• Title/Summary/Keyword: 17자유도

Search Result 420, Processing Time 0.03 seconds

Six D.O.F Ultra Fine Stage using Electromagnetic Force Control (전자기력 제어를 이용한 6 자유도 초정밀 스테이지)

  • 정광석;백윤수
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.3
    • /
    • pp.158-164
    • /
    • 2000
  • In recent year, desire and request fer micro automation are growing rapidly covering the whole range of the industry. This has been caused mainly by request of more accurate manufacturing process due to a higher density of integrated circuits in semiconductor industry. This paper presents a six d.o.f fine motion stage using magnetic levitation technique, which is one of actuating techniques that have the potential for achieving such a micro motion. There is no limit in motion resolution theoretically that the magnetically levitated part over a fixed stator can realize. In addition, it Is possible to manipulate the position and the force of the moving part at the same time. Then, the magnetic levitation technique is chosen into the actuating method. However, we discuss issues of design, kinematics, dynamics, and control of the proposed system. And a few experimental results fur step input are given.

  • PDF

한국 선거운동의 민주적 품질: 자유와 공정의 관점에서

  • Kim, Yong-Cheol
    • Korean Journal of Legislative Studies
    • /
    • v.17 no.3
    • /
    • pp.83-116
    • /
    • 2011
  • 선거운동에 있어서 자유와 공정은 선거과정의 민주적 품질을 가늠하는 핵심적 가치이다. 선거과정에서 자유와 공정이 충분히 보장될 때, 유권자와 후보자 간의 역동적이며 설득적인 커뮤니케이션이 가능하다. 이 점에서 한국 선거운동의 민주적 품질은 아직 낮은 상태에 머무르고 있다. 한국의 선거법은 대단히 규제 중심적이며, 이는 과거 부정선거 및 타락선거의 경험에서 비롯된다. 하지만 선거환경은 빠르게 변화하여 왔다. 유권자의 선거문화 및 의식수준이 크게 개선되었으며, 인터넷의 확산은 더욱 능동적이고 참여적인 유권자를 탄생시키고 있다. 선거환경의 변화는 규제 중심적 선거규칙의 변경을 요구하고 있다. 하지만 선거운동의 민주적 품질은 법제도적 개선만으로 향상되는 것은 아니다. 선거경쟁의 장에서 공명정대한 관리자로서 선관위의 위상정립과 더불어, 유권자들의 건전한 선거문화의 형성을 위한 끊임없는 노력이 함께 병행될 때 비로소 선거운동을 둘러싼 민주적 품질의 실질적 향상이 성취될 수 있을 것이다.

Inference of Context-Free Grammars using Binary Third-order Recurrent Neural Networks with Genetic Algorithm (이진 삼차 재귀 신경망과 유전자 알고리즘을 이용한 문맥-자유 문법의 추론)

  • Jung, Soon-Ho
    • Journal of the Korea Society of Computer and Information
    • /
    • v.17 no.3
    • /
    • pp.11-25
    • /
    • 2012
  • We present the method to infer Context-Free Grammars by applying genetic algorithm to the Binary Third-order Recurrent Neural Networks(BTRNN). BTRNN is a multiple-layered architecture of recurrent neural networks, each of which is corresponding to an input symbol, and is combined with external stack. All parameters of BTRNN are represented as binary numbers and each state transition is performed with any stack operation simultaneously. We apply Genetic Algorithm to BTRNN chromosomes and obtain the optimal BTRNN inferring context-free grammar of positive and negative input patterns. This proposed method infers BTRNN, which includes the number of its states equal to or less than those of existing methods of Discrete Recurrent Neural Networks, with less examples and less learning trials. Also BTRNN is superior to the recent method of chromosomes representing grammars at recognition time complexity because of performing deterministic state transitions and stack operations at parsing process. If the number of non-terminals is p, the number of terminals q, the length of an input string k, and the max number of BTRNN states m, the parallel processing time is O(k) and the sequential processing time is O(km).

A Comparative Study on the Regulation-Free Special Zone and the Regional Special Development Zone (규제자유특구와 지역특화발전특구에 대한 비교 연구)

  • Choi, Ho-Sung;Kim, Jung-Dae
    • Journal of Digital Convergence
    • /
    • v.17 no.2
    • /
    • pp.31-36
    • /
    • 2019
  • New technologies are being created and resulted as new types of fusion complex as the barrier between technology and industries are being broken and convergence is becoming more activated in the global economy of the era of fourth industrial revolution. Korea government is trying to foster innovative technologies for new technologies and new services to prepare for the fourth industrial revolution and gain global competitiveness, but many regulations make it difficult to verify and commercialize them. In response, the Korea government is pushing for the introduction of a regulation-free special zone system in which sandboxes are applied so that new technology and new service-based innovation projects can be freely commercialized through experiment and demonstration. This study aims to examine the limitations of the special zones for regional specialization development applied to the zones that are applied uniformly throughout the country and suggest ways for the deregulation special zone to be fostered as an empirical test bed based on new technologies and as a base for regional innovation.

Could European Media Freedom Act solve the problems of traditional media's content in the online sphere? (온라인 영역에서 유럽 미디어 자유법의 전통 미디어 콘텐츠 문제 해결 가능성에 관한 연구)

  • Gosztonyi, Gergely;Lendvai, Ferenc Gergely
    • Informatization Policy
    • /
    • v.31 no.1
    • /
    • pp.72-82
    • /
    • 2024
  • The presence of traditional media content on online platforms is one of the critical issues nowadays, and Article 17 of the European Media Freedom Act (EMFA) seeks to regulate this. However, it can be seen that the current version of the text is not yet free of flaws: both its harmonisation with the Digital Services Regulation, its use of definitions and the media fast track mechanism it contains would require careful legislative scrutiny before the final text is adopted. The article examines if the self-declaration procedure envisaged by the EMFA would create a loophole for rogue media actors and bring confusion at both the European and horizontal levels or if it would fit the original goal of the EMFA, which is to improve the functioning of the internal European media market and to reinforce the independent media.

A Study on the Partial Path Loss Model By Using the Free Space and Rata Path Loss Model (자유 공간 모델과 하타 모델을 이용한 구간별 경로 손실 모델 설정에 관한 연구)

  • Park, Kyung-Tae;Cho, Hyung-Rae
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.12 no.3
    • /
    • pp.194-198
    • /
    • 2011
  • In this paper, we obtained the path loss characteristics in the 850 MHz for Russia area by using the free space path loss model and Okumura-Hata path loss model. In order to extract the additional path loss model parameter from the new Russian regional properties, the mean square error technique is used to obtain the correction factor. According to the obtained correction factor, the differences for the free space and Hata path loss model are 17, 6 dB in the 5 ~ 10 Km, 28, 14 dB in the 10 ~ 15 Km, and 35, 18 dB in the 15 ~ 20 Km. By applying the correction factors, the appropriate partial path loss models for the measured Russain area are proposed.

Weather-insensitive Optical Free-space Communication Using the Gain-Saturated Optical Fiber Amplifier (이득 포화된 광섬유증폭기를 사용하는 기상에 둔감한 무선광통신)

  • Shin, Kyung-Woon;Hurh, Yoon-Suk;Lee, Sang-Hoon;Lee, Jae-Seung
    • Korean Journal of Optics and Photonics
    • /
    • v.17 no.5
    • /
    • pp.396-400
    • /
    • 2006
  • We present a weather-insensitive optical free-space communication method supporting optical packet channels. It operates optical fiber amplifiers in gain-saturation regions. When the propagation loss gets too high, it decreases the average packet rate, or the average packet length, or both, to increase the optical power level launched into the free-space. As a demonstration, we transmit $8{\times}10$ Gigabit Ethernet channels over a terrestrial distance of 2.4 km. One gain-saturated free-space optical repeater is used at the halfway point.

Cumulative Effects of Trade Liberalization : The Case of Korean Manufacturing (무역자유화의 동태적 누적효과: 한국 제조업)

  • Park, Soonchan
    • Economic Analysis
    • /
    • v.17 no.4
    • /
    • pp.30-51
    • /
    • 2011
  • Since the previous studies on the effects of trade liberalization implicitly assume that trade liberalization affects economic performance only in any point in time, they inevitably are static. Static evaluations fail to account for cumulative dynamic effects of trade liberalization that affect continuously economic performance. This paper tries to fill this gap of the previous studies in this field, estimating cumulative effects of trade liberalization on economic performance by employing an dynamic version of empirical model. One of important empirical issue is controlling bias from endogeneity. To resolve this problem, this paper employes system GMM that uses lagged first-differences as instruments for level equations and lagged levels as instruments for first-differences equations. It improves upon cross-section estimators because it controls for the potential bias induced by the omission of industry-specific effects and the endogeneity of all regressors. This study investigates the effects of trade liberalization in Korean manufacturing for the period from 1988 to 2005 and finds that cumulative dynamic effects of trade liberalization are present and bigger than static effects.

Development of a Snake Robot with 2-DOF Actuator Modules (2 자유도 작동기 모듈로 구성된 뱀 로봇 개발)

  • Shin, Ho-Cheol;Jeong, Kyung-Min;Kwon, Jeong-Joo
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.17 no.7
    • /
    • pp.697-703
    • /
    • 2011
  • This article describes a snake robot with 2-DOF actuator modules. The 2-DOF actuator modules make the snake robot move in the 3D space so that the snake robot can cross obstacles and rough terrain. Each 2-DOF actuator module is designed to have high torque output and an embedded controller. A cross bracket connecting the modules is designed be able to support the weight of two actuator modules. The developed snake robot shows 3-D motions such as side winding, standing/monitoring, and can climb in a narrow pipe with high torque modules. The snake robot moves fast with passive wheels in a plane while crossing obstacles.