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

이재우 ProQuest LLC 2017 국내박사

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

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.

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.

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.

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.

(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.

(A) Numerical Study on Heat and Mass Transfer Characteristics of Plate Absorber

판탄통 부경대학교대학원 2002 국내석사

Efficient evaluation of maximizing range sum queries in a road network

Phan, Tien Khoi Sungkyunkwan University 2016 국내박사

Given a set of positive-weighted points and a query rectangle r (specified by a client) of given extents, the goal of a maximizing range sum (MaxRS) query is to find the optimal location of r such that the total weights of all the points cov-ered by r is maximized. All existing methods for processing MaxRS queries as-sume the Euclidean distance metric. In many location-based applications, how-ever, the motion of a client may be constrained by an underlying (spatial) road network, i.e., the client cannot move freely in space. This thesis addresses the problem of processing MaxRS queries in a road network. In this thesis, we pro-pose three external-memory methods that are suited for a large road network database. In contrast to the existing methods, which retrieve only one optimal location, our proposed methods retrieve all the possible optimal locations. Through a set of simulations, we evaluate the performance of the proposed methods.