• Journal of Life Science
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• v.29 no.10
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• pp.1120-1125
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• 2019

The short-lived nematode Caenorhabditis elegans has been used as a model organism for many studies, including lifespan extension. To screen common seaweeds for natural anti-aging agents, the lifespan of C. elegans (N2 wild-type strain) was measured by its hatch rate, growth rate, survival rate, chemotaxis, brood size, and egg-laying time after exposure to nematode growth medium (NGM) containing seaweed extracts. Approximately 30 animals synchronized at the first larval stage were incubated until they reached their adult stages before laying their eggs and were transferred to fresh NGM every 3 days. We also identified the major active compound from the seaweed by gas chromatography-mass spectrometry and tested its optimal dose for longevity. Of 13 common seaweed species, an ethanol extract of the brown seaweed Hizikia fusiformis showed the greatest effect on hatching, growth, and survival rates. The lifespan of C. elegans was significantly expanded 1.54-fold and 1.23-fold in the presence of the ethanol extract (0.05 mg/ml) and the main active component, fucosterol (0.05 mg/ml), respectively. Exposure to the ethanol extract also increased chemotaxis 1.13-fold, decreased brood size 0.74-fold, and shortened egg-laying time 0.96-fold. These results suggest that the aquaculturable H. fusiformis may be a promising source of a diet supplement to support health care.

• Journal of Intelligence and Information Systems
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• v.23 no.4
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• pp.111-126
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• 2017

Recommender systems based on association rule mining significantly contribute to seller's sales by reducing consumers' time to search for products that they want. Recommendations based on the frequency of transactions such as orders can effectively screen out the products that are statistically marketable among multiple products. A product with a high possibility of sales, however, can be omitted from the recommendation if it records insufficient number of transactions at the beginning of the sale. Products missing from the associated recommendations may lose the chance of exposure to consumers, which leads to a decline in the number of transactions. In turn, diminished transactions may create a vicious circle of lost opportunity to be recommended. Thus, initial sales are likely to remain stagnant for a certain period of time. Products that are susceptible to fashion or seasonality, such as clothing, may be greatly affected. This study was aimed at expanding association rules to include into the list of recommendations those products whose initial trading frequency of transactions is low despite the possibility of high sales. The particular purpose is to predict the strength of the direct connection of two unconnected items through the properties of the paths located between them. An association between two items revealed in transactions can be interpreted as the interaction between them, which can be expressed as a link in a social network whose nodes are items. The first step calculates the centralities of the nodes in the middle of the paths that indirectly connect the two nodes without direct connection. The next step identifies the number of the paths and the shortest among them. These extracts are used as independent variables in the regression analysis to predict future connection strength between the nodes. The strength of the connection between the two nodes of the model, which is defined by the number of nodes between the two nodes, is measured after a certain period of time. The regression analysis results confirm that the number of paths between the two products, the distance of the shortest path, and the number of neighboring items connected to the products are significantly related to their potential strength. This study used actual order transaction data collected for three months from February to April in 2016 from an online commerce company. To reduce the complexity of analytics as the scale of the network grows, the analysis was performed only on miscellaneous goods. Two consecutively purchased items were chosen from each customer's transactions to obtain a pair of antecedent and consequent, which secures a link needed for constituting a social network. The direction of the link was determined in the order in which the goods were purchased. Except for the last ten days of the data collection period, the social network of associated items was built for the extraction of independent variables. The model predicts the number of links to be connected in the next ten days from the explanatory variables. Of the 5,711 previously unconnected links, 611 were newly connected for the last ten days. Through experiments, the proposed model demonstrated excellent predictions. Of the 571 links that the proposed model predicts, 269 were confirmed to have been connected. This is 4.4 times more than the average of 61, which can be found without any prediction model. This study is expected to be useful regarding industries whose new products launch quickly with short life cycles, since their exposure time is critical. Also, it can be used to detect diseases that are rarely found in the early stages of medical treatment because of the low incidence of outbreaks. Since the complexity of the social networking analysis is sensitive to the number of nodes and links that make up the network, this study was conducted in a particular category of miscellaneous goods. Future research should consider that this condition may limit the opportunity to detect unexpected associations between products belonging to different categories of classification.

• The Journal of Korean Academy of Sensory Integration
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• v.7 no.1
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• pp.27-36
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• 2009

Introduction : Occupational therapists commonly use clinical observation to assess neuromuscular function witch is a fundamental component of sensory integration function. Clinical Observation of Motor and Postural Skills (COMPS) is a standardized assessment with seven items and used to screen if a child's problem is due to neuromuscular and sensory integration system. However, developmental standard of the test need to be validated with Korean children. Objective : This study is purposed to propose developmental standard of the COMPS for Korean children. Method : Seven to nine years old students (76 male and 70 female) participated in this study. In order to find out any difference by gender and age, the data was analyzed using t-test and ANOVA. Results : There is no significant difference by gender for all other items except Prone Extension Position (PEP). There is significant difference between children who are 7 years old and those who are 9 years old for Slow Motion(SM), Finger-Nose Touching (FNT), Asymmetrical Tonic Neck Reflex (ATNR), Supine Flexion(SF). There is also significant difference between those who are 8 years old and 9 years old for SM, FNT, ATNR. However, there is no significant difference between those who are 7 years and 8 years old. Conclusions : This study examines any difference in neuromuscular characteristics by age among school-aged children, based on the COMPS. The result of this study will provide a good evidence to establish developmental standard of COMPS for Korean children. It issuggested to continue further standardization work of the COMPS in order to establish a developmental standard for Korean children.

• The Journal of Korean Academy of Sensory Integration
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• v.7 no.1
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• pp.37-46
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• 2009

Background : Theory of Sensory Integration (SI) was initially developed with an effort to understand children's behavior by Jean Ayres and has been evolved with extensive research by occupational therapist practitioners and researchers since in the latter of the 20 century. With extension of recognition to SI, various professions begin to refer their clients who are children with sensory integration dysfunction. Upon those referrals, occupational therapists normally use Short Sensory Profile (SSP) to screen and decide whether SI therapeutic intervention is needed or not. Objective : Purpose of this study is (1) to examine any difference between different age groups and genders for children who are seven to nine years old; (2) to compare the score results of those Korean children with the original Standard which is established for American children: and (3) to compare tendency of response for each item between children with- and without SI dysfunction. This study was intended to validate test items of the SSP and determine whether the original standard of SSP is applicable for Korean children. Method : 155 students (81 for male, 74 for female) underwent SI evaluation using the Korean-translated SSP. 52 student (22 for male, 30 for female) were 7 years old, 54 students (32 for male, 22 for female) were 8 years old, 49 students (27for male, 22 for female) were 9 years old. Results : There is no significant difference of SSP score by neither age nor gender. In comparison the average score and sensory integrative disorder with the American Standard, there is significant difference on score of sub-item and total score. For six items, there is no significant difference on the tendency of response between children with- and without SI dysfunction. Conclusions : It is concluded that the original standard is suitable for Korean children aged seven to nine. The six test items that children without SI dysfunction shown similar tendency to respond are questionable to be appropriate as screening test item. It is suggested to proceed to do further item analysis study and extend the study to broad age groups, so develop the most appropriate Standard of SSP for Korean children.