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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
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Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 29, Issue 12 - Dec 2012
Volume 29, Issue 11 - Nov 2012
Volume 29, Issue 10 - Oct 2012
Volume 29, Issue 9 - Sep 2012
Volume 29, Issue 8 - Aug 2012
Volume 29, Issue 7 - Jul 2012
Volume 29, Issue 6 - Jun 2012
Volume 29, Issue 5 - May 2012
Volume 29, Issue 4 - Apr 2012
Volume 29, Issue 3 - Mar 2012
Volume 29, Issue 2 - Feb 2012
Volume 29, Issue 1 - Jan 2012
Selecting the target year
Study on Compound Humidifier Employing UV-LED using Environmental Life Cycle Assessment
Choi, Won-Sik ; Park, Si-Hyun ; Lee, Si-Wang ; Jung, Young-Mi ; Yi, Hwa-Cho ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 931~937
DOI : 10.7736/KSPE.2012.29.9.931
In this study, we assessed environmental impacts of compound humidifiers using environmental life cycle assessment and presented the ways to improvements in energy consumption of them. We found eco-design parameters and
-eq emissions in each stage of raw material acquisition, manufacturing, transportation, use and disuse in life cycle of the compound humidifiers. The highest
emission is found to be in the stage of use among all stages of life cycle, which is mainly due to power consumption in thermal heating of heating coil for sterilization during humidification. The power consumption and
emission in the stage of use can be reduced to 1/4 and 1/3 at the highest estimate through improvement of sterilization method, respectively. We suggested the replacement of conventional thermal heating coil by ultra violet light-emitting diodes (UV-LED) for sterilization and then presented the experimental results on the sterilization effects of UV-LEDs.
Finite Element Analysis for Performance Evaluation of Type III Hydrogen Pressure Vessel for the Clean Tech Fuel Cell Vehicles
Son, Dae-Sung ; Chang, Seung-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 938~945
DOI : 10.7736/KSPE.2012.29.9.938
To design and estimate material failures of Type III pressure vessels, which have excellent stability and performance, various modeling techniques have been introduced. This paper provided a hybrid modeling technique composed of ply-based modeling for a cylinder part and laminate-base modeling technique for a dome part for enhancing modeling efficiency. The ply-based modeling technique provided accurate ply stresses directly for predicting material failure, on the other hand, additional manipulations in stress calculations, which may cause some errors, were needed for the case of the laminate-based modeling technique. The ply stresses in fiber, transverse and in-plane shear directions were compared with the corresponding material strengths to predict material failure.
A Study on the Development of a Thin Flat Panel Photo-bioreactor Case
Ahn, Dong-Gyu ; Ahn, Yeong-Su ; Jeong, Sang-Hwa ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 946~957
DOI : 10.7736/KSPE.2012.29.9.946
The objective of this paper is to investigate into the development of a thin flat panel photo-bioreactor case with characteristics shapes. The thin flat panel photo-bioreactor case was designed to be manufactured from a plastic thermoforming process. A proper design with a relatively high rigidity was obtained through the structural analyses for different designs of the photo-bioreactor case. The thermoforming analyses were performed. From the results of the thermoforming analyses, a proper forming condition and the formability of the designed plastic photo-bioreactor case were estimated. The thermoforming moulds for the flat panel photobioreactor cases were manufactured. The thermoforming experiments were performed to examine the manufacturability of the designed flat panel photo-bioreactor cases. From the results of the thermoforming experiments, it was shown that thin flat panel photo-bioreactor cases with characteristic shapes can be manufactured from the designed thermoforming mould and process.
Formation Strategy of Renewable Energy Sources for High Mountain Off-grid System Considering Sustainability
Ahn, Sung-Hoon ; Lee, Kyung-Tae ; Bhandari, Binayak ; Lee, Gil-Yong ; Lee, Caroline Sun-Yong ; Song, Chul-Ki ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 958~963
DOI : 10.7736/KSPE.2012.29.9.958
Characteristics of off-grid hybrid renewable energy sources for high mountain villages are discussed. Considering reliability of electric power generation, Photovoltaic (PV)-wind hybrid and PV-hydro hybrid system are suggested. Connecting two or more villages with these hybrid systems, an extended hybrid off-grid can be formed. Sustainability of entire system is important in design of off-grid system, and income generation of the village people using the electricity should be considered.
Characterization of Eco-Design Checklists
Masoudi, Ali ; You, Hee-Cheon ; Suh, Suk-Hwan ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 964~970
DOI : 10.7736/KSPE.2012.29.9.964
Various eco-design tools have been developed which can be classified into quantitative, semi-quantitative, and qualitative tools. Practitioners are reluctant to utilize quantitative tools in light of their time-demanding nature. Among the qualitative tools, checklists are simple tools that allow a quick and effective evaluation and consideration of environmental impacts over the entire life cycle of a product. A profound and better understanding of eco-design checklists is needed so that practitioners can apply them appropriately to their product development context. Various types of eco-design checklists are analyzed in the present study based on their attributes and classified in a structured way for their efficient utilization in product development contexts.
Theoretical Analyses on Actuator Stiffness and Structural Stiffness of Non-redundant and Redundant Symmetric 5R Parallel Mechanisms
Jin, Sang-Rok ; Kim, Jong-Won ; Seo, Tae-Won ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 971~977
DOI : 10.7736/KSPE.2012.29.9.971
Redundant actuated parallel kinematic machines (PKMs) have been widely researched to increase stiffness of PKMs. This paper presents theoretical analyses on the stiffness of non-redundant and redundant actuated PKM. Stiffness of each mechanism is defined by summation of actuator and structural stiffness; the actuator stiffness is determined from displacements of actuators, and the structural stiffness is determined from deformations of links by external forces. Calculated actuator and structural stiffness of non-redundant PKM show same distribution in entire workspace. On the contrary, the actuator and the structural stiffness of a redundant PKM has very different distribution in the workspace; so, we conclude the structural stiffness of redundant PKM should be considered to design the redundant PKM. The results can be used to design and analyze non-redundant and redundant PKMs.
Starfish Capture Robotic Platform: Conceptual Design and Analysis
Jin, Sang-Rok ; Lee, Suk-Woo ; Kim, Jong-Won ; Seo, Tae-Won ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 978~985
DOI : 10.7736/KSPE.2012.29.9.978
Starfish are a critical problem for fishermen since they eat every farming product including shellfish. The number of starfish is increasing dramatically because they have no natural enemy underwater. We consider the concept of capturing starfish using a semi-autonomous robot. A new underwater robot design to capture starfish is proposed using cooperation between humans and the robot. A requirements list for the robot is developed and two conceptual designs are proposed. Each robot is designed as a modular platform. The kinematic and dynamic performance of each robot is analyzed and compared. This study is a starting point for developing a starfish capture robot and designing underwater robots for other applications. In the near future, a prototype will be assembled and tested in a marine environment.
A Study on the Effect of Weighting Matrix of Robot Vision Control Algorithm in Robot Point Placement Task
Son, Jae-Kyung ; Jang, Wan-Shik ; Sung, Yoon-Gyung ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 986~994
DOI : 10.7736/KSPE.2012.29.9.986
This paper is concerned with the application of the vision control algorithm with weighting matrix in robot point placement task. The proposed vision control algorithm involves four models, which are the robot kinematic model, vision system model, the parameter estimation scheme and robot joint angle estimation scheme. This proposed algorithm is to make the robot move actively, even if relative position between camera and robot, and camera`s focal length are unknown. The parameter estimation scheme and joint angle estimation scheme in this proposed algorithm have form of nonlinear equation. In particular, the joint angle estimation model includes several restrictive conditions. For this study, the weighting matrix which gave various weighting near the target was applied to the parameter estimation scheme. Then, this study is to investigate how this change of the weighting matrix will affect the presented vision control algorithm. Finally, the effect of the weighting matrix of robot vision control algorithm is demonstrated experimentally by performing the robot point placement.
Development of a Flow-duct for Uniform Flow of Chilly Air in a Refrigerator
Yu, Jae-Hyun ; Kim, Pan-Gun ; Park, Sang-Hu ; Bae, Won-Byong ; Kim, Ju-Wan ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 995~1002
DOI : 10.7736/KSPE.2012.29.9.995
In a refrigerator, many food boxes are stored, so the flow of chilly air has very complicate stream paths inside the room of a refrigerator. Moreover, on some occasions, there is no flow of chilly air in a space due to blocking flow paths by food boxes, which is an important issue to be settled for improving the ability of food storage with fresh states. One of methods to solve this problem is to redesign the flow-pattern of chilly air to be uniform flow inside room, if possible. In this work, we have tried to design the duct-structure for the uniform flow of a chilly air using a FE-analysis method. And we conducted real commercial tests using a refrigerator having the redesigned duct. The results showed that good agreements with general requirements.
Development of Rotor for Internal Gear Pump using Cycloid and Polycircular-arc Curves
Kim, Min-Soo ; Lee, Hyun-Woo ; Jung, Sung-Yuen ; Kim, Chul ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 1003~1011
DOI : 10.7736/KSPE.2012.29.9.1003
A new type of gerotor developed in this paper has the inner rotor designed by inserting a polycircular-arc between the hypocycloid and epicycloid curves, and we also suggest that the outer rotor be designed using the closed-form equation for the inner rotor and a method of modification. Thus, it is possible to design a gerotor for which there is no cusp and loop, as in this case undercut is prevented. We developed automated program for rotor design and calculation of the flow rate and flow rate irregularity. And we also demonstrate the superior performance of the gerotor developed in this study by analyzing the internal fluid flow using a commercial computation fluid dynamics-code (CFD).
Optimal Design for CNG Composite Vessel Using Coupled Model with Liner and Composite Layer
Bae, Jun-Ho ; Lee, Hyun-Woo ; Kim, Moon-Saeng ; Kim, Chul ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 1012~1019
DOI : 10.7736/KSPE.2012.29.9.1012
In this study, CNG composite vessel is analyzed by using coupled model with liner and composite layer. For the coupled model, a method using theoretical analysis and FEA is suggested: elastic solution for laminated tube is used for theoretical analysis of the composite vessel, FEA is performed to the model of CNG composite vessel in actual conditions. On the basis of these results, optimal thickness and winding angle of the composite layer considering the material properties and thickness of the liner are determined. The results of theoretical analysis and FEA are compared with those carried out in previous studies for verifying the suggested analysis method.
Fabrication of a Micro/Nano-scaled Super-water-repellent Surface and Its Impact Behaviors of a Shooting Water Droplet
Kim, Hyung-Mo ; Lee, Sang-Min ; Lee, Chan ; Kim, Moo-Hwan ; Kim, Joon-Won ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 1020~1025
DOI : 10.7736/KSPE.2012.29.9.1020
In this study, we fabricated the superhydrophobic and super-water-repellent surface with the micro/nano scale structures using simple conventional silicon wet-etching technique and the black silicon method by deep reactive ion etching. These fabrication methods are simple but very effective. Also we reported the droplet impact experimental results on the micro/nano-scaled surface. There are two representative impact behaviors as "rebound" and "fragmentation". We found the transition Weber number between "rebound" and "fragmentation" statements, experimentally. Additionally, we concerned about the dimensionless spreading diameters for our super-water-repellent surface. The novel characterization method was introduced for analysis including the "fragmentation" region. As a result, our super-water-repellent surface with the micro/nano-scaled structures shows the different impact behaviors compared with a reference smooth surface, by some meaningful experiments.
Effect on Improvement of Muscle Strength Imbalance according to Load Deviation Pattern of Left and Right Arms in Upper Limbs
Kang, Seung-Rok ; Seo, Shin-Bae ; Jeong, Gu-Young ; Bae, Jong-Jin ; Yu, Chang-Ho ; Yu, Mi ; Moon, Dong-An ; Jeong, Jang-Sik ; Kwon, Tae-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 1026~1034
DOI : 10.7736/KSPE.2012.29.9.1026
The purpose of this study was to verify the validation of effect on improvement of muscle strength unbalance according to exercise load deviation during rowing exercise. We performed evaluation of muscular activity and joint torque before the test. We recruited twenty subjects who one side`s muscle strength is bigger in more 20% than other side. Subjects divided two groups. One is dominant left side and the other was dominant right side. Subjects performed rowing exercise in electric load deviation rowing equipment (Robo.gym, Humonic Co., Ltd., Daegu, Korea). Exercise performed four sets a day including 25 times a set, and three days a week. Measurements consist of evaluation of muscular activity and joint torque. Exercise load deviation adapted that different value of muscle strength in both arms multiplied 1RM% and added 1RM 50%. The results in adapted load deviation showed that the differences of maximal peak torque in 22.75% were getting increase significantly during exercise in 5.72%. This interpreted that rowing exercise with loading deviation types could provide muscle strength and muscular endurance exercise in same time for balance. Our study found out that loading deviation could provide muscle strength and muscular endurance exercise for improving muscle unbalance.
Effect of Intraoperative Deep Brain Stimulation on Viscoelastic Properties of Parkinsonian Rigidity during Surgery
Kwon, Yu-Ri ; Eom, Gwang-Moon ; Park, Sang-Hun ; Kim, Ji-Won ; Koh, Seong-Beom ; Park, Byung-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 9, 2012, Pages 1035~1040
DOI : 10.7736/KSPE.2012.29.9.1035
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been found to be effective treatment of Parkinson`s disease (PD). This study aims to evaluate the effect of DBS for rigidity during DBS surgery. Six Parkinsonian patients who received STN-DBS surgery participated in this study. The examiner imposed flexion and extension of a patient`s wrist randomly. Resistance to passive movement was quantified by viscoelastic properties (two damping constants for each of flexion and extension phase and one spring constant throughout both phases). All Viscoelastic constants decreased by DBS (p<0.01). Specifically, reduction in damping constant during flexion (
) was greater than those of damping constant during extension (
) and of spring constant (p<0.05).
would be appropriate for evaluation of effect of DBS for rigidity during DBS surgery.