• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.6
• /
• pp.25-34
• /
• 2017

Since the 30-year-old facility is expected to surge from 10.5% to 23.9% in 10 years, the new evaluation system is needed to establish efficient maintenance system for securing the safety and extending the life span of existing facilities. In this study, Delphi and AHP(Analytic Hierarchy Process) was conducted to provide a systematic new evaluation system for the NATM tunnel, which is the most frequently constructed structure of the existing tunnel. Since the existing assessment systems are limited in scope of evlauatuon criteria, the survey was conducted in conjunction with closed questionnaires on existing items and open questionnaires for eliciting new items. In results, suitable evaluation factors were derived for the NATM tunnel through the validation of the survey results. Also after calculating weighted value of the derived assessment item using AHP technique, a new evaluation system is proposed to meet the characteristics of the NATM tunnel, so that they can be used as reference materials for revising and supplementing detatiled guidelines in the future.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.1
• /
• pp.49-54
• /
• 2012

The purpose of this study is to define emergency response procedures by BDMS [Building Disaster Management System] when earthquake occurs on long-span bridge structures. The study is about developing a computer-based algorithm for various earthquake intensities that works with the System. Presently, long-span bridge disaster prevention relies on closed-system centered on human intervention alone. However, this study combines IT technology and internet-based open system creating a more practical system. Additionally, assigned duties and tasks are clearly defined to all personnel involved in various disaster situations using the Active Action Diagram(AAD) techniques. Also, the design of 3-dimensional view assists to determine the appropriate initial response in times of earthquake and other disasters. The combination of the existing manual emergency response procedures and the scenario-based (IT) response system being developed will create an efficiency and fast response actions in times of emergencies.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.5
• /
• pp.961-967
• /
• 2007

Automatic water feeding system for chickens is the one of the most important devices at poultry farms. Chickens drink water directly from a water feeder nipple of the automatic water feeder. Check valve inside the water feeder nipple is open when they drink water and is closed otherwise. There are two types of nipples. One is the piston nipple, and the other is the ball nipple. Because the nipple stick in the ball nipple can move freely, the sloping mechanism of the ball nipple works well. but it has complicated mechanism. On the other hand, the piston nipple has very simple structure, but its movement is limited so it can move only up-and-down. To overcome those limitation, the piston nipple with sphere valve seat face (sphere face piston nipple) has been developed and is just distributed at domestic markets. The experimental performance test of the commercialized sphere piston nipple has been conducted, and compared with the performance of the ball nipple and the piston nipple which are domestic products. As the result, sphere piston nipple shows excellent performance compared to that of the piston nipple but its performance is similar to ball type nipple.

• Journal of Chest Surgery
• /
• v.29 no.12
• /
• pp.1381-1384
• /
• 1996

Thymoma Is an anterior mediastinal tumor, arising from the thymus, but occasionally has ectopic focus such as neck, trachea, thyroid, pulmonary hilum, lung parenchyme and pleura. Forty-two year old male patient was admitted due to progressive development of shortness of breath in 4 months. He had a history of exposure to asbestos for About 10 years duration In recent 15 years. Radiologically, multiple pleural masses were seen rom apex to diaphrAgm, with no evidence of anterior mediastinal mass,with fluid in right pleural cavity. Closed thoracotomy drainage with open biopsy were performed. Effusion cell block showed many T cell marker positive Lymphocytes & some epithelial cells compatible with thymoma, and the tissue also showed cortical type thymoma. Pleuropneumonectomy and thymectomy followed by 60 Gy radiation therapy were done and the patient is well 8 months postoperatively. The pleura is markedly thickened by the invasion of thymoma and the interstitial space of the lung tissue,but the normal appearance of thymus was present in remote area (Masaoka classification IVa). We report a case of ectopic invasive thymoma arising from the right pleura with intact thymus.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.2
• /
• pp.267-281
• /
• 2012

SCADA system is a computer system that monitors and controls the national infrastructure or industrial process including transportation facilities, water treatment and distribution, electrical power transmission and distribution, and gas pipelines. The SCADA system has been operated in a closed network, but it changes to open network as information and communication technology is developed rapidly. As the way of connecting with outside user extends, the possibility of exploitation of vulnerability of SCADA system gets high. The methodology to protect the possible huge damage caused by malicious user should be developed. In this paper, we proposed anomaly detection based intrusion detection methodology by estimating self-similarity of SCADA system.

• Journal of Korea Entertainment Industry Association
• /
• v.14 no.8
• /
• pp.391-396
• /
• 2020

This study was to examined the effect of chain types exercise of lower limbs on the motor performance differences for the life-carement. For this, twenty normal adult women participated and they were examined the differences of exercise effects about abdominal muscle activity and balance ability by applying two types of chain exercise. In order to identify the differences we let them conduct exercise for 4 weeks with each type of exercise. And we used paired t-test and Independent sample t-test for comparing the differences in the group and inter groups. There was a significant difference in the value of 0.05 to verify statistical significance. As a result of this research, it was found that closed chain exercise is more effective than open chain exercise in muscle activity and balance function. Therefore, in the clinical therapeutic environment, if you apply chain exercise for patient to improve lower limb motor performance, we would recommend the close kinematic chain exercise.

• Journal of the Korean Institute of Gas
• /
• v.27 no.4
• /
• pp.50-55
• /
• 2023

Lithium-ion secondary batteries are currently in high demand and supply. The purpose of this study is to secure the safety of the process by studying the combustion characteristics of EC(Ethylene Carbonate), Which is mainly used as an electrolyte organic solvent for lithium ion batteries. The flash points of the EC by using Setaflash and Pensky-Martens closed-cup testers were experimented at 141 ℃ and 143 ℃, respectively. The flash points of the EC by Tag and Cleveland open cup testers were experimented at 152 ℃ and 156 ℃, respectively. The AIT(Auto Ignition Temperature) of the EC was experimented at 420 ℃. The LEL(Lower Explosive Limit) calculated by using lower flash point of Setaflash was calculated at 3.6 Vol.%.

• Journal of the Society of Disaster Information
• /
• v.17 no.1
• /
• pp.10-24
• /
• 2021

Purpose: The purpose of this study is to determine the dangers of biodiesel and general diesel mixtures currently used as alternative fuels by equipment (tag method and penski Marten method) and to determine the difference between flash point and combustion point (closed, open) according to test methods. It is intended to be used as a reference material for identification and evaluation of firecausing substances by confirming the risk of mixtures by comparative analysis and measurement, and establishing a risk assessment method for chemical substances. Method: Flash point test method and result treatment were tested based on ASTM and KS M mode, which are tag sealing and pen schematense test methods used as flash point and combustion point test methods for crude oil and petroleum products. The manufacturer of the equipment used in this experiment was a test equipment that satisfies the test standards of KS M 2010 with equipment produced by TANAKA of Japan. The flash point and combustion point were measured, and the flash point according to the test method of biodiesel and general diesel mixture ( Closed, open), and the ignition point of a mixture of biodiesel and general diesel was compared and analyzed for ignition risk compared with conventional diesel. Results: Looking at the experimental results, first, as an analysis of the risk of flammability of the mixture, the flash point of a substance containing 70% biodiesel was found to be about 92℃ based on general diesel with a flash point of 64.5℃, and gasoline and biodiesel or When the biodiesel mixture was synthesized, it was confirmed that the flash point tends to decrease. In addition, the difference between the flash point and the combustion point was analyzed as about 20 ~ 30℃, and when a small amount of gasoline or methanol was mixed, the flash point was lowered, but it was confirmed that the combustion point was similar to that of the existing mixture. Conclusion: In this study, in order to secure the effectiveness of the details of the criteria for judging dangerous materials in the existing Dangerous Materials Safety Management Act, and to secure the reliability and reproducibility of the judgment of dangerous materials, we confirm the criteria for judging the risk of the mixture through an experimental study on flammable mixtures. It will be able to provide reference data for experimental criteria for flammable liquids that are regulated in the field. In addition, if this study accumulates know-how on experiment by test method, it is expected that it can be used as a basis for research on risk assessment and research on dangerous goods.

• The Journal of Engineering Geology
• /
• v.3 no.2
• /
• pp.149-165
• /
• 1993

Nowadays, the field hydraulic test is still an only method to evaluate groundwater characteristics in subsurface. The results of hydraulic test are very important for the concept model of fracture hydrogeology as well as the geometric pattern of fractures. The hydraulic tests performed in Korea are generally analysed under such assumption as steady radial flow in homogeneous aquifer or along simple geometry of fractures. Also the transmissivity measured in a fixed interval length is equivalent to a sum of individual fracture transmissivities in test legth. The boundary effects of weH hydraulics and the geometry of flow paths are hardly obtained from the test results analysed by a steady flow method. To circumvent this problem, the flow dimensional analysis was attempted from the results of constant pressure injection test carried out in a fractured granite area. A comparison of the hydraulic conductivity values from the transient and steady analysis shows that the latter is about a factor of 2~3 higher than the former. However, it was possible to analyse a flow dimension of each test interval from flow rate variation with time. The upper part of the bedrock(<10m deep) indicates an open boundary and the flow dimension shows nearly steady states, while the lower part of the bedrock(>25m deep) is characterized as sublinear flow dimension with a dosed boundary. In one of the test sections(15m deep), the flow dimension was changed from linear flow to spherical flow. From the experience of this study, one of the immediate problems to be solved is to enhance the field testing equipments, i.e., an accurate flowmeter with autorecording and a pressure detecting device to be able to install in the test section.

• Journal of Service Research and Studies
• /
• v.7 no.1
• /
• pp.1-14
• /
• 2017

Despite that Korea has tried 50 years of service development policies, the result has been unsatisfactory. Borrowing the policy stream model of policy change and narrative policy framework one tried to explain the weaknesses of the policy process for the service development policies. Before 2000 lacking knowledge resulted in poor policy narratives while after 2000 despite sufficient knowledge base and well articulated narratives policy window would not open. Adversarial politics under conservative party caused the window to be closed. One suggests that paradigm shift in value and world view treats is necessary to overcome the policy failures in service development policy. According these analyses one expects a new initiative of policy narrative construction.