• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.821-829
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• 2006

Traffic load comprise primary input to pavement design causing pavement damage. therefore it should be proceeded suitable traffic load distribution modeling for pavement design and analysis. Traffic load have been represented by equivalent single axle loads (ESALs) which convert mixed traffic stream into one value for design purposes. But there are some limit to apply ESALs to other roads because it is empirical value developed as part of the original AASHO(American Association of State Highway Officials) road test. There have been many efforts to solve these problems. Several leading country have implemented M-E(Mechanistic-Empirical) design procedures based on mechanical concept. As a result, they established traffic load quantification method using load distribution model known as Axle Load Spectra. This paper details Axle Load Spectra and presents axle load distribution model based on normal mixture distribution function using truck load data collected by WIM system installed in national highway. Axle load spectra and axle load distribution model presented in this paper could be useful for basic data when making traffic load quantification plan for pavement design, overweight vehicle permit plan and pavement maintenance cost plan.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.767-774
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• 2006

This study has focused on the possibility for recycling of tailings from the sangdong tungsten mine as powder (TA) of self-compacting concrete (SCC). The experimental tests for entrapped water ratio were carried out in accordance with the specified method by Okamura. The rheological measurements of cement paste were conducted by using a commercially digital Brookfield viscometer (Model LVDV-II+) equipped with cylindrical spindles, also tests for slump-flow, time required to reach 500 mm of slump flow (sec), time required to flow through V-funnel (sec) and filling height of U-box test (mm) were carried out in accordance with the specified by the Japanese Society of Civil Engineering (JSCE). The results of this study, entrapped water ratio was decreased with increasing replacement of TA. Thickness of pseudo water film was increased, and mean plastic viscosity was decreased with increasing replacement of TA. And slump-flow of SCC was decreased with increasing replacement of TA. But time required to reach 500 mm of slump flow (sec), time required to flow through V-funnel (sec) and filling height of U-box test (mm) were satisfied a prescribed range. The mechanical properties including compressive strength, splitting tensile strength and elastic modulus were checked with the requirements specified by Korean Industrial Standard (KS). The compressive strength of SCC was decreased with increasing replacement of TA, splitting tensile strength and elastic modulus were similar to those of normal concrete.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.176-183
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• 2023

The extraction and filtration of red ginseng with a mixed solvent of water and alcohol-a common processing method-and the production of a concentrate through heat treatment, such as steaming, leads to its hydrolysis or polymerization. Approximately 200 ginsenosides have consequently been detected in small amounts, in addition to the identification of the functions of approximately 30 major ginsenosides. This complicates the identification of the functionality of red ginseng and its efficacy, and has negative effects as a functional food, as the astringent taste becomes stronger with an increase in the number of extractions. The red ginseng concentrate was, therefore, extracted at a low temperature (less than 40 ℃) and processed to eliminate these negative aspects, with a specific focus on the characteristics of the functional components of ginsenosides.

• 한국노년학
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• v.30 no.4
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• pp.1197-1211
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• 2010

This research was concucted to present a model of advance directives(AD) when a patient, who is in consciousness, shows a preference for an end of life care as an act of preparing for an uncertain situation that may arise in the forseeable future. The subjects of the research are 383 doctors/nurese and adults, who live in six cities and provinces, to investigate the status of AD, attitude regarding a meaningless life-prolonging treatment, and moreover, an understanding of and a preference for AD. The research was done by the well-structured questionnaire. Also, SPSS 14.0 is used to analyse the collected data, focused on frequency analysis, avearage and standard deviation, X2 test. As the results of the study, the most of the surveyed doctors/nurese knew DNR orders and AD and a few of them used DNR orders and AD practically. Also, the result shows that there is a negative conception of meaningless life-prolonging treatment among the responents, in addition, most of them agreed upon the idea of introducing AD to Korea, filling it out and making it legally effective. As a method of making AD out, the respondents wanted to use a form that mixed living will with an Power of Attorney in a document. Also, considering the appropriate time, respondents prefered when they are diagnosed with terminal illness. At the moment, the introductory model for AD, which is suitable for the Korean culture and current situation is presented based on the result of this research. In the future, other researches should deal with specific measures that can lead to a social consensus to adopt AD in Korea.

• 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.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.226-233
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• 2023

In this study, two phases were conducted to investigate the direct injection of gaseous CO₂ into cement mortar. The aim was to advance carbon capture, utilization, and storage (CCUS) technology by harnessing industrial waste CO₂ from the domestic ready-mixed concrete industry. In the first phase, the factors influencing the physical properties of cement mortar when using gaseous CO₂ were identified. This included a review of materials to achieve physical properties comparable to a reference formulation. As a result of this phase, it was confirmed that traditional approaches, such as adjusting the water-to-cement ratio, had limitations in achieving the desired physical properties. Consequently, the second phase focused on the optimization of CO₂-injected mortar. This involved studying the CO₂ application and mixing method for cement mortar. Changes in properties were observed when gaseous CO₂ was injected into the mortar. The optimal injection quantity and time to enhance the compressive strength of mortar were determinded. As a result, this study indicated that an extra mixing time exceeding 120 seconds was necessary, compared to conventional mortar. The optimal CO₂ injection rate was identified as 0.1 to 0.2 % by weight of cement, taking both flowability and compressive strength performance into account. Increasing the CO₂ injection time did not further enhance strength. For this approach to be employed as a CCUS technology, additional studies are required, including a microstructural analysis evaluating the amount of immobilized CO₂.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.440-448
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• 2023

Utilizing admixture, which is one of the raw material replacement method in the cement industry, is expected to be easily and quickly put to practical use as it is relatively more accessible than other methods. Among cement admixtures, limestone powder is reported to be able to improve cement performance through nucleation effects, chemical effects, and filler effects, so it is a material expected to be suitable as a cement admixture. Meanwhile, as high-quality limestone is depleted around the world, the use of limestone with clay or high magnesia (MgO) content is becoming increasingly inevitable. Therefore, in this study, we attempted to evaluate the suitability of limestone cement as a admixture by measuring the basic properties of limestone cement mixed with limestone of different qualities commonly used in Korea. As a result, the effect of alite reaction promotion was confirmed regardless of the chemical composition of the limestone binder. However, the dilution effect depending on the substitution amount was greater than the chemical composition. It is believed that normal-grade limestone can be used as a mixture as long as the limestone content in cement is within 15 % in this scope of study. In the future, we plan to evaluate the impact of the chemical composition of the limestone mixture through additional experiments depending on the chemical composition of cement.

• Journal of Korean Academy of Rural Health Nursing
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• v.18 no.2
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• pp.80-91
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• 2023

Purpose: The purpose of the study quantitatively investigates the experience of unmet healthcare service utilization by rural populations in vulnerable areas during the COVID-19 pandemic based on Andersen's behavior model. At the same time, this study attempts to describe the experiences of unmet healthcare service utilization among participants in vulnerable rural areas by analyzing qualitative contents through open-ended question. Methods: Data were collected from October to November 2022 using Qualtrix, a web-based survey platform. A total of 863 participants completed an online survey. Quantitative data were analyzed using 𝑥² test and logistic regression analysis. Qualitative data were analyzed using content analysis. Results: The factors affecting participants' unmet healthcare service utilization were type of residential area and underlying disease. The qualitative analysis identified; four categories and nine sub-categories. Conclusion: Based on these findings, it is necessary to develop a disaster nursing response model according to the type of residential areas and the number of people.

• Membrane Journal
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• v.33 no.6
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• pp.352-361
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• 2023

Steam methane reforming is currently the most widely used technology for producing hydrogen, a clean fuel. Hydrogen produced by steam methane reforming contains impurities such as carbon monoxide, and it is essential to undergo an appropriate post-purification step for commercial usage, such as fuel cells. Recently, membrane separation technology has been gaining great attention as an effective purification method; in this study, we evaluated the feasibility of using commercial polysulfone membranes for biogas upgrading to separate and recover hydrogen from a hydrogen/carbon monoxide gas mixture. Initially, we examined the physicochemical properties of the commercial membrane used. We then conducted performance evaluations of the commercial membrane module under various conditions using mixed gas, considering factors such as stage-cut and operating pressure. Finally, based on the evaluation results, we carried out simulations for process design. The maximum H₂ permeability and H₂/CO separation factor for the commercial membrane process were recorded at 361 GPU and 20.6, respectively. Additionally, the CO removal efficiency reached up to 94%, and the produced hydrogen concentration achieved a maximum of 99.1%.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1467-1475
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• 2023

The public-interest direct payment program involves providing direct payments to agricultural producers and rural residents through public funds, premised on performing public functions such as environmental conservation, stable food supply, and maintaining rural communities via agricultural activities. Scientific estimation of crop cultivation areas and production levels is crucial for formulating agricultural policies linked to regulating food supply, which increasingly impacts the national economy. Conducting comprehensive on-site inspections for compliance monitoring of direct payment programs has shown very low efficiency in relation to budget and time. The expansion of areas subject to compliance monitoring and various challenges in on-site inspections necessitate streamlining current monitoring methods and devising effective strategies. As a solution, the application of Remote Sensing technology and spatial information utilization, allowing swift acquisition of necessary information for policies without overall on-site visits, is being discussed as an efficient compliance monitoring method. Therefore, this study evaluated the potential use of remote sensing for improving operational efficiency in monitoring compliance with public-interest direct payment programs. Using satellite images during farming seasons in Gimje and Hapcheon, vegetation indices and spatial variations were utilized to identify cultivated areas, presence of mixed crops, validated against on-site inspection data.