• Journal of Information Technology Applications and Management
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• 제17권2호
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• pp.71-90
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• 2010

Electronic learning(or e-learning) has created hype for companies, universities, and other educational institutions. It has led to the phenomenal growth in the use of web-based learning and experimentation with multimedia, video conferencing, and internet-based technologies. Many researchers are interested in the factors that affect to the performance of e-learning or e-learning services. In this sense, this study is aimed at proposing e-learning system reuse prediction models in which e-learner intention to reuse influence factors(i.e., system accessibility, system stability, information clarity, information validity, self-regulated efficacy, computer self-efficacy, perceived usefulness, perceived ease of use, flow, and parental expectation) affect e-learner intention to reuse positively. A web survey was conducted for the full members of the e-learning education institute A in Seoul, Republic of Korea, an exclusive e-learning company that provides real time video lectures via the desktop conferencing system. The web survey was conducted for 20 days from November 5, 2009, through the e-learning web site of the company A. In this study, three data mining techniques were used : the multivariate discriminant analysis, CART, and C5.0 algorithm. This study was conducted to provide the e-learning service providers, e-learning operators, and contents developers with marketing and management strategies for improving the e-learning service companies, based on the data mining analysis results.

• 대한환경공학회지
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• 제34권12호
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• pp.792-800
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• 2012

본 연구는 남한강과 북한강 유역 내 경작지 각 3개소(site A, B, C)를 대상으로 Web GIS-based VFSMOD System의 HUFF & SCS UH-based VFS Design Module을 적용하여 강우 시 경작지에서 유출되는 고형물질 유출저감을 모의하였다. 북한강 유역 내에 위치한 site A의 노지 밭의 토지경사도 5%, 강우 106.2 mm 조건에서 고추 및 옥수수를 재배할 경우, 70% 이상의 고형물질 유출저감 효율을 얻기 위해서는 초생대 폭이 최소 0.5 m 이상, 토지경사도 10%인 경우 70% 이상의 고형물질 유출저감 효율을 얻기 위해서는 초생대 폭이 최소 1.0~1.5 m 이상 유지해야 한다. 남한강 유역 내에 site B의 노지 밭의 토지경사도 5%, 강우량 95.1 mm 조건에서 토마토 및 땅콩을 재배할 경우, 70% 이상의 고형물질 유출저감을 위해서는 초생대의 폭이 최소 0.5 m, 토지경사도 10%인 경우 50% 이상의 고형물질 유출저감을 위해서는 최소 1.0 m 이상의 폭을 갖는 초생대를 설치해야 하는 것으로 나타났다. 남한강 유역 내에 site C의 노지 밭의 토지경사도 5%, 강우량 102.6 mm 조건에서 고구마 및 콩을 재배할 경우, 64.0% 이상의 고형물질 유출저감을 위해서는 초생대의 폭이 최소 1.0 m, 초생대를 설치해야 하는 것을 분석되었다. 또한, 동일한 조건에서 강우지속시간 2시간의 강우량을 151.2 mm로 증가시킬 경우, 62.0% 이상의 고형물질 유출저감을 위한 초생대의 최소 폭은 1.0 m 이상 설치해야 하는 것으로 분석되었다. 초생대 시설은 경작지와 같은 토지이용 시 친환경적인 고형물질 유출저감 방안으로 검토될 수 있으며, Web GIS-based VFSMOD System을 이용하여 다양한 토지특성과 강우 사상을 반영하여 적정한 규모의 초생대 설계가 가능할 것으로 분석되었다.

• Journal of Information Technology Applications and Management
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• 제12권2호
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• pp.15-27
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• 2005

Text categorization systems generally use single words (unigrams) as features. A deceptively simple algorithm for improving text categorization is investigated here, an idea previously shown not to work. It is to identify useful word pairs (bigrams) made up of adjacent unigrams. The bigrams it found, while small in numbers, can substantially raise the quality of feature sets. The algorithm was tested on two pre-classified datasets, Reuters-21578 for English and Korea-web for Korean. The results show that the algorithm was successful in extracting high quality bigrams and increased the quality of overall features. To find out the role of bigrams, we trained the Na$\"{i}$ve Bayes classifiers using both unigrams and bigrams as features. The results show that recall values were higher than those of unigrams alone. Break-even points and F1 values improved in most documents, especially when documents were classified along the large classes. In Reuters-21578 break-even points increased by 2.1%, with the highest at 18.8%, and F1 improved by 1.5%, with the highest at 3.2%. In Korea-web break-even points increased by 1.0%, with the highest at 4.5%, and F1 improved by 0.4%, with the highest at 4.2%. We can conclude that text classification using unigrams and bigrams together is more efficient than using only unigrams.

• Steel and Composite Structures
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• 제44권5호
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• pp.691-705
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• 2022

Shear failure in reinforced concrete (RC) structures is very hazardous. This failure is rarely predicted and may occur without any prior signs. Accurate shear strength prediction of the RC members is challenging, and traditional methods have difficulty solving it. This study develops a JAYA-GBRT model based on the JAYA algorithm and the gradient boosting regression tree (GBRT) to predict the shear strength of RC slender beams without stirrups. Firstly, 484 tests are carefully collected and divided into training and test sets. Then, the hyperparameters of the GBRT model are determined using the JAYA algorithm and 10-fold cross-validation. The performance of the JAYA-GBRT model is compared with five well-known empirical models. The comparative results show that the JAYA-GBRT model (R² = 0.982, RMSE = 9.466 kN, MAE = 6.299 kN, µ = 1.018, and Cov = 0.116) outperforms the other models. Moreover, the predictions of the JAYA-GBRT model are globally and locally explained using the Shapley Additive exPlanation (SHAP) method. The effective depth is determined as the most crucial parameter influencing the shear strength through the SHAP method. Finally, a Graphic User Interface (GUI) tool and a web application (WA) are developed to apply the JAYA-GBRT model for rapidly predicting the shear strength of RC slender beams without stirrups.

• Journal of Information Technology Applications and Management
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• 제16권4호
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• pp.167-184
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• 2009

New internet trend, such as Web 2.0, has brought about new roles of users and changes in the web ecosystem. In the age of information overload like nowadays, activities in the brand community sites help to make more reasonable decisions in choosing certain brands and products. In order to examine organizational strategic aspects of brand community, this study examine (1) what difference exists in user satisfaction according to the brand community types (the user-initiated type and the corporate-established type), and (2) which dimensions of service quality affect brand community users' satisfaction. Research findings show that types of brand community influence perceived user satisfaction, and tangibility, reliability, interactivity, and stability dimensions of service quality make a positive influence on user satisfaction as well. Practical implications for managing brand community sites in marketing perspectives are further discussed.

• 한국임상약학회지
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• 제33권2호
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• pp.128-134
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• 2023

Background: This systematic review and meta-analysis aimed to evaluate the efficacy and cardiovascular safety of romosozumab compared with placebo. Methods: Randomized controlled trials (RCTs) were searched from Medline, EMBASE, Cochrane Central, and Web of Science until July 2022. Primary outcomes included the change in bone mineral density (BMD) from baseline at month 6. The secondary outcomes were the change of bone turnover markers (N-terminal propeptide of type 1 procollagen (P1NP); C-terminal telopeptide of type 1 collagen (CTX)) from baseline at month 3, and the incidence of cardiovascular adverse events for the total follow-up period. Results: A total of 7 RCTs on 8,370patients were included. Romosozumab showed better effects in improving BMD in both lumbar spine and femoral neck at month 6 (standardized mean difference, SMD 2.20 [95% CI: 1.89-2.52], SMD 0.63 [95% CI: 0.41-0.86]). In contrast to placebo, romosozumab significantly increased PINP levels and reduced CTX levels at month 3 (SMD 0.93 [95% CI: 0.65-1.22], SMD -1.03 [95% CI: -1.23~ -0.82]. However, there was no significant difference in the composite incidence of cardiovascular adverse events and major adverse cardiovascular events (OR 1.16 [95% CI: 0.82-1.65], OR 1.08 [95% CI: 0.75-1.56]). Conclusion: This analysis showed that romosozumab significantly improved BMD compared to placebo and was beneficial for change in bone turnover markers. There is no significant difference in the incidence of cardiovascular adverse events compared to placebo.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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• pp.56-64
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• 2015

The personal image information compiled through closed-circuit television (CCTV) will be open to the internet with the technology such as Long-Tail, Mash-Up, Collective Intelligence, Tagging, Open Application Programming Interface (Open-API), Syndication, Podcasting and Asynchronous JavaScript and XML (AJAX). The movie User Created Contents (UCC) connected to the internet with the skill of web 2.0 has the effects of abuse and threat without precedent. The purpose of this research is to develop the institutional and technological method to reduce these effects. As a result of this research, in terms of technology this paper suggests Privacy Zone Masking, IP Filtering, Intrusion-detection System (IDS), Secure Sockets Layer (SSL), public key infrastructure (PKI), Hash and PDF Socket. While in terms of management this paper suggests Privacy Commons and Privacy Zone. Based on CCTV-UCC linked to the above network, the research regarding personal image information security is expected to aid in realizing insight and practical personal image information as a specific device in the following research.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.853-856
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• 2012

모바일 디바이스의 대중화와 SNS(Social Networking Service)의 발전은 각 개인이 데이터와 정보를 생성하는 Web 2.0 의 페러다임을 앞당겼으며 최근 SNS 서비스를 통하여 새로운 형태의 커뮤니케이션 형태가 생성되었다. 이러한 커뮤니케이션 도구를 이용하는 유저는 대부분 ID 와 Password를 기반으로 사용자를 인증하여 서비스를 제공받는다. 이와 같은 서비스에서는 각 사용자의 정보자체보다 사용자의 사회적 위치와 사용자간의 관계를 이용한 보안사고가 우려된다. 근래의 ID/Password로 인증하는 방식의 웹서비스 또는 정보서비스들은 대부분 개인 PC, 스마트폰, 업무 PC 등에서 접근하는 추세이며, 임의적 장소에서 임의의 기기로 해당 서비스에 접근하는 양상은 과거에 비하여 감소하는 추세다. 이 같은 추세에 따라, 주로 사용하는 기기에 HTML5의 keygen과 Web-Storage 기능을 사용하여 암호화된 Key를 생성하고 저장하여 ID 와 Password가 노출되어도 해당 기기가 아니면 인증되지 않는 시스템을 구현 할 수 있으며 타 기기의 경우 일회성을 갖는 인증 방식을 사용하여, 기존 보다 안전한 인증 시스템을 적은 비용으로 구축 할 수 있다.

• TTA 저널
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• 통권105호
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• pp.12-18
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• 2006

1989년에 월드와이드웹(WWW)이 처음 만들어진 이후로 웹 기술은 인터넷 발전의 중추적인 역할을 해오고 있으며, 1998년에 XML(eXtensible Markup Language)기술이 개발되면서 이를 기반으로 웹서비스(Web Services), 시맨틱 웹, 유비쿼터스 웹 기술 등 다양한 차세대 웹 기술 발전이 이루어지고 있다. 이제 웹 기술은 기존 컴퓨팅 환경을 넘어서 다양한 단말 환경에서의 유비쿼터스 응용 표준으로 발전되고 있으며, 최근 들어 웹 2.0이 등장하면서 사용자 중심의 컴퓨팅 환경으로의 발전과 더불어 새로운 가치 창조 방식을 창출하면서 웹은 제2의 중흥기를 맞이하고 있다. 그리고이러한 차세대 웹 기술은 다양한 네트워크와 단말 서비스를 자연스럽게 융 · 통합시킬 수 있는 소프트웨어의 중요한 인프라 기술로서 그 중요성이 어느 때 보다 강조되고 있다고 할 수 있다.

• Journal of information and communication convergence engineering
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• 제10권2호
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• pp.168-174
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• 2012

Flash is the most popular 2D animation and game development software, supporting vector and media technology at the core, which enables the development of small and pithy games. It is widely used in Web animation, courseware, TV commercials, game development, and other works of design. In this paper, we propose a control movement function and auxiliary functions for an alpine skiing game based on ActionScript 3.0. The control movement function is designed with moving phases (i.e., free fall, sliding, projectile, and landing). The auxiliary functions include drawing path, start/restart movement, and saving the highest score. In addition, for the visual design of our game, we designed animations in connection with a character and background. In order to facilitate testing the friction, users can input a chosen friction value. Without user input, the friction default is set at 0.97.