Straight Region Research Articles

A Study on the Determinants of Housing Price Using Data Mining

This study empirically analyzed the determinants of housing price using decision tree analysis, multiple regression analysis, and neural network analysis. The dependent variables are apartment real transaction price, independent variables are apartment size, apartment floor, construction year, city hall straight distance, 2 lane straight distance, 4 lane straight distance, subway station straight distance, Gangnam area, Gangseo area, urban area and Gangbuk area. As a result, the mean absolute error (MAE) of the neural network analysis is the smallest, and the linear correlation value shows the highest correlation between the real and predicted values. According to the decision tree analysis, the small size is divided into 70m2 instead of 59m2 , so it can be seen that the small and medium area is popular because 2-3 person households are popular. As a result of multiple regression analysis, apartment size, number of floors, 2 lane straight distance, and 4 lane straight distance were positively affected by housing price, while city hall straight distance, subway station straight distance, population density and region from Gangnam area to Gangseo area, Gangbuk area and urban area were negative.

Impact of Entanglement Density on Solution Electrospinning: A Phenomenological Model for Fiber Diameter

The rheological properties of poly(N-isopropylacrylamide, PNIPAM) in dimethylformamide solvent were investigated and correlated with solution electrospinnability. The jet diameter was measured by using the light scattering technique during the electrospinning in the straight jet region prior to the jet whipping. The diameter of the straight jet end is independent of the solution concentration (or viscosity within the range of 15–2000 mPa·s). Thus, the final fiber diameter df observed on the grounded collector is dominantly controlled by the jet-whipping process. According to the present PNIPAM solution and other different polymer solutions, df is correlated with the solution concentration ϕ. A master curve is constructed by using the following equation: df/df,e = (ϕ/ϕe)2.5, where df,e is the diameter of the fibers electrospun from the solutions with an entanglement concentration of ϕe, above which the specific viscosity starts to increase with ϕ according to ϕ3.7 or ϕ4.7, depending upon the given polymer/...

Smooth and flat phase-locked Kerr frequency comb generation by higher order mode suppression.

High-Q microresonator is perceived as a promising platform for optical frequency comb generation, via dissipative soliton formation. In order to achieve a higher quality factor and obtain the necessary anomalous dispersion, multi-mode waveguides were previously implemented in Si3N4 microresonators. However, coupling between different transverse mode families in multi-mode waveguides results in periodic disruption of dispersion and quality factor, and consequently causes perturbation to dissipative soliton formation and amplitude modulation to the corresponding spectrum. Careful choice of pump wavelength to avoid the mode crossing region is thus critical in conventional Si3N4 microresonators. Here, we report a novel design of Si3N4 microresonator in which single-mode operation, high quality factor, and anomalous dispersion are attained simultaneously. The novel microresonator is consisted of uniform single-mode waveguides in the semi-circle region, to eliminate bending induced mode coupling, and adiabatically tapered waveguides in the straight region, to avoid excitation of higher order modes. The intrinsic quality factor of the microresonator reaches 1.36 × 106 while the group velocity dispersion remains to be anomalous at −50 fs2/mm. With this novel microresonator, we demonstrate that broadband phase-locked Kerr frequency combs with flat and smooth spectra can be generated by pumping at any resonances in the optical C-band.

Fast Computing of Conformal Mapping and Its Inverse of Bounded Multiply Connected Regions onto Second, Third and Fourth Categories of Koebe’s Canonical Slit Regions

This paper presents a boundary integral method with the adjoint generalized Neumann kernel for conformal mapping of a bounded multiply connected region onto a disk with spiral slits region $$\varOmega _1$$Ω1. This extends the methods that have recently been given for mappings onto annulus with spiral slits region $$\varOmega _2$$Ω2, spiral slits region $$\varOmega _3$$Ω3, and straight slits region $$\varOmega _4$$Ω4 but with different right-hand sides. This paper also presents a fast implementation of the boundary integral equation method for computing numerical conformal mapping of bounded multiply connected region onto all four regions $$\varOmega _1$$Ω1, $$\varOmega _2$$Ω2, $$\varOmega _3$$Ω3, and $$\varOmega _4$$Ω4 as well as their inverses. The integral equations are solved numerically using combination of Nystrom method, GMRES method, and fast multipole method (FMM). The complexity of this new algorithm is $$O((m + 1)n)$$O((m+1)n), where $$m+1$$m+1 is the multiplicity of the multiply connected region and n is the number of nodes on each boundary component. Previous algorithms require $$O((m+1)^3 n^3)$$O((m+1)3n3) operations. The algorithm is tested on several test regions with complex geometries and high connectivities. The numerical results illustrate the efficiency of the proposed method.

Radial InP/InAsP/InP heterostructure nanowires on patterned Si substrates using self-catalyzed growth for vertical-type optical devices

Radial InP/InAsP/InP heterostructure nanowires (NWs) on SiO2-mask-pattered Si substrates were reported using self-catalyzed InP NWs. Self-catalyzed growth was performed using low growth temperatures and high group-III flow rates, and vertical InP NWs were formed on the mask openings. The diameter and tapering of the self-catalyzed InP NWs were controlled by the introduction of HCl and H2S gases during the NW growth, and InP NWs that have a straight region with decreased diameter were formed. Radial InP/InAsP/InP quantum wells (QWs) were grown on the sidewall of the vertical InP NWs on Si substrates. Room-temperature photoluminescence of single NWs from the QW was clearly observed, which exhibited the potential of building blocks for vertical-type optical devices on Si substrates.

Development of secondary flows in viscoelastic curved ducts and the influence of outlet region

This paper presents numerical simulations of Newtonian and viscoelastic flows through a 180° curved duct of square cross section with a long straight outlet region. A particular attention is paid to the development of the flow in the output rectangular region after the curved part. The viscoelastic fluid is modeled using the constitutive equation proposed by Phan–Thien–Tanner (PTT). The numerical results, obtained with a finite-volume method, are shown for three different Dean numbers (125,137,150) and for three Deborah numbers (0.1,0.2,0.3). The necessary outlet length to impose boundary conditions is presented and discussed for these cases. Streamlines and vortex formation are shown to illustrate and analyze the evolution of the secondary flow in this region.

Straight slits map and its inverse of bounded multiply connected regions

This paper presents a boundary integral equation method for computing numerical conformal mapping of bounded multiply connected region onto a straight slits region. The method is an extension of the author's method for computing the parallel slits map of bounded multiply connected regions (Sangawi et al., J. Math. Anal. Appl. 389, 1280---1290 (2012)). Several numerical examples are given to prove the effectiveness of the proposed methods.

In vitro determination of the 30 nm chromatin fiber structure (564.1)

To be able to fit 6 ft. of human DNA into a cell’s nucleus, an elaborate organizational system is necessary to compact the genomic DNA first into nucleosomes, and then into a 30 nm chromatin fiber. The ability to figure out the spatial conformation between these nucleosomes is vital in understanding gene regulation of underlying DNA. Literature data support two different models of the chromatin fiber that differ in their geometry and possible impact on the accessibility of the underlying DNA sequence. The “zig‐zag” model uses a straight linker DNA region, while the “solenoid” model illustrates a bent DNA linker, greatly influencing which nucleosomes are in close space in relation to one another. However, there is debate about which of these models actually represents the true structure. High resolution in vivo nucleosome maps show that the length of DNA between two nucleosomes is not constant across a genome. Computational studies have shown that changing this linker‐length can drastically change the available compacted structures accessible to an array of nucleosomes. To determine how much the properties of the linker DNA affect chromatin structure, we are developing a quantitative crosslinking assay. In our studies, we use this method to investigate the linker‐length dependence of chromatin structure in synthetic nucleosome arrays. Initial results have shown evidence for both zig‐zag and solenoid models depending on solution conditions.

A non-parametric bubble size correlation for a Two-Section Two-Zone Fluidized Bed Reactor (TS-TZFBR)

The Two-Zone Fluidized Bed Reactor (TZFBR) provides a high level of process integration, allowing heterogeneous catalytic reaction and simultaneous catalyst regeneration in two different zones of a single fluidized bed. This work considers a new reactor design that incorporates a different cross-sectional area in each zone to allow low flow rates in the regeneration zone. The reactor geometry, e.g. the transition angle α between the two zones in this Two-Section Two-Zone Fluidized Bed Reactor (TS-TZFBR), has a strong effect on the bubbling behavior. The present study focuses on obtaining a bubble size (db) correlation able to predict the experimental hydrodynamic behavior inside this novel TS-TZFBR. Experimental studies have been conducted on acrylic glass pseudo-2D TS-TZFBRs using several particle types and reactor geometries (α). Experimental results validate classical db correlations within the straight region of the reactor. A novel non-parametric bubble size correlation has been developed to predict the bubbling behavior within the tapered bed section, where an additional gas feed is also applied. This non-parametric model agrees with experimental results along the whole TS-TZFBR bed height for a wide range of operational conditions: ugas/umf=1.5–3.5, ugas−umf=5–25cm/s, α=0°–85°, umf=1.2–20.5cm/s.

Reproductive system and spermatozoa ultrastructure support the phylogenetic proximity of Megadasys and Crasiella (Gastrotricha, Macrodasyida)

The reproductive system and the spermatozoon of Megadasys sterreri from Lanzarote (Canary Islands, Spain) were studied at structural and ultrastructural levels. The species is a simultaneous hermaphrodite with cross-fertilization and shows paired gonads, the male anterior and the female posterior, and both gametes mature in a caudo-cephalic direction. Sperm ducts converge on the midline and open into a ventral common pore. Two sexual accessory organs are present in the caudal trunk. A pipe-like frontal organ lies between the ovaries and the caudal organ, and is composed of a long, thin region connected to a large zone containing mature and degenerating spermatozoa. The cigar-like caudal organ is elongate, bulky and is made of an anterior glandulo-muscular region and a posterior muscular one. Spermatozoa are long, filiform cells formed by an acrosome, a nucleus-mitochondrial complex, and a flagellum. The long acrosome is composed of an apical twisted region and a basal straight region. The nucleo-mitochondrial complex is formed by a spring-shaped nucleus surrounding basally the mitochondrion and apically a granular material. The flagellum has a 9x2+2 axoneme, characterized by a dense and prominent central sheath surrounding the central tubules. Megadasys sterreri (Cephalodasyidae) shows the same reproductive layout as Crasiella (Planodasyidae): paired gonads, caudo-cephalic maturation of gametes, sperm ducts converging into a common ventral pore, and two sexual accessory organs. Also the spermatozoa ultrastructure shows two similarities in the two genera: a peculiar prominent central sheath in the axoneme and a similar structure of the basal region of the acrosome. Considering the likely polyphyletic nature of the family Cephalodasyidae, and the sister- taxon relationship of Megadasys and Crasiella that emerged from a recent molecular phylogenetic study, a close relationship between the two taxa appears to be very likely; consequently, we propose to remove Megadasys from the family Cephalodasyidae and affiliate it to the family Planodasyidae.

Damage Characteristics of Cracked TMT Reinforcement Bars

Thermo-mechanically treated (TMT) bars have rapidly replaced the conventional High Yield Stress Deformed (HYSD) bars in RCC constructions. Due to the heat treatment on TMT bars, the surface toughness of such bars gets altered. Crack initiation and propagation characteristics of such bars vary significantly from that of conventional HYSD bars. Micro-cracks usually develop in bars at bend regions or may be appearing in straight region due to accidental overloads. Prominent cracks may develop due to the 90o bends at various locations, for example at beam ends. These cracks reduce the load carrying capacity and may lead to failure at stress levels much below the yield stress. Moreover, the surface cracks at bends are larger in bars with diameters over 16 mm, amplifying their effect on the bars. Hence, it becomes imperative to study the failure characteristics of TMT bars and understand the progression of damage or cracks in the bars once the surface region has been already damaged.

Mode coupling and field distribution in sub-mm permanently bent single mode optical fibers

A simple mechanism useful to tailor the field profile in single mode optical fibers is proposed. It involves the local and permanent bend of the fiber with bending radius of few hundred micrometers. The permanent bend is obtained by local thermal treatment using the electric arc discharge method. The resultant sub-mm bend leads to a significant power coupling from the fundamental core mode to guided cladding modes. The order and number of the excited cladding modes depend on the geometrical features of the bent region, like angle and curvature rate. Also, since the light propagated by guided cladding modes interacts with the surrounding medium by evanescent wave, the field distribution can be additionally tailored by changing the refractive index of the medium surrounding the straight fiber region after the permanent bend. Here, the effects of permanent bend on the guided mode in single mode fiber is first theoretically introduced and then widely experimentally investigated. Finally, preliminary results of light re-coupling from excited cladding modes to the core mode using long period fiber gratings are reported opening new avenues for light manipulation within optical fibers.

Design of a transverse electric–pass/transverse magnetic–splitting three-guide directional coupler composed of two slot waveguides and one silicon wire

A three-guide directional coupler composed of two slot waveguides and one silicon wire with a function of transverse electric (TE)-pass/transverse magnetic (TM)-splitting is proposed and designed using a modified 3-D full-vectorial beam propagation method. In our design, quasi-TE modes fed in the middle silicon wire pass through without coupling, whereas quasi-TM modes fed in the same channel are evenly split into the outer slot waveguides. With properly chosen parameters, a TE-pass/TM-splitting directional coupler with a length of 22.6 μm, including the straight coupling region and the S-bends, is achieved with the crosstalk of −31 and −35 dB for quasi-TE and quasi-TM modes, respectively. In addition, the tolerances to the structural parameters and operating wavelength are also investigated in detail.

Design of LD1, a Large-Aperture High-Field ${\rm Nb}_{3}{\rm Sn}$ Dipole Magnet

In order to continue supporting the development of accelerator magnets for the next generation of particle colliders, the LBNL Superconducting Magnet Program has started the design and fabrication of the Large-aperture Dipole LD1. The goal of the magnet is to generate a dipole field of 13 T to 15 T in a clear aperture of 144 mm × 94 mm, enabling high-field tests of Rutherford cables and insert coils made of or high temperature superconductors (HTS), like Bi-2212, YBCO, and Bi-2223. The bore size will also accommodate large Cable-In-Conduit Conductors (CICC's), including ITER cables. We describe in this paper the design of LD1, in particular cable geometry, coil lay-out and support structure. Operational conditions based on strand measurements will be discussed, focusing on coil peak fields in straight section and end region, bore field homogeneity, and stress on the conductor during assembly, cool-down and excitation.

Experimental investigation of wavelength-selective optical feedback for a high-power quantum dot superluminescent device with two-section structure

In this work, a high-power and broadband quantum dot superluminescent diode (QD-SLD) is achieved by using a two-section structure. The QD-SLD device consists of a tapered titled ridge waveguide section supplying for high optical gain and a straight titled ridge waveguide section to tune optical feedback from the rear facet of the device. The key point of our design is to achieve the wavelength-selective optical feedback to the emission of the QDs' ground state (GS) and 1st excited state (ES) by tuning the current densities injected in the straight titled section. With GS-dominant optical feedback under proper current-injection of the straight titled region, a high output power of 338 mW and a broad bandwidth of 65 nm is obtained simultaneously by the contribution associated to the QDs' GS and 1st ES emission.

OS0315 純マグネシウム中に導入される変形双晶の原子構造

In order to clarify the atomic structure of deformation twin boundary in pure magnesium, 99.9 % purity magnesium single crystal was prepared by modified Bridgeman technique. Thin foils were thinned by a mechanical polishing, a mechanical gliding and ion-beam thinning. The microstructure and the atomic structure of the twin boundary of magnesium were observed by transmission electron microscopy (TEM) and high resolution TEM. In this study, all of the observed twins were lenticular {1012} twins with curved and straight regions. In both regions, it was found that these twin boundaries consisted of the symmetric tilt boundary planes and the (0001) faceted planes. The atomic structure of symmetric tilt boundary plane on these twins corresponded to the calculated atomic structure of {1012} twin boundary. It was also found that the curved region was a step-like structure and the straight region was a zig-zag structure.

Analytic Approximate Solutions for MHD Boundary‐Layer Viscoelastic Fluid Flow over Continuously Moving Stretching Surface by Homotopy Analysis Method with Two Auxiliary Parameters

In this study, a steady, incompressible, and laminar‐free convective flow of a two‐dimensional electrically conducting viscoelastic fluid over a moving stretching surface through a porous medium is considered. The boundary‐layer equations are derived by considering Boussinesq and boundary‐layer approximations. The nonlinear ordinary differential equations for the momentum and energy equations are obtained and solved analytically by using homotopy analysis method (HAM) with two auxiliary parameters for two classes of visco‐elastic fluid (Walters’ liquid B and second‐grade fluid). It is clear that by the use of second auxiliary parameter, the straight line region in ℏ‐curve increases and the convergence accelerates. This research is performed by considering two different boundary conditions: (a) prescribed surface temperature (PST) and (b) prescribed heat flux (PHF). The effect of involved parameters on velocity and temperature is investigated.

Structure and Mutagenesis of the Parainfluenza Virus 5 Hemagglutinin-Neuraminidase Stalk Domain Reveals a Four-Helix Bundle and the Role of the Stalk in Fusion Promotion

Paramyxovirus entry into cells requires the fusion protein (F) and a receptor binding protein (hemagglutinin-neuraminidase [HN], H, or G). The multifunctional HN protein of some paramyxoviruses, besides functioning as the receptor (sialic acid) binding protein (hemagglutinin activity) and the receptor-destroying protein (neuraminidase activity), enhances F activity, presumably by lowering the activation energy required for F to mediate fusion of viral and cellular membranes. Before or upon receptor binding by the HN globular head, F is believed to interact with the HN stalk. Unfortunately, until recently none of the receptor binding protein crystal structures have shown electron density for the stalk domain. Parainfluenza virus 5 (PIV5) HN exists as a noncovalent dimer-of-dimers on the surface of cells, linked by a single disulfide bond in the stalk. Here we present the crystal structure of the PIV5-HN stalk domain at a resolution of 2.65 Å, revealing a four-helix bundle (4HB) with an upper (N-terminal) straight region and a lower (C-terminal) supercoiled part. The hydrophobic core residues are a mix of an 11-mer repeat and a 3- to 4-heptad repeat. To functionally characterize the role of the HN stalk in F interactions and fusion, we designed mutants along the PIV5-HN stalk that are N-glycosylated to physically disrupt F-HN interactions. By extensive study of receptor binding, neuraminidase activity, oligomerization, and fusion-promoting functions of the mutant proteins, we found a correlation between the position of the N-glycosylation mutants on the stalk structure and their neuraminidase activities as well as their abilities to promote fusion.

Ultimate tensile strength testing campaign on ITER pre-compression ring mock-ups

ENEA has developed and characterized a high strength glass fibre-epoxy composite as reference material for the manufacture of the two sets of 3 pre-compression rings located at top and bottom of the inner straight leg region of the ITER Toroidal Field (TF) coils. These rings will provide a radial force of about 70 MN/coil at cryogenic temperature pulling the TF coils into contact and reducing toroidal tension in the four outer intercoil structures. The paper describes the ultimate tensile strength (UTS) testing campaign carried out at ENEA Frascati laboratories on six different rings manufactured winding S2 glass fibers on a diameter of 1 m (1/5 of the full scale) by both vacuum pressure epoxy impregnation and filament wet winding techniques. The volumetric glass content was around 70%. The rings were expanded with radial steps of 0.1 mm into a dedicated hydraulic testing machine consisting of 18 radial actuators working in position control with a total capability of 1000 tons. All the mock-ups showed very high tensile strength (1550 MPa is the average of the mean hoop stresses at failure) and a practically constant tensile modulus. The test results are reported and discussed.

EFFECT OF COLD DEFORMATION ON THE CORROSION BEHAVIOUR OF Mn–CONTAINING ALUMINIUM ALLOY TUBE

Aluminium alloys are extensively employed as heat transfer tube materials in heat exchangers.Previous work has focused on the corrosion behaviour of tube materials in brazed heat exchangers.However,very little attention has been devoted to corrosion of tubes in mechanically-expanded heat exchangers despite the observation of some instances of early corrosion failure in bent region of aluminium alloy tube.The effects of cold deformation on the corrosion behaviour of aluminium tube materials have been studied in 0.6 mol/L NaCl and SWAAT solutions by SEM,TEM, potentiodynamic polarizations and immersion test.The results show that high Mn content(0.22%, mass fraction) can experience preferential corrosion and early failure in the bent region,but not for one with a lower Mn content(0.08%).SEM/TEM observations of the microstructure of the alloys show that each alloy has one main type of coarse intermetallic particle.However,TEM observations show that there is a distinct difference in particle morphology between the bent and straight regions of the high Mn alloy tube,the bent region has more nano-scale Mn-rich particles than the straight region, and no such effects are observed on the low Mn alloy.The microelectrochemical polarisation measurements show that the straight region of high Mn has highest pitting potential,but cold deformation can decrease the pitting potential of bent region of high Mn tube,but no such effects on low Mn tube. The immersion test shows that the bent region of high Mn alloy has highest attack;this is associated with precipitation of 20—100 nm Mn-rich particles,which cause increased anodic reactivity as they provide further pit initiation sites and cause solute depletion in the matrix.In addition,the Mn-rich particles are also sites for enhanced cathodic reactivity.The relationship between the microstructure and electrochemical properties of tube materials before and after cold deformation is established.The results indicate Mn can improve the corrosion resistance of aluminium alloy,but the mechanical cold deformation will weaken the effect.