• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.37-46
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• 2001

Pile load tests were carried out to investigate the contribution of the pile cap to the carrying capacity of a pile group and load transfer characteristics of piles in the group. A group of 24 piles$(4 \times6 array)$ of 92.5mm diameter steel pipe were installed to the depth of 3m fron the ground surface, the top of weathered rock. A maximum load of 320ton was applied to the pile cap, $1.5\times2.3m$, in contact with the ground surface. At the maximum load of 320ton, the pile cap has carried 22% of the total load. Average ultimate capacity of pile in the pile group was estimated to be 16.4ton, substantially higher than that of single pile, installed at the corner and tested before pile cap construction. For the same magnitude of settlement, the pile in the center carried less load than the pile at the perimeter due to strain superposition effect. Piles in the group showed almost constant contribution(approx. 60%) of side friction to the total capacity for all of the loading stages, while that of single pile decreased from 82% to 65%.

• Journal of Korean Foot and Ankle Society
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• v.8 no.2
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• pp.117-120
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• 2004

Purpose: The purpose of this study was to evaluate the effect and short-term results of the modified Mau osteotomy designed by the author. Materials and Methods: Seventeen feet treated with newly designed osteotomy from 2003 to 2004 were included. We performed metatarsal osteotomy and distal soft tissue procedure on 17 feet (12 patients) and additional Akin osteotomy on 6 feet (4 patients). An oblique osteotomy was made from the neck in the dorsum, aiming proximal to the base of the first metatarsal with vertical short arm on the base. We performed long arm of osteotomy parellel to the acrylic plate which was supposed as ground plane. Preoperative radiographs and follow up radiographs at three month were used for radiologic evaluation. Results: Mean hallux valgus angle was $43.6^{\circ}$ and mean intermetatarsal angle was $20.4^{\circ}$ on preoperative weight bearing radiograph. Mean amount of correction of the hallux valgus angle was $37.5^{\circ}$ and intermetatarsal angle was $14.2^{\circ}$ at three months after operation. There was no fixation loss or malunion, and the clinical result was subjectively exellent. Conclusion: More proximal rotational axis can achieve sufficient intermetatarsal angle correction, and vertical arm can provide more stable contact. So this newly modified Mau osteotomy was considered as a good alternative procedure in the treatment of severe hallux valgus.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.90-97
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• 2008

Wedged insoles are frequently used to reduce the pains caused by the knee arthritis or the foot overuse syndrome. The present study analyzed the effect of wedged rear-foot insoles on the foot pressure in walking. Three medially wedged insoles with three angles (5, 8 and 15") and three laterally wedged insoles with the same angles were made, and a flat insole were prepared. Ten healthy males in twenties walked in a specified line with each insole. Center of pressure (COP), relative vertical force and maximum force on anatomical areas were analyzed from the measured foot pressure data. At heel contact, medially wedged insoles significantly increased the pressure of the medial foot side (COP moved medially by 2-5 mm and maximum pressure of 1st metatarsal head increased by 110-120% relative to the flat insole), In contrast, laterally wedged insoles significantly increased the lateral side pressure (COP moved laterally by 1-5 mm and the ratio of $2^{nd}$ metatarsal head pressure to $1^{st}$ metatarsal head increased by 0.5-2.0 relative to the flat insole). At toe off, both wedged insoles significantly increased the pressure of the medial foot side (COP moved medially by 0.5-10 mm and the ratio of $1^{st}$ metatarsal head pressure to $5^{th}$ metatarsal head increased by 2.0 relative to the flat insole). Especially, the laterally wedged insoles significantly increased the relative vertical force (6-12%) of the rear-foot more than the flat insole.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1370-1374
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• 2018

A heterojunction $SnS_2/p-Si$ photodetector was fabricated by RF magnetron sputtering system. $SnS_2$ was formed with 2-inch $SnS_2$ target. Al was applied as the front and the back metal contacts. Rapid thermal process was conducted at $500^{\circ}C$ to enhance the contact quality. 2D material such as $SnS_2$, MoS2 is very attractive in various fields such as field effect transistors (FET), photovoltaic fields such as photovoltaic devices, optical sensors and gas sensors. 2D material can play a significant role in the development of high performance sensors, especially due to the advantages of large surface area, nanoscale thickness and easy surface treatment. Especially, $SnS_2$ has a indirect bandgap in the single and bulk states and its value is 2 eV-2.6 eV which is considerably larger than that of the other 2D material. The large bandgap of $SnS_2$ offers the advantage for the large on-off current ratio and low leakage current. The $SnS_2/p-Si$ photodetector clearly shows the current rectification when the thickness of $SnS_2$ is 80 nm compared to when it is 135 nm. The highest photocurrent is $19.73{\mu}A$ at the wavelength of 740 nm with $SnS_2$ thickness of 80 nm. The combination of 2D materials with Si may enhance the Si photoelectric device performance with controlling the thickness of 2D layer.

• Journal of Korean Neurosurgical Society
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• v.52 no.4
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• pp.312-319
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• 2012

Objective : In patients with spontaneous intracerebral hemorrhage (ICH), the risk factors for seizure and the effect of prophylactic anticonvulsants are not well known. This study aimed to determine the risk factor for seizures and the role for prophylactic anticonvulsants after spontaneous ICH. Methods : Between 2005 and 2010, 263 consecutive patients with spontaneous ICH were retrospectively assessed with a mean follow-up of 19.5 months using medical records, updated clinical information and, when necessary, direct patient contact. The seizures were classified as early (within 1 week of ICH) or late (more than 1 week after ICH). The outcomes were measured with the Glasgow Outcome Scale at discharge and the modified Rankin Scale (mRS) at both 2 weeks and discharge. Results : Twenty-two patients (8.4%; 9 patients with early seizures and 13 patients with late seizures) developed seizures after spontaneous ICH. Out of 263 patients, prophylactic anticonvulsants were administered in 216 patients. The prophylactic anticonvulsants were not associated with a reduced risk of early (p=0.094) or late seizures (p=0.326). Instead, the factors associated with early seizure were cortical involvement (p<0.001) and younger age (60 years or less) (p=0.046). The risk of late seizure was increased by cortical involvement (p<0.001) and communicating hydrocephalus (p=0.004). The prophylactic anticonvulsants were associated with a worse mRS at 2 weeks (p=0.024) and at last follow-up (p=0.034). Conclusion : Cortical involvement may be a factor for provoked seizures. Although the incidence of early seizures tended to decrease in patients prescribed prophylactic anticonvulsants, no statistical difference was found.

• The Journal of Korean Physical Therapy
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• v.6 no.1
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• pp.171-183
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• 1994

Purphose. This present study examines the effect of brief, intense transcutaneous electrical nerve stimulation(BTENS) on sensory nerve conduction, electrical pain threshold, and two-point discrimination measured at the superficial radial nevre distribution in 20 healthy subjects. Subjects. Twenty volunteercs, (10 females and 10 males(age range : 20-38 years : $mean{\pm}SD\;:\;27.00{\pm}5.12$), only subjects without prior traumatological and pathological were eligible to participated in this study. Methods. Nerve conduction were determined for the right superficial radial nerve. Electrical pain threshold were determined for the right wrist ipsilateral to the site of BTENS. Small disc electrodes were attached to the surface of the skin stradding the end of the radius. Square wave electrical pulses were delivered from an isolated stimulator through a constant current device at a frequency of 2 Hz(5 ms pulse width). Two-point discrimination, measured on the sensory distribution of superficial radial nerve. BTENS was delivered using a Max-SD( Medical design co.) portable battery powered stimulator. A cicular Ag/AgCl electrode in contact with hypertonic saline gel was attached to the lateral(radial side) surface of the forearm. Results. No significant effects were observed between stimulation methods in the prestimulation cycle(multi-way ANOVA repeated measures : distal latency ; F1.14=0.332. amplitude ; F 0.80=0.445, pain threshold ; F0.06=0.940.2 point discrimination ; F1.50=0.236). Highly significant effects were observed time with the pretreatment and 6 posttreatment cycles(p<0.01). Mighty significants differences in nerve conduction and pain threshold were found using un multi-way ANOVA repeated measures among stimulation methods for each cycles(p<0.01). Conclusion and Discussion The authors concludes that both nerve conduction and pain threshold changes are associated with therapy (stimulation) level of BTENS.

• Tunnel and Underground Space
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• v.16 no.4 s.63
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• pp.334-346
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• 2006

The discrete element code in 2-D, PFC2D, has been used as a tool to simulate various phenomena in rock mechanics and rock engineering. However, the code has an disadvantage that procedure to determine micro-parameters, namely properties of particles and contacts is repetitive and time-consuming. In this study, we analyzed the effect of micro-parameters(for generation of a contact-bonded model) on macro-properties(that were measured numerically by uniaxial compressive test). Based on the analysis, also, the time-saving and reliable method was suggested to determine a complete set of micro-parameters. In order to verify the suggested method, numerical specimens were generated in PFC2D for 10 different rock types at home and abroad. By the two trials for each specimen, in the result, the Young's modulus, Poisson's ratio and uniaxial compressive strength could be reproduced with being in relative error by about 5% to the values obtained by laboratory tests.

• Journal of the Korean School Mathematics Society
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• v.1 no.1
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• pp.97-109
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• 1998

The activities of teaching and learning are to try to reach the lesson object most closely in many ways. Considering that the lesson objects are to get the principle or law of a concept, to acquire the mathematical function, to master it through repeated exercises and to solve mathematical problems, we need many ways to reach such objects. Among the many ways, we can first think of one: the students will learn with curiosity and according to their own ability or advancing level in learning when teachers study and prepare necessary contents enough in advance by using computers, showing the right program to learners' needs. For example, defining definite integral by measuration by parts will help understand measuration by parts well and know the meaning of definite integral correctly, In teaching and learning by the use of this program, the educational effects are expected as follows. 1. It is thought that this program will stimulate the desire for and interest in learning because it used animation and acoustic effect. And voluntary and positive thinking activity will be shown. 2. It is expected that the conviction of formulas will be got and the concept of definite integral will be remembered firmly by showing how to measure the width of circle with the use of measuration by parts in various other ways instead of the ways used at present. 3. It is expected that students will feel the pleasure of mathematics in life when they recognize mathematical facts scattered really in our life rather than mathematical difficulties. 4. It is expected that the repeated review of programs already designed will remove the fear of incomplete parts and help review again. 5. It is certain that positive attitude in life will be formed as teacher-centered class is changed into learner-centered class and unwilling study is changed into self-oriented study. However, I think this program is insufficient for humanbeing-centered education given directly in contact with students on the ground of the variety in mathematical education and applications in many ways. And mechanically inhuman computers leave some solutions to be desired

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.73-82
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• 2017

PURPOSE: Proprioceptive Neuromuscular Facilitation (PNF) has been shown to improve body function and activity/participation in people with functional dysfunctions. This study evaluates if active exercise using theraband in PNF pattern may induce similar benefits as exercise using manual PNF pattern performed by physiotherapists on promoting mobility, balance and fear of fall in community-dwelling elderly. METHODS: Twenty-three community-dwelling elderly with independent activities of daily living were recruited and randomly allocated into either PNF group - exercise in PNF pattern by trained physiotherapists or Theraband-PNF (T-PNF) group - exercise using theraband in PNF pattern, for an hour, twice weekly for 4 weeks. Functional outcomes such as Timed Up and Go test, Elderly Mobility Scale, Berg balance scale, functional reach and subjective measures including fear of fall (FOF) scale, bodily pain in visual analogue scale were measured pre and post-program. RESULTS: Twenty-one participants completed the program. PNF group demonstrated significant within-group improvements in all subjective measures and objective measures. Similar within-group improvements were demonstrated in all outcome measures except FOFS in T-PNF group. However, no between-group differences were found in any of the outcome measures. CONCLUSION: Comparable improvements in functional outcomes in community dwelling elderly were demonstrated in both groups. As manual PNF exercise traditionally need clinicians' contact and feedback on patient which limit the training to be carried out extensively in community setting. The current findings suggest that exercise using theraband in PNF pattern is feasible to be adopted as self-practice exercise for community-dwelling elderly to induce beneficial effects on functional outcomes.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.344-350
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• 2009

The goal of this study is to introduce the theoretical background of acoustic nonlinearity in surface wave and to verify its characteristics by experiments. It has been known by theory that the nonlinear parameter of surface wave is proportional to the ratio of $2^{nd}$ harmonic amplitude and the power of primary component in the propagated surface wave, as like as in bulk waves. In this paper, in order to verify this characteristics we constructed a measurement system using contact angle beam transducers and measured the nonlinear parameter of surface wave in an Aluminum 6061 alloy block specimen while changing the distance of wave propagation and the input amplitude. We also considered the effect of frequency-dependent attenuation to the measurement of nonlinear parameter. Results showed good agreement with the theoretical expectation that the nonlinear parameter should be independent on the input amplitude and linearly dependent on the input amplitude and the $2^{nd}$ harmonic amplitude is linearly dependant on the propagation distance.