• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.355-366
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• 2002

Background : The heat shock protein (HSP) 70 families are known to protect cells against the irreversible tissue injury induced by stress and to induce the recovery of cell function during stress. Heat pretreatment was reported to decrease the acute lung injury (ALI) of rats induced by lipopolysaccharide (LPS). However, the role of heat shock with LPS co-treatmenton ALI is unclear. The purpose of this study was to investigate the effect of heat treatment, which was given immediately after the beginning of ALI induced by LPS intratracheally administered in rats. Methods : Either saline (saline group) or LPS was intratracheally instilled without heat treatment (LPS group). In addition, heat was conducted 18 hours prior to the instillation of LPS (pre-treatment group) and conducted immediately after instillation of LPS (co-treatment group). Six hours after the LPS or saline treatment, blood, bronchoalveolar lavage (BAL) fluid and lung tissue samples were obtained. The myeloperoxidase (MPO) activity and the heat shock protein expression in the lung tissue, the differential counts of the polymorphonuclear leukocytes (PMN) in the BAL fluids, and the LDH, protein, $IL-1{\beta}$, $TNF-{\alpha}$ and IL-10 levels in BAL fluid and serum were measured. Results : 1) The MPO activity, the differential PMN counts in the BAL fluid, BAL fluid and serum cytokines were higher in the LPS, the heat pre-treatment and co-treatment group than those of the saline group (p value <0.05). 2) The MPO activity and the protein level in the BAL fluid from the heat co-treatment group were similar to those of the LPS group. 3) The serum $TNF-{\alpha}$ level of the heat co-treatment group was significantly higher than that of the LPS group (p=0.01). Conclusion : Heat shock response administered immediately after a LPS instillation did not attenuate the ALI in this model.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.6
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• pp.607-614
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• 2015

In this research, the structural analysis and safety evaluation for Sungnyemun -No.1 national treasure of Korea- was performed. Roof loads were calculated in detail, and structural analysis model was constructed using Midas Gen ver.820. Static structural analysis under vertical loads was performed and safety of main structural members and serviceability of main horizontal members were evaluated. To evaluate dynamic characteristics of Sungnyemun, both field measurements by impact hammer test and eigenvalue analysis by structural analysis software were performed and the results were compared. Sungnyemun showed rooms in their structural capacity.

• Magazine of the Korea Concrete Institute
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• v.2 no.2
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• pp.73-80
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• 1990

The current analytical techniques for R/C elements under severe dynamic repeated loads, like earth¬quake or impact, have two major problems; one is that the effects of strain rate are not considered and the other one is the current analytical model was developed based on flexural behavior only. This study develops computer software that can idealize the flexural and shear behavior of R/C elements using several parameters and also can consider the effects of strain rate. The analytical results using the developed technique were compared with serveral experimental results and they were generally satisfied.

• Korean Journal of Veterinary Research
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• v.7 no.1
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• pp.1-7
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• 1967

Clinically healthy Korean adult cattle (20 females and 20 males) were selected and subjected to the experiments on the determination of erythrocytes and total leukocytes values at the stages of pre and post-slaughting. Throughout the studies the following results were obtained. 1. The erythrocytes values, at the stage of the pre-slaughter, of females and males were $6.070{\times}10^6/cmm$ and $6.175{\times}10^6/cmm$ respectively. In the case of post-slaughter stage, $7.780{\times}10^6/cmm$ and $7.705{\times}10^6/cmm$ were obtained for female and male respectively. In comparison on the values of erythrocytes between pre and post-slauglnter stages, the mean value of the latter has been increased significantly. 2. The total leukocytes value, at the stage of the pre-slaughter of females and males were 9,525/cmm and 9,630/cmm respectively. In the case of post-slaughter stage, 7,545/cmm and 7,510/cmm were obtained for females and males respectively. In comparison on the values of total leukocytes between pre and post-slaughter stages, the mean value of the latter has been decreased significantly.

• The Journal of the Acoustical Society of Korea
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• v.26 no.7
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• pp.343-352
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• 2007

The present study aims to investigate the design standard for acoustic criteria of Korean traditional music which could be used for the design of Korean traditional music halls. In order to do this, subjective listening tests were undertaken to musicians using auralized sounds which were convolved with the impulse response of traditional instruments recorded in an anechoic chamber. 94 pairs of sound were made which have different value of acoustic parameters including RT, BR, Brilliance, G, C80, ITDG, IACC. A paired comparison method(PCM) was used to analyze the results from the subjective listening tests. The results show that the preference of acoustic criteria for the Korean traditional music is far different from those of western music. As a result, specific range of acoustic criteria were suggested for the appropriate acoustic conditions of Korean traditional music. Also, a guideline of the acoustic design of halls for performing the Korean traditional music was suggested which could be used as a basic reference in the future works.

• Journal of Korean Society of Steel Construction
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• v.13 no.4
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• pp.381-393
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• 2001

The current traffic situation in Korea can be described as rapid change in traffic volume and diversity in vehicle size from compact cars to large trucks. W-beam barrier most widely used in Korea was found not to satisfy the stiffness requirement for the Koran impact condition of 14 ton-60Km/h-15deg. and it was too stiff for small vehicles impacting with more realistic speed to satisfy the safety of vehicle occupants. To develop a guardrail system satisfying the two contradicting goals, a thrie-beam guardrail system, which had the beam thickness of 3.2mm and rubber cushions, was conceived. Even though the height of the thrie-beam(450mm) is increased by 100mm as compared to that of W-beam (350mm), there was only 2% increase in the weight of the thrie-beam. The new thrie-beam barrier system could contain more wide range of vehicle bumper heights, and showed better performance in the viewpoint of stiffness and energy absorbing capability than the W-beam system. The impact performance was evaluated from a crash test. The developed thrie-beam guardrail system satisfied all applicable criteria for NCHRP 350 test designation 3-10.

• Journal of Korean Society of Forest Science
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• v.88 no.1
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• pp.1-10
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• 1999

The dynamic relationships among import prices of roundwood are analyzed using the time series approach. A vector autoregression(VAR) model is estimated for six import prices(New Zealand, Chile, Russia, U.S.A., PNG, and Malaysia). Then Granger's causality test, variance decomposition analysis, and impulse response function analysis are also conducted. The major results are summarized as follows : (1) The prices of New Zealand and Russia are caused by only own lagged prices. (2) The prices of Chile and PNG are effected by New Zealand, the price of PNG is effected by New Zealand and Russia, and the price of U.S.A. is effected by those of Chile and PNG, respectively. (3) An exogenous shock in New Zealand will affect the prices of New Zealand, PNG, U.S.A., Chile, Russia. (4) An exogenous shock in Chile may also affect the prices of Chile, U.S.A., Russia.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.353-358
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• 2018

In this study, it is describe to an optimization analysis process for the weight reduction of the voltage converter in the electric vehicle charging systems. The optimization design is a technique that finds the optimal material distribution under a given material quantity constraint by combining the design sensitivity with the material properties and the mathematical optimization. Among the topology optimization, a lightweight design is performed by a solid isotropic material with penalization with simple formula and well-convergence. The lightweight design consists of three steps. As a first step, a finite element model for the basic design of the on-board voltage converter was constructed and static analysis was performed on the load. In the second step, the optimum shape is obtained for the lightweight by performing the topology optimization using the solid isotropic material with penalization applying the stiffness coefficient of the isotropic material to the static analysis result. As a final step, impact analysis was performed by applying a half-sinusoidal pulse shape impact load which satisfies the impact test standard of the vehicle-mounted part with respect to the optimum shape. In the topology optimization, the design domain was defined as the mounting bracket area, and the design technology was finally achieved by optimizing the mounting bracket to achieve a weight reduction of 20% over the basic design.

• The Journal of Bigdata
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• v.7 no.1
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• pp.15-27
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• 2022

In the past five years, the fatality rate of single-vehicle accidents has been 4.7 times higher than that of all accidents, so it is necessary to establish a system that can detect and respond to single-vehicle accidents immediately. The IoT(Internet of Thing)-based real-time traffic accident recognition system proposed in this study is as following. By attaching an IoT sensor which detects the impact and vehicle ingress to the guardrail, when an impact occurs to the guardrail, the image of the accident site is analyzed through artificial intelligence technology and transmitted to a rescue organization to perform quick rescue operations to damage minimization. An IoT sensor module that recognizes vehicles entering the monitoring area and detects the impact of a guardrail and an AI-based object detection module based on vehicle image data learning were implemented. In addition, a monitoring and operation module that imanages sensor information and image data in integrate was also implemented. For the validation of the system, it was confirmed that the target values were all met by measuring the shock detection transmission speed, the object detection accuracy of vehicles and people, and the sensor failure detection accuracy. In the future, we plan to apply it to actual roads to verify the validity using real data and to commercialize it. This system will contribute to improving road safety.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.429-438
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• 2011

In this paper, experiment of thermal conductivity among thermal properties for CCS insulation material was carried out under the condition ranged from room temperature to cryogenic temperature. CCS insulation system should be sustained under cryogenic temperature($-163^{\circ}C$), and lots of investigations will be conducted how to block the heat to insulation material. CCS components which consist of various materials are especially the main interests, and how the temperature of the entire CCS along the location is should be investigated through these studies. With the experimental thermal properties, the steady state thermal analysis of the entire cargo system was conducted. When the LNG leaked through the insulation system with external impact, temperature distribution and thermal safety of secondary barrier, especially plywood and hull structure, was observed.