External Dynamics Research Articles

الاتجاهات السلمیة والعسکریة للمشروع النووی الإیرانی وتداعیاته على منطقة الخلیج العربی

لاتزال الديناميات الداخلية والخارجية المعقدة في إي ا رن تشکل عقبة رئيسية أمام بناء نواياصادقة، قابلة للديمومة طويلة الأمد، اوعتمد مسار المفاوضات حول النووي الإي ا رنيعلى عدة متغي ا رت هي: رؤية المؤسسات الصلبة المنضوية تحت قيادة بيت القائد، الرئاسة،لعملية التفاوض. فالمسألة النووية لا تنحصر فقط في ذلک الإطار، في الوقت الذي تتسمترکيبة النظام فيه بالتعقيد، وأحيانا يختلف قادته حول أفضل السبل لخدمة ما اصطلح عليهأمنيت ملى المصالح القومية. بالنسبة للمرشد؛ هناک دعم حذر يبديه المرشد الأعلى عليخامنئي للمحادثات النووية مع الغرب في ظل محاولاته المتکررة التأرجح في المواقف بيندعم الفريق المفاوض من خلال إطلاق ما اصطلح عليه المرونة البطولية، وبين القبولوالرضوخ لمنطق التيار المتشدد الداعي لعسکرة النووي، واطلاق شعار أن الکلفالتي تم تحملها في سبيل الاستم ا رر في النووي، تساوي المخاطر، في ظل مشاريعإي ا رن للهيمنة وبسط النفوذ لتوسيع مجالها الحيوي المذهبي؛ هذا عدا عن تأثير هذا البرنامجعلى الدول العربية عموما والخليجية خصوصا في ظل وجود مؤش ا رت مهمة لعسکرة هذاالبرنامج، وما يفرضه ذلک من تحديات خطيرة على الأمن الإقليمي مع وجود ب ا رمج موازيةتدعم هذا التوجه البرنامج الصاروخي الإي ا رني، اولبرنامج الفضائي، اولمنشآت النووية -الموازية التي جهدت إي ا رن بإنشائها وتطويرها. -Abstract The Peaceful and Military Attitudes of Irani Nuclear Project and its Consequences on Arab Gulf Region First researcher: Dr. Nabeel Al – Autoom Second researcher: Dr. Omar Khudeirat Third researcher: Dr. Taruq Al-Azzam Complicated internal and external dynamics in Iran still form a main obstacle facing building of durable honest intentions. The course of negotiations about Irani nuclear program has been based on several variables: vision of hard institutions attached to home of leader, leadership and negotiation process. The nuclear issue is not just confined to that frame. The regime structure is characterized by complexity in away that its leaders differ in regard to best ways of serving what has been termed Aumneit Milly (national welfare) for spiritual guide. There is a cautions support expressed by highest spiritual guide, Ali Khamin'i toward nuclear talks with west in light of his repetitive attempts to swing in his stands between supporting negotiating team thtough term nirmish Kahramanah (heroic flexibility) and acceptance and subdued stand to logic of extremist current calling for militarizing nuclear program and launching slogan that costs paid for sake of continuing nuclear program equal dangers in light of Iran's projects of domination and expansion of influence in order to expand its vital sectarian sphere, as well as impact of this program on Arab countries in general and Gulf countries in particular, in light of existence of important indicators of militarizing this program which imposes dangerous challenges against regional security, with existence of parallel programs supporting this attitude the Iranic missile program, space program and paralel nuclear installations which Iran has done its best for their installation and development.

Fast finite-time backstepping for helicopters under input constraints and perturbations

This work addresses the issue of trajectory tracking of helicopters under disturbances and input constraints via the proposed fast finite-time backstepping framework. Backstepping with the property of fast finite-time convergence exhibits fast transient convergence both at a distance from and at a close range of the equilibrium. Moreover, finite-time disturbance observers based on multivariable super-twisting are employed to counteract the effect of perturbations. Aiming at the adverse effect of input saturation, a novel auxiliary system is developed to avoid the singularity by transforming auxiliary variables for three times. In addition, the framework is also applied into helicopter control problem, in which thrust magnitude and thrust direction are used as intermediate control variables, connecting external translational dynamics and internal angular dynamics. A rigorous proof of finite-time stability of the closed-loop system is derived from Lyapunov theory. Finally, the effectiveness and superiority of the proposed framework are verified by comparative simulation.

Unveiling external motion dynamics of solitons in passively mode-locked fiber lasers.

Real-time measurement of ultrafast pulses together with high temporal resolution and long recording length is an urgent requirement of all optical communication systems and nonlinear science. Here, external motion dynamics of soliton pairs in mode-locking ultrafast fiber lasers can be single-shot characterized with long recording length, by using an asynchronous four-wave-mixing (FWM)-based temporal magnifier (AFTM) system. Recording length of more than one thousand roundtrips can be achieved through the AFTM system. Temporal propagation dynamics of soliton pairs with tunable separations are observed, revealing that soliton pairs with narrower separation display vibration-like dynamics, while the two solitons with wider separation remain relatively unchanged. We believe our results will provide a promising solution for real-time measurement of ultrafast pulse and can offer novel insights for ultrafast transient dynamics in nonlinear optics.

Group dynamics analysis and the correction of coal miners' unsafe behaviors

The rate of coal mine accidents in China is still high and most coal mine accidents are caused by human unsafe behavior, and the correction of the behavior is, therefore, paramount. In this article, a group dynamics field model and a hierarchical index system of the group dynamics factors of the unsafe behavior of coal miners are established. The internal and external dynamics of groups are analyzed and the importance of each factor is calculated and determined. On this basis, suggested correction measures are put forward. Then, in combination with a questionnaire, the corrective measures of unsafe behaviors are determined and simulated. The results show that, while the correction of unsafe behaviors both in progress and after implementation can achieve good results, the former is more effective than the latter. Via the present research, both unsafe behaviors and the occurrence of coal mine accidents can be effectively prevented, and the safety of coal mine production can be ensured.

Multidisciplinary approach for the characterization of a deep-seated landslide in a semi-arid region (Cañón de Yerbabuena, San Luis Potosí, Mexico)

Multidisciplinary approaches for the characterization of deep-seated landslides (DSLs) are useful in comprehending the internal and external dynamics of the phenomena. This paper examines and characterizes the active Canon de Yerbabuena DSL (in Ahualulco, San Luis Potosi, Mexico), for which there are over 30 years of damage records to Federal Highway 63. Hence, the integrated study carried out includes lithological and structural characterization, geomorphological mapping, Persistent Scatterer Interferometry (PSI) analysis, and electrical geophysical surveys. The slope deformation extends over the highly weathered and fractured volcanic rocks of the Ahualulco Volcanic Complex in an area comprising 741,000 m2 and mobilizes an estimated rock volume of 6,950,459 m3. Geomorphological features within the DSL include a counter-scarp, minor scarps, tension cracks, small landslides, avalanche breccias, toppling, and colluvial deposits. Furthermore, the velocity rate in the upper section of the slope reaches up to 10 mm/year with a linear behavior that changes to a faster non-linear deformation (up to 30 mm/year) in the middle-lower part of the DSL. This change is the result of a multiple-complex dynamic linked to the presence of two normal faults fragmenting the middle section of the slope and an interbedded volcaniclastic clayey-siltstone layer acting as a possible sliding plane; the latter being defined by a resistivity survey. The acceleration of the velocity rates at the foot of the DSL are linked to torrential rains in the area and cause the most severe damage to the highway. Furthermore, the general slow deformation within the DSL is triggered by severe erosion from the seasonal river at the foot and the run-off on both flanks.

Porcine reproductive and respiratory syndrome virus dissemination across pig production systems in the United States

Porcine reproductive and respiratory syndrome virus (PRRSV) remains widespread in the North American pig population. Despite improvements in virus characterization, it is unclear whether PRRSV infections are a product of viral circulation within production systems (local) or across production systems (external). Here, we examined the local and external dissemination dynamics of PRRSV and the processes facilitating its spread in three production systems. Overall, PRRSV genetic diversity has declined since 2018, while phylodynamic results support frequent external transmission. We found that PRRSV dissemination predominantly occurred mostly through transmission between farms of different production companies for several months, especially from November until May, a timeframe already established as PRRSV season. Although local PRRSV dissemination occurred mainly through regular pig flow (from sow to nursery and then to finisher farms), an important flux of PRRSV dissemination also occurred in the opposite direction, from finisher to sow and nursery farms, highlighting the importance of downstream farms as sources of the virus. Our results also showed that farms with pig densities of 500 to 1,000 pig/km2 and farms located at a range within 0.5km and 0.7km from major roads were more likely to be infected by PRRSV, whereas farms at an elevation of 41 to 61 meters and surrounded by denser vegetation were less likely to be infected, indicating their role as dissemination barriers. In conclusion, our results demonstrate that external dissemination was intense, and reinforce the importance of farm proximity on PRRSV spread. Thus, consideration of farm location, geographic characteristics and animal densities across production systems may help to forecast PRRSV collateral dissemination.

Sorption of trichloroethylene under dynamic conditions

The solution to the problem of obtaining water that is safe against organohalogen pollutants, including trichloroethylene, can be the use of adsorption purification methods. For engineering calculations of the treatment plant, adsorption constants, kinetic parameters and dynamic characteristics of the adsorption process are required. It is advisable, at the stage of technology development, to optimize the parameters and modes of the sorption columns using mathematical modeling based on equations of external diffusion dynamics of adsorption.

ASPECTS OF PRECOLONIAL ISOKO SOCIO-POLITICAL RELATIONS WITH THEIR NEIGHBOURS IN SOUTH CENTRAL NIGERIA

This work focused on aspects of pre-colonial Isoko socio-political relations with their neighbours in the Niger Delta region of South Central Nigeria. It attempts to illuminate the nexus between internal and external dynamics and the concomitant changes and continuities in Isoko relations with their Urhobo, Ijaw, Ukwuani and Aboh neighbours. The work is premised on the historical method and interpretations deploying primary and secondary data to achieve its objective. The study concludes that intergroup relations in the region is largely influenced by their somewhat common ancestral origin; geographical contiguity; a shared common environmental and cultural practices; and the experience of similar external influences. This is done within the context of contemporary trajectory of the socio-political conflicts in the Niger Delta with serious implications for both National and International interests.

Transboundary crisis management under the volcano: The case of the Icelandic ash cloud

AbstractThis paper discusses the intricacies of external transboundary crises, namely those cross‐border threats whose management requires coordination among EU and non‐EU countries. Specifically, it explores the extent to which European integration theories shed light on the coordination of external transboundary crisis responses by assessing the weight and role of the actor constellations involved in the civil aviation response to the 2010 Icelandic ash cloud crisis. The use of social network analysis as a methodological tool generates novel empirical evidence on the configuration of crisis management structures. The analysis shows that many EU Member States led decision‐making, whereas supranational organizations were instrumental in the coordination of the ash cloud crisis response. The centrality of these bodies contrasts with the peripheral position of most interest groups. This paper also suggests that external transboundary crises present complex management dynamics that distinguish them from generic transboundary threats. For example, the response to the ash cloud crisis was not commanded by the European Economic Area/European Free Trade Association countries where its epicentre was located. The empirical analysis was based on information extracted from a survey to experts involved in the management of this episode, as well as from ten semi‐structured elite interviews.

Active Brownian particles simulated in molecular dynamics**Project supported by Hong Kong RGC CRF, China (Grant No. C1018-17G), GRF, China (Grant No. 16228216), and Jiangsu University Foundation (Grant No. 20JDG20).

In the numerical studies of active particles, models consisting of a solid body and a fluid body have been well established and widely used. In this work, such an active Brownian particle (ABP) is realized in molecular dynamics (MD) simulations. Immersed in a fluid, each ABP consists of a head particle and a spherical phantom region of fluid where the flagellum of a microswimmer takes effect. Quantitative control over the orientational persistence time is achieved via an external stochastic dynamics. This control makes it possible to validate ABP’s diffusion property in a wide range of particle activity. In molecular description, the axial velocity of ABP exhibits a Gaussian distribution. Its mean value defines the active velocity which increases with the active force linearly, but shows no dependence on the rotational diffusion coefficient. For the active diffusion coefficient measured in free space, it shows semi-quantitative agreement with the analytical result predicted by a minimal ABP model. Furthermore, the active diffusion coefficient is also calculated by performing a quantitative analysis on the ABP’s distribution along x axis in a confinement potential. Comparing the active diffusion coefficients in the above two cases (in free space and in confinement), the validity of the ABP modeling implemented in MD simulations is confirmed. Possible reasons for the small deviation between the two diffusion coefficients are also discussed.

A War of Words

This position paper stakes out a potential contribution from Chinese Studies for making sense of political claims about accountability for Covid-19, conspiracy theories, cover-ups, misinformation, public health responses, and vulnerabilities in societies. The broader picture is much more complex than implied in media coverage and official state sources which typically simplify and dramatise the claims with disregard for evidence or comparison of competing perspectives. By drawing on the discipline’s strengths in analysing contemporary China and its internal and external dynamics, Chinese studies can assist in critically examining the claims and their interpretive complexities, as well as the processes through which they have been conceptualised and have come to public attention, an explanatory model with considerable leverage for encouraging more meaningful dialogue.

Parallel structure of six wheel-legged robot trajectory tracking control with heavy payload under uncertain physical interaction

PurposeThis paper aims on the trajectory tracking of the developed six wheel-legged robot with heavy load conditions under uncertain physical interaction. The accuracy of trajectory tracking and stable operation with heavy load are the main challenges of parallel mechanism for wheel-legged robots, especially in complex road conditions. To guarantee the tracking performance in an uncertain environment, the disturbances, including the internal friction, external environment interaction, should be considered in the practical robot system.Design/methodology/approachIn this paper, a fuzzy approximation-based model predictive tracking scheme (FMPC) for reliable tracking control is developed to the six wheel-legged robot, in which the fuzzy logic approximation is applied to estimate the uncertain physical interaction and external dynamics of the robot system. Meanwhile, the advanced parallel mechanism of the electric six wheel-legged robot (BIT-NAZA) is presented.FindingsCo-simulation and comparative experimental results using the BIT-NAZA robot derived from the developed hybrid control scheme indicate that the methodology can achieve satisfactory tracking performance in terms of accuracy and stability.Originality/valueThis research can provide theoretical and engineering guidance for lateral stability of intelligent robots under unknown disturbances and uncertain nonlinearities and facilitate the control performance of the mobile robots in a practical system.

DISSIDENCE, DICTATORSHIP, AND DEMOCRACY: THE STRUGGLES OF MALIAN EXILES IN AFRICA AND BEYOND, 1968–91

AbstractIn contrast with the imperial period, historians have overlooked African exile politics during the subsequent decades of one-party and military rule. Focusing on the Malian case, this article proceeds in three parts. The first section explores the creation in Africa, in particular in Ivory Coast and Senegal, of clandestine opposition movements to Moussa Traoré's regime. The second section focuses on Europe, particularly France, where dissidents benefitted from an unparalleled openness of the political system compared to that seen in African countries. The final section investigates the influence of these networks spanning Africa and Europe on the formation of pro-democracy organizations in Mali and the final overthrow of the Traoré regime in 1991. Theorizing exile as a process which enabled activists to operate in abeyance despite repression – before being able to emerge more openly – refines our understanding of political transitions which were driven by the juncture of internal and external dynamics.

Export surpluses and complementarities of countries: a note on realism of balance of payment constrained growth models

The present note develops an argument in which the connection between exports and growth should underpin the demand side role of exports. The role of exports supports the external economies and supply dynamics in the Young-Kaldor cumulative causation growth. Perhaps most important, the export-led growth in a developed country and its need of proper, dynamic supply response induces imports that, in turn, can support effective export-led growth of its trading partners. This perspective brings in the crucial role of a broad range of domestic Keynesian policies, supporting the demand side role of investment and exports that ensures the proper interactions of domestic growth and the broader participation in the export-led growth. The resultant macro increasing returns at the international stage—export-led advanced growth in one country associated with such growth in other participating countries—provides the Keynesian understanding of the short run adjustment underlying interaction of exports, imports and domestic growth that permits the long run transition toward the balance of payment constrained growth. The Keynesian insight into the role of demand also underpins how additional participation in export-led growth brings forth further enhanced, endogenous export-led growth propensities for the trading partners that propagate in a cumulative way.

Is Doing Bad Always Punished? A Moderated Longitudinal Analysis on Corporate Social Irresponsibility and Firm Value

Theoretical evidence suggests that corporate social irresponsibility (CSI) should produce long-lasting negative influences on firm performance. Yet, little empirical evidence exists in the literature to support this time-embedded research frame. This research was conducted by collecting a large set of firm data and by employing a series of vector autoregressive models to map out the longitudinal dynamic relationships between CSI and firm value under high versus low levels of two external factors, environmental dynamism and competition intensity, and one internal factor, firm capability. The results show that CSI’s negative influences endure in scenarios such as high dynamism, high competition intensity, and low capability, but it has only a short-term impact on low-dynamism markets and does not produce significant effects on firm value under low-competition or high-capability conditions. These findings yield useful implications for CSI, resource-based theory, and environment theories as well as for managerial effectiveness of coping with social negativities.

Neural fuzzy approximation enhanced autonomous tracking control of the wheel-legged robot under uncertain physical interaction

The accuracy of trajectory tracking and stable operation with heavy load are the main challenges of parallel mechanism for wheel-legged robots, especially in complex road conditions. To guarantee the tracking performance in an uncertain environment, the disturbances, including the internal-robot friction and external-robot and environment interaction forces, should be considered in the robot’s dynamical system. In this article, a neural fuzzy-based model predictive tracking scheme (NFMPC) for reliable tracking control is proposed to the developed four wheel-legged robot, and the fuzzy neural network approximation is applied to estimate the unknown physical interaction and external dynamics of the robot system. Meanwhile, the advanced parallel mechanism of the four wheel-legged robot (BIT-NAZA) is introduced. Finally, co-simulation and experiment results using the BIT-NAZA robot derived from the proposed hybrid control strategy indicate that the methodology can achieve satisfactory tracking performance in terms of accuracy and stability. This research can provide theoretical and engineering guidance for lateral stability of intelligent robots under unknown disturbances and uncertain nonlinearities, and facilitate the control performance of the wheel-legged robot in a practical system.

External Switching Dynamics of Optical Bistability System Simulation

In this work, the external switching dynamics of a Fabry-Perot etalon are studied via optical bistability system simulation. The simulated set-up of this investigation consists of two laser beams; the first beam is continuous (CW) which is considered as a biasing beam and capable of holding the bistable system for a certain range, which we are interested in, from a point that is very close self-switching to a point where the switching is unachievable. The second beam is modulated by passing the first beam through an acousto-optic modulator (AOM) to produce pulses with a minimum rise time and is used as an external source (coherent switching). In this work, we obtained the optical bistable loops by applying absorption coefficient (α) = 20cm-1, e sample etalon thickness (D) = 110μm, forward mirror reflectivity (Rf) = 0.6, and backward mirror reflectivity (Rb) = 0.95. The steady state characteristic of an initial detuning of the cavity (φ0) = 0.8 was studied at the conditions of no external input pulse intensity (M(t) = 0) and switching that takes place at Is(ON)= 0.57mW and Is(OFF) = 0.4mW.

Rebel governance, rebel legitimacy, and external intervention: assessing three phases of Taliban rule in Afghanistan

ABSTRACT This article focuses on rebel governance and rebel legitimacy during civil war. It investigates how external intervention in support of an incumbent government and withdrawal of external forces shape rebel legitimacy dynamics and rebels’ opportunities to govern. It adopts a longitudinal perspective on Afghanistan’s Taliban, analyzing three phases of the movement’s existence. Moral forms of legitimacy resonated particularly during instances of external intervention, whereas pragmatic forms of legitimacy became more relevant after the withdrawal of external forces and during periods of the Taliban’s opponents’ ineffective governance. The article is based on a literature review and fieldwork in Afghanistan.

External dynamics of OF-462Z he projectiles

Theoretical studies of the determination of the components of the air resistance forces to the projectile's propulsion are quite complex and do not always give the desired accuracy of calculations. Therefore, the main methods for their determination are experimental studies. The most common method is to conduct special firing at landfills. This allows us to estimate the integral value of the air resistance forces and to determine the value of certain parameters of the dynamics of projectile movement. Based on the results of the firing range and theoretical studies, tables of firing on ground targets by artillery shells were constructed. In the case of firing under conditions other than normal, corrections must be made. Formulas for determining their values, are obtained, preferably, by decomposing the corresponding dependences into a numerical series taking into account its first terms. If the values of the parameters change slightly, then the values of the amendments give little discrepancy with the practice of their application. However, otherwise, the differences become significant.In this article a mathematical model for determining the functional dependence of the magnitude of the frontal air resistance force of the projectile on its velocity, mass and caliber, temperature and density of air, atmospheric pressure, speed of sound in air is investigated and proposed by the authors. Functional dependence has the same form of recording when a projectile moves with supersonic or subsonic speeds, but the values of their coefficients are different. To determine their values, the inverse dynamics problem is solved, that is, knowing the results of experimental studies for this type of projectile by the method of iteration, their values are selected.Based on the proposed mathematical model kinematic parameters of the movement of HE projectiles OF-462Z 122 mm caliber were determined and the values of the corrections if the air temperature is different from the standard were obtained.Therefore, the proposed mathematical model of determining the functional dependence of the magnitude of the frontal air resistance force of the projectile’s movement allows us to investigate the influence of deterministic and non-deterministic factors on the kinematic parameters of the motion of the projectile that is to determine the magnitude of corrections and to create the appropriate software.

Effect of an echo sequence to a trapped single-atom interferometer with photon momentum kicks.

We investigate a single-atom interferometer (SAI) in an optical dipole trap (ODT) with photon momentum kicks. An echo sequence is used for the SAI. We find experimentally that interference visibilities of a counter-propagating Raman type SAI decay much faster than the co-propagating case. To understand the underlying mechanism, a wave-packet propagating simulation is developed for the ODT-guided SAI. We show that in state dependent dipole potentials, the coupling between external dynamics and internal states makes the atom evolve in different paths during the interfering process. The acquired momentum from counter-propagating Raman pulses forces the external motional wave packets of two paths be completely separated and the interferometer visibility decays quickly compared to that of the co-propagating Raman pulses process. Meanwhile, the echo interference visibility experiences revival or instantaneous collapse which depends on the π pulse adding time at approximate integer multiples or half integer multiples of the trap period.