Quorum-based synchronization protocols for multimedia replicas

Multiple replicas of multimedia objects are distributed to peers in overlay networks. In quorum-based (QB) protocols, every replica may not be up-to-date and the up-to-date replica can be found in the version counter. Multimedia objects are characterized in terms of not only data structure but also quality of service (QoS) parameters like frame rate. A transaction reads a parameter of a replica while there is a type of read operation to read a whole state of a replica. Each parameter of a replica is changed through a write operation. Thus, the data structure and QoS parameters of a replica are independently manipulated. In the multimedia quorum-based (MQB) protocol, multiple replicas of a multimedia object are synchronized based on the newness precedent relation. An object is an encapsulation of data and abstract operations for manipulating the data. There are enriching and impoverishing types of write operations. Some data is added to a replica in an enriching operation. On the other hand, some data in a replica is removed in an impoverishing operation. In order to reduce the overhead to write every replica in a quorum, we take an approach that the state of each replica is not always updated. If a transaction issues an enriching write operation, every replica in the write quorum is updated in the same way as the QB protocol. On the other hand, if an impoverishing write operation is issued, every replica is not updated in the quorum. Impoverishing operations are just recorded in replicas. On receipt of a read operation to read a whole state, impoverishing operations recorded are performed on a replica. The MQB protocol is evaluated in terms of the processing overhead of replicas. We show that the processing overhead of each replica can be reduced in the MQB protocol.     

Group communication support for distributed collaboration systems

The Collaborative Computing Transport Layer (CCTL) is a communication substrate consisting of a suite of group communication protocols. The design of CCTL supports the needs of distributed collaborative applications. CCTL is based on a two-level group hierarchy that naturally matches the structure of many collaborative applications and that allows several implementation optimizations. Logical interconnections among processes, called channels, define an efficient, light-weight group mechanism, providing a variety of communication services such as reliability and message ordering. Related channels are associated with a heavy-weight group, called a session, that provides group management services, such as membership, for its associated channels. Sessions and channels run different protocol stacks, allowing a flexible and useful separation of group management semantics and communication service quality. This also allows the efficient reuse of existing group management services when introducing new communication services. This revised version was published online in July 2006 with corrections to the Cover Date.     

Design and implementation of a distributed multimedia collaborative environment

Multimedia applications are being developed and used for many aspects of our lives today. New high-speed, broadband networks have emerged and made the operation of these high-bandwidth requiring applications readily feasible. However, the development of distributed multimedia applications and efficient and reliable operation of these applications are still very difficult. This paper presents a flexible and reliable distributed multimedia collaborative environment called MAESTRO which provides a rich multimedia collaborative service API and which provides distributed multimedia services that can be used to develop a variety of multimedia applications easily. MAESTRO has been designed using CORBA. The system as well as applications running on it are managed and controlled in order to provide a reliable and efficient multimedia operations environment. We validate our claim by developing a number of multimedia applications using our distributed multimedia system and by using them for supporting distributed collaborative scientific and engineering research experiments. This revised version was published online in July 2006 with corrections to the Cover Date.     

Postural control adaptability to floor oscillation in the elderly

We established a method to evaluate postural control adaptability, applying it to 341 subjects, aged 18-29 years (young subjects) and 50-79 years, in order to investigate the influences of age and gender on adaptability. Subjects stood with eyes closed on a force plate fixed to a floor oscillator, which was sinusoidally oscillated in the anteroposterior direction with 0.5 Hz frequency and 2.5 cm amplitude. Five trials of 1-minute oscillation were conducted, with a short rest between trials. The mean speed of fluctuation of the center of foot pressure (CFP), as detected by the force plate, was calculated as an index of postural steadiness. Mean CFP speed decreased significantly in all age groups with trial repetition. The adaptability capability of elderly subjects was categorized as "good," "moderate," or "poor," as evaluated against a standard value, based on the variation of the regression of mean CFP speed between the 1st and 5th trials in young subjects. Results showed that the magnitude of reduction in the mean speed, with practice, was linearly related to the initial mean speed. We found a general decline in adaptability, and increase in initial mean speed, in subjects aged 60 years and older, with no gender difference detected in any age group. The proportion of subjects exhibiting moderate and poor adaptability increased gradually with age. In conclusion, age, but not gender, appears to affect adaptation of postural sway with short-term practice, although some elderly subjects maintain postural sway velocity and adaptability capabilities similar to those of young subjects.     

The reproductive value in distributed optimal control models

We show that in a large class of distributed optimal control models (DOCM), where population is described by a McKendrick type equation with an endogenous number of newborns, the reproductive value of Fisher shows up as part of the shadow price of the population. Depending on the objective function, the reproductive value may be negative. Moreover, we show results of the reproductive value for changing vital rates. To motivate and demonstrate the general framework, we provide examples in health economics, epidemiology, and population biology.     

Application of the distributed control system in fermentation experiments

The distributed data acquisition and control system consisting of two process-oriented stations supervised by a master operator-oriented station was developed for fermentation experiment purposes. Ability of the system for study, analysis and control, as well as adequacy of the proposed methods and strategies for process investigation were proved. Some practical experiences with computer driven experiments on physiological state modulation ofC. utilis andB. megaterium in the laboratory fermentor are reported.     

Effect of traditional floor sitting on postural control after standing

Seiza is a Japanese traditional floor sitting style, sitting down with both legs set at about a 180 degree angle and both femurs on both lower legs. We examined the influence of the somatic dysesthesia and decrease in voluntary toe flexion strength (VTF) induced by Seiza on the center of pressure (COP) sway. Fifteen adults participated in this experiment. COP Sway was measured immediately after a chair resting (pre-test), when a plantar dysethesia occurred (post-test A), and when a decrease (under 30% of maximal voluntary contraction (MVC)) in the VTF set in (post-test B). Tissue oxygenation kinetics in the soleus muscle and plantar somatosensory thresholds (ST) were measured just before each COP test and during Seiza. From starting Seiza, oxygenated hemoglobin/myoglobin decreased markedly and reached a plateau within about 6 min. ST abruptly increased at about 19 min from starting Seiza. VTF decreased to less than 30% MVC in 33% of the participants after 10 min from the acute increase in ST, and in 100% after 20 min. When sustaining Seiza for 19 min, ST rose and sway velocity and antero-posterior sway increased. With continued Seiza, VTF decreased to below 30% MVC at 10 - 20 min, and the above stated body sway further markedly increase.     

Efficacy of Trichoderma longibrachiatum in the control of Heterodera avenae

Trichoderma longibrachiatum can be used for the control of Heterodera avenae in crops, but the effectiveness and possible mechanisms are unknown. Here we determined the efficacy and the mechanism responsible for the nematode control in spring wheat (Triticum aestivum L.). Wheat seedlings inoculated with T. longibrachiatum at the concentrations from 1.5 × 10⁴ to 1.5 × 10⁸ spores ml^?1 significantly increased plant height, root length, and plant biomass; decreased H. avenae infection in both rhizospheric soil and roots; and enhanced chlorophyll content, root activity, and the specific activities of resistance-related enzymes (peroxidase, polyphenol oxidase and phenylalanine ammonia lyase), compared to the control. Those reactions occurred soon after T. longibrachiatum inoculation and the effect reached the maximum 7–9 days after inoculation. Promoting competitive plant growth and inducing enzyme-trigged resistance serve as the main mechanism responsible for T. longibrachiatum against H. avenae. T. longibrachiatum can be considered an effective biocontrol agent against H. avenae in wheat.     

Efficacy of four synchronization protocols on the estrus behavior and conception in native Korean cattle (Hanwoo)

Ineffective estrus detection is the foremost limiting factor in the fertility of farmed cattle worldwide. Failure to detect estrus or erroneous diagnosis of estrus results in great economic losses in Korea each year. This study was carried out in order to comprehensively describe the estrus behaviors and conception rates of different estrus synchronization protocols applied to 40 cycling native Korean cattle (Hanwoo). The cows were grouped into four (n = 10) and treated with the following protocols: (1) Day -15: controlled intravaginal drug-releasing device (CIDR) for 12 days; Day -5: prostaglandin F_2α (PGF_2α), (2) ovulation synchronization (OVS): Day -15: GnRH; Day -6: PGF_2α; Day -4: GnRH, (3) Day -15: progesterone-releasing intravaginal device for 12 days; Day -5: PGF_2α; and (4) Day -15: PGF_2α; Day -4: PGF_2α. Artificial insemination was performed 12 hours after the detection of estrus using frozen-thawed semen. Estrus signs were compared using a charge-coupled device camera (CCDC) and a control method (direct visual observation). The pregnancy of the cows was determined by transrectal ultrasonography at Days 25 to 30 postinsemination. The results indicated that the day of estrus return was significantly earlier using the CCDC method compared with direct visualization (P < 0.05). Mounting of other cows was the most predominant sign of estrus among the flock (P < 0.05), as analyzed using the CCDC. In the OVS group, a lower rate of mounting was observed than in the other three groups. Moreover, significantly fewer estrus behaviors were noticed in the OVS protocol group (P < 0.05). Both first service conception and overall conception rates were significantly higher (P < 0.05) in the CIDR and OVS treatment groups. In conclusion, the CIDR and OVS protocols appear to be the best practice for the synchronization of estrus for reproductive competence through the CCDC in Hanwoo cows. However, CIDR has a practical advantage over OVS with respect to estrus detection.     

Efficacy of permethrin-impregnated curtains for malaria vector control

Preliminary results obtained by the use of permethrin-impregnated curtains against the Afrotropical malaria vectors Anopheles gambiae Giles s.l. and An.funestus Giles are reported and discussed. Field trials were carried out in villages near Ouagadougou, Burkina Faso. Houses were provided with curtains made from 100% cotton netting, impregnated with permethrin at the dose of 1 g a.i./m2, to cover the doorway, the window(s) and the space under the eaves. Entomological data collected during the period 1985-86 showed residual permethrin activity for about a year, and almost complete prevention of indoor-resting mosquitoes. Increased exit-rate and mortality-rate of house-entering malaria vectors were also obtained. Utilization of this malaria vector control method in primary health care programmes is advocated.     

A distributed control model for the air-righting reflex of a cat

A multisegment, multijoint model of a falling animal is presented to examine the effectiveness of a two-stage control scheme in a zero-momentum self-righting maneuver. The model contains a much larger number of degrees of freedom than is required to execute a self-righting maneuver and is thus capable of providing multiple solutions for the same task. The decentralized control scheme is designed to achieve gross turning in minimum time and to maintain a steady orientation relative to gravity after the turn has been achieved. The scheme is able to determine the sequence of steps necessary to execute the motor task and also incorporates learning features. Results from various simulations are presented and their implications discussed. Received: 26 June 1995 / Accepted in revised form: 30 June 1998     

Group control of multi-car elevator systems without accurate information of floor stoppage time

A multi-car elevator system is an elevator system that has more than one car installed in each elevator shaft. This system enables us to improve the transportation capability without increasing the occupied floor space. The primary purpose of this study is to consider the group control problem of operating cars efficiently without collision nor reversal in a multi-car elevator system, based on a detailed and realistic model where floor stoppage time of cars cannot be known in advance. In the context of elevator systems, reversal means that a car travels in the direction opposite to the desired direction of on-board passengers, which is prohibited because it makes passengers uncomfortable. We first propose an optimization-based collision and reversal avoidance method to operate cars in the same shaft. Next, we construct simple methods to allocate calls to individual cars under immediate and delayed guidance policies. Under the immediate guidance policy a call is allocated to a car immediately after it is registered, while under the delayed guidance policy the allocation may be changed until it is actually served. The effectiveness of the proposed group control method is examined by computer simulation.     

Hindbrain neurons as an essential hub in the neuroanatomically distributed control of energy balance

This Review highlights the processing and integration performed by hindbrain nuclei, focusing on the inputs received by nucleus tractus solitarius (NTS) neurons. These inputs include vagally mediated gastrointestinal satiation signals, blood-borne energy-related hormonal and nutrient signals, and descending neural signals from the forebrain. We propose that NTS (and hindbrain neurons, more broadly) integrate these multiple energy status signals and issue-output commands controlling the behavioral, autonomic, and endocrine responses that collectively govern energy balance. These hindbrain-mediated controls are neuroanatomically distributed; they involve endemic hindbrain neurons and circuits, hindbrain projections to peripheral circuits, and projections to and from midbrain and forebrain nuclei.     

六种杀虫剂防治甜椒烟青虫田间试验

烟青虫 H elicoverpa assulta Guenée是云南省大理州农业生产上的重要害虫 ,主要危害烤烟、甜椒及十字花科蔬菜。 1 999年春夏季 ,由于高温干旱 ,烟青虫在大理州 2 0 0 0 hm2甜椒上暴发危害 ,轻的损失 2～ 3成 ,重的损失 5成以上 ,其经济损失在 1 0 0 0万元以上。菜农在防治该虫时 ,普遍反映药剂的防治效果差 ,为了筛选出生产上需要的有效防治药剂 ,本文进行了此项试验。1　材料与方法1 .1　供试药剂1 .8%害极灭乳油 (阿维菌素 ,瑞士诺华公司 ) ,5 %锐劲特悬浮剂 (氟虫腈 ,法国罗纳普朗克公司 ) ,40 %乐果乳油 (重庆农药厂 ) ,80 %敌敌畏…