• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.75-82
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• 2010

The paper proposed CBIRS/EFI with contents based search technique using edge feature information of the object from image information of the object which is uncertain. In order to search specially efficiently case of partial image information of the object, we used the search technique which extracts outline information and color information in feature information of object. In order to experiment this, we extracted side edge feature information of the vehicle for feature information of the object after capture the car image of the underground garage. This is the system which applies a contents base search by the result which analyzes the image which extracts a feature, an original image to search and a last similar measurement result. This system compared in FE-CBIRS systems which are an existing feature extraction contents base image retrieval system and the function which improves the accuracy and an effectiveness of search rate was complemented. The performance appraisal of CBIRS/EFI systems applied edge extraction feature information and color information of the cars. And we compared a color feature search time, a shape characteristic search time and a search rate from the process which searches area feature information. We extracted the case 91.84% of car edge feature extraction rate. And a average search time of CBIRS/EFI is showing a difference of average 0.4-0.9 seconds than FE-CBIRS from vehicle. color search time, shape characteristic search time and similar search time. So, it was proven with the fact that is excellent.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.48-57
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• 2005

A lot of manufacturing knowledge and method have applied to increase manufacturing efficiency in industry field. DES(Discrete Event Simulation) is one of solution to deal with manufacturing problems in factory. Beginning of research, old maintenance system of KNR ( Korea National Railroad) and its technical problems are basically investigated. KNR has maintained railway vehicle with their own solution based on experience. Very advanced railway vehicles such as KTX (Korea Train Express) and TTX(Tilting Train Express) will be difficult to maintain with their old maintenance method. In order to apply knowledge of DES, maintenance field of railway must be considered. Imaginary maintenance machine are selected to variable of DES. Maintenance capability of each machine will be evaluated base on imaginary data from imaginary machine. The machine could be very expensive as well as difficult to replace. Target of research is minimization of number of machine in railway workshop. So basic knowledge of discrete event simulation is introduced. Then five essential stages of discrete event simulation are provided. Each maintenance case defined as event. Each event is discrete and simulated base on different case such as one maintenance line with one machine and one maintenance line with two machines in railway workshop. simple maintenance method, discrete event simulation, will be come out very powerful in complicate maintenance system and will be helpful to reduce maintenance cost as well as maintenance labor.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.4
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• pp.84-91
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• 2011

Recently, WBAN(Wireless Body Area Network) which has progressed standardization based on IEEE 802.15.6 standardization is a network for the purpose of the short-range wireless communications within around 3 meters from the inner or outer human body. Effective QoS control technique and data efficient management in limited bandwidth such as audio and video are important elements in terms of users and loads in short-range wireless networks. In this paper, for high-speed WBAN IEEE 802.15.6 standard, the dynamic allocation to give an efficient bandwidth management and weighted fair queueing algorithm have been proposed through the adjustment of the super-frame about limited data and Quality of Service (QoS) based on the queuing algorithm. Weighted Fair Queueing(WFQ) Algorithm represents the robust performance about elements to qualitative aspects as well as maintaining fairness and maximization of system performance. The performance results show that the dynamic allocation expanded transmission bandwidth five times and the weighted fair queueing increased maximum 24.3 % throughput and also resolved delay bound problem.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.69-79
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• 1998

It is one of the most crutial thing to secure efficient infrastructure of social infrastructure Including rna drinking water, sewer, gas, and electricity, etc. in modern society. Among them, the sourer system need to be properly maintained so as to sustain water quality over the large watershed thereby to provide reasonable level of living environment A few municipalities and private firms have so in been using sewer management system for assessing existing sewer network and auxiliary facilities. Such existing system can only provide functions to manage the sewer pipe itself and they can not fully estimate the amount of sewage water over the pipe through 4he network analysis due to the deficiency of the system Such a limited sewer network analysis function can only analyze the whole network under the assumption of uniformity. The results from such a process can not be fully implemented in the field. Therefore, this study emphasized the development of a sewer management system which can provide practical values from network analysts considering areal peculiarities using a zoning map utilizing a GIS. The system can support analyzing scenarios due to the changes of sewer amounts from the changes of population densities and rainfall amounts not to mention of calculating sewer amount for individual sewer pipes. furthermore, the system can support the decision making for better designing sewer facilities from the expansion of metropolitan areas and constructing satellite cities. Eventually, it will contribute to enhance the effectiveness of sewer-related works and services for residents as well as supporting a decision making for minor and major trouble-shootings.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.1-12
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• 2012

In this study, $CO_2$ adsorbent was developed for removing low concentration of $CO_2$ in multiple-use facilities. The efficiency of the adsorbent which was improved selective $CO_2$ adsorption capabilities was evaluated. The pellet type adsorbent was modified from a commercial zeolite with mixing LiOH, binder, additives, and $H_2O$. Column tests showed over 90 % of $CO_2$ was adsorbed within 400min. Chamber tests including batch and continuous types were performed for evaluating the adsorbent module. By batch tests, it was evaluated that about 92% of $CO_2$ was removed within 30 min. By continuous tests, 70% of $CO_2$ was removed within 30 min. It was analyzed that over 2,500 ppm of $CO_2$ was continuously removed as shown chamber tests. The reproducibility tests repeatedly performed for 15 days shows that over 1,000 ppm of $CO_2$ was continuously removed. Adsorption capacity of the developed adsorbent was 5.0mmol $CO_2/g$ adsorbent which was analyzed by TGA. It was estimated that the modified adsorbent was applicable to low $CO_2$ concentration and low temperature of indoor environment.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.448-461
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• 2011

H.264/AVC significantly outperforms the previous video coding standards with many new coding tools. Among these tools, several intra-block coding tools can particularly improve coding efficiency. For intra prediction, H.264/AVC supports most probable mode in the entropy coding process to reduce syntax elements indicating intra prediction modes and most probable mode selection ratio is very high. Also, in general, natural images and videos have many homogeneous regions whose high correlation with neighbouring blocks. In this paper, we propose intra prediction mode SKIP mode using decoder-side prediction to improve the coding efficiency. The proposed method is determined the optimal prediction mode using only neighbouring block's information and coded on the basis of the conventional prediction/transform coding. And the prediction modes are not send to decoder at all. Skipped intra prediction mode is determined by decoder. Experimental results show that the proposed method achieves coding gains of 1.40% for common intermediate format(CIF), 3.24% for 720p sequences against the H.264/AVC JM 17.0 reference software.

• Journal of KIISE:Databases
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• v.35 no.6
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• pp.459-468
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• 2008

A data stream which is a massive unbounded sequence of data elements continuously generated at a rapid rate. Many recent research activities for emerging applications often need to deal with the data stream. Such applications can be web click monitoring, sensor data processing, network traffic analysis. telephone records and multi-media data. For this. data processing over a data stream are not performed on the stored data but performed the newly updated data with pre-registered queries, and then return a result immediately or periodically. Recently, many studies are focused on dealing with a data stream more than a stored data set. Especially. there are many researches to optimize continuous queries in order to perform them efficiently. This paper proposes a query optimization algorithm to manage continuous query which has multiple join operators(Multi-way join) over data streams. It is called by an Extended Greedy query optimization based on a greedy algorithm. It defines a join cost by a required operation to compute a join and an operation to process a result and then stores all information for computing join cost and join cost in the statistics catalog. To overcome a weak point of greedy algorithm which has poor performance, the algorithm selects the set of operators with a small lay, instead of operator with the smallest cost. The set is influenced the accuracy and execution time of the algorithm and can be controlled adaptively by two user-defined values. Experiment results illustrate the performance of the EGA algorithm in various stream environments.

• Journal of KIISE:Information Networking
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• v.32 no.2
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• pp.203-214
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• 2005

The integration of 3G networks and WLANs as complementary has been begun to attract much attention in industry as well as academia. This topic is becoming a burning issue, and one of the key questions which it raises is how to support a seamless vertical handoff. This paper introduces a new network interface selection algorithm for energy-efficient vertical handoff in tightly coupled systems capable of supporting seamless handoff. Our proposed scheme, Wise Interface Selection (WISE) switches the active network interface, after taking into consideration the characteristics of the network interface cards and the current level of data traffic, with the cooperation of the mobile terminals and network. Network interface switching operates independently on both the downlink and the uplink for the purpose of energy conservation. We show through simulation that less energy is consumed with WISE than when only a 3G network or WLAN interface is used, resulting in a longer lifetime for the mobile terminals. In the case of TCP connections, additional throughput gain can also be obtained.

• Journal of Sensor Science and Technology
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• v.9 no.1
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• pp.70-75
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• 2000

The recycled single crystal silicon wafers have been fabricated into solar cells. It can be a solution for the high cost in materials for solar cells and recycling of materials. So, p-type (100) single crystal silicon wafers with high resistivity of $10-14\;{\Omega}cm$ and the thickness of $650\;{\mu}m$ were used for the fabrication of solar cells. Optimistic conditions of formation of back surface field, surface texturing and anti-reflection coating were studied for getting high efficiency. In addition, thickness variation of solar cell was also studied for increase of efficiency. As a result, the solar cell with efficiency of 10% with a curve fill factor of 0.53 was fabricated with the wafers which have the area of $4\;cm^2$ and thickness of $300\;{\mu}m$. According to above results, recycling possibility of wasted wafers to single crystal silicon solar cells was confirmed.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.92-99
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• 2017

In Korea, the zero energy building was designated as the 7 new industries in the Ministry of Land and the 8 new industries in the Ministry of Industry. In order to maximize the insulation performance of the building envelope, improve the efficiency of building equipment, We are aiming. It is necessary to analyze the energy requirements of the buildings (cooling, heating, hot water supply, lighting, ventilation) of buildings with energy efficiency level of 1++ which is equivalent to the zero energy building certification system in Korea, It is aimed to be used as basic data for the advancement of energy building certification system. Zero Energy Building certification is estimated to be 61 buildings by 2017, and the approximate reference value and the first energy requirement for each of the five loads are calculated considering passive and active aspects. It is difficult to say that it is a clear standard because there is a small sample of data for calculating the load standard. However, it is necessary to interpret various methods in order to upgrade the Zero Energy Building certification standard in the future.