• Journal of Mechanical Science and Technology
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• v.17 no.8
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• pp.1156-1163
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• 2003

The pseudospectral method is applied to the analysis of in-plane free vibration of circularly curved Timoshenko beams. The analysis is based on the Chebyshev polynomials and the basis functions are chosen to satisfy the boundary conditions. Natural frequencies are calculated for curved beams of rectangular and circular cross sections under hinged-hinged, clamped-clamped and hinged-clamped end conditions and the results are compared with those by transfer matrix method. The present method gives good accuracy with only a limited number of collocation points.

• Journal of Korean Foot and Ankle Society
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• v.13 no.2
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• pp.133-137
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• 2009

Purpose: The purpose of this study was to evaluate the clinical results of the old Achilles tendon rupture treated with modified flexor hallucis longus (FHL) tendon transfer. Materials and Methods: Seventeen patients with old Achilles tendon rupture treated with modified FHL tendon transfer between March 2004 and February 2008 were enrolled in this study. Technically FHL was pass through the distal portion of the ruptured tendon instead of the drilled hole made on the calcaneus. The mean age of the patients was 37 years (range, 22~67 years), mean follow-up period was 28 months (range, 12~30 months). Patients' subjective satisfaction, calf circumferential diameter, range of motion of ankle and AOFAS ankle-hind foot score and Arner-Lidholm score was evaluated. Results: The average gap between the ruptured tendon was 52 mm (range, 47~56 mm). The AOFAS score improved from 47 pre-operatively to 91 points at the last follow-up. Sixteen patients were satisfied with the result free from discomfort, a patient had mild discomfort who had DM. fourteen patients had decreased range of motion less than 5 degrees while 2 patients had more than 7 degrees decrease compared to the intact side but had no discomfort in daily activities. Nine patients had less than 1 cm calf circumferential diameter difference and 7 patients had 1 to 3 cm diameter difference compared to the intact side. One who had more than 3 cm diameter difference had deteriorated muscle strength. Conclusion: Modified FHL tendon transfer can be a useful technique for the treatment of old Achilles tendon rupture when the gap is with large gap placed too proximal.

• The Journal of Korean Medicine
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• v.31 no.2
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• pp.71-77
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• 2010

Objectives: We investigated whether oriental medical therapy influences the results of in vitro fertilization-embryo transfer. Methods: 19 women with infertility were treated by oriental treatment from August 1999 to June 2000 in the department of obstetrics and gynecology of an oriental medical center. The women were planning in vitro fertilization-embryo transfer after oriental medicine treatment. The data from the women was analyzed, we obtained the following results. Results: The average age of infertile women was $35.42{\pm}4.86$; infertility caused by male factor or tubal factor were the most frequent. The average number of previous failed IVF treatments was $2.21{\pm}1.81$. The number of aspirated oocytes was $9.00{\pm}6.09$ in IVF cycle before oriental therapy, increasing to $9.80{\pm}5.41$ after therapy, but it was not statistically significant. In IVF before oriental therapy, the average number of embryos transfer was $3.20{\pm}1.90$, and it significantly increased to $4.40{\pm}1.45$ after treatment. The quality points of embryos were $10.00{\pm}6.02$ before treatment, but statistically significantly improved to $14.07{\pm}4.98$ after. The characteristics of women being pregnant and non-successful women were compared with age, period of taking herbal medicine and the number of failed IVF treatments, but there was no significant difference. Conclusion: Oriental treatment before IVF could be expected to have good results in treatment of infertility.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.24-30
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• 2013

To guarantee the exact control of missile warhead, it is inevitable to ensure the stabilities in the view points of structural and fluid/thermo dynamics of the rocket motor. Specially, despite of shortness in operating time of the rocket motor which is initial turning type of missile, it occurs frequently some problems of ablation at the neighborhood of the nozzle throat, with the result that the system itself gets to failure. In these connections, in the present study, the effect of the operating time of a rocket motor on the coefficient of convective heat transfer at the nozzle wall is investigated by numerical analysis. As a result, it is turned out that the heat transfer coefficient is largest at the just ahead of nozzle throat and decreases with the increase of operating time of the rocket motor. Furthermore, we found that the radius of curvature of throat becomes smaller, the maximum coefficient of convective heat transfer becomes larger.

• Journal of Korea Technology Innovation Society
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• v.18 no.3
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• pp.468-491
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• 2015

The major objective of this research is to suggest the proactive strategy and management of public R&D for the active transfer of technology based on the influential factor analysis of technology transfer. This study identified influential factors which make the greatest impact on the success of public technology transfer and commercialization through three points of view-technology supplier's view, technology adopter's view and view of commercialization-which contribute to successful technology transfer and commercialization. The core influential variables for blocking technology transfer are identified such as additional technological development, search for technology adopter followed by mass production technology and testing of confidence. Technology adopter is to create new markets or expand existing markets through the superiority (innovation) of licensing technology, increasing the internal innovation capabilities and maximizing the impacts of technology. This research suggests two effective strategies for improving technology transfer such as technology planning and marketing in the view of technology license. The strategy of technology planning should be established and executed to meet both technology trends and adopter's needs. And strong patents should be secured in terms of licensing of technology. Also the technological performance should be evaluated at mid-term appraisal, confirming the needs of adopter and competitive advantage of technology and patent. In addition to this, the customized technology marketing strategy for different fields of applications is also required in order to improve the likelihood of technology transfer. If the performance of R&D organization could be evaluated by global technological competitiveness and spillover effects of commercialization rather than quantitative output, the flow of technology transfer and commercialization would be accelerated.

• Korean Journal of Environmental Biology
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• v.34 no.4
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• pp.365-373
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• 2016

Much of the data used in the analysis of environmental ecological data is being obtained over time. If the number of time points is small, the data will not be given enough information, so repeated measurements or multiple survey points data should be used to perform a comprehensive analysis. The method used for that case is longitudinal data analysis or mixed model analysis. However, if the amount of information is sufficient due to the large number of time points, repetitive data are not needed and these data are analyzed using time series analysis technique. In particular, with a large number of data points in the current situation, when we want to predict how each variable affects each other, or what trends will be expected in the future, we should analyze the data using time series analysis techniques. In this study, we introduce univariate time series analysis, intervention time series model, transfer function model, and multivariate time series model and review research papers studied in Korea. We also introduce an error correction model, which can be used to analyze environmental ecological data.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11b
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• pp.3-38
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• 2000

Slope draperies in soil and rock are a well known method to avoid rockfalls into the roads or onto housings. Common wire mesh or a combination of wire mesh and wire rope nets are pinned to the slope by the means of fully grouted nails or anchors. Most of these installations have not been designed to stabilize the slope, but simply avoid the rocks from bouncing. The combination of soil- or rocknailing with a designable flexible facing system offers the advantage of a longterm stabilization of slopes and can replace other standard methods for slope stabilization. The capability to transfer axial and shear loads from the flexible facing system to the anchor points is most decisive for the design of the stabilization system. But the transfer of forces by mesh as pure surface protection devices is limited on account of their tensile strength and above all also by the possible force transmission to the anchoring points. Strong wire rope nets increase the performance for slope stabilizations with greater distances between nails and anchors and are widely used in Europe. However, they are comparatively expensive in relation to the protected surface. Today, special processes enable the production of diagonally structured mesh from high-tensile steel wire. These mesh provide tensile strengths comparable to wire rope nets. The interaction of mesh and fastening to nail / anchor has been investigated in comprehensive laboratory tests. This also in an effort to find a suitable fastening plates which allows an optimal utilization of the strength of the mesh in tangential (slope-parallel) as well as in vertical direction (perpendicular to the slope). The trials also confirmed that these new mesh, in combination with suitable plates, enable substantial pretensioning of the system. Such pretensioning increases the efficiency of the protection system. This restricts deformations in the surface section of critical slopes which might otherwise cause slides and movements as a result of dilatation. Suitable dimensioning models permit to correctly dimension such systems. The new mesh with the adapted fastening elements have already been installed in first pilot projects in Switzerland and Germany and provide useful information on handling and effects.

• Korean Journal of Health Education and Promotion
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• v.17 no.2
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• pp.57-73
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• 2000

A study on drug abuse of young people who failed in college entrance examinations and preparing the next examination and those enrolled at colleges but trying to transfer to other colleges was conducted from February 3 to May 31, 1999 in order to determine current drug abuse status of them and factors affecting their behavior related to drug abuse. A total of 1,771 people were selected from college entrance preparation institutes in Seoul, Pusan, Taegu, Taejon and Kwangju and interviewed by using questionnaires. The results are summarized as follows; 1. 49.78％ of them experienced drinking, 22.8％ smoking, and 6.7％ drug previously. More males smoked cigarettes than females. The young in the age group of 25 to 29 years old, and the young living in small towns, and subjects who finished junior colleges and those without religions drank more than those in other categories. The subjects in the age group of 20 to 24 years old and those with one parent, and those living in small towns used more drugs than those in other categories. 2. 60.1％ of those with drug using experience used the drug in their or friends' homes. 53.6％ of them used drugs with their friends, junior or senior classmates. 36.6％ of them purchased drugs from drug stores. 76.0％ of them spent their pocket money for buying drugs. 3. The drugs (excluding alcohol and tobacco) they used were bond and butane gas (29.6％), stimulants (20.6％), marijuana 02.0％) LSD (4.8％), cocaine, heroine and opium (4.2％), and others (28.8％). 4. 21.5％ of those with drug using experience had detoxification treatment previously. The ajmor sufferings they experienced were distraction (42.6％), fear 01.7％), and others. 5. 51.0％ of the subjects experienced drug related health education in schools, and 14.6％ had that kind of education through social program. 6. 64.3％ of the subjects got information about drug abuse through mass media, 16.4％ through printed materials, and 11.4％ through public health professionals. 7. The knowledge level of drug abuse was 16.48:1:2.76 points out of 24 (68.6 points out of 100).

• Journal of Korean Foot and Ankle Society
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• v.17 no.2
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• pp.115-120
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• 2013

Purpose: Calcaneal lengthening osteotomy is one option for the treatment of symptomatic flexible flatfoot in adults. The aim of the study was to evaluate the short term clinical and radiologic results and analyze its complications. Materials and Methods: Twelve feet who had undergone calcaneal lengthening osteotomy without flexor digitorum longus transfer between December 2009 and July 2011 were included. The mean age was 40.6 years (23~75 years). The mean followup was 17.3 months (13~25 months). Clinical outcome were assessed using American Orthopadics Foot ans Ankle Society (AOFAS) score and visual analogue scale (VAS) for pain. Four radiologic parameters were measured from weightbearing radiographs to evaluate the difference between preoperatively and postoperatively measures. To analyze the complications, calcaneocuboid joint subluxation and degenerative change were measured postoperatively. Results: The mean AOFAS score improved from 55.3 points preoperatively to 82.2 points at lastest follow-up (p=0.000). The mean VAS improved from 6.3 points preoperatively to 3.2 points postoperatively (p=0.002).All radiologic parameters, the mean talonavicular coverage angle on AP view, the mean talo-1st metatarsal angle on AP and lateral view and the mean calcaneal pitch angle, significantly improved after calcaneal lengthening osteotomy. Nine feets (75%) were shown the degenerative change in the calcaneocuboid joint at latest follow-up radiographs. Conclusion: Calcaneal lengthening osteotomy for the symptomatic flexible flatfoot in adults produced significant improvement in clinical and radiologic parameters, but calcaneocuboid joint osteoarthritis occurred postoperatively remained a major problem.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1069-1078
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• 2013

Recently, condensation heat exchangers have been studied for applications to the passive cooling systems of nuclear plants. To design vertical-type condensation heat exchangers in secondary passive cooling systems, TSCON (Thermal Sizing of CONdenser), a thermal sizing program for a condensation heat exchanger, was developed at KAERI (Korea Atomic Energy Research Institute). In this study, the existing condensation heat transfer correlation of TSCON was evaluated using 1,157 collected experimental data points from the heat exchanger of a secondary passive cooling system for the case of pure steam condensation. The investigation showed that the Shah correlation, published in 2009, provided the most satisfactory results for the heat transfer coefficient with a mean absolute error of 34.8%. It is suggested that the Shah correlation is appropriate for designing a condensation heat exchanger in TSCON.