• Title/Summary/Keyword: temporal difference

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Effect of Perceived Risk and Psychological Distance on Gift Purchase

  • KIM, Dong-Tae
    • Journal of Distribution Science
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    • v.18 no.3
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    • pp.99-106
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    • 2020
  • Purpose: The purpose of this study is to investigate the influence of perceived risk and psychological distance on purchase intention when purchasing a gift. It focuses on social distances and temporal distances, and aims to identify the interactions between these psychological distances and perceived risk. Data were collected through experiments. Research design, data and methodology: The experiment was carried out through the design of 2 (perceived risk: high/low) × 2 (social distance: far / near) × 2 (temporal distance: far / near) between-subjects design. Participants were 241 undergraduates from two universities in Chungnam and Gangwon, and randomly assigned to one of eight groups. Results: It was confirmed that there is a difference in purchase intention according to the risk perceived by consumers when purchasing a gift. In particular, the difference in purchase intention based on the risk perceived by the buyer was found to be greater as the social distance between the gift giver and the recipient is shorter. In addition, it was confirmed that the intention to purchase a gift was simultaneously influenced by three factors: social distance, perceived risk, and time remaining to purchase a gift. In other words, when both temporal distance and social distance were short, the difference in purchase intention according to perceived risk was greatest. Conclusions: The purpose of this study was to examine how the relationship between perceived risk and purchase intention when purchasing a gift varies with psychological distance. This study found that the closer the relationship between the gift purchaser and the beneficiary and the shorter the time remaining before the gift purchase, the greater the difference in the willingness to purchase due to the perceptual risk. In practice, the results of this study can be used to establish sales promotion strategies for various gift products. Above all, the closer the relationship between the gift buyer and the person receiving the gift, the more differentially there should be a guarantee program that can reduce or eliminate the risk perceived by the buyer. There is also a need to use step-by-step product recommendation programs that can reduce perceptual risk depending on the time remaining until a particular season, such as graduation or Christmas.

Multi Colony Intensification.Diversification Interaction Ant Reinforcement Learning Using Temporal Difference Learning (Temporal Difference 학습을 이용한 다중 집단 강화.다양화 상호작용 개미 강화학습)

  • Lee Seung-Gwan
    • The Journal of the Korea Contents Association
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    • v.5 no.5
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    • pp.1-9
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    • 2005
  • In this paper, we suggest multi colony interaction ant reinforcement learning model. This method is a hybrid of multi colony interaction by elite strategy and reinforcement teaming applying Temporal Difference(TD) learning to Ant-Q loaming. Proposed model is consisted of some independent AS colonies, and interaction achieves search according to elite strategy(Intensification, Diversification strategy) between the colonies. Intensification strategy enables to select of good path to use heuristic information of other agent colony. This makes to select the high frequency of the visit of a edge by agents through positive interaction of between the colonies. Diversification strategy makes to escape selection of the high frequency of the visit of a edge by agents achieve negative interaction by search information of other agent colony. Through this strategies, we could know that proposed reinforcement loaming method converges faster to optimal solution than original ACS and Ant-Q.

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Mapping Paddy Rice Varieties Using Multi-temporal RADARSAT SAR Images

  • Jang, Min-Won;Kim, Yi-Hyun;Park, No-Wook;Hong, Suk-Young
    • Korean Journal of Remote Sensing
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    • v.28 no.6
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    • pp.653-660
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    • 2012
  • This study classified paddy fields according to rice varieties and monitored temporal changes in rice growth using SAR backscatter coefficients (${\sigma}^{\circ}$). A growing period time-series of backscatter coefficients was set up for nine fine-beam mode RADARSAT-1 SAR images from April to October 2005. The images were compared with field-measured rice growth parameters such as leaf area index (LAI), plant height, fresh and dry biomass, and water content in grain and plants for 45 parcels in Dangjin-gun, Chungnam Province, South Korea. The average backscatter coefficients for early-maturing rice varieties (13 parcels) ranged from -18.17 dB to -6.06 dB and were lower than those for medium-late maturing rice varieties during most of the growing season. Both crops showed the highest backscatter coefficient values at the heading stage (late July) for early-maturing rice, and the difference was greatest before harvest for early-maturing rice. The temporal difference in backscatter coefficients between rice varieties may play a key role in identifying early-maturing rice fields. On the other hand, comparisons with field-measured parameters of rice growth showed that backscatter coefficients decreased or remained on a plateau after the heading stage, even though the growth of the rice canopy had advanced.

Experimental Observation of Temporal Dark Image Sticking in AC PDP with Face-to-Face Sustain Electrode Structure

  • Kim, Jae-Hyun;Park, Choon-Sang;Kim, Bo-Sung;Park, Ki-Hyung;Tae, Heung-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.617-620
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    • 2007
  • The temporal dark image sticking phenomena for both the face-to-face and coplanar sustain electrode structures were compared. For both structures, the temporal dark image sticking phenomena were examined by measuring the difference in the IR emission, display luminance, perceived luminance, and temperature between the image sticking and the no image sticking cells. For the face-to-face structure, the 10-min sustain discharge causes a small increment of the panel temperature thanks to the ITO-less electrode structure, thereby resulting in mitigating the temporal dark image sticking phenomenon.

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Resolution of Temporal-Multiplexing and Spatial-Multiplexing Stereoscopic Televisions

  • Kim, Joohwan;Banks, Martin S.
    • Current Optics and Photonics
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    • v.1 no.1
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    • pp.34-44
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    • 2017
  • Stereoscopic (S3D) displays present different images to the two eyes. Temporal multiplexing and spatial multiplexing are two common techniques for accomplishing this. We compared the effective resolution provided by these two techniques. In a psychophysical experiment, we measured resolution at various viewing distances on a display employing temporal multiplexing, and on another display employing spatial multiplexing. In another experiment, we simulated the two multiplexing techniques on one display and again measured resolution. The results show that temporal multiplexing provides greater effective resolution than spatial multiplexing at short and medium viewing distances, and that the two techniques provide similar resolution at long viewing distance. Importantly, we observed a significant difference in resolution at the viewing distance that is generally recommended for high-definition television.

Salient Motion Information Detection Method Using Weighted Subtraction Image and Motion Vector (가중치 차 영상과 움직임 벡터를 이용한 두드러진 움직임 정보 검출 방법)

  • Kim, Sun-Woo;Ha, Tae-Ryeong;Park, Chun-Bae;Choi, Yeon-Sung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.4
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    • pp.779-785
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    • 2007
  • Moving object detection is very important for video surveillance in modern days. In special case, we can categorize motions into two types-salient and non-salient motion. In this paper, we first calculate temporal difference image for extract moving objects and adapt to dynamic environments and next, we also propose a new algorithm to detect salient motion information in complex environment by combining temporal difference image and binary block image which is calculated by motion vector using the newest MPEG-4 and EPZS, and it is very effective to detect objects in a complex environment that many various motions are mixed.

Measurement of electron density of atmospheric pressure Ar plasma jet by using Michelson interferometer

  • Lim, Jun-Sup;Hong, Young June;Choi, Eun Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.195.1-195.1
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    • 2016
  • Currently, as Plasma application is expanded to the industrial and medical industrial, low temperature plasma applications became important. Especially in medical and biology, many researchers have studied about generated radical species in atmospheric pressure low temperature plasma directly adapted to human body. Therefore, so measurement their plasma parameter is very important work and is widely studied all around world. One of the plasma parameters is electron density and it is closely relative to radical production through the plasma source. some kinds of method to measuring the electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods have very expensive cost and complex configuration to composed of experiment system. We selected Michelson interferometer system which is very cheap and simple to setting up, so we tried to measuring electron density by laser interferometer with laser beam chopping module for measurement of temporal phase difference in plasma jet. To measuring electron density at atmospheric pressure Ar plasma jet, we obtained the temporal phase shift signal of interferometer. Phase difference of interferometer can occur because of change by refractive index of electron density in plasma jet. The electron density was able to estimate with this phase difference values by using physical formula about refractive index change of external electromagnetic wave in plasma. Our guiding laser used Helium-Neon laser of the centered wavelength of 632 nm. We installed chopper module which can make a 4kHz pulse laser signal at the laser front side. In this experiment, we obtained more exact synchronized phase difference between with and without plasma jet than reported data at last year. Especially, we found the phase difference between time range of discharge current. Electron density is changed from Townsend discharge's electron bombardment, so we observed the phase difference phenomenon and calculated the temporal electron density by using phase shift. In our result, we suggest that the electron density have approximately range between 1014~ 1015 cm-3 in atmospheric pressure Ar plasma jet.

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The Impact of Spatio-temporal Resolution of GEO-KOMPSAT-2A Rapid Scan Imagery on the Retrieval of Mesoscale Atmospheric Motion Vector (천리안위성 2A호 고속 관측 영상의 시·공간 해상도가 중규모 대기운동벡터 산출에 미치는 영향 분석)

  • Kim, Hee-Ae;Chung, Sung-Rae;Oh, Soo Min;Lee, Byung-Il;Shin, In-Chul
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.885-901
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    • 2021
  • This paper illustratesthe impact of the temporal gap between satellite images and targetsize in mesoscale atmospheric motion vector (AMV) algorithm. A test has been performed using GEO-KOMPSAT-2A (GK2A) rapid-scan data sets with a temporal gap varying between 2 and 10 minutes and a targetsize between 8×8 and 40×40. Resultsshow the variation of the number of AMVs produced, mean AMV speed, and validation scores as a function of temporal gap and target size. As a results, it was confirmed that the change in the number of vectors and the normalized root-mean squared vector difference (NRMSVD) became more pronounced when smaller targets are used. In addition, it was advantageous to use shorter temporal gap and smaller target size for the AMV calculation in the lower layer, where the average speed is low and the spatio-temporal scale of atmospheric phenomena is small. The temporal gap and the targetsize are closely related to the spatial and temporalscale of the atmospheric circulation to be observed with AMVs. Thus, selecting the target size and temporal gap for an optimum calculation of AMVsrequires considering them. This paper recommendsthat the optimized configuration to be used operationally for the near-real time analysis of mesoscale meteorological phenomena is 4-min temporal gap and 16×16 pixel target size, respectively.

Moving Object Extraction Using Spatio-Temporal Difference (시공간적 차를 이용한 동영상의 움직임 객체 추출)

  • 김동욱
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.8
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    • pp.1319-1324
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    • 2002
  • In this paper, we present a new technique for extraction of moving objects in moving image sequence. The detection method of change regions is based on spatial gradient difference and temporal difference. Moving objects are extracted by motion information and prediction error of each region. In the simulation results, the proposed technique shows good performance.

Multi-temporal Analysis of High-resolution Satellite Images for Detecting and Monitoring Canopy Decline by Pine Pitch Canker

  • Lee, Hwa-Seon;Lee, Kyu-Sung
    • Korean Journal of Remote Sensing
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    • v.35 no.4
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    • pp.545-560
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    • 2019
  • Unlike other critical forest diseases, pine pitch canker in Korea has shown rather mild symptoms of partial loss of crown foliage and leaf discoloration. This study used high-resolution satellite images to detect and monitor canopy decline by pine pitch canker. To enhance the subtle change of canopy reflectance in pitch canker damaged tree crowns, multi-temporal analysis was applied to two KOMPSAT multispectral images obtained in 2011 and 2015. To assure the spectral consistency between the two images, radiometric corrections of atmospheric and shadow effects were applied prior to multi-temporal analysis. The normalized difference vegetation index (NDVI) of each image and the NDVI difference (${\Delta}NDVI=NDVI_{2015}-NDVI_{2011}$) between two images were derived. All negative ΔNDVI values were initially considered any pine stands, including both pitch canker damaged trees and other trees, that showed the decrease of crown foliage from 2011 to 2015. Next, $NDVI_{2015}$ was used to exclude the canopy decline unrelated to the pitch canker damage. Field survey data were used to find the spectral characteristics of the damaged canopy and to evaluate the detection accuracy from further analysis.Although the detection accuracy as assessed by limited number of field survey on 21 sites was 71%, there were also many false alarms that were spectrally very similar to the damaged canopy. The false alarms were mostly found at the mixed stands of pine and young deciduous trees, which might invade these sites after the pine canopy had already opened by any crown damages. Using both ${\Delta}NDVI$ and $NDVI_{2015}$ could be an effective way to narrow down the potential area of the pitch canker damage in Korea.