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Agregação de tráfego em redes ópticas com multiplexação por comprimetos de onda; Traffic grooming in wavelenght division multiplexing optical networks

Andre Costa Drummond
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/11/2010 PT
Relevância na Pesquisa
76.68%
Em redes ópticas com multiplexação por comprimento de onda (WDM), a alocação de banda passante ocorre em múltiplos da capacidade de um comprimento de onda, que, nos dias de hoje, corresponde a 40 Gbps. No entanto, a demanda de banda passante dos fluxos em redes IP sobre WDM é da ordem de Mbps, o que é, consideravelmente inferior a capacidade de um comprimento de onda. Para a utilização eficiente da grande capacidade disponível em redes WDM, agrega-se diversos fluxos com pequena demandas de banda em caminhos ópticos compostos pelos comprimentos de onda. A referida agregação é realizada pelo mecanismo chamado agregação de tráfego (em Inglês, traffic grooming). Para a agregação, é necessário, que se defina a rota a ser utilizada para o estabelecimento de uma conexão entre pares comunicantes, bem como o comprimento de onda a ser utilizado ao longo da rota, ou seja, é necessário resolver o chamado problema de roteamento e alocação de comprimento de onda (do Inglês, routing ou wavelength assignment, usualmente abreviado por RWA). Por outro lado, aplicações emergente em e-Ciência e novas aplicações multimídia demandam banda passante superior `a capacidade de um comprimento de onda, requerendo que o fluxo seja transmitido em vários caminhos ópticos...

Implementação de WDM com 4 canais no espetro do visível

Reis, João Pedro Alves
Fonte: Instituto Politécnico de Lisboa Publicador: Instituto Politécnico de Lisboa
Tipo: Dissertação de Mestrado
Publicado em /12/2013 POR
Relevância na Pesquisa
76.68%
O presente relatório apresenta a análise optoelectrónica de uma heteroestrutura semicondutora empilhada de fotodíodos PIN, baseada numa liga de silício amorfo hidrogenado (a-Si:H – Hyrogenated Amorphous Silicon) e siliceto de carbono amorfo hidrogenado (a-SiC:H – Hydrogenated Amorphous Silicon Carbide), cujos fotodíodos foram otimizados para deteção de sinais óticos no domínio do visível. O objetivo desta tese é avaliar as capacidades da heteroestrutura em redes WDM (Wavelength Division Multiplexing), para transmissão de sinais óticos a curta distância, utilizando como meio de transmissão as fibra óticas de plástico (POF – Plastic Optical Fiber). O trabalho aqui apresentado vem na sequência de trabalhos anteriores, em que a mesma estrutura foi analisada segundo determinados critérios, para o mesmo fim. A transmissão é feita através de quatro dispositivos LED (Light Emitting Diode) com as cores: vio leta (400 nm), azul (470 nm), verde (525 nm) e vermelho (626 nm). É utilizada radiação de fundo frontal e posterior, de cor violeta, já que testes recentes concluíram ser a que mais beneficia a eficiência na deteção dos sinais. Faz-se uma sucinta caracter ização optoelectrónica da estrutura semicondutora com o objetivo de aferir a influência da radiação de fundo de cor violeta sobre a transmissão...

Sistema WDM de 4 canais

Sousa, Fábio André Rosário
Fonte: Instituto Politécnico de Lisboa Publicador: Instituto Politécnico de Lisboa
Tipo: Dissertação de Mestrado
Publicado em /11/2014 POR
Relevância na Pesquisa
86.77%
O presente relatório apresenta uma análise optoeletrónica de uma heteroestrutura semicondutora empilhada de fotodíodos PIN, baseada numa liga de silício amorfo hidrogenado (a-Si:H – Hydrogenated Amorphous Silicon) e silício de carbeto amorfo hidrogenado (a-SiC:H –Hydrogenated Amorphous Silicon Carbide), cujos fotodíodos foram otimizados para deteção de sinais óticos no domínio do visível. O objetivo desta tese é analisar as capacidades da heteroestrutura nas redes WDM (Wavelength Division Multiplexing), para transmissão de sinais óticos a curta distância, com fibra óticas de plástico (POF – Plastic Optical Fiber) como meio de transmissão. O trabalho desenvolvido surge na sequência de trabalhos anteriormente desenvolvidos, onde foi realizada uma caracterização optoelectrónica da estrutura semicondutora sob diferentes condições de iluminação, variando o comprimento de onda e a radiação de fundo. A transmissão é feita através de quatro dispositivos LED (Light Emitting Diode) com as cores: violeta (400nm), azul (470nm), verde (525nm) e vermelho (626nm). É utilizada radiação de fundo frontal e posterior, de cor violeta, já que testes recentes concluíram ser a que mais beneficia a eficiência na deteção dos sinais. A caracterização optoeletrónica da estrutura semicondutora demonstra a influência da radiação de fundo de cor violeta nos canais de transmissão. A análise aos canais individuais verifica...

Particle swarm optimization in WDM/OCDM networks with physical impairments

Durand,Fábio R.; Abrão,Taufik
Fonte: Sociedade Brasileira de Microondas e Optoeletrônica e Sociedade Brasileira de Eletromagnetismo Publicador: Sociedade Brasileira de Microondas e Optoeletrônica e Sociedade Brasileira de Eletromagnetismo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
76.61%
In this paper, optimization procedures based on particle swarm optimization (PSO) are investigated, aiming to efficiently solve the optimal resource allocation for signal-to-noise plus interference ratio (SNIR) optimization of optical code paths (OCPs) from wavelength division multiplexing/optical code division multiplexing (WDM/OCDM) considering imperfections on physical layer. The characteristic of the PSO is attractive due their performance-complexity tradeoff and fairness regarding the optimization methods that use numerical methods, matrix inversion and other heuristics. The SNIR model considers multiple access interference (MAI) between the OCP based on 2-D codes (time/wavelength), amplifier spontaneous emission (ASE) at cascaded amplified spans, and group velocity dispersion (GVD) and polarization mode dispersion (PMD) dispersion effects. The numerical results have revealed the viability of the PSO algorithm considering solution quality and convergence. Besides, the numerical results have shown a penalty when the ASE, GVD and PMD effects are considered.

Wavelength assignment for realizing parallel FFT on regular optical networks

Chen, Y.; Shen, H.; Liu, F.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
96.67%
Routing and wavelength assignment (RWA) is a central issue to increase efficiency and reduce cost in Wavelength Division Multiplexing (WDM) optical networks. In this paper, we address the problem of wavelength assignment for realizing parallel FFT on a class of regular optical WDM networks. We propose two methods for sequential mapping and shift-reversal mapping of FFT communication pattern to the optical WDM networks concerned. By sequential mapping, the numbers of wavelengths required to realize parallel FFT with 2n nodes on WDM linear arrays, rings, 2-D meshes and 2-D tori are 2n − 1, 2n − 1, 2max (k,n − k) − 1 and 2max (k,n − k) − 1 respectively. By shift-reversal mapping, the numbers of wavelengths required are max (3× 2n − 3,2), 2n − 2, max (3× 2max (k,n − k) − 3,2) and 2max (k,n − k) − 2. These results show that shift-reversal mapping outperforms sequential mapping. Our results have a clear significance for applications because FFT represents a common computation pattern shared by a large class of scientific and engineering problems and WDM optical networks as a promising technology in networking has an increasing popularity.; Yawen Chen, Hong Shen and Fangai Liu; The original publication is available at www.springerlink.com

Multicasting in multihop optical WDM networks with limited wavelength conversion

Shen, H.; Pan, Y.; Sum, J.; Horiguchi, S.
Fonte: IEICE-Inst Electronics Information Communications Eng Publicador: IEICE-Inst Electronics Information Communications Eng
Tipo: Artigo de Revista Científica
Publicado em //2003 EN
Relevância na Pesquisa
86.5%
This paper provides an overview on efficient algorithms for multicasting in optical networks supported by Wavelength Division Multiplexing (WDM) with limited wavelength conversion. We classify the multicast problems according to off-line and on-line in both reliable and unreliable networks. In each problem class, we present efficient algorithms for multicast and multiple multicast and show their performance. We also present efficient schemes for dynamic multicast group membership updating. We conclude the paper by showing possible extension of the presented algorithms for QoS provision.; Hong Shen, Yi Pan, John Sum, Susumu Horiguchi

Wavelength encoding to reduce four-wave mixing crosstalk in multi-wavelength channels

Guo, Yuanbin; Aazhang, Behnaam; Young, James F.; Guo, Yuanbin; Aazhang, Behnaam; Young, James F.
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Conference paper
ENG
Relevância na Pesquisa
96.84%
Conference Paper; The trend toward higher bit rates in lightwave communications has increased interest in dispersion-shifted fiber (DSF) to minimize dispersion penalties. In addition, wavelength-division multiplexing (WDM) is being used to gain even greater capacity, and broad bandwidth erbium-doped fiber amplifiers are extending link distances between signal regeneration. Taken together, these techniques can result in severe performance degradation due to four-wave mixing (FWM). Several different ways of reducing the FWM degradation in WDM systems have been proposed, but all of the approaches increase system complexity and make it difficult to add channels to the system. We show that wavelength-coded multiplexing can provide multiple channels on a simple fiber link while significantly reducing four-wave mixing interference compared to a WDM system. The FWM spectrum is symmetric and use of an antisymmetric code cancels the interference. Wavelength-coded multiplexing is also known as spectral code-division multiplexing (SCDM). We have calculated the error probability in the SCDM system considering only shot noise, thermal noise and FWM crosstalk, all of which are assumed to have a Gaussian distribution. For comparison, we also derived an expression for the error probability in a WDM system.

Wavelength-division-multiplexed distributed fiber Raman amplifier bus network for sensors

Díaz Lucas, Silvia; Lasheras, Gorka; López Amo, Manuel; Urquhart, Paul; Jáuregui Misas, César; López Higuera, José Miguel
Fonte: SPIE Society of Photo-Optical Instrumentation Engineers Publicador: SPIE Society of Photo-Optical Instrumentation Engineers
Tipo: info:eu-repo/semantics/conferenceObject; publishedVersion
ENG
Relevância na Pesquisa
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We experimentally demonstrate a novel application of distributed fibre Raman amplification to a bus network for the wavelength multiplexing of optical sensors. Each sensor is uniquely identified by reflection from a fibre Bragg grating (FBG) and the distributed gain allows the number of sensors to be increased without using costly remote amplifiers. We show how the topology allows the received powers from the sensors to be equalised, even though only one Raman pump wavelength is used and we investigate how the performance depends on the launched pump power. The spectral filtering of the FBGs, combined with the distributed gain, jointly reduce the noise and we report measured signal to noise ratios.

Electrical FIR Filter With Optical Coefficients for Self-Referencing WDM Intensity Sensors

Montalvo, Julio; Araujo, F.M.; Ferreira, L.A.; Vázquez, Carmen; Baptista, José Manuel
Fonte: IEEE Publicador: IEEE
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em 01/01/2008 ENG
Relevância na Pesquisa
76.3%
In this letter, a novel radio-frequency finite impulse reponse (FIR) electrooptical configuration for self-referencing optical wavelength-division-multiplexed intensity sensors is reported. By employing the proposed low-cost electronic FIR filter at the reception stage, the use of a 14-km fiber delay coil is avoided for a 2-kHz modulation frequency, preserving sensitivity and self-reference. The technique is analyzed following the Z-transform formalism and measurements validating the theoretical model are reported.

Fiber optic sensors and self-reference techniques for temperature measurements in different industrial sectors

Tapetado Moraleda, Alberto
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
76.69%
El objetivo de este trabajo se centra especialmente en el desarrollo de sensores de fibra óptica y técnicas de autoreferencia para la medida de la temperatura en diferentes entornos industriales. El primer objetivo de este trabajo consiste en el diseño y desarrollo de un sensor de fibra óptica de bajo coste para la medida de la temperatura en transformadores de potencia y aplicaciones biomédicas. En estas aplicaciones, el uso de sensores de temperatura tradicionales resulta inadecuado debido a la presencia de fuertes interferencias electromagnéticas que pueden perturbar la lectura de la temperatura. Uno de los requisitos fundamentales para diseñar un sensor de temperatura que pueda usarse en aplicaciones biomédicas es el uso de materiales biocompatibles en su fabricación. En este sentido, una configuración simple que permite cumplir con los requisitos mencionados anteriormente es la modulación por intensidad en fibras poliméricas. Este tipo de sensores basan la lectura de la temperatura en medir las variaciones de potencia óptica en función de los cambios de temperatura que se aplican sobre el sensor. En este contexto, el uso de la tecnología asociada con la fibra óptica de plástico ofrece ventajas competitivas frente a otros materiales...

Proposta e implementação de um receptor optoeletrônico integrado para redes ópticas passivas (PONs) empregando multiplexação por divisão de comprimento de onda (WDM); Proposal and implementation of a optoelectronic integrated receiver for passive optical networks (PONs) employing wavelength division multiplexing (WDM)

Manfrin, Stilante Koch
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 01/07/2003 PT
Relevância na Pesquisa
126.71%
O presente trabalho descreve o desenvolvimento e implementação de duas configurações distintas de um receptor optoeletrônico integrado. A primeira configuração é similar a um projeto encontrado na literatura mas apresenta diversas modificações que lhe conferiram melhor desempenho em comparação ao projeto original. A segunda configuração é uma nova proposta deste trabalho. O receptor foi desenvolvido e implementado visando sua aplicação em redes de comunicações ópticas passivas (PONs) de alta velocidade comutadas a pacote, para possibilitar a utilização da técnica de multiplexação em comprimento de onda (WDM), aumentando assim a capacidade de transmissão da rede, em particular no ramo de ligação da rede de serviços com o usuário final, denominado rede de acesso. O principal objetivo do receptor aqui desenvolvido foi proporcionar uma sintonia rápida entre os canais disponíveis na rede, possibilitando sua seleção num tempo inferior àquele necessário para a transmissão de um único pacote de informação, diminuindo assim o atraso de sintonia e, por conseguinte, a perda de informação. Para tanto, os circuitos integrados implementados e caracterizados referem-se aos circuitos de chaveamento eletrônico e do amplificador de transimpedância das duas configurações investigadas. Os dados experimentais obtidos para as duas configurações confirmaram a previsão de chaveamento dos canais de entrada num intervalo de tempo da ordem de alguns nanosegundos...

Simultaneous Mode and Wavelength Division Multiplexing On-Chip

Luo, Lian-Wee; Ophir, Noam; Chen, Christine; Gabrielli, Lucas H.; Poitras, Carl B.; Bergman, Keren; Lipson, Michal
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/06/2013
Relevância na Pesquisa
76.48%
Significant effort in optical-fiber research has been put in recent years into realizing mode-division multiplexing (MDM) in conjunction with wavelength-division multiplexing (WDM) to enable further scaling of the communication bandwidth per fiber. In contrast almost all integrated photonics operate exclusively in the single-mode regime. MDM is rarely considered for integrated photonics due to the difficulty in coupling selectively to high-order modes which usually results in high inter-modal crosstalk. Here we show the first demonstration of simultaneous on-chip mode and wavelength division multiplexing with low modal crosstalk and loss. Our approach can potentially increase the aggregate data rate by many times for on-chip ultra-high bandwidth communications.

Ultra fast quantum key distribution over a 97 km installed telecom fiber with wavelength-division multiplexing clock synchronization

Tanaka, Akihiro; Fujiwara, Mikio; Nam, Sae Woo; Nambu, Yoshihiro; Takahashi, Seigo; Maeda, Wakako; Yoshino, Ken-ichiro; Miki, Shigehito; Baek, Burm; Wang, Zhen; Tajima, Akio; Sasaki, Masahide; Tomita, Akihisa
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
76.29%
We demonstrated ultra fast BB84 quantum key distribution (QKD) transmission at 625 MHz clock rate through a 97 km field-installed fiber using practical clock synchronization based on wavelength-division multiplexing (WDM). We succeeded in over-one-hour stable key generation at a high sifted key rate of 2.4 kbps and a low quantum bit error rate (QBER) of 2.9%. The asymptotic secure key rate was estimated to be 0.78-0.82 kbps from the transmission data with the decoy method of average photon numbers 0, 0.15, and 0.4 photons/pulse.; Comment: 7 pages, 3 figures, v2 : We added a comment on the significance of our work, some minor corrections, and references

Integrated switch for simultaneous mode-division multiplexing (MDM) and wavelength-division multiplexing (WDM)

Stern, Brian; Zhu, Xiaoliang; Chen, Christine P.; Tzuang, Lawrence D.; Cardenas, Jaime; Bergman, Keren; Lipson, Michal
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 16/02/2015
Relevância na Pesquisa
86.57%
Leveraging the spatial modes of multimode waveguides using mode-division multiplexing (MDM) on an integrated photonic chip allows unprecedented scaling of bandwidth density for on-chip communication. Switching channels between waveguides is critical for future scalable optical networks, but its implementation in multimode waveguides must address how to simultaneously control modes with vastly different optical properties. Here we present a platform for switching signals between multimode waveguides based on individually processing the spatial mode channels using single-mode elements. Using this wavelength-division multiplexing (WDM) compatible platform, we demonstrate a 1x2 multimode switch for a silicon chip which routes four data channels with low (<-20 dB) crosstalk. We show bit-error rates below 10^-9 and power penalties below 1.4 dB on all channels while routing 10 Gbps data when each channel is input and routed separately. The switch exhibits an additional power penalty of less than 2.4 dB when all four channels are simultaneously routed.; Comment: 13 pages; 6 figures

Deterministic Raman crosstalk effects in amplified wavelength division multiplexing transmission

Nguyen, Quan M.; Peleg, Avner
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
76.41%
We study the deterministic effects of Raman-induced crosstalk in amplified wavelength division multiplexing (WDM) optical fiber transmission lines. We show that the dynamics of pulse amplitudes in an N-channel transmission system is described by an N-dimensional predator-prey model. We find the equilibrium states with non-zero amplitudes and prove their stability by obtaining the Lyapunov function. The stability is independent of the exact details of the approximation for the Raman gain curve. Furthermore, we investigate the impact of cross phase modulation and Raman self and cross frequency shifts on the dynamics and establish the stability of the equilibrium state with respect to these perturbations. Our results provide a quantitative explanation for the robustness of differential-phase-shift-keyed WDM transmission against Raman crosstalk effects.; Comment: 34 pages and 12 figures. Revised paper. Submitted to Optics Communications

Relaxed laser control of uncooled multiple-input and multiple-output dense wavelength-division multiplexing systems for low power consumption data communication links

von Lindeiner, J. B.; Ingham, J. D.; Penty, R. V.; White, I. H.
Fonte: IEEE Publicador: IEEE
Tipo: Article; accepted version
Relevância na Pesquisa
76.29%
This is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1049/iet-opt.2014.0003; A simulation based assessment is made of the benefits of using advanced modulation formats including Pulse Amplitude Modulation (PAM) and Carrierless Amplitude/Phase Modulation (CAP) to ease laser control requirements of a recently proposed novel uncooled Multiple-input and Multiple-output (MIMO) Wavelength-Division Multiplexing (WDM) system. At a per channel bit rate of 25 Gb/s, the spectral efficiency improvements inherent to these schemes provide additional optical system power margin over NRZ modulation (0.4 dB for PAM-4 and 4.4 dB for CAP-16) for a link distance of 20 km. This allows the minimum channel spacing between channels to be reduced from 0.4 nm (NRZ) to 0.3 nm for PAM-4 and to 0.14 nm for CAP-16, this in turn allowing for a more stable operating region to be realised. Compared with a traditional 16 x 25 Gb/s DWDM system, a power consumption saving of 30% can be realised using NRZ while PAM-4 and CAP-16 offer 29% and 27% savings respectively.; RCUK

Acousto-optic wavelength division multiplexing system

Helaly, Anwar; Abushagur, Mustafa
Fonte: Wiley Periodicals - Microwave and Optical Technology Letters Publicador: Wiley Periodicals - Microwave and Optical Technology Letters
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
96.45%
A novel wavelength division multiplexing/demultiplexing (WDM) system using acousto-optic Bragg cell is presented. The system is adaptable for any wavelength deviation of light sources caused by temperature changes and allows changing the operating wavelengths over a wide range. High diffraction efficiency, high resolution, and a large number of channels are obtained. Computer simulation for a five-channel system in the 0.8-m region is presented.; Microwave and Optical Technology Letters article. Please see www3.interscience.wiley.com for more information.

Two-wavelength planar add/drop WDM filter employing a three-mode coupling Bragg grating

Gaff, K; Ladouceur, Francois; Love, John
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
76.33%
A novel six-port planar waveguide device for adding and dropping two wavelengths from a wavelength division multiplexing singlemode fibre using a single blazed grating is presented. By writing a Bragg grating into a multi-moded core at a particular angle

Multiple End-To-End Delay Contrained Multicasting in Multi-Hop Optical WDM Networks

Liang, Weifa; Vishwanath, Arun
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
86.5%
This paper considers the problem of establishing multiple multicast sessions in a multi-hop optical wavelength division multiplexing (WDM) network simultaneously, such that the sum of the cost of realizing these sessions is minimized and at the same time, the end-to-end delay between each source-destination pair is bounded. The cost of a multicast session is expressed in terms of the cost of using a wavelength on a link and the cost of wavelength conversion at a node. The end-to-end delay is bounded by the sum of communication delays on links and the wavelength conversion delays at intermediate nodes. In this paper, we present a solution to the problem by formulating it into an Integer Linear Program (ILP) and solving the ILP on a representative sized mesh network.

Wavelength Rerouting for On-line Multicast in WDM Networks

Liang, Weifa; Wan, Yingyu
Fonte: Institute of Electrical and Electronics Engineers (IEEE Inc) Publicador: Institute of Electrical and Electronics Engineers (IEEE Inc)
Tipo: Conference paper
Relevância na Pesquisa
86.65%
In this paper we consider wavelength rerouting for on-line multicast in all-optical Wavelength Division Multiplexing (WDM) networks where the multicast requests arrive and depart randomly. One limitation of such networks is the wavelength continuity constraint imposed by the all-optical cross-connect switches that requires the same wavelength be used on all the links in a multicast tree. With random arrivals and departures of multicast requests, it happens quite often that a new multicast request has to be blocked due to the fact that there are not enough available resources (e.g. wavelength) to realize the request. Wavelength rerouting, a viable and cost-effective method, has been proposed to improve the blocking probability, which rearranges the wavelengths on certain existing multicast routes to free a wavelength continuous route for the new request. In this paper, we study the wavelength rerouting problem for on-line multicast in both undirected and directed WDM networks with an objective to minimize the disruption incurred to the existing multicast services, or equivalently, to minimize the number of existing multicast routes to be wavelength-rerouted. We first show that the problem is not only NP-hard but also hard to approximate. We then devise approximation algorithms for it with provable approximation guarantees.