Data Transmission with Reduced Delay for Distributed Acoustic Sensors

This paper proposes a channel access control scheme fit to dense acoustic sensor nodes in a sensor network. In the considered scenario, multiple acoustic sensor nodes within communication range of a cluster head are grouped into clusters. Acoustic sensor nodes in a cluster detect acoustic signals and convert them into electric signals (packets). Detection by acoustic sensors can be executed periodically or randomly and random detection by acoustic sensors is event driven. As a result, each acoustic sensor generates their packets (50bytes each) periodically or randomly over short time intervals (400ms~4seconds) and transmits directly to a cluster head (coordinator node). Our approach proposes to use a slotted carrier sense multiple access. All acoustic sensor nodes in a cluster are allocated to time slots and the number of allocated sensor nodes to each time slot is uniform. All sensor nodes allocated to a time slot listen for packet transmission from the beginning of the time slot for a duration proportional to their priority. The first node that detect the channel to be free for its whole window is allowed to transmit. The order of packet transmissions with the acoustic sensor nodes in the time slot is autonomously adjusted according to the history of packet transmissions in the time slot. In simulations, performances of the proposed scheme are demonstrated by the comparisons with other low rate wireless channel access schemes.Comment: Accepted to IJDSN, final preprinted versio

Quark number Susceptibility and Phase Transition in hQCD Models

We study the quark number susceptibility, an indicator of QCD phase transition, in the hard wall and soft wall models of hQCD. We find that the susceptibilities in both models are the same, jumping up at the deconfinement phase transition temperature. We also find that the diffusion constant in the soft wall model is enhanced compared to the one in the hard wall model.Comment: 14 pages, 2 figure

Information Quality Assessment in Korean manufacturing Organization

Information quality is a complex problem. Issues relating to information quality are strongly embedded in the context of the operations of information systems. Information quality issues, therefore, have qualitative as well as quantitative underpinnings, which affect on the various dimensions of information quality. In order to improve information quality, it is essential to assess its various dimensions. This assessment provides the gaps that work as the building blocks for improving quality of information. However, assessing information quality dimensions is extremely intricate because each dimension depends upon other dimensions, which makes it difficult to objectively assess these dimensions. This research utilizes a product perspective of information and applies Six-Sigma methodology to assess information quality. It describes a case study of a Korean manufacturing organization where analytical hierarchy process and quality function deployment was utilized to determine the mutual relationships of information quality dimensions and critical to information quality factors

Practice Of Accounting Conservatism In MBE Firms

Managers sometimes manage earnings upward (i.e., engage in earnings management) or guide analyst forecasts downward (i.e., engage in expectation management) to meet or beat analysts’ earnings forecasts (MBE). Our results suggest that certain management behavior to achieve MBE is highly associated with firms’ level of accounting conservatism. In detail, we find that (1) the level of accounting conservatism decreases as firms achieve MBE in consecutive years, (2) engaging in earnings management to achieve MBE lowers firms’ level of conservatism, and (3) firms that achieve MBE in consecutive years (CMBE firms) whose credit rating had been elevated practice less conservative accounting implying that the MBE string itself might act as a substitute for conservative accounting in lowering firms’ cost of debt