• Korean Journal of Optics and Photonics
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• v.9 no.6
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• pp.368-372
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• 1998

A 16-views 3 dimensional imaging system is designed by spatially combinding two 8-views time multiplexed image channels. Each 8-views channel composed of 3 primary color CRTs and a dichroic beam splitter which combining the three CRTs as one channel. Each CRT displays 8-view images time sequentially. These images are projected to a holographic screen of a size 1$\times$0.8 $m^2$ through a projection optics. Characteristics of the three different configurations of projection optics are examined with the optics designing program "DEMOS" to select an optimized projection optics for the system. The configulation of the optimized projection optics is found like following; images from each channel combined by two-fold mirror are projected by a projection objective through a 16-strips LCD shutter. In this configuration, the shutter should be located at the entrance pupil of the objective, and the folded edge of the two-fold mirror should contact symmetrically to the center line of the shutter.e shutter.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.87-96
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• 2006

Selectivity estimation is one of the query optimization techniques. It is difficult for the previous selectivity estimation techniques for moving objects to apply the position change of moving objects to synopsis. Therefore, they result in much error when estimating selectivity for queries, because they are based on the extended spatial synopsis which does not consider the property of the moving objects. In order to reduce the estimation error, the existing techniques should often rebuild the synopsis. Consequently problem occurs, that is, the whole database should be read frequently. In this paper, we proposed a moving object histogram method based on quad tree to develop a selectivity estimation technique for moving object queries. We then analyzed the performance of the proposed method through the implementation and evaluation of the proposed method. Our method can be used in various location management systems such as vehicle location tracking systems, location based services, telematics services, emergency rescue service, etc in which the location information of moving objects changes over time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.717-731
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• 2011

To clarify relationships between the abundance and biological characteristics of Pacific salmon Oncorhynchus spp., we analyzed spatiotemporal changes in fork length, body weight, and an index of relative abundance (catch per unit effort, CPUE) for pink salmon (O. gorbuscha), chum salmon (O. keta), and sockeye salmon (O. nerka) collected by research gill-nets from the T/V Oshoro-maru and the T/V Hokusei-maru of Hokkaido University in the North Pacific during 1953-2007. Populations of each species were distributed throughout the western Bering Sea, eastern Bering Sea (EB), western North Pacific (WNP), central North Pacific (CNP), eastern North Pacific (ENP), and Okhotsk Sea. Since 1970, the average body size of chum salmon at ocean ages 0.3-0.4 has generally declined in the WNP and CNP. However, the average body sizes of sockeye and pink salmon have not shown temporal changes. Chum salmon showed significant negative (positive) correlations between CPUE and body size for populations in CNP (ENP) at ocean ages 0.2-0.3 (age 0.1) for both sexes. In general, sockeye salmon also showed significant negative (positive) correlations between CPUE and body size for populations in the EB at ocean ages X.2-X.3 (age X.1) for both sexes, except in CNP at age 2. Our results suggest that better growth by chum and sockeye salmon in the early periods of their ocean life histories might produce higher abundance. This higher abundance, which might also be affected by overlapping distributions among Pacific salmon species and populations in certain seas, in turn appears to cause density-dependent declines in growth in the following ocean life history period due to the limited carrying capacity of the seas. To understand complex dynamics in Pacific salmon species in the North Pacific Ocean, research on interactions among species and populations is needed.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.1
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• pp.172-183
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• 2012

In 2011, floods were at the worst stage of devastation in Chao Phraya river basin of Thailand. The purpose of this study is to trace the flood inundation area around Chao Phraya river basin by using Terra MODIS image because it has the ability of spatiotemporal dynamics. The MODIS indices, which included the enhanced vegetation index(EVI), land surface water index(LSWI), and the difference in the values of EVI and LSWI(DVEL), were extracted from MODIS product MOD09 8-day composite datasets with a spatial resolution of 500m from Jul. 29, 2011 to Jan. 09, 2012. We found that combined application of EVI, LSWI, and DVEL was suitable for monitoring flood inundation. For the extracted flood inundation area and water-related area. The result can be used to acquire the flood inundation data scattered and demonstrate the potential for the use of MODIS data for temporal and spatial detection of flood effects.

• IMMUNE NETWORK
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• v.11 no.1
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• pp.1-10
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• 2011

Interleukin-7 (IL-7) is an essential cytokine for T cells. However, IL-7 is not produced by T cells themselves such that T cells are dependent on extrinsic IL-7. In fact, in the absence of IL-7, T cell development in the thymus as well as survival of naive T cells in the periphery is severely impaired. Furthermore, modulating IL-7 availability in vivo either by genetic means or other experimental approaches determines the size, composition and function of the T cell pool. Consequently, understanding IL-7 expression is critical for understanding T cell immunity. Until most recently, however, the spatiotemporal expression of in vivo IL-7 has remained obscured. Shortage of such information was partly due to scarce expression of IL-7 itself but mainly due to the lack of adequate reagents to monitor IL-7 expression in vivo. This situation dramatically changed with a recent rush of four independent studies that describe the generation and characterization of IL-7 reporter mice, all utilizing bacterial artificial chromosome transgene technology. The emerging consensus of these studies confirmed thymic stromal cells as the major producers of IL-7 but also identified IL-7 reporter activities in various peripheral tissues including skin, intestine and lymph nodes. Strikingly, developmental and environmental cues actively modulated IL-7 reporter activities in vivo suggesting that IL-7 regulation might be a new mechanism of shaping T cell development and homeostasis. Collectively, the availability of these new tools opens up new venues to assess unanswered questions in IL-7 biology in T cells and beyond.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.6
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• pp.49-58
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• 2002

Based on electrophysiological retina mechanism, a retina model is proposed, which has similar response characteristics compared with the real primate retina. Photoreceptors, horizontal cells, and bipolar cells are modeled based on the previously studied retina models. And amacrine cells known to have relation to movements detection, and bipolar cell terminals are newly modeled using 3 NDP mechanism. The proposed model verified by analyzing the spatial response characteristics to stationary and moving stimuli, and characteristics for different speeds. Through this retina model, human vision system could be applied to computer vision systems for movement detection, and it could be the basic research for the implantable artificial retina.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1797-1806
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• 2014

By far, groundwater management has been conducted by 'safe yield' policy based on the estimation of annual average of groundwater recharge throughout the world. However, as groundwater recharge show spatiotemporal variation, dynamic analysis must be carried out to evaluate the sustainable groundwater resources. In this study, an integrated surface-groundwater model, SWAT-MODFLOW was used to compute the spatial distribution of groundwater recharge in Gyungju region. Frequency analysis is adopted to evaluate the existing values of potential amount of groundwater development which is made by the 10 year drought frequency rainfall multiplied by recharge coefficient. The conservative methods for estimating recharge rates of 10 year drought frequency in subbains are newly suggested and compared with the existing values of potential amount of groundwater development. This process will promote the limitations for existing precesses used for computing potential amount of groundwater development.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1193-1201
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• 2016

In epidemiology or etiology, we are often interested in identifying areas of elevated risk, so called, hot spot or cluster. Many existing clustering methods only tend to a result if there exists any clustering pattern in study area. Recently, however, lots of newly introduced clustering methods can identify the location, size, and shape of clusters and test if the clusters are statistically significant as well. In this paper, one of most commonly used clustering methods, scan statistic, and its implementation SaTScan software, which is freely available, will be introduced. To exemplify the usage of SaTScan software, we used cancer data from the SEER program of National Cancer Institute of U.S.A.We aimed to help researchers and practitioners, who are interested in spatial cluster detection, using female lung cancer mortality data of the SEER program.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.574-577
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• 2007

We have measured the excited Xe atoms density in the $1s_5$ metastable states by laser absorption spectroscopy in counter discharged type AC-PDP. This experiment has shown the characteristic of the excited Xe atoms density which is relation to the visible light efficiency of PDP. The density of counter discharged AC-PDP have measured to be $9.47\;{\times}\;10^{13}\;cm{-3}$. The result has been shown to higher value than $1.45\;{\times}\;10^{13}\;cm^{-3}$ of conventional AC-PDP.

• Journal of Korean Dental Science
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• v.10 no.2
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• pp.45-52
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• 2017

Calcium has versatile roles in diverse physiological functions. Among these functions, intracellular $Ca^{2+}$ plays a key role during the secretion of salivary glands. In this review, we introduce the diverse cellular components involved in the saliva secretion and related dynamic intracellular $Ca^{2+}$ signals. Calcium acts as a critical second messenger for channel activation, protein translocation, and volume regulation, which are essential events for achieving the salivary secretion. In the secretory process, $Ca^{2+}$ activates $K^+$ and $Cl^-$ channels to transport water and electrolyte constituting whole saliva. We also focus on the $Ca^{2+}$ signals from intracellular stores with discussion about detailed molecular mechanism underlying the generation of characteristic $Ca^{2+}$ patterns. In particular, inositol triphosphate signal is a main trigger for inducing $Ca^{2+}$ signals required for the salivary gland functions. The biphasic response of inositol triphosphate receptor and $Ca^{2+}$ pumps generate a self-limiting pattern of $Ca^{2+}$ efflux, resulting in $Ca^{2+}$ oscillations. The regenerative $Ca^{2+}$ oscillations have been detected in salivary gland cells, but the exact mechanism and function of the signals need to be elucidated. In future, we expect that further investigations will be performed toward better understanding of the spatiotemporal role of $Ca^{2+}$ signals in regulating salivary secretion.