• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.377-381
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• 2005

We tried to extract bone morphogenetic protein (BMP) from the freeze-dried bovine cortical bone (FBCB) for bone graft, which were defatted with chloroform-methanol for 20 days, freeze-dried at $-80^{\circ}C$ for 7 days and sterilized by ethylene oxide gas. Two kg of FBCB were pulverized in a wheel mill to $0.5-2.0mm^3$ cubic in size. The bone particles were demineralized in 0.6N HCI for 10 days at chloroform-methanol$4^{\circ}C$ and defatted with chloroform-methanol for 6 hours at room temperature, which was going to be defatting and demineralized cortical bone (DDM). For extracting BMP, DDM was agitated continuously through 72 hours with magnetic stirrer at $4^{\circ}C$ into 12 times of volume of 6 M guanidine hydrochloride (Gdn-HCl) solution containing proteinase inhibitors to protect BMP such as 2mM N-ethylaleimide, 1mM iodoacetic acid, 1mM phenylmethylsulfonyl fluoride and a sterilizer, 1mM sodium azide. The extraction procedure was repeated for three times. All extracted solution was centrifuged at 10,000 rpm for 30 min and then, the supernatant was dialyzed with 12 times of volume of deionized water at $4^{\circ}C$ for 24-72 hours, which cut off below 6,000-8,000 molecular weight. The dialyzed specimen contained crude-BMP was centrifuged, freeze-dried, and weighted. Through these processing, we could obtained $84.9\%$ as FBCB, $17.8\%$ as DDM and $0.71\%$ as crude-BMP from the wet cortical bone without cancellous bone, marrow and muscles. The crude-BMP were obtained $68.3\%$ from the first extraction, $29.6\%$ from secondary and $2.1\%$ from tertiary, respectively. It was suggested that high yield of crude-BMP migth be explained by three-time repetition of the extraction processing for crude-BMP with Gdn-Hcl sol.

• Restorative Dentistry and Endodontics
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• v.27 no.5
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• pp.502-514
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• 2002

The aim of this study was to evaluate the marginal adaptation of direct class II sandwich restoration with packable composites(P-60), resin modified glass ionomer cement(Fuji-II LC), flowable compomer(Dyract Flow), flowable composites(Filtek Flow) in comparison with total bond restorations. In addition, for sandwich restorations, influence of different sandwich techniques was also evaluated. Large butt-joint box typed class II cavites with cervical margins 1mm below the cemento-enamel junction were cut into 70 extracted human molars. The cavities(7 groups, n=10) were filled using a closed/open sandwich restoration or total bond restoration technique with materials according to the manufacturer's recommandation using the single-component bonding agent for each system. Teeth were thermocycled 500 times between 5$^{\circ}C$ and 55$^{\circ}C$ with 30-second dwell time. The teeth were then coated with nail polish 1mm short of the restoration, placed in a 2% methylene blue for 24 hours, and sectioned with diamond wheel. Sections were examined with a stereoscope to determine the extent of microleakage. Dentine /Cementum margins were analyzed for microleakage on scale of 0(no leakage) to 4(entire axial wall) and interface between materials, on scale of 0(no leakage) to 3(axial wall). Results were evaluated with Kruskal Wallis Test, corrected for ties, to determine whether there were statistically significant differences among the seven groups. Pairs of groups were analyzed using the Student-Newman-Keuls Method and Dunn s Method. The results were as follows : 1. All groups showed some micoleakage in cervical portion. But there were no microleakage in interface between materials. 2. Closed sandwich restorations with Fuji-II LC and Filtek Flow had significantly lower leakage rating than total restorations with only P-60. However, open sandwich restorations with Dyract Flow showed significantly higher (P<0.05) 3. Closed sandwich restorations had significantly lower leakage rating than total restorations. However open sandwich restoration s showed significantly higher (P<0.05). 4. Sandwich restorations with Fuji-II LC were iou$.$or leakage than only P-60. Filtek Flow, Dyract Flow. But there were no statistically differences among the materials. From the results above, it could be concluded, closed sandwich restorations was effective in reducing microleakage of class II restorations. The best results showing the least microleakage were for the closed sandwich technique with Fuji-II LC and Filtek Flow.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.399-406
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• 2009

The purpose of this study was to compare the effect of wearing roller shoes and jogging shoes on kinematic characteristics in lower extremity during walking. Eight male middle school students(age: $15.0{\pm}0.0^{\circ}$ yrs, height $175.9{\pm}6.6cm$, weight: $616.3{\pm}84.9$ N) who have no musculoskeletal disorder were recruited as the subjects. Temporal parameters, step length, stride length, center of mass, velocity of CM, angle of segment, angular velocity and range of motion were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions(p < .05). The results showed that stride length and velocity of CM in wearing roller shoes were significantly less than those found in wearing jogging shoes. These indicated that walking patterns may be changed by different shoe conditions and unstable braking condition because of wheel. Angle of ankle joint at LHC1 and LHC2 in wearing roller shoes was greater than the corresponding value for wearing jogging shoes. It seems that the ankle joints are locked in an awkward fashion at the heel contact to compensate for imbalance. Otherwise, dorsi flexion was not produced at the heel contact point in wearing roller shoes.

• Restorative Dentistry and Endodontics
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• v.34 no.2
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• pp.103-112
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• 2009

The purpose of this study was to compare the effect of curing methods of adhesive resins and resin cements in the root canal. Crown portions of 32 single-rooted mandibular premolars were removed. Routine endodontic treatment was done, and 9 mm deep post spaces were prepared within root canals. No.3 FRC Postec posts (Ivoclar-Vivadent AG, Liechtensteih) were cemented in the post spaces by self-(SC) or light-curing (LC) using two dual-cured adhesives (Adper Scotchbond multi-purpose plus and Exite DSC )and resin cements (RelyX ARC and Variolink II). They were assigned to 4 groups (n=8): R-SC, R-LC, V-SC, V-LC group. After stored in distilled water for 24 hours, each root was transversally sectioned with 1.5 mm thick and made three slices. The specimens were subjected to push-out test in a universal testing machine (EZ Test, Shimadzu Co., Japan) with a crosshead speed of 1 mm/min. The data were analyzed with repeated ANOVA and one-way ANOVA. Also the interface of post-resin cement and resin cement-canal wall of each group was observed under FE-SEM. When fiber posts were cemented into the root canal using total-etch adhesives, the bond strength and adaptation between post and root canal dentin was affected by curing method. Self-cure of adhesives and resin cements showed higher bond strength and closer adaptation than light-cure of them.

• Archives of Plastic Surgery
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• v.34 no.2
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• pp.209-216
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• 2007

Purpose: The ischial area is by far the most common site of pressure sores found in wheel chair bound paraplegic patients, because greatest pressure is exerted from the body on this area in a sitting position. Even after a series of successful pressure sore treatments, the site is very prone to relapse by the simplest ordinary tasks of everyday life. Therefore, it is crucial to preserve the main pedicle during primary surgery. Various surgical procedures employed to treat pressure sores such as myocutaneous flap and perforator flap have been introduced. After introduction of ischial sore treatment using the inferior gluteal artery perforator (IGAP) has been made, the authors experienced favorable clinical results of patients who have undergone IGAP flap procedure in a three year time period. Methods: A total of 17 patients received IGAP flap surgery in our hospital from January 2003 to May 2006, among which 14 of them being males and 3 females. Surgery was performed on the same site again in 6(35%) patients who had originally relapsed after receiving the conventional method of pressure sore surgery. Patients' average age was 49.4(27-71) years old. Most of the patients were paraplegic(11 cases, 65%) and others were either quadriplegic(4 cases, 23%) or ambulatory(2 cases, 12%). Based on hospital records and clinical photographs, we have attempted to assess the feasibility and practicability of the IGAP flap procedure through comparative analysis of several parameters: size of defective area, treatment modalities, occurrence of relapses, complications, and postoperative treatments. Results: The average follow-up duration of 17 subjects was 25.4 months(5-42 months). All flaps survived without any necrosis. Six cases were relapsed cases from conventional surgical procedures. All of them healed well during our follow-up study. Postoperative complications such as wound dehiscence and fistula developed in some subjects, but all were well healed through secondary treatment. A total of 2 cases relapsed after surgery. Conclusion: The inferior gluteal artery perforator flap is an effective method that can be primarily applied in replacement to the conventional ischial pressure sore reconstructive surgery owing to its many advantages: ability to preserve peripheral muscle tissue, numerous possible flap designs, relatively good durability, and the low donor site morbidity rate.

• Journal of Drive and Control
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• v.17 no.4
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• pp.133-140
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• 2020

Traction performance of a tractor varies depending on soil conditions. Sinkage and slip of the driving wheel for tractor frequently occur in a reclaimed land. The objective of this study was to develop a tractor suitable for a reclaimed land. Traction performance was evaluated according to soil conditions of reclaimed land and paddy field. Field experiments were conducted at two test sites (Fields A: paddy field; and Field B: reclaimed land). The tractor load measurement system was composed of an axle rotation speed sensor, a torque meter, a six-component load cell, GPS, and a DAQ (Data Acquisition System). Soil properties including soil texture, water content, cone index, and electrical conductivity (EC) were measured. Referring to previous researches, the tractor traveling speed was set to B3 (7.05 km/h), which was frequently used in ridge plow tillage. Soil moisture contents were 33.2% and 48.6% in fields A and B, respectively. Cone index was 2.1 times higher in field A than in field B. When working in the reclaimed land, slip ratios were about 10.5% and 33.1% for fields A and B, respectively. The engine load was used almost 100% of all tractors under the two field conditions. Traction powers were 31.9 kW and 24.2 kW for fields A and B, respectively. Tractive efficiencies were 83.3% and 54.4% for fields A and B, respectively. As soil moisture increased by 16.4%, the tractive efficiency was lowered by about 28.9%. Traction performance of tractor was significantly different according to soil conditions of fields A and B. Therefore, it is necessary to improve the traction performance of tractor for smooth operations in all soil conditions including a reclaimed land by reflecting data of this study.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.1
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• pp.1-13
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• 2010

A comparative study between a computation and an experiment has been conducted to predict the performance of a Pod type waterjet for cm amphibious wheeled vehicle. The Pod type waterjet has been chosen on the basis of the required specific speed of more than 2500. As the Pod type waterjet is an extreme type of axial flow type waterjet, theoretical as well as experimental works about Pod type waterjets are very rare. The main purpose of the present study is to validate and compare to the experimental results of the Pod type waterjet with the developed CFD in-house code based on the RANS equations. The developed code has been validated by comparing with the experimental results of the well-known turbine problem. The validation also extended to the flush type waterjet where the pressures along the duct surface and also velocities at nozzle area have been compared with experimental results. The Pod type waterjet has been designed and the performance of the designed waterjet system including duct, impeller and stator was analyzed by the previously mentioned m-house CFD Code. The pressure distributions and limiting streamlines on the blade surfaces were computed to confirm the performance of the designed waterjets. In addition, the torque and momentum were computed to find the entire efficiency and these were compared with the model test results. Measurements were taken of the flow rate at the nozzle exit, static pressure at the various sections along the duct and also the nozzle, revolution of the impeller, torque, thrust and towing forces at various advance speed's for the prediction of performance as well as for comparison with the computations. Based on these measurements, the performance was analyzed according to the ITTC96 standard analysis method. The full-scale effective and the delivered power of the wheeled vehicle were estimated for the prediction of the service speed. This paper emphasizes the confirmation of the ITTC96 analysis method and the developed analysis code for the design and analysis of the Pod type waterjet system.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.491-497
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• 2014

The corrosion of steel reinforcement in reinforced concrete bridge decks significantly affects the degradation of the capacity. Due to the advantageous characteristics such as high tensile strength and non-corrosive property, fiber reinforced polymer (FRP) has been gathering much interest from designers and engineers for possible usage as a alternative reinforcement for a steel reinforcing bar. However, its application has not been widespread, because there data for short- and long-term performance data of FRP reinforced concrete members are insufficient. In this paper, seven full-scale decks with dimensions of $4000{\times}3000{\times}240mm$ were prepared and tested to failure in the laboratory. The test parameter was the bottom reinforcement ratio in transverse direction. The decks were subjected to various levels of concentrated cyclic load with a contact area of $577{\times}231mm$ to simulate the vehicle loading of DB-24 truck wheel loads acting on the center span of the deck. It was observed that the glass FRP (GFRP) reinforced deck on a restraint girder is strongly effected to the level of the applied load rather than the bottom reinforcement ratio. The study results showed that the maximum load less than 58% of the maximum static load can be applied to the deck to resist a fatigue load of 2 million cycles. The fatigue life of the GFRP decks from this study showed the lower and higher fatigue performance than that of ordinary steel and CFRP rebar reinforced concrete deck. respectively.

• Journal of the Korean Society of Costume
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• v.59 no.3
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• pp.109-130
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• 2009

This study examines the rotor characteristics of Guybang culture (women's living in Joseon) relics which the life images and mental world of women in Joseon if expressed to prepare rotor data to be utilized in modern design and information for color identity establishment of Korean women culture. The result of this study is as following: 1. From 176 pieces of relic photos, total of 1380 color chips were extracted. For color analysis, 1368 units (99.1%) of color data excluding achromatic 12 units (0.9%) among 1380 units of colors were used. With the standard of 10 color wheel of Munsell Color System, the result of studying distributions according to frequency, red was the highest by 25.9%, yellow was 21.4% in women's goods in Joseon period which the ratio of red and yellow was 473%. Other than that, GY 14.6%, YR 11.3% and RP 11.1% followed next which is studied that the warm colors that conveys enjoyable and glamorous feelings composed 84.3%; 2. As a result of tone analysis, high value low chroma ltg color showed highest distribution of 20% and d was 12.2%, b was 11.7% and sf was 8.8%. Generally, it showed high frequency in high value cocors such as ltg, sf and b of 40.5%t and in low chroma (ltg) and medium chroma (d, sf) of 41% and colors in bright and calm image was used the most. 3. As a result of analyzing relationship between hue & tone, the ltg tone of Y close to white in traditional color sensibility showed the highest frequency of 9.6% and ltg tone of GY(6.4%), b tone of RP(6.1%), and v(5.4%), b(5.4%), dp(5.3%) of R followed next. 4. As a result of analyzing the characteristics of coloring, it showed that in case of coloring contrasting hues, it is adjusted similar tones and in case of coloring less contrasting hue, the difference in tone is adjusted to be rather large to make harmonized coloring. Moreover, in case of coloring similar hues, the ratio of using same tone and similar tone was large which the coloring of calm image and dynamic image is all used.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.275-282
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• 2018

Mountain trams are an environmental-friendly transportation system that run wirelessly on an embedded track constructed on previous mountain roads, and can run despite the frozen road. On the other hand, there is some difficulty on sharp and steep tracks. In this study, after possible technical problems were defined in mountain trams running on a sharp and steep track, the design solutions for the interface structure of bogie and carbody were proposed. In addition, a prototype was made and its performance was tested to verify the solutions. Because the difference in the distance of the inner and outer rails on a sharp curve is severe enough to interrupt running, independent rotating wheels with different angular speeds were developed and applied. To prevent derailment due to the large attack angle and lateral force caused by the previous vehicle of 2bogie-and-1carbody on the sharp curve, a vehicle with 1bogie-and-1carbody was designed and applied. A prototype vehicle of 1bogie-and-1carbody with independent rotating wheels was made to improve the performance during the test running on a small track. A coupler was designed to absorb the large rotations of 3 degrees-of-freedom between the carbodies of a mountain tram running on the steep curved track. After a small scale prototype was made, the performance was verified by a function test.