• Title/Summary/Keyword: The development of technology

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Analysis on the Characteristics of Ventilation and Cooling for Greenhouses Constructed in Reclaimed Lands (간척지 온실의 환기 및 냉방 특성 분석)

  • Nam, Sang-Woon;Shin, Hyun-Ho
    • Journal of Bio-Environment Control
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    • v.26 no.3
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    • pp.181-187
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    • 2017
  • The purpose of this study was to provide basic data for development of environmental design technology for greenhouses constructed in reclaimed lands. The climatic conditions around seven major reclaimed land areas with a plan to install advanced horticultural complexes in Korea were analyzed. The characteristics of natural ventilation and temperature rise through the thermal environment measurement of the greenhouse in Saemangeum were analyzed. The part to be applied to the environmental design of the greenhouses in reclaimed lands were reviewed. Results of comparing the ventilation rate of the greenhouse according to the presence or absence of plants showed the greenhouse with plants had the lower ventilation rate, but the smaller rise of indoor temperature due to the evapotranspiration of plants. In the greenhouse with plants, the number of air changes was in the range of 0.3 to 0.9 volumes/min and the average was 0.7 volumes/min. The rise of indoor temperature relative to outdoor temperature was in the range of 1 to $5^{\circ}C$ and the average $2.5^{\circ}C$. The natural ventilation performance of the experimental greenhouse constructed in the reclaimed land almost satisfied the recommended ventilation rate in summer and the rise of indoor temperature relative to outdoor temperature did not deviate considerably from the cultivation environment of plants. Therefore, it was determined that the greenhouse cultivation in Saemangeum reclaimed land is possible with only natural ventilation systems without cooling facilities. As the reclaimed land is located in the seaside, the wind is stronger than the inland area, and the fog is frequent. This strong wind speed increases the ventilation rate of greenhouses, which is considered to be a factor for reducing the cooling load. In addition, since the fog duration is remarkably longer than that of inland area, the seasonal cooling load is expected to decrease, which is considered to be advantageous in terms of the operation cost of cooling facilities.

Analysis of the Effects of E-commerce User Ratings and Review Helfulness on Performance Improvement of Product Recommender System (E-커머스 사용자의 평점과 리뷰 유용성이 상품 추천 시스템의 성능 향상에 미치는 영향 분석)

  • FAN, LIU;Lee, Byunghyun;Choi, Ilyoung;Jeong, Jaeho;Kim, Jaekyeong
    • Journal of Intelligence and Information Systems
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    • v.28 no.1
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    • pp.311-328
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    • 2022
  • Because of the spread of smartphones due to the development of information and communication technology, online shopping mall services can be used on computers and mobile devices. As a result, the number of users using the online shopping mall service increases rapidly, and the types of products traded are also growing. Therefore, to maximize profits, companies need to provide information that may interest users. To this end, the recommendation system presents necessary information or products to the user based on the user's past behavioral data or behavioral purchase records. Representative overseas companies that currently provide recommendation services include Netflix, Amazon, and YouTube. These companies support users' purchase decisions by recommending products to users using ratings, purchase records, and clickstream data that users give to the items. In addition, users refer to the ratings left by other users about the product before buying a product. Most users tend to provide ratings only to products they are satisfied with, and the higher the rating, the higher the purchase intention. And recently, e-commerce sites have provided users with the ability to vote on whether product reviews are helpful. Through this, the user makes a purchase decision by referring to reviews and ratings of products judged to be beneficial. Therefore, in this study, the correlation between the product rating and the helpful information of the review is identified. The valuable data of the evaluation is reflected in the recommendation system to check the recommendation performance. In addition, we want to compare the results of skipping all the ratings in the traditional collaborative filtering technique with the recommended performance results that reflect only the 4 and 5 ratings. For this purpose, electronic product data collected from Amazon was used in this study, and the experimental results confirmed a correlation between ratings and review usefulness information. In addition, as a result of comparing the recommendation performance by reflecting all the ratings and only the 4 and 5 points in the recommendation system, the recommendation performance of remembering only the 4 and 5 points in the recommendation system was higher. In addition, as a result of reflecting review usefulness information in the recommendation system, it was confirmed that the more valuable the review, the higher the recommendation performance. Therefore, these experimental results are expected to improve the performance of personalized recommendation services in the future and provide implications for e-commerce sites.

The Development of Students' Scientific Perspectives on Historical Heritages through the Science Field Trip of Hwasong Fortress (수원 화성 과학 탐방을 통한 문화재에 대한 과학적 안목 형성 지도)

  • Choi, Jae-Hyeok;Pak, Sung-Jae
    • Journal of The Korean Association For Science Education
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    • v.24 no.5
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    • pp.930-936
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    • 2004
  • Science field trip on historical heritages in Korea has developed since 1998. There are a few discussion of effectiveness of science field trip on historical heritages. In this research, the aim of science field trip on historical heritages was discussed in view of developing scientific perspectives on historical heritages with cases of science field trip of Hwasong fortress. Material for science field trip of Hwasong fortress was developed and instructional strategy was designed. The material contained convergent and divergent scientific inquiry activities. The goal of the activity was to help students to build scientific perspectives on the historical heritage, so they can evaluate the scientific excellency of historical heritage. The subjects were ten ninth grade students of middle school science club in Seoul. A questionnaire, "evaluation of scientific excellency of historical heritage" was administered before and after the field trip. From the analysis of a change in perspective by field trip, it was investigated how the scientific perspective on historical heritages was developed. The first draft of material for science field trip of Hwasong fortress was developed based on science education experts' discussion. The material has three parts; activities before the trip, activities during the trip and activities after trip. Instructor's guide has the same structure. Before the field trip, students watched the videotape and learned the short history lesson about Hwasong fortress to develop familiarity. During the trip, there were exploring stage and intensive inquiring stage. These activities were designed to develop scientific perspective on historical heritage. After the field trip, evaluation activity about scientific value of Hwasong was done based on the activities done during the trip. After the science field trip of Hwasong fortress, most of students showed positive changes. Some of them reflected on their previous thoughts. Some recognized the necessity of the proper criteria for scientific excellency of historical heritage. All changed in their perspective on evaluating scientific aspects on historical heritage, such as considering the social environment, scientific principles and the influence of science and technology of that age on the society, when the fortress was built. These results show that the science field trip focused on the criteria for evaluating the scientific excellency of historical heritage was significant in helping students to develop the scientific perspective on historical heritage.

A Study on the Development and usefulness of the x/y Plane and z Axis Resolution Phantom for MDCT Detector (MDCT 검출기의 x/y plane과 z축 분해능 팬텀 개발 및 유용성에 관한 연구)

  • Kim, Yung-Kyoon;Han, Dong-Kyoon
    • Journal of the Korean Society of Radiology
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    • v.16 no.1
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    • pp.67-75
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    • 2022
  • The aim of this study is to establish a new QC method that can simultaneously evaluate the resolution of the x/y plane and the z-axis by producing a phantom that can reflect exposure and reconstruction parameter of MDCT system. It was used with Aquilion ONE(Cannon Medical System, Otawara, Japan), and the examination was scanned using of 120 kV, 260 mA, and the D-FOV of 300 mm2. It produced new SSP phantom modules in which two aluminum plates inclined at 45° to a vertical axis and a transverse axis to evaluate high contrast resolution of x/y plane and z axis. And it changed factors such as the algorithm, distance from gantry iso-center. All images were reconstructed in five steps from 0.6 mm to 10.0 mm slice thickness to measure resolution of x/y plane and z-axis. The image data measured FWHM and FWTM using Profile tool of Aquarius iNtusion Edition ver. 4.4.13 P6 software(Terarecon, California, USA), and analysed SPQI and signal intensity by ImageJ program(v1.53n, National Institutes of Health, USA). It decreased by 4.09~11.99%, 4.12~35.52%, and 4.70~37.64% in slice thickness of 2.5 mm, 5.0 mm, and 10.0 mm for evaluating the high contrast resolution of x/y plane according to distance from gantry iso-center. Therefore, the high contrast resolution of the x/y plane decreased when the distance from the iso-center increased or the slice thickness increased. Additionally, the slice thicknesses of 2.5 mm, 5.0 mm, and 10.0 mm with a high algorithm increased 74.83, 15.18 and 81.25%. The FWHM was almost constant on the measured SSP graph for evaluating the accuracy of slice thickness which represents the resolution of x/y plane and z-axis, but it was measured to be higher than the nominal slice thickness set by user. The FWHM and FWTM of z-axis with axial scan mode tended to increase significantly as the distance increased from gantry iso-center than the helical mode. Particularly, the thinner slice thickness that increased error range compare with the nominal slice thickness. The SPQI increased with thick slice thickness, and that was closer to 90% in the helical scan than the axial scan. In conclusion, by producing a phantom suitable for MDCT detectors and capable of quantitative resolution evaluation, it can be used as a specific method in the management of research quality and management of outdated equipment. Thus, it is expected to contribute greatly to the discrimination of lesions in the field of CT imaging.

A Study on Ecological Characteristics and Changes of Vegetation in Hamyangsangrim (함양상림 식생의 생태적 특성 변화 연구)

  • Kim, Dong-Wook;Lee, Seung-Joo;Lee, Soo-Dong;Kim, Ji-Seok;Han, Bong-Ho
    • Korean Journal of Environment and Ecology
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    • v.26 no.4
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    • pp.537-549
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    • 2012
  • The purpose of this study was to provide data for the basic research to found the effective conservation and management plan for the Hamyangsangrim designated as Natural Monument No. 154 and surround areas by analyzing the ecological characteristics such as landuse and actual vegetation, plant community structure, soil chemical property and also to identify the tendency of the ecosystem changes through comparison with past studies. According to analysis the results, the landuse and actual vegetation of survey site was classified as 8 types which were forest, artificial greenspace, plaza and open-space, bare ground and the pavement, water bodies, facilities, agricultural land and etc.. It was also categorized as 38 types according to detailed characteristic. 15 kinds of forest vegetation community types comprising silva were classified among them. The changes of actual vegetation showed little variation that the Quercus serrata-Carpinus tschonoskii forest was the most widely distributed in 2003(forest area ratio is 48.3%) and 2010(forest area ratio is 48.1%), whereas, the Quercus serrata forest declined a more dramatic from 11.6% to 23.2%. The Quercus serrata-Carpinus tschonoskii forest increased sharply(11.6% ${\rightarrow}$ 23.2%) and also the Quercus serrata-Zelkova serrata forest increased steadily(2.2% ${\rightarrow}$ 7.9%). The agricultural land around forest was transformed into artificial green zone. Moreover, water bodies, bare ground and the pavement of areas have increased. In addition, the urbanized area has decreased because the damaged areas inside forest have been restored to the woodlands. According to the result of typical 6 types vegetation communities change, the middle layer trees grew up to the canopy layer trees and was formed the canopy layer structure. The middle layer trees expanded their forces widely. Also new species appeared. And the shrub individuals also more dramatically increased due to the growth of shrubs. The force of Quercus serrata declined as well. However the force of Carpinus tschonoskii and Zelkova serrata expanded and increased in the forest. It must be the result of the ecological vegetation succession and environmentally soundly health recovery by influence of the projects of forest surrounding environment improvement and limitation of access to forest have managed and maintained since 2003. Those sorts of changes seems to be going to develop continuously. In the future Carpinus tschonoskii and Zelkova serrata will not be only codominant in the canopy layer but also Carpinus Tschonoskii, Zelkova serrata, Meliosma myriantha, Sapium japonicum. Styrax obassia and Acer pseudo-sieboldianum will be codominant in the middle layer. As a result, the forest's codominance species are going to be changed such like that.

Effects of NaCl Concentration on Mycelial Growth and Fruiting Body Yields of Oyster Mushrooms, Pleurotus spp. (NaCl의 농도가 병재배 느타리버섯 균사생장 및 자실체수량에 미치는 영향)

  • Jhune, Chang-Sung;Sul, Hwa-Jin;Kong, Won-Sik;You, Young-Bok;Kim, Jin-Ho;Cheong, Jong-Chun;Lee, Chan-Jung
    • Journal of Mushroom
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    • v.7 no.4
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    • pp.173-181
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    • 2009
  • These studies were investigated for effect of concentration of sodium chloride on occurrence and growth of fruitbody in oyster mushroom, Pleurotus ostreatus. When the mycelia were inoculated and cultured on the PDA plate added with the different concentrations of sodium chloride, the growth of them were not affected at the concentration of 0.5%, started to decrease at 1.0% as compared with the PDA plate without sodium chloride, and they did not grow at 5.0%. When tested at the column filled with sawdust, the tendency was similar, but the decreasing rate of mycelial growth was gentle. In sawdust bottle cultivation sprinkled with the different concentration of sodium chloride solution at the different stage, the productivity and quality of fruitbody started to decrease at 3.0% of the solution and the yield at the treatment of 10.0% solution was only 47% of that in non-treated bottles. Treated at the different stages of mushroom development, treatment just after mushroom sprout did not show any different from that just after scraping spawn from the complete grown bottles. The sprinkle treatment at this stage looked better than that of the soaking with the solution before mushroom sprout. The yield at this treatment with 10% solution showed little damage with that of 90% of non-treated bottle. Sprinkle treatment during mushroom growth stage did not affect and showed almost same to non-treated bottle except the treatment with 10.0% solution. The treatment of this stage showed better results of growing characters than the treatment after and before mushroom sprouting even 10% solution. Morphological characteristics of oyster mushroom do not distinguish to treatment of different stage and concentration of sodium chloride solution. The analyzing data of quality on underwater usually used for oyster mushroom in Inchon, Yeongjong and Kanghwa area showed over-concentration to the standard for edible water and agricultural water. But it was not confirmed whether this water quality could affect to mushroom cultivation.

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Diagnostic Performance of HPV E6/E7 mRNA and HPV DNA Assays for the Detection and Screening of Oncogenic Human Papillomavirus Infection among Woman with Cervical Lesions in China

  • Wang, Hye-young;Lee, Dongsup;Park, Sunyoung;Kim, Geehyuk;Kim, Sunghyun;Han, Lin;Yubo, Ren;Li, Yingxue;Park, Kwang Hwa;Lee, Hyeyoung
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.17
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    • pp.7633-7640
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    • 2015
  • Background: Human papillomavirus (HPV) is the most common sexually transmitted infection worldwide and it is responsible for most cases of cervical uterine cancer. Although HPV infections of the cervix do not always progress to cancer, 90% of cervical cancer cases have been found to be associated with high risk HPV (HR-HPV) infection. HPV DNA testing is widely used, along with Papanicolaou (Pap) testing, to screen for cervical abnormalities. However, there are no data on the prevalence of genotype-specific HPV infections assessed by measuring HPV E6/E7 mRNA in women representative of the Chinese population across a broad age range. Materials and Methods: In the present study, we compared the results with the CervicGen HPV RT-qDx assay, which detects 16 HR-HPV genotypes (Alpha-9: HPV 16, 31, 33, 35, 52, and 58; Alpha-7: HPV 18, 39, 45, 51, 59, and 68; and Alpha-5, 6: HPV 53, 56, 66, and 69), and the REBA HPV-ID assay, which detects 32 HPV genotypes based on the reverse blot hybridization assay (REBA) for the detection of oncogenic HPV infection according to cytological diagnosis. We also investigated the prevalence and genotype distribution of HPV infection with a total of 324 liquid-based cytology samples collected in western Shandong province, East China. Results: The overall HPV prevalences determined by HPV DNA and HPV E6/E7 mRNA assays in this study were 79.9% (259/324) and 55.6% (180/324), respectively. Although the positivity of HPV E6/E7 mRNA expression was significantly lower than HPV DNA positivity, the HPV E6/E7 mRNA assay showed greater specificity than the HPV DNA assay (88.6% vs. 48.1%) in normal cytology samples. The prevalence of Alpha-9 (HPV 16, 31, 33, 35, 52, and 58) HPV infection among these women accounted for up to 80.3% and 76.1% of the high-grade lesions detected in the HPV mRNA and DNA tests, respectively. The HR-HPV genotype distribution, based on HPV DNA and E6/E7 mRNA expression by age group in patients with cytologically confirmed lesions, was highest in women aged 40 to 49 years (35.9% for cytologically confirmed cases, Pearson correlation r value=0.993, p<0.001) for high-grade lesions. Among the oncogenic HR-HPV genotypes for all age groups, there was little difference in the distribution of HPV genotypes between the HPV DNA (HPV -16, 53, 18, 58, and 33) and HPV E6/E7 mRNA (HPV -16, 53, 33, 58, and 18) assays. HPV 16 was the most common HPV genotype among women with high-grade lesions. Conclusions: Our results suggest that the HPV E6/E7 mRNA assay can be a sensitive and specific tool for the screening and investigation of cervical cancer. Furthermore, it may provide useful information regarding the necessity for early cervical cancer screenings and the development of additional effective HPV vaccines, such as one for HPV 53 and 58. Additionally, gaining knowledge of HPV distribution may also inform us about ecological changes in HPV after the vaccination.

A Study on the Buyer's Decision Making Models for Introducing Intelligent Online Handmade Services (지능형 온라인 핸드메이드 서비스 도입을 위한 구매자 의사결정모형에 관한 연구)

  • Park, Jong-Won;Yang, Sung-Byung
    • Journal of Intelligence and Information Systems
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    • v.22 no.1
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    • pp.119-138
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    • 2016
  • Since the Industrial Revolution, which made the mass production and mass distribution of standardized goods possible, machine-made (manufactured) products have accounted for the majority of the market. However, in recent years, the phenomenon of purchasing even more expensive handmade products has become a noticeable trend as consumers have started to acknowledge the value of handmade products, such as the craftsman's commitment, belief in their quality and scarcity, and the sense of self-esteem from having them,. Consumer interest in these handmade products has shown explosive growth and has been coupled with the recent development of three-dimensional (3D) printing technologies. Etsy.com is the world's largest online handmade platform. It is no different from any other online platform; it provides an online market where buyers and sellers virtually meet to share information and transact business. However, Etsy.com is different in that shops within this platform only deal with handmade products in a variety of categories, ranging from jewelry to toys. Since its establishment in 2005, despite being limited to handmade products, Etsy.com has enjoyed rapid growth in membership, transaction volume, and revenue. Most recently in April 2015, it raised funds through an initial public offering (IPO) of more than 1.8 billion USD, which demonstrates the huge potential of online handmade platforms. After the success of Etsy.com, various types of online handmade platforms such as Handmade at Amazon, ArtFire, DaWanda, and Craft is ART have emerged and are now competing with each other, at the same time, which has increased the size of the market. According to Deloitte's 2015 holiday survey on which types of gifts the respondents plan to buy during the holiday season, about 16% of U.S. consumers chose "homemade or craft items (e.g., Etsy purchase)," which was the same rate as those for the computer game and shoes categories. This indicates that consumer interests in online handmade platforms will continue to rise in the future. However, this high interest in the market for handmade products and their platforms has not yet led to academic research. Most extant studies have only focused on machine-made products and intelligent services for them. This indicates a lack of studies on handmade products and their intelligent services on virtual platforms. Therefore, this study used signaling theory and prior research on the effects of sellers' characteristics on their performance (e.g., total sales and price premiums) in the buyer-seller relationship to identify the key influencing e-Image factors (e.g., reputation, size, information sharing, and length of relationship). Then, their impacts on the performance of shops within the online handmade platform were empirically examined; the dataset was collected from Etsy.com through the application of web harvesting technology. The results from the structural equation modeling revealed that the reputation, size, and information sharing have significant effects on the total sales, while the reputation and length of relationship influence price premiums. This study extended the online platform research into online handmade platform research by identifying key influencing e-Image factors on within-platform shop's total sales and price premiums based on signaling theory and then performed a statistical investigation. These findings are expected to be a stepping stone for future studies on intelligent online handmade services as well as handmade products themselves. Furthermore, the findings of the study provide online handmade platform operators with practical guidelines on how to implement intelligent online handmade services. They should also help shop managers build their marketing strategies in a more specific and effective manner by suggesting key influencing e-Image factors. The results of this study should contribute to the vitalization of intelligent online handmade services by providing clues on how to maximize within-platform shops' total sales and price premiums.

Knowledge graph-based knowledge map for efficient expression and inference of associated knowledge (연관지식의 효율적인 표현 및 추론이 가능한 지식그래프 기반 지식지도)

  • Yoo, Keedong
    • Journal of Intelligence and Information Systems
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    • v.27 no.4
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    • pp.49-71
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    • 2021
  • Users who intend to utilize knowledge to actively solve given problems proceed their jobs with cross- and sequential exploration of associated knowledge related each other in terms of certain criteria, such as content relevance. A knowledge map is the diagram or taxonomy overviewing status of currently managed knowledge in a knowledge-base, and supports users' knowledge exploration based on certain relationships between knowledge. A knowledge map, therefore, must be expressed in a networked form by linking related knowledge based on certain types of relationships, and should be implemented by deploying proper technologies or tools specialized in defining and inferring them. To meet this end, this study suggests a methodology for developing the knowledge graph-based knowledge map using the Graph DB known to exhibit proper functionality in expressing and inferring relationships between entities and their relationships stored in a knowledge-base. Procedures of the proposed methodology are modeling graph data, creating nodes, properties, relationships, and composing knowledge networks by combining identified links between knowledge. Among various Graph DBs, the Neo4j is used in this study for its high credibility and applicability through wide and various application cases. To examine the validity of the proposed methodology, a knowledge graph-based knowledge map is implemented deploying the Graph DB, and a performance comparison test is performed, by applying previous research's data to check whether this study's knowledge map can yield the same level of performance as the previous one did. Previous research's case is concerned with building a process-based knowledge map using the ontology technology, which identifies links between related knowledge based on the sequences of tasks producing or being activated by knowledge. In other words, since a task not only is activated by knowledge as an input but also produces knowledge as an output, input and output knowledge are linked as a flow by the task. Also since a business process is composed of affiliated tasks to fulfill the purpose of the process, the knowledge networks within a business process can be concluded by the sequences of the tasks composing the process. Therefore, using the Neo4j, considered process, task, and knowledge as well as the relationships among them are defined as nodes and relationships so that knowledge links can be identified based on the sequences of tasks. The resultant knowledge network by aggregating identified knowledge links is the knowledge map equipping functionality as a knowledge graph, and therefore its performance needs to be tested whether it meets the level of previous research's validation results. The performance test examines two aspects, the correctness of knowledge links and the possibility of inferring new types of knowledge: the former is examined using 7 questions, and the latter is checked by extracting two new-typed knowledge. As a result, the knowledge map constructed through the proposed methodology has showed the same level of performance as the previous one, and processed knowledge definition as well as knowledge relationship inference in a more efficient manner. Furthermore, comparing to the previous research's ontology-based approach, this study's Graph DB-based approach has also showed more beneficial functionality in intensively managing only the knowledge of interest, dynamically defining knowledge and relationships by reflecting various meanings from situations to purposes, agilely inferring knowledge and relationships through Cypher-based query, and easily creating a new relationship by aggregating existing ones, etc. This study's artifacts can be applied to implement the user-friendly function of knowledge exploration reflecting user's cognitive process toward associated knowledge, and can further underpin the development of an intelligent knowledge-base expanding autonomously through the discovery of new knowledge and their relationships by inference. This study, moreover than these, has an instant effect on implementing the networked knowledge map essential to satisfying contemporary users eagerly excavating the way to find proper knowledge to use.

Personalized Exhibition Booth Recommendation Methodology Using Sequential Association Rule (순차 연관 규칙을 이용한 개인화된 전시 부스 추천 방법)

  • Moon, Hyun-Sil;Jung, Min-Kyu;Kim, Jae-Kyeong;Kim, Hyea-Kyeong
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.195-211
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    • 2010
  • An exhibition is defined as market events for specific duration to present exhibitors' main product range to either business or private visitors, and it also plays a key role as effective marketing channels. Especially, as the effect of the opinions of the visitors after the exhibition impacts directly on sales or the image of companies, exhibition organizers must consider various needs of visitors. To meet needs of visitors, ubiquitous technologies have been applied in some exhibitions. However, despite of the development of the ubiquitous technologies, their services cannot always reflect visitors' preferences as they only generate information when visitors request. As a result, they have reached their limit to meet needs of visitors, which consequently might lead them to loss of marketing opportunity. Recommendation systems can be the right type to overcome these limitations. They can recommend the booths to coincide with visitors' preferences, so that they help visitors who are in difficulty for choices in exhibition environment. One of the most successful and widely used technologies for building recommender systems is called Collaborative Filtering. Traditional recommender systems, however, only use neighbors' evaluations or behaviors for a personalized prediction. Therefore, they can not reflect visitors' dynamic preference, and also lack of accuracy in exhibition environment. Although there is much useful information to infer visitors' preference in ubiquitous environment (e.g., visitors' current location, booth visit path, and so on), they use only limited information for recommendation. In this study, we propose a booth recommendation methodology using Sequential Association Rule which considers the sequence of visiting. Recent studies of Sequential Association Rule use the constraints to improve the performance. However, since traditional Sequential Association Rule considers the whole rules to recommendation, they have a scalability problem when they are adapted to a large exhibition scale. To solve this problem, our methodology composes the confidence database before recommendation process. To compose the confidence database, we first search preceding rules which have the frequency above threshold. Next, we compute the confidences of each preceding rules to each booth which is not contained in preceding rules. Therefore, the confidence database has two kinds of information which are preceding rules and their confidence to each booth. In recommendation process, we just generate preceding rules of the target visitors based on the records of the visits, and recommend booths according to the confidence database. Throughout these steps, we expect reduction of time spent on recommendation process. To evaluate proposed methodology, we use real booth visit records which are collected by RFID technology in IT exhibition. Booth visit records also contain the visit sequence of each visitor. We compare the performance of proposed methodology with traditional Collaborative Filtering system. As a result, our proposed methodology generally shows higher performance than traditional Collaborative Filtering. We can also see some features of it in experimental results. First, it shows the highest performance at one booth recommendation. It detects preceding rules with some portions of visitors. Therefore, if there is a visitor who moved with very a different pattern compared to the whole visitors, it cannot give a correct recommendation for him/her even though we increase the number of recommendation. Trained by the whole visitors, it cannot correctly give recommendation to visitors who have a unique path. Second, the performance of general recommendation systems increase as time expands. However, our methodology shows higher performance with limited information like one or two time periods. Therefore, not only can it recommend even if there is not much information of the target visitors' booth visit records, but also it uses only small amount of information in recommendation process. We expect that it can give real?time recommendations in exhibition environment. Overall, our methodology shows higher performance ability than traditional Collaborative Filtering systems, we expect it could be applied in booth recommendation system to satisfy visitors in exhibition environment.