• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.203-214
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• 2022

A model is developed for estimating optimal cultivation areas for apples to maximize the total profit of apple farming by region, focusing on Gyeongsangbuk-do, Chungchungbuk-do, Gyeongsangnam-do, and Jeonllabuk-do in Korea. Comparing the current cultivation areas to the optimal areas according to the model estimation during the period 1999 - 2019, the former has exceeded the latter since 2015 in all regions except for Jeonllabuk-do. This result stems from a lack of the regulation of production quantity among apple producers' regional organizations. Accordingly, the decreasing rate of the market price was greater than the increasing rate of the production quantity, and the total profit of apple farming has fallen in conjunction with increasing agricultural wage rates. Therefore, in order to reverse the current decreasing trend in the profits of apple farming, it is necessary to regulate nationwide apple cultivation areas through regional producers' associations. Ex-ante forecasting for 2019 posits the following regional optimal cultivation areas for maximizing the total income from apple farming. The Gyeongbuk apple producers' association needs to reduce its current cultivation area by 1,089 ha and to maintain 18,373 ha. In the Chungbuk region, current cultivated area should be reduced by 1,027 ha to maintain 2,722 ha, and in the Gyeongnam region, the current cultivated area should be reduced by 582 ha to maintain 2,730 ha. In contrast, the Jeonbuk region needs to increase its current cultivation area by 174 ha and to maintain at a level of 2,872 ha.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.651-659
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• 2008

Autoreclosing techniques have been used in power systems to maintain system stability and continuity of supply. Environmental and economical issues have driven significant increases in the development of distributed generation (DG). DG connected to distribution systems, however, may impose negative influences with respect to power quality, protection, and stability, because DG can cause some challenges to protection, especially to reclosing. For this reason, in order to improve the reliability and safety of the distribution system, the rules and guidelines suggest that the DG system needs to be rapidly disconnected from the system before reclosing. We present, in this paper, an adaptive reclosing algorithm considering the DG. The algorithm consists of an angle oscillation's judgment, the emergency extended equal-area criterion (EEEAC), the calculation of an optimal reclosing time, and a reconnection algorithm. Our simulation results for three different DG technologies with Electromagnetic Transient Program (EMTP) indicate that we can maintain transient stability while the DG is protected against disturbances.

• International Commerce and Information Review
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• v.12 no.2
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• pp.291-322
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• 2010

Many companies make active use of loyalty programs to improve their customers' loyalty to the company. Loyalty programs are widely used in various industries and sectors, including oil, telecommunications, credit card, department stores, and internet shopping malls; their performance seems to be successful in building a positive relationship with customers. This study emphasizes the role of affiliate programs in creating loyalty, thereby helping companies to maintain their competitive advantage. To objectives of this study are to investigate which antecedent variables(affiliate program benefit, service company characteristic , consumer characteristic) have significant effects on consumer perceived affiliate program satisfaction and to examine whether these factors have differences between Korean and Japanese consumers. The useful results will provide marketing strategy for marketers of service companies. The results also show that affiliate program is very important in order to maintain relationship with customers in service companies.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.648-651
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• 2004

Biped robot has better mobility than other mobile robot, but it is hard to maintain balance during walking. In order to maintain balance, stability analysis is a key point for a biped robot. The zero moment point analysis has been used most in stability analysis. In this paper, we propose different method of stability analysis using wrench system. It is possible to generate a wrench system by applying a force along an axis in space and simultaneously applying a moment about the same axis. Wrench system is equivalent to a force and moment applied along the same axis. We compare the result of wrench system analysis with that of zero moment analysis in biped robot stability using simulation program.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.726-729
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• 2004

Spatiotemporal phenomena are ubiquitous aspects of real world. In the spatial and temporal databases, integrity constraints maintain the semantics of specific application domain and relationship between domains when proceed update in the database. Efficient maintenance of data integrity has become a critical problem, since testing the validity of a large number of constraints in a large database and after each transaction is an expensive task. Especially, in spatiotemporal domain, data is more complex than traditional domains and very active. Additionally, it is not considered that unified frameworks deal with both spatial and temporal properties to handle integrity constraints. Therefore, there need a model to maintain integrity constraints in the unified frameworks and enforcement and management techniques in order to preserve consistence.

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.63-66
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• 2017

All passenger ships aboard more than 36 passengers are to be able to easily find escape routes when the escape way by fire with flame spread were onboard vessel (incl. Ferry, Passenger, Ro-pax, Inland Ferry) It should be impossible by ordinary emergency lights. The international Maritime Organization (IMO) gives special requirement for luminescent evaluation onboard test procedure and applicable location of low location lighting. In order to maintain the residual light source for a certain time in the low location lighting with a strip-shaped light source, the light source material must be sufficiently exposed to the light due to the proper placement of the escape route. The lighting arrangement influence how maintain low location lighting strip luminescent which measured onboard in connection with what elements are mainly sustain luminescent.

• Structural Monitoring and Maintenance
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• v.2 no.1
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• pp.49-64
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• 2015

This paper presents a method for assessing the risk of wave run-up and overtopping of existing coastal defences and for analysing the probability of failure of the structures under future hydraulic conditions. The recent UK climate projections are employed in the investigations of the influence of changing environments on the long-term performance of sea defences. In order to reduce the risk of wave run-up and overtopping caused by rising sea level and to maintain the present-day allowances for wave run-up height and overtopping discharge, the future necessary increase in crest level of existing structures is investigated. Various critical failure mechanisms are considered for reliability analysis, i.e., erosion of crest by wave overtopping, failure of seaside revetment, and internal erosions within earth sea dykes. The time-dependent reliability of sea dykes is analysed to give probability of failure with time. The results for an example earth dyke section show that the necessary increase in crest level is approximately double of sea level rise to maintain the current allowances. The probability of failure for various failure modes of the earth dyke has a significant increase with time under future hydraulic conditions.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1211-1220
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• 2015

Soil is the most important factor in natural environment for bio-diversity. Urbanization and development of city devastate urban soil by the fraternization of green network and run off pollution. In these facts, preservation of soil is the main issue in maintain of quality urban environment. In order to handle this issue, the gold network that link fragment soil patches is considered in maintain quality soil. This study researched the infiltration Treebox design technique based on the Low Impact Development. This technique suggest reduction of impervious area of the soil due to urbanization. The main concept of this study is encourage more permeable surfaces in urban area by using a infiltration planter. The function of the planter is hold run off as much as possible from intensive rainfall, and utilizes it in drought season. Also, this planter provides fertile soil for organism habitat by keeping appropriate moisture supplying.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.5
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• pp.548-552
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• 2015

In this paper, we describe the quadruped walking-control algorithm of the complete full-size humanoid DARPA Robotics Challenge-HUBO (DRC-HUBO) robot. Although DRC-HUBO is a biped robot, we require a quadruped walking function using two legs and two arms to overcome uneven terrains in the DRC. We design a wave-type quadruped walking pattern as a feedforward control using several walking parameters, and we design zero moment point (ZMP) controllers to maintain stable walking using an inverted pendulum model and an observed-state feedback control scheme. In particular, we propose a switching algorithm for ZMP controllers using supporting value and weighting factors in order to maintain the ZMP control performance during foot switching. Finally, we verify the proposed algorithm by performing quadruped walking experiments using DRC-HUBO.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.2
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• pp.1-9
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• 1994

In distributed environments, data replication increases availability and decreases communication cost. However, it is difficult to maintain consistency and availability of data if site failure occurs. When we use the conventional hierarchical quorum consensus(HQC) method in order to maintain the consistency of data, occurrence of site failures makes it harder to perform the operation on replicated data because of insufficient votes. The objective of this paper is to improve the possibility of retaining necessary votes by reconstructing the HQC structure, when the site failure occurs. Furthermore, we compare the modified HQC method with the conventional HQC and QC methods in terms of improvement of availability.