• 전기학회논문지P
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• 제62권4호
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• pp.210-215
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• 2013

This paper analyze the bus voltage sags in the power distribution system with a small scale cogeneration system when the superconducting fault current limiter was introduced. Among the solutions to decrease the short-circuit current considering the locations of the small scale cogeneration system, the superconducting fault current limiter (SFCL) has been announced as one of the promising methods to reduce the fault current because the installation of the small scale cogeneration system which increases the short-circuit current. According to the application locations of the small scale cogeneration system in a power distribution system, it has caused the variations of voltage sag and duration which depends on the change of the short-circuit current, which can make the operation of the protective device deviate from its original set value when the fault occurs. To investigate the voltage sag when a SFCL was applied into a power distribution system where the small scale cogeneration system was introduced into various locations, the SFCL, small scale cogeneration system, and power system are modeled using PSCAD/EMTDC. In this paper, the effects on voltage sags are assessed when the SFCL is installed in power distribution system with various locations of the small scale cogeneration system.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.135-142
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• 2021

Estimating the locations of workers in a shipyard is beneficial for a variety of applications such as selecting potential forwarders for transferring data in IoT services and quickly rescuing workers in the event of industrial disasters or accidents. In this work, we propose a human movement stream processing system for estimating worker locations in shipyards based on Apache Spark and TensorFlow serving. First, we use Apache Spark to process location data streams. Then, we design a worker location prediction model to estimate the locations of workers. TensorFlow serving manages and executes the worker location prediction model. When there are requirements from clients, Apache Spark extracts input data from the processed data for the prediction model and then sends it to TensorFlow serving for estimating workers' locations. The worker movement data is needed to evaluate the proposed system but there are no available worker movement traces in shipyards. Therefore, we also develop a mobility model for generating the workers' movements in shipyards. Based on synthetic data, the proposed system is evaluated. It obtains a high performance and could be used for a variety of tasksin shipyards.

• 한국작물학회지
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• 제39권1호
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• pp.85-91
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• 1994

고구마 품종들의 저장중 품질성분 함량을 탐색하여 고품질 품종 육성에 기초자료로 제공하고자 경기도 화성과 수원에 여섯개의 장려품종을, 매매하여 전분가, glucose, fructose, maltose 및 sucrose함량을 조사한 바 그 결과를 요약하면 다음과 같다. 1. 전분가는 두 지역에서 모두 신율미가 가장 높았다. 2. Glucose와 fructose 함량은 품종간 지역간 변이가 심했다. 3. 두 지역 모두 maltose함량은 신율미가 가장 높았고 sucrose함량은 율미가 가장 높았다. 4. 총당함량은 식용품종인 신율미와 율미가 높았다. 5. 저장기간중 전분가, glucose, fructose, maltose 및 Sucrose함량의 큰 변화는 없었으나 지역간 차이가 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권7호
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• pp.1868-1887
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• 2024

Recommendation systems research is a subfield of information retrieval, as these systems recommend appropriate items to users during their visits. Appropriate recommendation results will help users save time searching while increasing productivity at work, travel, or shopping. The problem becomes more difficult when the items are geographical locations on the ground, as they are associated with a wealth of contextual information, such as geographical location, opening time, and sequence of related locations. Furthermore, on social networking platforms that allow users to check in or express interest when visiting a specific location, their friends receive this signal by spreading the word on that online social network. Consideration should be given to relationship data extracted from online social networking platforms, as well as their impact on the geolocation recommendation process. In this study, we compare the similarity of geographic locations based on their distance on the ground and their correlation with users who have checked in at those locations. When calculating feature embeddings for users and locations, social relationships are also considered as attention signals. The similarity value between location and correlation between users will be exploited in the overall architecture of the recommendation model, which will employ graph convolution networks to generate recommendations with high precision and recall. The proposed model is implemented and executed on popular datasets, then compared to baseline models to assess its overall effectiveness.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.445-456
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• 2003

Spatial data are usually obtained at selected locations even though they are potentially available at all locations in a continuous region. Moreover the monitoring locations are clustered in some regions, sparse in other regions. One important goal of spatial data analysis is to predict unknown response values at any location throughout a region of interest. Thus, an appropriate space model should be set up and their estimates and predictions must be accompanied by measures of uncertainty. In this study we see that a space model proposed allows a best interpolation to annual rainfall data in South Korea.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.468-470
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• 1997

This paper presents an estimation method of the number of partial discharge(PD) sources and their locations in power transformer. To identify multiple PD sources and their locations, the directions-of-arrival estimation algorithm is employed. The results of simulations shows that the proposed method could be accurately detect the number of PD sources and their locations in power transformer.

• Industrial Engineering and Management Systems
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• 제4권2호
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• pp.136-144
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• 2005

This research deals with an order picking problem in automated storage and retrieval systems (AS/RS). When retrieval requests consist of multiple items and the items are in multiple stock locations, the storage/retrieval (S/R) machine must travel to numerous storage locations to complete each order. The aim of this research is to propose algorithms for the resolution of order picking problems with multiple stock locations to minimize the total time traveled by the S/R machine. We present and compare three alternatives for solving the problem based on enumeration, ordinary heuristic and genetic algorithms. We used a set of 180 different problems that are solved by these three algorithms. The results show that our proposed genetic algorithm is more efficient than the other two.

• 대한의용생체공학회:의공학회지
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• 제15권1호
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• pp.105-110
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• 1994

In this paper, we present a method to evaluate source locations and distributed region which is specified brain activity, as indicated by locations and strengths of intracranial sources, using potential gradients of interpolation polynomials and topographic mapping of the EEG records. This method can analyze the variance of source temporally or spatially and leads to enable a quantitative evaluation of potential gradients drawing methods which is now being used in the clinic. In the result, we obtained the overall potentials distribution on the entire scalp and the information of potential source locations from the EEG records of a patient which was known to epilepsy.

• Journal of Positioning, Navigation, and Timing
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• 제5권3호
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• pp.145-156
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• 2016

A variety of methods for indoor positioning systems have been underway to ensure the safety of emergency rescuers who are working in dangerous situations such as fire fighters. However, since most systems display locations of rescue workers in two-dimension (2D)-based maps, it is difficult for a commander located in the outside to recognize locations of rescuers inside the building intuitively. An augmented reality (AR)-based indoor positioning monitoring system can display locations of rescuer inside the building that can be seen by commanders to help intuitive recognition of positioning. To monitor AR-based indoor positioning, it is necessary to have an estimation technique of line of sight vector of observers. In the present study, an estimation technique of a line of sight vector using ultra-wide band tranceiver installed inside the indoor to trace locations is presented.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.787-791
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• 1996

In injection molding, location of gates have great influence on the quality of plastic parts. Usually, they are located by releated trial and errors of experienced mold designers. In this topic we will present the numerical algorithm for finding the optimal gate locations. Optimization algorithm is devided into two stages. In the first stage, candidated optimal gate locations can be found by geometry of part only; whereas in the next step, more acculate gate locations are selected byiterative computation with optimization part and analysis part. So from the following study, we suggested the modified flow-volume method, which will define the optimal gate locations in injection mold design.