• Journal of information and communication convergence engineering
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• v.12 no.3
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• pp.161-167
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• 2014

Web caches help to reduce latencies arising from slow networks through storing and reusing what was used before. Repeat access to a cached resource does not incur network latencies. However, resources that have never been used will not be found in the cache. Cache prefetching is a technique that helps to fill a cache with still-unused resources in anticipation that these resources will be used in the near future. Typically these unused resources are related to the resources that have been accessed in the recent past. While web caching exploits temporal locality, prefetching attempts to exploit spatial locality. Access to the prefetched resources will be cache hits, and therefore reduces the latency as perceived by the user. This paper reviews the cache infrastructure supported by the hypertext transfer protocol and discusses web cache prefetching in general, including Mozilla's prefetching infrastructure. It then classifies and reviews some prefetching techniques.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.4-6
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• 2001

데이터베이스 관리시스템에서 데이터를 디스크에서 읽어오는 작업은 많은 비용을 필요로 한다. 따라서 시스템의 성능을 향상시키기 위해서는 I/O의 횟수를 최소화는 것이 가장 중요한 문제이다. 특히 공간데이터베이스 환경에서는 클라이언트 버퍼의 크기가 데이터베이스의 크기에 비해 매우 작기 때문에 버퍼를 효율적으로 사용하여 I/O 회수를 줄이는 문제는 더욱 중요하게 고려하여야 한다. 지금까지 디스크 I/O 횟수를 줄이기 위해서 많은 버퍼관리 기법들이 제안되었지만, 그 기법들은 시간적 근접성만을 고려해왔기 때문에 공간적 근접성도 존재하는 공간데이터베이스 환경에서는 최적의 성능을 보여주지 못했다. 본 논문에서는 공간 데이터베이스의 시간적 근접성과 공간적 근접성을 동시에 고려하는 새로운 버퍼관리기법인 SLM-tree Buffer Management Strategy를 제안한다. 제안한 버퍼관리기법은 공간 데이터베이스 환경에서 디스크 I/O의 횟수를 현저하게 줄임으로서 기존의 방법들에 비해 월등한 성능을 보여준다.

• Journal of Ubiquitous Convergence Technology
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• v.1 no.1
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• pp.28-34
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• 2007

Tree-based reliable multicast protocols provide scalability by distributing error-recovery tasks among several repair nodes. These repair nodes perform local error recovery for their receiver nodes using the data stored in their buffers. We propose a packet loss patterns adaptive feedback scheduling scheme to manage these buffers in an efficient manner. Under our scheme, receiver nodes send NAKs to repair nodes to request packet retransmissions only when the packet losses are independent events from other nodes. At dynamic and infrequent intervals, they also send ACKs to indicate which packets can be safely discarded from the repair node's buffer. Our scheme reduces delay in error recovery because the requested packets are almost always available in the repair node's buffers. It also reduces the repair node's workload because (a) each receiver node sends infrequent ACKs with non-fixed intervals and (b) their sending times are fairly distributed among all the receiver nodes.

• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.252-259
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• 2012

The aim of this study is in emphasizing the importance of the use of material and the tectonic and their influence on the spatial quality by analyzing Peter Zumthor's projects as case studies. In the research, Zumthor's choice of material, construction method (detail and structure) and the relationship with the context were analyzed in order to illustrate Zumthor's approach in making a strong tie with the locality. Three of Zumthor's projects of different sizes and programs were chosen to heighten the sensitivity of Zumthor's unique working method for each project. Peter Zumthor's architecture is neither superficial nor visually complex. On the contrary, he aims to express through the use of material and construction method, a unique relationship with the physical context, social context and most importantly the actual experience of the space itself. This study aims to contribute towards increasing the awareness and the interest in the materiality and the tectonics which are the fundamentals in spatial experience and spatial identity.

• Journal of the Economic Geographical Society of Korea
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• v.6 no.1
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• pp.119-144
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• 2003

This study attempts to figure out the impact of Information and communication technologies (ICTs) on spatial structure and to speculate on spatial strategies in the electronic economy from a geographical perspective. The unprecedented development of ICTs based on the explosive use of the Internet was enough to lead to the expectation that physical distance would not be a significant barrier in business activities. In fact, however, at least at a current stage, the development of ICTs has not automatically removed the inequality in spatial structure. The accessibility to electronic space is different by economic and social status within a country as well as between countries. The importance of place, locality, and place-specific assets has been strengthened in the global economy. Physical proximity is still of great importance because it helps to minimize transaction costs, to exploit place-specific social networks, and to accumulate credibility for successful businesses. Likewise, the development of electronic commerce such as B2B and B2C EC also does not necessarily result in the ignorance of place and locality. Rather, the recognition of the importance of spatial strategies is extremely important for the success in online businesses. As a conclusion, the spatial dimension becomes more important in the digital era for successful businesses and balanced regional developments than ever before. The need for the improvement of ICT infrastructures, the development of human resources, and the establishment of regional innovation systems in peripheral areas cannot be overemphasized even in the digital era.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.928-930
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• 2004

명령어간의 데이터 종속 관계는 동적으로 스케줄 되는 파이프라인 프로세서의 병렬 처리에 중요한 장애로 남아 있다. 마이크로프로세서의 데이터 종속에 기인한 파이프라인 대기 시간을 줄일 대표적인 두 가지 방법으로 생성 값의 지역성에 기초를 둔 데이터 값 예측과 공간 지역성에 기반으로 예측하는 주소 예측이 있다. 본 논문에서는 성능 개선을 위해 이 두 가지 기술을 독립적으로 수행하는 것 보다 혼합한 형태의 예측이 더 좋은 예측 정확성이 나타나는 것을 보인다.

• Journal of the Korean association of regional geographers
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• v.19 no.2
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• pp.362-374
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• 2013

ICTs(Information and Communication Technologies) have changed the ways of social activities and communications, and in the process, online and offline spaces have been thought of as binary spaces in which online spaces substitute and erode offline spaces. The aim of this study is to explore how urban space where local social activities and communications are performed is constructed in terms of timespace through the intersection of online and offline communications and how the urban space is 'remediated' through online spaces. For this, the study looks at the case of a workshop on 'locality education' held at the Yeungnam University Museum in January 2013. Criticizing the dichotomist viewpoint that increasing in communications through online spaces results in the expansion of 'absent presence' or 'placelessness' in offline spaces, the study argues that online spaces remediating offline spaces are spaces not transcending the timespace constraints of the offline spaces but rather reflecting the spatial, temporal, material, social, cultural environments of urban space and place.

• Journal of the Economic Geographical Society of Korea
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• v.16 no.1
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• pp.50-70
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• 2013

The creation of new economic paradigm shift in creative economy age have influence on the characteristics of social networks and space, it leads to the formation of new relationship in space depending on social network service development. In this paper, it gives a name to 'social network resource' the power affecting these features and to find the meaning of spatial changes in the economic geography perspectives. 'Social network resource' shows the characteristics of openness, sharing, participation and cooperation, with features of encompassing all the features of local and global characteristics in space. This features are related the meaning of 'trans-locality' and can be found in the case of 'WikiSeoul.com (http:/www.wikiseoul.com)', Seoul's social knowledge sharing web platform. In particular, physical resources, human resources, information resources, and the characteristics of the relationship as a resource features was found and these features appear in space is projected to the space of social relations, it reflects the characteristics of qualitative space regarding social network resource.

• Atmosphere
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• v.24 no.2
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• pp.159-171
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• 2014

This study investigated the temporal and spatial characteristics of summertime (June-August) precipitation over Korean peninsula, using Korea Meteorological Administration (KMA)is Automated Synoptic Observing System (ASOS) data for the period of 1973-2010 and Automatic Weather System (AWS) data for the period of 1998-2010.The authors looked through climatological features of the summertime precipitation, then examined the degree of locality of the precipitation, and probable precipitation amount and its return period of 100 years (i.e., an extreme precipitation event). The amount of monthly total precipitation showed increasing trends for all the summer months during the investigated 38-year period. In particular, the increasing trends were more significant for the months of July and August. The increasing trend of July was seen to be more attributable to the increase of precipitation intensity than that of frequency, while the increasing trend of August was seen to be played more importantly by the increase of the precipitation frequency. The e-folding distance, which is calculated using the correlation of the precipitation at the reference station with those at all other stations, revealed that it is August that has the highest locality of hourly precipitation, indicating higher potential of localized heavy rainfall in August compared to other summer months. More localized precipitation was observed over the western parts of the Korean peninsula where terrain is relatively smooth. Using the 38-years long series of maximum daily and hourly precipitation as input for FARD2006 (Frequency Analysis of Rainfall Data Program 2006), it was revealed that precipitation events with either 360 mm $day^{-1}$ or 80 mm $h^{-1}$ can occur with the return period of 100 years over the Korean Peninsula.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.3-17
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• 2004

With the rapid growth of the Internet geographic information services through the WWW such as a location-based service and so on. Web GISs (Geographic Information Systems) have also come to be a cluster-based architecture like most other information systems. That is, in order to guarntee high quality of geographic information service without regard to the rapid growth of the number of users, web GISs need cluster-based architecture that will be cost-effective and have high availability and scalability. This paper proposes the design of the cluster-based web GIS with high availability and scalability. For this, each node within a cluster-based web GIS consists of main memory spatial databases which accomplish role of caching by using data declustering and the locality of spatial query. Not only simple region queries but also the proposed system processed spatial join queries effectively. Compare to the existing method. Parallel R-tree spatial join for a shared-Nothing architecture, the result of simulation experiments represents that the proposed spatial join method achieves improvement of performance respectively 23% and 30% as data quantity and nodes of cluster become large.