• Title/Summary/Keyword: 잠김효과

Search Result 17, Processing Time 0.021 seconds

Analysis of Frequency Lock-in Breakings with Random Dithering in a Ring Laser Gyroscope (랜덤 디더링을 이용한 링레이저 자이로 주파수 잠김 깨짐 특성 분석)

  • Woo-Seok Choi;Byung-Yoon Park
    • Korean Journal of Optics and Photonics
    • /
    • v.34 no.2
    • /
    • pp.76-83
    • /
    • 2023
  • In this paper, the results of analyzing the frequency lock-in breaking characteristics of a ring laser gyroscope with random dithering through numerical experiments are presented. By observing the variant features in the frequency lock-in characteristics according to the dithering amplitude noise, it was possible to analyze the minimum noise condition that causes the frequency lock-in to be broken. It was confirmed that the result is closely related to the relative difference between the dynamic frequency lock-in corresponding to the average dithering amplitude and the frequency determined by the Sagnac effect corresponding to an input rotational angular velocity.

The Improvement Direction on Valuation System of Competitive Conditions for Effective Regulation in Telecommunications Market (통신시장의 효과적 규제를 위한 경쟁상황 평가제도 관련 개선방향)

  • 신용희
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 2003.05a
    • /
    • pp.158-162
    • /
    • 2003
  • 정보통신산업은 대규모 설비투자, 자연독점성, 망의 부성이 지배적으로 나타나고, 공급 및 수요의 잠김효과와 쏠림현상이 크며 기술의 혁신정도가 매우 크다는 규제의 대상이 되어 오고 있다. 그러나 최근 정보통신업은 다각적인 측면에서 급변하고 있다. 이러한 급격한 재반 변화는 규제자체에 대한 재고의 여지가 있고, 경쟁상황평가에 대한 근본적 인식의 전환이 요구되는 것이다. 본 고는 규제의 시발점이라고 할 수 있는 시장의 정의, 관련시장의 경쟁상황 평가와 시장지배적사업자 선정에 이어 규제옵션 및 규제수준을 설정하는 합리적 방향에 대해서 서술하고 있다.

  • PDF

Characteristics of an External-Cavity Semiconductor Laser with a Fabry-Perrot Etalon inside the External reflector (외부공진기 내에 훼브리 페롯 에탈론이 삽입된 반도체 레이저의 특성)

  • 이명우;서동선
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.18 no.6
    • /
    • pp.793-801
    • /
    • 1993
  • We show theoretically that the performance characteristics of an external cavity semiconductor laser, such as frequency locking and frequency noise reduction, can be greatly improved by just inserting a high finesse Fabry-Perrot(F-P) etalon inside the external reflector. For example, when the F-P etalon of finesse 30 and optical thickness 1.5cm is inserted inside the external cavity of length 3.0cm, the frequency locking accuracy and the linewidth reduction ration are increased up to 7.6 times and 86 times respectively compared with the conventional external-cavity laser under the same operation condition.

  • PDF

Design of Electronic Parking Brake Control Simulator for Emergency Vehicle Braking (차량 비상제동을 위한 전자식 주차 브레이크 제어 시뮬레이터 설계)

  • Park, Jaeeun;Im, Changhyon;Kim, Taesung;Kim, Youngkeun
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.25 no.1
    • /
    • pp.19-27
    • /
    • 2017
  • In this paper, a simulator hardware and control design for an electronic parking brake (EPB) are proposed for emergency vehicle braking when the hydraulic break and anti-lock brake systems (ABS) fail to function. EPB systems are designed specifically for park braking and are usually installed on the rear wheels. However, in an emergency situation when all vehicle brake systems fail, the EPB can be utilized to stop the vehicle and track the target slip ratio as the ABS. This paper analyzed the non-linear EBP of the type of motor on caliper (MoC) based on experiments. A simulator hardware is also designed to validate the performance of the designed EPB controller in terms of braking distance and performance in tracking the target slip ratio. Through the experimental analysis, it is confirmed that a sliding mode controller can be applied on a non-linear EPB to track the target slip ratio.

Shielding Effects of Bimaterial Interfaces by Crack Surface Asperities (균열 표면거칠기에 의한 이종재료 계면의 차단효과)

  • 채영석;권용수;최병선
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.18 no.3
    • /
    • pp.540-547
    • /
    • 1994
  • Contact and frictional locking conditions and the effect of shielding due to contact at the facet, which could be represented by the difference in energy release rate, as a function of phase angle of loading are analyzed in this study for the case of interfacial cracks by assuming single crack-kink model. The analysis of contact effects on interfacial fracture resistance shows that relative shielding increases as the shear component was increased, which indicates a qualitative agreement with the previous experimental results.

Theoretical Approaches to Regional Transformation: Path Dependence Theory and Regional Resilience Concept (경로의존론과 지역회복력 개념: 지역격차에 대한 새로운 이론적 접근)

  • Shin, Dong-Ho
    • Journal of the Economic Geographical Society of Korea
    • /
    • v.20 no.1
    • /
    • pp.70-83
    • /
    • 2017
  • Traditionally, economic growth has been uneven over the space. It has also been true for the recovery from social and economic crisis in old industrial areas of the advanced economies. Even if many of such old industrial areas were seriously affected by de-industrialization, some areas have been showing progress, while others have not been so. While interpreting this phenomenon used to be a key issue in economics, main stream liberal economic theorists' explanation was uneven distribution of economic resources, such as raw materials, labour and money. However, some revolutionary economic theorists have brought in the concept of "history" in explaining the phenomenon. Path dependence theorists, for example, interpretate the emergence of different growth paths with the concept of historical accidents. This contrasts to the recent argument of the group of scholars suggesting the concept of "regional resilience," who argue that uneven growth and different growth paths are originated from different regional resilience. This paper introduces the backgrounds, characteristics and utilities of the two theories: path dependence theory and the concept of regional resilience.

An Assumed Strain Beam Element for Spatial Post-Buckling Analysis of Non-symmetric and Shear Flexible Thin-Walled Beams (박벽보의 3차원 후좌굴 해석을 위한 Locking-Free 보요소)

  • Lee, Kyoung-Chan;Kim, Moon-Young;Park, Jung-Il;Chang, Sung-Pil
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.20 no.6
    • /
    • pp.719-730
    • /
    • 2007
  • This study presents a thin-walled space frame element based on the classical Timoshenko beam theory. The element is derived according to the assumed strain field in order to resolve the shear-locking phenomenon. The shape function is developed in accordance with the strain field which is assumed to be constant at a 2-noded straight frame element. In this study, the geometrically nonlinear analysis applies the Corotational procedure in order to evaluate unbalanced loads. The bowing effect is also considered faithfully. Two numerical examples are given; monosymmetric curved and nonsymmetric straight cantilever. When these example structures behave lateral-torsional bucking, the critical loads are obtained by this study and ABAQUS shell elements. Also, the post-buckling behavior is examined. The results give good agreement between this study and ABAQUS shell.

Determinants of International Standardization: An Empirical Analysis in the ICT field (ICT 국제표준화 결정요인에 관한 실증분석 연구)

  • Kim, Bum-Hoan;Park, Jongbong
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.37C no.11
    • /
    • pp.1064-1076
    • /
    • 2012
  • This study is an attempt to identify factors determining the success of international standardization and understand the relationship between the factors, such as government-driven standardization activities. Six factors were identified through factor analysis; namely, 'Direct government support', 'Indirect government support', 'Utilization of standardization bodies', 'Standardization strategy', 'Attainment of a dominant market power', and 'Adoption as an international standard.' The results showed that firstly, support from the government, whether direct or indirect, had no direct effect on the outcome of international standardization efforts, but produced an indirect influence on it through mediating factors such as the attainment of a dominant market power. Secondly, the attainment of a dominant market power proved to be the most important success factor of international standardization, suggesting that the government must direct its efforts to help boost the market power of target standards through measures like promoting a timely market entry and the development of high-quality standards, in a manner to induce market satisfaction, increasing lock-in effects and building a quasi-vertical integration system. Thirdly, direct support from the government holds the key to the success of international standardization with de jure standardization bodies, while the strategic use of standardization bodies appears the most important for the positive outcome of standardization concerning de facto standardization bodies.

A Study on Innovation and Competitive Strategy in Network-Based Economy: Case Analysis on Network Effects, Incremental Innovation in Korean Mobile Telecommunication Industry (네트워크 경제 하에서 혁신과 경쟁 전략에 대한 기반 연구: 한국 이동통신 산업 사례를 중심으로)

  • An, Kwang-Jun;Shin, Dong-Hyung
    • Journal of Korea Technology Innovation Society
    • /
    • v.11 no.2
    • /
    • pp.145-170
    • /
    • 2008
  • The existence of network is indeed the single most important factor that brings about new business phenomena in the new digital economy, especially in the IT industry. Network effect refers to a phenomenon that the increase in size of the network leads to increased network value and user utility. It determines the competitive structure of an industry and the performances of industry competitors (Shapiro and Varian, 1999). The phenomenon of increasing returns and winner-take-all enjoyed by the early winner in the competition can be attributed to the existence of positive feedback which increases the value of network and induces more users into join the network (Arthur, 1996; Shapiro and Varian, 1999; Song and Lee, 2003). This research attempts to shed light on the topic of innovation and competitive strategy of network-based industries. We analyze the case of the Korean mobile communications industry, in which a shift in technological paradigm from 2G to 3G brought new changes to the competitive structure of the industry. The Korean mobile communications industry makes an ideal case for analysis since it is an industry whose value is inherently dependent upon its user network. It is characterized by the typical increasing returns, in which a monopolizing player is enjoying firstmover's network effects. Because of the existence of network in the mobile communications industry, latecomers' disruptive innovations could not outcompete the incumbent's sustaining innovations. The contribution of this research lies in laying a groundwork for future studies by introducing a numerical simulation model to analyze the complexity theory and network effect.

  • PDF

An Essay on the Relationship between Standards and Technological Innovation (표준과 기술혁신의 연관성에 관한 소고)

  • Sung, Tae-Kyung
    • Management & Information Systems Review
    • /
    • v.29 no.4
    • /
    • pp.225-244
    • /
    • 2010
  • In the information society, characterized by knowledge and network economy, standards and standardization became a very important factor in determining the competitiveness of nations and firms. This paper defines the concept of standards and standardization and reconstructs the theory on the relationship between standards and technological innovation. The findings and policy implications are as follows. First, the effect of standards on technological innovation differs according to its function(compatibility, minimum quality, information, and variety reduction) and types(product-related and non-product). On the other hand, standards can impede technological innovation. Second, in terms of national innovation system(NIS), standards are an infra-technology, which is a public good. Therefore, government should decide the optimal level of investment on standards and standardization. Third, since standards foster firms' innovation over the all stages of business activities company, industry, and government should connect standardization activities with R&D, manufacturing, marketing, supply chain, and technology transfer, Fourth, standards play an important role in product innovation as well as process innovation. Based on these theoretical background and hypotheses, the empirical study of the Korean firms is needed.

  • PDF