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In this letter, we propose a novel two-layered structured overlay, called a distributed Bloom filter table (DBFT), which is capable of substantially reducing overhead imposed by highly-dynamic peer-to-peer (P2P) distributed storage systems. More specifically, in our DBFT scheme, each node's ID remains unchanged, when the associated cluster changes due to the physical movement of the node. This provides us with an exclusive benefit of maintaining the rule of structured overlay without imposing any additional overhead to reconfigure index between saved information and its stored node, which cannot be achieved by the previous P2P techniques designed for mobile ad hoc networks. Moreover, another merit of the proposed scheme is that stored packets per node become more equally distributed than {in} the conventional schemes, because each node maintains to have its own {addressing- and content-}data when it moves within a storage area.

Driver assistance systems require the function of precise localisation. However, the accuracy of standard global positioning system (GPS) is inadequate for this. In this paper, a new method for precise localisation using the tightly coupled integration of inertial navigation system (INS) and raw GPS data is investigated. GPS Doppler corresponds to the relative velocity between the satellite and the receiver. Our new method enables us to make a robust and accurate estimation of the vehicle trajectory based on INS and GPS Doppler. Furthermore, the total optimisation by combining GPS pseudorange data with the accurate trajectory enables us to estimate the position of the vehicle precisely.

In integrated systems for accurate positioning, which consist of GNSS, INS, and other sensors, the GNSS positioning accuracy has a decisive influence on the performance of the entire system and thus is very important. However, GNSS usually exhibits poor positioning results in urban canyon environments due to pseudorange measurement errors caused by multipath creation, which leads to performance degradation of the entire positioning system. For this reason, in order to maintain the accuracy of an integrated positioning system, it is necessary to determine when the GNSS positioning is accurate and which satellites can have their pseudorange measured accurately without multipath errors. Thus, the objective of our work is to detect the multipath errors in the satellite signals and exclude these signals to improve the positioning accuracy of GNSS, especially in an urban canyon environment. One of the previous technologies for tackling this problem is RAIM, which checks the residual of the least square and identifies the suspicious satellites. However, it presumes a Gaussian measurement error that is more common in an open-sky environment than in the urban canyon environment. On the other hand, our proposed method can estimate the size of the pseudorange error directly from the information of altitude positioning error, which is available with an altitude map. This method can estimate even the size of non-Gaussian error due to multipath in the urban canyon environment. Then, the estimated pseudorange error is utilized to weight satellite signals and improve the positioning accuracy. The proposed method was tested with a low-cost GNSS receiver mounted on a test vehicle in a test drive in Nagoya, Japan, which is a typical urban canyon environment. The experimental result shows that the estimated pseudorange error is accurate enough to exclude erroneous satellites and improve the GNSS positioning accuracy.

The previous knowledge of road environments is vital for driver assistance systems, and an accurate map, which provides information on the roads to be traveled, is desired. Accurate road information map preparation is still costly because a highly accurate positioning system and manual mapmaking operations are required. This paper proposes a method for automatic high accuracy map generation at low cost, using a standard in-vehicle camera and a standard GPS. The positioning results from GPS have relatively large error, so that the accuracy of a map based on these positioning results is not adequate. Our proposed method enables accurate map generation of a local area by a vehicle, and improves global accuracy by optimal integration of many local maps. This paper describes accurate local map generation based on precise trajectories derived from GPS Doppler, and evaluates the effectiveness of this method using actual data.

The application of cement-treated soil as a backfill material is becoming more common in Japan. The large shear strength of treated soil can reduce the earth pressure acting on the wall. In the present study, a series of dynamic shaking model tests using a centrifuge facility was performed to investigate the seismic characteristics of the sheet pile quay wall backfilled with the treated soil. In the case of subjection to horizontal seismic force the characteristics of vibration and earth pressure of treated soil are so complicated that the improvement effects of treated soil have not been clarified yet. In addition, the treated soil is anticipated to fail with tensile cracking due to its brittle characteristics, because the treated soil cannot follow any large deformation of the surrounding soft ground. The model tests revealed the failure mode of improved ground and the effects on the deformation behaviour of a crack and dimensions of cement-treated soil.

The present study investigates a Medium Access Control (MAC) protocol for reliable inter-vehicle communications (IVC) to support safe driving with the goal of reducing road traffic accidents. A number of studies have evaluated the performance of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. However, the communication quality provided by the CSMA/CA protocol is seriously degraded by the hidden terminal problem in IVC. Therefore, we propose a new MAC protocol, referred to as Periodic Broadcast-Timing Reservation Multiple Access (PB-TRMA), which can autonomously control transmission timing and avoid packet collisions by enhancing the Network Allocation Vector (NAV) for periodic broadcast communications. The simulation results show that the proposed protocol can resolve the hidden terminal problem and mitigate data packet collisions. Moreover, the behavior of PB-TRMA is similar to that of Time-Division Multiple Access (TDMA). In addition, we show that two procedures, namely, packet collision retrieval and hidden terminal detection, are essential ingredients in PB-TRMA in order to achieve high quality performance.

In port areas, a wide-angle underwater imaging system has been in strong demand for wide-range inspections of undersea structures for periodic maintenance and for rapid checks in case of disasters. However, seawater in such areas is often turbid due to urban activities, which makes underwater imaging more difficult. We developed a three-dimensional imaging sonar system (hereinafter called System 08) for surveying of portside underwater constructions based on a prototype named System 07, which was for off-line viewing of 3-D images made in tank experiments. System 08 could be printed on-line 3-D acoustic image at 1/8 screen/0.125 sec. and surveyed height of a slope within ± 5 % or less in water tank measurement.

The hydride-vapour-phase-epitaxial (HVPE) growth of semi-polar (1 1 2¯ 2)GaN is attempted on a GaN template layer grown on a patterned (1 1 3) Si substrate. It is found that the chemical reaction between the GaN grown layer and the Si substrate during the growth is suppressed substantially by lowering the growth temperatures no higher than 900 °C. And the surface morphology is improved by decreasing the V/III ratio. It is shown that a 230-μm-thick (1 1 2¯ 2)GaN with smooth surface is obtained at a growth temperature of 870 °C with V/III of 14.

At port areas, a wide-angle underwater imaging system has been in strong demand for wide-range inspections of undersea-structures for periodic maintenance and for rapid check in case of disaster-affected. However, seawater in such areas is often turbid due to urban activities, which makes underwater imaging more difficult. Thus, we developed a prototype of three-dimensional sonar system 07 (hereinafter called System 07) with surveying support feature for portside underwater constructions. System 07 was used in a water tank, and its image performance was experimentally measured for a 6 m x 6 m field of view, with 0.1 m x 0.1 m x 0.13 m spatial resolution at an approximately 10-m range. In addition, System 07 successfully acquired acoustic images for a 1-mm-thick H-shaped aluminum plate target 1.4 m wide and high at approximately an 11-m range.

A novel timing synchronizing scheme is proposed for use in inter-vehicle communication (IVC) with an autonomous distributed intelligent transport system (ITS). The scheme determines the timing of packet signal transmission in the IVC network and employs the guard interval (GI) timing in the orthogonal frequency divisional multiplexing (OFDM) signal currently used for terrestrial broadcasts in the Japanese digital television system (ISDB-T). This signal is used because it is expected that the automotive market will demand the capability for cars to receive terrestrial digital TV broadcasts in the near future. The use of broadcasts by automobiles presupposes that the on-board receivers are capable of accurately detecting the GI timing data in an extremely low carrier-to-noise ratio (CNR) condition regardless of a severe multipath environment which will introduce broad scatter in signal arrival times. Therefore, we analyzed actual broadcast signals received in a moving vehicle in a field experiment and showed that the GI timing signal is detected with the desired accuracy even in the case of extremely low-CNR environments. Some considerations were also given about how to use these findings.

We herein investigate the effect of the number of elements of a previously studied reactively loaded ring antenna array with respect to electronically variable beamwidth performance. The antenna has a unique ability to increase the effective antenna length by adding parasitic ring elements, which contributes to higher performance with respect to beamwidth variation. Monte Carlo (MC) simulations clarify that variable range of beamwidth can be improved effectively by increasing the number of ring elements M to 5. It is herein demonstrated for the case of M = 5 that the beamwidth toward the broadside direction can be controlled from 40deg to 145deg in the E plane, while maintaining the voltage standing-wave ratio (VSWR) to less than 3.0, where the antenna size is 0.32lambda times 1.32lambda. In addition, it is also confirmed that the number of estimated directions-of-arrival (DOAs) based on the reactance-domain multiple signal classification (MUSIC) algorithm can be also increased by increasing the number of ring elements.

We studied the effects of castration and testosterone (T) replacement on intracavernous pressure (ICP) elicited with electrical stimulation of the medial preoptic area (MPOA) and cavernous nerve (CN) in male rats. We measured the ICP during electrical stimulation of the MPOA and CN in castrated male rats with and without testosterone replacement. The experimental group consisted of 20-week-old male rats at 2 weeks (n=8), 4 weeks (n=8) and 8 weeks (n=8) after castration, and at 8 weeks after castration with T replacement (n=4). Intact 20-week-old rats (n=8) served as controls. The erectile response was expressed as the ICP/blood pressure (BP) ratio. The ICP/BP ratios during CN stimulation of the animals at 2, 4, and 8 weeks after castration were significantly lower than those of the intact animals. However, the erectile responses were not eliminated. In contrast to these peripherally evoked responses, erectile responses elicited by electrical stimulation of the MPOA were eliminated following castration. After testosterone replacement, both erectile responses were restored. Testosterone plays important roles in both the central and peripheral neural pathways for the maintenance and restoration of erectile capacity. The central control of erection shows more extensive changes following testosterone replacement than the peripheral control.

In this paper, we propose a new concept of receiver structure with diversity reception technique to realize multi-service simultaneous reception, which shares diversity branches between receiving communication services. In the proposed receiver structure, each diversity branch selects the receiving services dynamically according to channel states, and each communication service is always selected by at least one branch to realize multi-service simultaneous reception. A basic algorithm is also described to select combinations of a diversity branch and a receiving communication service. The total number of branches decreases and the effective number of branches per communication service increases, by sharing the branches between communication services in the proposed receiver. Simulation results are shown that the proposed diversity receiver achieves both complexity reduction and performance improvement.

The crystal morphological shapes of A15 Cr smoke particles were studied by electron microscopy and subsequent geometric modelling made on the basis of thermodynamic considerations. The predominant shape was the {211} icositetrahedron. In addition, icositetrahedra truncated by {110} planes were frequently observed. By consideration of the surface energy at 0 K, the stable Wulff polyhedron was found to be the {211} icositetrahedron as the fundamental form, and it was found to be slightly truncated by {100}, {110} and {210} planes. The discrepancy in the degree of truncation between the experimentally observed and the theoretical particle shapes may be explained by the influence of the surface entropy. The icositetrahedral particles are characteristic of the A15 structure itself but not of the specific composition of the material.

Purpose: To examine the effects of altered nitric oxide (NO) levels in the paraventricular nucleus (PVN) on copulatory behavior and reflexive erections in male rats. Materials and Methods: Extracellular nitrite (NO 2 − ) and nitrate (NO 3 − ) levels were measured in the PVN following administration of the NO precursor L-arginine (L-arg, 10 mM), the NO synthase inhibitor N G -monomethyl L-arginine (L-NMMA, 10 mM), or Ringer's solution via a dialysis probe to the PVN. The effects of alterations in extracellular NO on reflexive erections and copulatory behavior were assessed. Results: L-arg administration was associated with significant elevations of extracellular NO 2 − and NO 3 − in the PVN, while L-NMMA significantly reduced NO 2 − and NO 3 − levels. A corresponding increase in reflexive erections was noted during infusion of L-arg in the PVN, with a corresponding decrease in reflexive erections observed during administration of L-NMMA into the PVN (Student's t test for paired samples, p Conclusions: Altered NO levels in the PVN affected the frequency of reflexive erections, but not the mount rate. These studies contrast with previous observations of the effects of altered NO levels in the MPOA, and support the hypothesis that physiological specificity in the actions of NO on discrete brain nuclei may have important implications to erectile physiology and dysfunction.

We used infrared absorption spectroscopy to clarify the characteristics of black pigment in gallstones, which is insoluble and amorphous, and is considered to be a polymer of bilirubin or calcium bilirubinate with tetrapyrrol units. Black stones contain several metallic elemental components that exist as complex compounds with bilirubin. Chemical analysis of gallbladder bile indicates that the mechanism by which unconjugated bilirubin is precipitated depends on the pH level or on bile acid components. Black pigment is formed by the bridging action of mucin, forming complexes with metal ions in the bile. Hemolytic jaundice, liver cirrhosis, and cardiac valve replacement have been implicated in the etiology of black stone formation. In hemolytic jaundice and cardiac valve replacement, overproduction of bilirubin, due to hemolysis, is responsible for black stone formation, while in liver cirrhosis, a high concentration of ionized calcium and increased pH levels are the main factors in such stone formation.

Objectives To investigate the effect of limaprost, an oral prostaglandin E1 (PGE1) derivative, on erectile dysfunction and to compare the effects of limaprost with a Chinese herbal drug, gosyajinki-gan. Patients and methods The study comprised 50 consecutive patients with mild erectile dysfunction who showed a good erectile response to intracavernosal injection with 20 mg of PGE1. Limaprost was administered to the first 25 patients (30 mg three times daily) and gosyajinki-gan (7.5 g three times daily) to the next 25 patients, for 8 consecutive weeks. Patients were evaluated by their ability to achieve vaginal penetration and by a subjective assessment of erectile function (penile rigidity and maintenance of erection) before and after the treatment, using a self-administered questionnaire. Objective measurements (nocturnal penile tumescence, NPT, values) were also evaluated. Results Eleven of the 24 patients who received limaprost without interruption and four of the 24 taking gosyajinki-gan succeeded in vaginal penetration; the difference in the positive response rate was significant. The mean increment of NPT was significantly higher with limaprost treatment. However, all positive responders in both groups did not experience a full erection. There were no side-effects in any patient except one in the limaprost group who developed a facial flush. Thus the treatment was mild enough to be tolerated. Conclusion Limaprost was more effective for mild erectile dysfunction than was gosyajinki-gan.

BACKGROUND Sexual dysfunction after transurethral resection of the prostate (TUR-P) depends on multiple factors including preoperative erectile function itself. Using the Sapporo Medical University-questionnaire, we analyzed background factors contributing to loss of sexual intercourse after the operation. PATIENTS AND METHODS We sent the self-administered questionnaires to 1,000 patients who had received TUR-P. Answers to questions were ranked as scores. Multiple regression analysis was used to identify factors significant for loss intercourse after TUR-P. RESULTS The response rate was 63.5%. Patient with incomplete answers and those having diseases affecting voiding or sexual function and antiandrogen medication were excluded from the study. Leaving 536 patients for the final analysis. Scores for sexual desire and erectile function in the patients who received TUR-P were lower than those of age-matched healthy males. When we divided the patients according to frequency of sexual intercourse before and after TUR-P, there was distinct differences in age, scores for sensory disturbance, depression, the cooperative value of the sexual partner, sexual desire, erectile function, nocturia, residual sensation and urgency between those maintaining sexual intercourse and those having lost it. Multiple regression analysis using these factors indicated that the scores of erectile function was the most significant determinant for maintaining sexual intercourse after TUR-P in patients aged from 50 to 69 years, followed by the cooperative value of the sexual partner, residual sensation and sensory disturbance. In those 70 old and older, the score for erectile function was the most significant determinant, followed by the cooperative value of sexual partner. CONCLUSION Our results suggest that, irrespective of age, the cooperation of the patient's sexual partner as well as erectile function significantly influence the maintenance of sexual intercourse after TUR-P. In addition, voiding condition and psychological status after TUR-P may affect the maintenance of sexual intercourse in patients in their fifties and sixties.

An improved technique for making thin sections of gallstones has enabled us to examine their morphology microscopically. Using this technique in various types of gallstones, we found a network of mucin, which was considered to play an important role in gallstone formation. The effectiveness of a mucolytic agent, acetylcysteine, for the direct dissolution of gallstones was evaluated in this study. Immersion in acetycysteine led to the prompt disintegration of various types of gallstones into small fragments. As acetylcysteine is commercially available as a mucolytic agent, a clinical trial was undertaken for the treatment of cholelithiasis (hepatolithiasis,n=5; choledocholithiasis,n=1). Because of the disintegrating effect of acetylcysteine, after the injection of this agent, many fragments flowed out through the percutaneous transhepatic biliary drainage tube. Acetylcysteine gallstone dissolution combined with percutaneous transhepatic cholangioscopic lithotripsy significantly aided the lithotriptic action, due to the disappearance of mucin from the bile duct. No side effects were observed either during or after the treatment. We concluded that acetylcysteine can be used as a new agent for the direct dissolution of most types of gallstones in patients with cholelithiasis.

Decentralized time division multiple access (D-TDMA) is an autonomous slotted protocol originally designed for the single-hop periodic broadcast of safety messages. With the arrival of new ITS applications based on multiple wireless link transmissions, however, the introduction of new mechanisms is essential to share the time domain between single-hop periodic broadcast (safety messages) and multi-hop transmission. Because the scarce 10 MHz-band is going to be used as one communication channel in Japan, a highly reliable medium access control (MAC) scheme is required to handle both safety and multi-hop messages. We propose the multi-hop transmission scheme compatible with single-hop periodic broadcast. In our solution, each terminal that transmits a multi-hop packet first starts a slot reservation procedure to avoid packet collisions with safety messages and thus maintain as high a delivery rate as possible. Then, the transmitting nodes use the D-TDMA structure to check the reception of the multi-hop packet at the relay side. If any failure is detected, the packet is retransmitted as soon as possible. Concerning the routing algorithm, we assume that messages are routed to the destination along the road having the best vehicular traffic and that the road information is provided by D-TDMA. Computer simulations were conducted for an urban environment in which vehicles are moving. The simulation results show that our scheme maintains the delivery rate of safety messages and can recover multi-hop packets in the case of transmission failure.

Ytterbium smoke particles were produced by the gas evaporation method in an argon atmosphere. In addition to the typical shapes of fcc metal particles such as twinned or non-twinned truncated octahedra and icosahedron, morphological shapes which have not yet been studied for other fcc smoke particles were found. The size of the particle was much larger than the value found in other fcc metals. After the irradiation of these particles by a high electron dose, hollow Yb 2 O 3 particles were obtained.

きわめてまれな先天奇形である肝右葉欠損症の1例を経験したので報告する.症例は60歳女性で, 右季肋部痛を主訴として来院した.軽度の黄疸を認めたためpercutaneous transhepatic cholangiographyを施行した所, 右肝管は造影されず, 左肝管は肝門部で狭窄し, その拡張した末梢側に数個の結石を認めた.computed tomographyでは肝右葉の欠損と左葉の代償性肥大, 胆嚢の位置異常を認めた.肝右葉欠損症に併存した肝内結石症の術前診断にて手術を施行したところ, 肝右葉は欠損し, 左肝管が肝門部付近で屈曲しその末梢側に多数の黒色石を認めた.手術は, 胆嚢摘出, 総胆管切開Tチューブドレナージ, 左肝管切石, 左肝管空腸側々吻合術を施行した.肝右葉欠損症の報告は1956年以降25例を数えるのみで, 本邦では自験例が第2例目の報告で, 肝内結石併存例は自験例が世界で初めてとなる.結石種類は黒色石であったが, これには先天的形態異常という背景因子の関与が考えられた.

When the volume of traffic on a roadway is so high such as traffic jam, medium access control (MAC) protocols in inter-vehicle communication (IVC) systems do not work well. The primary reason is the huge amount of communication traffic, which could be resolved by conventional transmission cycle control (TCC) schemes. However, when using TCC schemes, the failure of packet transmission extends the communication interval between vehicles, which can cause driving support systems that use IVC to malfunction. This paper proposes an advanced TCC scheme for realizing a safe driving support system. The proposed scheme exploits the frame-information exchange in the autonomous decentralized TDMA protocol, so that subsequent packets are transmitted rapidly even when failure occurs. Such a scheme is shown to be effective in terms of both communication quality and driving support systems.

胃切除後胆石の成因を明らかにする目的で胃切除術胆石53例の結石種類, 胆汁中細菌, 胆汁組成の検討を行った. 結石種類は, 胃切再建術式に関わらず黒色石が多くみられた. 胃切除後黒色石例の胆汁組成では胆汁酸およびリン脂質濃度の低値とイオン化カルシウム (Ca++) 濃度の高値が特徴であった. 胆汁中Ca++高値は, 胆汁酸およびリン脂質の低下の結果と考えられ, この高濃度の胆汁中Ca++が胃切除術後での黒色石生成に重要な役割を果たしていることが示唆された. 十二指腸が空置される再建術式 (B-II群) においては黒色石とともにピリルビンカルシウム石が高頻度にみられ, 胆汁中細菌も高率に陽性であった. これらの再建術式後では空置された十二指腸内の細菌叢の変化から胆道感染が引き起こされ, ビ石形成の原因となっていることが考えられた.

This paper presents a prediction formula of propagation loss for low antenna height scenarios on a line-of-sight (LOS) straight-line road having an intersection, for modeling the propagation loss characteristic in inter-vehicle communications (IVCs). The regression analysis is applied to the propagation loss data generated by computer simulation based on the geometrical optics theory, and the regression formula is established as a dual-slope model having variables of propagation distance, frequency, road width, and antenna height. In this analysis, the position of breakpoint is determined so that the RMS error of the regression becomes the smallest on both slope regions because its position is an important factor for good prediction accuracy. Furthermore, the comparison between predicted and measured propagation losses is performed in 2 GHz and 5 GHz bands, and the effectiveness of the prediction formula is confirmed by evaluating the prediction errors.

A primary retroperitoneal teratoma is a relatively rare neoplasm in adults. We report 1 such case evaluated by CT and MRI scans. The preoperative MRI was important in that it delineated the precise position of the tumor relative to the surrounding organs.

The multi-carrier modulation (MCM) technique is an attractive approach for high-speed digital radio communication systems in order to achieve a high spectral efficiency and to combat the frequency selectivity of the channel. Orthogonal frequency division multiplexing (OFDM) is a kind of MCM technique. Wavelet packet modulation (WPM) is another kind of MCM technique using the wavelet transformation instead of the Fourier transformation to multiplex information symbol sequences. In this paper we propose a maximum likelihood decoding method for WPM without coding before transmitting the signal. The proposed method performs maximum likelihood sequence estimation by utilizing a signal obtained in an intermediate stage of the demultiplexing process. Then, bit error performance under a flat fading channel and frequency-selective fading channel is evaluated by computer simulation. According to the results, the proposed method can improve the bit error performance in the region of high Doppler frequency.

The authors have proposed a novel algorithm for an adaptive array that is suitable for the multi-carrier transmission. It has already been confirmed that multi-carrier waves can be suppressed by the adaptive array in the multi-carrier transmission system (Fujimoto et al.). In this paper it is shown through computer simulation that not only the multipath waves but also the co-channel interference waves can be suppressed by the adaptive array.

A case of erosion of a penile prosthesis caused by indwelling of a catheter in the urethra is reported. A 73-year-old man had maintained sexual intercourse with penile prostheses (Jonas prosthesis, 19 cm) for 11 years without any complications until he developed cerebral infarction. One month after starting an indwelling urethral catheter in a neurosurgery clinic, the left-side penile prosthesis eroded from the area of the fossa navicularis, and was immediately removed. This type of complication is not unusual in patients with a neurogenic bladder. However, it is not well recognized in patients who suddenly develop a neurogenic bladder following a long-term uneventful period after the implantation of penile prostheses. Therefore, urologists should inform patients who receive this type of treatment that erosion of the prosthesis may develop when they need an indwelling urethral catheter as a late complication.

We report herein the case of a patient in whom metastatic colon carcinoma was found within an inguinal hernia sac. According to Lejar's classification, colon carcinomas within inguinal hernias are categorized as intrasaccular- and saccular-type tumors. In our patient, asymptomatic transverse colon carcinoma was the primary lesion, and to the best of our knowledge, this is only the fourth case of such a saccular-type tumor to be reported in the literature. To date, 21 cases of intrasaccular tumors have been reported, and saccular-type tumors are considered to be an even rarer entity, unless the patients have obvious ascites, indicating peritonitis carcinomatosa. Histologic examination of the hernia sac is recommended for male patients of advanced age with an inguinal hernia, especially those who have previously undergone surgery for colorectal carcinoma.