• Journal of KIISE:Computing Practices and Letters
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• v.10 no.3
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• pp.259-272
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• 2004

This paper suggests a new security architecture for facilitating secure OSGi service platform environment. The security architecture includes 1) user authentication mechanism, 2) bundle authentication mechanism, 3) key sharing mechanism, and 4) authorization mechanism. The user authentication mechanism supplies SSO(single sign-on) functions which are useful for safe and easy user authentications. The bundle authentication mechanism utilizes both PKI-based and MAC-based digital signatures for efficiently authenticating service bundles. The key sharing mechanism, which is performed during bootstrapping phase of a service gateway, supplies a safe way for sharing secret keys that are required for authentication mechanisms. Finally, the authorization mechanism suggests distributed authorization among service providers and an operator by establishing their own security policies. The main contributions of the parer are twofold. First, we examine several security requirements of current OSGi specification when its security functions can be applied in real OSGi environments. Second, we describe the ways to resolve the problems by means of designing and implementing concrete security mechanisms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2465-2471
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• 2012

For the steel structures those are used in harsh sea environments, corrosion fatigue is a challenging issue in connection with design life. In this research, in order to investigate the influence of cathodic overprotection on the corrosion fatigue crack propagation behavior, corrosion fatigue crack propagation test under the condition of -950mV vs SCE was conducted by using of high tensile TMCP steel plate and the relationships between da/dN-${\Delta}K$ were obtained. At this test, when ${\Delta}K$ is low, the crack propagation rates were accelerated compared to those of seawater condition, however, when ${\Delta}K$ is high, the crack propagation rates were lower than those of seawater condition. As the cause for the acceleration and deceleration of corrosion fatigue crack propagation rates under the condition of cathodic overprotection, the role of hydrogen and calcareous deposits are discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.4
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• pp.840-846
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• 2016

Recently, with the rapid demand expansion on the devices of digital image processing, the excellent quality of the images is required. However, the degradation of the images occurs in the processes of data acquisition, processing, and transmission by various external causes and the noise has been well known as the major cause of image degradation. There are a variety of noises to be added on the images, with typical example of AWGN. Hence, in this article, we suggested average filter algorithm processed by the threshold values using them applying standard deviation of local mask under the AWGN environment in this study. As the result of the simulation, The proposed algorithm shows a high PSNR of 24.56[dB] for Barbara images that had been damaged of AWGN(${\sigma}=15$), compared to the existing MF, CWMF and AWMF there were improvements by 3.34[dB], 2.57[dB], and 3.32[dB], respectively.

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1478-1485
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• 2009

A sensor network which is composed of a large number of sensors that perform various sensing is applied in a variety of fields. The sensor networks can be widely used for various application area like as home automation, fire detection and security area. Development of new sensor to have appropriate functions and deployment of networks for suitable application are served actively. In this paper, we design and implement a system that monitors various factory facilities by deploying sensor network at a working place which threatens the worker's safety. A sensor node reports its sensing data like as temperature and humidity to monitor facilities to a sink node. And the server which is connect to the sink node gathers and provides information by user interface. In addition, digital data which are generated at a work place can be transferred via the sensor network to increase the efficiency of works. The proposed sensor network provides the convenience of working, since it is deployed at a garbage collection company to monitor a temperature and humidity of garbage and to transmit data about the weight of trucks which enters the company.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.726-730
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• 2009

The proliferation of the web and digital photography has drastically increased multimedia data and has resulted in the need of the high quality internet service based on the moving picture like user generated contents(UGC). The keyword-based search on large scale images and video collections is too expensive and requires much manual intervention. Therefore the web search engine may provide the content-based retrieval on the multimedia data for search accuracy and customer satisfaction. In this paper, we propose a novel distributed index structure based on multiple length signature files according to data distribution. In addition, we describe how our scalable index technique can be used to find the nearest neighbors in the cluster environments.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.993-997
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• 2009

Designs in the modernism era were produced for the purpose of standardization of items and devices centered on efficiency and functions, and the will of design consumers in the industrial era, when consumption exceeded production, was limited to the objects of consumption. But, after the post-modernism era, design consumers have started to entail acts of exclusive possession such as participation in the design idolization, partipation, tuning, control and parody as design consumers in the digital environment do not passively accept what is given to them anymore, and aggressively intervene in the process of design production and management. It is expected that designs will change from the system in which only professionals can produce and manage its production to that of cooperating with consumers to produce designs, and various forms of consumers' exclusive possession will change all sort of design environments including production methods surrounding design products and distribution. Therefore, this study seeks to induce efficient design production by understanding changes of consumers' cultural environment resisting standardization and structuralization with smoothy perception between producers and consumers through classification of consumers' appropriation into de-construction, re-signification and self-identification.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.252-262
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• 2010

Recently, the USN (Ubiquitous Sensor Network) technology is emerging as an aspect of digital convergence trends which is being rapidly evolving in the whole society. The technological feasibility for the various application services using the USN is researched in numerous industries, but, in the agricultural field, the market of USN application service, technology adoption and commercialization have been delayed. In the agricultural field, the ubiquitous technologies could lead to huge change in the conventional surroundings such as growth environment of livestock, crop cultivation and harvest. In this paper, to offer a integrated management, we construct a u-swinery(ubiquitous swinery) system which is consisted with USN environmental sensors to collect information from physical phenomenon such as luminance, relative humidity, temperature and ammonia gas. Numbers of CCTV were also installed to monitor inside and outside of the swinery. The u-swinery integrated management system can monitor and control the condition of swinery from remote sites. Furthermore, by gathering the cumulative environmental data from the system, the optimal growth condition for the livestock could be created.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.188-191
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• 2018

To know if deforestation practice affects the distribution and abundance of herpetofauna in Mt. Gariwang, South Korea, we conducted field surveys over 12 times both at deforested (n=9 sites) and un-touched (control, n=12 sites) forest areas from March to October, 2017. Each survey site was approximately $100m\;long{\times}20m$ wide area, which in the middle of the site, mountain road presented. During each survey, we recorded the species and the number of amphibians and reptiles which identified. To compare environments between the two areas, we analyzed eight environmental variables, extracted from digital sources. Overall, we found one amphibian and four reptile species at deforested area, while each five amphibian and reptile species at un-touched area. The number of amphibian species significantly tended to be smaller at deforested area. The number of the survey sites where amphibians found and the number of amphibian individuals showed the same trend. For reptiles, although the number of reptile individuals showed some increases, all variables investigated were not significantly changed by deforestation practice. Our results imply that deforestation practice negatively affects amphibians, but effects of that on reptiles are not evident.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.633-642
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• 2004

This study tries to generalize the stream network by constructing rule-based modelling. A study on the map generalization tends to be concentrated on development of algorithms for modification of linear features and evaluations to the limited cartographic elements. Rule-based modelling can help to improve previous algorithms by application of generalization process with the results that analyzing mapping principles and spatial distribution patterns of geographical phenomena. Rule-based modelling can be applied to generalize various cartographic elements, and make an effective on multi-scaling mapping in the digital environments. In this research, nile-based modelling for stream network is composed of generalization rule, algorithm for centerline extraction and linear features. Before generalization, drainage pattern was analyzed by the connectivity with lake to minimize logical errors. As a result, 17 streams with centerline are extracted from 108 double-lined streams. Total length of stream networks is reduced as 17% in 1:25,000 scale, and as 29% in 1:50,000. Simoo algorithm, which is developed to generalize linear features, is compared to Douglas-Peucker(D-P) algorithm. D-P made linear features rough due to the increase of data point distance and widening of external angle. But in Simoo, linear features are smoothed with the decrease of scale.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.3
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• pp.219-229
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• 1996

Path loss prediction method, one of the most essential parts in measuring the service area in mobile telecommunication, has been developed for many years. But, wave propagation depends on many kinds of environmental factors such as frequency, distance, the heights of transmitting and receiving antenna and the terrain status(buildings in large city, hilly terrain, mountain). These are the main reasons that the propagation models developed in foreign environments can not fit into Korean propagation condition. In this paper, therefore, we performed the measurement in Korean terrain environment in pager frequency band after deviding the terrain characteristics into six types. With this measured data, we derived several curves that follows the long-term wave progagation behavior and developed the wave propagftion prediction model which calculates the field strength at any point in the service area. The proposed model estimates the field strength in two categories, LOS(line-of-sight), or non LOS. We applied this model using the digital terrain data base and compared with the measured data. The result shows that the errors were between 3~9dB, which turned out to be practical.