• Journal of the Korean Society of Radiology
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• v.1 no.3
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• pp.11-16
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• 2007

In this study, the potential of a newly developed simulation toolkit, GATE for the simulation of electronic portal imaging devices (EPID) in radiation therapy was evaluated by characterizing the performance of the metal plate/phosphor screen detector for EPID. We compared the performances of the GATE simulator against MCNP4B code and experimental data obtained with the EPID system in order to validate its use for radiation therapy.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.183-188
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• 2021

The study aimed to assess the state of electronic security for the website of the Deanship of Library Affairs at Northern Border University, as one of the university's electronic portals, which provides distinguished knowledge services to faculty members, through the Saudi Digital Library, and the integrated automated system for libraries (Symphony) with the definition of cyber security of the university, and the most important threats The study sought to analyze the opinions of a wide sample of faculty members, towards evaluating the state of electronic security for the Deanship of Library Affairs portal, through the use of both the analytical method, as well as the survey, using the questionnaire tool, and the study sample consisted of 95 A faculty member of all academic categories and degrees, and university faculties, and the study concluded that it is necessary to work to overcome the relative slowness of the university's Internet, with the faculty members notifying the information security services through e-mail and SMS service, with the continuous updating of operating systems, Apply and use the latest anti-spyware, hacking, and antivirus software at the university, while conducting extensive research studies towards information security services, and contracting It aims to introduce information security risks, and ways to combat and overcome them, and spread the culture of information security among faculty members.

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.16-21
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• 1999

Purpose : The aim of this study is to conform the possibility of the liquid type EPID as a QC tools to clinical indication and of replacement of the film dosimetry. Aditional aim is to describe a procedure for the use of a EPID as a physics calibration tool in the measurements of radiation beam parameters which are typically carried out with film. Method & Materials : In this study we used the Clinac 2100c/d with EPID. This system contains 65536 liquid-filled ion chambers arranged in a $256{\times}256$ matrix and the imaging area is $32.5{\times}32.5cm$ with liquid layer thickness of 1mm. The EPID was tested for different field sizes under typical clinical conditions and pixel values were calibrated against dose by producing images using various thickness of lead attenuators(lead step wedge) using 6 & 10MV x-ray. We placed various thickness of lead on the table of linear accelerator and set the portal vision an SDD of 100cm. To acquire portal image we change the field size and energy, and we recorded the average pixel value in a $3{\times}3$ pixel region of interest(ROI) at field center was recorded. The pixel values were also measured for different field sizes in order to evaluate the dependence of pixel value on x-ray energy spectrum and various scatter components. Result : The EPID, as a whole, was useful as a QA tool and dosimetry device. In mechanical check, cross-hair centering was well matched and the error was less than ?2mm and light/radiation field coincidence was less than 1mm also. In portal dosimetry the wider the field size the the higher the pixel value and as the lead thickness increase, the pixel value was exponentially decreased. Conclusions : The EPID was very suitable for QA tools and it can be used to measure exit dose during patients treatment with reasonable accuracy. But when indicate the EPID to clincal study deep consideration required

• Korean Journal of Radiology
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• v.23 no.1
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• pp.68-76
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• 2022

Objective: Percutaneous portal vein (PV) stent placement can be an effective treatment for symptoms associated with portal hypertension. This study aimed to evaluate the effect of PV stenting on the overall survival (OS) in patients with malignant PV stenosis. Materials and Methods: Two groups of patients with malignant PV stenosis were compared in this retrospective study involving two institutions. A total of 197 patients who underwent PV stenting between November 2016 and August 2019 were established as the stent group, whereas 29 patients with PV stenosis who were treated conservatively between July 2013 and October 2016 constituted the no-stent group. OS was compared between the two groups before and after propensity score matching (PSM). Risk factors associated with OS were evaluated using the Cox proportional hazards model. Procedure-associated adverse events were also evaluated. Results: The stent group finally included 100 patients (median age, 65 [interquartile range, 58-71] years; 64 male). The no-stent group included 22 patients (69 [61-75] years, 13 male). Stent placement was successful in 95% of attempted cases, and the 1- and 2-year stent occlusion-free survival rate was 56% (95% confidence interval, 45%-69%) and 44% (32%-60%), respectively. The median stent occlusion-free survival time was 176 (interquartile range, 70-440) days. OS was significantly longer in the stent group than in the no-stent group (median 294 vs. 87 days, p < 0.001 before PSM, p = 0.011 after PSM). The 1- and 3-year OS rates before PSM were 40% and 11%, respectively, in the stent group. The 1-year OS rate after PSM was 32% and 5% in the stent and no-stent groups, respectively. Anemia requiring transfusion (n = 2) and acute thrombosis necessitating re-stenting (n = 1) occurred in three patients in the stent group within 1 week. Conclusion: Percutaneous placement of a PV stent may be effective in improving OS in patients with malignant PV stenosis.

• Architectural research
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• v.3 no.1
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• pp.71-80
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• 2001

It is quite difficult to calculate the collapse probability of a system such as statically indeterminate structure that has many possible modes or paths to complete failure and the problem has remained essentially unsolved. A structure is synthesized by several components or elements and its capacity to resist the given loads is a function of the capacity of the individual element. Thus it is reasonable to assess the probability of failure of the system based upon those of its elements. This paper proposes an efficient technique to directly assess the reliability of a complex structural system from the reliabilities of its components or elements. The theory for the calculation of the probability of a structural system is presented. The target requirements of the method and the fundamental assumptions governing the method are clearly stated. A portal frame and two trusses are selected to demonstrate the efficiency of the method by comparing the results obtained from the proposed method to those from the existing methods in the literature.

• Korean Journal of Computational Design and Engineering
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• v.14 no.5
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• pp.338-345
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• 2009

c-PMS(collaborative project management system) is a business process(BP) based tool to manage collaborative projects which accomplish common business objectives determined by mutual agreement of companies using limited resources and time. This study analyzes collaborative BP, collaborative projects, and their relation, and proposes the architecture and operation scenario of c-PMS consisted of business process asset management(BPAM) sub-system and project manage(PM) sub-system. BPAM sub-system models private and public BP using a client/server based modeler, defines collaborative BPs process from public BPs, and manages them as companies' asset on a web portal. PM sub-system globally manages collaborative project using planning, execution, monitoring, and analyzing functions.

• The Journal of the Korea Contents Association
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• v.8 no.10
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• pp.151-157
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• 2008

This study aims to construct the aged portal sites based on multimedia DB on the basis of request for systematic collection and management of the aged-related specific information which are spreading and construct Multimedia Information System for the Aged by developing digital contents to offer the aged-related information. It also tries to construct ontology based information repository for the aged that includes on/off-line. It extracts semantic relationship of each information by analysing the aged information, knows the hierarchical structure of each vocabulary, and designs and constructs an ontology based repository by designing function of each agent through that. It has also developed a variety of information and digital contents, constructed a systematic multimedia DB for the aged welfare homes, developed web framework which makes automatic registration of the aged welfare homes possible, and designed in order to support the use state of enterprises/homes and statistics state.

• The Journal of Information Systems
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• v.23 no.1
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• pp.225-246
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• 2014

With the recent establishment of a ubiquitous environment and the paradigm shift to a smart society, the use of mobile devices, such as smart phones and tablet PCs, has become widespread. Thus, the trend is gradually shifting from using Web-based Instant Messenger to using Mobile-based Instant Messenger. Mobile Instant Messenger refers to a service that allows instant messaging as well as data sending and receiving between individuals with exclusive application programs(mobile Apps), which can be used in portable devices-such as smart phones-with wireless Internet access. Korea's portal sites, telecommunication companies, and even big companies have all rushed into the MIM market to join the competition. The reason so many companies are showing interest in the MIM business is because it is rising as a core platform to substitute portal sites in the mobile society, and MIM is perceived as the best means to attract and secure users. The intention to reuse or use continually was considered an important factor in maintaining a dominant position amidst such fierce competition, and consequently, most research thus far has reflected such thought. However, the frequent or long-term use of a system alone cannot indicate the definite success of the system, nor guarantee its dominant position in the market. On the contrary, MIM dependence, which goes beyond simple repetitive use and indicates a state where users actually or emotionally depend on a specific system, can better explain the user action. However, not much research has been conducted on dependence. The research results showed that lively message, concise message, message responsiveness, and social belonging significantly affected perceived usefulness. Message responsiveness, Link, and social belonging significantly affected flow. Flow significantly affected MIM dependence, and perceived usefulness did not affect MIM dependence. This study has proven that lively message, concise message, message responsiveness, Link, social belonging and perceived usefulness are important antecedents and mediating factors of MIM dependence. Moreover, this study is significant in that it explains the overall process of MIM dependence, and expands on the variety and scope of research that can be applied to MIM-related studies.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.319-325
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• 2019

The importance of social responsibility is growing, and as a result of social awareness, many universities and institutions are carrying out community service activities. Although the volunteer portal site has excellent performance and good accessibility, the overall service performance of a specific organization cannot be managed because of personal information. Almost community service managers of a organization manually manage their community service activities without the support of a community service management program. In this study, have been feature analysis of existing portal site for volunteer coordination, then a prototype was designed and developed as a model of social contribution management system so that universities and organizations can systematically support and manage the social service activities of members based on the questionnaire about social contribution management system.

• Agribusiness and Information Management
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• v.2 no.1
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• pp.117-128
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• 2010

Coordination has been identified as a concern in the cross-cutting issues of food security and nutrition (FSN) in Cambodia. Food Security and Nutrition Information System (FSNIS) in Cambodia is the only "entry portal" to support policy formulation and decision-making with regard to FSN. While this knowledge and information management system has earned a respectful reputation, Council for Agricultural and Rural Development (CARD) faces many challenges in the implementation of the system. This paper will present how FSNIS has been developed and impacts on policy or strategy related to FSN. In addition, sustainability of the system is a key challenge for FSNIS; yet it is interesting to see how it works. Along with a success story, FSNIS is recognized by its stakeholders as the most successful knowledge and information management system in the field of FSN in Cambodia.