• Journal of the Korean association of regional geographers
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• v.13 no.6
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• pp.674-694
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• 2007

Recently private procurement projects for urban infrastructure have been emphasized and introduced by government(both central and local) as an important method to supplement public budget shortage and to improve creativity and efficiency in its construction and operation, and hence to promote regional development. But these private procurement projects seem to be implemented under the neoliberal condition of urban policy for private capital to extend its sphere of investment and to ensure its opportunity of profit. Such private procurement projects for urban infrastructure have been legislated and widely applied since 1994 in S. Korea, but in recent years they have triggered out a variety of serious problems. In results of this study on the private procurement for construction and operation of Burnan Road in Daegu, it can be pointed out, it has led serious problems such as overestimation of traffic volume in plan, over-appropriation of construction cost and appurtenant business, irYational operation and account of the operating firm, problem in refinancing and change in contents of practical agreement, and over-compensation of minimum operation revenue. Some measures that can be considered as alternatives to resolve those problems and to operate more rationally the Buman Road include those of increasing traffic revenues, of reducing supports of public financing, and withdrawal of (part or whole of) operational right from the private firm.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.321-337
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• 1997

Rapid change in the technological environment of marine transportation and the development of the ocean shipping industry have fostered a revolution in the port system. This in turn has caused major changes in the function and use of port in Korea. Aside from this. Mokpo Port, however continues to decline, because the existing port facilities and related subsystem are already obsolete with no chance of regaining operational effectiveness and treatment for proper implementation. Although a few studies have been done on the Mokpo Port, has not been found, any reseach for the analytical approach to the transportation system of it. This paper aims to make an extensive analysis of the physical distribution system in Mokpo Port focusing on the coordination of subsystems such as navigational aids system, quay handling and transfer system, storage system and inland transport system. The base of introduced simulation tool here is the queueing theory. The overall findings are as follows; 1. Among those vessels called at Mokpo Port in 1994, the average size of oceangoing vessels is 4,922.1 G/T, and the domestic is 317.8 G/T. The average arrival interval and service time of the domestic vessels are 6.0 hours and 24.1 hours respectively marking the berth occupation rate over 100%. Those for oceangoing vessels are 34.5 hours, 120.0 hours and 37.2%. In order to maintainin the berth occupation rate to 70% the capacity considering the 1994 of domestic piers must be extended to 145% and oceangoing vessels must be increased to 165% year called. 2. The capacity of approaching channel is enough to handle the total traffic volume. 3. Tugs are sufficiently being provided to handle all ships requiring their services 4. The capacity of storage and inland transportation systems are sufficient to handle the throughput and the yard stroage utilization rate of No.1 $\cdots$ No.5 is 4.5% and No.6 1S 30% of 1993's. 5. The utilization rate of LLc(Level Looping Crane) and PNT(PNeumaTic) are 2.7% and 18.8%, respectively. Practical solution and proposal for improvement of Transportation System in Mokpo Port are as follows; 1. To avoid the congestion in domestic pier introduction of a new port operation system is necessary allowing the domestic vessel to use the oceangoing pier. 2. To establish the port management information system to improve the efficiency of port operation. 3. To build a new storage system for high valued cargos including modernization of the present storage and handling system. 4. To insure the safety of navigation in approaching channel, The Vessel Traffic System including separation scheme is introduced. 5. To interest enormously on public relation to ship owner's association, shippers and consignees by showing that they can save cost and ship turnaround time in order to promote the call to Mokpo Port. At last, to be strategically change the function of Mokpo Port to the Leisure, Fishing & Ferry as well as Maritime port.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.5
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• pp.787-799
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• 2023

As IoT devices are widely used at home, IoT automation system that is integrate IoT devices for users' demand are gaining populrity. There is automation rule in IoT automation system that is collecting event and command action. But attacker delay the packet and make time that real state is inconsistent with state recongnized by the system. During the time, the system does not work correctly by predefined automation rule. There is proposed some detection method for delay attack, they have limitations for application to IoT systems that are sensitive to traffic volume and battery consumption. This paper proposes a practical packet delay attack detection technique that can be applied to IoT systems. The proposal scheme in this paper can recognize that, for example, when a sensor transmits an message, an broadcast packet notifying the transmission of a message is sent to the Server recognized that event has occurred. For evaluation purposes, an IoT system implemented using Raspberry Pi was configured, and it was demonstrated that the system can detect packet delay attacks within an average of 2.2 sec. The experimental results showed a power consumption Overhead of an average of 2.5 mA per second and a traffic Overhead of 15%. We demonstrate that our method can detect delay attack efficiently compared to preciously proposed method.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.107-115
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• 2011

Since 2009 The Korean National Police Agency has been pushed "permissive left-turn" forward in order to making progress in Korean traffic operations system. Preceding researches manuals and guidelines present 6 standards(# of accidents # of lanes, pedestrian volume sight # of permissive left-turn lanes vehicle volume) as installation permissive left-turn. But in practical affairs it is most important that secure enough Gap-time between permissive left-turn vehicle and opposite through lane vehicle to make permissive left-turn vehicle move safer and more efficiently. This study suggests applying gap acceptance theory in microscopic model to permissive left-turn installation standards. Analysis methods of this study are field data survey statistical analysis and microscopic simulation analysis. This study collected field data by using AVI recording and measured permissive left-turn vehicle intersection passing time(T1) and against the opposite through lane vehicle Gap-time(T2). And statistical analysis performed about two values that measured before to predict the functionality between T1 and T2. These studies to overcome the limit of sample size carried out a microscopic simulation(VISSIM) plan and collect more samples to input statistical analysis.

• Journal of Intelligence and Information Systems
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• v.27 no.4
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• pp.23-48
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• 2021

The Korean economy has achieved continuous economic growth for the past several decades thanks to the government's export strategy policy. This increase in exports is playing a leading role in driving Korea's economic growth by improving economic efficiency, creating jobs, and promoting technology development. Traditionally, the main factors affecting Korea's exports can be found from two perspectives: economic factors and industrial structural factors. First, economic factors are related to exchange rates and global economic fluctuations. The impact of the exchange rate on Korea's exports depends on the exchange rate level and exchange rate volatility. Global economic fluctuations affect global import demand, which is an absolute factor influencing Korea's exports. Second, industrial structural factors are unique characteristics that occur depending on industries or products, such as slow international division of labor, increased domestic substitution of certain imported goods by China, and changes in overseas production patterns of major export industries. Looking at the most recent studies related to global exchanges, several literatures show the importance of cultural aspects as well as economic and industrial structural factors. Therefore, this study attempted to develop a forecasting model by considering cultural factors along with economic and industrial structural factors in calculating the import volume of each country from Korea. In particular, this study approaches the influence of cultural factors on imports of Korean products from the perspective of PUSH-PULL framework. The PUSH dimension is a perspective that Korea develops and actively promotes its own brand and can be defined as the degree of interest in each country for Korean brands represented by K-POP, K-FOOD, and K-CULTURE. In addition, the PULL dimension is a perspective centered on the cultural and psychological characteristics of the people of each country. This can be defined as how much they are inclined to accept Korean Flow as each country's cultural code represented by the country's governance system, masculinity, risk avoidance, and short-term/long-term orientation. The unique feature of this study is that the proposed final prediction model can be selected based on Design Principles. The design principles we presented are as follows. 1) A model was developed to reflect interest in Korea and cultural characteristics through newly added data sources. 2) It was designed in a practical and convenient way so that the forecast value can be immediately recalled by inputting changes in economic factors, item code and country code. 3) In order to derive theoretically meaningful results, an algorithm was selected that can interpret the relationship between the input and the target variable. This study can suggest meaningful implications from the technical, economic and policy aspects, and is expected to make a meaningful contribution to the export support strategies of small and medium-sized enterprises by using the import forecasting model.

• Journal of Distribution Science
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• v.5 no.2
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• pp.55-78
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• 2007

Northeast Asia is one of the regions which have been developing so rapidly. Yellow sea, located between Korea and China, became a very important logistical zone because of its huge volume of cargo and big passenger traffic. These two countries continuously are enlarging their port facilities such as berths, container yards, storage capacity and their information system in this the Pan Yellow sea area. Two countries also introduce many new liner routes and car-ferry shipping services. Therefore there must be a severe competitions and conflicts among the countries and their companies and ports as well. Some experts worry about the over capacity of port and logistics facilities. This paper investigated the current conditions of Korea-China shipping route, container and car-ferry route, and found out the problems and tasks, with the support of many experts. There are so many alternatives and strategies to solve and rationalize the shipping route and the problems of ports of two countries. This paper suggest many strategies connecting with marketing 4Ps. As port service is also a kind of service product, we can categorize the strategies into 4Ps suggested by McCarthy. And this paper classify all these alternatives into 3 dimensions. There are competitive strategies, cooperative strategies and coopetition strategies. This paper propose some directions and ideas for adopting the strategy in the port and logistical topics between Korea and China, suggesting 3 dimensions of strategies. After this paper, many diagnoses and practical investigations should be executed to introduce optimal solutions and minimize the additional cost.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.227-241
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• 2005

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology for steel bridges considering the long-term effect of environmental stressors such as corrosion and heavy truck traffics on bridge reliability. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost, and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure, which depends upon the prior and updated load and resistance histories, should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model, which takes into consideration corrosion initiation, corrosion rate, and repainting effect, are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40m+50m+40m=130m). Various sensitivity analyses are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the volume of truck traffic significantly influence the LCC-effective optimum design of steel bridges. Thus, these conditions should be considered as crucial parameters for the optimum LCC-effective design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.75-89
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• 2006

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology of steel bridges considering time effect of bridge reliability under environmental stressors such as corrosion and heavy truck traffics. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure which depends upon the prior and updated load and resistance histories should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model considering corrosion initiation, corrosion rate, and repainting effect are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40 m+50 m+40 m=130 m), and various sensitivity analyses of types of steel, local corrosion environments, average daily traffic volume, and discount rates are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the number of truck traffics significantly influence the LCC-effective optimum design of steel bridges, and thus realized that these conditions should be considered as crucial parameters for the optimum LCC-effective design.