• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.7
• /
• pp.9-16
• /
• 2008

For the efficient routing on a Sensor Network, one may consider a deployment problem to interconnect the sensor nodes optimally. There is an analogous theoretic problem: the Steiner Tree problem of finding the tree that interconnects given points on a plane optimally. One may use the approximation algorithm for the problem to find out the deployment that interconnects the sensor nodes almost optimally. However, the Steiner Tree problem is to interconnect mathematical set of points on a Euclidean plane, and so involves particular cases that do not occur on Sensor Networks. Thus the approach of using the algorithm does not make a proper way of analysis. Differently from the randomly given locations of mathematical points on a Euclidean plane, the locations of sensors on Sensor Networks are assumed to be physically dispersed over some moderate distance with each other. By designing an approximation algorithm for the Sensor Networks in terms of that physical property, one may produce the execution time and the approximation ratio to the optimality that are appropriate for the problem of interconnecting Sensor Networks.

• The Journal of Korean Association of Computer Education
• /
• v.18 no.2
• /
• pp.83-90
• /
• 2015

In an virtualization environment, several virtual machines use physical resources together. If a specific virtual machine uses to much of the computing resources, other machines may not be working properly. There are various method to solve this problem. Most representative study is to migrate a specified virtual machines to a different server, a target server. In this study, server load can be transferred to a target server by the remigrate of the load imposed on virtual machine. It is still problematic that virtual machine has to remigrate to a different server. This thesis has proposed the algorithm determining the remigration targets by applying dynamic thresholds to solve those problems. The migration algorithm applies dynamic thresholds according to the following criteria. Firstly, the usage of CPU, network and memory; secondly, decide the set of artificial machine and the target server based on the resources surpassed thresholds; thirdly, determine artificial machines based on the resource usage in the target server.

• Journal of the Korean Magnetics Society
• /
• v.14 no.6
• /
• pp.207-212
• /
• 2004

Eddy current (EC) testing methods are widely used in a variety of applications including the inspection of steam generator tubes in nuclear power plants, aircraft parts and airframes. A key factor that affects the EC signal is lift-off which means the physical distance between a sensor and a specimen in the testing. In practice, it is difficult to keep track of the actual value of the lift -off during a specific experiment, simulation or testing in the field, which is essential for accurate interpretation of the signal to be used in the following steps. Hence it is necessary to have a scheme to render the EC signal invariant to the effects of lift-off in spite of the changes in the real world. This paper describes a new method for compensating EC signals for variations in lift-off by acquiring an invariance feature using a homomorphic operator and neural network techniques. The signals from various lift-offs are transformed to obtain a zero lift-off equivalent signal that can be subsequently used for defect characterization in the next step.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.236.1-236.1
• /
• 2012

We conducted simultaneous 22GHz water maser and 44GHz class I methanol maser surveys of newly-identified 282 H2 emission features from the $2.122{\mu}m$ H2 narrowband image survey in the Galactic plane (UWISH2 project) using Korea VLBI Network (KVN) 21-m radio telescopes. We detected 16 and 13 new water and methanol maser sources, respectively. This result indicates that at least ~5% of the H2 emission features originate from young stellar objects (YSOs) that are in the right physical condition to produce the water and methanol masers. The masers are closely related to the current outflow activities in the Galactic plane. The power sources of these 23 diffused/collimated H2 emission features (six sources are detected for both masers) are likely to be intermediate-to high-mass YSOs, based on a comparison with the maser luminosities of other well-studied YSOs. Both maser velocities are mostly close to their own systemic velocities within 5 km/s, even though water masers generally show larger variabilities in the line intensities, velocities, and shapes than methanol masers. We also discovered three new water maser sources with high-velocity components: ~25 km/s red-shifted CMHO019, ~50 km/s blue-shifted CMHO132, and ~120 km/s blue-shifted CMHO182. In particular, we propose that the dominant blue-shifted water maser of CHMO182 could become a unique laboratory for the study of high-mass stellar jet and their accelerations.

• Journal of the Korea Society for Simulation
• /
• v.20 no.4
• /
• pp.21-29
• /
• 2011

Wireless sensor nodes operate in open environments. The deployed sensor nodes are very vulnerable to physical attacks from outside. Attackers compromise some sensor nodes. The compromised nodes by attackers can lead to false data injection into sensor networks. These attacks deplete the limited energy of sensor nodes. Ye et al. proposed the Statistical En-Route Filtering (SEF) as a countermeasure of the attacks. The sensor node in SEF examines the event reports based on certain uniform probability. Thus, the same energies are consumed in both legitimate reports and false reports. In this paper, we propose a method that each node controls the probability of attempts to verify a report to reduce energy consumption of sensor nodes. The probability is determined in consideration of the remaining energy of the node, the number of hops from the node to SINK node, the ratio of false reports. the proposed method can have security which is similar with SEF and consumes lower energy than SEF.

• Journal of Korea Water Resources Association
• /
• v.42 no.3
• /
• pp.259-270
• /
• 2009

The applicability of the developed distributed rainfall runoff model using a multi-directional flow allocation algorithm and a real-time updating algorithm was evaluated. The rainfall runoff processes were simulated for the events of the Andong dam basin and the Namgang dam basin using raingauge network data and weather radar rainfall data, respectively. Model parameters of the basins were estimated using previous storm event then those parameters were applied to a current storm event. The physical propriety of the multi-directional flow allocation algorithm for flow routing was validated by presenting the result of flow grouping for the Andong dam basin. Results demonstrated that the developed model has efficiency of simulation time with maintaining accuracy by applying the multi-directional flow allocation algorithm and it can obtain more accurate results by applying the real-time updating algorithm. In this study, we demonstrated the applicability of a distributed rainfall runoff model for the advanced basin-wide flood management.

• Journal of Fashion Business
• /
• v.15 no.6
• /
• pp.1-22
• /
• 2011

This paper is a study on the information required for developing Korean clothing products intended for Chinese students in Korea and for opening markets of Korean clothing and brands in China. It analyses the buying behaviors, purchasing ability, the favourite apparel type for clothing, and satisfaction with Korean clothing and brands of Chinese students in Korea, with which it seeks a program for South Korea branding to enter into the Chinese clothing market. Three hundred fifty seven students of Hannam University and PaiChai University Chung nam National University in Daejeon-city took part in this study. This paper adopts Descriptive Analysis, Crossing Analysis, Bivariate Correlations, and One-way ANOVA in SPSS 17.0 with Post Hoc Multiple Comparisons to know about the impact of demographic variables of Chinese students in Korea on buying information sources, the criteria for store selection, buying capacity, praise degree on various properties of Korean clothes products and their satisfaction with Korean clothes products. The first proposal of expanding China market for Korean merchants is to achieve maximum sales based on sales promotion strategies, such as the credit card corporations, the store display and sales person service development, SPA, design size development, and to upgrade consumption values. The second proposal is Korean clothes corporations should open the Internet shopping corresponding to the physical stores, the most frequently used information source of Chinese students is the network, from the age distribution of Internet users in 2008 in China, population above 10 and below 30 accounts for 66.7% of all users, In recommending clothes made in Korea to Chinese young people, on-line advertising will get better effects than other strategies, specially during advertisement, they should take good use of Korean television shows and variety shows or help Chinese poor areas to do the social contribution hereby to improve the public image of Korean clothes corporations, which can bring good sale promotion effects as well.

• Journal of the Korea Convergence Society
• /
• v.8 no.6
• /
• pp.227-235
• /
• 2017

The essence of architecture is space acquired as a result of architect's design act, but the object of the design is not the space and it is the physical elements to construct it. The masters of modern architecture have described the types of spaces that can be composed of these elements, but there is a difficulty in constructing the space because they does not mention how to construct it. From this point of view, if architecture is the techniques for human behavior and the art of building space, it is recognized that there is a need for concrete research on how to construct a space with ambiguous substance. Therefore, I conducted research on the extensibility of diagonal spaces through '4 Logements Studio' by Henri Ciriani, a representative architect of Neo Corbusian. The 'network for identity' method proposed by Ciriani was examined as a methode to realize spatial expansion and the furniture should be designed as an element of reading space and 3 optimal alternatives for 4 housing arrangements were obtained based on the Equivalence, Lighting, View, and Community life.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.11A
• /
• pp.1147-1158
• /
• 2006

Clustering algorithm is an essential element to implement a hierarchical routing protocol, especially for a large-scale wireless sensor network. In this paper, we propose a new type of energy-efficient clustering algorithm, which maximizes the physical distance between cluster head and gateway by a neighbor node discovery mechanism. Furthermore, a slave/master patching scheme is introduced as a useful means of further improving the energy-efficiency. It has been shown that the number of cluster heads can be reduced by as many as 21% as compared with the existing clustering algorithms.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.29 no.6
• /
• pp.1-10
• /
• 2002

The purpose of this study is to establish a model of cultural sustainability in the traditional village. Cultural sustainability is being advanced by promoting the viability of traditional arts and the unique regional features of traditional culture, such as folklore, traditional landscapes, buildings and other environments of outstanding historical value. These cultural resources were also created or occurred at specific geographic locations at certain points in time by different individuals. The content of this study was to develop a model using indicators for cultural sustainability, and to apply and evaluate the model. In older to evaluate the model, Sonwon-ri village in Yongchon, located in Kyungsangbuk-do, was selected as the case study area. The major findings are as follows: 1) Sonwon-ri village has maintained the vernacular landscape except at the entrance of village. Also, the village people have pride and have adapted to the natural environment. 2) Sonwon-ri village has a self-sustaining system and circular network within its environmental capacity. Sonwon-ri village has many historical sites and buildings such as important folk resources, cultural assets, traditional houses and pavilions. 3) The people how the theory of fens-shui which interprets the location of village in relationship to a crane mountain with the village situated as a crane head. These symbolic and cultural elements have an important role in establishing the boundary of the village. From the research it can be seen that Sonwon-ri village kept many cultural sustainability indicators in terms of active factors, physical factors and psychological factors. By analysing the participation of different scientific disciplines and identifying disciplinary categories, this study provides a basis for understanding how cultural sustainability is subjected to research in the field of landscape planning and design.