic systems. These are called vibration localization phenomena and it is of great importance to accurately predict the localization phenomena for safe and reliable designs of the periodic structural systems. In this study, a simple discrete system which represents periodic structural systems is employed to analyze the vibration localization phenomena. The statistical effects of mistuning, stiffness coupling, and damping on the vibration localization phenomena are investigated through Monte Carlo simulation. It is found that the probability of vibration localization was significantly influenced by the statistical properties except the standard deviation of coupling stiffness.

To improve the security, controllability, and efficiency of ethanol fuel production systems, this paper proposes the Modeling-Virtualization-Rehearsal-Execution (MVRE) feedback control method. This method involves the development of a comprehensive operational process model that integrates technical, procedural, and social interactions to address multi-layered threats. Leveraging virtualization technology, this paper creates a digital twin of the production environment, facilitating performance simulation and the training of unsupervised anomaly detection models. Experimental results show that our approach outperforms baseline methods in terms of precision, recall, F1 score, and training efficiency.

We present a new state-space approach to construct a dynamic output feedback controller which stabilizes a class of linear time invariant systems. All the states of the given system are not measurable and only the output is used to design the stabilizing control law. In the design scheme, however, we first assume that the given system can be stabilized by a feedback law composed of the output and its derivatives of a certain order. Beginning with this assumption, we systematically construct a dynamic system which removes the need of the derivatives. The main advantage of the proposed controller is regarding the controller order, which may be smaller than that of conventional output feedback controller. Using a simple numerical example, it is shown that the order of the proposed controller is indeed smaller than that of reduced-order observer based output feedback controller.

Mmillimeter-wave (mmWave) massive multiuser multiple-input multiple-output (MU-MIMO) system usually utilizes hybrid precoding to reduce complex hardware and high energy consumption. However, most hybrid precoding scheme consider the fully connected architecture, which may result in a significant loss of energy efficiency. In this paper, we propose a hybrid precoding scheme based on the overlapped subarray architecture (OSA), where the analog part of the MU-MIMO system is realized by a OSA network. Based on the OSA architecture, a modified generalized low rank approximation of matrices (GLRAM) based hybrid precoding scheme is designed to maximize the achievable sum-rate, where the analog precoding algorithm apply the phase alignment technology and GLRAM approach to obtain RF precoder/combiner with high array gain provided by massive MIMO system. Then, the block diagonalization (BD) technology is performed to obtain the digital precoding matrix for the multiplexing gain. Simulation results show that the modified GLRAM based hybrid precoding algorithm for OSA architecture can reduce the number of iterations. Compared with the existing hybrid precoding algorithm, it achieves higher spectral efficiency and lower complexity.

In this paper, a transmitter-based multipath processing and inter-channel interference (ICI) cancellation scheme for a ultra-wideband (UWB) spatial multiplexing (SM) multiple input multiple output (MIMO) system is presented. It consists of taps delayed lines and zero-forcing (ZF) filters in the transmitter and correlators in the receiver. For a UWB SM MIMO system with N transmit antennas, M receive antennas, and Q resolvable multipath components, the BER performance of a linear transmit ZF scheme is analyzed in a log-normal fading channel and also compared with that of a receiver-based ICI rejection approach. It is found that when M ${\leq}$ N, the transmit ZF processing approach outperforms the ZF receiver while making the mobile units low-cost and low-power.

This paper explores to the usefulness of Peter Checkland’s Soft Systems Methodology (SSM) to designing Information Systems, and to propose a different way of looking at the effect of Information Systems and Technology on both individuals and organizations, effects which go beyond the quantitative analysis. SSM is known as the methodological approach to tackling real-world problems which is based on the fact that all-real-world ‘management’ problem situations in which people are interested in seeking to take purposeful action. The idea of a ‘human activity system’ is introduced to suggest a new kind of system concepts to designing information systems in organizations.

Modern businesses increasingly depend on large and continuously growing volumes of data to inform strategic decision-making. However, the rapid pace of data generation presents significant challenges for traditional analytical methods to remain timely and effective. This has led to a growing need for AI-based Decision Support System (AI-DSS) to assist business management processes. The effectiveness of an AI-DSS extends beyond its technical capabilities; it also depends on alignment with business goals, ease of use, and its support for ethical and responsible decision-making. This paper evaluates and compares AI-DSS tools within business contexts using Multi-Criteria Decision-Making (MCDM) frameworks. They have been reliably used in selecting systems tailored to given priorities. The proposed MCDM framework considers key evaluation dimensions, including technical performance, strategic compatibility, usability, cost-effectiveness and other factors. By integrating these factors, the study offers a systematic approach to help organizations make more informed and context-sensitive decisions when selecting AI-DSS tools.

Advanced Persistent Threats (APTs) represent a major headache for Security Operations Centers (SOCs) of the 21st century. Apart from being able to withstand constant monitoring, detection, and response, APTs are also extremely sophisticated and stealthy in nature. Centralized Intrusion Detection Systems (IDS), which are of a traditional nature, are usually not capable of providing adaptive, privacy-preserving, and collaborative detection functionalities across distributed networks. In this paper, a Federated Intrusion Detection Framework (FIDF), which uses Federated Learning (FL) to allow multiple SOC nodes to jointly train a smart detection model without the need to share raw data, is introduced. Local IDS agents, a central SOC aggregator, and a secure threat intelligence exchange mechanism are components of the system. The experimental performance is successful in showing that the detection accuracy is improved, the false positives are reduced, and the response time is enhanced for APT defense. The presented framework is a step toward federated solutions for the creation of a cybersecurity ecosystem that is scalable, privacy-aware, and resilient and is suitable for national defense infrastructures.

신경생물학 접근법은 정신학에서의 심신 이원론 문제를 해결하고 새로운 진단과 치료법을 발달시키는 데 도움을 주었다. 하지만 신경정신장애의 복합성 때문에 신경생물학의 신경해부학 부분을 너무 강조하는 것은 문제가 될 수 있다. 예를 들어, 발달성 협응장애 (DCD)는 일반적으로 움직임과 관련된 장애이지만 종종 지각과도 긴밀한 관 계가 있다. 뇌의 기능적 분류에 입각한 두 시각 이론은 대뇌의 복측은 물체의 재인을, 배측은 움직임, 위치와 관련되 어 있다고 주장한다. 하지만 물체의 지각은 시각적으로 유도되는 행동과 밀접한 관련이 있다. 이 논문에서는 두 시 각 이론을 설명하는 기본적인 연구들을 검토하고, 이 이론에 대한 비판을 제시한다. 특히, 발달성 협응장애와 같은 운동뿐만 아니라 지각과 관련이 있는 신경정신장애에 구조적인 신경생물학 접근법을 적용하는 것의 한계점을 제시한 다. 결론적으로, 현대의 신경정신분야에 융복합적으로 사용되는 신경생물학 접근법은 유용하지만, 신경구조적 분류에 너무 집중하면 한계점이 나타날 수 있다.

Neurobiological approach helps to resolve the mind-body dualism and develop new assessment and treatment approaches in psychiatry. However, it could be a problem to place too much emphasis on certain aspects of neurobiology, specifically structural neuroanatomy, because of the complexity or comorbidity of neuropsychiatric disorders. Developmental Coordination Disorder (DCD), for instance, is generally related to problems in motor skills and this movement disability is often related to perception. One account, two visual systems theory, relied on functional distinction in brain; ventral stream is responsible for visual recognition, and dorsal stream is responsible for the guidance of actions. However, Studies are now showing that shape perception is relevant to visually guided action, such as reaching-to-grasp an object. In this article, I reviewed fundamental findings of two-visual system theory and suggested problems of visually guided action to consider what shape perception implies for the two visual systems. Questions raised highlight possible limitations of adopting a structural neuroanatomical approach to account for perception and action effects, and by extent related psychiatric conditions such as DCD. In conclusion, neurobiological approach converging to neuropsychiatry, while useful, would be limited if it focuses too much on anatomical distinction.