-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: This paper shows that orthogonal coding and iterative decoding improve coding gain. The encoder maps a block of data into a block of bi-orthogonal codes. The decoder is a correlation receiver, which performs iterative decoding to reduce the error and enhance the coding gain. To illustrate this concept, BER performance analysis of rate frac12 orthogonal coding and iterative decoding is presented.
Electro/Information Technology, 2008. EIT 2008. IEEE International Conference on; 06/2008
-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a traffic engineering solution for multi-rate data transmission over 3G-4G networks. It is shown that the RF coverage footprint shrinks due to high-speed data, which can be compensated by introducing delays. The queuing theory is used to quantify the delay, where the incoming data forms a queue in a buffer and waits for radio transmission. This delay, which is a function of the bit rate, is used to compensate the deficit in the link budget. Consequently, the RF coverage foot print remains the same for all bit rates.
Electro/Information Technology, 2008. EIT 2008. IEEE International Conference on; 06/2008
-
[show abstract]
[hide abstract]
ABSTRACT: A method of bandwidth efficient coded modulation and its implementation on FPGA is presented. The proposed coding technique parses the input data into two blocks corresponding to ODD parity block and EVEN parity block, calculates and appends the vertical parity from the columns, and transmits the coded blocks across the channel. Horizontal parity bits from the rows are not calculated since they are ODD and EVEN corresponding to the respective blocks. This technique reduces the number of redundant bits and enhances bandwidth efficiency. Simulation results are presented to verify the concept. The method will be experimentally verified in the laboratory by implementing it on a field programmable gate array (FPGA).
Electro/Information Technology, 2007 IEEE International Conference on; 06/2007
-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: The classical Fresnel zone criterion is used to examine microwave propagation through an open ended cylindrical metallic tube. It is shown that there exists a near free-space propagation region between the transmit antenna and the receive antenna. This principle is used to develop a microwave absorption spectrometer. Experimental results are presented to validate the concept.
Electro/Information Technology, 2007 IEEE International Conference on; 06/2007
-
[show abstract]
[hide abstract]
ABSTRACT: When data is stored, compressed, or communicated through a media such as cable or air, sources of noise and other parameters such as EMI, crosstalk, and distance can considerably affect the reliability of these data. Error detection and correction techniques are therefore required. Orthogonal Code is one of the codes that can detect errors and correct corrupted data. An n-bit orthogonal code has n/2 is and n/2 0s. In a previous work these properties have been exploited to detect and correct errors. In this paper we present a new methodology to enhance error detection capabilities of the orthogonal code. The technique was implemented experimentally using field programmable gate arrays (FPGA). The results show that the proposed technique improves the detection capabilities of the orthogonal code by approximately 50%, resulting in 99.9% error detection, and corrects as predicted up to (n/4-1) bits of error in the received impaired code with bandwidth efficiency.
Electro/Information Technology, 2007 IEEE International Conference on; 06/2007
-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: In this paper we investigate the distance properties of orthogonal codes and evaluate its error control properties. We examine this by noting that an n-bit orthogonal code has n/2 1's and n/2 0's; i.e., there are n/2 positions where 1's and 0's differ. Therefore, the distance between two orthogonal codes is also n/2. By exploiting this distance property, we show that a code rate r=k/n, where n is the code length and k is the data length, is available out of orthogonal codes with error control capabilities. We then develop a method of coded modulation with bandwidth efficiency. The proposed technique offers a simpler solution to error control coding with bandwidth efficiency. Finally, the construction of an orthogonal coded modulation scheme is presented to illustrate the concept.
Military Communications Conference, 2003. MILCOM 2003. IEEE; 11/2003
-
[show abstract]
[hide abstract]
ABSTRACT: The authors discuss work on the magnetic characterization and recording performance of Co/Pd multilayers deposited on various soft underlayer (SUL) and exchange break layer (EBL) structures. The dependence of various recording parametrics were measured as a function of the SUL and EBL thickness and the dimensions of the pole head were investigated. Significant issues behind the transition from dual layer to single layer perpendicular recording are also discussed.
Joint NAPMRC 2003. Digest of Technical Papers [Perpendicular Magnetic Recording Conference 2003]; 02/2003
-
[show abstract]
[hide abstract]
ABSTRACT: Summary form only given. With decreasing trackwidth, track density increases while jitter goes up, limiting the linear density. Overall, we expect a gain in areal density with reducing bit aspect ratio (BAR). In order to create narrow trackwidths thereby achieve small BAR, we utilized the microtrack technique. This novel approach enabled us to produce narrow tracks with varying widths without using special heads. We measured the jitter of microtracks, verified jitter dependence on the effective reader width and established the areal density relationship with BAR.
Joint NAPMRC 2003. Digest of Technical Papers [Perpendicular Magnetic Recording Conference 2003]; 02/2003
-
Nephrology Dialysis Transplantation 06/1999; 14(5):1260-2. · 3.40 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Small ethnographic and clinic-based studies indicate that crack-smoking sex workers are at high risk for human immunodeficiency virus (HIV) and sexually transmitted diseases (STD). STUDY GOALS: To examine the prevalence of risky sexual behaviors and HIV and STD in a large sample of street-recruited crack-smoking sex workers.
From 1991 to 1992, 419 crack-smoking sex workers were recruited from urban neighborhoods, interviewed, and serologically tested.
Many female and male sex workers reported sex with injectors (30% to 41%) or HIV-infected persons (8% to 19%), past STD (73% to 93%), and inconsistent condom use (> 50% for all types of sex). Sex workers who worked in crack houses or vacant lots, were paid with crack, or injected drugs had the riskiest sex practices. Most sex workers initiated sex work before they first smoked crack. More than 25% were infected with HIV (27.9%), syphilis (37.5%), or herpes simplex virus type 2 (66.8%).
Interventions to prevent HIV/STD transmission among crack-smoking sex workers are urgently needed.
Sex Transm Dis 04/1998; 25(4):187-93. · 2.87 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study examines the relationship between sex trading and psychological distress and the implications of that relationship for prevention of human immunodeficiency virus among a sample of young women recruited from the streets of Harlem.
Interviews were conducted with 346 predominantly drug-using women, aged 18 to 29 years, of whom 176 had exchanged sex for money or drugs in the previous 30 days and were categorized as "sex traders." Psychological distress was measured by using the Brief Symptom Inventory.
Sex traders scored significantly higher than non-sex traders on the General Severity Index and on eight of the nine subscales of the Brief Symptom Inventory. Multivariate analysis indicated that after adjustments were made for age; ethnicity; pregnancy; recent rape; perceived risk for acquired immunodeficiency syndrome; current, regular crack use; and current, regular alcohol use, sex traders scored 0.240 units higher on the General Severity Index than non-sex traders.
Poor mental health and drug dependence may under-mine the motivation and ability of these sex traders to adopt safer sex behavior. Therefore, interventions need to be integrated with mental health services and drug treatment to reduce risk behavior in this population.
American Journal of Public Health 02/1997; 87(1):66-70. · 3.93 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A survey of 1220 street-recruited crack cocaine smokers revealed that crack smokers may turn to drug injection to ease crack withdrawal. Crack smokers who later injected tended to smoke crack more heavily and for longer periods than those who did not inject. The initiation of injection was significantly associated with ever snorting heroin (prevalence ratio [PR] = 3.4, 95% confidence interval [CI] = 2.0-5.9) or snorting heroin specifically while smoking crack (PR = 2.3, 95% CI = 1.3-4.0), suggesting that snorted heroin use may mediate the transition to injection among crack smokers. Programs to prevent and treat crack dependence may prevent later injection and injection-related infections including HIV.
Drug and Alcohol Dependence 11/1996; 42(2):85-92. · 3.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Crack cocaine causes blisters, sores, and cuts on the lips and in the mouths of persons who smoke it, and such sores may facilitate the oral transmission of HIV. We recruited young adults aged 18-29 years, who either were current regular crack smokers, or who had never smoked crack, from inner city neighborhoods in New York, Miami, and San Francisco. Participants were interviewed for HIV risk behaviors and history of recent oral sores and were tested for HIV, syphilis, and herpes simplex virus (HSV) antibodies. Among the 2,323 participants recruited, 1,404 (60%) were crack smokers. Crack smokers (10.0%) were more likely than nonsmokers (4.5%) to report having had oral sores in the past 30 days [prevalence odds ratio (POR) 2.4, 95% confidence interval (CI) 1.7-3.4]. Sores were also more prevalent among those who had ever injected drugs (14.3%) than among those who had not (6.7%; POR 2.3, 95% CI 1.7-3.4), and among those with HIV infection (14.3%) than among those without it (8.0%; POR 1.9, 95% CI 1.3-2.8). Among the 429 participants who reported receptive oral sex, those who reported oral sores were more likely than those who did not to have HIV infection, after other HIV risk factors were controlled for (adjusted POR 1.9, 95% CI 1.0-3.6). Our results confirm that crack smokers have a high prevalence of oral sores and provides evidence that these sores, although infrequently, may facilitate oral transmission of HIV.
Journal of Acquired Immune Deficiency Syndromes and Human Retrovirology 10/1996; 13(1):87-92.
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper we examine risk behavior, exposure to street outreach, and condom use in samples of injecting drug users (IDUs) and high-risk youth. We used systematic sampling methods to produce representative samples of injecting drug users IDUs (five sites) and high-risk youth (three sites). The populations surveyed engaged in high levels of sexual risk behavior: 20% to 46% reported two or more sex partners in the last month. The majority (62% to 97%) knew someone infected with HIV. Condom use rates approached national health promotion goals for nonsteady partners but not for steady or main partners. Having a condom at time of interview was the most consistent predictor of condom use at last intercourse. Many of the respondents have been in contact with street outreach programs and many acknowledged some personal risk for HIV infection. However, most of the injecting drug users and high-risk youth interviewed (and their sex partners) were still at risk through unprotected sex.
AIDS Education and Prevention 07/1996; 8(3):191-204. · 1.59 Impact Factor
-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a three ray propagation model for PCS and
μ-cellular services. The salient concept of the proposed model is to
maintain cell radii within the Fresnel zone break point. In this region,
the path loss slope is similar to free space loss, irrespective of the
propagation medium. This analogy is then used to predict cell radii for
indoor and outdoor deployment of PCS; requiring virtually no computer
aided prediction tools. It is further shown that the ceiling height
plays an important role in antenna placement. The proposed method is
appropriate for low power PCS and micro-cellular services, offering a
greatly simplified and cost-effective deployment process
Military Communications Conference, 1995. MILCOM '95, Conference Record, IEEE; 12/1995
-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: This paper presents a family of N=4 and N=3 tri-cellular plans for
high density, high capacity cellular networks. The N-4 tri-cellular plan
is based on dividing the available channels into 12 or multiples of 12
frequency groups, distributed evenly among 4 tri-cells. The N=3
tri-cellular plan is based on dividing the available channels into 9 or
multiples of 9 frequency groups, distributed evenly among 3 tri-cells.
The tri-cell is based on three identical cells, driven by a single
source. Frequency assignment is based on an ODD/EVEN cyclic and
alternate distribution of frequency groups which eliminates adjacent
channels, ensuring better adjacent channel performance
Military Communications Conference, 1995. MILCOM '95, Conference Record, IEEE; 12/1995
-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: The mechanism of interference between two FSK modulated signals is examined. It is shown that the deviation in the instantaneous frequency due to interference causes a corresponding deviation in the eye opening, thereby resulting in a corresponding degradation in the signal to noise ratio (SNR). This analogy is then used to derive the C/I performance as a function of the eye opening. The analysis applies to FSK, MSK and GMSK modulation schemes
Military Communications Conference, 1995. MILCOM '95, Conference Record, IEEE; 12/1995
-
S. Faruque
[show abstract]
[hide abstract]
ABSTRACT: This paper presents three ray propagation model for line of sight (LOS) PCS and μ-cellular services. The proposed model is based on Fresnel zone break point where the path loss slope is similar to the free space loss. This analogy is then used to predict the cell radii for indoor and outdoor deployment of PCS; requiring virtually no computer aided prediction tools. It is further shown that the ceiling height plays an important role in determining the optimum location of the antenna. The proposed method is appropriate for low power PCS and micro-cellular services, offering a greatly simplified and cost-effective deployment process
Personal, Indoor and Mobile Radio Communications, 1995. PIMRC'95. 'Wireless: Merging onto the Information Superhighway'., Sixth IEEE International Symposium on; 10/1995
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the prevalence of recent rape, the characteristics or recent rape survivors, and the seroprevalence of human immunodeficiency virus (HIV), syphilis, and genital herpes (HSV-2) among recent rape survivors.
We surveyed women 18-29 years old who were recruited from places unassociated with medical or drug treatment or the criminal justice system in three urban communities where illicit drug use is common. We compared characteristics and HIV, syphilis, and HSV-2 seroprevalence of women who reported recent rape with those of women who denied recent rape.
One hundred fifty-one of 1104 (13.7%) women reported having been raped in the year before our interview. Rape survivors were more likely than women who denied recent rape to smoke crack cocaine (86.8 versus 56.7%; odds ratio [OR] 5.0, 95% confidence interval [CI] 3.2-7.8), to be homeless (17.2 versus 6.1%; OR 3.2, CI 2.0-5.2), to report a recent sexually transmitted disease (38.7 versus 18.7%; OR 2.7, CI 1.9-3.9), and to be infected with syphilis (42.4 versus 28.4%; OR 1.9, CI 1.3-2.6) and HSV-2 (71.9 versus 57.5%; OR 1.9, CI 1.3-2.8). Survivors were more likely to acknowledge any HIV risk behavior (including sex work) (85.4 versus 49.5%; OR 5.9, CI 3.9-9.0) and to be HIV-infected (23.3 versus 13.4%; OR 1.9, CI 1.3-2.9). Rape was not independently associated with HIV (OR 0.8, 95% CI 0.4-1.3), syphilis (OR 0.9, 95% CI 0.6-1.3), or HSV-2 (OR 1.3, 95% CI 0.9-2.0) infections after adjustment for confounding factors.
One in seven women reported being raped recently. Rape was most common among sex workers, crack smokers, and the homeless. Most survivors reported HIV risk behaviors, and many were HIV-infected. Programs to prevent repeated rape, voluntary HIV counseling and testing, and other medical and social services may benefit survivors in these and similar communities.
Obstetrics and Gynecology 04/1995; 85(3):330-6. · 4.73 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The smoking of "crack" cocaine is thought to be associated with high-risk sexual practices that accelerate the spread of infection with the human immunodeficiency virus (HIV). We studied 2323 young adults, 18 to 29 years of age, who smoked crack regularly or who had never smoked crack. The study participants, recruited from the streets of inner-city neighborhoods in New York, Miami, and San Francisco, were interviewed and tested for HIV. This report presents the findings for the 1967 participants (85 percent) who had never injected drugs.
Of the 1137 crack smokers, 15.7 percent were positive for HIV antibody, as compared with 5.2 percent of the 830 nonsmokers (prevalence ratio adjusted for the city, 2.4; 99 percent confidence interval, 1.7 to 3.6). The prevalence of HIV was highest among the crack-smoking women in New York (29.6 percent) and Miami (23.0 percent). Of the 283 women who had sex in exchange for money or drugs, 30.4 percent were infected with HIV as compared with 9.1 percent of the 286 other women (prevalence ratio, 3.1; 99 percent confidence interval, 1.9 to 5.1); of the 91 men who had anal sex with other men, 42.9 percent were infected with HIV as compared with 9.3 percent of the 582 men who did not have anal sex with other men (prevalence ratio, 4.7; 99 percent confidence interval, 3.0 to 7.4). In multivariable analyses, these high-risk sexual practices accounted for the higher prevalence of HIV infection among the crack smokers, as compared with those who did not smoke crack. Women who had recently had unprotected sex in exchange for money or drugs were as likely to be infected as men who had had sex with men (40.9 percent vs. 42.9 percent).
In poor, inner-city communities young smokers of crack cocaine, particularly women who have sex in exchange for money or drugs, are at high risk for HIV infection. Crack use promotes the heterosexual transmission of HIV.
New England Journal of Medicine 12/1994; 331(21):1422-7. · 53.30 Impact Factor
