• ETRI Journal
• /
• 제44권4호
• /
• pp.599-612
• /
• 2022

This study focuses on improving a word embedding model to enhance the performance of downstream tasks, such as those of dialog systems. To improve traditional word embedding models, such as skip-gram, it is critical to refine the word features and expand the context model. In this paper, we approach the word model from the perspective of subword embedding and attempt to extend the context model by integrating various sentence models. Our proposed sentence model is a subword-based skip-thought model that integrates self-attention and relative position encoding techniques. We also propose a clustering-based dialog model for downstream task verification and evaluate its relationship with the sentence-model-based subword embedding technique. The proposed subword embedding method produces better results than previous methods in evaluating word and sentence similarity. In addition, the downstream task verification, a clustering-based dialog system, demonstrates an improvement of up to 4.86% over the results of FastText in previous research.

• 한국물환경학회지
• /
• 제24권6호
• /
• pp.784-792
• /
• 2008

Greater focus must be placed on ensuring that the water quality model (WQM) reflects the objective of its application and the characteristics of the water environment properly before it is selected. In the development or application of WQM, various factors influencing the model predictions should be reviewed so that it can perform more properly and reasonably based on scientific theory. This study reviewed the characteristic of existing WQM and the domestic river environment to find the requirements of the model application for TMDLs management in Korea. In this study, a water quality model, QUAL-NIER, was developed based on the USEPA's QUAL2E. The core structure and reaction scheme of the model was established followed by the formulation of equations according to the scheme with some supplements on the reaction mechanisms which are necessary for domestic rivers. Algorithms on the equations were set up and programmed to form a computer-based model. The developed model, QUAL-NIER was applied to the main stem of the Nakdong river. The model was calibrated and verified to data measured in 2004. The model results displayed good agrement with the field measurements for both calibration and verification. From this study, it was concluded that the developed QUAL-NIER model was very powerful with regard to the water quality simulation in domestic rivers.

• Current Photovoltaic Research
• /
• 제11권1호
• /
• pp.27-33
• /
• 2023

In this paper, a machine learning model by using a regression algorithm is proposed to estimate the power generation performance of the BIPV system. The physical model formula for estimating the generation performance and the proposed model were compared and analyzed. For the physical model formula, simple efficiency model, temperature correction model, and regressive physics model for changing an irradiance were used. As a result, when comparing the regressive physics model for changing an irradiance and the proposed model with the actual generation measured data, the respective RMSE values are 0.1497 kW, 0.0451 kW and the accuracy values are 86.44%, and 96.56%. Therefore, the proposed model implemented in this experiment can be useful in estimating power generation.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 1997년도 춘계학술발표회논문집(2)
• /
• pp.407-412
• /
• 1997

The predictive results between a dynamic food-chain model (DYNACON) and an equilibrium model (NRC model) were compared to show the physical validity of DYNACON. Although the mathematical formulations and transport processes of radionuclides in the environment are different between two models, the comparative study shows good agreement for deposition events that occur during the growing season of plants.

• 대기
• /
• 제16권4호
• /
• pp.279-301
• /
• 2006

This study analyzed the characteristics of the wind waves near the Korean marginal seas in the 2002 - 2005 year using the third generation wave model, WAVEWATCH - III model. In order to investigate the model performance, model results were compared with the marine meteorological observation results. The 4 years average correlation coefficient between model and observation shows very high value of about 0.77. The model of this study represents very well the characteristics of wind waves near the Korean marginal seas. Simulated monthly sea surface winds and wind waves show the evident spatial variations and this model also simulates very well seasonal characteristics of wind waves in this region.

• ETRI Journal
• /
• 제42권1호
• /
• pp.7-16
• /
• 2020

Assuming omnidirectional antenna reception, the ITU-R recently developed a new propagation model on building entry loss (BEL) for 5G millimeter-wave frequency sharing and compatibility studies, which is a simplified outdoor-to-indoor path loss model. Considering the utilization of high-gain narrow-beamwidth beamforming, the omnidirectional-based ITU-R BEL model may not be appropriate to predict propagation characteristics for directional beamforming scenarios. This paper studies the effects of beamwidth on the ITU-R BEL model. This study is based on field measurements collected with four different beamwidth antennas: omnidirectional, 10° horn, 30° horn, and 60° horn. The measurement campaigns were conducted at two types of building sites: traditional and thermally efficient buildings. These sites, as well as the measurement scenarios, were carefully chosen to comply with the ITU-R BEL measurement guidelines and the ITU-R building types. We observed the importance of accurate beam alignment from the BEL variation range. We were able to quantify the beamwidth dependency by fitting to a model that is inversely proportional to the beamwidth.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
• /
• pp.167-170
• /
• 2003

In this paper, a design and experiment of PCI Express Core verification Model is described. The model targeting Endpoint core verification is designed by using newly-emerging SystemC which is a system design language based on a new C++ class library and simulation engine. In the verification model, we developed a SystemC Host System model which act as a Root Complex and Device Driver dedicated to the PCI Express Endpoint RTL Core. The test of Host System Model is guided by scenarios which implements and acts point of Device Driver and Root Complex and shows the result of simulation. Also, We present the full structure of verification model and Host model.

• 한국통신학회논문지
• /
• 제28권8A호
• /
• pp.650-656
• /
• 2003

In 1995, a group of representatives from the integrated circuits and computer-aided design industries presented a industry standard bipolar model called the VBIC model. The VBIC model includes the improved Early effect, quasi-saturation, substrate parasitic, avalanche multiplication, and self-heating which are not available in the conventional SGP model. This paper applies VBIC model for SiGe HBT device and develops an accurate and efficient methodology to extract all the DC and AC parameters of the VBIC model for SiGe HBT device at room temperature. Simulated results by the extracted VBIC model parameter are compared with the measurement data and show very good agreement in both DC and s-parameters prediction.

• 방사선산업학회지
• /
• 제2권3호
• /
• pp.155-161
• /
• 2008

A hydraulic scale model was constructed to investigate the characteristics of flows and pollutant transport in laboratory. The distorted hydraulic scale model by assuming Froude similarity was adopted to represent hydrodynamics and dispersion in a river system. The scale model was composed of water reservoir, slope control part, booster pump, distributing plate and main channel. A constructed scale model will be used to present the overall concentration profiles of tracer and a research will be performed to convert the measured values using a hydraulic scale model to real field scale.

• 한국항공우주학회지
• /
• 제49권3호
• /
• pp.167-174
• /
• 2021

NASA Common Research Model의 29.7% 축소 모형에 대하여 저속 풍동시험 조건으로 수치해석을 수행하였다. 낮은 레이놀즈수 영역인 0.3×106에서 Belly sting 모형 지지부를 장착한 CRM의 공력계수를 측정하는 시험이 수행되었으며, 수치해석 결과와 비교하였다. 해석의 타당성을 검증하기 위해 선행연구 조건으로 전산해석을 수행하여 비교하였다. Belly sting 모형 지지부 유무에 대한 해석 결과 지지부에 의한 간섭 효과로 동체뿐만 아니라 주날개, 꼬리날개까지 공력에 영향이 있음을 확인하였다.