• Journal of the Korean Society of Hazard Mitigation
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• 제10권5호
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• pp.35-40
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• 2010

The present study proposes the strengthening method to use Conclinic Advanced FiberWrep(CAF) so as to improve Load Carrying Capacity of the RC slab bridge. In order to evaluate the strengthening performance, we strengthen 50cm per unit-width of CAF to the slab's bottom of the test bridge that designed with DB 18, then perform Static and Dynamic Field Load Test. As a result of this, 14.7% of the maximum displacement, 5.0% of the strain and 33.7% of the impact factor are reduced after strengthening. At the middle of the test spans, nominal resisting ratio is increased by 27% and Service Load Carrying Capacity is increased by 44.6%, 48.9% of each span 1 and 2. In conclusion, this study indicates that the strengthening method using CAF is very effective to improve the deteriorated RC slab bridge designed with DB 18, to the DB 24 of the first class bridge design load.

• Korean Journal of Cleft Lip And Palate
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• 제4권1호
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• pp.39-43
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• 2001

The design of osteotomy plane in orthognathic surgery has been developed to diminish the nerve injury. Intraoral Vertico-Sagittal Ramus Osteotomy (IVSRO) is the one of the best way to minimize untoward results, which is designed not to expose the lingula. We evaluated the nerve damage before and after with current perception threshold (CPT) test which is modem and numerically expressible way of nerve damages. Sixty patients underwent IVSRO since 1998 were evaluated. They were divided into 2 groups; one group underwent IVSRO only, and the other underwent IVSRO plus genioplasty. The both groups were evaluated with CPT test 1 week before surgery, and 1, 3 and 6 months after surgery. The CPT test was performed on A-beta, A-delta and C fiber respectively. 111e result showed that the recovery of sensory function of damaged nerve fibers was observed at the period of three to six months after surgery. There was no impairment of nerve function after only the IVSRO . But there were sensory disturbances in cases of additional genioplasty group. We thought that one of major factors on nerve damages were exposure of nerve and traction injury during genioplasty.

• KIEAE Journal
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• 제16권6호
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• pp.167-172
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• 2016

Purpose: The solar water heater with natural circulation has been used for several decades in the world as it is automatically operated without a pump and controller and is easy to maintain and repair. After the subsidy was offered from 2012, the solar water heater with natural circulation is becoming increasingly popular in Korea. Recently, the development of a wall-integrated solar water heater, which improves the applicability of buildings and prevents the overheating in the summer, is being developed. On the other hand, the design and performance evaluation data of solar water heaters are very inadequate, and analysis of heat and flow is required to develop a new type of solar water heater. Method: Therefore, in this study, we proposed a new simplified system analysis model that reflects heat and pressure loss from the test results of KS B ISO 9806-1 (Solar collector test method), assuming that the collector is a simple pipe system, the validity of which was verified through experiments. Result: As a result, first, the RMSE of the system circulation flow rate and the average temperature of the inlet and outlet of the collector according to the experimental results and the simulation are 0.05563 and 0.88530, respectively, which are very consistent. Secondly, the mass flow rate is increased linearly with the increase of the solar radiation, and the mass flow rate is 0.0104 ~ 0.0180kg/s in the range of $200{\sim}380W/m^2$ of solar irradiance. Compared with the test flow rate 0.0764kg / s of the test collector, it showed a level of less than 20%.

• Journal of the Korean Geotechnical Society
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• 제19권6호
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• pp.285-298
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• 2003

Shear properies of geosynthetic/geosynthetic and geosynthetic/soil interfaces which are widely met in landfill sites were evaluated from the inclined board tests. The inclined board testing apparatus is known to reproduce the shear behavior on the low normal stress most accurately. In this study, the friction angle of each interface was estimated and the tensile force mobilized at the geosynthetic was measured as well. The test results showed that the friction angle of each interface and the tensile force of the geosynthetics depended on the amount of normal stress, the type of the geosynthetics used, and the combinations of geosynthetics and soils. In addition, the sand/geotextile/geomembrane interface system was simulated in this study, and it was observed that the tensile force developed at the geomembrane decreased due to the protection effect of the geotextile located above the geomembrane. The test results of this research was compared with those of direct shear tests published, too. Finally, by comparing the measured tensile force of the geosynthetics when the initial displacement of the box occurs, when the slope is called as the critical slope, with suggested analytic solution, the accuracy of analytic solution and the applicability to design were identified.

• Korean Journal of Rural Living Science
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• 제5권2호
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• pp.93-106
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• 1994

The purpose of this study was to develop the pattern of bodysuit and to identify the wear fitness of it The methods of statistical analysis applied to the study were ANOVA and cluster analysis. The materials used in making bodysuit were Nylon/Polyurethane, lace, power net, binding tape, and hook eye. The try-on test was administered in two aspects ; (1) the comparison of anthropometric data before and after trying on the experimentally constructed bodysuit with those of marketing bodysuit, (2) the sensory evaluation to estimate the wear fitness in terms of appearance and motion function. The conclusions obtained are as follows ; 1. In the survey of wearing state, 52.2% of respondents had experience of wearing bodysuit. 60.6% of them responded to the item, “well-balanced body” in the question about the purpose of wearing it. 55.7% considered the item, “feel choky in the chest” as uncomfortable point in putting on bodysuit. 48.3% felt the portion of crotch drawn above in taking exercise or behaving routinely in everyday life. 2. As for the characteristics of the bodysuit design, the scooped neckline and horizontal outline without wire in lower bust was used, the adjust point being located right above the perineum point, and the length of bodysuit is as far as trochanteric point. 3. In comparing anthropometric data of the subjects, there was significant difference in the height of lower bust the distance around abdomen, and the length of bust point(right, left) between the experimentally constructed bodysuit and the marketing bodysuit. 4. Concerning the results of the try-on test in appearance, the estimates of expert panel, which were in agreement with those of subjects in mean value and composite reliability coefficient, showed that the pattern fitness of experimentally designed bodysuit was higher than that of marketing bodysuit. 5. To take try-on test in motion function, motion was classified the five steps. The results of the test showed that experimentally designed bodysuit was fitter in each steps of motion than marketing bodysuit.

• Journal of the Korea institute for structural maintenance and inspection
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• 제19권1호
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• pp.13-22
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• 2015

In this study, a new RCSF (Reinforced Concrete Steel Frame) external connection method is proposed for seismic strengthening of medium-and low-rise reinforced concrete buildings. The RCSF method, proposed in this study, is capable of carrying out the seismic retrofitting construction while residents can live inside structures. The method is one of the strength design approach by retrofit which can easily increase the ultimate lateral load capacity of concrete buildings controlled by shear. The pseudo-dynamic test, designed using a existing school building in Korea, was carried out in order to verify the seismic strengthening effects of the proposed method in terms of the maximum load carrying capacity and ductility. Test results revealed that the proposed RCSF strengthening method installed in RC frame enhanced conspicuously the strength and displacement capacities, and the method can resist markedly under the large scaled earthquake intensity level.

• Journal of the Korea institute for structural maintenance and inspection
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• 제22권3호
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• pp.97-102
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• 2018

Conventional PSC I type girders were adversely affected by the self - weight of concrete, anchorage, prestressing. In order to overcome this problem, PSC girder was constructed with a hollow in the web and developed a hollow web PSC type I girder which is applicable to 50 - 70m span by multistage stressing and then actually long span hollow web PSC girder bridge was constructed. In this study, the results of Static Load Test and the Finite Element Analysis of the hollow web PSC I girder bridges were compared and analyzed, and the Load Carrying Capacity and safety of PSC girder bridges were evaluated. The Static Load Test and the numerical analysis results of this bridge showed similar tendency and the behavior of the hollow web PSC I girder was well simulated. The entire girders of the bridges had sufficient Load Carrying Capacity under the live load design condition and the bridges satisfied the safety and confirmed the appropriateness of the construction.

• Journal of the Korean Society of Hazard Mitigation
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• 제7권2호통권25호
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• pp.53-63
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• 2007

This study is to evaluate the probable snowfall depth by the point frequency analysis and to draw the map of probable snowfall depth in Korea. The 14 probability distributions which has been widely used in hydrologic frequency analysis are applied to the annual maximum depth of snowfall data. The parameters of each probability distribution are estimated by method of moments, maximum likelihood method and method of probability weighted moments. The estimated parameters were checked by parameter validity conditions of each assumed probability distribution. Four tests that are $X^2-test$, Kolmogorov-Smirnov test, Cramer von Mises test and probability plot correlation coefficient test are used in this study to determine the goodness of fit of the distributions. Mostly the 2-parameter gamma distribution was determined as appropriate distribution for the annual maximum new snowfall depth. The probable snowfall depth were obtained from appropriate distribution for the selected return periods and the maps of probable snowfall depth were presented. It will be useful to specify the snowfall load for the design of agricultural facilities such as vinyl house and cattle shed.

• Journal of Korea Water Resources Association
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• 제34권3호
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• pp.231-240
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• 2001

The problem of the flocculation basin was induced by installing the pilot plant using tracer test at Yang-Duck water treatment plant in Pohang cite. The flocculation basin model downscaled as 1/20 was made of acryl and evaluated hydraulically by transforming the section of the effluent in the flocculation basin. The optimum section of the effluent was suggested and applied to the plant. The efficiency of the flocculation basin according to improvement was evaluated by the particle counter which can count the number of particles each size fraction. The results of this study are as follows : First, it was desirable to make the retention time as short as possible because the flow and the index value were similar regardless of the retention time. Second, after the modification in Yang-Duck water treatment plant, the problem of destruction of floe was improved and the plant was operated satisfactorily. The hydraulic experiment with tracer test can be applied to the performance evaluation as well as improvement of facility in unit process of existing water treatment plant. Additionally, it can be used to find a design factor in the new water treatment plant.

• Magazine of the Korean Society of Agricultural Engineers
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• 제40권5호
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• pp.68-79
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• 1998

In the years, the concern about high-strength concrete which is new material has been heightened as a result of active research and development. Recently, as the building structure has been being bigger, higher, longer and more specialized, the demand of material with high-strength concrete for building has been increasing. The demand of high -strength concrete is expected to increase with expansion of usage about the complex concrete structures such as bridge structure as well as nuclear plants, underground structures, hydraulic structures and arctic area sturctures. In this research, silica-fume was used as an admixture in order to get a high-strength concrete. Water/binder ration was limited no more than 18 percent and the amount of unit cement was increased. In this study, a number of trial in concrete mix was carried out to get optimal mix design, and the target slump with $10{\pm}2cm$ was set for in-situ construction. High-strength concrete with cylinder strength of 1,200kgf/$cm^2$ in the 28-days was produced and tested. The static test was carried out to measure the ultimate load, the initial load of flexural and diagonal cracking, crack patterns, fracture modes. The load versus strain and load versus deflection relations were obtained form the static test. The test results were compared with the shear strengths predicted by the equations of ACI code 318-89 and orther researchers. Based on the test results, shear strength equation of reinforced concrete beam using high strength concrete was proposed. Form an evaluation of the results of this experimental investigation, it was concluded that shear strength after diagonal tention cracking diminished with the increase in compressive strength for beams.