Sukjae Jeong

This study examines the extent to which the passive protection design verification framework for Korean satellites has been procedurally institutionalized under growing space debris collision risk and discusses directions for its further development. To this end, it reviews the United Nations Committee on the Peaceful Uses of Outer Space (UN COPUOS) and Inter-Agency Space Debris Coordination Committee (IADC) guidelines, as well as International Organization for Standardization (ISO) 24113 and ISO 16126, and compares the hypervelocity impact (HVI) testing and verification systems of National Aeronautics and Space Administration (NASA), Japan Aerospace Exploration Agency (JAXA), and European Space Agency (ESA) across three dimensions: test infrastructure, test–analysis linkage, and risk assessment and standard application. The analysis shows that major space agencies operate integrated verification procedures that combine environment models, three-dimensional geometry models, and ballistic limit equations (BLEs) to derive system-level survivability metrics such as the probability of no failure (PNF) and the probability of no catastrophic failure (PNCF). In contrast, although South Korea possesses basic HVI test infrastructure and operational collision-risk response capabilities, the procedural structures required to connect these elements to system design verification are not clearly identifiable in the public literature. The central challenge for South Korea lies not in the lack of individual component technologies, but in establishing a framework in which HVI testing, numerical analysis, risk assessment, and standard application are systematically integrated into a unified design verification process. By reconstructing international norms, technical standards, and the verification practices of major space agencies based on a common set of criteria, this study provides an analytical basis for assessing Korea’s passive protection design verification system in terms of procedural institutionalization. It further proposes three development directions: the construction of a Korean BLE database, the establishment of a micrometeoroid and orbital debris (MMOD) risk assessment framework applicable to domestic design procedures, and phased standardization driven by the establishment of a centralized management governance under the Korea AeroSpace Administration (KASA).

The military of the Republic of Korea utilizes technology readiness assessment (TRA) to quantitatively evaluate the maturity of domestic technologies. TRA is a key tool for determining the research and development potential in the country. As TRA employs hardware (HW)-oriented technology readiness levels (TRLs), it is suitable for independently assessing individual technologies. However, it has limitations in terms of evaluation from a system-integration perspective. Additionally, the results of checklist-based assessments are highly likely to involve subjectivity, which may yield sparse quantitative insights. This study proposes an enhanced TRA framework in which TRA procedures and criteria are redefined from the system-integration perspective. A framework that can overcome the limitations of the current TRL and TRA frameworks and enable easier, more intuitive assessments is developed. The proposed framework distinguishes between a technology element and a critical technology element (CTE) in terms of HW, software (SW), and interface (IF) and redefines TRLs. Under this framework, TRA is performed according to the TRLs that are redefined in terms of HW, SW, and IF; considering risk management, the lowest evaluation value is used as the system maturity level. The proposed CTE selection method minimizes external evaluator interventions by considering the quantitative goals of the key required operational capabilities, development difficulties, and applications of commercial off-the-shelf technologies. The effectiveness of this framework is confirmed through a case study involving three systems of systems. The results of this study can inspire research at the framework level and contribute to the improvement of existing TRA systems.

한국국방기술학회 논문지(Journal of The Korean Institute of Defense Technology)

The Russian invasion of Ukraine highlights the importance of strengthening combat readiness in the military. The purpose of this study was to devise a policy implementation that can ensure the appropriateness of the evaluation using the improvement elements of the current combat readiness evaluation in the Korean Army. To do so, the acts and regulations of combat readiness assessment and application cases in field units were analyzed, and the necessary improvements of elements were derived by collecting expert opinions using a Delphi survey. The analysis revealed that the weights for each evaluation element through the analytic hierarchy process survey were presented to assess the quantitative elements (troops, equipment, supplies, and competency) at the C-level, and the use of a judgment process was suggested to assist the commander in reasonably determining the level of qualitative evaluation factors when evaluating the grade (final decision of the level of combat readiness of the unit) at the mission assessment (MA-level). The results of this study can be applied to the assessment of combat readiness level to identify the poor elements of the field units objectively and report them accurately to the upper unit. Future, research must study topics related to the elaboration of assessment elements that can ensure the accuracy and reliability of the evaluation of combat readiness in terms of organizational competency development.

Reuse of products has become increasingly critical to reduce manufacturing costs and revitalize the new product market. With two different investment perspectives, manufacturers cooperate with retailers and recyclers to collect products from customers. By investing in the retailer, manufacturers gain an opportunity to sell new products, whereas by investing in the recycler, manufacturers can reduce production costs through remanufacturing. Therefore, manufacturers must determine the appropriate investment strategies to be applied to the two channels by analyzing the trade‐offs between these opportunities. For this purpose, we discuss three investment strategies: Revenue‐Sharing Investment, Direct Subsidy per Unit Returned Cartridge, and Hybrid Investment. The system dynamics model is used to construct scenarios of various investment strategies used by the manufacturer with the collection partners and analyze the corresponding changes in the revenues of the manufacturer. The results indicate that the application of the revenue‐sharing strategy and the hybrid strategy to support retailers and recyclers is effective in increasing manufacturer profit. More specifically, by considering the hybrid investment strategy of revenue‐sharing investment and the direct subsidy per unit returned cartridge for the recycler, the manufacturer can simultaneously avoid excess investment by the recycler and promote return activities through the recycler.

The Sustainability Editorial Office has been made aware that the published paper

한국멀티미디어학회(The Journal of Curriculum Evaluation)

The Sustainability Editorial Office has been made aware that the published paper [1]

With the rapid development of information and communication technologies, inventory information sharing between a manufacturer and its suppliers is becoming easier than ever. In line with this trend, we focus on the virtual warehouse where only inventory information on all of the material provided by the suppliers can be stored and shared. Unlike traditional supplier management, the manufacturer constructs and operates this virtual warehouse to check the inventory levels of all the required material at the same time, but each supplier can access only the information about its inventory. This virtual warehouse-based approach can foster a tight relationship between the manufacturer and its suppliers and can handle suppliers as a single company without a large investment in constructing a physical warehouse. The virtual warehouse-based approach seems to be more economically sustainable. To investigate the effect of inventory information sharing via the virtual warehouse, we developed and analyzed a system dynamics-based simulation model. The experiment results show that sharing the inventory information of the suppliers via the virtual warehouse can help manufacturers to achieve better operational performance on several important measures, such as the reduction of finished goods inventory, parts purchasing quantity, degree of backlogs, and total cost.