48 research outputs found
Forecasting technology costs via the Learning Curve – Myth or Magic?
To further our understanding of the effectiveness of learning or experience curves to forecast technology costs, a statistical analysis using historical data has been carried out. Three hypotheses have been tested using available data sets that together shed light on the ability of experience curves to forecast future technology costs. The results indicate that the Single Factor Learning Curve is a highly effective estimator of future costs with little bias when errors were viewed in their log format. However it was also found that due to the convexity of the log curve an overestimation of potential cost reductions arises when returned to their monetary units. Furthermore the effectiveness of increasing weights for more recent data was tested using Weighted Least Squares with exponentially increasing weights. This resulted in forecasts that were typically less biased than when using Ordinary Least Square and highlighted the potential benefits of this method.Forecasting, Learning curves, Renewable energy
SELEKSI TEKNOLOGI PENANGKAPAN IKAN PELAGIS KECIL YANG BERWAWASAN LINGKUNGAN DI PERAIRAN KOTA AMBON
Penelitian ini dilakukan pada bulan Mei hingga Juli 2021 melalui survei pada nelayan perikanan pelagis kecil di kota Ambon. Hasil penelitian menunjukkan bahwa berdasarkan pendapat nelayan teknologi penangkapan ikan skala kecil di wilayah Kota Ambon tergolong sangat ramah lingkungan dan cukup berkelanjutan. Dari tujuh (7) kriteria teknologi penangkapan ikan ramah lingkungan, kriteria selektivitas skornya sangat rendah yaitu 59,57%, sedangkan dari lima (5) kriteria teknologi penangkapan berkelanjutan, kriteria investasinya rendah dengan skor 65,50%. . Hasil analisis AHP menunjukkan terdapat tiga alternatif pilihan prioritas utama teknologi penangkapan ikan ramah lingkungan, yaitu selektivitas tinggi dengan skor 0,343, kualitas tangkapan tinggi 0,238, dan penerimaan sosial 0,135. Hasil analisis ini memiliki rasio inkonsistensi sebesar 0,05 (<0,1). Dua prioritas dalam pilihan teknologi berkelanjutan adalah teknologi tangkap yang menerapkan prinsip ramah lingkungan (0,333), dan aspek hukum (0,333). Rasio inkonsistensi dari analisis ini adalah 0,000 (<0,1). Secara keseluruhan, prioritas teknologi penangkapan ikan pelagis kecil yang ramah lingkungan berkelanjutan di Kota Ambon adalah pancing ulur 0,445, jaring insang hanyut 0,247, purse seine 0,171, bagan 0,089, dan jaring pantai 0,049
Statistical Basis for Predicting Technological Progress
Forecasting technological progress is of great interest to engineers, policy
makers, and private investors. Several models have been proposed for predicting
technological improvement, but how well do these models perform? An early
hypothesis made by Theodore Wright in 1936 is that cost decreases as a power
law of cumulative production. An alternative hypothesis is Moore's law, which
can be generalized to say that technologies improve exponentially with time.
Other alternatives were proposed by Goddard, Sinclair et al., and Nordhaus.
These hypotheses have not previously been rigorously tested. Using a new
database on the cost and production of 62 different technologies, which is the
most expansive of its kind, we test the ability of six different postulated
laws to predict future costs. Our approach involves hindcasting and developing
a statistical model to rank the performance of the postulated laws. Wright's
law produces the best forecasts, but Moore's law is not far behind. We discover
a previously unobserved regularity that production tends to increase
exponentially. A combination of an exponential decrease in cost and an
exponential increase in production would make Moore's law and Wright's law
indistinguishable, as originally pointed out by Sahal. We show for the first
time that these regularities are observed in data to such a degree that the
performance of these two laws is nearly tied. Our results show that
technological progress is forecastable, with the square root of the logarithmic
error growing linearly with the forecasting horizon at a typical rate of 2.5%
per year. These results have implications for theories of technological change,
and assessments of candidate technologies and policies for climate change
mitigation
DESAIN PROTOTIPE KAPAL PENANGKAP DI PERAIRAN MALUKU
Desain prototipe teknologi yang akan dikembangkan mempunyai keunggulan yang lebih baik biladibandingkan dengan kondisi kapal penangkap saat ini. Keunggulan-keunggulannya dapat berpengaruhterhadap pengoperasian kapal serta sumberdaya perikanan di perairan Maluku. Pengembangan desain joranpancing dengan menggunakan fiber glass mempunyai kelebihan lebih ringan, kuat, dan tahan lama walaupunharganya mahal tapi dapat diimbangi dengan hasil tangkapan yang diperoleh dengan alat tangkap ini.Disamping itu juga penggunaan styro foam sangat berpengaruh terhadap desain kapal huhate yang diusulkanuntuk dikembangkan serta mempunyai beberapa keunggulan bila dibandingkan dengan kapal yang dipakainelayan saat ini. Pada kapal dengan inboard engine, desain palka hanya menghasilkan produk untuk pasaranlokal dan belum dimodifikasi untuk menghasilkan produk skipjack loin yang merupakan suatu bentuk produkekspor, yang belakangan ini permintaan akan produk tersebut sangat tinggi
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Towards disappearing user interfaces for ubiquitous computing: human enhancement from sixth sense to super senses
The enhancement of human senses electronically is possible when pervasive computers interact unnoticeably with humans in Ubiquitous Computing. The design of computer user interfaces towards “disappearing” forces the interaction with humans using a content rather than a menu driven approach, thus the emerging requirement for huge number of non-technical users interfacing intuitively with billions of computers in the Internet of Things is met. Learning to use particular applications in Ubiquitous Computing is either too slow or sometimes impossible so the design of user interfaces must be naturally enough to facilitate intuitive human behaviours. Although humans from different racial, cultural and ethnic backgrounds own the same physiological sensory system, the perception to the same stimuli outside the human bodies can be different. A novel taxonomy for Disappearing User Interfaces (DUIs) to stimulate human senses and to capture human responses is proposed. Furthermore, applications of DUIs are reviewed. DUIs with sensor and data fusion to simulate the Sixth Sense is explored. Enhancement of human senses through DUIs and Context Awareness is discussed as the groundwork enabling smarter wearable devices for interfacing with human emotional memories
Multi-species biofilm of Candida albicans and non-Candida albicans Candida species on acrylic substrate
OBJECTIVE: In polymicrobial biofilms bacteria extensively interact with Candida species, but the interaction among the different species of the Candida is yet to be completely evaluated. In the present study, the difference in biofilm formation ability of clinical isolates of four species of Candida in both single-species and multi-species combinations on the surface of dental acrylic resin strips was evaluated. MATERIAL AND METHODS: The species of Candida, isolated from multiple species oral candidiasis of the neutropenic patients, were used for the experiment. Organisms were cultured on Sabouraud dextrose broth with 8% glucose (SDB). Biofilm production on the acrylic resins strips was determined by crystal violet assay. Student's t-test and ANOVA were used to compare in vitro biofilm formation for the individual species of Candida and its different multi-species combinations. RESULTS: In the present study, differences between the mean values of the biofilm-forming ability of individual species (C. glabrata>C. krusei>C. tropicalis>C. albicans) and in its multi-species' combinations (the highest for C. albicans with C. glabrata and the lowest for all the four species combination) were reported. CONCLUSIONS: The findings of this study showed that biofilm-forming ability was found greater for non-Candida albicans Candida species (NCAC) than for C. albicans species with intra-species variation. Presence of C. albicans in multi-species biofilms increased, whereas; C. tropicalis decreased the biofilm production with all other NCAC species
Forecasting technology costs via the experience curve - Myth or magic?
To further understand the effectiveness of experience curves to forecast technology costs, a statistical analysis using historical data is carried out. Three hypotheses are tested using available datasets that together shed light on the historical ability of experience curves to forecast technology costs. The results indicate that the Single Factor Experience Curve is a useful forecasting model when errors are viewed in their log format. Practitioners should note that due to the convexity of the log curve a mean overestimation of potential cost reductions can arise as values are converted into monetary units. Time is also tested as an explanatory variable, however forecasts made with endogenous learning based on cumulative capacity as used in traditional experience curves are shown to be vastly superior. Furthermore the effectiveness of increasing weights for more recent data is tested using Weighted Least Squares with exponentially increasing weights. This results in forecasts that are less biased, though have increased spread when compared to Ordinary Least Squares