• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.18-24
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• 2015

Non-destructive testing (NDT) methods are widely used in the construction industry to diagnose the defects/strength of the concrete structure. However, it has been reported that the results obtained from NDT are having low reliability. In order to resolve this issue, four kinds of NDT test (ultrasonic velocity measurements by P-wave and S-wave and the impact resonance methods by longitudinal vibration and deformation vibration) were carried out on 180 concrete cylinders made with two kinds of mix proportions. The reliability of the NDT results was analyzed and compared through the measurement of the actual compressive strength of the concrete cylinders. The statistical analysis of the results was revealed that the ultrasonic velocity method by S-wave is having lowest coefficient of variation and also most capable of stable observation. Analytical equations were established to estimate the compressive strength of the concrete from the obtained NDT results by relating the actual compressive strength. Moreover the equation established by the ultrasonic velocity method by S-wave had the highest coefficient of determination. Further studies on the stability of non-destructive testing depending on various mixing conditions will be necessary in the future.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.632-639
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• 2015

Working in the forest would require a wide range of skills and experience for specific tasks which involve with a high level of risks to worker's safety. However, there has been a concern on the current standard wage system for forest workers because it does not effectively reflect the characteristics of typical working conditions in the forest. In addition, the current standard wages for forestry workers was estimated based on the construction industry's wage system. Therefore, the purpose of this study is to assess a current wage system through the mail survey method and to develop a new wage system for forest worker which effectively reflects skill sets and experience required for successful completion of the work in the forest. We mailed the survey questionnaire consisting of 19 questions to 659 forest workers and received 188 responses resulting in a 28.5% response rate. The results showed that the current average optimal wages of forest worker, special worker and feller were 97,680won/day, 127,559won/day and 152,403won/day, respectively though there were variations depending on the regions. In developing the new standard wage system, this study suggest the current work types(worker, special worker and feller) could be divided into 5 work types (forest-environment workers, forest operations in beginner, forest operations in intermediate, forest operations in advanced and forest equipment operator) reflecting specialty of forest operation thereby stabilizing the new wage system for forest workers.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.1-9
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• 2015

As the use of software is more wider in the safety-critical nuclear fields, so study to improve safety and quality of the software has been actively carried out for more than the past decade. In the nuclear power plant, nuclear man-machine interface systems (MMIS) performs the function of the brain and neural networks of human and consists of fully digitalized equipments. Therefore, errors in the software for nuclear MMIS may occur an abnormal operation of nuclear power plant, can result in economic loss due to the consequential trip of the nuclear power plant. Verification and validation (V&V) is a software-engineering discipline that helps to build quality into software, and the nuclear industry has been defined by laws and regulations to implement and adhere to a through verification and validation activities along the software lifecycle. V&V is a collection of analysis and testing activities across the full lifecycle and complements the efforts of other quality-engineering functions. This study propose a methodology based on V&V activities and related tool-chain to improve quality for software in the nuclear power plant. The optimized methodology consists of a document evaluation, requirement traceability, source code review, and software testing. The proposed methodology has been applied and approved to the real MMIS project for Shin-Hanul units 1&2.

• Spatial Information Research
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• v.22 no.5
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• pp.27-41
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• 2014

Recently, BIM(Building Information Modeling) has been applied to the infrastructure such as road and bridge, and information about the outside environment of buildings is needed for maintaining and managing the large urban facilities. In addition, the convergence between spatial information and Big-data has a large potentiality, in respect that considerable profits and developments in other application problems such as various simulations and urban plans, national land security, may be brought about on the basis of the interoperability of information between BIM and GIS. Therefore, this study attempted to suggest the development direction of a model integrating building for spatial information analysis and city on the subject by comparing and analyzing difference between information system and shape expression of IFC, CityGML and LandXML to efficiently link information between IFC as a standard model of BIM and CityGML as a standard model in the GIS sector and to prepare a basic fusion strategy and a method of utilization between BIM and GIS. The result of the study are as follow. Firstly, contents and structure of IFC, CityGML and LandXML are compared and analyzed. Secondly, the development direction of iBUM(Integrated Building and Urban Model) suggested, which is based on convergence technology for analysis of space information. Finally, a strategy and method of the BIM and GIS are proposed in the iBUM environment.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.173-191
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• 1998

The Purpose of this study is to Present the tourism development Plan of Muan County in relation to the establishment of the Muau international Airport. This study criticizes the stereotypical tourism development plans carried out by numerous loyal self-governments. The highest purpose of tourism is to create an experience that cannot be had In a Person's daily life. Tourism development in Muan must be loyal to this philosophy of tourism. This study raises three key questions: What is the nature of tourism\ulcorner; For whom is tourism developed\ulcorner , Why is tourism being developed\ulcorner The answers to the three key questions are very basic ones. but are not being fulfilled in the tourism development of Korea, as fellows. Firstly, tourism development should be carried out to strengthen the special characteristics of tourism resources. Secondly, tourism development should encourage the participation of local residents within the Process, and it should be helpful to the local industry and the resident's income. lastly, the development should refrain from relying heavily on money-making businesses but seek to enrich the lives of visitors and hosts together. This study presents five distinctive tourism development schemes for Muan. They are as follows: the establishment of a scenic byway leading to the Airport: the development of Hoeshan lotus reservoir as a tourist resort for Buddhists and as a traditional health care center: the utilization of the .Japanese military airport relics as an historical and cultural tourist attraction: the establishment of a salt-water spa complex: and the vitalization of agricultural tourism by utilizing the advantage of the Muan international Airport.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.475-481
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• 2013

Although the lightly burnt MgO at $850{\sim}1000^{\circ}C$ has expansibility, it does not lead to unsound concrete. The expansion of MgO could compensate for shrinkage of concrete for a long-term, because the hydration of MgO occurs at a slow pace. Recently, the study and application of mineral admixture such as fly ash and blast furnace slag have increased for the hydration heat reduction, durability improvement, and reducing $CO_2$ emission in the construction industry. Thus, it is necessary to research on the concrete that contains both a mineral admixture and MgO as an expansion agent. This study investigates fundamental properties of fly ash concrete with lightly burnt MgO through various experiments. The adiabatic temperature test results showed that the fly ash concrete with MgO of the 5% replacement ratio had the slower pace of the temperature rise and the lower final temperature than the fly ash concrete. The influences of MgO on long-term compressive strength varied depending on water-binder ratio, and the long-term length change test results indicated the expansion effects of the FA concrete containing MgO.

• Advances in concrete construction
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• v.10 no.2
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• pp.171-183
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• 2020

The main objective of this study is the assessment of the ability of limestone mortars to resist to different chemical attacks. The ability of polypropylene (PP) fibres waste used as reinforcement of these concrete materials to enhance their durability is also studied. Crushed sand 0/2 mm which is a fine limestone residue obtained by the crushing of natural rocks in aggregates industry is used for the fabrication of the mortar. The fibres used, which are obtained from the waste of domestic plastic sweeps' fabrication, have a length of 20 mm and a diameter ranging between 0.38 and 0.51 mm. Two weight fibres contents are used, 0.5 and 1%. The durability tests carried out in this investigation included the water absorption by capillarity, the mass variation, the flexural and the compressive strengths of the mortar specimens immersed for 366 days in 5% sodium chloride, 5% magnesium sulphate and 5% sulphuric acid solutions. A mineralogical analysis by X-ray diffraction (XRD) and a visual inspection are used for a better examination of the quality of tested mortars and for better interpretation of their behaviour in different solutions. The results indicate that the reinforcement of limestone mortar by PP fibres waste is an excellent solution to improve its chemical resistance and durability. Moreover, the presence of PP fibres waste does not affect significantly the water absorption by capillarity of mortar nether its mass variation, when exposed to chloride and sulphate solutions. While in sulphuric acid, the mass loss is higher with the presence of PP fibres waste, especially after an exposure of 180 days. The results reveal that these fibres have a considerable effect of the flexural and the compressive behaviour of mortar especially in acid solution, where a reduction of strength loss is observed. The mineralogical analysis confirms the good behaviour of mortar immersed in sulphate and chloride solutions; and shows that more gypsum is formed in mortar exposed to acid environment causing its rapid degradation. The visual observation reveals that only samples exposed to acid attack during 366 days have showed a surface damage extending over a depth of approximately 300 ㎛.

• Journal of the Korea Society of Computer and Information
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• v.15 no.6
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• pp.111-120
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• 2010

Looking at the application examples related to RFID systems around the world, it is easy to find that RFID systems are introduced in various industries, such as retail and consumer goods sectors, financial and security sectors, automotive and transport sector, leisure and sports sector, logistics, and health-related fields. This is because they can get their operational efficiency and competitiveness by means of product's visibility and transparency of information through RFID systems. However, it is required that evaluation of effectiveness on introducing RFID systems should be performed to strengthen construction willingness of RFID systems before actual introduction of the RFID systems in the process. This activity affects to introduction of RFID systems in industry-wide and then, will be able to create a synergy effect such as national industrial competitiveness improvement. The purpose of this study is to offer rational method on effectiveness analysis before and after RFID based process. Accordingly, the proposed Choquet fuzzy integral-based model will be allowed rational analysis by integrating quantitative and qualitative analysis. Through the effectiveness analysis of C company's RFID based process using the proposed evaluation model, we could identify that RFID-based logistics process was more effective than existing process.

• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.215-229
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• 2020

In response to the recent 4th industrial revolution, the demand for 3D object models in the latest fields of digital twin, autonomous driving, and VR/AR, as well as the existing fields such as city, construction, transportation, and energy has increased significantly. It is expected that the demand for 3D object models with various precision from LOD1 to LOD4 will increase more and more in various industry fields. However, the Ministry of Land, Infrastructure and Transport, and the local government and the private sector have partially built 3D object models of different precisions for some specific regions because of the huge cost. Therefore, this study proposes a feasible plan that can solve the cost problem in generating 3D object models for the whole territory. For our purpose, we first analyzed usage, demand, generation technology and generation cost for 3D object models. Afterwards, we proposed LOD3 model generation plan for all territory using automatic 3D object model generation technology based on image matching. Additionally, we supplemented the proposed plan by using LOD4 generation plan for landmarks and LOD2 generation plan non-urban area. In the near future, we expect this would be a great help in establishing a feasible and effective 3D object model generation plan for the whole country.

• Korean Journal of Health Education and Promotion
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• v.18 no.1
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• pp.35-47
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• 2001

As the complexity of the our environment is further complicated by advancements in industry and increase in vehicle traffic flow, the incidents of injury causing accidents are on the rise. Consequently, there is increasing emphasis on the importance of systematic and continual safety education for injury preventive behaviors. This study investigates safety related problems of elementary school students based on the PRECEDE model, proposed by Green et al.(1980 Green), to comprehensively identify the requirements of school safety education. The identified requirements were used to diagnose the current state of elementary school safety education through the analysis of multidimensional factors. A questionnaire survey was conducted on 594 sixth grade students from randomly selected 4 schools in Seoul to examine their injury preventive behaviors and to determine the educational diagnosis variables that affect it. The duration of the survey was 3 weeks starting from April 12, 1999 to May 8, 1999. A summary of the survey results are presented below; 1. Situations in which accidents have occurred were, in their order of frequency, ‘during play or sports activities within the school grounds’ was most frequent at 59.6％, ‘during play on local streets’ at 49.5％, and ‘traffic accidents’ at 41.6％. 2. Categorization of the injury preventive behavior showed that ‘not playing at high traffic flow locations such as streets and construction sites’ had the higher level of observance, while ‘wearing of helmets and joint protection devices during playing’ was least observed. 3. Considering injury preventive behaviors in relation to educational diagnosis variables indicated, for predisposing factors, lower ‘perception to injury accidents’ (p〈0.001) combined with higher ‘concerns for injury accidents’(p〈0.001), ‘practice of preventive behavior’(p〈0.001), and ‘the level of safety knowledge’(p〈0.001) resulted in significantly higher observance of injury preventive behaviors. For enabling factors, higher ‘perceived level of the school safety education’ (p〈0.001) and ‘availability of safety education resources’(p〈0.01) indicated significantly higher observance of injury preventive behaviors. For the reinforcing factor, frequent exposure to ‘safety education brochure’ (p〈0.01) and ‘audio-visual material for safety education’(p〈0.01) combined with more ‘regional safety education’ (p〈0.01), ‘home safety education’ (p〈0.01), ‘school safety education’(p〈0.001), and, ‘parents’ observance of preventive behaviors' (p〈0.001) showed significantly higher observance of injury preventive behaviors. 4. An analysis of the factors that affect injury preventive behaviors showed that the enabling factor ‘awareness of school safety education’ had the highest correlation with injury preventive behaviors followed by factors, in their order of significance, ‘practice of preventive behavior’, ‘perception to injury accidents’, ‘level of safety knowledge’, ‘parents’ observances of preventive behaviors', and ‘concerns for injury accidents.’