• 한국CDE학회논문집
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• 제17권1호
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• pp.1-6
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• 2012

The End Coupling is main component of the aluminum hot roll process. The End Coupling is used for transmission of rotational power with heavy-duty load. Fracture of the End Coupling cause serious economic losses because an End Coupling is a very expensive component and it takes a long time to repair it. Therefore, preventing the destruction of the End Coupling is essential for ensuring a long mechanical life cycle. In this paper, the parametric study on the End Coupling was performed in order to minimize maximum stress under operation loads. To verify the interference of spindle assembly with modified End Coupling, kinematics simulation was performed by applying the various combination type and dynamic boundary condition of the spindle assembly. The interference of optimized model was not occurred during combination process and driving process. As a result of an optimum design for life extension on End Coupling, the maximum stress of modified End Coupling was lower than that of the initial model by 26%.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.309-315
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• 1996

An analysis is presented on the stability of elastic cantilever column subjected to uniformly distributed follower forces as to the influence of the elastic restraints and a tip mass at the free end. The elastic restraints are formed by both the translational and the rotatory springs. For this purpose, the governing equations and boundary conditions are derived by using Hamilton's principle, and the critical flutter loads and frequencies are obtained from the numerical evaluation of the eigenvalue functions of this elastic system. The added tip mass increases as a whole the critical flutter load in this system, but the presence of its moment of inertia of mass has a destabilizing effect. The existence of the translational and rotatory spring at the free end increases the critical flutter load of the elastic cantilever column. Nevertheless their effects on the critical flutter load are not uniform because of their coupling. The translational spring restraining the end of cantilever column decreases the critical flutter load by coupling with a large value of tip mass, while by coupling with the moment of inertia of tip mass its effect on the critical flutter load is contrary. The rotatory spring restraining the free end of cantilever column increases the critical flutter load by coupling with the tip mass, but decreases it by coupling with the moment of inertia of tip mass.

• 소음진동
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• 제7권1호
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• pp.91-97
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• 1997

An analysis is presented on the stability of an elastic cantilever column having the elastic restraints at its free end, carrying an added tip mass, and subjected to uniformly distributed follower forces. The elastic restraints are formed by both a translational spring and a rotatory spring. For this purpose, the governing equations and boundary conditions are derived by using Hamilton's principle, and the critical flutter loads and frequencies are obtained from the numerical evaluation of the eigenvalue functions of this elastic system. The added tip mass increases as a whole the critical flutter load of the elastic cantilever column, but the presence of its moment of inertia of mass has a destabilizing effect. The existence of the translational and rotatory springs at the free end increases the critical flutter load of the elastic cantilever column. Nevertheless, their effects on the critical flutter load are not uniform because of their coupling. The translational spring restraining the free end of the cantilever column decreases the critical flutter load by coupling with a large value of tip mass, while by coupling with the moment of inertia of tip pass its effect on the critical flutter load is contrary. The rotatory spring restraining the free end of the cantilever column increases the critical flutter load by coupling with the tip mass, but decreases it by coupling with the moment of inertia of the tip mass.

• 대한전자공학회논문지
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• 제16권4호
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• pp.22-26
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• 1979

LED나 laser diode와 optical fiber의 coupling efficiency를 높이기 위해서는 lens의 곡율반경을 작게 하는 것이 효과적이다. 본 연구에서는 heating and pulling 반경에 의한 tapered lens를 고안함으로써 최적 size의 lens 제작을 용이하게 하였으며, taper의 특성을 이용하여 고효율 coupling을 가능하게 하였다. 이론적 계산에 의하여 90%까지의 light coupling이 가능함을 보였으며, 실험결과 flat end에 대한 improvement factor는 LED에서 3dB, laser diode에서 6dB까지 증가시킬 수 있었다. epoxy를 사용하여 LED에 pigital을 부착한 결과 온도특성 및 기계적 안정성에서 실용화에 충분할 정도로 우수하였다.

• 한국전자파학회지:전자파기술
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• 제24권2호
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• pp.35-50
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• 2013

This paper discusses effects of mesh planes on signal integrity in high-speed glass ceramic packages. One of serious signal integrity issues in high-speed glass ceramic packages is high far-end (FE) noise coupling between signal interconnects. Based on signal integrity analysis, a methodology is presented for reducing far-end noise coupling between signal interconnects in high-speed glass ceramic modules. This methodology employing power/ground mesh planes with alternating spacing and a via-connected coplanar-type shield (VCS) structure is suggested to minimize far-end noise coupling between signal lines in high-speed glass ceramic packages. Optimized interconnect structure based on this methodology has demonstrated that the saturated far-end noise coupling of a typical interconnect structure in glass ceramic modules could be reduced significantly by 73.3 %.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.674-680
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• 2005

The top spindle, end coupling and slipper metal are important components of the hot rolling process and are used for transmission of heavy rotational power. In this study, kinematic analysis is conducted using finite element method for hot rolling process under slipper metal combination types and operation situations. The structural analysis is performed by applying the combination type, rotational boundary condition of top spindle, end coupling and slipper metal. This study aims to minimize the mechanical problems which might happen in the production process.

• 전자공학회논문지S
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• 제35S권4호
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• pp.20-29
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• 1998

In this paper, we find the values of near-end crosstalk coefficients in dual-offset stripline of a FR-4 multilayer PCB by an analytic method and a HSPICE simulation method, define calculation errors inananlytic method and the application range, simulate near-end crosstalk coefficients of the FCT(Fast CMOS TTL) in complicated dual-offset stripline by HSPICE and analyze near-end crosstalk and far-end crosstalk coefficients in dual-offset stripline. So, we analyze coupling structure of the near-end crosstalk and far-end crosstalk in the complicated dual-offset striplines that are 1[pF] capacitors termainated, and define a coupling formula of near-end crosstalk and far-end crosstalk coefficients dual-offset striplines.

• 한국생산제조학회지
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• 제22권5호
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• pp.774-781
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• 2013

A structural analysis was carried out for a 60 N.m class flexible disk coupling. Flexible disk couplings are used to transmit power between two shafts. When a flexible coupling is used, some amount of misalignments such as angle of deviation and end play can be allowed in assembling the shafts. However, the maximum allowable misalignment should be decided to guarantee the fatigue life. In this study, the effect of the angle of deviation and end play on the maximum stress was investigated. From the analysis results, it was shown that the angle of deviation has a greater effect on the maximum stress than the end play. Furthermore, the dimensions of the disk plate were optimized to realize a better design. From the optimization, the maximum stress could be reduced by up to 5.2%.

• 한국전자파학회논문지
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• 제23권7호
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• pp.774-783
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• 2012

본 논문에서는 주기적인 요철 모양의 구조를 이용하여 인접해 있는 선로 간의 누화(crosstalk) 감소 효과를 갖는 전송 선로를 제안한다. 요철 모양의 전송 선로는 인접한 선로 간의 유도성 커플링과 용량성 커플링의 크기를 동일하게 조절이 가능하다. 따라서 유도성과 용량성의 커플링이 서로 상쇄되기 때문에 누화 감소 효과를 갖는다. 요철 모양의 전송 선로는 비유전율이 3.38이며, 두께가 0.508 mm인 RO4003 기판 위에 설계하였다. 전산모의 실험 결과, 일반적인 전송 선로와 주기 간격이 A=1 mm인 요철 모양 전송 선로의 far-end 누화는 30 GHz까지 각각 최대 -3.6 dB와 -22 dB 값을 가진다. 측정 결과, 일반적인 전송 선로와 A=1 mm인 요철 모양 전송 선로의 far-end 누화는 30 GHz까지 각각 최대 -6.3 dB와 -20.5 dB 값을 가진다.

• Macromolecular Research
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• 제15권6호
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• pp.541-546
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• 2007

The combination of atom transfer radical polymerization (ATRP) and click chemistry was employed for the efficient preparation of well-defined block copolymers. Bromo terminated poly(methyl acrylate) (pMA-Br) was prepared by an ATRP initiator, ethyl-2-bromoisobutyrate (EBiB). Subsequently, the bromine chain end of pMA-Br was converted to an azide group by simple nucleophilic substitution reaction. ${\alpha}-Alkyn-{\omega}-bromo-functionalized$ polystyrene was also synthesized by ATRP using the alkyn-functionalized initiator, propargyl-2-bromoisobutyrate (PgBiB). In both cases, the conversion was limited to a low level to ensure a high degree of chain end functionality. Then the coupling reaction between the azide end group in $pMA-N_3$ and alkyn-functionalized PgBiB-pSt was performed by Cu(I)catalysis. This coupling reaction was monitored by gel permeation chromatography (GPC). The synthesized block copolymer was characterized by FT-IR, $^1H-NMR$ spectroscopy and $^1H-^1H$ COSY correlation spectroscopy.