Primary Control Strategy Research Articles

Research and Optimization of Thermal Power Unit's Automatic Control Based on Frequency Regulation Ability of Power Grid

Wind power and other new energy connected to power grid bring new challenges to optimal operation of power systems. The stability of power grid mainly depends on primary frequency compensation and secondary frequency compensation of thermal power units. By analyzing the theory and practice of DEH and coordinated control system (CCS) of thermal power units, combined with the insufficient of actual primary frequency compensation and automatic power generation control (AGC) strategy response to frequency of accidents, the optimization of primary frequency compensation and AGC of thermal power units automatic control were offered. The practical application results show that the proposed control strategy can effectively control the thermal power units to achieve the stability of power grid frequency.

Effect of Bait Quantity and Trap Color on the Trapping Efficacy of the Pheromone Trap for the Red Palm Weevil,Rhynchophorus ferrugineus

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Curculionidae: Coleoptera), is not native to the United Arab Emirates (UAE). Since its arrival in 1985, it has been causing major damage to date palm trees. A primary control strategy has been the use of pheromone baited traps. The objectives of this study were to determine the quantity of bait, and the best trap color, to obtain the maximum catch of R. ferrugineus under field conditions in the UAE. Traps with 100, 300, or 500 g of dates as bait collected the same number of R. ferrugineus adults. Captures in black traps were significantly higher than captures in red, yellow, or white traps. Thus, using a black pheromone trap containing 100 g of dates can significantly enhance R. ferrugineus control efforts, and can help considerably in reducing the red palm weevil's deleterious impact on date palm production in UAE.

Susceptability ofListronotus maculicollis(Coleoptera: Curculionidae) Adults from Southern New England Golf Courses to Chlorpyrifos

The annual bluegrass weevil, Listronotus maculicollis Kirby (Cole?ptera: Curculionidae) is a serious pest of Poa annua L. (Poales: Poaceae) turfgrass in the Northeastern U.S. Historically, the primary control strategy has been to intercept adults with insecticide residues as they emerge from overwintering sites (Cowles et al. 2008; Pot ter 1998; Vittum et al. 1999). Chlorinated hydro carbons were used to manage weevil populations until around 1969, but in the 1970s and 1980s less persistent organophosphates were utilized; today pyrethroids and chlorpyrifos are used to control adults (Cameron & Johnson 1971; Kop penh?fer & McGraw 2005; Schread 1970; Tashiro 1976). In 2009 several adult L. maculicollis popula tions from Connecticut, Massachusetts, and Rhode Island demonstrated varying levels of re sistance to pyrethroids (Ramoutar et al. 2009ab), but no data are available for L. maculicollis resis tance to chlorpyrifos, an organophosphate. Tash iro (1976) first communicated diminished organo phosphate effectiveness, but there are no further studies conducted on this topic. The objective of this study was to obtain toxicity data on the sus ceptibility of L. maculicollis populations from sev eral golf courses in southern New England to chlorpyrifos. In 2008 and 2009 from May-Sep adult wee vils were collected from 8 golf courses in Con necticut, Massachusetts, and Rhode Island (Fig. 1). Insects were collected by hand from golf course fairways or greens and kept at 21-23?C on P. annua plugs until bioassays were con ducted, within 48 h of collection. Chlorpyrifos (technical, 99.9% purity) was dissolved in re agent quality acetone (>95% purity) (Sigma-Al drich, St. Louis, MO) and 1 of chlorpyrifos or acetone (control) was applied per insect dor sally to the intersegmental membrane between the prothorax and the elytra (Metcalf 1958; Perez-Mendoza 1999). Mortality data were esti mated from 6-8 concentrations and 10-15 un sexed adults per concentration. Applications

노인 일자리 사업 참여자의 통제 귀인과 활동의 요구-조절-지지 정도 및 통제 전략이 자신의 주관적 안녕감에 미치는 영향

This study tested the path model with regard to how certain variables (control attribution, demand-control-support ofactivity, and control strategy) affected the elderly workers’ subjective well-being(swb). In the path model, the exogenousvariables were internal and external control attribution. We used demand-control-support of activity, and primary andsecondary control strategies as mediating variables. The endogenous variable was each elderly worker’s swb. Studyparticipants were 205 elders participating in an “education activity”. We used descriptive statistical analysis, Pearson’scorrelation and hierarchical multiple regression to examine data collected from structured interviews with theparticipants. Path analysis revealed the followings: First, secondary control strategy was the strongest predictor ofparticipants’ swb but internal control attribution, demand of activity, and support of activity also positively affectedparticipants’ swb. Second, internal control attribution indirectly affected the participants’ swb. Finally primary controlstrategy negatively affected on the participants’ swb.± ¯ ,FZ
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How not to fight a rabies epidemic: a history in Bali

Abstract Bali, an island, should never have been afflicted with canine rabies, but in 2008 a lack of surveillance allowed the import of an unvaccinated rabid dog from Flores, a distant island where canine rabies was similarly introduced in 1997 and has since become endemic. The initial rabies outbreak on Bali occurred in a remote village at the end of an isolated peninsula, but five months elapsed before the outbreak was officially recognized. Even then, rabies had yet to escape the peninsula. However, Bali officials relied on exterminating dogs as their primary control strategy. They did not vaccinate enough dogs on the neck of the peninsula to keep the outbreak confined, they prevented nongovernmental organizations and private citizens from vaccinating dogs until approximately a year after the outbreak started, they used unreliable indigenous vaccines of only short-term potency; killed vaccinated dogs, and they repeatedly disregarded the advice of visiting rabies control experts. Two years after the outbreak started, 44,000 people had received post-exposure vaccination after suffering bites from suspected rabid dogs. The number of human rabies deaths had doubled each six months since the first death occurred.

The Myriad Strategies for Seeking Control in the Dying Process

This study explored the role control plays in the dying process of terminally ill elders by investigating the aspects of the dying process over which they seek to exercise control, the strategies they use, and whether they desire to exercise more control. In-depth face-to-face interviews were conducted with 84 terminally ill elders receiving hospice care. Directed and conventional content analysis methods were used to identify main themes and patterns. The results revealed that all 84 elders were using at least 1 primary control strategy in their dying process, 83 of whom did so in combination with another primary or compensatory secondary control strategy. Decision making, independence, mental attitude, instrumental activities of daily living, activities of daily living, and relationships were aspects of the dying process over which the respondents sought to exercise control. Over half of the respondents wanted more control; however, they felt their illness prevented it. The findings highlight the importance of terminally ill elders' having opportunities to exercise control in their dying process. Practitioners need to ensure that these opportunities exist and to be aware that elders are adaptive and use multiple strategies in exercising control.

Primary and Secondary Control Strategies: Implications for Health and Well-Being Among Older Adults

As people move into advanced old age, they face increasing levels of age-related activity restriction. It becomes important that older adults adjust their goal-striving to age-related control restrictions in order to optimize physical and psychological well-being in this advanced and !nal stage of life. Older adults may use a variety of different control strategies to adjust to age-related activity restriction, initially in attempts to accomplish tasks, and then to ameliorate the negative psychological consequences of being unable to do so. In this study, cluster analysis revealed four unique patterns of primary and secondary control strategy use among 190 very old (79‐98 years) community-dwelling adults. The majority of individuals were classi!ed in a Primary Control Group (42.1%) characterized by continued task persistence. Second, a Multi-Strategy Group (16.3%) endorsed a combination of modi!ed primary control strategies and compensatory secondary strategies. Third, a Relinquished Control Group (22.1%) was characterized by the abandonment of primary strategies and only modest use of supplemental compensatory secondary strategies. Finally, a Failure to Compensate Group (19.5%) This study was supported by a Social Science and Humanities Research Council of Canada (SSHRC) doctoral scholarship and a Manitoba Graduate Studentship (MGS) to the first author, a Canadian Institutes of Health Research (CIHR) operating grant and a Mid Career Award in Aging to the third author, a Canadian Institutes of Health Research (CIHR) doctoral scholarship to the fourth author, and a Social Sciences and Humanities Research Council of Canada (SSHRC) operating grant #410-2007-2225 to the

Fuzzy Logic Supervisor-Based Primary Frequency Control Experiments of a Variable-Speed Wind Generator

In this paper, a primary frequency control strategy based on fuzzy logic, designed for variable-speed wind generators, is proposed and tested on a 2.2 kW test bench. The fuzzy logic supervisor ensures a regular primary reserve for a large range of wind speeds without any wind speed measurement. This supervisor controls simultaneously the generator torque and the pitch angle to keep the primary reserve; it determines in real time the generator power reference value. The fuzzy logic supervisor is compared to a simpler strategy, based only on the control of the generator torque. This classical strategy ensures a regular power reserve only when the wind generator operates at full load, and the generator power reference needs to be determined previously or by the network manager. A procedure for implementing a fuzzy logic supervisor in real time is proposed. The experiments indicate the regularity of the power reserve and the ability to contribute to frequency control.

Intestinal helminths

Intestinal helminths are common in the developing world; current estimates suggest that one-third of the world’s population is infected. Although most infections are light and asymptomatic, they are a significant cause of morbidity in heavily infected individuals. Hookworms cause iron-deficiency anaemia, malnutrition results from heavy Ascaris infections, and dysentery and rectal prolapse are seen in children heavily infected with Trichuris. Disseminated strongyloidiasis may be a fatal outcome of immunosupression in infected patients. Even moderate infections may have profound effects on pregnancy outcome, growth and cognitive function, and worldwide and national policies are focusing on the relative public health priority of helminth eradication. The availability of safe and effective antihelminthic drugs, particularly single-dose albendazole, make mass treatment of communities in endemic regions the primary control strategy for reducing the burden of disease caused by these organisms. Other manifestations of helminthic infection include epilepsy as a result of neurocysticercosis, respiratory symptoms from the migratory phase of recent hookworm or Ascaris infection, and dermatological consequences such as larva currens from Strongyloides stercoralis and cutaneous larva migrans. Pruritus ani caused by Enterobius infection is common in temperature countries. The immune response induced by helminthic infection may subvert responses to other pathogens such as HIV, tuberculosis and malaria. Related mechanisms by which helminths might suppress the immune response have been suggested as contributing factors in the increasing prevalence of atopy and asthma in more industrialized regions of the world where the prevalence of helminths has been declining.

Pharmacy clerks' prescribing practices for STD patients in Porto Alegre, Brazil: missed opportunities for improving STD control.

STDs are a significant public health problem in Brazil. A primary control strategy is the immediate treatment of symptomatic individuals. When services are unavailable, STD patients seek care in alternative settings. Probably the most frequently used settings are commercial pharmacies, where pharmacy clerks provide treatment, although Brazilian law prohibits selling antibiotics without prescription. Our objective was to evaluate prescribing practices by pharmacy clerks for STDs. We performed a cross-sectional study. Trained medical students visited 62 pharmacies in the city of Porto Alegre during March 2002. These were randomly chosen from a list of 863 registered pharmacies. The students presented to the pharmacy complaining of dysuria and urethral discharge. After obtaining a prescription, or not, they asked for additional instructions to be followed. Immediately after leaving the premises, the instructions were anonymously recorded. Of the 62 pharmacies visited, a clerk in 56 (90.3%, 95% confidence interval [CI]: 80.1%-96.4%) provided a prescription. Most frequently prescribed drugs were ampicillin with probenecide (29/51.8%) and rosoxacin (11/19.6%). Ministry of Health-recommended treatment was not suggested by any of the clerks. Forty-six additional recommendations were given. The use of condoms was the most frequent additional advice (42/46). Prescribing by pharmacy clerks is very prevalent in Porto Alegre. This may represent a lost opportunity for more comprehensive prevention effort (counselling, partner management, and diagnosing other STDs). Additionally, the most frequently prescribed drugs are not recommended by international or national health authorities for treatment of STDs, and none of these drugs covers chlamydia. We conclude that pharmacy clerks are a potentially important source of STD treatment and control but that their practices are in need of vast improvement.

Time and Frequency Domain Analyses of the Surface Mechanomyogram During Submaximal to Maximal Isokinetic Muscle Actions of the Biceps Brachii

2346 PURPOSE: The purpose of this study was to examine the mechanomyographic (MMG) amplitude and mean power frequency (MPF) versus torque relationships during isokinetic muscle actions of the biceps brachii. METHODS: Ten adults (mean ± SD age = 21.6 ± 1.7 yrs) performed submaximal to maximal isokinetic muscle actions of the dominant forearm flexors at a velocity of 30°·s−1 on a calibrated Cybex II dynamometer. Following determination of isokinetic peak torque (PT), the subjects randomly performed submaximal step muscle actions in 10% increments from 10% to 90% PT. RESULTS: Polynomial regression analyses indicated that MMG amplitude increased linearly (r2 = 0.982), while MMG MPF was best fit with a cubic (R2 = 0.786) model with increases in isokinetic torque from 10% to 100% PT. There were no significant mean differences, however, in MMG MPF from 10% to 100% PT. CONCLUSION: The linear increase in MMG amplitude and relatively stable MMG MPF with increases in isokinetic torque to 100% PT may indicate that recruitment of additional motor units, with little change in the global motor unit firing rate, is the primary motor control strategy for increasing torque production during dynamic muscle actions of the biceps brachii.

Time and Frequency Domain Analyses of the Surface Mechanomyogram During Submaximal to Maximal Isokinetic Muscle Actions of the Biceps Brachii

2346 PURPOSE: The purpose of this study was to examine the mechanomyographic (MMG) amplitude and mean power frequency (MPF) versus torque relationships during isokinetic muscle actions of the biceps brachii. METHODS: Ten adults (mean ± SD age = 21.6 ± 1.7 yrs) performed submaximal to maximal isokinetic muscle actions of the dominant forearm flexors at a velocity of 30°·s−1 on a calibrated Cybex II dynamometer. Following determination of isokinetic peak torque (PT), the subjects randomly performed submaximal step muscle actions in 10% increments from 10% to 90% PT. RESULTS: Polynomial regression analyses indicated that MMG amplitude increased linearly (r2 = 0.982), while MMG MPF was best fit with a cubic (R2 = 0.786) model with increases in isokinetic torque from 10% to 100% PT. There were no significant mean differences, however, in MMG MPF from 10% to 100% PT. CONCLUSION: The linear increase in MMG amplitude and relatively stable MMG MPF with increases in isokinetic torque to 100% PT may indicate that recruitment of additional motor units, with little change in the global motor unit firing rate, is the primary motor control strategy for increasing torque production during dynamic muscle actions of the biceps brachii.

DEMONSTRATION OF DOWNSPOUT DISCONNECTION EFFECTIVENESS

DEMONSTRATION OF DOWNSPOUT DISCONNECTION EFFECTIVENESSThe Detroit Water and Sewerage Department (DWSD) has undertaken a comprehensive program to control Combined Sewer Overflows (CSOs) from the City of Detroit wastewater collection system. A primary component of this program has been the development of a Long Term CSO Control Plan in 1996. The Long Term CSO Control Plan identified rainwater control as a primary CSO control strategy. One of the...Author(s)Imad SalimMirza RabbaigMark GrazioliAnthony IgweJames SherrillSourceProceedings of the Water Environment FederationSubjectSession 2 – Combined Sewers and Wet Weather IssuesDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2002ISSN1938-6478SICI1938-6478(20020101)2002:6L.65;1-DOI10.2175/193864702785300674Volume / Issue2002 / 6Content sourceUtility Management ConferenceFirst / last page(s)65 - 76Copyright2002Word count444

Sexually transmitted diseases

The full impact of sexually transmitted diseases (STDs) on public health in developing countries has been highlighted by the emergence of HIV infections. For 2 decades the public health implications of STDs have been recognized and research has detailed the impact of STDs on health particularly of women and children. Pelvic inflammatory disease (PID) for example causes infertility ectopic pregnancies maternal mortality and chronic pain and is the major reason women in many parts of the developing world seek gynecological help. The classic STDs (such as gonorrhea syphilis chancroid and chlamydial infection) share a primary mode of transmission with HIV infection and may interact with HIV in other ways especially because the presence of a STD seems to facilitate infection with HIV. Reduction of risky sexual behavior a primary control strategy for STDs has received a lot of attention since AIDS emerged. Now that health education campaigns are targeted to this goal it has become apparent that we have a woeful lack of understanding of human sexual behavior and its influences. Diagnosis and treatment of STDs is hampered by a lack of symptoms in the afflicted particularly in women a preference of patients to consult traditional healers and a lack of trained personnel and of drugs. This last factor is aggravated by STDs which have developed a resistance to antibiotics; to compound this problem alternate drugs are more expensive. The traditional approach to STD control should be replace by a more cost-effective and equitable integrated public health approach. STD control should be integrated in primary health care services and with AIDS control programs. Public health guidelines which prioritize STD activities should include 1) primary prevention activities 2) promotion of timely use of health services by afflicted individuals 3) the use of simple flow-charts and standardized treatment regimes for case management with minimal use of essential drugs 4) intensified interventions in high-risk groups and 5) screening for syphilis in pregnant women and prevention of optithalmia neonatorum which should be integrated in maternal and child health services. Operational research is also needed especially to develop appropriate diagnostic tools in low-resource settings. Finally women need female-controlled safe sex methods such as the female condom and viricidal agents. The low status of women prevents them from being able to negotiate for safe sex; yet the subclinical course of STDs in women can have disastrous consequences.

A systematic approach to the design and reliability analysis of a fault-tolerant controller—I. Design aspects

A systematic approach is developed, based on sound software engineering principles, for design and reliability analysis of fault-tolerant controllers (FTC). The approach involves design and design synthesis of components, and integration of the software and hardware. Implementation of the design aspects of the approach is demonstrated in the design process of an FTC aimed at partial or full automation of complex process of an FTC functions have to be in concert with maintenance of high levels of productivity and safety. The design incorporates setting up fault-tolerance goals, conceptual design, verification of specifications and logic, control strategy evaluation, synthesis of components to support fault-tolerance goal, and design implementation. Enhancement of the reliability is achieved by redundancy and diversity in the controller algorithms. The FTC employs an adaptive direct digital controller (ADDC) as a primary control strategy appropriate for time-variant systems. Simultaneously, a fuzzy expert controller (FEC) provides back-up control policies based on fuzzy logic. Control actions issued by the ADDC have to be verified by an interface system comprising fault detection flags based on a predetermined acceptance criteria. Control commands are delegated to the FEC whenever a fault is detected in the ADDC performance. The control authority is then returned back to the primary controller unless the error persists.

Atmospheric Carbon Particles and the Los Angeles Visibility Problem

The control of atmospheric primary carbonaceous particles is central to protecting visibility. In the Los Angeles area, fine particulate carbon accounts for 40% of fine particulate mass concentration on an annual average basis and 33% of the fine aerosol mass during summer midday periods. Visibility modeling shows that aerosol carbon contributes up to 39% of the total scattering coefficient and up to 44% of the extinction coefficient in the Los Angeles area during summer midday periods. Using the results of the primary aerosol carbon emission control strategy study by Gray (1986), which determined the least costly set of controls necessary to achieve reduced levels of primary carbonaceous aerosol in the Los Angeles area, it is estimated that an 8%–14% decrease in the average 1984 summer midday extinction coefficient could be achieved at Pasadena if primary aerosol carbon emission controls costing $80.4 × 10^6 year^(−1) (1982 dollars) had been in place at that time. An 11%–19% decrease in the extinction coefficient is estimated to result from controls costing $423.5 × 10^6 year^(−1) (1982 dollars).