Dynamic Bayesian Networks and Variable Length Genetic Algorithm for Dialogue Act Recognition

The recognition of dialogue act is a task of crucial importance for the processing of natural language in many applications such as dialogue system. However, it is one of the most challenging problems. The current dialogue act recognition models, namely cue-based models, are based on machine learning techniques, particularly statistical ones. Despite the success of the cue-based models, they still have serious drawbacks. Among them are, inadequate representation of dialogue context, intra-utterance and inter-utterances independencies assumptions, inaccurate estimation of the recognition accuracy and suboptimality of the lexical cues selection approaches. Motivating by these drawbacks, this research proposes a new model of dialogue act recognition in which dynamic Bayesian machine learning is applied to induce dynamic Bayesian networks models from task-oriented dialogue corpus using sets of lexical cues selected automatically by means of new variable length genetic algorithm. In achieving this, the research is planned in three main stages. In the initial stage, the dynamic Bayesian networks models are constructed based on a set of lexical cues selected tentatively from the dialogue corpus. The results are compared with the results of static Bayesian networks and naïve bayes. The results confirm the merits of using dynamic Bayesian networks for dialogue act recognition. In the second stage, the previous ranking approaches are investigated for the selection of lexical cues. The main drawbacks of these approaches are highlighted, and based on that an alternative approach is proposed. The proposed approach consists of preparation phase and selection phase. The preparation phase transforms the original dialogue corpus into phrases space. In the selection phase, a new variable length genetic algorithm is applied to select the lexical cues. The results of the proposed approach are compared with the results of the ranking approaches. The results provide experimental evidences on the ability of the proposed approach to avoid the drawbacks of the ranking approaches. In the final stage; the dynamic Bayesian networks models are redesigned using the lexical cues generated from the proposed lexical cues selection approaches. The results confirm the effectiveness of proposed approaches for the design of dialogue act recognition model

The effects and usefulness of blending asynchronous online discussion with face-to-face classes on students’ reading comprehension, participation and learning at first year of secondary school in Saudi Arabia

This study examined the effects and usefulness of blending asynchronous online discussion (AOD) with face-to-face (FTF) reading classes on first-year Saudi Arabian secondary school students’ Arabic reading comprehension, participation, interaction and learning processes. A sequential mixed methodology approach was applied, including quantitative and qualitative research data collection and analysis. Two teachers and 64 students participated. The first part involved a quasi-experimental quantitative design with two groups to examine the impact of BL on students’ comprehension scores. In the control group, 32 students participated in traditional FTF learning only. In contrast, 32 students in the experimental group participated in both FTF and AOD learning via 12 online group discussions over six weeks. Both groups were given the same pre-and post-comprehension tests. The second part involved qualitative semi-structured interviews with 16 students from the experimental, blended group and the two teachers. The third part involved quantitative and qualitative analysis of the AODs. The main finding of this study was that students in the experimental BL group did not improve significantly more than those in the FTF group in overall comprehension post-test scores, or literal, inferential and evaluative comprehension sub-levels. However a comparison within groups revealed that the experimental BL group demonstrated a significant improvement in test scores for overall and all sub-levels of comprehension while students in the control, FTF group only improved significantly in overall and literal comprehension. Overall, this study concludes that although there was no significant effect of blending AOD with FTF reading classes in terms of students’ reading comprehension compared to FTF learning, the integration of AOD design has the potential to benefit students’ participation, learning about comprehension strategies, and interaction. However, there were some challenges that must be considered. A number of recommendations are provided for designing effective AOD activities to support teaching and learning in Arabic reading classes

The Swahili Manuscripts Project at SOAS

Researchers in the field of Swahili studies have noted the need for a comprehensive, detailed catalogue of the Swahili manuscripts at the School of Oriental and African Studies (SOAS, University of London). They have had occasion to make this recommendation in print (see, for example, Omar and Frankl 1994 and Frankl 1999) and - presumably many more times, and to no specified audience - in life, as they pored over unitemised or inaccurately labelled files of eminent scholars in the field. It is precisely this need for a comprehensive, widely accessible catalogue that the Swahili Manuscripts Project at SOAS was established, in October 2001, to address. In this article, the present authors undertake to describe the catalogue being created and to discuss problems they have encountered and observations they have had opportunity to make in the course of their work

Use of Intraoperative Ultrasound (IOUS) in Liver Surgery

Over the last many years, diagnostic imaging has grown from a state of infancy to a high level of maturity. The various imaging modalities were developed over the last 50 years. Ultrasonography is one of the valuable tools in diagnosis of many diseases for a long time. It replaced X-ray in the diagnosis of many different diseases. It is noninvasive and has no complications if used many times in the day even if it is safe during pregnancy. The use of ultrasonography was spread over the years in all branches of medicine. It is promptly used in emergency medicine. Its use was introduced during operations. It showed excellent results when used for the assessment of liver tumors either primary or secondary liver tumors during open surgery and laparoscopy. The use of high-frequency ultrasound probe intraoperatively will nullify the abdominal wall and bowel gas effects on the result

Damage Control in Liver Surgery

Damage control surgery is an old type of surgery practiced for many years to save the lives of badly injured patients. Damage control was first practiced in the American navy where a damaged vessel would receive minimal repair to keep it afloat. This translates to the field of medicine where minimal surgery is performed to save the life of a patient, and minimal action is taken to avoid major ailments, including hypothermia, acidosis, and coagulation defects during major trauma. Before World War II damage control surgery was popular, but later this type of surgery was abandoned. However, with a better understanding of the physiology of trauma and a revision of the outcome of badly injured patients, surgeons have reverted to damage control surgery, for example the packing of bleeding organs such as the liver and the controlling of sepsis, rather than taking patients to intensive care for further assessment. Damage control surgery has many benefits for badly injured patients and improves their chances of survival

Collective Robot Reinforcement Learning with Distributed Asynchronous Guided Policy Search

In principle, reinforcement learning and policy search methods can enable robots to learn highly complex and general skills that may allow them to function amid the complexity and diversity of the real world. However, training a policy that generalizes well across a wide range of real-world conditions requires far greater quantity and diversity of experience than is practical to collect with a single robot. Fortunately, it is possible for multiple robots to share their experience with one another, and thereby, learn a policy collectively. In this work, we explore distributed and asynchronous policy learning as a means to achieve generalization and improved training times on challenging, real-world manipulation tasks. We propose a distributed and asynchronous version of Guided Policy Search and use it to demonstrate collective policy learning on a vision-based door opening task using four robots. We show that it achieves better generalization, utilization, and training times than the single robot alternative.Comment: Submitted to the IEEE International Conference on Robotics and Automation 201

Seismic Velocities and Depth Conversion across the Intisar "D" Field, Sirte Basin, Libya

The Intisar "D" field is one of the oldest fields in the Sirte Basin (Libya), It was discovered by Occidental company in 1966. In 1986 a new 2-D seismic survey was carried out to define the field more accurately, as well as 3-D work being done in the eastern part of the field. This study is concerned mainly with the recent seismic lines and well logs, to produce a new interpretation. The field is situated on the southeast of the Concession 103 area, which lies to the southeast of the Agedabya trough, with the Rakb high to the east and the Zelten platform somewhat farther to the west. The geology of the Intisar "D" field and the Concession 103 was outlined previously by two papers published, more than ten years ago. One was a study of the geology and the depositional history of Intisar "A" field in the northern part of the Concession, while the second paper described the geology and depositional history of Intisar "D" field, together with the exploration techniques and the production system used. The main reservoir is an Upper Palaeocene pinnacle reef containing more than one billion bbl (160 million cu m) of recoverable oil. The reef grew at the same time as the Upper-Sabil platform carbonates were being deposited, At the end of reef growth time near the end of the Palaeocene time, the reefs stopped growing with the introduction of the lower Kheir shales. Seven seismic lines are available, U-14, U-25, U-51, U-53, U-54, U-6, and U-9, and nineteen wells in the field selected for different purposes lithological information, correlation, and velocity information. The main aim of this study, new seismic interpretation of important horizons, and velocity interpretation, with a discussion of why the seismic velocities in the area are inaccurate, and the reprocessing part of line U-14. The tying of well (D1/103) and seismic sections (U14, U25, U51, U53, and U54) are reasonably closely particularly at the Lower Eocene and Upper Palaeocene levels. The other horizons match with small mis-ties approximately (+30 ms). The interpreted horizons are the Upper-Sabil (Upper Palaeocene), Kheir (Upper Palaeocene - Lower Eocene), Gir (top of Lower Eocene), and El-giza (Middle Eocene). The seismic characteristics indicate strongly contrasting acoustic impedance mostly between the sequences of shales from one side and the limestone from the other. The reprocessing of part of line U-14 has resulted in a better defined seismic section, displayed both in migrated time and in depth