• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.11a
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• pp.84-86
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• 2018

요즘 자율주행과 같은 최신 기술의 발전과 더불어 촬영된 영상 장면에 대한 깊이있는 이해가 필요하게 되었다. 특히, 기계학습 기술이 발전하면서 카메라로 찍은 영상에 대한 의미론적 분할 기술에 대한 연구도 활발히 진행되고 있다. FuseNet은 인코더-디코더 구조를 이용하여 장면 내에 있는 객체에 대한 의미론적 분할 기술을 적용할 수 있는 신경망 모델이다. FuseNet은 오직 RGB 입력을 받는 기존의 FCN보다 깊이정보까지 활용하여 RGB 정보를 기반으로 추출한 특징지도와의 요소합 연산을 통해 멀티 모달 구조를 구현했다. 의미론적 분할 연구에서는 객체의 전역 컨텍스트가 고려되는 것이 중요한데, 이를 위해 여러 계층을 깊게 쌓으면 연산량이 많아지는 단점이 있다. 이를 극복하기 위해서 기존의 합성곱 방식을 벗어나 새롭게 제안된 팽창 합성곱 연산(Dilated Convolution)을 이용하면 객체의 수용 영역이 효과적으로 넓어지고 연산량이 적어질 수 있다. 본 논문에서는 컨볼루션 연산의 새로운 방법론적 접근 중 하나인 팽창된 합성곱 연산을 이용해 의미론적 분할 연구에서 새로운 멀티 모달 네트워크의 성능 향상 방법을 적용하여 계층을 더 깊게 쌓지 않더라도 파라미터의 증가 없이 해상도를 유지하면서 네트워크의 전체 성능을 향상할 수 있는 최적화된 방법을 제안한다.

• 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 Korea Water Resources Association
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• v.52 no.8
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• pp.515-529
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• 2019

Geospatial information for river network and watershed boundary have played a fundamental roles in terms of river management, planning and design, hydrological and hydraulic analysis. Irrespective of their importance, the lack of punctual update and improper maintenance in currently available river-related geospatial information systems has revealed inconsistency issues between individual systems and spatial inaccuracy with regard to reflecting dynamically transferring riverine geography. Given that digital elevation models (DEMs) of high spatial resolution enabling to reproduce precise river network are only available adjacent to national rivers, DEMs with poor spatial resolution lead to generate unreliable river network information and thereby reduce their extensible applicabilities. This study first of all evaluated published spatial information available in Korea with respect to their spatial accuracy and consistency, and also provides a methodology and tool to modify existing low resolution of DEMs by means of striation of conventional or digitized river network to replicate input river network in various degree of further delineation. The tool named FSND was designed to be operated in ArcGIS ModelBuilder which ensures to automatically simulate river network striation to DEMs and delineation with different flow accumulation threshold. The FNSD was successfully validated in Seom River basin to identify its replication of given river network manually digitized based on recent aerial photograph in conjunction with a DEM with 30 meter spatial resolution. With the derived accuracy of reproducibility, substantiation of a various order of river network and watershed boundary from the striated DEM posed tangible possibility for highly extending DEMs with low resolution to be capable of producing reliable riverine spatial information subsequently.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.227-235
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• 2014

Supply chain management for complex project requires continuous integration activities with the suppliers and subcontractors. This study proposes the firm performances, trust, relational norms, interfirm conflict and cooperation as major research variables, and collected the survey responses from the suppliers and subcontractors having experiences with complex projects. The statistical results indicate that the cooperation and conflict influence the firm performances, and that the inter-firm trust have some impact on the level of cooperation and conflict. It was also found that the inter-firm cooperation is influenced by relational norm. But on the contrary to our expectation, the relational norm has no significant impact on the inter-firm conflict. These findings may offer the significant implications leading to successful implementation of collaborative supply chain management in the context of project engineering area.

• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.271-280
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• 1999

인공신경망을 시계열예측에 적용하는 경우에 고려되어야 할 문제중, 특히 모형에 적합한 입력변수의 생성이 중요시되고 있는데, 이러한 분야는 인공신경망의 모형생성과정에서 입력변수에 대한 전처리기법으로써 다양하게 제시되어 왔다. 가장 최근의 입력변수 전처리기법으로써 제시되고 있는 신호처리기법은 전통적 주기분할처리방법인 푸리에변환기법(Fourier transforms)을 비롯하여 이를 확장시킨 개념인 웨이블릿변환기법(wavelet transforms) 등으로 대별될 수 있다. 이는 기본적으로 시계열이 다수의 주기(cycle)들로 구성된 상이한 시계열들의 집합이라는 가정에서 출발하고 있다. 전통적으로 이러한 시계열은 전기 또는 전자공학에서 주파수영역분할, 즉 고주파 및 저주파수를 분할하기 위한 기법에 적용되어 왔다. 그러나, 최근에는 이러한 연구가 다양한 분야에 활발하게 응용되기 시작하였으며, 그 중의 대표적인 예가 바로 경영분야의 재무시계열에 대한 분석이다 전통적으로 재무시계열은 장, 단기의사결정을 가진 시장참여자들간의 거래특성이 시계열에 각기 달리 가격으로 반영되기 때문에 이러한 상이한 집단들의 고유한 거래움직임으로 말미암아 예를 들어, 주식시장이 프랙탈구조를 가지고 있다고 보기도 한다. 이처럼 재무시계열은 다양한 사회현상의 집합체라고 볼 수 있으며, 그만큼 예측모형을 구축하는데 어려움이 따른다. 본 연구는 이러한 시계열의 주기적 특성에 기반을 둔 신호처리분석으로서 기존의 시계열로부터 노이즈를 줄여 주면서 보다 의미 있는 정보로 변환시켜 줄 수 있는 웨이블릿분석 방법론을 새로운 필터링기법으로 사용하여 현재 많은 연구가 진행되고 있는 인공신경망과의 모형결합을 통해 기존연구와는 다른 새로운 통합예측방법론을 제시하고자 한다. 본 연구에서 제시하는 통합방법론은 크게 2단계 과정을 거쳐 예측모형으로 완성이 된다. 즉, 1차 모형단계에서 원시 재무시계열은 먼저 웨이블릿분석을 통해서 노이즈가 필터링 되는 동시에, 과거 재무시계열의 프랙탈 구조, 즉 비선형적인 움직임을 보다 잘 반영시켜 주는 다차원 주기요소를 가지는 시계열로 분해, 생성되며, 이렇게 주기에 따라 장단기로 분할된 시계열들은 2차 모형단계에서 신경망의 새로운 입력변수로서 사용되어 최종적인 인공 신경망모델을 구축하는 데 반영된다.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.6
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• pp.47-53
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• 2008

This research focuses on the issue of seismic retrofit prioritization based on the Caltrans' highway network serving Los Angeles and Orange counties. Retrofit prioritization is one of most important problems in earthquake engineering, and it is a problem that most decision makers face in the process of resource allocation. This study demonstrates the methods of prioritized resource allocation in the process of retrofitting a regional highway network. For the criteria of a retrofit ranking, seismic vulnerability and the importance of network link are first introduced. Subsequently, link-based seismic retrofit cases are simulated, investigating the effects of the seismic retrofit in terms of seismic performance, such as driver's delay. In this study, probabilistic scenario earthquakes are used to perform a probabilistic seismic risk analysis. The results show that the retrofit prioritization can be differently defined and ranked depending on the stakeholders. This study provides general guidelines for prioritization strategy for the effective retrofitting of a highway network system.

• Journal of Korean Society of Transportation
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• v.23 no.2
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• pp.161-172
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• 2005

This study is to develop Bus Transit Route Analysis and Evaluation Model that can product the quantitative performance measures for Bus Transit Route Network Design. So far, in Korea, there are no so many models that evaluate a variety of other performance measures or service quality that are of concern to both the transit users and operator because of lower-level bus database system and transit route network analysis algorithm's limit. The BTRAEM in this research differ from the previous approach in that the BTRAEM employs a multiple path transit trip assignment model that explicitly considers the transfer and different travel time after boarding. And we develop input-output data structure and quantitative performance measure for the BTRAEM. In the numerical experimental applying BTRAEM to Mandl transit network, We got the meaningful results on performance measure of bus transit route network. In the future, we expect BTRAEM to give a good solution in real transit network.

• (The)Korea Educational Review
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• v.18 no.1
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• pp.253-281
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• 2012

This qualitative study explores how Mongolian migrant workers, with a marked tendency for family migration, plan and put into practice their child's education and attach meaning to it in relation to the social network they form during their stay in Korea. Specifically, it analyzes in particular ways the social network Mongolian migrant workers form affect their settlement in Korea, the process by which the social network affects their planning of their child's education, and how the education planning and its realization lead to the formation of new social networks. The results show that parents were divided between those who made a deliberate decision in sending their child to the Seoul Mongol School as a part of their plan and those who chose the school due to forced circumstances. While some parents preferred the Seoul Mongol School over regular Korean schools for their child's education and future, others sent their child to the Seoul Mongol School, regardless of their preference, because they did not have access to information about regular Korean schools, were afraid of divulging their illegal status, or were afraid their child would not be able to adjust to the school life in Korean schools. Based on such analysis, this paper stresses the urgency of further research in this area, and suggests direction for future policy measures.

• Journal of Internet Computing and Services
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• v.22 no.4
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• pp.123-134
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• 2021

This paper suggests that the Internet is not free through analysis of U.S. Internet history and lawsuits related to the Charter merger in 2016. Generally speaking, the players in internet connectivity market agree to Non-Disclosure Agreement, when connecting their facilities and networks each other. So, I adopted the case study & analysis as research methodologies due to limitation of collecting the transaction data between them. The former finds that Internet access has never been free in U.S Internet history. As we know, some including Content Providers(CPs) argue that the Internet is a free network and there are many cases to use the internet for free, so they came to conclusion that ISPs have no right to charge the users like CPs. This study refutes these arguments in two ways. One is that using the internet has never been free. From ARPANET, known as the beginning of the U.S. Internet, to the commercialization of backbone, no Internet has been considered or implemented for free since the early Internet network was devised. Also, the U.S government was paying subsidies or institutions were paying fees to secure network operations for the NSFNET backbone. the other is that "free peering" refers to barter transactions between ISPs, not to free access to counterpart internet networks. Second, this study analyze the FCC' executive order of conditioned merger approval and the court's related ruling and verify that using the internet is not free. According to the analysis, this study finds that it's real situation to make paid settlements between ISP-CPs (including OTTs) in the US Internet market at the moment. This study concludes that the Internet has never been free in terms of its technical characteristics, network structure, network operation, and system. Also it proposes how to improve the domestic settlement system between ISPs-CPs in terms of policy and regulation.

• (The) Research of the performance art and culture
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• no.18
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• pp.73-100
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• 2009

This article is considered how to utilize mime in the mudang gut. Actually, mime can't be the crux of mudang gut, and the only factors of mime is utilized. Therefore, the purpose of this article is to draw another nets of meanings in Mudang gut, not to study mime. First of all, I surveyed the constituent factors of mudang gut. One gutpan is combined with various factors. As a shamans(mudang), a musician, a jang gu player, a gongyangju(taking charge of food), a sibongja(helper for a shaman), and madangsoe (an under servant), they played their roles. The gut consists of equipment, food, clothes, music and dance. Next, I derived two nets of meaning out of considering a mudang gut performance of mudang (shaman). First, god in a general gutgeori appears expressing their existence by using mime with the music. Second, the following god appears expressing themselves using only mime without music. After showing who he is through action and facial expression, he continues to play a gut. Accordingly, mime of seoul gutpan plays a role to reveal the existence of god. Also, I divided the way of performing mudang gut into language performance and motions and then suggested that mime was mainly used in the motions. I surveyed a gutgeori using mime in the concrete. Through this, I suggested that the shaman used mime, when sending a deadman to the next world in a Jinogi gut. I suggested that mime was utilized repeatedly at the process of repelling the misfortune in a jaesu gut.