• 제목/요약/키워드: variant

검색결과 1,941건 처리시간 0.024초

트레일러-트렉터문제에 대한 연구 (An analysis on Trailer and Tractor Problem (TTP))

  • 한윤택;장수영
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회 2006년도 추계학술대회
    • /
    • pp.284-287
    • /
    • 2006
  • We consider the transportation problem of optimizing the use of trailers and tractors. Several variants with fixed loading and unloading time are discussed. We show that the variant requiring on-time delivery can be solved in polynomial time, whereas the other variant requiring time-window delivery is NP-hard. We also discuss that if the number of loading and unloading operations assigned to each trailer or tractor is limited, even the variant requiring on-time delivery becomes NP-hard.

  • PDF

패키지의 주파수 의존형 파워 및 그라운드 평판 모델 (Frequency-Variant Power and Ground Plane Model for Electronic Package)

  • 이동훈;어영선
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 1999년도 하계종합학술대회 논문집
    • /
    • pp.385-388
    • /
    • 1999
  • A new frequency-variant equivalent circuit model of power/ground plane is presented. The equivalent circuit is modeled with grid cells. The circuit parameters of each cell were extracted by using Fasthenry. To verify the developed circuit model, its s-parameters are compared with the measured s-parameters 〔2〕 and the full-wave simulation-based s-parameters. Consequently, it is shown that our frequency-variant equivalent circuit model can accurately predict imperfect ground effects under the high frequency operation of electronic package.

  • PDF

서로 다른 CNC 환경을 갖는 공작기계의 인터넷 기반 점검 (Overview of Internet-based checking for machine tools with a variant CNC environment)

  • 김동훈;김선호;김경돈;김찬봉;고광식
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 2004년도 춘계학술대회 논문집
    • /
    • pp.329-334
    • /
    • 2004
  • This paper proposes Internet-based checking scheme for machine-tools with a variant CNC. Checking points defined in this research are classified into two categories such as structured point and operational point. The formal includes the vibration of bearing, temperature of spindle unit and another periodical management. And the latter includes oil checking, clamp locking/unlocking and machining on/off status. Through this research, for the global management of variant CNC machines interspersed with CAC and OAC in manufacturing system, the suitable environment for Internet-based checking of variant CNC machines was designed and the checking methods for CAC and OAC machines were compared with each other.

  • PDF

전기유압 서보밸브 플랩퍼-노즐에 대한 변동 배유 오리피스의 영향 해석 1 (An Analysis of the Effect of a Variant Drain Orifice Damping on an Electrohydraulic Servovalve Flapper-Nozzle Stage)

  • 이재천
    • 한국정밀공학회지
    • /
    • 제16권2호통권95호
    • /
    • pp.50-59
    • /
    • 1999
  • The effect of a variant drain orifice damping on the characteristics of a servovalve flapper-nozzle stage is analyzed. Steady-state characteristics of flapper-nozzle stage and the linearized dynamics of flapper-nozzle assembly with a spool valve show that the variant drain orifice damping could improve such null performance characteristics as null pressure sensitivity and linearity of gain function. Generalized design criterion and a sufficient condition for servovalve stability are also established.

  • PDF

시간지연을 고려한 ATM 망에서의 체증제어를 위한 $H_{\infty}$ 제어기 설계 (Robust $H_{\infty}$ State Feed back Congestion Contro1 of ATM for lineardiscrete-time systems with Uncertain Time-Variant Delav)

  • 강래청;정우채;김영중;임묘택
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2004년도 하계학술대회 논문집 D
    • /
    • pp.2161-2163
    • /
    • 2004
  • This paper focuses on congestion control for ATM network with uncertain time-variant delays. The time-variant delays can be distinguished into two distinct components. The first one that is represented by time-variant queueing delays in the intermediate switches is occurred in the return paths of RM cells. The next one is a forward path delay. It is solved by the VBR Model which quantifies the data propagation from the sources to the switch. Robust $H_{\infty}$ control is studied for solving congestion problem with norm-bounded time-varying uncertain parameters. The suitable robust $H_{\infty}$ controller is obtained from the solution of a convex optimization problem including terms of LMIs.

  • PDF

Hydrophobic Core Variant Ubiquitin Forms a Molten Globule Conformation at Acidic pH

  • Park, Soon-Ho
    • BMB Reports
    • /
    • 제37권6호
    • /
    • pp.676-683
    • /
    • 2004
  • The conformational properties of hydrophobic core variant ubiquitin (Val26 to Ala mutation) in an acidic solution were studied. The intrinsic tryptophan fluorescence emission spectrum, far-UV and near-UV circular dichroic spectra, the fluorescence emission spectrum of 8-anilinonaphthalene-1-sulfonic acid in the presence of V26A ubiquitin, and urea-induced unfolding measurements indicate this variant ubiquitin to be in the partially folded molten globule conformation in solution at pH 2. The folding kinetics from molten globule to the native state was nearly identical to those from the unfolded state to the native state. This observation suggests that the equilibrium molten globule state of hydrophobic core variant ubiquitin is an on-pathway folding intermediate.

STEP 기반 LCC 분석 데이터구조를 이용한 LCC 분석모듈 개발 (Development of LCCA Module Using STEP-based LCCA Data Structure)

  • 김동현;;김봉근;이상호
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
    • /
    • pp.803-808
    • /
    • 2007
  • LCCA module enabling to estimate LCC and analyze time-variant reliability index of a plate girder bridge was developed. The developed module was based on the designed data structure following the standardized methodology of ISO/STEP, LCCA module consisted of LCC estimation module, which is composed of six sub modules according to the cost category, and reliability index analysis module, which is composed of time-variant corrosion sub module, time-variant live load sub module, and element reliability analysis sub module, The effectiveness of the developed LCCA module was verified by estimating LCC and analyzing time-variant reliability index of a plate girder bridge on the basis of the constructed test database.

  • PDF

Bilateral sternocleidomastoid variant with six distinct insertions along the superior nuchal line

  • Dupont, Graham;Iwanaga, Joe;Altafulla, Juan J.;Lachkar, Stefan;Oskouian, Rod J.;Tubbs, R. Shane
    • Anatomy and Cell Biology
    • /
    • 제51권4호
    • /
    • pp.305-308
    • /
    • 2018
  • Anatomical variations of the sternocleidomastoid muscle (SCM) have been observed to occupy multiple origins and insertion points and have supernumerary heads, sometimes varying in thickness. During routine dissection, a SCM was observed to have six distinct insertions that interface with the course of the superior nuchal line, ending at the midline, bilaterally. This variation was also seen to receive innervation from the accessory nerve as well as the great auricular nerve. To our knowledge, this variant of supernumerary insertions and nerve innervations has not yet been reported. These variants may pose as problematic during surgical approaches to the upper neck and occiput, and should thus be appreciated by the clinician. Herein we discuss the case report, possible embryological origins, and the clinical significance of the observed variant SCM.

떡납줄갱이(Rhodeus notatus)의 Transparent-Scaled Variant Type 출현 보고 (Manifestation of Transparent-Scaled Variant Type in Rhodeus notatus)

  • 박재민;조성장;사공진;유정남
    • 한국수산과학회지
    • /
    • 제55권3호
    • /
    • pp.338-344
    • /
    • 2022
  • This study evaluated the external form of Rhodeus notatus TSV (transparent-scaled variant) type identified in Korea for the first time and compared it with that of the normal type. The TSV units newly found on Rhodeus notatus are iii10 of dorsal fin and anal fin iii10, which are similar to that in the normal type, considering the observing coefficient of each part's fins. The external form is, transparent enough to see the red gill filament in the operculum, the spiral digestive organ is observed opaquely, and numerous melanophores are stained at the upper part of abdomen. The coloration and scales are different between TSV type and normal type; however, there is no difference in the external form and meristic character.