Many parts of platforms are expected to be replaced by unmanned systems in modern warfare. All the assets and supporting vehicles are linked to each other with a communication network, and it is called the network-centric warfare environment. Hence, it is critical when communication failure occurs during engagement in ground battlefield because this failure will directly affect overall combat effectiveness of one’s owned assets. However, research regarding communication failure issues is scarce. We herein propose a new agent-based modeling process to measure the overall combat effectiveness combined with communication success ratio, based on the terrain condition of the ground engagement. Additionally, we provide the effectiveness analysis result when a communication repeater is applied during communication failure as an alternative measure.

We study the ship speed optimization problem with the objective of minimizing the total fuel consumption. We consider multiple time windows for each port call as constraints and formulate the problem as a nonlinear mixed integer program. We derive intrinsic properties of the problem and develop an exact algorithm based on the properties. Computational experiments show that the suggested algorithm is very efficient in finding an optimal solution.

Objective: Romosozumab is increasingly employed to manage osteoporosis. However, no studies have analyzed its effects on recent osteoporotic vertebral compression fractures (OVCFs). Therefore, this study aimed to evaluate the efficacy of romosozumab compared with teriparatide in managing OVCFs.Methods: The electronic medical records of postmenopausal patients with recent OVCFs who were administered romosozumab or teriparatide for one year from March 2018 to August 2022 were retrospectively reviewed. We compared the 2 groups for demographics, radiological outcomes (compression ratio, Cobb angle, and bone mineral density [BMD]), and clinical outcomes (Numerical Rating Scale [NRS] for back pain).Results: Fifty-five patients with OVCFs, 32 patients treated with romosozumab and 23 with teriparatide, were included in this study. The change of BMD (g/cm2) values was significantly higher (p = 0.016) in the romosozumab (0.04 ± 0.06) than in the teriparatide group (0.00 ± 0.08) in the femur total. Furthermore, in subgroup analysis, the change of BMD (g/cm2) values in the lumbar spine was significantly higher (p = 0.016) in the romosozumab (0.12 ± 0.06) than in the teriparatide group (0.07 ± 0.06) in the lumbar spine. The decrease in NRS was significantly higher (p = 0.013) in the romosozumab (6.6 ± 2.0) than in the teriparatide group (5.5 ± 2.1). However, there was no significant difference in radiologic outcomes between the 2 groups.Conclusion: Our findings suggest that romosozumab may be more effective than teriparatide in treating OVCFs in postmenopausal females, particularly in improving BMD and reducing back pain as measured by NRS.

The atlantoaxial (C1–2) junction is among the most technically demanding regions for cervical spine surgery owing to its complex osseoligamentous anatomy and proximity to critical neurovascular structures. Numerous posterior fixation constructs have been developed to optimize biomechanical rigidity and promote arthrodesis. Since Gallie’s introduction of posterior wiring with autologous bone grafts in 1939, evolving techniques have focused on enhancing fusion rates while minimizing risk to adjacent structures. This paper outlines the historical evolution of C1–2 posterior instrumentation, current fixation strategies, bone fusion techniques, and reduction methods. A systematic literature search identified 61 relevant studies on C1–2 fusion. Additional references were manually reviewed to provide a comprehensive context. Of these, 41 studies were narratively summarized to outline the historical and conceptual evolution of C1–2 fusion techniques, while the remaining 20 post-2000 studies on contemporary surgical modifications were systematically reviewed and tabulated for technical details and clinical outcomes. C1–2 fusion techniques have evolved significantly over time. Early methods primarily involved posterior wiring with autologous bone grafts, but later transitioned to rigid segmental fixation using pedicle screw constructs, resulting in improved fusion rates and clinical outcomes. Interarticular fusion, when concurrently performed, enhances the biological fusion environment, contributing to favorable clinical results. C1 lateral mass, posterior arch, pedicle screws and C2 pedicle, lamina screws give us much stronger stability and higher fusion rates. Interarticular fusion using local bone also gives us technical easiness guaranteeing high fusion rate overcoming inconvenience of wiring and iliac bone harvest. Interarticular height reduction and interarticular fusion should be discriminated.

Objective: The cervical spine presents challenges in treating metastatic cervical spinal tumors (MCSTs). Although the efficacy of cervical pedicle screw placement (CPS) has been well established, its use in combination with 5.5-mm rods for MCST has not been reported. This study aimed to evaluate the efficacy of CPS combined with 5.5-mm rods in treating MCST and compare it with that of CPS combined with traditional 3.5-mm rods.Methods: This retrospective study analyzed 58 patients with MCST who underwent posterior cervical spinal fusion surgery by a single surgeon between March 2012 and December 2022. Data included demographics, surgical details, imaging results, numerical rating scale score for neck pain, Eastern Cooperative Oncology Group performance status, and Spine Oncology Study Group Outcomes Questionnaire responses.Results: Preoperative Spinal Instability Neoplastic Scores were significantly higher in the 5.5-mm rod group. Greater kyphotic changes in the index vertebra were observed in the 3.5-mm rod group. Neck pain reduction was significantly better in the 5.5-mm rod group.Conclusion: CPS with 5.5-mm rods provides superior biomechanical stability and effectively resists forward bending momentum in posterior MCST fusion surgery. These findings support the use of 5.5-mm rods to enhance surgical outcomes.