Universal Three Dimensional Optical Logic

Modern integrated circuits are essentially two-dimensional (2D). Partial three-dimensional (3D) integration and 3D-transistor-level integrated circuits have long been anticipated as routes to improve the performance, cost and size of electronic computing systems. Even as electronics approach fundamental limits however, stubborn challenges in 3D circuits, and innovations in planar technology have delayed the dimensional transition. Optical computing offers potential for new computing approaches, substantially greater performance and would complement technologies in optical interconnects and data storage. Nevertheless, despite some progress, few proposed optical transistors possess essential features required for integration into real computing systems. Here we demonstrate a logic gate based on universal features of nonlinear wave propagation: spatiotemporal instability and collapse. It meets the scaling criteria and enables a 3D, reconfigurable, globally-hyperconnected architecture that may achieve an exponential speed up over conventional platforms. It provides an attractive building block for future optical computers, where its universality should facilitate flexible implementations.Comment: manuscript (5 pages, 3 figures) with supplementary information (6 pages, 5 figures

Demonstration of superluminal effects in an absorptionless, non-reflective system

We present an experimental and theoretical study of a simple, passive system consisting of a birefringent, two-dimensional photonic crystal and a polarizer in series, and show that superluminal dispersive effects can arise even though no incident radiation is absorbed or reflected. We demonstrate that a vector formulation of the Kramers-Kronig dispersion relations facilitates an understanding of these counter-intuitive effects.Comment: 6 pages, 3 figures, accepted on Physical Review Letter

The impact of paternity leave on long-term father involvement

.Household production; Father involvement; paternal leave

The Impact of Paternity Leave on Long-term Father Involvement

Using Norwegian registry data we investigate how paternity leave affects fathers’ long-term earnings. In 1993 Norway introduced a paternity quota of the paid parental leave. We estimate a difference-in-differences model which exploits differences in fathers' exposure to the paternity quota. Our analysis suggests that four weeks paternity leave during the child’s first year decreases fathers’ future earnings by 2.1 percent. Importantly, this effect persists up until our last point of observation when the child is five years old. The earnings effect is consistent with increased long-term father involvement, as fathers shift time and effort from market to home production. In an investigation of Norwegian time use data we find additional evidence for this hypothesis.father involvement, household production, parental leave

Faster-than-light effects and negative group delays in optics and electronics, and their applications

Recent manifestations of apparently faster-than-light effects confirmed our predictions that the group velocity in transparent optical media can exceed c. Special relativity is not violated by these phenomena. Moreover, in the electronic domain, the causality principle does not forbid negative group delays of analytic signals in electronic circuits, in which the peak of an output pulse leaves the exit port of a circuit before the peak of the input pulse enters the input port. Furthermore, pulse distortion for these superluminal analytic signals can be negligible in both the optical and electronic domains. Here we suggest an extension of these ideas to the microelectronic domain. The underlying principle is that negative feedback can be used to produce negative group delays. Such negative group delays can be used to cancel out the positive group delays due to transistor latency (e.g., the finite RC rise time of MOSFETS caused by their intrinsic gate capacitance), as well as the propagation delays due to the interconnects between transistors. Using this principle, it is possible to speed up computer systems.Comment: 13 pages, 5 figures, 2001 Photonic West Plenary Tal

Review of Writing Your Master’s Thesis: From A to Zen

This is a review of the book Writing Your Master’s Thesis: From A to Zen by Lynn P. Nygaard

ANALISA BIAYA PROYEK PEMBANGUNAN JALAN BATAS BALIKPAPAN – SIMPANG SAMBOJA MENGGUNAKAN METODE KONSEP NILAI HASIL KABUPATEN KUTAI KARTANEGARA

Pemerintah mengambil langkah aktif dalam mengatasi kesenjangan infrastruktur antarwilayah, salah satunya melalui program pembangunan jalan untuk mempercepat pertumbuhanekonomi masyarakat pedesaan. Untuk mencapai hasil yang diinginkan, manajemen konstruksiyang baik dan tepat waktu, biaya, dan mutu sangat penting. Setiap proyek konstruksi unik dandipengaruhi oleh berbagai faktor seperti lokasi geografis, iklim, dan karakteristik penduduksetempat. Dalam konteks pelaksanaan proyek di Kabupaten Kutai Kartanegara, metode KonsepNilai Hasil digunakan untuk menganalisis biaya, waktu, dan keuntungan pada akhir pelaksanaanproyek dengan detail.Besaran biaya aktual akhir waktu pada pelaksanaan proyek PembangunanJalan Batas Batas Balikpapan – Simpang Samboja Kabupaten Kutai Kartanegara.ialah sebesarRp. 1,430,100,104.99. Besaran persentasi keuntungan yang didapat oleh pelaksana pada akhirwaktu pelaksanaan pekerjaan proyek Pembangunan Gedung Prasarana Pendukung PertanianDesa Sidomulyo Kecamatan Anggana Kabupaten Kutai Kartanegara ialah sebesar : 20 % (Halini dengan ditunjukannya nilai CPI (cost performance index) pada akhir waktu pelaksanaanproyek minggu ke 11 dengan indeks biaya sebesar 1,25 > 1 yang artinya kinerja penyelenggaraanproyek lebih baik dari pada perencanaan atau biaya pengeluaran lebih kecil dari biaya anggaranrencana.)

Examining the relationship between student performance and video interactions

In this work, we attempted to predict student performance on a suite of laboratory assessments using students' interactions with associated instructional videos. The students' performance is measured by a graded presentation for each of four laboratory presentations in an introductory mechanics course. Each lab assessment was associated with between one and three videos of instructional content. Using video clickstream data, we define summary features (number of pauses, seeks) and contextual information (fraction of time played, in-semester order). These features serve as inputs to a logistic regression (LR) model that aims to predict student performance on the laboratory assessments. Our findings show that LR models are unable to predict student performance. Adding contextual information did not change the model performance. We compare our findings to findings from other studies and explore caveats to the null-result such as representation of the features, the possibility of underfitting, and the complexity of the assessment.Comment: 4 pages, 1 figure, submitted to the PERC 2018 proceeding