Capacity of Locally Recoverable Codes

Motivated by applications in distributed storage, the notion of a locally recoverable code (LRC) was introduced a few years back. In an LRC, any coordinate of a codeword is recoverable by accessing only a small number of other coordinates. While different properties of LRCs have been well-studied, their performance on channels with random erasures or errors has been mostly unexplored. In this note, we analyze the performance of LRCs over such stochastic channels. In particular, for input-symmetric discrete memoryless channels, we give a tight characterization of the gap to Shannon capacity when LRCs are used over the channel.Comment: Invited paper to the Information Theory Workshop (ITW) 201

Construction of Almost Disjunct Matrices for Group Testing

In a \emph{group testing} scheme, a set of tests is designed to identify a small number $t$ of defective items among a large set (of size $N$) of items. In the non-adaptive scenario the set of tests has to be designed in one-shot. In this setting, designing a testing scheme is equivalent to the construction of a \emph{disjunct matrix}, an $M \times N$ matrix where the union of supports of any $t$ columns does not contain the support of any other column. In principle, one wants to have such a matrix with minimum possible number $M$ of rows (tests). One of the main ways of constructing disjunct matrices relies on \emph{constant weight error-correcting codes} and their \emph{minimum distance}. In this paper, we consider a relaxed definition of a disjunct matrix known as \emph{almost disjunct matrix}. This concept is also studied under the name of \emph{weakly separated design} in the literature. The relaxed definition allows one to come up with group testing schemes where a close-to-one fraction of all possible sets of defective items are identifiable. Our main contribution is twofold. First, we go beyond the minimum distance analysis and connect the \emph{average distance} of a constant weight code to the parameters of an almost disjunct matrix constructed from it. Our second contribution is to explicitly construct almost disjunct matrices based on our average distance analysis, that have much smaller number of rows than any previous explicit construction of disjunct matrices. The parameters of our construction can be varied to cover a large range of relations for $t$ and $N$.Comment: 15 Page

On a Duality Between Recoverable Distributed Storage and Index Coding

In this paper, we introduce a model of a single-failure locally recoverable distributed storage system. This model appears to give rise to a problem seemingly dual of the well-studied index coding problem. The relation between the dimensions of an optimal index code and optimal distributed storage code of our model has been established in this paper. We also show some extensions to vector codes.Comment: A small new section and new references added. A minor error corrected from the previous versio

Rancang Bangun Tempat Sampah Pintar dengan Sistem Monitoring Berbasis Cloud dan Internet of Things (IoT) Menggunakan Metode Rule-Based

Cleaning staff sometimes experience delays in emptying trash bins because inspections are conducted manually. This method is inefficient as it can lead to trash accumulation, causing odors and potential health hazards. Therefore, this study aims to improve the efficiency of waste management. The research method used in this study includes design and development, involving needs analysis, system design, system implementation, and system testing. In this study, a trash bin monitoring system was designed using the ESP32 microcontroller, the HC-SR04 sensor to detect bin capacity, and the MQ-135 sensor to detect ammonia gas content in the trash. The system can detect the bin's capacity, the last cleaning time, and the ammonia odor in the trash. The determination of trash collection actions is carried out using a rule-based method with 100% accuracy, and notifications are sent via Telegram

Social Engineering Approach to Air Quality Challenge: The Case of Kathmandu

Occasional Papers in Sociology and Anthropology - Volume 6, 200

Profesionalism in Balinese Traditional Performing Art its Challenge and Opportunity

The change in paradigm of how to view and define the actuality of arts such as professionalism has caused a new discourse to appear. Currently, an artist, as the main doer of an art, does not only face the matter pertaining to how to create new creations but also the matter pertaining to the quality of life through arts. As far as the Balinese traditional performing art is concerned, professionalism which contributes to the income of an artist still matters. It is true that some artists of the Balinese traditional performing art have earned a living from the performing art they perform; however, their number is too limited. The opportunity is wide enough as the performing art has been an integrated part of the Balinese community and one form of the Balinese culture which is highly compatible. To make the opportunity come true, that is, being highly holistic professional, the Balinese traditional performing art artists should be able to face challenges and acquire support from the community and government. They should continuously make achievements and be able to read situation. The community is expected to give opportunity and support to them. In addition, the government with its political and economic strengths is expected to be able to give protection to what the artists are entitled to. Keywords: Professionalism, Maecenas, and performing art

Evacuated glazing with tempered glass

The application of tempered glass has made it possible to significantly reduce the support pillar number within evacuated glazing (EG) since tempered glass (T-glass) is four to ten times mechanically stronger than annealed glass (A-glass). The thermal transmittance (U-value) of 0.4 m by 0.4 m double evacuated glazing (DEG) with 4 mm thick T-glass and A-glass panes with emittance of 0.03 were determined to be 0.3 Wm−2K−1 and 0.57 Wm−2K−1, respectively (47.4% improvement) using previously experimentally validated finite volume model. The thermal transmittance (U-value) of 0.4 m by 0.4 m triple evacuated glazing (TEG) with 4 mm thick T-glass and A-glass panes with emittance of 0.03 were determined to be 0.11 Wm−2K−1 and 0.28 Wm−2K−1, respectively (60.7% improvement). The improvement in the U-value of EG with T-glass is due to a reduction in support pillar number, leading to reduction in heat conduction through pillar array. The impact of tempered glass on the thermal transmittance for TEG is greater than that of DEG since radiative heat transfer in TEG is much lower than that in DEG, thus the reduction in heat conduction resulted from the reduction of support pillar number in TEG is much larger than that in DE