• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.527-539
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• 2018

The subway used by many passengers is required to maintain a safe and comfortable environment and PSD (Platform Screen Door) must be installed in the platform after reinforcing the standard in 2003. In the previous research, in case of subway fire to control it, it is necessary to design the optimal ventilation and smoke exhaust system according to equipment capacity of the smoke exhaust system. Therefore, in this study, based on the results of previous research, three-dimensional numerical analysis was performed for the CO gas and smoke flow by the subway ventilation system in case of platform fire. As a result of this study, it was found that in case of emergency, if only the upper-level smoke exhaust system is activated, the risk of evacuation is high due to CO gas (653.8 ppm) and smoke concentration ($768.4mg/m^3$). And when all the smoke exhaust systems are activated and only the fire side PSD is opened, CO gas (36.0 ppm) and smoke concentration ($26.2mg/m^3$) are detected and the propagation range of smoke flow was reduced. When all the smoke exhaust systems are activated and only the fire side PSD is closed, it was analyzed as the most effective ventilation mode in the evacuation environment due to the absence of smoke-recirculation.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.303-312
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• 2006

The main objective of this experimental study is to examine the feasibilities of each testing method with various kinds of grip systems for the analysis of tensile strength of GFRP(glass fiber reinforced polymer) reinforcing bars. Three types of grip systems were examined such as resin-sleeved pipe-type grip proposed by CSA(Canadian Standard Association), frictional resistance type metal grip by ASTM(American Standard for Testing and Materials) and wedge-inserted cone-type grip normally used in prestressing tendons. Also, mechanical properties of GFRP rebars with different surface deformations were investigated for each different type of testing grip used in this study. All testing procedures including specimens preparation, set-up of test equipments and measuring devices were made according to the CSA S806-02 recommendations. From the test results, it was found that the highest tensile strengths of GFRP rebars were observed when tested by resin-sleeved grip system regardless of their different surface deformations. But tensile strengths of GFRP rebars by ASTM grip system are only 10% less than those by CSA grip system. On the other hand, CSA grip is not only difficult to prepare but also not disposable. Therefore, ASTM grip system is recommended as a practical alternative to estimate the tensile strength of GFRP rebars.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.161-168
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• 2009

In an architectural construction, underground construction is a critical path forming a major part of the total construction period and cost, and particularly in big cities, its size has been increasing every year. A basement wall currently constructed in the field needs a large functional work force, and the construction is under progress by the Euroform and Soldier system, which is disadvantageous in terms of the construction period. Therefore, in this research, non-supporting forms which are applicable to the buildings construction were developed, based on the non-supporting forms partly used in some civil engineering works. In addition, the size of a form was assumed and its economical efficiency was compared to that of the Euroform and Soldier system which is used most in construction fields, and the results were analyzed. The study results showed that the construction cost of composite non-supporting forms was higher than that of the Euroform and Soldier system by about 8%, and the construction cost of non-composite non-supporting forms were lower than that of the Euroform and Soldier system by about 9%. However, in the case of composite non-supporting forms, the amount of concrete and reinforcing rods remarkably decreased in structural construction, so it has the effect of an economical cost reduction compared to the construction cost of existing walls by about 35%

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.78-87
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• 2015

Recently, Police integrity has been issued on the media, which cause discredit of police organization. Although high level of morality and integrity are required compared to other occupational groups due to their authority to exert legal force to the citizens and a variety of policies have been enforced by the National Police Agency for the purpose of uplifting the integrity of the officers, in reality, corruption had not yet been eradicated. At this point in time, this study attempted to draw implications for uplifting integrity by utilizing domestic and foreign preceding studies and statistical data related to police corruption and uplifting integrity. The inspection system through whistle-blowing was pointed out as a problem in the institutional framework that hinders uplifting integrity of the police officers and the perception in which police officers are regarded as potential criminals was also pointed out as a problem. Also, vague standards of disciplinary action in examining an offense of a police officer and lack of care for those who were disciplined in the past which affects loyalty to the organization were presented as problems. Based on such suggested concerns, policies for uplifting integrity and restoring citizens' trust in the policies officers were proposed. The proposed agenda were warning the police officers by presenting clear and specific category of corruptive behaviors, expressing the necessity of devising a system that prevents the officers from committing serious crimes by discovering problematic officers earlier through introduction of Early Warning System(EWS) of US and Australian police in order to break away from exposure-oriented inspection system, and reinforcing the testing of integrity in the new employment process.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.1
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• pp.40-52
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• 2020

The purpose of this study is to explore ways to change high school earth science elective courses with the introduction of the high school credit system in 2025, and ways to restructure them in preparation for the next curriculum revision. For this purpose, Delphi surveys with earth science education experts, a survey with in-service earth science teachers, and in-depth interviews with experts were conducted. According to the results, we need to consider four keywords such as cultivation of earth science literacy, connection with student career paths, emphasis on the fun of earth science itself, and student selection rate and college entrance exam in restructuring Earth science electives. Based on this direction, we composed four subjects: Earth System Science emphasizing earth science literacy, and three such subjects reinforcing career connection as Solid Earth Science, Atmospheric and Ocean Science, and Space Science. To resolve concerns about falling selection rate of earth science courses with the introduction of the high school credit system, it is necessary to re-establish the status of the earth science subjects including enhancing the career connection of the earth science electives. Follow-up studies are necessary to elaborate and publicize the titles and core concepts of Earth science electives.

• The Journal of Engineering Geology
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• v.26 no.1
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• pp.51-61
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• 2016

New building methods are needed to aid increased inner-city redevelopment and industrial construction. A particular area of improvement is the efficient use of cut slopes, with the minimization of associated problems. A retaining wall of precast panels can resist the horizontal earth pressure by increasing the shear strength of the ground and reinforcing it through contact with the panels. Precast panels allow quick construction and avoid the problem of concrete deterioration. Other problems to be solved include the digging of borrow pits, the disposal of material cut from the slope, and degradation of the landscape caused by the exposed concrete retaining wall.This study suggest the methods of improvement of an existing precast panel wall system by changing the appearance of the panels to that of natural rock and improving the process of adhering the panel to a vertical slope. The panels were tested in the laboratory and in the field. The laboratory test verified their specific strength and behavior, and the field test assessed the panels' ground adherence at a vertical cutting. Reinforcement of the cutting slope was also measured and compared with the results of 3D numerical analysis. The results of laboratory test, identified that the shear bar increase the punching resistance of panel. And as a results of test construction, identified the construct ability and field applicability of the panel wall system adhered to in-situ ground. In addition to that, extended measurement and numerical analysis, identified the long-term stability of panel wall system adhered to in-situ ground.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.565-572
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• 2008

It is a trend to increase safekeeping properties in financial company as the world economy situation has been globalized and advanced. The development of a securable vault door resisting to malicious trespass is needed. Therefore, this study focuses on developing high performance concrete placed at the inside of the vault door, and all materials used in this study is easy to obtain in domestic considering economic competitiveness. The compressive strength over 170 MPa was targeted, and structurally strengthening was also planned in order to resist to over $3,000^{\circ}C$ heating by torch and extreme impact loading by hammer drilling machine. Several types of fibers and reinforcing structures were used in order to resist those external heating and loading. This purpose was required to satisfy UL 608 standard of a vault door. Consequently, the result from this study is expected to be applied to construction field of major facilities, which should guarantee the safety from an external attack such as terror.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.1026-1035
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• 2013

The construction field is implementing cost savings and business process improvements by adopting and applying various information technologies to secure the construction sector's technological competitiveness amid the economic recessions inside and outside South Korea. Therefore, affiliated agencies of the Ministry of Land, Infrastructure, and Transport are reinforcing transparency and efficiency in construction project management through informatization. These agencies are also performing construction project management and maintenance and management businesses by constructing various information systems to create higher added values and secure competitiveness. However, as the application of the constructed information system is limited to a portion of public construction projects, it is not yet possible to understand the whole status of the national infrastructures. Therefore, this paper aims to propose a construction information service plan, its future promotion method and procedure of application on the entire national infrastructures. This plan would be carried out by collecting, linking and fabricating the main construction information from the information systems of the affiliated agencies around the construction project information system(Construction CALS System) being applied at the organizations under the Ministry of Land, Infrastructure, and Transport. Such a plan is expected to facilitate effective project management and maintenance of public construction projects and serve as a useful tool for major decision making endeavors such as future policy planning. The proposed plan is also expected to facilitate the management and application of construction information from the construction up to the maintenance management of the national infrastructures.

• Journal of the Korea Concrete Institute
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• v.19 no.2
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• pp.233-239
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• 2007

The main objective of this study was to evaluate the effect of recycled PET fiber made from waste PET bottle on the control of plastic shrinkage cracking of cement based composites. PET is blown as a plastic material and used in a variety products such as a beverage bottle. However, waste PET bottles are thrown after the usage, raising huge problems in terms of the environment. Thus, the research on the method to recycle the PET bottles indicates important aspects in environment and economy. The method to recycle waste PET bottles as a reinforcing fiber for cement based composites is one of effective methods in terms of the recycle of waste PET bottles. In this research, the effect of recycled PET fiber geometry and length on the control of plastic shrinkage was examined through thin slab tests. A test program was carried out to understand the influence of fiber geometry, length and fiber volume fraction. Three type of recycled PET fibers including straight, twist crimped and embossed type. Three volume fraction and two fiber length were investigated for each of the three fiber geometry. Test results indicated that recycled PET fibers are effective in controlling plastic shrinkage cracking in cement based composites. In respect to effect of length of fiber, longer fiber was observed to have efficient cracking controlling with low volume fraction in same fiber geometry while shorter fiber controled plastic shrinkage cracking efficiently as addition rate increase. Also, embossed type fibers were more effective in controlling plastic shrinkage cracking than other geometry fiber at low volume fraction. But, for high volume fraction, straight type fibers were most effective in plastic shrinkage cracking controlling in cement based composites.

• Information Systems Review
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• v.11 no.2
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• pp.183-207
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• 2009

In general, the introduction of information technology to domestic small and middle size firms is depending on the governmental supporting policy. However, even under this situation there is also a case that the building up of information technology is initiated by the management of small and middle size firms. An accumulated know-how for information technology and powerful leadership in such firms are considered as success factors. This study attempts to analyze a case for 'THEFACESHOP', in which MIS is successfully built. To achieve corporate goals, the CEO of THEFACESHOP based on the extensive knowledge of information technology drove to build up information system. Also, the board of directors supported him, and employees committed to their organization. Through the strong leadership of the CEO, the information system of THEFACESHOP became sufficient and efficient. And it led the organization and the information system to be competitive. In particular, the systematic approach of THEF ACESHOP reinforcing its competitiveness can be summarized as follows: First, it tried to construct basic information systems as like ERP etc. to increase work-efficiency. Second, it completed CRM related systems for analysis to maximize its customer orientation and marketing effect. Third, the last step can be stated as the building up of operation related CRM systems to improve the responsiveness of target marketing activities and the profitability of its agencies. Such endeavors of THEFACESHOP contributed to increase productivity and performance of the organization. As a result, THEFACESHOP has had its own 'Natural Story' and price competitiveness. For that reason THEFACESHOP became the best of brand-shop cosmetic firms. This success based on the strong leadership and the systematic investment on the information system.