• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.115-117
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• 2005

버퍼의 효율적인 관리는 시스템의 성능과 밀접한 관련성을 가지고 있다. 따라서, 최근까지 다양한 버퍼 관리 기법들이 제안되었다. 그러나, 지금까지 알려진 기법들의 대부분은 시간 근접성만을 고려하고 있다. 그러나, 공간 데이터베이스와 같은 환경에서는 시간 근접성뿐 만 아니라, 유사한 위치에 있는 공간 객체들은 서로 같이 접근 될 가능성이 높다는 공간 근접성도 존재한다. 따라서, 본 논문에서는 공간 데이터베이스 환경에서 시간 근접성과 공간 근접성 같이 효과적으로 고려하는 버퍼 관리 기법을 제안하다. 또한, 실험을 통하여 제안 기법의 효율성을 보인다.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.7-15
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• 2005

• The KIPS Transactions:PartB
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• v.17B no.5
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• pp.399-404
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• 2010

In this paper, we propose a method for precision improvement based on core clusters and term proximity. The method is composed by three steps. The initial retrieval documents are clustered based on query term combination, which occurred in the document. Core clusters are selected by using proximity between query terms. Then, the documents in core clusters are reranked based on context information of query. On TREC AP test collection, experimental results in precision at the top documents(P@100) show that the proposed method improved 11.2% over the language model.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.6
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• pp.603-608
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• 2014

In the maritime traffic environment, the near-miss between vessels is the situation approaching on collision course but collision accident is not occurred. In this study, in order to calculate the near-miss between navigating vessels, the discriminating equation using ship bumper theory and vessel position clustering methods are proposed. Applying proposed module to the vessel trajectories of the WANDO waterway, we assessment navigational risk factors of vessel type, navigational speed, meeting situation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2140-2146
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• 2009

Since tags do not have location informations, the identifiers of tags which are symbolic data are used as the location informations. Therefore, it is difficult to define the proxmity between two trajectories of tags and inefficient to process the user queries for tags. In this paper, we define the perceptual space to model the location of a tag and propose the proximity of the perceptual spaces. The proximity of the perceptual spaces is composed of the static proximity and dynamic proximity. Using the proximity of the perceptual spaces, it is possible to measure the proximity between two trajectories of tags and build the efficient indexes for tag trajectories. We evaluated the performance of the proposed proximity function for tag trajectories on the IR-tree and the $R^*$-tree.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.783-790
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• 2017

An acceptable proximity assessment collision probability is widely considered to be less than $10^{-4}$ in maritime traffic safety audit schemes. In the 1970s, Fujii, Macduff and colleagues introduced various models for collision probability of aberrancy in the community. Although existing studies ensured acceptable proximity collision probability, around $10^{-4}$, they were constrained by assumptions. A lack of support for the proximity probability criterion has been investigated in this study for practical use. The appropriate proximity probability for different size vessels in both straight and curved lanes has been analyzed based on GICOMS data. As a result, reasonable proximity collision probabilities were determined for various vessel traffic conditions. Accordingly, necessary improvements in the maritime traffic system have been suggested in consideration for various maritime traffic situations and conditions.

• Tunnel and Underground Space
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• v.34 no.4
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• pp.283-300
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• 2024

Due to the revitalization of urban development, the number of cases of excavating tunnels adjacent to existing subways is increasing. This may affect the structure and track of the existing subway, resulting in reduced stability and usability. In this study, we verified the adequacy of the proximity evaluation range to ensure the stability of new tunnels and existing subways when excavating adjacent to tunnels, and proposed a quantitative correction rate considering various conditions. Conditions for applying the correction rate considered rock grade, geologically weak section, structurally weak section, and structural deterioration section. It is hoped that a more accurate proximity evaluation will be performed by applying a quantitative correction rate that considers rock and geological conditions, structure status, etc. to the proximity evaluation standard.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.21-32
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• 2010

This study investigated the effects of contiguity and reading mode on cognitive load factors measured by Galvanic Skin Response(GSR). In this study two experimental conditions were imposed to participants to measure cognitive load with the high contiguity picture and low contiguity picture. Thirty-four college students participated to this experiment(experiment group=17, control group=17), and spilt-plot factorial design was applied to control individual difference in galvanic skin response. Tasks of this experiment were reading and summary. The dependent variables were skin conductance response, and perceived difficulty. The independent variables were the degree of contiguity of visual material(high contiguity vs. low contiguity). The major result of this study was identification of a significant difference of GSR with low contiguity condition. Indeed it was identified that more complex reading condition required more cognitive loads. This finding supported that different cognitive process might require different amounts of cognitive loads. For the further research, this study discussed the validity of applying physiological signals to assess cognitive loads and relationships the associated affective reactions.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.164-165
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• 2000

구멍에 의한 빛의 회절은 광학의 기본적인 문제로서, 최근 근접장 광학(Near-Field Optics)의 발전과 더불어서 파장보다 작은 구멍에서 일어나는 빛의 회절에 대한 관심이 고조되고 있다.$^{(1)(2)(3)}$ 본 연구에서는 그동안 주로 이론적으로 다루어지고 있던 파장보다 작은 금속 구멍을 통한 빛의 회절에 대해 실험결과들을 보고한다. 회절된 빛의 먼장(Far-field)과, 근접장(Near-field)을 모두 측정하기 위해서 고체각 주사기(Solid angle scanner)와 근접장 주사 광학 현미경(Near-field Scanning Optical Microscopy)이 사용되었다. 고체각 주사기(Solid angle scanner)를 사용하여 반구면 위에서의 빛의 이차원 세기 분포가 다양한 편광 상태에 따라서 측정되었고$^{(4)}$ 근접장 탐침(NSOM probe)으로 작은 금속 구멍주변을 주사함으로서 근접장이 측정되었다. 작은 구멍은 최근에 개발된 고출력 근접장 광섬유 탐침(High-power near-field fiber probe)구조를 이용하여 제작되었다.$^{(5)}$

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.162-163
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• 2000

근접장 주사 광학 현미경(Near-field scanning optical microscope)에서 가장 중요한 부분은 바로 근접장 탐침(Near-field optical probe)이다. 가간 널리 사용되는 근접장 탐침은 끝 부분에 매우 작은 구멍만 남기고 나머지 부분은 금속으로 코팅한 뾰족한 광섬유(Metal-clad tapered optical fiber)이다. 탐침의 끝에 형성된 작은 구멍은 진행하지 못하는 근접장(Near-field)을 진행하는 먼장(Far-field)으로 바꾸어줌으로서 회절한계를 뛰어넘는 분해능을 가능하게 한다. 그러나, 이러한 작은 구멍은 매우 작은 투과 효율(Transmission efficiency)을 가지기 때문에 고밀도 광기록(High-density optical recording)등에 이용하는데 큰 어려움이 있었다.$^{(1).(3)}$ 따라서 금속이 코팅된 뾰족한 광섬유 내에서 빛이 어떻게 진행되는지에 대한 연구를 통해 보다 높은 효율을 가지는 근접장 탐침을 개발하는 것이 중요한 과제가 되고 있다. 본 연구에서는 금속이 코팅된 뾰족한 광섬유 도파로 내에서 구멍의 크기와 빛의 투과 효율의 관계를 보고한다. (중략)