Multi-node optimization using Boolean relations is a powerful approach for network minimization. The approach has been studied in theory, and so far its superiority over single node optimization techniques has only been conjectured for practical designs. This is due to the highly memory intensive computations involved in the calculation of Boolean relations representing the multi-node optimization exibility. In this thesis, an algorithm to perform Boolean relation-based multi-node optimization using a robust, fast and memory efcient algorithm is presented. In particular, two nodes are simultaneously optimized at a time. Results are reported on large designs, demonstrating the initial power of this multi-node optimization algorithm. The robustness of the approach arises from the use of a window-based technique for computing these Boolean relations. Secondly, aggressive early quantication is performed during the computation, keeping memory utilization low. Finally, smart heuristics are employed for selecting the node pair to be optimized simultaneously. These features allow the approach to scale well and provide good results for large designs. Experiments are performed on a set of large benchmarks and the algorithm's performance is compared to a SAT-based network optimization technique using complete don't cares. On average, the approach presented in this thesis achieves a 12% reduction in literal count across all the large designs compared to the complete don't cares, while maintaining small runtimes and low memory usage.

Solving the waste problem is one of the most challenging environmental missions for Hong Kong. Currently, the amount of waste generated has reached an unsustainable level. Hong Kong’s domestic waste disposal rate is significantly higher than other international cities like Tokyo, Taipei City and Seoul. With present trends, this mounting waste has been filled up the three landfill sites at a rate much faster than anticipated. Hong Kong SAR Government is hoping to expand the landfill site and build incinerator(s). However, these plans have not been well-received by the public. Waste reduction at source would be a significant alternative for Hong Kong instead. Environmental education (EE) is a vital component of achieving sustainable waste management. This is the best strategy to help reduce waste at source. Among all the targeted trainees, it is found that little local and international research has been done on the potential role of Foreign Domestic Helpers (FDHs) in waste management. FDHs make up a significant proportion of the Hong Kong population. They are one of the best candidates to learn and implement sustainable waste management in the households. Thus, this study looks into the current EE to FDHs and analyses how to send green message among FDHs in an effective way. A framework of indicators for an effective waste reduction education program to FDHs is constructed as to help evaluate the performance of EE providers for FDHs. Information regarding current EE to FDHs is obtained from reviewing publicly available information and by conducting in-depth interviews with related personnel and stakeholders. To reconfirm the need and importance of providing EE to FDHs, a questionnaire survey to FDHs is developed and a pilot EE program to FDHs is designed and implemented. This study found that the current EE to FDHs is inadequate and ineffective. The knowledge of FDHs in waste reduction is not comprehensive and few of them have had green housekeeping habits. Through providing appropriate training incorporating the indicators identified, FDHs are enabled to proceed from having the right awareness to taking action in the households. The success of the pilot EE program to FDHs also gave us an insight into the importance of adequate and quality EE to the community. It is hoped that the suggestions being put forward in this study can guide Hong Kong in achieving the target of zero waste. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Waste management is always a headache to the policy makers to tackle with nowadays as we are generating more waste than the past generations. Landfill is the only disposal method in Hong Kong since the early of the 1990s and the three strategic landfills are going to be filled. Therefore, the quantity-based waste charging is going to be implemented in the near future in order to reduce waste generation. A complementary recycling system is a must to complete the newly proposed waste management policy to reduce waste volume. There are some obvious problems existing in the current recycling efforts, which hinder the success of waste separation for recycling so as to reduce waste generation. As a result, it is important to review the current Programme on Source Separation of Domestic Waste. Moreover, a successful waste separation programme for waste reduction requires fulfilling the criteria in the aspects of Recycling Facilities/Services, Public Education & Promotion and Statutory Requirement & Complementary Policy. Based on the survey results, 40% of the current recycling facilities are inconvenient or inconvenient at all and most of the respondents think that there are insufficient recycling facilities in the territory. Nearly 70% of them agree or fully agree to implement mandatory waste separation and more than a half of them prefer to fine each non-compliance below $500. Moreover, the majority of the respondents suggest that the incentives for them to recycle are not enough or not enough at all, which take up 55% of the total. And 60% of them agree or fully agree to reward people who recycle. From the site visit, it is obvious that the public abuses the roadside 3-coloured bins especially in the Hong Kong Island and the New Territories. Meanwhile, the misuse of the recycling bins leads to the cleanness problem. The tendered contractors are not doing well in terms of emptying and locking the 3-coloured bins. There are fewer problems arising from the recycling facilities or bins collecting other recyclables as these recycling bins are designed for collecting specific types of recyclables and they are not adjacent to the rubbish bins. Also, the centers for collecting bulky recyclables have management staff to collect the recyclables. According to the reply from the Environmental Protection Department, there are many monitoring works to ensure the services quality provided by the service contractors. However, it is questionable that it can maintain the performance of the contractors. Since there are increasing complaints on the unsatisfactory performance of the service contractors. As a result, the Government should review the current Programme on Source Separation of Domestic Waste in accordance with recommendations proposed in the scopes of Physical Enhancement to Recycling Facilities/Services, Education and Promotion and Policy Recommendations, including increasing the convenience and availability of the recycling facilities and the range of separation; implementing compulsory environmental education and improving the promotion on waste separation; implementing complementary policy and regulations for waste separation, monitoring the performance of waste separation and providing incentives to encourage recycling. / published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

This thesis presents a new method for the controllable damping of deformable objects. The method evolves from physically based techniques; however, it allows for non-physical, but visually plausible motion. This flexibility leads to a simple interface, with intuitive control over the behaviour of the material. This method is particularly suited for strongly damped materials, which account for the majority of objects of interest to animation, since it produces non-oscillatory behaviour. This is similar to critical damping, except that it affects all modes independently. The new method is based on the minimization of a slightly modified version of total energy. This framework can be used to simulate many other physical phenomena, and therefore lends itself to coupling with other simulations. Implementation details for a simple example are given. Results are shown for varying parameters and compared to those produced by a traditional method.

Darbe nagrinėjame ėmimo planus, kurių priklausymo imčiai tikimybės yra dviejų komponenčių mišiniai. Pirmoji komponentė yra proporcinga papildoma informacija nusakytam populiacijos elemento dydžiui, o antroji yra vienoda visiems elementams. Ieškome tokių mišinių, kurie minimizuoja įvairių populiacijos sumos įvertinių dispersijas ir parodome kaip, naudojantis papildoma informacija, apytiksliai nustatyti optimalų mišinį. Pateikiame teorinius ir kompiuterinio modeliavimo rezultatus Poisson'o imtims, renkamoms iš populiacijų, kurios yra generuotos naudojant tiesinės regresijos modelį. / We consider sampling designs, where inclusion (to sample) probabilities are mixtures of two components. The first component is proportional to the size of a population unit (described by means of an auxiliary information available). The second component is the same for every unit. We look for mixtures that minimize variances of various estimators of the population total and show how auxiliary information could help to find an approximate location of such mixtures. We report theoretical and simulation results in the case of Poisson samples drawn from populations which are generated by a linear regression model.

Chemical synthesis is not complete without waste treatment. There is no chemical process that does not produce waste. The untreated effluent discharged by chemical industries poses a major environmental concern. This dissertation describes the results of an investigation carried out on the formation of by-products (impurities) during the synthesis of atrazine by neutralization of the reaction mixture during the actual synthesis procedure, and prior to disposal using carbon dioxide or hydrochloric acid. The main objectives for the said investigation were: {u100083} To optimise the reaction parameters to obtain a higher yield and purity of atrazine. {u100083} To evaluate the use of carbon dioxide and hydrochloric acid to neutralise the reaction mixture. {u100083} To study the solids present in the effluent. Synthetic reactions were carried out in the presence of an organic solvent, methyl isobutyl ketone (MIBK). The synthesis of atrazine was optimised in terms of addition sequence and rates of amine reagents and base (proton acceptor) additions by means of bench scale reactions. It was found that addition of a neutralising step (hydrochloric acid or carbon dioxide) to neutralise the basic reaction mixture prior to and after addition of the secondary amine and the base minimizes the formation of by-products. Of particular importance in ensuring high yields and selectivity to the atrazine product was temperature control, pH control, reagent ratios, addition rates and mixing. The latter was important in view of the rapid reaction of amine/NaOH with cyanuric chloride, as well as the possible reaction of mono-i, the reaction intermediate, with IPA in cases of excesses of reagent. Under optimum conditions, an atrazine composition of >97% was achieved where the resultant product was well within stipulated product specifications.

This thesis presents a new method for the controllable damping of deformable objects. The method evolves from physically based techniques; however, it allows for non-physical, but visually plausible motion. This flexibility leads to a simple interface, with intuitive control over the behaviour of the material. This method is particularly suited for strongly damped materials, which account for the majority of objects of interest to animation, since it produces non-oscillatory behaviour. This is similar to critical damping, except that it affects all modes independently. The new method is based on the minimization of a slightly modified version of total energy. This framework can be used to simulate many other physical phenomena, and therefore lends itself to coupling with other simulations. Implementation details for a simple example are given. Results are shown for varying parameters and compared to those produced by a traditional method. / Science, Faculty of / Computer Science, Department of / Graduate

Thesis (M. Sc.)--University of Hong Kong, 1997. / Includes bibliographical references (leaf 60-67).

Waste minimisation involves reducing waste (emissions, effluent, solid waste) in companies, at source. v 7, 8 Its benefits include cost savings, environmental improvement, increased throughput and risk and liability reduction. 7, 8, 13 Through implementation of a structured waste minimisation programme, companies can identify waste minimisation opportunities: broad focus areas that will benefit from a more detailed waste minimisation assessment. More specific waste minimisation solutions can then be identified. In this study, the waste minimisation opportunity was identified by the company, Ben Booysen, a priori. Ben Booysen is a local air-conditioning and refrigeration company in Pietermaritzburg, which services air-conditioner units. They identified the waste minimisation opportunity of optimising the process conditions for cleaning the airconditioner units. At the time at Ben Booysen, Alukleen, an acid cleaner (RT Chemicals®, RTCM 64) , was applied manually (by a paintbrush) at an effective dilution of 1:3 to clean the aluminium air-conditioner coils. Handy Andy and green soap were used to clean the plastic covers of the units. Concerns about the effluent, cost and safety of handling Alukleen led to their identification of this waste minimisation opportunity. The initial objectives of this project were thus the qualification and quantification of the species present in Alukleen; the quantification of the species present in the Ben Booysen effluent and the subsequent comparison of these values to limits for disposal to stormwater and Darvill. A further objective was the optimisation of the cleaning system with regard to Alukleen concentration and contact (soaking) time. Wet chemical analysis was employed as a qualitative tool for identification of the components present in Alukleen. This analysis indicated that fluoride, sulfate, sulfide, arsenite and chloride ions are present in Alukleen. Further quantitative analysis using the Ion chromatograph, the ICP-OES and a fluoride ion selective electrode indicated that only sulfate (152600 ppm) and fluoride (25400 ppm) are present in significant quantities. Studies were conducted on aluminium coil pieces in which both the contact (soaking) times and Alukleen concentrations were varied. These tests indicated that the effect of soaking time on the cleanliness achieved was negligible. Although a greater amount of dirt was removed when using more concentrated Alukleen solutions, etching of the metal occurred at higher concentrations, resulting in a loss of sheen and malleability of the metal. Etching of the aluminium air-conditioner coils by Alukleen, as indicated by both digital photography and electron microscopy, resulted in extending the objectives of this project to include the investigation of alternative aluminium cleaners. Hence, the cleaning action of three degreasers was investigated: Powerkleen (RT Chemicals®, RTCMI23), Technicians' Choice (Auto Brite (PTY) Ltd.) and Klengine (Auto Brite (PTY) Ltd.) . Powerkleen was found to be the most effective degreaser and did not compromise the metal's sheen or malleability. Further studies were then conducted to characterise the major components ofPowerkleen and to optimise its use with regard to concentration and contact (soaking) time. The suitability oftwo methods of application was also tested. The main component of Powerkleen, determined through the use of ICP-OES, was found to be potassium hydroxide, present at a concentration of 0.711 M. The optimum Powerkleen concentration range for cleaning the aluminium coils was found to be between a 1:20 and 1:40 dilution. Contact (soaking) time of Powerkleen with the aluminium coils was found to have a negligible effect on the mass of dirt removed by the degreaser. Application of the Powerkleen to the aluminium coils by an air gun at a pressure of 4 bars (for units serviced at Ben Booysen) and by a pump bottle (for units serviced in industry) were both found to achieve an acceptable degree of cleanliness of the aluminium. A feasibility analysis (technical , economical and environmental) indicated that a 1:40 dilution of Powerkleen is a feasible, cost-effective and environmentally compliant alternative to Alukleen. Implementation of the Powerkleen cleaning system would result in a R5030 annual saving with a payback period of 5.9 months and an internal rate of return of 214.9%. It would further eliminate the fluoride effluent problems associated with Alukleen and reduce the quantity of chemical raw materials required for the process from 2100 Llannum to 260 Llannum. In industry, an effective dilution of 1:39 would be used for the sake of eas y dilution. A 1:79 dilution of Powerkleen was also found to be a feasible replacement for Handy Andy and green soap in the cleaning of the plastic covers of the units. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

Cisco’s embedded logic analyzer module (ELAM) is a debugging device used for many of Cisco’s application specific integrated chips (ASICs). The ELAM is used to capture data of interest to the user and stored for analysis purposes. The user enters a trigger expression containing data fields of interest in the form of a logical equation. The data fields associated with the trigger expression are stored in a set of Match and Mask (MM) registers. Incoming data packets are matched against these registers, and if the user-specified data pattern is detected, the ELAM triggers and begins a countdown sequence to stop data capture. The current ELAM implementation is restricted in the form of trigger expressions that are allowed and in the allocation of resources. Currently, data fields in the trigger expression can only be logically ANDed together, Match and Mask registers are inefficiently utilized, and a static state machine exists in the ELAM trigger logic. To optimize the usage of the ELAM, a trigger expression is first treated as a Boolean expression so that minimization algorithms can be run. Next, the data stored in the Match and Mask registers is analyzed for redundancies. Finally, a dynamic state machine is programmed with a distinct set of states generated from the trigger expression. This set of states is further minimized. A feasibility study is done to analyze the validity of the results.