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[en] This book describes how to use the internet with world wide web. It is divided into six chapters, which are Let's go to the internet ocean, the internet in information superhighway are, connecting the world with a telephone wire such as link with the internet cable and telephone modem, internet service providers, text mode connection, Domain and IP address, the principle and use of world wide web ; business, music, fashion, movie and photo, internet news and e-mail, making internet map with web language, and from installation to application of base program such as TCP/IP, SLIP/PPP 3270 Emulator, Finger and NCSA Mosaic.
[en] Complete text of publication follows. The health concerns have been raised following the enormous increase in the use of wireless mobile telephones through out the world. This investigation had been taken, with the motive to find out whether mobile phone radiations cause any in vivo effects on the frequency of micronucleated exfoliated cells in the exposed subjects. A total of 109 subjects including 85 regular mobile phone users (exposed) and 24 non-users (controls) had participated in this study. Exfoliated cells were obtained by swabbing the buccal-mucosa from exposed as well as sex-age-matched controls. One thousand exfoliated cells were screened from each individual for nuclear anomalies including micronuclei (MN), karyolysis (KL), karyorrhexis (KH), broken egg (BE) and bi-nucleated (BN) cells. The average daily duration of exposure to mobile phone radiations is 61.26 minutes with an overall average duration of exposure in term of years is 2.35 years in exposed subjects along with the 9.84±0.745 MNC (micronucleated cells) and 10.72±0.889 TMN (total micronuclei) as compared to zero duration of exposure along with average 3.75±0.774 MNC and 4.00±0.808 TMN in controls. The means are significantly different in case MNC and TMN at 0.01% level of significance. For all other nuclear anomalies (KL, KH, BE and BN cells) the means are found statistically nonsignificant. A positive correlation was found in the frequency of MNC and TMN with respect to duration of exposure time.
[en] It concentrates on development of Korea telecommunication technology, which is made up seven chapters. It gives description of manual central telephone exchange or private automatic telephone exchange, transmission technology on wire line and cable line technology and optical transmission, radio communication technology on mobile and natural satellite communication, network technology with intelligent network, broadband ISDN and packet switched Data Network, terminal technology with telephone and data communication terminal and development of Information Technology in Korea. It has an appendix about development of military communication system.
[en] The measures that are applied to regulate a certain practice, are based on the risk that implies the practice and in the acceptance of the above mentioned risk from the part affected by the practice. If the perception of the risk does not correspond to the reality the situation is unstable and it is possible to lose the control of the situation. When discrepancies exist in the Perception of the Risk on the part of different sectors of the society, they can produce serious conflicts that affect the establishment of the protection measures. The problem of 'the perception of the risk' rests on the fact that the technical people and the public use generally different reasonings and therefore its coincidence is almost fortuitous. The intuitive perception of the risk is often narrowly tied to a 'symbolic mechanism' and once established the symbolic relation can produce a psychological phenomenon by means of which the individuals resist to the reality, and the symbols make prevail over the facts in order not to alter the interior symbolic pre-established scheme. The perception of the risk appears in two different groups of persons: 1) the persons affected by the risk (the public) and 2) the persons who can modify this risk (operators). It is important that the perception of the risk is compatible with the scientific hypotheses to avoid conflicts in the situation 1 and to assure the control in the situation 2 (safety culture). The 'perception of the risk' is fundamental to support the control of a practice and it is possible to modify it across the communication. It is necessary to know which are all The Factors that affect the perception of the risk to be able to design a strategy of suitable communication Across different studies it has been learned which are the factors that affect the perception of risk: 1) some factors depend on the proper characteristics of the risk, 2) others depend on the proper characteristics of the individuals and finally 3) other factors depend on the conditions of the external environment or on the social local context. One of the most important factors is the related with the direct benefits that are perceived. This determines, for example, that a person perceives minor risks of his cellular telephone that of the antennas (That allows that the system should work) when the situation is exactly the opposite one... It is very important that the society establishes a system of rational and independent communication with all the affected parts (stakeholders) that allows to safeguard the systems of control. The system of communication must be independent and cannot be handled or influenced by those that perceive an economic benefit since they are an interested part. In this presentation a methodology and strategy is proposed for the communication with different groups affected by the risks come so much of the ionizing or non ionizing radiation. (author)
[en] There have been some reports about possible effect of the hand presence on the head SAR if hand phantom is included in the measurements of the head SAR compliance assessment procedure. The objective of this computational study was to examine the reported effect by using realistic head models and realistic CAD based phone models. A commercially available FDTD based EM solver was used to carry out the computational work. Based on the results of this study considering the SAR values without hand phantom as reference, following conclusions can be made: 1. In general presence of the hand lead to significantly less conservative SAR values in the head for large majority of cases 2. For lower band GSM frequencies the presence of the hand decreases the head SAR up to ∼70%. 3. For the upper band GSM frequencies the presence of the hand decreases the head SAR up to ∼55%. Based on the results of this study the present SAR compliance protocol where hand phantom is not included leads to more conservative head SAR results compared to the cases where hand is included.
[en] Dental trauma is frequently unpredictable. The initial assessment and urgent treatment are essential for dentists to save the patient's teeth. Mobile-phone-assisted teleconsultation and telediagnosis for dental trauma could be an aid when a dentist is not available. In the present in-vitro study, we evaluated the success rate and time to transfer images under various conditions. We analyzed the image quality of cameras built into mobile phones based on their resolution, autofocus, white-balance, and anti-movement functions. The image quality of most built-in cameras was acceptable to perform the initial assessment, with the autofocus function being essential to obtain high-quality images. The transmission failure rate increased markedly when the image size exceeded 500 kB and the additional text messaging did not improve the success rate or the transmission time. Our optimal protocol could be useful for emergency programs running on the mobile phones.
[en] Modern radio telecommunications are spreading through our civilisation like undesired wind. This new harmless technologies are pushed into the hands of our youngest population, children, in the way that nobody is aware of the possible social disaster which can be released if there will be no control over the harmful technology overflow. The deep ecology philosophy states that not only humans have the right to guide over the earth future but that whole biota living in given habitat and everything non-organic in the nature have this right too. They are suddenly suffering enormous artificial energy overflow. The radio communications are spreading over our heads for more than one hundred years. Humans were trying to find the harm or benefit from that powerful tool. Till today, the benefit was obvious and there was no health damage found which can be directly connected to the radio telecommunication energies produced. Though, every day humans are producing new devices, which produce more harmful electromagnetic fields all around us. Some of us are concerned, not because we are feared from the direct harm but because we are concerned about the influence through our habitat, which will affect our future at the end. That is why we have decided to perform and discuss measurements on the sites, which are not really inhabited with humans but which are important from the ecological point of view. This approach can lead us to some new results and conclusions and lead our knowledge towards even more harmless thinking. That simply means that humans have to take responsibility not only for themselves but for everything that exists on the planet. The use of mobile telecommunications is just one of the responsibilities. (author)
[en] A common feature of cellular telephony is the use of a 'hands-free' audio extension lead connected to a waist-worn handset. Interaction between the transmitting antenna, the wire and the user's body can occur, with detrimental effects including polar pattern degradation, reduced efficiency and localized increases in specific absorption rate (SAR). Using a realistic full-body model of an adult male, finite difference time domain analysis was employed to investigate the coupling between a hip-mounted 1.8 GHz handset fitted with a monopole antenna and a 1 m long wire representing a hands-free wire. Conduction current densities were computed for three identifiable coupling modes: magnetic-only, conductive-only and combined conductive-and-magnetic. Magnetic-only coupling was dominant. Without the lead, placing the handset at waist height led to a 42.8% increase in the total energy deposited in the body, compared to use at the head. Introducing the lead further increased the body loss, with a reduction in system radiation efficiency from 52% to 43.7%. Without the hands-free lead, the peak 1 g and 10 g SARs were 0.450 W kg-1 and 0.265 W kg-1, respectively, for 125 mW transmit power. With the hands-free lead connected, these values increased to 1.14 W kg-1 and 0.430 W kg-1, respectively
[en] Background: There is some concern about potential health risks of cellular telephone use to children. We assessed data on how many children own a cellular telephone and on how often they use it in a population-based sample. Methods: We carried out a cross-sectional study among children in their fourth elementary school year, with a median-age of 10 years. The study was carried out in Mainz (Germany), a city with about 200,000 inhabitants. The study base comprised all 37 primary schools in Mainz and near surroundings. Altogether, 1933 children from 34 primary schools took part in the survey (participation rate of 87.8%). Results: Roughly a third of all children (n = 671, 34.7%) reported to own a cellular telephone. Overall, 119 (6.2%) children used a cellular telephone for making calls at least once a day, 123 (6.4%) used it several times a week and 876 (45.3%) children used it only once in a while. The remaining 805 (41.6%) children had never used a cellular telephone. The probability of owning a cellular telephone among children was associated with older age, being male, having no siblings, giving full particulars to height and weight, more time spent watching TV and playing computer games, being picked up by their parents from school by car (instead of walking or cycling) and going to bed late. The proportion of cellular telephone owners was somewhat higher in classes with more children from socially disadvantaged families. Conclusions: Our study shows that both ownership of a cellular telephone as well as the regular use of it are already quite frequent among children in the fourth grade of primary school. With regard to potential long-term effects, we recommend follow-up studies with children
[en] The authors present some data on the effects of electromagnetic fields (EMF) generated by mobile phones on the nervous system. The main attention was paid to the usefulness of some neurophysiological methods, such as electroencephalography (EEG), multimodality evoked potentials (MEP), and event related potentials (ERP) in the evaluation of the bioelectrical activity of the brain. The majority of the cited articles underline the difficulties in the evaluation of adverse effects of EMF generated by mobile phones, which can result from their nonspecific influence on biological structures. (author)