Abstract
Over the past 18 months, we have performed hundreds of temperature characterizations of fiber Bragg gratings inscribed in different germanium-doped silica glass fibers. Under experimental conditions, the main conclusions are as follows: the temperature dependence of the temperature gauge factor or the normalized temperature sensitivity, K-T, was found to be quadratic in the -50-200 degrees C range, while it may be considered linear for the -20-100 degrees C range; K-T values at 20 degrees C vary from 5.176 x 10(-6) K-1, for a B/Ge co-doped fiber up to 6.724 x 10(-6) K-1, for a highly Ge-doped fiber; K-T does not depend on the hydrogen-loading process or the gratings coupling strength; K-T is essentially independent of wavelength in the 1500-1600 nm range, its value being accurately determined with a relative error similar to 0.2%; based on the accurate value of K-T = 6.165 x 10(-6) K-1, at 20 degrees C, obtained for gratings inscribed in the SMF-28 fiber, we calculated a value of 19.4 x 10(-6) K-1 for the thermo-optic coefficient of bulk germanium glass; and gratings produced by femtosecond-laser radiation and UV-laser radiation exhibit comparable values of K-T. The previous achievements allow, by having knowledge of K-T for a single grating, the accurate determination of the temperature dependence of the Bragg wavelength for any other grating inscribed in the same fiber; the presented methodology enables one to determine the unknown gratings' temperature sensitivity, typically with an error of 0.01 pm/degrees C, being, therefore, very useful in research labs and computer simulations. Thus, expressions for the temperature dependence of K-T for gratings inscribed in several fibers are given, as well as an expression for K-T as a function of the effective refractive index. We have also fully analyzed the potential sources of error in K-T determination.

Abstract
Technological advances in global communications depend significantly on robust and efficient long-distance infrastructures. One notable example is the submarine cable network. Installed on the ocean floor, these cables use fiber optic technology to transmit large volumes of data at high speed and low latency between continents. Beyond their primary communication function, recent innovations allow these cables to serve as Distributed Acoustic Sensing (DAS) systems, effectively converting tens of kilometers of passive fiber into massive, coherent arrays of vibration sensors. The primary objective of this project is to enhance maritime surveillance capabilities by integrating DAS technology with advanced kinematic modeling. This paper establishes a rigorous physical and mathematical framework for interpreting the acoustic signatures of surface vessels detected by bottom-mounted fibers. We derive the complete opto-acoustic transfer function, formulate the hyperbolic moveout equations based on a moving point-source solution to the wave equation, and implement a stochastic inversion scheme using Differential Evolution. By optimizing a correlation-based loss function, we demonstrate the ability to recover vessel trajectory, speed, and depth from complex interferometric patterns with speed estimation errors consistently below 1%. This approach allows for the extraction of quantitative physical parameters from raw optical data, bridging the gap between photonics and hydroacoustics.

Abstract
Small-and-medium-sized enterprises (SMEs) increasingly depend on business partnerships to access markets and scale operations, yet they often face trust barriers during contract formation due to the complexity of the verification of their cybersecurity posture and compliance status by their partners. This problem is intensified by rising regulatory expectations, notably the EU Cyber Resilience Act (CRA), which many SMEs struggle to interpret and operationalize under constraints of budget, skills, and fragmented responsibilities. This study adopts a Design Science Research approach to blueprint and evaluate a lightweight mapping framework that links commonly implemented security controls to CRA requirements and to widely recognized benchmarks (ISO/IEC 27001 and CIS). Grounded in Institutional Theory and Socio-Technical Systems Theory, the artefact translates regulatory obligations into actionable, evidence-backed controls and produces partner-facing outputs that support transparency in negotiations and service level agreements. The framework is iteratively co-created with a multidisciplinary expert community. Expected contributions include a practical mechanism for making cybersecurity maturity visible, accelerating partnership formation, and enabling sustainable interorganizational relationships while remaining feasible for resource-constrained SMEs.

Abstract
[No abstract available]

Abstract
PurposeThis study aims to explore how identity is formed and evolves within entrepreneurial teams operating in dynamic and uncertain environments. It examines how individual and shared identities interact with knowledge processes and influence collaboration, trust and decision-making, shaping the formation and development of entrepreneurial teams.Design/methodology/approachThis research adopts a multiple-case study approach to explore the entrepreneurial team identity formation and development. It uses one-to-one semi-structured interviews with active entrepreneurial team members who have completed the Central European University iLab Incubation Program. First, an inductive coding strategy was applied. In addition, secondary data were collected through manual web scraping.FindingsThis study shows that knowledge sharing, resource exchange and mentorship through proactive networking shape teams' entrepreneurial identity. Networking and social interactions reinforce each other, while incubation increases legitimacy and identity strength. Trust, open communication and feedback foster adaptability, agility and performance, further consolidating entrepreneurial identity.Originality/valueThis study shifts the focus from individual to collective identity in entrepreneurship, examining how team identity forms and evolves in incubation settings. It highlights the dynamic interplay of networking, knowledge sharing, legitimacy, team dynamics and feedback in shaping shared identity. By emphasizing collaboration and context, it advances understanding of entrepreneurial identity as a collective process.

Abstract
PurposeThis study aims to investigate the relationship between fun at work (FW) and organizational cohesion (OC), using an integrative model where FW acts as a precursor to cohesion. Psychological empowerment (PE) and intrinsic motivation (IM) are examined as potential mediating mechanisms.Design/methodology/approachData was collected through a questionnaire distributed via Google Forms between April and July 2025 to small and medium-sized enterprises (SMEs) identified through Informa D&B. Of the 315 responses, 288 valid cases were retained for analysis. Structural equation modeling was applied to test the proposed integrative model linking FW, PE, IM and OC.FindingsThe results show that FW positively influences PE and OC, both directly and indirectly. PE also significantly enhances cohesion, reinforcing its mediating role. In contrast, IM does not significantly mediate the relationship between FW and cohesion, suggesting that enjoyable workplace practices may strengthen empowerment and collective bonds without necessarily fostering deeper intrinsic drivers.Originality/valueThis study advances knowledge by integrating two previously disconnected domains (i.e. FW and OC) into a single empirical model. The research offers practical value for managers seeking to enhance team dynamics through targeted workplace interventions, highlighting the strategic role of fun in fostering empowerment and collective bonds. In addition, it identifies the nuanced, limited role of IM, opening avenues for further exploration of contextual and cultural factors shaping these relationships.