• Information and Communications Magazine
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• v.31 no.8
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• pp.33-37
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• 2014

최근 ISO, IEC, ITU-T 등 국제표준화 기구에서는 스마트시티(Smart Cities)에 대한 표준화가 활발히 추진 중에 있다. 아직은 초기 단계로 개념 정립 및 표준화 추진에 대한 준비 단계에 있지만 곧 전담 그룹 설치 등 활발한 표준화가 추진될 것으로 예상된다. 본고에서는 스마트시티의 국내 및 국제 표준화 추진 동향을 살펴본다.

• International Journal of Computer Science & Network Security
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• v.21 no.5
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• pp.121-128
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• 2021

In this work, a noble walkway approach suitable for Saudi Arabia (SA) towards its aim to develop a wide range of smart cities is considered scientifically. This work intends to minimize the errors at each level by testing the events that take place in the walkway environment. similarly, the minimum requirements to develop a walkway to the additional features to be considered while designing a walkway are discussed in this paper with sensitive areas such as environmental factors, healthcare issues, patients visiting the walkways, etc. The applications of different monitoring devices such as CCTV's, global positioning systems (GPS), etc. are carefully addressed to help the proposed method for improving the monitoring activities of a variety of events that possibly cause problems to a common man. The ultimate goal of this work to ensure a safe and satisfied journey of pedestrians while they come for a walk with all suitable safety measures. The safety measures included in this work are for pollution, noise, temperature, humidity and traffic jams on the roads. To improve the accuracy and to test the proposed approach some polices are defined and will be tested for the consistency of the proposed system. The obtained accuracy of the proposed system is proved to be far better with an accuracy of 93% improvement in the results.

• The Journal of Economics, Marketing and Management
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• v.11 no.2
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• pp.13-22
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• 2023

Purpose: The purpose of this study is to examine the policy implications of establishing a compact city in Seoul, analyzing whether it is an appropriate and efficient eco-friendly housing supply alternative. Research design, data, and methodology: The analysis criteria include efficiency, safety, and comfort, with efficiency encompassing economic, energy, and public transport links' efficiency. Safety and comfort are aspects of eco-friendliness, housing safety, and improvement in living environments. Results: In terms of economic efficiency, compact cities are a less expensive option than purchasing land for housing construction. To increase energy efficiency, we plan to adopt eco-friendly energy sources. Transportation efficiency is high in locations near public transport stations. To enhance safety and comfort, we intend to create large-scale parks and forests in Seoul. To ensure residential safety, measures will be taken to reduce road vibration, vehicle noise, and scattering dust. Conclusions: Selecting an appropriate location that provides convenient public transportation is essential for creating a compact city for housing in a large city. Combining a compact and smart city is necessary, and implementing smart technologies is needed to prevent dust, noise, and vibrations, which are undesirable in a residential environment.

• Geomechanics and Engineering
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• v.33 no.1
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• pp.113-120
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• 2023

Coastal and offshore structures such as ports and offshore wind farms will often need to be built on fine-grained sediments. Geotechnical properties associated with sediment compressibility are key parameters for marine construction designs especially on soft grounds, which involve clay-mineral dominated fines that can consolidate and settle significantly in response to engineered and environmental loads. We conduct liquid limit tests and 1D consolidation tests with fine-grained soils (silica silt, mica, kaolin and bentonite) and biogenic soils (diatom). The pore fluids for the liquid limit tests include deionized water and a series of brines with NaCl salt concentrations of 0.001 m, 0.01 m, 0.1 m, 0.6 m and 2.0 m, and the pore fluids for the consolidation tests deionized water, 0.01 m, 0.6 m, 2 m. The salt concentrations help the liquid limits of kaolin and bentonite decrease, but those of diatom slightly increase. The silica silt and mica show minimal changes in liquid limit due to salt concentrations. Accordingly, compression indices of soils follow the trend of the liquid limit as the liquid limit determined the initial void ratio of the consolidation test. Diatoms are more likely to be broken than clastic sediments during to loading, and diatom-rich sediment is therefore generally more compressible than clastic-rich sediment.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.136-136
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• 2022

This study investigates the possibility of coupling empirical mode decomposition (EMD) for runoff prediction from machine learning (ML) models. Here, support vector regression (SVR) and convolutional neural network (CNN) were considered for ML algorithms. Precipitation (P), minimum temperature (Tmin), maximum temperature (Tmax) and their intrinsic mode functions (IMF) values were used for input variables at a monthly scale from Jan. 1973 to Dec. 2020 in the Grand river basin, Canada. The support vector machine-recursive feature elimination (SVM-RFE) technique was applied for finding the best combination of predictors among input variables. The results show that the proposed method outperformed the individual performance of SVR and CNN during the training and testing periods in the study area. According to the correlation coefficient (R), the EMD-SVR model outperformed the EMD-CNN model in both training and testing even though the CNN indicated a better performance than the SVR before using IMF values. The EMD-SVR model showed higher improvement in R value (38.7%) than that from the EMD-CNN model (7.1%). It should be noted that the coupled models of EMD-SVR and EMD-CNN represented much higher accuracy in runoff prediction with respect to the considered evaluation indicators, including root mean square error (RMSE) and R values.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.135-135
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• 2022

In this study, we evaluated uncertainties in baseflow separation filter methods focusing on changes in recession constant (𝛼) values, which include Lynie & Holick (LH) algorithm, Chapman algorithm, Eckhardt filter, and EWMA filter. Here, we analyzed daily streamflow data at 14 stations in the Urmia Lake basin, Iran, from 2015 to 2019. The 𝛼 values were computed using three different approaches from calculating the slope of a recession curve by averaging the flow over all seasons, a correlation method, and a mean value of the ratio of Q_t+1 to Q_t. In addition to the 𝛼 values, the BFImax (maximum value of the baseflow index (BFI)) was determined for the Eckhardt filter through the backward filter method. As results, it indicates that the estimated baseflow is dependent upon the selection of filter methods, their parameters, and catchment characteristics at different stations. In particular, the EWMA filter showed the least changes in estimating the baseflow value by changing the 𝛼 value, and the Eckhardt filter and LH algorithm showed the highest sensitivity to this parameter at different stations.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.150-150
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• 2022

This study investigates the roles of decomposition methods on high accuracy in daily rainfall prediction from light gradient boosting machine (LightGBM) algorithm. Here, empirical mode decomposition (EMD) and singular spectrum analysis (SSA) methods were considered to decompose and reconstruct input time series into trend terms, fluctuating terms, and noise components. The decomposed time series from EMD and SSA methods were used as input data for LightGBM algorithm in two hybrid models, including empirical mode-based light gradient boosting machine (EMDGBM) and singular spectrum analysis-based light gradient boosting machine (SSAGBM), respectively. A total of four parameters (i.e., temperature, humidity, wind speed, and rainfall) at a daily scale from 2003 to 2017 is used as input data for daily rainfall prediction. As results from statistical performance indicators, it indicates that the SSAGBM model shows a better performance than the EMDGBM model and the original LightGBM algorithm with no decomposition methods. It represents that the accuracy of LightGBM algorithm in rainfall prediction was improved with the SSA method when using multivariate dataset.

• Current Optics and Photonics
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• v.7 no.5
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• pp.485-495
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• 2023

The pixel size in high-resolution complementary metal-oxide-semiconductor (CMOS) image sensors continues to shrink due to chip size limitations. However, the pixel pitch's miniaturization causes deterioration of optical performance. As one solution, a quad color filter (CF) array with pixel binning has been developed to enhance sensitivity. For high sensitivity, the microlens structure also needs to be optimized as the CF arrays change. In this paper, the covered microlens, which consist of four microlenses covered by one large microlens, are proposed for the quad CF array in the backside illumination pixel structure. To evaluate the optical performance, the suggested microlens structure was simulated from 0.5 ㎛ to 1.0 ㎛ pixels at the center and edge of the sensors. Moreover, all pixel structures were compared with and without in-pixel deep trench isolation (DTI), which works to distribute incident light uniformly into each photodiode. The suggested structure was evaluated with an optical simulation using the finite-difference time-domain method for numerical analysis of the optical characteristics. Compared to the conventional microlens, the suggested microlens show 29.1% and 33.9% maximum enhancement of sensitivity at the center and edge of the sensor, respectively. Therefore, the covered microlens demonstrated the highly sensitive image sensor with a quad CF array.

• International Journal of High-Rise Buildings
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• v.13 no.1
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• pp.97-102
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• 2024

In this paper, we would like to share our ongoing research on global population and demographic shifts and the corresponding need for diverse responses. As population growth varies worldwide, the pressing issue is the current global housing shortage. The USA alone lacks 4 million homes, underlining the urgency for new construction and renewal of existing. Our focus is primarily on new building processes, which must also incorporate elements of renewal for future sustainability. Our research addresses several key questions: How will roles for construction professionals change? What should be the primary goal of the design process? What types of technologies are currently available, and which aspects of the process can be enhanced with AI? A significant part of our study is exploring sustainable building methods that reduce embodied carbon and increase speed of construction. Our goal is to extend the transition from smart homes to cities, analyzing the evolution towards smart communities and cities. A critical aspect of our research is the 'kit of parts concept, involving prefabrication and modular construction. This approach is essential for both rebuilding and new projects, potentially lowering costs in manufacturing and design for long term. Lastly, we present a detailed comparison of the construction industry with manufacturing.

• International Journal of Computer Science & Network Security
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• v.23 no.12
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• pp.115-122
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• 2023

Makkah Al-Mukarramah is the capital of Islamic world. It receives special attention from the Saudi government's rulers to transform it into a smart city for the benefit of millions of pilgrims. One of the 2030 vision objectives is to transform specific cities to smart ones with advanced technological facilitation, Makkah is one of these cities. The history of Makkah is not well known for some Muslims. As a result, we built the concepts of our application "Ain Makkah" to enable visitors of Makkah to know the history of Makkah by using technology. In particular "Ain Makkah" uses Augmented Reality to view the history of Al-Kaaba. A 3D model will overlay Al-Kaaba to show it in the last years. Our project will use Augmented Reality to build a 3D model to overlay Al-Kaaba. Future work will expand the number of historical landmarks of Makkah.