• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.18-21
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• 2003

Fused Deposition Modeling (FDM) parts are made by piling up thin layers that cause the stair stepping effect at the surface of FDM parts. This effect brings about poor surface roughness of the part and requires additional post machining such as manual finishing that is detrimental to the part geometry and time consuming. Determining optimal build orientation for FDM parts can be one solution to minimize the post machining. However, by using the CAD model, calculating the optimal build orientation is impractical due to heavy computing process. In order to calculate the optimal build orientation with high speed. the surface roughness model based on measured data and interpolation is newly developed in this research. Also. the genetic algorithm (GA) is applied for acquiring reliable solution. Finally, It is verified from the test that the presented approach is very efficient for reducing the additional post machining process fer FDM parts.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.6
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• pp.1341-1348
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• 1994

This is a comparative study on applications of finite analytic method (FAM) and finite difference method (FDM) to rectangular smalI basin circulation. To do such a comparison, the circulation model in small rectangular basin is established using FAM and the nurmerical solution from the FAM model is compared with that from the FDM model. As the grid size approaches Von Neumann stablity condition, the convergence time to steady state increases in Askren's model, but does not increase in finite analytic model. Especially in the FAM model, the numerical solution converges stably even in the grid size range beyond the stablity condition whereas that diverges in the FDM model. In the case of large basin Reynolds number, it is found that steady state solution is obtained in the FAM model with smaller calculating steps than those of in the FDM model.

• The Journal of Korean Physical Therapy
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• v.31 no.1
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• pp.24-30
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• 2019

Purpose: This study compared the effectiveness of three methods, fascial distortion model (FDM), myofascial release (MFR), self-myofascial release (SMR), on the neck range of motion and pain. Methods: In this study, the collected data were processed statistically using SPSS version 22.0 for Windows. Descriptive statistics were used to analyze the general characteristics of the subjects. Repeated measure ANOVA was conducted to analyze the range of motion of the neck of the group and VAS, and Contras was used to see the difference in significance over time. One-way ANOVA was used to compare the differences among the groups and a post-hoc test was used. The significance level (${\alpha}$) was 0.05. Results: In the range of motion, the flexion and extension of the neck, right rotation, and left rotation were significantly different in the SMR, FDM, and MFR groups. The right lateral flexion showed significant differences in the FDM, MFR, and SMR groups. The VAS was similar in the groups at 2 and 4 weeks, but there was a significant difference among the FDM, MFR, and SMR groups at 6 weeks. Conclusion: In this study, MFR and MSR as well as FDM were effective in controlling the range of motion and pain control of the neck. Further studies will be needed to determine the effects of long-lasting treatments other than pain control. These studies and the present study will be used as a basis for ongoing research into the duration and method of application for musculoskeletal therapies.

• The Journal of Korean Physical Therapy
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• v.32 no.4
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• pp.238-244
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• 2020

Purpose: This study compared the effects of the fascial distortion model (FDM), foam rolling (FR), and self-stretching (SS) on the ankle dorsiflexion range of motion (ROM). Methods: Thirty subjects who had no more than 30° of ankle dorsiflexion ROM at the weight-bearing lunge test were recruited in this study. They were divided into three groups: (FDM, FR, and SS), and underwent each intervention for five minutes. Before and after the intervention, the ankle dorsiflexion ROM in the supine (the open-) and standing (the closed-kinetic chain) of the subjects were tested. The changes in the ROM between pre- and post-intervention and among the groups were analyzed. Results: All groups showed increased ankle dorsiflexion ROM after the intervention in both positions. In the position of the open kinetic chain, the changes in the ROM between pre- and post-intervention had significant differences among the groups, and the FDM was higher than the FR and SS. In the position of the closed kinetic chain, the ROM after the interventions and the changes in the ROM had significant differences among the groups, and FDM was higher than the FR (ROM after the intervention, the change in ROM) and SS (the change in ROM). Conclusion: These findings showed that FDM had more efficiency than the FR and SS as FDM had a stronger effect on increasing ankle dorsiflexion in a short, limited time. Clinicians who have limited time to treat their patients, particularly trying to increase ankle dorsiflexion ROM, should consider the application of FDM.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.33-40
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• 2021

Purpose : The fascia is the body's largest sensory organ affected by mechanical stimuli such as pressure. Fascial distortion model (FDM) is one of the fascia treatment techniques, and it is based that most musculoskeletal problems are caused by three-dimensional distortion of the fascia. Until now, some studies have been conducted to investigate the effect of FDM, but it is still not enough. In this study, among the six techniques of FDM, trigger band (TB) and cylinder distortion (CyD) were applied to the forearm to investigate the immediate effect on the maximal grip strength, force sense and range of motion. Methods : 22 healthy adults in their 20s and 30s participated. Before and after the application of FDM, maximal grip strength, force sense and range of motion were measured. For analysis, a paired t-test was performed, and the significance level was set to p<.05. Results : After FDM, there were a significant differences that increased the force sense and the range of motion (p<.05). But the maximal grip strength did not show a significant difference (p>.05). Conclusion : The results of this study, the FDM did not affect maximal grip strength, but it was shown to increase the sense of force and range of motion. We assumed that it is the result of the changes in the states of the fascia and changes in the activity of mechanical receptors induced by pressure and stretch from FDM application.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.485-490
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• 1999

We will calculate concentration of air pollutants using ISCST3, FDM and AERMOD of models recommended in U. S. EPA which are able to predict concentration of short term for point source, complex like industrial complex, power plant and burn-up institution. Before executing model, as analyzing computational result of many cases according to selecting of input data, we will increasing predictable ability of model in limit range of model. Especially, we analyzed three cases-case of considering various emission rate according to time scale and not, case considering effect of atmospheric pollution materials removed by physical process. In our study, after comparing and analyzing results of three model, we choose the atmospheric dispersion model reflected well the characteristic of the area. And we will investigate how large the complex pollutant sources such as industrial complex contribute to atmospheric environment and air quality of the surrounding the area as predicting and estimating chosen model.

• Korean Journal of Computational Design and Engineering
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• v.22 no.1
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• pp.37-43
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• 2017

3D printing techniques can be used in various application fields and many researches have been reported. FDM (Fused Deposition modeling) can make multi-material or multi-color models with the simultaneous use of two or more filaments. In a dual-nozzle FDM printers, while the active nozzle is working, the remaining nozzle will be idle. The remaining molten resins inside an idle nozzle can ooze out unwantedly. The spill over from the resting nozzle produces unwanted remaining on the fabricated product. In this research, we suggest a method for optimizing building position of a model to minimize the unwanted spill-over that could possibly contaminate the final product. The method is based on minimizing the two intersection volumes. The first intersection volume is obtained by intersecting the volume defined by the first material and the Minkowski sum between the volume of the first material and the vector obtained by subtracting the center point of the first nozzle from the center point of the second nozzle. The second intersection volume can be obtained by reversing the role of the first and second volumes and nozzles. Some results obtained from the implementation using the Parasolid (Siemens) geometric modeling kernel is presented.

• Journal of the korean society of oceanography
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• v.39 no.2
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• pp.136-147
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• 2004

Different model formulations in available models were compared with Microplankton-Detritus (MPB) model, and well documented FDM and ERSEM models were the candidate for these comparison. Different formulations in both candidate models were expressed in terms of MPD parameterization. Even though there are differences in the control of autotroph growth among models, it was found that some of the more important microplankton parameters expressed incomparable terms have broadly similar values in all the models. However, an important difference was proved to be the direct contribution of microheterotrophs to the Detritus compartment in FDM and ERSEM, whereas in MPD microplankton biomass passes to Detritus only by way of mesozooplankton grazing.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.300-305
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• 2001

Competitive power is rapidly manufacture product required consumers. Therefore, modern industry have changed from small item many production to many item small production. rapid production is necessary thing at the product development. Thus, rapid prototyping is appeared. If the graphic model was made by CAD, the production can be made in short term. That provide what the part was directly tested by the worker. It provide believable data. This study is experiment on surface roughness of part at FDM

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.1
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• pp.66-73
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• 2021

In this paper, we analyzed and considered the precision of parts produced by 3D printing methods. For the latch systems applied to the Wingline folding doors, the 3D shape of the door hinge part was printed using FDM and DLP methods. Then, the 3D printed shape was scanned to measure the dimensions and dimensional changes of the actual model. In the comparison and analysis of the 3D printed door hinge parts, because the output filling density is 100% owing to the characteristics of DLP 3D printing, the filling density in FDM 3D printing was also set to 100%.