• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.49-56
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• 2015

For designing working devices of construction equipment, it is necessary to consider not only sufficient working ability but also available working range. Therefore, it is important to select the appropriate pivot positions of links. This paper presents a study on selection of pivot points of links used in construction equipment. To analyze the effect of each pivot point, a design program for pivot selection is developed. A conventional pivot design method requires a complicated process because it needs to create a certain working position manually to evaluate its performance. However, the developed program includes an automatic link assembly algorithm; thus, the working device can easily be analyzed by using pivot information of links. The developed program also included a kinematic/static analysis module and characteristic analysis algorithms. Therefore, it is possible to easily analyze a working device model created through the automatic assembly algorithm, whereby users can easily analyze the effect of each link pivot point for the actual product design.

• Journal of the Korea Furniture Society
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• v.18 no.2
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• pp.91-99
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• 2007

Modernity which is superficial phenomenon set off the mass scale for mass consumption and provide uniformly artificial environment. But natural destruction, environment pollution, resources exhaustion and so on has been caused by this and now ecology is threatened by destruction and damage beyond the limitation and human beings survival is even threatened. Accordingly furniture development for environment preservation considered environment problem is the urgent real situation. Recent paradigm is the concept of Eco-design which is the green design possible to live together in symbiosis, and new types of alternative furniture are needed in Korea as well. 'Furniture for disassembly' is presented as new method for alternative furniture. Furniture for disassembly can be presented by mainly two directions. The first main characteristic is what is assembled by the use of woodworking joints technique as an assembly structure system without any hardware. The second is what is presented as the structure possible to be assembled by simple manual tools with hardware without any glue. The advantages of furniture for disassembly are environment preservation, space application, transportation efficiency and shapeliness. In manufacture method which is different from present furniture, the application of traditional truss technique which uses various types of custom-made and connection technique in case of assemble structure system without hardware is the typical differences. This assembly method expects not only interest induction about assembly and disassembly of diagram per sub materials but also the development of emotion, the improvement of collaboration, space perception ability and shape sense, the improvement of solid body structure insight and so on, when it use in the furniture for children with the application to many kinds of structure with BANGDOOSANJ (Wedged), JUMUGJANGBU (Dovetail) or NABIEUNJANG (Dovetail Keys) and so on.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1844-1846
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• 2005

The characteristic of negative differential resistance(NDR) is decreased current when the applied voltage is increased. The NDR is potentially very useful in molecular electronics device schemes. Here, we investigated the NDR property of self-assembled 4,4- Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene, which has been well known as a conducting molecule. Self-assembly monolayers(SAMs) were prepared on Au(111), which had been thermally deposited onto pre-treatment$(H_2SO_4:H_2O_2=3:1)$ Si. The Au substrate was exposed to a 1mM/l solution of 1-dodecanethiol in ethanol for 24 hours to form a monolayer. After thorough rinsing the sample, it was exposed to a $0.1{\mu}M/l$ solution of 4,4-Di(ethynylphenyl)-2'-nitro-1-(thioacetyl)benzene in dimethylformamide(DMF) for 30 min and kept in the dark during immersion to avoid photo-oxidation. After the assembly, the samples were removed from the solutions, rinsed thoroughly with methanol, acetone, and $CH_2Cl_2$, and finally blown dry with $N_2$. Under these conditions, we measured electrical properties of self-assembly monolayers(SAMs) using ultra high vacuum scanning tunneling microscopy(UHV-STM). The applied voltages were from -2V to +2V with 299K temperature. The vacuum condition is $6{\times}10^{-8}$ Torr. As a result, we found the NDR voltage of the nitro-benzene is $-1.61{\pm}0.26$ V(negative region) and $1.84{\pm}0.33$ (positive region), respectively.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.307-319
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• 2021

This reserch categorizes the workplace recipient into selection criteria and studies the difference of demographic characteristics, counseling usage characteristics, job burnout, and differentiation of counseling behavior according to the subtype criteria. The survey has been collected 398 employee's responses who have no experience in counseling, who belong to the companies deploying counseling program and the companies are located in Seoul and Kyunggi area. As a result of the cluster analysis, the group was divided into "People-Product Oriented Type", "People-Product-Place Oriented Type", "People-Product-Process of service assembly Oriented Type". Subtype differentiates demographic characteristic and counseling usage characteristic and it convinces that junior employees belong to "People-Product Oriented Type" and senior employees belong to "People-Product-Place Oriented Type" and "People-Product-Process of service assembly Oriented Type". "People-Product-Process of service assembly Oriented Type" is the cluster who takes counseling services most likely if the counseling requirements are raised. Each subtype shows the differentiation of job burnout and "People-Product Oriented Type" is more exposed in job burnout among the subtypes which required urgent counseling assistance. This research is meaningful to take differentiated marketing strategies in subtype basis by considering workplace counseling service selection and recipient characteristics. Furthermore, it discusses the meaning of this research and the proposal for the further investigation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.21-27
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• 2022

This study was conducted to evaluate the structural stability of a CNC automatic lathe structure and avoid resonance. The analysis conditions were analyzed by applying the weight of the upper assembly. From the structural analysis, the stress and deformation were low, and the safety factor was high. From the dynamic characteristic analysis, it was determined that resonance does not occur because the natural frequency is outside the driving range. The error between the dynamic characteristic analysis and vibration test results is very low; thus, the reliability of the analysis results can be secured.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.1-13
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• 2008

This Study is to analyze the characteristics of arson fire under fire dynamics to protect people and property from arson fire which has been radically increased with the development of the Korean economy. Assembly and merchandise purposes such as theater, retail, and exhibition has been performed as the arson fire study. The experiment for this study is based on the analysis of the characteristic for its own combustion process and smoke spread when arson fire occurs. This study presents the analysis through comparing the condition of setting fire using liquid fuel such as thinner on purpose to the condition of setting fire naturally depending on each occupancy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.12-22
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• 2007

This paper presents to predict the powertrain structure-borne noise which is primary resource of interior noise. As the first step, it is built up a hybrid powertrain model which is based on the real powertrain which is verified with static and dynamic properties. The methods for verifying are modal analysis and running vibration testing which are experimentally implemented. Based on the Hybrid powertrain component model, an initial predictive assembly model is simulated. As the second step, the characteristic transfer functions are measured that are dynamic stiffness of rubber mounts and vibro-acoustic transfer function based on the acoustic reciprocity. Several techniques utilizing special experimental devices have been proposed for this research. Finally, the structure-borne noise by powertrain will be predict and verify with dynamic simulation and experiment.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1133-1137
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• 2011

Ordered array of gold nanoparticles (Au NPs) over ITO glass was investigated in terms of ITO pretreatment, particle size, and diamines with different chain length. Owing to the indium-tin-oxide (ITO) layer coated on the glass, the substrate surface has a limited number of hydroxyl groups which can produce functionalized amine groups for Au binding, which resulted in the loosely-packed array of Au NPs on the ITO surface. Diamine ligand as a molecular linker was introduced to enhance the lateral binding of adjacent Au NPs immobilized on the amine-functionalized ITO glass, consequently leading to the densely-packed array of Au NPs over the ITO substrate. The molecular bridging effect was strengthened with the increase of chain length of diamines: C-12 > C-8. The packing density of small Au NPs (< 40 nm) was significantly increased with the increase of C-8 diamine, but large Au NPs (> 60 nm) did not produce densely-packed array on the ITO glass even for the dosage of C-12 diamine.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.334-339
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• 1994

In this work, we propose a planar three degree-of-freedom parallel mechanism as another type of assembly device which utilized joint compliances. These joint compliances can be adjusted either by properly replacing the joint compliances or by actively controlling stiffness at joints, in order to generate the desired operational compliance characteristics at RCC point, The operational compliance matrix for this mechanism is explicitly obtained by symbolic manipulation and its operational compliance characteristics are examined, it is found that the RCC point exists at the center of the workspace when the mechanism maintains symmetric configurations. Compliance characteristic and its sensitivity of this mechanism is analyzed with respect to the magnitude of the diagonal compliance components and two different matrix norms measuring compliance sensitivity. It is expected that the analysis results provide the designer with a helpful information to determine a set of optimal parameters of this RCC mechanism.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.431-437
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• 2003

KAERI has contrived 14 kinds of spacer grid shapes of its own since 1997 and applied for Korean and US patents. To date. KAERI has obtained US and Korean patents for 6 kinds of spacer grid shapes among them. Tn this study. performance test on two spacer grid shapes that are assumed to be the most effective candidates for the spacer grid of the next generation nuclear fuel in Korea was carried Qui through the mechanical/structural test and analysis. The test result has shown thai the performances of the candidates are better or not worse than that of the current spacer grid.