• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.103-109
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• 2009

We build the web document recommending agent system which offers a certain amount of web documents to each user by monitoring and learning the user's action of web browsing. We also propose a method of query expansion using the Korean thesaurus. The queries to search for new web documents generate a candidate set using the Korean thesaurus. We extract the words which are mostly correlated with the queries, among the words in the candidate set, by using TF-IDF and mutual information. Then, we expand the query. If we adopt the system of query expansion, we can recommend a lot of web documents which have potential interests to users. We thus conclude that the system of query expansion is more effective than a base system of recommending web-documents to users.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.592-600
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• 2018

As the field of robots is evolving to intelligent robots that can replace even humans' mental or emotional labor, 'robot ethics' needed in relationship between humans and robots is becoming a crucial issue these days. The purpose of this study is to consider the ethics of robots and humans that is essential in this post-human age. It will deal with the followings as the main contents. First, with the cases of developing ethics software intended to make robots practice ethics, the authors begin this research being conscious about the matter of whether robots can really judge what is right or wrong only with the ethics codes entered forcibly. Second, regarding robot ethics, we should consider unethicality that might arise from learning data internalizing human biasness and also reflect ethical differences between countries or between cultures, that is, ethical relativism. Third, robot ethics should not be just about ethics codes intended for robots but reflect the new concept of 'human ethics' that allows humans and robots to coevolve.

• The KIPS Transactions:PartB
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• v.13B no.5 s.108
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• pp.533-540
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• 2006

The semantic web environment promise semantic search of heterogeneous data from distributed web page. Semantic search would resuit in an overwhelming number of results for users is increased, therefore elevating the need for appropriate personalized ranking schemes. Culture Finder helps semantic web agents obtain personalized culture information. It extracts meta data for each web page(culture news, culture performance, culture exhibition), perform semantic search and compute result ranking point to base user profile. In order to work efficient, Culture Finder uses five major technique: Machine learning technique for generating user profile from user search behavior and meta data repository, an efficient semantic search system for semantic web agent, query analysis for representing query and query result, personalized ranking method to provide suitable search result to user, upper ontology for generating meta data. In this paper, we also present the structure used in the Culture Finder to support personalized search service.

• Korean Journal of Pharmacognosy
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• v.51 no.1
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• pp.70-77
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• 2020

Mentha arvensis is used traditional medicine to treat various disorders. In the present study, M. arvensis were extracted by the solid-phase microextraction (SPME) method and analyzed by gas chromatograph-mass spectrometry (GC-MS). We investigated the protective effects and mechanisms of a M. arvensis extract on scopolamine-induced cognitive and memory impairment. Mice were orally pretreated with a M. arvensis extract or normal saline, and then behavior tests were conducted 30 min after scopolamine injection. The antioxidant capacities were analyzed by free radical scavenging (DPPH and ABTS). Acetylcholinesterase (AChE) activity were also measured using Ellman's method ex vivo test. In behavior tests, percent of spontaneous alteration, escape latency and swimming time in target quadrant were improved by the administration of the M. arvensis extract, which suggests that the M. arvensis extract improves memory function in the scopolamine-treated mice model. In addition, M. arvensis extract showed inhibition of the free radical and AChE activity. The results of the present study suggest that the M. arvensis extract ameliorates scopolamine-induced cognitive and memory deficits through the inhibition of free radicals and AChE activity. Therefore, M. arvensis may be a promising neuroprotective agent for management of learning and memory improvements in human dementia patients.

• The Korean Journal of Food And Nutrition
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• v.33 no.3
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• pp.347-355
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• 2020

Cognitive impairment is considered to be key research topics in the field of neurodegenerative diseases and in understanding of learning and memory. In the present study, we investigated neuroprotective effects of Schisandra chinensis (SC) and Ribes fasciculatum (RF) extracts in hydrogen peroxide-induced neuronal cell death in vitro and scopolamine-induced cognitive impairment in Sprague Dawley^® (SD) rat in vivo. Apoptotic cell death in neuroblastic PC12 cell line was induced by hydrogen peroxide for 1 hour at 100 μM. However, mixture of SC and RF treatment prevented peroxide induced PC12 cell death with no neurotoxic effects. For in vivo experiment, the effect of SC and RF extracts on scopolamine-induced cognitive impairment in SD rat was evaluated by spontaneous alternation behavior in Y-Maze test. After 30 min scopolamine injection, the scopolamine-induced rats presented significantly decreased % spontaneous alteration and acetylcholine level, compared to non-induced group. However, treatment of SC+RF extracts rescued the reduced % spontaneous alteration with acetylcholine concentration from hippocampus in scopolamine-induced rats. These results suggested that mixture of SC and RF extract may be a potential natural therapeutic agent for the prevention of cognitive impairment.

• The Journal of Internal Korean Medicine
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• v.36 no.4
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• pp.507-517
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• 2015

The bark of Magnolia officinalis has been used in traditional oriental medicine to treat a variety of mental disorders including anxiety and depression. The purpose of this study was to examine the effect of M. officinalis ethanol extract on stress-induced alterations in learning and cognitive function using a passive avoidance test (PAT) and also on anxiety-related behavior using the elevated plus-maze test (EPM) in female rats . The degree of Tyrosine hydroxylase (TH) in the region of the ventral tegmental area (VTA) and the locus coeruleus (LC) was measured using an immunohistochemical method. Corticosterone concentrations in serum were also measured. The ethanol extract from Magnolia officinalis was orally administered to female rats 30 minutes before evaluating their immobilization stress and anxiety-related behavior using an elevated plus-maze test and a passive avoidance test. Time spent in the open arms of the EPM increased in the M. officinalis-treated group compared with that of the saline-treated control group. In the passive avoidance test, the memory and cognitive function improved in the M. officinalis extract-treated group. M. officinalis extracts reduced elevated corticosterone concentrations in serum. Also, stress-induced TH increases were suppressed in the M. officinalis extract-treated group in the LC and the VTA region. These results suggest that M. officinalis might prove to be an effective anxiolytic anti-stress agent.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2001.12a
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• pp.69-73
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• 2001

Two opioid peptides, YPLDL and YPLDLF, were isolated from enzymatic digests of spinach ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO) and named rubiscolin-5 and -6, respectively. These peptides were selective for delta-receptor and the latter was about 3 times more potent than the former. After oral administration in mice at the dose of 100 mg/kg, rubiscolin-6 showed analgesic activity in tail pinch test. It also stimutated learning performance at the same dose in passive avoidance experiment using step-through apparatus. An immunostimulating peptide, MITLAIPVNKPGR, was isolated from a trypsin digest of soybean protein and named soymetide. Immunostimulating activy of soymetide was mediated by fMLP receptor. Interestingly, after oral administration in rats at a dose of 300 mg/kg (po.), soymetide-4 (MITL) protected alopecia (hair-loss) induced by etoposide, a cancer chemotherapy agent. Stimulation of IL-1 release by the peptide was involved in the mechanism. Ovokinin(2-7), RADHPF, is a vasorelaxing peptide released from ovalbumin by the action of chymotrypsin. It lowered blood pressure of spontaneously hypersensive rats (SHR) after oral administration at a dose of 10 mg/kg. RPLKPW, which was designed by replacing 4 amino acid residues in ovokinin(2-7), exhibited hypotensive activity at a dose of 0.1 mg/kg (po.). This peptides was introduced into 3 homologous sites in soybean beta-conglycinin alpha' subunit by site-directed mutagenesis of the cDNA and expressed in E. coli. The minimum effective dose for hypotensive activity of the genetically modified beta-conglycinin alpha' subunit was 10 mg/kg (po.), which is about 1/200 that of ovalbumin.

• Genomics & Informatics
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• v.14 no.2
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• pp.53-61
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• 2016

Toxoplasma gondii is an intracellular Apicomplexan parasite and a causative agent of toxoplasmosis in human. It causes encephalitis, uveitis, chorioretinitis, and congenital infection. T. gondii invades the host cell by forming a moving junction (MJ) complex. This complex formation is initiated by intermolecular interactions between the two secretory parasitic proteins-namely, apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2) and is critically essential for the host invasion process. By this study, we propose two potential leads, NSC95522 and NSC179676 that can efficiently target the AMA1 hydrophobic cleft, which is a hotspot for targeting MJ complex formation. The proposed leads are the result of an exhaustive conformational search-based virtual screen with multilevel precision scoring of the docking affinities. These two compounds surpassed all the precision levels of docking and also the stringent post docking and cumulative molecular dynamics evaluations. Moreover, the backbone flexibility of hotspot residues in the hydrophobic cleft, which has been previously reported to be essential for accommodative binding of RON2 to AMA1, was also highly perturbed by these compounds. Furthermore, binding free energy calculations of these two compounds also revealed a significant affinity to AMA1. Machine learning approaches also predicted these two compounds to possess more relevant activities. Hence, these two leads, NSC95522 and NSC179676, may prove to be potential inhibitors targeting AMA1-RON2 complex formation towards combating toxoplasmosis.

• Journal of Information Processing Systems
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• v.11 no.3
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• pp.370-388
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• 2015

The localization of multi-agents, such as people, animals, or robots, is a requirement to accomplish several tasks. Especially in the case of multi-robotic applications, localization is the process for determining the positions of robots and targets in an unknown environment. Many sensors like GPS, lasers, and cameras are utilized in the localization process. However, these sensors produce a large amount of computational resources to process complex algorithms, because the process requires environmental mapping. Currently, combination multi-robots or swarm robots and sensor networks, as mobile sensor nodes have been widely available in indoor and outdoor environments. They allow for a type of efficient global localization that demands a relatively low amount of computational resources and for the independence of specific environmental features. However, the inherent instability in the wireless signal does not allow for it to be directly used for very accurate position estimations and making difficulty associated with conducting the localization processes of swarm robotics system. Furthermore, these swarm systems are usually highly decentralized, which makes it hard to synthesize and access global maps, it can be decrease its flexibility. In this paper, a simple pyramid RAM-based Neural Network architecture is proposed to improve the localization process of mobile sensor nodes in indoor environments. Our approach uses the capabilities of learning and generalization to reduce the effect of incorrect information and increases the accuracy of the agent's position. The results show that by using simple pyramid RAM-base Neural Network approach, produces low computational resources, a fast response for processing every changing in environmental situation and mobile sensor nodes have the ability to finish several tasks especially in localization processes in real time.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.160-167
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• 2019

Depression is a major mood disorder. Abnormal expression of glial glutamate transporter-1 (GLT-1) is associated with depression. Schisantherin B (STB) is one bioactive of lignans isolated from Schisandra chinensis (Turcz.) Baill which has been commonly used as a traditional herbal medicine for thousands of years. This paper was designed to investigate the effects of STB on depressive mice induced by forced swimming test (FST). Additionally, we also assessed the impairment of FST on cognitive function in mice with different ages. FST and open field test (OFT) were used for assessing depressive symptoms, and Y-maze was used for evaluating cognition processes. Our study showed that STB acting as an antidepressant, which increased GLT-1 levels by promoting PI3K/AKT/mTOR pathway. Although the damage is reversible, short-term learning and memory impairment caused by FST test is more serious in the aged mice, and STB also exerts cognition improvement ability in the meanwhile. Our findings suggested that STB might be a promising therapeutic agent of depression by regulating the GLT-1 restoration as well as activating PI3K/AKT/mTOR pathway.