On the expected diameter, width, and complexity of a stochastic convex-hull

We investigate several computational problems related to the stochastic convex hull (SCH). Given a stochastic dataset consisting of $n$ points in $\mathbb{R}^d$ each of which has an existence probability, a SCH refers to the convex hull of a realization of the dataset, i.e., a random sample including each point with its existence probability. We are interested in computing certain expected statistics of a SCH, including diameter, width, and combinatorial complexity. For diameter, we establish the first deterministic 1.633-approximation algorithm with a time complexity polynomial in both $n$ and $d$. For width, two approximation algorithms are provided: a deterministic $O(1)$-approximation running in $O(n^{d+1} \log n)$ time, and a fully polynomial-time randomized approximation scheme (FPRAS). For combinatorial complexity, we propose an exact $O(n^d)$-time algorithm. Our solutions exploit many geometric insights in Euclidean space, some of which might be of independent interest

Mesin Pengering Kapasitas Limapuluh Baju Sistem Tertutup

Bagi pengusaha laundry, mesin pengering baju sangat diperlukan. Dengan adanya mesin pengering baju, pada saat musim hujan tiba, pengusaha laundry tidak perlu merasa cemas dan takut kalau bajunya tidak akan kering, jika sewaktu-waktu hujan datang. Selain itu, dengan adanya mesin pengering, target jumlah baju yang akan dikeringkan per hari mudah ditentukan, karena waktu pengeringan baju tertentu dan bersifat tetap. Proses pengeringan juga dapat dilakukan setiap saat, baik siang hari maupun malam hari. Selain merakit mesin pengering baju, tujuan dari penelitian ini adalah (a) mengetahui kondisi udara masuk ruang pengering baju, dan (b) mendapatkan waktu yang diperlukan mesin pengering untuk mengeringkan 50 baju secara serentak. Mesin pengering baju bekerja dengan sumber energi listrik, mempergunakan mesin yang bekerja dengan siklus kompresi uap. Energi listrik dipergunakan untuk menggerakkan kompresor dari mesin kompresi uap dan menggerakkan kipas angin untuk mengalirkan udara yang dipergunakan untuk proses pengeringan baju. Komponen utama mesin siklus kompresi uap adalah: kompresor, kondensor, pipa kapiler, evaporator dan peralatan tambahan filter, dengan fluida kerja R134a. Kompresor yang dipergunakan sebanyak 2 buah, masing masing dengan daya 1,5 PK, sedangkan ukuran komponen yang lain menyesuaikan dengan besarnya daya kompresor. Kipas angin yang dipergunakan sebanyak 2 buah masing masing dengan daya sebesar 54 watt yang dipasang di dekat kondensor, dan 2 buah kipas, masing masing dengan dengan daya 50 watt, yang difungsikan untuk mengalirkan udara dari ruang pengering ke ruang mesin siklus kompresi uap. Almari pengering dirancang untuk kapasitas 50 baju, dengan sistem tertutup. Penelitian dilakukan dengan memvariasikan kondisi awal pakaian basah: (a) hasil perasan tangan dan (b) hasil perasan mesin cuci. Jenis pakaian: batik, ukuran XL. Penelitian memberikan hasil, mesin pengering baju yang dirakit dapat bekerja dengan baik, dan (a) mampu mengkondisikan udara masuk ke dalam ruang pengeringan baju dengan suhu udara bola kering (Tdb) sekitar 74 C dan suhu udara bola basah sekitar 34 C. (b) mampu mengeringkan 50 baju basah hasil perasan tangan secara serentak dalam waktu sekitar 150 menit dan mampu mengeringkan 50 baju basah hasil perasan mesin cuci secara serentak dalam waktu sekitar 70 menit

Hybrid solid state qubits: the powerful role of electron spins

We review progress on the use of electron spins to store and process quantum information, with particular focus on the ability of the electron spin to interact with multiple quantum degrees of freedom. We examine the benefits of hybrid quantum bits (qubits) in the solid state that are based on coupling electron spins to nuclear spin, electron charge, optical photons, and superconducting qubits. These benefits include the coherent storage of qubits for times exceeding seconds, fast qubit manipulation, single qubit measurement, and scalable methods for entangling spatially separated matter-based qubits. In this way, the key strengths of different physical qubit implementations are brought together, laying the foundation for practical solid-state quantum technologies.Comment: 54 pages, 7 figure

Filopodia: molecular architecture and cellular functions

Filopodia are thin, actin-rich plasma-membrane protrusions that function as antennae for cells to probe their environment. Consequently, filopodia have an important role in cell migration, neurite outgrowth and wound healing and serve as precursors for dendritic spines in neurons. The initiation and elongation of filopodia depend on the precisely regulated polymerization, convergence and crosslinking of actin filaments. The increased understanding of the functions of various actin-associated proteins during the initiation and elongation of filopodia has provided new information on the mechanisms of filopodia formation in distinct cell types

Thin film refractive index and thickness

Integrated optics are a contemporaneous reality in which thin-film technology and methods utilized in the development of integrated circuitry, are applied to both optical circuits and devices. This provides systems that show improved characteristics when compared to their electronic counterparts. Optical systems enable wider bandwidth operation, less power consumption, more immunity to interference and higher cost-efficiency. These features definitely represent a huge improvement in our daily lives when completely embedded in Information and Communications Technologies, replacing a large percentage of contemporaneous electronic based systems. The building blocks of these optical systems consist on waveguides and structures formed by deposited thin films. Two characteristics of utmost importance for these structures are the height and refractive index of the deposited film. In this work and by using a prism coupler, we will be presenting an optical setup and the experimental method that is used to determine both refractive index and thickness of the wave guiding structure.info:eu-repo/semantics/publishedVersio

Regenerating Rat Liver: Correlations Between Estrogen Receptor Localization and Deoxyribonucleic Acid Synthesis

Estrogen receptor activity was quantitated in the cytosol and nucleus of normal rat liver and in regenerating rat liver at several time intervals after 75% hepatectomy. Cytosolic estradiol binding in regenerating liver decreases at 12, 24, and 48 h after hepatectomy and at 48 h is 30% of that in normal rat liver. Nuclear estrogen binding 48 h after surgery is elevated fivefold over normal values. No alterations in affinity of the receptor for estrogen have been observed. Specificity studies indicate that the estrogen receptors from both normal and regenerating liver were similar and are highly specific for estrogens. These changes in cellular distribution of receptors parallel increases in nuclear deoxyribonucleic acid synthesis and mitotic indices in the liver. © 1984, American Gastroenterological Association. All rights reserved

Effect of an antiandrogenic H<inf>2</inf> receptor antagonist on hepatic regeneration in rats

Because biochemical 'feminization' of the liver in males is observed with hepatic regeneration and because the hepatic regenerative response in females is greater than that in males, the posibility that antiandrogens might potentiate liver regeneration was investigated. Before 70% hepatectomy, adult male Wistar rats were treated with cimetidine, and antiandrogenic H2 antagonist, at doses up to 10 times greater than those used clinically. Control animals received either the saline vehicle or ranitidine, an H2 antagonist without antiandrogenic properties. Treatment with cimetidine reduced the hepatic cytosolic androgen receptor content compared with ranitidine treatment. Hepatectomy caused a further reduction in androgen receptor activity in all groups. Hepatic cytosolic estrogen receptor activity was comparable in all groups throughout the study. Moreover, the rate of liver growth and the levels of ornithine decarboxylase and thymidine kinase activity induced as part of the regenerative response were similar in all groups. Thus, cimetidine, despite its ability to bind to androgen receptors, and ranitidine, an H2 receptor antagonist without antiandrogen action, do not modulate the hepatic regenerative response to a 70% partial hepatectomy

Inovasi Mesin Pengering Pakaian yang Praktis, Aman dan Ramah Lingkungan

Pada saat ini mesin pengering pakaian sangat diperlukan terutama pada saat musim hujan tiba atau ketika sinar matahari sulit untuk diperoleh. Tujuan dari penelitian ini adalah mendapatkan mesin pengering yang praktis, aman dan ramah lingkungan. Hasil dari pengeringan pakaian ini adalah kondisi pakaian kering yang siap untuk disetrika. Mesin pengering pakaian yang diteliti mempergunakan sumber energi dari listrik. Energi listrik dipergunakan untuk menggerakkan kompresor rotari dan kipas angin. Dalam bekerjanya, mesin pengering mempergunakan mesin siklus kompresi uap dengan komponen utama : kompresor, kondensor, pipa kapiler, evaporator dan peralatan tambahan filter. Kompresor yang dipergunakan sebanyak 2 buah, masing masing sebesar 1 PK, sedangkan ukuran komponen yang lain menyesuaikan dengan besarnya daya kompresor. Untuk mengalirkan udara, dipergunakan 2 kipas angin masing masing berdaya 54 watt. Almari pengering dirancang untuk kapasitas 20 pakaian, dengan ukuran p x l x t : 120 cm x 60 cm x 130 cm, dengan sistem terbuka. Mesin pengering pakaian yang dirakit (a) mampu mengkondisikan udara di dalam lemari tanpa beban, pada suhu udara kering (Tdb) 59,5oC dan dengan kelembaban udara (RH) sekitar 5%. (b) mampu mengeringkan 20 pakaian baju basah hasil perasan tangan sekaligus dalam waktu 120 menit dan mampu mengeringkan 20 pakaian baju basah hasil perasan mesin cuci sekaligus dalam waktu 60 menit. Untuk 15 pakaian basah hasil perasan tangan diperlukan waktu 110 menit. Kata kunci : mesin pengering pakaian, siklus kompresi uap, kecepatan pengeringan

Estrogen Binding Protein Activity in Morris Hepatoma 7777 Compared With Normal Rat Liver

Estrogen binding protein activities were determined in the cytosol from adult male Buffalo rat liver and Morris hepatoma 7777. Estrogen receptors were prepared using the protamine sulfate precipitation technique of Chamness. The ability of various unlabeled steroids competing with [3H]estradiol was examined to establish the binding specificity. Estradiol binding in Morris hepatoma 7777 cytosol was greatly decreased compared with that present in hepatic cytosol prepared from normal rat liver. The receptor concentration expressed as femtomoles per milligram of cytoplasmic protein was 31.1 ± 2.9 SD for normal rat liver and 0.41 ± 0.88 SD for the hepatoma. Gel filtration chromatography revealed the presence of an estrogen binder in hepatoma cytosol which was not present in either normal liver or in the protamine sulfate precipitates of hepatoma cytosol. The molecular weight, binding specificity, and precipitation of this protein by specific antiserum suggests that it is α-fetoprotein. © 1984, American Gastroenterological Association. All rights reserved