In this digital era, transmitting data through a computer network has become common. Moreover, some applications have also been developed to do it. Nevertheless, users may not be aware of the security aspect of this data transmission, which can lead to disclosing this private message. In a case when a sensitive message is the object to transmit, a security mechanism should be applied. Data hiding is one of the methods introduced to work for this issue. In this algorithm, the message is embedded into the cover, such as an audio file, before being transmitted; on the other side, the recipient extracts it. However, the size of the message and the quality of the resulted stego data are still challenging. In this paper, we focus on these two problems by considering some factors: embedding space, embedding process, reducing, and smoothing steps. Firstly, the audio signal is discretized to obtain audio samples. Next, these samples are interpolated to provide spaces for hiding the secret. Considering that the quality of the generated stego audio is likely to drop, reducing and smoothing steps are designed. The experimental results show that this approach can improve the quality of the stego based on the specified payload capacity. That is, there is an increase in PSNR value of at least 10 dB, depending on the payload size and the methods.

Well-designed instructional material is equally important for successful e-Learning implementation. Teachers and instructors play a major role in terms of designing and building learning content. In one respect, it requires costs in terms of effort, time and experience. In other respects, a good learning content is likely a result of recurring revisions as a result of teaching experience as well as evaluating student activities. In the case of higher educational institutions (HEI) in developing countries (such as Indonesia), resource sharing in many aspects is highly recommended effort against high cost and redundant works, e-Learning is no exception. Sharing and re-using e-Learning content on particular subject between Learning Management Systems (LMS) can be one of the methods. In addition, collaborative teaching may cause a content develops gradually while conducting content sharing. Thus, the capability of synchronizing the content between LMS is necessary. On the other hand, typical e-Learning implementation might not be appropriate due to the concerns of network infrastructure in developing countries. In some areas, the network has less bandwidth and even frequent disconnections. This paper introduces a novel method of sharing e-Learning content between distributed Learning Management Systems by using dynamic content synchronization. This method also suites the need of course sharing which supports collaborative teaching activity. Moreover, this approach is designed to address the needs of content sharing in areas with network infrastructure limitation in terms of bandwidth and availability.

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