Circular Type Research Articles

The Research and Simulation of a Prey Pursuit Algorithm

General prey pursuit problem used capture strategy between agents in limited grid space. In prey pursuit problem, there are a lot of problems such as occurrence of collision between agents, imperfection capture that can be produced from corner of restricted grid space. But, this causes actuality deficiency problem of experiment environment itself. In this paper, we propose an experiment environment that considers actuality and new capture strategy that using direction vector to solve prey pursuit problem that is typical experiment model of multi agent system. Therefore, we proposed continuous experiment space of grid space of circular type that is environment similar to the actuality world in this paper, and agents in proposed experiment space solved prey pursuit problem through direction vector that uses distance information and direction information between each others. The proposed method could capture prey effectively through using direction vector in new environment, and we solved imperfection capture and agent collision problem that happens in general research.

Computational Methods for Distributed Control of Heterogeneous Cyclic Interconnection Structures

We address the problem of fast system analysis and controller synthesis for heterogeneous subsystems interconnected in a loop. Such distributed systems have state-space realizations with a special matrix structure, which we show to be a generalization of the Sequentially Semi-Separable (SSS) structure employed in recent research on systems interconnected in a Cartesian array. By extending the O(N) structure-preserving SSS arithmetic to the matrices induced by this circular type of interconnection, we introduce a new cyclic SSS matrix structure and arithmetic which leads to fast and efficient procedures for linear computational complexity optimal distributed controller synthesis for arbitrarily heterogeneous subsystems connected in a loop. In the homogeneous case, where all subsystems are identical, the computational complexity reduces to O(1) and an interesting relationship with the infinite case is demonstrated. CSSS matrices can be non-Toeplitz (as compared to circulant matrices), a great expansion of domain, but when restricted to be Toeplitz (and thus circulant), the arithmetic reduces to O(1), a huge cost-savings. The procedures are demonstrated on two computational examples, using a freely available MATLAB toolbox implementation of these algorithms.

Effect of surface roughness on pure squeeze EHL motion of circular contacts

PurposeThe purpose of this paper is to explore the pure squeeze elastohydrodynamic lubrication motion of circular contacts with surface roughness under constant load conditions. The proposed model can reasonably calculate the effects of surface roughness on the transient pressure profiles, film shapes, and normal squeeze velocities during the pure squeeze process.Design/methodology/approachBased on Christensen's stochastic theory, the transient modified Reynolds equation is derived in polar coordinates to consider the effects of surface roughness. The finite difference method and the Gauss‐Seidel iteration method are used to solve the transient modified Reynolds equation, the elasticity deformation equation, load balance equation, and lubricant rheology equations simultaneously.FindingsThe simulation results reveal that the circular type roughness possesses storage oil capacity. Comparatively, the radial type roughness possesses leak oil capacity. Therefore, the film thickness is found with circular type roughness, followed by smooth, and then radial type roughness. In additional, the central dimensionless pressure is found with radial type roughness, followed by smooth, and then circular type roughness.Originality/valueA numerical method for general applications with surface roughness was developed to investigate the pure squeeze action in an isothermal EHL spherical conjunction under constant load conditions, but without asperities contact.

SAFETY AND EFFICACY OF BUTORPHANOL-ACEPROMAZINE-GLYCOPYRROLATE AS PREMEDICANT COMBINATION TO MIDAZOLAM-KETAMINE INDUCTION AND ISOFLURANE MAINTENANCE IN CANINE ORTHOPAEDIC SURGERY

The objective of this study was to evaluate anaesthetic efficacy and safety of BAG (Butorphanol, Acepromazine and Glycopyrrolate) as premedicant to midazolam-ketamine induction and isoflurane maintenance in clinical canine orthopaedic cases. The clinical study was carried out in 18 cases. Dogs were premedicated with intramuscular injection of butorphanol, acepromazine and glycopyrrolate @ 0.2, 0.04 and 0.01 mg/kg b.wt. respectively, mixed in a single syringe. Induction was performed using midazolam – ketamine @ 5mg/kg b.wt. and 0.28 mg/kg b.wt., respectively administered intravenously. Anaesthesia was maintained with isoflurane. The preanaesthetic combination provided moderate to profound sedation. Induction was smooth and satisfactory in all the dogs with ketamine-midazolam and stable maintenance with isoflurane during orthopaedic procedures, viz., intramedullary pinning, limb amputation, setting Ilizarov circular external fixator and type II external fixator. BAG as preanaesthetic to ketamine-midazolam induction and isoflurane maintenance proved safe and effective in orthopaedic surgery in dogs.

A New Approach for Modeling Electro-Osmotic Flow Micro-Cooling Systems

The problem of entropy generation due to heat transfer in an electro-osmotic flow with circular type area section micro-channels for small values of electro-kinetic parameterκα(whereκis the Debye length andais the radius of the micro-channel) is investigated analytically. The momentum and energy conservation equations in cylindrical coordinates for an electro-osmotic flow are derived in non-dimensional form. The momentum equation is solved and velocity distribution in terms of modified Bessel function of the first kind is obtained. An approximation is used for the Bessel function of first kind. Considering the approximate velocity profile, the energy equation including viscous dissipation effects is solved to obtain the temperature distribution in terms of parametric values of the electro-kinetic parameter and the Brinkman number. A uniform surface heat flux boundary condition is considered. The importance of this investigation is development of an engineering simple method of design for electro-osmotic circular micro-electronic cooling systems and possible optimizations of these kinds of flows with respect to the second-law of thermodynamics through the micro-coolers.

Validation of the finite element model of the femur and a novel internal distractible plate system

For distraction osteogenesis, external fixators such as mono or circular type were used popularly. However, there are many reported complications such as infection of pin site, vascular and neurological injury and the discomfort during walking. The purpose of this study is to introduce a novel internal distractible plate system (IDPS) and to validate of the finite element model of the femur and IDPS before clinical application and finite element analysis with multiple biomechanical factors. After validating the finite element model of femur and femur with IDPS using the structural stiffness and strain of cadaveric femur during compression test, biomechanical stability of a novel IDPS was analyzed. Reconstructed finite element models showed similar result comparing with the values of cadaveric test in vitro. Through validation procedures using the finite element model of the intact femur and the 30mmdistracted femur with the IDPS, the material properties and the coefficient of friction of the finite element models for finite element analysis can be understood as reliable. Also, clinical stability of a novel IDPS was confirmed.

Hydration/Dehydration Behavior of Polyalcoholic Compounds Governed by Development of Intramolecular Hydrogen Bonds

Hydration/dehydration behavior of polyalcoholic compounds with a rigid cyclohexane-type aliphatic molecular frame, such as 1,4-cyclohexanediol (ch(OH)2), 1α,3α,5α-cyclohexanetriol (cis-phloroglucitol, ch(OH)3), and cis-1,2,3,5-trans-4,6-cyclohexanehexaol (myo-inositol, ch(OH)6) was investigated using extremely high-frequency dielectric relaxation measurements up to 50 GHz over a temperature range from 10 to 70 °C. The temperature dependencies of hydration numbers per hydroxy group (mOH) in the polyalcoholic compounds were determined. Although the obtained mOH value was ca. 5 in a temperature range lower than 30 °C, it decreased and approached to ca. 3 with increasing temperature for ch(OH)2 and ch(OH)3, in which hydroxy groups hardly form intramolecular hydrogen bonds due to separations between them. This temperature-dependent hydration/dehydration behavior is characteristic of isolated hydroxy groups without intramolecular hydrogen bond formation. On the other hand, a constant mOH value of ca. 1 was observed irrespective of temperature for ch(OH)6. Because all the separations between adjacent hydroxy groups in ch(OH)6 are proper for (circular type) intramolecular hydrogen bond formation, the obtained temperature-independent small mOH value resulted from an inherent feature of intramolecularly hydrogen bonded hydroxy groups.

Two-Phase Flow in Micro-Channel Heat Sink Review Paper

The micro channel heat sink (MCHS) is the most widely used heat sink. It is continuously studied by different researchers and companies who improve the effectiveness and efficiency with which it removes heat from devices. This review paper focuses on two-phase flow in MCHS and includes the mathematical and numerical analysis of the two-phase flow in MCHS. It also provides an overview of the types of MCHS with respect to the arrangement of the fins. These types include rectangular, circular, and other types of MCHS. It includes some applications in which the MCHS is preferably used. In addition to these applications of the MCHS, this review paper includes a brief explanation of the fluids used in the MCHS to increase its effectiveness.

Milled Groove Square Shape Conformal Cooling Channels in Injection Molding Process

In designing molds for injection molding process, it is very difficult to achieve efficient cooling with uniform thermal distribution. To overcome these issues, the uses of conformal cooling channels with the uniform distance between the center of the cooling channels and the mold surfaces have more advantages, offering a better thermal distribution and reducing the cooling time. This article presents Milled Grooved Square Shape (MGSS) conformal cooling channels which have a more effective cooling surface area and are more efficient in cooling compared to circular and other types of cooling channels with similar cross-sections. A case study on front panel housing is investigated, and the possibility of fabricating the conformal cooling channels on hard tooling for injection molding process, which is easier to design, fabricate, and assemble compared to other methods, is presented. The performance designs of straight drilled are compared with two types of MGSS conformal cooling channels by using Autodesk Mold flow Insight (AMI) 2012. The results show that the variations of thermal distributions were improved within 12 to 50%, and cooling time was shortened within 6 to 8%. Thus, the capabilities of MGSS conformal cooling channels should not be underestimated by molding industries.

Dielectric resonator antenna for applications in nanophotonics

Optical nanoantennas, especially of the dipole type, have been theoretically and experimentally demonstrated by many research groups. Likewise, the plasmonic waveguides and optical circuits have experienced significant advances. In radio frequencies and microwaves a category of antenna known as dielectric resonator antenna (DRA), whose radiant element is a dielectric resonator (DR), has been designed for several applications, including satellite and radar systems. In this letter, we explore the possibilities and advantages to design nano DRAs (NDRAs), i. e., DRAs for nanophotonics applications. Numerical demonstrations showing the fundamental antenna parameters for a circular cylindrical NDRA type have been carried out for the short (S), conventional (C), and long (L) bands of the optical communication spectrum.

WIDEBAND DGS CIRCULAR RING MICROSTRIP ANTENNA DESIGN USING FUZZY APPROACH WITH SUPPRESSED CROSS-POLAR RADIATIONS

This paper presents a novel design of a circular ring defected ground structure (DGS) antenna for bandwidth enhancement using fuzzy logic approach. The ground plane of the antenna is defected by introducing circular ring sector type of defect beneath the circular ring patch. The position of the defect in the ground plane to attain the highest return loss and corresponding frequency is determined by using Fuzzy Inference System (FIS). The antenna resonates in X-band showing wideband characteristics with improved gain and reduced cross polar components. The return loss and analogous frequency obtained from simulated results and fuzzy system are compared and are in good agreement. The return loss and input impedance is measured experimentally and compared with the simulated results. Parameters like impedance bandwidth, VSWR and antenna gain are likewise calculated and discussed. The simulated results for the radiation pattern of the proposed design with polarization (Co-polar and Cross- polar) are also presented. The simulated impedance bandwidth of about 1.33GHz (1.2GHz experimentally) in X-band is obtained with a gain of 6.43dB and also cross-polarized radiations have an isolation of 20dB.

レジンコーティングした円弧型GFRC 製クラスプの疲労耐久性

レジンコーティングした円弧型GFRC 製クラスプの疲労耐久性

횡방향 판재에 의한 횡구속 효과 및 철근콘크리트 기둥에서 고강도 철근의 사용성 검토

Dept. of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, KoreaABSTRACT The limitation of the yield strength in reinforced concrete columns is given for the effective use of high-strengthsteel bar, because very high-strength steel bar does not yield while concrete fails in compression. In order to overcome this limita-tion, it is required to increase peak strain of the concrete. The objective of this study is to examine the confinement effect of platetype lateral reinforcement in reinforced concrete columns. From this experimental study, the reinforced concrete columns confinedby plate type carbon fiber sheets showed higher compressive strength and peak concrete strain comparing to the unconfined col-umns. The confinement effect is higher when cross-sectional type is a circular one than a square one. Moreover, the confinementeffect was also higher for circular type confinement. Based on this study, high-strength steel bars with strength exceeding 800MPacan be effectively used for reinforced concrete columns confined by plate type lateral reinforcements.Keywords : confinement effect, carbon fiber sheets (CFS), high-strength steel bar, reinforced concrete (RC) columns

Coordinated road-network search route planning by a team of UAVs

This paper presents a road-network search route planning algorithm by which multiple autonomous vehicles are able to efficiently visit every road identified in the map in the context of the Chinese postman problem. Since the typical Chinese postman algorithm can be applied solely to a connected road-network in which ground vehicles are involved, it is modified to be used for a general type of road map including unconnected roads as well as the operational and physical constraints of unmanned aerial vehicles (UAVs). For this, a multi-choice multi-dimensional knapsack problem is formulated to find an optimal solution minimising flight time and then solved via mixed integer linear programming. To deal with the dynamic constraints of the UAVs, the Dubins theory is used for path generation. In particular, a circular–circular–circular type of the Dubins path is exploited based on a differential geometry to guarantee that the vehicles follow the road precisely in a densely distributed road environment. Moreover, to overcome the computational burden of the multi-choice multi-dimensional knapsack algorithm, a nearest insertion and auction-based approximation algorithm is newly introduced. The properties and performance of the proposed algorithm are evaluated via numerical simulations operating on a real village map and randomly generated maps with different parameters.

Comparative analysis of two impact-sensitive sensors for improved estimation of time difference of arrivals

In this study, an intensive comparative analysis of two impact-sensitive cantilever sensors for improved estimation of time difference of arrivals on plates is presented. Precise locating of the impact point requires exact bending wave propagation velocity due to the impact and time differences between each sensor. However since the bending wave velocity is dispersive on a plate, it is very difficult to decide the velocity when a vibration sensor such as an accelerometer is used. The new sensor philosophy is to provide a more exact bending wave velocity by designing the sensor as a cantilever type with a piezo transducer. Thus in this paper, two different cantilever sensors are considered: a rectangular type with a piezoelectric magnesium niobate — lead titanate single crystal patch and a circular type with a piezoelectric zirconate titanate disc. Their responses against impacts are compared with the response of a commercial accelerometer. The two sensors were manufactured and tested on a glass plate and an MDF plate separately. The impact test results showed that the two sensors give narrow band responses against impacts on the both plates and can provide a constant bending wave propagation velocity.

Behavior of ultrasonic waves in wood with presence of holes

This work aimed to analyze the pattern of variation in wave lengths in presence of wood holes and to develop a model capable of describing the process. To attain that end, wood pieces were used from species pequiá (Aspidosperma desmanthum), on which circular and linear artificial holes were made and gradually enlarged. Ultrasonic tests were performed using USLab equipment and 45 kHz transducers. Measurements were taken first on the intact piece and then after each stage of artificial hole enlargement. Results demonstrated that propagation velocities of ultrasonic waves are affected by presence of holes and also that reduction in velocity is caused by changes in wave path, since waves tend to deviate from empty space and travel through matter. The circular hole type had a slightly stronger influence on velocity reduction than the linear hole type. Variation in velocity as a function of increasing percentage of hollow space relative to the intact piece can be represented by a linear model.

Effects of surface forces and surface roughness on squeeze thin film of elastohydrodynamic lubricated spherical conjunction

ABSTRACTThe pure squeeze thin film elastohydrodynamic lubrication motion of circular contacts with effects of surface forces and surface roughness taken into account is explored under constant load conditions. The coupled transient stochastic Reynolds, elasticity deformation, the load balance, surface forces (hydrodynamic, solvation and van der Waals pressure) and lubricant rheology equations were solved simultaneously by using the finite difference method and the Gauss–Seidel iteration method. The simulation results reveal that the differences between radial type roughness and circular type roughness problems are apparent as the film thickness is thinner than 5 nm. The oscillation phenomena in pressure and film thickness come mainly from the action of solvation forces. The effects of surface forces become significant as the film thickness becomes thinner. The film thickness with circular type roughness is thicker than that with radial type roughness. Copyright © 2012 John Wiley & Sons, Ltd.

Design Consideration of a Circular Type Magnetic Flux Pump Device

As a variation of the thermally actuated flux pump and the linear type magnetic flux pump (LTMFP), the circular type magnetic flux pump (CTMFP) device is proposed to magnetize a circular shape type-II superconducting thin film and bulk. The basic concept is the same as the thermally actuated flux pump: a circularly symmetric traveling magnetic field is generated below a circular shape superconductor to increase its trapping field. However, this traveling field is created by the three phase windings instead of heating gadolinium block. Apart from the LTMFP, the three phase windings are wound concentrically instead of linearly. The speed of the traveling field is controlled by the AC frequency and the magnitude of the field is controlled by the magnitudes of AC currents. In addition, a coil with DC current is wound around the three phase windings to provide a background field. The concept design is presented in this paper. The magnetic waveforms are analysed numerically by the COMSOL 3.5a software. The impedances of the three phase windings are calculated and a corresponding circuit design is presented. This rig can be used as an advanced tool to study the flux pump behavior of a circular shape superconductor.

LTCC 의사 유전체 공진기를 이용한 초소형 전압제어발진기 설계

본 논문에서는 LTCC(Low Temperature Co-fired Ceramics) 공정을 이용하여 다층 구조의 의사 유전체 공진기를 설계하고, 이를 HMIC(Hybrid Microwave Integrated Circuit) 형태의 증폭기, 위상천이기와 함께 폐루프를 구성하여 초소형 전압 제어 의사 유전체 공진기 발진기(Vt-ADRO: Voltage-tuned Artificial Dielectric Resonator Oscillator)를 제작하였다. 의사 유전체 공진기는 주기적인 도체 패턴과 적층을 통해 기존의 유전체 공진기보다 소형의 크기를 갖는 공진기이다. 의사 유전체 공진기의 형상은 기본 도체 패턴 원판형을 갖고 이것을 적층하는 구조를 선정하였으며, 공진기의 물리적 치수 및 적층 수에 따른 공진 특성을 분석하였다. 소형의 크기로 제작하기 위하여 LTCC 기판의 상부에 의사 유전체 공진기를 내장하고, 하부에 증폭기, 위상천이기를 집적하였다. 제작된 의사 유전체 공진기 발진기는 <TEX>$13{\times}13{\times}3mm^3$</TEX>로 초소형이며, SMT(Surface Mount Technology) 형태를 갖는다. 설계된 발진기는 설계 주파수에서 개루프 발진 조건을 만족하였으며, 폐루프 측정 결과, 발진 주파수는 조정 전압 0~5 V에서 2.025~2.108 GHz, 위상 잡음은 100 kHz offset에서 <TEX>$-109{\pm}4$</TEX> dBc/Hz, 출력 전력은 <TEX>$6.8{\pm}0.2$</TEX> dBm을 보이며, PFTN(Power Frequency Tuning Normalized) FOM(Figure Of Merit)은 -30.88 dB를 보인다. In this paper, we present an ultra miniaturized voltage tuned oscillator, with HMIC-type amplifier and phase shifter, using LTCC artificial dielectric resonator. ADR which consists of periodic conductor patterns and stacked layers has a smaller size than a dielectric resonator. The design specification of ADR is obtained from the design goal of oscillator. The structure of the ADR with a stacked circular disk type is chosen. The resonance characteristic, physical dimension and stack number are analyzed. For miniaturization of ADRO, the ADR is internally implemented at the upper part of the LTCC substrate and the other circuits, which are amplifier and phase shifter are integrated at the bottom side respectively. The fabricated ADRO has ultra small size of <TEX>$13{\times}13{\times}3mm^3$</TEX> and is a SMT type. The designed ADRO satisfies the open-loop oscillation condition at the design frequency. As a results, the oscillation frequency range is 2.025~2.108 GHz at a tuning voltage of 0~5 V. The phase noise is <TEX>$-109{\pm}4$</TEX> dBc/Hz at 100 kHz offset frequency and the power is <TEX>$6.8{\pm}0.2$</TEX> dBm. The power frequency tuning normalized figure of merit is -30.88 dB.

Trephination and Intentional Cranial Deformations in Ancient Pre-Columbian Cultures (P04.008)

Objective: The aim of this study is to analyze trephination and intentional cranial (ICD) deformation techniques in ancient pre-Columbian cultures. Background Trephination and ICD are the oldest known surgical techniques developed by some pre-Columbian cultures. ICD is defined as the product of the dynamic distortion of the normal vectors of infantile neurocranial growth through the agency of externally applied forces. Design/Methods: An anthropological field study was performed in the Andean region of South America. Skulls from Inca, Nazca and Paracas Peruvian cultures, Tiwanaku and Cochabamba Bolivian cultures were analyzed. Results: The practice of ICD was performed by the application of either boards or bandages to the infant9s head to change the shape of the growing skull. The circular Aymara type was the most common ICD in the Peruvian and Bolivian Andes. On the coast, the application of boards to the front and back of the head was the preferred deformation method. In pre-Columbian Peru, permission to shape the heads of children was an act of kindness granted by the rulers to some nobles. This practice also had the intention of altering the shape of the head in accordance with certain preconceived ideas of beauty. The earliest trephined skulls in the Americas were found in the burial caves of Paracas, Peru. Craniotomy was performed by abrasion, scraping, crosscut sawing, and drilling. Trephining was initially performed with a triangular knife-like instrument made of obsidian and fixed in a wooden handle. Later, t-shaped tumis were used. The holes outlined a large bone excavation, which was filled with a sheet of silver or gold. Bone reactions around the various trephinations suggest differing durations of long-term survival. Conclusions: The practice of ICD was common and persisted until Spanish colonial period. Success of skull trephination was frequent in spite of rudimentary methods and instruments. Disclosure: Dr. Carod has received personal compensation for activities with Allergan, Inc., Merck Sharp & Dohme Limitd, Lundbeck, Biogen Idec, Esteve, and Pfizer Inc. Dr. Vazquez Cabrera has nothing to disclose.