Computed tomography (CT) scanning has attracted increasing attention as a non-destructive technique for evaluating the internal structure and performance of asphalt mixtures. Conventional performance evaluation methods generally rely on destructive mechanical testing and provide limited information about the internal characteristics of the material. In contrast, CT scanning enables high-resolution visualization and quantitative analysis of important structural features, including air-void connectivity, aggregate contact, and mastic coverage, which strongly influence the durability and mechanical performance of asphalt mixtures..

목적 : 본 연구는 기능 제한 고령자의 디지털 수단적 일상생활활동(Digital Instrumental Activities of Daily Living, D-IADL) 수행 패턴을 분석하여, 디지털 기술이 오프라인의 고비용 이동을 대체하고 시간 주권을 회복시키는 현실적인 해결 방안임을 실증적으로 확인하고자 한다. 연구방법 : 2024년 한국생활시간조사 마이크로데이터를 활용하여 만 65세 이상 고령자 6,093,592명(모집단 추정치)을 분석하였다. 디지털 활동 참여 수준을 반영하는 디지털 관여지수(Digital Engagement Index, DEI)와 오프라인 활동 대 비 디지털 활동의 상대적 비중을 나타내는 디지털 대체비율(Digital Substitution Ratio, DSR), 그리고 기능 제한과 관 련될 가능성이 있는 필수 시간 부담을 나타내는 기능적 시간비용지수(Functional Time Cost Index, FTCI)를 구성하였 다. 분석은 복합표본 일반선형모형과 1:1 성향점수매칭 기법을 적용하여 기능 제한 유무에 따른 시간 사용 구조의 조정된 격차를 실증적으로 분석하였다. 결과 : 기능 제한 고령자 집단은 대조군에 비해 D-IADL 수행 시간이 유의하게 짧았으나(MD = -2.94, p = 0.008), 재 량시간은 유의하게 길게 나타났다(MD = 44.15, p = 0.008). 반면, 오프라인 시간비용과 DSR은 두 집단 간 통계적으로 유의한 차이를 보이지 않았다. 이와 달리, 높은 수준의 DEI는 무의미한 비자발적 유휴 시간을 능동적 재량시간으로 전환 함으로써, 기능 제한 고령자의 주도적인 시간 활용 구조 개선과 시간 주권 확장에 기여할 가능성을 시사하였다. 결론 : D-IADL은 기능 제한 고령자의 재량시간 확보와 시간 활용 구조 개선에 기여할 가능성을 시사한다. 따라서 보조 공학 지원 체계는 단순 기기 보급을 넘어 기능적 제약을 고려한 접근성 중심의 디지털 활용 지원과 교육을 강화할 필요가 있다.

In response to the global demand for cleaner energy, this research presents a resourceful and sustainable route for biodiesel production through the design of a novel catalyst derived from two agro-waste materials: chicken eggshells and coconut shell–pith biomass. The CaO/activated carbon (CaO/AC) composite catalysts were synthesized via calcination, carbonization, and wet impregnation, followed by thermal treatment, without the use of surfactants, binders, or toxic chemicals, ensuring an environmentally benign process. Characterization by XRD confirmed the presence of crystalline CaO phases and amorphous carbon. FTIR and SEM analyses further validated the functional group interactions and porous surface morphology, which are critical for catalytic performance. The catalyst was evaluated by transesterifying waste cooking oil (WCO) at varying methanol-to-oil ratios (8:1–10:1), catalyst loadings (6–8 wt%), and reaction temperatures (60–65 °C). The best performance was observed with the C-CCS catalyst (derived from coconut shell), achieving a maximum biodiesel yield of 92.48% at a 10:1 MeOH: oil ratio, 8 wt% catalyst loading, 65 °C, and 90 min. The resulting biodiesel met ASTM D6751 specifications in all key fuel properties, including viscosity, density, flash point, acid value, and moisture content. This research presents a low-cost and scalable synthesis strategy that valorizes dual biowaste streams while producing engine-grade biodiesel. Its operational simplicity and high efficiency make it a strong candidate for industrial biodiesel applications, particularly in resource-constrained settings.

This study investigates the effects of digital interface structure on the operational performance of unmanned and manned–unmanned integrated mechanical systems from a human factors perspective. Using case-based comparative analysis, changes in response time, operation error rate, and situational awareness accuracy before and after interface redesign were examined. The results indicate that improvements in interface integration, procedural simplification, and consistency significantly enhance operational performance without modifying mechanical hardware or control algorithms. The study highlights the importance of incorporating human factors engineering into the early design and evaluation stages of complex mechanical systems.

With high redox activity, superior conductivity, abundant pores, and large specific surface area, nitrogen-doped graphitic carbon featuring a hierarchically porous structure is regarded as ideal electrode material for supercapacitors. In this work, hierarchically porous nitrogen-doped graphitic carbon (PG-PZC50) was fabricated via non-solvent induced phase separation and high-temperature calcination processes. SEM images showed its three-dimensional network structure, with abundant macro- and mesopores distributed throughout. XRD and Raman spectra confirmed the phase purity and graphitic nature of the as-prepared material, while XPS revealed its surface elemental composition, especially the content and doping states of nitrogen atoms. The graphene oxide-induced three-dimensional network, combined with the mesoporous structure of metalorganic framework-derived N-doped carbon particles, creates abundant migration channels and a large adsorption surface area for the electrolyte ions. Benefiting from its hierarchically porous structure and high nitrogen-doping content, the formed PG-PZC50 reached high specific capacitances of 499.7 F g− 1 at 0.1 A g− 1 and 179.6 F g− 1 at 20 A g− 1. Notably, the material also demonstrated robust cyclic stability with no capacitance loss after 10,000 charge–discharge cycles. The proposed synthetic strategy provides new ideas for the facile and reproducible construction of nitrogen-doped graphitic carbon with 3D hierarchically porous structure and high capacitive performances.

21세기 들어 인공지능(Artificial Intelligence)은 예술 창작의 구조와 개념을 근본적으로 변 화시키고 있다. 특히 음악 분야에서 생성형 AI의 등장은 작곡과 편곡의 경계를 허물며, 인간의 감정과 기술의 연산이 결합된 새로운 예술 형태를 출현시켰다. 본 연구는 AI 기반 음원 제작이 공연예술, 특히 무용 창작 구조에 미치는 영향을 분석하는 데 목적을 둔다. 연구 방법으로 질적 사례연구를 채택하고, 국내에서 이루어진 두 가지 공연 사례 ― ① 국립국악원 『세종탄신 하례 연』<AI 복원 궁중음악 공연>(2024), ② 『G·Artience 2024』<무용×AI 융합 공연> 를 중심으로 고찰하였다. 분석틀로는 앤드류 핀버그(Andrew Feenberg)의 기술철학과 볼터와 그루신(Bolter & Grusin)의 재매개 이론을 바탕으로 ‘학습–모방–공진–종결’의 4단계 퍼포먼스 구조를 설정하였 다.『세종 탄신 하례연』은 전통음악의 복원을 통해 ‘기억된 예술’의 현대적 재해석을 보여주 었으며, 『G·Artience 2024』는 인간의 신체 데이터를 AI가 실시간으로 해석하고 음악·시각 효 과를 공진적으로 생성함으로써 공동지능 예술의 가능성을 제시하였다. 이와 같은 분석은 AI 기술 이 예술 창작의 민주화와 감정 표현의 확장을 동시에 이끌고 있음을 보여준다. 본 연구는 기술이 예술의 협업 구조와 주체성을 어떻게 재구성하는지를 실증적으로 제시함으로써, AI 시대 공연예 술의 지속적 발전 방향을 탐색하는 학문적 기초를 마련하고자 하는데 그 의의가 있다.

The constituents of coal tar pitch (CTP) significantly impact the wettability of calcined coke (CC) and the performance of prebaked anodes (PA) used in aluminum electrolysis. However, balancing wettability and carbon residue within CTP remains a central challenge in material applications. In addition, limited pore permeability and structural stability in these composites hinder the effective utilization of PA. Enhancing CTP fluidity is crucial for overcoming these challenges. In this work, a novel method was developed to modify CTP utilizing various coal tar fractions, enabling controlled modulation of CTP composition and wettability. Incorporating different fractions allowed for substantial control over interfacial bonding and pore structure. The chemical composition, functional groups, and elemental content of the CTP were analyzed via X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance (1H NMR). Subsequently, systematic comparisons of PA materials produced from different CTP formulations demonstrated improved wettability and enhanced mechanical properties. Moreover, DFT calculations were performed to compare the adsorption energies of small molecules from different coal tar fractions with coke, reflecting the interaction strength between the molecules and the solid surface. Using micro-computed tomography (μ-CT), the refined pore structure was examined, resulting in a PA composite with an optimized balance of high strength and toughness.

The K2 tank not only has excellent mobility but also has excellent protection performance. Armor steel is used to provide structural protection, and the turret structure is made of rolled homogeneous armor (RHA) plates. Most processes for fabricating structures involve welding, but RHA steel has the problem of being susceptible to thermal deformation. To compensate for this, a plan to apply the bending method was considered. In this study, prior to applying the bending method to an actual vehicle, mechanical property evaluations were performed on materials, welding, and bending specimens. It has been proven that the bending method can achieve performance equivalent to or better than the welding method. The verification tests included hardness tests, tensile tests, fatigue tests, and impact tests. All tests except the impact test confirmed that the bending method was superior to the welding method. In the case of the impact test, the impact value of the bending method was lower, but it satisfied the standard with a value higher than the minimum requirement according to the standard, so it is judged that there will be no problem in applying the bending method.

In this study, a response model of a beam structure was established through finite element analysis by analyzing the vibration response to external excitation. The vibration control performance of the beam was then evaluated by applying the narrow-band Fx-LMS algorithm for active structural control. The transfer function was obtained at the error sensor location when the structure was excited and the three-axis actuator was operated. The performance of the active control was investigated with 18 channels for error input and actuator output. When the equipment is exciting, the response of the error sensor is the primary path, and when the inertial 3-axis actuator operates, the response of the error sensor position is the secondary path, and the Fx-LMS algorithm is applied. The simulation was performed by changing the control parameters so that the response of the error sensor can satisfy the target performance. From the results of this study, the acceleration results over time showed about 70% vibration reduction after active control, and the average error value of the error sensor also decreased by about 68%. In addition, it was confirmed that real-time control of a system with 18 sensors and 18 actuators is possible even if the secondary path is configured in two orders.

국제경영 환경에서 지속 가능한 발전 목표가 널리 수용됨에 따라, 기업의 ESG(환경/Environment, 사회/Social, 거버넌스/Governance) 성과는 글로벌 시장에서 다국적기업의 성공을 결정하는 핵심 지표 중 하나로 자리 잡고 있다. 본 연구는 제도이론에 근거하여 신흥시장 다국적기업의 ESG 성과가 국제화 속도에 어떻게 영향을 미치는가 를 탐구하였다. 이와 더불어 본 연구는 ESG 성과와 국제화 속도 간 관계에 대해 최고경영자의 해외 경험과 기업 의 소유구조, 즉 국유기업 여부가 어떠한 조절 효과를 미치는지에 대해서 검증하였다. 2010년부터 2022년까지 중국 A주 시장에 상장된 1,648개 기업의 8,329개 표본을 분석한 결과, 신흥시장 다국적기업의 ESG 성과는 국 제화 속도에 긍정적인 영향을 미치는 것으로 나타났다. 조절 효과의 분석 결과, 다국적기업 최고경영자의 해외 경 험은 이러한 관계를 약화시키는 것으로 나타났는데, 이는 높은 해외 경험을 가진 최고경영자의 경우, 국제화 속도 를 결정하는 데 있어 ESG 성과에 대한 의존도를 줄이는 한편, 보다 신중한 국제화 전략을 취하기 때문으로 해석 할 수 있다. 또한 신흥시장 다국적기업이 국유기업일 경우에, 민간기업에 비해 ESG 성과와 국제화 속도 간의 긍정 적인 관계가 약화되는 것으로 나타났는데, 이는 국유기업이 ESG 성과를 통해 빠른 국제화 속도를 추진할 때 정당 성 확보의 어려움에 직면할 수 있음을 시사한다. 본 연구의 결과는 다국적기업의 ESG 전략 및 성과가 글로벌 시장 에서 정당성을 강화하고 국제화 전략의 중요한 요인이 될 수 있음을 강조하는 동시에, 그 효과가 최고경영자의 특 성과 기업의 소유구조에 따라 달라질 수 있음을 보여준다. 이러한 결과는 신흥시장 다국적기업이 ESG 전략을 효 과적으로 활용하기 위해서는 경영진의 리더십과 소유구조를 함께 고려한 종합적인 접근이 필요함을 시사한다.

In today’s rapidly changing business environment, rapid decision making and effective project management are essential for business growth. This study examines how project manager competencies and organizational structures affect business performance. Successful project execution depends on the strategic use of project managers’ skills and organizational resources to maximize performance. An empirical study was conducted with 475 participants from the construction and engineering sectors. The applied analyses included multiple regression analysis and two-way ANOVA to assess how project manager competencies and organizational types affect business performance. The results of the study show that project manager competencies significantly improve business performance, especially when combined with appropriate organizational types. Effective use of organizational frameworks leads to better financial results, increased market competitiveness, and greater innovation. The results of the study are as follows: First, project manager competencies were found to have a significant positive effect on business performance. Second, the use of functional, project, and matrix organizations had a significant positive effect on business performance. This suggests that aligning organizational structures with business objectives is important for achieving optimal performance. Overall, this study provides valuable insights into the academic literature and practical applications of project management and organizational research. In addition, if we can select organizational members based on the learning effects of previous projects when operating new projects in the future, it will help reduce risks. Ultimately, it will improve the project manager’s competency level, promote the individual abilities and knowledge sharing of team members, and provide opportunities for the company to build efficient new systems. This will be evaluated as a valuable study in terms of academic and practical productivity.

The purpose of this study is to examine the determinants of management performance in the remaining offshore fishing industry after the resource management-oriented fisheries structure improvement policy by the fisheries vessel buy-back program and Total Allowable Catch (TAC). The results of the analysis of the determinants of management performance of offshore fishing can be summarized as follows. First, based on the management performance determinant model of offshore fishing, it is confirmed that the government's resource-managed fishing structure improvement policy, such as the fishing boat reduction project and the TAC policy, is improving the management performance of the resource-managed remaining fishing boat. Second, looking at the specific management performance determinants based on the management performance model of offshore fishing, the leverage ratio (TLTA), which is the total debt ratio, shows a statistically significant positive (+) relationship with management performance, which increases management performance directly proportional to the leverage ratio. The increase in the leverage ratio (total debt ratio) was expected to lead to a high interest cost burden, resulting in a reverse (-) financial leverage effect; however, rather a positive (+) financial leverage effect occurred with a high profit covering interest costs. The total catch (TCATCH) has a positive (+) relationship with management performance at a statistical significance level of less than 1%, indicating that an increase in catch is improving or increasing the management performance of fishing companies. The selling price (UPRICE) shows a positive (+) relationship with management performance at a very high statistical significance level of less than 1%, and it can be seen that high fishing prices are a major factor in improving or increasing the management performance of offshore fishing. On the other hand, fishing vessel tonnage (TON), fishing vessel horsepower (RHP), and operating days (WDAYS), which indicate have a statistically significant negative (-) relationship with management performance, which deviates from the existing fisheries common sense that the size of fishing vessel tonnage and fishing vessel horsepower and the increase in the number of operating days is proportional to management performance. As a result of the increase in fishing vessel tonnage, horsepower, and the number of operating days, it was confirmed that the higher the fishing cost, such as oil costs, is worsening the management performance of fishing companies. Participation in TAC has a statistically significant positive (+) value with management performance, indicating that the remaining offshore fishing companies participating in TAC are improving or increasing management performance compared to offshore fishing companies that do not. Third, there are conflicting results depending on the industry as a result of estimating the management performance determinants of offshore fishing by TAC participation, and TAC participation had a negative impact on management performance in anchovy boat seine and southern west sea bottom trawl in fishing industry while TAC participation had a positive impact on management performance in large stow nets on anchor in fishing industry.

기체 분리막의 상업적 발전은 CO2 분리 효율을 향상시키는 데 중요한 역할을 한다. 고분자량 PEO (high-Mw PEO)는 높은 CO2 용해도, 가격 경쟁성 및 견고한 기계적 특성을 가져 분리막 제조용 고분자로 유력하지만 그 특유의 결정성 으로 인해 기체 분리막에 응용이 어렵다. 본 연구에서는 결정성 감소를 위해 다양한 고분자 첨가제를 고분자량 PEO에 혼합 하는 방법을 제시하였다. 폴리에틸렌글리콜(PEG), 폴리프로필렌글리콜(PPG), 폴리아크릴산(PAA) 및 폴리비닐피롤리돈(PVP) 과 같은 상업적으로 이용 가능하고 섞임성이 좋은 수용성 고분자를 첨가제로 사용하여 PEO 결정성을 감소시킴으로써 가스 분리 성능을 향상시키고자 하였다. PEG 및 PPG의 경우 PEO의 결정 구조를 억제하지 못하고 분리막의 결함을 초래하였으나, PAA 및 PVP는 PEO의 결정 구조를 바꿔 결함이 없는 분리막을 제조하는 데 성공하였다. 고분자량 PEO 혼합막의 결정 구조 변화와 기체 분리 성능의 상관관계를 조사하여 본 연구의 결과와 이전에 기록된 결과를 바탕으로 고분자량 PEO에 대한 첨가 제 고분자의 설계 및 선택에 대한 통찰력을 제공하며, 이를 통해 비용 효율적이고 상업적으로 실용적인 CO2 분리막을 제조하 고자 하였다.