• Journal of the Korean Geotechnical Society
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• v.29 no.7
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• pp.75-89
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• 2013

This paper describes a GIS-based geohydrologic methodology, called YSGWF (YonSei GroundWater Flow) for predicting the rainfall infiltration-groundwater flow of slopes. This physical-based model was developed by the combination of modified Green-Ampt model that considers the unsaturated soil parameters and GIS-based raster model using Darcy's law that reflects the groundwater flow. In the model, raster data are used to simulate the three dimensional inclination of bedrock surface as actual topographic data, and the groundwater flow is governed by the slope. Also, soil profile is ideally subdivided into three zones, i.e., the wetting band zone, partially saturated zone, and fully saturated zone. In the wetting band and partially saturated zones the vertical infiltration of water (rainfall) from surface into ground is modeled. When the infiltrated water recharges into the fully saturated zone, the horizontal flow of groundwater is introduced. A comparison between the numerical calculation and real landslide data shows a reasonable agreement, which indicate that the model can be used to simulate real rainfall infiltration-groundwater flow.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.11
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• pp.481-492
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• 2023

This study explores how to build a Korean dataset to extract information from text using generative large language models. In modern society, mixed information circulates rapidly, and effectively categorizing and extracting it is crucial to the decision-making process. However, there is still a lack of Korean datasets for training. To overcome this, this study attempts to extract information using text-based zero-shot learning using a generative large language model to build a purposeful Korean dataset. In this study, the language model is instructed to output the desired result through prompt engineering in the form of "system"-"instruction"-"source input"-"output format", and the dataset is built by utilizing the in-context learning characteristics of the language model through input sentences. We validate our approach by comparing the generated dataset with the existing benchmark dataset, and achieve 25.47% higher performance compared to the KLUE-RoBERTa-large model for the relation information extraction task. The results of this study are expected to contribute to AI research by showing the feasibility of extracting knowledge elements from Korean text. Furthermore, this methodology can be utilized for various fields and purposes, and has potential for building various Korean datasets.

• Advanced Industrial SCIence
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• v.3 no.2
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• pp.8-16
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• 2024

This paper shows the system of drug classification, the goal of this is to foretell the apt drug for the patients based on their demographic and physiological traits. The dataset consists of various attributes like Age, Sex, BP (Blood Pressure), Cholesterol Level, and Na_to_K (Sodium to Potassium ratio), with the objective to determine the kind of drug being given. The models used in this paper are K-Nearest Neighbors (KNN), Logistic Regression and Random Forest. Further to fine-tune hyper parameters using 5-fold cross-validation, GridSearchCV was used and each model was trained and tested on the dataset. To assess the performance of each model both with and without hyper parameter tuning evaluation metrics like accuracy, confusion matrices, and classification reports were used and the accuracy of the models without GridSearchCV was 0.7, 0.875, 0.975 and with GridSearchCV was 0.75, 1.0, 0.975. According to GridSearchCV Logistic Regression is the most suitable model for drug classification among the three-model used followed by the K-Nearest Neighbors. Also, Na_to_K is an essential feature in predicting the outcome.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.247-262
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• 2016

The importance of coaching leadership has been highlighted to enhance creativity and competence of human resources in convergence environment. This paper was validated through a structural relationships model, the impact of coaching leadership on behavioral dimensions of organizational effectiveness by focusing on mediating role of job characteristics. Coaching leadership activities showed a significant positive effect on job characteristics and turnover intentions. Job characteristics appear to have a mediating effect on the relationship between coaching leadership and organizational effectiveness, especially the coaching leadership itself not necessarily to improve organizational citizenship behavior, can increase organizational citizenship behavior when formed into a positive awareness of the job characteristics of organizational members.

• The Journal of the Acoustical Society of Korea
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• v.30 no.6
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• pp.344-352
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• 2011

In this paper, the resonant characteristic of a Tonpilz transducer with a fixed tail mass has been studied by means of an equivalent circuit approach. An equivalent circuit has been designed to describe the characteristic of a Tonpilz transducer that has an additional resonance because of its fixed tail mass. The transmitting voltage response of the transducer calculated by the designed circuit has been compared with that by the FEA (finite element analysis) to confirm the validity of the circuit. This equivalent circuit approach produces identical results with the FEA, in which the variation of resonant frequencies and TVR has been clearly figured out in relation to the stiffness of the mounting fixture and the mass of the tail mass. The suggested equivalent circuit can be utilized to figure out the characteristics of the Tonpilz transducer more efficiently than FEA that requires much calculation time and revision of the models in accordance with the variation of design variables.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2844-2850
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• 2015

Rolling noise caused by the contact between the train wheels and rails is the main factor of noise generated by the operation of railway, therefore the features of rail vibration and its correlations with noise radiation should be identified. In this study, noise radiation generated from vibration were predicted by utilizing FE model with boundary element method. Noise radiation generated from vibration were predicted by utilizing FE model with boundary element method, and were compared with the measured noise in order to validate the reliability of the analysis method. In addition, the features of noise radiation according to the rail attenuation were examined in the frequency domain, and the noise radiation has been reduced by approximately 3dB(A) with additional rail damping.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.4
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• pp.463-468
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• 2007

Some network equipments made in Korea were exposed to severe earthquake in Japan several years ago. More than a hundred slim base transfer network stations had been seized with the severe earthquake at Nigata and it was reported that less than fifteen sets showed blackout by interruption of electricity, not by the structural failure. The purpose of this paper is to check the structural safety of the network equipments by performing table test, and the static and dynamic finite element analysis. For the dynamic test, the station weighing 200 kg was subjected to the Zone 3 earthquake loading of GR-63-CORE on the shaking table to obtain the dynamic responses to compare with the analysis results. It is shown that the FE analysis results are a little bit larger than that of the experimental values. And the sensitivity analysis and optimization for the natural frequency is performed and it is found that the first natural frequency is sensitive to small design change as shown in the results. And the dynamic response of optimized design is less than the original design.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.5
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• pp.76-84
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• 2007

In this paper, we measured the propagation characteristics of I-UWB channel in time domain and in frequency domain. The measurements carried out in apartment environment while furniture and household electric appliance. Typical indoor scenarios, including line-of-sight(LOS), non-line-of-sight(NLOS) in room-to-room, within-the-room. A transmitting and receiving antenna is a biconical antenna. Results for indoor propagation measurements are presented for power delay profiles(PDP). We extracted the channel characteristic parameters from a power delay profile. Finally, we designed I-UWB channel model in indoor environment, and I-UWB simulator. The results of simulation shows BER characteristics below $10^{-5}$ for SNR over 20[dB].

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.5
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• pp.442-448
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• 1999

We introduce the systematization design method using similarity theory which is profitable in the c compatability and standardization of the developed products and the reduction of construction time and price to d develop and design a machine equipment. Systematization design method is to select the standard model for d designing and developing from the large machinery to the super precision one and then to induce the c characteristic of machines step by step in advance in case of miniaturizing and making largelongleftarrowscale. With this m method, we extract the peculiar characteristics through the close analysis on the physical and ttx:hnical part a and predict the characteristic experiment for the magnitude we desire by an머ogical mathematical analysis. At l last, we will get the design sample the users demand with the verification of the data on optimum design p previously. In this paper, we could predict the characteristic of the product the users rC'Quire in advance with the d design method applying similarity theor${\gamma}$ and suggested the design method which could meet the various r requirements the users want. Also, it is shown that the standardization design by the similarity theory is a available as comparing the characteristic values expc'Cted through the experiment of the actual actuator with t the theoretical character data of similarity theoη after selecting the linear actuator as a model.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.95-100
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• 2013

Several observation equipments are being used for determination of the water vapor content and precipitable water vapor (PWV) because the water vapor is highly variable temporally and spatially. In this study, we used GNSS systems such as GPS and GLONASS in standalone and combined modes to compute PWV and validated their accuracy with respect to the results of other water-vapor monitoring systems. The other systems used were radiosonde and microwave radiometer, and the comparisons were convenient because all three systems were collocated at the test site. The differences of PWW were in the range of 0.6-3.4 mm in the mean sense, and their standard deviations were 1.0-3.8 mm. The relatively large difference of GNSS compared with the other two systems were believed to be caused by the fact that the GNSS antenna used in this study was the kind for which the international standard of phase center variations (PCV) calibration is not available. We expect better accuracy of PWV determination and improved availability of it through integrated data processing of GPS/GLONASS when an appropriate antenna with PCV correction model is used.