| 1. |
- Geijer Lundin, Erik, et al.
(författare)
-
Robust Uplink Resource Allocation in CDMA Cellular Radio Systems
- 2005
-
Ingår i: Proceedings of the 44th IEEE Conference on Decision and Control and European Control Conference 2005. - Linköping : Linköping University Electronic Press. - 0780395670 ; , s. 1848-1853
-
Konferensbidrag (refereegranskat)abstract
- Radio resource management (RRM) in cellular radio system is an example of automatic control. The system performance may be increased by introducing decentralization, shorter delays and increased adaptation to local demands. However, it is hard to guarantee system stability without being, too conservative while using decentralized resource management. In this paper, two algorithms that both guarantee system stability and use local resource control are proposed for the uplink (mobile to base station). While one of the algorithms uses only local decisions, the other uses a central node to coordinate resources among different local nodes. In the chosen design approach, a feasible solution to the optimization problems corresponds to a stable system. Therefore, the algorithms will never assign resources that lead to an unstable system. Simulations indicate that the proposed algorithms also provide high capacity at any given uplink load level.
|
|
| 2. |
- Gunnarsson, Fredrik, et al.
(författare)
-
Uplink Load and Link Budget with Stochastic Noise Rise Levels in CDMA Cellular Systems
- 2005
-
Ingår i: Proceedings of Radiovetenskap och Kommunikation 2005. ; , s. 491-
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The limiting factor in the uplink of all CDMA cellular systems is the relation between uplink noise rise and intended coverage. In link budgets, noise rise is usually simply handled as a constant contribution to the background noise in logarithmic scale, often referred to as interference margin. In practice, however, it is not constant. We model the uplink noise rise as a lognormal distribution, and investigate the impact to link budgets. Simulations and numerical calculations show that the uplink noise rise variance does not critically affect the uplink capacity and coverage. System feasibility and its relation to the uplink load is also discussed. It is shown that approximative load expressions provides an upper bound on the uplink load and therefore they can be used to imply system feasibility. Furthermore, the uplink load expressions provide accurate approximations of the load given that the load is within the practical limits given by the link budgets.
|
|
| 3. |
- Al-Minawi, Ali Z., et al.
(författare)
-
The ERCC1/XPF endonuclease is required for completion of homologous recombination at DNA replication forks stalled by inter-strand cross-links
- 2009
-
Ingår i: Nucleic Acids Research. - : Oxford University Press (OUP). - 0305-1048 .- 1362-4962. ; 37:19, s. 6400-6413
-
Tidskriftsartikel (refereegranskat)abstract
- Both the ERCC1-XPF complex and the proteins involved in homoIogous recombination (HR) have critical roles in inter-strand cross-link (ICL) repair. Here, we report that mitomycin C-induced lesions inhibit replication fork elongation. Furthermore, mitomycin C-induced DNA double-strand breaks (DSBs) are the result of the collapse of ICL-stalled replication forks. These are not formed through replication run off, as we show that mitomycin C or cisplatin-induced DNA lesions are not incised by global genome nucleotide excision repair (GGR). We also suggest that ICL-lesion repair is initiated either by replication or transcription, as the GGR does not incise ICL-lesions. Furthermore, we report that RAD51 foci are induced by cisplatin or mitomycin C independently of ERCC1, but that mitomycin C-induced HR measured in a reporter construct is impaired in ERCC1-defective cells. These data suggest that ERCC1-XPF plays a role in completion of HR in ICL repair. We also find no additional sensitivity to cisplatin by siRNA co-depletion of XRCC3 and ERCC1, showing that the two proteins act on the same pathway to promote survival.
|
|
| 4. |
- Ausen, Dag, et al.
(författare)
-
Foresight Biomedical Sensors
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The foresight study on biomedical sensors has addressed different approaches with future use of biomedical sensors in the health care sector, like: How will biomedical sensors shape the healthcare systems of the future? How can they impact the quality and cost of healthcare and what are the business opportunities in the Nordic region?
|
|
| 5. |
- Axell, Erik, et al.
(författare)
-
Coexistence of Speech and Best Effort Services in Enhanced Uplink WCDMA
- 2005
-
Ingår i: in Proc. of Radiovetenskap och Kommunikation (RVK).
-
Konferensbidrag (refereegranskat)abstract
- An evaluation of the performance of coexistent voice and best effort data users in Enhanced Uplink WCDMA is studied in this paper. The main focus is on deriving the capacity regions and compare with previous WCDMA releases. It is shown that the Enhanced Uplink yields a large capacity gain in many aspects for all fractions of voice users compared to previous WCDMA releases. It is also shown, by the cumulative distribution functions of noise rise at the capacity limits, that the best effort data users experience bad quality at lower noise rise than voice users. This means that the capacity is in fact limited by the best effort users.
|
|
| 6. |
- Barabash, Stas, et al.
(författare)
-
Mars Orbiting Plasma Surveyor (MOPS)
- 2006
-
Ingår i: Proceedings of the 6th IAA International Conference on Low-Cost Planetary Missions. ; , s. 227-232
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Mars Orbiting Plasma Surveyor (MOPS) is a microsatellite mission focused on studies of the near -Mars environment and the planet - solar wind interaction. The recent findings by the ESA Mars Express mission further highlighted the complexity of the processes taking place at the planet resulting from the solar wind interaction that strongly affect the planet's atmosphere. However, despite many previous Martian missions carrying different types of space plasma experiments, a comprehensive investigation including simultaneous measurements of particles, fields, and waves has never been performed. We consider a spinning spacecraft of a wet mass of 76.1 kg with a 9.7 kg payload, which can “hitchhike” on another platform until Mars orbit insertion, and then be released into a suitable orbit. The spacecraft design is based on the experience gained in very successful Swedish space plasma missions, Viking, Freja, Astrid-1, and Astrid-2. In the present mission design, the MOPS spacecraft is equipped with its own 1m high gain antenna for direct communication with the Earth. The payload includes a wave experiment with wire booms, magnetometer with a rigid boom, Langmuir probes, electron and ion energy spectrometers and an ion mass analyzer. An energetic neutral atom imager and an UV photometer may complete the core payload. One of the proposed scenarios is piggy - backing on the Russian Phobos - Grunt mission to be launched to Mars in 2011.
|
|
| 7. |
- Geijer Lundin, Erik, et al.
(författare)
-
Uplink Load in CDMA Cellular Radio Systems
- 2006
-
Ingår i: IEEE Transactions on Vehicular Technology. - : IEEE Vehicular Technology Society. - 0018-9545 .- 1939-9359. ; 55:4, s. 1331-1346
-
Tidskriftsartikel (refereegranskat)abstract
- Well-operating resource-management algorithms are crucial in wireless networks for ensuring the quality of service and, perhaps more importantly, for securing stability when operating at high load. These algorithms benefit from accurate feedback of the current network load. In the uplink of a code-division-multiple-access cellular network, the load is strongly related to the uplink noise rise, i.e., the ratio between total received power and background-noise power. This paper is primarily concerned with characterizing and approximating the uplink load. Two different load definitions are made. These relate to the received and transmitted carrier powers, respectively. Bounds that can be established in practice, e.g., before a resource decision is made, are used to develop a procedure for approximating the uplink load in practice. Furthermore, a stochastic approach to link budgets is used to establish the uplink load's role in the tradeoff between coverage and individual user satisfaction. Simulations indicate that the average error of the proposed load approximations is small for all load levels expected to appear in practice.
|
|
| 8. |
- Geijer Lundin, Erik, 1976-
(författare)
-
Uplink Load in CDMA Cellular Radio Systems
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The uplink of code division multiple access (CDMA) cellular radio systems is often interference limited. The interference originates from many users whose transmission powers are not observable for the system. This thesis introduces uplink load and applies means of explicitly considering the users’ radio environment when approximating and controlling the load.A desirable property of all cellular radio systems is uplink feasibility, i.e., existence of finite user transmission powers to support the allocated services. Uplink load can be considered as a measure of how far from infeasibility the system is. The performed characterization of uplink load lead to two concrete definitions related to the amount of received and transmitted power, respectively.An important part of the total load is the intercell load which is caused by users connected to neighboring base stations. If not carefully handled, the intercell load can jeopardize uplink feasibility. Conversely, knowledge of a lower intercell load can be used to increase the resource assignments. A common denominator in all the work in this thesis is that the intercell load is explicitly considered.When approximating uplink load, a centralized approach is adopted to study information gathered in several base stations. This yields good approximations of the average load. However, centralized approximations can not detect momentarily peaks in the load. A number of resource allocation algorithms making control decisions in the local base stations are proposed based on experience from characterizing uplink load. As the algorithms study the intercell load, yet without measuring the interference power, they are robust in the sense that they will never assign resources yielding an infeasible system.A straightforward way of controlling the uplink load is to use measurements of the received interference power. This approach, just as the proposed load approximations, can gain from knowing the background noise power. The same framework used for designing robust resource allocation algorithms, is also used for estimating the background noise power.
|
|
| 9. |
- Idahl, Annika, 1965-
(författare)
-
Chlamydia trachomatis as a risk factor for infertility in women and men, and ovarian tumor development
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Chlamydia trachomatis in women is a risk factor for tubal factor infertility and extra uterine pregnancies, but the impact of a C. trachomatis infection on male fertility is unclear. It is also hypothesized that persistent infection with C. trachomatis, or other microorganisms, might initiate/promote ovarian tumor development. The aims of the thesis were to study whether C. trachomatis serum antibodies in women and men had an impact on infertility diagnoses, semen characteristics, pregnancy rates and pregnancy outcomes; furthermore, to explore associations of C. trachomatis, and Mycoplasma genitalium, plasma antibodies with epithelial ovarian cancer and borderline ovarian tumors, as well as the presence of C. trachomatis bacteria, and other microorganisms, in ovarian tissues. Materials and methods: Papers I and II: 244/226 infertile couples were tested for serum C. trachomatis IgG, IgA, IgM and chlamydial Heat Shock Protein 60 (cHSP60) IgG antibodies. C. trachomatis IgG positive couples were also tested for C. trachomatis DNA in a urine sample. The follow-up period was 14-54 months. 244 spontaneously pregnant women were also tested for serum C. trachomatis IgG antibodies. Papers III and IV: Plasma samples from 291 women with epithelial ovarian cancer, borderline ovarian tumors and benign conditions, and plasma samples from 271 healthy controls, were analyzed for C. trachomatis IgG, IgA and cHSP60-1 IgG and M. genitalium IgG antibodies. Ovarian tissues from 186 women with benign ovaries, borderline ovarian tumors and epithelial ovarian cancer, as well as tissues from the contra lateral ovary in 126 women, were analyzed for the presence of C. trachomatis, M. genitalium, Neisseria gonorrhoeae, HPV and the polyoma viruses BKV and JCV with nucleic acid amplification tests. Results: Papers I and II: The prevalence of C. trachomatis IgG antibodies was higher among infertile than fertile women, and there were 9 couples with ongoing C. trachomatis infections. In men, C. trachomatis IgG and IgA antibodies were associated with a reduced likelihood to achieve pregnancy for the couple, as well as lower sperm concentration, reduced sperm motility and vitality, increased teratozoospermia index and the occurrence of leukocytes. C. trachomatis IgG and cHSP60 IgG antibodies in infertile women were associated with tubal factor infertility, but not with reduced pregnancy rates or outcomes. Paper III: cHSP60-1 IgG antibodies were associated with ovarian cancer belonging to the postulated type II pathogenetic pathway when plasma samples obtained more than one year prior to diagnosis were analyzed. M. genitalium IgG antibodies were associated with borderline ovarian tumors; however a statistical type 1 error cannot be excluded. Paper IV: None of the microorganisms studied were found in the ovarian tissue samples. Conclusions: C. trachomatis IgG and IgA antibodies in the man substantially decreases the chances of the infertile couple to achieve pregnancy, and are associated with subtle negative changes in semen characteristics. C. trachomatis IgG and cHSP60 IgG antibodies in the woman are risk factors for tubal factor infertility. Prospective plasma cHSP60-1 IgG antibodies are associated with type II ovarian carcinomas, but C. trachomatis bacteria, or the other microorganisms studied, could not be detected in benign, borderline or malignant ovarian tissues.
|
|
| 10. |
- Karlsson, Sune, 1960-, et al.
(författare)
-
Foreign Firms and Chinese Employment
- 2009
-
Ingår i: The World Economy. - Oxford : Wiley-Blackwell Publishing Inc.. - 0378-5920 .- 1467-9701. ; 32:1, s. 178-201
-
Tidskriftsartikel (refereegranskat)abstract
- This paper examines the effect of foreign direct investment (FDI) on employment in the Chinese manufacturing sector. As one of the world's largest recipients of FDI, China has arguably benefited from foreign multinational enterprises in various respects. However, one of the main challenges for China, and other developing countries, is job creation, and the effect of FDI on employment is uncertain. The effect depends on the amount of jobs created within foreign firms as well as the effect of FDI on employment in domestic firms. We analyse FDI and employment in China using a large sample of manufacturing firms for the period 1998–2004. Our results show that FDI has positive effects on employment growth. The relatively high employment growth in foreign firms is associated with their firm characteristics and their high survival rate. Employment growth is also relatively high in private domestic Chinese firms. There also seems to be a positive indirect effect of FDI on employment in private domestically-owned firms, presumably caused by spillovers.
|
|
