• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10b
• /
• pp.223-225
• /
• 2003

분산 데이터베이스 시스템 환경에서는 특정 노드로 집중되는 부하의 분산이나 가용성 및 안정성 제공을 위해 데이터 분할기법 (fragmentation)과 복제기법(replication)을 사용한다. 이때 전송된 데이터에 대한 기존의 색인 재활용 기법과 벌크 로딩(bulk loading) 기법은 효율적인 색인 구성을 위해 논리적인 페이지 포인터를 물리적 주소로 변환하는 물리적 사상구조를 필요로 하거나, 색인 구성시간과 검색성능 모두를 향상시키지 못하는 문제점을 지닌다. 본 논문에서는 이와 같은 문제점을 해결하기 위해 색인 전송기법을 제안한다. 본 기법은 색인 재활용을 위해 물리적 사상구조를 추가로 유지하거나, 검색 성능을 향상시키기 위해 전체 데이터 집합을 정렬하는 것이 아니라, 데이터가 전송될 사이트에 색인구조물 저장하기 위한 물리적 공간은 예약하고 예약된 공간에 색인구조를 전송, 기록함으로써 색인 구성비용을 줄이게 된다. 또한 예약된 공간을 연속적인 페이지구조로 구성함으로써 색인 구성 시 자식노드에 대한 위치정보를 예상하여 부모노드가 지니는 자식노드에 대한 위치정보 기록 비용을 줄일 수 있다.

• Journal of Korea Spatial Information System Society
• /
• v.7 no.3 s.15
• /
• pp.119-130
• /
• 2005

A spatial data warehouse is a system that stores geographical information as a subject oriented, integrated, time-variant, non-volatile collection for efficiently supporting decision. This system consists of a builder and a spatial data warehouse server. A spatial data warehouse server suspends user services, stores transferred data in the data repository and constructs index using stored data for short response time. Existing methods that construct index are bulk-insertion and index transfer methods. The Bulk-insertion method has high clustering cost for constructing index and searching cost. The Index transfer method has improper for the index reconstruction method of a spatial data warehouse where periodic source data are inserted. In this paper, the efficient index reconstruction method using a partial index in a spatial data warehouse is proposed. This method is an efficient reconstruction method that transfers a partial index and stores a partial index with expecting physical location. This method clusters a spatial data making it suitable to construct index and change treated clusters to a partial index and transfers pages that store a partial index. A spatial data warehouse server reserves sequent physical space of a disk and stores a partial index in the reserved space. Through inserting a partial index into constructed index in a spatial data warehouse server, searching, splitting, remodifing costs are reduced to the minimum.

• Archives of design research
• /
• v.15 no.3
• /
• pp.167-180
• /
• 2002

This study investigates effective ways to help users form a correct mental model of the hierarchical information space (HIS) in small display. The focus is the effect of color cue on understanding the structure and navigating the information space. The concept of color space (CS) corresponds well to the HIS - one color has a unique position in the CS as a piece of information does in HIS. In this study, we empirically examined two types of color cue, namely, categorical and depth cue. Hue was used as a categorical cue and tone was used as a depth cue. In our experiment, we evaluate the effectiveness of the color cues in the mobile internet system. Subjects were asked to perform four searching tasks and four comparison tasks. The results of experiment reveal that the categorical cues significantly improve the user's mental model whereas decrease navigation performances. The depth cues cannot aid in understanding the HIS as well as improve navigation performances. This study concludes with limitations of the study and descriptions of future studies.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04b
• /
• pp.31-33
• /
• 2001

고비용의 공간 연산을 수행해야 하는 공간 질의 처리는 여과-정제의 2단계 처리가 일반적이다. 그러나, 2단계 색인 방법은 여과율이 좋지 못한 단점이 있으므로, 최근 다단계 여과 과정이 많이 연구되고 있다. 다단계 여과 과정은 1차 여과된 객체에 대하여 더욱 정밀한 필터를 적용함으로써 후부 객체 수를 줄이는 방법으로 접근하고 있으나, 여러 번의 여과 단계를 거치므로 수행 시간이 길어지고 추가 정보유지로 인한 저장 공간 낭비 등의 단점이 있다. 본 논문에서는 전체 공간 영역을 격자로 분할하고, 객체를 격자 위에 구성하는 2단계의 공간 색인 방법을 제안한다. 제안된 색인 방법은 Dead Space의 크기를 줄이고, 한 번의 여과 과정으로 높은 여과율을 갖는다.

• Science of Emotion and Sensibility
• /
• v.10 no.1
• /
• pp.37-47
• /
• 2007

Color planning system can be treated as a decision support system which includes both the recommendation of main color and harmonious colors. In this paper, we propose techniques that are useful to enhance the harmonious color recommendation with the main color selected by user. In order to reflect the knowledge about suggestion of harmonious colors, we use Ostwald color harmony theory, that is very systematical and easy to implement. Actually, Ostwald color space is similar to HMMD color model in MPEG-7. Due to the similarity between two color spaces, Ostwald color space can be represented as a virtual HMMD color space. Accordingly, we propose a technique to align the HMMD color space with Ostwald color space, thereby it is capable of enhancing a performance to search the harmonious colors according to Ostwald harmony theory. For recommendation of delicate and more exquisite harmonious colors in equal hue plane, we made the virtual color space continuous. The system can recommend various harmonious colors according to Ostwald color harmony. He(she) can select harmonious colors among the suggestions from the system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2019.05a
• /
• pp.551-555
• /
• 2019

본 논문에서는 색채에 대한 아동의 심리를 분석하기 위해서 CRR(Colour Reflection Reading) 및 주조색를 이용한 심리 분석 기법을 제안한다. CRR은 이미 그려진 그림에 아동이 색을 칠하는 것으로 색이 칠해진 데이터를 바탕으로 아동의 심리 상태를 분석한다. 주조색 심리 분석 기법은 원하는 색을 선택하여 그림을 그리고, 그린 그림을 이용하여 심리를 분석한다. 따라서 본 논문에서는 퍼지 논리를 적용하여 색채에 대한 심리 분석 결과를 도출하고 그린 그림을 기반으로 공간 배치도 분석 기법을 이용하여 공간 배치도에 따른 아동의 심리 상태도 분석한다.

• Journal of Korean Ophthalmic Optics Society
• /
• v.10 no.1
• /
• pp.1-8
• /
• 2005

Color vision of color vision deficiency is possible using Color space's conversion of color image. Color vision of the RG-Color vision deficiency is possible by the case to maximize the G channel(+100), the case to minimize the G channel(-100), the case to maximize the R channel(+100), the case to convert the R channel to the yellow(Y) channel that is the value of $(-)b^*$ coordinate in CIE $L^*a^*b^*$ color space, the case to separate with only the B channel and the G channel and to appear by the light and darkness difference again, and the case to receive the image only by the light and darkness after separation of saturation and conversion of RGB channel.

• Journal of Korea Spatial Information System Society
• /
• v.7 no.2 s.14
• /
• pp.81-89
• /
• 2005

Declustering and parallel index structures are important research areas to improve a performance of databases. Previous researches proposed several distribution schemes for parallel R-trees, however there is no search schemes to be suitable for the index. In this paper, we propose schemes to improve the performance of range queries for distribute parallel indexes. The proposed schemes use the features that a parallel disk can read multiple nodes from various disks. The proposed schemes are verified using various implementations and performance evaluations. We propose new schemes which can read multiple nodes from multiple disks in contrast that to the previous schemes which can read a node from disk. The experimental evaluation shows that the proposed schemes give us the performance improvement by 40% from the previous researches.

• Journal of Korea Multimedia Society
• /
• v.4 no.4
• /
• pp.316-323
• /
• 2001

Gamut mapping is a technique that acts on cross-media color reproduction to transform a color between devices for the purpose of enhancing the appearance or preserving the appearance of an image. Gamut mapping essentially produces color conversion error which depends on the gamut mapping method, source and destination devices, and sample points for gamut modeling. For color space conversion between monitor colors and printer colors, empirical representation using sample measurements is currently widely utilized. Color samples are uniformly selected in the device space such as CMY or RGB, represented as color patches, and then measured. However, in the case of printer, these color samples are not evenly distributed inside the printer gamut and the color conversion error is increased. Accordingly, this paper introduces a equally distributed color sampling method in CIELAB space, a device- independent color space, to reduce color conversion error, and the performance is analyzed via color space conversion experiments using three-dimensional interpolation.

• Journal of KIISE:Databases
• /
• v.34 no.5
• /
• pp.420-436
• /
• 2007

The choice of an effective indexing method is crucial to guarantee the performance of the spatial join operator which is heavily used in geographical information systems. The $R^*$-tree based method is renowned as one of the most representative indexing methods. In this paper, we propose an efficient spatial join technique based on the DOT(Double Transformation) index, and compare it with the spatial Join technique based on the $R^*$-tree index. The DOT index transforms the MBR of an spatial object into a single numeric value using a space filling curve, and builds the $B^+$-tree from a set of numeric values transformed as such. The DOT index is possible to be employed as a primary index for spatial objects. The proposed spatial join technique exploits the regularities in the moving patterns of space filling curves to divide a query region into a set of maximal sub-regions within which space filling curves traverse without interruption. Such division reduces the number of spatial transformations required to perform the spatial join and thus improves the performance of join processing. The experiments with the data sets of various distributions and sizes revealed that the proposed join technique is up to three times faster than the spatial join method based on the $R^*$-tree index.