• Journal of Positioning, Navigation, and Timing
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• v.6 no.4
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• pp.195-203
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• 2017

A 2U cube satellite called SNUGLITE has been developed by GNSS Research Laboratory in Seoul National University. Its main mission is to perform actual operation by mounting dual-frequency global positioning system (GPS) receivers. Its scientific mission aims to observe space environments and collect data. It is essential for a cube satellite to control an Earth-oriented attitude for reliable and successful data transmission and reception. To this end, an attitude estimation and control algorithm, Attitude Determination and Control System (ADCS), has been implemented in the on-board computer (OBC) processor in real time. In this paper, the Extended Kalman Filter (EKF) was employed as the attitude estimation algorithm. For the attitude control technique, the Linear Quadratic Gaussian (LQG) was utilized. The algorithm was verified through the processor in the loop simulation (PILS) procedure. To validate the ADCS algorithm in the ground, the experimental verification via a single axis Hardware-in-the-loop simulation (HILS) was used due to the simplicity and cost effectiveness, rather than using the 3-axis HILS verification (Schwartz et al. 2003) with complex air-bearing mechanism design and high cost.

• Journal of Acupuncture Research
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• v.21 no.5
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• pp.137-147
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• 2004

Objective : The aim of the study was to compare the therapeutic effect of the superficial and in-depth insertion of acupuncture needles in the treatment of patients with ankle sprain. Design : A prospective randomized single-blind study of superficial and deep acupuncture was conducted. Setting : The study was conducted in the Kang-nam Oriental Hosp. of Dong-Guk University. Patients: The study comprised 14 patients with ankle sprain who were divided into two groups (A and B). Intervention : In group A, the needle was introduced in the skin at a depth of 2 mm, whereas in group B the needle was placed deeply into muscular tissue or the articular capsule at a depth more than 1.5 Cm The treatment was planned for a duration of 1 week, 3 times. Outcome Measures : The intensity of pain was evaluated with the Ankle grade pain chart(AGPC) before and after treatment and at the 1-week follow-up examination. The AGPC includes Swelling, Tenderness, Exudation, Bruise, Medial/Lateral. stability test, Anterior drawer test, Squeeze test, Bearing weight, Pressure Algometer, Walking state and VAS. Results : Although at the end of the treatment there was no evidence of significant statistical differences between the two different groups, Pain reduction(VAS) was greater in the group treated with deep acupuncture. A statistical difference existed between the two groups at the 1 week follow up, with a better result in the deeply stimulated group in VAS. Conclusion : Clinical results show that deep stimulation has a better analgesic effect when compared with superficial stimulation in pain reduction(VAS, Visual analogic scale).

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.255-259
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• 2013

Background: Cancer is the leading cause of death in Taiwan. Spouses are generally the main caregivers of affectyed patients but previous studies have seldom investigated the needs of male spouses of patients with metastatic cancer. Purpose: To explore the lived experiences of such male spouses. Methods: A qualitative design using in-depth interviewswasconducted with male spouses of patients with metastatic cancer being treated at the oncology outpatient department in a teaching hospital in northern Taiwan. Results: Nine participants aged 31-78 were interviewed. Content analysis of the interviews revealed five themes: suffering and struggling, difficulty in focusing on communication and interaction, shouldering responsibility, cherishing the love between husband and wife, and enabling each other to live better. This study demonstrated how male spousse experienced physical and psychological suffering when their wives suffered from metastatic cancer. They had to bear the pain of their wife's suffering, and also had to shoulder the responsibility for everything. All their efforts were put towards enabling each other to live a better life. They cherished the rest of the time they could spend with their wives, even though they had to live a hard life. As the male spouses of patients with metastatic cancer, the participants exhibited both the masculinity of men and the ability to express care and tenderness. Conclusions: The results showed that male spouses need more attention in terms of communication and bearing with suffering. Health care professionals should more actively understand the needs and provide assistance when facing the male spouse of patients with cancer, so as make sure that they possess the ability to take care of their wives. Health care professionals should also assist and properly act as a bridge of communication between husbands and wives.

• Structural Engineering and Mechanics
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• v.23 no.6
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• pp.615-634
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• 2006

Seismic response of the liquid storage tanks isolated by the elastomeric bearings and sliding systems is investigated under near-fault earthquake motions. The fault normal and parallel components of near-fault motion are applied in two horizontal directions of the tank. The continuous liquid mass of the tank is modeled as lumped masses known as sloshing mass, impulsive mass and rigid mass. The corresponding stiffness associated with these lumped masses has been worked out depending upon the properties of the tank wall and liquid mass. It is observed that the resultant response of the isolated tank is mainly governed by fault normal component with minor contribution from the fault parallel component. Further, a parametric study is also carried out to study the effects of important system parameters on the effectiveness of seismic isolation for liquid storage tanks. The various important parameters considered are: aspect ratio of tank, the period of isolation and the damping of isolation bearings. There exists an optimum value of isolation damping for which the base shear in the tank attains the minimum value under near-fault motion. The increase of damping beyond the optimum value will reduce the bearing and sloshing displacements but increases the base shear. A comparative performance of five isolation systems for liquid storage tanks is also studied under normal component of near-fault motion and found that the EDF type isolation system may be a better choice for design of isolated tank in near-fault locations. Finally, it is also observed that the satisfactory response can be obtained by analysing the base-isolated tanks under simple cycloidal pulse instead of complete acceleration history.

• Journal of Korean Society of Steel Construction
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• v.24 no.2
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• pp.189-197
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• 2012

The cold-formed steel stud, which has been used as a load-bearing member of wall panels for steel houses, poses a significant problem in insulation due to heat bridging of the web. Therefore, some additional thermal insulating materials are required. In order to solve this problem, the cold-formed steel thermal stud with slits in the web was developed. However, estimating the structural strength of thermal studs is very difficult because of the arrangement of perforations. In this paper, an analytical and experimental research on thermal studs is described. Three types of studs with different length, pitch and arrangement of slits were tested to failure. A simple design approach was proposed based on the test results. The proposed method adopted the direct strength method, based on the elastic local and distortional buckling stress of plain studs with equivalent thickness in the web instead of thermal studs. The predictions using the proposed method were compared with test results for verification and the adequacy of the proposed method was confirmed.

• Geotechnical Engineering
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• v.3 no.1
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• pp.7-24
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• 1987

Preloading surcharge method along with vertical drains was adopted to improve the performance of a very soft marine clay deposit. The onshore deposit, located in the Ulsan Bay area, consists of a 2 to 10m thick, very soft, highly compressible marine clay layer developed just below. the sea water level. The initial undrained shear strength of the clay layer was about 0.6 ton/m2. But, the deposit was designed after treatment to support some auxiliary facilities for a new ilo refinery plant, requiring bearing capacities of 3.6 to 5.4 ton/m2 and maximum allowablee settlement of less than 7.5cm. A total of 35, 000 wick drains Ivas installed to expedite drainage during preloading, and surcharge loads of up to 5m above the original ground level were applied in a step-by-step loading sequence to prevent ground failure by excess surcharge loads. An extensive program of field instrumentation was implemented to monitor the behavior of the clay deposit. Measurers!ends included settlements, excess pore pressure and its dissipation, ground farmer level fluctuation, and lateral movement of the so(t clay layer under the preloads. This paper describes the design concepts, construction methods and control procedures used for improvement of the clay layer. It also presents the ground behavior measured during construction, rind comparisons with theoretical predictions.

• Korean Journal of Clinical Pharmacy
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• v.17 no.1
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• pp.38-45
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• 2007

Background: The multitude of the therapeutic usefulness of intra-articular injection of hyaluronate on oateoarthritis of the knee is still in question. The objective of this systemic review was to elucidate both the therapeutic efficacy and the safety of intra-articular administration of hyaluronic acid for degenerative osteoarthritis of the knee joints. Methods: I searched MEDLINE and Korea Medical Database (KMbase) from January 1990 to April 2007 using a combination search terms for knee osteoarthritis and hyaluronic acid and a filter for randomized controlled trials. I extracted data on pain at rest, and during or just after movement, on joint function, and on adverse events. Results: Ten trials that reported usable quantitative information on any of the predefined end points were identified and included in the systemic review. Intra-articular injection of hyaluronic acid can decrease symptoms of osteoarthritis of the knee. The study revealed significant improvements in pain and functional outcomes with few adverse effects. However, there was significant between-study heterogeneity in the estimates of the efficacy of hyaluronic acid. Sub-group analysis showed that lower methodological quality such as a single-blind or single-center design resulted in higher estimates hyaluronic acid efficacy, and that patients older than sixty years of age and those with the most advanced radiographic stage of osteoarthritis were less likely to benefit from intra-articular injection of hyaluronic acid. Conclusion: According to the currently available evidence, intra-articular hyaluronic acid has been proven clinically effective for the patients bearing the knee osteoarthritis with NSAID-induced GI troubles or inapplicable to any surgery, and may be associated with lower risk of adverse events.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.8
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• pp.10-17
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• 2011

As the data path of the processor widens and the depth of the pipeline deepens, the number of required registers increases. Consequently, careful attention must be paid to the design of clocked storage elements like latches and flipflops as they have a significant bearing on the overall performance of a synchronous VLSI circuit. As technology is also scaling down, noise immunity is becoming an important factor. In this paper, we present a new flipflop which has an improved noise immunity when compared to the hybrid latch flipflop and the conditional precharge flipflop. Simulation results in 65nm CMOS technology with 1.2V supply voltage are used to demonstrate the effectiveness of the proposed flipflop structure.

• The Journal of Advanced Prosthodontics
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• v.9 no.6
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• pp.423-431
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• 2017

PURPOSE. The goal of this study was to evaluate the fracture resistances of various monolithic crowns fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) with different thickness. MATERIALS AND METHODS. Test dies were fabricated as mandibular molar forms with occlusal reductions using CAD/CAM. With different occlusal thickness (1.0 or 1.5 mm), a polymer-infiltrated ceramic network (Enamic, EN), and zirconia-reinforced lithium silicate (Suprinity, SU and Celtra-Duo, CD) were used to fabricate molar crowns. Lithium disilicate (e.max CAD, EM) crowns (occlusal: 1.5 mm) were fabricated as control. Seventy crowns (n=10 per group) were bonded to abutments and stored in water for 24 hours. A universal testing machine was used to apply load to crown until fracture. The fractured specimens were examined with a scanning electron microscopy. RESULTS. The type of ceramics and the occlusal thickness showed a significant interaction. With a recommended thickness (1.5 mm), the SU revealed the mean load similar to the EM, higher compared with those of the EN and CD. The fracture loads in a reduced thickness (1.0 mm) were similar among the SU, CD, and EN. The mean fracture load of the SU and CD enhanced significantly when the occlusal thickness increased, whereas that of the EN did not. CONCLUSION. The fracture loads of monolithic crowns were differently influenced by the changes in occlusal thickness, depending on the type of ceramics. Within the limitations of this study, all the tested crowns withstood the physiological masticatory loads both at the recommended and reduced occlusal thickness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.788-792
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• 2003

Rotating machines are widely used in industrial world and especially motor and generator take up much part of it. As for this kind of motor and generator, electrical loss due to eddy current is the very important factor and that is also a primary factor causes heat generation. To solve this kind of problem like the above. insulated laminating silicon steel sheet is used to prevent eddy current effect. Laminated rotor is widely used as rotating shaft of motor and generator. Due to that, electrical loss and heat problem can be solved but designer meets another problem. In general. most of the motor and generator can be normally operated under 3,600 rpm because they are designed to have the first critical speed more than that speed. But nowadays, they should be operated more than the first critical speed as usual with the trend of high speed, large scale and high precision in industrial world. The critical speed can be determined from the inertia and stillness for the rotor and bearing of rotating systems. The laminated rotor stiffness can be hardly determined because it can be derived a lot factors for instance rotor material and shape, lamination material and shape, insulation material. lamination force and so on. In this paper, the change of the natural frequency of the motor was examined with the change of the lamination force as an experimental method and design criteria will be presented for motor & generator designer, who can apply the result of numerical analysis with equivalent diameter scheme with ease.