• Journal of Broadcast Engineering
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• v.26 no.7
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• pp.844-854
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• 2021

Semi-supervised learning (SSL) and few-shot learning (FSL) have shown impressive performance even then the volume of labeled data is very limited. However, SSL and FSL can encounter a significant performance degradation if the diversity gap between the labeled and unlabeled data is high. To reduce this diversity gap, we propose a novel scheme that relies on an autoencoder for generating pseudo examples. Specifically, the autoencoder is trained on a specific class using the available labeled data and the decoder of the trained autoencoder is then used to generate N samples of that specific class based on N random noise, sampled from a standard normal distribution. The above process is repeated for all the classes. Consequently, the generated data reduces the diversity gap and enhances the model performance. Extensive experiments on MNIST and FashionMNIST datasets for SSL and FSL verify the effectiveness of the proposed approach in terms of classification accuracy and robustness against adversarial attacks.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.423-438
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• 1997

Today's building and fire prevention codes are mostly prescriptive. Prescriptive codes are based on major fires in earlier years that created a need for specific building provision. These codes provide a minimum level of safety. As the general and engineering uses of computers have increased over the years, so has use of computers in the fire protection engineering. This has allowed fire protection engineers to develop alternative approaches to solve today's fire protection problems or to evaluate the performance of a specific fire safety goal. A performance based approach to building and fire codes involves the following: 1) identifying specific goals, such as, safely getting out of the building in 10 minutes, 2) obtain conceptual approval from authorities, 3) define performance level, 4) develop design solutions and identify tools such as, fire tests, models, or methods, to demonstrate that a design will meet the fire protection objective 5) test solutions, 6) present test method and results to the authorities. Some people in the fire protection community consider this to be nothing more than an intellectual exercise, while the others view it as a way to reduce expenses on large project$^4$ Others in fire protection community view this as a way to refine the design process to design fire protection systems to better protect the fire hazards. This paper will focus on application of these tools, specifically computer fire models, to actual cases such as: design of a smoke control system heat transfer analysis and egress of building occupants during potential fires.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.89-100
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• 2023

Recently, as ESG management has become an important issue, major companies in the automotive parts manufacturing industry are conducting ESG evaluations of their suppliers for the purpose of supply chain management. The results of these evaluations are being incorporated into contractual agreements. However, many small and medium-sized enterprises(SMEs) are lacking in their capacity and resources to effectively respond to ESG evaluations. Furthermore, existing ESG management guidelines do not provide an industry-specific guidance, making it necessary to establish industry-specific guidelines that SMEs can refer to. Therefore, in this study, the evaluation Indicators of ESG supply chain assessments are surveyed, which is conducted by domestic major automotive parts companies and global automobile manufacturers. Then 56 supply chain ESG evaluation Indicators are derived. Also, ESG management indicators for SMEs is analyzed through the Importance-Performance Analysis(IPA), based on an interview of expert groups. Therefore, this study could propose industry-specific ESG guidelines, based on the results of the derived indicators, which reflects the need for SMEs to practice ESG management within certain boundaries.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.134-143
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• 2000

A train performance simulation (TPS) software is a computer program that simulates the operation of a train system over a specified railway route and it is widely used in railroad operation and research applications. Numerical and graphical results from the simulation software, which is developed in this study, provide information on such performance variables as travel time. running speed, energy consumption at a specific time interval and in overall service time as the train moves along the route. Three types of input data are required for a computer simulation: track information, train information, and running conditions. The simulation of train performance starts with several simple mathematical models including train configuration. traction efforts, running resistance. and braking requirements. Based on the basic specifications of Korean High Speed Railway, System. this study, puts a focus on the estimation and assessment of train performance comparing. the specific train configurations of KEST20/11. CPLE20/10. PROP20/10, which are proposed from the previous G7 projects.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.733-739
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• 2021

This study investigates the relationships of energy firm-level characteristics, namely; firm size, firm leverage, and firm performance with board diligence among companies listed in Saudi Stock Exchange (Tadawul) for the periods ranging from 2012 to 2019. The final sample of this study consists of 32 firm-year observations. A quantitative approach was adopted to test 3 specific hypotheses developed for the board diligence model. Using the Pooled OLS regression, this study finds that firm size and firm performance are negatively associated with board diligence. The results of this study indicate an insignificant association of firm leverage with board diligence. Besides, firm performance is related negatively to board diligence. This indicates that the board of companies with poor performance increases the number of its meetings because of the increased pressure on the board to improve its oversight operations and address the severe performance challenges. The increased number of board meetings observe the daily management of the company, increase the chances for discussions concerning the performance challenges, and come up with solutions faster. The directors are also likely to encounter heightened pressure to appear more engaged during a company's financial distress since lenders require a meeting of the board or with the board.

• Journal of Biosystems Engineering
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• v.8 no.1
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• pp.70-74
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• 1983

This study was conducted to determine whether or not the form and angle of the precombustion chamber affected the performance of agricultural diesel engines. Twenty different types of precombustion chambers were designed and tested using a two way classification with four individual tests. The output power and specific fuel consumption ratio at full load were measured and analyzed. The results of the study were summarized as follows; 1. The diameter of main passageway giving the best power output and specific fuel consumption ratio at full load was between 5.8 and 6.1mm. The ratio of area of main passageway bore to that of piston head was from 0.4 to 0.44 percent at the highest engine power. 2. The angle of main passageway giving the best power output and specific fuel consumption ratio at full load was between 41 and 43 degrees. 3. The change of the diameter of main passageway affected the output of engine more significantly than the change of angle, however, on the specific fuel consumption ratio the angle of main passageway had more effect than the diameter.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2298-2315
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• 2024

This paper introduces a method aimed at diagnosing the presence or absence of lesions by detecting anomalies in Chest X-ray images. The proposed approach is based on the PatchCore anomaly detection method, which extracts a feature vector containing location information of an image patch from normal image data and calculates the anomaly distance from the normal vector. However, applying PatchCore directly to medical image processing presents challenges due to the possibility of diseases occurring only in specific organs and the presence of image noise unrelated to lesions. In this study, we present an image alignment method that utilizes affine transformation parameter prediction to standardize already captured X-ray images into a specific composition. Additionally, we introduce a region-specific abnormality detection method that requires affine-transformed chest X-ray images. Furthermore, we propose a method to enhance application efficiency and performance through feature map hard masking. The experimental results demonstrate that our proposed approach achieved a maximum AUROC (Area Under the Receiver Operating Characteristic) of 0.774. Compared to a previous study conducted on the same dataset, our method shows a 6.9% higher performance and improved accuracy.

• Journal of the Korea Institute of Building Construction
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• v.3 no.1
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• pp.139-146
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• 2003

The special requirements of high-performance concrete(HPC) could be enhanced property over others such as compressive strength, durability, and construction practices. In order to satisfy these requirements a series of laboratory trial mixes and following mock-up test of reinforced concrete wall at field were performed in this study. The objective of this study was to quantitatively evaluate the workability, compressive strength, and the increased heat of hydration caused by the increase of the specific weight of cement according to various variables. Six example series designed about a minimum compressive strength of 500kgf/$\textrm{cm}^2$ at 28 days, and an approximately slump and slump flow of 25cm and 60cm respectively were tested. The selection process of the specific weight of water and the percentage of fly-ash transposition determined to be most suitable for the production of HPC is presented in the following paper.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.605-612
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• 2003

In this study, the performance of the cut-off wall with the specific functional adsorption layers(containing SAC), which are formed in order to block harmful materials such as heavy metal ions contained in leachate (or outflow water) from either waste landfills or exhausted mines, was Investigated by determining experimental data such as hydraulic conductivities, unconfined compression strengths, adsorption capacities. The performance was compare to those of the present cut-off wall materials such as clay, bentonite-mixed soil, and soil-cement.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.4
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• pp.434-443
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• 2014

A turbo fan engine performance analysis and the optimization using particle swarm optimization(PSO) algorithm have been conducted to investigate the effects of major performance design parameters of an aircraft gas turbine engine. The FJ44-2C turbofan engine, which is widely used in the small business jet, CJ2 has been selected as the basic model. The design parameters consists of the bypass ratio, burner exit temperature, HP compressor ratio, fan inlet mass flow, and nozzle cooling air ratio. The sensitivity analysis of the parameters has been evaluated and the optimization of the parameters has been performed to achieve high net thrust or low specific fuel consumption.