• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.163-166
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• 2002

The underwater acoustic communication has been widely applied to various objects such as ocean exploration-development and military affairs. And recently for embodiment of the communication system that is installed in a submarine and underwater work system, many studies have been progressing. This scope of the main studies in the meantime. It made it possible for a diver and a scuba diver who arc difficult to notice the situation of the outside because of staying in the water to hear a sound through a small speaker by using a ultra sound transducer that a central frequency is 32KHz after modulation of a voice to give the information of the outside. Also in case of happening an emergency to a diver in the water, it made him/her ask for help to a person in the outside by pressing a key and send a letter data to a person in the outside by using a keyboard. Through this system, it is possible to send a voice or data between the underwater and the outside and it is available to a diver or skin scuba diver.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.59-64
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• 2010

The synthesis of a series of fluorinated thiadiazoles 3, triazoles 4 and oxadiazoles 5 are synthesized from thiosemicarbazides 2 containing (2-(6-methyl-2-p-tolyl-lH-imidazo[1,2-a]pyridin-3-yl nucleus. These reactions were carried out by conventional method as well as ultra sound irradiation method. All products have been characterized by IR, 1H NMR, MS study and screened for their antimicrobial activity.

• Journal of Acupuncture Research
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• v.27 no.3
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• pp.167-172
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• 2010

Objectives : This observation was to report the clinical effects of acupotomy in treating wrist ganglion. Methods : From 7th April, 2010 to 12th May, 2010, 1 female patient who had a wrist ganglion was treated with ultra sound-guided acupotomy therapy and self moxibustion & massage. Results : The patient's wrist ganglion was disappeared on the surface of the skin after just one time acupotomy therapy. Hypoechoic lesion was turned into hyperechoic lesion on a ultrasonographic. After 1 month, a wrist ganglion was recurred, but the size of wrist ganglion was reduced. Conclusions : Acuputomy therapy has an effect of reducing the wrist ganglion size, but patient self management is important in preventing recurrence. The ganglion not visible on the surface of the skin must be considered as a treatment target.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.4
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• pp.405-409
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• 2008

This technical paper is proposing a sound concept in the application of the rehabilitation method of the water supply steel pipe in the large diameter ranged from 1,800mm to 3,500mm. There were conducted the experimental tests for the specimens as well as the real steel pipe of diameter 2,200mm. The water pressure ejected from nozzle tip should be at least 2,500bar to have the satisfied surface profiles required in the design criterion. The most difficult thing is to keep the water pressure at the nozzle tip as 2,500bar during the consecutive work in the interval of the work site more than 1km. It is found that the method suggested in this study is adequate method to meet the specified design criteria. The results of this study provide the useful information how to setup the equipments for the successful work. This method also provides not only the omission of the blasting process but also the effect of the budget reduction.

• Korean Journal of Materials Research
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• v.19 no.8
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• pp.432-436
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• 2009

A Cu-Fe-P copper alloy was processed by accumulative roll-bonding (ARB) for ultra grain refinement and high strengthening. Two 1mm thick copper sheets, 30 mm wide and 300 mm long, were first degreased and wire-brushed for sound bonding. The sheets were then stacked on top of each other and roll-bonded by about 50% reduction rolling without lubrication at ambient temperature. The bonded sheet was then cut into two pieces of the same dimensions and the same procedure was repeated for the sheets up to eight cycles. Microstructural evolution of the copper alloy with the number of the ARB cycles was investigated by optical microscopy (OM), transmission electron microscopy(TEM), and electron back scatter diffraction(EBSD). The grain size decreased gradually with the number of ARB cycles, and was reduced to 290 nm after eight cycles. The boundaries above 60% of ultrafine grains formed exhibited high angle boundaries above 15 degrees. In addition, the average misorientation angle of ultrafine grains was 30 degrees.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.517-520
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• 2008

In this study, corrosion resistance of steel in cracked-reinforced concrete was performed according to experimental method. Mixed design is OPC, 30% PFA, 60% GGBS and 10% SF, respectively. Moreover, corrosion resistance test was measured using ultra testing machine for 0.3mm crack induction. The corrosion resistance of blended concrete shows the results following OPC > 10%SF > 30% PFA > 60% GGBS after 60days curing. In case of mass loss test, embedded reinforcement in OPC concrete surveyed the minimum corrosion and appeared better corrosion resistance than blended concrete. As a result, corrosion resistance of sound concrete is higher than cracked concrete. Moreover, corrosion resistance of binary concrete is lower than OPC.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.15 no.2
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• pp.15-24
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• 2009

Objectives : The purpose of this study is to compare the effectiveness between myofascial release technique and ultrasound in subjects with myofascial pain syndrome. Method : Twenty subjects with myofascial pain syndrome were randomly assigned to a myofascial release technique group(n=10) or an ultrsound group(n=10). The Cervical Range of Motion(C-ROM) instrument was used to measure cervical range of motion. Electromyography(EMG) was used to measure muscle power sternocleidomastoid and upper trapezius. Result : The result of this study shows there were no significant differences in ROM increase and muscle power increase between the myofascial release technique group and the ultrasound group. In the group with Myofascial Release Technique, the average score was $61.40{\pm}11.12$ in SCM flexion of C-ROM and $127.87{\pm}4.24$ in Rt. upper trapezius extension of EMG. In the group with ultra sound, the average score was $68.60{\pm}10.02$ in SCM flexion of C-ROM and $131.50{\pm}5.45$ in Rt. upper trapezius extension of EMG. Conclusion : The results suggest that there was no significant difference between two therapeutic techniques.

• The Journal of Korean Physical Therapy
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• v.16 no.1
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• pp.124-139
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• 2004

Taping treatment is frequently used in the management of musculoskeletal pain The purpose of this study was to assess the effectiveness of ultrasound and taping treatment on the pain and grip strength with lateral epicondylitis. Pain and grip strength were assessed prior, after first, after second, after third, after fourth, and after fifth treatment. All 6 times calculated pain and grip strength. To find out the effectiveness of taping treatment, we were divide two groups. the one group was consisted of 20 patients that treated with H/P, electrical therapy and ultrasound, and the other group was consisted of 20 patients that treated with H/P, electrical therapy and taping. The results were as follow: 1. There were statistical significance on the pain and grip strength with ultrasound group(P<0.05). 2. There were statistical significance on the pain and grip strength with taping group(P<0.05). 3. Taping group was more statistical significance than ultrasound group on the pain(P<0.05). 4. There was no statistical significance between ultrasound group and taping group on the grip strength(P>0.05).

• Journal of the Korean Society of Physical Medicine
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• v.14 no.1
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• pp.15-23
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• 2019

PURPOSE: This study was conducted to investigate the effects of the myofascial meridians release technique on pain and postural control of college students with forward head posture and to compare the intervention effects of the Grastone massage and the Rollfing massage. METHODS: Thirty subjects with forward head posture were randomly and equally allocated to experimental group I (myofascial meridians release technique using Grastone massage, n=15) or experimental group II (myofascial meridians release using Rollfing massage, n=15). All subjects underwent 30 minutes of different myofascial meridians release techniques in addition to general physical therapy (hot pack: 15 min, interferential current therapy: 15 min, ultra sound: 5 min) three times a week for a total of 6 weeks. Outcome was measured before and after 4 weeks of intervention. RESULTS: In both groups, the numerical rating scale of pain was significantly decreased after intervention, with experimental group I showing a greater decrease than experimental group II. The neck disability index decreased significantly after intervention in both groups, with experimental group I showing a significantly greater decrease than the controls. The distance of the head forward displacement did not differ significantly between the two groups (p>.05). CONCLUSION: This study suggests that the Grastone method combined with the myofascial meridians release technique is a more effective intervention for improvement of pain and postural control in adults with moderate forward head posture.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.3
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• pp.317-327
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• 2021

Low Frequency Active Sonobuoy(hereinafter referred to as LFAS) are being developed in Korea in consideration of compatibility with existing overseas sonobuoys, and a communication device for acoustic signals receiving and operating control of LFAS has been developed. The communication device needs to verify compatibility with the existing Sonobuoy, and for this purpose, the standardized Sonobuoy communication protocol was applied. The communication device is designed/manufactured to transmit the acoustic signal received in real time from the Sonobuoy through VHF band RF communication to the data processing device, and transmit CFS/CSG commands for operation control to the Sonobuoy through UHF band RF communication. In order to verify the manufactured communication device, the communication status and performance were verified by interlocking test through Ultra Electronics' PASS-II equipment and domestically developed electronic device of Sonobuoy. In addition, operability was verified through environmental tests, water tanks, and marine operations. In the future, the communication device of sonobuoy can be used for verification of the Sonobuoy developed in Korea.