• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.403-414
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• 2004

In the accompanying paper, we proposed a real. time volumetric imaging method using a cross array based on receive dynamic focusing and synthetic aperture focusing along lateral and elevational directions, respetively. But synthetic aperture methods using spherical waves are subject to beam spreading with increasing depth due to the wave diffraction phenomenon. Moreover, since the proposed method uses only one element for each transmission, it has a limited transmit power. To overcome these limitations, we propose a new real. time volumetric imaging method using cross arrays based on synthetic aperture technique with linear wave fronts. In the proposed method, linear wave fronts having different angles on the horizontal plane is transmitted successively from all transmit array elements. On receive, by employing the conventional dynamic focusing and synthetic aperture methods along lateral and elevational directions, respectively, ultrasound waves can be focused effectively at all imaging points. Mathematical analysis and computer simulation results show that the proposed method can provide uniform elevational resolution over a large depth of field. Especially, since the new method can construct a volume image with a limited number of transmit receive events using a full transmit aperture, it is suitable for real-time 3D imaging with high transmit power and volume rate.

• Progress in Medical Physics
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• v.14 no.2
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• pp.124-130
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• 2003

Currently, as a consequence of PACS (Picture Archiving Communication System) implementation many hospitals are replacing conventional film-type interpretations of diagnostic medical images with new digital-format interpretations that can also be saved, and retrieve However, the big limitation in PACS is considered to be the lack of mobility. The purpose of this study is to determine the optimal communication packet size. This was done by considering the terms occurred in the wireless communication. After encoding medical image using JPGE2000 image compression method, This method embodied auto-error correction technique preventing the loss of packets occurred during wireless communication. A PC class server, with capabilities to load, collect data, save images, and connect with other network, was installed. Image data were compressed using JPEG2000 algorithm which supports the capability of high energy density and compression ratio, to communicate through a wireless network. Image data were also transmitted in block units coeded by JPEG2000 to prevent the loss of the packets in a wireless network. When JPGE2000 image data were decoded in a PUA (Personal Digital Assistant), it was instantaneous for a MR (Magnetic Resonance) head image of 256${\times}$256 pixels, while it took approximately 5 seconds to decode a CR (Computed Radiography) chest image of 800${\times}$790 pixels. In the transmission of the image data using a CDMA 1X module (Code-Division Multiple Access 1st Generation), 256 byte/sec was considered a stable transmission rate, but packets were lost in the intervals at the transmission rate of 1Kbyte/sec. However, even with a transmission rate above 1 Kbyte/sec, packets were not lost in wireless LAN. Current PACS are not compatible with wireless networks. because it does not have an interface between wired and wireless. Thus, the mobile JPEG2000 image viewing system was developed in order to complement mobility-a limitation in PACS. Moreover, the weak-connections of the wireless network was enhanced by re-transmitting image data within a limitations The results of this study are expected to play an interface role between the current wired-networks PACS and the mobile devices.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.21-41
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• 2010

This paper proposes a system that can serve users with appropriate search results through real time filtering, and implemented adaptive user profiling based personalized information retrieval system(PIRS) using users' implicit feedbacks in order to deal with the problem of existing search systems such as Google or MSN that does not satisfy various user' personal search needs. One of the reasons that existing search systems hard to satisfy various user' personal needs is that it is not easy to recognize users' search intentions because of the uncertainty of search intentions. The uncertainty of search intentions means that users may want to different search results using the same query. For example, when a user inputs "java" query, the user may want to be retrieved "java" results as a computer programming language, a coffee of java, or a island of Indonesia. In other words, this uncertainty is due to ambiguity of search queries. Moreover, if the number of the used words for a query is fewer, this uncertainty will be more increased. Real-time filtering for search results returns only those results that belong to user-selected domain for a given query. Although it looks similar to a general directory search, it is different in that the search is executed for all web documents rather than sites, and each document in the search results is classified into the given domain in real time. By applying information filtering using real time directory classifying technology for search results to personalization, the number of delivering results to users is effectively decreased, and the satisfaction for the results is improved. In this paper, a user preference profile has a hierarchical structure, and consists of domains, used queries, and selected documents. Because the hierarchy structure of user preference profile can apply the context when users perfomed search, the structure is able to deal with the uncertainty of user intentions, when search is carried out, the intention may differ according to the context such as time or place for the same query. Furthermore, this structure is able to more effectively track web documents search behaviors of a user for each domain, and timely recognize the changes of user intentions. An IP address of each device was used to identify each user, and the user preference profile is continuously updated based on the observed user behaviors for search results. Also, we measured user satisfaction for search results by observing the user behaviors for the selected search result. Our proposed system automatically recognizes user preferences by using implicit feedbacks from users such as staying time on the selected search result and the exit condition from the page, and dynamically updates their preferences. Whenever search is performed by a user, our system finds the user preference profile for the given IP address, and if the file is not exist then a new user preference profile is created in the server, otherwise the file is updated with the transmitted information. If the file is not exist in the server, the system provides Google' results to users, and the reflection value is increased/decreased whenever user search. We carried out some experiments to evaluate the performance of adaptive user preference profile technique and real time filtering, and the results are satisfactory. According to our experimental results, participants are satisfied with average 4.7 documents in the top 10 search list by using adaptive user preference profile technique with real time filtering, and this result shows that our method outperforms Google's by 23.2%.

• Progress in Medical Physics
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• v.24 no.4
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• pp.253-258
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• 2013

The purpose of this study is to evaluate and analyze the relationship between the external radiation dose reconstruction which is transmitted from the patient who receives radiation treatment through electronic portal imaging device (EPID) and the internal dose derived from the Monte Carlo simulation. As a comparative analysis of the two cases, it is performed to provide a basic indicator for similar studies. The geometric information of the experiment and that of the radiation source were entered into Monte Carlo n-particle (MCNPX) which is the computer simulation tool and to derive the EPID images, a tally card in MCNPX was used for visualizing and the imaging of the dose information. We set to source to surface distance (SSD) 100 cm for internal measurement and EPID. And the water phantom was set to be 100 cm of the source to surface distance (SSD) for the internal measurement and EPID was set to 90 cm of SSD which is 10 cm below. The internal dose was collected from the water phantom by using mesh tally function in MCNPX, accumulated dose data was acquired by four-portal beam exposures. At the same time, after getting the dose which had been passed through water phantom, dose reconstruction was performed using back-projection method. In order to analyze about two cases, we compared the penetrated dose by calibration of itself with the absorbed one. We also evaluated the reconstructed dose using EPID and partially accumulated (overlapped) dose in water phantom by four-portal beam exposures. The sum dose data of two cases were calculated as each 3.4580 MeV/g (absorbed dose in water) and 3.4354 MeV/g (EPID reconstruction). The result of sum dose match from two cases shows good agreement with 0.6536% dose error.

• Sijohaknonchong
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• v.42
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• pp.29-68
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• 2015

This article focused on the development and current status of Sijo-chang, the Korean classical vocal genre, which is the text as a fixed form of Korean classical poems. Historically, Sijo-chang has originally emerged from Hyangga鄕歌 during Silla period (BC. 57- AD. 935). However, the current Sijo-chang has been developed from the latter of Joseon朝鮮 period(AD. 1392-1910) in 1800s. Since 1800s, Sijo-chang derived from the Gyeong-je Pyeong sijo京制 平時調, which was established in Seoul, was able to accelerate its musical types and regional characteristics among the Korean peninsula. By setting a clear division of two time periods between 1800s and those periods since 1900s to today, this article mainly explains how Sijo-chang has been developed historically. First of all, in order to appraise the musical styles and characteristics of Sijo-chang in 1800s, comparing the current musical types of Sijo-chang and those printed old score books which has its historical musical characteristics during 1800s is necessary. Secondly, this paper concentrated on the transmitted lineages of representative vocalists among the regional-based Sijo-chang from 1900s to today. During those periods, the Sijo-chang has formed its particular regional-based musical characteristics among the Korean peninsula such as Yeong-je嶺制 of Gyeongsang province慶尙道, Naepo-je內浦制 of Chungcheong province忠淸道 and Wan-je完制 of Cheolla province全羅道. Although it was not a type of regional-based Sijo-chang, as a creation with reference based on certain regional types of Sijo-chang in 1960s, this paper introduced the inheritance process of Seogam-je石菴制 which was made by Jung Gyeong-tae鄭坰兌 named Seogam石菴 as his pen name. Since Seogam-je has been singing as the most influential musical types of Sijo-chang through the mainly southern region of Korean peninsula and even in Seoul, it was highly significant to research it. In addition, this paper elaborately highlighted the developments of various Sijo-chang based on its historical performances, studies, and the composed pieces from the early 1900s or the mid-1900s. In conclusion, in order to set a vigorous development of Sijo-chang, this paper raised several concerns among the future of Sijo-Chang and the significance of its traditional value.

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.69-77
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• 2005

The purposes of this study were to develop and introduce a novel intraoral appliance for bruxism composed of power switch and biofeedback device and further to examine inter- and intra-reliability of the appliance prior to clinical tests. The newly-developed appliance consisted of detection sensors, a central processing unit (CPU), a reactor and a storage unit and a displayer. Compact-sized, waterproof switches were selected as bruxism detection sensor and any sensor activation by clenching or grinding event was processed at the CPU and transmitted, by radio wave, to the reactor and storage unit and triggered auditory or vibratory signal, subsequently producing biofeedback to the patient with bruxism. The data on bruxing event in the storage unit can be displayed on the computer, making it possible analyzing frequency, duration and nature of bruxism. Cast models were obtained from ten volunteers with normal occlusion to evaluate reliability of the appliances. For inter-operator reliability on the intraoral appliances, each operator of the two fabricated the appliance for the same subject and compared the minimal contact forces provoking auditory biofeedback reaction in vertical, lateral and central directions. Intra-operator reliability was also investigated on the appliances made by a single operator at two separate times with an interval of two days. Conclusively, the newly-developed appliance is compact and safe to use in oral circumstance and easy to make. Furthermore, it had to be proven reliability excellent enough to apply in clinical settings. Thus, it is assumed that this appliance with the processor and the storage of data and auditory or vibratory biofeedback function is available and useful to analyze and control bruxism.

• Korea journal of population studies
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• v.20 no.2
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• pp.181-198
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• 1997

Going beyond the previous formulations of development theories, the present paper explores the effects other than political economy on quality of life in a rapidly developing country. The major analysis takes up the historical trend and nature of the developmental transformation that is partially a consequences of state structures and partially autonomous form it in South Korea. Also, it diagnoses developmental pathways for the future track by constructing a baseline model for state transition on the basis of power game between the state and civil society in the country. The results of the historical analysis show that civil society has been transformed in the course of confrontations and interactions between the state and nationalist social movement. The distinction between developmental(or bureaucratic authoritarian) and democratic state is presented to show that these are two qualitatively different aspects of state of state power, requiring separate analytical treatment. Furthermore, the state-centric approach which emphasizes the active role of the state at the sacrifice of societal fabric-constraining social conditions for quality of life - appears to be modified. On the contrary, the impact of civil society is transmitted both directly and indirectly via labor and ecological movement for quality of life, which is critical to the formation of the welfare state in the country. The prospect for sustainable development in Korea lies in providng and expanding quality of life in terms of the financial feasibility of the state through the public-private cooperation, and abstaining from drastic and radical commitment to welfare services as is the case with the European declines in welfare state, Further studies are needed to examine the interrelationships in different historical and cultural settings of developing counties to estimate a theory of quality of life and social justice.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.94-105
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• 2009

Black locust (Robinia pseudoacacia) stand is representative lowland exotic plantation with low ecological quality and arrested succession in South Korea. To facilitate succession and restore natural vegetation, small canopy gaps (${\sim}57m^2$), which can modify minimally structural variables and reduce restoration related disturbances on stand, was established in the black locust stand, and oak (Quercus serrata) seedlings were introduced in the gap. Two types of varying levels were introduced for gap creation; cutting (C) and girdling (G) on canopies. Understory removal (CU and GU) treatment was applied as subtypes of structural modification. Growth (diameter, height and leaf area) of target species and responses (species composition, diversity and coverage) of understory community were monitored during study years (2007~2008). Canopy openness was different significantly among treatments but not for light availability. Based on the result of logistic regression, growth of height and leaf area of seedlings were significant variables on seedling survival. Height and leaf area of seedlings were increased during study years, although radial growth was reduced. During study years, there were no significant differences in species composition and diversity, and total coverage increased about 20%. Increase of resources by gap creation and understory removal likely affect growth of target species. Small gap creation was effective to reduce understory responses in composition and diverstiy. Synthesized, growth of target species and responses of understory community to small canopy gap creation exhibited, in short term, possibility of utilization in alternative forest restoration and management option. Long-term monitoring is necessary to certificate effect of artificial gap creation on forest restoration.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.5
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• pp.82-93
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• 2008

This research focused on the process in which 'the same scenery' is recognized and represented as 'a different landscape' to determine the symbols and meaning of the scenery and landscape included in real-scenery landscape paintings of the 18th-19th centuries. As a result of analyzing the visual points, the content and expressions of 25 real-scenery landscape paintings of Chong Seok Jeong(叢石亭), it can be seen that the transmission of a kind of semiotic landscape on the basis of a specific symbol was accomplished naturally through imitation and representation for the purpose of the expression of Chong Seok Jeong-like idealized scenery. This shows that the unique images of Chong Seok Jeong have long been passed down after taking root as a unique benchmark The meaningful symbol of 'a strange Saseonbong(四仙峰)', which is broken by the spray after rising high, and 'a pine forest' have both been transmitted as being in the manner of Chong Seok Jeong. This has been equipped with the stereo-type scene by being a collective symbolization as the psycho-scenes in memory element of Chong Seok Jeong. Through the pictures of both Gyeomjae(謙齋) and Danweon(檀園), the process by which a specific painter's pictures become acculturated is highly interesting. The scenery expressed in these pictures was clearly that of a landscape of which its particularly emotions and remembrances were repainted through the experience of several places and original sketches. This can be explained as the concept in which the image from 'a specific scenery' gained through actual experience, that is, a personal feeling, has been expressed. The picture that was expressed as a different figure even at the same visual point for the same scenery is the result that was redefined through the scenery subject's recognition. Also, the modification of the scenery object can be colorful through meditation and Sachu(邪推: guessing with wicked doubt). The scenery recognized newly through adoption, omission and emphasis, it is 'the specific scenery' in the heart and is a figure having been more similar to 'a landscape' if the objective life reproduction before being acculturated is a figure similar to the scenery. So, the concept looks like being very persuasive that 'the nature with objectivity captured sensuously' simply is the scenery, and that 'the subjective phenomenon having acquired the cultural nature by being introspected in the method of aesthetic nostalgia is a landscape'.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5
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• pp.53-63
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• 2010

The purposes of this study are to classify the characteristics of parks by park use patterns and the understanding of design concepts and to analyze the difference of cognition of design concept between designers and park users. The literature studies and surveys were performed to analyze park use patterns and understanding of design concepts for Seoul Forest Park, Yeouido Park and Seonyudo Park. Several statistical methods have been used such as descriptive analysis and importance-performance analysis. The results of this research are as follows. As the results of an analysis of park use patterns, Seonyudo Park may he qualified as an urban landmark park, while Yeouido Park can he classified as a neighborhood park. Seoul Forest Park bas characteristics of both. Second, the higher frequency of visits generally leads higher preference. Third, the overall cognition of the design concepts of parks shows 3.51 on average, which is comparatively high. The functional concepts are better transmitted to the users compared to abstract concepts. The cognition of the design concepts of each park are evaluated in the higher order of Seonyudo Park, Seoul Forest Park and Yeouido Park. Fourth, the cognition levels of detailed design concepts for each place are lower than the overall design concepts. On the other hand, levels of satisfaction are increased after the design concepts are noticed. It would he necessary make the effort to give information about the design concept of each space. The results of this study are limited in that it covers only three parks in Seoul, and did not consider seasonal variables. Nevertheless, this study may he significant in that it dealt with the cognition of design concepts for urban parks, focusing on the difference between designers and visitors.