• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.2
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• pp.65-85
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• 2023

The use of TBM (Tunnel boring machine) has increased worldwide due to its performance together with the benefit of being safely and environmentally friendly compared to conventional tunneling. In particular, EPB (Earth Pressure Balanced) TBM is widely used because it can be applied to various grounds compared to Open TBM. Also EPB TBM has a simple mechanical structure and advantages in cost, requires less ground area than Slurry TBM. EPB TBM has advantages in soft ground, and more importantly, can extend its applicability by use of appropriate soil conditioning, which improves mechanical and hydrological properties of excavated soil and increases the excavation performance of EPB TBM. Various studies suggested the proper mixing ratio and injection ratio, but almost they are limited to laboratory test under atmospheric pressure such as slump test. Actual field conditions may differ depending on the ground and mechanical condition. In this study, first the amount of used soil conditioning used in the field with various grounds from hard rock to soft ground was estimated through laboratory tests and compared with the estimate in design stage. And also it was compared with the amount used during actual excavation. In addition, experience of soil conditioning for the problems of cutter head clogging and groundwater inrush that occurred during excavation is discussed. Finally, lesson learned for the use of soil conditioning in difficult ground condition such as mixed ground are reviewed.

• Journal of Intelligence and Information Systems
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• v.29 no.2
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• pp.85-100
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• 2023

Corporate ESG performance (environmental, social, and corporate governance) reflecting a company's strategic sustainability has emerged as one of the main factors in today's investment decisions. The traditional ESG performance rating process is largely performed in a qualitative and subjective manner based on the institution-specific criteria, entailing limitations in reliability, predictability, and timeliness when making investment decisions. This study attempted to predict the corporate ESG rating through automated machine learning based on quantitative and disclosed corporate financial information. Using 12 types (21,360 cases) of market-disclosed financial information and 1,780 ESG measures available through the Korea Institute of Corporate Governance and Sustainability during 2019 to 2021, we suggested a deep neural network prediction model. Our model yielded about 86% of accurate classification performance in predicting ESG rating, showing better performance than other comparative models. This study contributed the literature in a way that the model achieved relatively accurate ESG rating predictions through an automated process using quantitative and publicly available corporate financial information. In terms of practical implications, the general investors can benefit from the prediction accuracy and time efficiency of our proposed model with nominal cost. In addition, this study can be expanded by accumulating more Korean and international data and by developing a more robust and complex model in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3B
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• pp.271-281
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• 2008

To determine the flood protection elevation (FPE) in urban built-up areas, this study examines four possible methods: using the highest flood elevation in the past, extending base flood elevations of nearby watercourse to inland, and two simulation methods of inland flood under the same rainfall used in the watercourse planning nearby. According to the case study of the Jang-An Drainage Area, Seoul, the highest flood elevation in the past and simulation results of inland flood under the same rainfall in the watercourse planning nearby tend to get similar results, while extending base flood elevations of nearby watercourse to inland shows much higher elevations than other results. Meanwhile, cost-benefit analysis, when regulating residential/commercial uses below the FPE by each of four methods, suggest that planners need to consider carefully the economic feasibility of FPE used to choose appropriate methods.

• Knowledge Management Research
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• v.24 no.3
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• pp.95-125
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• 2023

As the aviation industry has rapidly been grown, there are more factors for customers to consider when choosing an airline. In response, airlines are trying to increase customer value by providing high-quality services and differentiated experiential value. While early customer value research centered on utilitarian value, which is the trade-off between cost and benefit in terms of utility for products and services, the importance of experiential value has recently been emphasized. However, experiential value needs to be studied in a specific context that fully represents customer preferences because what constitutes customer value changes depending on the product or service context. In addition, customer value has an important influence on customers' decision-making, so it is necessary for airlines to accurately understand what constitutes customer value. In this study, we collected customer reviews and ratings from Skytrax, a website specializing in airlines, and utilized the BERTopic technique to derive factors of customer value. The results revealed nine factors that constitute customer value in airlines, and six of them are related to customer satisfaction. This study proposes a new methodology that enables a granular understanding of customer value and provides airlines with specific directions for improving service quality.

• The Korean Society of Law and Medicine
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• v.24 no.4
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• pp.37-63
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• 2023

In medical litigation, there are various cases where a doctor's 'explanation' of a patient becomes problematic. Medical explanations and guidance are required from the doctor, starting from the beginning of diagnosis, through treatment processes such as surgery, when hospitalization is necessary for treatment, during hospitalization, upon discharge, and after discharge. Furthermore, notification from the doctor or medical institution may be requested regarding the economic costs that will be incurred due to medical treatment. South Korea's judiciary has been developing legal principles regarding such doctor's explanations by distinguishing between explanations for obtaining consent for medical treatment and medical explanations related to guidance on patient treatment methods, taking into account related laws such as the stage of treatment and the Medical Service Act. Additionally, the Constitutional Court recently ruled on the non-benefit cost notification system linked to the explanation of economic costs. However, holding a doctor accountable solely because the doctor's explanation was insufficient has aspects that do not correspond to the actual situation in clinical reality, and may have a reflexive disadvantage that results in a decline in legal rights. Therefore, the doctor's explanation needs to be examined from both perspectives: guaranteeing the patient's right to self-determination and protecting his or her right to decision.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.6
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• pp.33-50
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• 2023

This study is to propose the ecosystem service valuation method as a complementary or alternative tool to overcome the limitations of the contingent valuation method(CVM), typically used to assess social benefits in preliminary feasibility studies. With an increasing interest in natural and environmental restoration projects, we assessed social benefits with theses CVM and ecosystem service valuation method from a case of Janghang wetland restoration project and compared the extent of the two social benefits. For quantitative evaluation of ecosystem services, the biophysical quantity for each ecosystem service indicator was calculated and then converted into currency (KRW) units to estimate the economic value of ecosystem services. The four ecosystem regulating service indicators were selected including greenhouse gas capture/storage, air pollution, water quantity and quality regulation. The amounts of CO₂ sequestration and storage as a ecosystem's greenhouse gas regulating service in the study area were 73.04 tCO₂/yr and 5,867.53 tCO₂/yr respectively. The reduction of SO₂, one of air pollutant gases by ecosystems was calculated to be 180.27 kg/yr, the reduction of NO₂ to be 378.90 kg/yr, and the reduction of fine dust (PM10) to be 9,713.92 kg/yr. The amount of freshwater regulating service by the ecosystem was estimated to be 459,394,319ℓ/yr, and the amount of nitrogen in freshwater removed by the ecosystem was 78.00kg/yr. Study results show that the benefits derived from the CVM were KRW 227.8 billion over the 30-year analysis period and those from the ecosystem service valuation method were KRW 41.4 billion for regulatory services and KRW 148.8 billion for cultural services, totaling KRW 189.5 billion. With KRW 184.8 billion of the total costs, the benefit/cost ratio using the CVM was 1.23 and that with the ecosystem service valuation method was 1.03. This study implications include that the CVM and ecosystem service valuation method can be applied together to assess and compare social benefits for natural and environmental restoration projects.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.267-273
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• 1977

Rainbow trout were reared in a small indoor aquarium which was equipped with a simple recirculating biofilter combined with a small amount of inflowing water for 199 days from April 25 to November 10, 1977 in Busan where very hot summer air temperature is encountered, and results obtained were promissing as following; 1. The aquarium has dimensions of $1m\;\times\;1m\;\times\;67cm(depth)$, and a bottom center sedimentation chamber of conical type through which out-flowing water is pushing fecal matter and other detritus outward. The conical sedimentation chamber measures 20 cm depth and 20 cm diameter at its upper mouth and tapers to the bottom end which is connected to 4 cm diameter draining pipe. The draining pipe goes through under the tank and then is elevated on the side. The water depth was maintained at about 40 cm depth by adjusting the heigh of draining pipe. The filter bed contained 16 l of $3\~5\;mm$ zeolite gravels, and water circulation rate was about 1030 l/hr. 2. Continuous inflowing water resulted in a good elimination of waste materials through its outflowing water thus reducing waste loading in the filter. 3. Mean temperature of water in the rearing aquarium containing about 400 l water volume was maintained at around 20 to $22^{\circ}C$ by 0.59 l/min of the inflowing well water which usually maintained the temperature of $17^{\circ}C$ during the hot summer season from the first of July to the first of October when the 10-days-mean air temperature ranged from $20^{\circ}\;to\;27.3^{\circ}C$ $(total\;mean\;24.6^{\circ}C) $ and under this condition the fish continued normal growth. 4. The production per 1 l/min of inflowing water with this simple biofilteration reached 30 hg. 5. The total cost including all feed and power during this experimental rearing period fell well within the economic establishment and if the feed and filteration system are improved the benefit-cost ratio will be much increased.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.12
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• pp.913-921
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• 2011

This study examined the overall feasibility of low carbon green village formed in rural area. The check method is analyzing its environmental and economic feasibility and energy self-reliance. The biomass of the villages was set as 28 ton/day of livestock feces and 2 ton/day of cut fruit tree branches which make up the total of 30 ton/day. The facility consisted of a bio gasfication facility using wet (livestock feces) biomass and combined heat power generator, composting facility and wood boiler using dry (cut fruit tree branches) biomass. When operating the system, 540,540 kWh/yr of electricity and 1,762 Gcal/yr of heat energy was produced. The region's electricity energy and heat energy self-reliance rate will be 100%. The economic feasibility was found as a loss of 140 million won where the facility installation cost is 5.04 billion won, operation cost is 485.09 million won and profit is 337.12 million won. There will be a loss of about 2.2 billion won in 15 years but in the environmental analysis, it was found that crude replacement effect is about 178 million won, greenhouse gas reduction effect is about 92 million won making up the total environmental benefit of 270 million won. This means, there will be a yearly profit of about 130 million won. In terms of its environmental and economic feasibility and energy self-reliance, this project seemed to be a feasible project in overall even if it manages to get help from the government or local government.

• Journal of Society of Preventive Korean Medicine
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• v.7 no.1
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• pp.17-28
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• 2003

We met results like the followings through the literatures and questionnaires about the tasks and solutions about the insurance fee of packed medical herbs. 1) It's turned out that 74.8% of herb doctors agrees to the insurance fee of packed medical herbs. However, in comparison with the same survey of the herb doctor association the percentage of general approval went somewhat lower, and especially the percentage of 'positive approval' became notably lower$(43.7%{\rightarrow}26.5%)$ and the percentage of 'active objection' raised about 2 times$(6.8%{\rightarrow}12.9%)$. Inquiring into the approval reasons on the insurance fee application of packed medical herbs some heads such as 'development toward treatment medical science' and 'decrease of publics burden' were higher than the one of 'management income and expenditure.' 2) As a result of the research, 36.0% of the patients and 42.8% of the residents recognized that the pay range of Chinese herb health insurance is narrow. They recognized that less people have the experiences of Chinese medical hospital use and internal application of the packed medical herbs as they are older, men rather than women. 85.4% of the patients and 74.9% of the residents agreed on the insurance pay of packed medical herbs. It's shown that they agree on the Chinese medical hospital use more as the economic standard is lower, on the insurance pay as they have ever taken the packed medical herbs. In the aspect of increase of insurance fee, 66.7% of the patients and 44.3% of the residents agreed on the insurance pay of packed medical herbs, and 18.1% and 36.1% disagreed on the insurance pay of packed medical herbs. The main objective reason why they disagree on the insurance pay of packed medical herbs was 'because the insurance fee goes up higher,' which answered 95.2% of the patients and 78.8% of the residents. 7.22% of the patients and 1.80% of the residents answered that they can pay more insurance fee in case of the insurance pay of packed medical herbs. However, in the priority order of the insurance pay, it hold the 5th position between 2 target research groups which was less than medical examination, charges for hospital accommodation and taking MRI. 3) According to the result of analysis about the cost of packed medical herbs, current practice price is 115,000 won and the average prime cost of a packed medical herb is 73,000 to 106,000 won. It's examined that the herb doctors regard that 95,000 won will be reasonable when the packed medical herb is payed in insurance. However, it was found out that the public generally thinks that the price would be appropriate on the level of 30,000 to 40,000 won and the percentage of the answers of 20,000 won to 30,000 was fairly high. 4) the central system of a prescription should be change into the central system of demonstration and the sick and wounded. 5) To solve this problem, the government should regulate it to pass by the circulation gradation of [importer, $peasantry{\rightarrow}manufacturer{\rightarrow}wholesaler{\rightarrow}distributor$(Chinese medical hospital, pharmacy dispensary of Chinese medicine)]And it should intervene into the quality and the circulation steps of Chinese medicine through 'the office or organization which is in charge of certification of Chinese medicine' and 'the office or organization which is in charge of the circulation of Chinese medicine.' And some actions such as simple severance, lavation, drying should be included into the conception of manufacture and the boundary between food and medical supplies should be made at a manufactory. And the regulation of standardized goods at one's own house should be improved so that, the peasantry can sell the materials of Chinese medicine only to the manufacturer. 6) In company with the insurance pay of packed medical herbs, the study about the separation of dispensary from medical practice in the Chinese medicine should be accomplished.

• Journal of Korean Clinical Health Science
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• v.2 no.1
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• pp.1-16
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• 2014

Purpose. For a more efficient hospital management, this study aims to provide basic data so that the hospital management and staff in charge of hospital administration may systematically classify and collect hospital information, by analyzing the ordinary characters of an upper-level general hospital system and its common-type balance sheet, common-type profit and loss statement and financial ratio. Methods. By using information about an upper-level general hospital in C Province, provided by Alio(www.alio.go.kr), a public organization information provision site, Health Insurance Review & Assessment Service(www.hira.or.kr) and Ministry of Health and Welfare(www.mw.go.kr), this study analyzed 3 year's data from 2010 to 2012 and provided basic data by analyzing the ordinary characters of an upper-level general hospital system, and its common-type balance sheet, common-type profit and loss statement and financial ratio. Results. After analyzing the ordinary characters, common-type balance sheet, common-type proft and loss statement and financial ration of this general hospital, based on the 2010 to 2012 data, this study came to the following conclusions. Firstly, out of all the 1,069 hospital staff, there were 272 doctors working for 24 medical departments, out of whom the majority was 33 physicians. Most of the nurses were third-class ones, and about 2,000 outpatients and 600 inpatients on average were treated per day. Secondly, as a result of analyzing the common-type balance sheet, this study discovered that intangible assets out of fixed assets accounted for 41%, the majority, out of which usable and profitable donation asset buildings were of great importance, and the liquid assets increased more in 2012 than 2011. In the financial structure, the ratio of liquid liabilities was over 50% out of all the liabilities in 2012, and the ratio of purchase payables was high as well. The ratio of fixed liabilities reached up to 40%, out of which the retirement benefit appropriation fund was quite high. The capital was over 80%, but the surplus was in a deficit state. Compared to the capital, the ratio of total liabilities was about 90%, which indicates the financial structure of this general hospital was vulnerable. Thirdly, as a result of analyzing the common-type profit and loss statement, this study found out that the medical profits from inpatients were higher than profits from outpatients. The material cost was related to the medical quality of this general hospital, and it was as high as 30% out of the total costs and was about 45% of the labor cost. This general hospital showed 10% in the ratio of non-medical profits, and it seemed because of government subsidies. The ratios of medical profits and current net income were gradually changing for the better in 2012, compared to 2011. Lastly, as a result of analyzing the financial ratio, it was found that the liquidity ratio kept decreasing, from 110.7% in 2010 and 102.0% in 2011 to 77.2% in 2012. Besides, it was analyzed that the liquidity ratio and the net working capital ratio greatly decreased, while the quick ratio and the liquid ratio kept decreasing. Conclusions. 1. It is necessary to take the risk management into more consideration, and particularly, it is needed to differentiate and manage the levels of risk in detail. 2. By considering the fact that investments into hospital infrastructures were mostly based on liabilities, it is needed to deal with the scale of losses when evaluating risks. 3. By reflecting the character that investments into hospital infrastructures were based on liabilities, it is necessary to consider the ratio of ordinary profits as well as the ratio of operating profits to sales, and it is also important to consider sales productivity factors, such as the sales amount per a sickbed, by comparing them with other hospitals. As for limitations of this study, there may be some problems in terms of data interpretation because of the lack of information about the number of inpatients and the number of outpatients per year, which are needed for the break-even point analysis. Besides, to suggest a direction for the improvement of hospital management through analyses, non-financial factors should be reflected, such as the trend of economy, medical policies, and politic backgrounds. However, this study only focused on the common-type balance sheet, common-type profit and loss statement and financial ratio, so this study is actually limited to generalizing all the factors by analyzing public data only.