• Title/Summary/Keyword: Stability test

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Concurrent Validity and Test-retest Reliability of the Core Stability Test Using Ultrasound Imaging and Electromyography Measurements

  • Yoo, Seungju;Lee, Nam-Gi;Park, Chanhee;You, Joshua (Sung) Hyun
    • Physical Therapy Korea
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    • v.28 no.3
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    • pp.186-193
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    • 2021
  • Background: While the formal test has been used to provide a quantitative measurement of core stability, studies have reported inconsistent results regarding its test-retest and intraobserver reliabilities. Furthermore, the validity of the formal test has never been established. Objects: This study aimed to establish the concurrent validity and test-retest reliability of the formal test. Methods: Twenty-two young adults with and without core instability (23.1 ± 2.0 years) were recruited. Concurrent validity was determined by comparing the muscle thickness changes of the external oblique, internal oblique, and transverse abdominal muscle to changes in core stability pressure during the formal test using ultrasound (US) imaging and pressure biofeedback, respectively. For the test-retest reliability, muscle thickness and pressure changes were repeatedly measured approximately 24 hours apart. Electromyography (EMG) was used to monitor trunk muscle activity during the formal test. Results: The Pearson's correlation analysis showed an excellent correlation between transverse abdominal thickness and pressure biofeedback unit (PBU) pressure as well as internal oblique thickness and PBU pressure, ranging from r = 0.856-0.980, p < 0.05. The test-retest reliability was good, intraclass correlation coefficient (ICC1,2) = 0.876 for the core stability pressure measure and ICC1,2 = 0.939 to 0.989 for the abdominal muscle thickness measure. Conclusion: Our results provide clinical evidence that the formal test is valid and reliable, when concurrently incorporated into EMG and US measurements.

A Study of the Limits of Stability in Hemiplegic Patients (편마비환자의 안정성한계에 대한 연구)

  • Kwon, Oh-Yun
    • Journal of Korean Physical Therapy Science
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    • v.2 no.4
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    • pp.739-747
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    • 1995
  • The purpose of this study was to evaluate and compare the Limits of stability(LOS) in hemiplegic patients who can walking independently. The LOS was measured at stable surface, unstable surface with eye open and eye closed. In this study, 18 out-patients were evaluated who were treated at Yonsei University Medical Center Rehabilitation Hospital. In order to determine the statistical significance of results, T-test, paired t-test, and Kruskal-Wallis 1-way ANOVA were applied at 0.05 level of significance. The results were as follows: 1. The mean of lateral limits of stability was 9.89 degree. 2. The mean of anteroposterior limits of stability was 6.43 degree. 3. There was a significant difference of limits of stability between sound side and affected side(p<0.05). 4. The limits of stability was significantly decreased with eye closed(p<0.05) 5. The limits of stability was significantly decreased at unstable surface(p<0.05). 6. The limits of stability was a significant difference as spasticity degree of ankle plantar flexors(p<0.05). These results showed that the limits of stability in hemiplegic patients was more decreased than that of normal adult. In order to improve the balance in hemiplegic patients, we need to increase the limits of stability.

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Characteristics of dairy goat milk positive reaction of the alcohol precipitation test in Korea (우리나라 유산양 알코올 양성유의 특징에 관한 연구)

  • Kim, Hye-Ra;Jung, Ji-Young;Cho, In-Young;Yu, Do-Hyeon;Shin, Sung-Shik;Son, Chang-Ho;Ok, Ki-Seok;Hur, Tai-Young;Jung, Young-Hun;Choi, Chang-Yong;Suh, Guk-Hyun
    • Korean Journal of Veterinary Service
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    • v.36 no.4
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    • pp.255-261
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    • 2013
  • The objective of the present study was to determine the minimum alcohol (ethanol) concentration that gives rise to the coagulation of goat milk for the alcohol precipitation test, and to evaluate the physical parameters of goat milk which include alcohol and heat stability. A total of 1,295 udder-half milk samples from 648 lactating dairy goats were collected from seven farms in Jeonnam province, Republic of Korea, to determine the alcohol and heat stability. The majority (99.6%) of the samples were coagulated when 70% ethanol was added to the milk, while only 11.0% of the samples were precipitated by the addition of an equal volume of 45% ethanol. With the concentration of 65%, 60%, 55% and 50% aqueous ethanol, 99.2%, 96.8%, 81.0% and 52.8% of the milk samples were coagulated, respectively. Of 1,295 dairy goat milk samples tested for heat stability, 127 (9.8%) were coagulated by boiling. Among the 143 alcohol test-positive udder-half milk samples, 52 (4.0%) were unstable by heat test, while 1,032 (79.7%) of the 1,152 alcohol test-negative milk samples were stable by heat test. According to the results of boiling test, sensitivity and specificity of 45% alcohol precipitation test were 0.3023 (95% CI: 0.2346~0.3772) and 0.9190 (95% CI: 0.9017~0.9344), respectively. The contents of protein and the specific gravity were higher in the milk samples of 45% alcohol test-positive than in those of 45% alcohol test-negative. However, lower levels of lactose and milk urea nitrogen were observed in the milk samples of 45% alcohol test-positive compared to the alcohol test-negative milk samples. The lowest pH values ($6.73{\pm}0.20$) were shown in the 45% alcohol test-negative and heat-unstable milk samples, while the lowest values of somatic cell counts and bacterial counts were shown in the 45% alcohol test-negative and heat-stable milk samples. Results of this study suggest that the alcohol precipitation for dairy goat milk may have to be tested with ethanol concentration less than 45% for the determination of freshness and heat-stability.

Synergistic Effect of Tocopherol, Citric Acid and Sodium Polyphosphate on the Thermal Oxidation of Blending Oil (혼합유(混合油)의 열산화(熱酸化)에 대(對)한 Tocopherol, 구연산 및 인산염(燐酸鹽)의 상승효과)

  • Chang, Hun-Ki
    • Journal of the Korean Applied Science and Technology
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    • v.7 no.1
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    • pp.63-70
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    • 1990
  • Influence of mixing ratio of blending oil (rice bran oil : RBD palm olein = 1 : 1, 1 : 4 mixture: w/w) and natural tocopherol, citric acid, and sodium polyphosphate on enhancement of oxidation stability of blending oil under the condition of tap water infulx(1 ml/min/200g oil) were compared by AOM test after heating these system at l80$^{\circ}C$. In addition, the effects of tocopherol, and synergist on oxidition stability were also tested with potato chips fried with blending oil(1 : 4 mixture). The result obtained were as followes; 1. The test of RBD palm olein addition of 50% and 80% against rice bran oil on oxidation stability showed that the higher the palm olein contents in blending oil, the higher the oxidation stability. 2. The test of oxidation stability, adding l00ppm, 200ppm and 400ppm of natural tocopherol in two different types of blending oils, A(1 : 1 mixture) and B(1 : 4 mixture), disclosed that blending oil B was more positively effective, and this trend was superior at 200ppm level particularly, Furthermore, oxidation stability was enhanced remarkably upon addition of 100ppm of natural tocopherol, and 50ppm of citric acid together with 50ppm, 100ppm and 200ppm of sodium polyphosphate in general. Especially, 200ppm of sodium polyphosphate addition induced the most synergetic effect on oxidation stability showing as much as 3 times compare to control. 3. The results of oxidation stability obtained by peroxide value on potato chips fried with blending oil (1:4 mixture} added tocopherol, citric acid and sodium polyphosphate and preserved at $60^{\circ}C$ revealed that addition of tocopherol and 50ppm of citric acid together with 200ppm of sodium polyphosphate treatment was the most synergistic coinciding with AOM test results.

Using a Borehole Stability Device for Hydraulic Testing in Unconsolidated Alluvium (공벽 유지장치를 이용한 미고결 충적층의 수리특성 평가)

  • Won, Kyoung-Sik;Kim, Chunsoo;Chae, Soo-Yong;Shin, Dong-Min
    • The Journal of Engineering Geology
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    • v.26 no.1
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    • pp.15-22
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    • 2016
  • Hydraulic falling head and slug tests were carried out in an alluvium aquifer using a borehole stability device. The hydraulic testing had proved difficult in alluvial formations of sands and gravels due to borehole collapse and unstable borehole walls within the test section. This study aims to improve the hydraulic test results by using a borehole stability device. The device can minimize the collapse of borehole walls, and the use of a filter with a constant opening ratio improves the calculations per unit area of the test section. Permeability obtained from the falling head test without a borehole stability device was 8.82 × 10−5m/sec. When the borehole stability device was installed in the same test section the measured permeability increased to 4.00 × 10−4m/sec, which is 4.5 times that obtained without the borehole device. The relatively low permeability obtained using the conventional test method is attributed to the presence of a fine-grained slime generated during drilling and a reduction of the test area in the test interval due to a gradual collapse of the borehole walls. This study considers how the use of a borehole stability device to prevent borehole collapse can influence the results of hydraulic tests in alluvial formations. It is expected that the results can be used as a basis for improving the reliability and applicability of hydraulic tests performed in alluvial aquifers.

Development and Effectiveness of Smartphone Application for the Medication Confirmation of High-alert Medications (고 위험약물의 투약확인을 위한 스마트 폰 어플리케이션의 개발 및 효과)

  • Kim, Myoung Soo
    • Korean Journal of Adult Nursing
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    • v.26 no.3
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    • pp.253-265
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    • 2014
  • Purpose: This study was done to develop and evaluate a smartphone application for the medication confirmation of high-alert medications. Methods: A nonequivalent control group non-synchronized design was used for this study. Participants in the treatment group used the application for four weeks. Data were analyzed using descriptive analysis, ${\chi}^2$-test, and t-test for the homogeneity of participants, and a paired t-test for effectiveness in each group with the SPSS 18.0. Results: Stability of medication administration was estimated by knowledge and certainty, ranged from a score of one to three. A correct answer with high certainty was coded as high stability, low certainty regardless of correct answer was coded as a moderate stability, and incorrect answers with high certainty were rated as low stability. There were no differences in 'knowledge of high alert medication', 'Certainty of knowledge', 'stability of medication administration', 'confidence of single checking medication', and 'medication safety activities' between the treatment group and the comparison group. The treatment group reported a greater difference between pretest and post-test in 'certainty of medication knowledge' (t=3.51, p=.001) than the comparison group. Conclusion: Smartphone application for medication confirmation of high-alert medications will provide an important platform for reducing medication errors risk.

The Vibration Characteristic and Fatigue Life Estimation of a Small-scaled Hingeless Hub System with Composite Rectangular Blades (복합재료 기준형 블레이드를 장착한 축소 힌지없는 허브시스템의 진동특성과 피로수명 예측)

  • Song, Keun-Woong;Kim, Jun-Ho;Kim, Duck-Kwan;Joo, Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.310-315
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    • 2003
  • This paper described that rotating test and fatigue test of a small-scale hingeless hub system with composite rectangular blades. Generally Rotating stability and fatigue test technique is one of Key-technology on test and evaluation for helicopter rotor system Rotating test of hingeless rotor system was achieved by means of rotor vibration characteristic and aeroelastic stability test GSRTS, equipped with hydraulic actuator and 6-component rotating balance was used to test hingeless rotor system especially for an observation of blade motion including flawing, lagging and feathering. Rotating test was done in hover and forward flight condition. Small-scaled blade fatigue test condition was determined by blade load analysis with the reference table of composite materials(S-N curve). Fatigue test bench was developed for the estimation of blade fatigue life, and tested its characteristic.

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Stability Test and Quantitative and Qualitative Analyses of the Amino Acids in Pharmacopuncture Extracted from Scolopendra subspinipes mutilans

  • Cho, GyeYoon;Han, KyuChul;Yoon, JinYoung
    • Journal of Pharmacopuncture
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    • v.18 no.1
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    • pp.44-55
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    • 2015
  • Objectives: Scolopendra subspinipes mutilans (S. subspinipes mutilans) is known as a traditional medicine and includes various amino acids, peptides and proteins. The amino acids in the pharmacopuncture extracted from S. subspinipes mutilans by using derivatization methods were analyzed quantitatively and qualitatively by using high performance liquid chromatography (HPLC) over a 12 month period to confirm its stability. Methods: Amino acids of pharmacopuncture extracted from S. subspinipes mutilans were derived by using O-phthaldialdehyde (OPA) & 9-fluorenyl methoxy carbonyl chloride (FMOC) reagent and were analyzed using HPLC. The amino acids were detected by using a diode array detector (DAD) and a fluorescence detector (FLD) to compare a mixed amino acid standard (STD) to the pharmacopuncture from centipedes. The stability tests on the pharmacopuncture from centipedes were done using HPLC for three conditions: a room temperature test chamber, an acceleration test chamber, and a cold test chamber. Results: The pharmacopuncture from centipedes was prepared by using the method of the Korean Pharmacopuncture Institute (KPI) and through quantitative analyses was shown to contain 9 amino acids of the 16 amino acids in the mixed amino acid STD. The amounts of the amino acids in the pharmacopuncture from centipedes were 34.37 ppm of aspartate, 123.72 ppm of arginine, 170.63 ppm of alanine, 59.55 ppm of leucine and 57 ppm of lysine. The relative standard deviation (RSD %) results for the pharmacopuncture from centipedes had a maximum value of 14.95% and minimum value of 1.795% on the room temperature test chamber, the acceleration test chamber and the cold test chamber stability tests. Conclusion: Stability tests on and quantitative and qualitative analyses of the amino acids in the pharmacopuncture extracted from centipedes by using derivatization methods were performed by using HPLC. Through research, we hope to determine the relationship between time and the concentrations of the amino acids in the pharmacopuncture extracted from centipedes.

Evaluation of Rutting and Deformation Strength Properties of Polymer Modified SMA Mixtures (개질재 첨가에 따른 SMA 혼합물의 소성변형 및 변형강도 특성 연구)

  • Kim, Hyun-H.;Choi, Young-R.;Kim, Kwang-W.;Doh, Young-S.
    • International Journal of Highway Engineering
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    • v.11 no.4
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    • pp.25-31
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    • 2009
  • In general, it is well known fact that the stone mastic asphalt (SMA) pavement has a high resistance against rutting. However, performance of SMA is not well measured by general method used in the laboratory. The objective of this study is to investigate an applicability of deformation strength ($S_D$) for performance estimation of SMA, and to find out the correlation between rut depth and dynamic stability, and $S_D$ of SMA. This study carried out wheel tracking test and Kim-test with optimum asphalt content (OAC) determined by mix design. The results indicated that the $S_D$ of SMA was very poorer than those of dense-graded asphalt mixtures. $S_D$ showed similar WT dynamic stability and rut-depth level. It was found that Kim-test was not reflected higher rutting resistance of SMA like as indirect tensile strength (ITS) test and Marshall stability test. Also, it was revealed that dynamic stability and rut-depth of WT had some problems to estimate rutting resistance of SMA mixtures.

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Reinforced Earth Retaining Wall of The Collapsed-A Case Study. (보강토옹벽의 사고사례에 관한 연구)

  • Yoo, Chung-Sik;Jung, Hyuk-Sang;Lee, Soung-Woo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.958-967
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    • 2004
  • This paper deal with cause and analysis about case of collapsed reinforced-soil retaining wall. The analysis of the cause was carried through experimentation, slop stability analysis and literature study. The experimentation treated the large direct shear test, the hydraulic conductivity test and the other basic test through backfill extracted from collapsed reinforced-soil retaining wall. The ultimate tensile strength was established by rib tensile strength test of geogrid. The analysis of internal and external stability of reinforced-soil retaining wall was performed on the basis of parameters. The result of analysis, reinforced-soil retaining wall and the slope at the dry season are stable. However, the factors that fine-grained soil at hydrometer test exceed the standard of the design, rainfall duration is too long at the time of collapse and monthly pricipitation is heavy are cause of the collapse.

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