• Korean Journal of Remote Sensing
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• v.16 no.2
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• pp.189-198
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• 2000

This study introduces the CEOS (Committee for Earth Obseuing Satellites) standard format structure that is applicable to image formats of Earth observation systems, and describes several important parameters for post-process applications, especially in precise SAR geocoding and terrain correction application. ERS and RADARSAT were chosen as a representative case and the meaning and usage of various fields in LEADER file were investigated in detail from the viewpoint of SAR geocoding and terrain correction applications.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.83-93
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• 1982

In this work, lipid oxidation and the kinetics of the oxidation reaction in fried file-fish meat were investigated when sun-dried file-fish was stored under the conditions of various water activities and temperature, 35, 45, 55 and $35/55^{\circ}C$. The storage stability and the development of browning by oxidative rancidity were also discussed. Monolayer coverage value of water content in dried file-fish was $8.03\%$ at $0.21\;a_w$Lipid oxidation at $35^{\circ}C$ was developed with increasing water activity but at $45^{\circ}C$and $55^{\circ}C$ it was rapidly progressed without clear differences between water activities except $0.44\;a_w$. The rate of reaction was more sensitive to storage temperature than to water activity. Browning in methanol-chloroform fraction was developed linearly by the progress of lipid oxidation which suggested that lipid oxidation was greatly influential to the development of browning in dried fish meat. In kinetical analysis the oxidation followed a zero order reaction mechanism as a function of carbonyl value. The activation energies obtained from the Arrhenius plot ranged 9.0 to 10.8 Kcal/mol and $Q_10$ values, 1.6-1.7. Shelf-lives at the storage of 35,45 and $55^{\circ}C$ ranged 58 days to 8 days. And in the fluctuating temperature storage at $35/55^{\circ}C$, shelf-lives were 17, 16, 15 and 13 days at 0.44, 0.52, 0.65 and $0.75\;a_w$, respectively. The shelf-lives for assessed from the accelerated shelf-life test were 125, 123, 120 and 106 days at 0.44, 0.52, 0.65 and $0.75\;a_w$, respectively, in the case of storage at $25^{\circ}C$.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.717-727
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• 2009

P2P (Peer-to-Peer) network depends on cooperation of peers considerably. However, some peers do not share files at all and only download files. Peers also share low quality files or unpopular files. These selfish behavior of peers is referred to 'free riding'. The free riding of peer may decrease participation of other peers or the system performance. In this paper, we propose an incentive mechanism, called IcMFS (Incentive Mechanism for File Sharing System), which provides the correct use of incentive mechanism using trust peer, computes contribution values referring behavior of peers and rewards peers. The proposed mechanism assigns bandwidth and TTL(Time-To-Live) to a peer and differentiates the use of service. A case study on simulations shows the service differentiation according to the contribution value of peer, the correct use of incentive mechanism using trust peer and the advantage by use of trust peer. To prove the stability of proposed mechanism, we also show the disadvantage that a peer receives from the incorrect use of incentive mechanism.

• Proceedings of the Korean Printing Society Conference
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• 2001.06a
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• pp.63-77
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• 2001

PDF(Portable Document Format) is a file format that Adobe advances postscritp technique and use in managing document information or electric publishing(internet, CD-ROM, DVD). PDF is a devised document type for being able to read and print anywhere, independent of OS, printer type, resolution, and the kind of computer etc. Because this includes a compressing function, it transfers document through a small size of file in internet or intranet. In addition, that is a file format has various advantages-sharing of information and transfering documents in on line or off line environment. In this paper, we developed electronic document system using PDF format. Electronic document system consists of filter, automatic indexing, special searching system and web server. The information used in this paper is database made using Zwon\`s DocuCom. The filter recognizes various kinds of document structure. And according to property of document, it produces ASCII output. In addition to processing various formats of document, the filter can extract keywords in documents of MS WORD, Excel, Powerpoint, PDF, CAD etc. This filter uses the structure of window printer drive and can extract the information for text, page, font type and size from relevant document. The automatic indexing recognizes the formatted tag of document form ASCII text produced by filter and extracts adequate keyword to structure and property of document. PDF electronic document systems proposed in this paper can be used in Internet, PC communication. Users can choose and read electronic documents by two ways. First, users can choose and read relevant books using PDF electronic document homepage. Second, users can use PDF integrated-search system. User can search after inputing keyword and choose reference field and type of data. But, now, PDF products of Adobe can\`t support the Korean character. If this problem is resolved, we thick that PDF applications system looks active. Although there is limited function in case of using Zwon DocuCom used in this study, we think that there isn\`t a great deal of difficulty in electronic document and building digital database.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4B
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• pp.333-343
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• 2006

MANET and P2P applications have a common nature that they don't have any fixed infrastructures that might maintain network topologies. With such common characteristics, a P2P application can be a killer application over MANET. Due to absence of reliable node which serves indexing services in MANET, fully distributed P2P applications are more suitable for MANET. By using DHT like Chord, we can save network bandwidth and avoid a point of failure of a directory server. However, since MANET allows nodes to depart from network freely, P2P file sharing applications using Chord lookup protocol should address how to recover the keys stored at the departed node. In this paper, we propose BU-Chord in order to detect and recover the departure of nodes by creating and storing backup file information in distributed manner. Our BU-Chord shows off better performance than existing Chord especially in case of high departure rate of nodes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.567-575
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• 2015

Species composition in the coastal waters off Ulleungdo of Korea were examined based on catches bimonthly collected by trammel net in 2013. A total of 711 individuals and 181.9 Kg were caught and catches were composed of 4 classes 15 orders 27 families 52 species including 44 Pisces, 4 Gastropoda, 3 Cephalopoda, and 1 Echinodermata. The dominant species in biomass were File fish (Thamnaconus modestus), Atka mackerel (Pleurogrammus azonus), and Greenling (Hexagrammos otakii). Data were summarized using hierarchical cluster analysis (HCA) and detrended correspondence analysis (DCA) to examine similarity in species composition for each month, and community structure in Ulleungdo was divided into two groups. Community structures in February, April and December with low temperature and well-mixed surface water were distinguished from those in June, August and October with high temperature and strong stratification, which could be attributed to temporal changes in dominant species. Atka mackerel and Spear squid mainly caught in February and April, disappearing in June, August and October, and File fish outburst was shown in October. Because the water off Ulleungdo has been under low human pressure, it could be a good case study to elucidate effects of climate change on community structure and ecosystem in the East sea. Continuous surveys and further studies are required to demonstrate migration route and distribution of dominant species and long-term changes in community structure in the water of Ulleungdo.

• Journal of Communications and Networks
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• v.12 no.1
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• pp.52-66
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• 2010

Since large objects consume substantial resources, web proxy caching incurs a fundamental trade-off between performance (i.e., hit-ratio and latency) and overhead (i.e., resource usage), in terms of caching and relaying large objects to users. This paper investigates how and to what extent the current dedicated-server based web proxy caching scheme is affected by large file transfers in a high bandwidth campus network environment. We use a series of trace-based performance analyses and profiling of various resource components in our experimental squid proxy cache server. Large file transfers often overwhelm our cache server. This causes a bottleneck in a web network, by saturating the network bandwidth of the cache server. Due to the requests for large objects, response times required for delivery of concurrently requested small objects increase, by a factor as high as a few million, in the worst cases. We argue that this cache bandwidth bottleneck problem is due to the fundamental limitations of the current centralized web proxy caching model that scales poorly when there are a limited amount of dedicated resources. This is a serious threat to the viability of the current web proxy caching model, particularly in a high bandwidth access network, since it leads to sporadic disconnections of the downstream access network from the global web network. We propose a peer-to-peer cooperative web caching scheme to address the cache bandwidth bottleneck problem. We show that it performs the task of caching and delivery of large objects in an efficient and cost-effective manner, without generating significant overheads for participating peers.

• Journal of Digital Contents Society
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• v.17 no.3
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• pp.181-188
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• 2016

Video streaming traffics which are arrived in receiver have irregular traffic patterns by many problems over the network path. Particularly, if these received traffics enter into replay buffer without any operation, the overflow and underflow effects are made according to the buffer status. There was an existing scheme which automatically set up token bucket parameters using the video information file under the assumption of the lossless packet on network. The existing scheme has a problem which can set up the wrong token bucket parameters by the lost packets on the practical networks with video packet loss. Therefore, this paper proposes a new scheme which reset up video file information to correct the wrong token bucket parameters in case of packet loss in practical networks with packet loss. Through the simulation, it was found that the proposed scheme would have better performance than the existing scheme in terms of overflow generation and packet loss.

• Journal of the Korea Society of Computer and Information
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• v.26 no.10
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• pp.147-155
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• 2021

If one wants to file a lawsuit against the administrative office, he or she should decide whether to file a civil lawsuit or an administrative lawsuit. The type of lawsuit must be determined to determine which court to file the lawsuit with. Korea seems to have a clear distinction between administrative and judicial legal relationships, but it is not easy to distinguish between public and judicial cases unless the public and judicial discrimination are maintained. The practice or precedent of litigation is always difficult to distinguish because the litigation is based on the discrimination of whether the litigation belongs to a legal relationship in public law or judicial law. I believe that if the administrative litigation law establishes a provision related to the designation of a duty and stipulates that "if a litigation case is questioned whether it is an administrative or civil lawsuit, the Supreme Court-related court shall designate the competent court at the request of the parties," the lower court will be guaranteed the right to swift a trial, and the legal representatives will be freed from the exhaustive agony.

• Journal of Platform Technology
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• v.6 no.4
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• pp.69-77
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• 2018

In the case of personal information files containing personal information, there is insufficient awareness of personal information protection in end-point areas such as personal computers, smart terminals, and personal storage devices. In this study, we use Diffie-Hellman method to securely retrieve personal information files generated by web crawler. We designed SEED and ARIA using hybrid slicing to protect against attack on personal information file. The encryption performance of the personal information file collected by the Web crawling method is compared with the encryption decryption rate according to the key generation and the encryption decryption sharing according to the user key level. The simulation was performed on the personal information file delivered to the external agency transmission process. As a result, we compared the performance of existing methods and found that the detection rate is improved by 4.64 times and the information protection rate is improved by 18.3%.