This study proposes a method to improve the seismic performance of a stacked stone pagoda by applying a Ball Vibration Absorber (BVA) with a non-fixed connection. The governing equations of motion were derived by analyzing the structure's primary failure mode under seismic excitation and sliding behavior, and a numerical model was constructed. To verify the model's reliability, a shaking table experiment with a two-layer rectangular block structure was conducted, and the experimental results were compared with numerical simulations. Based on the validated numerical model, both artificial and real earthquake records were used for parametric analyses to determine the optimal design parameters that maximize the damping efficiency of the BVA system. The main findings of this study are as follows. First, when the difference between the rolling path radius and the ball radius is small, the damping performance of the BVA decreases. Still, this effect becomes negligible once the difference exceeds a certain threshold. Second, when the friction coefficient between the BVA container and the target structure is small, the non-fixed connection type exhibits superior damping performance; as the friction coefficient increases, its performance converges to that of the fixed connection type. Third, the damping performance of the BVA improves significantly as the mass of the ball increases. Fourth, the damping efficiency of the BVA is inversely proportional to the amplitude of seismic acceleration. However, its performance slightly weakens under strong ground motions; it still maintains a stable damping capacity.

In conventional construction methods, the slab-balcony junction often experiences thermal bridging. This phenomenon arises from the discontinuity of insulation materials, leading to energy loss and condensation that can compromise the structure's usability and durability. To address this issue, thermal break insulation systems were installed between the slab and balcony to effectively prevent thermal bridging and energy loss, thereby improving the overall energy efficiency of buildings. This study aims to enhance both the structural performance and thermal efficiency of slab-balcony connections in residential buildings. To assess the impact of the thermal break insulation system, two experimental specimens were prepared: one incorporating the system and the other without it. Experimental results confirmed that the inclusion of reinforcing bars significantly improved the connection's structural load-bearing capacity. Furthermore, thermal analysis revealed that the thermal break insulation system outperformed conventional insulation methods by reducing the thermal damage ratio and maintaining higher surface temperatures at the connection. In addition, a structural analysis using an FEM (finite element analysis) program was conducted to evaluate the load distribution across the specimens, demonstrating that the experimental data accurately predicted the structural behavior of the connections.

기후변화에 따른 관리형 화분매개자 부족은 온실 딸기 재배에서 대체 화분매개자의 필요성을 높이고 있다. 재래꿀벌(Apis cerana)은 양봉꿀벌 (Apis mellifera)의 대체종으로 제안되었으나, 온실 조건에서의 직접 비교 연구는 제한적이다. 본 연구에서는 2024년 11월부터 2025년 3월까지 대 한민국 충남 논산의 딸기 온실에 두 종의 봉군을 설치하고, 봉군세력, 먹이활동, 화분매개 효율을 모니터링 하였다. 두 종 모두 세력이 감소했으나, 양봉꿀벌에서 감소 폭이 더 컸다. 종 간 먹이활동 차이는 정오 무렵에만 나타났으며, 세력으로 보정하면 사라졌다. 꽃 방문 및 정상 수과 형성률로 측정한 화분매개 효율은 종 간 유의한 차이가 없었으나, 방문당 효율은 양봉꿀벌에서 다소 낮은 경향을 보였다. 화분매개 효율은 먹이활동과는 양의 상관을, 봉군 세력과는 음의 상관을 나타냈다. 이러한 결과는 재래꿀벌이 겨울철 봉군세력을 더 안정적으로 유지하면서도 유사한 화분매개 서비스 를 제공함을 보여주며, 온실 딸기 재배에서 대체 화분매개자로서의 잠재성을 뒷받침한다.

Hot pepper (Capsicum annuum L.) is a key vegetable crop in Ethiopia, significantly contributing to nutrition, income generation, and foreign currency earnings. However, its production faces ch allenges f rom pests and a shortage o f improved v arieties t h at o ffer acceptable y ields and quality. T his study aimed to identify varieties with higher green pod yields and quality. A field experiment was conducted at four agricultural research centers—Melkassa, Woramit, Debre Markos, and Wendogenet—and one commercial farm in Koka during 2021 and 2022. Six hot pepper genotypes (CCA-984-A, CCA-321, CCA-323, Mr. Lee no. 3 selex, Melka Awaze, and Chala) were evaluated using a Randomized Complete Block Design (RCBD) with three replications. The combined analysis of variance across locations and years revealed significant differences among the genotypes in both marketable and total yield. CCA-323 achieved the highest marketable pod yield at 225.72 q/ha, followed closely by the Chala check at 204.81 q/ha. A similar trend was noted for total green pod yield. The performance of the genotypes was highly significant (P<0.01) under both irrigation and rain-fed conditions. Additionally, significant differences genowere observed in various traits, including days to 50% flowering, plant height, plant width, pod weight per plant, pod length, pod diameter, and pod wall thickness. The CCA-323 genotype demonstrated an elongated pod shape, dark green color, smooth surface, high storability, and medium pungency, aligning well with consumer preferences in the green pod market. It proved to be a highly stable and high-yielding genotype. As a result, CCA-323 was released as ‘Koka-1’ for green pod production in the tested sites and similar agro-ecologies of Ethiopia. This variety is expected to enhance both the economic and nutritional value for hot pepper farmers and consumers and can serve as a parental line for future breeding programs.

This study examined the relationship between food safety culture and quality innovation performance within the food manufacturing industry, emphasizing the mediating role of organizational effectiveness. A conceptual framework was developed to define food safety culture across five sub-dimensions: executive leadership, employee engagement, communication, continuous improvement, and customer-focused orientation. Quality innovation performance was assessed in terms of quality improvement, customer satisfaction, and cost reduction. Additionally, organizational effectiveness, encompassing job satisfaction, organizational commitment, and innovation behavior, was also examined as a mediating variable between food safety culture and quality innovation performance. Survey data were collected from employees in food-related companies, and Structural Equation Modeling (SEM) was employed to empirically test the proposed relationships. The analysis reveals that food safety culture exerts a significant positive impact on quality innovation performance. Specifically, a strong food safety culture enhances quality innovation performance, both directly and indirectly, with the latter effect mediated through organizational effectiveness. These findings highlight the role of organizational effectiveness as a critical pathway through which food safety culture drives sustainable improvements in food manufacturing performance. This study offers both theoretical and practical contributions to the literature. From a theoretical perspective, this study advances the literature by linking food safety culture to quality innovation performance and organizational effectiveness, thereby deepening our understanding of how safety-oriented values and practices shape organizational performance. Practically, the results suggest that managers can improve quality and long-term competitiveness by fostering a strong food safety culture. Strategies such as reinforcing leadership commitment, encouraging employee participation, strengthening internal communication, promoting continuous improvement initiatives, and embedding customer-focused thinking are essential for institutionalizing a food safety culture into organizational routines. By implementing these strategies, companies can achieve both enhanced food safety while simultaneously strengthening long-term organizational sustainability.

The growing global demand for Agaricus bisporus has focused on automated harvesting systems, prompting the adoption of artificial intelligence to enhance precision and efficiency. This study aimed to prove the possibility of automated analysis for mushroom phenotypic traits including pileus diameter and color parameters (L*, a*, b*) by using AI model, YOLOv11-seg. Mushroom images were obtained in custom-designed imaging chamber and image training was processed using YOLOv11-seg. By achieving an mAP50 of 0.96, model demonstrated high detection and segmentation performance with stable predictive behavior. To evaluate biological validity, predicted phenotypic traits were compared with mechanically measured values. Pearson correlation coefficient analysis showed that the correlation coefficient for chromaticity was above 0.69, while the correlation coefficient for shoulder diameter was very low at 0.03. Linear regression analysis showed correlations above 0.69 for all phenotypic traits, indicating that the model analysis reflected the actual measurement variation well. Mean absolute error (MAE) analysis showed less than 10% error of 1.32, 2.43, 0.55, and 0.90 in pileus diameter, L*, a*, and b*, respectively, resulting in significant model accuracy. Based on these results, YOLO-based estimation of pileus area was processed to prove the model’s capacity to extract phenotypic traits beyond the limits of traditional analysis. These results indicate that AI models including YOLOv11 show the possibility of the automated growth monitoring for the next-generation smart cultivation systems.

This study aims to evaluate the high-precision positioning capability and lane-level localization accuracy of low-cost RTK-GNSS(Real- Time Kinematic Global Navigation Satellite System) technology. This study compares the positioning accuracy and lane-level localization performance of a low-cost RTK-GNSS module with those of a commercial high-precision receiver under identical conditions. Specifically, the root-mean-square, lateral offsets from HD-map(High-Definition Map) lane centerlines, and lane-change detection rates were evaluated to examine the applicability of the module to advanced mobility systems. Based on experiments conducted using a two-axis linear motion device and actual-vehicle tests on expressways, the low-cost RTK-GNSS module demonstrated precision positioning and lane-level localization comparable to that of a commercial high-precision receiver under the same test conditions. In the precision-positioning evaluation, the maximum positioning error of the low-cost module is approximately 2 cm, which is larger than that of a commercial receiver. Nevertheless, its average error generally remained within the typical range of 1–2 cm, which is the expected range for fixed RTK solutions in opensky environments. Furthermore, the difference in the lane-level localization accuracy between the low-cost and high-precision modules remained at approximately 1 cm. Although the low-cost RTK-GNSS module employs fewer receiver channels compared with commercial high-precision units, the integration of the RTK-OMEGA solution, which supports robust integer ambiguity resolution and is a key element of RTK correction, enables it to perform comparably to a commercial module under identical test conditions. The performance-evaluation indicators and methodologies presented herein are expected to provide a meaningful foundation for future studies aimed at ensuring the reliability and safety of cost-effective RTK-GNSS technologies.

This study develops a post-value for money (post-VfM) evaluation model for public–private partnership (PPP) road projects in Korea. Following the abolition of the minimum revenue guarantee system, the demand risk was transferred to the private sector, thus necessitating an unbiased and data-driven assessment under the new adjusted build-transfer-operate (BTO-a) framework. The proposed model extends the existing ex-ante VfM analysis by incorporating actual operational data and estimating government payments for both public-sector comparator and private finance initiative alternatives on a lifecycle cost basis. Using an actual BTO project restructured as BTO-a, the simulation shows that the post-VfM ratio increases from 23.5% to 37.9%, thus confirming fiscal efficiency and balanced risk sharing. This model enables feedback between planning and operation, supports transparent policy evaluation, and provides a foundation for sustainable PPP governance in future infrastructure projects.

As renewable energy penetration continues to increase, the output variability and forecasting uncertainty of photovoltaic generation have emerged as major operational risks in power systems. This study establishes a sensor-based data quality control procedure to ensure the reliability of meteorological data collected at a PV plant. For temperature, humidity, and wind speed, a four stage QC process physical range check, persistence check, step change check, and median filtering was applied. Solar radiation, which exhibits strong temporal and distributional characteristics, was processed using a three-stage QC procedure consisting of physical range, step change, and frequency distribution checks. Using the quality-controlled meteorological data, PV generation forecasting was performed with SVM and XGBoost models. As a result, the MAPE values improved to 6.32% for SVM and 6.08% for XGBoost after QC application. The findings confirm that meteorological data quality control significantly enhances PV forecasting accuracy and can support future strategies for distributed energy resource management, curtailment mitigation, and power system risk reduction.

본 연구는 발언행동이 직무성과에 미치는 영향을 규명하고, 이 관계에서 자기효능감의 매개효과와 개 인–직무 적합성(P–J fit)의 조절효과를 통합적으로 검증하였다. 사회적 인지이론과 적합성이론을 기반 으로, 구성원의 발언이 어떠한 심리적 과정을 통해 성과로 전환되며, 직무 환경과의 적합성이 이 전환 과 정의 강도를 어떻게 조절하는지를 이론적으로 조명하였다. 실증 분석을 위해 근로자와 직접 상사의 응답 을 매칭하여 자료를 수집하였으며, 위계적 회귀분석과 부트스트래핑 기반의 매개·조절 효과 분석을 통해 가설을 검증하였다. 분석 결과, 첫째, 발언행동은 직무성과에 유의한 정(+)의 영향을 미치는 것으로 나타 났다. 둘째, 자기효능감은 발언행동과 직무성과 간의 관계를 부분 매개하는 것으로 확인되어, 구성원이 발언을 통해 형성한 자신감과 문제해결 기대가 성과 향상으로 연결됨을 보여주었다. 셋째, 개인–직무 적 합성은 자기효능감이 직무성과에 미치는 영향을 조절하였으며, 직무가 개인의 능력·가치와 잘 부합할수 록 효능감이 성과로 이어지는 힘이 더욱 강화되는 것으로 나타났다. 넷째, 발언행동이 자기효능감을 거쳐 직무성과로 이어지는 간접효과 또한 P–J fit 수준에 따라 달라지는 조절된 매개효과로 유의하게 검증되 었다. 이러한 결과는 구성원의 발언행동이 단순한 의견 제시를 넘어, 심리적 자원과 직무 적합성이 결합될 때 조직 성과로 연결되는 복합적 작동 메커니즘을 지닌다는 점을 시사한다.

Purpose: This study examined the effects of a virtual reality (VR)-based self-directed practice program for indwelling catheterization on the practice immersion, performance confidence, and practice satisfaction of nursing students. Methods: A quasi-experimental study employing a non-equivalent control group pretest–posttest design was conducted with 59 nursing students. The experimental group (n = 26) performed VR-based, self-directed practice, while the control group (n = 33) conducted conventional mannequin-based practice. Data were analyzed using generalized estimating equations, independent t-test and the Mann–Whitney U test. Results: A significant group-by-time interaction effect was observed for performance confidence (Waldχ² = 6.88, p = .009), indicating a greater improvement in the experimental group. Practice immersion was significantly higher in the experimental group than in the control group (t = 2.31, p = .025). However, no significant difference was observed in practice satisfaction between the groups (Z = -0.07, p = .944). Conclusion: The VR-based self-directed practice program effectively enhanced performance confidence and practice immersion of nursing students. VR simulation is recommended as a valuable educational strategy to complement conventional mannequin-based practice in self-directed learning environments.

This study experimentally evaluated the flexural behavior of reinforced concrete (RC) beams incorporating a high-performance cementitious composite (VC) with 1.0 vol.% Vectran fibers. Three-point bending tests were conducted on a reference high-strength concrete beam (RCB) and two VC beams (VCB-1, VCB-2). Compared with RCB, the maximum load increased by +19.8% (VCB-1) and +9.0% (VCB-2), while the yield load rose by +18.9% and +16.0%, respectively. The ductility index (Δu/Δy) improved from 1.89 (RCB) to 5.22 (VCB-1), confirming the crack control effect based on multiple micro-cracking. The improved performance indicates not only enhanced flexural capacity and ductility but also suggests the potential for carbon-neutral structural design through material reduction and service-life extension enabled by the Vectran fiber-reinforced composite system.

본 연구는 도심 차량 방호용 볼라드의 기초 치수와 형상이 충돌 성능에 미치는 영향을 평가하였다. 1,500 kg 승용차 30 km/h 의 속도로 정면충돌 시험에서 현행 200-200-250 mm 독립기초는 전도 및 이탈이 발생했고 차량 감속은 미미하였다. 이를 바탕으로 LS-DYNA 모델을 검증하고, 정사각 기초의 치수(200–700) 및 동일 면적 원형과 정사각형 기초 비교해석을 수행하였다. 결과적으로 기초의 치수가 커질수록 감속률이 증가했으며 700-700-250의 기초에서 60%의 감속(잔류 12 km/h)이 확인되었다. 동일 면적 비교에 서 정사각형 기초가 원형 기초보다 우수하였고, 이는 측면 접촉면 증가와 회전 저항 증대에 기인한다. 현행 국내 볼라드는 기존 관행만으 로 요구되는 성능을 충족하기 어려운 실정이다. 본 연구는 국내 도심 조건에서 볼라드 독립기초의 치수와 형상에 따른 차량 감속 특성을 정량적으로 제시하였으며, 향후 볼라드 기초 설계 기준 및 방호 성능 평가 체계를 정립하는 데 활용가능한 기초자료를 제공한다.

본 연구에서는 그래핀 나노플레이트(GNPs)가 혼입된 모르타르의 기계적 및 전기적 특성을 보통 포틀랜드 시멘트(OPC)와 비교하여 체계적으로 분석하였다. 시멘트 대비 0.1 wt.%의 GNPs를 첨가한 결과, 28일 양생 시 압축강도가 약 12% 증가하였으며, 7일 초기 재령에서 휨강도는 약 50% 향상되었다. 또한 GNPs가 혼입된 모르타르는 연속적이고 균일한 전도성 네트워크를 형성하여, OPC에 비해 약 49% 높은 전기전도도를 나타냈다. 열중량-미분열중량(TG–DTG) 분석 결과, GNPs의 도입이 핵생성 부위를 증가시키 고 C–S–H(Calcium Silicate Hydrate) 구조 생성을 촉진함으로써 시멘트의 수화 반응 속도를 향상시키는 것으로 확인되었다. 이러한 결과는 GNPs가 수화 반응 촉진과 미세균열 가교(micro-crack bridging) 역할을 통해 모르타르의 기계적 특성을 개선함과 동시에, 재료를 반도전성 복합체(semi-conductive composite)로 전환시킨다는 것을 보여준다.

This paper proposes an Adjustable Circular Steel Connector(ACS) to enable immediate response to construction errors that may occur during the on-site assembly of modular members. To evaluate its flexural performance, one rectangular steel tube beam specimen without ACS and three specimens with ACS(with varying ACS lengths) were fabricated. Experimental results showed no pull-out occurred between Shank A and Shank B, and the application of ACS facilitated stress distribution in the rectangular steel tube. The specimens with ACS exhibited up to 92% of the maximum load capacity of the monolithic specimen, and showed increasingly ductile behavior as the ACS length increased. Due to the cross-sectional difference between Shank A and Shank B within the ACS, yielding was observed in Shank B. Further studies are needed on this part, as well as on the behavior of the ACS under cyclic loading conditions.

In this study, a new Lattice integrated Rib-Type Deck Plate system is proposed to enhance the flexural stiffness and strength. This system integrated a rib-type corrugated deck with a steel wire lattice designed for short spans, which is placed on top of the corrugated deck. To validate the flexural performance of the proposed system, experimental programs were conducted for both the construction stage and the composite stage. Construction stage test results showed that all specimens exhibited deflections less than 13mm under the construction load, satisfying the maximum deflection limit of 19mm. Composite stage test results indicated that increasing the amount of tension and compression reinforcement led to improvements in initial stiffness, yield strength, and maximum strength. Furthermore, specimens with reinforcement in the compression zone demonstrated superior ductility. The flexural strength of all tested specimens was confirmed to be safely evaluated by the flexural strength equation specified in the Korea Design Standard.

본 연구는 철근 부식 문제의 대안으로 주목받는 섬유보강폴리머(FRP) 보강 콘크리트 구조물의 성능을 통합적으로 평가하고 최적 설계 기준을 제시하기 위해 메타분석을 수행하였다. 부착, 휨, 압축 성능을 다룬 선행 연구 6편에서 도출된 355개의 정량적 데이 터 셋을 종합하여, 개별 연구에서는 파악하기 어려운 설계 변수 간의 상호작용과 성능의 임계 조건을 규명하였다. 분석 결과, 특정 조건에서 FRP 보강 부재의 성능이 오히려 철근콘크리트(RC)보다 저하되는 ‘성능 전이 현상’을 최초로 정량화하였다. 휨 부재에서는 보강비(ρ)에 따라 요구되는 최소 탄성계수(      )를, 압축 부재에서는 RC 대비 성능 우위를 확보하기 위한 임계 보강비 (  )와 최소 콘크리트 강도(  40MPa)를 제시했다. 또한, 기둥의 취성파괴 위험을 설계 초기 단계에서 정량적으로 평가할 수 있는 ‘취성파괴 위험지수(BFRI)’를 개발하여 안전성 검증을 위한 새로운 척도를 제안했다. 본 연구의 성과는 기존의 정성적 지침을 넘어, 실무 설계자가 FRP의 성능을 극대화하고 취성파괴 위험을 체계적으로 관리할 수 있는 정량적 설계 프레임워크를 제공한다는 점에서 중요한 의의를 가진다.

Recently, fire evacuation problems in high-rise buildings have been increasing due to increased occupant density and limited evacuation routes, leading to increased casualties. To address this issue, this study proposes a distributed evacuation performance evaluation method that considers floor-by-floor distribution ratios. Using FDS+EVAC-based simulations, various floor-by-floor distribution scenarios were designed and their impact on evacuation times and bottlenecks was quantitatively analyzed. The results confirmed that rationally adjusting the floor-by-floor exit and elevator utilization ratios shortened overall evacuation times and reduced congestion in specific areas. This method can serve as a foundation for establishing evacuation plans and fire safety design standards for high-rise buildings.

This study focuses on the issue of premature failure in patched sections of asphalt concrete overlays during the service life of existing concrete slabs. These failures are typically exacerbated by extreme weather and heavy traffic. To overcome the low durability and moisture susceptibility of conventional patching materials, the applicability of the GA (Guss Asphalt) mixture, which is known for its excellent waterproofing and adhesion properties, was investigated. Additionally, the fundamental performance characteristics of GA, including its initial stability, moisture resistance, porosity, and plastic-deformation resistance, were evaluated. In this laboratory study, the stability, flow value, and porosity (V a) of six types of pavement patch materials (including GA/MA (Mastic Asphalt), HMA (Hot Mix Asphalt), and CMA (Cold Mix Asphalt) mixtures) were evaluated under various initial curing conditions (3–48 h) and environmental conditions (air and water at 25 °C). Additionally, a wheel tracking test was performed in air conditions at 25 °C to compare and analyze the dynamic stability and plastic-deformation resistance. The results show that GA exhibited the highest stability under all conditions. Its stability increased significantly after 48 h of curing in water, thus demonstrating its superior moisture resistance compared with that of HMA, whose stability decreased significantly. Porosity analysis indicates that the GA/MA mixtures (GMA, PMA, and PGMA) exhibited low porosity (< 1%) and high saturation (> 97%), thus confirming a dense pore structure. Furthermore, the results of the wheel tracking test show that the HMA and GA mixtures exhibited the highest dynamic stability under both 24- and 48-h curing durations. In particular, the GA mixture showed the smallest rutting depth (0.9–1.0 mm), thus indicating its superior resistance to plastic deformation. By contrast, the CP-A mixture showed the largest rutting depth (32.5–38.4 mm), thus indicating the greatest susceptibility to plastic deformation, whereas the CP-B mixture exhibited relatively stable performance with a rutting depth of 5.4–5.6 mm. In general, the GA/MA mixtures exhibited the best performance in terms of long-term stability (48 h of curing), moisture resistance, and plastic-deformation resistance compared with conventional HMA and CMA (CP-A and CP-B) mixtures. GA mixtures are considered the optimal alternative for road patching and repair owing to their excellent moisture resistance and plastic-deformation resistance at 25 °C. However, their field application requires consideration of various environmental conditions, thus necessitating further comprehensive investigations into their crack resistance, adhesion, and plastic-deformation behavior.