On-off Type Research Articles

Designs of Access Mechanisms in IEEE 802.16e Mobile Systems

In this paper, we first propose a call admission control algorithm for IEEE 802.16e mobile WiMAX system. We then design the handover mechanism according to the general handover procedure specified by the IEEE 802.16e-2005 standard. Performance evaluations via simulations are conducted to compare the system performance for the network with or without handover procedures employed. It is also found that the transmission quality is subject to the modulation rate change significantly in the mobile environments. The proposed mechanisms are shown to reduce connection blocking rate and packet dropping rate effectively to enhance the efficiency of the mobile WiMAX system. Polling Service), nrtPS (Non Real-time Polling Service), and BE (Best Effort). The UGS is designed to support real-time service flow that generates fixed-size data periodically, such as T1/E1, VoIP without silence suppression. The ertPS is designed to represent real-time service flow that generates ON-OFF type data on the periodical interval, such as VoIP with silence suppression. The rtPS is designed to support real-time service flow that generates variable size data, such as video streaming services. The nrtPS is designed to support non real-time service flow that generates variable size data, such as FTP. The BE is designed to support best effort service, such as email. In the mobile WiMAX environment, the handover procedure occurs when the MS moves into the service range of another BS. Two HO (handover) processes are defined in IEEE 802.16e-2005 standard: the hard handover process and the soft handover process. The hard handover is also called break-before-make handover. The MS starts connections with target BS only after disconnecting service with the serving BS. On the other hand, the soft handover is also called make-before-break handover. The MS starts connections with target BS before disconnecting service with the serving BS. In this paper, the QoS mechanisms for the employment in the mobile WiMAX environment are proposed. We compare the performance of various traffic type data with or without handover procedures in the mobile WiMAX environment via simulations. The connection blocking probability and packet dropping rate under various scenarios are investigated. The rest of this paper is organized as follows. Related

On-Off Type Micro-plate Visual Determination of Residual Chlorine in Tap Water

比色試薬であるN,N'-ビス（2,4-ジスルホベンジル）トルイジン（SBT）を用いる水道水中残留塩素の比色反応に阻害物質であるアスコルビン酸を共存させることを検討した．アスコルビン酸の濃度を調節することで，無色〜淡青色間の変色に要する試料濃度をコントロールすることが可能であった．この知見に基づき，種々の濃度のアスコルビン酸を含むSBTを添加したマイクロプレートに列単位で試料を加えると，試料濃度に応じて変色数が変化することから，変色数による残留塩素のオン・オフ型目視−マイクロプレート分析法を開発した．その結果，1.0 × 10−5〜8.0 × 10−5 mol L−1の残留塩素の目視計測が可能であった．また，本法を既知濃度の残留塩素を添加した水道水試料に適用したところ，良好な結果が得られた．

Research of a Giant Magnetostrictive Valve With Internal Cooling Structure

This paper proposes a giant magnetostrictive valve (GMV) which uses a tube giant magnetostrictive material (GMM) rod as the actuator. Based on the analysis of the structure and magnetic field of giant magnetostrictive actuator (GMA), a GMV is designed and manufactured. The output displacement characteristics of the GMA under different temperatures are tested. The maximum magneto-strain is about 1500 ppm and the response time is about 1.8 ms. Compared with the simulation of temperature-rise characteristic computed by finite element analysis software, the results show that the internal cooling effect is significant, and the GMA continues working in a relatively stable temperature range. Then, the test bench of the GMV is set and the flow control characteristic is tested. The results show that the internal cooling on-off type giant magnetostrictive valve has many merits including a fast response speed, a stable working temperature range and high precision flow control.

Intermittent behavior at the boundary of noise-induced synchronization

The intermittent behavior at the boundary of noise-induced synchronization is investigated. It is shown that the on-off type intermittence takes place. The observed effect is illustrated by analyzing model systems with discrete time, as well as stream dynamic systems under the action of a common noise source.

산업용 냉각기의 압축기 회전수 변화에 따른 용량제어 특성

This paper presents the capacity-control characteristics in an industrial cooler with a variable speed compressor. The inverter-type compressor is controlled by the rotational speed of the operational frequency. This type of the compressor performs the wide range of load compared to the on-off type. When the load of the system reduces, the rotational speed will be reduced. Thus, the system leads to the less power consumption and extends the longer durability of the compressor. With the variable rotational speed of the compressor the cooling capacity of the cooler is about 1.6-3.6 kW and the capacity control is about 40-100%. The system showed the highest efficiency when the rotational speed is about 45-70 Hz. The results can be used as the basic design data to control an industrial cooler.

8-Hydroxyquinoline-Substituted Boron–Dipyrromethene Compounds: Synthesis, Structure, and OFF–ON–OFF Type of pH-Sensing Properties

A series of four novel 8-hydroxyquinoline-substituted boron-dipyrromethene derivatives, namely 4,4-difluoro-8-(5-(8-hydroxyquinoline))-3,5-dimethyl-4-bora-3a,4a-diaza-s-indacene (1), 4,4-difluoro-8-(5-(8-hydroxyquinoline))-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (2), 4,4-difluoro-8-(5-azastyryl-(8-hydroxyquinoline))-3,5-dimethyl-4-bora-3a,4a-diaza-s-indacene (3), and 4,4-difluoro-8-(5-azastyryl-(8-hydroxyquinoline))-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (4), have been synthesized and characterized by a series of spectroscopic methods. The molecular structures of 1 and 2 have been determined by single-crystal X-ray diffraction analyses. The two methyl substituents attached at C-1 and C-7 positions of boron-dipyrromethene (Bodipy) in compound 2 was revealed to prevent the free rotation of the 8-hydroxyquinoline (8-HQ) moiety, resulting in an almost vertical 8-HQ-Bodipy configuration of this compound. This is obviously different from those for 1 with the dihedral angle between 8-hydroxyquinoline and Bodipy moieties of 65.44 and 66.79° due to the lack of methyl substituents in the latter compound. The intense fluorescence from the Bodipy subunit of these compounds was revealed to gradually get diminished along with either decreasing or increasing the pH value under acidic and basic conditions, respectively, in particular for 1, 2, and 4 because of the photoinduced intramolecular electron transfer from excited Bodipy moiety to 8-HQ unit and just an opposite process. This renders these compounds the first OFF-ON-OFF type of pH-dependent fluorescent sensors. Nevertheless, both the intrinsic fluorescence of these compounds and their fluorescent quenching properties along with the change in the pH value have been found to depend on the steric configuration as well as the linking group between 8-hydroxyquinoline and Bodipy moieties, revealing the effect of molecular structure on their fluorescence properties.

Facile synthesis of rhodamine-based highly sensitive and fast responsive colorimetric and off-on fluorescent reversible chemosensors for Hg2+: preparation of a fluorescent thin film sensor

Fluorescence-active chemosensors (L1-L4), comprising a rhodamine scaffold and a pseudo azacrown cation-binding subunit, have been proposed and characterized as a fluorescent chemosensor for Hg(2+). An on-off type fluorescent enhancement was observed by the formation of the ring-opened amide form of the rhodamine moiety, which was induced by the interactions between Hg(2+) and the chemosensor. Upon the addition of Hg(2+), an overall emission change of 350-fold was observed, and the selectivity was calculated to be 300 times higher than Cu(2+) for receptors L2-L4. A polymeric thin film can be obtained by doping poly(methyl methacrylate) or PMMA with chemosensor L2. Such a thin film sensor can be used to detect Hg(2+) with high sensitivity and can be recovered using diluted NaOH.

ChemInform Abstract: Synthetic Application of Benzothiazole Ring System as an On-Off Type of Leaving Group. Synthesis of Ketones and Carboxylic Acid Derivatives from 2-(1-Substituted 1-Hydroxyalkyl)- and 2-(1-Hydroxyalkyl) benzothiazoles.

A synthetic and systematic use of benzothiazole ring system as an “on-off” type of leaving group was developed for the preparation of ketones and carboxylic acid derivatives from a variety of 2-(1-substituted 1-hydroxyalkyl)- and 2-(1-hydroxyalkyl)benzothiazoles (off state) via the corresponding benzothiazolium salts (on state) obtained by the quaternization (on switch). A variety of 3-methyl-2-(1-substituted 1-hydroxyalkyl)benzothiazolium iodides (1) underwent a carbon–carbon bond cleavage at the 2-position to give the corresponding ketones on the simple treatment with a base under mild reaction conditions. The similar reaction of 3-methyl-2-(1-hydroxy-alkyl)benzothiazolium iodides (2) to aldehydes proceeded less efficiently. The oxidative reaction of a variety of 2 with base and nonactivated MnO2 in ethanol afforded the corresponding ethyl esters. This type of oxidative reaction could be also achieved in THF with different nucleophiles such as alcohol, water, thiol, and amine to give the corresponding e...

Anthracene coupled adenine for the selective sensing of copper ions

Anthracene-based adenines 1 and 2 have been designed and synthesized, and their metal ion recognition properties have been established fluorometrically. Both molecules exhibit Cu2+ induced ON-OFF type signaling patterns over the other representative metal ions studied. Compound 1 exhibits 97% quenching of emission in the presence of Cu2+ whilst derivative 2 shows 81% quenching under similar experimental conditions.

Synthesis of a Novel Fluorescent Sensor Bearing Dansyl Fluorophores for the Highly Selective Detection of Mercury (II) Ions

A new macromolecule possessing two dansyl moieties and based on 2-[4-(2-aminoethylthio)butylthio]ethanamine was prepared as a fluorescent sensor and its mercury sensing properties toward various transition metal, alkali, and alkali earth ions were investigated. The designed compound exhibited pronounced Hg2+-selective ON-OFF type fluorescence switching upon binding. The new compound provided highly selective sensing to Hg2+ in acetonitrile-water solvent mixtures with a detection limit of 2.49 x 10-7 M or 50 ppb. The molecular modeling results indicated that ions-recognition of the sensor originated from a self assembly process of the reagent and Hg2+ to form a helical wrapping structure with the favorable electrostatic interactions of Hg2+coordinated with sulfur, oxygen, nitrogen atoms and aromatic moieties.

Neutral Search Technique for Short-Term Pump Schedule Optimization

This paper deals with the computation of short-term (typically 1 day ) least-cost pump schedule for water distribution systems with on-off type pumps and well-defined operating points. The objective function is to minimize the overall energy charge for a prescribed water consumption while several constraints are considered, such as storage and source limitations, pump setting bounds, nodal mass balances, and the power demand charge. In this study a neutral search technique with genetic algorithms (GAs) is proposed to solve the least-cost pump schedule problem where neutrality is achieved through objective-fitness mapping instead of representational redundancy. We introduce a fitness assignment technique for groups of individuals where grouping is based on objective similarity. As a consequence two different individuals can be equally fit (belonging to the same group) which implies the neutrality. We compare the neutral search technique to two conventional GA approaches on a hypothetical water distribution...

The effect of L-Deprenyl on on-off phenomena in Parkinson's disease

L-Deprenyl, a specific monoamine oxidase subtype B inhibitor, has been reported a valuable adjunct to conventional treatment of Parkinsonism. A double-blind cross-over controlled study was performed in 19 parkinsonian patients with on-off type problems. Five mg L-Deprenyl per day reduced the number of on-off episodes. Side effects such as hyperkinesias, vivid dreams, dizziness with diaphoresis were frequent. Severe side effects such as nightmares, postural hypotension, confusion, and dizziness with headaches necessitated discontinuation of the drug in 4 patients. L-Deprenyl was of limited value in this group of patients with longstanding Parkinsonism.

Cellular Mechanisms for Direction Selectivity in the Retina

Direction selectivity represents a fundamental computation found across multiple sensory systems. In the mammalian visual system, direction selectivity appears first in the retina, where excitatory and inhibitory interneurons release neurotransmitter most rapidly during movement in a preferred direction. Two parallel sets of interneuron signals are integrated by a direction-selective ganglion cell, which creates a direction preference for both bright and dark moving objects. Direction selectivity of synaptic input becomes amplified by action potentials in the ganglion cell dendrites. Recent work has elucidated direction-selective mechanisms in inhibitory circuitry, but mechanisms in excitatory circuitry remain unexplained.

Automatic Reading System for On-off Type DNA Chip

In this study we propose an automatic reading system for diagnostic DNA chips. We define a general specification for an automatic reading system and propose a possible implementation method. The proposed system performs the whole reading process automatically without any user intervention, covering image acquisition, image analysis, and report generation. We applied the system for the automatic report generation of a commercialized DNA chip for cervical cancer detection. The fluorescence image of the hybridization result was acquired with a GenePix TM scanner using its library running in HTML pages. The processing of the acquired image and the report generation were executed by a component object module programmed with Microsoft Visual C++ 6.0. To generate the report document, we made an HWP 2002 document template with marker strings that were supposed to be searched and replaced with the corresponding information such as patient information and diagnosis results. The proposed system generates the report document by reading the template and changing the marker strings with the resultant contents. The system is expected to facilitate the usage of a diagnostic DNA chip for mass screening by the automation of a conventional manual reading process, shortening its processing time, and quantifying the reading criteria.

템플릿 정합법을 이용한 온-오프 형태 DNA 칩의 탐색자 구분

본 연구는 카운팅 정합도라 불리는, 비선형 정합도를 척도로 하는 템플릿 정합법을 이용하여 온-오프 형태 DNA칩의 탐색자를 구분하는 방법을 제안한다. 또한, 스팟 템플릿의 다양한 위치나 크기에 따른 응답의 최대값을 찾는 최대 응답 탐색법을 제안한다. 각 스팟의 교잡반응 여부만을 분류하는 온-오프 형태의 DNA 칩의 탐색자를 구분하는 용도에 제안된 방법을 적용하였다 2390명의 환자에 대한 인유두종 바이러스 DNA 칩 검사에 적용하여, 카운팅 정합도를 기존의 정규상관도나 메디안과 비교하였다. 카운팅 정합도가 최대 응답 탐색법에 관계없이 최고의 성능을 보였다. 실험결과 위치탐색을 결합한 카운팅 정합도가 가장 적절하였다. This paper proposes a nonlinear template matching measure, called counting measure, as a signal detection measure that is defined as the number of on pixels in the spot area. It is applied to classify probes for an on-off type DNA chip, where each probe spot is classified as hybridized or not. The counting measure also incorporates the maximum response search method, where the expected signal is obtained by taking the maximum among the measured responses of the various positions and sizes of the spot template. The counting measure was compared to existing signal detection measures such as the normalized correlation and the median for 2390 patient samples tested on the human papiliomavirus (HPV) DNA chip. The counting measure performed the best regardless of whether or not the maximum response search method was used. The experimental results showed that the counting measure combined with the positional search was the most preferable.

Queueing systems fed by many exponential on-off sources: an infinite-intersection approach

In queueing theory, an important class of events can be written as `infinite intersections'. For instance, in a queue with constant service rate c, busy periods starting at 0 and exceeding L > 0 are determined by the intersection of the events $$\bigcap_{t\in[0,L]}\{Q_0=0,\;A_t > ct\}$$ , i.e., queue Q t is empty at 0 and for all t? [0, L] the amount of traffic A t arriving in [0,t) exceeds the server capacity. Also the event of exceeding some predefined threshold in a tandem queue, or a priority queue, can be written in terms of this kind of infinite intersections. This paper studies the probability of such infinite intersections in queueing systems fed by a large number n of i.i.d. traffic sources (the so-called `many-sources regime'). If the sources are of the exponential on-off type, and the queueing resources are scaled proportional to n, the probabilities under consideration decay exponentially; we explicitly characterize the corresponding decay rate. The techniques used stem from large deviations theory (particularly sample-path large deviations).

Induced pulsing in trickle beds — Particle shape and size effects on pulse characteristics

Periodic liquid feeding of the ON–OFF type is investigated — at sufficiently high frequencies to be classified as “fast” mode of induced pulsing — in the range of mean gas and liquid flow rates corresponding to the steady “trickling flow” regime. Two of the most common types of catalyst-support particles, i.e. porous spherical and cylindrical extrudates, are employed to study the imposed pulse characteristics. Detailed information is obtained, on the axial propagation and attenuation of pulses, from instantaneous, cross-sectionally averaged holdup measurements. Key fluid-mechanical parameters studied include, aside from dynamic holdup and pressure drop, pulse celerity and intensity, as a function of fluid feed rates ( G , L ) and liquid cyclic frequency. Similar published data, for 6 mm glass spheres, are employed for comparison; it is shown that, for the particles examined, particle size has a pronounced effect, but not as significant as that of particle shape. For particles of comparable size, the cylindrical shape is associated with much greater global dynamic holdup and pressure drop, and with increased pulse attenuation. Moreover, packed extrudates exhibit a significant increase of holdup in the axial direction, recently also observed in steady trickling flow. For spherical particles, both time-average holdup and pulse celerity are practically constant along the bed for fixed L , G . Pressure drop, global holdup and pulse celerity are not affected by cyclic liquid feeding frequency, for both spherical and cylindrical extrudate particles. Based on the pulse attenuation characteristics, for the three particle types examined, recommendations are made on preferred conditions for induced pulsing (from the fluid dynamics point of view) which would maximize benefits. Overall, it appears that spherical packings hold significant advantages over cylindrical extrudates of comparable size. Finally, in view of the observed significant decay of imposed pulses along the bed, care should be exercised to properly interpret data obtained in short laboratory reactors (where pulse attenuation is limited) for scale-up of the much longer industrial beds.

Mechanical Means of Enhancing Drying Rates: Effect on Drying Kinetics and Quality

ABSTRACT The effect of various pretreatments on drying kinetics as well as quality parameters of selected vegetables and fruits was studied experimentally in a convective dryer. The pretreatments tested include application of pinholes and drilled holes of different diameters and densities, blanching and freezing. Potato, cassava, dragon fruit and red chilli were used as the sample drying materials. As expected, increase of the diameter and density of the holes under fixed drying conditions increased the drying rate. Samples with drilled holes showed better drying performance than those with pinholes. The improvement of the drying rate was found to be dependent on the physical properties and the initial moisture content of the material. Results show that the drying performance of the products that possess a skin of low moisture diffusivity, such as chilli, can be improved significantly by blanching and making perforations in the skin. Overall changes of color and volume shrinkage during drying of the samples with and without holes were similar. The effect of different modes of heat input, such as convection, conduction and radiation, on the drying performance of the treated samples was also experimentally investigated. On-off type controllers were used to regulate the power of the heaters and maintain the product temperature within a range of pre-set values. Convection combined with radiation displayed the highest drying rate.

Probe classification of on-off type DNA microarray images with a nonlinear matching measure

We propose a nonlinear matching measure, called counting measure, as a signal detection measure that is defined as the number of on pixels in the spot area. It is applied to classify probes for an on-off type DNA microarray, where each probe spot is classified as hybridized or not. The counting measure also incorporates the maximum response search method, where the expected signal is obtained by taking the maximum among the measured responses of the various positions and sizes of the spot template. The counting measure was compared to existing signal detection measures such as the normalized covariance and the median for 2390 patient samples tested on the human papillomavirus (HPV) DNA chip. The counting measure performed the best regardless of whether or not the maximum response search method was used. The experimental results showed that the counting measure combined with the positional search was the most preferable.

Effective squeezing enhancement via measurement-induced non-Gaussian operation and its application to the dense coding scheme

We study the measurement-induced non-Gaussian operation on the single- and two-mode \textit{Gaussian} squeezed vacuum states with beam splitters and on-off type photon detectors, with which \textit{mixed non-Gaussian} states are generally obtained in the conditional process. It is known that the entanglement can be enhanced via this non-Gaussian operation on the two-mode squeezed vacuum state. We show that, in the range of practical squeezing parameters, the conditional outputs are still close to Gaussian states, but their second order variances of quantum fluctuations and correlations are effectively suppressed and enhanced, respectively. To investigate an operational meaning of these states, especially entangled states, we also evaluate the quantum dense coding scheme from the viewpoint of the mutual information, and we show that non-Gaussian entangled state can be advantageous compared with the original two-mode squeezed state.