Oliver Po

dblp:35/2314 · DBLP profile ↗
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24ranked-venue papers
0as first author
4since 2021 · last 2022
—ORCID · none

Domains — the database's venue-derived domains; a paper can count in several

Databases, data management, data science and information retrieval · 17Artificial intelligence and machine learning · 5 · 2 since 2021Applied, interdisciplinary, general and emerging computing · 3 · 1 since 2021Systems, architecture and hardware · 1Computer networks · 1 · 1 since 2021Software engineering, systems software and programming languages · 1Graphics, computer vision, multimedia, augmented reality and games · 1 · 1 since 2021

Expertise — from the expertise taxonomy: the topics of the expert's papers under the CCF categories. A weight counts papers with recency: 1 for a paper about the topic, 0.3 when the topic is its context, halved every five years.

Databases, data mining, and information retrieval
9 papers
Transaction processing and concurrency control · 28% Data integration and cleaning · 14% Distributed and cloud data management · 12%
Artificial intelligence
1 paper
Video understanding and tracking · 50% Reinforcement learning · 50%
Computer networks
4 papers
Edge and fog computing · 64% Content delivery and video streaming · 36%
Computer architecture, parallel and distributed computing, and storage systems
5 papers
Cloud and datacenter computing · 54% Distributed systems · 31% Memory systems · 15%

Topics — the 23 heaviest of 29, each with the papers that count most for it

TopicWeightPapersLastEvidence papers
Computer vision › Video understanding and tracking
video analytics
0.612022
Enhancing Video Analytics Accuracy via Real-time Automated Camera Parameter Tuning · SenSys 2022
Edge and fog computing › video analytics
video analytics pipeline
0.212022
Enhancing Video Analytics Accuracy via Real-time Automated Camera Parameter Tuning · SenSys 2022
Indexing and storage engines
key-value store
0.112012
Partiqle: an elastic SQL engine over key-value stores · SIGMOD Conference 2012
Transaction processing and concurrency control › OLTP
OLTP engine
0.112012
Partiqle: an elastic SQL engine over key-value stores · SIGMOD Conference 2012
Data models and query languages › query interface
query by example
0.112008
UQBE: uncertain query by example for web service mashup · SIGMOD Conference 2008
Data integration and cleaning
schema matching
0.112008
UQBE: uncertain query by example for web service mashup · SIGMOD Conference 2008
Data integration and cleaning › schema matching
uncertain schema matching
0.112008
UQBE: uncertain query by example for web service mashup · SIGMOD Conference 2008
Services computing and microservices › service composition
service mashup
0.112008
UQBE: uncertain query by example for web service mashup · SIGMOD Conference 2008
Cloud and datacenter computing › datacenter services › online service systems › internet services
dynamic content caching
0.122003
Engineering and hosting adaptive freshness-sensitive web applications on data centers · WWW 2003
View Invalidation for Dynamic Content Caching in Multitiered Architectures · VLDB 2002
Data stream processing
continuous query processing
0.112007
Mashup Feeds: : continuous queries over web services · SIGMOD Conference 2007
Data integration and cleaning
web service integration
0.112007
Mashup Feeds: : continuous queries over web services · SIGMOD Conference 2007
Query processing and optimization › view maintenance
incremental view maintenance
0.112005
Incremental Maintenance of Path Expression Views · SIGMOD Conference 2005
Query processing and optimization
materialized view
0.112005
Incremental Maintenance of Path Expression Views · SIGMOD Conference 2005
Query processing and optimization
view maintenance
0.112005
Incremental Maintenance of Path Expression Views · SIGMOD Conference 2005
Content delivery and video streaming › caching
dynamic content caching
0.012004
Challenges and practices in deploying web acceleration solutions for distributed enterprise systems · WWW 2004
Content delivery and video streaming › web content delivery
web acceleration
0.012004
Challenges and practices in deploying web acceleration solutions for distributed enterprise systems · WWW 2004
Distributed systems › replication
database replication
0.012003
Engineering and hosting adaptive freshness-sensitive web applications on data centers · WWW 2003
Indexing and storage engines › caching
database caching
0.012002
Issues and Evaluations of Caching Solutions for Web Application Acceleration · VLDB 2002
Memory systems
cache
0.012002
Issues and Evaluations of Caching Solutions for Web Application Acceleration · VLDB 2002
Distributed systems
query result caching
0.012002
Issues and Evaluations of Caching Solutions for Web Application Acceleration · VLDB 2002
Edge and fog computing
edge caching
0.012003
Engineering and hosting adaptive freshness-sensitive web applications on data centers · WWW 2003
Content delivery and video streaming › caching
web caching
0.012002
View Invalidation for Dynamic Content Caching in Multitiered Architectures · VLDB 2002
Indexing and storage engines
caching
0.012001
Cache Portal: Technology for Accelerating Database-driven e-commerce Web Sites · VLDB 2001

Methods — techniques the papers use, named apart from their topics

reinforcement learning · 1.1SARSA · 1.1workload-driven design · 0.2iterative user feedback · 0.2optimization · 0.2lineage · 0.2caching · 0.2microsharding · 0.1case study · 0.1query result caching · 0.1adaptive caching policy · 0.1stream processing semantics · 0.1incremental view maintenance · 0.1
YearPublicationVenuePosition
2022 Cosine Similarity based Few-Shot Video Classifier with Attention-based Aggregation
abstract
Meta learning algorithms for few-shot video recognition use complex, episodic training but they often fail to learn effective feature representations. In contrast, we propose a new and simpler few-shot video recognition method that does not use meta-learning, but its performance compares well with the best meta-learning proposals. Our new few-shot video classification pipeline consists of two distinct phases. In the pre-training phase, we learn a good video feature extraction network that generates a feature vector for each video. After a sparse sampling strategy selects frames from the video, we generate a video feature vector from the sampled frames. Our proposed video feature extractor network, which consists of an image feature extraction network followed by a new transformer encoder, is trained end-to-end by including a classifier head that uses cosine similarity layer instead of the traditional linear layer to classify a corpus of labeled video examples. Unlike prior work in meta learning, we do not use episodic training to learn the image feature vector. Also, unlike prior work that averages frame-level feature vectors into a single video feature vector, we combine individual frame-level feature vectors by using a new Transformer encoder that explicitly captures the key, temporal properties in the sequence of sampled frames. End-to-end training of the video feature extractor ensures that the proposed Transformer encoder captures important temporal properties in the video, while the cosine similarity layer explicitly reduces the intra-class variance of videos that belong to the same class. Next, in the few-shot adaptation phase, we use the learned video feature extractor to train a new video classifier by using the few available examples from novel classes. Results on SSV2-100 and Kinetics-100 benchmarks show that our proposed few-shot video classifier outperforms the meta-learning-based methods and achieves the best state-of-the-art accuracy. We also show that our method can easily discern between actions and their inverse (for example, picking something up vs. putting something down), while prior art, which averages image feature vectors, is unable to do so.
Biplob Debnath, Oliver Po, Farhan Asif Chowdhury, Srimat T. Chakradhar
ICPR2
2022 ROMA: Resource Orchestration for Microservices-based 5G Applications
abstract
With the growth of 5G, Internet of Things (IoT), edge computing and cloud computing technologies, the infrastructure (compute and network) available to emerging applications (AR/VR, autonomous driving, industry 4.0, etc.) has become quite complex. There are multiple tiers of computing (IoT devices, near edge, far edge, cloud, etc.) that are connected with different types of networking technologies (LAN, LTE, 5G, MAN, WAN, etc.). Deployment and management of applications in such an environment is quite challenging. In this paper, we propose ROMA, which performs resource orchestration for microservices-based 5G applications in a dynamic, heterogeneous, multi-tiered compute and network fabric. We assume that only application-level requirements are known, and the detailed requirements of the individual microservices in the application are not specified. As part of our solution, ROMA identifies and leverages the coupling relationship between compute and network usage for various microservices and solves an optimization problem in order to appropriately identify how each microservice should be deployed in the complex, multi-tiered compute and network fabric, so that the end-to-end application requirements are optimally met. We implemented two real-world 5G applications in video surveillance and intelligent transportation system (ITS) domains. Through extensive experiments, we show that ROMA is able to save up to 90%, 55% and 44% compute and up to 80%, 95% and 75% network bandwidth for the surveillance (watchlist) and transportation application (person and car detection), respectively. This improvement is achieved while honoring the application performance requirements, and it is over an alternative scheme that employs a static and overprovisioned resource allocation strategy by ignoring the resource coupling relationships.
Anousheh Gholami, Kunal Rao, Wang-Pin Hsiung, Oliver Po, Murugan Sankaradass, Srimat T. Chakradhar
NOMS4
2022 Enhancing Video Analytics Accuracy via Real-time Automated Camera Parameter Tuning
abstract
In Video Analytics Pipelines (VAP), Analytics Units (AUs) such as object detection and face recognition running on remote servers critically rely on surveillance cameras to capture high-quality video streams in order to achieve high accuracy. Modern IP cameras come with a large number of camera parameters that directly affect the quality of the video stream capture. While a few of such parameters, e.g., exposure, focus, white balance are automatically adjusted by the camera internally, the remaining ones are not. We denote such camera parameters as non-automated (NAUTO) parameters. In this paper, we first show that environmental condition changes can have significant adverse effect on the accuracy of insights from the AUs, but such adverse impact can potentially be mitigated by dynamically adjusting NAUTO camera parameters in response to changes in environmental conditions. We then present CamTuner, to our knowledge, the first framework that dynamically adapts NAUTO camera parameters to optimize the accuracy of AUs in a VAP in response to adverse changes in environmental conditions. CamTuner is based on SARSA reinforcement learning and it incorporates two novel components: a light-weight analytics quality estimator and a virtual camera that drastically speed up offline RL training. Our controlled experiments and real-world VAP deployment show that compared to a VAP using the default camera setting, CamTuner enhances VAP accuracy by detecting 15.9% additional persons and 2.6%--4.2% additional cars (without any false positives) in a large enterprise parking lot and 9.7% additional cars in a 5G smart traffic intersection scenario, which enables a new usecase of accurate and reliable automatic vehicle collision prediction (AVCP). CamTuner opens doors for new ways to significantly enhance video analytics accuracy beyond incremental improvements from refining deep-learning models.
Sibendu Paul, Kunal Rao, Giuseppe Coviello, Murugan Sankaradass, Oliver Po, Y. Charlie Hu, Srimat T. Chakradhar
SenSys5
2021 F3S: Free Flow Fever Screening
abstract
Identification of people with elevated body temperature can reduce or dramatically slow down the spread of infectious diseases like COVID-19. We present a novel fever-screening system, F3S, that uses edge machine learning techniques to accurately measure core body temperatures of multiple individuals in a free-flow setting. F3S performs real-time sensor fusion of visual camera with thermal camera data streams to detect elevated body temperature, and it has several unique features: (a) visual and thermal streams represent very different modalities, and we dynamically associate semantically-equivalent regions across visual and thermal frames by using a new, dynamic alignment technique that analyzes content and context in real-time, (b) we track people through occlusions, identify the eye (inner canthus), forehead, face and head regions where possible, and provide an accurate temperature reading by using a prioritized refinement algorithm, and (c) we robustly detect elevated body temperature even in the presence of personal protective equipment like masks, or sunglasses or hats, all of which can be affected by hot weather and lead to spurious temperature readings. F3S has been deployed at over a dozen large commercial establishments, providing contact-less, free-flow, real-time fever screening for thousands of employees and customers in indoors and outdoor settings.
Kunal Rao, Giuseppe Coviello, Min Feng 0001, Biplob Debnath, Wang-Pin Hsiung, Murugan Sankaradass, Yi Yang 0018, Oliver Po, Utsav Drolia, Srimat T. Chakradhar
SMARTCOMP8
2016 Strudel: A Framework for Transaction Performance Analyses on SQL/NoSQL Systems
abstract
The paper introduces Strudel, a development and execution framework for transactional workloads both on SQL and NoSQL systems. Whereas a rich set of benchmarks and performance analysis platforms have been developed for SQLbased systems (RDBMSs), it is challenging for application developers to evaluate both SQL and NoSQL systems for their specific needs. The Strudel framework, which we have released as open-source software, helps such developers (as well as providers of NoSQL stores) to build, customize, and share benchmarks that can run on various SQL/NoSQL systems. We describe Strudel’s architecture and APIs, its components for supporting various NoSQL stores (e.g., HBase, MongoDB), example benchmarks included in the release, and performance experiments to demonstrate usefulness of the framework.
Jun'ichi Tatemura, Oliver Po, Hakan Hacigümüs
EDBT2
2014 Automatic entity-grouping for OLTP workloads
abstract
Supporting an online transaction processing (OLTP) workload in a scalable and elastic fashion is a challenging task. Recently, a new breed of scalable systems have shown significant throughput gains by limiting consistency to small units of data called “entity-groups” (e.g., a user's account information stored together with all her emails in an online email service.) Transactions that access the data from only one entity-group are guaranteed of full ACID, but those that access multiple entity-groups are not. Defining entity-groups has direct impact on workload consistency and performance, and doing so for data with a complex schema is very challenging. It is prone to go to extremes - groups that are too fine-grained cause excessive number of expensive distributed transactions while those that are too coarse lead to excessive serialization and performance degradation. It is also difficult to balance conflicting requirements from different transactions. In commercially available entity-group systems, creating entity-groups is usually a manual process, which severely limits the usability of those systems. This paper is the first systematic effort on automating the entity-group design process. Our goal is to build a user-friendly design tool for automatically creating entity-groups based on a given workload and to help users trade consistency for performance in a principled manner. For advanced users, we allow them to provide feedback to the entity-group design and iteratively improve the final output. We demonstrate the effectiveness of our approach with widely used benchmarks. We also present the user experience of a prototype we built.
Jun'ichi Tatemura, Oliver Po, Wang-Pin Hsiung, Hakan Hacigümüs
ICDE3
2012 Partiqle: an elastic SQL engine over key-value stores
abstract
The demo features Partiqle, a SQL engine over key-value stores as a relational alternative for the recent procedural approaches to support OLTP workloads elastically. Based on our microsharding framework [12], it employs a declarative specification, called transaction classes, of constraints applied on the transactions in a workload. We demonstrate use of a transaction class in design and analysis of OLTP workloads. We then demonstrate live-scaling of our fully functioning system on a server cluster.
Jun'ichi Tatemura, Oliver Po, Wang-Pin Hsiung, Hakan Hacigümüs
SIGMOD Conference2
2012 Performance Evaluation of Range Queries in Key Value Stores
Pouria Pirzadeh, Jun'ichi Tatemura, Oliver Po, Hakan Hacigümüs
J. Grid Comput.3
2010 CloudDB: One Size Fits All Revived
abstract
We present a data management platform in the cloud, CloudDB. The guiding principle of CloudDB’s design is establishing data independence for the applications that need to use diverse underlying data stores that are optimized for varying workload needs and characteristics. The applications should not have to be aware of the physical organization of the data and how the data is accessed. Ideally, an application only needs a logical specification of the data access layer and the data access requests are handled in a declarative way. CloudDB hosts variety of specialized databases that deliver high performance, scalability, and cost efficiency for varying application needs. CloudDB’s API layer is designed in such a way to give data independence to the higher level applications. The goal is to let the clients use just a simple, standard, and uniform language API to access data management functions as a service.
Hakan Hacigümüs, Jun'ichi Tatemura, Wang-Pin Hsiung, Hyun Jin Moon, Oliver Po, Arsany Sawires, Yun Chi, Hojjat Jafarpour
SERVICES5
2008 UQBE: uncertain query by example for web service mashup
abstract
The UQBE is a mashup tool for non-programmers that supports query-by-example (QBE) over a schema made up by the user without knowing the schema of the original sources. Based on automated schema matching with uncertainty, the UQBE system returns the best confident results. The system lets the user refine them interactively. A tuple in the query result is associated with lineage that is a boolean formula over schema matching decisions representing underlying conditions on which the corresponding tuple is included in the result. Given binary feedbacks on tuples by the user, which are possibly imprecise, the system solves it as an optimization problem to refine confidence values of matching decisions. The demo features graphical user interaction on the UQBE system, including querying and refinement.
Jun'ichi Tatemura, Songting Chen, Fenglin Liao, Oliver Po, K. Selçuk Candan, Divyakant Agrawal
SIGMOD Conference4
2007 Mashup Feeds: : continuous queries over web services
abstract
Mashup Feeds is a system that supports integrated web service feeds as continuous queries. We introduce collection-based stream processing semantics to enable information extraction by monitoring source evolution over time.
Jun'ichi Tatemura, Arsany Sawires, Oliver Po, Songting Chen, K. Selçuk Candan, Divyakant Agrawal, Maria Goveas
SIGMOD Conference3
2006 Maintaining XPath Views In Loosely Coupled Systems
Arsany Sawires, Jun'ichi Tatemura, Oliver Po, Divyakant Agrawal, Amr El Abbadi, K. Selçuk Candan
VLDB3
2005 WreC: A Scalable Middleware Architecture to Enable XML Caching for Web-Services
Jun'ichi Tatemura, Oliver Po, Arsany Sawires, Divyakant Agrawal, K. Selçuk Candan
Middleware2
2005 Incremental Maintenance of Path Expression Views
abstract
Caching data by maintaining materialized views typically requires updating the cache appropriately to reflect dynamic source updates. Extensive research has addressed the problem of incremental view maintenance for relational data but only few works have addressed it for semi-structured data. In this paper we address the problem of incremental maintenance of views defined over XML documents using path-expressions. The approach described in this paper has the following main features that distinguish it from the previous works: (1) The view specification language is powerful and standardized enough to be used in realistic applications. (2) The size of the auxiliary data maintained with the views depends on the expression size and the answer size regardless of the source data size.(3) No source schema is assumed to exist; the source data can be any general well-formed XML document. Experimental evaluation is conducted to assess the performance benefits of the proposed approach.
Arsany Sawires, Jun'ichi Tatemura, Oliver Po, Divyakant Agrawal, K. Selçuk Candan
SIGMOD Conference3
2004 Challenges and practices in deploying web acceleration solutions for distributed enterprise systems
abstract
For most Web-based applications, contents are created dynamically based on the current state of a business, such as product prices and inventory, stored in database systems. These applications demand personalized content and track user behavior while maintaining application integrity. Many of such practices are not compatible with Web acceleration solutions. Consequently, although many web acceleration solutions have shown promising performance improvement and scalability, architecting and engineering distributed enterprise Web applications to utilize available content delivery networks remains a challenge. In this paper, we examine the challenge to accelerate J2EE-based enterprise web applications. We list obstacles and recommend some practices to transform typical database-driven J2EE applications to cache friendly Web applications where Web acceleration solutions can be applied. Furthermore, such transformation should be done without modification to the underlying application business logic and without sacrificing functions that are essential to e-commerce. We take the J2EE reference software, the Java PetStore, as a case study. By using the proposed guideline, we are able to cache more than 90% of the content in the PetStore and scale up the Web site more than 20 times.
Wen-Syan Li, Wang-Pin Hsiung, Oliver Po, Koji Hino, K. Selçuk Candan, Divyakant Agrawal
WWW3
2003 Freshness-driven Adaptive Caching for Dynamic Content
abstract
With the wide availability of content delivery networks, many e-commerce Web applications utilize edge cache servers to cache and deliver dynamic contents at locations much closer to users, avoiding network latency. By caching a large number of dynamic content pages in the edge cache servers, response time can be reduced, benefiting from higher cache hit rates. However this is achieved at the expense of higher invalidation cost. On the other hand, a higher invalidation cost leads to a longer invalidation cycle (time to perform the invalidation check on the pages in caches) at the expense of freshness of cached dynamic content. In this paper we propose a freshness-driven adaptive dynamic content caching technique, which monitors response time and invalidation cycle length and dynamically adjusts caching policies. We have implemented the proposed technique within NECs CachePortal Web acceleration solution. The experimental results show that the proposed technique consistently maintains the best content freshness to users. The experimental results also show that even a Web site with dynamic content caching enabled can further benefit from deployment of our solution with improvement of its content freshness up to 10 times especially during heavy traffic.
Wen-Syan Li, Oliver Po, Wang-Pin Hsiung, K. Selçuk Candan, Divyakant Agrawal
DASFAA2
2003 CachePortal II: Acceleration of Very Large Scale Data Center-Hosted Database-driven Web Applications
Wen-Syan Li, Oliver Po, Wang-Pin Hsiung, K. Selçuk Candan, Divyakant Agrawal, Yusuf Akca, Kunihiro Taniguchi
VLDB2
2003 Engineering and hosting adaptive freshness-sensitive web applications on data centers
abstract
Wide-area database replication technologies and the availability of content delivery networks allow Web applications to be hosted and served from powerful data centers. This form of application support requires a complete Web application suite to be distributed along with the database replicas. A major advantage of this approach is that dynamic content is served from locations closer to users, leading into reduced network latency and fast response times. However, this is achieved at the expense of overheads due to (a) invalidation of cached dynamic content in the edge caches and (b) synchronization of database replicas in the data center. These have adverse effects on the freshness of delivered content. In this paper, we propose a freshness-driven adaptive dynamic content caching, which monitors the system status and adjusts caching policies to provide content freshness guarantees. The proposed technique has been intensively evaluated to validate its effectiveness. The experimental results show that the freshness-driven adaptive dynamic content caching technique consistently provides good content freshness. Furthermore, even a Web site that enables dynamic content caching can further benefit from our solution, which improves content freshness up to 7 times, especially under heavy user request traffic and long network latency conditions. Our approach also provides better scalability and significantly reduced response times up to 70% in the experiments.
Wen-Syan Li, Oliver Po, Wang-Pin Hsiung, K. Selçuk Candan, Divyakant Agrawal
WWW2
2003 Freshness-driven adaptive caching for dynamic content Web sites
Wen-Syan Li, Oliver Po, Wang-Pin Hsiung, K. Selçuk Candan, Divyakant Agrawal
Data Knowl. Eng.2
2003 Corrigendum to: "Freshness-driven adaptive caching for dynamic content web sites" [Data & Knowledge Engineering 47 (2) (2003) 269-296]
Wen-Syan Li, Oliver Po, Wang-Pin Hsiung, K. Selçuk Candan, Divyakant Agrawal
Data Knowl. Eng.2
2002 View Invalidation for Dynamic Content Caching in Multitiered Architectures
K. Selçuk Candan, Divyakant Agrawal, Wen-Syan Li, Oliver Po, Wang-Pin Hsiung
VLDB4
2002 Issues and Evaluations of Caching Solutions for Web Application Acceleration
Wen-Syan Li, Wang-Pin Hsiung, Dmitri V. Kalashnikov, Radu Sion, Oliver Po, Divyakant Agrawal, K. Selçuk Candan
VLDB5
2002 Evaluations of architectural designs and implementation for database-driven web sites
Wen-Syan Li, Wang-Pin Hsiung, Oliver Po, K. Selçuk Candan, Divyakant Agrawal
Data Knowl. Eng.3
2001 Cache Portal: Technology for Accelerating Database-driven e-commerce Web Sites
Wen-Syan Li, K. Selçuk Candan, Wang-Pin Hsiung, Oliver Po, Divyakant Agrawal, Qiong Luo 0001, Wei-Kuang Waine Huang, Yusuf Akca
VLDB4