• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1183-1185
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• 2017

사물인터넷 기술의 사용이 증가하고 있으나 장치 및 플랫폼의 종류가 다양하여 한 번 구현한 응용 프로그램을 재사용하기 어렵다. 사물인터넷 장치에서 가상기계를 사용하여 이러한 문제점을 해결할 수 있지만 가상기계의 응용 프로그램 실행 속도는 네이티브 코드에 비해 속도가 느려 가상기계의 실행 속도를 개선할 필요가 있다. AoT 컴파일은 바이트코드를 네이티브 코드로 사전에 컴파일하여 가상기계의 실행 속도를 향상시키는 기법이다. 본 논문에서는 IoT-Cloud 융합 가상기계 시스템을 위한 AoT 컴파일 시스템을 설계한다. 설계한 시스템은 사물인터넷과 클라우드의 융합 환경에 적합하며, 바이트코드 중 일부만을 네이티브 코드로 컴파일하므로 네이티브 코드 로드에 의한 가상기계의 메모리 부담이 적다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.9A
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• pp.1525-1534
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• 2001

국내 통신사업자들이 xDSL 등 초고속 인터넷 액세스 서비스를 왜곡된 요금구조로 경쟁적으로 보급함에 따라 급속히 확산되고 있으나, 엄밀히 원가를 감안한다면 여전히 AO/DI는 인터넷 트래픽 폭증으로 인한 전기통신망의 과부하를 통신사업자가 경제적이며 효과적으로 대처할 수 있는 현실적인 대안이라 할 수 있다. 본 논문은 AO/DI의 동적 채널 할당 및 해지에 있어서 VIA가 권고한 정책보다 효율적으로 대역폭을 할당, 해지할 수 있는 알고리즘을 제안한다. 관찰 시점까지의 누적된 트래픽의 양과 변화를 감안하여 평균 트래픽과 분산을 추정함으로써 트래픽의 변화에 적응하여 채널 할당, 해지 시점을 결정할 수 있으며 트래픽 특성에 따라 매개 변수의 조정을 통하여 D 채널, B 채널의 이용률을 제어할 수 있고 평균 대기시간 등의 성능을 최적화할 수 있음을 보인다. 또한, 이를 기초로 응용 프로토콜을 감지하여 응용이 갖는 고유의 트래픽 특성과 요구사항에 적합한 채널 할당/해지 방안도 제시한다.

• Journal of the Korean Geographical Society
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• v.49 no.5
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• pp.675-689
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• 2014

This study applied Ensemble Empirical Mode Decomposition(EEMD), a new methodology to define the timing of spring onset over the Republic of Korea and to examine its spatio-temporal change. Also this study identified the relationship between spring onet timing and some atmospheric variations, and figured out synoptic factors which affect the timing of spring onset. The averaged spring onset timing for the period of 1974-2011 was 11th, March in Republic of Korea. In general, the spring onset timing was later with higher latitude and altitude regions, and it was later in inland regions than in costal ones. The correlation analysis has been carried out to find out the factors which affect spring onset timing, and global annual mean temperature, Arctic Oscillation(AO), Siberian High had a significant correlation with spring onset timing. The multiple regression analysis was conducted with three indices which were related to spring onset timing, and the model explained 64.7%. As a result of multiple regression analysis, the effect of annual mean temperature was the greatest and that of AO was the second. To find out synoptic factors affecting spring onset timing, the synoptic analysis has been carried out. As a result the intensity of meridional circulation represented as the major factor affect spring onset timing.

• Food Science and Preservation
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• v.18 no.3
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• pp.397-406
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• 2011

To industrialize meju, four kinds of meju (Korean-style soybean koji) were made with humidity-controlled fermentation for 12 days at $28^{\circ}C$ after they were inoculated with selected strains such as Aspergillus otyzae (AO meju), Aspergillus sojae (AS meju), combined Aspergillus sojae and Bacillus subtilis (ASBS meju), and combined Aspergillus oryzae and Bacillus subtilis (AOBS meju) as starter microorganisms. The changes in the quality characteristics in the four kinds of meju were investigated during fermentation. Their enzyme activities were compared with those of the traditional meju that is made in Sunchang Folk Village according to the traditional method. In the meju that were inoculated with selective strains, the aerobic bacteria counts and mold counts exceeded 8 log cfu/g and 6 log cfu/g respectively, which were the highest fermentation values after 2 days. The aerobic bacteria counts were maintained from 2-day to the 12-day fermentation. The mold counts tended to decreased gradually after the 2-day fermentation. The amino-type nitrogen contents reached 430.5-577.5 mg%, which were the highest values after 2-day fermentation. The neutral protease activities of these mejus had the highest levels in the following order: traditional meju, $1,258.0{\pm}38.8$; AS meju, $1,238.3{\pm}38.6$; AO meju. $1,204.1{\pm}24.1$; ASBS meju, $1,040.6{\pm}10.6$; and AOBS meju, $1,033.5{\pm}11.2$ unit/g. The acidic protease activities of these meju had the highest levels in the following order: AO meju, $1,030.1{\pm}19.1$, traditional meju, $1,007.7{\pm}30.5$; AS meju, $990.9{\pm}25.0$; AOBS meju, $910.9{\pm}15.3$; and ASBS meju, $888.2{\pm}15.7$ unit/g.

• Journal of the Korean earth science society
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• v.36 no.3
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• pp.199-209
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• 2015

The Atlantic meridional overturning circulation (AMOC), driven by high density water sinking around Greenland serves as a global climate regulator, because it transports heat and materials in the climate system. We analyzed the mechanism of AMOC on a decadal time scale simulated with the HadGEM2-AO model. The lead-lag regression analysis with AMOC index shows that the decadal variability of the thermohaline circulation in the Atlantic Ocean can be considered as a self-sustained variability. This means that the long-term change of AMOC is related to the instability which is originated from the phase difference between the meridional temperature gradient and the ocean circulation. When the overturning circulation becomes stronger, the heat moves northward and decreases the horizontal temperature-dominated density gradients. Subsequently, this leads to weakening of the circulation, which in turn generates the anomalous cooling at high latitudes and, thereby strengthening the AMOC. In this mechanism, the density anomalies at high latitudes are controlled by the thermal advection from low latitudes, meaning that the variation of the AMOC is thermally driven and not salinity driven.

• Korean Journal of Cognitive Science
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• v.24 no.4
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• pp.339-363
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• 2013

The age of acquisition effect is the phenomenon in which the words acquired early in life are processed better than the words acquired later in life. Age of acquisition and word frequency are critical factors in lexical processing. In this study we examined the age of acquisition effects in Hangul word recognition. In Experiment 1, we examined the AoA effects in word naming and lexical decision tasks. The results showed that there was an interaction between task and age of acquisition. The AoA effects appeared only in the lexical decision task. In Experiment 2, we examined the relationship between age of acquisition and word frequency in the lexical decision task. The results showed that the two variables were significant. The early-acquired words were processed better than the words acquired later, and the words with high frequency were processed better than the words with low frequency. However, there was no interaction between the two variables. In Experiment 3, we examined how phonological changes in Hangul words influence the AoA effects. The results show that the AoA effects were similar whether phonological changes occur or not. Our results are discussed in terms of several theoretical hypotheses.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.4
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• pp.171-176
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• 2008

Heat shock proteins (HSPs) serve as molecular chaperones and play a role in cell protection from damage in response to stress stimuli. The aim of this article is to investigate whether HSP22 affects IL-8 expression in vascular smooth muscle cells (VSMCs), and which cellular factors are involved in the HSP-mediated IL-8 induction in that cell type in terms of mitogen activated protein kinase (MAPK) and transcription element. Exposure of aortic smooth muscle cells (AoSMCs) to HSP22 not only enhanced IL-8 release but also induced IL-8 transcript via promoter activation. HSP22 activated ERK and p38 MAPK in AoSMCs. HSP22-induced IL-8 release was inhibited by U0126, but not by SB202190. A mutation in the IL-8 promoter region at the binding site of NF-${\kappa}$ B, but not AP-1 or C/EBP, impaired promoter activation in response to HSP22. Delivery of I ${\kappa}$ B, but not dominant negative c-Jun, lowered HSP22-induced IL-8 release from AoSMCs. These results suggest that HS P22 induces IL-8 in VSMCs via ERK1/2, and that transcription factor NF-kB may be required for the HSP22-induced IL-8 up-regulation.

• Journal of Families and Better Life
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• v.29 no.6
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• pp.9-25
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• 2011

This study was performed to explore the factors that affect debt-use intention of young defaulters. In addition, this study compares three models that predict the intention to use debt by young defaulters: the theory of reasoned action and two variations of it. Specifically, this study proposes an extended theory of reasoned action by introducing Ao in place of the cognitive structure in the theory of reasoned action. In addition, this study proposes Ao as an independent variable that acts on BI rather than a dependent variable. Self-administered questionnaires were completed by 196 young defaulters attending a credit management education session held by the Credit Counseling & Recovery Service in Kwang-ju, Korea. Based on the study, the conclusions are as follows: the extended theory of reasoned action as proposed in this article most suitably explained the intention to use debt by young defaulters. It was also found that young defaulters were affected by attitudes toward debt, attitudes toward using debt, and subjective norms. It is therefore suggested that an attitudinal message would change the behavior effectively for young defaulters. The findings appeared to support the usefulness of the extended theory of reasoned action and the role of Ao as an independent variable as proposed in this article to explain the intention to use debt by young defaulters. These findings have an important theoretical meaning in that they modify two existing attitude theories in the context of consumer behavior.

• Tuberculosis and Respiratory Diseases
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• v.87 no.1
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• pp.52-64
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• 2024

Chronic respiratory diseases such as idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, and respiratory infections injure the alveoli; the damage evoked is mostly irreversible and occasionally leads to death. Achieving a detailed understanding of the pathogenesis of these fatal respiratory diseases has been hampered by limited access to human alveolar tissue and the differences between mice and humans. Thus, the development of human alveolar organoid (AO) models that mimic in vivo physiology and pathophysiology has gained tremendous attention over the last decade. In recent years, human pluripotent stem cells (hPSCs) have been successfully employed to generate several types of organoids representing different respiratory compartments, including alveolar regions. However, despite continued advances in three-dimensional culture techniques and single-cell genomics, there is still a profound need to improve the cellular heterogeneity and maturity of AOs to recapitulate the key histological and functional features of in vivo alveolar tissue. In particular, the incorporation of immune cells such as macrophages into hPSC-AO systems is crucial for disease modeling and subsequent drug screening. In this review, we summarize current methods for differentiating alveolar epithelial cells from hPSCs followed by AO generation and their applications in disease modeling, drug testing, and toxicity evaluation. In addition, we review how current hPSC-AOs closely resemble in vivo alveoli in terms of phenotype, cellular heterogeneity, and maturity.

• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.167-176
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• 2022

Adaptive optics (AO) systems compensate for atmospheric disturbance, especially phase distortion, by introducing counter-wavefront deformation calculated from real-time wavefront sensing or prediction. Because AO system implementations are time-consuming and costly, it is highly desirable to estimate the system's performance during the development of the AO system or its parts. Among several techniques, we mostly apply statistical analysis, computational simulation, and optical-bench tests. Statistical analysis estimates performance based on the sum of performance variances due to all design parameters, but ignores any correlation between them. Computational simulation models every part of an adaptive optics system, including atmospheric disturbance and a closed loop between wavefront sensor and deformable mirror, as close as possible to reality, but there are still some differences between simulation models and reality. The optical-bench test implements an almost identical AO system on an optical bench, to confirm the predictions of the previous methods. We are currently developing an AO system for a 1.6-m ground telescope using a deformable mirror that was recently developed in South Korea. This paper reports the results of the statistical analysis and computer simulation for the system's design and confirmation. For the analysis, we apply the Strehl ratio as the performance criterion, and the median seeing conditions at the Bohyun observatory in Korea. The statistical analysis predicts a Strehl ratio of 0.31. The simulation method similarly reports a slightly larger value of 0.32. During the study, the simulation method exhibits run-to-run variation due to the random nature of atmospheric disturbance, which converges when the simulation time is longer than 0.9 seconds, i.e., approximately 240 times the critical time constant of the applied atmospheric disturbance.