• 한국기계가공학회지
• /
• 제2권2호
• /
• pp.52-59
• /
• 2003

Cam mechanism is a machine part frequently used in machinery. Specially, conjugate cam mechanism is very suitable for the high speed working and the heavy power translation. Then a conjugate cam mechanism need high precision for the relations between cam profiles and follower rollers. So, its design and manufacturing are very difficult. Thus, this study is a branch of exclusive CAM systems for design and NC machining of conjugate earn mechanism based on a master plate earn profile in order to exchange an old plate cam mechanism to a new conjugate earn mechanism. For the design of the other cam profile by using a master cam profile, some calculation processes were used by vector summation methods, from master cam profile data to the center data of master follower, from the center data of master follower to the center data of the other follower considered in link mechanism, and offsetting in the center direction of base circle of the other cam from the center data of the other follower. Finally, a sample conjugate cam was selected and machined m order to prove the contents of this study.

• Journal of Biosystems Engineering
• /
• 제38권2호
• /
• pp.129-137
• /
• 2013

Purpose: Modeling has been used for elucidating the mechanism of complex biosystems. In spite of importance and uniqueness of adolescent calcium (Ca) metabolism characterized by a threshold Ca intake, its regulatory mechanism has not been covered and even not proposed. Hence, this study aims at model-based proposing potential mechanisms regulating adolescent Ca metabolism. Methods: Two different hypothetic mechanisms were proposed. The main mechanism is conceived based on Ca-protein binding which induces renal Ca filtration, while additional mechanism assumed that active renal Ca re-absorption regulated Ca metabolism in adolescents. Mathematical models were developed to represent the proposed mechanism and simulated them whether they could produce adolescent Ca profiles in serum and urine. Results: Simulation showed that both mechanisms resulted in the unique behavior of Ca metabolism in adolescents. Based on the simulation insulin-like growth factor-1 (IGF-1) is suggested as a potential regulator because it is related to both growth, a remarkable characteristic of adolescence, and Ca metabolism including absorption and bone accretion. Then, descriptive modeling is employed to conceptualize the hypothesized mechanisms governing adolescent Ca metabolism. Conclusions: This study demonstrated that modeling is a powerful tool for elucidating an unknown mechanism by simulating potential regulatory mechanisms in adolescent Ca metabolism. It is expected that various analytic applications would be plausible in the study of biosystems, particularly with combination of experimental and modeling approaches.

• 산업경영시스템학회지
• /
• 제34권4호
• /
• pp.66-71
• /
• 2011

This article proposes a novel shift automation mechanism for an automated manual transmission (AMT). The development of an automated manual transmission is currently being paid considerable attention by vehicle manufacturers, with the prospects of combining the comfort of an automatic transmission and the high efficiency of a manual transmission. In order to automate the shift mechanism of a manual transmission, the proposed shift automation mechanism consists of two electric motors, cross shaped pinion gears, rack type shift rails, and a ball splined hollow shaft. First we describe the shift mechanism and operating principles of a manual transmission to investigate important design criteria for the shift automation device. And a new shift automation mechanism is described with its structure, elements, and operating principles in detail. Using a conventional manual transmission, we develop a full three-dimensional CAD model of an AMT which includes main components of the manual transmission and the designed shift automation mechanism. Finally we investigate the operating performances and feasibility of the designed AMT by a dynamic analysis.

• 한국환경과학회지
• /
• 제12권11호
• /
• pp.1159-1165
• /
• 2003

The Carbon Bond Mechanism IV has been developed for use in urban- and regional-scale oxidant models. The photochemical mechanism, CBM4, contains extensive improvements to earlier carbon bond mechanisms in the chemical representations of aromatics, biogenic hydrocarbons, peroxyacetyl nitartes, and formaldehyde. Ozone is produced mainly by nitrogen oxides and hydrocarbon. By altering the initial concentrations of the mechanism, an analysis of the sensitivity of ozone concentrations to VOC/NO$\_$x/ ratios and VOC composition is conducted in this one-dimensional mechanism. Note that it is considered a chemical mechanism in order to understand the photochemical reactions within this mechanism. It analyzed the results of these simulations by applying a NO$\_$x/-sensitive and a VOC-sensitive regime. These sensitivity regimes are changed to match the relative contribution of VOC and NO$\_$x/ concentrations to ozone production in simulations of two sets.

• EDISON SW 활용 경진대회 논문집
• /
• 제5회(2016년)
• /
• pp.493-497
• /
• 2016

Walking mechanism, there are many types. Prior to the modeling and design, we thought about a variety of mechanisms based on the Janssen mechanism to design a walking mechanism optimized for walking. The more the legs increases the stability of the structure, while the weight is heavy and if that advantage had the disadvantage, the legs are easier to walk in the utilization and structural aspects of the torque had fewer advantages. The disadvantage is that the instability mechanism, four-legged, but improve it and look forward to the idea of utilization and cost-effectiveness, its future utilization will be endless. To study this, we utilized a variety of software, such as m-sketch, Edison design program, we have seen the actual production through scientific experiments box.

• 대한기계학회논문집B
• /
• 제22권2호
• /
• pp.193-204
• /
• 1998

Numerical analysis was performed with multicomponent transport properties and detailed reaction mechanisms for axisymmetric 2-D CH$_{4}$ jet diffusion flame. Calculations were carried out twice with the $C_{2}$-Thermal Mechanism including $C_{2}$ and thermal NO reactions and the $C_{2}$-Full Mechanism including prompt NO reactions in addition to the above $C_{2}$-Thermal NO mechanism. The results show that the flame structures such as flame temperature, major and minor species concentration are indifferent to respective mechanisms. The production path of Thermal NO is dominant comparing with that of Prompt NO in total NO production of pure CH$_{4}$ jet diffusion flame. This is because thermal NO mechanism mainly contributes to positive formation of NO in the whole flame region, but Prompt NO mechanism contributes to negative formation in the fuel rich region. In addition, 0$_{2}$ penetration near the nozzle outlet affects the flame structures, especially N0$_{2}$ formation characteristics.

• 로봇학회논문지
• /
• 제17권4호
• /
• pp.484-492
• /
• 2022

This paper presents a simple and robust under-actuated robotic finger mechanism that enables self-adaptive grip, fingertip pinch, and caging grasp functions. In order to perform daily activities using hands, the fingers should be able to perform adaptive gripping and pinching motion, and the caging grasp function is required to realize natural gripping motions and improve grip reliability. However, general commercial prosthetic hands cannot implement all three functions because they use under-actuation mechanism and simple mechanical structure to achieve light-weight and high robustness characteristic. In this paper, new mechanism is proposed that maintains structural simplicity and implements all the three finger functions with simple one degree-of-freedom control through a combination of a four-bar linkage mechanism and a wire-driven mechanism. The basic structure and operating principle of the proposed finger mechanism were explained, and simulation and experiments using the prototype were conducted to verify the gripping performance of the proposed finger mechanism.

• 한국통신학회논문지
• /
• 제21권3호
• /
• pp.713-720
• /
• 1996

최근에 이동 통신의 수요가 급속히 증가하는 반면에 무선자원은 제한되어 있으므로 이를 효율적으로 이용할 수 있는 적합한 프로토콜이 요구되고 있다. 기존에 연구된 CDMA_ALOHA 기법중에 MS_CDMA_ALOHA(Mini Slotted CDMA_ALOHA) 방식이 S_COMA_ALOHA(Slotted COMA_ALOHA)보다 성능이 우수한 것으로 나타났다. 또한 CDMA 디지탈 셀룰러 시스템의 CAI 프로토콜로서 IS-95 다중 엑세스 방식이 제안되었다. 하지만 기존의 연구에서는 무선통신 환경의 채널특성을 고려한 성능분석이 이루어지지 않았다. 본 논문에서는 DS/CDMA 셀룰러 환경에서 성능개선을 위한 새로운 기법을 제시하였으며, 이는 기존의 MS_ COMA_ALOHA 방식을 기반으로 한 것으로서 채널상태에 적용할 수 있는 기법이다. 또한 컴퓨터 시뮬레이션을 통하여 기존의 방식과 비교 분석 하였다. 그 결과 새로 제안한 NA_COMA_ALOHA(Noise Adaptation COMA ALOHA) 방식은 기존의 COMA_ALOHA 방식보다 시스템 처리율 및 평균 지연특성면에서 우수한 성능을 보였다. 이는 NA_COMA_ALOHA 방식이 시스템의 과부하 환경에서 채널상태에 따라 사용자의 액세스 시도를 제어 하기 때문이다.

• 지질공학
• /
• 제1권1호
• /
• pp.121-136
• /
• 1991

본 연구에서는 P파형의 초동극성 분포를 이용하여 홍성지진의 Focal Mechanism을 평가하였다. 비선형 전산처리과정을 이용하여 원지진진앙거리에서 관측된 9개의 P파형의 초동극성 분포와 주향, 경사 및 상반변위방향의 변화로부터 구한 Focal Mechanism과의 부합성을 조사하였다. 위의 과정을 이용하여 처리한 결과 주단층면의 주향 및 겅사는 약 247도 및 약 78도로서 홍성부근지역의 선구조와 잘 일치함을 보여주었다. 그러나, 주단층면의 상반변위 방향은 약 40도에서 약 160도 까지의 광범위한 값을 보여주었으나, 이는 관측점의 방위각 분포가 불충분하기 때문인 것으로 분석되었다. 위에서 결정된 Focal Mechanism이 의미하는 주응력 방향은 일본 트렌치를 따라서 태평양판이 유라시아판 아래로 Subduction할 때 가능한 지응력장가 상반되지 않음을 보여 주었다. 또한, 이러한 Focal Mechanism으로부터 원자력발전소나 핵폐기물 처리장 및 처분장 건설시, 부지고유응답 스펙트럼 및 강지진동 자료와 같은 내진설계기준을 위해 필요한 한반도의 지진지체구조 특성에 대한 정보를 얻을 수 있다.

• International Journal of Automotive Technology
• /
• 제7권4호
• /
• pp.501-508
• /
• 2006

The effect of chemical additives, such as dimethyl ether(DME), ethanol, carbon disulfide on the soot formation were examined numerically. ill this study, the Frenklach soot mechanism was used as a base mechanism to predict the soot formation in the ethane flame. The combination of Westbrook's DME mechanism, Marinov's ethanol mechanism, and chemical kinetic mechanism for hydrogen sulfide and carbon disulfide flames was made with the base mechanism because the DME, ethanol, $CS_2$ additives are added into the ethane fuel. CHEMKIN code was used as a numerical analysis software to simulate the effect of chemical additives on reduction of the polycyclic aromatic hydrocarbons(PAH's) which are soot precursors. From the numerical results it is observed that addition of DME, ethanol and $CS_2$ into ethane fuel can reduce PAH species significantly. That means theses additives can reduce soot formation significantly. Results also strongly suggest suppression of soot formation by these additives to be mainly a chemical effect. Hand OH radicals may be the key species to the reduction of PAH species for additives.