• The Journal of Korea Robotics Society
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• v.4 no.3
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• pp.225-232
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• 2009

In the high precision robot systems, the most popular tasks may be handling of micro-scale objects on a surface such as a micromanipulation robot system. In handling of micro-scale objects, the stiction effect becomes a fundamental issue since the micro-contact mechanics dominates the micromanipulation robot system. In the paper, a theoretical non-stick condition derived from the micro-contact mechanics is carried out for the propose of micro-scale object manipulation. To verify the non-stick condition, a micro-manipulation robot system equipped with a high precision stage system and a microscope system is developed. Experimental results show that the proposed non-stick condition guarantees successful micro-scale object manipulation.

• Tribology and Lubricants
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• v.28 no.3
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• pp.117-123
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• 2012

Tribological properties of hybrid type friction materials were studied. Hybrid friction materials were produced by combining non-steel(NS) and low-steel(LS) type friction materials. The emphasis of the investigation was given to possible synergistic effects from the two different friction materials, in terms of friction stability at high temperatures and the amplitude of friction oscillation, also known as stick-slip at low sliding speeds. The high temperature friction test results showed that the friction effectiveness of the hybrid friction material was well sustained compared to LS and NS friction materials. Wear resistance of the hybrid type was similar to LS friction materials. Examination of the rubbing surfaces after tests revealed that the friction characteristics of the hybrid friction material were attributed to the wear debris produced from low-steel friction materials, which were migrated to the surface of the non-steel friction material, forming new contact plateaus. The stick-slip amplitude and its frequency were pronounced when non-steel friction material was tested, while hybrid and low-steel types showed relatively small stick-slip amplitudes. These results suggest possible improvement of tribological properties by designing a hybrid composite of low-steel and non-steel friction materials.

• Honam Mathematical Journal
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• v.30 no.1
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• pp.165-170
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• 2008

We will examine the stick number of knots on the cubic lattice which is called the lattice stick number. The lattice stick numbers of knots $3_1$ and $4_1$ are known as 12 and 14, respectively. In this paper, we will show that only $3_1$ and $4_1$ have representations of irreducible non-trivial polygons, both numbers of whose sticks parallel to the y-axis and the z-axis are exactly four.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.89-91
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• 2012

The numerical simulation for detonation failure of ammonium nitrate (AN) based non-ideal explosives is carried out with an accurate and state-of-the-art Eulerian method. Detonation failure is readily observed in the rate stick experiments utilizing the AN mixture explosives and the inert confinements of varying thicknesses. The composition of non-ideal explosives and thickness of the confinements influence the characteristics of detonation failure. Calculated results are compared against the experimental data of both unconfined and confined rate stick problems and provide a reliable guideline to establish a fine-tuned chemical kinetic model for detonation failure.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.3
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• pp.121-130
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• 2024

Purpose : This study was conducted to investigate the effect of neck stabilization exercises using a stick on the pain, headache, and quality of life of adult patients with chronic non-specific neck pain. Methods : The participants of this study were 28 adult patients with chronic non-specific neck pain. The subjects were assigned to the experimental group (n=15, neck stabilization exercises using a stick after conservative physical therapy) and the control group (n=13, conservative physical therapy) according to the order of participation in the study and the intervention methods. The intervention was conducted three times a week for four weeks. The neck stabilization exercises using a stick consisted of isometric exercises of the muscles around the neck and strengthening exercises of the muscles around the scapula. The visual analog scale (VAS) and headache impact test (HIT-6) were used to measure the pain and headache, and the SF 36 health questionnaire (SF-36) was used to measure the quality of life. Results : In the comparison of VAS, HIT-6, and SF-36, there were significant differences between before and after the intervention in both the experimental and control groups (p<.05). The pre-post comparisons between the two groups according to the experiment showed significant differences between the experimental group and the control group (p=.001). However, the experimental group showed greater changes than the control group. Conclusion : Through this study, it was confirmed that neck stabilization exercises using a stick have positive effects on reducing the neck pain and headaches and improving the quality of life of adult patients with chronic neck pain. Therefore, it is considered that neck stabilization exercises using a stick can be used as an effective exercise method for the treatment and prevention of patients with chronic neck pain in the future.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.49-59
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• 2024

Recently, the electric vehicle market is gradually growing due to strengthened environmental regulations and high oil prices. also, in internal combustion engine vehicles, the sensitivity of Buzz, Squeak, Rattle (BSR) noise is increasing as engine Noise, Vibration, and Harshness (NVH)-related noise is reduced and technology for shielding noise coming from outside is developed. In this study, the stick-slip noise that occurs in Panoramic Curved Display (PCD) of automobile was analyzed for the correlation between the surface energy of polymer plastic and the polar component. For polar polymer materials, Acrylonitrile Butadiene Styrene (ABS) and PolyCarbonate-Acrylonitrile Butadiene Styrene (PC-ABS), compound materials were fabricated and evaluated. As a result, when the polar component of the polymer plastic was 3.86 mN/m or higher, stick-slip motion occurred, and as the absolute transition slope increased in the friction behavior over time, the possibility of stick-slip noise increased and the value of the friction coefficient The greater the difference, the greater the strength of the stick-slip noise.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2063-2066
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• 2005

This paper presents an approach to detect the dielectric condition of FRP Hot Stick in EHV high voltage cable whereas shutting down the power system is not necessary. The radio frequency generating method is adopted by transmitting radio wave into the Electrodes. This instrument is small, easy to use and also inexpensive. Furthermore, the impurity level of dirt on high voltage insulator (non-ceramic type) will be analyzed by using the methods based on IEEE Std.978-1984 at 105 kV.DC. /305 mm. and OSHA Regulation 1910.269 Part J - live line tools. The frequency at 10-20 MHz is applied to FRP Hot Stick via Electrode1 and from FRP Hot Stick surface to Electrode 2. After that the results will be evaluated by testing in each condition of FRP Hot Stick, such as dry surface, hot surface, foil winding and conductor inserting. Finally, the watt loss will be examined and compared with the loss from humidity and Carbon tracking. The important components of this system are radio frequency generating unit, frequency stabilizing unit, frequency amplifier, FRP Hot Stick frequency counter, processing unit, and display unit.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.5 s.108
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• pp.29-35
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• 2004

Fiber dimensions, their derived values and chemical properties of cotton stalks (Gosypium hirsutum L), jute stick (Corchorus capsularis) and dhancha (Sesbania aculeate) have been examined to assess their suitability for paper production. Cotton stalks have a good derived values especially slender ratio, which is comparable to hardwood. The flexibility coefficient of these three non wood plants is better than hardwood. Anatomical analysis shows higher percentage of fibers and vessels than in general non wood plants. Lignin, $\alpha$-cellulose and pentosan contents in these three nonwood plants are within the range of hardwood. Neutral sugar analysis of cotton stalks, jute stick and dhancha shows that the glucose in the major sugar followed by xylose and mannose. The arabinose and galactose are present in minor amount. Alkaline nitrobenzene oxidation of cotton stalks, jute stick and dhancha wood meal exhibits that these nonwood plant lignins mainly consist of syringyl (S) and guaiacyl (V) units. The S/V ratios are 1.6, 1.2 and 2.1 for cotton stalks, jute stick and dhancha, respectively.

• Korean Journal of Acupuncture
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• v.34 no.3
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• pp.109-115
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• 2017

Objectives : Many researches have studied warm needling technique to standardize its treatment by temperature measurement and material differences in the effectiveness. The purpose of this study is to compare the temperature changes of the acupuncture needle shaft during the combustion process of the moxa stick to determine the heat transfer pattern of the warn needling. Methods : A moxa stick($7{\times}8mm$) was connected to one side of the needle shaft using a stainless steel needle(ø 0.3 mm, ø 0.5 mm, ø 0.8 mm, shaft length 40 mm) with the needle handle removed. During the warm needling, temperature changes of the needle shaft were observed with an infrared camera(Flir E30) and an infrared thermometer(TESTO 845). Results : In the normal condition, heat transmit of needle shaft increased at spots 10 mm and 25 mm below the moxa stick. The amount of heat transmit increased with the diameter of needle shaft. However, when the heat shield was installed to exclude radiant heat from the moxa stick, heat transfer was less at 10 mm below the moxa stick and no temperature change was observed at 25 mm below the moxa stick. Heat transfer by warm needling does not reach the end of needle shaft even in ø 0.8 mm needle. Conclusions : It is suggested that the radiant heat of moxa stick results in the heat transmit of acupuncture needle shaft. Thus, radiant heat transmit must be considered as one of the heat transfer characteristics of the warm needling.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.717-720
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• 2002

An Amplitude Proportional Friction Damper (APFD) system is considered in order to improve the stick-slip characteristics of Coulomb friction damper. The frictional force is proportional to the amplitude in APFD system and the system is non-linear as is Coulomb damper system. The free vibration analysis on an 1-DOF system has conducted to demonstrate the characteristics of the APFD system and the results show that the APFD system has similar damping characteristics to the viscous damper system. It is concluded that the APFD system may become a cost effective substitution for the viscous damper and it also has certain advantages over Coulomb damper system since the APFD system can be designed to work with no stick-slip.