• Smart Structures and Systems
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• v.3 no.4
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• pp.405-422
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• 2007

A new hybrid damping technique for vibration reduction in flexible structures, wherein a combination of layers of hard passive damping alloys and active (smart) magnetostrictive material is used to reduce vibrations, is proposed. While most conventional vibration control treatments are based exclusively on either passive or active based systems, this technique aims to combine the advantages of these systems and simultaneously, to overcome the inherent disadvantages in the individual systems. Two types of combined damping systems are idealized and studied here, viz., the Noninteractive system and the Interactive system. Frequency domain studies are carried out to investigate their performance. Finite element simulations using previously developed smart beam elements are carried out on typical metallic and laminated composite cantilever beams treated with hybrid damping. The influence of various parameters like excitation levels, frequency (mode) and control gain on the damping performance is investigated. It is shown that the proposed system could be used effectively to dampen the structural vibration over a wide frequency range. The interaction between the active and passive damping layers is brought out by a comparative study of the combined systems. Illustrative comparisons with 'only passive' and 'only active' damping schemes are also made. The influence and the mode dependence of control gain in a hybrid system is clearly illustrated. This study also demonstrates the significance and the exploitation of strain dependency of passive damping on the overall damping of the hybrid system. Further, the influence of the depthwise location of damping layers in laminated structures is also investigated.

• Tribology and Lubricants
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• v.24 no.6
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• pp.320-325
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• 2008

The recent industrial application requires technical methods to get the cutting fluid droplet surfaces in particular from the viewpoint of topography and micro texture. To characterize the surface topography of droplet, the combination of the confocal laser scanning microscope (CLSM) and wavelet filtering is well suited for obtaining the droplet geometry encountered in tribological research. This technique indicates a better agreement in obtaining an appropriate droplet surface obtained by the CLSM over a detail range of surface accuracy (resolution: $2{\mu}m$). And the results allow an excellent accuracy in a measurement of a droplet surface. The combination of extended focal depth measurement configured and multi-scale wavelet filtering has proven that it can construct a droplet surface in a successive and accurate way. A multi-scale approach of wavelet filtering was developed based on the decomposition and reconstruction of droplet surface by 2D wavelet transform using db9 (a mother wavelet of daubechies). Also this technique can be extended to characterize the quantification of droplet properties and other field in a wide range of scales. Finally this method is verified to be a better droplet surface modeling in a micro scale arising in a mist machining.

• Journal of the Korea Institute of Building Construction
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• v.13 no.1
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• pp.29-37
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• 2013

In this study, a zero-cement brick is manufactured by replacing cement with recycled aggregates and blast furnace slag powder. Experimental tests were conducted with standard sized samples of $190{\times}57{\times}90mm$ (KS F 4004), and this manufacturing technique was simulated in practice. Results showed that the zero-cement brick with 0.35 W/B had the highest compressive strength, but the lowest absorption ratio. This absorption ratio of zero-cement brick with 0.35 W/B was lower than the required level determined by KS F 4004. Hence, to increase the absorption ratio, crushed fine aggregate (CA) and emulsified waste vegetable oil (EWO) were used in combination in the zero-cement brick. It was found that the zero-cement brick with CA of 20% and EWO of 1% had the optimum combination, in terms of having the optimum strength development (12 MPa) and the optimum absorption ratio (8.4%) that satisfies the level required by KS. In addition, it is demonstrated that for the manufacturing of zero-cement brick of 1000, this technique reduces the manufacturing cost by 5% compared with conventional cement brick.

• Journal of Korean Medicine Rehabilitation
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• v.27 no.2
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• pp.109-115
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• 2017

The purpose of this study is to illustrate the potential for clinical improvement in treating a patient with a case of Posttraumatic Knee Stiffness with a combination of Korean medicine therapy. We treated the patient with acupuncture, electroacupuncture, CHUNA manual therapy and Interferential Current Therapy from $5^{th}$ December 2016 to $13^{th}$ January 2017 (total 29 times) by evaluating knee function with VAS score. After six weeks of treatment, this patient achieved effective outcome following the technique, showing that clinical symptom as able to walked and pain was relieved, VAS changed from 10 to 2 and the knee flexion ROM (active/passive) changed from 30/60 degrees to 120/140 degrees. This result shows that Korean Medicine therapy may be an effective option for Posttraumatic Knee Stiffness. Further clinical studies are needed to clarify the effect of Korean Medicine therapy on Posttraumatic Knee Stiffness.

• Journal of Ginseng Research
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• v.37 no.4
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• pp.491-495
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• 2013

Wood-cultivated ginseng, including roots in its dried form, is produced in forest land without using artificial facilities such as light barriers. To identify suitable sites for the propagation of wood-cultivated ginseng, factor combination technique (FCT) and linear combination technique (LCT) were used with geographic information system and the results were superimposed onto an actual wood-cultivated ginseng plantation. The LCT more extensively searched for suitable sites of cultivation than that by the FCT; further, the LCT probed wide areas considering the predominance of precipitous mountains in Korea. In addition, the LCT showed the much higher degree of overlap with the actual cultivation sites; therefore, the LCT more comprehensively reflects the cultivator's intention for site selection. On the other hand, the inclusion of additional factors for the selection of suitable cultivation sites and experts' opinions may enhance the effectiveness and accuracy of the LCT for site application.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.14 no.1
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• pp.61-76
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• 2019

Objectives : The purpose of this study was to report the clinical results of various medical methods (including Chuna joint mobilization) used to treat a single patient with polyneuritis. Methods : We treated a 46 year-old female patient diagnosed with polyneuritis using various methods, including acupuncture, moxibustion, infrared therapy, herbal medication, Western medication, Chuna manual therapy, and physical therapy. We evaluated the results using the numeric rating scale (NRS), manual muscle test (MMT), active range of motion (ROM), modified barthel index (MBI). Other evaluation scale included Deep tendon reflex and thickness of muscle especially forearm and lower leg. Results : Following treatment using a combination of the above methods, the general overall condition of the patients was significantly improved. Furthermore, the NRS, MMT, MBI, and the active ROM scores were numerically improved. Conclusions : In this case, a single patient with polyneuritis was treated using a combination of Korean and Western medical methods. Although this study provides useful insight into treatment methods, further studies are required to determine the treatment effects of Korean medicine, specifically Chuna manual therapy, in patients with polyneuritis.

• Journal of the Korea Furniture Society
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• v.27 no.3
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• pp.185-196
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• 2016

This study is about watching the changes in Modern and Contemporary ages, through Traditional Ottchil Painting analyzed the formative characteristics presented on 23 pieces of Najeon Master Bong-Ryong Kim. He restored and reproduced the Ottchil Painting Technique by making Najeon ware (lacquer ware inlaid with the mother-of-pearl) on the Korean Modern and Contemporary period. The formative characteristics of his Ottchil Painting Technique are as follows. He used a lot of the Myochilchaehoi Technique as the technique of expression, along with the Najeon Yanggam Technique mixed with Myochilchaehoi Technique. The frame material of Ottchil Painting Ware is handcrafted wood. And in the painting foundation, red is presented more than black. The colors of painting and the pattern drawn on the foundation of Ottchil painting are mainly bright red, blue, yellow, black, and white (five-color). The main pattern used is the dragon, and the subordinate patterns are clouds and Arabesque. Also, the main pattern is solo, and the subordinate pattern is mostly an arrangement combination of radiation symmetry. This style of art was most commonly used for painting fruit trays. As stated above, Bong-Ryong Kim presented various and masterful aesthetic quality based on sincere and exquisite Najeon ware production skills.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.114-114
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• 2014

We present our activities linking to planning of possible forms of large program to study on circumstellar H2O and SiO maser sources with KaVA. A great advantage of KaVA for the stellar maser observations is the combination of the unique capability of the multi-frequency phase referencing technique of KVN and the dual-beam astrometry of VERA with the KaVA's relative dense antenna configuration. We have demonstrated this advantage through the test observations conducted by the KaVA Evolved Stars Sub-working Group since 2012 March. Snapshot KaVA imaging is confirmed to be possible in integration time of 0.5 hour at the 22 GHz band and 1.0 hour at the 43 GHz band in typical cases. This implies that large snapshot imaging surveys towards many H2O and SiO stellar masers are possible within a reasonable machine time (e.g., scans on ~100 maser sources within 200 hours). This possibility enables us to select the maser sources, which are suitable for future long-term (10 years) intensive (biweekly-monthly) monitoring observations, from 1000 potential target candidates selected from dual-frequency band (K/Q-bands) KVN single-dish observations. The output of the survey programs will be used for statistical analysis of the structures of individual stellar maser clumps and the spatio-kinematical structures of circumstellar envelopes with accelerating outflows. The combination of astrometry in milliarcsecond(mas) level and the multi-phase referencing technique yields not only trigonometric parallax distances to the masers but also precise position reference for registration of different maser lines. The accuracy of the map registration affects interpretation of the excitation mechanism of the SiO maser lines and the origin of the variety of the maser actions, which are expected to reflect periodic behaviors of the circumstellar envelope with stellar pulsation. Currently we are checking the technical feasibility of KaVA operations for this combination. After this feasibility test, the long-term monitoring campaign program will run as one of KaVA's legacy projects.

• Radiation Oncology Journal
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• v.12 no.3
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• pp.307-313
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• 1994

Purpose : Maxillary sinus cancers usually are locally advanced and involve the structures around sinus. It is uncommon for this cancer to spread to the regional lymph-nodes. For this reason, local control is of paramount important for cure. A policy of combined treatment is generally accepted as the most effective means of enhancing cure rartes. This paper reports our experience of a retrospective study of 31 Patients treated with radiation therapy alone and combination therapy of surgery and radiation. Materials and Methods: Between July 1974 and January 1992, 47 Patients with maxillary sinus cancers underwent either radiation therpay alone or combination therapy of surgery and radiation. Of these, only 31 patients were eligible for analysis. The distribution of clinical stage by the AJCC system was $26\%$(8/31) for T2 and $74\%$(23/31) for T3 and T4. Eight patients had palpable lymphadenopathy at diagnosis. Primary site was treated by Cobalt-60 radiation therapy using through a $45^{\circ}$ wedge-pair technique. Elective neck irradiation was not routinely given. Of these 8 patients, the six who had clinically involved nodes were treated with definite radiation therapy. The other two patients had received radical neck dissection. The twenty-two patients were treated with radiation alone and 9 patients were treated with combination radiation therapy, The RT alone patients with RT dose less than 60 Gy were 9 and those above 60 Gy were 13. Results : The overall 5 year survival rate was $23.8\%$. The 5 year survival rate by T-stage was $60.5\%$ and $7.9\%$ for T2 and T3,4, respectively. Statistical significance was found by T-stage(p<0.005). The 5 year survival rate by N-stage was $30\%$ for N (-) and $8.3\%$ for N(+), but statistically no significant difference was seen(p${\geq}$0.1). The 5 year survival rate for RT alone and combination RT was $22.5\%$ and $27.4\%$, respectively. The primary local control rate was $65\%$ (20/31). Conclusion : This study did not show significant difference in survival between RT alone and combination RT. There is still much controversy with regard to which treatment is optimum. Improved RT technique and development of multimodality treatment are essential to improve the local control and the survival rate in patients with advanced maxillary sinus cancer.

• Journal of applied mathematics & informatics
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• v.31 no.1_2
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• pp.299-309
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• 2013

In this paper, we introduce a new numerical technique which we call fractional Chebyshev finite difference method (FChFD). The algorithm is based on a combination of the useful properties of Chebyshev polynomials approximation and finite difference method. We tested this technique to solve numerically fractional BVPs. The proposed technique is based on using matrix operator expressions which applies to the differential terms. The operational matrix method is derived in our approach in order to approximate the fractional derivatives. This operational matrix method can be regarded as a non-uniform finite difference scheme. The error bound for the fractional derivatives is introduced. The fractional derivatives are presented in terms of Caputo sense. The application of the method to fractional BVPs leads to algebraic systems which can be solved by an appropriate method. Several numerical examples are provided to confirm the accuracy and the effectiveness of the proposed method.