• 제목/요약/키워드: Binary Systems

검색결과 1,167건 처리시간 0.032초

A Search for Exoplanets in Short-Period Binary Star Systems

  • Kaitchuck, Ronald;Turner, Garrison;Childers, Joseph
    • Journal of Astronomy and Space Sciences
    • /
    • 제29권1호
    • /
    • pp.41-45
    • /
    • 2012
  • This paper reports the progress of a search for exoplanets with S-type orbits in short-period binary star systems. The selected targets have stellar orbital periods of just a few days. These systems are eclipsing binaries so that exoplanet transits, if planets exist, will be highly likely. We report the results for seven binary star systems.

AN APPLICATION OF BINARY SOFT MAPPINGS TO THE PROBLEM IN MEDICAL EXPERT SYSTEMS

  • HUSSAIN, SABIR;ALKHALIFAH, MASHAEL M.A.
    • Journal of applied mathematics & informatics
    • /
    • 제38권5_6호
    • /
    • pp.533-545
    • /
    • 2020
  • We initiate and introduce the notion of binary soft mapping, which is defined on collection of binary soft sets named as binary soft class over two initial universes U1 and U2 with fixed set of parameters. We also define and study the properties of binary soft images and binary soft inverse images of binary soft sets. Examples and counter examples are also given in support of presented properties. Moreover, these concepts are applied to the problem of medical diagnosis in medical expert systems.

Formation of short-period black hole binary systems from Population III stars as grativational wave radiation sources

  • Lee, Hunchul;Yoon, Sung-Chul
    • 천문학회보
    • /
    • 제42권1호
    • /
    • pp.59.1-59.1
    • /
    • 2017
  • Massive Population III black hole binary systems are one of the suggested candidate sources of the recently detected gravitational wave radiation (GWR). GWR detection from a black hole binary system requires a sufficiently short orbital separation at the time of their formation, such that they would undergo coalescence within the Hubble time. This condition cannot be simply fulfilled by a short initial period, because binary interactions such as mass transfer and common envelope evolution can largely change the orbital parameters and the masses of stellar components. Here, we discuss the possibility of black hole binary mergers from massive Pop III binary systems, using a new grid of Pop III binary evolutionary models with various initial primary masses ($20M_{\odot}{\leq}M{\leq}100M_{\odot}$) and initial separations, for different initial mass ratios (q = 0.5 - 0.9).

  • PDF

Binary CDMA Pico-Cell 네트워크간의 데이터 중계를 위한 무선 라우터에 대한 연구 (Research on Wireless Router for Data Relay between Binary CDMA Pico-Cell Networks)

  • 박종범
    • 한국ITS학회 논문지
    • /
    • 제10권4호
    • /
    • pp.116-124
    • /
    • 2011
  • Binary CDMA네트워크에서는 네트워크 각 엔터티들의 네트워크 자원을 마스터 스테이션이 관리하므로 마스터 스테이션의 관리 범위한계를 경계로 하는 Pico-net내에서만 통신이 이루어질 수 있다. 본 연구에서는 이러한 제한을 극복하여 보다 광역적인 네트워크에 Binary CDMA를 응용할 수 있는 방안으로서 네트워크를 Cell단위로 분할하여 다중의 Pico-net들로 구분하고 각 Pico-Cell에 고유의 네트워크 주소체계를 만들어 Pico-Cell간에 데이터를 중계하는 기능을 가지는 Binary CDMA 라우터 장치의 고안방법에 대하여 제시하였다.

Binary Cure Systems of 1,6-Bis(N,N'-dibenzylthiocarbamoyldithio)-hexane and Benzothiazole Sulfenamides in Carbon Black-filled Natural Rubber Compounds

  • Choi, Sung-Seen;Park, Byung-Ho;Lee, Seung-Goo;Kim, Beom-Tae
    • Bulletin of the Korean Chemical Society
    • /
    • 제23권2호
    • /
    • pp.320-324
    • /
    • 2002
  • Binary cure system is composed of different two cure accelerators, which can cause a synergy effect to delay the scorch time and to increase the cure rate. In this study, binary cure systems between 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)-hexane (DBTH) and benzothiazole sulfenamides were investigated using carbon black-filled natural rubber compounds. N-Cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazole sulfenamide (TBBS), and 2-(morpholinothio) benzothiazole (MOR) were employed as benzothiazole sulfenamides. The binary cure systems show scorch safty at high temperature. The binary cure systems have faster cure rate and better reversion resistance than the single cure system of the benzothiazole sulfenamides. DBTH is found to be more effective to decrease the viscosity of a compound than the benzothiazole sulfenamides. Physical properties of the vulcanizates with the binary cure system are better than those of the vulcanizates with the single one.

Type Ibc Supernova Progenitors in Binary Systems: Observational Constraints on the Progenitor Candidate of the Supernova iPTF13bvn

  • Kim, Hyun-Jeong;Yoon, Sung-Chul;Koo, Bon-Chul
    • 천문학회보
    • /
    • 제39권2호
    • /
    • pp.85.1-85.1
    • /
    • 2014
  • The progenitors of Type Ibc supernovae (SNe Ibc) have been believed to be massive Wolf-Rayet (WR) stars, formed either through stellar wind mass loss or Roche-lobe outflow in a binary system. But observations indicate that ordinary SNe Ibc have relatively low ejecta masses (~2 Msun), which is not compatible with the WR star scenario for SN Ibc progenitors. On the other hand, helium stars in binary systems which can be produced via mass transfer are also suggested as a possible candidate for SN Ibc progenitors. Binary star evolution models predict that SN Ibc progenitors having final masses of 3-7 Msun can be produced, but their observational properties are not well understood. In this study, we present the parameter study on the observational constraints of helium stars of 3-5 Msun in binary systems using evolutionary models and the atmospheric radiative transfer code CMFGEN. We present the predicted magnitudes and spectra of helium stars in optical bands for different wind velocity profiles and mass loss rates. We also present those observables of the progenitor binary system considering O-type companion stars. Based on the results, we discuss the expected observational properties of SN Ibc progenitors in binary systems. In particular, we discuss the constraints on the progenitor of the SN Ib iPTF13bvn of which progenitor candidate has been identified for the first time in pre-explosion images among SNe Ibc.

  • PDF

PERIOD VARIATION OF EROS ECLIPSING BINARY SYSTEMS IN THE LARGE MAGELLAN CLOUD

  • RITTIPRUK, P.;HONG, K.S.;KANG, Y.W.
    • 천문학논총
    • /
    • 제30권2호
    • /
    • pp.211-214
    • /
    • 2015
  • We investigated the period variation for 79 eclipsing binary systems using 20 years (1990-2009) of EROS, Macho, and OGLE survey observations. We discovered 9 apsidal motions, 8 mass transfers, 5 period increasing and decreasing systems, 12 light-travel-time effects, 5 eccentric systems and 40 other systems showing no period variations. We select 3 representative eclipsing binary systems; EROS 1052 for apsidal motion, EROS 1056 for mass transfer, and EROS 1037 for the light-travel-time effect. We determine the period variation rate (dP/dt), orbital parameters of the 3rd body (e3, ${\omega}_3$, $f(m_3)$, $P_3$, $T_3$), apsidal motion parameters ($d{\omega}/dt$, U, Ps, Pa, e) and apsidal motion period by analyzing the light curves and O-C diagrams.

Physiochemical Properties of Binary Pluronic Systems for Reversal of Multi-drug Resistant (MDR) Cancers

  • Yun, Jung-Min;Park, Ga-Young;Kim, Ha-Hyung;Lee, Jae-Hwi;Lee, Eun-Seong;Youn, Yu-Seok;Lee, Beom-Jin;Oh, Young-Taik;Oh, Kyung-Taek
    • Journal of Pharmaceutical Investigation
    • /
    • 제40권4호
    • /
    • pp.255-261
    • /
    • 2010
  • Pluronic as pharmaceutical excipients are listed in the US and British Pharmacopoeia. In particular, Pluronics exist as different compositions and display abundant phases as self-assembling into polymeric micelles with various morphologies depending on the aqueous solvent quality, the composition of structure, and hydrophilic-lipophilic balance (HLB). Pluronics were also known as a P-gp modulator, which was exploited as a reversal molecule of multi-drug resistant (MDR) cancers. We selected a lamella forming Pluronic L92 which has high hydrophobicity and relatively long PEO block among L series of Pluronics. The dispersion of L92 showed great size particles and low stability. To increase the stability and to decrease the particle size, secondary Pluronics (F68, F88, F98, F127, P85, P105, and P123) with relatively long PEO chain were added into 0.1 wt% Pluronic L92 dispersion. The stability of binary systems was increased due to incorporated long PEO chain. Their particle sizes slightly decreased to over 200~400 nm and their solubilization capacity of binary systems didn't change except Pluronic L92/P123 mixtures. The L92/P123 systems showed ca. 100 nm sizes and lowest turbidity among the all systems. The solubilization capacity of 0.1 wt% L92/0.1 wt% P123 was slightly increased compared to 0.1 wt% L92 mono system and other binary systems. These nano-sized binary systems may have potential as alternative drug delivery systems with simple preparation method and overcome the drawbacks of mono systems such as low stability and loading capacity.

AETLA를 이용한 이진 신경회로망의 최적 합성방법 (Optimal Method for Binary Neural Network using AETLA)

  • 성상규;정종원;이준탁
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 2001년도 춘계학술대회 학술발표 논문집
    • /
    • pp.105-108
    • /
    • 2001
  • In this paper, the learning algorithm called advanced expanded and truncate algorithm(AETLA) is proposed to training multilayer binary neural network to approximate binary to binary mapping. AETLA used merit of ETL and MTGA learning algorithm. We proposed to new learning algorithm to decrease number of hidden layer. Therefore, learning speed of the proposed AETLA learning algorithm is much faster than other learning algorithm.

  • PDF

Investigating Exoplanet Orbital Evolution Around Binary Star Systems with Mass Loss

  • Rahoma, Walid A.
    • Journal of Astronomy and Space Sciences
    • /
    • 제33권4호
    • /
    • pp.257-264
    • /
    • 2016
  • A planet revolving around binary star system is a familiar system. Studies of these systems are important because they provide precise knowledge of planet formation and orbit evolution. In this study, a method to determine the evolution of an exoplanet revolving around a binary star system using different rates of stellar mass loss will be introduced. Using a hierarchical triple body system, in which the outer body can be moved with the center of mass of the inner binary star as a two-body problem, the long period evolution of the exoplanet orbit is determined depending on a Hamiltonian formulation. The model is simulated by numerical integrations of the Hamiltonian equations for the system over a long time. As a conclusion, the behavior of the planet orbital elements is quite affected by the rate of the mass loss from the accompanying binary star.