• 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.

• Clean Technology
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• v.30 no.2
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• pp.94-104
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• 2024

Remanufacturing re-commercializes a used product to achieve an equal or higher performance level than the original product by disassembling, cleaning, inspecting, repairing, reconditioning, and reassembling the used product. The remanufacturing industry is a key industry necessary to realize carbon neutrality by 2050. This study uses life cycle assessment to analyze the resource reduction and greenhouse gas reduction effects with and without considering the avoided effect for an injector, which is an automobile part that is actively being remanufactured. The results of this study showed that the resource reduction effect and greenhouse gas reduction effect induced by injector remanufacturing were reduced by 95.30% and 93.88%, respectively, based on one unit without considering the avoided effect. However, when considering the avoided effect, which in this case is the environmental impact of not disposing of the used injector and not having to use natural resources to manufacture a new injector because the used injector was reused during remanufacturing, the resource reduction effect and greenhouse gas reduction effect were 190.91% and 188.33%, respectively. The results of this study are expected to be used in the future to evaluate the amount of environmental impact reduction while considering the avoided effect during remanufacturing and to help develop research methodology for remanufacturing.

• Korean Journal of Environment and Ecology
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• v.37 no.6
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• pp.499-507
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• 2023

This study conducted an empirical analysis on a land purchase requisition policy in Bukhansan National Park to draw the efficacy, limitations and implications of this policy. A logistic regression analysis was conducted to identify factors that affected the landowners' decision on applying for land purchase requisition using the government's records on acquisition of private lands in the park since 2006 when this policy began to be implemented. Results illustrate that the probability that a landowner applied for purchase requisition increased if the land was classified as forest, if a large proportion of the land was designated as the nature conservation district, if it was located farther from park boundary, and if it had higher appraised value per square meter. These results indicate that as the landowners had less chance to utilize their lands, they more likely apply for purchase requisition. These results also imply that the government can achieve a high conservation performance level if private lands are acquire by the land acquisition requisition policy. The logistic regression model also predict that 401m² of the private lands in Bukhansan National Park will likely be purchase-requested in future. Despites its usefulness in mitigating landowners' complaints in national parks, the land purchase requisition policy has not been widely utilized. Based on these empirical results, this study provides policy implications to facilitate the ulitization of this policy.

• The Journal of the Acoustical Society of Korea
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• v.25 no.7
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• pp.346-355
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• 2006

Acoustic data from a shallow water experiment in the East Sea of Korea (MAPLE IV) is Processed to investigate the Performance of matched-field geo-acoustic inversion and source localization. The receiver array consists of two legs as in an L-shape. one vertical and the other horizontal lying on the seabed. Narrowband multi-tone CW source was towed along a slightly inclined bathymetry track. The matched-field geo-acoustic inversion includes comparisons between three processing techniques. all based on the Bartlett processor as; (1) the coherent processing of the data from the full array, (2) the incoherent Product of each output from both the horizontal and vertical arrays, and (3) the cross correlation between the horizontal and vertical arrays. as well as processing each array leg separately. To verify the inversion results. matched-field source localization for low level source signal components were performed using the same Processors used at the inversion stage.

• The Journal of the Acoustical Society of Korea
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• v.26 no.2
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• pp.61-68
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• 2007

The frequency response of a microphone, which indicates the frequency range that a microphone can output within the approved level, is one of the most significant standards used to measure the characteristics of a microphone. At present, conventional methods of measuring the frequency response are complicated and involve the use of expensive equipment. To complement the disadvantages, this paper suggests a new algorithm that can measure the frequency response of a microphone in a simple manner. The algorithm suggested in this paper generates the Optimized Aoshima's Time Stretched Pulse(OATSP) signal from a computer via a standard speaker and measures the impulse response of a microphone by convolution the inverse OATSP signal and the received by the microphone to be measured. Then, the frequency response of the microphone to be measured is calculated using the signals. The performance test for the algorithm suggested in the study was conducted through a comparative analysis of the frequency response data and the measures of frequency response of the microphone measured by the algorithm. It proved that the algorithm is suitable for measuring the frequency response of a microphone, and that despite a few errors they are all within the error tolerance.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.71-86
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• 2023

Although starting a business plays a key role in strengthening national competitiveness and creating jobs, it is recognized as a risky choice. Failure to start a business can result in a wide range of negative effects, such as loss of personal wealth as well as deterioration of national competitiveness. This study considers startups that have reached a level of sustainable growth by achieving performance above the minimum profitability and sales standards for KOSDAQ listing, or achieved EXIT through sale or listing, as successful startups. based on the practical experiences of 23 successful entrepreneurs and Based on perception, the importance and priorities of startup success factors were derived through stratification analysis (Analytic Hierarchy Process, AHP), and interviews were conducted. In particular, using the ERIS model, we comprehensively analyze various variables of a start-up by considering the four elements of the entrepreneur, resources, industry, and strategy, and examine the changes and importance of success factors according to the characteristics of each growth stage of the start-up. As a goal, we specifically identified the challenges and opportunities faced by entrepreneurs at each stage. As a result of the study, the order of importance of the top factors of success factors in the start-up period was found to be the entrepreneur, resources, industry, and strategy. In particular, the importance of the entrepreneur's entrepreneurship spirit, special capabilities, general capabilities, and human resources was emphasized. The order of importance of the top factors of success factors during the growth period was found in the following order: entrepreneur, resources, industry, and strategy. In particular, the importance of general capabilities, entrepreneurship, and human and organizational resources was emphasized. This study is significant in that it analyzes startup success factors from the perspective of successful entrepreneurs and provides useful insights and directions to entrepreneurs and policy makers.

• Journal of Adhesion and Interface
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• v.24 no.3
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• pp.77-85
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• 2023

In this research, polymeric anionic surfactants having various molecular weights and acid values were synthesized using a continuous stirred tank reactor (CSTR). The CSTR has an advantage of higher production rate and more constant product properties compared to batch and semi-batch reactors. The polymeric surfactants were made using butyl acrylate as a hydrophobic group and acrylic acid as a hydrophilic group. The synthesized polymeric surfactants were ionized with alkali solution and were used as an anionic surfactant. To investigate the properties as a surfactant, the properties of the synthesized surfactant, such as acid value, critical micelle concentration (CMC) and molecular weight, were measured. The results showed that the acid values of the polymeric surfactants were 60 to 380 and a number average molecular weight were 8,000 to 13,000 g/mol. Also, it was found that the CMC was around 0.01 g/ml, which showed similar level values with ordinary surfactant. To prove the performance of the polymeric surfactant, acrylic emulsion PSAs were synthesized using the acquired polymeric surfactant. The results showed that the maximum peel strength of 21.24 N/25mm when acid value was 150 and molecular weight was 8,500 g/mol. The values of peel strength and initial tack of acrylic emulsion PSAs using polymeric surfactant synthesized in this study showed much higher than those of reference PSAs synthesized using ordinary anionic surfactant, SDS (Sodium Dodecyl Sulfate) and SDS/TRX (Triton X-100).

• Tunnel and Underground Space
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• v.34 no.3
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• pp.231-247
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• 2024

In the field of high-level radioactive waste disposal targeting deep rock environments, hydraulic characteristic information serves as the most important key factor in selecting relevant disposal sites, detailed design of disposal facilities, derivation of optimal construction plans, and safety evaluation during operation. Since various rock types are mixed and distributed in a small area in Korea, it is important to conduct preliminary work to analyze the hydrogeological characteristics of rock aquifers for various rock types and compile the resulting data into a database. In this paper, we obtained hydraulic conductivity data, which is the most representative field hydraulic characteristic of a high-depth volcanic bedrock aquifer, and also analyzed and evaluated the field data. To acquire field data, we used a high-performance hydraulic testing system developed in-house and applied standardized test methods and investigation procedures. In the process of hydraulic characteristic data analysis, hydraulic conductivity values were obtained for each depth, and the pattern of groundwater flow through permeable rock joints located in the test section was also evaluated. It is expected that the series of data acquisition methods, procedures, and analysis results proposed in this report can be used to build a database of hydraulic characteristics data for high-depth rock aquifers in Korea. In addition, it is expected that it will play a role in improving technical know-how to be applied to research on hydraulic characteristic according to various bedrock types in the future.

• Journal of Cadastre & Land InformatiX
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• v.54 no.1
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• pp.19-32
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• 2024

This study examined the feasibility of image-based surveys by detecting objects in facilities and agricultural land using the YOLO algorithm based on drone images and comparing them with the land category by law. As a result of detecting objects through the YOLO algorithm, buildings showed a performance of detecting objects corresponding to 96.3% of the buildings provided in the existing digital map. In addition, the YOLO algorithm developed in this study detected 136 additional buildings that were not located in the digital map. Plastic greenhouses detected a total of 297 objects, but the detection rate was low for some plastic greenhouses for fruit trees. Also, agricultural land had the lowest detection rate. This result is because agricultural land has a larger area and irregular shape than buildings, so the accuracy is lower than buildings due to the inconsistency of training data. Therefore, segmentation detection, rather than box-shaped detection, is likely to be more effective for agricultural fields. Comparing the detected objects with the land category by law, it was analyzed that some buildings exist in agricultural and forest areas where it is difficult to locate buildings. It seems that it is necessary to link with administrative information to understand that these buildings are used illegally. Therefore, at the current level, it is possible to objectively determine the existence of buildings in fields where it is difficult to locate buildings.

• Knowledge Management Research
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• v.25 no.2
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• pp.95-114
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• 2024

Because it is difficult to respond to a constantly changing environment with individual ability and creativity alone, many organizations are forming teams and seeking ways to make the teams more active. Team learning behavior allows team members to and create better performance based on such accumulated knowledge and experience within a team. In particular, the process of team learning not only explicit and formalized knowledge but also implicit and informal experiences is important from the perspective of knowledge management. However, there were limitations in utilizing research results on team learning behavior because the concepts were fragmented and the measurements were different for each researcher. In this study, an integrated model was presented by examining concepts related to team learning behaviors. Moreover, the measurement model of team learning behaviors was validated for the Korean context. The measurement model consisted of five factors: sharing and elaboration, constructive conflict, team reflection, team activity, and storage and utilization. This tool was confirmed through exploratory factor analysis and confirmatory factor analysis. The results of this study are expected to have implications for team researchers and practitioners who diagnose and improve the level of team learning behavior within an organization.