Telecommunication Lines Research Articles

A Study of Wireless Sensor Network Routing Protocols for Maintenance Access Hatch Condition Surveillance

Maintenance Access Hatches are used to ensure urban safety and aesthetics while facilitating the management of power lines, telecommunication lines, and gas pipes. Such facilities necessitate affordable and effective surveillance. In this paper, we propose a FiCHS (Fixed Cluster head centralized Hierarchical Static clustering) routing protocol that is suitable for underground maintenance hatches using WSN (Wireless Sensor Network) technology. FiCHS is compared with three other protocols, LEACH, LEACH-C, and a simplified LEACH, based on an ns-2 simulation. FiCHS was observed to exhibit the highest levels of power and data transfer efficiency.

Tunable Assembly of sp3 Cross‐Linked 3D Graphene Monoliths: A First‐Principles Prediction

AbstractOne of the biggest challenges in graphene applications is how one can fabricate 3D architectures comprising graphene sheets in which the resulting architectures have inherited graphene's excellent intrinsic properties but have overcome its shortcomings. Two series of 3D graphene monoliths (GMs) using zigzag or armchair graphene nanoribbons as building blocks and sp3 carbon chains as junction nodes are constructued, and calculations based on first principles are performed in order to predict their mechanical and electronic properties. The perfect match between sp2 nanoribbons and sp3 linkers results in favorable energy and mechanical/dynamic stability. Owing to their tailored motifs, wine‐rack‐like pores, and rigid sp3 linkers, these GMs possess high surface areas, appreciable mechanical strength, and tunable band gaps. Negative linear compressibilities in a wide range are found for the zigzag GMs. By solving the problems of zero gap and dimensionality of graphene sheets simultaneously, these GMs offer a viable strategy towards many applications, e.g., microelectronic devices, energy storage, molecular sieves, sensitive pressure detectors, and telecommunication line systems.

A Review of HEMP Activities in Europe (1970–1995)

This paper presents a review of the high altitude EMP (HEMP) activities in European countries between 1970 and 1995. HEMP simulators built in different countries are presented together with measurements performed under them and calculation methods developed in order to simulate the currents or voltages induced by an HEMP in power or telecommunication lines or in other types of circuits. Comparison between calculations and measurements are shown. This paper focuses on this period, which was of historical importance for the hardening of vital military and governmental installations, but which permitted also the development and validation of models to study the electromagnetic effects of lightning.

Method to Evaluate the Appropriateness of Introducing a High Speed Data Transmission System Using Metallic Telecommunication Lines onto Railways

This paper proposes a new method to evaluate the suitability of high speed data transmission systems using metallic telecommunication lines, such as digital subscriber lines (DSL), for railway systems. These systems are increasingly being used in place of analog systems, both when the use of an optical carrier is not cost effective and as a supplement to optical carrier systems between stations with and without optical terminal equipment. The authors' new proposal takes into account the influence of line disturbance on telecommunication lines' electrical characteristics, and considers delay time and jitter when transmission systems are connected.

30 MHz 이하에서 무선 서비스와 유도성 시스템 간의 보호 거리 산출

본 논문은 30 MHz 이하에서 동작하는 유도성 시스템과 전파통신 서비스의 공존을 위해서, 유도성 시스템의 간섭으로부터 전파통신 서비스를 보호하기 위한 보호 거리에 관한 것이다. 보호 거리 산출을 위해 유도성 시스템과 전파통신 서비스 간의 간섭 시나리오 모델을 제시하고 이를 기반으로 유도성 시스템의 방사 전력과 희생원의 허용 가능한 전계 강도를 비교하여 적용된 전파 모델에 따른 보호 거리를 산출하는 방법을 제안하였으며 이 방법을 적용한 RFID(Radio Frequency IDentification), PDP(Plasma Display Panel) TV의 간섭 분석을 통해, 30 MHz 이하의 전파통신 서비스 보호를 위한 보호 거리를 도출하였다. 제안한 방법은 2012년 6월 SG(Study Group) 1 회의에서 ISM 기기에 대한 결의 63과 관련된 ITU-R 권고서로 채택되어 유도성 시스템뿐만 아니라 무선전력 전송 및 전력선 통신 등에 의한 간섭 영향 분석에 활용될 전망이다. This paper describes separation distance to protect radiocommunication services from the interference of inductive systems using frequencies below 30 MHz for the co-existence between radiocommunication services and inductive systems. For the analysis, the interference scenario model is proposed between inductive system and radiocommunication services. Then the calculation method of protection distance is suggested by comparing the radiation power of inductive system with the allowable interference level of victim services, radiocommunication services, according to the applied propagation model. Also, the protection distance for protecting radiocommunication services in the 30 MHz below is calculated through the interference analysis from RFID(Radio Frequency IDentification) and PDP(Plasma Display Panel) TV based on the suggested method. The proposed calculation method was adopted as ITU-R recommendation in related with resolution 63 at ITU-R SG(Study Group) 1 meeting in June, 2012. It will be available to use for the protection of radiocommunication services from the interference of wireless power transfer system and power line telecommunication system.

INTERNAL FINANCIAL CONSTRAINTS, EXTERNAL FINANCIAL CONSTRAINTS AND INVESTMENT CHOICE: EVIDENCE FROM PAKISTANI FIRMS

The purpose of this study is to analyze the impact of internal and external financial constraints on investment choice. The data have been taken from 9 major sectors (52 listed firms in the Karachi Stock Exchange) namely; Pharmaceutical & Bio Technology, Textile, Sugar, Tobacco, Chemicals, Oil and Gas, Fixed line Telecommunication, Industrial metal and Mining, and Cement sectors for the time period 2004 to 2010 on annual basis. Multiple regression analysis has been done to examine the relationship among firm’s size, dividend payout ratio, firm’s age, and investment. The empirical findings show that there is positive relationship between the firms’ size and investment while a negative relationship exists between firms’ age and investment. It also reports that there is negative relationship between dividend payout ratio and the investment. This shows that if a firm grows old or high dividend payout ratio then it will tend to spend less for expansion as compared to the young firms.

The motion and deformation rate of a flexible hose connected to a mother ship

The motion of a flexible hose connected to a mother ship continually changes according to the motion of the mother ship. In such a case, telecommunication lines protected by the hose can give rise to serious problems like cutting or connecting error. It is very important to accurately analyze and predict the motion of an underwater flexible hose, because large deformation motions of the hose in axial and normal directions determine the vehicle’s driving conditions. In a realistic situation, it is difficult to carry out an experiment because the length of the hose is at least 10 m. Therefore, the behavior has to be predicted by computer simulation. In this paper, a mother ship was considered as a rigid body with six degrees of freedom driven at a specific rudder angle and surge propulsion velocity. And to model the flexible hose, absolute nodal coordinate formulation (ANCF) was adopted, whose formulation is accurate enough to express both the large deformation effect and various forms of behavior of the flexible hose. In ANCF, the concept of continuum mechanics is introduced to derive the tensile and bending stiffness of the hose. Hence, nonlinear effects of elastic forces can be considered more effectively. Fluid drag is also imposed, which has a significant effect on both the vehicle and the flexible hose.

Legal Bases for Medical Supervision via Mobile Telecommunications in Japan

This paper discusses the legal basis for mobile telecommunications-based medical supervision in Japan and bulletin from the Ministry of Health, Labour and Welfare. According to Article 44 of the Emergency Life-Saving Technician’s Act, an emergency technician shall not perform certain emergency medical procedures unless specifically authorized to do so by a medical practitioner. Actual conditions make these requirements unwieldy to put into practice. When requested to provide medical control in response to an ambulance call, a licensed physician has no choice but to allow the emergency technician to administer medical care. These circumstances expose medical practitioners to significant legal risks and societal ramifications. Is a mobile telecommunications environment characterized by insufficient information satisfactory for the medical care needed in ambulances? This paper discusses such medical care and its legal ramifications, including: how to implement such medical care under Article 21 of the Basic Act on Establishing a Networked Society Based on Advanced Information and Telecommunications. The Japanese government is obligated to provide citizens with broadband telecommunication lines in the near future to enable the smooth implementation of medical control over medical supervision provided in ambulances.

Can Information and Communications Technology Application Contribute to Poverty Reduction? Lessons from Nigeria

There is a growing optimism among international organizations such as United Nations Development Programme (UNDP) that Information and Communication Technology (ICT) can transform developing countries such as Nigeria to developed ones in a relatively short time. Experiences from Asian and European countries such as India, Bangladesh, Malaysia, Thailand, Serbia and Ukraine tend to confirm this claim. However, there are very few of such studies on African sub-regional experience. This study attempts to provide evidences from African sub-region particularly Nigeria. Data collected from Central Bank of Nigeria (CBN) is used to find relationships between poverty reduction indicators and telecommunication in Nigeria. The study reveals that generally, telecommunication contributions to indicators of poverty reduction are not significant. The major reason that can be adduced for the minimal contribution of telecommunication lines to poverty reduction is their concentration in urban centre coupled with level of literacy and poor infrastructural facilities in the sub-region and indeed Nigeria. Similarly, the poor’s are not properly linked to demand and supply chains information including produce and labour markets as well as services such as credits extension, inputs and research information. The pervasive and widespread “quiet corruption” in public institutions in Nigeria also reduces effects of telecommunication on poverty reduction. Key words: Information and Communications Technology, Nigeria, telecommunication, Central Bank of Nigeria.

STRUCTURAL ASSESSMENT OF TELECOMMUNICATION TOWER UNDER SEISMIC EXCITATIONS

Uninterrupted service is an essential design criterion for utilities subjected to natural hazards. As one of the utilities, telecommunication lines play a significant role in the operation of a reliable telecommunication system. Recent earthquakes reveal that telecommunication towers are vital components since impacts of shaking to several telecommunication towers caused delays in the national communication systems through out the most critical rescue and recovery period, namely the hours immediately following the earthquake. Therefore, in order to minimize the disruption to telecommunication systems, the reliability and safety of these towers against natural forces should be assessed. In this study, an actually built steel telecommunication tower having a height of 40 m was selected in order to assess its structural response under the effect of earthquake. All computer simulations were conducted using finite element modeling software of SAP 2000. The structural analysis considered as acting vertical loads as well as wind effects over the steel towers. Moreover, four different natural ground motion records were utilized to identify the dynamic behavior of the tower under seismic excitations. As a result, the structural response of the telecommunication tower and its behavior under seismic and wind forces were discussed comparatively.

Field Measurements of EM Radiation From In-House Power Line Telecommunications (PLT) Devices

This paper presents the results of the tests performed by the Communications Research Centre Canada (CRC) to determine the levels of electromagnetic radiation resulting from the operation of commercially available in-house power line telecommunication (PLT) devices, and to evaluate their potential effects on FM radio and low-VHF TV broadcasting services. The tests were performed when the devices were operating under real conditions in a number of typical Canadian suburban residential houses. The corresponding field strength measurements were made at specific distances from the houses and could then be compared with the present regulatory limits.

“The effects of market liberalization and privatization on Chinese telecommunications”

Abstract The Chinese telecommunications sector is undergoing fundamental changes as it moves towards liberalization. This paper examines how liberalization and privatization have affected the performance of Chinese telecommunications industry. We identify greater liberalization with increases competition as measured by reductions in industrial concentration and privatization with deceases in state equity-ownership in firms. With a new panel dataset of thirty-one Chinese provinces from 1998 through 2007, we examine the effects of reforms on prices and subscription levels of both of mobile and fixed line telecommunications operators within both the mobile and fixed line platforms. We find large gains in market performance from decreased concentration among mobile providers not for fixed-line service. The evidence on the effects of state-ownership is similarly mixed. We then estimate substitution patterns between these telecommunications platforms and find evidence of consumer substitution between the fixed and mobile platforms for subscription, but not usage.

雷サージ解析のための通信線など共架線のモデリング

With the progress of the information-oriented society, telecommunication lines are often installed on concrete poles along with power distribution lines. When a lightning stroke hits a distribution pole, the lightning current flows also through the telecommunication line in addition to the concrete pole and the ground wire. And, it is easily estimated that the existence of the telecommunication line reduces the currents through the concrete pole and the ground wire, and thus, reduces the voltage across the insulators to support the phase wires. However, its quantitative study has not yet been carried out.Considering the above, we have measured the surge impedance matrix of an actual-scale test distribution line equipped with a telecommunication line. Using this result, a method to model the distribution line system with the telecommunication line for lightning overvoltage simulations is proposed in this paper. Simulation results obtained by the proposed modeling method are compared with field-test results, and good agreement is obtained.

低圧配電システムの雷過電圧

The portion of the faults of a medium-voltage line, cause by lightning, tends to increase with often reaching beyond 30%. However, due to the recent progress of the lightning protection design, the number of faults has decreased to 1/3 of that at 30 years ago. As for the low-voltage distribution line, the fault rate has been estimated primarily, although the details of the overvoltages have not been studied yet. For the further development of highly information-oriented society, improvement of reliability of electric power supply to the appliance in a low-voltage customer will be socially expected. Therefore, it is important to establish effective lightning protection design of the low-voltage distribution system, defined to be composed of lines having mutual interaction on the customers' electric circuits, such as a low-voltage distribution line, an antenna line and a telecommunication line. In this report, the author interprets the recent research on the lightning overvoltage on a low-voltage distribution system.

The Design and Management of Intelligent Systems in Mechanical Domestic Water Meters

The design and implementation of mechanical domestic water meters in current industrial organization and intellectual properties have been registered as an invention to solve the problems of current meters. The device operation includes inquiry of printing, subscription connection and disconnection in an emergency. This system includes a software and hardware parts on the users and the control center connecting with two-way mobile phone. Central control software sends the message through the wireless telecommunication lines to the user’s software, requesting the desired information and also provides the commands needed to be sent through the same. The same information can also be submitted to the control center. Through the same way, some of advantages of this method are as follows: installing on existing meters, cheap cost of inquiry call meter, the possibility of declaring illegal manipulation to the control center, the exchange of information using information encoding, and manipulating digital meters applying minor changes.

Experimental Verification of Induction Phenomenon on Telecommunication Lines by Applying Its Occurrence Mechanisms Using an Artificial ELF Source Generator

In this paper, an electromagnetic induction on a telecommunication line by the distribution line of a power provision system or a feeder line of an electrified railway system has been verified through experiments. The basic cause of induction occurrence by these practical power provision systems is the returning current through the earth. This principle has been confirmed by the experiments documented in this paper which implemented these mechanisms to incur an induction. Experimental methods were used to produce the returning current through the earth. The experiment to find a relationship between inducing strength and the distance between the two phase lines in a power provision line has also been included to confirm that, when the distance is enlarged, the induction effect increases as the cross-nullification effect of magnetic fluxes decreases. An experiment for the existence of a shielding effect by another conduction length material has been addedas a protection measure against the induction.

Model Test and Numerical Analysis Methods in Tunnel Excavation Problem

Tunnels serve various functions such as in subway systems, underground electric power lines, gas pipes, telecommunication lines, water supplies and sewer lines and many other pipelines. The trend of tunnel construction is toward deeper and longer tunnels. In addition, the excavation of tunnels in difficult ground conditions is now not uncommon, though the tunnels themselves are still difficult to construct. Advanced studying methods have been developed for the prediction, monitoring and evaluation of the performance of tunnels and ground. Today, experimental methods and analytical methods are the main approaches used in tunnel studies. In this paper, the present state of tunnel construction and the main study methods are discussed, and the various experimental and analysis methods and their usage are compared. Tunnel excavation is very complex because it involves soils, structure and interaction problems. There is no one perfect studying method, though there are good combinations of numerical analyses and experimental methods which provide the optimum approach for solving tunnel related problems.

Next Generation Networks

At present there is no one definition of the term ‘International Digital Divide’. It is often defined in different ways, but nevertheless, factors that influence its definition include access to telecommunication lines, the ratio of internet hosts to GDP, and the level of development of the human capital base. The lack of a clear definition will have knock-on effects in the loan documentation of aid agencies involved in infrastructure development and capacity building. However, a clear definition of the divide could help to focus and better target the necessary investment to help address the inequalities the divide attempts to capture, particularly with the rollout of NGNs. This paper attempts to (a) provide a brief overview on the rise and structure of the internet and evolution to Next Generation Networks, (b) set out basic indicators of the Digital Divide and clarify the significance of these linkages, and (c) to review various definitions of the Digital Divide available in current literature so as to arrive at one new overriding definition.

Simulation Model for Lightning Overvoltages in Residences Caused by Lightning Strike to the Ground

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Lightning overvoltages coming from overhead lines, such as power distribution lines, telecommunication lines, and antennas to residences have been actively studied. However, the relation between a lightning strike to the ground and overvoltages in residences remains unclear. This paper proposes a simulation model to estimate lightning overvoltages caused by ground potential rise due to the lightning strike to the ground. The proposed model is derived on the basis of the Thevenin theorem, and can be realized in the Electromagnetic Transients Program. </para>

Some Urban Problems in Dhaka City of Bangladesh and Proposal for Introducing 'Service Tunne' (Setu) and 'Planned Urban Residential Area' (Pura)

The paper deals with some burning problems related to supplies of utilities, transportation of people, livable space in the residential area, social infra-structure, open space, social interaction arena, pollution etc. of Dhaka city of Bangladesh. The problems are expressive and acute such that the dwellers of the city do not need any statistics to grasp those. The suffering dwellers are in need of immediate solutions to these problems. In such a context, without going into detail explanations of these problems the authors have proposed altogether two new proposals, which they believe, are capable of solving some of these problems. Excellent neighborly relation, that was considered as a great wealth of the people of this region is on wane, and the authors believe, the present system of urban planning along with interferences of the agents with vested interest nets are responsible for it. The authors also believe that the solutions followed in the developed countries might not be equally effective in our context. Also the huge cost required for such solutions might be a great burden for a poor developing country. The authors have proposed for a two or three tier structure to be constructed along the centre of wide roads. The lowest tier, which is an underground tunnel would carry sewerage at the bottom and fresh water supply line at the roof level. The second tier is a tunnel above the ground and it would contain cable lines like power line, telecommunication line, dish-line cables etc. The roof of this structure would be used as a raised walkway. Such a structure would eliminate the constant digging and re-digging of roads in order to provide the ever changing quantities of the utilities. It would also relieve the city from the ugly scenes of crisscrossing overhead wires and provide additional walking routes. In the second proposal the authors have proposed for creating residential areas self-reliant in points of essential amenities. Proposal has been made for conducting questionnaire survey in order to find out the amenities which are surplus and which are lacking in any area. Then, the authors have suggested for administrative measures in which the administration has been requested to give tax facilities for establishing the missing amenities.