• Geomechanics and Engineering
• /
• v.35 no.2
• /
• pp.135-147
• /
• 2023

Sand columns in clayey soil are considered one of the most economical and environmentally-friendly soil-improving techniques. It improves the shear strength parameters, reduces the settlement, and increases the bearing capacity of clayey soils. The aim of this paper is to study the effect of grain shape in sand columns on their performance in improving the mechanical properties of clayey soils. An intensive series of consolidated-drained triaxial tests were performed on clay specimens only and clay specimens with sand columns. The parameters examined during the experimental work were grain shape in sand columns (angular, rounded, sub-rounded) and effective confining pressure (50 kPa, 100 kPa, 200 kPa). The results indicated that there is a significant improvement in the deviatoric stress and stiffness values of specimens with sand columns. Improving deviatoric stress values in the use of angular sand grains was found to be higher than those in the use of sub-rounded and rounded sand grains. A 187%, 159%, and 153% increment in deviatoric stress values were observed for the sand columns with angular, sub-rounded, and rounded grain shapes, respectively. The specimens were observed to be more contractive as the sand column was installed, and as the angularity of grains in the sand column was increased. Sand column installation improves significantly the angle of internal friction, and the effective angle of internal friction increases as the angularity of the sand grains increases.

• Journal of Acupuncture Research
• /
• v.41 no.2
• /
• pp.129-134
• /
• 2024

Knee osteoarthritis (KOA) is a prevalent degenerative joint disease causing significant pain and dysfunction. This case report presents the use of electromagnetic acupuncture utilizing a Whata 153 device generating a magnetic field to enhance acupuncture stimulation for the treatment of KOA. A 69-year-old female diagnosed with KOA experienced a reduction in pain (numerical rating scale score from 7 to 4), improved gait, and decreased stiffness and swelling after daily electromagnetic acupuncture treatments during hospitalization. In addition, the Korean Western Ontario and McMaster Universities Osteoarthritis Index scoreimproved from 20 to 14, and the patient rated her overall improvement as "significantly improved" on the patient's global impression of change scale. Although these findings suggest potential benefits of electromagnetic acupuncture for KOA, the case report design limits its generalizability. More controlled trials are warranted to confirm the efficacy and safety of electromagnetic acupuncture as a treatment of KOA.

• Journal of the Korean Wood Science and Technology
• /
• v.15 no.3
• /
• pp.44-55
• /
• 1987

In order to study the effect of sawdustboard combined with plastic chips, 0.5mm($T_1$), 1mm($T_2$), 1.4mm($T_3$) thick nylon fiber. polypropylene rope fiber(RP), and 0.23mm thick moth-proof polypropylene net fiber(NP) were cut into 0.5, 1, 2cm long plastic chips. Thereafter, sawdustboard combined with plastic chips prepared as the above and plastic non-combined sawdustboard(control) were manufactured into 3 types of one-, two-, and three layer with 5 or 10% combination level. By the discussions and results at this study, the significant conclusions of mechanical and physical properties were summarized as follows: 1. The MORs were shown in the order of 3 layer> 2 layer> 1 layer among plastic non-combined boards, and $T_3$ < $T_2$ < $T_1$ < RP (NP(5%) < NP(l0%) among plastic combined boards. In 2cm long plastic chip in 1 layer board, the highest strength through all the composition was recognized. 1 layer board showing the lower strength with 0.5cm plastic chip rendered to the bending strength improvement by 2 or 3 layer board composition. On the other hand, 2 or 3 layer combined with 1, 2cm long polypropylene net fiber chips incurred MOR's conspicuous decrease requiring optimum plastic chip combined level and consideration to combined type. 2. MOE in plastic non-combined 3 layer board exhibited sandwich construction effect by higher resin content application to surface layer in the order of 3layer>1layer>2layer with the highest stiffness of the board combined with polypropylene chip, while nylon chip-combined board had little difference from plastic non-combined board. In relevant to length and layer effect, 3 layer board combined with the 0.5cm long polypropylene net fiber chip in 5% and 10% combined level presented 34-43% and 44-76% stiffness increase against plastic non-combined board(control), respectively. Moreover, in 1 layer board, 30% stiffness increase with 10% against 5% combined level in the 1 and 2cm long polypropylene net fiber chip was obtained. 3. Stress at proportional limit(Spl) showing the fiber relationship (r: 0.81-0.97) between MOR presented in the order of 1 layer<2 layer<3 layer in plastic non-combined board. Correspondingly, combined effect by layer and plastic chip length was similar to MOR's. 4. Differently from previous properties(MOR, MOE, Spl). work to maximum load(Wml) of 2 layer board approached to that of 3 layer board. Conforming the above phenomenon. 2 layer combined with 0.5cm long polypropylene net fiber chip kept the greater work than 1 layer. The polypropylene combined board superior to nylon -and plastic non - combined board seemed to have greater anti - failing capacity. 5. Internal bond strength(IB), in contrast to MOR's tendency. showed in the order of T1

• Journal of Acupuncture Research
• /
• v.25 no.2
• /
• pp.151-164
• /
• 2008

Objectives : This study was designed to compare the effects on Korean Western Ontario and McMaster Universities Osteoarthritis Index(KWOMAC), 36-ltems Short-Form Health Survey(SF-36), Visual Analog Scale(VAS) and Nine Point Scale between 'Intramuscular Bee Venom Herbal Acupuncture' and 'Intracutaneous Bee Venom Herbal Acupuncture' in knee osteoarthritis patients for 4weeks. Methods : All the voluntary subject were diagnosed as knee osteoarthritis. Patients were randomly assigned either to two groups : Intramuscular bee venom herbal acupuncture treatment group(IM-BV group) or Intracutaneous bee venom herbal acupuncture treatment group(IC-BV group). The IM-BV group received bee venom herbal acupuncture intramuscularly on muscles closest to the pathologic site on ultrasonography. The IC-BV group received bee venom herbal acupuncture intracutaneously on $LE_{110}$, $LE_{201}$, $ST_{35}$, $ST_{36}$ and $LR_8$. Bee venom herbal acupuncture was applied twice a week for 4 weeks by an oriental medical doctor at Kyung-hee Oriental Medical Hospital. Both groups were checked of pathologic site by ultrasonography before treatment and follow up after four-week treatment. The patients were assessed by KWOMAC and SF-36 before and after four-week treatment. The changes in patients' pain was measured by VAS before treatment and after one-, two-, three- and four-week treatment. The patients' overall treatment outcome assesment was measured by Nine Point Scale after four-week treatment. Results : The results were as follows ; 1. The IM-BV group showed significant improvement on total, pain, stiffness and physical function in KWOMAC, and the IC-BV group showed significant improvement on total and physical function in KWOMAC after 4weeks compared to the pre-treatment. In KWOMAC, the IM-BV group showed more improvement on average compared to the IC-BV group, but there were no significant difference between two groups. 2. The IM-BV group showed significant improvement on VAS after one-week treatment. The IC-BV group showed significant improvement on VAS after two-week treatment. But there were no significant difference between two groups. 3. The IM-BV group showed significant improvement on physical functioning(PF) and bodily pain(BP) in SF-36, and the IC-BV group showed significant improvement on vitality(VT) and bodily pain(BP) in SF-36 after 4weeks compared to the pre-treatment. But there were no significant difference between two groups. 4. 88.2% of IM-BV group and 93.3% of IC-BV group graded their improvement as 'Fair' or better on Nine Point Scale. But there were no significant difference between two groups. Conclusions : This study suggests that in the treatment of knee osteoarthtitis patients, effects of 'Intramuscular Bee Venom Herbal Acupuncture' were not different from 'Intracutaneous Bee Venom Herbal Acupuncture' statistically. But both treatment showed effects on pain and physical function in knee osteoarthtitis patients.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.480-493
• /
• 2007

Many railway-advanced countries are using the various types of track to reduce the track maintenance and repair cost according to the improvement of velocity. It spends on much maintenance and repair cost for ballast track due to abrasion of ballast, track irregularity and unisotropical ballast-support stiffness. The ballast track on railway bridge is accelerating the deterioration of ballast according to interaction of railway bridge and track. As continuing the deterioration, it is caused dynamic loads. Due to these effects, it increases negative loads of track and bridge. However, when designing the railway bridge, the effect of ballast track was applicate only dead load, so elastic behavior effect of ballast track is not influenced. Therefore, this paper presumes the stiffness of ballast track on railway bridge considering dynamic behavior of railway bridge, it was evaluated that effect on dynamic behaviors of railway bridge according to ballast track stiffness.

• Journal of the Korean Arthroscopy Society
• /
• v.4 no.1
• /
• pp.42-48
• /
• 2000

We retrospectively reviewed the results of arthroscopic adhesiolysis on postoperative knee stiffness in order to observe the clinical improvement and to evaluate the prognostic factors. Arthroscopic adhesiolysis without extraarticular procedure was performed in 31 knees displaying persistent flexion or extension loss. The causes of arthrofobrosis were previous ligament surgeries in 17 knees, surgery for a fracture involving the articular surface of the knee in 10 cases and other causes in four cases. The average range of motion was $60^{\circ}(range,\;14^{\circ}-74^{\circ})$ preoperatively, and improved by $120^{\circ}(range,\;7^{\circ}-127^{\circ})$ immediately following the procedure. The range of motion at the final follow-up (average 34 months) was $129^{\circ}(range,\;3^{\circ}-132^{\circ})$. In the 17 patients with arthrofibrosis fellowing ligament surgery, the range of motion was improved from $65^{\circ}$ preoperatively to $135^{\circ}$ at final follow-up. The improvement in function and motion was achieved during the first postoperative year. In the 10 patients with arthrofibosis following intraarticular fractures, the range of motion was improved from $60^{\circ}$ preoperatively to $125^{\circ}$ at the final follow-up, and most of the increase in motion was achieved within the first 6 months. Patients who suffered from a limitation of motion for less than 7 months gained an average $70^{\circ}$ improvement in total range of motion following arthroscopic surgery. However, the total range of motion in patients with a duration of symptoms greater than 7 months improved by an average $49^{\circ}$ postoperatively. In conclusion, arthroscopic adhesiolysis without incisional procedure is an effective therapeutic modality in arthrofibrosis of intraarticular origin. Improved outcomes can be expected in stiffness after ligament surgery and a symptom duration of arthrofibrosis less than 7 months.

• Journal of Pharmacopuncture
• /
• v.5 no.2
• /
• pp.63-70
• /
• 2002

Objective: To evaluate the effects of bee venom acupuncture(BVA) on the rehabilitation and quality of life in rheumatoid arthritis(RA) patients Methods: Patients with RA were treated with the BVA therapy twice a week for 3 months. Tender joint counts, swollen joint counts, morning stiffness, Erythrocyte Sedimentation Rate(ESR), C-reactive protein(CRP), patient global assessment, physician global assessment, Korean health assessment questionnaire(KHAQ) were estimated and analyzed before and after BVA therapy. Results: Tender joint counts, swollen joint counts, morning stiffness showed significant decrease after BVA therapy. But, as acute inflammatory reactants, ESR showed no significant difference and CRP showed significant increase after BVA therapy. Patient global assessment, physician global assessment, and KHAQ index showed significant improvement after BVA therapy. Conclusions: BVA therapy can improve rehabilitation and health-related quality of life in RA patients as well as clinical symptoms and signs. Further study is required in more population with large scale including acute inflammatory reaction of BVA therapy.

• The Journal of Korean Physical Therapy
• /
• v.18 no.6
• /
• pp.1-11
• /
• 2006

Purpose: This study compared the effects of non-cold and cold conditions on the viscoelastic properties of tendon structures in vivo. Methods: Seven male subjects perfomed plantar flesion exercise with maximal isokinetic voluntary contraction, which consisted of muscle contraction for 6 see and relaxation for 60 secs, 10 times for 1 set, Totally 10 sets were repeated. Before and after each task, the elongation of the tendon and aponeurosis of the medial gastrocnemius muscle (MG) was directly measured by ultrasonography. (The relationship between the estimated tendon force and tendon elongation.) Tendon cross-sectional area and ankle joint moment arm were obtained from magnetic resonance imaging (MRI). The tendon force was calculated from the joint moments and the tendon moment arm and stress was obtained by dividing force by cross-sectional areas (CSA). The strain was measured from the displacements normalized to tendon length. Results: After cooling, the tendon force was larger in cold than non-cold. The value of the tendon stiffness of MVC were significantly higher under the cold condition than under the non-cold condition. The maximal strain and stress of $7.4{\pm}0.7%$ and $36.4{\pm}1.8$ MPa in non-cold and $7.8{\pm}8.5%,\;31.8{\pm}1.1$ MPa in cold (P<0.05). Conclusion: This study shows for the first time that the muscle endurance in cooling increases the stiffness and Young's modulus of human tendons. The improvement in muscle endurance with cooling was directly related to muscle and tendon.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.3
• /
• pp.68-79
• /
• 2008

Aortic AIx(augmentation index) has been used to measure aortic stiffness quantitatively and even to evaluate ventricular load. However, in order to calculate aortic AIx catheters should be inserted to the subjects' artery, which hampers its clinical usage. To overcome such limitation, aortic AIx has been indirectly calculated by estimating aortic pressure wave from the peripheral arterial pulse by applying transfer functions. In this study, central aortic pressure waves using Millar catheter and radial artery pulse waves using tonometry pressure sensor were measured to establish transfer functions for an estimation of central aortic pressure waves from radial artery pulse waves. Also, an algorithm which detects augmentation point for the calculation of AIx were developed. Developed algorithm for the detection of augmentation point gradually increases the differential order to detect inflection point rather than detects the distinctive point that appears after a specific time. Transfer functions were established using 10th order ARX model and were verified for the stability of the transfer function through residual analysis. Evaluation of an algorithm for the detection of augmentation point were performed by comparing the augmentation points obtained from developed algorithm with the known augmentation points synthesized in various conditions. In addition, developed algorithm for the AIx is proved to provide more accurate results than the ones developed by previous studies. The significance of the study was in two folds. Firstly, the results could provide the basis for the measurement of aortic stiffness using easily-measurable radial artery pulse waves, and secondly, extension of the study may enable the early diagnosis of various vascular diseases.

• Journal of the Microelectronics and Packaging Society
• /
• v.16 no.2
• /
• pp.33-42
• /
• 2009

A polymer-based flexible neural probe was fabricated for monitoring of neural activities from a brain. To improve the insertion stiffness, a 5 ${\mu}m$ thick biocompatible Au layer was electroplated between the top and bottom polymer layers. The developed neural probe penetrated a gel whose elastic modulus is similar to that of a live brain tissue without any fracture, To minimize mechanical residual stress and bending from the probe, two new methods were employed: (1) use of a thermal annealing process after completing the device and (2) incorporation of multiple different layers to compensate the residual stress between top and bottom layers. Mechanical bending around the probe tip was clearly removed after employing the two processes. In electrical test, the developed probe showed a proper impedance value to record neural signals from a brain and the result remained the same for 72 hours. In simple in-vitro probe characterization, the probe showed a great removal of residual stress and an excellent recording performance. The in-vitro recording results did not change even after 1 week, suggesting that this electrode has the potential for great recording from neuron firing and long-term implant performance.