• Title/Summary/Keyword: regular map

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Path-finding by using generalized visibility graphs in computer game environments (컴퓨터 게임 환경에서 일반화 가시성 그래프를 이용한 경로찾기)

  • Yu, Kyeon-Ah;Jeon, Hyun-Joo
    • Journal of the Korea Society for Simulation
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    • v.14 no.3
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    • pp.21-31
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    • 2005
  • In state-of-the-art games, characters can move in a goal-directed manner so that they can move to the goal position without colliding obstacles. Many path-finding methods have been proposed and implemented for these characters and most of them use the A* search algorithm. When .the map is represented with a regular grid of squares or a navigation mesh, it often takes a long time for the A* to search the state space because the number of cells used In the grid or the mesh increases for higher resolution. Moreover the A* search on the grid often causes a zigzag effect, which is not optimal and realistic. In this paper we propose to use visibility graphs to improve the search time by reducing the search space and to find the optimal path. We also propose a method of taking into account the size of moving characters in the phase of planning to prevent them from colliding with obstacles as they move. Simulation results show that the proposed method performs better than the grid-based A* algorithm in terms of the search time and space and that the resulting paths are more realistic.

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Enhancement Method of Depth Accuracy in DIBR-Based Multiview Image Generation (다시점 영상 생성을 위한 DIBR 기반의 깊이 정확도 향상 방법)

  • Kim, Minyoung;Cho, Yongjoo;Park, Kyoung Shin
    • KIPS Transactions on Computer and Communication Systems
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    • v.5 no.9
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    • pp.237-246
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    • 2016
  • DIBR (Depth Image Based Rendering) is a multimedia technology that generates the virtual multi-view images using a color image and a depth image, and it is used for creating glasses-less 3-dimensional display contents. This research describes the effect of depth accuracy about the objective quality of DIBR-based multi-view images. It first evaluated the minimum depth quantization bit that enables the minimum distortion so that people cannot recognize the quality degradation. It then presented the comparative analysis of non-uniform domain-division quantization versus regular linear quantization to find out how effectively express the accuracy of the depth information in same quantization levels according to scene properties.

Stochastic Non-linear Hashing for Near-Duplicate Video Retrieval using Deep Feature applicable to Large-scale Datasets

  • Byun, Sung-Woo;Lee, Seok-Pil
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.8
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    • pp.4300-4314
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    • 2019
  • With the development of video-related applications, media content has increased dramatically through applications. There is a substantial amount of near-duplicate videos (NDVs) among Internet videos, thus NDVR is important for eliminating near-duplicates from web video searches. This paper proposes a novel NDVR system that supports large-scale retrieval and contributes to the efficient and accurate retrieval performance. For this, we extracted keyframes from each video at regular intervals and then extracted both commonly used features (LBP and HSV) and new image features from each keyframe. A recent study introduced a new image feature that can provide more robust information than existing features even if there are geometric changes to and complex editing of images. We convert a vector set that consists of the extracted features to binary code through a set of hash functions so that the similarity comparison can be more efficient as similar videos are more likely to map into the same buckets. Lastly, we calculate similarity to search for NDVs; we examine the effectiveness of the NDVR system and compare this against previous NDVR systems using the public video collections CC_WEB_VIDEO. The proposed NDVR system's performance is very promising compared to previous NDVR systems.

Machine Learning-based Prediction of Relative Regional Air Volume Change from Healthy Human Lung CTs

  • Eunchan Kim;YongHyun Lee;Jiwoong Choi;Byungjoon Yoo;Kum Ju Chae;Chang Hyun Lee
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.2
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    • pp.576-590
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    • 2023
  • Machine learning is widely used in various academic fields, and recently it has been actively applied in the medical research. In the medical field, machine learning is used in a variety of ways, such as speeding up diagnosis, discovering new biomarkers, or discovering latent traits of a disease. In the respiratory field, a relative regional air volume change (RRAVC) map based on quantitative inspiratory and expiratory computed tomography (CT) imaging can be used as a useful functional imaging biomarker for characterizing regional ventilation. In this study, we seek to predict RRAVC using various regular machine learning models such as extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM), and multi-layer perceptron (MLP). We experimentally show that MLP performs best, followed by XGBoost. We also propose several relative coordinate systems to minimize intersubjective variability. We confirm a significant experimental performance improvement when we apply a subject's relative proportion coordinates over conventional absolute coordinates.

The Status of Damage and Monitoring of Subterranean Termite (Reticulitermes spp.) (Blattodea: Rhinotermitidae) for Wooden Cultural Heritage in Korea (국내 목조문화재에 대한 지중 흰개미 피해 및 모니터링 현황)

  • Im, Ik-Gyun;Cha, Hyun-Seok;Kang, Won-Chul;Lee, Sang-Bin;Han, Gyu-Seong
    • Journal of Conservation Science
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    • v.37 no.3
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    • pp.191-208
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    • 2021
  • In this study, the status of damage by subterranean termites and their management according to the region and type of domestic wooden cultural properties were identified. This was based on the survey reports of agencies conducting regular nationwide and regional monitoring of subterranean termites. In addition, using geographical information system (GIS) based on the survey contents, a map was constructed of termite infestation and its progress on 2,805 wooden cultural properties that were surveyed nationwide. Based on the map produced, a total of 486 cases of termite infestation were confirmed in wooden cultural properties during 2018-2019, of which 143 cases (approximately 29.4%) were confirmed to be owing to the invasion of termites in the ground and infestation of wood materials. A web platform and an application using a mapping application program interface were created to increase accessibility to the investigated damage status data. The methods employed by each institution for investigating and monitoring the invasion of termites in the ground included the use of detection dogs, visual observation, installation of wood specimens made of pine, and microwave equipment. However, it was confirmed that monitoring and survey methods were not applied to determine the territorial range of the subterranean termite colonies. Accordingly, the use of dyeing and mark-release-recapture methods were deemed necessary to understand the current status, such as calculating the scope of the target wooden cultural property, when monitoring subterranean termite colonies.

A study on the discriminant analysis of node deployment based on cable type Wi-Fi in indoor (케이블형 Wi-Fi 기반 실내 공간의 노드 배치 판별 분석에 관한 연구)

  • Zin, Hyeon-Cheol;Kim, Won-Yeol;Kim, Jong-Chan;Kim, Yoon-Sik;Seo, Dong-Hoan
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.9
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    • pp.836-841
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    • 2016
  • An indoor positioning system using Wi-Fi is essential to produce a radio map that combines the indoor space of two or more dimensions, the information of node positions, and etc. in processing for constructing the radio map, the measurement of the received signal strength indicator(RSSI) and the confirmation of node placement information counsume substantial time. Especially, when the installed wireless environment is changed or a new space is created, easy installation of the node and fast indoor radio mapping are needed to provide indoor location-based services. In this paper, to reduce the time consumption, we propose an algorithm to distinguish the straight and curve lines of a corridor section by RSSI visualization and Sobel filter-based edge detection that enable accurate node deployment and space analysis using cable-type Wi-Fi node installed at a 3 m interval. Because the cable type Wi-Fi is connected by a same power line, it has an advantage that the installation order of nodes at regular intervals could be confirmed accurately. To be able to analyze specific sections in space based on this advantage, the distribution of the signal was confirmed and analyzed by Sobel filter based edge detection and total RSSI distribution(TRD) computation through a visualization process based on the measured RSSI. As a result to compare the raw data with the performance of the proposed algorithm, the signal intensity of proposed algorithm is improved by 13.73 % in the curve section. Besides, the characteristics of the straight and the curve line were enhanced as the signal intensity of the straight line decreased by an average of 34.16 %.

Beneficial effect of Combination with Korean Red Ginseng, Gastrodia Rhizoma and Polygoni Multiflori on Cholesterol and Erectile Dysfunction in Hyperlipidemia rats (홍삼, 천마, 적하수오 병용투여에 의한 고지혈증 랫드에서의 콜레스테롤 및 발기부전 개선효과)

  • Lee, Yun Jung;Kho, Min Chul;Tan, Rui;Lee, Jae Yun;Hwang, Jin Seok;Cha, Jeong Dan;Choi, Kyung Min;Kang, Dae Gill
    • The Korea Journal of Herbology
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    • v.30 no.6
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    • pp.69-75
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    • 2015
  • Objectives : This study was designed to investigate effects of the combination with Korean Red Ginseng (Panax ginseng C.A. Meyer), Gastrodia Rhizoma (Gastrodia elata Blume) and Polygoni Multiflori Radix (Polygonum multiflorum Thunberg) on metabolic disorders including cholesterol and erectile dysfunction in hyperlipidemia rats.Methods : Animals were divided into six groups; Control with normal diet, high fat/cholesterol-diet (HFCD), fluvastatin, Korean Red Ginseng treated (KRG), and the combination treated (Korean Red Ginseng, Gastrodia Rhizoma and Polygoni Multiflori Radix; 1:1:1 for KGP1 and 2:1:1 for KGP2). The experimental groups initially received HFCD for 10 weeks and then treated orally with fluvastatin, KRG, KGP1 and KGP2 during the final 6 weeks. Erectile function was determined by the measurements of intracavernosal pressure (ICP) and maximal arterial pressure (MAP) after electrical stimulation of the cavernosal nerve.Results : KGP2 decreased the level of total cholesterol and LDL cholesterol in the sera of HFCD rats without no changes of body weights. KRG, KGP1 and KGP2 decreased the level of C-reactive protein (CRP) levels except of fluvastatin, synthetic HMG-CoA reductase inhibitor. KRG, KGP1 and KGP2 significantly increased the ICP, ICP/MAP ratio, area under the curve (AUC) compared with those of normal rat. Morphometric analyses showed that KRG, KGP1 and KGP2 increased the volume of smooth muscle and the regular arrangement of collagen fibers in corpus cavernosum of HFCD rats. The penile expression of eNOS was increased by KRG, KGP1 and KGP2.Conclusions : Based on these results, we suggest that the combination with Korean Red Ginseng, Gastrodia Rhizoma and Polygoni Multiflori may improve hyperlipidemia through regulating the lipid profiles and erectile dysfunction in rats.

한강하류지형면의 분류와 지형발달에 대한 연구 (양수리에서 능곡까지)

  • Park, No-Sik
    • Journal of the Speleological Society of Korea
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    • no.68
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    • pp.23-73
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    • 2005
  • Purpose of study; The purpose of this study is specifically classified as two parts. The one is to attempt the chronological annals of Quaternary topographic surface through the study over the formation process of alluvial surfaces in our country, setting forth the alluvial surfaces lower-parts of Han River area, as the basic deposit, and comparing it to the marginal landform surfaces. The other is to attempt the classification of micro morphology based on the and condition premising the land use as a link for the regional development in the lower-parts of Han river area. Reasons why selected the Lower-parts of Han river area as study objects: 1. The change of river course in this area is very serve both in vertical and horizontal sides. With a situation it is very easy to know about the old geography related to the formation process of topography. 2. The component materials of gravel, sand, silt and clay are deposited in this area. Making it the available data, it is possible to consider about not oかy the formation process of topography but alsoon the development history to some extent. 3. The earthen vessel, a fossil shell fish, bone, cnarcoal and sea-weed are included in the alluvial deposition in this area. These can be also valuable data related to the chronological annals. 4. The bottom set conglometate beds is also included in the alluvial deposits. This can be also valuable data related to the research of geomorphological development. 5. Around of this area the medium landform surface, lower landform surface, pediment and basin, are existed, and these enable the comparison between the erosion surfaces and the alluvial surfaces. Approach : 1. Referring to the change of river beds, I have calculated the vertical and horizontal differences comparing the topographic map published in 1916 with that published in 1966 and through the field work 2. In classifying the landform, I have applied the method of micro morphological classification in accordance with the synthetic index based upon the land conditions, and furthermore used the classification method comparing the topographic map published in 1916 and in that of 1966. 3. I have accorded this classification with the classification by mapping through appliying the method of classification in the development history for the field work making the component materials as the available data. 4. I have used the component materials, which were picked up form the outcrop of 10 places and bored at 5 places, as the available data. 5. I have referred to Hydrological survey data of the ministry of Construction (since 1916) on the overflow of Han-river, and used geologic map of Seoul metropolitan area. Survey Data, and general map published in 1916 by the Japanese Army Survbey Dept., and map published in 1966 by the Construction Research Laboratory and ROK Army Survey Dept., respectively. Conclusion: 1. Classification of Morphology: I have added the historical consideration for development, making the component materials and fossil as the data, to the typical consideration in accordance with the map of summit level, reliefe and slope distribution. In connection with the erosion surface, I have divided into three classification such as high, medium and low-,level landform surfaces which were classified as high and low level landform surfaces in past. furthermore I have divided the low level landform surface two parts, namely upper-parts(200-300m) and bellow-parts(${\pm}100m$). Accordingly, we can recognize the three-parts of erosion surface including the medium level landform surface (500-600m) in this area. (see table 22). In condition with the alluvial surfaces I have classified as two landform surfaces (old and new) which was regarded as one face in past. Meamwhile, under the premise of land use, the synthetic, micro morphological classification based upon the land condition is as per the draw No. 19-1. This is the quite new method of classification which was at first attempted in this country. 2. I have learned that the change of river was most severe at seeing the river meandering rate from Dangjung-ni to Nanjido. As you seee the table and the vertical and horizontal change of river beds is justly proportionable to the river meandering rate. 3. It can be learned at seeing the analysis of component materials of alluvial deposits that the component from each other by areas, however, in the deposits relationship upper stream, and between upper parts and below parts I couldn't always find out the regular ones. 4. Having earthern vessel, shell bone, fossil charcoal and and seaweeds includen in the component materials such as gravel, clay, sand and silt in Dukso and Songpa deposits area. I have become to attempt the compilation of chronicle as yon see in the table 22. 5. In according to hearing of basemen excavation, the bottom set conglomerate beds of Dukso beds of Dukso-beds is 7m and Songpa-beds is 10m. In according to information of dredger it is approx. 20m in the down stream. 6. Making these two beds as the standard beds, I have compared it to other beds. 7 The coarse sand beds which is covering the clay-beds of Dukso-beds and Nanjidobeds is shown the existence of so-called erosion period which formed the gap among the alluvial deposits of stratum. The former has been proved by the sorting, bedding and roundness which was supplied by the main stream and later by the branch stream, respectively. 8. If the clay-beds of Dukeo-bed and Songpa-bed is called as being transgressive overlap, by the Eustatic movement after glacial age, the bottom set conglomerate beds shall be called as being regressive overlap at the holocene. This has the closest relationship with the basin formation movement of Seoul besides the Eustatic movement. 9. The silt-beds which is the main component of deposits of flood plain, is regarded as being deposited at the Holocene in the comb ceramic and plain pottery ages. This has the closest relationship with the change of river course and river beds.

Recursive SPIHT(Set Partitioning in Hierarchy Trees) Algorithm for Embedded Image Coding (내장형 영상코딩을 위한 재귀적 SPIHT 알고리즘)

  • 박영석
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.4
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    • pp.7-14
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    • 2003
  • A number of embedded wavelet image coding methods have been proposed since the introduction of EZW(Embedded Zerotree Wavelet) algorithm. A common characteristic of these methods is that they use fundamental ideas found in the EZW algorithm. Especially, one of these methods is the SPIHT(Set Partitioning in Hierarchy Trees) algorithm, which became very popular since it was able to achieve equal or better performance than EZW without having to use an arithmetic encoder. In this paper We propose a recursive set partitioning in hierarchy trees(RSPIHT) algorithm for embedded image coding and evaluate it's effectiveness experimentally. The proposed RSPIHT algorithm takes the simple and regular form and the worst case time complexity of O(n). From the viewpoint of processing time, the RSPIHT algorithm takes about 16.4% improvement in average than the SPIHT algorithm at T-layer over 4 of experimental images. Also from the viewpoint of coding rate, the RSPIHT algorithm takes similar results at T-layer under 7 but the improved results at other T-layer of experimental images.

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Features of EEG Signal during Attentional Status by Independent Component Analysis in Frequency-Domain (독립성분 분석기법에 의한 집중 상태 뇌파의 주파수 요소 특성)

  • Kim, Byeong-Nam;Yoo, Sun-Kook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2170-2178
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    • 2014
  • In this paper, electroencephalographic (EEG) signal of one among subjects measured biosignal with visual evoked stimuli inducing the concentration was analyzed to detect the changes in the attention status during attention task fulfillment from January to February, 2011. The independent component analysis (ICA) was applied to EEG signals to isolate the attention related innate source signal within the brain and Electroculogram (EOG) artifact from measured EEG signals at the scalp. The consecutive accumulation of short time Fourier transformed (STFT) attention source signal with excluded EOG artifact can enhance the regular depiction of EPOCH graph and spectral color map representing time-varying pattern. The extracted attention indices associated with somatosensory rhythm (SMR: 12-15 Hz), and theta wave (4-7 Hz) increase marginally over time. Throughout experimental observation, the ICA with STFT can be used for the assessment of participants' status of attention.