• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.1
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• pp.17-28
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• 2014

The increase of smartphone users have made mobile carriers offload increasingly congested traffic of 3/4G by providing Wi-Fi hot-spots in the public places such as coffee shops and subway stations. In the traditional authentication in WLAN, the users should convince the service providers that they are valid customers before they use WLAN services. Since the authentication protocol is designed for service providers. Even with the mutual authentication based on the IEEE 802.1X, which is supported by IEEE 802.11 standard, it is difficult to be convinced of that the service providers really have installed the WLAN APs, which users are confronted with. An attacker can install rogue APs that masquerade as legitimate APs by copying the SSID, MAC address, etc. in order to obtain users' private information. In this paper, we introduce a method of authenticating legitimate APs for smartphone users. And we show our proposal can be well utilized for the current Wi-Fi hot-spots as a security plug-in and prove it through our experiments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.103-110
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• 2012

The population growth along with the urbanization, has caused more problems in many public areas, such as subway airport terminals, hospital, etc. Many surveillance systems have been installed in the public areas, but not all of those can be monitored in real-time, because the operators that observe the monitors are very small compared with the number of the monitors. For example, the observer can miss some crucial accidents or detect after considerable delays. Thus, intelligent surveillance system for preventing the accidents are needed, such as Intelligent Surveillance Systems. in this paper, we propose a new crowd density estimation method which aims at estimating moving crowd using images from surveillance cameras situated in outdoor locations. The moving crowd is estimated from the area where using optical flow. The edge information is also used as feature to measure the crowd density, so we improve the accuracy of estimation of crowd density. A multilayer neural network is designed to classify crowd density into 5 classes. Finally the proposed method is experimented with PETS 2009 images.

• Journal of the Korean Society for Railway
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• v.19 no.3
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• pp.314-323
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• 2016

Overhead line voltage of DC railway traction substations has rising or falling characteristics depending on the acceleration and regenerative braking of the subway train loads. The suppression of this irregular fluctuation of the line voltage gives rise to improved energy efficiency of both the railway substation and the trains. This paper presents parameter estimation schemes using the RC circuit model for an overhead line voltage at a 1500V DC electric railway traction substation. A linear artificial neural network with a back-propagation learning algorithm was trained using the measurement data for an overhead line voltage and four feeder currents. The least square estimation method was configured to implement batch processing of these measurement data. These estimation results have been presented and performance analysis has been achieved through raw data simulation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.84-91
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• 2015

In this paper, to overcome disadvantages of existing lining boards, the parametric studies to evaluate safety and verify performance of newly suggested lining boards was performed. Since the calculated stresses of steel plates are lower than the allowable stress for considered all analytical variables, end reinforcement locations, and crane rail loads, it can be concluded that the suggested lining board is structurally safe. Where, "$3,000{\times}2,000{\times}6t$" was select to be optimized cross-section and the reinforcement from the end to 200mm to the internal direction looks like the best case. In addition, the suggested lining board is economical since the steel amount per unit area compared to existing lining board is reduced by 36% and it can apply to the lining structural system of subway and underpass since construction speed is past due to the less installation number of lining boards.

• Journal of Urban Science
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• v.6 no.2
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• pp.29-34
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• 2017

Although the supply of public parking lots in major cities is steadily increasing, there is still a shortage of parking spaces that take into account the characteristics of actual available parking spaces. These parking problems are caused by conflicts between users, illegal occupation and privatization of roads, interference with traffic roads, and business stagnation in commercial areas and illegal parking problems. In addition, despite various parking demand management policies and continuous supply of public parking facilities, the solution to the parking problem is uneasy due to increased construction costs and changes in social conditions. In order to solve this problem, it was judged that it would be necessary to utilize the existing public parking lots efficiently. Therefore, we collect the variables expected to affect the turnover, and use multiple regression models. The results are summarized as follows. Firstly, public parking lots can be classified into four types using utilization rate and turnover rate. Secondly, influencing factors are found including index of public transportation usage convenience, index of illegal parking, and land use characteristics in central commercial district. Thirdly, it was shown that there was little impact by the size of public parking lots, separation distance to subway distance, separation distance to bus stops, transfer zone, residential zone, and second-rated lots by parking costs. Finally, it is found that public parking lots can be improved by proving accessibility of public transit, enforcement of illegal parking, active approaches supporting public parking lots. It is also recommended that public parking cost rating system based mainly on land use characteristics should be remedied and rearranged.

• Journal of the Korean Society of Costume
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• v.51 no.4
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• pp.71-80
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• 2001

Since the beginning of the 90's, Fashion shows appear to be a type of performance form of art combining with other areas to visually entertain the viewers. This can be explained by the modern tendency to escape from society which requires formality and complicated lifestyles. Fashion shows take place in a scene Influenced by the idea of post-modernism which redefines the definition of space. A church, old factory, unoccupied ground, subway stations, or even place like a waste disposal are used as a setting. The stage set is no longer the T shape run way and the procinium arch has disappeared. The gap between audience and stage has diminished and theatrical element is added to the fashion performance by using viewers living and working environments as setting of the show. The human relation with machine based on the cutting edge technology such as the stage automation, robots and mist making sprinkler system introduces new elements with spontaneity and detailed planning in the stage performance. Music also plays an Important role in attracting viewers. The sound track covers house music to techno music. Instead of music being abstract, folks orchestral music, choirs, piano. even live concert performed by pop artist provide the liveliness of the fashion show. And the catwalk itself is a performance. Model needs to be well trained as the capable talent who can handle sensitive gestures, facial expressions, dancing and choreography. The improvisatorial interaction between audience and model lead to audience participation. Models now range from pop star, ordinary people, handicapped people, to elderly and so on. John Galliano introduced the theatrical factors for the fashion show and Alexander Mcqueen approached the fashion show as the visual art of communication. Hussein Chalayan utilized high technology skewing futurism as if in a magic show. Today the Fashion show tends to be a total performance which includes audience participation, impromptu, and that break the limitation that fashion shows previously had. This will lead the fashion industry in opening new horizon of its own.

• Archives of design research
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• v.16 no.3
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• pp.15-22
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• 2003

At public spaces, signs have purposes of communicating their information clearly. Especially directional signs point out the proper route showing our surroundings. The present directional signs which are indicating 3-dimensional direction in a 2-dimensional mode seem to be difficult to understand as we are moving. This study has the purpose of investigating the role of present signs and suggesting visually effective directional signs, in particular arrows. Firstly, this study surveyed the user's attitude on directional signs in case of subway station. The research shows that the present directional signs hardly perform their roles to communicate the directional information, which means the need of newly expressed arrows. In this study we consider a new effective expression on the viewpoint of human cognition mechanism. So it is thought that those trials are helpful to efficient sign system.

• Korean Journal of Remote Sensing
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• v.27 no.6
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• pp.637-651
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• 2011

This study presents a rule-based urban image classification method for time series analysis of changes in the vicinity of Asan-si and Cheonan-si in Chungcheongnam-do, using Landsat satellite images (1991-2006). The area has been highly developed through the relocation of industrial facilities, land development, construction of a high-speed railroad, and an extension of the subway. To determine the yearly changing pattern of the urban area, eleven classes were made depending on the trend of development. An algorithm was generalized for the rules to be applied as an unsupervised classification, without the need of training area. The analysis results show that the urban zone of the research area has increased by about 1.53 times, and each correlation graph confirmed the distribution of the Built Up Index (BUI) values for each class. To evaluate the rule-based classification, coverage and accuracy were assessed. When Optimal allowable factor=0.36, the coverage of the rule was 98.4%, and for the test using ground data from 1991 to 2006, overall accuracy was 99.49%. It was confirmed that the method suggested to determine the maximum allowable factor correlates to the accuracy test results using ground data. Among the multiple images, available data was used as best as possible and classification accuracy could be improved since optimal classification to suit objectives was possible. The rule-based urban image classification method is expected to be applied to time series image analyses such as thematic mapping for urban development, urban development, and monitoring of environmental changes.

• Tunnel and Underground Space
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• v.15 no.1 s.54
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• pp.71-79
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• 2005

The stability of the intersection area of two tunnels is analyzed by observational method. The depth from ground surface to the intersected area is shallow and the geology around the area consists of soil and/or weathered rock. The tunnel is supported by reinforced protective umbrella method with 12 m long 3-layer steel-pipes and the intersected area is additionally reinforced with 6 m long rockbolts. The measured displacements are converged and mechanical stability of the intersected area of two tunnels is confirmed; tunnel arch settles to 6-7 mm at the crown and the sidewalls converges to about 5 mm. So based on the displacement measurements, the supporting system for the tunnel intersection proves to be effective to not only reduce the deformation of tunnels but also maintain the stability of tunnels.

• Korean Institute of Interior Design Journal
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• v.15 no.5 s.58
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• pp.157-166
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• 2006

Recently, it appears several counterproposals about desirable figures of urban architecture. All of them proposes 'publicity' with cohernt tendency. The reason why it concentrates quantitative expansion of city without united design by urban plannar is that neglect quality values of city. As a solution of poor environment, there cue out the various efforts, about problem of each building, problem of city space, problem of laws and so forth. The reason why necessity of public space was embossed in that architecture extend the activity of citizen and make up the city space. But, each building pursues the private interest, so it is difficult to secure a public space with a high hand. Thus, architecture law has been revised in 1991 and bring the system of open space to match up the publicity and the private interest. Actually, western country brought it and obtained excellent results. While quantity of open space have increased since 1991, a lot of problems revealed in real usage and quality. By means of problem's solution, this study focus on the diversion of recognition for necessity of various open space. In result, on the occasion of approach and openess, except for several building, most glass a facade and the pedestrian can approach easily. Moreover, office buildings near the subway station connected with their low floor. So, the office buildings give openess to pedestrian and a people can approach easily to the buildings. On the occasion of amenity, most have bank and lobby on the first floor and have facilities on the underground floor. It leave open. But the reason why they have bank and lobby is that the space is dry and boring(without elements of nature and rest space). Hence, to make a space full of vitality, it have to plan various design elements and facilities. First of all, plan of indoor public space have to make up facility for the public interest. This study is basic investigation for necessity of indoor public space and through the survey of office buildings, it analyze the character of plan and find out the method of publicity's realization.