Resource-efficient scheduling of multiprocessor mixed-criticality real-time systems

이재우 ProQuest LLC 2017 국내박사

(A) study on the healing performance of hot mix asphalt with microwave heating

Phan, Tam Minh Kunsan National University 2019 국내석사

Development and validation of a micellar electrokinetic chromatography method for the determination of the L-enantiomer of nateglinide in pharmaceutical formulations

Phan, Thanh Dung Kangwon National Univ. 2009 국내박사

A simple, rapid and reliable micellar electrokinetic chromatographic (MEKC) method was developed and validated for the determination of the L-enantiomer of nateglinide. L-enantiomer of nateglinide was prepared by a crystallization method and determined by high performance liquid chromatography (HPLC). The purity of L-enantiomer was evaluated by using HPLC, melting point measurement, IR- and 13C-NMR spectroscopy. The purities of L-enantiomer were at least 99.8%. The influence of borate buffer, sodium dodecyl sulfate (SDS) and methyl-β-cyclodextrin concentrations, capillary temperature and applied voltage was systemically investigated in a fused silica capillary (I.D. of 50 μm, total length of 64.5 cm and effective length of 56 cm). Optimum results were obtained with 75 mM borate buffer pH 9.2 containing 50 mM sodium dodecyl sulfate (SDS) and 25 mg/mL methyl-β-cyclodextrin as a background electrolyte, applied voltage of 20 kV and capillary temperature of 15℃. The samples were injected hydrodynamically for 3 s at 50 mbar. Detection wavelength was set at 210 nm. The method was suitably validated with respect to linearity, sensitivity (limit of detection and quantification), accuracy, precision, stability and robustness. The assay was validate for the L-enantiomer in the range of 1-24 μg/mL (0.2 - 4.58% of L-enantiomer in racemic nateglinide) and the limits of detection and quantification were 0.07% and 0.2% with R.S.D of 2.27 and 1.32%, respectively (relative to a concentration of nateglinide of 0.5 mg/mL) Intra-day precision of peak area ratio of L-enantiomer in racemic nateglinide was in the range of 0.12 - 1.70% with the relative standard deviation between 0.73% and 1.73%. The proposed method was applied for the determination of the L-enantiomer of nateglinide in pharmaceutical formulations. 우리는 나테글리니드 L-에난티오머를 위한 간편하고 신속하며 신뢰성이 있는 모세관전기영동분석법(micellar electrokinetic chromatographic (MEKC)method)을 개발하였으며, 밸리데이션을 수행하였다. 나테글리니드 L-에난티오머는 재결정방법을 이용하여 준비하였다. 나테글리니드 L-에난티오머를 고성능액체크로마토그래프법으로 분석을 하였다. 위의 나테글리니드 L-에난티오머를 고성능액체크로마토그래프법, 적외선분광분석법, 녹는점, 핵자기공명분석법을 통하여 그 순도를 결정하였다. 위 결과 나테글리니드 L-에난티오머의 순도는 99.8% 이상으로 판명되었다. 붕산염 완충용액, 도데실황산 나트륨 및 메틸-베타-시클로덱스트린 농도, 모세관 온도, 부하 전압의 영향을 실리카 모세관(직경 : 50㎛, 총길이 64.5 ㎝, 유효 길이 :56 ㎝)을 적용한 시스템에 대하여 조사하였다. 위의 실험으로 얻어진 최적 조건은 75mM 붕산염 완충용액, 50mM pH 9.2 도데실황산 나트륨 및 25mg/mL 메틸-베타-시클로덱스트린을 배경전해질로 하고, 부하전합을 20 kV로 모세관의 온도를 15 ℃로 조정할 때이다. 검체를 유체역학적으로 50 mbar에서 3초간 주입하였다. 파장은 210 ㎚로 조정하였다. 이 분석법은 직선성, LOD, LOQ, 정확성, 재현성, 안정성 및 견뢰성에서 밸리데이션하여 적합하였다. 직선상의 검량선 범위는 1~24ug/mL (라세믹 나테글리니드로서 0.2 ~ 4.58%) 이었으며, LOD 및 LOQ 는 각각 0.07%, 0.2% 이었으며 각 상대표준편차는 2.27%, 1.32%로 나타났다. 라세믹 나테글리니드와 L-에난티오머 라테글리니드의 피크 면적 비로의 일내 재현성은 상대표준편차로서 0.12 ~ 1.70% 였으며, 일간표준편차는 0.73 ~1.73%로 나타났다. 위의 실험 결과에서 제시된 분석법을 상용의약품의 L-에난티오머 나테글리니드의 분석법으로서 적용하였으며, 그 결과 상용의약품중 L-에 난티오머 나테글리니드의 함량을 구할 수 있었다.

Development of theta-burst ultrasound as a non-invasive paradigm for pain management and bidirectional neuromodulation

Phan, Thuy Tien University of Science and Technology 2024 국내박사

이 연구에서는 초음파의 통증 관리 대한 새로운 응용 기법 및 관련 기전에 대한 연구를 수행하였습니다. 제 1 장에서는 만성 신경병증성 통증에서 척수 성상교세포의 기능 및 역할을 연구하였고, 치료기법으로써 BDNF 관련 경로를 치료 전략의 대상으로 제안하였습니다. 제 2 장에서는 저강도 초음파의 진통 효과와 관련한 성상교세포의 역할과 이에 기반한 통증 완화의 가능성을 고찰하였습니다. 이러한 연구 결과들은 다양한 형태의 신경 조율을 위한 저강도 초음파의 잠재력을 보여주며, 만성 통증 조절을 위한 표적 솔루션으로써의 초음파의 임상 적용 가능성을 제시하고 있습니다. 제 1 장: 말초 부분 신경손상으로 인한 신경병증성 통증 기전에서의 성상교세포 특이적 기능 연구 신경병증성 만성 통증은 기존의 진통 치료로는 치료하기 어려운 임상적인 문제로 인식되고 있습니다. 척수 성상교세포에 대한 연구는 발전되고 있지만, 말초 좌골신경 부분적인 눌림 손상에 따른 신경병증성 통증에서의 성상교세포의 기능 변화와 역할에 대한 연구는 부족한 실정입니다. 이 연구에서는 만성 신경병증성 통증과 관련된 척수 성상교세포의 형태와 기능 변화를 통해서 초기 통증 반응에서 만성 통증으로의 이행되는 과정에서의 성상교세포의 중요성을 보여주었습니다. 또한, 기계적 알로디니아 (이질통) 지속과정에 있어서 척수내 뇌유래 신경영양인자(BDNF) 발현 증가와 성상교세포의 상관관계를 통해, 신경병증성 통증에서의 척수 신경계의 성상교세포 활성화와 BDNF 신호 전달의 연관성을 확인했습니다. 그리고 BDNF/TrkB 억제제를 통한 성상교세포의 활성화 억제가 기계적 알로디니아 완화를 유도함을 입증함으로써, 신경병증성 만성 통증 치료 및 관리를 위한 새로운 유형의 치료 방법을 제안하였습니다. 제 2 장: 초음파를 통한 신경병적 통증 관리 초음파 자극은 비침습적인 신경 조절 기술로 통증 치료의 새로운 기술로 조명되고 있습니다. 본 연구에서는 부분 압박 손상에 의한 신경병증성 통증에 대한 저강도 Theta-burst 초음파 (LI-cTBUS)의 진통 효과 및 관련 기전에 대한 연구를 수행하였습니다. 이 연구에서는 LI-cTBUS 가 기계적 자극에 대한 반응의 역치 증가를 통해서 현저한 신경병증성 만성 통증 상황하에서의 기계적 자극에 대한 유의한 수준의 진통 효과를 나타냄을 관찰하였으며, 이는 기계적 자극에 반응하는 TRPA1 의 활성화를 통해 중재됨을 규명하였습니다. 또한, LI-cTBUS 는 척수 성상교세포의 기능 조절 및 척수 통증 유발 인자로써 중요한 세포외 BDNF 의 흡수를 촉진함으로써 척수 BDNF/KCC2 경로의 균형 유지에 중요한 역할을 수행함을 규명하였습니다. 이 연구 결과는 LI-cTBUS 가 신경병증성 통증의 기계적 알로디니아 (이질통)를 효과적으로 완화시킨다는 것을 보여 주는 결과이며, 저강도 초음파 기술을 통한 신경병증성 만성 통증에 대한 진통유발 기전에서의 성상교세포와 기계적 감수기인 TRPA1 가 중요한 역할에 연구 결과를 보여주고 있습니다. In this study, we collectively explore innovative applications of ultrasound for pain management and brain modulation. Chapter I highlights astrocytes' role in chronic neuropathic pain, proposing a BDNF-related pathway as a target for treatment strategies. Chapter II introduces low-intensity ultrasound's analgesic effects mediated through astrocyte involvement, demonstrating potential for pain alleviation. These chapters underscore ultrasound's potential for diverse neurological applications, offering targeted solutions for pain and brain function modulation.   Chapter I Neuropathic pain poses a formidable clinical challenge due to its persistent nature and resistance to conventional analgesic approaches. Although considerable insights have been gained into spinal astrocyte involvement in neuropathic pain, the alterations and contributions of these cells subsequent to a partial crush injury (PCI) remain inadequately explored. Our investigation centered on delineating the structural and functional adaptations of spinal astrocytes during the enduring phase of neuropathic pain employing a specific injury model. This model serves as a valuable tool in comprehending the mechanisms perpetuating chronic pain and underscores the indispensability of astrocytes in pain maintenance and sensitization. Through the examination of mechanical allodynia, a painful sensation in response to innocuous tactile stimuli, and the correlation with increased levels of brain-derived neurotrophic factor (BDNF) along with reactive astrocytes, we identified a potential correlation between astrocytic activity and BDNF signaling. Ultimately, our research provides evidence that inhibiting astrocyte activation through a BDNF/TrkB inhibitor alleviates mechanical allodynia, underscoring the therapeutic potential of targeting glial BDNF-related pathways for pain management. These findings offer critical insights into the cellular and molecular dynamics of neuropathic pain, paving the way for innovative and targeted treatment strategies for this challenging condition.   Chapter II Ultrasound stimulation, an emerging non-invasive neuromodulation approach, shows promise in pain management despite lacking a clear mechanism of action. This study unveils the analgesic impact of a specific ultrasound variant, low-intensity theta burst ultrasound with a continuous paradigm (LI-cTBUS), on neuropathic pain triggered by partial crush injury (PCI). We observe a significant pain-alleviating effect, characterized by an increase in mechanical thresholds, during and after LI-cTBUS treatments on the spinal cord. Interestingly, this analgesic effect is mediated through the activation of mechanosensitive TRPA1. Furthermore, LI-cTBUS induces a critical involvement of spinal astrocytes in pain modulation, facilitating the uptake of extracellular BDNF by these astrocytes, leading to the rebalance of the spinal BDNF/KCC2 pathway. Additionally, LI-cTBUS exhibits efficacy in reducing spinal astrogliosis and levels of astrocytic GABA, both in vivo and in vitro. Overall, this study demonstrates the efficient mitigation of mechanical allodynia in neuropathic pain through LI-cTBUS, shedding light on its therapeutic promise in pain management. The study underscores the indispensable role of astrocytes and the involvement of mechanosensitive TRPA1 in mediating LI-cTBUS's analgesic effects, offering significant scientific insights into potential therapeutic applications.

Chemical vapor deposition growth and high-k dielectric properties of hydrofluorocarbon films

PHAN THI KIM UYEN 忠南大學校 大學院 2024 국내석사

Chemical vapor deposition growth and high-k dielectric properties of hydrofluorocarbon films Phan Thi Kim Uyen Department of Materials Science and Engineering, Graduate School Chungnam National University Daejeon, Korea (Supervised by Professor Eui-Tae Kim) High-k dielectrics are crucial parts of the present generation and prospective electronic circuits. In complementary metal-oxide-semiconductor (CMOS) structures, particularly, they have been broadly studied for modern memory devices and logic microelectronics. In accordance with Moore's rule, an integrated circuit's transistor count doubles every two years, and the size of the transistors also shrinks predictably. To maintain transistor functionality, the gate dielectric thickness will be reduced to less than the oxide equivalent thickness (EOT) of a deca-nanometer, leaving high-k materials as the only practical option for such a small-scale EOT. However, for sub- 10nm thickness of about 1-2nm is beyond their elementary material limits forced by electron tunneling effect. Most of studies on high-k dielectric materials have been concentrated on inorganic thin film including metal oxides (MOs), nitrides (Si3N4, AlN), perovskites, and hybrids comprising them. Intriguingly, novel class of propitious candidates are organic such as fluorocarbon (FC), hydrocarbon (HC) or the most recent hydrofluorocarbon (HFC), irrespective of the fact how low-k they are commonly considered. An amorphous carbon monolayer, for example, is a strong insulator. HFC films (HFCs) have carbon backbones with hydrogen and fluorine atoms that distribute randomly along different sides of the backbone carbon atom. This affects the electric and dielectric properties of an HFC. As a result, HFCs with high k values show promise. A brief literature review on ultrathin high-k dielectric films of HFC films were fabricated and their exceptional features were utilized to develop the applications in metal-insulator-semiconductor (MIS) devices. For further application, they were employed as surface passivation layers in graphene field-effect transistors (GFET) to suppress Coulomb scattering from adsorbing ambient environment of graphene channel fabricated by inductively-coupled plasma chemical vapor deposition (ICP- CVD) using the plasma gas mixtures (CH4, CF4 and H2). This approach supplies a straightforward and commercial fabrication of high-k dielectric thin films for prospective applications in microelectronic devices. The surface passivation of HFC films for the enhanced mobility of graphene channel. This emergent structure is an auspicious candidate used as affordable, effective, and simple high-k dielectric films for alternatives of CMOS devices to provide insights for future research.

링 마우스 : 손가락 움직임에 의한 컴퓨터 무선 입력 장치

Phan, Ke Hien 한국산업기술대학교 일반대학원 2018 국내석사

국문요약 링 마우스: 손가락 움직임에 의한 컴퓨터 무선 입력 장치 한국산업기술대학교 일반대학원 전자공학과: 판게히엔 지도교수: 정 두 희 이 논문에서는 링과 같이 손가락으로 감싸는 컴퓨터 용 무선 장치를 연구했습니다. Ring Mouse는 Bluetooth를 통해 컴퓨터에 무선으로 연결된 마우스 역할을하는 스마트 장치입니다. 손가락 움직임으로 컴퓨터의 마우스 커서를 제어 할 수 있습니다. 마이크로 컨트롤러 Cortex M4와 함께 nRF52832를 사용함으로써 우리는 전력 효율이 높고 비용 효율적인 회로를 만들었습니다. 모션 데이터는 MPU-9250 모듈을 사용하여 획득합니다. 장치의 기계적 케이스는 3D 인쇄 기술로 설계 및 제작되었습니다. ABSTRACT Ring Mouse: A Wireless Input Device for Computers by Finger Motions By Phan Ke Hien Advisor: Professor Jung Doo Hee Course for Electronics Engineering Graduate School Korea Polytechnic University In this thesis, we studied a wireless device for the computer which is carried on the finger like a ring. Ring Mouse is a smart device that acts as a mouse that is connected wirelessly to a computer via Bluetooth. One can control the mouse cursor on the computer with finger motions. By using nRF52832 with microcontroller Cortex M4, we made a circuit that is power-efficient and cost-effective. Motion data is acquired by using an MPU-9250 module. The mechanical case of the device is designed and made by 3D printing technologies.

Expanding constraint theory to determine well-posedness of large mathematical models

Phan, Phan University of Southern California 2011 해외박사(DDOD)

Mathematical modeling represents one of the major tools for the conception and management of the ever increasing complexity of systems engineering. Unfortunately, present approaches to math modeling suffer from several theoretical problems which include: model consistency, computational allowability, management of the topologically complex flow of software algorithms, rearrangement of independent and dependent variables, distinction between the model structure and software programs and perhaps the most challenging, the exponential explosions resulting from the management of even medium sized models as well as the large models of the thousands of dimensions necessary to define and manage the complex systems of the future. Constraint theory was designed to solve the above problems employing a rigorous application of graph theory and attempts to employ the generalizability of mathematics to extend the math model manager's conceptual understanding from half a dozen dimensions to the desired thousands of dimensions. Constraint theory (CT) went through several stages of detail and maturity, starting with the PhD dissertation in the 1960's and progressing through several papers and two other PhD research programs. CT's present frontier can be characterized by the Constraint Theory book written by Dr. George Friedman and published by Springer in 2005. CT differs from linear programming (LP) in several ways. LP requires a full model of explicit mathematical expressions in linear form whereas CT employs a meta-model based upon relevancy between general (linear or non-linear) relations and variables. CT seeks to determine a model consistency and computational allowability without having to actually solve for a specific solution set whereas LP assumes that the problem is well-posed while attempting to solve for an optimal solution within a given constrained trade space. As mentioned above, the exponential explosions associated with the management of thousand-dimensional models is truly enormous, on the order of 2 N examinations of a model's N equations are required to determine consistency, for example. CT has converged this process---which would take several universe lifetimes even with nanosecond computer cycle times---by a factor of trillions. This convergence is based on an ordered series of graph theoretic steps involving connected-ness, tree-ness, circuit-ness and cluster-ness. A constraint theoretic structure called the "Basic Nodal Square" (BNS) is identified as the kernel of constraint in a math model. An n x n BNS is essentially a complete sub-system of n relations and n variables within the overall model. However, Friedman's book effectively stops at the identification of circuit clusters of approximately 30 relations, and suggests that BNS within these clusters can be found by modern computers in a few hours. It is suggested that perhaps more research can employ the topological property of adjacency to converge the search for BNS within larger circuit clusters. The central contribution resultant from this investigation realizes and improves the computational efficiency of BNS search by factors of trillions, asymptotically (see Figure 10-2). This improvement has been accomplished by innovative application of graph theory, topology, algorithm analysis and linear algebra, which were not addressed to sufficient depth in the original efforts. Leveraging research results in graph theory since the early 1970's, several BNS search methods, based on nodal adjacency, circuit adjacency and nodal degree, have been developed and compared against the baseline (brute-force) approach of 2N. Primary key research findings and enablers include: (a) Decomposition of a model graph into its connected components by employing the graph-theoretic concept of a spanning tree and applying the depth-first search algorithm. (b) Innovation of the edge-centric method, over the legacy approach of vertex-centricity, to identify, and remove, internal trees (or bridges) within a connected component. (c) Further isolation of circuit clusters containing potential BNS by using the graph-theoretic concept of articulation point (or separating vertex). (d) Rigorous proof of circuit vector-based theorems to simplify the computational complexity of constructing unions of adjacent circuits, and thus reduce BNS search space. (e) Application of vectorial dot product to detect adjacency among circuits, and overlapping among nodes or BNSs. (f) Development and demonstration of a meta-meta-model graph to represent overlapping among nodes and to reduce the solution-time for BNS search, from exponential to polynomial. Additional accomplishments further improve the utility of CT by developing an integrated set of efficient computing algorithms to determine model consistency and computational allowability. The output of these algorithms can also advise the model builder of repair alternatives to correct any model inconsistency detected. Such algorithms are necessary to bridge the gap between theoretical abstracts and practical realization of CT in terms of an effective computer-assisted tool for math model management.

Research on insurance fraud and regulations on prevention of automobile insurance fraud : experiences from the United States of America and proposals for Vietnam

Phan, Thi Huong Giang TLBU Graduate School of Law 2019 국내석사

Defending denial-of-service attacks in SDNFV-enabled cloud computing

Phan, Van Trung Soongsil University 2017 국내석사

In my thesis, I propose a novel S2eH scheme to tackle Denial-of-Service (DoS) attacks in the Software-Defined Network Functions Virtualization (SDNFV) cloud computing environment. I firstly introduce a new machine learning hybrid model for DoS attack classification based on Support Vector Machine (SVM) and Self Organizing Map (SOM) algorithms to enhance the performance of classification network traffic. The proposed combination mainly focuses on taking advantages of two classification algorithms by utilizing both algorithm advantages that SVM takes a little time to produce outputs with a high accuracy and SOM makes a reliable prediction based on their neurons. Then, I propose an enhanced History-based IP Filtering scheme (eHIPF) to improve attack detection rate and speed. Finally, I propose a novel mechanism combining both the machine learning hybrid model SVMs-SOM and the eHIPF scheme, called S2eH, to make a DoS attack defender in the SDNFV-enabled cloud computing. The S2eH testbed is implemented in the SDNFV cloud environment with Service Function Chaining. Through practical experiments in this testbed, it is proved that the proposed SVMs-SOM combination and eHIPF scheme outperforms existing mechanisms for DoS attack classification and detection. By analyzing comprehensive experiments conducted with various DoS attack levels, I prove that the novel S2eH mechanism is an effective and innovative approach to defend DoS attacks in the SDNFV-based cloud computing. 본 논문에서는 Software-Defined Network Functions Virtualization (SDNFV) Cloud computing 환경에서 서비스 거부 공격을 저지하는 새로운 S2eH 스키마를 제안한다. 먼저, DoS 공격 분류를 위해 Network 분류 성능을 높이는 Support Vector Machine (SVM) 과 Self-Organizing Map(SOM) 알고리즘 기반 새로운 Hybrid Machine Learning을 소개한다. 제안된 결합 시스템은 주로 두 가지 분류 알고리즘의 이점을 가져오는데 초점을 둔다. SVM은 짧은 시간에 높은 정확도로 분류를 하고, SOM은 SOM의 신경망기반으로 신뢰성이 높은 예측을 한다. 또한, 공격 탐지 비율과 속도를 개선하기 위해 History 기반 IP Filtering 스키마(eHIPF)를 제안한다. 본 논문에서는 SDNFV가 가능한 Cloud Computing 에서 DoS공격을 방어하기 위해 SVMs-SOM을 결합한 Hybrid Machine Learning 모델과 eHIPF 스키마를 결합한 새로운 메커니즘 S2eH을 제안한다. S2eH testbed는 Service Function Chaining이 가능한 SDNFV Cloud 환경에서 실험했다. 이 testbed에서 실제 실험을 통해 본 논문에서 제안된 SVMs-SOM 결합과 eHIPF 스키마가 DoS공격 분류와 탐지에 다른 메커니즘보다 좋은 결과 가져오는 것을 증명했다. 다양한 DoS공격 레벨로 수행 된 포괄적인 실험을 분석하여 새로운 S2eH메커니즘이 SDNFV기반 Cloud computing에서 DoS 공격을 방어하기 위한 효과적이고 혁신적인 방법임을 증명했다.

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