• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.3
• /
• pp.463-470
• /
• 2023

In this study, an electronic parts assembly training system using Leap Motion was developed in consideration of the processes actually operated in the assembly process of electronic products. Based on Leap Motion and Oculus VR equipment, the system was developed to transfer user's hand movement data in real time and convert it into hand movement in virtual space so that electronic parts assembly simulation can be performed step by step. Through this, it was confirmed that the user can obtain an experience similar to the actual electronic parts assembly work, prevent errors that may occur during the assembly process, and improve proficiency. It is expected that this thesis will provide directions for the quality improvement and development of various education and training programs for virtual reality-based manufacturing processes.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.94-101
• /
• 2019

In this study, the FEM technique was applied to design the shape of the horn that transmits ultrasonic vibration energy to the base material, and the shape of the welding horn with a one-wavelength bar shape used in the 20kHz region was designed. The shape design of the horn was performed by applying the rod longitudinal vibration theory to Ansys APDL (Ansys Parametric Design Language). Twenty-five models were designed using the ratio of the area of the input and output surfaces of the vibration and the length of the horn to derive the appropriate horn shape. The horn was designed with a total length of 130mm, a step length of 65mm, and an output area of 28.79mm. The horn was fabricated using the optimized dimensions, and the vibration and displacement characteristics of the horn were evaluated using the measurement system. Finally, a uniform longitudinal step horn was designed, and more than 97.4% of the uniformity of the tip was secured. The amplitude ratio of the optimized horn was improved by 51%.

• International Area Studies Review
• /
• v.14 no.3
• /
• pp.454-476
• /
• 2010

In this paper is two-step trade model introduced. It is assumed that countries have 3 basic factors- capital(K), land (Z)and population(N)-as national factor endowments. As the first step, education 'produces' 'educated labor(EL)' which embodies new knowledge or new technology by using the population and capital as inputs. As the second step, manufacturing goods is produced with EL and uneducated labor(UL), and agriculture goods with land and UL. According to this model, the higher the increase rate of capital in a country is, the lower the usage rate of land is, the lower the increase rate of discount is, the country tends to export the manufacturing goods and import the agriculture goods. Trade widens the discrepancy of increase rate of EL in both countries but reduces the gap of increase rate of relative wage of EL as far as the gap of usage rate is not so big. Trade also affect real income rather than nominal income. This model can be extended to explain the migration from rural areas to urban areas when the manufacturing sector and education organization exist in urban area while the agricultural sector exist in rural area.

• Journal of the Society of Naval Architects of Korea
• /
• v.38 no.2
• /
• pp.71-78
• /
• 2001

In ship building industry, CNC and CAM are mostly applied to NC cutting and manufacturing of propeller and prototype ship model. Herein, prototype ship model is producted by CAD/CAM process. Hull form data is obtained from the ship drawing and used for 3D modeling by CAD software Pro/Engineer. CAD data is transferred into CAM s/w SPEEDplus to perform CNC process and the prototype small ship model is manufactured by CNC machine. To solve data transfer among different systems. IGES and STEP neutral formats are currently used. Herein IGES format is adopted for data transfer between CAD/CAM softwares.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.15 no.5
• /
• pp.14-20
• /
• 2006

In recent year, as the robot technology is developed, the researches on the artificial muscle actuator that enables robot to move dexterously like biological organ become active. Actuators are key technologies underpinning robotics. Breakthroughs in actuator technology, particular in terms of power-to-weight ratio, or energy-density, will have significant impacts upon the design and control of robotic system. In this paper, a new approach to design and control of shape memory alloy(SMA) actuator is presented to drive the robot hand. SMA wire is divided into many segments and their thermal states of the SMA are controlled individually in a binary manner. This control manner will reduce the hysteresis that the SMA material has and it becomes the fundamental technology to develop the anthropomorphic robot hand. In this paper, the mechanism In the digital step motor of the shape memory alloy that is driven by the segmented binary control, which is a new control technique, is studied. This SMA digital step actuator applies for the robot hand and the driving mechanism of the robot hand is investigated.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.5 s.236
• /
• pp.609-616
• /
• 2005

While the SIMPLE algorithm is most widely used for the simulations of flow phenomena that take place in the industrial equipments or the manufacturing processes, it is less adopted for the simulations of the free surface flow. Though the SIMPLE algorithm is free from the limitation of time step, the free surface behavior imposes the restriction on the time step. As a result, the explicit schemes are faster than the implicit scheme in terms of computation time when the same time step is applied to, since the implicit scheme includes the numerical method to solve the simultaneous equations in its procedure. If the computation time of SIMPLE algorithm can be reduced when it is applied to the unsteady free surface flow problems, the calculation can be carried out in the more stable way and, in the design process, the process variables can be controlled based on the more accurate data base. In this study, a modified SIMPLE algorithm is presented fur the free surface flow. The broken water column problem is adopted for the validation of the modified algorithm (MoSIMPLE) and for comparison to the conventional SIMPLE algorithm.

• International Journal of CAD/CAM
• /
• v.3 no.1_2
• /
• pp.51-60
• /
• 2003

The growth of the World Wide Web and the advances in high-speed network access have greatly changed existing CAD/CAE environment. The WWW has enabled us to share various distributed product data and to collaborate in the design process. An international standard for the product model data, STEP, and a standard for the distributed object technology, CORBA, are very important technological components for the interoperability in the advanced design and manufacturing environment. These two technologies provide background for the sharing of product data and the integration of applications on the network. This paper describes a distributed CAD/CAE environment that is integrated on the network by CORBA and product model data standard STEP. Several prototype application modules were implemented to verify the proposed concept and the test result is discussed. Finite element analysis server are further distributed into several frontal servers for the implementation of distributed parallel solution of finite element system equations. Distributed computation of analysis server is also implemented by using CORBA for the generalization of the proposed method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.464-469
• /
• 1999

Recently, the need for designing multi-stage gear drive has been increased as the hear drives are used more in the applications with high-speed and small volume. The design of multi-stage gear drives includes not only dimensional design but also configuration design of various machine elements. Until now, however, the researches on the design of gear drives are mainly focused on the single-stage gear drives and the design practices for multi-stage gear drives, especially in configuration design activity, mainly depend on the experiences and 'sense' of the designer by trial and error. We propose a design algorithm to automate the dimension design and the configuration design of multi-stage gear drives. The design process consists of four steps. The number of stage should be determined in the first step. In second step, the gear ratios of each reduction stage are determined using random search, and the ratios are basic input for the dimension design of gears, which is performed by the exhaustive search in third step. The designs of gears are guaranteed by the pitting resistance and bending strength rating practices by AGMA rating formulas. In configuration design, the positions of gears are determined to minimize the volume of gearbox using simulated annealing algorithm. The effectiveness of the algorithm is assured by the design example of a 4-stage gear drive.

• International Journal of Precision Engineering and Manufacturing
• /
• v.6 no.2
• /
• pp.55-60
• /
• 2005

In order to develop the hydrostatic guideways driven by a core less linear motor for ultra precision machine tools, a prototype of guideway is designed and tested. A coreless linear DC motor with a continuous force of 156 N and a laser scale with a resolution of 0.01 ㎛ are used in the system. Experimental analysis on the static stiffness, motion errors, positioning error and its repeatability, micro step response and velocity variation of the guideway are performed. The guideway shows infinite stiffness within 50 N applied load in the feed direction, and by the motion error compensation method using the Active Controlled Capillary, 0.08 ㎛ linear motion error and 0.1 arcsec angular motion error are acquired. The guideway also reveals 0.21 ㎛ positioning error and 0.09 ㎛ repeatability, and it shows stable responses following a 0.01 ㎛ resolution step command. The velocity variation of feeding system is less than 0.6 ％. From these results, it is estimated that the hydrostatic guideway driven by a coreless linear motor is very useful for the ultra precision machine tools.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.144-147
• /
• 2008

A glass bulb is the most reliable and simplest device for a fire sprinkler head system. We had developed an accurate glass bulb. The glass bulb is composed with a glass ampoule, liquid filled within the ampoule and an air bubble in the liquid. The first step of the development was to establish a stable mass production system for uniform glass ampoule. The second step is to optimize the composition of the liquid and the size of the bubble. It was also a difficult problem to devise manufacturing process to form uniform bubble size. The final step for the development is to control the mechanics for glass breaking by surface treatment for the glass bulb.