Adaptive deblocking techniques for H.264/AVC video compression standard

Ha, Le Thanh Graduate School, Korea University 2010 국내박사

Abstract Adaptive Deblocking Techniques for H.264/AVC Video Compression Standard Author Le Thanh Ha Advised by Prof. Sung-Jea Ko Dept. of Electronics Engineering Graduate School Korea University Blockiness is a typical artifact in reconstructed frames that have been coded by a block-based discrete cosine transform (DCT) video coding standards including H.264/AVC due to the independent transformation, quantization, and motion estimation of image blocks. Since the blockiness deteriorates both visual quality and coding efficiency, numerous blockiness reduction algorithms, called deblocking filters, have been proposed for H.264/AVC. However, these deblocking filters are applied to reconstructed images, and the filtered images are used as references. Thus, the coded bitstream contains information which will be eliminated after deblocking filtering. In this dissertation, we briefly introduce the H.264/AVC video compression standards along with deblocking filter techniques which are proposed to H.264/AVC. We also propose a macroblock-level deblocking method for H.264/AVC, in which the blocking artifacts are effectively eliminated in the DCT domain at the macroblock encoding stage. In addition, an analysis for the performance of the proposed method is made based on the probabilistic approach. Then, based on the results of the analysis, an algorithm to reduce the computational complexity for the proposed method is introduced. Experimental results show that the proposed algorithm outperforms conventional H.264/AVC in terms of coding efficiency without reconstruction quality loss.

Accurate Path Tracking of Ground Mobile Robot for Simultaneous Localization and Mapping

HA XUAN VINH 울산대학교 2014 국내박사

In trend of science development, mobile robots have been an essential element in the use of specific tasks, as exploration, building maps, surveillance, assistance, logistic services, demining, environmental monitoring, and others in an unknown environment. These tasks can be performed alone or with other devices in collaborating teams, with a various degree of autonomy, from the simple human supervisor remote-operated systems to a truly autonomous system capable to high level planning and decision making. Additionally, for intelligent mobile robots, they must determine their location and the environment map precisely. Therefore, the Simultaneous Localization and Mapping (SLAM) algorithm is considered as a basic capability of mobile robots necessary for autonomous navigation. The research effort in this field has thus increased over the past few years. In fact, the accuracy of the path tracking of ground mobile robot is very effective to perform the localization which is a part of SLAM algorithm. The sensor noises, which come from sensor such as Inertial Measurement Unit (IMU), incremental encoder, laser range finder (LRF) and etc… as well as the wheel slip phenomenon, lead to inaccurate estimation path of mobile robot. This dissertation focuses on the optimization algorithm of noise covariance parameters and wheel slip compensation in order to obtain accurate path tracking for SLAM of ground mobile robot in indoor environment. The first work in this dissertation is the combination of the Particle Swarm Optimization (PSO) and Mesh Adaptive Direct Search (MADS) algorithms, so-called PSO-MADS, in tuning Extended Kalman Filter (EKF) problem. In the robotic research, the Kalman filter (KF) is a well-known filtering algorithm to determine a robot's position based on sensor fusion technique. The performance of the filter depends largely on the knowledge accuracy of the process noise covariance matrix and the measurement noise covariance matrix. Several global optimization algorithms are applied to tune the EKF. However, these global optimization algorithms can easily get trapped in local optima when solving a complicated cost function, with a large number of local optima. The experimental results proved that the proposed PSO-MADS algorithm is an effective method to obtain more accurate estimated trajectories than the other algorithms, such as GA and PSO based EKF tuning. Next, based on the more accuracy of the robot position and heading by using the PSO-MADS algorithm, the wheel slip of mobile robot is investigated. Wheel slip limits the traction and braking ability of the robot when the robot is travelling on different ground surfaces with different and longer trajectory shapes. Therefore, a novel method for online wheel slip estimation based on a Discrete KF (DKF) to compensate for the velocity constraints is introduced. Additionally, the tuning fuzzy Vector Field Orientation (FVFO) feedback control, which is a control strategy, is developed by using the Fuzzy Logic Control (FLC) to tune parameters of the VFO method. The experimental results show that the novel wheel slip compensation method overcomes the limitations of the others in the trajectory tracking control problem. Finally, this work deals with a probabilistic SLAM formulation and it is focused on EKF-SLAM, which is the most frequently implemented SLAM framework. The use of the optimization and slip compensation methods above is very effective to obtain high accuracy of robot’s path tracking and environment map for SLAM application in the mobile robot field.

Structural Verification and Retrieval of Generic Process Models Using Refined Process Structure Trees

Ngoc Long Ha 인제대학교 일반대학원 2021 국내석사

Structural Verification and Retrieval of Generic Process Models Using Refined Process Structure Trees Ngoc Long Ha (Advisor: Prof. Yongsun Choi, Ph.D.) Department of Information and Communication Systems Graduate School, Inje University Business Process Management (BPM) is an interdisciplinary field of business science and computer science, information systems engineering, and information management. Its goal is to increase operational efficiency and effectiveness. Business process models define strict semantics for the execution of business processes. In various organizations, there are large process repositories with a large number of business process models. The existence of inclusive gateways as a business process routing element is a big challenge for every contemporary business process analysis technique. The challenge has ranged from how to analyze each individual business process (i.e., in the micro-level) to managing a big collection of business processes in process repositories (i.e., at the macro-level). This dissertation proposed a series of methods that aim to address the mentioned challenge. At the micro-level, the errors of a business process must be detected as early as possible in order to minimize development costs. It is good to know why and where the error happens. At the macro-level, to efficiently manage the process repositories, it is crucial to have an efficient retrieving method that could retrieve a process model in a real-time scenario. An efficient retrieving method will benefit many managing functionalities of the process repositories. Finally, the dissertation shows how the presented techniques can handle the industrial business processes by implementing the prototype system to demonstrate the feasibility of the proposed method. It contains two main functionalities. The first functionality was designed to help the process designer in detecting, locating, and understanding structural errors. The second functionality aims to support the process repositories owners to efficiently and intuitively retrieve the process model from these repositories. Several experiments are conducted. The analysis results show the feasibility of the proposed approaches in the industrial setting, both usability and responsiveness.

Functionalized Monodisperse Mesoporous Silica Nanospheres with Schiff-Base for the Metal Ions Adsorption

하형민 부산대학교 대학원 2017 국내석사

다공성 실리카 물질은 메조포러스 실리카는 실리카 전구체, 계면활성제 그리고 성장 억제제를 통하여 적합한 기공 구조, 다양한 형태 그리고 입자의 형태를 조절할 수 있다. 또한, 졸-겔 합성법을 통한 다양한 합성을 통하여 유기물질의 기능을 다공성 실리카의 표면에 부여함으로써 촉매, 크로마토그래피, 나노 구조체 등 다양한 분야에 적용이 가능하다. 특히, 실리카 물질은 높은 열적안정성 및 산 안정성을 가지고 있어 산업 폐수 및 해수에서 유기물질 혹은 금속이온과 같은 환경오염 물질의 흡착 및 탈착제로도 활용이 가능하다. 시프 염기는 포르밀-, 케토- 그리고 일차 아민의 반응을 중심으로 산소와 질소 등으로 구성된 리간드 물질로써 우수한 유기물질 중 하나이다. 또한 시프 염기는 약물, 촉매, 염료 고분자 등 다양한 분야에 적용이 가능한 물질이며 그 중 전이 금속이온에 대한 높은 선택성을 나타낸 것으로 알려져 있다. 본 연구에서는 선택적 금속이온 흡착을 위하여 시프 염기를 가지는 새로운 형태의 메조포러스 실리카 나노 흡착제를 (ⅰ) 시프 염기로 표면 개질된 메조포러스 실리카와 (ⅱ) 시프 염기를 기공통로에 담지를 함으로써 pH에 민감하게 반응하는 나노 밸브 실리카를 구상하였다. 먼저, 실리카 나노 세공물질 중 하나인 M41S의 실리카 물질을 사용하여 50nm~100nm 의 입자크기를 가진 나노입자를 합성하였으며, 아민과 알데히드 반응을 통하여 시프 염기를 합성하였다. (ⅰ) 시프 염기를 표면에 성공적으로 합성을 위하여 염소기(Cl-)을 도입한 후 시프 염기를 성공적으로 실리카 표면에 개질하였다(MSNs-AH). (ⅱ) 나노 밸브를 구상하기 위하여 아닐린(C6H7N-)을 가진 물질을 표면에 개질하고 게이트 키퍼로써 베타-사이클로덱스트린(β-CD)을 활용하였다. 위 물질의 합성여부를 확인하기 위하여 다양한 분석방법을 통하여 증명하였다. 그러나 나노 밸브 (ⅱ)의 합성을 확인하기 위한 단계 중 메틸렌 블루를 게스트 분자로 활용하는 단계에 있어서 아닐린과 pH에 민감한 흡착 반응을 나타내는 것을 알 수 있었다. 또한, 시프 염기 또한 β-CD와 반응을 하는 것을 알 수 있었다. 시프 염기로 기능화 된 물질((ⅰ), MSNs-AH)의 금속이온의 선택성을 알고자 인공 폐수 및 인공 해수에서 다양한 조건에 따른 연구를 진행하였다. 그 결과, 인공 폐수에서는 리튬이온에 대한 높은 선택성(92.51%) 과 흡착량 (36.91 mol/g x 10-2)을 보였으며 50℃에서 흡착 능력이 가장 높아지는 것을 알 수 있었다. 또한 인공 해수 중 대상 금속 이온 결과에서는 거의 100%의 흡착 능력을 보였으며, 40℃에서 가장 높은 흡착능력을 확인할 수 있었다. 그 결과, 인공 폐수 및 해수에서 희소 금속이온중 하나인 리튬이온에 대한 다양한 흡착 연구가 기대된다.

Implementation of Mongolian Speech Recognition System using PCA and LDA

Sharkhuu Battsooj University of seoul 2010 해외석사

Speaker Recognition Using K-Means Support Vector Data Description

Niu, Chanyuan University of seoul 2010 해외석사

High temperature stress response of agronomic traits in soybean and mungbean

하수연 Seoul National University 2016 국내석사

Climate change is an important factor for agricultural which is caused by the release of ‘greenhouse gases’ into the atmosphere. It causes global warming which is predicted to have a negative effect on plant growth generally and crop yield due to the damaging effect of high temperatures on plant development. In this study, we conducted to investigate the response of phenotype of agronomic traits on high temperature in soybean [Glycine max] and mungbean [Vigna radiata] and finally to find the breeding material adaptive to high-temperature stress. We used nine soybean genotypes and two mungbean genotypes as planting materials. It was grown in four different temperature level plastic houses (normal field condition without plastic cover as the control (T1), T1+1.5℃(T2), T1+3.0℃(T3) and T1+5.0℃(T4)) to evaluate physiological response to high-temperature stress. Growth type traits such as plant height and the number of branches increased up to T3 treatment and decreased from T3 treatment in soybean. Flowering was faster with higher temperature and yield components like the number of pods and the number of seeds per pod continuously increased with increasing temperature. SS0404-T5-76 is one of the nine genotype we used, which was very highly significant on major agronomic traits at high temperature and was the increased production with increasing temperature. As a result, it is a promising breeding material to adaptive on high-temperature stress. Plant height and the number of pods consistently increased with increasing temperature in Sunhwanogdu and Gyunggijaerae and yield component like the number of pods and number of seed per pods also increased on high temperature in mungbean. Sunhwanogdu had a much pods number, and it had adaptability of high temperature than Gyunggijaerae. 기후변화에 따른 고온 스트레스에 대한 콩과 녹두의 반응양상을 관찰하고 이에 적응력이 강한 품종을 찾고자 수행되었다. 콩은 총 9개의 품종을 사용하였고, 녹두는 2개의 품종으로 연구를 진행하였다. 고온 스트레스의 정도에 대한 생리적 반응을 평가하기 위해 온도처리는 외기온도를 기준으로, 1.5℃, 3.0℃, 5.0℃ 높은 온도를 처리해준 상태로 콩과 녹두를 생육하였다. 전체적으로 콩의 생육에 영향을 주는 표현형인 경장과 가지(branch)의 개수가 지속적으로 증가하다가 외기온도보다 5.0℃ 높은 처리 구에서는 생육이 다시 감소하는 추세를 관찰할 수 있었던 반면, 온도가 증가할수록 개화기는 점차 빨라졌으며 콩의 생산량에 영향을 미치는 꼬투리의 개수나 한 꼬투리 내 종자의 개수 역시 점점 증가하는 양상을 보였다. 콩은 9개의 품종 가운데 SS0404-T5-76 품종의 경우 온도변화와 그에 따라 주요 농업형질의 표현형이 모두 매우 높은 유의성을 가지고 있었으며, 온도가 증가함에도 수량의 증가 양상을 보였기에 다른 품종에 비해서 고온 스트레스에 적응력이 뛰어난 품종임을 확인 할 수 있었다. 녹두는 콩보다 열대기후에 좀 더 강한 작물이기에 공시한 2품종 모두에서 생육에 영향을 주는 경장과 가지의 개수가 꾸준히 증가하는 양상을 보이고 있었으며, 수량 구성요소인 꼬투리의 개수와 한 꼬투리 내 종자의 개수는 선화녹두의 경우 고온에 지속적으로 증가하는 추세를 보였으므로 고온적응성이 경기재래에 비해 더 우수한 것으로 판단되었다.

Resistance mechanism and fitness of PROTOX inhibitor-resistant transgenic rice overexpressing a Myxococcus xanthus PROTOX gene

정하일 Chonnam National Univ. 2007 국내박사

PROTOX (Protoporphyrinogen oxidase) 저해 제초제는 제초제로써 많은 이상적 특성들을 지니고 있다. 즉, PROTOX 저해 제초제는 저약량 처리로도 살초효과가 뛰어나고, 환경에 있어 빠르게 분해되며, 잡초방제에 있어서도 넓은 살초범위를 지니고 있다. 하지만, 대두, 땅콩 및 당근과 같이 몇 가지 작물만이 이들 제초제들에 내성이 있는 것으로 알려져 있다. 이와 같이 좁은 작물 선택성은 작물재배에 있어 PROTOX 저해 제초제의 사용을 제한한다. 만일 PROTOX 저해 제초제에 저항성 작물이 개발된다면 제초제들의 선택과 적용 시기를 더욱 더 융통성 있게 사용할 수 있을 것이며 많은 문제 잡초들을 방제할 수 있게 될 것이다. PROTOX 저해 제초제들은 엽록소와 heme 합성 경로의 마지막 효소인 PROTOX를 저해한다. PROTOX는 2가지 동위효소가 존재하는 데, 하나는 엽록체에 위치하고 다른 하나는 미토콘드리아에 위치하고 있다. 특이하게, 부가적인 색소체 운반 서열이 없는 Myxocuccus xanthus PROTOX 유전자는 엽록체와 미토콘드리아 양쪽에 발현되었다. 이 연구에서, M. xanthus PROTOX를 발현한 8개의 형질전환 벼 계통(M1, M2, M3, M4, M5, M6, M7, 그리고 M8)들은 하이그로마이신에 저항성 수준을 판별하기 위하여 시험되었다. 형질전환 벼 계통 M4만이 하이그로마이신에 완전한 저항성을 보여 M. xanthus PROTOX 유전자가 T3 세대로의 유전적인 고정되었음을 알 수 있었고, 다른 형질전환 벼 계통(M1, M2, M3, M5, M6, M7, 그리고 M8)들은 불완전한 저항성을 나타냈다. 또한 형질전환 계통들 중에 벼 수량을 비교하였으나 M3, M5, M6, 그리고 M7의 수량은 비형질전환 벼와 비교하여 10-18% 감소되었다. 형질전환 계통들에서 수량감소는 주로 이삭당 영화수와 천립중의 감소에 의해 야기되었다. 무처리 조건에서 형질전환 벼의 엽록체와 미토콘드리아의 부분을 혼합하여 측정한 총 PROTOX 활성은 비형질전환 벼에서 보다 17배 더 높았었다. 비형질전환 벼에서 PROTOX 활성은 acifluorfen, oxyfluorfen, carfentrazone-ethyl, 그리고 oxadiazon 처리에 의해 각각 55%, 59%, 53%, 그리고 60% 저해되었다. 그렇지만, 형질전환 벼의 PROTOX 활성들은 무처리 것들과 비슷했다. PROTOX 저해 제초제인, acifluorfen, oxyfluorfen, carfentrazone-ethyl, 그리고 oxadiazon에 의한 형질전환 벼의 생리적 반응은 세포내 전해물질누출과 지질과산화작용에 중점을 두어 평가되었다. 처리된 모든 제초제들은 암기에서 12시간 배양한 다음 광하에 노출시켜진 비형질전환 벼의 처리된 잎 절편으로부터 세포내 전해물질이 다량 누출되었고, 세포내 전해물질은 제초제들의 농도 증대에 따라 증가되었다. 그렇지만, 형질전환 벼의 세포내 전해물질은 1,000 μM 이상의 oxyfluorfen, carfentrazone-ethyl, 그리고 oxadiazon 농도에서도 증가되지 않았다. 비록 형질전환 벼의 세포내 전해물질이 100과 1,000 μM acifluorfen에서 증가하였지만, 그 세포내 전해물질 누출의 크기는 비형질전환 벼보다 형질전환 벼에서 훨씬 적었다. 유사한 결과들은 지질과산화작용의 반응에서도 관찰되었다. 무처리 형질전환 벼의 Proto IX 함량은 무처리 비형질전환 벼의 것보다 약 2배 더 높았다. 벼 식물체가 제초제들에 노출되었을 때, 비형질전환 벼의 Proto IX 축적은 형질전환 벼보다 훨씬 더 높았다. 즉, 비형질전환 벼에 acifluorfen, oxadiazon, oxyfluorfen, 그리고 carfentrazone-ethyl 처리는 무처리에 비해 각각 15, 16, 20, 그리고 21배 더 높았다. Oxyfluorfen (50 g ai ha-1) 처리에 따른 표피와 미세구조의 특징 변화를 확인하기 위한 현미경적 관찰결과, 비형질전환 벼의 처리 후 48시간에 epicuticular wax의 심한 붕괴가 관찰되었지만, 형질전환 벼에서는 관찰되지 않았다. 따라서 형질전환 벼에서 저항성을 보였던 것은 형질전환 벼가 엽록체 및 미토콘드리아 PROTOX가 과다 생성으로 인하여 PROTOX 저해 제초제에 저항성이 유도되어 Proto IX이 축적되지 않았을 것이다. 활성산소종을 소거하는 효소들이 저항성 기작에 관련되어 있는지를 구명하기 위하여, 그 저항성 수준들은 PROTOX 저해 제초제 (acifluorfen, oxyfluorfen, carfentrazone-ethyl, 그리고 oxadiazon)들에 노출시킨 다음에 M. xanthus PROTOX를 발현한 형질전환 벼와 비 형질전환 벼에서 항산화효소를 조사하였다. 형질전환 벼는 비형질전환 벼에 비교하여 oxyfluorfen에서 200배 이상 훨씬 큰 저항성을 지였다. 이 형질전환 벼는 또한 acifluorfen, carfentrazone-ethyl, 그리고 oxadiazon처럼 다른 PROTOX 저해 제초제들에도 교차저항성을 나타냈지만, imazapyr나 paraquat처럼 다른 작용점을 지닌 제초제에선 다중저항성은 보이지 않았다. 비형질전환 벼에 있어, 잎의 엽록소 함량은 oxadiazon 뿐만 아니라 acifluorfen, oxyfluorfen, 및 carfentrazone-ethyl에 의해서도 유의적으로 감소하였으나 형질전환 벼는 감소하지 않았다. 또한 그 PROTOX 저해 제초제들은 비형질전환 벼 잎에서 지질과산화도 야기하였다. 그러나, 형질전환 벼에서의 엽록소 함량과 MDA 생성은 PROTOX 저해 제초제들에 의하여 영향하지 않았다. 한편 비형질전환 벼는 PROTOX 저해 제초제들에 노출된 다음에 형질전환 벼보다 superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, 그리고 glutathione reductase와 같은 항산화효소 활성들이 훨씬 높았다. 유사한 결과는 항산화 동위효소 패턴에서도 관찰되어졌다. 그럼에도 불구하고, 비형질전환 벼에서 유도된 항산화 활성은 PROTOX 저해 제초제들의 독성영향을 회복하기에 충분하지 않았다. 따라서 이들의 결과는 항산화효소들이 PROTOX 저해 제초제에 형질전환 벼의 저항성 기작과 관련이 없음을 의미한다. 형질전환 벼는 이앙 및 담수직파 벼 재배 조건에서 4가지 PROTOX 저해 제초제, acifluorfen, oxyfluorfen, carfentrazone-ethyl, 그리고 oxadiazon에 저항성이었다. 형질전환 벼와 비형질전환 벼는 초장과 분얼수에 있어 유사한 생육양상을 나타냈다. 그렇지만, T4와 T5 세대 형질전환 벼의 수량은 비형질전환 벼의 수량보다 7-8% 더 적었다. 형질전환 벼에서 수량 감소는 이삭당 영화수 및 천립중의 감소에 의해 야기되었다. 비형질전환 벼와 형질전환 벼 사이에 완전미, 미숙미, 그리고 피해미와 같은 미질에 있어선 차이가 없었다. 식미, 단백질, 그리고 아밀로오스 함량은 비형질전환 벼와 형질전환 벼 사이에 유사하였다. 저온피해에 있어 비형질전환 벼와 형질전환 벼 간에 차이가 없었다. 그렇지만, 형질전환 벼와 비형질전환 벼를 한발(旱魃) 스트레스에 7일 동안 노출시켰을 때, 형질전환 벼는 비형질전환 벼보다 한발에 더 내성이 있었다. 이들의 결과를 종합해 볼 때 PROTOX 저해제 저항성 형질전환 벼가 벼 재배에 있어 잡초 저항성 관리에 도움이 될 것이다. 그러나, 비형질전환 벼와 형질전환 벼 사이에 수량 차이와 한발(旱魃) 반응에 근원적인 차이에 대한 기작은 추후 연구가 요망된다. Protoporphyrinogen oxidase (PROTOX)-inhibiting herbicides possess many ideal herbicidal properties; they are effective at low application dosage, rapidly degraded in the environment, and have a broad spectrum for weed control. However, only a few crops such as soybean, peanut, and cotton are known to be relatively tolerant to these herbicides. Such narrow crop selectivity limits the utility of PROTOX-inhibitor herbicides in crop culture. If crops can be made resistant to PROTOX-inhibitor herbicides, the choice and application times of the herbicides would become more flexible, and many troublesome weeds can be controlled. PROTOX-inhibitor herbicides inhibit PROTOX, the last enzyme of the common branch of the chlorophyll- and heme-synthesis pathways. There are two isoenzymes of PROTOX, one of which is located in the chloroplasts and the other in the mitochondria. In particular, a Myxococcus xanthus PROTOX gene, without an additional plastidal transit sequence, is expressed in both the chloroplasts and mitochondria of rice. In this study, eight transgenic rice lines (M1, M2, M3, M4, M5, M6, M7, and M8) expressing M. xanthus PROTOX were tested to know resistance levels to the hygromycin. The transgenic rice line M4 only was perfectly resistant to hygromycin, while other transgenic rice lines (M1, M2, M3, M5, M6, M7, and M8) showed an incomplete resistance, indicating that M. xanthus PROTOX gene was hereditaritly fixed to T3 generation. Grain yields among the transgenic lines were also compared; the yields of M3, M5, M6, and M7, were reduced by 10-18%, compared with wild type (WT). The decreased yield in the transgenic lines was mainly caused by reduction both spikelets per panicle and 1,000 grain weight. The total PROTOX activity, determined with the combined fractions of crude chloroplasts and mitochondria, of transgenic rice in nontreated control was 17-fold higher than in WT rice. PROTOX activities in the WT rice were inhibited by 55%, 59%, 53%, and 60% with acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon treatment, respectively. However, PROTOX activities in transgenic rice were similar to those in nontreated control. The physiological response of transgenic rice to PROTOX-inhibitor herbicides, acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon, was evaluated, focusing on cellular leakage and lipid peroxidation. All tested herbicides caused considerable cellular leakage from the treated leaf squares of WT rice plants upon the exposure of light following 12 h incubation in darkness. The cellular leakage increased with increasing the concentration of the herbicides. For transgenic rice, however, the cellular leakage was not increased with oxyfluorfen, carfentrazone-ethyl, and oxadiazon concentrations of up to 1000 μM. Although cellular leakage in transgenic rice was increased with acifluorfen 100 and 1000 μM, the magnitude of the cellular leakage was much lower in transgenic rice than in WT. Similar results were observed for the response of lipid peroxidation to herbicides. The Proto Ⅸ content of nontreated transgenic rice was about 2-fold greater than that of the nontreated WT. When rice plants were exposed to herbicides, however, the accumulation of Proto IX in WT was much more greater than in transgenic rice; it was a 15, 16, 20, and 21-fold higher in WT with acifluorfen, oxadiazon, oxyfluorfen, and carfentrazone-ethyl treatment, respectively, compared with nontreated control. With oxyfluorfen (50 g ai ha-1) treatment, to confirm the changes of epidermal and ultrastructural features, microscopic observation was conducted. In WT, serious damage was observed in epicuticular wax at 48 h after treatment (HAT), but not for transgenic rice. These results suggest that the transgenic rice did not accumulate Proto IX, probably due to overproduction of chloroplastic and mitichondrial PROTOX, leading to resistance to PROTOX-inhibiting herbicides. To investigate whether active oxygen species-scavenging enzymes are involved in the resistance mechanism, the levels of resistance were quantified on the transgenic rice plants expressing M. xanthus PROTOX when exposed to PROTOX-inhibiting herbicides (i.e. acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon). The transgenic rice had greater resistance more than 200-fold to oxyfluorfen, compared with WT rice plants. This transgenic rice also showed a cross-resistance to other PROTOX-inhibiting herbicides like acifluorfen, carfentrazone-ethyl and oxadiazon, though did not show a multi-resistance to herbicides with different target sites such as imazapyr and paraquat. In WT rice, leaf chlorophyll content was significantly reduced by acifluorfen, oxyfluorfen, and carfentrazone-ethyl as well as by oxadiazon, but not in transgenic rice. Also, the PROTOX-inhibiting herbicides caused a significant lipid peroxidation in WT rice leaves. In transgenic rice, however, the MDA production was not affected by PROTOX-inhibiting herbicides. In addition, the WT rice had greater antioxidant enzyme activities like superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase than transgenic rice, when exposed to PROTOX-inhibiting herbicides. Similar result, in terms of antioxidant isozyme profiles, was observed. Nevertheless, the induced antioxidant activity in WT rice was not enough to overcome a toxic effect of PROTOX-inhibitor herbicides. Inversely, therefore, these results suggest that the antioxidative enzymes were not involved in the resistance mechanism of transgenic rice to PROTOX-inhibiting herbicides. The transgenic rice was resistant to five PROTOX inhibitors, oxyfluorfen, acifluorfen, carfentrazone-ethyl, and oxadiazon in the transplanted and direct-seeded rice culture. The transgenic and WT rice exhibited similar growth behavior, in terms of plant height and number of tillers. However, the grain yield of T4 and T5 transgenic rice was 7-8% less than that of WT. The reduction of yield in the transgenic rice was caused by reduced number of spikelets per panicle and 1,000 grain weight. There were no differences in qualities of milled rice such as head rice, immature rice, and damaged kernel between WT and transgenic rice. The palatability, protein, and amylose contents were similar between WT and transgenic rice. It turned out that there was no difference in chilling injury between WT and transgenic rice. However, when transgenic and WT rice plants were exposed to drought-stress for 7 d, transgenic rice was more tolerant to drought than WT. These results indicate that PROTOX inhibitor-resistant transgenic rice will help in weed resistance management in rice culture. However, more research is required to elucidate the mechanisms underlying the slight yield difference and differential drought response between WT and transgenic rice.

Realistic Dynamic Spectrum Allocation Algorithms for Future Wireless Networks

하정락 충남대학교 대학원 2010 국내박사

Owing to the great progress of radio communication technologies and successful deployment of wireless networks we have various wireless networks around us. A fundamental resource to limit the usage of the wireless networks is the radio frequency spectrum, which is rigidly allocated by the radio regulation authority. The increased demand for high-quality mobile multimedia services requires more allocation of radio spectrum resource but there is no much spectrum left for new assignment. However recent studies show that most of the spectrum in current wireless networks is under-utilized, even unused, most of the time, while some spectrum is heavily used. Dynamic Spectrum Allocation (DSA) is a new and promising alternative to solve this spectrum inefficiency problem allowing dynamic access to the time-varying radio spectrum under consideration of regulatory and technical restrictions. In regard to the spectrum sharing schemes of DSA, there are two major sharing mechanisms: Primary-Primary shared spectrum Usage (PPU) and Primary-Secondary shared spectrum Usage (PSU). The PPU is occurred among Primary Users (PUs) and the PSU among PUs and Secondary Users (SUs). The PU is one who owns the license of the spectrum resource and it may let a SU use some part of its spectrum resource with certain conditions, while the PU does not use it. This dissertation proposes realistic spectrum allocation algorithms for the PPU and the PSU. Regarding the PPU, we propose a realistic spectrum allocation algorithm among PUs that considers the history and prediction of spectrum resource utilization performance. PUs of today (e.g., wireless network operators) are expected to hold their ownership of the present radio frequency spectrum and share some part of their spectrum with other Pus during the intermediate time before a complete transition to the age of a fully common spectrum. Unlike assumptions of the previous studies, the spectrum sharing environment during the intermediate period will not be the \all common," in which all PUs use a common spectrum resources. We present an analytical model of DSA between two networks using a 4-D Markov chain. The presented analytical model is not restricted to a limited scope of DSA, and can be applied to general resource sharing studies. We argue that there may exist a break-even point for deciding whether to adopt DSA in a system. The performance of DSA against the degree of resource sharing using the proposed analytical model and simulations is discussed. In regard to the PSU, we propose a spectrum resource allocation algorithm for a SU with multiple Spectrum Blocks (SBs), where the PUs' utilization of the SBs may differ. Since some modes of the secondary usage of spectrum are granted on the condition that the SU releases the spectrum resource immediately whenever the PU requests. The SU may hop to an idle spectrum resource, if one is available, or the connection is dropped. This Spectrum Hando?? (SHO) lets the ongoing connection continue the session with some possible degradation of Quality of Service (QoS) for a while. We eliminate unrealistic assumptions in some of previous studies and propose a realistic spectrum allocation algorithm to reduce the chances of SHOs among the SBs of PUs. The SBs are prioritized and the SUs' access is allocated to the SBs considering the priority of the SBs. In this dissertation we present a generalized model to efficiently make use of multiple SBs and an analytical model for prioritized resource allocation. The performance is measured by analyzing a Markov chain-based model and simulation results. Besides the proposed spectrum allocation algorithms of PPU and PSU, we discuss several issues related to the spectrum allocation. We suggest a DSA architecture with “community" concept on which the proposed DSA algorithms are carried out. The community concept, in which radio resources of various wireless access networks are managed together, incorporates radio resource management functional entities of wireless access networks that cooperatively work in the community. Regarding the DSA architecture we not only discuss community concept but also model spectrum allocation cycle and spectrum allocation unit. The proposed model simplifies the discussion of DSA algorithms providing abstraction of user traffic in terms of modeling time and spectrum allocation unit.

Optimal separation of toluene and p-Xylene by using the simulated moving bed process : SMB 공정을 이용한 Toluene과 p-Xylene의 최적 분리

임성하 Graduate School, Yonsei University 2004 국내박사

모델 성분으로서 toluene 과 p-xylene 을 사용하여 흡착 특성과 최적의 SMB분리 조건을 연구하였다. 이 논문에서는 크로마토그래프와 실험적인 분석 방법뿐 아니라 강건성 시험, 그리고 최적분리 공정을 위한 SMB 공정 모사를 이용하여 toluene 과 p-xylene 흡착 특성을 알아보았다. Toluene 과 p-xylene의 흡착 특성을 나타내기 위해, 250mm×8.0mm (Eurosil 100-30-C_18) column을 장착한 역상 HPLC를 사용하였고 이동상으로써 일정 조성의 물과 메탄올 2성분을 사용하였다. 크로마토그래프 실험은 농도 C_o 인 흡착 성분의 pulse input과 bed 입구에서의 체류시간 τ 에 기초하였다. 또한 배출 피크 C_e(t)의 정량적인 분석을 위해 moment method를 사용하여 평형과 전달 parameters를 결정하였다. HPLC실험에서 Eurosil 100-30-C_18 흡착제에 대해toluene보다 p-xylene 이 강흡착질임이 밝혀졌다. 저농도 영역에서, 두 성분 사이의 분리도와 선택도는 온도, 유량, 이동상의 조성과 같은 몇몇 공정 조건에 크게 영향을 받았다. 흡착 등온선은 전 온도범위에 걸쳐 거의 “선형적”인 형태를 보였다. 그렇지만 온도가 흡착량에 미치는 영향은 미미하였다. 결과적으로 SMB 공정에서 p-xylene은 강흡착질로, toluene은 약흡착질로 결정되었다. Triangle 이론에 기초하여, 평형 및 전달 parameters로부터 KNAUER (베를린, 독일)사의 모사 프로그램인 SMB_Guide을 사용하여 SMB장치의 공정 조건을 수립하였다. 이것은 초기 공정 조건(초기 밸브 교체 시간, 4개 펌프의 초기 유량, 초기 내부 유량, 초기 feed 유량)으로 사용되었다. 이 초기 공정 조건으로부터 시작하여 각 조작 변수를 조작하여 99% 이상의 toluene과 p-xylene 고순도 생성물을 얻기 위한 최적의 공정 조건을 구할 수 있었다. 게다가, SMB 장비의 각 밸브 교체 시간, 4개 펌프의 유량, 내부 유량, 그리고 feed 유량과 같은 조작 변수의 동적 특성을 자세히 조사해보았다. 그리고 SMB 공정의 강건성 테스트를 통해, feed의 유량과 triangle 구역 내 각 zone의 유량비의 영향을 조사해 보았다. 또한, 모든 실험 결과로부터 구한 생산물의 순도나 농도는 g-PROMS를 이용한 수학적 모델을 이용해 예측되었다. The adsorption characteristics and optimal Simulated Moving Bed (SMB) separating condition for toluene and p-xylene as the model components are studied. This thesis presents not only the adsorption characteristics of toluene and p-xylene by using a chromatographic method but also the experimental analysis, robustness test and simulation of the SMB process for optimizing the separating condition. The Reversed-Phase High Performance Liquid Chromatograph (RP-HPLC) with columns (250mm×8.0mm, Eurosil 100-30-C_18), was employed for the adsorption characteristics in the separation of toluene and p-xylene. Methanol and water were used as the binary mobile phases in the isocratic condition of mobile phase composition. The chromatographic experiments were based on a pulse input of adsorbable tracer of concentration, C_o, and duration time τ into the entrance of the bed. For quantitative analysis of the effluent peak C_e(t), the moment method was used to determine equilibrium and transport parameters [1]. From the preparative HPLC experiment, it was found that p-xylene was stronger adsorbable component than toluene. At the dilute concentration region, the resolution and selectivity between toluene and p-xylene were strongly influenced by the several operating conditions such as temperature, the flow rate, and the composition of eluents. The adsorption isotherms showed the almost "linear" shape for all the temperatures and the effect of temperature was very minute. As a result, it was confirmed that toluene acted as a raffinate and p-xylene as an extract in SMB process. Based on the "triangle method," a shortcut method established by the equilibrium and the transport parameters of a SMB unit was determined by using the KNAUER (Berlin, Germany) simulation program-SMB_1Guide-. It was used as a possible initial operating condition (the initial switching time, the flow rate of the four pumps, the internal flow rate, and the feed flow rate). From this initial operation condition, the optimal operating condition for toluene and p-xylene with over 99% purity was obtained from changing each variable. In addition, the dynamic behaviors by operating variables were investigated in detail, which were the switching time, the flow rate of the four pumps and the internal flow rate at a fixed feed flow rate in SMB unit. As the robustness test in designing the SMB process, the effects of the feed flow rate and flow rate ratio of each zone at "triangle region" were investigated. Moreover, purity and product concentration profiles of all experimental results were predicted by a mathematical model using g-PROMS.