Health System for Dengue Control in Singapore

Dengue fever/dengue haemorrhagic fever (DF/DHF) first appeared in Singapore in an outbreak in 1960. In 1966, the Ministry of Health established the Vector Control Unit which was charged with the responsibility of controlling the dengue vector mosquitoes, Aedes aegypti and Aedes albopictus. The Unit immediately launched an Aedes control programme based on source reduction and public health education. To obtain reliable statistics on disease incidence, DF/DHF was made administratively notifiable in 1966, and finally, legally notifiable in 1977. It was also recognized early in the control programme that long-term and active participation by the community was essential for its implementation. A new legislation called the Destruction of Disease-Bearing Insects Act was thus enacted in 1968. The Act empowers vector control officers to enter and examine houses for mosquito breeding, to take appropriate control measures, and to serve offenders with orders and summonses which carry a fine or imprisonment by the court. With the new legislation in force, the Aedes control programme adopted an integrated approach of source reduction, public health education and law enforcement. When the new Ministry of the Environment was formed in 1972 to take over the responsibility of environmental health, its Vector Control and Research Department and the Quarantine & Epidemiology Department became responsible for the surveillance and control of DF/DHF in the country. Surveillance of disease incidence and Aedes vectors is important in the prevention and control of DF/DHF outbreaks. Disease surveillance is conducted by officers of the Quarantine & Epidemiology Department based on notifications on clinically diagnosed cases as well as on the number of blood specimens submitted by hospitals, clinics, and private practitioners to the Virology Division of the Department of Pathology in the Ministry of Health and the Department of Microbiology of the National University of Singapore for laboratory confirmation of dengue infection. Aedes surveillance depends on regular surveys of mosquito larvae and adults in designated DF/DHF-sensitive areas. In addition to destruction of breeding habitats, fogging is carried out when the Aedes house index is 2% and above, or when a potential outbreak situation arises such as the occurrence of a focus of two or more DF/DHF cases in an area

Epidemiology of Dengue in Singapore-Current Situation

There has been a resurgence of dengue fever/dengue haemorrhagic fever (DF/DHF) cases in Singapore in recent years. Following the large outreak in 1973 with 1,187 cases and 27 deaths, the incidence of DF/DHF declined with minor bi-annual outbreaks occurring in 1978, 1980 and 1982. Beginning from 1986, however, the DF/DHF situation changed for the worse when outbreaks of increasing size occurred almost annually. In the past 3 years, there were 1,733 cases in 1990, 2,179 cases in 1991 and 2,878 cases in 1992. In the 1991 and 1992 outbreaks, 93-95% of the notified cases required hospitalization and 92-95% of them were serologically confirmed by the IgM capture ELISA and/or the commercial Dengue Blot assay. The number of fatal cases, however, remained low with 3-6 reported deaths in the three outbreaks. All age groups were affected with the highest morbidity rate in children and young adults between 15 and 24 years of age. In contrast, in the earlier 1973 and 1978 outbreaks, more patients below the age of 15 years were observed. There was a slight predominance among males and Chinese had the highest morbidity rate compared with Malays and Indians. The recent outbreaks occurred mainly in highly populated urban and suburban areas in the eastern, northeastern and southeastern parts of the island. Patients living in landed property such as compound houses had a 9X higher morbidity rate than those living in high-rise flats. Cases were reported throughout the year and the number increased during May and June. The increased DF/DHF incidence was preceded by an increase in the Aedes mosquito population. In the 1991 and 1992 outbreaks, although the overall Aedes house index was<1 for both Ae aegypti and Ae albopictus higher indices were detected in localized areas with high dengue transmission. The proportion of compound houses found breeding Ae aegypti was 3-4 times and Ae albopictus 7-10 times higher than that of flats. The major breeding habitats were ornamental and domestic containers and discarded receptacles

Detecting Solenoid Valve Deterioration in In-Use Electronic Diesel Fuel Injection Control Systems

The diesel engine is the main power source for most agricultural vehicles. The control of diesel engine emissions is an important global issue. Fuel injection control systems directly affect fuel efficiency and emissions of diesel engines. Deterioration faults, such as rack deformation, solenoid valve failure, and rack-travel sensor malfunction, are possibly in the fuel injection module of electronic diesel control (EDC) systems. Among these faults, solenoid valve failure is most likely to occur for in-use diesel engines. According to the previous studies, this failure is a result of the wear of the plunger and sleeve, based on a long period of usage, lubricant degradation, or engine overheating. Due to the difficulty in identifying solenoid valve deterioration, this study focuses on developing a sensor identification algorithm that can clearly classify the usability of the solenoid valve, without disassembling the fuel pump of an EDC system for in-use agricultural vehicles. A diagnostic algorithm is proposed, including a feedback controller, a parameter identifier, a linear variable differential transformer (LVDT) sensor, and a neural network classifier. Experimental results show that the proposed algorithm can accurately identify the usability of solenoid valves

Distributionally robust multi-item newsvendor problem with covariate information

This dissertation investigates robust optimization for use in demand forecasting. Techniques of robust optimization such as construction of ambiguity set, robust counterpart and affine recourse approximation are carefully studied. In addition, we’ve included the use of machine-learning technique in our ambiguity set construction and evaluated methods of machine-learning such as K-means Clustering and Classification and Regression Tree (CART). In our project, we considered the problem of a manager selling multiple product in a single period model. We evaluated cases where the seller considers/include uncertain covariates and/or cross-price elasticity using two different linear decision rule, i.e. Partial Affine Recourse Approximation (PARA) and Full Affine Recourse Approximation (FARA).Bachelor of Science in Mathematics and Economic

Effective monitoring of busy boards and Japanese corporate governance.

To investigate the effectiveness of busy boards in Japan in monitoring firms. 6 year

of wireless Local Area Networks (WLANs), WLAN-based positioning

Abstract — With the rapid development and wide deploymen