• Title/Summary/Keyword: Power regulation

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Analysis of Acceleration and Deceleration on High Performance Train for A Metropolitan Rapid Transit System (대피선 최소화를 고려한 광역·도시철도 급행화를 위한 고성능 열차 가감속도 분석)

  • KO, Kyeong Jun;KIM, Jung Tai;KIM, Moo Sun;JANG, Dong Uk;HONG, Jae Sung;RYU, Sang Hwan;JUNG, Jong Deok
    • Journal of Korean Society of Transportation
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    • v.33 no.6
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    • pp.564-574
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    • 2015
  • As shown by the popularity of the rapid train in the Seoul Metro Line No. 9, the demand for the rapidization of the metro transit has been continuously increased. However, it needs tremendous cost to construct new additional infrastructures to the existing line for the rapidization. In order to overcome the problem, utilizing the existing infrastructures such as crossing tracks as railroad sidetracks can be considered to be a good method of reducing the cost. In this case, there is a way exploiting the existing train as an express train and the advanced train, which increases both acceleration and deceleration, as a local train, but achievable acceleration and deceleration have not been analyzed rigorously. In this paper, we analyze feasible ranges and optimal values of both acceleration and deceleration of the advanced train analytically when we consider the rapidization of the metro transit utilizing the existing infrastructures and verify the results in Seoul Metro Line No. 3. Simulation results show ranges and optimal values of achievable acceleration and deceleration exist when minimum gap between an express train and a local train is smaller than 40 seconds.

Study on the Plan for Reduction of Credit Risk of Medium-size Construction Companies Preparing for Restructuring (구조조정에 대비한 중견건설사 신용리스크 저감방안에 관한 연구)

  • Lee, YunHong
    • Korean Journal of Construction Engineering and Management
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    • v.21 no.5
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    • pp.64-73
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    • 2020
  • The government announced a plan for fund support to the enterprises with high possibility of recovery and early restructuring for the enterprises with low recovery by objectifying credit assessment system. Such announcement of government could be extended to restructuring risk of middle standing enterprises with low financial soundness by establishing the basis to prepare prompt restructuring by reinforcing the basis for restructuring through capital market. This research analyzed financial soundness based on the financial evaluation of bank by selecting 10 middle standing construction companies which focused on housing business in 2019, based on such analysis result, it was confirmed that there was a high possibility of restructuring risk. This research determined that there would be a decrease in growth rate of construction industry on the whole in 2020 due to fall of economic growth rate and reinforced real estate regulation, accordingly, there's a big possibility for middle standing construction companies with paid-in capital ratio due to its low possibility of maintenance of stable credit rating. This research established KCSI assessment model by utilizing the material of a reliable research institute in order for middle standing construction companies to evade restructuring risk, and indicated risk ratio differentiated per each item through a working-level expert survey. Such research result could suggest credit risk reduction method to middle standing construction company management staffs, and prepare a basis to evade restructuring risk.

Regression Analysis on the Relationship Between Elderly Ship Officers and Marine Accidents in Korea (고령 해기사와 해양사고와의 회귀분석)

  • Yoo, Sang-Lok;Jung, Cho-young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.4
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    • pp.415-421
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    • 2018
  • The Republic of Korea has a more rapidly aging society than any other country in the world. In order to prepare for the attendant challenges, this research provides basic data for policies related to aging ship officers, analyzing the relationship between elderly ship officers and marine accidents. The data used here spans 11 years, from 2006 to 2016, and the survey and regression analysis were conducted only on ship officers, excluding crew. As a result of this research, first, it was found that the number of employed ship officers older than 60 has increased 2.7 times over the past 11 years and the range of this increase was larger than for other age categories. Second, the number of elderly ship officers disciplined for marine accidents increased by around 2.6 times. Third, elderly ship officers had around 1.5 times the rate of marine accidents compared to non-elderly ship officers. Fourth, as a result of conducting regression analysis between the number of employed elderly ship officers and the number of officers disciplined, the degree of explanatory power of elderly ship officers for disciplined officials was 75.1%. Since our society will age quickly, policies such as license renewal education for elderly ship officers and regulation enforcing the quality of renewal will be needed.

Study on the Experiences of Subsurface Soil Remediation at Commercial Nuclear Power Plants in the United States (미국 원전의 심층토양 제염사례 연구)

  • Lee, Hyoung-Woo;Kim, Ju-Youl;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.2
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    • pp.213-226
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    • 2019
  • Regulatory agency and licensee are preparing for the site restoration of Kori unit 1, the first commercial NPP in Korea, scheduled for 2031. Developing regulatory guidelines and strategies is essential for effective restoration work. Unfortunately, Korea does not have experience of site restoration of commercial NPPs. Therefore, it is important to review cases from experienced countries to establish a strategy and regulatory standards. The U.S. has had numerous soil remediation experiences using RESRAD and MARSSIM. However, formalized evaluation methodologies for subsurface soil have not yet been established in MARSSIM. This survey focused on subsurface soil remediation by reviewing the five decommissioned NPPs under regulation of the US NRC. Overall process of remediating a contaminated subsurface soil and groundwater was reviewed to identify considerations and lessons that could be applicable in Korea. In addition, an applied methodology for evaluation of contaminated subsurface soil and related major issues between regulatory agency and licensees were reviewed in detail to support establishment of remediation strategy for Kori unit 1.

Study on Significance and limitations of the Enactment of the Advanced Regenerative Bio Act (첨단재생바이오법의 제정 의의와 제한점)

  • Sohn, Seong Goo;Kwon, Kyeng Hee
    • The Korean Society of Law and Medicine
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    • v.22 no.4
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    • pp.159-184
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    • 2021
  • The significance of the enactment of the 「Act On The Safety Of And Support For Advanced Regenerative Medicine And Advanced Biological Products」 is to break away from the regulation of the Pharmaceutical Affairs Act and expand patient treatment opportunities through a medical technology approach to regenerative medicine, which is essentially a medical practice called 'transplantation'. However, more than a year after the law was enacted, clinical study has not been activated, with not a single high-risk study approved by the Ministry of Food and Drug Safety being approved. The reason is that despite the legal purpose of expanding patient treatment opportunities, the data requirements for clinical study approval are set in connection with drug development despite the insufficient legal basis, making it difficult for many researchers to meet the data requirements. Prior to the enactment of the Act, submitted data for clinical study on cell therapy products within the Pharmaceutical Affairs Act were cosiderably exempted from quality and non-clinical test data, but with the enforcement of the Advanced Regenerative Bio Act, quality and non-clinical test data are required in accordance with pharmaceuticals when applying for approval of a clinical study plan. To rectify this, when considering the identity of clinical study on advanced regenerative medicine to expand treatment opportunities, recognize that there are limitations in connection with drug development. And it is necessary to preserve the identity of clinical study on advanced regenerative medicine, and on the other hand, in the case of drug product approval, clinical study results should be utilized while specifying usage requirements. Therefore, with the power of the market and the voluntary motive of the clinical researcher, it is necessary to prepare the necessary data by themselves rather than the basic requirements for clinical study approval.

Apartment Price Prediction Using Deep Learning and Machine Learning (딥러닝과 머신러닝을 이용한 아파트 실거래가 예측)

  • Hakhyun Kim;Hwankyu Yoo;Hayoung Oh
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.2
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    • pp.59-76
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    • 2023
  • Since the COVID-19 era, the rise in apartment prices has been unconventional. In this uncertain real estate market, price prediction research is very important. In this paper, a model is created to predict the actual transaction price of future apartments after building a vast data set of 870,000 from 2015 to 2020 through data collection and crawling on various real estate sites and collecting as many variables as possible. This study first solved the multicollinearity problem by removing and combining variables. After that, a total of five variable selection algorithms were used to extract meaningful independent variables, such as Forward Selection, Backward Elimination, Stepwise Selection, L1 Regulation, and Principal Component Analysis(PCA). In addition, a total of four machine learning and deep learning algorithms were used for deep neural network(DNN), XGBoost, CatBoost, and Linear Regression to learn the model after hyperparameter optimization and compare predictive power between models. In the additional experiment, the experiment was conducted while changing the number of nodes and layers of the DNN to find the most appropriate number of nodes and layers. In conclusion, as a model with the best performance, the actual transaction price of apartments in 2021 was predicted and compared with the actual data in 2021. Through this, I am confident that machine learning and deep learning will help investors make the right decisions when purchasing homes in various economic situations.

A Study of Energy Security Cooperation and its Integration Potential in South America through Brazilian Leadership (남미지역 에너지안보 협력과 통합 가능성 연구 : 브라질의 리더십 역할 고찰)

  • Ha, Sang-Sub
    • Journal of International Area Studies (JIAS)
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    • v.15 no.1
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    • pp.83-108
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    • 2011
  • South America has vast energy resources with the renewable and non-renewable sources. However, many countries in the region are unable to guarantee adequate energy security both of energy supply and demand. Currently the possibility of energy security is high through regional energy integration based on the potential economic benefits. The difference of regulation system with the individual countries in the region impose strong barriers to integration process. Security of energy supply and its demand as well is fundamental issues in this region and regional energy cooperation is essential for getting rid of the insecurity of energy supplies. Despite of this problem, currently Latin American countries made a great effort to make multilateral energy security regime through projecting great energy infrastructure network(e.g. IIRSA) or mechanism especially in South America, which can give countries access to the region's reserve supplies by providing regulations and pricing mechanism with a shared energy market in this region. Brazil's active leading in the formulation of such movement toward energy security integration and participation of energy infrastructure network is good initiative to enforce this great energy security change. Politically and economically, Brazil's geographical position and the level of market size and oil and natural gas resources, in addition the leadership in renewable energy sources make it a sound candidate to take over the coordination of the secure integration of region's energy market. However, on the conditions of existing many obstacles such as, control of the output of the region's power plant, energy flows, the environmental matter within local community must be overcome to make more advance process and steps. Finally, to secure more institutional approach, this region must settle regional disputes resolution regime urgently.

Regulation of Acid Contents in Kiwifruit Irradiated by Various Wavelength of Light Emitting Diode during Postharvest Storage (다양한 파장의 LED 조사를 통한 참다래 과실의 산 함량 조절)

  • Baek, Kwang-Hyun;Jang, Myung-Hwan;Kwack, Yong-Bum;Lee, Se-Weon;Yun, Hae-Keun
    • Clean Technology
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    • v.16 no.2
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    • pp.88-94
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    • 2010
  • The physiological roles of various wavelength of light emitting diode (LED) on ‘Hayward’ kiwifruit experiencing after-ripening were investigated. Various wavelengths from LED light source were irradiated on kiwifruits kept in plastic bags or under open air at $25^{\circ}C$. During two weeks of storage, firmness of Hayward kiwifruits was decreased by $25^{\circ}C$ treatment than by $4^{\circ}C$ treatment. In the $25^{\circ}C$ storage condition, the firmness of kiwifruits was decreased by the treatment of 380 nm UV and 470nm white LED light source. Sweetness of kiwifruits treated with 380 nm UV LED and dark condition at $25^{\circ}C$ increased higher than $15^{\circ}$Brix. The acidity of kiwifruits under open air was decreased 52% by incubating at $25^{\circ}C$ with 660 nm red LED treatment. The acidity of kiwifruits in plastic bags was decreased 52.6, 55.6, 52.8% by the treatment of 440 nm blue, 470 nm white and 660 nm red LED light source, respectively, compared to that of kiwifruits incubated in darkness at $25^{\circ}C$. Decreased acidity irradiated by 660 nm red LED light source can be applied for regulating periods of the kiwifruit after-ripening process. LED light sources emit very narrow wavelength with a power-saving mode, therefore, the usage of these LED light source for regulating the after-ripening process can be classified as a clean biotechnology producing safe and environment-friendly kiwifruits.

Investigation of Applying Technical Measures for Improving Energy Efficiency Design Index (EEDI) for KCS and KVLCC2

  • Jun-Yup Park;Jong-Yeon Jung;Yu-Taek Seo
    • Journal of Ocean Engineering and Technology
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    • v.37 no.2
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    • pp.58-67
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    • 2023
  • While extensive research is being conducted to reduce greenhouse gases in industrial fields, the International Maritime Organization (IMO) has implemented regulations to actively reduce CO2 emissions from ships, such as energy efficiency design index (EEDI), energy efficiency existing ship index (EEXI), energy efficiency operational indicator (EEOI), and carbon intensity indicator (CII). These regulations play an important role for the design and operation of ships. However, the calculation of the index and indicator might be complex depending on the types and size of the ship. Here, to calculate the EEDI of two target vessels, first, the ships were set as Deadweight (DWT) 50K container and 300K very large crude-oil carrier (VLCC) considering the type and size of those ships along with the engine types and power. Equations and parameters from the marine pollution treaty (MARPOL) Annex VI, IMO marine environment protection committee (MEPC) resolution were used to estimate the EEDI and their changes. Technical measures were subsequently applied to satisfy the IMO regulations, such as reducing speed, energy saving devices (ESD), and onboard CO2 capture system. Process simulation model using Aspen Plus v10 was developed for the onboard CO2 capture system. The obtained results suggested that the fuel change from Marine diesel oil (MDO) to liquefied natural gas (LNG) was the most effective way to reduce EEDI, considering the limited supply of the alternative clean fuels. Decreasing ship speed was the next effective option to meet the regulation until Phase 4. In case of container, the attained EEDI while converting fuel from Diesel oil (DO) to LNG was reduced by 27.35%. With speed reduction, the EEDI was improved by 21.76% of the EEDI based on DO. Pertaining to VLCC, 27.31% and 22.10% improvements were observed, which were comparable to those for the container. However, for both vessels, additional measure is required to meet Phase 5, demanding the reduction of 70%. Therefore, onboard CO2 capture system was designed for both KCS (Korea Research Institute of Ships & Ocean Engineering (KRISO) container ship) and KVLCC2 (KRISO VLCC) to meet the Phase 5 standard in the process simulation. The absorber column was designed with a diameter of 1.2-3.5 m and height of 11.3 m. The stripper column was 0.6-1.5 m in diameter and 8.8-9.6 m in height. The obtained results suggested that a combination of ESD, speed reduction, and fuel change was effective for reducing the EEDI; and onboard CO2 capture system may be required for Phase 5.

A Comparative Study of the Function of Nursing Management According to the Position of Nursing Department in Hospital Organization (병원조직내 간호부서의 위치에 따른 간호관리 기능 비교 연구)

  • Lee, Kum-Ja
    • Journal of Korean Academy of Nursing Administration
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    • v.4 no.2
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    • pp.387-403
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    • 1998
  • These days our nation is standing on tiptoe of welfare nation. so hospital in authority have done reformation to provide quality medical services. This effective nursing work to provide quality nursing by keeping pace with the reformation of management of hospital for quality medical function might be well said to be depending on the degree of function of nursing management of nursing department. This essay has been aimed to prepare the data to build the position of nursing organization which can elevate the quality of nursing by clarifying the difference of the degree of the function of nursing management according to the position of nursing department in hospital organization. 135 nurses of 1 general hospital in Seoul which has independent nursing organization of the hospitals of over 600 beds and 155 nurses of 1 general hospital in Seoul which has the nursing organization under the management of medical department have been the objects of this study. The tool of Yoon. Young Ae(1988) has been used by having it amended and complemented and the degree of reliability of the tool was resulted in Cronbach's Alpha .9155. The collected data have been analysed by SPSS program as mean. frequency, chi-square. t-test. F-test(ANOVA) and the results are as the follows; 1. Compared result of general characteristics of the two groups by $x^2$-test showed statistically significant difference between religion ($x^2$=10.375, p=.015) and educational background($x^2$=51.222. p=.000) 2. The t-test aimed to compare the degree of function of nursing management according to the position of nursing department is as the below: Compared result of the degree of the function of nursing management according to the areas has shown higher point in independent type(M=3.22) than in the type under the management of medical department(M=2.85) in the personnel and administrative activities of nursing department. the standard and regulation of nursing duty also showed higher point in independent than in the type under the management of medical department (M=3.37) and the education of nursing showed higher point in independent type(M=3.53) than in the type under the management of medical department(M=3.19) and the evaluation of nursing quality has shown higher point in independent type(M=3.33) than in the type under the management of medical department(M=3.05), The area which showed the highest difference of the degree of the function of nursing management between the two organizations was in the activities of personnel and administration management of nursing department (independent type M=3.22. the type under the management of medical department(M=2.85). The degree of function of general nursing management showed higher in independent type nursing organization than in the type under the management of medical department by 3.41 in independent type and 3.11 in the type under the management of medical department. The items which showed the lowest degree of function of nursing management of both organizations have been suitable nursing man power and distribution and the reflection of the opinion of nursing department. In conclusion. the degree of function of nursing management to be able to provide quality nursing for the hospital goal of quality medical works showed visibly higher in independent nursing organization than in the nursing organization under the management of medical department. Therefore it is desirable for the hospital to operate the nursing department in hospital organization by independent type rather than the type under the management of medical department and the chief of nursing department of the nursing organization of the type under the management of medical department should make effort to reform its structure to be able to establish the position of performing independent nursing management. And also the chief of the nursing organization of independent type should endeavor to build substantial independent type organization more than ever under the viewpoint of securing suitable nursing man power and the low degree of management in the reflection of the opinion of nursing department.

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