• Journal of the Korea Institute of Building Construction
• /
• v.7 no.4
• /
• pp.109-116
• /
• 2007

Building structures are generally large in size and have a long life, and the construction of such structures requires the investment of a huge amount of money and social infrastructure. Furthermore, building structures are closely related to people's life. Recently, however, the rapid development of society has been worsening air pollution, which is in turn accelerating the degradation of building structures. Thus, the safety of building structure is emerging as a critical issue. To cope with this problem, the government enacted "The Special Act on Safety Control for Infrastructure" but we need engineers' higher concern over the maintenance and reinforcement of existing structures. Recently researches are being made actively on repair mortar using ultra rapid hardening cement for recovering the performance of structures. The present study conducted an experiment on the basic physical properties of ultra rapid hardening mortar for repairing and reinforcing building structures using magnesia cement and mono-ammonium phosphate. In the experiment, we changed the water-cement ratio and carried out replacement at different ratio of MAP/MgO(%). We used retarder to have working life, and made comparative analysis through evaluating working life and fluidity and measuring strength by age.

• Korean Management Science Review
• /
• v.21 no.1
• /
• pp.57-76
• /
• 2004

The development of informational technology has lead to a sharp change in not only the existing way of operations and management, but the way of human life or thinking as well. Those shifts of the paradigm in information technology have also affected Individuals to the organizational structure. A series of unexpected problems was, however, accompanied by the advance in informational technology, which had broaden its own area of application. Those problems include the losses of property or data the malfunction of systems and their wastefulness would result in, continuous increases in computer crimes, reliability and efficiency of the functional process with the development of information systems, such as the processing problems of inaccurate data, economical issues, and subjects related to safety, as interruptions of privacy, which would result from lots of one's exposure to the drains of personal information. Accordingly, Auditors' roles of information systems, for now, is more important than anything else in that they are responsible for the objective assessment of relevance and effectiveness of internal control systems under the environment of information systems. The objective of the study is, so as to obtain safety of information systems： First, to provide data to line-design internal control systems after finding internal control factors to prevent and eliminate the risks of information systems. Second, to evaluate the priorities of internal control factors with their effective management being considered as the key to settle the problems of risks of information systems. Third, to discriminate what factors affect In evaluating the relative degrees of Importance of internal control factors.

• Journal of the Korean Society of Safety
• /
• v.29 no.5
• /
• pp.88-96
• /
• 2014

Each year, it seems inevitable that major accidents will occur on construction sites. Industrial accidents, sometimes involving foreign laborers, have been constantly increasing. Construction laborers have higher hazard rates and higher work intensity than other industries, which means that they experience more job stress, as a result of the subcontracting structure. Therefore, this study performed an influence factor analysis on job stress and its relevance to industrial accidents involving Korean and foreign construction laborers, and proposed its effectiveness with the job stress and construction accident management measures based on the results of those. A questionnaire to measure job stress was performed targeting Korean and foreign laborers, and the results were analyzed. The results of this study can be utilized as important reference materials in efforts to reduce the job stress of foreign laborers on construction sites, and can be expected to contribute to preventing construction accidents related to job stress in the future.

• Journal of the Korean Society of Safety
• /
• v.29 no.5
• /
• pp.154-159
• /
• 2014

This study deals with the pedestrian accidents of intersections in case of Cheongju. The objective is to develop the pedestrian accident models using Tobit regression model. In pursuing the above, the pedestrian accident data from 2007 to 2011 were collected from TAAS data set of Road Traffic Authority. To analyze the accident, Poisson, negative binomial and Tobit regression models were utilized in this study. The dependent variable were the number of accident by intersection. Independent variables are traffic volume, intersection geometric structure and the transportation facility. The main results were as follows. First, Tobit model was judged to be more appropriate model than other models. Also, these models were analyzed to be statistically significant. Second, such the main variables related to accidents as traffic volume, pedestrian volume, number of traffic island, crossing length and the pedestrian countdown signal systems were adopted in the above model.

• Transactions of the Korean Society of Pressure Vessels and Piping
• /
• v.16 no.1
• /
• pp.37-41
• /
• 2020

The Nuclear containment building is a main safety-related structure that performs shielding and conservation functions to prevent highly radioactive materials from leakage to the outside environment in the case of various environmental conditions and postulated accidents. The containment building contains a reactor, steam generator, pressurizer, tank, reactor coolant system, auxiliary system and engineering safety system, and is designed so that highly radioactive materials above the limits specified in 10 CFR 100 do not escape to the outside environment in the case of LOCA(Loss of Coolant Accident) for instance. The containment metal liner plate(CLP) is a carbon steel plate with a nominal plate thickness of 6 mm, which functions as a mold for the wall and dome of the containment building when concrete is filled, fulfills airtightness to prevent leakage of seriously radioactive materials. In recent years, backside corrosion was found on the liner plate in some domestic nuclear power plants. The main cause of backside corrosion was unfilled concrete. In this paper, an inspection technique of assessing filling suitability for CLP backside concrete is developed. Results show that the validity of inspection technique for CLP backside concrete using vibration sensor is successfully verified.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.881-886
• /
• 2003

In spite of its simple design, structure and operating mechanism, swing check valves are one of the critical components which adversely affect the safety of the nuclear power plants if they fail to function properly. Therefore, it is important to evaluate the performance condition of the swing check valves in safety-related systems. The performance characteristics of swing check valves include opening characteristics, the minimum required flow velocity, the pressure drop at design flow, the disc stability, and the effect of the upstream disturbances. Among factors to identify the performance of a swing check valve, a method to evaluate the opening characteristics and the minimum required flow velocity, which guarantees to fully open the disc and hold the disc without motion, are presented to determine the operating region of the swing check valve, such as stable, tapping, or oscillation. Based on the determined operating region and opening characteristics, the simple methods of wear and fatigue analyses of the specific parts of the valve are also described.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.41 no.4
• /
• pp.771-781
• /
• 2017

The helmet is an imperative personal protective equipment. This protective device must be able to guard the human head against potential risks. Helmets are classified according into the purpose of use; therefore, the required performance and specifications depend on the type of products. Military helmets are intended to protect the wearer's head from bullets and shrapnel. Generally, lightweight super fibers and fiber reinforced composite materials are used as helmet shell materials, and NIJ STD of U.S. Department of Justice is most widely used as international standard related to bulletproof helmets. Safety helmets are widely used for industrial application and sports leisure. In general, the performance of shock absorption must be ensured, and various lining systems are applied in material, design, and combination methods. Evaluation standards have also been classified and strictly controlled for each purpose; therefore, it is difficult to certify with the existing standards such as the recently developed convergence helmets. However, it is possible to launch the product through a separate national integrated certification procedure.

• Proceedings of the Safety Management and Science Conference
• /
• 2008.04a
• /
• pp.157-179
• /
• 2008

This study demonstrates some major traits of digital contents as information, playfulness, individuality, perceived recognition as perceived usefulness and perceived ease of use, relationship quality as satisfaction and commitment, user behavior as use intention. To make an empirical analysis the study, it is hypothesized that traits of digital contents and perceived recognition, traits of digital contents and relationship quality, perceived recognition and relationship quality, relationship quality and user behavior. Proposed theoretical model was based on TAM and was tested by the structure equation model for validity, credibility, goodness of fit. The major finding of this study can be summarized as follows, traits of digital contents are positively affected by perceived recognition, satisfaction in relationship quality and use intention via perceived recognition. Theoretical implication of this study are as follows. First, users wanted to choice only needed information. Second, users recognized digital contents as a part of life. So, user's ability is very important in this environment. According to this, business related with or interested in digital contents must have developed digital contents in variety aspect. Users must have concerned using digital contents, also.

• Journal of the Korea Safety Management & Science
• /
• v.21 no.3
• /
• pp.1-9
• /
• 2019

The Industrial Innovation Movement, based on win-win cooperation with SMEs, is a structure that enables suppliers who have struggled with corporate growth through productivity innovation due to poor manufacturing environment and lack of innovation. To this end, consultants and technical experts will support production innovation activities to improve production methods and improve productivity through process and management consulting. The purpose of this study was to explore the driving factors of the industrial innovation movement to improve the corporate ecosystem by improving the productivity of SMEs using modified IPA. The research results are as follows. First, in order to revitalize the Industrial Innovation Movement, the CEO-related elements of the participating companies should be maintained and strengthened. The motivation, education support, innovation organizational culture, the establishment of an innovation promotion system requires centralization of efforts for improvement. Second, in order to revitalize the Industrial Innovation Movement, the consultant's ability to analyze problems and suggest alternatives should be continuously strengthened. Third, in terms of the Central Promotion Headquarters, it was found that the Industrial Innovation Movement would be successful if the public information, industrial inspection for benchmarking, and provision of various information to support innovation activities were urgently improved.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.3
• /
• pp.354-365
• /
• 2019

Megabenthos samples were collected using 10-min trawls towed at 17 stations from 2015 to 2016. The dominant species (>1% of the total density) were Stegophiura sterea (10.4%) and two subtropical species, Mactrinula dolabrata (9.0%) and Acila divaricate (8.3%), respectively. The community structure of the megabenthos fell into four groups: the southeast, the southernmost region off Jeju Island, the frontal zone of the South Sea with C3, and a diagonal area from the south coast to the western side of Jeju Island. The total numbers of species, diversity, density and biomass were higher in the C3 region of the South Sea. Environmental factor analysis showed that differences in the megabenthos community were related to depth, gravel contents, and sorting value (${\sigma}$). These results indicate that changes in the marine environmental conditions in the South Sea of Korea affect the megabenthos species' composition and diversity.