• Title/Summary/Keyword: Temporal focusing

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Institutional Complement on In-Network Caching of Copyrighted Works (저작물의 In-network Caching에 관한 제도적 보완)

  • Cho, Eun-Sang;Hwang, Ji-Hyun;Kwon, Ted Tae-Kyoung;Choi, Yang-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.8C
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    • pp.703-710
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    • 2012
  • The new article, related to temporary copy on exploitation of copyrighted works, has been introduced in the copyright law as partly revised on December 2, 2011. While number of researches on in-network caching including Content-Centric Networking are conducted quite actively in recent years, the need for legal and institutional considerations has arisen since temporal storage (i.e. temporal copy) may be made not only at user devices but also in routers such as network equipments. This paper examines issues on temporary copy of copyrighted works mainly focusing on the articles and the related articles of the recently revised copyright law as well as the Free Trade Agreement between the Republic of Korea and the United States of America and further studies necessary institutions required to actualize in-network caching.

Effects of Financial Crises on the Long Memory Volatility Dependency of Foreign Exchange Rates: the Asian Crisis vs. the Global Crisis

  • Han, Young Wook
    • East Asian Economic Review
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    • v.18 no.1
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    • pp.3-27
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    • 2014
  • This paper examines the effects of financial crises on the long memory volatility dependency of daily exchange returns focusing on the Asian crisis in 97-98 and the Global crisis in 08-09. By using the daily KRW-USD and JPY-USD exchange rates which have different trading regions and volumes, this paper first applies both the parametric FIGARCH model and the semi-parametric Local Whittle method to estimate the long memory volatility dependency of the daily returns and the temporally aggregated returns of the two exchange rates. Then it compares the effects of the two financial crises on the long memory volatility dependency of the daily returns. The estimation results reflect that the long memory volatility dependency of the KRW-USD is generally greater than that of the JPY-USD returns and the long memory dependency of the two returns appears to be invariant to temporal aggregation. And, the two financial crises appear to affect the volatility dynamics of all the returns by inducing greater long memory dependency in the volatility process of the exchange returns, but the degree of the effects of the two crises seems to be different on the exchange rates.

Determination of Impact Source Location Using a Single Transducer and Time Reversal Technique (단일센서와 시간역전법을 이용한 판에서의 충격위치 결정에 관한 연구)

  • Jeong, Hyun-Jo;Cho, Sung-Jong
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.1
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    • pp.47-55
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    • 2012
  • A structural health monitoring technique for locating impact position in a plate structure is presented in this paper. The method employs a single sensor and spatial focusing of time reversal (TR) acoustics. We first examine the TR focusing effect at the impact position and its surroundings through simulation and experiment. The imaging results of impact points show that the impact source location can be accurately estimated in any position of the plate. Compared to existing techniques for locating impact or acoustic emission source, the proposed method has the benefits of using a single sensor and not requiring material properties and geometry of structures. Furthermore, it does not depend on a particular mode of dispersive Lamb waves that is frequently used in other ultrasonic testings of plate-like structures.

An Analysis on Spatio-Temporal Changes of Land Cover focusing on NDVI Using GIS and RS in Pyeongbuk Province, Northwest Korea (GIS와 RS를 이용한 토지피복 및 식생 분포의 시ㆍ공간적 변화 - 평안북도 서부 지역을 중심으로 -)

  • 이민부;김남신;최한성;신근하
    • Journal of the Korean Geographical Society
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    • v.38 no.5
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    • pp.835-848
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    • 2003
  • This study deals with the spatio-temporal change of land cover and vegetation distribution between 1988 and 2001 using remote sensing images and CIS techniques in west area of Pyeongbuk Province, northwest Korea. Landsat TM and ETM images are geometrically and radiometrically corrected for the analysis of land cover and NDVI. Forested areas are decreased during 13 year from 1988 to 2001 in study area including Sakju, Daegwan, Guseong and Euiju of Pyeongbuk Province, because wasteland are increased by human impact and denuded land by landslide and flooding. DEM analysis presents that settlement and cropland are developed toward higher and steeper mountain slope, together with decrease NDIV values. these changes have resulted from unplanned increase of cropland without consideration of geomorphic condition. Therefore, more researches and reasonable policies are required to protect forest and cropland and stable food supply against natural hazard like landslide.

Some Notes on the Temporal Single-System Interpretation of Marxian Value Theory (마르크스 가치론의 이시적 단일체계 해석에 대한 몇 가지 비판적 논점)

  • Park, Hyun Woong
    • 사회경제평론
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    • v.31 no.2
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    • pp.105-126
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    • 2018
  • In this paper, I makes some critical comments on the temporal single-system interpretation (TSSI) of Marxian value theory. The first concerns the claim that the Fundamental Marxian Theorem (FMT) holds within the TSSI under completely general conditions. Based on the idea that the nominal profit does not well fit the FMT, the TSSI proponents suggest that more relevant for proving the TSSI FMT is the real profit, defined by deflating the output prices. In contrast, I propose a more general approach where three possible concepts of profit are all considered, in which case the result is that whether the FMT holds within the TSSI is indeterminate. Second, the refutation of the Okishio theorem presented in Kliman (1996) is critically examined, focusing on the criticism raised in the literature that the Kliman model ignores the cost-reduction criterion as for the technical change and therefore cannot be considered as an internal refutation of the Okishio theorem. Drawing upon the criticism, I explicitly incorporate the cost-reduction criterion into the Kliman model and show that the continuous labor-saving technical change of the Kliman model is not necessarily cost-reducing and under certain conditions is cost-neutral or cost-raising.

Performance Evaluation of Machine Learning Algorithms for Cloud Removal of Optical Imagery: A Case Study in Cropland (광학 영상의 구름 제거를 위한 기계학습 알고리즘의 예측 성능 평가: 농경지 사례 연구)

  • Soyeon Park;Geun-Ho Kwak;Ho-Yong Ahn;No-Wook Park
    • Korean Journal of Remote Sensing
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    • v.39 no.5_1
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    • pp.507-519
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    • 2023
  • Multi-temporal optical images have been utilized for time-series monitoring of croplands. However, the presence of clouds imposes limitations on image availability, often requiring a cloud removal procedure. This study assesses the applicability of various machine learning algorithms for effective cloud removal in optical imagery. We conducted comparative experiments by focusing on two key variables that significantly influence the predictive performance of machine learning algorithms: (1) land-cover types of training data and (2) temporal variability of land-cover types. Three machine learning algorithms, including Gaussian process regression (GPR), support vector machine (SVM), and random forest (RF), were employed for the experiments using simulated cloudy images in paddy fields of Gunsan. GPR and SVM exhibited superior prediction accuracy when the training data had the same land-cover types as the cloud region, and GPR showed the best stability with respect to sampling fluctuations. In addition, RF was the least affected by the land-cover types and temporal variations of training data. These results indicate that GPR is recommended when the land-cover type and spectral characteristics of the training data are the same as those of the cloud region. On the other hand, RF should be applied when it is difficult to obtain training data with the same land-cover types as the cloud region. Therefore, the land-cover types in cloud areas should be taken into account for extracting informative training data along with selecting the optimal machine learning algorithm.

A Study on the Quality Evaluation Method of Spatial Database - Focusing on Land Database - (공간데이터베이스의 품질평가 방법에 관한 연구 - 토지데이터베이스를 중심으로 -)

  • 김미정;안종천;조우현
    • Spatial Information Research
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    • v.11 no.4
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    • pp.327-340
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    • 2003
  • Quality elements and evaluation methods should be considered according to the characteristics of spatial database. The purpose of this study is to propose specific methods for quality evaluation focusing on land database which are an important parts of spatial database. Through the study, of quality evaluation for selected quality elements are specified, which are based on the construction processes of the topogaphical database, cadastral database, and zoning database. Position accuracy, attribute accuracy, consistency, completeness, temporal accuracy, believability, and lineage are selected as the quality elements of land database. A various statistical and mathematical skills are proposed for measurement and assesment methods of quality elements.

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A Study of Aleksandr Vampilov's Play and Film (알렉산드르 밤필로프 희곡의 영상화 연구 《9월의 휴가》를 중심으로)

  • Ahn, Byong Yong
    • Cross-Cultural Studies
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    • v.29
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    • pp.7-24
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    • 2012
  • "Duck Hunting" is the most psychological play with unique structure written by Aleksandr Vampilov. The play describes protagonist hero's furious behavior with psychological instability, therefore, this play tends to be recognized as serious and complicated one. After the death of Vampilov, "Duck Hunting" was reproduced as a film, titled as "Vacation in September." This study is designed to shed light on the play's psychological-dramatic factors by focusing on the structure of narrative and spatial-temporal objet. Also, this study compared the screenshots of the play with their textual meanings, then concentrated on main character's psychological features. By focusing on protagonist hero's mind, this study tries to look into the features of the play and its meanings for modern period. The film's plot is a kind of story telling structure based on main character's memory. The short stories of main character represents that Jilov(main character's name)'s losing his own life. The audience can acknowledge that Jilov's life as a duck hunter who is cynical, ideological, lazy, and self-interest oriented person. This play provokes the audience to compare their life to Jilov's one because such comparison helps the audience recognize their lives as surplus style of life with nihilism. Jilov as a character represents one of Soviet's generation with the feeling of great loss in 1960s.

A comprehensive analysis of temporal characteristics in independent rainstorm events in Seoul: focusing on changes in unit time and secondary peak constant (서울특별시 내 독립 호우사상의 시간분포 특성 분석: 분 단위와 차첨두 상수의 조건 변화를 중심으로)

  • Cha, Hoyoung;Lee, Jinwook;Jun, Changhyun;Byun, Jongyun;Baik, Jongjin
    • Journal of Korea Water Resources Association
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    • v.56 no.11
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    • pp.785-799
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    • 2023
  • In this study, we proposed a new concept termed the Secondary Peak Constant (SPC) and discerned the temporal characteristics of independent rainstorm events based on unit time and SPC about 24 observation stations in Seoul. Utilizing rainfall observations from 2000 to 2022, independent rainstorm events discreted from rainfall data per unit time. The temporal characteristics of these events were derived according to unit time, and temporal characteristics of the peak rainfall were identified through the SPC. Finally, the temporal characteristics of independent rainstorm events were examined distinctively when analyzed by unit time and SPC. Independent rainstorm events with smaller unit time showed significantly larger total rainfall, rainfall duration, and rainfall intensity. The temporal characteristics of the largest peak rainfall (1st Peak) within independent rainstorm events followed a sequence of Q4>Q2>Q3>Q1. Additionally, the 2nd Peak rainfall predominantly occurred the location where the 1st Peak appeared. The proportion of independent rainstorm events with multiple peak rainfalls exceeded 50.0% when the SPC was 0.7 or lower. The average number of peak rainfalls within independent rainstorm events ranged from 1.5 to 3.4. This study identified the temporal characteristics of independent rainstorm events based on unit time. Then, the peak rainfall of temporal characteristics was quantified by SPC on this study. Hence, it is evident that the temporal characteristics of independent rainstorm events for specific area can be anlayzed and quantified based on unit time and SPC.

Ultra Wideband Channel Model for Indoor Environments

  • Alvarez, Alvaro;Valera, Gustavo;Manuel Lobeira;Torres, Rafael-Pedro;Garcia, Jose-Luis
    • Journal of Communications and Networks
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    • v.5 no.4
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    • pp.309-318
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    • 2003
  • This paper presents an in-depth study of a UWB indoor radio channel between 1 and 9 GHz, which was used for the subsequent development of a new statistical UWB multipath channel model, focusing on short range indoor scenarios. The channel sounding process was carried out covering different indoor environments, such as laboratories, halls or corridors. A combination of new and traditional parameters has been used to accurately model the channel impulse response in order to perform a precise temporal estimation of the received pulse shape. This model is designed specifically for UWB digital systems, where the received pulse is correlated with an estimated replica of itself. The precision of the model has been verified through the comparison with measured data from equivalent scenarios and cases, and highly satisfactory results were obtained.