• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.386-389
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• 2009

SCADA 시스템은 대개 생산 공정을 감시하고 제어하는데 사용되는 소프트웨어 패키지로써, 대부분 대규모 플랜트 상태를 감시하고 제어하기 위해 사용된다. 특히, 전력, 댐 철도, 원자력 등과 같은 주요 핵심기반시설에서 이를 활용한다. 기존 SCADA 시스템은 일반적으로 분리된 독자적 네트워크상에서 존재했기 때문에 보안에 소홀할 수밖에 없었다. 그러나 최근 기업정보시스템과의 연동 필요성으로 인해 아주 적게나마 원격에서 접속가능한 지점이 존재하고 이로 인한 취약성이 드러나고 있다. 이처럼 외부 공격에서의 취약성 분석을 통한 연구는 현재 진행 중에 있지만, 물리적인 접속을 통한 RTU Master와 Slave의 데이터를 직접적인 변조에 대한 연구는 이루어지지 않고 있다. Modbus RS485통신을 사용하는 SCADA 시스템의 특성상 RTU Master와 Slave는 RJ11 케이블을 통해 1km까지도 연결될 수 있는 상황이므로, 이러한 케이블에 물리적인 접속을 통하여 데이터를 Sniffing하고 Spoofing하는 것이 가능하다. 따라서 본 논문에서는 이러한 물리적인 접속을 통한 데이터 변조 공격에 대비하기 위하여 RSS를 활용한 보안 향상 방안에 대하여 연구하였고, 이러한 데이터 변조 공격을 검출해 낼 수 있는 모니터링 시스템에 대하여 제안하였다.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.65-78
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• 2006

This paper investigates the cost structure ot the Korea and Japan railroad industry with respect to density, scale and scope economies as well as productivity growth rate using a generalized trans)og multiproduct cost function model. The paper then assumes that the Korea and Japan railway companies pi·educe three outputs (incumbent railway passenger-kilometers. Shinkansen passenger-kilometers, ton-kilometers of freight) using four input factors (labor, fuel, maintenance, rolling stock and capital). The specified cost function includes foul other independent variables: track lengths to reflect network effects, two dummies to reflect nation and ownership effects, and time trend as a proxy for technical change. The simultaneous equation system consisting of a cost function and three input share equations is estimated with the Zellner's iterative seemingly unrelated regression. The unbalanced panel data used in the paper, a total of 154 observations. are collected from the annual records of the Korea National Railroad (KNR) for the yews $1977{\sim}2003$, Japan National Railways (JNR) for the years $1977{\sim}1984$. seven Japan Railways (JR's) for the years $1987{\sim}2003$. The findings show that the Korean and Japanese railways exhibit product-specific and overall economies of density but product-specific diseconomies of scale with respect to incumbent railway passenger-kilometers, Shinkansen-kilometers and ton-kilometers. However, the railways experience mild overall economies of scale which result from economies of scope associated with the joint production of incumbent railway/Shinkansen and feight, freight/incumbent railway and Shinkansen except Shinkansen/incumbent railway and freight. In addition, the economies of density and scale in the KNR, JR east, JR central, and JR west companies at the point of the years $1990{\sim}2003$ average is generally analogous to the above results at the point of sample average. There also appear to be economies of ssope associated with the joint Production of the incumbent railway and Shinkansen in JR central but diseconomies of scope in JR East and JR West. The findings also indicate that the productivity growth rate of the privately-owned JR's is larger than that of the government-owned KNR.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.1
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• pp.112-123
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• 2011

This study focused on developing strategies of cyber-compact city, combining compact city with information and communications technologies(ICTs), in order to enhance sustainable transportation. The cyber-compact city development is defined as a development that is able to reduce travel by ICTs and encourage people to use transit or non-motorized vehicles such as bicycles for ICT-induced travel (especially, discretionary travel) by compact and mixed land use. It can be achieved with combining cyber and compact strategies with respect to network, node, and area. For example, ICT network may use transit network facility, a transfer station may be a hub of ICTs, and transit influenced zone may work with ICT service area. We proposed three cohesive strategies for the cyber-compact city based on literature review and case studies on cyber and compact cities. The first strategy is a cohesion between public transportation and telecommunication network by centering on the two for national and urban spatial linkage structure. That is, cities or urban centers and its peripheral areas can be connected by rail network, and extra space of railway network can be used for constructing telecommunication network infrastructure. The second strategy is a cohesion between public transportation node and telecommunication node by building up regional and urban telecommunication centers near to or at main railway stations. For this strategy, telework centers and communication service centers should be established mainly at transfer stations. The third strategy is a cohesion between public transportation impact zone and telecommunication impact zone as transit oriented development.

• Journal of Korea Port Economic Association
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• v.23 no.4
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• pp.139-157
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• 2007

The purpose of this paper is to analyze the competitiveness of the logistics industry of three countries - Korea, China and Japan - by looking into their logistics industry structure and the related regulations. For this aim, the paper examined the modal distribution of transportation, transport infrastructure, freight cost structure and regulation in transport sector in these countries. Furthermore, this study suggests some proposals for the further cooperation to bring sustainable progress in the logistics sector across Northeast Asia. The main suggestions of this paper are as follows: First, Korean government needs to strategize its options in the logistics industry, the most competitive in the country’s service sector, in upcoming FTA negotiations with China and Japan. Second, Korea needs to foster Busan into a strategic point for the Rail Ferry System and Road Feeder System. Third, Korea should participate in establishing shuttle flight service in Northeast Asia amid exploding flight demand from active economic interchange and tourism industry development.

• The Korean Journal of Archival Studies
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• no.36
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• pp.233-269
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• 2013

This study aims to explore practicable and sustainable strategies for locality documentation through networking, linking, and recontextualization of records in digital environments. It applies the 'spanDoc(SPAace-based Networked Documentation) Model to document Donghae-Nambu Railway areas placed in Busan Metropolitan City tentatively. Considering that mobility and openness are the main characteristics of Busan, railway areas and their stations can be proper places for representing such localities of the city. Moreover, there can be much experiences and memories of residents surrounding those areas, because Donghae-Nambu Railway has been used as short distance transportation facilities across the inner city of Busan since 1930's. This study tries to implement the documentation strategy for the selected space, following the procedures of the spanDoc Model. Firstly, this study develops the structure of the subjects through investigating the related information sources and archives from various collecting institutions. Secondly, it carries out records surveys to identify the essential records types for documenting the Donghae-Nambu Railway areas. Thirdly, it describes the subjects and sub-subjects, and the entries of places, people and subjects for adding to the dictionaries. Finally, it links many entities such as subjects, records, and dictionary, and builds the databases regarding the inter-links and systematic accumulation of the outputs of each step.

• Information Systems Review
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• v.14 no.1
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• pp.67-84
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• 2012

Recent increases in uncertainty and speed of market change are driving the adoption of new intelligent mobile office systems. Organizational information systems paradigm suggests that a right match between organizational characteristics and the use of technology is critical in producing desired results. Following such perspective this study developed the mobile office system case of Seoul Metropolitan Railway Transit(SMRT) in Korea. SMRT developed the mobile task-supporting environment that help the management of subway lines real-time without the restriction of time and space. They named the system as ST&F(SMRT Talk and Flash). They decided to develop the application systems in-houses they did not want to be overly dependent on external services in future changes and developments of the system. The new practice reduced the time for moving back and forth to 10% of their working time from previous 20%. The time used for paper works and administration chore also reduce to 10% of their working time from previous 30% on the average. The employees could use 80% of their time to concentrate on the completion of assigned task. The effects of this improvement resulted in the heightened efficiency of the use of human resources and the heightened level of railway safety. The case of SMRT shows that the mobile office system can be applied and extended to various business areas such as facility management and maintenance beyond such typical uses as sales and marketing support. Also, The result of case study will be a useful guideline on the construction and using of mobile office system.

• Journal of the Korean association of regional geographers
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• v.12 no.1
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• pp.44-58
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• 2006

This study of Shintoism is to inquire the relationships between social-political ideology and place of Shinto shrine(神社). In Korea, the Shinto shrine was a place of the center of Japanese colonial policy that symbolized the goal of Japanese Imperialism. This was one of the strategies of "Japan and Korea Are One". Before the China and Japan War in 1937, the number of shrines amounted to 51 sites, 12 of them were closely related to open ports, and the others were located at inland major cities. They also were associated with railroad transportation systems that tied coast and inland major cities. This spatial distribution of shrines was so called "Shrine Network" that was essential in tracing Japanese invasion into Korea. It was an imperial place where Japanese residence and colonial landscape were combined together to show the strength of Japanese Imperialism. Most of shrines were located at a hill with a view on the slope of a mountain and honored Goddess Amaterasu and the Meiji Emperor. I presume from these facts that Shinto Shrine was a supervisionary organization for strategic purpose. The Jeonju Shrine was located on a small hill, Dagasan(65m) where commanded a splendid view of Jeonju city and honored Goddess Amaterasu and the Meiji Emperor. It was a place which was adjacent to Japanese residence and colonial landscape. The Dagasan was changed as a symbolic site for Japanese Imperialism. But, after liberation in 1945, the social-political symbol of the hill was changed. By the strong will of civil, there was a monument to the loyal dead and the national poet, Yi Byeng-gi placed for national identity at the site of the demolished Jeonju Shrine. Dagasan as a place of national identity, shows the symbolic decolonization and the changing ideology. After all, this shows that political ideology is represented in a place with landscape.

• International Commerce and Information Review
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• v.15 no.2
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• pp.3-23
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• 2013

In 1997, 180 countries signed the Kyoto Protocol in Kyoto, Japan. The Kyoto Protocol came into force in February 2005. The agreement calls for industrialized nations to cut greenhouse gas emissions by 5 percent from 1990 levels by 2008 to 2012. One of those polices is a modal shift that change from road freight to sea, inland waterway and railroad transportation that is eco-friendly. The increase of road freight brings road congestion, accidents, logistic costs, air pollution and greenhouse gases. Railroads are superior than the other modes of transportation in mass transportability, high speed, timeliness, safety and environmental-friendliness, but the railway industry has been pushed behind in competition. Korean railroads were used by passengers and freight transport popularly until the middle of 20th century, however, by the sudden change of logistics environments, a shaving time efficiency being most important, railroad logistic lost its competitive power against the transportation by truck. From the research which sees consequently investigated a various policy, a system and a law about Chinese logistics industry and present condition of the Chinese goods enterprise and instance analysis of the large Chinese corporation that branch out to undeveloped markets led and a Chinese logistics industry and problem point escape hereafter the heightening of competitiveness plan which is rational under prsenting boil.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.91-98
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• 2023

Recently, according to development of artificial intelligence, a wide range of industry being automatic and optimized. Also we can find out some research of using supervised learning for deteceting defect of railway in domestic rail industry. However, there are structures other than rails on the track, and the fastener is a device that binds the rail to other structures, and periodic inspections are required to prevent safety accidents. In this paper, we present a method of reducing cost for labeling using semi-supervised and transfer model trained on rail fastener data. We use Resnet50 as the backbone network pretrained on ImageNet. At first we randomly take training data from unlabeled data and then labeled that data to train model. After predict unlabeled data by trained model, we adopted a method of adding the data with the highest probability for each class to the training data by a predetermined size. Futhermore, we also conducted some experiments to investigate the influence of the number of initially labeled data. As a result of the experiment, model reaches 92% accuracy which has a performance difference of around 5% compared to supervised learning. This is expected to improve the performance of the classifier by using relatively few labels without additional labeling processes through the proposed method.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.3
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• pp.67-79
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• 2017

Increasing transportation dependence on the metro system has lead to the convenience of passengers becoming as important as the transportation capacity. In this study, a pedestrian simulator has been developed that can quantitatively assess the pedestrian environment in terms of attributes such as speed and distance. The simulator consists of modules designed for 3D indoor map authoring and algorithmic pedestrian modeling. Module functions for 3D indoor map authoring include 3D spatial modeling, network generation, and evaluation of obtained results. The pedestrian modeling algorithm executes functions such as conducting a path search, allocation of users, and evaluation of level of service (LOS). The primary objective behind developing the said functions is to apply and analyze various scenarios repeatedly, such as before and after the improvement of the pedestrian environment, and to integrate the spatial information database with the dynamic information database. Furthermore, to demonstrate the practical applicability of the proposed simulator in the future, a test-bed was constructed for a currently operational metro station and the quantitative index of the proposed improvement effect was calculated by analyzing the walking speed of pedestrians before and after the improvement of the passage. The possibility of database extension for further analysis has also been discussed in this study.