• Journal of the Korean Society of Radiology
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• v.18 no.1
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• pp.45-52
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• 2024

In this study, an AI-based algorithm was developed to prevent image quality deterioration and reading errors due to patient movement in PET/CT examinations that use radioisotopes in medical institutions to test cancer and other diseases. Using the Mothion Free software developed using, we checked the degree of correction of movement due to breathing, evaluated its usefulness, and conducted a study for clinical application. The experimental method was to use an RPM Phantom to inject the radioisotope 18F-FDG into a vacuum vial and a sphere of a NEMA IEC body Phantom of different sizes, and to produce images by directing the movement of the radioisotope into a moving lesion during respiration. The vacuum vial had different degrees of movement at different positions, and the spheres of the NEMA IEC body Phantom of different sizes produced different sizes of lesions. Through the acquired images, the lesion volume, maximum SUV, and average SUV were each measured to quantitatively evaluate the degree of motion correction by Motion Free. The average SUV of vacuum vial A, with a large degree of movement, was reduced by 23.36 %, and the error rate of vacuum vial B, with a small degree of movement, was reduced by 29.3 %. The average SUV error rate at the sphere 37mm and 22mm of the NEMA IEC body Phantom was reduced by 29.3 % and 26.51 %, respectively. The average error rate of the four measurements from which the error rate was calculated decreased by 30.03 %, indicating a more accurate average SUV value. In this study, only two-dimensional movements could be produced, so in order to obtain more accurate data, a Phantom that can embody the actual breathing movement of the human body was used, and if the diversity of the range of movement was configured, a more accurate evaluation of usability could be made.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.73-81
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• 2024

This study compared the cortical thickness of patients with mood disorders and a control group to assess structural abnormalities. A retrospective study was conducted from September 2020 to August 2022 at the Department of Psychiatry, P Hospital in Yangsan, Gyeongsangnam-do. The study included 44 individuals diagnosed with mood disorders and 59 healthy individuals without any pathological lesions. The 3D-T1 MPRAGE images obtained from magnetic resonance imaging examinations were utilized, and FreeSurfer software was employed to measure cortical thickness. Statistical analysis involved independent samples t-tests to measure the differences in means between the two groups, and Cohen's d test was used to compare the effect sizes of the differences. Furthermore, the correlation between the measured average cortical thickness and Positive and Negative Syndrome Scale scores was analyzed. The research results revealed that patients with mood disorders exhibited decreased cortical thickness compared to the normal control group in both superior frontal regions, both rostral middle frontal regions, both caudal middle frontal regions, both pars opercularis, pars orbitals, pars triangularis regions, both superior temporal regions, both inferior temporal regions, both lateral orbitofrontal regions, both medial orbitofrontal regions, both fusiform regions, both posterior cingulate regions, both isthmus cingulate regions, both superior parietal regions, both inferior parietal regions, both supramarginal regions, left postcentral region, right bank of the superior temporal sulcus region, right middle temporal region, right rostral anterior cingulate region, and right insula region. Among them, regions that showed differences with effect sizes of 0.8 or higher were left fusiform (d=0.82), pars opercularis (d=0.94), superior frontal (d=0.88), right lateral orbitofrontal (d=0.85), and pars orbitalis (d=0.89). Additionally, there was a weak negative correlation between PANSS scores and average cortical thickness in both the left hemisphere (r=-0.234) and right hemisphere (r=-0.230). These findings are expected to be helpful in identifying areas of cortical thickness reduction in patients with mood disorders compared to healthy individuals and understanding the relationship between symptom severity and cortical thickness changes.

• Geophysics and Geophysical Exploration
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• v.8 no.4
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• pp.262-269
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• 2005

Since the buried cultural relics are three-dimensional (3-D) objects in nature, 3-D survey is more preferable in archeological exploration. 3-D Ground Penetrating Radar (GPR) survey based on very dense data in principle, however, might need much higher cost and longer time of exploration than other geophysical methods commonly used for the archeological exploration, such as magnetic and electromagnetic methods. We developed a small-scale continuous data acquisition system which consists of two sets of GPR antennas and the precise positioning device tracking the moving-path of GPR antenna automatically and continuously. Since the high cost of field work may be partly attributed to establishing many profile lines, we adopted a concept of data acquisition at arbitrary locations not along the pre-established profile lines. Besides this hardware system, we also developed several software packages in order to effectively process and visualize the 3-D data obtained by the developed system and the data acquisition concept. Using the developed system, we performed 3-D GPR survey to investigate the possible historical remains of Baekje Kingdom at Buyeo city, South Korea, prior to the excavation. Owing to the newly devised system, we could obtain 3-D GPR data of this survey area having areal extent over about $17,000m^2$ within only six-hours field work. Although the GPR data were obtained at random locations not along the pre-established profile lines, we could obtain high-resolution 3-D images showing many distinctive anomalies, which could be interpreted as old agricultural lands, waterways, and artificial structures or remains. This cast: history led us to the conclusion that 3-D GPR method is very useful not only to examine a small anomalous area but also to investigate the wider region of the archeological interests.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.79-90
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• 2014

User authentication based on ID and PW has been widely used. As the Internet has become a growing part of people' lives, input times of ID/PW have been increased for a variety of services. People have already learned enough to perform the authentication procedure and have entered ID/PW while ones are unconscious. This is referred to as the adaptive unconscious, a set of mental processes incoming information and producing judgements and behaviors without our conscious awareness and within a second. Most people have joined up for various websites with a small number of IDs/PWs, because they relied on their memory for managing IDs/PWs. Human memory decays with the passing of time and knowledges in human memory tend to interfere with each other. For that reason, there is the potential for people to enter an invalid ID/PW. Therefore, these characteristics above mentioned regarding of user authentication with ID/PW can lead to human vulnerabilities: people use a few PWs for various websites, manage IDs/PWs depending on their memory, and enter ID/PW unconsciously. Based on the vulnerability of human factors, a variety of information leakage attacks such as phishing and pharming attacks have been increasing exponentially. In the past, information leakage attacks exploited vulnerabilities of hardware, operating system, software and so on. However, most of current attacks tend to exploit the vulnerabilities of the human factors. These attacks based on the vulnerability of the human factor are called social-engineering attacks. Recently, malicious social-engineering technique such as phishing and pharming attacks is one of the biggest security problems. Phishing is an attack of attempting to obtain valuable information such as ID/PW and pharming is an attack intended to steal personal data by redirecting a website's traffic to a fraudulent copy of a legitimate website. Screens of fraudulent copies used for both phishing and pharming attacks are almost identical to those of legitimate websites, and even the pharming can include the deceptive URL address. Therefore, without the supports of prevention and detection techniques such as vaccines and reputation system, it is difficult for users to determine intuitively whether the site is the phishing and pharming sites or legitimate site. The previous researches in terms of phishing and pharming attacks have mainly studied on technical solutions. In this paper, we focus on human behaviour when users are confronted by phishing and pharming attacks without knowing them. We conducted an attack experiment in order to find out how many IDs/PWs are leaked from pharming and phishing attack. We firstly configured the experimental settings in the same condition of phishing and pharming attacks and build a phishing site for the experiment. We then recruited 64 voluntary participants and asked them to log in our experimental site. For each participant, we conducted a questionnaire survey with regard to the experiment. Through the attack experiment and survey, we observed whether their password are leaked out when logging in the experimental phishing site, and how many different passwords are leaked among the total number of passwords of each participant. Consequently, we found out that most participants unconsciously logged in the site and the ID/PW management dependent on human memory caused the leakage of multiple passwords. The user should actively utilize repudiation systems and the service provider with online site should support prevention techniques that the user can intuitively determined whether the site is phishing.

• Korean Business Review
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• v.17
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• pp.53-81
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• 2004

The purpose of this study is to understand the realities and the subject of environmental management for small and medium-sized companies in Gwangwon area, through surveying the present status as to acquiring the certification of ISO14001, and to seek for a plan to facilitate environmental management. Given summarizing key results, those are as follows. First, while the number of companies in our country which acquired the certification of ISO14001, amounts to 1,215 businesses as of April of 2003, the number of small and medium-sized companies in Gwangwon area which obtained the certification of ISO14001 reached only 26 businesses, the lowest level among metropolitan municipalities. Second, for the reason that companies who didn't acquire the certification, strive not to receive the certification, it did present the point that' costs to be needed in acquiring and maintaining the certification are larger than practical benefit. Third, the biggest reason for either companies which did not acquire the certification of ISO14001 or companies which did (try to) acquire the certification of ISO1400, was, enhancement of a corporate image,' and the effect after a company who obtained the certification introduced the environmental management system, was also shown to be 'the improvement of a corporate image.' Fourth, many companies who acquired the certification of ISO1400 pointed out the response related to 'burden on document creation and costs' and 'lack of manpower' as problems when introducing the environmental management system. On the basis of major results of a study as the above, given presenting the subject and a plan for activating the environmental management of small and medium-sized companies in Gwangwon area, those are as follows. First, because most of companies who did not obtain the certification of ISO1400 have low recognition of ISO14001, it needs continuous and positive publicity, education and a training system. Second, it requires to carry out an educational program to nurture professional manpower due to lack of manpower relevant to environmental management, to expand payment of subsidies, to open exclusive-charge department and consulting contact, to have the relevant information be database and to develop software. Third, in order to make the certification obtained through inexpensive costs and simple procedures, it needs to positively consider the creation of public approval system for a small and medium-sized company, group approval system, industrial-complex approval system, and others.

• Journal of Life Science
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• v.30 no.1
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• pp.45-57
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• 2020

The prenatal period in livestock animals is crucial for meat production because net increase in the number of muscle fibers is finished before birth. However, there is no study on the growth and development mechanism of muscles in Hanwoo during this period. Therefore, to find candidate genes involved in muscle growth and development during this period in Hanwoo, mRNA expression data of longissimus in Hanwoo at 6 and 9 months post-conceptional age (MPA) were analyzed. We independently identified differentially expressed genes (DEGs) using DESeq2 and edgeR which are R software packages, and considered the overlaps of the results as final-DEGs to use in downstream analysis. The DEGs were classified into several modules using WGCNA then the modules' functions were analyzed to identify modules which involved in myogenesis and adipogenesis. Finally, the hub genes which had the highest WGCNA module membership among the top 10% genes of the STRING network maximal clique centrality were identified. 913(6 MPA specific DEGs) and 233(9 MPA specific DEGs) DEGs were figured out, and these were classified into five and two modules, respectively. Two of the identified modules'(one was in 6, and another was in 9 MPA specific modules) functions was found to be related to myogenesis and adipogenesis. One of the hub genes belonging to the 6 MPA specific module was axin1 (AXIN1) which is known as an inhibitor of Wnt signaling pathway, another was succinate-CoA ligase ADP-forming beta subunit (SUCLA2) which is known as a crucial component of citrate cycle.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.826-833
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• 2014

Driven by both environmental and economic reasons, the development of small to medium scale GTL(gas-to-liquid) process for offshore applications and for utilizing other stranded or associated gas has recently been studied increasingly. Microchannel GTL reactors have been prefrered over the conventional GTL reactors for such applications, due to its compactness, and additional advantages of small heat and mass transfer distance desired for high heat transfer performance and reactor conversion. In this work, multi-microchannel reactor was simulated by using commercial CFD code, ANSYS FLUENT, to study the geometric effect of the microchannels on the heat transfer phenomena. A heat generation curve was first calculated by modeling a Fischer-Tropsch reaction in a single-microchannel reactor model using Matlab-ASPEN integration platform. The calculated heat generation curve was implemented to the CFD model. Four design variables based on the microchannel geometry namely coolant channel width, coolant channel height, coolant channel to process channel distance, and coolant channel to coolant channel distance, were selected for calculating three dependent variables namely, heat flux, maximum temperature of coolant channel, and maximum temperature of process channel. The simulation results were visualized to understand the effects of the design variables on the dependent variables. Heat flux and maximum temperature of cooling channel and process channel were found to be increasing when coolant channel width and height were decreased. Coolant channel to process channel distance was found to have no effect on the heat transfer phenomena. Finally, total heat flux was found to be increasing and maximum coolant channel temperature to be decreasing when coolant channel to coolant channel distance was decreased. Using the qualitative trend revealed from the present study, an appropriate process channel and coolant channel geometry along with the distance between the adjacent channels can be recommended for a microchannel reactor that meet a desired reactor performance on heat transfer phenomena and hence reactor conversion of a Fischer-Tropsch microchannel reactor.

• Archives of design research
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• v.20 no.3 s.71
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• pp.279-288
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• 2007

Today, design is not free from fashion, which emerges and vanishes temporarily, and aims at equalization. As a result, products quickly become obsolete because of fashion. This means that the span of products is determined by a social concept, which is not clarified, regardless of their functions. Usable products will gradually disappear from us and it will cause serious environmental problems, unless we can find out measures against fashion. As such, it is important to study the characteristics of the shaker's design in this circumstance. The Shaker's community has a distinguishable difference from other general societies. Temporary fashion and misled information cannot interfere with their consciousness. Religion, the life and the principle of design have developed on the same level in their community. Especially, any decoration or the difference of materials is not allowed in shaker's design. It reflects their thinking that all people are equal in the sight of God. Therefore, any decoration for social and economical superiority can not be used. Through this consciousness, they can be free from fashion or decoration. They, also, believe that they can reach perfection through practicality and simplicity. The reason why shaker's design is not disturbed by fashion is that their belief is involved in their design. Consequently, if religious or conscious contents are primarily set up, design can be free from fashion and products can be used for a long time.

• Archives of design research
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• v.20 no.3 s.71
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• pp.299-314
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• 2007

For the past 20 years, the growth and development of university-design-educational institutes contributed to the industrial development of our country. Due to the technological fluctuation and changes in the industrial structure in the latter half of the 20th century, the enterprise is demanding professionally-oriented design manpower. The principle which appears from instances of the advanced nations is to accommodate the demands in social changes and apply them to educational design programs. In order to respond promptly to the industrial demand especially, the advanced nations adopted "multidisciplinary design education programs" to lead innovation in the area of design globally. The objective of the research consequently is to suggest an educational system and a program through which the designer can be educated to obtain complex knowledge and the technique demanded by the industry and enterprise. Nowadays in order to adapt to a new business environment, designers specially should have both the knowledge and techniques in engineering and business administration. We suggest that the IPDI, a multidisciplinary design educational system and program is made up of the coordinated operation of major classes, on-the-job training connection, educational system for research base creation, renovation design development program for the application and the synthesis of alternative proposals about the training facility joint ownership by connecting with the education of design, business administration and engineering.

• Archives of design research
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• v.20 no.3 s.71
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• pp.151-162
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• 2007

How can new media devices and networks provide an effective response to the world's growing sector of cultural and historically-minded travelers? This study emerged from the question of how mobile handsets can change the nature of cultural and historical tourism in ubiquitous city environments. As wireless network and mobile IT have rapidly developed, it becomes possible to deliver cultural and historical information on the site through mobile handset as a tour guidance system. The paper describes the development of a new type of mobile tourism platform for site-specific cultural and historical information. The central objective of the project was to organize this cultural and historical walking tour around the mobile handset and its unique advantages (i.e. portability, multi-media capacity, access to wireless internet, and location-awareness potential) and then integrate the tour with a historical story and role-playing game that would deepen the mobile user's interest in the sites being visited, and enhance his or her overall experience of the area. The project was based on twelve locations that were culturally and historically significant to Korean War era in Busan. After the mobile tour game prototype was developed for this route, it was evaluated at the 10th PIFF (Pusan International Film Festival). After use test, some new strategies for developing mobile "edutainment content" to deliver cultural historical contents of the location were discussed. Combining 'edutainment' with a cultural and historical mobile walking tour brings a new dimension to existing approaches of the tourism and mobile content industry.