| 14171. |
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| 14172. |
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| 14173. |
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| 14174. |
- Österlund, Helene, et al.
(författare)
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Determination of total chlorine and bromine in solid wastes by sintering and inductively coupled plasma-sector field mass spectrometry
- 2009
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 29:4, s. 1258-1264
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Tidskriftsartikel (refereegranskat)abstract
- A sample preparation method based on sintering, followed by analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS) for the simultaneous determination of chloride and bromide in diverse and mixed solid wastes, has been evaluated. Samples and reference materials of known composition were mixed with a sintering agent containing Na2CO3 and ZnO and placed in an oven at 560 °C for 1 h. After cooling, the residues were leached with water prior to a cation-exchange assisted clean-up. Alternatively, a simple microwave-assisted digestion using only nitric acid was applied for comparison. Thereafter the samples were prepared for quantitative analysis by ICP-SFMS. The sintering method was evaluated by analysis of certified reference materials (CRMs) and by comparison with US EPA Method 5050 and ion chromatography with good agreement. Median RSDs for the sintering method were determined to 10% for both chlorine and bromine, and median recovery to 96% and 97%, respectively. Limits of detection (LODs) were 200 mg/kg for chlorine and 20 mg/kg for bromine. It was concluded that the sintering method is suitable for chlorine and bromine determination in several matrices like sewage sludge, plastics, and edible waste, as well as for waste mixtures. The sintering method was also applied for determination of other elements present in anionic forms, such as sulfur, arsenic, selenium and iodine.
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| 14175. |
- Östmark, Åke, et al.
(författare)
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A wireless network of EIS devices [sensor networks]
- 2004
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Ingår i: From the electrometer to the networked instruments : a giant step toward a deeper knowledge. - Piscataway, NJ : IEEE Communications Society. - 078038248X ; , s. 1199-1202
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Konferensbidrag (refereegranskat)abstract
- By using a sensor connected to a generic wireless embedded Internet system (EIS) platform, data can be presented on-line over the Internet using a standard WWW-browser. When started, the EIS device automatically searches and connects to other devices providing Internet connectivity. The EIS can also provide Internet access for other devices, for example other EIS platforms, thus creating a local network. In this paper we focus on mobile phones with GPRS as the means for wireless Internet connectivity as it provides enhanced area coverage in today's networks. To overcome the problem of non-public IP addresses, a basic server based solution is developed. Our experiments confirm that within GPRS coverage, the EIS device successfully provides Internet access and presents data for on-line monitoring over the Internet.
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| 14176. |
- Östmark, Åke
(författare)
-
An infrastructure for service-oriented embedded internet systems
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Embedded systems are in general designed to do some specific task, rather than be a general-purpose computer for multiple tasks. Common for embedded systems is that processing devices, sensors, transceivers, actuators, networks, and software are built into a system, encapsulated by the device it controls. Often, the development of various applications requires an embedded system that is small and lightweight, both in terms of hardware and software. Technology advances in ASIC design have enabled digital and analog components on a single chip by integrating e.g. processing, storage, and Micro-Electro-Mechanical System. The vision due to the improved miniaturization is to have self-configured, low-power, and small form-factor platforms that share resources, have access to the environment, and are deployed in an ad hoc fashion. This, together with wireless communication standards, enables ubiquitous access to information anywhere and anytime. Feeding the digital world with information, as measurements of physical phenomenon, is done by the use of sensors. Extending the control from the digital world to the physical world can be achieved by actuators. Combining those sensors and actuators with wireless networking capabilities enables a new paradigm for e.g. scientists, medical personnel, and engineers to observe physical phenomena. The world of networking sensor and actuator devices is vast and covers aspects such as energy-efficient hardware design principles, medium access protocols, routing and transport protocols, embedded operating systems, security, low-power operations, localization, data storage, mobility, and network management etc. All these areas are important for embedded systems targeting the interconnection of small devices. In the scope of this thesis, the embedded system is realized in the form of a small sensor and actuator node, a device with interfaces to measure physical phenomenon and/or affect the surrounding environment. Our primary hypothesis is that standards-based protocols and de facto standards can be utilized as the fundamental operational infrastructure of the sensor and actuator nodes. Using a universal widespread standard protocol can be advantageous in respective to a custom made solution when developing and deploying networking nodes. Today, TCP/IP is the most widespread networking protocol suite in computer communication in use. As a consequence, we show how the readily available TCP/IP protocol suite can be used as a foundation for intra/internetworking even for resource constrained sensor and actuator nodes. A platform that is intelligent and accessible over the Internet opens new possibilities for control, maintenance, and remote monitoring. In this thesis commercial off-the-shelf hardware components are used in combination with software based on standard protocols as a basis for the platform architecture. First, a small wireless networking node accessible from devices in close proximity is presented. The generic architecture enables the rapid development of various applications, adaptable to different usage scenarios. Second, it is shown that a small spontaneous network of mobile nodes can be established, even though the resources on the nodes are very limited. Third, many applications require a large number of small and lightweight nodes to cooperate. However, one of the challenges with networking sensor and actuator nodes is the distributed functionality without central control. The approach taken in this thesis was to leverage emerging technologies to model the functionality of the nodes, thus nodes are provided with the capability and mechanisms to present themselves and to discover peer nodes. Consequently, application-level interoperability is enabled by introducing service discovery techniques which have the potential to automate the discovery of nodes and required services.
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| 14177. |
- Östmark, Åke, et al.
(författare)
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An infrastructure for service oriented sensor networks
- 2006
-
Ingår i: Journal of Computers. - 1796-203X. ; 1:5, s. 20-29
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Tidskriftsartikel (refereegranskat)abstract
- Emerging wireless technologies enable ubiquitous access to networked services. Integration of wireless technologies into sensor and actuator nodes provides the means for remote access and control. However, ad hoc deployment of nodes complicates the process of finding, selecting and sing these in a meaningful way. The use of a service discovery framework enables nodes to present themselves and the resources they hold. In this paper, we review the applicability of a number of well-known service discovery protocols in the context of networked nodes. Multicast DNS and Service Discovery (mDNS-SD) stands out with its auto-configuration, distributed architecture,sharing of resources, and wide area access. For wireless battery operated and resource constrained nodes, we seek to integrate SD and power management techniques. This leads us to a standards based infrastructure for service oriented sensor networks where; 1) nodes collaborate in an ad hoc fashion by using SD techniques to discover (and announce) resources locally and over the public Internet, 2) nodes preserve power through aggressive utilization of low power (sleep) modes, while yet being reachable for clients according to defined schemas, and 3) clients may access and configure nodes, and (if possible) access sleeping nodes by implicit wake-up procedures. To demonstrate the proposed infrastructure a complete experimental setup has been devised featuring; Bluetooth enabled nodes, lightweight implementations of mDNS-SD and communication stacks, Internet access through cellular/wired gateways, together with a public DNS server. Our experiments verify that mDNS-SD can be effectively deployed on small wireless sensor and actuator nodes and provides the basis of a service oriented infrastructure for low power sensor networks.
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| 14178. |
- Östmark, Åke
(författare)
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Embedded internet system architectures
- 2004
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today, using computers is a daily thing for many people over the world. We use computers to for example communicate, read news, search for sport events, correspond with e-mail, participate in meetings, and download the latest polyphonic ring tones for our mobile phones. This digital world is often distinguished from the outside world, or the physical world. Feeding the digital world with information, as measurements of physical phenomenon, is done by the use of sensors. Extending the control from the digital world to the physical world can be achieved by controlling actuators. Combining those sensor and actuators with wireless networking capabilities enables a new paradigm to for example scientists, medical personnel, and engineers to observe physical phenomena and react to it. The world of networking sensors is vast and covers aspects such as communication protocols, ubiquitous computing environments, embedded operating systems, embedded system designs, security, low-power operations, location- awareness, and middleware issues etc. At EISLAB, the development of various applications requires a platform, in terms of both hardware and software, to form a network of wireless nodes. A platform that is intelligent and accessible over the Internet opens new possibilities for system fault detection, control, maintenance, and remote monitoring. In this thesis commercial off-the-shelf hardware components are used in combination with software based on standard protocols as a basis for the platform architecture. The focus has been on a collection of small, battery-operated, and autonomous wireless networking nodes. The thesis makes contribution to the area by exploring and elaborating the possibilities of making those resource limited nodes accessible over the public Internet. First, a small wireless networking sensor unit accessible from devices in close proximity is presented. The generic architecture enables the rapid development of various applications, adaptable to different usage scenarios. Second, an architecture (and the implementation of the architecture) is presented where devices like simple sensors become accessible as nodes on the public Internet. The architecture enables direct access to collected measurements and events from the physical world. Third, it is shown that a small spontaneous network of mobile nodes can be established, even though the resources on the nodes are very limited. The nodes do not have to be user operated and can self-establish a connection with an appropriate access point.
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| 14179. |
- Östmark, Åke, et al.
(författare)
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Mobile medical applications made feasible through use of EIS platforms
- 2003
-
Ingår i: Proceedings of the 20th IEEE Instrumentation and Measurement Technology Conference. - : IEEE Communications Society. - 0780377052 ; , s. 292-295
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Konferensbidrag (refereegranskat)abstract
- Monitoring of medical parameters often limits the mobility of the patient, eg., to the hospital. We present the first steps toward a solution where the patient is offered safety, while allowed the mobility to carry on with daily activities. A pulse oximeter is interfaced to a wireless sensor platform. The sensor system acts as a Bluetooth device providing a TCP/IP interface for configuration and maintenance. This allows user interaction through standardized WWW-browser technology. The sensor provides platform independent client software for data presentation. Sensor data can be transferred over IP/UDP and displayed in real time on the client device.
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| 14180. |
- Östmark, Åke, et al.
(författare)
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Service and device discovery of nodes in a wireless sensor network
- 2006
-
Ingår i: IEEE Consumer Communications and Networking Conference. - Piscataway, NJ : IEEE Communications Society. - 1424400864 ; , s. 218-222
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Konferensbidrag (refereegranskat)abstract
- Emerging wireless communication standards and more capable sensors and actuators have pushed further development of wireless sensor networks. Deploying a large number of sensor nodes requires a high-level framework enabling the devices to present themselves and the resources they hold. The device and the resources can be described as services, and in this paper, we review a number of well-known service discovery protocols. Bonjour stands out with its auto-configuration, distributed architecture, and sharing of resources. We also present a lightweight implementation in order to demonstrate that an emerging standards-based device and service discovery protocol can actually be deployed on small wireless sensor nodes.
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