• KIISE Transactions on Computing Practices
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• v.22 no.1
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• pp.44-49
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• 2016

Recently, data has been growing dramatically along with the growth of social media and digital devices. A distributed memory processing system has been used to efficiently process large amounts of data. However, if a load is concentrated in a certain node in distributed environments, a node performance significantly degrades. In this paper, we propose a load balancing scheme to distribute load in a distributed memory environment. The proposed scheme replicates hot data to multiple nodes for managing a node's load and migrates the data by considering the load of the nodes when nodes are added or removed. The client reduces the number of accesses to the central server by directly accessing the data node through the metadata information of the hot data. In order to show the superiority of the proposed scheme, we compare it with the existing load balancing scheme through performance evaluation.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.4
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• pp.302-306
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• 2011

Objectives : To investigate the cognitive functions of pediatric cancer patients and to test the hypotheses that the impairment of processing speed and working memory are more prevalent in children with medulloblastoma (MBL) compared to children with neuroblastoma (NBL). Methods : We gave the Korean version of the Wechsler Intelligent Scale for Children-III to 21 children with MBL and 24 children with NBL during outpatient follow-up after the treatment was completed. Results : Children with MBL showed below average performance across most of the sub-tests. The full scale IQ, verbal IQ, and performance IQ of children with MBL were significantly lower than those of children with NBL. There were significant differences between two groups in coding and Digit Span subtest scores. Children with MBL performed especially poorly in the coding subtest. Conclusion : These findings support previous reports of generally low IQ and the dysfunction of processing speed and working memory among children with MBL, a kind of central nervous system tumor. Further investigation is needed to determine how the deficit of processing speed and working memory affect neurocognitive development and general intelligent functions.

• Journal of Oriental Neuropsychiatry
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• v.17 no.3
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• pp.21-43
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• 2006

This study was designed to assess Effects of jingansikpungtanggagam-bang on Central Nerve System. Method : jingansikpungtanggagam-bang, a Korean traditional prescription, was evaluated for its anticonvulsant effect, hypnotic activity, analgesic action, anxiolytic effect, memory enhancement, and MAO inhibitory activity and detennined the content of neurotransmitter in brain by HPLC method. Result : 1. The extract increased potently anticonvulsant effect at 1g/kg by 5.6-fold extention of onset time against control group. 2. The extract increased hvrmsis at 500mg/kg by over twofold length of sleeping time compared to control. 3. The extract showed a significant analgesic effect with 86.0% inhibition on writhing frequency at 500mg/kg by phenylquinone-induced writhing test. 4. The extract inhibited dose-dependently the activity of monoamine oxidase in vitro. 5. This prescription increased the brain levels of serotonin and 5-hydroxyindoleacetic acid by 3.3% and 1.4%, respectively. 6. the extract exhibited the anxiolytic effect with 21.3% decrease of the immobility duration against control group. 7. the extract enhanced memory recovery on scopolamine-induced impairment of passive avoidance performance at 1g/kg pretreatment with 20.2% increase of latency time. Conclusion : The result sugguest that jiugansikpungtanggagam-bang can be used effectively as a sedative prescription in Korean traditional medicine.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3185-3199
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• 2018

Middle- and old-aged driver's capability in recognition for driving scene elements was compared. Central and ambient stimuli were selected from natural driving scene and sensitivity, bias and reaction time were measured as dependent measures. The results are as follows. First, in general, older drivers showed lower sensitivity than middle-aged drivers. In particular, the older drivers' sensitivity was significantly lower for the ambient stimuli than central stimuli, whereas the middle-aged drivers showed no significant difference between the two types of stimuli. Second, the older drivers tended to show more lenient responses whereas the middle-aged drivers responded more conservatively. Third, the older drivers showed longer reaction time than the middle-aged drivers, in particular, in the responses of miss and correct rejection. This results suggested that the older drivers' retention for driving scene elements in their working memory may not be stable, which can be resulted in difficulties in rapid and accurate responses in a real life driving.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.335-342
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• 2005

The effects of ginsenosides Rg$_3$(R) , Rg$_3$(S) and Rg$_5$/Rk$_1$ (a mixture of Rg$_5$ and Rk$_1$ 1:1, w/w), which are components isolated from processed Panax ginseng C.A. Meyer (Araliaceae), on memory dysfunction were examined in mice using a passive avoidance test. The ginsenosides Rg3(R), Rg3(S) or Rg$_5$/Rk$_1$, when orally administered for 4 days, significantly ameliorated the memory impairment induced by the single oral administration of ethanol. The memory impairment induced by the intraperitoneal injection of scopolamine was also significantly recovered by ginsenosides Rg3(S) and Rg$_5$/Rk$_1$. Among the three ginsenosides tested in this study, Rg$_5$/Rk$_1$ enhanced the memory function of mice most effectively in both the ethanol­and scopolamine-induced amnesia models. Moreover, the latency period of the Rg$_5$/Rk$_1$­treated mice was 1.2 times longer than that of the control (no amnesia) group in both models, implying that Rg$_5$/Rk$_1$ may also exert beneficial effects in the normal brain. We also evaluated the effects of these ginsenosides on the excitotoxic and oxidative stress-induced neuronal cell damage in primary cultured rat cortical cells. The excitotoxicity induced by glutamate or N­methyl-D-aspartate (NMDA) was dramatically inhibited by the three ginsenosides. Rg$_3$(S) and Rg$_5$/Rk$_1$ exhibited a more potent inhibition of excitotoxicity than did Rg$_3$(R). In contrast, these ginsenosides were all ineffective against the H$_2$O$_2$- or xanthine/xanthine oxidase-induced oxidative neuronal damage. Taken together, these results indicate that ginsenosides Rg$_3$(S) and Rg$_5$/Rk$_1$ significantly reversed the memory dysfunction induced by ethanol or scopolamine, and their neuroprotective actions against excitotoxicity may be attributed to their memory enhancing effects.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.2101-2101
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• 2001

Near-infrared spectroscopy is now being used in clinical diagnosis as a non-invasive monitor of tissue oxygenation state. However, due to lack of the optical pathlength information within tissues, it is still difficult to quantitate the hemoglobin concentration with present CW techniques. Time-resolved spectroscopy (TRS), which measures temporal profiles of emerging light from tissues, enables to estimate the pathlength distribution within tissues by converting time to distance. Consequently, quantitative measurement of tissue oxygenation is possible by analyzing the data with optical diffusion equation 1) or our Microscopic Beer-Lambert law2). Time-Resolved Spectroscopy System : TRS-1O3) Our TRS-10 system consists of a three-wavelength (759, 797, 833 nm) PLP as pulsed light source, a high speed PMT with high sensitivity and three signal-processing circuits for time-resolved measurement (CFD/TAC, A/D converter and histogram memory). Optical pulse train consisting of 759, 797 and 833nm is generated by PLP at 5㎒ repetition rate and irradiated a sample through a single optical fiber. The diffuse-reflected light from the sample is collected by a bundle fiber and then detected by the PMT for single photon measurement. After being amplified by a following fast amplifier, the electrical signals for each wavelength are picked out by CFD/TAC module. Then, a signal processing circuit integrated the TRS data for each wavelength individually. The simultaneous TRS measurement for three wavelengths achieved without any optical or mechanical switch. Experiment and Results Input and detection fibers of TRS-10 were attached at the human forehead with a fiber separation of 3cm. TRS measurements were continuously performed for about 20 minutes including 2 minutes hyper ventilation. It was observed that the total hemoglobin concentration was decreasing during the hyper ventilation and recovered until 2 minutes after hyper ventilation. On the other hand, the deoxy-hemoglobin concentration began to increase after hyper ventilation and had its peak at around 2 minute later, showing 502 drop from 75% to 60% due to inhibition of breathing by performing hyper ventilation. The results showed that this system might be able to quantitate the concentrations of oxy- and deoxy-hemoglobin in the human brain.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.23-34
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• 2023

Purpose: This study aims to investigate the force delivery profile of thermoformed aligners (TFA) compared with direct-printed aligners (DPA) and to explore the effect of different activation amounts on forces and moments of respective groups. A secondary objective is to observe the amount of stress relaxation that occurs over the 7~14 days when aligners are maintained in a simulated intraoral environment. Materials and Methods: An in vitro setup was created to quantify forces and moments. It consisted of a three dimensional-printed base plate and segmented maxillary teeth, placed in a semi-enclosed chamber to maintain a temperature of 37℃. Ninety clear aligners were divided into nine groups of ten aligners each based on material types (Zendura, ATMOS, TC-85) and activation amounts. Aligners were created with 0.00, 0.25- and 0.50-mm activations for lingual bodily movement of the upper left central incisor and kept on models in the "stressed" position in a 37℃ water bath. Three force components acting on the upper left lateral incisor, upper left central incisor, and upper right central incisor were measured for each time point, beginning from the initial baseline measurement, 8 hours, 16 hours, 24 hours, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, and lastly, 14 days. Result: TC-85 aligners in every activation group showed less force on teeth than Zendura and ATMOS. Significant force levels from 0.0 mm activation were present and stayed consistent over the course of 14 days. Comparisons made for baseline measurements to 7-days and 14-days showed statistically significant change from the baseline force level. Conclusion: TC-85 aligners demonstrated lower, more consistent forces with fewer side effects. Aligners can generate forces even when no activation is programmed. No major decreases in force levels over time were observed; the intra-oral clinical simulated environment and length of observation time could contribute to this.

• Korean Journal of Cognitive Science
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• v.21 no.4
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• pp.559-602
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• 2010

This study examines the concepts and functional characteristics of consciousness in comparison of memory and attention from the perspective of information processing. It also provides an understanding of the relationships between the three as hypothetical constructs. Consciousness is regarded as too ambiguous a concept to be understood and accepted as a mental construct without the inclusion of memory and attention in any conceptualization. We need one criterion to count satisfactorily as an explanation of consciousness in information processing. Consciousness would be a subjective awareness of momentary experience and also have the characteristic of an operating system performing control and consolidation in information processing. This could be called cognitive consciousness which refers to a subjective awareness and an executive control system, even though those are not equivalent concepts. Consciousness, memory and attention, three mental constructs could operate dependently or independently depending on the specific tasks conditioned in many information processing levels whose modules with three mental constructs could operate in hierarchy. In this premise, working memory could not be a unitary system, contrary to those of Baddeley and Hitch(1974) and Baddeley(1992, 2000), just being a mental workplace consisting of two components: the phonological loop, and the visual-spatial sketchpad without the episodic buffer and a central executive which are the characteristics of consciousness. In the continuum of information processing, the conscious processes and the unconscious processes seem not to be totally different and contrasting processes.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.1
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• pp.37-47
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• 2008

Exploitation of address generation units which are typically provided in DSPs plays an important role in DSP code generation since that perform fast address computation in parallel to the central data path. Offset assignment is optimization of memory layout for program variables by taking advantage of the capabilities of address generation units, consists of memory layout generation and address pointer assignment steps. In this paper, we propose an effective address pointer assignment method to minimize the number of address calculation instructions in DSP code generation. The proposed approach reduces the time complexity of a conventional address pointer assignment algorithm with fixed memory layouts by using minimum cost-nodes breaking. In order to contract memory size and processing time, we employ a powerful pruning technique. Moreover our proposed approach improves the initial solution iteratively by changing the memory layout for each iteration because the memory layout affects the result of the address pointer assignment algorithm. We applied the proposed approach to about 3,000 sequences of the OffsetStone benchmarks to demonstrate the effectiveness of the our approach. Experimental results with benchmarks show an average improvement of 25.9% in the address codes over previous works.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.89-91
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• 2004

In SCADA systems, an RTU is a device installed at a remote location that collects data, codes the data into a format that is transmittable and transmits the data back to a central station, or MTU. An RTU also collects information from the master device and implements processes that are directed by master device. RTUs are equipped with input channels for sensing or metering, output channels for control, indication or alarms and a communications port. In general, the data are transmitted via a wired communication infrastructure such as RS422 or RS485 between RTU and MTU. But, limited range of wired communication doesn't allow the system to cover remote areas over the limitation, and building a wired communication network is not easy in the circumstances. In this Paper, we design and implement a smart cost-effective Web-RTU that can communicate with MTU via Web. Web is of benefit to the Web-RTU, because it is not only free from the distance limitations, but also is built easily and cost-effectively wherever Internet resources are available. Additionally, Web can be easily applied to the SCADA system with the development of hardware and software for communications. The Web-RTU has a program memory, a data memory and a RAM inside, and uses Atmega128, low-cost 8 bit micro-processor with eight AI(Analog Input). It performs well enough to implement all existing roles of RTU.