• Journal of the Korean BIBLIA Society for library and Information Science
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• v.7 no.1
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• pp.319-351
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• 1994

This rearch is a case study for the newspaper libraries in Seoul and the primary purpose of the this study are to investigate its document delivery capability. To achieve the above-mentioned purpose, representative rsers visited seven the newspaper library and checked their searching time. Document delivery capability was checked by units of hour, minute, second(searching time). Retrieval effectiveness was tested through the recall ratio and the precision ratio. The major findings of the study are summarized as follows： 1) Most of the newspaper libraries excellent to the document delivery capability； 6 newspaper libraries deliverived the data related subject. 2) The newspaper libraries were came out 50.1% the mean recall ratio and 84.8% the mean precision ratio about the all materials. 3) Concerned their own articles, the newspaper libraries showed 71.4% the recall ratio and 90.0% the precision ratio. That moaned their own articles were more effectived than others. 4) The Kookmin Ilbo library had the most excellent system, and the precision ratio of The Dong-A Ilbo library prior to the recall ratio. The Han Kyoreh Shinmun library had a excellent arragement in own articles, but The Segye Times library had problem in every parties.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.177-184
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• 2008

The design goal of protocols in wireless sensor networks (WSN) is mainly energy efficiency because of their stringent resource and energy constraints. In this paper, we propose a simple cross-layered protocol for WSNs, so called EATD(Energy-Aware Tree based Delivery scheme). EATD is a tree-based energy aware data delivery algorithm by using a SYNC packet with link and node cost to maximize the network lifetime. Our simulation results show significant improvements compared with existing schemes in terms of energy efficiency and delay.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.59-67
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• 2009

In wireless sensor networks (WSNs), geographic greedy forwarding fails to move a packet further towards its destination if the sender does not have any closer node to the destination in its one hop transmission region. In this paper, we propose a enhanced geographic routing, called CGR(Cost based Geographic Routing) for efficient data delivery against void problem environment. CGR first establishes Shadow Bound Region and then accomplishes Renewing Cost Function Algorithm for effective greedy forwarding data delivery. Our simulation results show significant improvements compared with existing schemes in terms of routing path length, success delivery ratio and energy efficiency.

• Journal of KIISE:Information Networking
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• v.36 no.2
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• pp.137-142
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• 2009

In traditional message ferrying schemes, only ferries carry messages between partitioned networks. In this paper, we propose a new approach to make both ferries and mobile nodes carry messages so that we reduce message delivery delay in disruption tolerant networks. We evaluate our scheme against conventional message ferrying in terms of message delivery delay, throughput, ferry buffer usage and mobile nodes buffer usage.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5981-5997
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• 2017

Advanced Television Systems Committee (ATSC) produced ATSC 2.0 standard, which has been used for a HD/SD digital broadcasting service with MPEG-2 Transport Stream (TS) as a delivery protocol. Recently, users might want to consume multimedia services without being constrained by transport network. However, MPEG-2 TS is not suitable protocol for IP network. Thus, ATSC has enacted ATSC 3.0 standard, which is designed for a hybrid service through a conversion of both broadcasting and broadband channels. The ATSC 3.0 specifies delivery protocols as MPEG Media Transport (MMT) for a broadcasting environment and Dynamic Adaptive Streaming over HTTP (DASH) for a broadband. However, it seems difficult to combine broadcast and broadband for hybrid broadcasting, and it is difficult to synchronize media data between MMT and DASH. This paper suggests various new service scenarios to be brought up by a hybrid broadcasting, ATSC 3.0, and also proposes a stable mechanism for switching contents between different delivery protocols such as MMT and DASH.

• Journal of Communications and Networks
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• v.16 no.6
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• pp.613-619
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• 2014

Multicast routing algorithms designed for wireline networks are not suitable for wireless environments since they cannot efficiently exploit the inherent characteristics of wireless networks such as the broadcast advantage. There are many routing protocols trying to use these advantages to decrease the number of required transmissions or increase the reception probability of data (e.g., opportunistic routing).Reducing the number of transmissions in a multicast tree directly decreases the bandwidth consumption and interference and increases the overall throughput of the network. In this paper, we introduce a distributed multicast routing protocol for wireless mesh networks called NCast which take into account the data delivery delay and path length when constructing the tree. Furthermore, it effectively uses wireless broadcast advantage to decrease the number of forwarding nodes dynamically when a new receiver joins the tree.Our simulation results show that NCast improves network throughput, data delivery ratio and data delivery delay in comparison with on demand multicast routing protocol. It is also comparable with multichannel multicast even though it does not use channeling technique which eliminates the interference inherently.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.2
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• pp.39-47
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• 2011

Adapting content services to the needs of the users requires content adaptation for context and sensibility. Adapting to context may necessitate distinguishing between video delivery to a PC versus a smart phone, while adapting to sensibility may necessitate between video delivery outside, in a quiet environment, or at home, or offering different movie choices on a sunny summer day, a cold winter day or a holiday season. One key area to address in providing adaptive content services is the design of the delivery system architecture of the adaptive content server. This paper describes several alternatives for this architecture, and outlines some additional concerns that must be considered when the chosen architecture is implemented.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.261-262
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• 2014

최근 택배산업의 급격한 성장과 모바일 웹앱 환경의 급격한 발달 및 택배물량이 증가하면서 택배 피해 사례도 증가하고 있다. 현재 택배서비스 이용시 피해 발생시 책임소재 입증불가 및 책임회피의 문제점이 대두되었고, 택배기사를 사칭한 각종 여성 범죄 사고가 증가하고 있다. 본 논문에서는 모바일 환경에서의 택배정보 및 위치정보를 확인할 수 있도록 음성을 저장 및 인식할 수 있는 안심택배 관리 시스템을 연구하고 설계하였다.

• Transactions of the Society of Information Storage Systems
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• v.7 no.1
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• pp.36-41
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• 2011

The micro laser module was designed and prepared to deliver the light to the HAMR head. It consists of laser diode, photo diode and actuator to realize stable light delivery even though the head is fluctuated during the disk rotation. The optical evaluation was carried out with the actual distance between the light source and HAMR head with a range of reflectivity and it was found that the incident angle could be controlled within ${\pm}0.125^{\circ}$ to maintain same intensity into the HAMR head. It was also confirmed that the designed micro laser module is thermally stable without any severe effect on the magnetic head.

• International journal of advanced smart convergence
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• v.8 no.3
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• pp.167-176
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• 2019

Building skins are expanding even beyond theirfunctions as a simple boundary between the exterior and interior and into the realm of linguistic functions thanks to the development of media art. LED has been used as material on outer walls following the advancement of building materials, so the outerskins of large buildings are evolving into a messenger of language capable of communication. In big cities, buildings send out video images to enable communication between people and architecture, which plays a huge role in determining the identity of a building beyond simple advertising. Such media fa?ade technologies can be understood based on the concept of outerskin change, which refers to the idea that animals change the colors or textures of their skins to show their various states. In addition, various message delivery functions in human clothes should be included in such a discussion. We need to research on the possibilities of seeing media facades for their information delivery function and expanding them into information delivery between buildings as well as just between buildings and people.