• Journal of the Korean Institute of Gas
• /
• v.19 no.2
• /
• pp.29-36
• /
• 2015

This study is an 1-D numerical study prior to modification of diesel engine for power plants to natural gas/diesel dual fuel engine using GT-Power with 1.5MW diesel engine for power generation. Natural gas injector was installed to intake manifold for dual fuel engine model. Effects on engine performance and characteristics were investigated when dual fuel is used in unmodified diesel engine. The analysis was done under 5 conditions from 0% to 40% of mixing rate on 720RPM engine speed. As a result of research, the engine performance was decreased as increasing ratio of natural gas. Engine brake power was decreased by 18.4% under 40% mixing rate condition. To clarify the reason, effects of injection timing and period were evaluated with DOE method. Considering this result, optimization was done for these parameters. Also, comparison between performances of dual fueled engine and diesel engine was made after optimizing the timing of injection by DOE method. As a result, engine brake power was decreased by 8.55% under mixing rate 40% condition showing 12.5% improvement.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.9
• /
• pp.178-187
• /
• 2016

The purpose of this study is to analyze governance in the business processes of Jeju's proposed 'Happy Living Area.' This study found Jeju's 'Happy Living Area' plans for governance were realized and conflicts may frequently occur in future business processes. Furthermore, roles and support systems were measured for the development council of 'Happy Living Area.' This paper reports findings from a case study on community planning for a public art project. This study recommends public-private governance in terms of process factors as well as role considerations. With respect to process factors, administrative agencies and citizen participation are examined. Second, the Living Area Council should play a mediating role between central and local governments as well as residents. Third, Happy Living Zones' Advisory Centre should undertake an advisory role. Fourth, consultation between public and private sectors is needed to establish evaluation criteria for reviewing proposals from subordinate administrative agencies. Fifth, local government systems should be managed by autonomous municipalities. Concerning role considerations, a new 'Personality for Governance' position should be established for performing different roles in the project implementation stage.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.41 no.5
• /
• pp.533-541
• /
• 2021

Retaining walls have been used to prevent slope failure through resistance of earth pressure in railway, road, nuclear power plant, dam, and river infrastructure. To calculate dynamic earth pressure and determine the characteristics for seismic behavior, many researchers have analyzed the nonlinear response of ground and structure based on various numerical analyses (FLAC, PLAXIS, ABAQUS etc). In addition, seismic fragility evaluation is performed to ensure safety against earthquakes for structures. In this study, we used the FLAC2D program to understand the seismic response of the inverted T-type wall with a backfill slope, and evaluated seismic fragility based on relative horizontal displacements of the wall. Nonlinear site response analysis was performed for each site (S2 and S4) using the seven ground motions to calculate various seismic loadings reflecting site characteristics. The numerical model was validated based on other numerical models, experiment results, and generalized formula for dynamic active earth pressure. We also determined the damage state and damage index based on the height of retaining wall, and developed the seismic fragility curves. The damage probabilities of the retaining wall for the S4 site were computed to be larger than those for the S2 site.

• Journal of the Korea Convergence Society
• /
• v.9 no.11
• /
• pp.307-313
• /
• 2018

In this study, analyzed the effect of the introduction and operation of internal control system of a company on accounting information usefulness in a rapidly changing business environment. In order to conduct this study, we studied a comprehensive analysis on the usefulness of internal control and accounting information, and applied the research model to the purpose of this study. In this study, we analyzed the degree of the relationship between variables based on the discretionary accruals of the modified Jones model using the internal control evaluation index based on the components of the internal control system for China. In the empirical analysis, analyzed that the operation of internal control has a negative influence on discretionary accruals, which is a substitute for usability of accounting information. In addition, the risk management factors of the internal control system have a negative correlation with the usefulness of accounting information. The results of this study suggest that it is possible to present the positive function of internal control system to many firms where the introduction and operation of internal control is important, and to provide useful guidance in the study of the relationship between the operation of internal control and discretionary accruals for foreign company.

• Journal of Korea Water Resources Association
• /
• v.52 no.9
• /
• pp.647-655
• /
• 2019

Although problems such as river management and flood control have occurred continuously in the Imjin and Bukhan river basin, which are shared by South and North Korea, efforts to manage the basin have not been carried out consistently due to limited cooperation. As the magnitude and frequency of hydrologic phenomena are changing due to global climate change, it is necessary to prepare countermeasures for the rainfall variation in the shared river basin area. Therefore, this study was aimed to project future changes in extreme precipitation in South-North Korea shared river basin by applying 13 Global Climate Models (GCM). Results showed that the probability rainfall compared to the reference period (1981-2005) of the shared river basin increased in the future periods of 2011-2040, 2041-2070 and 2071-2100 under the Representative Concentration Pathways (RCP)4.5 and RCP8.5 scenarios. In addition, the rainfall frequency over the 20-year return period was increased in all periods except for the future periods of 2041-2070 and 2071-2100 under the RCP4.5 scenario. The extreme precipitation in the shared river basin has increased both in magnitude and frequency, and it is expected that the region will have a significant impact from climate change.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.9
• /
• pp.306-314
• /
• 2019

As dipeptidyl peptidase-4(DPP-4) inhibitors are used widely as a secondary treatment for type 2 diabetes because they tend to be well tolerated with minimal side effects, the human DPP-4(hDPP-4) gene was injected into a pig zygote through micro-injection, and 1-cell stage fertilized embryos were then transplanted surgically into the oviduct. Three pigs were fertilized with hDPP-4 genes and produced sixteen piglets, in which one male piglet was identified to be transgenic. Finally, transgenic pigs showing hDPP-4 gene expression in the tail were produced. Western blot and RT-PCR analysis confirmed that the hDPP-4 is expressed strongly in the membrane cells of the transgenic pig, and that the hDPP-4 gene appears in various tissues and tails. This suggests that the expression vector is normally expressed in transgenic pigs. These results are anticipated to be a model animal to check the endocrine function for insulin resistance that occurs in a hDPP-4 transgenic pig and to increase its value for use as a material in newly developed medicines.

• The Journal of Korean Philosophical History
• /
• no.35
• /
• pp.189-222
• /
• 2012

This study aims to explore Yulgok Yi I(栗谷 李珥)'s political intention through his presenting Seonghakjibyo(The Essentials of the Studies of the Sages, 聖學輯要) to the King Seonjo(宣祖), paying attention to his political situation in early reign of the King. Until presenting the book to the King in December 1576(the 8th year of King Seonjo's reign), Yulgok had been neglected from the political development of the King. So his presenting Seonghakjibyo, which basically professed the perfection of the studies of the Sages(聖學), to the King included another aim to convert the King's negative view on him by synthesizing his political views and appealing to the King. Yulgok's political views are intensively summarized in the book's beginning "Jincha(進箚)" and the final chapter "Seonghyeondotong(聖賢道統)". Through "Jincha", he recalled the past of his political situation during early reign of the King and expressed his own will to participate in the government again by presenting this book that was the summary of his political views. Then through "Seonghyeondotong", he suggested his own specific political opinions to the King as the successor of Taotong(道統) in Chosun by expressing such an ethos that he succeeded directly to Chutzu(朱子). This study firstly tries to identify Toegye Yi Hwang(退溪 李滉)'s presenting Seonghaksibdo(The Ten Diagrams on Sage Learning, 聖學十圖) to the King and Yulgok's successive will on it. Then we will review the times till presenting Seonghakjibyo to the King, 8 years of early reign of King Seonjo when he had been neglected from the political development of the King. Finally we will specifically analyze how his political views are expressed in each beginning and final chapter of the book.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.3
• /
• pp.181-189
• /
• 2021

This study uses a structural equation model for the turnover intention of female nurses performing shift work at a tertiary hospital. Data collection was conducted from November 11 to December 20, 2015, and 283 samples were included in the final analysis. As a result, 12 of the 19 hypotheses of the final model were supported. It was confirmed that external employment opportunities, nursing professional value, nursing organizational culture, job stress, job satisfaction, organizational commitment, and burn out accounted for 47.8% of the turnover intention. Burn out(+) and organizational commitment(-)had direct effects on turnover intentions, and nursing professional, relationship-oriented nursing organizational culture, and job stress showed indirect effects. Therefore, in order to reduce the turnover intention of female nurses working in shifts at tertiary hospitals, it is necessary to prevent burnout, increase organizational commitment, and job satisfaction. For this purpose, measures to strengthen relation-oriented nursing organizational culture and nursing professional intuition are required. In terms of hospital manpower management, the institutional arrangements of hospitals that enable flexible working hours adjustment, mutually respectful relationship-centered organizational culture, education, and policy support to reinforce nursing professional intuition, and the institutional system of hospitals to work with pride should be implemented.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.1
• /
• pp.184-205
• /
• 2021

Governance is valued as a new concept and principle of social operation and public policy management, and its influence is gradually expanding. Among the various governance theories being put into practice and in case analysis studies, collaborative governance embracing various governance concepts has been found to increase interdependence and responsibility beyond participation and compromise, and create new public values by integrating and utilizing optimal social coordination forms. In the field of cultural assets, governance-related research is also being conducted for the efficiency, sustainability, and scalability of public policy enforcement. This study explored the government's role (promotion, arbitration, and condition creation) in collaborative governance, focusing on the "Cultural Heritage Guardians" to understand how collaborative governance operates in the cultural heritage sector. Regarding governance policies in the cultural asset sector, the cultural asset guardians highlighted the status, role, and characteristics of policies by examining their introduction, development, and implementation. The results of the analysis revealed that private-led, horizontal public-private cooperation, collaborative governance, policy introduction, solidarity, professionalism, resource/knowledge imbalance, cooperation precedence, etc., facilitate increased participation. The government has accordingly proposed measures to establish comprehensive legal stability centered on cooperation; strategic reorganization of dedicated organizations; strengthened, supportive intermediate organizations; and individual and multi-party consultative bodies.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.2
• /
• pp.131-140
• /
• 2022

Installing Continuous Welded Rail (CWR) is one of the economical ways to resolve the challenges of noise, vibration, and the open-deck steel railway bridge impact, and the SSF method using the interlocking sleeper fastener has recently been developed. In this study, the method employed for determining the optimum vertical stiffness of the sleeper pad installed under the bridge sleeper, which is utilized to adjust the rail height and absorb shock when the train passes when the interlocking sleeper fastener is applied, is presented. To determine the optimal vertical stiffness of the sleeper pad, related existing design codes are reviewed, and, running safety, ride comfort, track safety, and bridge vibration according to the change in the vertical stiffness of the sleeper pad are estimated via flexible multi-body dynamic analysis,. The flexible multi-body dynamic analysis is performed using commercial programs ABAQUS and VI-Rail. The numerical analysis is conducted using the bridge model for a 30m-long plate girder bridge, and the response is calculated when passing ITX Saemaeul and KTX vehicles and freight wagon when the vertical stiffness of the sleeper pad is altered from 7.5 kN/mm to 240 kN/mm. The optimum stiffness of the sleeper pad is calculated as 200 kN/mm under the conditions of the track components applied to the numerical analysis.