bluuebunny/crossref_metadata_2025 huggingface dataset:
Progressive coding scheme for binary images
Authors: Endoh Toshiaki , Kato Hisaharu , Yamazaki Yasuhiro
Published: July 2007

The progressive coding scheme (PCS) has been proposed as the coding scheme for the binary image with the progressive build‐up function. However, a problem in PCS is that a simple subsampling is employed in the resolution conversion, and the image quality is not sufficiently high in the intermediate stage.

This paper proposes a progressive coding scheme using block reduction (PCSB) as a new coding method for the binary image with progressive build‐up function, with emphasis on the image quality. It is shown first by a subjective evaluation experiment that the progressive build‐up display has a better image quality in the intermediate stage than in the conventional scheme. Then the result of examining the coding efficiency is described in detail.

By a simulation experiment using CCITT test documents Nos. 1 through 8, it is shown that the coding efficiency is improved by approximately 17 percent at the final stage, compared to the MMR scheme. It is shown also that dither image can be encoded with a high efficiency. Finally, it is shown that the proposed scheme can be applied to the highly efficient image storage at the image database center, as well as to efficient transmission to the receiver terminals with various performances.
Implementation and evaluation of X.25 and X.32 on personal computers
Authors: Suzuki Kenji , Kato Toshihiko , Obana Sadao
Published: July 2007

With the increased use of personal computers (PCs) in communication environments have come the expectation of reliable communication protocols. This paper describes the implementation details of two very similar packet communication protocol interfaces on PCs. One is the X.25 interface for packet‐switched public data networks, and the other is the X.32 interface for public‐switched telephone networks. The implementation of these protocols is performed with consideration of the future introductions of OSI higher‐layer protocols.

This paper describes also that the addition of the assigning mechanism of level 2 address to the Rec. X.32 enables powerful personal computer communication through public‐switched telephone networks. Furthermore, the results of the performance evaluation are described which show the high throughput of more than 90 percent on various speeds of the physical circuit.
Optical loss variation due to fiber handling at the jointing point on the subscriber loop
Authors: Tomita Shigeru , Sutoh Kouichi
Published: July 2007

In response to the need for construction of new customer lines, usually the construction takes place at the joints where in‐service lines are accommodated. It is very difficult to select and establish connection to a specific line without touching other in‐service lines, thereby imposing additional curvatures upon them. Therefore, the losses are increased because of fiber bending; and, in such construction works, there is the fear that the transmission‐loss variations exceed the tolerable threshold.

To eliminate such fears, experiments on optical fiber handling are carried out and the factors which influence the transmission losses and the magnitude of such variations are clarified. Further, it is shown that by proper choice of the mode field diameter and the cut‐off wavelength, it is possible to limit the variations of the transmission losses. The guidelines in the design of optical receivers which can tolerate these variations also are given.
Frequency diversity effects in multicarrier digital radio systems
Authors: Ichikawa Hirofumi , Murase Takehiro
Published: July 2007

Frequency diversity usually is employed in microwave radio systems, where protection channels with different frequencies are prepared and the transmitting data signal is switched to the protection channel to secure the channel reliability when the channel quality is deteriorated by the fading. In multicarrier radio systems, there can be various channel switching configurations, since the protection channel is composed of more than one primary carriers.

This paper discusses the effects of the frequency diversity in various switching schemes in the multicarrier radio system. As the model for the theoretical analysis for the microwave fading, the three‐ray multipath fading model is assumed which is close to the actual transmission path. The frequency correlation coefficient and the joint probability for the received power distribution in different radio channels also are derived by a simulation calculation.

The effects of the frequency diversity of various switching schemes in the multicarrier system are evaluated. The validity of the presented result is verified by the simultaneous measurement of more than one channel with different frequencies in the actual over‐water transmission path by the measurements of the frequency correlation coefficient and the joint probability distribution for the received power.
Performance of a digital FM demodulator using a fixed‐point arithmetic operation
Authors: Kondo Shoji , Nakamura Noboru , Takizawa Osamu
Published: July 2007

Performance of a DSP demodulator for FM broadcasting receiver is examined by computer simulation and system parameters suitable for obtaining demodulated signal quality (SNR) are clarified. The DSP demodulator is preceded by an m‐digit linear A‐D converter operating at the IF stage of the receiver. A relation between required values of n, the register length of the processor, and m is investigated under the condition that a demodulated signal SNR of 60 dB and 55 dB for monophonic and stereophonic signals, respectively, is ensured. Moreover, only a slight increment of C/Ni (C is input carrier power; Ni is thermal noise power at the receiver input) is necessary to recover degradation due to quantization noise and mathematical rounding‐off errors. Simulation results show that demodulation can be performed with a margin by using parameters n = 16 with m = 7 and 10 under the condition of C/Ni = 23.5 dB and 40.5 dB for monophonic and stereophonic signals, respectively. However, an ideal analog receiver requires C/Ni of 23.2 and 40.0 dB to obtain the previously mentioned demodulated SNRs.
Design and sea trial results of a 48‐fiber submarine optical fiber cable
Authors: Yoshizawa Nobuyuki , Tada Hidenobu , Horiguch Tsuneo , Kurashima Toshio
Published: July 2007

A new 48‐fiber submarine optical fiber cable and the technology for a multifiber joint box have been developed to provide compatibility with the number of fibers in land cables. Submarine optical fiber cables require durable construction to cross distances as long as tens of kilometers and to withstand high water pressure. In particular, they must be sufficiently waterproof to prevent moisture penetration into the fiber area in the event of cable damage.

Simply increasing the number of fibers in a cable, however, degrades the forementioned characteristics, and the following technology has been developed to allow for fiber expansion without harmful effects.

A new pressure‐resistant pipe configuration has been constructed which does not require an inner pressure‐resistant pipe and which can house the increased number of fibers, specifically, a 48‐fiber unit assembly containing four 12‐fiber units. A cable diameter equivalent to that of conventional 12‐fiber cables, a unit length of 30 km, and a loss due to laying of 2 mdB/km have been achieved.

For the joint box, a mass fusion splicing technique has been developed in which four fibers are spliced at one time, thereby achieving an average fusion‐splicing loss of 0.13 dB for DSF fibers. This mass fusion splicing can be performed on a small scale in a short period of time on board a repair ship.

The foregoing technology has enabled the construction of the first 48‐fiber submarine optical fiber cable in the world. In addition, as a result of strain distribution measurements performed during a sea trial using Brillouin OTDA, the residual elongation train in optical fibers due to new cable construction, laying, and recovery was found to be under 0.1 percent.
A multiple access scheme for radio access loop carrying multiple‐service traffic—virtual circuit multiple access (VCMA)
Authors: Kubota Fumito , Okada Kazunori
Published: July 2007

The integrated services digital network (ISDN), which is under construction at present, will enlarge the range of communication service by developing radio access systems, with the digital mobile communication systems as the core. The purpose of such a radio access system is to realize the communication capability, which is as flexible as that of the fixed system, while utilizing the features of the radio system. The following problems arise in the traditional access schemes, however, when multiple types of calls with various information characteristics and rates are to be handled. The immediate (circuit switching) system cannot contain efficiently the multiple type of traffic, while the waiting (packet switching) system may produce a delay with a long variation.

This paper proposes a new scheme for radio channel access, aiming at a positive integration of the multiple type of traffic. In this scheme, the blank of information is compressed to construct a block (cell) with a constant length, and the physical channel is controlled to be assigned to each cell. The blank is inserted on the receiving side to ensure the time‐transparency. Then, the flexibility to various types of immediate and waiting calls, as well as the efficient operation of the channels, are realized.

This paper describes also the concept of the scheme and fundamental composition. The channel capacity and the channel occupancy are evaluated by a computer simulation, and it is shown that the proposed scheme has the desirable property that the statistical multiplexing effect is utilized.
Wide‐angle radiation pattern improvement of a shaped offset tri‐reflector antenna by reducing higher‐order periodical reflector distortion
Authors: Karikomi Masahiro , Yamada Yoshihide , Kagoshima Ken‐Ichi
Published: July 2007

This paper describes the improvement of characteristics of an offset tri‐reflector antenna by introduction of reflector surface shaping, and the importance and allowance of suppression of the higher periodic components of the reflector surface distortion caused in the fabrication process. In an antenna with a good wide‐angle radiation pattern, degradation of the sidelobe characteristics due to the higher‐order periodical components of the surface distortion cannot be taken lightly.

In this paper, the angle and the level of the side‐lobe peak due to the periodic aperture phase error are expressed in simple formulas. These formulas are combined with an approximate expression of the wide‐angle radiation pattern so that the allowance of the periodic reflector surface distortion is given. Next, a design and measured characteristics are described for a shaped offset tri‐reflector antenna with its aperture diameter of 3600 mm to be used at frequencies of 3.6 to 6.475 GHz. Two prototypes with difference values of surface accuracy are compared. By means of measured examples, it is pointed out that suppression of higher‐order periodic components of the surface distortion is important. By means of reflector shaping, a nonaxisymmetric aperture distortion is important. By means of reflector shaping, a nonaxisymmetric aperture distribution is realized so that the edge level in the horizontal cross section is made small. Further, by suppressing the higher‐order periodic components of the surface distortion, an offset tri‐reflector antenna with a good wide‐angle pattern and a good cross‐polarization characteristic was realized.
A local area radio network utilizing CSMA/CD scheme for its inter‐radio base station network
Authors: Serizawa Mutsumu , Sakakibara Katsumi
Published: July 2007

The cordless configuration of computer terminals and other systems is considered in various applications in recent years. Cordless terminals are expected to have the following advantages: the flexibility of the terminal user is enhanced; the geographical range of the service is enlarged; and the reconstruction of the local‐area network is made unnecessary when the office organization is to be modified.

On the other hand, excellent communication quality is difficult to maintain in radio transmissions due to the effects of fading and shadowing. Moreover, the efficient use of limited frequency resources should be considered. Previous studies have already pointed out that the communication quality and the throughput are greatly improved by providing more than one base station for the random access radio channels in the radio communication system. In that case, however, the selection control of a packet received by more than one base station is not easy. No study on this problem has been made. This paper proposes an autonomous and distributed selection control of a packet received by more than one base station, on CSMA/CD LAN. The fundamental performances are analyzed and evaluated, and the usefulness of the system as an inter‐radio base station network in CSMA/CD LAN is indicated.
An experimental TDMA transmission system using 1.5 GHz‐band π/4 shifted QPSK
Authors: Kubo Tokuro , Oishi Yasuyuki , Fukuda Eisuke , Takano Takeshi
Published: July 2007

The π/4‐shift QPSK transmission system with TDMA scheme is constructed and an experiment is conducted, aiming at the digital cellular automobile telephone system. Various detection methods are first compared and it is decided that differential detection is advantageous, considering the operation in TDMA system where the burst modulated wave must be demodulated. Then, by varying the bandwidth of the receiving filter in the differential detection demodulator, the biterror rate and the adjacent channel emission are examined using simulation. The optimal receiver bandwidth is determined.

In the differential detection, the bit‐error rate depends greatly on the carrier frequency drift. A highspeed automatic frequency control (AFC) circuit is newly proposed to solve this problem.

The post‐detection, two‐branch selection diversity demodulator is experimentally constructed and a satisfactory performance is obtained, with the deviation from the theoretical value being 2.3 dB under the static condition, and the diversity gain is 6 to 7 dB. Based on those results, it is experimentally verified that the π/4‐shifted QPSK differential detection with TDMA scheme is practically useful.
Approximate analysis for bulk arrival queueing system with bulk departure
Authors: Suzuki Muneyoshi
Published: July 2007

A bulk arrival queueing model with bulk departure is presented for information and communication processing systems where each transaction requires different memory size; moreover, each transaction cannot be divided and is analyzed. This model is characterized by customers arriving in bulks to a system that consists of a finite number of servers and waiting rooms, and customers belonging to the same bulk are served by the same server. Further, whenever customers are being served, they reserve their waiting room until the service of all customers in the bulks is completed. For its exact analysis a system of 2N state equations need be solved, where N is the waiting room size. Hence, it is practically difficult to obtain exact solutions and we evaluate the steady‐state probabilities of the system by using successive approximation. Approximate values of the traffic characteristics are compared with simulation results. They agree well with each other.
A packet switch architecture with channel group virtual circuit scheme in high‐speed communication networks
Authors: Ohtsuki Kazuhiro , Okada Hiromi , Hasegawa Toshiharu
Published: July 2007

This paper discusses the channel assignment problem in the multichannel, high‐speed packet network. It is assumed that multiple channels exist between a pair of switches in the network. It is expected that by regarding those channels as a single channel group and executing the packet transmission, a more efficient high‐speed and large‐capacity transmission will be realized.

This paper newly introduces, in contrast to the virtual circuit in the multichannel network, the concept of a channel group‐virtual circuit (CG‐VC) for the multichannel network, where the packets are assigned to the channels based on the concept of the overflow traffic. To realize the CG‐VC system in the high‐speed environment, a simple and practical switch structure is proposed. The switch uses optical fibering as the basic module and the system is constructed by superposing the basic modules.

Each packet automatically selects an appropriate channel from the set of output channels belonging to the same channel group. It is shown as a result of performance evaluation that, compared to the conventional VC packet switching system, the proposed system greatly improves the transmission delay and utilizes efficiently the channel.
A realtime management system for optical fiber outside plants
Authors: Yamashita Katsuya , Furukawa Shin‐Ichi , Ishihara Koushi
Published: July 2007

Traditional outside plant management for communication cables uses a concentrated database. Plant data are inputted manually when a new plant is introduced or the plant is modified. A problem then is the deterioration of the data through incorrect manual input and the manpower/cost issue for manual input. Another problem is that the realtime property is not provided in the database due to the data input/update scheme that made it impossible to know the state of the plant at any instant.

This paper attempts to solve these problems. Included is a proposal for an outside plant management system in which data can be updated by a remote automatic execution in realtime and high‐level maintenance support information can be supported. Basic concepts and the construction of this proposed system is also described here.

A prototype system was constructed as follows. The semiconductor memory is built into the outside plant. Plant information is automatically transferred and managed in realtime, using the dedicated compact communication device and the dedicated cable. By adding the core matching, terminal box environment monitor and cable test functions to such a system, the construction and maintenance of the outside plant can be supported. Thus, a high‐level system can be realized by integrating plant management and construction/maintenance.
Feasibility of dispersion‐shifted fiber to the home
Authors: Ohashi Masaharu , Kawase Masaaki
Published: July 2007

To introduce the optical fiber into the subscriber network, economy, immediate response, reliability and other factors must be considered. A 1.3‐μm zero‐dispersion single‐mode fiber is investigated as the transmission medium for fiber to the home (FTTH) because of its broadband, low cost, and easy connection. In the trunk transmission line system, on the other hand, a dispersion‐shifted fiber is commercially used. There have been four investigations into the application of dispersion‐shifted fiber to the subscriber network.

This paper describes the feasibility of a unified trunk and subscriber network through the use of dispersion‐shifted fiber and problems related to the application of dispersion‐shifted fiber to subscriber networks. Particular attention is paid to the requirements for splice loss and a quantitative investigation of the tolerance of the fiber parameters. First, a fiber parameter design with a mode field diameter 2 W and a cutoff wavelength λce is presented as a model for the subscriber network. Second, using the results of the foregoing applications of dispersion‐shifted fiber to the 1.5‐μm band, 1.3/1.55‐μm wavelength multiplex systems are discussed and problems of application are presented.
Analysis on squeezing properties of degenerate parametric amplifier for quantum communication
Authors: Koyano Hidenori , Uyematsu Tomohiko , Yoshida Norihiro , Hirota Osamu
Published: July 2007

In this paper, characteristics of degenerate parametric amplifiers are analyzed and are expected to be useful as a generator of a squeezed state or a noiseless amplifier for an optical wave. Especially, when a degenerate parametric amplifier is used as a noiseless amplifier or a squeezed‐state generator (squeezer), the depletion of the pumping light which has been neglected affects the quantum noise characteristic of the squeezed light. This effect is analyzed in this paper. Further, when the incident light does not satisfy the phase matching condition, the effect of this phase shift on the gain and quantum noise characteristics of the degenerate parametric amplifier is studied.

On the other hand, when a degenerate parametric amplifier is used as a preamplifier for the receiving side of the communication system, the phase noise of the pumping light can be a cause of degradation of the communication system performance. The phase noise of the pumping light is classified as the phase shift and the phase fluctuation caused by the quantum noise and then the effects of these phase noises on the quantum noise characteristics of the squeezed light are analyzed.

Further, in the BPSK optical coherent communication system, the effect of the phase noise on the bit error rate is analyzed. A quantitative evaluation is made to determine how small the phase noise of the pumping light should be in order not to degrade the error rate.
The radiation field from the dielectric‐rod antenna with two‐layered, rectangular cross section
Authors: Marumoto Tsunehisa , Kuroda Michiko , Kasai Yutaka , Soejima Teruzane
Published: July 2007

It is difficult to operate a single‐layered dielectric waveguide for the millimeter‐wave frequency range in a single mode with a small dielectric loss while the electromagnetic field is sufficiently trapped in the guide. On the other hand, this becomes possible in a two‐layered dielectric waveguide if the dimensions of the core and the clad are appropriately well chosen.

In this paper, the electric field distributions of the amplitude and phase on the truncated plane and the radiation pattern of a two‐layered dielectric rod antenna with a rectangular cross section are analyzed theoretically. By the “generalized effective dielectric constant method” [2], the electromagnetic field distribution on the truncated plane of the waveguide cross section is derived. The boundary conditions at the discontinuity are Fourier transformed in the x and y directions. The results are multiplied to compute the electromagnetic field distributions.

In comparison with the two‐dimensional Fourier transformation, this method has an advantage in that the computation time is shorter and the method can be applied to more complicated geometries. The results are compared with the assumption that the electromagnetic field on the cross section is identical to the one propagating in the waveguide.

As for the electromagnetic amplitude distribution, the discontinuities of the electric field amplitude distributions are smaller at the boundary between the core and the clad in the present method. In regard to the phase distribution, the variation of the phase is smaller near the center axis so that the effect on the radiation pattern is negligible. The present method can be applied to analyze the problem of the discontinuities and truncations of a multilayered dielectric waveguide in the millimeter‐wave and submillimeter‐waves and of the radiation from an optical source.
Study of rotary mechanical optical fiber switch
Authors: Kobayashi Hideo , Shimizu Masatoshi
Published: July 2007

A novel mechanical optical fiber switch by rotation has been proposed; the dynamic and switching characteristics have been studied. The structure, operational principle and analysis of the mechanical property, e.g., switching torque, have been evaluated.

To characterize dynamic motion, the rotational transfer response time of switching and the transfer function were investigated. It was theoretically and experimentally confirmed that the optical switch has an internal feedback mechanism. The connection loss between multimode fibers caused by deviations of the rods, balls, and optical fibers has also been theoretically and experimentally investigated. In the test optical switch, the switching connection loss was 0.68 dB and the rotational transfer response time in 1 × 6 switching was 134 ms. These experimental results agree with the theoretical results.
Use of signal processing techniques to improve the dynamic range of coherent OTDRs
Authors: Nakamoto Hiroshi , Ohta Norihisa , Koyamada Yahei
Published: July 2007

In the development of OTDRs, which are indispensable in the conduction of highly accurate cable supervisions of optical subscriber systems, the loss increases of the lines due to introduction of optical branches and improvements of the resolution become problems. In optical subscriber systems presently under investigation, one‐way dynamic ranges in excess of 40 dB are required so the increase of the dynamic range of 20 dB must be realized.

In this paper, both the average and the correlation techniques are employed in the heterodyne detection of OTDRs. The bipolarity correlation processing and the average processing methods exploiting the phase and the amplitude of the optical signals are proposed and the relationships between the source spectral linewidth and the improved minimum detectable optical power due to both schemes are clarified.

Finally, taking the presently required and the future characteristics of the source linewidth into account, the configuration of the wide dynamic range OTDR is proposed and the improvement of the dynamic range is explained quantitatively. As a result, the maximum improvement is obtained when the combined bipolar correlation and the average processes are employed in the heterodyne detection method. It is shown that achievement of more than 40 dB one‐way dynamic range is possible even at the present source linewidth.
Design of a perfect reconstructive subband image coding scheme
Authors: Irie Kazunari , Kishimoto Ryozou
Published: July 2007

The Broadband Integrated Services Digital Network (B‐ISDN) is being designed to support multimedia signals. Nationwide image‐signal transmission systems will be constructed to offer high‐quality and reliable services to customers. The largest users of image transmission systems will be broadcasting stations. The transmission of image signals within and between studios or broadcasting stations requires the ability to multiply encode/decode signals without visible degradation. The ideal system would be free of quantization noise.

A subband coding scheme is presented which can achieve distortion‐free encoding. It is provided that the required entropy can be reduced by using two‐tap filters for subband splitting; the original picture quality is maintained. A new short‐kernel subband filter architecture is proposed which can further reduce the entropy of subband signals.

Experimental results show that four‐band splitting with adaptive DPCM coding is the most promising of the various subband configurations. This subband DPCM coding scheme has higher performance than full‐band DPCM coding.
A low‐intermodulation, high‐efficiency harmonic‐controlled amplifier for high‐power applications in mobile communications satellites
Authors: Dooi Yoshikazu , Iso Akio , Sekine Kenji , Okubo Naofumi , Hunaki Haruhiko
Published: July 2007

Recently, research and development of mobile communications satellites has progressed in every country, and the key technologies for improvement have increased the output power and efficiency of solid‐state power amplifiers used in high‐output transponders for satellite payloads and decreased intermodulation distortion during multicarrier amplification.

This paper describes the design method and experimental results for a harmonic‐controlled amplifier (HCA) having a theoretical efficiency more than 20 percent higher than existing solid‐state power amplifiers (SSPAs) and with nearly the same amount of intermodulation distortion.

The HCA is a new type of SSPA which uses the harmonics to produce an amplifier with high efficiency in low‐distortion operation. Its operation is analyzed theoretically and experimentally, and new design methods are clarified. The HCA's output power is designed to be below saturation, and the output circuit is designed so that power‐added efficiency is maximum in the intermodulation distortion region. Experimental results show that at 69‐W output power in the UHF band, power‐added efficiency was SI percent. At 110‐W output power in the S band, power‐added efficiency was 42.5 percent, intermodulation distortion was 20 dBc in the UHF band, and 23 dBc in the S band (output back‐off 3‐dB point).
Reduction of lower sidelobe levels in a large deployable mesh reflector antenna as a means of decreasing the effective mass of communication equipment
Authors: Sato Shin‐Ichi , Iso Akio , Orikasa Teruaki , Sugimoto Toshio , Dooi Yoshikazu
Published: July 2007

Reducing sidelobe levels and lowering the effective mass of the equipment are important measures in the design of large deployable mesh reflector multibeam antennas used for mobile communication satellites with frequency reuse.

In this paper, a method of converting from sidelobe levels to effective mass is described. Then the effects produced by the sidelobe level on the mass of the mesh reflector and the communication equipment are analyzed in the case of a cluster‐fed offset parabolic mesh reflector antenna. The surface density of the mesh reflector decreases with an increase in the aperture diameter, and the output efficiency of the solid‐state power amplifier decreases with an increase in output power.

Next, assuming one transponder for each beam and using the EIRP of all the beams as a parameter, the relations between the sidelobe level, the minimum communication equipment mass, and the antenna aperture are described. The relation between the gain and the number of beams when the communication equipment mass is minimum is derived and the ratio of mesh reflector mass to the total mass of communication equipment is determined.
Throughput analysis of HDLC‐based data link protocols in a bridged network
Authors: Ikegawa Takashi , Motomura Kota
Published: July 2007

This paper presents an approximate analysis of the maximum throughput of an HDLC‐based data link protocol for a bridged network. To model an end‐to‐end data link connection, which is connected across multiple transmission lines and bridge processors, a specific server, denoted as a bottleneck server, is defined. This is identified as the server (i.e., transmission line or processor) which gives the largest service time (i.e., transmission time or processing time) among all the servers over the connection.

The interval of receipt of information (I) frames at the receiver to that of the departure of corresponding I‐frames at the bottleneck server is approximated. This approximation enables an analytical throughput expression to be derived by observing the bottleneck server only.

Compared with simulation results, analytical results obtained are in fairly good agreement if I‐frames are discarded at the bridges located between the bottleneck server and the receiver. However, they are relatively overestimated if I‐frames are discarded at the bridges located between the transmitter and the bottleneck server. It is shown also that the optimum window size is obtained as the smallest integer not less than the minimum acknowledgement delay over the service time of the bottleneck server.
Receiving system for the voyager‐2 neptune occultation experiment
Authors: Takano Tadashi , Yamamoto Zenichi , Hirosawa Haruto , Hayashi Tomonao , Yamada Mitsuo , Kawashima Nobuki , Mizuno Eiichi , Oh‐Hashi Seiichi , Tsuchiya Makio
Published: July 2007

A radio science experiment was carried out when the deep‐space probe Voyager‐2 travelled behind Neptune. This paper describes the receiving and recording systems which were developed for the experiment and gives a summary of the experiment itself. The object of the experiment was to detect the very small fluctuations in the phase and amplitude of the radiowave carrier as it passed through the atmosphere and rings of Neptune.

To achieve this, a 64‐m diameter antenna and high‐performance maser amplifiers were used together and a high G/T value was obtained. The heterodyne receiver was controlled by open loops and the local signal was changed with continuous phase to match the predicted Doppler value, stabilizing the signal within the bandwidth. A local frequency generator with stable frequency and phase and a signal bandwidth filter were developed.

Also, to counter antenna distortion caused by changes in the elevation angle, a method of compensation was introduced which kept the phase stable and suppressed gain reduction.
The T‐vector and generalized optical theorems
Authors: Hosono Toshio
Published: July 2007

The energy relationship is discussed for an arbitrary polarized plane wave. A representation with a clear physical meaning in a dispersive medium is provided to the energy portion of the 7‐vector discussed by Tokumaru. Next, using the formulas obtained by Tokumaru, the optical theorem is extended to include circularly polarized waves. Further, a quaternionlike representation of the electromagnetic fields is proposed to discuss deeper relationships between the Poynting vector and the T‐vector.
Distributed cooperative multiagent model for intelligent telecommunication networks
Authors: Kishimoto Ryozo
Published: July 2007

This paper treats the high‐functionality layer as a large‐scale distributed cooperative computing system and proposes a distributed cooperative multiagent model for intelligent telecommunication network. The intelligent telecommunication network is viewed from the distributed cooperative computing environment, and the five‐viewpoint model is proposed by viewing the functions of the intelligent telecommunication network from five aspects.

Finally, as a practical application example, the idea of the distributed cooperative multiagent is applied to the distributed cooperative control of the virtual path network in the ATM network. Through such discussions, it is indicated how the intelligent network can be constructed by the distributed cooperative computing techniques and how the communication network is impacted upon by those techniques. Thus, the future direction of research concerning the telecommunication network is indicated.
Traffic characteristics of a free access network with selective circuits: Influence on channel mismatch
Authors: Shikata Yoshiaki , Funakawa Kimitoshi , Shimada Katsunori , Nakura Masamitsu
Published: July 2007

When the blocking probability of the traffic between nodes is to be estimated in the free access network with selective circuits, the loss generated by the channel mismatch between the originating/terminating node and the circuit group must be considered.

This paper proposes a method of estimating the mismatch probability, considering the properties of the free access network construction. The estimation method is proposed with the following features: (1) the effect of mismatch on the joint connection distribution for the circuit group and all nodes is considered; (2) the number of simultaneous connections and connection probability on more than one circuit is considered; and (3) the different mismatch probability is considered for each originating and terminating node pair.

Based on the actual result of estimation, the effects of the network construction conditions (number of time slots, number of circuits, and the number of access devices) as well as the time‐slot selection method in channel assignment are examined. The effect of the mismatch for the case of multitraffic is evaluated by traffic simulation. A method is proposed to improve the blocking probability for the high‐speed calls, considering the mismatch condition. The effect also is evaluated by the traffic simulation.
Approximate analysis for delay queueing systems with two different classes of quasi‐random input
Authors: Hoshiai Takashige
Published: July 2007

Multidimensional traffic models where calls of more than two classes of different properties share the same resource are very important as basic models for tightly coupled multiprocessor systems, etc. Thus,‐ this type of research has long been actively performed. So far, some papers on finite‐source loss models have been presented. However, neither finite‐source delay models nor their approximate analyses have been investigated much.

As an approximate analysis method of delay queueing model with two different classes of quasi‐random input (M1, M2/M1, M2/S/N1, N2 model), this paper proposes a method which approximates combination states of waiting calls of each call class by the ratio of numbers of waiting calls of each call class. Moreover, by comparing numerical results of this approximate analysis with exact solutions and simulation values, it is shown that this approximate analysis method has very good accuracy.
Enhancement of otdr performance with an optical fiber amplifier
Authors: Furukawa Shin‐Ichi , Koyamada Yahei , Sankawa Izumi , Izumita Hisashi
Published: July 2007

The optical time domain reflectometer (OTDR) displays time‐dependent optical power when light is reflected back to the input edge of an optical fiber, and it can show an abnormal point of an optical fiber and also measure an optical loss. Hence, OTDR has become a useful tool at the time of optical fiber fabrications and also maintenance of optical fibers. Thus, considerable work has been done on the high performance such as dynamic range and high spatial resolution of OTDR.

This paper discusses the enhancement of OTDR using optical fiber amplifiers. First, on the basis of signal‐to‐noise ratio (SNR) calculation, it is demonstrated that the application of an optical amplification as a post‐amplifier for OTDR is quite useful. Next, a two‐stage cascade series Er‐doped fiber amplifier is realized. By cutting off the spontaneously emitted light by means of a fast switching, the output light of 30 dBm is obtained. Finally, in the case of a direct detection OTDR using the optical fiber amplifier, 30.5 dB dynamic range is obtained for 1‐μs pulsewidth and 216 integration. For the coherent detection OTDR, 36 dB is obtained for 1‐μs pulsewidth and 212 integration. Based on these results, the application of optical fiber amplifiers to OTDR is demonstrated clearly to be powerful.
Better than average and better with time: relative evaluations of self and others in the past, present, and future
Authors: Kanten Alf Børre , Teigen Karl Halvor
Published: July 2007

Evaluations of self and others in the past, present, and future were examined by asking 385 students to rate themselves or an acquaintance relative to their peers on a number of personality traits. We predicted, and found, evidence for self‐enhancement, as most participants regarded themselves superior to ‘most others’ at all points in time. We also found a better than average improvement effect, as participants considered themselves more superior now, than they were in the past, and expected to become even more superior in the future. Expected improvement in the future was larger than improvement over an equal span of time in the past. It is suggested that favorable self‐constructions are possible to the extent that the past and the future are perceived as ambiguous. Singular acquaintances were also rated better than most others, and were believed to improve over time, but their rate of improvement in the future was smaller than the expected improvement for oneself. Copyright © 2007 John Wiley & Sons, Ltd.
Numerical Methods for Parameter Estimation in Nonlinear Differential Algebraic Equations
Authors: Bock Hans Georg , Kostina Ekaterina , Schlöder Johannes P.
Published: July 2007

Nonlinear Differential Algebraic Equations (DAEs) are an important class of models for dynamic processes. To establish models that describe the process behavior in a quantitatvely correct way, often parameters in the model have to be determined from observations or measurements of the process.

This paper reviews numerical methods for parameter estimation in DAEs. In particular the so‐called boundary value problem approach and a versatile realisation, the multiple shooting method for parameter estimation, are discussed. Several applications are given to show the numerical performance and the wide applicability of the methods. A difficulty that occurs in practical applications is that the experiments performed to obtain measurements for parameter estimation are expensive, but nevertheless do not guarantee satisfactory parameter accuracy. The optimization of one or more dynamic experiments in order to maximize the accuracy of the results of a parameter estimation subject to cost and further technical inequality constraints leads to very complex non‐standard optimal control problems. Newly developed methods for design of optimal experiments for nonlinear processes are briefly discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Desorption electrospray ionization mass spectrometry of intact bacteria
Authors: Meetani Mohammed A. , Shin Yong‐Seung , Zhang Shaofeng , Mayer Richard , Basile Franco
Published: July 2007

Desorption electrospray ionization (DESI) mass spectrometry (MS) was used to differentiate seven bacteria species on the basis of their measured DESI‐mass spectral profile. Both gram‐positive and gram‐negative bacteria were tested and included Escherichia coli, Staphyloccocus aureus, Enterococcus sp., Bordetella bronchiseptica, Bacillus thuringiensis, Bacillus subtilis and Salmonella typhimurium. Distinct DESI‐mass spectra, in the mass range of 50–500 u, were obtained from whole bacteria in either positive or negative ion modes in less than 2 mins analysis time. Positive ion DESI‐mass spectral fingerprints were compared using principal components analysis (PCA) to investigate reproducibility for the intraday and the day‐to‐day measurements and the method selectivity to differentiate the bacteria studied. Detailed study of variances in the assay revealed that a large contribution to the DESI‐mass spectral fingerprint variation was the growth media preparation procedure. Specifically, experiments conducted with the growth media prepared using the same batch yielded highly reproducible DESI‐mass spectra, both in intraday and in day‐to‐day analyses (i.e. one batch of growth media used over a 3‐day period versus a new batch every day over the same 3‐day period). Conclusions are drawn from our findings in terms of strategies for rapid biodetection with DESI‐MS. Copyright © 2007 John Wiley & Sons, Ltd.
Age grading: The implicit organizational timetable
Authors: Lawrence Barbara S.
Published: July 2007

The age distribution within an organization forms an implicit career timetable, and there is evidence that people use their perceptions of this timetable to determine whether their careers are on or off schedule. Questionnaire data were collected from managers (N = 488, 47 per cent) within a large electric utility. The results indicate that managers who see themselves as ‘behind time’ in their careers have more negative attitudes towards work than other managers, even when their perceptions of being ‘behind time’ are inaccurate. However, although these managers continue to have the most negative attitudes, differences between the on and off schedule managers are smaller when their position on the actual career timetable is controlled. Thus, work attitudes are influenced by both individual and demographic factors. Finally, the longer managers remain in the same job, the more likely they are to define themselves as ‘behind time’. This supports other research suggesting that lateral moves within organizations may be an important device for managing the normal ‐limitations of upward movement in managerial careers.
Accounting for the quality of work life
Authors: Mirvis Philip H. , Lawler Edward E.
Published: July 2007

This study describes the development and issuance of an independent report on the quality of work life in a Corporation. The theory underlying the report, criteria, definitions, measurement procedures, the properties of the measures, and report itself are presented. A survey indicating a favourable reception to the data by stockholders, financial analysts, and employees is analysed. Recommendations for increased collaboration between accountants and behavioural scientists in the measurement and assessment of the quality of work life are presented in an effort to stimulate further research in the development of standardized measures and in the preparation of independent reports on the quality of work life in organizations.
Work values and beliefs in Britain
Authors: Furnham Adrian
Published: July 2007

The aim of this study was to investigate demographic and belief‐system determinants of, and the relationship between, various standardized self‐report measures concerned with work values and general social attitudes. Over two hundred and fifty adults completed five questionnaires concerned with general, as well as specifically work‐related, beliefs. The correlational analysis showed that the Protestant Work Ethic was strongly positively related with Conservative beliefs but negatively related to the Leisure ethic and Marxist‐related beliefs. Of the demographic variables examined education and vote most strongly differentiated the subjects' work beliefs and values in predictable directions. Thirdly a canonical correlational analysis revealed two variates which indicated that age and education were most closely linked to the dependent belief variables. These results are discussed in terms of the aetiology and relationship between general social and specifically work‐related beliefs.
Self‐reported job burnout among female human service professionals
Authors: Brookings Jeffrey B. , Bolton Brian , Brown Clifford E. , McEvoy Alan
Published: July 2007

A sample of 135 female human service professionals completed the Maslach Burnout Inventory (MBI) and the Staff Burnout Scale for Health Professionals (SBS), along with measures of job satisfaction, role stress, self‐esteem, alienation, and locus of control. Principal components factor analysis of this battery indicates considerable covariation of self‐reported burnout with job dissatisfaction and perceived role stress, and moderate overlap with more general feelings of alienation and low self‐esteem. Item factor analysis of the 22 MBI items resulted in two independent factors, one defined by the Emotional Exhaustion and Depersonalization items, the other by the Personal Accomplishment items. Item factoring of the SBS produced one large factor which was highly correlated with the MBI exhaustion‐depersonalization factor. Implications of these findings for the construct validity of the MBI and SBS are discussed.
How car and steel workers in different countries see their work
Authors: Heiskanen Tuula Aulikki
Published: July 2007

This study is concerned with how car and steel workers in different countries see their work and what features of their work they feel important. The material is drawn from two international projects, namely the car and steel industry studies, both coordinated by the Vienna Centre. The former study was carried out in 15 countries, comprising in all 126 production units from 38 plants and 3214 interviews of workers. The latter study was carried out in 10 countries, in 24 plants and 47 production units, 1576 workers were interviewed.

Clear differences were found between countries in how critically the workers were oriented to the burdens and challenges of their work. This was interpreted to reflect country‐specific work assessment standards. However, differences should be seen as differences in emphasis rather than as manifestations of work cultures, which substantially differ from each other. The order of importance among work characteristics was roughly the same from country to country: matters related to physical and economic security were widely considered the most important aspects of work.