Generalized Interlinked Cycle Cover for Index Coding

A source coding problem over a noiseless broadcast channel where the source is pre-informed about the contents of the cache of all receivers, is an index coding problem. Furthermore, if each message is requested by one receiver, then we call this an index coding problem with a unicast message setting. This problem can be represented by a directed graph. In this paper, we first define a structure (we call generalized interlinked cycles (GIC)) in directed graphs. A GIC consists of cycles which are interlinked in some manner (i.e., not disjoint), and it turns out that the GIC is a generalization of cliques and cycles. We then propose a simple scalar linear encoding scheme with linear time encoding complexity. This scheme exploits GICs in the digraph. We prove that our scheme is optimal for a class of digraphs with message packets of any length. Moreover, we show that our scheme can outperform existing techniques, e.g., partial clique cover, local chromatic number, composite-coding, and interlinked cycle cover.Comment: Extended version of the paper which is to be presented at the IEEE Information Theory Workshop (ITW), 2015 Jej

A New Index Coding Scheme Exploiting Interlinked Cycles

We study the index coding problem in the unicast message setting, i.e., where each message is requested by one unique receiver. This problem can be modeled by a directed graph. We propose a new scheme called interlinked cycle cover, which exploits interlinked cycles in the directed graph, for designing index codes. This new scheme generalizes the existing clique cover and cycle cover schemes. We prove that for a class of infinitely many digraphs with messages of any length, interlinked cycle cover provides an optimal index code. Furthermore, the index code is linear with linear time encoding complexity.Comment: To be presented at the 2015 IEEE International Symposium on Information Theory (ISIT 2015), Hong Kon

Graph-Theoretic Approaches to Two-Sender Index Coding

Consider a communication scenario over a noiseless channel where a sender is required to broadcast messages to multiple receivers, each having side information about some messages. In this scenario, the sender can leverage the receivers' side information during the encoding of messages in order to reduce the required transmissions. This type of encoding is called index coding. In this paper, we study index coding with two cooperative senders, each with some subset of messages, and multiple receivers, each requesting one unique message. The index coding in this setup is called two-sender unicast index coding (TSUIC). The main aim of TSUIC is to minimize the total number of transmissions required by the two senders. Based on graph-theoretic approaches, we prove that TSUIC is equivalent to single-sender unicast index coding (SSUIC) for some special cases. Moreover, we extend the existing schemes for SSUIC, viz., the cycle-cover scheme, the clique-cover scheme, and the local-chromatic scheme to the corresponding schemes for TSUIC.Comment: To be presented at 2016 IEEE Global Communications Conference (GLOBECOM 2016) Workshop on Network Coding and Applications (NetCod), Washington, USA, 201

Does Information Transparency Decrease Coordination Failure?

This study experimentally tests the effect of information transparency on the probability of coordination failure in global games with finite signals. Prior theory has shown that in global games with unique equilibrium, the effect of information transparency is ambiguous. We find that in global games where the signal space is finite, increased transparency has two effects. First, increasing the level of transparency usually destroys uniqueness and precipitates multiple equilibria, so that the effect of transparency on coordination depends crucially upon which equilibrium is actually attained. Second, the level of transparency determines which of these equilibria is risk dominant. We find that increased transparency facilitates coordination only if it switches the risk-dominant equilibrium from the secure equilibrium to the efficient equilibrium. When the converse is true, improved transparency can be dysfunctional because it increases the probability of coordination failure.

KAJIAN REAKTIVITAS STABILITAS STRUKTUR SENYAWA MIRISTIN DAN TURUNANNYA DENGAN MENGGUNAKAN METODE FUNGSIONAL KERAPATAN

Perhitungan struktur elektronik dari senyawa miristisin beserta turunannya telah dilakukan guna menggali informasi mengenai reaktivitas dan stabilitas dari masing-masing struktur serta menentukan senyawa yang berpotensi memiliki efek terpeutik yang lebih besar. DFT indeks reaktivitas kimia global (kekerasan kimia, total energi, potensial kimia elektronik dan elektrofilitas) dihitung pada tingkat teori B3LYP/6-31G*. Seluruh perhitungan dilakukan dengan menggunakan perangkat lunak Spartan 14 terlisensi. Berkaitan dengan tujuan eksplorasi konsistensi hasil teoretis-eksperimental, investigasi spektroskopi UV/Vis, IR, 1H NMR, dan 13C NMR dari data eksperimental dan hasil perhitungan juga dilakukan. Hasil investigasi menunjukkan beberapa posisi dari spektra perhitungam memiliki kecocokan dengan spektra eksperimental. Berdasarkan hasil yang diperoleh, stabilitas senyawa tertinggi yang ditinjau berdasarkan perhitungan deskriptor kekerasan kimia (η) diperoleh dari senyawa miristisin-H (2,905 eV). Potensial kimia elektronik (µ) juga diperoleh dari perhitungan selisih HOMO-LUMO dengan nilai µ tertinggi dimiliki oleh miristisin-NH2 (-2,49 eV). Reaktivitas senyawa tertinggi yang ditinjau berdasarkan perhitungan deskriptor kekerasan kimia (η)  dan perhitungan potensial kimia elektronik (µ) diperoleh dari miristisin-Br dengan nilai η=1,33 eV dan ω =-4,56 eV. Sedangkan indeks elektrofilitas menentukan bahwa miristisin-NH2 adalah yang paling neukleofilik dan miristisin-Br adalah yang paling elektrofilik. Miristisin-normal bersifat nukleofilik. Keberadaan halida membuat turunan miristisin menjadi bersifat elektrofilik. Di sisi lain, miristisin dengan substituen amino turut menaikkan reaktivitas senyawa turunan tersebut dan tetap mempertahankan karakternya sebagai nukleofilik. Sehingga senyawa miristisin-NH2 adalah yang paling disarankan, karena diduga memiliki efek terapeutik yang lebih baik dibanding senyawa miristisin-normal

Restorative Practices in the Reduction of Disciplinary Alternative Education Program Placement and Recidivism

Johnson-Pearson, Chandra V., Restorative practices in the reduction of disciplinary alternative education program placement and recidivism. Doctor of Philosophy (Counselor Education), August, 2020, Sam Houston State University, Huntsville, Texas. The ASCA National Model charged professional school counselors with supporting the social-emotional/personal-social growth, development, and success of all students. The public school need for DAEP placement was driven by problematic behavior displayed by students, which spoke to the inadequate social-emotional/personal-social development of those students with behavioral challenges. As such, DAEP placement recidivism spoke to the inadequate social-emotional/personal-social development of students with behavioral challenges. Thus, concern for effective interventions to reduce DAEP placement and recidivism fell well within the realm of professional school counseling and the role of the professional school counselor. Therefore, the purpose of this case study was to describe how DAEP staff members, interacted with students placed in DAEP settings in ways that resulted in the students not returning to DAEPs for additional placements. The purpose was achieved by examining the data gathered from demographic questionnaires and virtual interviews with DAEP staff at a DAEP facility in an urban school district in southeast Texas. Alarmingly few studies of DAEP best practices had been conducted. Among the few studies that focused exclusively on DAEPs, only four in the last 20 years were statewide in focus with three being Texas-specific. The paucity of research focusing specifically on restorative practices related to DAEP re-enrollment is even more shocking. One central research question was relevant to this case study. What are the lived experiences of educational professionals working in Disciplinary Alternative Education Program settings who are implementing restorative justice practices for students placed in a Disciplinary Alternative Education Program? The emergent themes participants reported as consistently occurring aligned with Compliance Theory, the theoretical framework of this study, and could be identified as remunerative and normative organizational power types which resulted in the students reacting with commitment and calculative behaviors, positive types of behaviors conducive to a healthy school culture and climate. The emergent themes participants reported as primarily occurring at the home campus aligned with Compliance Theory coercive power tactics resulting in student alienative reactions leading to reduced organization effectiveness and dysfunction. The emergent themes not only aligned with theoretical underpinnings, but also previous research DAEP best practices and practices to avoid

Scavenge performance of an optimized shallow sump at various flow conditions

Oil scavenge flow in aero-engine bearing chamber remains largely a challenging problem for many engine designers. Research campaign on scavenge flow has been conducted by G2TRC - Gas Turbine and Transmissions Research Centre (previously Rolls Royce University Technology Centre in Gas Turbine Transmission Systems) at the University of Nottingham. It was recognized that a deep sump performs better than shallower one due to its ability to "shield"the collected oil in the sump from the shaft windage, thus reducing the amount of oil being picked up by the bulk air rotation. However, such a deep sump design cannot be employed in some engines and especially at certain locations where space is limited. A parametric study combined with phenomenological approach on shallow sump geometry has been conducted and presented in the previous publication, where a certain optimized shallow sump variant was proposed depending on whether the flow in the chamber is wall film dominated or airborne droplets dominated. The parametric phenomenological approach was employed since it can be done relatively quicker than typical data gathering through an experiment. However, the approach relies on qualitative interpretation of the flow features, and its application in bearing chamber flow research has never been validated before. This paper presents the results of quantitative measurements of residence volumes of an optimized shallow sump variant identified in the parametric phenomenological study. Comparison was then made with the residence volumes of some existing engine sumps. It was found that the optimized shallow sump for wall film dominated flow has lower residence volumes compared to some existing engine sumps. In some cases, the residence volume can be reduced by up to 75%. An optimized shallow sump variant for airborne droplets dominated was also identified in the previous parametric phenomenological study, although the residence volume measurement is yet to be conducted. The optimized shallow sump for wall film dominated flow was also identified as a good sump regardless of the flow regime. However, when it was tested in airborne droplets dominated flow, its residence volumes are higher than some of the existing engine sumps. This highlights the importance of considering the flow regime in the bearing chamber in any attempt to optimize a sump geometry