• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.6
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• pp.77-86
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• 2007

The repair technique utilizing surface impregnant is widely used due to its simple construction procedures and economical benefit. Surface protection through this reparing technique cannot increase the bearing capacity of concrete members much but increase the durability performance and service life efficiently. In this study, fundamental tests such as water suction and permeation are performed for concrete specimens with several organic/inorgarnic impregnant and suitable impregnant is selected on the basis of the results. Finally, durability tests such as carbonation, freezing and thawing, and chloride attack are carried out for the concrete specimens with selected impregnant and it is experimentally verified that they have good resistance to deteriorations.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.480-486
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• 2009

Background: The Fogarty thromboembolectomy catheter technique was devised to extract distal arterial emboli and it represents a milestone for the treatment of patients with acute arterial occlusion since the 1960s. The major causes of arterial occlusion have changed from emboli of a heart origin to atherosclerosis over the past 30 years. Accordingly, questions have been raised about the effectiveness of simple Fogarty thromboembolectomy. Material and Method: During the period from March 1990 through August 2008, 156 patients who requiring Fogarty thromboembolectomy were analyzed. The patients were divided into two groups: those with simple Fogarty thromboembolectomy (Group 1, 79 patients) and those with additional vascular bypass graft surgery (Group 2, 77 patients). The duration of symptoms, the cause of thrombi, admission via the emergency room, a history of acupuncture or misdiagnosis, combined diseases, the anatomic occlusion site and the cause of death were analyzed using T-tests, cross tab tests, Chi square tests and Kaplan-Meier tests, respectively. Result: The mean age was 64$\pm$10 years in the 2 groups. The duration of symptoms (pain) in Group 1 vs Group 2 was 12$\pm$4 days vs 71$\pm$14 days (p=0.001). 50 (63%) patients in Group 1 were admitted via the emergency room vs 18 (23%) patients in Group 2 (p=0.005). Misdiagnosis and the treatment for herniated intervertebral disc or acupuncture were given to, 20 (25%) patients in Group 1 vs 30 (39%) patients in Group 2. Anticoagulation treatment before admission was performed in 22 (28%) patients in Group 1 vs 11 (14%) patients in Group 2. The causes of thrombi were heart disease in, 24 (30%) patients in Group 1 vs 6 (8%) patients in Group 2 (p=0.001), atherosclerosis in 46 (58%) patients in Group 1 vs 67 (87%) patients in Group 2 (p=0.001) and trauma in 9 (11%) patients in Group 1 vs 6 (8%) patients in Group 2. The combined diseases were cerebrovascular accident, hypertension and diabetes mellitus in 22 $\sim$ 37% of the total patients. The occlusion sites were mainly in the iliac and femoral arteries. Endarterectomy was performed in 7 (9%) patients in Group 1 vs 18 (23%) patients in Group 2 (p=0.012). Treatment was successful in 27 (34%) patients in Group 1 and in 40 (52%) patients in Group 2 (p=0.019). Reocclusion occurred in 37(47%) patients in Group 1 vs 20 (26%) patients in Group 2 (p=0.000), Amputation was done in 4 (5%) patients in Group 1 vs 12 (16%) patients in Group 2 (p=0.012) and death occurred in 10 (13%) patients (Group 1) vs 3(4%) patients (Group 2) (p=0.044). Conclusion: The recent past has shown a decline in the effectiveness of simple Fogarty thromboembolectomy with a changing pattern of acute arterial occlusion from a rheumatic heart origin to atherosclerosis. Additional bypass procedures play a role for the treatment of arterial occlusion instead of always performing simple Fogarty thromboembolectomy.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.31-36
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• 2017

Purpose: This study aimed to examine the accuracy of rapid influenza diagnostic tests (RIDT) in children with an influenza-like illness and to evaluate factors associated with greater accuracy. Methods: Pediatric patients, who visited Hallym University Sacred Heart Hospital with an influenza-like illness between June 2011 and May 2016, were enrolled in this study. We tested 798 samples using a real-time polymerase chain reaction (PCR) for respiratory viruses and compared the results with rapid influenza tests. Results: In comparison with the results of the multiplex PCR, the positive agreement rates of RIDT for influenza A and B virus were 75.7% and 60.0%, respectively. The performance of RIDT varied according to days after fever onset. The positive agreement rates of RIDT for influenza A and B tests, performed within 4 days of fever onset, were 77.6% and 73.2%, but the rates for tests performed more than 5 days after fever onset were 66.7% and 21.4%, respectively. Conclusions: The RIDT is a quick and simple aid to diagnosis, but is less sensitive than the labeled sensitivity. Moreover, test performance varied according to days after fever onset. Test specimens for RIDT should be collected as soon as possible after the onset of symptoms (less than 4 days).

• Journal of the Korean GEO-environmental Society
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• v.6 no.3
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• pp.47-54
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• 2005

In many practical cases, design methods of pile have been used mainly semi empirical bearing capacity equations. It can be done that confirmation of pile bearing capacities through using of dynamic and static tests during constructing or after constructions. If a prediction of layered point pile bearing capacity could be done through simple tests during field investigation, it could be done that more reliable design of pile than a prediction of using semi empirical equations or static formulations. This paper suggests a method to estimated point bearing capacity during in-situ investigation by using the dynamic rod model pile and verifies the point bearing capacity compare with results of static pile load tests. From test results, the unit ultimate point bearing capacities are relatively similar through a dynamic rod model pile tests and static pile load tests. The unit ultimate point bearing capacity by using N value is shown about 50 % value of measured unit ultimate point bearing capacity from field test result and the prediction of the unit ultimate point bearing capacity by using N value is shown very conservative, illogical and uneconomical pile designs.

• Geotechnical Engineering
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• v.13 no.1
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• pp.35-46
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• 1997

The isotropic single-hardening constitutive model has been applied to predict the behavior of soils during reorientation of principal stresses in the field. The predicted response by the model agrees well with the measured behavior for a series of torsion shear tests performed on hollow cylinder specimens of Ko consoildated clay along various stress -paths. This indicates that the soil behavior during reorientation of principal stresses can be predicted by using the model with application of simple informations given by isotropic compression tests and conventional consolidated-undxained triaxial compression tests. Isotropic elasto-plastic soil behavior has been served during primary loading from both the torsion shear tests and the predictions by the model. However, the directions of maj or principal strain increment given by the model have not coincided with the directions for tests during stress reversal, such as unloading and reloading, within isotropic yield surface for Ko consolidated stress. This indicates that kinematic hardening model instead of isotropic hardening model should be developed to predict the soil behavior during stress reversal. The experimental strain increment vectors in the work-space have been compared with the directions expected for associated and nonassociated flow rules.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.1
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• pp.86-98
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• 2007

This paper presents a heuristic algorithm for the traveling salesman problem with time windows (TSPTW). Aniterative insertion algorithm as a constructive search heuristic and a hybrid meta heuristic combining simulatedannealing and tabu search with the randomized selection of 2-interchange and a simple move operator as animproving search heuristic are proposed, Computational tests performed on 400 benchmark problem instancesshow that the proposed algorithm generates optimal or near-optimal solutions in most cases. New best knownheuristic values for many benchmark problem sets were obtained using the proposed approach.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.197-204
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• 2004

An accumulator in hydraulic systems stores kinetic energy during braking action, and then that controls hasty surge pressure. An energy recovery system using accumulator seems to be advantageous for ERBS due to its high energy density. This study suggests a method to decide suitable accumulator volume for ERBS. The method is based upon energy conservation between kinetic energy of moving inertia and elastic energy of accumulator. The energy conversion was analyzed and a simple formula was derived. Also accumulator tests were conducted for different load mass and motor speed. A series of test work were carried out in the laboratory and the dynamic characteristics of the hydraulic motor system, such as the surge pressure and response time, were investigated in both brake action and acceleration action and these results show that the proposed design is effective for decision accumulator volume in ERBS.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1426-1431
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• 2011

A study on the standardization of design fire HRR(heat release rate) curve was conducted for various railcar from the fire simulation or the fire tests. These standard curves are listed on the tunnel fire safety manual which will be used for the QRA(quantitative risk analysis) process of the long railway tunnels. The design fire curve is based with four simple factor representing the key of fire curve characteristics. Flashover time, maximum HRR and burn out time are the key factors of the design fire curve. Specially total heat release is decided by the burnable material amount in the car.

• Structural Engineering and Mechanics
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• v.9 no.4
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• pp.365-374
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• 2000

The structural behavior of connections between concrete-filled rectangular tubular column (CFRT column) and steel beam has been studied in this paper through sub-assemblage loading tests. It is found that the sub-assemblages exhibit ductile restoring force characteristics under seismic loading. A formula for the prediction of the yield strength of each member in the connection is proposed by using the yield line theory under the assumption of a simple stress transfer mechanism. It is shown that the proposed formula can produce a reasonable prediction while providing a basis for further investigation.

• Structural Engineering and Mechanics
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• v.11 no.5
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• pp.469-484
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• 2001

A new beam system comprising two cantilever stems and an interspan composite beam has been developed and its design philosophy is described in this paper. The system provides the equivalent of a semi-continuous beam without the requirement to calculate the moment rotation capacity of the beam-to-column connection. The economy of braced frames using the system has been investigated and compared with simple, continuous or semi-rigid systems. It is shown that the costs of the proposed system are similar to the semi-rigid system and cheaper than both the simply supported and rigid beam systems. Two tests have been carried out on 6 meter span beams, which also incorporated an asymmetric flange steel section. The behaviour of the system is presented and the test results are compared with those obtained from the theory.