Estimation of growth parameters and mortality rates of kingfish (Scomberomorus commerson) in the north of Persian Gulf (Khuzestan Province)

Length composition data from monthly catches of Scomberomorus commerson landed in Choebdeh and Hendijan fish landing places in Khuzestan Province, north Persian Gulf, were collected from 2004 to 2005. We used the data to estimate growth parameters and mortality coefficients of the fish. Response surface analysis produced by the ELEFAN program provided a complete set of Von Bertalanffy growth parameters estimation. We found L infinity =120cm (fork length), K=0.49per year and t_0=-0.11 year for the fish. The length-weight relationship was estimated as W=0.022tL ^2.7575 with r^2=0.978S. Based on the calculated b, we conclude that the fish has an isometric growth pattern. The total, natural and fishing mortality coefficients were estimated as, Z=1.58, M=0.58 and F=1.0, respectively. Exploitation ratio (E) for this species was estimated as 0.63 per year. The E-value indicates that the kingfish in this part of the Persian Gulf has been overexploited. Current fishing pattern in the Khuzestan province shows that 97.07% of the cumulative length frequency and 78.18% of the cumulative weight frequency of the landed fish are under standard size. Results of this study indicate that exploitation of kingfish does not follow an optimum trend and if this trend continues, the stock of Scomberomorus commerson in this area will be threatened

Estimating growth parameters for Otolithes ruber in waters of Bushehr, Hormozgan and Sistan and Baluchestan Province, Southern Iran

Using length frequency of the Otolithes ruber collected in waters of three southern province of Iran, we estimated the fish growth parameters and monthly measured fork length of around 1000 fish caught using gill net with a mesh size of 6.5 centimeters in waters of this study area. The length infinity (L∞) in Bushehr, Hormozgan and Sistan and Baluchistan province was estimated as 58.5, 56, 59.5 centimeters, growth coefficient per year (K) as 0.48, 043, 0.32 and age at zero length (to) as -0.006, -0.002, -0.001 respectively. The relationship between length and weight of the fish in the three provinces determined. The parameters q, b and r (correlation coefficient) were 0.173, 2.868, 0.984 for Bushehr, 0.012, 2.962, 0.932 for Hormozgan and 0.056, 2.604, 0.921 for Sistan and Baluchestan province. We also evaluated the average length for the fish caught in different months and landing places. An ANOVA test showed a significant difference (P≤0.05) between the average lengths of the fish caught in different months

Age, growth and length at first maturity of Otolithes ruber in the northwestern part of the Persian Gulf, based on age estimation using otolith

Estimates of age, growth parameters, length-weight relationship and length and age at first maturity of the otolithes ruber are required for fishery management. We used counting annuli on the section of sagittal otoliths to age O.ruber from the Northwest Persian Gulf in south of Iran. Estimated ages ranged from 0 to 6 years, and maximum frequency of fishes was observed in age-group 1. The values of growth parameters L∞, k and to were calculated by von Bertalanffy model and the results were 67.57 (cm), 0.27 (year-1) and -0.43 respectively. Parameters b and an in length-weight relationship were calculated 3.19 and 0.005 respectively. Length and age at first maturity were estimated 28 cm and 1.55 year

Developing Prognostic Models Using Duality Principles for DC-to-DC Converters

Within the field of Integrated System Health Management, there is still a lack of technological approaches suitable for the creation of adequate prognostic model for large applications whereby a number of similar or even identical subsystems and components are used. Existing similarity among a number of different systems, which are comprised of similar components but with different topologies, can be employed to assign the prognostics of one system to other systems using an inference engine. In the process of developing prognostics, this approach will thereby save resources and time. This paper presents a radically novel approach for building prognostic models based on system similarity in cases where duality principle in electrical systems is utilized. In this regard, unified damage model is created based on standard Tee/Pi models, prognostics model based on transfer functions, and remaining useful life (RUL) estimator based on how energy relaxation time of system is changed due to degradation. An advantage is that the prognostic model can be generalized such that a new system could be developed on the basis and principles of the prognostic model of other systems. Simple electronic circuits, dc-to-dc converters, are to be used as an experiment to exemplify the potential success of the proposed technique validated with prognostics models from particle filter

Reliability enhanced EV using pattern recognition techniques

The following paper will contribute to the development of novel data transmission techniques from an IVHM perspective so that Electrical Vehicles (EV) will be able to communicate semantically by directly pointing out to the worst failure/threat scenarios. This is achieved by constructing an image-based data communication in which the data that is monitored by a vast number of different sensors are collected as images; and then, the meaningful failure/threat objects are transmitted among a number of EVs. The meanings of these objects that are clarified for each EV by a set of training patterns are semantically linked from one to other EVs through the similarities that the EVs share. This is a similar approach to wellknown image compression and retrieval techniques, but the difference is that the training patterns, codebook, and codewords within the different EVs are not the same. Hence, the initial image that is compressed at the transmitter side does not exactly match the image retrieved at the receiver's side; as it concerns both EVs semantically that mainly addresses the worst risky scenarios. As an advantage, connected EVs would require less number of communication channels to talk together while also reducing data bandwidth as it only sends the similarity rates and tags of patterns instead of sending the whole initial image that is constructed from various sensors, including cameras. As a case study, this concept is applied to DC-DC converters which refer to a system that presents one of the major problems for EVs

The appearance of a compact jet in the soft-intermediate state of 4U 1543-47

Recent advancements in the understanding of jet-disc coupling in black hole candidate X-ray binaries (BHXBs) have provided close links between radio jet emission and X-ray spectral and variability behaviour. In 'soft' X-ray states the jets are suppressed, but the current picture lacks an understanding of the X-ray features associated with the quenching or recovering of these jets. Here we show that a brief, ~4 day infrared (IR) brightening during a predominantly soft X-ray state of the BHXB 4U 1543-47 is contemporaneous with a strong X-ray Type B quasi-periodic oscillation (QPO), a slight spectral hardening and an increase in the rms variability, indicating an excursion to the soft-intermediate state (SIMS). This IR 'flare' has a spectral index consistent with optically thin synchrotron emission and most likely originates from the steady, compact jet. This core jet emitting in the IR is usually only associated with the hard state, and its appearance during the SIMS places the 'jet line' between the SIMS and the soft state in the hardness-intensity diagram for this source. IR emission is produced in a small region of the jets close to where they are launched (~ 0.1 light-seconds), and the timescale of the IR flare in 4U 1543-47 is far too long to be caused by a single, discrete ejection. We also present a summary of the evolution of the jet and X-ray spectral/variability properties throughout the whole outburst, constraining the jet contribution to the X-ray flux during the decay.Comment: Accepted to MNRAS. 11 pages, 6 figure

Principle of Duality on Prognostics

The accurate estimation of the remaining useful life (RUL) of various components and devices used in complex systems, e.g., airplanes remain to be addressed by scientists and engineers. Currently, there area wide range of innovative proposals put forward that intend on solving this problem. Integrated System Health Management (ISHM) has thus far seen some growth in this sector, as a result of the extensive progress shown in demonstrating feasible and viable techniques. The problems related to these techniques were that they often consumed time and were too expensive and resourceful to develop. In this paper we present a radically novel approach for building prognostic models that compensates and improves on the current prognostic models inconsistencies and problems. Broadly speaking, the new approach proposes a state of the art technique that utilizes the physics of a system rather than the physics of a component to develop its prognostic model. A positive aspect of this approach is that the prognostic model can be generalized such that a new system could be developed on the basis and principles of the prognostic model of another system. This paper will mainly explore single switch dc-to-dc converters which will be used as an experiment to exemplify the potential success that can be discovered from the development of a novel prognostic model that can efficiently estimate the remaining useful life of one system based on the prognostics of its dual system

Estimation growth parameters of Parastromateus niger in the coastal waters of Sistan and Baluchestan, Oman Sea

Using length frequency information collected for Parastromateus niger catch in the coastal waters of Sistan and Baluchestan, Oman Sea, we estimated growth parameters of the fish. The data were collected of the fork length of around 887 fish each month during 2001. The length infinity (L∞), growth coefficient (K) and the length at age zero (t0) of the fish measured as 57.8 cm, 0.3 per year and -0.003 respectively. The relationship between the length and weight of the fish was estimated as 0.0469 for “a” , 2.829 for "b" and 0.914 for the correlation coefficient. The average length of the fish in different months of the year calculated and a Tukey test showed that this was significantly different

Growth, mortality and spawning season of the spangled emperor (Lethrinus nebulosus Forsskal, 1775) in coastal waters of Hormozgan Province in the Persian Gulf and Oman Sea

The population parameters and spawning season of the Spangled emperor (Lethrinus nebulosus) were studied in coastal waters of Hormozgan province. The monthly calculated mean values of gonadosomatic index (GSI) of females were indicate to increase from February, reach the highest in March and decline in June. The spawning season peak of L. nebulosus occurred in March. The Von Bertalanffy growth parameters, L∞, K and t0 were estimated as, 67.2cm, 0.16.year^-1 and -1.161 year, respectively. The relationship between weight and length (Fork Length) can be expressed as W=0.051 L^2.722, which indicates that Spangled Emperor has negative allometric growth. Using length converted catch curve, total mortality (Z) was estimated as 1.13 year^-1 and natural mortality was estimated using Pauly's equation, as 0.57 per year. Finally, the fishing mortality (F) was 0.56, which gives an exploitation rate (E) of 0.50