• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1362-1369
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• 2007

Seoul Metro continuously converted the standard rail into continuous welded rail since the later part of 1990's, and currently, most of the sectors of the Seoul Metro are continuous welded rails. As the continuous welded rail is inhibited by the contraction and expansion force of the rail as well as rail-bed, this force is stored as the internal stress of the rail with the exception of portion of the both ends of the continuous welded rail. If the contraction and expansion of the rail is restricted, the internal stress, that is, the force in the direction of the axis, is proportional to the cross-sectional area of the rail. Therefore, with regards to the temperature changes, the internal stress changes in accordance with the type of rail, bolting apparatus, railroad tie and rail-bed. As such, the rail temperature becomes important data in securing the gap at the adjoining section of the rail in the standard rail section, and to determine the setting temperature for the continuous welded rail. In addition, it becomes basic data for maintenance of the track. Accordingly, this thesis introduces cases of installation of rail temperature detector in order to prevent and manage track defectiveness due to increase in rail temperature, and to utilize as basic data at the time of various construction and maintenance. Furthermore, this thesis aims to assist maintenance of track through systematic temperature management in the future by looking into means of its utilization.

• Journal of the Korean Chemical Society
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• v.60 no.4
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• pp.225-234
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• 2016

The activity of 34 sulfonamide derivatives has been estimated by means of multiple linear regression (MLR), artificial neural network (ANN), simulated annealing (SA) and genetic algorithm (GA) techniques. These models were also utilized to select the most efficient subsets of descriptors in a cross-validation procedure for non-linear -log (IC50) prediction. The results obtained using GA-ANN were compared with MLR-MLR, MLR-ANN, SA-ANN and GA-ANN approaches. A high predictive ability was observed for the MLR-MLR, MLR-ANN, SA-ANN and MLR-GA models, with root mean sum square errors (RMSE) of 0.3958, 0.1006, 0.0359, 0.0326 and 0.0282 in gas phase and 0.2871, 0.0475, 0.0268, 0.0376 and 0.0097 in solvent, respectively (N=34). The results obtained using the GA-ANN method indicated that the activity of derivatives of sulfonamides depends on different parameters including DP03, BID, AAC, RDF035v, JGI9, TIE, R7e+, BELM6 descriptors in gas phase and Mor 32u, ESpm03d, RDF070v, ATS8m, MATS2e and R4p, L1u and R3m in solvent. In conclusion, the comparison of the quality of the ANN with different MLR models showed that ANN has a better predictive ability.

• Journal of Appropriate Technology
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• v.5 no.1
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• pp.38-45
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• 2019

In 2017, aiming at developing, educating, and commercializing innovative appropriate technologies that are suitable for Tanzanian environment, the Ministry of Science and ICT in Korea established an innovative technology and energy center in a Tanzanian university. Using the qualitative methodologies such as an ethnography of a research project, document analyses of memoranda of understandings, journal articles, reports, announcements, and newspaper articles, participant observation of formal and informal meetings, and semi-structured interviews with participants engaging in an appropriate technology center, this study examines how triple helix model in S&T innovation has been applied to the development of the Korea-Tanzania appropriate technology center. Despite growing importance in national S&T policies, only few studies have discussed office development aid (ODA) in association with innovation. The analysis of the appropriate technology center with the framework of the triple-helix model shows the close tie between official development aid (ODA) and the cross national innovation promoted in Korea. This study also contributes to understanding embedded organizational structure, conflicts, and barriers of an ODA project in Korea.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.195-199
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• 2002

This article is to report a new technique for reconstruction of the anteromedial and posterolateral bundles of anterior cruciate ligament by separate tensioning and fixation of the each bundle. Method : Tibial and femoral tunnels were made with conventional technique of anterior cruciate ligament reconstruction. Tibial tunnel was enlarged $5\~7$ mm in anterior-posterior direction to make oval it in cross section. When preparing the Achilles tendon allograft, bone plug portion was trimmed as the conventional technique. The tendinous portion was trimmed as two separate bundles by dividing the tendinous portion longitudinally, so the graft is shaped like 'Y'. The bone plug portion of allograft was inserted into the femoral tunnel and fixed with absorbable cross pins. Two ligamentous portionss of the distal part of the grafts were tensioned separately at the external orifice. Anteromedial bundle was fastened under maximum tension with the knee flexed 90 degrees by post-tie method. The posterolateral bundle was fixed by the same technique with the knee in full extension. Then, an absorbable interference screw was inserted between the two bundles upto the upper end of the tibial tunnel, to get more initial rigidity of the reconstructed graft as well as to locate the two bundles in more anatomic position.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.9 no.1
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• pp.15-19
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• 2013

The auxiliary feedwater is an important to remove the heat from the reactor core when the main feedwater system is unavailable. In most initiating events in Probabilistic Safety Assessment(PSA), the operaton of this system is required to mitigate the accidents. For one of domestic nuclear power plants, a design change of a turbine-driven auxiliary feedwater pump(TD-AFWP), pipe, and valves in the auxiliary system is implemented due to the aging related deterioration by long time operation. This change includes the replacement of the TD-AFWP, the relocation of some valves for improving the system availability, a new cross-tie line, and the installation of manual valves for maintenance. The design modification affects the PSA because the system is critical to mitigate the accidents. In this paper, the safety effect of the change of the auxiliary feedwater system is assessed with regard to the PSA view point. The results demonstrate that this change can supply the auxiliary feedwater from the TD-AFWP in the accident with the motor-driven auxiliary feedwater pump(MD-AFWP) unavailable due to test or maintenance. In addition, the change of MOV's normal position from "close" to "open" can deliver the water to steam generator in the loss of offsite power(LOOP) event. Therefore, it is confirmed that the design change of the auxiliary feedwater system reduces the total core damage frequency(CDF).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.1
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• pp.9-16
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• 1996

A new stereo matching method for the relative orientation and the photogrammetric triangulation has been pro-posed. It matches the pairs of conjugate points to be used as pass points and tie points in digital aerial photographs instead of selecting these points with manual point transfer and measurements. Three unique steps included in the proposed matching method are as followings. The first step is searching interest points, and designating them as candidate points to be matched. The second is matching the points from the pair of images by the Cross Correlation Method in both direction(left to right direction and right to left). The third is selecting consistent pairs in the both matching directions. Computer programs based on the proposed matching method have been developed, and with digital aerial photographs which have full ground coordinate information tests were performed to know reliabiliy and positional accuracy of proposed method. Results of the tests reveal that the proposed matching method can eliminate the in-correctly matched pairs more efficiently than other matching methods, thus this can be more reliably applied to the relative orientation and the photogrammetric triangulation.

• Journal of Korean Society of Steel Construction
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• v.20 no.2
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• pp.289-301
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• 2008

Double skin composite (DSC) wall is a structural wall that is filed with concrete between two steel plate skins connected by tie bars. This type of wall was developed to enhance the structural performance of wall, to reduce wall thickness, and to enhance constructibility, eliminating the use of formwork and re-bars. In this study, cyclic tests were performed to investigate the inelastic behavior and earthquake resistance of isolated and coupled DSC walls with rectangular and T-shapedcross-sections. The DSC walls showed stable cyclic behaviors, exhibiting excellent energy dissipation capacity. The te st specimens failed by the tensile fracture of welded joints at the wall base and coupling beam and by the severe local buckling of the steel plate. The deformation capacity of the walls varied with the connection details at the wall base and their cross-sectional shapes. The specimens with well-detailed connections at the wall base showed relatively god deformation capacity ranging from 2.0% to 3.7% drift ratio. The load-carrying capacities of the isolated and coupled wall specimens were evaluated considering their inelastic behavior. The results were compared with the test results.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1828-1832
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• 2018

Objective: Environmental change is one of the stressful events in livestock production. Change in environment disturbs cow behavior and cows require several days to regain a stable behavioral pattern. Sleeping posture (SP) and lying posture (LP) have been used as indicators for animal that are relaxed and well-acclimated to their environment. The aim of this study was to examine the time required by Japanese black cows for stabilization of SP and LP after moving into new environment. Methods: Seven pregnant Japanese black cows were used. Cows were moved into new tie-stall shed and their sleeping and lying posture measured 17 times during 35 experimental days. Both SP and LP were detected by accelerometer fixed on middle occipital and hip-cross, respectively. Daily total time, frequency, and average bout of both SP and LP were calculated. Results: Daily SP time was the shortest on day 1 and increased to the highest on day 3. It then decreased until day 9, after that stabilized about 65 min/d till the end of experiment. Daily LP time changed in same manner as daily SP time. The average SP bout was the longest on day 1, and then decreased to stable level on day 7. On the other hand, the average LP bout was the shortest on day 1, and it increased to stable level on day 7. Conclusion: These results showed that pregnant Japanese black cows needed 1 week to stabilize their SP. However, there were different change patterns between the average SP and LP bout, even though the change pattern of daily SP and LP time were similar.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.18-25
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• 2012

This paper estimates the ductility of reinforced concrete columns according to configurations of transverse reinforcement. A total of 8 reinforced concrete columns were cast and tested in flexure. The test variables in this study were the configurations, yield strength, and amount of transverse reinforcement. The specimens had a cross-section of $250{\times}250mm$ and had a shear span-to-depth ratio of 4.1 to induce flexural failure. In the test, cyclic lateral load was applied to the specimens with a constant axial load. The experimental result indicated that the specimens with proposed configurations of transverse reinforcement showed higher ductility and energy dissipation capacity than the specimens with rectangular tie.

• Perspectives in Nursing Science
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• v.10 no.1
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• pp.65-76
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• 2013

Purpose: To identify an associations between health care workers' uniforms and health care-associated infection. Methods: Electronic databases, including Ovid-Medline, the Cochrane Library, CINAHL, EMBASE, KMbase, and KoreaMed, were searched. The search terms included doctor, nurse, health care worker/staff/assistant, clothing, (white) gown, uniform, (neck)tie, and attire. Only papers published in English and Korean were included. Results: 16 studies were selected from 1,900 references screened. All of the studies were non-comparative studies except for one. Four were conducted with doctors, six with nurses, one with health care workers including physiotherapists and one for medical staff plus visitors in a neonatal intensive care unit. Doctors more frequently changed their uniforms than neckties; therefore, the degree of contamination was more serious in neckties. The cuff zone was more likely to be heavily contaminated than other areas of long-sleeve gowns. Coats become contaminated quickly once worn, and colony counts reached a similar level within the first few hours after wearing them. Wearing a plastic apron or protective clothing did not prevent the bacterial contamination of nurses' uniforms, and the best way to decrease the contamination was changing to newly laundered uniforms before starting every duty. Conclusion: Healthcare workers' uniforms are a potential source of health care-associated infection although there was no robust evidence. The government must establish standards for laundering of uniforms or a requirement for institutions to provide a laundering service for healthcare workers' uniforms.