• Journal of Soil and Groundwater Environment
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• v.25 no.2
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• pp.1-8
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• 2020

In general, the estimation of optimum yield for the radial collector well is determined by the empirical equation or numerical modeling, in which hydraulic conductivity of the aquifer is a main influence factor. Hydraulic conductivities of 164 soil samples collected from boreholes and horizontal wells (average length: about 50 m) installed during well construction in the Anseong stream were drawn in two-dimensional map by the Kriging method and utilized in this study. Hydraulic conductivity analyses by Representative Elementary Count (REC) indicated the average hydraulic conductivity is similar to that of the pumping test when the number of samples reaches about 1,000, which correspond to 1,000 ㎡. Pumping test was also conducted at 1 pumping well and 13 observation wells to estimate hydraulic conductivities at each observation well. REC analysis indicated that the average value of hydraulic conductivity calculated from at least four observation wells is valid as a representative value. The overall result suggested that multiple observation wells or multiple pumping-observation well systems that are located within the range of horizontal wells should be utilized to properly estimate the representative hydraulic conductivity values and the yield of a radial collector well.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1149-1154
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• 2022

The purpose of this research is to select representative observation stations for winter observation equipment performance tests and to present indoor and outdoor conditions for performance tests by considering snowfall, snowfall days, latitude, and altitude distribution for observation stations operated by the Korea Meteorological Administration. Using the snowfall data observed during the winter for 30 years (1981-2010), ten representative observation stations are selected to consider the classification of snowfall days by class, latitude, and altitude distribution of observation stations. As a result of analysis, the suitable point for outdoor experiments was selected as Daegwallyeong, the average number of snowfall days and snowfall days of 5cm or more were 57.5 and 13.2 days, respectively. The indoor experimental conditions are considered to be suitable under temperatures of -15 to 5℃ and humidity of 50% or higher. Results of this research can be used as basic information for conditions and test beds for performance tests of equipment that can respond to heavy snow disasters in winter.

• The Korean Journal of Applied Statistics
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• v.18 no.1
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• pp.129-135
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• 2005

Representative observations are useful to express explicitly the distributional variation of the data by a few selected observations corresponding to the quantiles in the univariate situation. Jones and Rice(1992) extended it to the multidimensional case by the principal component based method. This study introduces a modified version of Jones and Rice exploiting the self-consistency of principal components in expressing the chosen observation vectors. Compared to that of Jones and Rice, the suggested method tends to provide with less susceptible representative observations to the sampling variation of the data and the resulted vectors benefits from the self-consistency.

• Korean Institute of Interior Design Journal
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• v.24 no.6
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• pp.145-153
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• 2015

For this research with the objects of spaces in two department stores which can be referred to as representative facility of commercial space, observation test has carried out to estimate how much visitors rivet their eyes to the display of shops. In addition, to find out what effect the difference among the department types has on the selective attention to space element, the observation time was applied as a medium for estimation. The followings are the result from analyzing the observation frequency and the observation intensity feature of each section where the characteristics of design could be found at attention. First, both images of A and B had concentrative dominant-observation at left shops. In case of Image A, Customers began to observe the right shops very attentively after 25 seconds, and with Image B, the attentive observation at right and left took place alternatively after 35 seconds. In other words, regardless of the characteristics of shop displays, the left shops were observed first while in case of the observation after the early and middle time-frame the characteristics of shops were found to have effects on observation. Second, the normal observation showed some difference among attention sections over time while on the whole both images of A and B had the same highly attentive observation at the middle space. Accordingly, it could be concluded that the middle space was playing a faithful role as background for commercial spaces. Third, the ignorant observation, which is the opposite to the attentive observation, was found different between the images of A and B. When the ignorant observation is considered to have intentionality, it will be possible to set up the display which may attract the attention aggressively by the process of figuring out the characteristics of ignored shops.

• Atmosphere
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• v.29 no.4
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• pp.451-461
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• 2019

Medium-range forecast is highly dependent on ensemble forecast data. However, operational weather forecasters have not enough time to digest all of detailed features revealed in ensemble forecast data. To utilize the ensemble data effectively in medium-range forecasting, representative weather patterns in East Asia in this study are defined. The k-means clustering analysis is applied for the objectivity of weather patterns. Input data used daily Mean Sea Level Pressure (MSLP) anomaly of the ECMWF ReAnalysis-Interim (ERA-Interim) during 1981~2010 (30 years) provided by the European Centre for Medium-Range Weather Forecasts (ECMWF). Using the Explained Variance (EV), the optimal study area is defined by 20~60°N, 100~150°E. The number of clusters defined by Explained Cluster Variance (ECV) is thirty (k = 30). 30 representative weather patterns with their frequencies are summarized. Weather pattern #1 occurred all seasons, but it was about 56% in summer (June~September). The relatively rare occurrence of weather pattern (#30) occurred mainly in winter. Additionally, we investigate the relationship between weather patterns and extreme weather events such as heat wave, cold wave, and heavy rainfall as well as snowfall. The weather patterns associated with heavy rainfall exceeding 110 mm day^-1 were #1, #4, and #9 with days (%) of more than 10%. Heavy snowfall events exceeding 24 cm day^-1 mainly occurred in weather pattern #28 (4%) and #29 (6%). High and low temperature events (> 34℃ and < -14℃) were associated with weather pattern #1~4 (14~18%) and #28~29 (27~29%), respectively. These results suggest that the classification of various weather patterns will be used as a reference for grouping all ensemble forecast data, which will be useful for the scenario-based medium-range ensemble forecast in the future.

• Journal of Korea Foundry Society
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• v.30 no.1
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• pp.5-13
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• 2010

This article aims to introduce the synchrotron radiation for its utilization in the casting and solidification fields as an unique tool for observation of real time phenomena of molten metal during solidification. General features of the synchrotron radiation were briefly introduced for readers in the casting and solidification fields, with no background regarding to synchrotron radiation. And basic principles of imaging technologies using synchrotron light for in-situ observation of molten metal were explained together with exemplary research works, which were reported on the casting and solidification fields in recent years. As a practical guide, real time observation of Al-Si casting alloy was introduced with experimental facilities, image acquisition, and processing together with representative results.

• Agribusiness and Information Management
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• v.7 no.1
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• pp.1-9
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• 2015

The purpose of this study is to develop a growth prediction model that can predict growth and development information influencing the production of citrus fruits: the growth model algorithm that can predict floral leaf ratio, number of fruit sets, fruit width, and overweight depending on the main period of growth and development with consideration of the applied weather factors. Every year, large scale of manpower was mobilized to investigate the production of outdoor-grown citrus fruits, but it was limited to recycling the data without an observation supporting system to systemize the database. This study intends to create a systematical database based on the basic data obtained through the observation supporting system in application of an algorithm according to the accumulated long term data and prepare a base for its continuous improvement and development. The importance of the observed data is increasingly recognized every year, and the citrus fruit observation supporting system is important for utilizing an effective policy and decision making according to various applications and analysis results through an interconnection and an integration of the investigated statistical data. The citrus fruit is a representative crop having a great ripple effect in Jeju agriculture. An early prediction of the growth and development information influencing the production of citrus fruits may be helpful for decision making in supply and demand control of agricultural products.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.1
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• pp.1-15
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• 2004

Sea/land circulation system is a representative mesoscale local circulation system in coastal area. In this study, wind fields around coastal area. Pohang, which is affected by this system was investigated and its detailed characteristic analysis was carried out. The following can be found out from the numerical simulation. Generally, at nighttime mountain winds prevail and land breeze toward the coastal area was well simulated During daytime, valley wind and sea breeze was simulated in detail. Especially, as a result of analyzing the land breeze path, it could be found along the coastline as it flows out through low land coastal area. In order to investigate the accuracy of model results. wind speed, temperature and wind direction of continuous typical sea/land breeze occurrence day was compared with observation data. Analyzing the characteristics of local circulation system was very hard because of horizontally sparse observation data but from the above result, a numerical simulation using RAMS, which satisfies the spatial high resolution, will provide more accurate results.

• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.87-99
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• 2019

Reinforcement learning is a type of machine learning paradigm that forces agents to repeat the observation-action-reward process to assess and predict the values of possible future action sequences. This allows the agents to incrementally reinforce the desired behavior for a given observation. Thanks to the recent advancements of deep learning, reinforcement learning has evolved into deep reinforcement learning that introduces promising results in various control and optimization domains, such as games, robotics, autonomous vehicles, computing, industrial control, and so on. In addition to this trend, a number of programming libraries have been developed for importing deep reinforcement learning into a variety of applications. In this article, we briefly review and summarize 10 representative deep reinforcement learning libraries and compare them from a development project perspective.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.5 s.164
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• pp.717-728
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• 2007

The purpose of this study is to suggest hospital clothing design which reflects ubiquitous info-communications technology as changing hospital environment in the information-oriented era of the 21st century. The methods of this study are documentary research of previous studies, observation research and deep interviews. Seoul national university hospital is selected as a target of observation for this study. Doctors, nurses, pharmacists, and patients who are the representative jobs in the hospital are interviewed from on July, 13, 2006 to on August, 1, 2006. According to observation research, the computers, OCR, and PACS are applied from registration to dosage through all courses of diagnosis. However, the most inconvenient problems to patients are the location of medical offices and confusion of reservation. Also, the needs and inconveniences of doctors, nurses, pharmacists, and patients are almost solved by using RFID technology as a result of deep interviews. They prefer wearing devices as an accessory to wearing devices as a clothing directly. In conclusion, suggested UFC design for hospital clothing with info-communications technology promotes efficiency, accuracy, convenience of work to medical personnel in changing hospital environment as the flow of the information-oriented era of the 21st century.