Interference detection in gaussian noise

Interference detection in gaussian noise is proposed. It can be applied for easy detection and editing of interference lines in radio spectral line observations. One need not know the position of occurence or keep track of interference in the band. Results obtained on real data have been displayed.Comment: 10 pages, 11 figure

Exporting Telecommunications Regulation: The U.S.-Japan Negotiations on Interconnection Pricing

Since 1997, the U.S. government has attempted to use the World Trade Organization (WTO) agreement on telecommunications services as a vehicle for 'exporting' American principles of telecommunications regulation to other nations. The United States took the position in 1997 that the WTO telecommunications agreement requires its signatory nations to follow the practices of the Federal Communications Commission (FCC) on telecommunications regulatory policy. Subsequently, the Office of the U.S. Trade Representative (USTR) has sought to influence, under the implicit threat of trade sanctions, Japan's domestic regulatory policy on the pricing of mandatory competitor access to the unbundled elements of the local network belonging to the operating companies of Nippon Telegraph and Telephone Corporation (NTT). In this Article, we examine the substantive difficulties of engrafting the FCC's interconnection policy onto the telecommunications marketplace of another nation. For more than five years, many American experts on telecommunications policy have disagreed whether American consumers have benefited from the very FCC policies that the USTR would have Japanese regulators emulate. The USTR's initiative appears to ignore that the transition to costoriented rates for interconnection and retail telecommunications services has been a difficult and unfinished process in the United States; that the cost models used by the FCC to set interconnection prices have significant deficiencies; that actual interconnection prices both within and outside the United States diverge considerably from the estimates of the FCC's cost models; that variations across countries in the prices of inputs have a significant effect on the costs of interconnection; and that, with respect to depreciation in particular, regulators treat this cost differently'and, from an economic perspective, more reasonably'in Japan than in the United States. Such substantive economic considerations suggest why the FCC's policy in this area has generated continuous litigation, including two Supreme Court cases, since 1996 and consequently is too unresolved at this point in the American experience for the United States to force on its trading partners. Next, we ask whether the USTR has the detailed knowledge required to negotiate trade agreements on interconnection pricing. We question the propriety of using the USTR to influence the domestic regulatory policy of another country on a topic as complex as the efficient pricing of mandatory access to unbundled network elements. The USTR's power to formulate trade policy on this subject resides in officials who are unlikely to possess the economic expertise and resources necessary to evaluate the consumer-welfare implications of the policies that they would have Japan and other nations adopt. For these reasons, the USTR cannot credibly make the interconnection pricing policies of another nation a legitimate concern of U.S. trade policy.

Problem-dependent attention and effort in neural networks with an application to image resolution

This paper assesses a new classification approach that examines low-resolution images first, only moving to higher resolution images if the classification from the initial pass does not have a high degree of confidence. This multi-stage strategy for classification can be used with any classifier and does not require additional training. The approach is tested on five common datasets using four different classification approaches. It is found to be effective for cases in which at least some fraction of cases can be correctly classified using coarser data than are typically used. neural networks performing digit recognition, for instance, the proposed approach reduces the resource cost of classifying test cases by 60% to 85% with less than 5% reduction in accuracy

The Role of Specific Subjects in Education Production Functions: Evidence from Morning Classes in Chicago Public High Schools

Absences in Chicago Public High Schools are 3-7 days per year higher in first period than at other times of the day. This study exploits this empirical regularity and the essentially random variation between students in the ordering of classes over the day to measure how the returns to classroom learning vary by course subject, and how much attendance in one class spills over into learning in other subjects. We find that having a class in first period reduces grades in that course and has little effect on long-term grades or grades in related subjects. We also find moderately-sized negative effects of having a class in first period on test scores in that subject and in related subjects, particularly for math classes.education production, subject-specific, math, English, morning classes, first period, course schedule, quasi-experimental, attendance, absenteeism, Chicago, high school

The US School Breakfast Program: Short- and Long-Term Academic Effects

This paper evaluates short- and long-term academic effects of the US School Breakfast Program (SBP). The paper divides into four sections: an introduction (page 4), a literature review (page 11), a statistical model (page 31), and an empirical model (page 38). In the first section, we cover general facts and details about the SBP. In the second section, we first review literature relevant to the SBP (supply, demand, and short-term effects studies). Next, we explore studies of the long-term effects of schooling and of school quality. Many of the techniques and information from these studies relate to our discussion of long-term effects of the SBP. In the third section, we formalize our argument that the SBP exercises short- and long-term effects on students\u27 performance. Our discussion of the statistical model follows the format of the flow chart on page 86. In the fourth section, we empirically test the hypotheses that the SBP improves students\u27 attendance and expected education levels. We use pooled statewide aggregate data to measure attendance rates, and we use cross-sectional longitudinal data to measure education levels. We find that the SBP does raise attendance and education levels. We are able to quantify the attendance effect and decompose it into two separate effects. We are not able to quantify the effect on educational attainment, but we do find a lower bound for the SBP\u27s effect on high school graduation. Given this lower bound, we are able to calculate a lower bound for the income effect of the SBP. We compare our calculated income effect with two possible alternatives. We find that a dollar spent on the SBP yields a substantially higher return than the 10-year Treasury Bill interest rate. We also find that, dollar for dollar, the SBP\u27s income effect rivals Card and Krueger\u27s estimated income effect for classroom size reduction. We do not find convincing evidence that this return can be achieved by indiscriminately increasing the number of SBP participants. These findings indicate that recent efforts to expand the SBP through universal free breakfasts could be better directed. Indiscriminate expansion of the SBP does earn a fairly high return. Nevertheless, our research suggests that selective expansion of the SBP could capitalize on significantly higher economic returns

Evidence of a mis-aligned secondary bar in the Large Magellanic Cloud

Evidence of a mis-aligned secondary bar, within the primary bar of the Large Magellanic Cloud (LMC) is presented. The density distribution and the de-reddened mean magnitudes ($I_0$) of the red clump stars in the bar obtained from the OGLE II data are used for this study. The bar region which predominantly showed wavy pattern in the line of sight in \citet{a03} was located. These points in the X-Z plane delineate an S-shaped pattern, clearly indicating a mis-aligned bar. This feature is statistically significant and does not depend on the considered value of $I_0$ for the LMC center. The rest of the bar region were not found to show the warp or the wavy pattern. The secondary bar is found to be considerably elongated in the Z-direction, with an inclination of 66$^o$.5 $\pm$ 0$^o$.9, whereas the undisturbed part of the primary bar is found to have an inclination of 15$^o$.1 $\pm$ 2$^o$.7, such that the eastern sides are closer to us with respect to the western sides of both the bars. The PA$_{maj}$ of the secondary bar is found to be 108$^o$.4 $\pm$ 7$^o$.3. The streaming motions found in the H I velocity map close to the LMC center could be caused by the secondary bar. The recent star formation and the gas distribution in LMC could be driven by the mis-aligned secondary bar.Comment: 10 pages, to appear in ApJ Letter