First results from the CAWSES-India Tidal Campaign

The first CAWSES-India Tidal Campaign was conducted by the Indian scientific community during March–April 2006. The objectives of this campaign were: (1) To determine the characteristics of tides in the troposphere and lower stratosphere (0–20 km) and mesosphere and lower thermosphere (MLT) region (80–100 km), (2) to explore and identify what lower atmospheric processes drive middle atmospheric tides in the Indian continental region and (3) to provide information on those short-term variabilities of MLT tides that are likely to have an impact on the ionospheric variabilities and contribute to the upper atmospheric weather. Data sets from experiments conducted at the three low latitude radar sites, namely, Trivandrum (8.5° N, 76.9° E), Tirunelveli (8.7° N, 77.8° E) and Gadanki (13.5° N, 79.2° E) and fortnightly rocket launches from Thumba were made use of in this study. An important observational finding reported in this work is that the radar observations at Tirunelveli/Trivandrum indicate the presence of 15–20 day modulation of diurnal tide activity at MLT heights during the February–March period. A similar variation in the OLR fields in the western Pacific (120–160° longitude region) suggests a possible link between the observed tidal variabilities and the variations in the deep tropical convection through the nonmigrating tides it generates

Gravity waves observed from the Equatorial Wave Studies (EWS) campaign during 1999 and 2000 and their role in the generation of stratospheric semiannual oscillations

International audienceThe altitude profiles of temperature fluctuations in the stratosphere and mesosphere observed with the Rayleigh Lidar at Gadanki (13.5° N, 79.2° E) on 30 nights during January to March 1999 and 21 nights during February to April 2000 were analysed to bring out the temporal and vertical propagation characteristics of gravity wave perturbations. The gravity wave perturbations showed periodicities in the 0.5?3-h range and attained large amplitudes (4?5 K) in the mesosphere. The phase propagation characteristics of gravity waves with different periods showed upward wave propagation with a vertical wavelength of 5?7 km. The mean flow acceleration computed from the divergence of momentum flux of gravity waves is compared with that calculated from monthly values of zonal wind obtained from RH-200 rockets flights. Thus, the contribution of gravity waves towards the generation of Stratospheric Semi Annual Oscillation (SSAO) is estimated

ONEChat: Enabling Group Chat and Messaging in Opportunistic Networks

Opportunistic networks, which are wireless network "islands" formed when transient and highly mobile nodes meet for a short period of time, are becoming commonplace as wireless devices become more and more popular. It is thus imperative to develop communication tools and applications that work well in opportunistic networks. In particular, group chat and instant messaging applications are particularly lacking for such opportunistic networks today. In this paper, we present ONEChat, a group chat and instant messaging program that works in such opportunistic networks. ONEChat uses message multicasting on top of service discovery protocols in order to support group chat and reduce bandwidth consumption in opportunistic networks. ONEChat does not require any pre-configuration, a fixed network infrastructure or a client-server architecture in order to operate. In addition, it supports features such as group chat, private rooms, line-by-line or character-by-character messaging, file transfer, etc. We also present our quantitative analysis of ONEChat, which we believe indicates that the ONEChat architecture is an efficient group collaboration platform for opportunistic networks

Measurements of Multicast Service Discovery in a Campus

Applications utilizing multicast service discovery protocols, such as iTunes, have become increasingly popular. However, multicast service discovery protocols are considered to generate network traffic overhead, especially in a wireless network. Therefore, it becomes important to evaluate the traffic and overhead caused by multicast service discovery packets in real-world networks. We measure and analyze the traffic of one of the mostly deployed multicast service discovery protocols, multicast DNS (mDNS) service discovery, in a campus wireless network that forms a single multicast domain of large users. We also analyze different service discovery models in terms of packet overhead and service discovery delay under different network sizes and churn rates. Our measurement shows that mDNS traffic consumes about 13 percent of the total bandwidth

Implementation of lean manufacturing and lean audit system in an auto parts manufacturing industry – an industrial case study

Lean manufacturing is one of the innovative manufacturing concepts being applied in many industries to avoid the wastages of resources and improving the quality of products and help the company to become more effective and productive. It also focuses on continuous improvements with the total involvement of all employees with optimum utilization of man power and machine by reducing idle time and reducing lead time with help of lean tools like value stream mapping and kaizen. This paper presents a case study carried out in a foundry division of an auto parts manufacturing industry, where lean tools are implemented for the defect reduction and productivity improvement. In this paper, a conceptualized implementation of total productive maintenance practices of lean tools: Kaizen or continuous improvement and value stream map in an auto parts industry are presented. The result shows improved performance in terms of average core rejections, sand leakage and air lock problem

Vertical propagation characteristics and seasonal variability of tidal wind oscillations in the MLT region over Trivandrum (8.5° N, 77° E): first results from SKiYMET Meteor Radar

Tidal activity in the Mesospheric Lower Thermosphere (MLT) region over Trivandrum (8.5° N, 77° E) is investigated using the observations from newly installed SKiYMET Meteor Radar. The seasonal variability and vertical propagation characteristics of atmospheric tides in the MLT region are addressed in the present communication. The observations revealed that the diurnal tide is more prominent than the semi/terdiurnal components over this latitude. It is also observed that the amplitudes of meridional components are stronger than that of zonal ones. The amplitude and phase structure shows the vertical propagation of diurnal tides with vertical wavelength of ~25 km. However, the vertical wavelength of the semidiurnal tide showed considerable variations. The vertical propagation characteristics of the terdiurnal tide showed some indications of their generating mechanisms. The observed features of tidal components are compared with Global Scale Wave Model (GSWM02) values and they showed a similar amplitude and phase structure for diurnal tides. Month-to-month variations in the tidal amplitudes have shown significant seasonal variation. The observed seasonal variation is discussed in light of the variation in tidal forcing and dissipation

Accelerating Service Discovery in Ad-Hoc Zero Configuration Networking

Zero Configuration Networking (Zeroconf) assigns IP addresses and host names, and discovers service without a central server. Zeroconf can be used in wireless mobile ad-hoc networks which are based on IEEE 802.11 and IP. However, Zeroconf has problems in mobile ad-hoc networks as it cannot detect changes in the network topology. In highly mobile networks, Zeroconf causes network overhead while discovering new services. In this paper, we propose an algorithm to accelerate service discovery for mobile ad-hoc networks. Our algorithm involves the monitoring of network interface changes that occur when a device with IEEE 802.11 enabled joins a new network area. This algorithm allows users to discover network topology changes and new services in real-time while minimizing network overhead

भारतातील आणि महाराष्ट्रातील पिंजऱ्यातील मत्स्यपैदास : सद्य आणि भविष्यातील प्रगतीच्या संधी

Sea farming is a popular area of aquaculture practice throughout the world. In Asian countries, it is rapidly growing to meet the increasing demand of high value marine fishes. Although India has a tradition of aquaculture, sea farming ventures on commercial scale were lacking. In this context, Central Marine Fisheries Research Institute started open sea floating cage culture activities in 2006-07 with Department of Animal Husbandry, Dairying and Fisheries (DAHD&F), Government of India assistance. Indigenous cage of 15 m diameter was fabricated following Norwegian open sea floating cage design and launched at Visakhapatnam. There was a technical setback with the design of cage, and consultation with Indian Institute of Technology, West Bengal helped to overcome technical issues with the cage structure. Open sea floating cage diameter was reduced to 6 m and 14 new open sea floating cages were launched at Sutrapada (Gujarat), Vasai (Maharashtra), Mangalore (Karnataka), Cochin (Kerala), Pulicat (Tamil Nadu), Nellore, Kakinada, Baruva (Andhra Pradesh) and Balasore (Odisha) in participation with National Fisheries Development Board (NFDB)

Survival and growth of juvenile silver pompano Trachinotus blochii (Lacepède, 1801) at different salinities in tropical conditions

The objectives of the present study were to evaluate the tolerance of juvenile silver pompano to different salinity conditions in order to determine the minimum salinity required for survival and also to study the effect of different salinities on survival and growth. Wild caught juveniles of the silver pompano Trachinotus blochii (average initial length: 4.38±0.44 cm, average initial weight: 1.6±0.09 g) were used in the experiments. The experiments were conducted in triplicate with 15 fish per tank. Control groups were maintained at 34±1 ppt. Juvenile silver pompano reared at ambient salinity (34±1ppt) were transferred directly to lower salinities (25, 15, 10, 5, 4, 3 and 1 ppt) and monitored for survival. Results indicated that the minimum salinity required for the survival of juvenile T. blochii is 4 ppt and 100% mortality was observed within 7-8 h in 1 ppt salinity. In another experiment, three salinity reduction protocols were followed and the three treatment groups were exposed to 25, 15 and 5 ppt salinity for a period of 56 days and the growth and survival were monitored. Survival and growth in terms of weight was not significantly different in the treatments from the control group except in the case of 5 ppt, which showed comparatively lower survival and specific growth rate (SGR). The results indicate that the culture of juvenile pompano might be feasible in salinities up to 15 ppt in tropical conditions