• Journal of KSNVE
• /
• v.9 no.4
• /
• pp.849-855
• /
• 1999

Neural Networks have shown potential to become an attractive alternative to classic methods for identification and control of non-linear dynamic systems. The purpose of this paper is to present an application of neural networks, that is a neural reconstruction of the input signal of a non-linear unknown system. This basic methodology could be used for practical purpose in several engineering fields. Clearly applications of the proposed scheme can be of interest for physical systems where a complete network of sensors measuring system inputs is not available. It should also be emphasized that the application of the reconstruction scheme is of little or no interest when the analyzed system works and operates at nominal conditions. In fact, only when failures and/or system anomailes occur, leasing to performance degradation and/or shutdown, the application of this scheme is of interest. The paper presents the results of the methodology applied to unknown non-linear dynamic systems and the robustness of the scheme to white and colored system noise was evaluated.

• Land and Housing Review
• /
• v.9 no.2
• /
• pp.33-40
• /
• 2018

Korea seems to have introduced the legal basis for supporting and revitalizing the 6th industry since about 2010. Problems such as lack of systematic support system, inadequacy of cooperation and cooperation between ministries, and poor efficiency have been raised. Also, there is a lack of information on the designation, development method, participant, and management plan of the 6th industrial complex. In this study, we review prior researches and cases related to the 6th industry and examine how to efficiently create the 6th industry-specific complex by analyzing the requirements of customers for the enterprises, residents, professionals and officials of the metropolitan area and non-metropolitan areas. As a result of the questionnaire survey, some suggestions for the establishment of the 6th industry specialization complex were drawn. First, 77.5% of the total requires a combination of public and mixed use, which can be expected to have positive effects such as sharing development gains with local residents and improving resettlement of local residents. Second, the 6th industrial complex should be harmonized with the 1st, 2nd and 3rd industries. However, unlike the standardized land use plan of existing industrial complex, it is necessary to expand the distribution and sales space to reflect the demand for tertiary industry. It is also necessary to consider measures for securing primary industrial sites or securing primary industrial sites through external procurement. Third, it is necessary to establish and operate a plan reflecting rent and rental demand after leasing for a certain period.

• Korean Journal of Soil Science and Fertilizer
• /
• v.11 no.3
• /
• pp.175-194
• /
• 1979

The soil organic matter contents in arable land are generally low in Korea. Thus it is generally agreed that the application of organic materials to soils would be much beneficial. Present paper is a review on the effectiveness of organic mat ter application in uplands and lowlands. 1. The effect of organic matter application in uplands are of more clear and simple to explain as compared to that in lowlands. In uplands, appropriate application of organic matters such as compost and various crops residues improves the physical properties of soils leasing to increased water holding capacity, better aeration, and decrease in soil erosion. 2. In lowland, rice soils under water logged conditions the effect of organic matter application on rice yield is not straight borward and demands more refined knowledges for the interpretation of it. 3. It is found that the application of compost in rice soils is more effective when nitrogen fertilizer application is limited it dicating that nitrogen contained in the organic maerials can become available to rice plant and plays an important role for increased yield of rice under the condition where nitrogen fertilizer supply is limited. 4. Application of organic matter does not always bring about the desirable effects. Very often the organic matter application results in more intensive soil reduction leading to the accumulation of harmful substances which would can cancel out the positive effects of organic matter. This is partiunlarly true in poorly drained soils. 5. Rice straw or compost, when applied rice soils, supply sizeable amounts of available silicate to rice plant resulting in yield increase. 6. Although the effectiveness of organic matter application on rice yield in short term experiments is not consistent due to many reasons, the long term effect of organic matter is significant. 7. The term of the $O.M/SiO_2$ ratio in rice soils can serve as a criterion for the judgement of whether organic matter or silicate fertilizer is needed to be applied in a certain soil.

• Journal of Biosystems Engineering
• /
• v.40 no.3
• /
• pp.178-185
• /
• 2015

Purpose: This research suggests a method of establishing criteria for working area and operating cost for a long-term lease of agricultural machinery. Methods: Eight crops were selected-three food crops and five open-field vegetables-and agricultural machines used for sowing, transplanting, and cultivation in dry-field farming were analyzed. Results: The break-even acreage for agricultural machinery under a long-term lease was found to differ by agricultural machine, ranging from 1.0 to 5.8 ha. In terms of arable land area, the break-even acreages for harvesting machinery and transplanters were 15.6 to 26.1 ha and 6.1 to 8.6 ha, respectively. The working area lessees should secure was divided into two cases: (1) 2.0 to 11.6 ha when leasing individual agricultural machines (sowing and transplanting) for a long-term period, and (2) more than 10 ha when farmers who cultivate beans, potatoes, garlic, onions, and so on lease sowing and transplanting machines as a set. When agricultural machinery was leased for a long term, the operating cost and working time were reduced by 27.6 to 74.4% and 2.5 to 21.6%, respectively, indicating considerable effect. Conclusions: A long-term lease project needs to be promoted to overcome the limitation of short-term leases of agricultural machinery. The local government should lead this project and facilitate the mechanization of dry-field farming. The department in charge of agricultural machinery lease projects needs to set the working area to cover the rate and maintenance cost for farmers who lease agricultural machinery for the long term.

• Journal of Biosystems Engineering
• /
• v.37 no.6
• /
• pp.434-438
• /
• 2012

Purpose: This study was performed in order to improve problems and to seek the efficient operating plan by surveying and analyzing the actual status of operating the agricultural machinery rental business supported by the government. Method: The data was collected through two times of survey targeting lease business operators and the leasing business reports published for the past 3 years ('08~'10) 120 cities and counties. Results: As a result of surveying 120 cities and counties nationwide of operating the agricultural machinery rental business, 96% of agricultural machinery rental businesses were indicated to be operated in the form of short-term rent for about 1~3 days centering on small-sized agricultural machinery and attachment for upland crop. As for the unit number of possessing rental agricultural machinery and the purchase cost, it was indicated to be greatly reduced the agricultural machinery for rice farming and to be expanded into upland crop whose mechanization is insufficient. The annual rental days ('10) are 9.5 days/unit, thereby being a little insufficient. Rental fee for 1 day is 0.2~0.8% of the initial purchase cost of agricultural machine, thereby being greatly lower compared to 2.0% (annually 10-day rent) of the proper rents, resulting in being demanded improvement. Conclusions: To be continuously driven the rental business of agricultural machinery with having the ability to propagate, it is judged to be likely to necessarily collect optimum rental fee in consideration of rental days as well as increasing the use days per unit by buying the agricultural machinery, which is secured the rental demand, and by possessing the reasonable unit number.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.8
• /
• pp.1770-1785
• /
• 2013

In this paper, a multi-hop transmission protocol based on parallel communication of secondary users (SUs) is proposed. The primary multi-hop network coexists with a set of SUs by cooperative spectrum sharing. The main optimization target of our protocol is the overall performance of the secondary system with the guarantee of the primary outage performance. The energy consumption of the primary system is reduced by the cooperation of SUs. The aim of the primary source is to communicate with the primary destination via a number of primary relays. SUs may serve as extra decode-and-forward relays for the primary network. When an SU acts as a relay for a primary user (PU), some other SUs that satisfy the condition for parallel communication are selected to simultaneously access the primary spectrum for secondary transmissions. For the proposed protocol, two opportunistic routing strategies are proposed, and a search algorithm to select the SUs for parallel communication is described. The throughput of the SUs and the PU is illustrated. Numerical results demonstrate that the average throughput of the SUs is greatly improved, and the end-to-end throughput of the PU is slightly increased in the proposed protocol when there are more than seven SUs.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.2
• /
• pp.24-31
• /
• 2018

As a system complexity increases and technology innovation progresses rapidly, leasing the equipment is considered as an important issue in many engineering areas. In practice, many engineering fields lease the equipment because it is an economical way to lease the equipment rather than to own the equipment. In addition, as the maintenance actions for the equipment are costly and need a specialist, the lessor is responsible for the maintenance actions in most leased contract. Hence, the lessor should establish the optimal maintenance strategy to minimize the maintenance cost. This paper proposes two periodic preventive maintenance policies for the leased equipment. The preventive maintenance action of policy 1 is performed with a periodic interval, in which their intervals are the same until the end of lease period. The other policy is to determine the periodic preventive maintenance interval minimizing total maintenance cost during the lease period. In addition, this paper presents two decision-making models to determine the preventive maintenance strategy for leased equipment based on the lessor's preference between the maintenance cost and the reliability at the end of lease period. The structural properties of the proposed decision-making model are investigated and algorithms to search the optimal maintenance policy that are satisfied by the lessor are provided. A numerical example is provided to illustrate the proposed model. The results show that a maintenance policy minimizing the maintenance cost is selected as a reasonable decision as the lease term becomes shorter. Moreover, the frequent preventive maintenance actions are performed when the minimal repair cost is higher than the preventive maintenance cost, resulting in higher maintenance cost.

• Journal of Korea Port Economic Association
• /
• v.30 no.4
• /
• pp.91-110
• /
• 2014

The Korean Government is planning to build commercial districts and amenities for the major port such as Busan, Gwangyang, and Incheon in order to activate the hinterland in each port. The foreign ports in Germany, Japan and China is competing with Korean ports are developing the commercial districts and amenities of seaport hinterland in order to support urban functions. The purpose of this study is to predict the demand for the facility of commercial districts and amenities planned in the Gwangyang seaport hinterland, then to propose its utilization plans. By the demand forecasting, the districts and amenities need to be full of office, accommodation and commercial facilities, etc. In addition, the districts need to be developed gradually for the target of 2035, considering the demand growth. Leasing out the property to secular tenants, it needs to charge rent for profits of port authority. Therefore, it is required to revise the National Ports Act for the private agency to take part in building the facilities of the commercial districts and amenities.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.1
• /
• pp.161-168
• /
• 2016

It has become the information medium that mediate between individuals of marketing with the new information media that use of the Internet in accordance with the progress of the IT industry- real estate marketing, real estate leasing, real estate auctions, etc. The real estate registration services should be disclosed to outside that include a schedule details the public book-register and problems caused by it should be reasonably resolved by handling a large amount of real estate registration work quickly, accurately handling to utilize Information Technology(IT) through the information system construction as the feature to process the information of register entries. Computerization of real estate registration will raise the efficiency of the registration as well as people can see the information related to real estate on the basis of published content without limitation the time and place and will pursue the ideal and reliability of the registration -web accessibility improving of the Internet Registry and permanent storage of preserving documents by electronic means. It is very large that impact on the real estate transaction if the accuracy of legal registration choosing formalism in the processing of real estate registration business through the Internet than written application is highly probable to occur incorrect registration. Also, It is necessary to manage it effectively -if you do not quickly and exactly respond to it, there is problems such as delays or poor registration service because real estate business activated and real estate registration services also increased sharply. In this paper, we will identify the problems of the real estate registration work and suggest improvements about it.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.503-508
• /
• 2007

The Equipment Expenses section of the Poom-Saem, that is used for Construction Cost Estimation on public sectors in Korea, has been rarely revised, and so does not reflect changes of construction equipment technology and construction methods, since it was established based on data from Japan and the U.S in the early 1960s. In order to make reasonable estimation of maintenance costs(Interest, Storage, Insurance, Tax), the equipment expenses section of the Poom-Saem and the domestic and overseas documentary records were investigated. Further, 16 construction sites were visited, and 20 Construction Equipment leasing services were surveyed. Based on results from analysing figures related with the estimation of maintenance costs, the maintenance cost is redefined. Then, construction equipment was classified into 6 exclusive construction equipment and general one, and realistic figures of the maintenance cost, which consists of interest, storage, insurance, tax, are suggested respectively. The optimum level of each item which consists of equipment costs was revealed based on the result of the analysis on the figures of equipment costs calculation from the Poom-Saem and the collected data. The research will be the foundation that helps to estimate appropriate construction costs and the ground work of related studies.