Counterpoint to the editorial - Paranagamage, Primali
This short article provides a alternative viewpoint to the editorial in this issue of the Sri Lanka Architect
Supervised learning of places from range data using adaboost - Martinez Mozos, Oscar
In the past, several researchers focused on building accurate metric or topological maps out of sensor data. The majority of approaches present solutions to simultaneous localization and mapping but only a few works try to acquire semantic information autonomously. In this work we address the problem of classifying places in environments into semantic classes based on range data only. We use a supervised learning algorithm to train a set of classifiers based on the Adaboost algorithm. Using our classification system, a mobile robot is able to distinguish different places like rooms, corridors, doorways, and hallways.
Semantic place labeling with mobile robots - Martinez Mozos, Oscar
Indoor environments can typically be divided into places with diﬀerent functionalities like corridors, rooms or doorways. The ability to learn such semantic categories from sensor data enables a mobile robot to extend the representation of
the environment, and to improve its capabilites. As an example, natural language
terms like corridor or room can be used to communicate the position of the robot
in a more intuitive way. Other tasks, like exploration or localization, can also be
carried out by the robot in a better way when semantic information is taken into
In this thesis, we present a method that enables a mobile robot to classify...
Efficiently learning metric and topological maps with autonomous service robots - Stachniss, Cyrill; Grisetti, Giorgio; Martinez Mozos, Oscar; Burgard, Wolfram
Models of the environment are needed for a wide range of robotic applications, from search and rescue to automated vacuum cleaning. Learning maps has therefore been a major research focus in the robotics community over the last decades. In general, one distinguishes between metric and topological maps. Metric maps model the environment based on grids or geometric representations whereas topological maps model the structure of the environment using a graph. The contribution of this paper is an approach that learns a metric as well as a topological map based on laser range data obtained with a mobile robot. Our approach...
Supervised semantic labeling of places using information extracted from sensor data - Martinez Mozos, Oscar; Triebel, Rudolph; Jensfelt, Patric; Rottmann, Axel; Burgard, Wolfram
Indoor environments can typically be divided into places with different functionalities like corridors, rooms or doorways. The ability to learn such semantic categories from sensor data enables a mobile robot to extend the representation of the environment facilitating interaction with humans. As an example, natural language terms like “corridor” or “room” can be used to communicate the position of the robot in a map in a more intuitive way. In this work, we first propose an approach based on supervised learning to classify the pose of a mobile robot into semantic classes. Our method uses AdaBoost to boost simple features...
Studies on the mechanism of blackspot development in Norway lobster (Nephrops norvegicus) - Yan, Xinjian; Taylor, K. D. Anthony; Hanson, Steven W.
The mechanism of blackspot development in Norway lobster (Nephrops norvegicus) was studied. A linear relationship was observed between phenolase activity and rate of colour development in homogenates. It was found that tyrosine could significantly influence the rate of colour development. Production of dihydroxyphenylalanine (DOPA) during colour development was demonstrated using an HPLC method. The production of DOPA, i.e. tyrosinase activity, and the rate of colour development in homogenates of Norway lobster were found to be directly related to the phenolase activity as measured using catechol oxidase activity. It is proposed that tyrosine is the initial substrate for blackspot development in...
Phenolase in Norway lobster (Nephrops norvegicus): activation and purification - Yan, Xinjian; Taylor, K. D. Anthony; Hanson, Steven W.
Increase in phenolase activity from Norway lobster was observed to take place immediately after making a crude enzyme preparation; the total enzyme activity increased by a factor of 3–4 over a period of 8–12 h. The process was associated with the appearance of a more active form of the phenolase. The initial natural form (Form I) and the more active form (Form II) of the enzyme were separated and partially purified by a combination of acetone precipitation and DEAE cellulose column chromatography. The natural form (Form I) was found to have an optimum temperature of 40°C, an isoelectric point of...
Studies of the mechanism of phenolase activation in Norway lobster (Nephrops norvegicus) - Yan, Xinjian; Taylor, K. D. Anthony
The mechanism of phenolase activation in Norway lobster was studied. It was found that phenolase activation in Norway lobster requires a protease. Trypsin and a bacterial protease from Streptomyces griseus, accelerate the rate of increase of phenolase activity in crude phenolase preparations from Norway lobster, but have little effect on the enzyme after being partially purified by acetone precipitation. It was also found that the process requires another factor(s), which has low molecular weight and is probably located in a subcellular fraction mainly containing the microsomes. Therefore the increase of phenolase activity appears to be a multiple component process and...
A spectrofluorimetric procedure for the determination of α-tocopherol in nutritional supplement products - Razagui, Ibrahim B.; Barlow, Philip J.; Taylor, Keith D. A.
A direct spectrofluorimetric method for the determination of vitamin E in nutritional supplement products is described. Samples analysed include single vitamin and multivitamin tablets and capsules as well as dietary formula preparations. The analytical procedure was carried out in a single reaction vessel and consisted of saponification of samples for 10 min in a water bath set at 85°C using absolute ethanol (5 ml) and 80% (w/v) potassium hydroxide solution (2 ml) as the saponification medium, with ascorbic acid (125 mg) as antioxidant. The analyte was extracted in situ with n-hexane (20 ml). Treatment of the n-hexane layer with 60%...
Studies on the protease activities in Norway lobster (Nephrops norvegicus) and their role in the phenolase activation process - Wang, Zhoubo; Taylor, K.D.Anthony; Yan, Xinjian
Proteolytic activity in Norway lobster (Nephrops norvegicus) was studied. Three proteases were separated and partially purified from Norway lobster heads by a combination of acetone precipitation and DEAE-Sepharose CL-6B column chromatography and designated as enzymes I, II and III. Enzyme III had a pH optimum at around 8.2 towards casein as substrate. Enzymes I and II were found to be very similar in most aspects; they showed multiple pH optima towards casein. Studies on sensitivity to different inhibitors suggested that enzymes I and II were likely to be thiol proteases and enzyme III a metal-dependent serine protease. It was found...
Further studies on the roles of proteases in the activation of phenolase from Norway lobster (Nephrops norvegicus) - Wang, Zhoubo; Taylor, K. D. Anthony; Yan, Xinjian
Phenolase activation in Norway lobster (Nephrops norvegicus) was found to be a result of proteolysis. Endogenous protease activity is shown to activate the phenolase activity directly. The three protease activities identified in Norway lobster all affected the phenolase-activation process. Protease III, a metal-dependent serine protease, was involved in the activation process, but proteases I and II, two thiol proteases, also affected the activation process by apparently degrading the phenolase present. The phenolase activation in Norway lobster appears to be a result of the balance of the specific proteolytic action of protease III and the presumably less discriminative degradation of protease...
Methods of extraction composition and stability of vitamin A and other components in dogfish (Squalus acanthias) liver oil - Sunarya,; Hole, Michael; Taylor, K. D. Anthony
Oil was extracted from dog fish (Squalus acanthias) livers by the Bligh and Dyer, Soxhlet and steaming extraction methods. Oil yields using the steaming method (22% ) were lower than from the solvent extraction methods (68% ). The vitamin A content of the oil produced by steaming was 54 mg retinol/100 g oil, and slightly higher (62–68 mg/100 g) contents were recorded in the solvent extracted oils.
The Bligh and Dyer extraction produced an oil containing 12% phospholipid, much higher than the 4% via the Soxhlet and 1 % in the steaming extractions. The level of squalene (40 mg/100 g) in...
Partial purification and characterization of proteases from Norway lobster (Nephrops norvegicus) and their role in the phenolase activation process - Zotos, A.; Taylor, K. D. A.
Proteolytic activity in Norway lobster (Nephrops norvegicus) was studied. An improved separation and partial purification of the three proteases (designated as proteases I, II and III) was achieved from Norway lobster heads by a combination of acetone precipitation and DEAE-Sepharose CL-6B column chromatography.
The purification achieved was 63-, 25- and 217-fold at pH 8.2, and 40-, 25- and 160-fold at pH 6.4 for protease I, II and III, respectively.
With casein as substrate, protease III was most active at pH 8.2, whilst proteases I and II showed activity over a wide range of pH.
Protease III was characterized as an alkaline Zn-serine protease...
Studies on the influence of small molecule factor(s) on protease activities in Norway lobster (Nephrops norvegicus) - Zotos, Anastasios; Taylor, K. D. Anthony
The interactions of small molecule(s) and proteases in the suggested multiple component process of phenolase activation in Norway lobster (Nephrops norvegicus) were studied.
It was observed that protease I is mainly a visceral protease, whilst proteases II and III exist in approximately equal amounts in viscera and flesh, respectively.
It was found that the small molecule factor(s) (molecular weight less than 10 000) inhibited proteases I, II and III at pH 6.7 and 8.2, except when it was freshly prepared and then it activated only protease III and only at pH 8.2. This indicates that the small molecule(s) may be modified on...
Studies on the roles and identification of the small molecule factors on phenolase activation in Norway lobster (Nephrops norvegiens) - Zotos, Anastasios; Taylor, K. D. Anthony
The direct effect of small molecule factor(s) on the activation of phenolase in the suggested multiple component process of blackspot development in Norway lobster (Nephrops norvegicus) was studied.
When acetone-precipitated phenolase was treated with the small molecule filtrate, the phenolase activation profile was lower compared to the control, particularly at pH 6.7. However, when purified form I phenolase was treated with small molecule filtrate no activation was observed, the assayed phenolase activity being constant but lower than the control. A similar effect was observed when form I phenolase was treated with 1.5 mM dihydroxyphenylalanine (DOPA) (approximately the concentration found in the...
Comparison of wild and cultured gilthead sea bream (Sparus aurata); composition, appearance and seasonal variations - Grigorakis, Kriton; Alexis, Maria N.; Taylor, K. D. Anthony; Hole, Michael
Major quality parameters, such as muscle composition, fat deposition, muscle fatty acid composition and external appearance were studied in wild and cultured gilthead sea bream. Muscle fat content and total depot fat (peritoneal and perivisceral fat) indicated a seasonal variation with minimum values observed in late spring and maximum in late summer. Gonadosomatic indices of cultured fish were lower than those found in wild specimens. Lipid content of cultured sea bream was much higher than that of wild fish. Differences were also observed in fatty acid profiles. Cultured fish were characterized by higher levels of monoenes, n-9 and 18:2n-6 fatty...
The effect of storage at tropical ambient temperature on the quality and shelf life of grouper (Plectropomus maculatus) - Surti, Titi; Taylor, Anthony; Ma'Ruf, Farid
Groupers (Plectropomus maculatus) were harvested from holding tanks and stored in ice until assessment rated them unacceptable. Groupers were also subjected to periods (2–12 h) of storage at tropical ambient (29–31 °C) immediately after harvest but prior to cooling in ice. The storage life of grouper stored continuously in ice was 18 days. A 2-h delay before cooling in ice approximately halves the storage life and for every further hour of malstorage the shelf-life was further reduced by approximately 1 day. The total volatile basic nitrogen (TVBN) and hypoxanthine contents were found to be good indicators of freshness in groupers,...
The effect of different salting procedures and qualities of raw material on some nutrients during processing and storage of salted-dried mackerel - Surono,; Taylor, K. D. Anthony; Smith, Gillian
Salted-dried mackerel (Scomber scombrus) was prepared using fresh fish or fish which had been stored in ice for 75h and four methods of salting, namely 15% brine, saturated brine, pickle and dry salting. Samples were analysed for available lysine, thiamine and riboflavin before salting, after salting, after drying and after 1 month's storage at 20°C. Final losses of each of these nutrients were lowest when the fish were pickle cured. Losses were also lower when fresher raw material was used. the use of good quality fish and a pickle salting method is therefore recommended for this type of product.
Improved utilization of flesh from mackerel as salted dried fish cakes - Akande, G. R.; Knowles, M. J.; Taylor, K. D. A.
The composition and yield of mince prepared by passing mackerel (S. scombrus) frames through a flesh-bone separator were determined. Salt (10 to 40%) was added to the unwashed mince to prepare dried cakes with enhanced keeping quality. The dried cakes were assessed for peroxide and TBA values, total viable count and for sensory attributes after preparation and after a 3-month storage period at 29±1°C. The cakes were reconstituted by desalting in boiling water. Salted dried cakes prepared with 15,20,30 and 40% salt were found to be stable and have little sensory deterioration over the 3-month storage period which is adequate...