• Journal of Korea Multimedia Society
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• v.6 no.3
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• pp.384-396
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• 2003

Hybrid query processing method is used for preventing server overload that is created by heavy user connection in Web GIS. In Hybrid query processing method, both server and client participate in spatial query processing. But, Hybrid query processing method is restricted in scalability of server and it can't be fundamentally solution for server overload. So, it is necessary for Web GIS to be brought in web clustering technique. In this thesis, we propose load-balancing method that uses proximity of query region. In this paper, we create tile groups that have relation each tile in same group is very close, and forward client request to the server that can have maximum rate of buffer reuse with considering characteristic of spatial query. With out load balancing method, buffet in server is optimized for exploring spatial index tree and increase rate of buffer reuse, so it can be reduced amount of disk access and increase system performance.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1571-1576
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• 2005

DCS has many processing components and various communication elements. And its communication delay characteristic is affected diverse operating situation and context. Especially, binding signal which traversed from one control-node to another control-node undergo all sort of delay conditions. So its delay value has large deviation with the lapse of time, and the measurement of delay statistics during long time is very difficult by using general oscilloscope or other normal instruments. This thesis introduces the design and implementation of PC-based BDAS(Binding Delay Analysis System) System developed to overcomes these hardships. The system has signal-generator, IO-card, data-acquisition module, delay-calculation and analyzer module, those are implemented on industrial standard PC/Ethernet hardware and Windows/Linux platforms. This system can detect accurate whole-system-wide delay time including io, control processing and network delay, in the resolution of msec unit, and can analyze each channel's delay-historic data which is maintained by realtime database. So, this system has strong points of open system architecture, for example, user-friendly environment, low cost, high compatibility, simplicity of maintenance and high extension ability. Of all things, the measuring capability of long-time delay-statistics obtained through historic-DB make the system more valuable and useful, which function is essential to analyze accurate delay performance of DCS system. Using this system, the verification of delay performance of DCS for nuclear power plants is succeeded in KNICS(Korea Nuclear Instrumentation & Control System) projects

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.47-54
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• 2007

Since impulse-radio-based ultra wideband (IR-UWB) do not use carrier frequency but use very short pulse to transmit data it sends data not continuously but discretely and this feature gives the potential to reduce collision in multi-user environment. In this paper, we analyse characteristic of IR-UWB and propose a new collision paradigm, Collision Distribution which changes collision level from packet to pulse. In Collision Distribution mechanical each node sends data with its own pulse interval in random time, distributed manner. It prevents packet drop due to packet collision. We show that Collision Distribution can reduce packet error and can provide real time packet transmission with analysis.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.5
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• pp.437-445
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• 2016

Recently, polyurethane foam has been used in various industry fields to preserve temperature environment of structures, and a wide range of loads from the static to the dynamic are imposed on the material during a life period. The biggest characteristic of polyurethane foam is porosity as being polymeric material, and it is generally known that insulation performance of the material strongly depends on internal void size. In addition, polyurethane foam's mechanical behavior has high dependence on strain rate and temperature as well as being highly non-linear ductile for compression. In the non-linear compressive behavior, volume fraction of voids and elastic modulus decrease as strain increases. Therefore, in this study, temperature-dependent viscoplastic-damage constitutive model was developed to describe the non-linear compressive behavior with the aforementioned features of polyurethane foam.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1590-1597
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• 1999

Advertisements on the Web, rising as a major profit source of Web services, have a distinctive characteristic of detailed classification of potential customers, compared with those of other conventional media such as TV and newspaper. It is therefore possible to advertise selectively according to personal characteristics and to record precise advertisement effects. Web-based advertisement management systems of nowadays have the capability to select ones compatible with personal environment characteristics and registered information, and to provide processed information and knowledge about advertisement effects based on usage recordings. However, they have severe problems in modeling diverse requirements or characteristics of users : customers, advertisers and ISP, and in matching and coordinating of them. In order to solve these problems, we propose a frame work for coordinating the needs of users, advertisers, and ISPs, which is built on top of tree-style classification of advertisements. Other schemes are supported around the framework as follows : (1) characteristics management of pages within themselves, (2) rule-based modeling of advertisement target, and (3) user modeling and case-based analysis. We propose a prototype system within the framework.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.1
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• pp.49-54
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• 2010

3GPP(Third Generation Partnership Project) LTE system that is the next step forward in cellular 3G services address the issues related to power saving at LTE base station. This is because that most of the energy in a typical telecommunication network is consumed by the wireless network's base station site. Power saving at LTE base station fall in with low-carbon green technology. This thesis proposes a power saving MAC protocol for LTE base station which utilizes different graded DRX/DTX(Discontinuous. Reception/Transmission). Considering traffic type in UE, proposed MAC protocol controls adaptive DRX/DTX cycle. The proposed method is more improve power saving performance than another method which is unchanged DRX/DTX by conditions. In this thesis, I propose an power saving MAC protocol in an environment where LTE base station are communicated with UE and prove improvement in performance through simulations.

• Smart Media Journal
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• v.6 no.3
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• pp.41-48
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• 2017

Event detection using social media has been widespread since social network services have been an active communication channel for connecting with others, diffusing news message. Especially, the real-time characteristic of social media has created the opportunity for supporting for real-time applications/systems. Social network such as Twitter is the potential data source to explore useful information by mining messages posted by the user community. This paper proposed a novel system for temporal event detection by analyzing social data. As a result, this information can be used by first responders, decision makers, or news agents to gain insight of the situation. The proposed approach takes advantages of deep learning methods that play core techniques on the main tasks including informative data identifying from a noisy environment and temporal event detection. The former is the responsibility of Convolutional Neural Network model trained from labeled Twitter data. The latter is for event detection supported by Recurrent Neural Network module. We demonstrated our approach and experimental results on the case study of earthquake situations. Our system is more adaptive than other systems used traditional methods since deep learning enables to extract the features of data without spending lots of time constructing feature by hand. This benefit makes our approach adaptive to extend to a new context of practice. Moreover, the proposed system promised to respond to acceptable delay within several minutes that will helpful mean for supporting news channel agents or belief plan in case of disaster events.

• Fashion & Textile Research Journal
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• v.20 no.6
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• pp.690-703
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• 2018

The purpose of this study is to help user understand the basic principles and interfaces of each program, and to provide a base material for the development of more efficient apparel CAD systems to compensate for each program's shortcomings by comparing the function of three apparel CAD systems: Yuka CAD, Opti-tex, and Style CAD. For this purpose, the skirt waistband and sleeve armhole line creation process were selected based on these two criteria. 1) There is a big difference between principle and method between CAD systems. 2) When CAD system is used rather than paper drawing process, the process is shortened and convenience is high. In this study, pros and cons and supplement point of each CAD system are suggested by comparing the functions of the CAD system performing the selected drafting process by four criteria: icon, key, method, and characteristic point. As a result of the study, it was confirmed that the three CAD systems differ in the basic principle and interface environment. As a result of analyzing the skirt waistband method function, it was confirmed that the band line is formed directly on the outline of the skirt and the band dart recognition function is the most efficient function and as a result of the analyzing the sleeve armhole line method function, it was confirmed that the curve generation function using the shape of the actual curve measure and the length adjustment function through the automation of the dimension calculation is the most efficient function.

• Journal of Internet of Things and Convergence
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• v.8 no.1
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• pp.11-16
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• 2022

Efforts to incorporate blockchain into various fields are continuing as cryptocurrency transactions become more active. Blockchain has the characteristic that once recorded facts cannot be modified or deleted. Due to these characteristics, the use in the field of recording and proving certain facts, such as voting or proof of ownership, is attracting attention. In this paper, users who want to participate in the transaction process using private blockchain, one of the types of blockchain, are divided into real estate brokers, building owners, and purchasers (lessors), and roles are assigned to each user. In addition, we would like to propose a system to increase reliability through the participation of institutions. Through this, we intend to not only present a real estate transaction system that prevents damage from real estate fraud related to false sales and fraudulent contracts, but also enhances reliability and contributes to finding ways to utilize blockchain in the future.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1342-1350
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• 2009

In accordance with the development of broadcasting, the style of using medium by users has been personalized in the propensity to consume. Recent advent of media convergence allowed users of medium to decide the received environment for their needs, thereby the position of users has become more important in the medium consumption. IPTV has the most advanced form of personalized information media. However, IPTV was made by media convergence, which has relation with a variety of interested parties, so there are a few troubles among them in the way of commercializing IPTV. As a matter of fact, although users play a leading role in the IPTV industry, there are still few discussions on the welfare of users. IPTV should be remained the characteristic of the medium of personalized information, and it should include the welfare of users in various fields of media convergence. That is Universal Service. It is necessary to be guaranteed the access right and the variety of contents in using IPTV. Moreover, in terms of telecommunication, IPTV should insure the reasonable fare system as a pay-services. On the basis of the analysis in local and international IPTV circumstances, in terms of content as a medium of personalized information, in terms of fares as a pay-services, and in terms of digital literacy as a new medium of digital access, policies for welfare of users are suggested.