• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.259-265
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• 2009

In the traditional percussion locks of small arms, a firing pin is struck by a hammer rotating on a single center of rotation, which makes the percussion mechanism simple and reliable. In order to strike the firing pin by the hammer, however, the firing pin should be located within the radius of rotation of the hammer. As the distance between the striking point of the firing pin and the center of rotation of the hammer becomes longer, the radius of rotation of the hammer should also be increased, which results in the increase of the volume and weight of the small arms because the hammer needs the more space for its operation inside of the small arms. In this paper, a link type percussion lock was newly proposed in order to overcome the limitation of designing small arms when using traditional percussion locks, as mentioned above. The link type percussion lock was modeled by using multi-body dynamics software and designed to satisfy the requirements such as striking force level of the hammer exerting on the firing pin enough to detonate the percussion cap of ammunitions and the safety on the accidental drop. It was applied to the newly developed dual-barrel weapon system, in which the weight and overall length are important design factors, and verified by durability test and drop test on the ground.

• Journal of Families and Better Life
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• v.29 no.5
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• pp.153-163
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• 2011

This study was to investigate the effects of percussion program on depression and self-esteem for the elderly lived in residential care. 12 older adults participated in the 40-min. percussion program for 4 weeks(10 sessions). The percussion program consisted of three steps; 1) introduction for creating rapport and relationship, 2) process for mood induction and increasing interaction, and ending for increasing self-achievement and confirming the changed mood. Korean Geriatric Depression Scale (KGDS) and Self-Esteem Scale (SES) were administered before the first session and after the completion of the program. Results showed statistical significance (p<.05) in KGDS (p=.020) and SES (p=.025). Findings imply that percussion program can induce positive changes in depression and self-esteem for elderly in the residential care, and more depressed elderly group may have better outcome in percussion playing. Future studies should consider various levels of depression among elderly, and design the program to be more sensitive to the level of functioning.

• Journal of Korean Academy of Nursing
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• v.21 no.2
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• pp.204-217
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• 1991

The purpose of this study is to verify the effect of lateral position and chest percussion on gas exchange in the decreased level of conscious patients. The Subjects for this study were 21 patients' admitted in ICU of CNUH from Dec 18th, 1989 to Aug 4th, 1990. The Data was analyzed by paired t - test. The results of this study as follows ; 1) In comparison of supine position, good -lung dependent position and good - lung dependent with chest percussion, the difference of PaO ㆍ was statistically significant (P＜0.05). 2) In comparison of supine position, good -lung dependent position and good - lung dependent with chest percussion, the difference of A-a Do ㆍ was statistically significant (p＜0.05). En conclusion, the use of good -lung dependent position and chest percussion was effective nursing intervention on decreased level of conscious patients in ICU.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.3
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• pp.355-365
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• 2000

The purpose of this research was to find out the effect of chest physiotherapy on the amount of tracheal secretion and $PaO_2$. After changing position of the neurosurgical patients who had tracheostomy cannula, experimental treatments were applied as bellows, manual chest percussion on groupI, chest percussion and manual chest vibration on groupII, chest percussion and mechanical chest vibration on groupIII were done. After these trials, we have analyzed the efficacy of each procedures comparing the group differences in the quantity of tracheal secretion and $PaO_2$. Target samples were sixty patients aged between 20 to 60 who have tracheostomy state and decreased consciousness status that were admitted in NICU of a university hospital from June 1 to August 31, 1999. They assigned randomly into three experimental groups. To compare the effect of each interventions, tracheal secretion quantify was measured and $PaO_2$ was analyzed via arterial blood gas analyzer. The data were analyzed by ANCOVA of 5% significance level using SPSS P/C program. The results were as bellows. 1) The first hypothesis 'There is a difference In the quantify of the secretion among GroupI, GroupII and GroupIII' was accepted.(F=29.27, p=0.00) 2) The second hypothesis 'There is a difference in $PaO_2$ among GroupI, GroupII and GroupIII' was rejected.(F=1.71, p=0.19) From this study results, positional change and manual chest vibration including chest percussion were the most effective treatment to get maximum amount of tracheal secretion and it was confirmed that mechanical chest vibration also made much better effect than sole chest percussion method. Therefore, we concluded that the mechanical or manual chest vibration with chest percussion is more effective respiratory care method than the sole chest percussion.

• Journal of Home Health Care Nursing
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• v.30 no.2
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• pp.194-201
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• 2023

Purpose: Post-burn pruritus is one of the most prevalent complications experienced by burn patients. Though medications are prescribed for pruritus, managing this condition can prove challenging. The aim of this research was to develop and disseminate non-pharmacological self-management educational resources, and subsequently evaluate the effectiveness of implementing a percussion therapy approach. Methods: A one-group pretest-posttest design was employed to evaluate the effect of percussion therapy on one hundred patients, all of whom had suffered deep second-degree burns and undergone skin graft surgery. Variables such as the severity of pruritus, distress caused by pruritus, and satisfaction with pruritus treatment were scrutinized. A paired t-test was conducted to compare these variables before and after the intervention. Results: The majority of participants were diagnosed with third-degree burns, and the average Total Body Surface Area (TBSA) affected was 25.2%. Post-test results revealed a marked reduction in both severity and distress caused by pruritus. The intervention led to significant decreases in average severity and pain due to itchiness, and an increase in the satisfaction level following the application of percussion therapy. Conclusions: The implementation of the percussion was identified as effective in diminishing post-burn pruritus, alleviating pruritus-associated pain, and enhancing satisfaction with pruritus treatment. The percussion approach presents itself as a non-invasive, non-pharmacological strategy for managing pruritus in burn patients.

• Smart Structures and Systems
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• v.29 no.3
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• pp.475-484
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• 2022

The loss of cable tension for civil infrastructure reduces structural bearing capacity and causes harmful deformation of structures. Currently, most of the structural health monitoring (SHM) approaches for cables rely on contact transducers. This paper proposes a cable tension identification technology using percussion sound, which provides a fast determination of steel cable tension without physical contact between cables and sensors. Notably, inspired by the concept of tensioning strings for piano tuning, this proposed technology predicts cable tension value by deep learning assisted classification of "percussion" sound from tapping a steel cable. To simulate the non-linear mapping of human ears to sound and to better quantify the minor changes in the high-frequency bands of the sound spectrum generated by percussions, Mel-frequency cepstral coefficients (MFCCs) were extracted as acoustic features to train the deep learning network. A convolutional neural network (CNN) with four convolutional layers and two global pooling layers was employed to identify the cable tension in a certain designed range. Moreover, theoretical and finite element methods (FEM) were conducted to prove the feasibility of the proposed technology. Finally, the identification performance of the proposed technology was experimentally investigated. Overall, results show that the proposed percussion-based technology has great potentials for estimating cable tension for in-situ structural safety assessment.

• Journal of Korean Critical Care Nursing
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• v.2 no.1
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• pp.15-25
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• 2009

Purpose: This study investigated the effects of chest physiotherapies on intensive care unit patients mechanical ventilated. Methods: Good lung down position, chest percussion, postural drainage was applied to patients who admitted to ICU. Each patients divided into four groups and each group received different treatments. Sputum amount, lung compliance, tidal volume and oxygen saturation were measured before treatment and immediately, and time flowing. Data was analyzed with frequency, percentage, ANOVA and paired t-test using via SPSSWIN 12.0 program. Results: There were significant differences in variables each characteristics of subjects. Chest percussion increased tidal volume, static lung compliance for the mean time. Desaturation related to suction. Conclusion: Chest percussion influences on lung compliance. Based on this study results and limitation, this study suggests repeated studies in various groups

• Restorative Dentistry and Endodontics
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• v.10 no.1
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• pp.187-191
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• 1984

Vital pulpotomies by conventional method were done in 120 male and female cases between the ages of 20 and 60 who visited to SNUDH. The pulpotomized surfaces were covered by FR paste and clinical symptoms were carefully examined 1 week and 4 weeks later. The results were as follows; 1. There was no distinct difference between male and female as a whole, and pain to cold and hot or percussion was increased by aging. 2. Incidence of pain to cold and hot or percussion in group examined 4 weeks later was slightly increased than in group examined 1 week later. 3. There was no case of pain to cold and hot or percussion over all ages after 1 week, but were 5 cases (male 2, female 3) in 40 age, and were 3 cases (male 1, female 2) in 50 age after 4 weeks. 4. In 20 and 30 age, there was no case of pain to cold and hot or percussion after 4 weeks, also.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1359-1360
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• 2013

• Proceedings of the Korean Geotechical Society Conference
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• 1998.06a
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• pp.99-110
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• 1998