• Journal of Digital Contents Society
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• v.19 no.4
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• pp.719-729
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• 2018

Abstract In 2017, it has been reported that Google had more than 90% of the market share in search-engines of desktops and mobiles. Most people may consider that Google surely searches the entire web area. However, according to many researches for web data, Google only searches less than 10%, surprisingly. The most region is called the Deep Web, and it is indexable by special search engines, which are different from Google because they focus on a specific segment of interest. Those engines build their own deep-web databases and run particular algorithms to provide accurate and professional search results. There is no search engine that indexes the entire Web, currently. The best way is to use several search engines together for broad and efficient searches as best as possible. This paper defines that kind of search engine as Hybrid Search Engine and provides characteristics and differences compared to conventional search engines, along with a frame of hybrid search engine.

• Journal of Korean Library and Information Science Society
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• v.27
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• pp.457-483
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• 1997

This study was intended to compare the effectiveness of the Savvy search and Metacrawler in terms of the total number of relevant documents retrieved, precision, recall, and the number of deadlines. In addition, this study measured whether the Meta-search engine and general web search engines retrieved different web documents. As a result, Savvy search produced a higher precision and recall as compared with motacrawler search engine while the metacrawler had lower deadlines ration than savvy search, Also, Meta search engine was more effective than the general web search engine, The results show that the hybrid methodology of integrating a variety of web search engines can help solve retrieval effectiveness problems on the Internet.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.2
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• pp.467-474
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• 1993

Viscous flow and heat transfer phenomena in an axisymmetric cylinder which models a diesel engine have been numerically studied. In order to search for a way to minimize numerical diffusion, the effectiveness and the appropriateness of two selected numerical schemes for convective terms in the governing equations have been tested. They are Linear Upwind Difference Scheme and Hybrid Scheme. Using a standard k-.epsilon. turbulence model, the calculation has been carried out basically up to 180.deg. of crank angle. As a result, it was shown from comparison with previous experimental data that Linear Upwind Difference Scheme is less influenced than Hybrid Scheme by the numerical diffusion and it was suggested that these effects of numerical diffusion can be more significant than those due to turbulence modeling.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.4
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• pp.412-429
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• 2008

As the amount of electronic documents increases rapidly with the growth of the Internet, a parallel search engine capable of handling a large number of documents are becoming ever important. To implement a parallel search engine, we need to partition the inverted index and search through the partitioned index in parallel. There are two methods of partitioning the inverted index: 1) document-identifier based partitioning and 2) keyword-identifier based partitioning. However, each method alone has the following drawbacks. The former is convenient in inserting documents and has high throughput, but has poor performance for top h query processing. The latter has good performance for top-k query processing, but is inconvenient in inserting documents and has low throughput. In this paper, we propose a hybrid partitioning method to compensate for the drawback of each method. We design and implement a parallel search engine that supports the hybrid partitioning method using the Odysseus DBMS tightly coupled with information retrieval capability. We first introduce the architecture of the parallel search engine-Odysseus/parallel-OOSQL. We then show the effectiveness of the proposed system through systematic experiments. The experimental results show that the query processing time of the document-identifier based partitioning method is approximately inversely proportional to the number of blocks in the partition of the inverted index. The results also show that the keyword-identifier based partitioning method has good performance in top-k query processing. The proposed parallel search engine can be optimized for performance by customizing the methods of partitioning the inverted index according to the application environment. The Odysseus/parallel OOSQL parallel search engine is capable of indexing, storing, and querying 100 million web documents per node or tens of billions of web documents for the entire system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1091-1110
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• 2016

Hybrid deployment under current cloud data centers is a combination of online and offline services, which improves the utilization of the cluster resources. However, the performance of the cluster is often affected by the online services in the hybrid deployment environment. To improve the response time of online service (e.g. search engine), an effective scheduling algorithm based on Storm is proposed. At the component level, the algorithm dispatches the component with more influence to the optimal performance node. Inside the component, a reasonable resource allocation strategy is used. By searching the compressed index first and then filtering the complete index, the execution speed of the component is improved with similar accuracy. Experiments show that our algorithm can guarantee search accuracy of 95.94%, while increasing the response speed by 68.03%.

• Journal of Korea Spatial Information System Society
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• v.11 no.4
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• pp.28-32
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• 2009

For the ubiquitous web environment internet, as an one of the R&D projects by Korean Land Spatialization Group, the project for platform technologies was initiated to provide customized land information and geospatial service. The platform technologies can be categorized for streaming, mashup and geosearch. More specifically, the 2D/3D hybrid streaming engine, mashup engine for u-GIS service and next generation search engine for land information have been developed. In this context, the patent analyses are required to propose the strategies for efficient development and use of these technologies. This study searches the related patents in Korea, US and EU, analyzes the trend of them for customized spatial information technologies, and finally proposes proper strategies.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.21-29
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• 2017

In this paper, we studied the control of the hybrid underwater glider (HUG), which has the advantage of high precision route search function and long-term mission capability. Dynamic modeling of HUG is based on numerical model of the attitude controller and buoyancy engine, thruster. We designed the control part considering the smooth control and precise sailing of HUG. A buoyancy engine capable of inhaling water is designed to control the buoyancy of HUG. And mass shifter carrying the battery was designed for controlling pitching motion of HUG. A control system for controlling the buoyancy engine and the attitude controller was constructed. In order to verify performance, we performed water tank test using manufactured HUG.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.427-432
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• 2001

This paper shows the optimum design of the fluid engine mount. The design has been modified by trial and error because there is many design parameters that can be varied in order to obtain resonant and notch frequencies, and notch depth. It seems to be a great application for optimal design for the mount. Many combinations of parameters are possible to give us the desired resonant and notch frequencies, but the question is which combination provides the lowest resonant peak and notch depth\ulcorner In this study, the enhanced artificial life algorithm is applied to get the desired notch frequency of a fluid mount and minimize transmissibility at the notch frequency. The present hybrid algorithm is the synthesis of an artificial life algorithm with the random tabu (R-tabu) search method. The hybrid algorithm has some advantages, which is not only faster than the conventional artificial life algorithm, but also gives a more accurate solution. In addition, this algorithm can find all global optimum solutions. The results show that the performance of a conventional engine mount can be improved significantly compared with the optimized mount.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.10
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• pp.595-602
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• 2003

This Paper presents an efficient hybrid techniques for a standard cell placement. The prototype tool adopts a middle-down methodology in which an n${\times}$m grid is imposed over the layout area and cells are assigned to bins forming a global placement. The optimization technique applied in this phase is based on the Relaxation-Based Local Search (RBLS) framework [12］in which a combinatorial search mechanism is driven by an analytical engine. This enables a more global view of the problem and results in complex modifications of the placement in a single search“move.”Details of this approach including a novel placement legalization procedure are presented. When a global placement converges, a detailed placement is formed and further optimized by the optimal interleaving technique[13］. Experimental results on MCNC benchmarking circuits are presented and compared with the Feng Shui's results in［14］. Solution Qualifies are almost the same as the Feng Shui's results.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.631-636
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• 2010

With the growing trends of communication- broadcasting convergence, a hybrid IPTV that supports both IP network-based on-demand media and terrestrial or cable-based broadcast media is gaining attraction. This paper proposes a rich media framework for hybrid IPTV with support of the latest H.264 codec. For this purpose, we design and implement a media component and a RIA run-time engine customized for TV with the hybrid media. The media component has been designed to provide a uniform and efficient application interface to the various playback methods for RF broadcast and IP-based stored or live media. For performance and portability, it exploits media stream abstraction, adaptive on-demand I-frame search, and automatic calculation of play duration. Based on the proposed media interface, we develop a RIA run-time prototype. It has been carefully designed to fully utilize the built-in graphic acceleration hardware for optimized rendering in the resource-constrained IPTV environments. Demonstration and experiment results validate the performance and usefulness of the developed framework. The framework is expected to be used effectively to support graphics and hybrid media in the applications of IPTV-based VOD, advertisement, and education.