• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.3
• /
• pp.9-16
• /
• 2019

Recently, precast PSC girder bridges have been widely applied for short and middle span bridges. The construction of the spliced girder bridges has been increasing to overcome the length limit of girder and transportation restrictions. In case of the spliced girder, the integrity of the segmental joints is very important to secure the structural soundness of bridge because the discontinuity on the segmental joints between adjacent segments could be vulnerable point. The study of segmental joint behavior with different influence factors of joint type, shear key installation, confining force is very important. In this research, finite element analysis and scaled model test with different shear key shapes and confining forces were carried out and the comparative study was performed to evaluate the segmental joint behavior of precast spliced PSC girder bridge. It was confirmed that the installation of shear key with height and depth ratio of 1/2~1/3 and applying of confining force of 1/2 of the concrete strength at the joint was effective in improving the integrity of segmental joint. In addition, the field loading test for existed precast spliced PSC girder bridge was performed and the measurement of the difference of deflection between adjacent segments at segmental joint was proposed as the assessment solution of the integrity of segmental joint.

• Research in Plant Disease
• /
• v.25 no.3
• /
• pp.143-148
• /
• 2019

An outbreak of new disease with leaf and stem blight symptom occurred at bracken-growing fields in Namhae-gun, Gyeongsangnam-do, Korea during the last 4 years. This new disease caused significant yield losses on bracken production in this area. We have collected diseased leaves and stems showing the blight symptom in May, July, and October 2018 to investigate causal pathogens. A total of 92 fungal isolates were obtained from the diseased samples and their pathogenicity was tested on healthy bracken leaves. From the total isolates, 22 isolates were able to produce the leaf blight symptom similar to the original one found in the fields. To identify two fungal pathogens which showed higher virulence levels compared to other pathogenic isolates, we constructed phylogenetic trees using the nucleotide sequences of genes for ribosomal RNA, RNA polymerase beta subunit, beta tubulin, and internal transcribed region. Most phylogenetic trees constructed indicate that both isolates, which are identical to each other, reside in a clade of the genus Didymella and possibly similar to D. rumicicola or D. acetosellae. Nevertheless, the exact identification of these pathogens at the species level needs further investigations. This is the first report of a blight disease on bracken by Didymella sp.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.5
• /
• pp.550-559
• /
• 2019

The sinking of the M/V SEWOL in April 2014 was not a mere marine accident, but a marine catastrophe. This grim case developed into a social tragedy that impinged the national sentiment and communal integrity. It is imperative that thorough provisions and measures be outlined at the national level with regard to massive marine accidents, oil pollution, and natural disasters that might critically affect government affairs. Pivoting on "The Black Swan Theory," a concept of improperly rationalizing a national crisis based on uncertainties, this research assesses a variety of response strategies that minimize the national economic and social damage caused by a large-scale marine disaster. Along with the effort of minimizing any potential defects in each protective barrier, the "Black Swan Detection System of the Marine Disaster" needs to be incorporated to prevent cases wherein such defects lead to an actual crisis. Maritime safety must be systematically unified under a supervisory organization, and a structure for maritime crisis on-scene command and cooperation must likewise be established in order that every force on the scene of a marine disaster may act effectively and consistently under the direction of an on-scene commander.

• Management & Information Systems Review
• /
• v.38 no.3
• /
• pp.187-210
• /
• 2019

Companies shall hold social responsibility as a member of the social community. Corporate social responsibility uses corporate resources, yet it plays important roles in reducing social imbalance. Their responsibilities are highly associated with the corporate sustainability. Many earlier studies on the association between corporate social responsibility and corporate sustainability have been attempted. Yet it should be mentioned that they do not show a variety of realities as linearity between dependent variables and independent variables were assumed. Thus, this study aims to analyze Markov blanket, a node of minimum descriptive variables that relieve a rigid assumption among variables and affect corporate sustainability by using Bayesian network. Sensitivity analysis was used to elicit how other variables affect by reflecting the complex reality when real factors are changed. As an important result of this study, the firm's future earnings sustainability is naturally related to operating earnings, and as the corporate governance structure is sound, the firm is able to steadily fulfill its social responsibility. However, the fact that the size of a company is large does not mean that it is in good compliance with corporate laws. This would not be unrelated to the fact that many of today's companies are not complying with the law and are suffering social condemnation. Results from this study will serve as a useful analytic tool when investors and creditors showing interests in corporate sustainability for assessing the value of companies and making investment decisions. Moreover, they can be used as references for relevant agency supervising capital markets to establish or improve appropriate institutions aimed at improving corporate sustainability.

• Tunnel and Underground Space
• /
• v.29 no.4
• /
• pp.262-279
• /
• 2019

In the engineering barriers of high-level radioactive waste disposal, gases could be generated through a number of processes. If the gas production rate exceeds the gas diffusion rate, the pressure of the gas increases and gases could migrate through the bentonite buffer. Because people and the environment can be exposed to radioactivity, it is very important to clarify gas migration in terms of long-term integrity of the engineered barrier system. In particular, it is necessary to identify the hydro-mechanical mechanism for the dilation flow, which is a very important gas flow phenomenon only in medium containing large amounts of clay materials such as bentonite buffer, and to develop and validate new numerical approach for the quantitative evaluation of the gas migration phenomenon. Therefore, in this study, we developed a two-phase flow model considering the mechanical damage model in order to simulate the gas migration in the engineered barrier system, and validated with 1D gas flow modelling through saturated bentonite under constant volume boundary conditions. As a result of numerical analysis, the rapid increase in pore water pressure, stress, and gas outflow could be simulated when the dilation flow was occurred.

• The Korean Journal of Archival Studies
• /
• no.30
• /
• pp.205-247
• /
• 2011

The Public Records and Archives Management Law was enacted on June 24, 2009 and was in effect in April 1, 2011. This Act is different from existing Public Archives Law and National Archives Law. Before enacting Public Records and Archives Management Law, Public Archives Law and Information Disclosure Law was the backbone of Japanese Public Records management system. Public Archives Law is composed of management and access for non-active records in Public Archives. Information Disclosure Law is prescribed management of active-records in administrative agency. Public Records and Archives Management Law is the first comprehensive law of managing administrative records including historical records (nonactive-records). The law is prescribed that the public records and archives are intellectual resources shared by citizens and allows people to have more access to them. The law states that public records is basis of democracy and accountability for current and future generation. This article analyzed the relationship of law and its implementing ordinance and Guideline of administrative public records management, and analyzed the law and record-schedule. Furthermore, this article examined significance of the law and democracy, administration's transparency. In accordance with enacting the law, Japanese Public Records Management System will develop. and we must pay close attention to that situation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.5
• /
• pp.13-19
• /
• 2019

After the Fukushima nuclear accident, a new power supply using a lithium polymer battery has been proposed the first time in the world as the safety of the emergency battery facility has been required. It is required to have the safety of the rack system in which the battery device is installed in order to apply the proposed technology to the field. Therefore, the purpose of this study is to evaluate the seismic performance of string and rack frame for lithium-polymer battery devices developed for the first time in the world to satisfy 72 hours capacity. (1) The natural frequency of the unit rack system was 9 Hz, and the natural frequency before and after the earthquake load did not change. This means that the connection between members is secured against the design earthquake load. (2) he vibration reduction effect by string design was about 20%. (3) As a result of the seismic performance test under OBE and SSE conditions, the rack frame system was confirmed to be safe. Therefore, the proposed rack system can be applied to the nuclear power plant because the rack system has been verified structural safety to the required seismic forces.

• Journal of the Korea Convergence Society
• /
• v.10 no.5
• /
• pp.279-286
• /
• 2019

The purpose of this study is to explore what causes medical college students to play games they will play and use them as academic foundation material. And lay a complex foundation for game addicts. To achieve this objective, an approach was taken as a method of exploratory case study. The participants in the study were recruited by their consent at the R meeting of the College of Medicine. Data collection was collected through a one-on-one interview with FGI. The data analysis was read repeatedly and classified into semantic units to derive the essential meaning. The study produced two essential topics and seven revealed topics. It is 'my job to play games' and 'know the importance of discrimination.'According to the analysis, the game behavior played by medical students was able to quit due to the self-efficacy experienced during the course of growth. When one's expectations were met and self-strengthened, one could see that self-control was possible through self-efficacy. It suggested that measures for sound game culture and complex strategy should be explored and measures to improve self-efficacy should be explored.

• Journal of Internet Computing and Services
• /
• v.20 no.2
• /
• pp.109-118
• /
• 2019

The purpose of this study is to deliver both market-practical and civil-centric political implication for sharing economy by investigating the nature of consumer-adoption for car-sharing service. With the global interest and market proliferation of the sharing economy, various service models for sharing idle resources have also been released in Korea. Particularly, in case of car sharing service, public - private partnership projects are spreading rapidly in various local governments including Seoul, along with the growing demand for alternative transportation system centering on the urban area. This study conducted an empirical study on the process of accepting the car sharing service by analyzing the data collected from users of the car sharing service "Sharing Car(Nanum Car)" of Seoul Metropolitan Government. A survey was conducted on 281 users in their twenties who are in the age of main use among the experienced users of the "Sharing Car(NaNum)" residing in Seoul. The result of analysis on the relationship between these users' perceived value and intention to use the vehicle sharing service would provide implications for establishing consumer(citizen)-centeric policies as well as market implications.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.46 no.1
• /
• pp.93-100
• /
• 2019

The objective of this study was to analyze the color distribution of the maxillary primary central incisors and the relationship between the color of each tooth region by dividing tooth into incisal, middle and cervical region using a spectrophotometer. The subjects were 105 sound maxillary primary central incisors from 3 to 6 years old children. Color measurements were performed by one dentist using same protocol. CIE $L^*$, $a^*$, $b^*$, $C^*$, $h^*$ data and the best matched shades with coverage error were obtained for each region and whole labial surface. There was a significant difference in CIE $L^*$, $a^*$, $b^*$ according to regions and the difference in color between each region was more than the clinical acceptance. By correlating the relationship between the color of each region with $L^*$, $a^*$, $b^*$ values, it is possible to extrapolate the color of other region with one color or to be used as data for making restorative materials and prostheses that are more aesthetically pleasing for primary teeth.