• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.5
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• pp.79-96
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• 2021

Green infrastructure planning represents landscape planning measures to reduce particulate matter. This study aimed to derive factors that may be used in planning green infrastructure for particulate matter reduction using text mining techniques. A range of analyses were carried out by focusing on keywords such as 'particulate matter reduction plan' and 'green infrastructure planning elements'. The analyses included Term Frequency-Inverse Document Frequency (TF-IDF) analysis, centrality analysis, related word analysis, and topic modeling analysis. These analyses were carried out via text mining by collecting information on previous related research, policy reports, and laws. Initially, TF-IDF analysis results were used to classify major keywords relating to particulate matter and green infrastructure into three groups: (1) environmental issues (e.g., particulate matter, environment, carbon, and atmosphere), target spaces (e.g., urban, park, and local green space), and application methods (e.g., analysis, planning, evaluation, development, ecological aspect, policy management, technology, and resilience). Second, the centrality analysis results were found to be similar to those of TF-IDF; it was confirmed that the central connectors to the major keywords were 'Green New Deal' and 'Vacant land'. The results from the analysis of related words verified that planning green infrastructure for particulate matter reduction required planning forests and ventilation corridors. Additionally, moisture must be considered for microclimate control. It was also confirmed that utilizing vacant space, establishing mixed forests, introducing particulate matter reduction technology, and understanding the system may be important for the effective planning of green infrastructure. Topic analysis was used to classify the planning elements of green infrastructure based on ecological, technological, and social functions. The planning elements of ecological function were classified into morphological (e.g., urban forest, green space, wall greening) and functional aspects (e.g., climate control, carbon storage and absorption, provision of habitats, and biodiversity for wildlife). The planning elements of technical function were classified into various themes, including the disaster prevention functions of green infrastructure, buffer effects, stormwater management, water purification, and energy reduction. The planning elements of the social function were classified into themes such as community function, improving the health of users, and scenery improvement. These results suggest that green infrastructure planning for particulate matter reduction requires approaches related to key concepts, such as resilience and sustainability. In particular, there is a need to apply green infrastructure planning elements in order to reduce exposure to particulate matter.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.68-80
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• 2019

This study is to provide basic data for the user-oriented design for a middle school meditation forest in the future by analyzing the physical environment characteristics of existing middle school meditation forests, the users' utilization behavior, and the degree of the importance satisfaction. For this purpose, 24 evaluation indices based on site characteristics, naturalness, functionality, and the effectiveness of meditation forest sites were selected for analysis of importance satisfaction. We surveyed and analyzed the students and teachers of two middle schools 'A' and 'B' in Gwangju Metropolitan City. The results of this study are as follows. First, the perception and utilization rates of the meditation forests by students was significantly lower than teachers at both schools. 'A' school has a better use and recognition rate than the 'B' school. Second, the purposes of using meditation forests were rest (49.6%), weekday lunchtime (63.6%), with friends (65.0%) or colleagues (60%), and short (less than 10 minutes) rests (68.6%). They preferred flowers (30.0%) and shading plants (28.9%), mainly using shelters (57.9%) and walking trails (37.1%). Third, as a result of the importance of satisfaction analysis, the average score of the 24 items importance (3.81), higher than the satisfaction (3.62). The 24 items positioned in 4 quadrants are as follows: Nine items are in the I quadrant for 'persistent maintenance'. Three items are in the II quadrant for 'priority correction'. Seven items are in the quadrant III for 'low priority in the management and operation'. Five items are in the quadrant IV for 'avoid over effort'. For the comparison of two middle schools' satisfaction, 'A' school satisfaction was higher than 'B' school for 16 items, which showed a statistically significant difference. It is believed that the users in 'A' school are more satisfied than 'B' school because it has more forests and trails, better accessibility, and a variety of plant types and planting areas in the A school meditation forest. The results of the overall satisfaction analysis showed a significant difference between 'A' school (68.0%) and 'B' school (47.2%) as 'A' school has better shelters and trails. The rankings of the most satisfying space are walking trails (1st place) and shelters (2nd place). The reason for the highest satisfaction was for rest (stress relief and emotional support) in both 'A' and 'B' schools.

• Cartoon and Animation Studies
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• s.15
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• pp.251-265
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• 2009

Motion Graphics are a great effective vehicle for precise communication between customers in various media and formats. The important thing in the expression of Motion Graphics is to deliver messages clearly. Some current Motion Graphics which are focused on only attracting attention or sensational expressions more than narrative are evaluated lower. This study aims to utilize easy and positive Motion Graphics to deliver messages by applying their utility to production of Motion Graphics, omitting time spent on delivering effective messages and analyzing their suggestive expression methods because of the nature of producing Motion Graphics. This thesis is to study several theoretical backgrounds of omission and implicated expressions mentioned in the similar studies from the view of Motion Graphics, and to search applied examples and functional things using the expression methods in some film title sequence. Excellent Motion Graphics use planned omission and implicated methods rather than to use entire narratives or complicated descriptions. Especially, a film title sequence should focus on symbolic visual expressions. They are necessary to attract the audience's interest. To overcome the limitation of time and space deliver a huge amount of information quickly and powerfully, Motion Graphics should properly use omission of image and time and suggestive expressions through symbols and metaphors. Then they will have a role to level up their current values and discussions.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.2
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• pp.113-130
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• 2004

Most multimedia data contain text to emphasize the meaning of the data, to present additional explanations about the situation, or to translate different languages. But, the left makes it difficult to reuse the images, and distorts not only the original images but also their meanings. Accordingly, this paper proposes a support vector machines (SVMs) and spatiotemporal restoration-based approach for automatic text detection and removal in video sequences. Given two consecutive frames, first, text regions in the current frame are detected by an SVM-based texture classifier Second, two stages are performed for the restoration of the regions occluded by the detected text regions: temporal restoration in consecutive frames and spatial restoration in the current frame. Utilizing text motion and background difference, an input video sequence is classified and a different temporal restoration scheme is applied to the sequence. Such a combination of temporal restoration and spatial restoration shows great potential for automatic detection and removal of objects of interest in various kinds of video sequences, and is applicable to many applications such as translation of captions and replacement of indirect advertisements in videos.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.105-115
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• 2011

User authentication service is an absolutely necessary condition while securely implementing an IT service system. It allows for valid users to securely log-in the system and even to access valid resources from database. For efficiently and securely authenticating users, smart-card has been used as a popular tool because of its convenience and popularity. Furthermore the smart-card can maintain its own power for computation and storage, which makes it easier to be used in all types of authenticating environment that usually needs temporary storage and additional computation for authenticating users and server. First, in 1981, Lamport has designed an authentication service protocol based on user's smart-card. However it has been criticized in aspects of efficiency and security because it uses hash chains and the revealment of server's secret values are not considered. Over the years, many smart-card based authentication service protocol have been designed. Very recently, Xu, Zhu, Feng have suggested a provable and secure smart-card based authentication protocol. In this paper, first, we define all types of attacks in the smart-card based authentication service. According to the defined attacks, however, the protocol by Xu, Zhu, Feng is weak against an attack that an attacker with secret values of server is able to impersonate a valid user without knowing password and secret values of user. An efficient and secure countermeasure is suggested, then the security is analyzed.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.53-53
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• 2017

연구목적: 국내 과일 산업의 한 단계 도약과 대외 경쟁력을 높이기 위해서는 수확작업의 기계화가 시급함. 이 연구는 국내외 과일 수확 기계화 현황과 문제점을 분석하고, 향후 수확작업 기계화 방향을 제시하고자 수행 수확기계 실용화 현황 및 고찰 (국내) 과일을 직접 수확이 아닌 수확 작업을 보조해주는 고지 작업기(수동형, 모터 진동형)와 고소 작업차가 대부분임. 수동형은 사과 감 등을 수확하지만, 작업능률이 낮고 작업자가 쉽게 피로하여 장시간 작업이 불가능하므로 실질적인 대안이 되지 못함. 진동형은 자체 동력을 이용하여 나무에 진동을 가하여 주로 대추 매실 등 소과류 수확에 이용되고, 수확능률은 우수하나 충격 손상이 많아 개선이 요구됨. 고소작업차는 동력원에 따라 충전식과 엔진식으로 구분되고, 충전식은 엔진식에 비해 진동 소음이 적어 쾌적하지만, 작업시간이 배터리 용량에 제한을 받음. 또한 작업대 작동방식에 따라 리프트형과 붐형으로 구분함. 리프트형은 리프트를 이용하여 작업대를 상하로 구동하는 방식으로 높은 위치의 과실 수확이 어렵고, 작업대 넓이 만큼의 작업 공간(과수간의 거리)이 필요함. 붐형은 필요한 곳으로 접근성이 우수하나 무거운 무게를 지탱하기 어렵기 때문에 본체를 무겁게 하거나 수시로 수확된 과일을 하차시켜야 함. (국외) 수확 후 가공되는 과일류와 포도 올리브 오렌지 매실 등 소과류 수확이 기계화되었지만, 사과 복숭아 등 신선과일은 아직도 외국의 값싼 노동자들에 의존하여 수확되고 있음. 현재 실용화된 수확 기계는 진동식 수확기계와 터널식 수확기계가 대표적임. 진동식은 집게형의 부착기를 나무 줄기에 고정한 후 트랙터 동력원으로 나무에 진동을 가하여 수확하고, 올리브 대추 등과 같은 소과류와 과피가 두꺼운 오렌지 등에 적용되고, 수확 작업능률이 매우 높으나 과일의 낙하 상처를 피할 수 없는 단점이 있음. 터널형은 규격화(과수 크기 및 형태, 재식거리)된 과수원에 잘 적응하도록 설계 제작되어, 과수 위를 지나가면서 내부에 설치된 진동장치와 컨테이너로 과일을 수확하고, 와인용 포도 수확기가 대표적임. 기계수확이 가능하도록 과수원 조성단계에서부터 재배양식(과수 좌우 및 전후 거리)을 기계의 제원(바퀴 간격, 작업부 간격 등)에 맞추어 재배함. 과일 수확로봇에 관한 연구는 활발하고 일부에서 실증시험단계에 있음. 결론: 구체적인 추진방향을 제시하면, 단기적으로는 과일 수확작업자의 작업편이성과 노동강도를 줄일 수 있도록 소형 저가 범용성이 우수한 보조기구/기계의 보급을 확대하고, 중장기적으로는 수확기계/수확로봇 개발을 위한 연구개발비 투자를 늘리는 동시에, 기계/로봇이 과수원에 잘 적응할 수 있도록 수형 재식거리 등 재배양식의 표준화가 추진되어야 함.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.19-29
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• 2005

The purpose of this study is to categorize subway station areas in Seoul by rail use characteristic. Most studies have categorized rail-oriented areas, based on land use patterns or/and urban spatial structure in Korea as well as the United States. However, the land use pattern of a subway station area tends to form by the real use of subway users since the latter plays an important role in forming the former. Therefore, the study is expected to contribute to the planning and policy of subway station areas in Seoul by analyzing characteristics of rail use. To achieve the purpose, the study uses a factor analysis for rail use, in terms of time of the day and day of the week. and then conducted a multidimensional scaling method to identify a relation of the real pattern to land use pattern. The results find that the Seoul subway station areas are categorized into residential, commercial and recreational, and office-centered ones. Furthermore, unlike the results of previous studies, the study identifies that many station areas have the mixed characteristics of economic activities. That is, they form more than a centered function such as residential and commercial, residential and office, commercial and office, residential, commercial and office. In addition, the study identifies that there is a close connection between rail use and land one. In short, identification of these mixed characteristics for subway station areas is expected to contribute to developing the planning and development method of TOD in Korea.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.2
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• pp.59-71
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• 2014

At present, Korean one-person households have been continuously increased in spite of the reduction of total population. The increasement of one-person household has become a social and institutional issue. It is necessary to response socially and economically to not only changes of housing demand but also the disadvantaged classes such as the socially weak and single elderly household from the national level. In this respect, this research examined the spatial distribution (such as the increasing area, high-density area, and majority area) of one-person household with census data in the city of Busan. The clusters of one-person households were selected by focusing on the spatial distributions by time series changes of 2000, 2005, and 2010 and considering their housing characteristics. In terms of policy efficiency, the clusters of one-person households to be supported by priority were derived by analyzing the census data from 6066 output areas in the city of Busan. As a result, lots of one-person households of juniors were distributed around the university town, office facility, and station service area. Lots of one-person households at middle-aged class were distributed in Busan's original downtown and mountain-side road. Generalizing these characteristics, cluster analysis was conducted. As a result, one-person household dense area in Busan could be classified into four types. This research should be utilized as a counterplan for increasing the housing demand of one-person household or basic data for supporting small housing supply policies in the future.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1116-1120
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• 2006

하천주변 저지대에 주택이나 공장 등의 시설물 집중과 산지의 개발 및 인구 집중으로 인한 도시화 지역의 증가로 홍수 피해는 더욱 커지고 있다. 특히, 상습침수지구의 주민들은 항상 재해로부터 위험을 느끼고 있으므로 새로운 재해관리체계를 구축하여 이에 대한 확고한 대책이 필요하다. 최근 인터넷 사용의 증가로 많은 사용자들이 웹을 통해 다양한 데이터를 공유하고 있으며, 이러한 추세는 더욱 더 증가할 것이다. 인터넷은 다양한 정보를 네트워크를 통해 사용자에게 실시간으로 제공하고 있으며, 통신기술의 발전, 네트워크 통합화 속에서 그 내용과 방식이 더욱 다양해지고 있다. GIS분야에 있어서도 인터넷 네트워크를 이용하여 분산되어 있는 많은 조직이나 사용자들에게 그 기능과 서비스를 제공하는 추세로 바뀌고 있다. Internet GIS는 원격 지리정보 데이타에 대한 접근, 전송, 분석 및 GIS를 표현하는 수단으로 인터넷을 이용하는 특별한 GIS 도구이다. Internet GIS는 전통적인 GIS 소프트웨어가 가지고 있는 대부분의 기능은 물론 인터넷 및 그와 관련된 WWW 및 FTP 프로토콜의 장점을 가지는 부가적인 기능들을 포함할 수 있다. 이들 부가적인 기능은 원격 데이타 및 응용 프로그램의 교환, 지역 컴퓨터에 GIS 응용 프로그램 없이 GIS 분석 기능을 수행, 인터넷상에서 상호작용하는 지도 및 데이타를 표현하는 기능들을 포함한다. Internet GIS는 객체지향적이고 상호운영적이며, 분산적이라는 주요한 특징을 갖는다. 인터넷에서 각각의 GIS 데이타 및 기능성은 하나의 객체로서 서로 다른 서버에 위치하며 필요시 조합 또는 통합되어 운영된다. Internet GIS를 이용한 상습침수지구 지역정보 제공사이트를 구축하기 위해서는 인터넷으로 서비스 할 수 있는 인터넷용 상습침수지구 GIS기본도를 구축이 필요하다. 인터넷 서비스를 위한 상습침수지구 기본도는 또 다른 형태의 주제도라고 볼 수 있으며, 이를 구축하기 위해서는 자료변환 및 가공이 필요하다. 즉, 각 상습침수지구에 필요한 지형도는 국립지리원에서 제작된 1:5,000 수치지형도가 있으나 이는 자료가 방대하고 상습침수지구에 필요하지 않은 자료들을 많이 포함하고 있으므로 상습침수지구의 데이터를 인터넷을 통해 서비스하기 위해서는 많은 불필요한 레이어의 삭제, 서비스 속도를 고려한 데이터의 일반화작업, 지도의 축소.확대 등 자료제공 방식에 따른 작업 그리고 가시성을 고려한 심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.