Urban traffic congestion continues to intensify owing to rapid urbanization and growing vehicle ownership, highlighting the limitations of fixed-time signal control systems. This paper proposes a real-time traffic signal optimization framework that integrates drone-based object detection and tracking with a genetic algorithm and rolling horizon structure. Traffic data were collected at the Hakha intersection in Daejeon, South Korea, using DJI M300 RTK and Mavic 3E drones during the evening peak hours. Vehicle detection and tracking were performed using YOLOv8n and ByteTrack, achieving an average detection accuracy of 88–98% for the total approach volume and 84–94% for the through-movement volume. The extracted traffic parameters (volume, delay, and queue length) were incorporated into a multi-objective fitness function with weights determined via the analytic hierarchy process. The optimized signal plans were validated using VISSIM microsimulation against a fixed-time baseline. Results show that the proposed framework reduced the average vehicle delay by 31.4% (37.91 to 25.99 sec/veh), stop delay by 37.1%, and average queue length by 34.8% (8.41 to 5.48 m), while improving the intersection level of service from D to C without sacrificing network throughput. This study demonstrated the practical feasibility of an integrated framework combining drone-based mobile sensing and metaheuristic optimization for real-time adaptive signal control.
This study proposes a distributed integrated control architecture based on Direct Digital Control(DDC) as an alternative to conventional centralized Distributed Control System(DCS) structures for a Canadian oil sands pilot plant, and theoretically analyzes its control characteristics and operational optimization potential. The target process consists of production and circulation, separation, water treatment, partial upgrading, and utility systems, and exhibits complex characteristics such as multiphase flow, high viscosity, time delay, strong coupling, and operation under extreme environmental conditions. In this study, an integrated control architecture combining independent DDC nodes for each process unit with a supervisory control layer is presented. A control model considering the coupling relationships among production, separation, water treatment, and upgrading processes is formulated, along with an objective function for energy optimization. Furthermore, through literature-based comparison and system architecture analysis, it is demonstrated that the DDC-based structure is suitable for oil sands pilot plants in terms of responsiveness, scalability, fault isolation, and energy efficiency.
This study proposes an automated torch angle and position adjustment mechanism for three-dimensional curved-surface welding in shipbuilding. Designed to replace manual operations, the mechanism actively responds to the relative angle between the base plate and stiffener, enabling simultaneous control of torch orientation and positioning using a single power source. The system is integrated into a tracker consisting of a pinion-sector gear assembly for angle adjustment and a cam mechanism for position control. Dynamic simulations confirmed that the torch stably follows the stiffener angle across varying welding speeds, with smooth compensatory motion between the carriage and tracker. Furthermore, a motor-torque-based PID control was implemented, maintaining the torch angle error within 0.23° and the wire tip position error within 0.02 mm. These results verify that the proposed mechanism is highly effective for the automated welding of complex curved structures.
This study proposes a dynamic evaluation framework for diagnosing signal control adequacy using high-resolution Automated Traffic Signal Performance Measures (ATSPM) data. Traditional signal performance assessments have primarily relied on aggregated metrics, such as average delay and volume-to-capacity ratio, which are effective for evaluating overall operational efficiency but insufficient for capturing cycle-level control limitations and temporal variability. Although split failure-based measures, including the Split Failure Ratio (SFR), provide more direct insights into green time adequacy, most existing applications focus on the failure frequency within a fixed analysis period. To address this limitation, this study introduces a Dynamic Operational Strain (DOS) index that extends the split failure into a time-evolving state variable incorporating accumulation and recovery mechanisms. By modeling the recursive evolution of the operational strain, the proposed framework captures how often failures occur and how they persist or dissipate over time. Phase-level DOS measures are subsequently aggregated at the intersection level to derive a priority score reflecting structural control inadequacy. The framework is further applied to classify intersections using DOS–SFR quadrant analysis, enabling the identification of distinct operational patterns, such as persistent oversaturation, localized phase imbalance, intermittent strain accumulation, and stable control conditions. The results demonstrate that intersections with similar SFR values may exhibit substantially different temporal strain structures, highlighting the importance of a dynamic state-based evaluation. The proposed approach provides a diagnostic foundation for data-driven signal re-timing and future adaptive control strategies by shifting the signal performance assessment from static frequency-based measures to dynamic structural adequacy analysis.
Background: Lumbar Joint Mobilization (LJM) applies rhythmic forces to lumbar joints to improve mechanics and pain. Recent evidence suggests potential benefits for somatosensory input and postural control, though direction-specific effects remain unclear. Objectives: To investigate short-term effects of LJM on standing stability and trunk control through pre-post intervention comparison. Design: Quasi-experimental study. Methods: Twenty-five participants were randomized to experimental (n=13) or control (n=12) groups. Single-leg balance was assessed using force platform measurement with eyes open/closed conditions. The experimental group received Maitland-technique LJM including spinal compression, lateral compression, transverse process mobilization, rotational oscillation, and traction. Balance parameters included medio-lateral standard deviation (ML-SD), anteroposterior standard deviation (AP-SD), sway area, and path length. Results: The experimental group demonstrated significant medio-lateral stability enhancement (64% ML-SD reduction, P =0.003) with significant group×time interaction (F=4.20, P=0.043, η²p=0.044). Sway area decreased by 67% and path length showed large effect size (d=1.19, P<0.001). Improvements occurred in both visual conditions without increased visual dependence (stable Romberg Quotient), indicating somatosensory-driven enhancement. Machine learning classification achieved near-perfect accuracy (AUC=1.000). Conclusion: LJM produces immediate, direction-specific improvements in lateral trunk control through enhanced somatosensory feedback. Larger trials with long-term follow-up are needed to confirm sustained benefits.
목적 : 본 연구는 성장기 아동을 대상으로 주변부 디포커스 렌즈와 단초점 렌즈의 1년 추적 결과를 비교하여 근시 진행 억제 효과를 평가하고, 굴절력과 각막곡률 기반 예측 안축장을 통해 근시 진행의 구조적 원인을 분석하고자 하였다. 방법 : 본 연구는 만 6–12세 근시 아동을 대상으로 단초점 렌즈 착용군과 주변부 디포커스 렌즈 착용군으로 무 작위 배정하여 1년간 추적 관찰한 비교 연구이다. 굴절력(SE)과 평균 각막곡률(Ave K)은 자동굴절검사 및 자각적 굴절검사를 통해 측정하였으며, 안축장은 Kim 등이 제시한 예측 공식(AL = 24 × AveK / 7.8 − 0.4 × SE)을 사용하여 산출하였다. 군 내 변화는 대응표본 t-검정, 군 간 비교는 독립표본 t-검정을 실시하였으며, 유의수준은 p<0.05로 설정하였다. 결과 : 1년 추적 관찰 결과, 두 군 모두에서 등가구면굴절력(SE)은 유의하게 근시 방향으로 진행하였다(p< 0.001). 평균 각막곡률(Ave K)은 두 군 모두 유의한 변화가 없었다(p<0.05). 반면 안축장은 두 군 모두에서 유의 하게 증가하였으나(p<0.001), 단초점군의 증가 폭이 마이오군보다 더 크게 나타났다. 계산식 기반 예측 안축장 또 한 마이오군에서 유의하게 낮은 증가량을 보였다(p<0.01). 결론 : 본 연구는 성장기 아동에서 주변부 디포커스 렌즈가 단초점 렌즈에 비해 근시 진행과 안축장 증가를 유 의하게 억제함을 확인하였다. 근시 진행은 각막곡률의 변화보다는 안축장 성장에 기인하는 것으로 나타났으며, SE 와 Ave K를 활용한 예측 안축장 모델 또한 임상적 추적 지표로 활용 가능함을 시사한다. 이는 실제 임상 환경에서 근시 관리 전략 수립에 유용한 근거를 제공한다.
Amid intensifying great-power competition over critical minerals, rare earth elements have become increasingly significant as strategic resources. In recent years, drawing on its structural advantages in the rare earth industry while responding to growing external constraints, China has gradually strengthened its rare earth export controls, attracting widespread international attention regarding the motivations and implications of these policies. Taking rare earth export controls as the analytical entry point, this study develops a Structure–Mechanism– Outcome framework to examine the policy logic underlying these measures from the dual perspective of structural advantages and constraints. The study finds that China’s tightening of rare earth export controls since 2023 should not be understood as a short-term retaliatory measure, but rather as an economic statecraft practice characterized by institutionalization and a defensive orientation, rooted in China’s structural advantages in the rare earth supply chain. Institutionalization is reflected in cross-ministerial coordination and the expansion of control targets from raw materials to technologies and key segments of the supply chain. The defensive orientation is manifested in the use of rule-based policy instruments—such as export licensing and control lists—to manage the cross-border flow of rare earth resources rather than imposing comprehensive trade restrictions. This analysis contributes to a deeper understanding of the policy logic and broader implications of critical mineral governance in the context of great-power competition.
Odor emissions from sewer systems are a persistent environmental concern in urban areas, particularly in combined sewer systems where septic tanks are widely used. However, the contribution of septic tanks as sources of sewer odor has not been sufficiently quantified. This study investigated the characteristics of hydrogen sulfide (H2S) generation in septic tanks and evaluated its potential influence on sewer odor, as well as the effectiveness of odor mitigation technologies. Field investigations were conducted in combined sewer areas to measure aqueous H2S concentrations in septic tanks. The results showed that H2S concentrations in septic tanks were not significantly affected by septic tank capacity (ANOVA, p > 0.05), suggesting that tank size or user population is not a primary determinant of sulfide generation. In contrast, aqueous H2S exhibited a positive correlation with chemical oxygen demand (COD), indicating that organic matter availability plays an important role in sulfide production through microbial sulfate reduction processes. A significant relationship was observed between aqueous H2S in septic tanks and gaseous H2S measured at catch basins, demonstrating that sulfide derived from septic tanks can transfer to the sewer atmosphere and potentially impact human odor exposure in urban environments. In addition, the performance of odor control technologies applied to septic tanks was evaluated with aeration-based technologies found to significantly reduce H2S concentrations. These findings suggest that septic tanks can serve as important sources of sewer odor highlighting the need for effective management and proper operation of septic tank odor control systems in combined sewer areas.
본 논문은 펫 휴머니제이션 현상으로 펫푸드 시장이 질적으로 고도화되었음에도, 불구하고, 여전히 「사료관 리법」상 축산 생산 수단적 관점에 머물러 있는 현행 관 리 체계의 한계를 조명하고 실증적인 물성 표준화 방안 을 제시하고자 수행되었다. 우선 KS H 4897 및 법정 관 리 체계와의 비교·분석을 통해 펫푸드 물성 규격화의 제 도적 미비점을 규명하였다. 또한, 반려견 보호자 71명을 대상으로 시행한 설문조사 결과, 응답자의 97.0%가 제품 구매 시 물성을 주요하게 고려하나 54.0%는 제조사별 다 른 마케팅 용어로 인해 선택의 어려움을 겪고 있음을 확 인하였다. 특히 단단한 제형으로 인한 치아 및 잇몸 손상 경험(15.0%)과 습식 급여 중 사레 경험(46.0%) 등 실질적 인 급여 안전사고 실태를 통해 정량적 지표 도입의 당위 성을 확보하였다. 이를 바탕으로 반려견의 해부학적 구조 와 체급별 치악력 등 수의학적 근거를 반영하여 유동식 부터 고강직식까지 아우르는 5단계의 ‘반려견 Texture-Code’를 도출하였다. 본 논문은 영양 성분에 치 중되었던 기존 품질 관리 패러다임을 물리적 섭식 안전 분야로 확장하고, 향후 반려동물의 지위 변화를 반영한 선진적 사료 관리 체계 수립을 위한 기초 자료를 제공한 다는 점에서 학술적·제도적 의의를 지닌다.
영구자석 선형 전동기인 VCM(Voice coil motor)은 직접 구동 방식의 액츄에이터로 기어나 변속장치가 필요 없어 높은 정밀도 를 가지고 구조적인 특성상 기계적 마찰이 적어 소음이 발생하지 않는 장점을 가지고 있다. 아울러 회전운동을 직선 운동으로 변환하기 위한 별도의 장치가 필요하지 않고, 구동부가 가벼워 응답속도가 빠른 특징이 있다. 본 연구에서는 이러한 VCM을 다양한 산업 분야에 적용하기 위한 기초연구로 VCM의 속도제어를 위해 PSO(Pariticle swarm optimization) 기법을 적용하여 제어기의 유용성 평가를 위한 수 치 시뮬레이션을 수행하였다. 제어계는 전류와 속도 제어를 위한 이중 루프로 구성하였고, 각각의 제어 루프에는 PI 제어기를 적용하여 속도 목표치에 추종하는 출력값을 얻기 위한 제어기를 설계하였다. 제어기 파라미터 추정에는 PSO기법을 적용하였고, 제어기의 유용성 을 검증하기 위해 주파수 영역에서의 모델매칭기법을 적용한 제어 기법과의 제어 결과를 비교하였다. 두 가지 제어 기법은 MATLAB을 이용하여 수치 시뮬레이션을 수행했고, 제어 결과는 IAEU(Integral of absolute error units) 평가 지수를 이용하여 비교하였다. 수치 시뮬레 이션 결과 제안한 제어 기법의 유용성을 확인할 수 있었다.
도시 불투수 지역에서 발생하는 초기 강우 유출수는 고농도의 비점오염물질을 단기간에 하천으로 유입시켜 수질 악화를 초래한다. 본 연구에서는 우수받이 및 맨홀에 설치 가능한 다단 폴리프로필렌 섬유 여과장치를 개발하고, 실험실 및 현장자료를 기반으로 오염물질 제거 효율을 평가하였다. 섬유 여재 조합 실험을 통해 53 μm, 20 μm, 10 μm 구성의 3단 여과가 TSS, TN, TP 제거에 가장 효과적인 것으로 나타났다. 현장 초기유출수 분석 결과, 평균 제거 효율은 TSS 79.7%, TN 31.6%, TP 43.1%로 확인되었다. 또한 SWMM을 이용하여 학사마을 도시유역에 적용 시 25%, 50%, 100% 설치비율에 대해 TSS 47.3∼99.2%, TN 21.6∼49.4%, TP 23.6∼67.7%의 저감효과가 모의되었다. 본 연구의 결과는 공간 제약이 큰 도시지역에서 초기세척효과(first flush)를 제어하기 위한 실용적인 비점오염 관리기술로서 활용 가능성을 제시한다.
최근 인테리어 디자인 플랫폼들이 AR 및 3D 렌더링 기술을 빠르게 도입하고 있으나, 기 존 온라인 시뮬레이터와 AR 서비스가 제공하는 조명 미리보기 기능은 광학 효과가 반영되 지 않아 실제 공간의 분위기를 체감하는 데 한계가 있다. 본 논문에서는 이러한 현실감의 격차를 해소하기 위해 AI 기반 2D 실내 리라이팅 시스템을 제안한다. 제안한 시스템은 이 미지 전체의 스타일을 변환하는 대신 실제 조명 기구 위치에 광원을 적용하는 조명 기구 기반 리라이팅을 수행하며, 사용자 경험 향상을 위해 다중 색상 조명 변경을 지원한다. Latent-Intrinsics와 확산 모델을 기반으로 램프 객체에 특화되도록 U-Net의 Cross-attention을 미세 조정하고, 안정적인 색상 주입을 위해 학습된 ControlNet과 Color Adaptor를 적용하였다. 실험 결과, 기존 베이스라인 모델 대비 우수한 색상재현력과 RMSE와 LPIPS 성능이 약 2.5배, SSIM은 약 1.2배 향상되었다. 연구 결과는 AR 기반 인테리어 서비 스를 위한 정교한 조명 미리보기 기술로 활용되기를 기대한다.
이 논문에서는 강화학습 기반 제어기와 전통적인 제어기를 동일한 조건에서 비교함으로써 구조 진동 제어 문제에서 강화학습 제 어기의 성능 특성과 한계를 규명하는 것을 목적으로 한다. 가장 단순한 비선형 제어로서 단자유도 가변 강성 시스템을 대상으로 심층 결정적 정책 경사(DDPG) 기반의 강화 학습 제어기를 설계하고, bang-bang 제어 및 제한 최적 제어와의 성능 비교를 수행하였다. 자유 진동 및 El Centro 지진 가속도에 의한 강제 진동 조건에서 공칭 성능과 센서 잡음이 존재하는 경우의 강인 성능을 분석하였다. 그 결 과, 강화학습 제어기는 자유 진동 조건에서 우수한 강인 성능을 보였으나, 강제 진동 제어에서는 기존 제어기를 일관되게 상회하지는 못하였다. 이 연구는 동일한 보상 함수와 시스템 조건 하에서 강화학습 기반 진동 제어의 실질적 기여와 적용상의 한계를 기초적으로 제시하였다.
In this study, a particle shape control process was developed to fabricate flake-like SUS316L powders about 20 μm for application in semiconductor gas filters. The Flake powder was produced through a wet milling process using a Planetary Mill by varying the rotation speed, milling time, solvent, and polyvinylpyrrolidone (PVP) dispersant conditions. The fabricated powders were then characterized to evaluate their morphological and phase transformation behaviors. In the ethanol-based Planetary Milling process, as the rotation speed increased from 300, 400, 500 rpm, the powder morphology was observed to gradually change from spherical to flake-like due to the increase in milling energy. According to the XRD, as the rotation speed increased, a phase transformation from austenite to martensite occurred due to the increase in heat generation and collisions between the powder and balls. In addition, an increase in Full Width at Half Maximum (FWHM) was observed, indicating a decrease in crystallinity. Under different solvent and dispersant conditions, the addition of 5 wt% PVP to the deionized water (DI Water) solvent suppressed particle fracture and produced more uniform flake-like particles compared with the DI Water process without PVP. In addition, a smaller FWHM and reduced oxygen content were observed.
Background: Lumbar radiculopathy caused by disc herniation is frequently accompanied by pain, functional disability, and impairments in sensorimotor control, including reduced proprioception and altered motor control. Interventions that integrate neural and mechanical components may enhance rehabilitation outcomes beyond exercise alone. Objectives: To investigate the effects of manual therapy combined with neurodynamic exercise and motor control exercise (MTN) with motor control exercise alone (MCE) on lumbar proprioception, motor control, and functional disability in patients with lumbar radiculopathy. Design: Randomized, single-blind clinical trial. Methods: Thirty patients with lumbar radiculopathy due to L4–S1 disc herniation were randomly assigned to either the MTN group or the MCE group. Both groups participated in supervised interventions three times per week for six weeks. The MTN group received lumbar joint mobilization and slider-based neurodynamic mobilization integrated with motor control exercise, whereas the MCE group performed motor control exercise only. Lumbar proprioception was assessed using joint position error during trunk flexion and extension. Motor control was evaluated using pressure biofeedback–based abdominal drawing- in performance. Functional disability was assessed using the Korean version of the Oswestry Disability Index. Outcomes were measured at baseline and during follow-up. Results: Significant group-by-time effects were observed for lumbar joint position error, motor control outcomes, and functional disability. The MTN group demonstrated earlier and greater improvements across all outcome measures compared with the MCE group, whereas improvements in the MCE group were more gradual. Conclusion: Compared with motor control exercise alone, the addition of manual therapy and neurodynamic exercise resulted in superior improvements in lumbar proprioception, motor control, and functional disability. An integrated MTN approach may be an effective rehabilitation strategy for patients with lumbar radiculopathy.