Dynamic Vehicular Route Guidance Using Traffic Prediction Information

We propose a dynamic vehicular routing algorithm with traffic prediction for improved routing performance. The primary idea of our algorithm is to use real-time as well as predictive traffic information provided by a central routing controller. In order to evaluate the performance, we develop a microtraffic simulator that provides road networks created from real maps, routing algorithms, and vehicles that travel from origins to destinations depending on traffic conditions. The performance is evaluated by newly defined metric that reveals travel time distributions more accurately than a commonly used metric of mean travel time. Our simulation results show that our dynamic routing algorithm with prediction outperforms both Static and Dynamic without prediction routing algorithms under various traffic conditions and road configurations. We also include traffic scenarios where not all vehicles comply with our dynamic routing with prediction strategy, and the results suggest that more than half the benefit of the new routing algorithm is realized even when only 30% of the vehicles comply

X-ray studies of the pulsar PSR J1420-6048 and its TeV pulsar wind nebula in the Kookaburra region

We present a detailed analysis of broadband X-ray observations of the pulsar PSR J1420-6048 and its wind nebula (PWN) in the Kookaburra region with Chandra, XMM-Newton, and NuSTAR. Using the archival XMM-Newton and new NuSTAR data, we detected 68 ms pulsations of the pulsar and characterized its X-ray pulse profile which exhibits a sharp spike and a broad bump separated by ~0.5 in phase. A high-resolution Chandra image revealed a complex morphology of the PWN: a torus-jet structure, a few knots around the torus, one long (~7') and two short tails extending in the northwest direction, and a bright diffuse emission region to the south. Spatially integrated Chandra and NuSTAR spectra of the PWN out to 2.5' are well described by a power law model with a photon index ${\Gamma} {\approx}$ 2. A spatially resolved spectroscopic study, as well as NuSTAR radial profiles of the 3--7 keV and 7--20 keV brightness, showed a hint of spectral softening with increasing distance from the pulsar. A multi-wavelength spectral energy distribution (SED) of the source was then obtained by supplementing our X-ray measurements with published radio, Fermi-LAT, and H.E.S.S. data. The SED and radial variations of the X-ray spectrum were fit with a leptonic multi-zone emission model. Our detailed study of the PWN may be suggestive of (1) particle transport dominated by advection, (2) a low magnetic-field strength (B ~ 5${\mu}$G), and (3) electron acceleration to ~PeV energies.Comment: 18 pages and 8 figures. Accepted for publication in Ap

A broadband X-ray study of the Rabbit pulsar wind nebula powered by PSR J1418-6058

We report on broadband X-ray properties of the Rabbit pulsar wind nebula (PWN) associated with the pulsar PSR J1418-6058 using archival Chandra and XMM-Newton data, and a new NuSTAR observation. NuSTAR data above 10 keV allowed us to detect the 110-ms spin period of the pulsar, characterize its hard X-ray pulse profile, and resolve hard X-ray emission from the PWN after removing contamination from the pulsar and other overlapping point sources. The extended PWN was detected up to $\sim$20 keV and is well described by a power-law model with a photon index $\Gamma\approx$2. The PWN shape does not vary significantly with energy, and its X-ray spectrum shows no clear evidence of softening away from the pulsar. We modeled the spatial profile of X-ray spectra and broadband spectral energy distribution in the radio to TeV band to infer the physical properties of the PWN. We found that a model with low magnetic field strength ($B\sim 10$ $\mu$G) and efficient diffusion ($D\sim 10^{27}$ cm$^2$ s$^{-1}$) fits the PWN data well. The extended hard X-ray and TeV emission, associated respectively with synchrotron radiation and inverse Compton scattering by relativistic electrons, suggests that particles are accelerated to very high energies ($\gtrsim500$ TeV), indicating that the Rabbit PWN is a Galactic PeVatron candidate.Comment: 21 pages, 10 figures. ApJ accepte

Heterogeneity of Skin Surface Oxygen Level of Wrist in Relation to Acupuncture Point

The distribution of partial oxygen pressure (pO2) is analyzed for the anterior aspect of the left wrist with an amperometric oxygen microsensor composed of a small planar Pt disk-sensing area (diameter = 25 μm). The pO2 levels vary depending on the measurement location over the wrist skin, and they are systematically monitored in the analysis for both one-dimensional single line (along the wrist transverse crease) and two-dimensional square area of the wrist region. Relatively higher pO2 values are observed at certain area in close proximity to the position of acupuncture points with statistical significance, indicating strong relationship between oxygen and acupuncture point. The used oxygen microsensor is sensitive enough to detect the pO2 variation depending on the location. This study may provide information helpful to understand possible physiological roles of the acupuncture points

Deep Learning-based Synthetic High-Resolution In-Depth Imaging Using an Attachable Dual-element Endoscopic Ultrasound Probe

Endoscopic ultrasound (EUS) imaging has a trade-off between resolution and penetration depth. By considering the in-vivo characteristics of human organs, it is necessary to provide clinicians with appropriate hardware specifications for precise diagnosis. Recently, super-resolution (SR) ultrasound imaging studies, including the SR task in deep learning fields, have been reported for enhancing ultrasound images. However, most of those studies did not consider ultrasound imaging natures, but rather they were conventional SR techniques based on downsampling of ultrasound images. In this study, we propose a novel deep learning-based high-resolution in-depth imaging probe capable of offering low- and high-frequency ultrasound image pairs. We developed an attachable dual-element EUS probe with customized low- and high-frequency ultrasound transducers under small hardware constraints. We also designed a special geared structure to enable the same image plane. The proposed system was evaluated with a wire phantom and a tissue-mimicking phantom. After the evaluation, 442 ultrasound image pairs from the tissue-mimicking phantom were acquired. We then applied several deep learning models to obtain synthetic high-resolution in-depth images, thus demonstrating the feasibility of our approach for clinical unmet needs. Furthermore, we quantitatively and qualitatively analyzed the results to find a suitable deep-learning model for our task. The obtained results demonstrate that our proposed dual-element EUS probe with an image-to-image translation network has the potential to provide synthetic high-frequency ultrasound images deep inside tissues.Comment: 10 pages, 9 figure

A Novel Incisionless Disposable Vaginal Device for Female Stress Urinary Incontinence: Efficacy and Quality of Life

Purpose This clinical study sought to evaluate the possible clinical effectiveness and practicality of URINO, an innovative, incisionless, and disposable intravaginal device, designed for patients suffering from stress urinary incontinence. Methods A prospective, multicenter, single-arm clinical trial was carried out, involving women diagnosed with stress urinary incontinence who used a self-inserted, disposable intravaginal pessary device. Comparisons were made between the results of the 20-minute pad-weight gain (PWG) test at baseline and visit 3, where the device was applied. After 1 week of device usage, compliance, satisfaction, the sensation of a foreign body, and adverse events were assessed. Results Out of 45 participants, 39 completed the trial and expressed satisfaction within the modified intention-to-treat group. The average 20-minute PWG of participants was 17.2±33.6 g at baseline and significantly dropped to 5.3±16.2 g at visit 3 with device application. A total of 87.2% of participants exhibited a reduction ratio of PWG by 50% or more, surpassing the clinical trial success benchmark of 76%. The mean compliance was recorded as 76.6%±26.6%, the average visual analogue scale score for patient satisfaction was 6.4±2.6, and the sensation of a foreign body, measured on a 5-point Likert scale, was 3.1±1.2 after 1 week of device use. No serious adverse events were reported; there was 1 instance of microscopic hematuria and 2 cases of pyuria, all of which recovered. Conclusions The investigated device demonstrated significant clinical effectiveness and safety for patients with stress urinary incontinence. It was easy to use, showing favorable patient compliance. We propose that these disposable intravaginal pessaries could potentially be an alternative treatment for patients with stress urinary incontinence who are seeking nonsurgical options or are unable to undergo surgery. Trial Registration The study was registered as a clinical trial (KCT0008369)

운영 효율과 자율 복원력을 위한 열차 제어 시스템

Resilient CPS framework, resilient CPS testbed, virtual coupling, robust gap control, resilient gap control철도의 운송량은 물류 운반 사업과 여행 사업의 발달로 인해 지속적으로 증가하고 있다. 결국 이는 선로 용량과 철도의 운영 효율 개선을 요구한다. 개선을 위한 수단으로서 무선통신 기반 열차 제어 (CBTC) 시스템은 상당한 운영적 이득을 달성하기 위한 목적으로 최근에 개설된 도시철도에 구현되었다. 그러나 CBTC는 사이버 공격과 보안 침입에 대한 취약점을 드러낸다. 실제로, 역사적인 사건들은 CBTC 시스템이 악의적인 공격의 타겟이 되었다는 사실을 보여준다. 이 학위 논문은 악의적인 공격으로부터 시스템을 보호하기 위해 최근에 개발된 자율복원 사이버 물리 시스템 체계를 CBTC 시스템에 적용하는 것을 고려한다. 특히, CBTC 시스템의 대부분의 요소들을 구현한 CBTC 기반 자율복원 CPS 테스트베드를 만들었다. 이 테스트베드를 통해 CBTC 시스템에 대한 다양한 공격의 취약점을 분석하고, 그 공격에 대한 자율복원성을 검증한다. CBTC 신호 시스템은 기존의 신호 시스템보다 열차 운행이 훨씬 더 유연하기 때문에, 최근 부상하고 있는 가상 열차 커플링의 혁신적인 기술을 지원하는 선구자 중 하나이다. 가상 결합은 선로 용량을 늘리고 철도의 운영 효율을 강화하기 위한 진보된 솔루션으로서 주목받고 있다. 이 개념은 다수의 열차가 마치 기계적으로 연결된 것처럼 그룹지어서 움직이는 것을 가능케하는 기술이다. 특히 이 기술은 열차들이 움직이면서 결합/분리할 수 있도록 하며, 이는 선로 용량과 운영의 유연성을 증가시킨다. 이 학위 논문에서는 열차의 가상결합을 위해 열차들간의 간격을 제어하기 위한 슬라이딩 모드 제어 (SMC) 기반 강인 간격 제어기를 제안한다. 이 제어기는 엑추에이션과 열차 질량에 대한 모델 불확실성과, 선로 커브, 구배, 그리고 주행 저항때문에 발생하는 외란이 존재하는 상황에서 간격 제어 성능과 가상 결합된 열차들의 간격 추종 에러들의 한계를 보장한다. 추가적으로, 열차들의 저크와 가속도 제한을 고려한 상황에서 주어진 지역 내에서 열차들의 결합/분리 완료를 보장하는 결합/분리를 위한 간격 레퍼런스를 계산하는 간격 레퍼런스 생성 방법을 소개한다. 게다가, 바퀴 지름의 불확실성으로 인해 발생하는 위치와 속도 측정 오류를 고려한다. 열차의 제어기는 발리스를 지날 때 발리스로부터 받은 절대 위치 정보를 기반으로 열차의 위치 정보를 조정한다. 이러한 조정은 간격 제어 성능의 섭동을 유발하기 때문에 발리스 기반 위치 측정 오류 보정 기법을 제안한다. 마지막으로, 우리는 가상으로 결합된 열차들의 간격 센서와 무선 통신에 대한 공격에 대한 취약점을 고려한다. 열차에 장착된 간격 센서는 앞 열차와의 간격을 측정하기 위해 사용되며, 무선 통신은 간격 제어 성능을 위해 열차의 상태 정보를 전송하는 역할을 한다. 이러한 공격에 대한 자율복원성을 위해서 우리는 슬라이딩 모드 관측기 기반 센서 공격 검출 기법, 앞 차의 상태 정보를 사용하지 않는 SMC 기반 간격 제어기, 그리고 자율복원 코디네이터를 포함하는 자율복원 간격 제어 알고리즘을 제안한다. 이 제안된 알고리즘들은 시뮬레이션을 통해 검증된다.The transport volume of railways has constantly increased with the development of the goods transportation industry and business travel. In turn, this requires improving line capacity and operational efficiency of railways. As a means to the improvement, communications-based train control (CBTC) systems have been realized in recently built urban railway lines that aim to achieve significant operational benefits. However, CBTC opens up vulnerabilities to cyberattacks and security breaches. Indeed, historical events confirm that CBTC systems have been the target of malicious attacks. This dissertation addresses applications of recently developed resilient cyber-physical system framework to CBTC systems in order to protect the system from malicious attacks. Specifically, a resilient CPS testbed for CBTC has been built that realizes most of the components in CBTC systems. On the testbed, the vulnerabilities to various attacks on CBTC systems are analyzed, and resiliency against such attacks is validated. Since CBTC signaling systems enable much more flexible train operations than conventional signaling systems, it is one of the precursors that support a recently emerging innovative technology of train virtual coupling. Virtual coupling has been highlighted as an advanced solution to increase line capacity and enhance operational efficiency. This concept is a technology that enables multiple trains to move as a group as if they were mechanically connected. Specifically, it enables trains to merge/separate on the move, which results in the increment of line capacity and operational flexibility. In this dissertation, the sliding mode control (SMC)-based robust gap control is proposed to control the gap between trains for virtual coupling of trains. This controller guarantees the gap control performance and the bounds of all the gap-tracking errors of virtually coupled trains under the model uncertainties in the actuation and train mass and external disturbances due to the rail curve, grade, and rolling resistance. Additionally, a gap reference generation scheme is introduced that computes a gap reference for merge/separation, ensuring the completion of merge/separation before a given location while respecting constraints on the jerk and acceleration of the trains. Furthermore, the position and velocity measurement errors arising from uncertainty of wheel diameters are considered. When passing over a balise, the controllers in the trains adjust their positional information based on the absolute location received from balise. Because it results in perturbation of the control performance, a balise-based position error correction scheme is proposed to reduce control perturbations at error correction instances. Finally, the vulnerabilities of virtually coupled trains to attacks on gap sensors and wireless communication are considered, where gap sensors equipped on trains are used to measure the gap with the preceding train, and wireless communication is the role of transmitting state information of trains for gap control performance. For resiliency against these attacks, we propose resilient gap control algorithms, including sliding mode observer-based sensor attack detection method, SMC-based gap controller without state information of preceding train, and resiliency coordinator. The proposed algorithms are validated through simulations.1 Introduction 1 1.1 Background 1 1.2 Motivation 2 1.3 Problem Addressed 3 1.4 Related Work 4 1.4.1 Virtual Coupling for Operational Efficiency 4 1.4.2 Gap Control for Virtual Coupling 5 1.4.3 Resiliency for Train Control Systems 6 1.5 Contributions 8 1.6 Remaining Problems 8 1.7 Dissertation Outline 9 2 Resilient CPS Testbed for Communications-Based Train Control 11 2.1 Preliminary Work 1: Attack-Resilient CPS Architecture for Hierarchical Control 13 2.1.1 Software Isolation in a CPS 13 2.1.2 Supporting Graceful Failure 14 2.1.3 Resilient Algorithms in the HP Module 14 2.1.4 CPS with SDN Capability 15 2.1.5 Resiliency in the Supervision Layer 16 2.2 Preliminary Work 2: Resiliency Coordinator 16 2.2.1 Purpose 16 2.2.2 Construction and Operation 17 2.2.3 Three Modes: Tolerate, Reduced Capacity and Graceful Degradation 21 2.3 Resilient CPS Testbed for Communications-Based Train Control 22 2.3.1 Communications-Based Train Control Testbed Implementation 23 2.3.2 Resilient Algorithms Implemented on the Testbed 25 2.4 Attack-Resiliency under Various Safety-Critical Scenarios 27 2.4.1 Scenario 1: Sensor Attacks 27 2.4.2 Scenario 2: HP Module Failure 30 2.4.3 Scenario 3: Link Failure after Sensor Attacks 31 2.5 Conclusions 33 3 Virtual Coupling of Railway Vehicles: Gap Reference for Merge and Separation, Robust Control, and Position Measurement 35 3.1 System Model 36 3.2 Control for Virtual Coupling 39 3.2.1 System Requirements 39 3.2.2 Three Modes for Virtual Coupling 40 3.2.3 Gap Reference Generation 42 3.2.4 SMC-based Gap Controller Design 45 3.3 Position Error Correction 52 3.3.1 Existing Position Error Correction Scheme 53 3.3.2 Proposed Position Error Correction Scheme 54 3.4 Simulations 56 3.4.1 Simulation Environments 56 3.4.2 Performance of SMC-based Gap Controller 59 3.4.3 Effectiveness of Proposed Position Error Correction Scheme 60 3.5 Conclusions 61 4 Resilient Gap Control for Virtual Coupling of Railway Vehicles against Attacks on Gap Sensors and Wireless Communication 67 4.1 System Structure for Resiliency of Virtual Coupling 68 4.2 Resilient Gap Control Algorithms against Gap Sensor Attacks and ARPSpoofing-based MITM Attacks 70 4.2.1 Response to Gap Sensor Attacks 70 4.2.2 Response to ARP-Spoofing-based MITM Attacks 73 4.3 Simulations 78 4.3.1 Effectiveness of Resilient Gap Control Algorithm against Gap Sensor Attacks 79 4.3.2 Effectiveness of Resilient Gap Control Algorithm against ARP-Spoofingbased MITM Attacks 80 4.4 Conclusions 82 5 Dissertation Conclusions and Future Work 85 5.1 Dissertation Conclusions 85 5.2 Future Work 86 Bibliography 87 국문초록 96DoctordCollectio

건물의 분할 영상을 위해 교차 크기의 비지역적 유사성을 활용하는 샴 네트워크 기반 항공 영상 초해상도 기법

Cross Scale Non-Local Similarity, Siamese Network, Super Resolution, Remote Sensing, Segmentation, 교차 크기의 비지역적 유사성, 샴 네트워크, 초해상도, 항공 영상, 분할 영상Ⅰ. INTRODUCTION 1 Ⅱ. RELATED WORKS 6 2.1 Image Self-Similarity 6 2.2 Deep Learning-based Super Resolution 7 Ⅲ. METHODS 9 3.1 Overall Network Structure 9 3.2 Siamese Residual Non-local Similarity Module (SRNSM) 13 3.3 Siamese Cross Scale Non-Local Similarity Module (SCSNLS Module) 16 Ⅳ. RESULTS 19 4.1 Experimental Dataset and Evaluation 19 4.2 Training Details 21 4.3 Comparison between previous and SRNSM methods 22 4.4 Super Resolution results on the UCMerced Dataset 23 4.5 Super Resolution Results on the WHU Dataset 28 4.6 Segmentation Results on the WHU Dataset 31 Ⅴ. DISCUSSION 34 Ⅵ. CONCLUSION 40 REFERENCES 42 국문요약문 47MasterdCollectio

Virtual Coupling of Railway Vehicles: Gap Reference for Merge and Separation, Robust Control, and Position Measurement

Virtual coupling, which refers to the operation of railway vehicles that enables the merge and separation of vehicles on the move by controlling the gap between the vehicles without any mechanical coupling, is one of the technologies for increasing the transport capacity and enhancing operational efficiency. This paper proposes a robust gap controller based on sliding mode control with a nonlinear train model with uncertainties. Additionally, a gap reference generation scheme is developed that ensures that the merge and separation of two trains is completed before a given location and respects constraints on acceleration and jerk. The position and velocity measurement errors arising from imperfect knowledge of wheel diameters are also considered, and a new error correction scheme is proposed to reduce the perturbation in the gap control performance. The proposed schemes are validated through simulations.FALS

Dynamic Vehicular Route Guidance Using Traffic Prediction Information

We propose a dynamic vehicular routing algorithm with traffic prediction for improved routing performance. The primary idea of our algorithm is to use real-time as well as predictive traffic information provided by a central routing controller. In order to evaluate the performance, we develop a microtraffic simulator that provides road networks created from real maps, routing algorithms, and vehicles that travel from origins to destinations depending on traffic conditions. The performance is evaluated by newly defined metric that reveals travel time distributions more accurately than a commonly used metric of mean travel time. Our simulation results show that our dynamic routing algorithm with prediction outperforms both Static and Dynamic without prediction routing algorithms under various traffic conditions and road configurations. We also include traffic scenarios where not all vehicles comply with our dynamic routing with prediction strategy, and the results suggest that more than half the benefit of the new routing algorithm is realized even when only 30% of the vehicles comply