On the Diversity-Multiplexing Tradeoff of Unconstrained Multiple-Access Channels

In this work the optimal diversity-multiplexing tradeoff (DMT) is investigated for the multiple-input multiple-output fading multiple-access channels with no power constraints (infinite constellations). For K users (K>1), M transmit antennas for each user, and N receive antennas, infinite constellations in general and lattices in particular are shown to attain the optimal DMT of finite constellations for the case N equals or greater than (K+1)M-1, i.e., user limited regime. On the other hand for N<(K+1)M-1 it is shown that infinite constellations can not attain the optimal DMT. This is in contrast to the point-to-point case in which infinite constellations are DMT optimal for any M and N. In general, this work shows that when the network is heavily loaded, i.e. K>max(1,(N-M+1)/M), taking into account the shaping region in the decoding process plays a crucial role in pursuing the optimal DMT. By investigating the cases where infinite constellations are optimal and suboptimal, this work also gives a geometrical interpretation to the DMT of infinite constellations in multiple-access channels

Increasing the Efficiency and Productivity in the Production of Low Voltage Switchboard Using Resource Constrained Project Scheduling

Purpose: This research was made with the aim to give a scheduling proposal for the assembly activity and the proposal to allocate those activities into available resources using the resource-constrained project scheduling. Design/methodology/approach: The research begins with the problem exposition in the existing system on the Assembly Department of panel manufacturer company. To overcome the problem, several scheduling alternatives are formulated to yield better productivity. The performance of proposed system using RCPS is assessed using simulation method. Considering the circumstance of demand rate, the scenarios chosen are based on the parameter such as product departure cycle time, resource utilization, product output, and number of resource required. Findings: The scheduling alternatives provides the better arrangement of work elements in the assembly activity, especially for the product that represent the highest demand rate. For further research, the paper gives encouragement so that the application of RCPS can be used broader in the manufacturing area. Research limitations/implications: Although the findings were addressed to improve the existing system on the Assembly Department, the practical application haven’t been undergone and the performance assessment only based on the simulation method. Practical implications: By implementing the proposed scheduling, the company will experience several benefits. First, the company could increase its productivity by better utilization of its resources. Second, based on the simulation result, the company could avoid the backorder option while dealing with the high demand rate, and even can fully maximize its resource utilization without adding more worker or apply the overtime policy. Finally, the proposed scheduling that converted into the work instruction could help the company to perform the knowledge transfer from the existing worker or resigned worker to the newly-hired worker. Originality/value: The outcome of the research could become the guidance for other companies which have similar assembly system to apply the same method. This is the best paper that represents the application of RCPS in the large-sized component assemblies, where the walking worker is responsible for carrying tasks to each unmoved unit.Peer Reviewe

A Model for Pairs of Beatty Sequences

Two Beatty sequences are recorded by athletes running in opposite directions in a round stadium. This approach suggests a nice interpretation for well known partitioning criteria: such sequences (eventually) partition the integers essentially when the athletes have the same starting point

Do Public Colleges in Developing Countries Provide Better Education than Private ones? Evidence from General Education Sector in India

College educational outcomes of students graduating from public colleges in many developing countries are better than those graduating from private colleges. This is attributed to better quality of education provided. However, public colleges are subsidized suggesting that the observed gap might reflect pre-determined differences among students sorting into public colleges. We evaluate the impact of public colleges using a unique dataset that links admission records to college educational outcomes in India. We exploit the features of admission rules in a Regression-Discontinuity-Design, and find that the public colleges have no added value in the neighborhood of the admission cutoff scores. Controlling for entry scores, we find no differences between the exit exam outcomes of students graduating from public and private colleges..

Evaluation of Exchange-Rate, Capital Market, and Dollarization Regimes in the Presence of Sudden Stops

The literature has not being able to identify clear-cut real effects of exchange-rate regimes on output growth. Similarly, no definitive view emerges from the literature in regard to the effects of open capital markets on macroeconomic performance. The paper attributes the failure of the literature to fundamental flaws, consisting of ignoring non-linearities in the effects of exchange rate and capital-market liberalization regimes, on the macroeconomic performance. The paper develops a methodology consisting of accounting for the "crisis-prone state of the economy", summarized by a projected probability of crisis, due to sudden stops in international capital inflows. We apply the new methodology to a cross-country panel of 100 low and middle-income countries. Findings indicate that the effects of exchange rate regimes, and liberalization regimes, on macroeconomic performance go through two distinct channels: a direct channel via the real side of the economy, and an indirect channel via the financial side, which influences the probability of sudden stops. We also analyze how the projected probability of sudden stops affects the level of dollarization, and provide estimates for the effect of dollarization on growth.

Evaluation of Currency Regimes: The Unique Role of Sudden Stops

This paper tackles two established puzzles in international macroeconomics literature. The first is the lack of systematic difference in the macroeconomic performance across exchange rate regimes. The second is the absence of a clear empirical relationship between macroeconomic performance and capital-account liberalization. We suggest that both may appear because empirical methodologies fail to account for a latent economic "crisis state," influenced by exchange-rate and capital account regimes, and to allow the effects of a policy regime on growth to depend on whether the economy is in a crisis-prone latent state. In practice, we model and estimate the latent state of the economy as a crisis probability. In the framework we propose, exchange rate and capital market liberalization regimes can have both a direct effect on short-term growth, and an indirect effect on growth that is channelled through their effects on the crisis probability.

Do Public Colleges in Developing Countries Provide Better Education than Private ones? Evidence from General Education Sector in India

Public college graduates in many developing countries outperform graduates of private ones on the college exit exams. This has often been attributed to the cutting edge education provided in public colleges. However, public colleges are highly subsidized, suggesting that the private-public education outcome gap might reflect the pre-determined quality of the students who sort into public colleges rather than the causal impact of the public tertiary education on students' outcomes. We evaluate the impact of public colleges using a newly assembled unique data set that links admission data with the educational outcomes on a set of common exit exams in India. Admission to general education public colleges is strictly based on the results of the Senior Secondary School examinations. We exploit this feature in a Regression Discontinuity Design, and find that the public colleges have no added value in the neighborhood of the admission cut off scores.private education, public education, India