• 한국분무공학회지
• /
• 제22권1호
• /
• pp.22-28
• /
• 2017

In this study, the effects of intake valve closing timing by using Cam-in-Cam system on combustion and emission characteristics for diesel engine were investigated under GT-POWER simulation environment. As a result, it was found that volumetric efficiency and effective compression ratio were decreased as the intake valve closing(IVC) timing is retarded due to its backflow effect. Also, we found that in-cylinder pressure, heat release rate and NOx emission were decreased as IVC timing was retarded. These show that the LIVC(late intake valve closing) can be effective to control AFR and mixing rate in diffusion combustion of diesel engine.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권4호
• /
• pp.2115-2118
• /
• 2016

Background: The study aimed to assess complementary and alternative medicine (CAM) use and their associated factors with breast cancer patients in Bandung, Indonesia. Materials and Methods: In total, 330 breast cancer patients were administered questionnaires on their CAM use and CAM predictive factors including socio-demographic parameters, clinical data and quality of life, trust in physicians, trust in hospitals, satisfaction and informational needs. Data were analyzed using univariate analysis and multivariate log regreesion analysis. Results: Overall 33.3% of patients reported use of CAM. Lower income, lower education, presence of metastasis, prolonged diagnosis, less trust in physician were found to be highly associated with CAM use. Conclusions: CAM use by breast cancer patients can be interpreted as an attempt to explore all possible options, an expression of an active coping style, or expression of unmet needs in the cancer care continuum. Physicians need to openly discuss the use of CAM with their patients and identify whether they have other unmet supportive needs.

• Journal of Preventive Medicine and Public Health
• /
• 제37권2호
• /
• pp.141-149
• /
• 2004

Objectives : To evaluate the cost and proportion of complementary and alternative medicines (CAM) in the total healthcare costs among the elderly in the last 6 months of life. Methods : The care-giving families of 301 persons older than 65 years, who died between July 1st and December 31st of 2001, and were also registered in Self-Employed Health Insurance Programs in Seoul, were interviewed. Results : The cost of CAM was 1.09 million Won, which as a proportion of the total healthcare cost was 38.1%. The elderly aged between 65 and 69 year-old, male, living with their spouse, Buddhist and having cancers had higher CAM costs in an ANOVA and simple regression analysis. After controlling of various factors, age was the only significant factor associated with the cost of CAM. The elderly above 80 years old, female, bereaved and Buddhist had higher proportional CAM costs, and the elderly having cancers or cardiovascular diseases had lower proportional CAM costs in an ANOVA and simple regression analysis. After adjusting for various factors, the elderly above 85 years old, female and Buddhist had higher proportional CAM costs, and the elderly having cancers had lower proportional CAM costs. Conclusion : The very old and Buddhist, and/or the ill with no clear diagnosis, may depend more on CAM. Further research will be needed on the meaning and impact of CAM and their costs to public health and the total healthcare system.

• 융합정보논문지
• /
• 제7권6호
• /
• pp.97-102
• /
• 2017

본 논문에서는 연구목적과 관련하여, 협업 지능형교통체계와 자율주행체계에 관심을 가지고 있으며, C-ITS 특성 가운데 핵심 전달 메시지인 CAM과 DENM 특성 분석, 또한 V2X 통신의 보안 특성과 함께 CAM 및 DENM 메시지의 보안 인증서 및 헤더 구조를 중심으로 분석에 초점을 맞추고 있다. 연구방법에 대해, 우리는 CAM 메시지인 차량의 위치와 상태를 알리는 메시지를 분석하고, DENM 메시지인 차량 사고와 같은 이벤트를 알리는 메시지를 분석하고, 이를 지원하는 보안통신 특성을 분석한다. 차량통신에 사용하는 보안헤더와 인증서 형식과 함께, 차량용 서명된 인증서 검증 절차, 그리고 차량용PKI 특성을 얻었다. 아울러, V2X 보안통신을 위해 필요로 하는 보안 동기패턴에 대한 특성과 전송능력에 대해서도 함께 유도할 수 있었다. 그러므로 본 논문은 C-ITS 환경에서 DENM 및 CAM을 전송하는 통신 서비스를 위한 보안 특성을 고려할 때 의미 있는 결과라 할 수 있다.

• 한국기계연구소 소보
• /
• 통권17호
• /
• pp.83-91
• /
• 1987

This paper is concerned on kinematic Analysis and Simulation of an automatic feeding mechanism and a curved inverse cam. The main objective is the development of an algorithm of the cam-feeding mechanism and a CAD program. The computer program CACAFS (Computer-Aided Cam and Automatic Feeding System is developed by using the state-of-the-art for CAD. Thus, the program CACAFS is independent of computer hardwares and also interactive. As the first part of paper, this paper introduces the algorithm to analyze the motion of the inverse cam and the automatic feeding mechanism. The second part of paper presents the technique for the mechanism simulation and graphics-oriented CAD programming.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
• /
• pp.181-184
• /
• 1998

CAM-Brain is a model to develop neural networks based in cellular automata by evolution, and finally aims at a model as and artificial brain,. In order to show the feasibility of evolutionary engineering to develop an artificial brain we have attempted to evolve a module of CAM-Brain for the problem to control a mobile robot, In this paper, we present some recent results obtained by analyzing the behaviors of the evolved neural module. Several experiments reveal a couple of problems that should be solved when CAM-Brain evolves to control a mobile robot. so that some modification of the original model is proposed to solve them. The modified CAM-Brain has evolved to behave well in a simulated environment, and a thorough analysis proves the power of evolution.

• 한국자동차공학회논문집
• /
• 제17권5호
• /
• pp.7-15
• /
• 2009

This paper introduces a new variable valve actuation mechanism with movable second cam center. Valve lift and open duration can be continuously varied according to engine speed and load conditions. A new method to analyze the kinematic relations between the first and second cam profiles and valve motion are also introduced. Because of rocker motion of the second cam, conventional motion conversion program could not be used in this problem. An example shows continuous variations of valve motion and adequate ramp incorporation throughout all valve lift modes. Valve acceleration profile at the high lift mode is similar to that of conventional valvetrains. Contact geometry analysis of the mechanism gives basic information on the load conditions between the components.

• Journal of Mechanical Science and Technology
• /
• 제15권6호
• /
• pp.685-692
• /
• 2001

This paper reports on the mixed lubrication characteristics between the cam and the tappet contact surface of direct acting type valve train systems. First, the dynamic characteristics are solved by using the lumped mass method to determine the load conditions at the contact point. Then, the minimum oil film thickness is calculated with consideration of elastohydrodynamic line contact theory and the friction force is obtained by using the mixed lubrication model which separates the hydrodynamic and the boundary friction. Finally, the average surface temperatures are calculated by using the flash temperature theory. The results show that, there are some peaks in the friction force due to the asperity contact friction, and flash temperature at the position of minimum oil film thickness. It is thought that there is a relationship between the surface temperature and cam surface wear, and therefore, the analysis on the worn cam profile has been performed.

• 소성∙가공
• /
• 제18권8호
• /
• pp.589-595
• /
• 2009

The hot forming process of an exhaust CAM for vessel engine was designed by finite element(FE) simulation and experimental analysis. An aim of process design was to achieve the near-net shaped CAM forgings by hot forging process. Based on the compression test results of the low alloy steel, power dissipation map was generated using the the dynamic materials model(DMM). From the map, the initial heating temperature was determined as 1200oC. FE analysis was simulated to predict the formation of forging defects and deformed shape with different forging designs. Optimum process design suggested in this work was made by comparing with the CAM for vessel engine manufactured by actual forging process.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2008년도 추계학술대회A
• /
• pp.1113-1118
• /
• 2008

In the hot forging process, The forging defects that are caused by metal were strain, temperate, and inclusion. In this paper, the computer simulation analyzed the effective plastic strain and temperature behaviors. The quantitative analyses which proposed the effective mold design of S/CAM shaft was executed. The parameters of forging shape that affected on the optimize conditions that was calculated with simple equation were investigated. it is expected that the developed analysis model and design technique would greatly contribute to the drum brake optimal design considering temperature affected and material behaviors. This development could save more than 20% of production cost and reduced failure rate to more than 30%. By improving the life span of mold from 15,000 to 25,000, financial difficulty of company imposed on a mold manufacture could be overcome.