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Design a Four Layer Depth-Encoding Detector Using Quasi-Block Scintillator for High Resolution and Sensitivity (고분해능 및 고민감도를 위한 준 블록 섬광체를 사용한 네 층의 반응 깊이 측정 검출기 설계)

  • Seung-Jae Lee;Byungdu Jo
    • Journal of the Korean Society of Radiology
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    • v.18 no.2
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    • pp.65-71
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    • 2024
  • To achieve high resolution and sensitivity of positron emission tomography (PET) for small animals, the detector is constructed using very thin and long scintillation pixels. Due to the structure of these scintillation pixels, spatial resolution deterioration occurs outside the system's field of view. To solve this problem, we designed a detector that could improve spatial resolution by measuring the interaction depth and improve sensitivity by using a quasi-block scintillator. A quasi-block scintillator size of 12.6 mm x 12.6 mm x 3 mm was arranged in four layers, and optical sensors were placed on all sides to collect light generated by the interaction between gamma rays and the scintillator. DETECT2000 simulation was performed to evaluate the performance of the designed detector. Flood images were acquired by generating gamma-ray events at 1 mm intervals from 1.3 mm to 11.3 mm within the scintillator of each layer. The spatial resolution and peak-to-peak distance for each location were measured in an 11 x 11 array of flood images. The average measured spatial resolution was 0.25 mm, and the average distance between peaks was 1.0 mm. Through this, it was confirmed that all locations were separated from each other. In addition, because the light signals of all layers were measured separately from each other, the layer of the scintillator that interacted with the gamma rays could be completely separated. When the designed detector is used as a detector in a PET system for small animals, it is considered that excellent spatial resolution and sensitivity can be achieved and image quality can be improved.

The Amplifying Aspects of SNS Comments: An Exploratory Study through the Sentiment Comparison between News Site Comments and SNS Comments (SNS 댓글의 정보 증폭 양상에 대한 연구: 뉴스 사이트 댓글과 SNS 댓글의 센티멘트 차원 비교를 통한 탐색적 분석)

  • Jinyoung Min
    • Information Systems Review
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    • v.22 no.4
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    • pp.163-184
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    • 2020
  • The information on SNS, which is created by the forms of postings and comments, is being magnified and redistributed to news media expanding its impacts on real words. This amplifying effects of SNS comments have been increasingly discussed but there still lacks the answers for which dimensions of information is magnified, and what affects the direction and the degree of the amplification. This study, therefore, explores the detailed dimensions that are magnified by SNS comments and how SNS posting structure and social network characteristics affect them by using sentiment analysis. By analyzing 2,378 Facebook postings and news articles and their 26,312 SNS and 74,730 news site comments, this study shows that SNS comments magnify the sentiments of the posting articles they are attached to. In comparison to news site comments, SNS comments magnify the cognitive and social dimensions more than the news site comments. In the affective dimension, they tend to magnify only the positive emotion more than news site comments. Also, the findings reveal that whether the article in the posting is written by the posting owner affects the degree of amplification when the comments are remained positive or switched positive, while the opposite determines the amplification when comments remain negatively, suggesting that the user relationship in social network is the important factor that affects the direction and the degree of the information amplification in SNS.

Full mouth rehabilitation with reorientation of occlusal plane using facial scan: a case report (교모 환자에서 안면 스캔을 활용하여 교합 평면을 재설정한 전악 보철 수복 증례)

  • Eun-Gyeong Kim;Sae-Eun Oh;Jee-Hwan Kim
    • The Journal of Korean Academy of Prosthodontics
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    • v.62 no.1
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    • pp.64-71
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    • 2024
  • The most critical aspect of full-arch prosthodontic treatment is evaluating whether the patient's vertical occlusal dimension is appropriate, and if necessary, restoring it through increasing vertical dimension. If the vertical occlusal dimension is too low, it can lead to reduced chewing efficiency, as well as not only aesthetic concerns but also potential issues like hyperactivity of muscles and posterior displacement of the mandible. This report is about the patient dissatisfied with pronunciation and aesthetics due to an inappropriate vertical occlusal dimension resulting from prior prosthetic interventions, underwent full-arch prosthodontic restoration treatment. Through the utilization of digital diagnostic apparatus, a comprehensive evaluation was undertaken for patient's vertical occlusal dimension, occlusal plane orientation, and the condition of prosthetic restorations. Through 3D facial scanning, the facial landmarks were discerned, and subsequently, the new occlusal plane was established. This provided the foundation for a digitally guided diagnostic wax-up. An elevation of 5 mm from the incisor was determined. Comprehensive dental rehabilitation was then executed for all remaining teeth, excluding the maxillary four incisors. The treatment protocol followed a systematic approach by initially creating implant-supported restorations on both sides of the dental arch to establish a stable occlusal contact. Subsequently, prosthetic restorations for the natural dentition were generated. Diagnostic and treatment planning were established through the utilization of facial scanning. This subsequently led to a reduction in treatment complexity and an expedited treatment timeline.

Symptoms of the subject in a movie based on Lacan's work on psychosis - Focusing On Lars von Trier's film (라캉의 정신병 연구에 근거한 영화 속 주체의 증상 - 라스 폰 트리에의 <살인마 잭의 집>을 중심으로)

  • HAN JINGZHI
    • Trans-
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    • v.16
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    • pp.69-105
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    • 2024
  • The House that Jack Built (2018), a film about how the protagonist Jack is reborn as a "mad artist" with psychotic symptoms during a 12-year killing spree, provides an interesting opportunity to analyze the film in terms of psychoanalysis and religion. Jack, an engineer who suffers from OCD, finds pleasure in the accidental murder of a character and considers killing people as an art form, overcoming his OCD in the process. The question we are interested in is whether the symptoms of OCD are truly overcome by the act of repeated killing. The idea is that Jack's OCD is not overcome by killing, but rather that the symptoms disappear as he moves from neurosis to a stabilized psychotic state. According to the theory of the famous French psychoanalyst Lacan, the hallucinations or delusions that human subjects experience when they lose their realistic stability are a phenomenon that occurs when they are confronted with The Real, which penetrates through the cracks of the symbolic system. Phenomena such as Jack's illusory reality and delusions in the movie are pathological symptoms of the absence of a paternal figure in his life, causing the Name-of-the-Father to fail to take hold. This paper deciphers the psychotic structure of Jack, the protagonist of Lars von Trier's House of Jack, through Lacanian psychoanalysis.

Development Trends of Thermal Control Design and Analysis of Robotic Arm Payload for Spacecraft (인공위성 로봇팔 탑재체의 열 제어 설계 및 해석 개발 동향 )

  • Han-Seop Shin;Hae-Dong Kim
    • Journal of Space Technology and Applications
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    • v.4 no.1
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    • pp.27-47
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    • 2024
  • In the New space era, satellites are being developed to perform on-orbit service (OOS) missions. Various missions for orbital service include failure repair, refueling, towing, component replacement, and space construction, and in order to do so, a robot arm payload must be mounted. Unlike conventional satellite payloads, the robot arm payload is not move in a fixed state, but is a payload that must move continuously to perform the mission. It is also characterized by the need to perform the mission while being directly exposed to outer space, rather than existing inside the structure of the satellite. Due to the characteristics of these payloads, thermal design and interpretation that can be operated smoothly in an extreme space thermal environment is essential, but there are not many papers on thermal design and interpretation of the robot arm. This paper introduces and summarizes cases of thermal design and interpretation of robot arm payloads developed so far, and finally, it intends to suggest directions for thermal design and interpretation of robot arm payloads to be developed in the future.

Adaptive Row Major Order: a Performance Optimization Method of the Transform-space View Join (적응형 행 기준 순서: 변환공간 뷰 조인의 성능 최적화 방법)

  • Lee Min-Jae;Han Wook-Shin;Whang Kyu-Young
    • Journal of KIISE:Databases
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    • v.32 no.4
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    • pp.345-361
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    • 2005
  • A transform-space index indexes objects represented as points in the transform space An advantage of a transform-space index is that optimization of join algorithms using these indexes becomes relatively simple. However, the disadvantage is that these algorithms cannot be applied to original-space indexes such as the R-tree. As a way of overcoming this disadvantages, the authors earlier proposed the transform-space view join algorithm that joins two original- space indexes in the transform space through the notion of the transform-space view. A transform-space view is a virtual transform-space index that allows us to perform join in the transform space using original-space indexes. In a transform-space view join algorithm, the order of accessing disk pages -for which various space filling curves could be used -makes a significant impact on the performance of joins. In this paper, we Propose a new space filling curve called the adaptive row major order (ARM order). The ARM order adaptively controls the order of accessing pages and significantly reduces the one-pass buffer size (the minimum buffer size required for guaranteeing one disk access per page) and the number of disk accesses for a given buffer size. Through analysis and experiments, we verify the excellence of the ARM order when used with the transform-space view join. The transform-space view join with the ARM order always outperforms existing ones in terms of both measures used: the one-pass buffer size and the number of disk accesses for a given buffer size. Compared to other conventional space filling curves used with the transform-space view join, it reduces the one-pass buffer size by up to 21.3 times and the number of disk accesses by up to $74.6\%$. In addition, compared to existing spatial join algorithms that use R-trees in the original space, it reduces the one-pass buffer size by up to 15.7 times and the number of disk accesses by up to $65.3\%$.

Vegetation Structure of Evergreen Broad-Leaved forest in Dongbaekdongsan(Mt.), Jeju-Do, Korea (제주도 동백동산 상록활엽수림의 식생구조)

  • Han, Bong-Ho;Kim, Jong-Yup;Choi, In-Tae;Lee, Kyong-Jae
    • Korean Journal of Environment and Ecology
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    • v.21 no.4
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    • pp.336-346
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    • 2007
  • This study was conducted to evaluate the vegetation structure of 34 plots for inspection(plot unit: $100m^2$)of evergreen broad-leaved forest in Dongbaekdongsan(Mt.), Jeju-do, Korea. In accordance with the results of TWINSPAN and mean importance percentage analysis, the target forest was aged $28{\sim}52$, and classified into seven community types in total: Ilex rotunda community, Castanopsis sieboldii community, Castanopsis sieboldii-Quercus glauca community, Quercus glauca-Castanopsis sieboldii community, Quercus glauca community, Quercus glauca-Camellia japonica community, and Quercus glauca-Styrax japonica community. According to the results of importance percentage analysis and DBH class distribution of major woody species, the vegetational aspects showed that the dominant species were Castanopsis sieboldii and Quercus glauca in the canopy layer and Camellia japonica in the subordinate layer. Ilex rotunda and Quercus glauca-Styrax japonica community were damaged vegetation in the canopy layer. According to the index of Shannon's diversity in the six communities including the dominant species - Quercus glauca and Castanopsis sieboldii, their species diversity degree was $0.8745{\sim}1.3018$ and that of Ilex rotunda community was the lowest 0.7619. Camellia japonica, Eurya japonica, Ilex rotunda, Trachelospermum asiaticum var. intermedium, Ardisia crenata appeared in all the seven communities. In addition, Litsea coreana and Cinnamomum japonicum as well as Neolitsea serica presumed as climax species in the warm temperate climate also appeared and the constancy ratio of Cinnamomum japonicum was more than 80%. As a result, the target forest in Dongbaekdongsan(Mt.) was mainly compose of Castanopsis sieboldii and Quercus glauca in the canopy layer as a mixed vegetational pattern, and Cameliia japonica was dominant in the subordinate layer. Continuous monitoring was required, since Camellia japonica was strong in the subordinate layer in contrast to the weakness of Litsea coreana and Neolitsea serica reported as the species of climax stage in the forest with Evergreen Broad-leaved Vegetation at a viewpoint of successional direction.

A Study on the Biotope Structure of Wintering Place and Behavior Characteristics of Anser fabalis in Cheongna Area, Incheon Free Economic Zone, Korea (인천경제자유구역 청라지구에서의 큰기러기 월동지 비오톱구조와 행동특성 연구)

  • Park, Byeong-Ku;Han, Bong-Ho;Lee, Kyong-Jae;Kwak, Jeong-In;Im, Seong-Soo
    • Korean Journal of Environment and Ecology
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    • v.27 no.3
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    • pp.305-315
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    • 2013
  • This study is aimed to provide the preliminary data for conservation and management of wintering site for Anser fabalis population in Cheongna Area, Incheon Free Economic Zone, Korea through analyzing the relationship between the biotop structure of its wintering site and behavior characteristics. The main types (size and ratio) of the biotope in Cheongna Area, Incheon Free Economic Zone are reed wetlands ($6,093,762m^2$, 47.8%), rice fields without rice straw ($2,927,916m^2$, 23.0%), and rice fields with rice straw ($1,915,655m^2$, 15.0%). According to the survey carried on 13th Feb., 2013, total 33 species and 6, 535 individual birds were observed and among of them, the dominant bird was Anser fabalis showing 5,128 indiviuals, 78% of total population. As the result of analyzing the migratory route of Anser fabalis, the bird moved from roosting site to foraging site before and after sunrise and from feeding site to roosting site before and after sunset. According to the analysis of interrelation between habitat characteristics and biotope types of the bird, population density was the highest in reed wetlands among habitat types and individual appearance was the highest in water-filled rice field melting ice. The bird ate the roots and bulb of hydrophytes in reed wetlands and showed various behaviors like eating dropped grains, resting and sleeping in water-filled rice fields and eating dropped grains and resting in rice fields with and without rice straw. It is shown that the number of Anser fabalis appearing in rice fields is depended on the presence of dropped grains than types of rice field.

Characteristics of Vegetation Structure of Managed Area by Oak Wilt Disease in Bukhansan National Park (북한산국립공원 참나무시들음병 방제지역 식생구조 특성 연구)

  • Han, Bong-Ho;Choi, Jin-Woo;Yeum, Jung-Hun;Lee, Kyong-Jae
    • Korean Journal of Environment and Ecology
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    • v.28 no.3
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    • pp.342-356
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    • 2014
  • This study aims to provide the fundamental data for restoration through the analysis of vegetation structure characteristic for managed area with deforest and fumigation among the places damaged by oak wilt disease in Bukhansan National Park. Study areas were selected in six damaged areas with 18 plots ($20m{\times}20m$) including comparing plots between year 2006 and year 2011 after preliminary study finding the exact location with easy access. Analysis items are density and coverage of under story layer, Importance Percentage of under story layer and Importance Percentage of urban adapted species and alien species. As a result, density and coverage under the canopy layer's vegetation was higher than comparing plot in Musugol valley and Soquicheon valley which 4 years and more passed. And Wondobong, Darakwon, Doseonsa and Dobong valley which had not been passed 3 years after deforestation and fumigation decreased in those of vegetation. However, the plots in Wondobong and Doseonsa was analyzed to be higher in density of shrubs than comparing plot. In terms of distirbution of species in under canopy layer which is grown as a upper vegetation, Quercus serrata and Sorbus alnifolia dominated each other in under canopy layer except for Wondobong and Darakwon. Wondobong continuously maintained Quercus mongolica and Q. mongolica and Pinus densiflora dominated in under canopy layer of Darakwon. S. alnifolia which is Urban adapted species were distributed in most study areas. In terms of alien species, Magnolia obovata and Robinia pseudoacacia were newly intruded in the opened crown, and Pueraria thunbergiana was distributed in Soquicheon valley. As the result of soil analysis, acidification(pH 4.49) and low level of organic matter(3.23%), available phosphate(1.40mg/kg) and exchangeable cation were analyzed and it was considered that those environment poorly support the vegetation growth.

Home Range and Behavioral Characteristics of the Endangered Korea Gorals(Naemorhedus caudatus) With GPS Collar (GPS Collar를 이용한 멸종위기 한국 산양(Naemorhedus caudatus)의 행동 특성)

  • Cho, Chea-Un;Gyun, Gu-Hee;Yang, Jung-Jin;Lim, Sang-Jin;Lee, An-Na;Park, Hee-Bok;Lee, Bae-Keun
    • Korean Journal of Environment and Ecology
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    • v.28 no.1
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    • pp.1-9
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    • 2014
  • This study was to understand the ecological characteristics of the goral through the study on goral behavioral characteristics and to be carried out to provide basic behavioral data such as annual home range, seasonal home range and monthly used altitude with 4,752 locations obtained during the study period through home range analysis of three long-tailed gorals (Naemorhedus caudatus) in Soeraksan. For this study, gorals who were rescued from heavy snow in Seoraksan were used. The gorals were equipped with GPS Collar, released at their natural habitats, and then monitored from May, 2010 to September, 2011. According to our results, annual home ranges of the gorals (n=3) have $0.88km^2$ of MCP 95%, $0.27km^2$ of MCP 50%, $0.43km^2$ of FK 95%, and $0.09km^2$ of FK 50% respectively. Seasonal home range of MCP 95% was $0.47km^2$ in spring, $0.45km^2$ in summer, $0.63km^2$ in fall and $0.50km^2$ in winter respectively and home ranges of fall was the largest. In the case of FK 95% analysis, home ranges were $0.23km^2$ in spring, $0.19km^2$ in summer, $0.33km^2$ in fall, and $0.22km^2$ in winter respectively and the largest seasonal home range was fall. Female and male annual home ranges of the gorals were $1.03km^2$ for female and $0.58km^2$ for male. In analysis of the monthly used altitudes which were used Jun, July, and August were higher than in the other months and the altitudes which were used in Dec, Jan, and Feb were lower than in the other months. This study was to secure basic data for the habitat management policy, restoration, and conservation of Korea gorals and to be conducted to contribute to the success in doing or planning stage of the wild animal restoration.