Improving an interactive simulator for computer systems with learning objects

In the 21st century, learning is a crucial activity through which people can assimilate or acquire new knowledge. However, many existing e-Iearning systems contain complicated knowledge structure that hinders the reuse or sharing of knowledge. In a previous project awarded by the Microsoft Research Asia, we successfully developed an interactive simulator to facilitate the learning of essential concepts related to computer systems through live animations. Here, we propose to integrate learning objects and relevant technologies into our interactive simulator to illustrate the underlying knowledge structure and, more importantly, facilitate the sharing and reuse of relevant concepts. Through adopting the IEEE learning object metadata (LOM) standard, our simulator can easily exchange relevant learning objects with other e-Iearning systems. The system design and prototype implementation of our LOM-based simulator is considered in this paper to evaluate how general and experienced users can benefit from our LOM-based simulator in various ways. © 2010 IEEE.published_or_final_versionThe 2nd International Conference on Education Technology and Computer (ICETC 2010), Shanghai, China, 22-24 June 2010. In Proceedings of the International Conference on Education Technology and Computer, 2010, v. 3, p. 16-2

Toward a complete e-learning system framework for semantic analysis, concept clustering and learning path optimization

Most online e-learning systems often demand the pre-requisite requirements between course modules and/or some relationship measures between involved concepts to be explicitly inputed by the course instructors so that an optimizer can be ultimately used to find an optimal learning sequence of involved concepts or modules for each individual learner after considering his/her past performance, learner's profile, learning style, etc. However, relying solely on the course instructor's input on the relationship among the involved concepts can be imprecise possibly due to the individual biases by human experts. Furthermore, the decision will become more complicated when various instructors hold conflicting views on the relationship among the involved concepts that may hinder any reasonable deduction. Therefore, we propose in this paper a complete system framework that can perform an explicit semantic analysis on the course materials, possibly aided by the relevant Wiki articles for any missing information about the involved concepts, to formulate the individual concepts, and followed by a heuristic-based concept clustering algorithm to group relevant concepts before finding their relationship measures. Lastly, an evolutionary optimizer will be used to return the optimal learning sequence after considering multiple experts' recommended learning sequences possibly containing conflicting views. To demonstrate the feasibility of our prototype, we implemented a prototype of the proposed e-learning system framework. Our empirical evaluation clearly revealed the possible advantages of our proposal with many possible directions for future investigation. © 2012 IEEE.published_or_final_versio

Applying an evolutionary approach for learning path optimization in the next-generation e-learning systems

Learning analytics is targeted to better understand and optimize the process of learning and its environments through the measurement, collection and analysis of learners' data and contexts. To advise people's learning in a specific subject, most intelligent e-learning systems would require course instructors to explicitly input some prior knowledge about the subject such as all the pre-requisite requirements between course modules. Yet human experts may sometimes have conflicting views leading to less desirable learning outcomes. In a previous study, we proposed a complete system framework of learning analytics to perform an explicit semantic analysis on the course materials, followed by a heuristic-based concept clustering algorithm to group relevant concepts before finding their relationship measures, and lastly employing a simple yet efficient evolutionary approach to return the optimal learning sequence. In this paper, we carefully consider to enhance the original evolutionary optimizer with the hill-climbing heuristic, and also critically evaluate the impacts of various experts' recommended learning sequences possibly with conflicting views to optimize the learning paths for the next-generation e-learning systems. More importantly, the integration of heuristics can make our proposed framework more self-adaptive to less structured knowledge domains with conflicting views. To demonstrate the feasibility of our prototype, we implemented a prototype of the proposed e-learning system framework for learning analytics. Our empirical evaluation clearly revealed many possible advantages of our proposal with interesting directions for future investigation. © 2013 IEEE.published_or_final_versio

Hepatic cancer stem cell marker granulin-epithelin precursor and β-catenin expression associate with recurrence in hepatocellular carcinoma

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Survival advantage of primary liver transplantation for hepatocellular carcinoma within the up-to-7 criteria with microvascular invasion

PURPOSE: Microvascular invasion of hepatocellular carcinoma (HCC) is considered a poor prognostic factor of liver resection (LR) and liver transplantation (LT), but its significance for lesions within the up-to-7 criteria is unclear. This study investigated the survival benefit of primary LT against LR for HCC with microvascular invasion and within the up-to-7 criteria. METHODS: Adult patients who underwent LR or LT as the primary treatment for HCC were included for study. Patients with prior local ablation, neoadjuvant systemic chemotherapy, targeted therapy, positive resection margin, or metastatic spread were excluded. RESULTS: There were 471 LR patients and 95 LT recipients (70 with living donor, 25 with deceased donor). Seventy-seven (81.1%) LT recipients had HCC within the up-to-7 criteria. Twenty-five (26.3%) LT recipients had HCC with either macrovascular (n = 4) or microvascular (n = 21) invasion. The 5-year survival rate was 85.7% for LT recipients with HCC within the up-to-7 criteria, unaffected by the presence or absence of vascular invasion (88.2 vs. 85.1%). The rate was comparable with that of LR patients with HCC without vascular invasion (81.2%, p 0.227), but far superior to that of LR patients with lesions with vascular invasion (50.0%, p < 0.0001). Overall survivals were compromised by multiple tumors [odds ratio (OR) 1.902, confidence interval (CI) 1.374-2.633, p = 0.0001], vascular invasion (OR 2.678, CI 1.952-3.674, p < 0.0001), blood transfusion (OR 2.046, CI 1.337-3.131, p = 0.001), and being beyond the up-to-7 criteria (OR 1.457, CI 1.041-2.037, p = 0.028). LT was a favorable factor for survival (OR 0.243, CI 0.130-0.454, p < 0.0001). CONCLUSION: Primary LT for HCC with microvascular invasion and within the up-to-7 criteria doubled the chance of cure as compared with LR.published_or_final_versio

Anode modification of polyfluorene-based polymer light-emitting devices

A glycerol-modified poly(3,4-ethylene dioxythiophene) (PEDOT): poly(styrene sulfonate) (PSS) layer was used as an anode buffer layer in polymer light-emitting devices using poly(9,9-dioctylfluorene) (F8) as the emitter. Devices with a configuration of indium tin oxide/PEDOT:PSS (with or without glycerol)/F8/CsF/Al were fabricated. It was found that the glycerol-modified device showed a much larger current density than the unmodified device. At an operating voltage of 6 V, the glycerol-modified device showed a luminance of 1300Cd/m 2 and a current efficiency of 1.7 Cd/A compared to the corresponding values of 500Cd/m 2 and 1.3 Cd/A in the unmodified device. Analysis by ultraviolet spectroscopy suggests that the two devices have the same energy level structure and the performance improvement should not be due to change in the PEDOT/polymer interface. It was further found that incorporating a suitable amount of glycerol into the PEDOT:PSS layer can increase its conductivity by six times. This leads to a better balance in the hole and electron currents and thus improved device efficiency. © 2002 American Institute of Physics.published_or_final_versio

Correlation of liver stiffness and histological features in healthy persons and in patients with occult hepatitis B, chronic active hepatitis B, or hepatitis B cirrhosis

OBJECTIVES: Liver stiffness measurement using transient elastography has become a popular tool to assess liver fibrosis. The aim of this study was to determine liver stiffness values and histological features in healthy subjects and in patients with chronic hepatitis B (CHB).METHODS: A total of 157 people were included (28 healthy subjects and 18 patients with occult hepatitis B infection, 102 with active CHB, and 9 with end-stage hepatitis B cirrhosis). Histology and liver stiffness measurements were obtained from all patients.RESULTS: The median liver stiffness in healthy subjects and in occult hepatitis B, active hepatitis B, and end-stage cirrhosis patients was 4.6, 4.2, 8.7, and 33.8 kPa, respectively. In healthy subjects and in patients with occult hepatitis B infection, none had significant fibrosis on histology, and all had liver stiffness 7.2 kPa. In patients with active CHB, 32 (31%) had liver stiffness 11.0 kPa, but only four (12%) had cirrhosis on histology. Using liver stiffness to predict cirrhosis in this group had a sensitivity of 100%, a specificity of 69%, a positive predictive value of 10%, and a negative predictive value of 100%. All nine patients with end-stage liver cirrhosis had liver stiffness 11.0 kPa. The overall area under the ROC curve (AUROC) for diagnosing cirrhosis using a cutoff of 11.3 kPa was 0.89.CONCLUSIONS: Liver stiffness measurement has an overall good diagnostic accuracy with excellent negative predictive value. However, in active CHB with elevated alanine aminotransferase (ALT) levels, the positive predictive value for diagnosing cirrhosis is poor, and further studies are needed to optimize the use of transient elastography in this important group. © 2010 by the American College of Gastroenterology.postprin

Clinical relevance and therapeutic potential of angiopoietin-like protein 4 in hepatocellular carcinoma

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