• The KIPS Transactions:PartA
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• v.18A no.5
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• pp.193-204
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• 2011

Since web applications are accessed by anonymous users via web, more security risks are imposed on those applications. In particular, because security vulnerabilities caused by insecure source codes cannot be properly handled by the system-level security system such as the intrusion detection system, it is necessary to eliminate such problems in advance. In this paper, to enhance the security of web applications, we develop a static analyzer for detecting the well-known security vulnerability of PHP file inclusion vulnerability. Using a semantic based static analysis, our vulnerability analyzer guarantees the soundness of the vulnerability detection and imposes no runtime overhead, differently from the other approaches such as the penetration test method and the application firewall method. For this end, our analyzer adopts abstract interpretation framework and uses an abstract analysis domain designed for the detection of the target vulnerability in PHP programs. Thus, our analyzer can efficiently analyze complicated data-flow relations in PHP programs caused by extensive usage of string data. The analysis results can be browsed using a JAVA GUI tool and the memory states and variable values at vulnerable program points can also be checked. To show the correctness and practicability of our analyzer, we analyzed the source codes of open PHP applications using the analyzer. Our experimental results show that our analyzer has practical performance in analysis capability and execution time.

• The KIPS Transactions:PartC
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• v.9C no.6
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• pp.935-944
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• 2002

It is the Mobile Ad Hoc Networks that constituted with serveral mobile node that can communicate with other mobile nodes. Until now, there were no routing protocols considering such as Multimediadata, VOD (Video On Demand), which is required of lots of bandwidth in Mobile Ad Hoc Network, io we are in the need of QoS (Quality of Service)routing protocol to transmit the data packets faster and more accurate. Also, there are an unidirectional links due to asymmetric property of mobile terminals or current wireless environments on practical mobile ad hoc networks. However, at present, the existing mobile ad hoc routing protocols are implemented to support only bidirectional links. In this paper, we propose the Advanced Routing routing protocol in order to implement a new routing protocol, which is fit to mobile ad hoc networks containing unidirectional links and to support QoS service. For the performance evaluation, we use NS-2 simulator of U.C. Berkeley. We could get not only increased received data rate and decreased average route discovery time, but also network load decreases with compared Best effort service.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.1
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• pp.215-241
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• 2017

This study analyzed teachers' Pedagogical Content Knowledge (PCK) regarding the pedagogical aspect of the instruction of ratio and rate in order to look into teachers' problems during the process of teaching ratio and rate. This study aims to clarify problems in teachers' PCK and promote the consideration of the materialization of an effective and practical class in teaching ratio and rate by identifying the improvements based on problems indicated in PCK. We subdivided teachers' PCK into four areas: mathematical content knowledge, teaching method and evaluation knowledge, understanding knowledge about students' learning, and class situation knowledge. The conclusion of this study based on analysis of the results is as follows. First, in the 'mathematical content knowledge' aspect of PCK, teachers need to understand the concept of ratio from the perspective of multiplicative comparison of two quantities, and the concept of rate based on understanding of two quantities that are related proportionally. Also, teachers need to introduce ratio and rate by providing students with real-life context, differentiate ratios from fractions, and teach the usefulness of percentage in real life. Second, in the 'teaching method and evaluation knowledge' aspect of PCK, teachers need to establish teaching goals about the students' comprehension of the concept of ratio and rate and need to operate performance evaluation of the students' understanding of ratio and rate. Also, teachers need to improve their teaching methods such as discovery learning, research study and activity oriented methods. Third, in the 'understanding knowledge about students' learning' aspect of PCK, teachers need to diversify their teaching methods for correcting errors by suggesting activities to explore students' own errors rather than using explanation oriented correction. Also, teachers need to reflect students' affective aspects in mathematics class. Fourth, in the 'class situation knowledge' aspect of PCK, teachers need to supplement textbook activities with independent consciousness and need to diversify the form of class groups according to the character of the activities.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.2
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• pp.98-103
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• 2004

Recently, a New Great Harbour Bridge between Mokpo City and Koha Island is planned to be built across Mokpo Inner Harbour, and Namak New Town is under construction adjacent to Mokpo. Citizels' concorn of and participation in 「Campaign for Shaping Mokpo into Beautiful Seaport」 are necessary to match the view of Mokpo harbour with natural scenery beautifully and with marine environment harmoniously. Citizens'ㄹ levels of consciousness of coastal and marine environment were ascertained through questionnaire surveys of local citizenry attitudes and opinions, and citizenry action plans for the conservation of coastal and marine environments around Mokpo harbour are suggested on the basis of the results of questionnaire surveys. Citizens' voluntary participations in local policy for the control of marine wastes production and in a campaign for the collections of marine debris and wastes around beaches and coastal areas are required. The operation of municipal sewage treatment plants is to be performed effectively and efficiently, and to be monitored and evaluated periodically by the general public, the local federation for environmental movement or NGO. The development and performance of marine environmental education programs and an enlightenment campaign for environment preservation are to be incessantly done in cooperation with local residents. Only when local government of Mokpo collects the public opinions and continues to shape Mokpo into international beautiful seaport in the direction of a reflex of public opinion, coastal and marine environment around Mokpo harbour can be kept in good condition with citizens' positive participation in citizenry long-term practical action plans for environment conservation.

• 대한공업교육학회지
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• v.31 no.2
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• pp.177-202
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• 2006

The purpose of this study was to determine the present teaching competency level and the educational needs of electricity electronic communication technical teachers. The population was electricity electronic communication technical teachers, 750 teachers were sampled for this study. A survey questionnaire consisted of teaching competencies scale including 3 domains based on Performance-Based Teacher Education Modules. The professional competencies scale consisted of 5-point Likert-type 30 items for them to rate the importance and also to indicate the teaching competency level. A questionnaire was mailed to the sample and 443 returned questionnaires were analyzed after data cleaning. The educational needs of teachers were calculated by using the Borich's needs assessment formula. The findings of this study were as follows. 1) electricity electronic communication technical teachers perceived all the thirty competencies as highly important ones. 2) They perceived that their current teaching competency level was just beyond the ordinary level but was lower than the good level. 3) The highest needs were 'determining learning level & interests of students', 'applying problem solving techniques', 'reconstructing lesson contents', 'establishing lesson objectives'. 4) They have a different level of educational needs on the competencies according to their gender, terminal education level, year of teaching experience, practical work experience, school type(national public school/private school), and school location.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1824-1832
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• 2011

In this paper, a smart home service robot McBot II is newly developed in much more practical and intelligent system than McBot I which we had developed a few years ago. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot McBot II to completely overcome this problem on real environments. The mechanical design and the basic control of McBot II, which performs mess-cleanup function etc. in house, is actually focused in this paper. McBot II is mechanically modeled in the same method that the human works in door by using the waist and the hands. The big-ranged vertical lift and the shoulder joints to be able to forward move are mechanically designed for the operating function as the human's waist when the robot works. The mobility of McBot II is designed in the holonomic mobile robot for the collision avoidance of obstacle and the high speed navigation on the small area in door. Finally, good performance of McBot II, which has been optimally desinged, is confirmed through the experimental results for the control of the robotic body, mobility, arms and hands in this paper.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.68-75
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• 2018

In this study, to solve the problems of the conventional crack repair and injection method, high elasticity latex was used as the material of the storage tube to withstand the high pressure in the center part differently from the general port. When the repair solution was injected into the crack part, The TPS method was developed so that the air existing in the TPS can be discharged. In addition, a new infusion port in which a valve blocking the backflow of the remediation solution was installed at the injection port was developed and the physical characteristics of the port were analyzed. As a result of the evaluation, it was found that the filling rate of the remedial solution was improved compared to the existing ordinary injector method, and the cracks were completely filled in the test conditions. Compressive strength and tensile strength after repair showed about 20% decrease after repair in case of using ordinary injector method, while TPS method showed about 2~7% increase after repair. The results of this study showed that the injection port method using the elastic storage tube increased the injection performance and the quality after repair compared to the conventional injector method. The result of this study is expected to be utilized as the basic data for application and commercialization of the result to the practical structure.

• The KIPS Transactions:PartA
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• v.15A no.4
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• pp.227-238
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• 2008

Recently, as network environment has broadened, the demands on VOD have been increased. The VOD services can be categorized into two types, RVOD and NVOD. Practical VOD services adopt one of them exclusively. Since a method using only one of RVOD and NVOD is not able to deal with frequently variable demand of clients, it leads to a result of overload on a server and a waste of server bandwidth. The efficiency of the network resource usage becomes lower. Hence this paper presents a study on the protocol for efficient VOD services. We propose a new protocol appliable for the existing VOD service algorithm, analyze its performance through simulation, and developed server/client systems applying the new protocol. We propose a mode switching protocol combined with protocols used in RVOD and NVOD. The proposed protocol is not able only to control both RVOD and NVOD but also to change the mode between RVOD and NVOD. As a result of using the proposed protocol to meet frequently variable demand, server bandwidth can be used efficiently. Especially, it can be applied to the existing VOD service algorithms. Therefore, we expect that the proposed protocol in this paper will be widely used in emerging VOD markets.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.395-405
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• 2005

This paper summarizes the test results of the flexible-stiff mixed system for the effective use of high-strength steel. Steel with a high degree of strength and performance is being increasingly required as buildings get larger and taller. High-strength steels cannot be used for many applications, though, because they have a number of defects. For instance, they have a high yield ratio, a small strain in maximum stress, and equal Young's modulus compared to mild steels. A new structural system is needed to effectively use high-strength steels with some defects. This paper proposes the flexible-stiff mixed system for the effective use of high-strength steels with high yield ratios. The possibility of using the system is discussed through the test of flexible-stiff mixed columns with high-strength steels. The main variable of the specimens is the yield displacement ratio, including both the force ratio and the stiffness ratio. The proper yield displacement ratio is proposed by adopting the flexible-stiff mixed system. The test results showed that the proposed flexible-stiff mixed system has a high capacity for energy absorption and the highest capacity for energy absorption when the yield displacement ratio of the flexible element to the stiff element ranges from 2.7 to 3.3.

• Land and Housing Review
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• v.8 no.3
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• pp.171-180
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• 2017

In 1990s, as the extreme weather events according to the global warming climate change are occurred frequently all around the world and the scale of the damage increases, the developed countries are promoting various policies for reducing greenhouse gas emissions setting the goal of greenhouse gas reduction with the level of State and local government. Especially for the greenhouse gas reduction of buildings and the inducement of eco-friendly design, the green certification system is strengthened with the assessment of energy and greenhouse management, and recently, according to the policy change of climate and energy, the certification system expanded from the buildings to the level of city and district is piloted. So this research is to understand the main contents and the assessment system of domestic green building certification system implemented in March 2013 in response to the policy change of climate and energy and to suggest the basic data for the improvement of present domestic greenhouse certification standard through the analysis of actual certification and the main case analysis of international green certification system. Recently in developed countries, in 1990s, for the reduction of building's greenhouse gas emission and the inducement of eco-friendly design, from the building of LEED, BREEAM, DGNB to the level of city and district such as LEED Neighborhood Development, BREEAM Communities, DGNB Stadtquartiere, the system is expanded and piloted. On the contrary, as for the domestic standard of green building certification system, the distribution ratio according to the assessment items in each category consists of the assessment system based on the buildings, and just the simple adjustment of some items and the improvement of weighted value are performed. Actually, as a result of selecting the 30 districts of apartment housing with the most certification performance by use among the 49 buildings certified by Institute of Land & Housing from December 2014 to July 2016 and analyzing the assessment score, the certification level is determined by the sectors of high distribution like indoor environment and energy not by the ineffective sector of external environment with low distribution so this system has a limitation to perform the practical means for the policy change of climate and energy. Thus for the national green building certification standards, the assessment system in the sector of external environment is to complemented and furthermore, reflecting domestic reality, through the introduction of certification system and the assessment system with the level of city and district, this system should be improved to meet the international certification standard.