• Journal of Korean Society for Geospatial Information Science
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• v.23 no.2
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• pp.79-88
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• 2015

In any production and construction of geospatial information covering surveying, survey control point is a vital geospatial information. Survey control points in South Korea are currently classified as following: national control points, public control points, and cadastral control points. Each of these different categories of survey control points act as a basis and sets perimeters for the production, management and operation of subjects within the category. Universal standard, the unified format between different survey control points, also, are not yet defined, causing difference in basic information provided by altering categories and disturbance in connecting, managing, utilizing and operating survey control points. Establishment of a standard regarding survey control points, is therefore required for the efficacy of their utilization. This study, to solve such inadequacies, selects management items for creation of standardized survey control point, by investigating domestically and internationally the status of operating survey control points, determining data model for management, establishing TTA and agency standards, and establishing of activation methodology for survey control point standards.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1903-1908
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• 2008

This paper presents a characteristics of linear induction motor considering airgap variation for railway transit in order to achieve high performance of the vehicle. The operating principle of a LIM(Linear induction motor) is identical to a rotary induction motor. Space-time variant magnetic fields are generated by the primary part across the airgap and induce the electro-motive force(EMF) in the secondary part, a conducting sheet. This EMF generates the eddy currents, which interact with the airgap flux and so produce the thrust force known as Loren's force. Even though the operating principal is exactly same as a rotary motor, the linear motor has a finite length of the primary or secondary parts and it causes static and dynamic end-effect which is the discontinuous airgap flux phenomenon. This end-effect causes the deterioration of the system performance, especially in high-speed operation. Another problem is that construction tolerance restricts the minimum airgap in order to prevent a collision between the primary part and the secondary reaction plate. More over, as the airgap length is getting smaller, the attraction force between the primary part and secondary parts is getting larger dramatically and the attraction force would be another friction against propulsion. Therefore, it is necessary to figure out the characteristics of linear induction motor considering airgap variation in order to achieve high performance of the vehicle. The dynamic model of LIM taking into account end-effects is derived. Then the modified mechanical load equation considering the effect of the attraction and thrust force according to the airgap variation is analyzed. The simulation results are presented to show the effect of the LIM according to the airgap variation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.285-293
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• 2011

Sewage treatment facilities are growing rapidly in quantitatively and qualitatively. However, privatization such as up-size and professionalism, etc. are insufficient, compared to global companies' cases. Infrastructure Asset management has not been applied widely despite of sewage treatment facilities are one of the most critical social infrastructure. Maintenance, repair, and rehabilitation (R&R) practices of sewage treatment facilities have been studied and infrastructures asset management techniques have been applied. Cost model which makes it possible to calculate managerial costs such as major cost, etc. needs to be developed only with project basic information when proceeding new sewage treatment facility construction and management and overseas sewage project. Effects to converse major repair cost into capital, application of sewage treatment facility's asset management, expected effects, etc. were analyzed and suggested an alternative on the improvements of legal system.

• Journal of Korea Port Economic Association
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• v.33 no.2
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• pp.83-96
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• 2017

As a way to address global warming, among the renewable energy sources, there have been heavy investments worldwide for the development of offshore wind farms. However, such development has a drawback: investment costs are higher than those for onshore wind farms due to required operations such as offshore transportation and installation. In particular, delays in installation due to adverse maritime weather conditions are factors that affect the economics of offshore wind farms' operation. Therefore, in this study, we analyze the optimal schedule of the construction of an offshore wind farm from a macro perspective by considering the weather conditions in Korea. For this purpose, we develop a mathematical model and apply it to a 2.5 GW offshore wind farm project on the southwestern coast of the country. We use data from the Korea Meteorological Agency for maritime weather conditions and attempt to reflect the actual input data based on precedent cases overseas. The results show that it takes 6 months to install 35 offshore wind turbines. More specifically, it is pointed out that it is possible to minimize costs by not working in winter.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.10
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• pp.544-551
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• 2015

This study was conducted to determine the LCC of apartment complexes with district heating and a cogeneration system. For the purpose of analyzing LCC according to the size of the apartment complex, 500, 1,500, and 4,000-unit model apartments were selected. Analysis was performed on the design of the heating system and the life cycle cost including total construction cost, maintenance and operation cost for the duration of the project period (15 years). According to the calculated results, 1) The initial cost of the cogeneration system for 500, 1,500, and 4,000-unit apartments is higher than that of the district heating system by 20%, 13%, and 12%, respectively. 2) In the case of the cogeneration system, the payback period by electric generation was found to be 5.21, 4.92 and 4.47 years, and saving cost was calculated to be 29 billion won, 94 billion won and 262 billion won after the payback period for 500, 1,500, and 4,000-unit apartments, respectively. 3) The LCC values of the cogeneration system were 1.12, 1.07 and 1.06 times larger than those of the district system according to the size of the apartment complex. In this study, the district heating system was found to be more efficient than the cogeneration system in terms of LCC reduction. 4) District heating is affected by fuel bills, so energy efficiency should be improved through recovering waste heat (incineration heat, etc.). Also, district cooling should be provided according to heat use to keep the temperature high in winter and low in summer.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.2
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• pp.137-146
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• 2001

Route selection needs the analysis function of GSIS to analyze and manipulate a lot of spatial information efficiently. Therefore, it needs the linkage of system requiring the knowledge and the experience of experts as a method that can estimate each quantitative route for an efficient route selection. In this study, the route selection model through construction and analysis procedure of position information using GSIS were presented, and route selection system linked with expert system was developed. This system is easy to be used and managed for presenting route alignment according to conditions as a graphic user interface environmental window system by applying three tiers based object-oriented method. Using GSIS, the various information required for route selections in database was constructed, the characteristics of subject area by executing three-dimensional terrain analysis was grasped effectively, and the control point through buffering, overlay and location operation was extracted. Three alternative routes between a beginning point and an end point inputted by route selection system were selected. Therefore, the applications of the route selection system are presented by applying this system to the real study area.

• Journal of Korean Society of Rural Planning
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• v.26 no.3
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• pp.91-102
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• 2020

The purpose of study was analyze the pumping characteristics, Irrigation Efficiency(IE), and irrigation pattern by period of rice growing stage with based on the performance of design irrigation water requirement and operational Galshin Pumping(GP) station in GP irrigation district constructed under rural water development project master plan. GP station was located in Yedang reservoir, Yesan-gun, Chungcheongnam-do and has been supplying irrigation water since 2006. The research data are the Irrigation Water Requirement(IWR) and the Pumping Water Amount(PWA) from 2006 to 2015 at the GP station, which is the supplied amount. The IWR were calculated using the Blaney-Criddle formula of the HOMWRS program, Hydrological Operation Model for Water Resource System, developed by Korea Rural Community Corporation. The Blaney-Criddle formula was used to calculate design irrigation water requirement of Galshin rural water development project master plan. During 2006-2015, the study period, the annual average IWR is 763.2(±149.1)mm, the annual PWA of the GP station is 397.4mm to 1,056.9mm, and those average annual PWA is 643.4(±208.4)mm. The annual IE of GP station 96.5% to 169.0%, and the average annual IE is 124.3%, which is higher than the research results conducted in other pumping stations. Analyzing the irrigation patterns of the GP irrigation district, the IWR Ratio per 10days(IWRR) and the PWA Ratio per 10days(PWAR) of the G P station were obtained. The IWRR is the percentage of IWR for each 10 days of a month to total IWR per year, and the PWAR is the percentage of PWA for each 10 days of a month to total PWA per year. The Kolmogorov- Smirnov(K-S) test results of IWRR and PWAR showed the characteristics classification by rice growing stage and stable normal distribution characteristics. Average IWRR(AIWRR) and Average PWAR(APWAR) are presented as irrigation patterns. Irrigation pattern analysis will be able to standardize comparison, analysis and probability calculation of the pumping station characteristics of different pumping stations and apply to objective evaluation of the pumping station district.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.1
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• pp.45-51
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• 2020

In this study, we developed an allocation optimization system for supply chain management in the shipbuilding and offshore construction industry. Supply chain operation is a way of operating manufacturing company responsible for the procurement of outfitting parts. The method about how to allocate the manufacturing volume to each partner company includes important decisions. According to the allocation method, the stability of the material supplied to the final installation process is guaranteed. We improved the allocation method that was previously decided by the person in charge. Based on the optimization engine, a system is developed that can automatically allocate the production volume. For optimization model configuration, factors affecting the volume allocation were analyzed and modeled as constraint factors. A target function is defined to minimize the difference in the load variance of each partner company. In order to use the same type of volume allocation engine for various outfitting products, the amount of work done by the partner company was standardized. We developed an engine that can allocate the same production load of each production partner. Using this engine, the operating system was developed and applied to the actual offshore project. It has been confirmed that the work load variance of suppliers can be maintained uniformly using the optimization engine rather than manual method. By this system, we stabilize the manufacturing process of partner suppliers.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.159-166
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• 2010

It is noteworthy that EIS Consulting Method by ISP based on ERP Linkage Type for Large Scale Enterprise Associate Company. In this thesis, IT Strategy plan and methodology are suggested in order to solve the several problems including standardization on implementation of EIS Introduction and operation between large-small enterprise. Integration of business and information technical is made by Business management group's continuous IT concern and future information strategy. Also this paper proposes ISP Planning method (environment analysis, present analysis, IT analysis, target IT plan etc..), EIS Construction (based ERP Real data/time). In addition to, we suggest to use electron industry model and LCD/LED field in this system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.6
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• pp.2148-2167
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• 2021

The proliferation of the Internet of Things (IoT) technologies and applications, especially the rapid rise in the use of mobile devices, from individuals to organizations, has led to the fundamental role of secure wireless networks in all aspects of services that presented with many opportunities and challenges. To ensure the CIA (confidentiality, integrity and accessibility) security model of the networks security and high efficiency of performance results in various resource-constrained applications and environments of the IoT platform, DDO-(data-driven operation) based constructions have been introduced as a primitive design that meet the demand of high speed encryption systems. Among of them, the TMN-family ciphers which were proposed by Tuan P.M., Do Thi B., etc., in 2016, are entirely suitable approaches for various communication applications of wireless mobile networks (WMNs) and advanced wireless sensor networks (WSNs) with high flexibility, applicability and mobility shown in two different algorithm selections, TMN64 and TMN128. The two ciphers provide strong security against known cryptanalysis, such as linear attacks and differential attacks. In this study, we demonstrate new probability results on the security of the two TMN construction versions - TMN64 and TMN128, by proposing efficient related-key recovery attacks. The high probability characteristics (DCs) are constructed under the related-key differential properties on a full number of function rounds of TMN64 and TMN128, as 10-rounds and 12-rounds, respectively. Hence, the amplified boomerang attacks can be applied to break these two ciphers with appropriate complexity of data and time consumptions. The work is expected to be extended and improved with the latest BCT technique for better cryptanalytic results in further research.